European Journal of Scientific Research - EuroJournals

European Journal of Scientific Research
ISSN: 1450-216X Volume 20, No 4 July, 2008
Editor-In-chief or e
Adrian M. Steinberg, Wissenschaftlicher Forscher
Editorial Advisory Board e
Parag Garhyan, Auburn University
Morteza Shahbazi, Edinburgh University
Raj Rajagopalan, National University of
Singapore
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Said Elnashaie, Auburn University
Subrata Chowdhury, University of Rhode
Island
Ghasem-Ali Omrani, Tehran University of
Medical Sciences
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Geosciences
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David Wang, Hsuan Chuang University
Cornelis A. Los, Kazakh-British Technical
University
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Chiaku Chukwuogor-Ndu, Eastern Connecticut
State University
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(Tutor)
M. Femi Ayadi, University of Houston-Clear
Lake
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Dimitrios Mavridis, Technological Educational
Institure of West Macedonia
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Petroleum & Minerals
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Richard Omotoye, Virginia State University
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Leo V. Ryan, DePaul University
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Contents
European Journal of Scientific Research
Volume 20, No 4 July 2008
Blast-Hole Cuttings: An Indicator of Drill Bit Wear in Quarries 721-736
Z.O. Opafunso and B. Adebayo
Assessment of Micro-Credit Supply by Country Women Association of
Nigeria (Cowan) to Rural Women in Ondo State, Nigeria 737-745
M.G. Olujide
Comparative Analysis of Pictorial Coverage of Events by Pakistan’s English Press 746-758
Muhammad Nawaz Mahsud, Muhammad Khalid and Firasat Jabeen
Design Space Exploration of Regular NoC Architectures: A Multi-Objective
Evolutionary Algorithm Approach 759-771
Rabindra Ku. Jena, Musbah M. Aqel, Gopal K. Sharma and Prabhat K. Mahanti
Etude Comparative des Méthodes D’évaluation de la Vulnérabilité à la
Pollution des Aquifères en Milieu Poreux: Application Aux Eaux Souterraines
du District D’abidjan (Sud de la Côte D’ivoire) 772-787
Kouamé Kan Jean, Jourda Jean Patrice, Adja Miessan Germain
Deh Serges Kouakou, Anani Abenan Tawa, Effini Adiow Thérèse and Biémi Jean
Development of an Integrated Poultry/Fishery Husbandry for Optimal Agricultural Production 788-795
F.R. Falayi, A.S. Ogunlowo and M.O. Alatise
Robust Control of a Doubly Fed Asynchronous Machine of a Wind Turbine System 796-804
S. Gherbi, S. Yahmedi and M. Sedraoui
Effects of Enviromental Variables on Poultry Performance and Pond Water
Quality in an Integrated Poultry/Fishery Farming 805-816
F.R. Falayi, A.S. Ogunlowo and M.O. Alatise
Spatial Distribution and Characterisation of the Sediments of the Estuary of
Comoe River (Grand-Bassam, Côte D’ivoire) 817-827
Adopo Kouassi Laurent, Kouassi Kouakou Lazare, Wognin Ama Valérie Irma
Monde Sylvain, Meledje N’Diaye Hermann and Aka Kouamé
Blind SIMO GSM Channel Identification 828-835
Taba Mohamed Tahar, S. Femmame and D. Mossadeg
The Chemical Control of the Pests in the Truck Farming and the Quality
of Vegetables in African Urban Cities: The Health Hazards and Security of Consumers 836-843
Dembele Ardjouma, Oumarou Badini, Traore Sory Karim, Mamadou Koné
Coulibaly D. Ténébé and A. Abba Toure

Database Interfacing using Natural Language Processing 844-851
Imran Sarwar Bajwa, Shahzad Mumtaz and M. Shahid Naweed
Role of Trade, External Debt, Labor Force and Education in Economic Growth
Empirical Evidence from Pakistan by using ARDL Approach 852-862
Arshad Hasan and Safdar Butt
Development of Mechanical Prosthetic Hand System for BCI Application 863-870
N. A Abu Osman, S. Yahud and S. Y Goh
Toxicity of Arsenic in the Ground Water of Comarca-Lagunera (Mexico) 871-881
Faten Semadi, Vincent Valles and Jose Luis Gonzalez Barrios
Modeling and Temperature Controller Design for Yazd Solar Power Plant 882-890
Aref Shahmansoorian and Abdolvahed Saidi
A Predictive Current Control Technique on Fuel Cell Based Distributed
Generation in a Standalone AC Power Supply 891-904
K. G. Firouzjah, H. Eshaghtabar, A. Sheikholeslami and S. Lesan
Effects of Ethyl acetate Portion of Syzygium Aromaticum Flower Bud Extract on
Indomethacin-Induced Gastric Ulceration and Gastric Secretion 905-913
Okasha Mohammad Abdul- Halim, Magaji Rabiu Abdussalam
Abubakar Mujtaba Suleiman and Fatihu Muhammad Yakasai
Real Digital TV Accessed by Cellular Mobile System 914-923
Basil M. Kasasbeh, Rafa E. Al-Qutaish, Muzhir S. Al-Ani and Khalid Al-Sarayreh
A Rule-Based Fuzzy Automatic Voltage Regulator for Power System Stability 924-933
Samuel N. Ndubisi and Marcel .U. Agu

European Journal of Scientific Research
ISSN 1450-216X Vol.20 No.4 (2008), pp.721-736
© EuroJournals Publishing, Inc. 2008
http://www.eurojournals.com/ejsr.htm
Blast-Hole Cuttings: An Indicator of Drill Bit Wear in Quarries
Z.O. Opafunso
Department of Mining Engineering, Federal University of Technology
Akure, NIGERIA
B. Adebayo
Department of Mining Engineering, Federal University of Technology
Akure, NIGERIA
Abstract
This paper deals with the evaluation of blast-hole cuttings generated in process
creating cavity in a rock mass as an indicator of bit wear. Blast-hole cuttings were collected
on each hole drilled until drill bit is worn completely and deterioration of button inserted on
the surface of the bit was measured as well. The size distribution of the blast-hole cuttings
collected from the three selected quarries in South Western Nigeria was determined using
sieve shaker. The results obtained show that weight retained on 850µm decreases while
weight of blast-hole cuttings retained on 75 µm increases. The regression carried out gives
values R² = 0.957, R² = 0.777, and R² = 0.729 for Geovertrag Quarry, Ado-Ekiti, Johnson
Quarry, Akure and Sonel Boneh Quarry, Ibadan respectively. This shows that there is
strong relationship between gauge button wear rate and weight of blast-hole cuttings
retained on 75 µm sieve size. Therefore, monitoring the blast-hole cuttings while drilling
could help to ascertained worn drill bit in a quarry.
Introduction
Rock penetration is the process by which ‘bit’ the applicator of energy advance into the rock in
response to drill tool power as well as thrust. Howarth et al (1986) carried out percussion drilling test
on ten sedimentary and crystalline rocks. Therefore, drilling is the process of creating artificial cavity
in a rock mass for the purpose of placement of explosives. Studies have shown that assessing drilling
mechanisms, it is a fact that besides compressive and tensile (percussive process) and shear strength
(bit rotation) the elastic characteristics of rock material is crucial.
However, blast-hole cuttings are produced in the course of rock drill bit advancing into the rock
mass. Thuro (1997) summarized crushing process leading to the production of blast-hole cuttings under
the buttons of a drill bit; around the contact of the button a new state of stress is induced in the rock,
where four important destruction mechanisms can be distinguished: under the bit button a crushed zone
of fine rock powder is formed (impact), starting from the from the crushed powdered zone, radial
cracks are developed (induced tensile stress) when stress the rock is high enough large fragments of the
rock can be sheared off between the button grooves (shear stress) and added to the mechanisms above
stress is induced periodically (dynamic process).
Chiang and Elias (2000) identified that the impact frequency rate, the workings of air pressure,
the thrust force and rotation torque are important in the generation of blast-hole cuttings. The last two
parameters are estimated by reading the impact pressure to the hydraulic motor or hydraulic cylinder
respectively. The brittleness which is defined as lack of ductility can aid fracture failure and formation

Blast-Hole Cuttings: An Indicator of Drill Bit Wear in Quarries 722
of fines (Morley, 1944 and Hetenyi, 1966). Blast-hole cuttings are debris, chippings or caving flushed
by compressed air rock is attacked mechanically.
In addition, to effectively remove the blast-hole cuttings, annular space should be about 17% of
the cross-sectional area of the blast-hole. If the percentage of the annular space is less than 17% then
for every 1% reduction in this percentage the bailing velocity must be increased by 2% (Gokhale,
2004). An estimated correlation factor on account of insufficient annular space is given as:
aa = (1+ 0.02) [17-A] (1)
Where A is the percentage of annular space for combination of bit and drill rods to be used in
actual drilling (if A is more than 17% then aa should be given a value 1).
Beste (2004) observed that it is difficult to get an overview of wear mechanisms of the rock
drill bit. Shah and Wong (1997) were of the view that the contact geometry between tungsten-carbide
insert and rock is complex. Wear of rock drill bit is a constant phenomenon in hard rock drilling which
cannot be avoided; this may be a severe factor of cost for effective management of quarries, hence, a
reasonable measurement and prediction would be desirable. Moreover, when the drilling time increases
as well as low penetration rate, one can infer that the button of the bit is likely to be dull or worn and of
course this can lead to regrinding of blast-hole cuttings.
Therefore, utilization of energy to achieve penetration, under normal condition depends on
drillability of the rock; a certain amount of energy will be dissipated by rock breakage. It was
discovered through research that when bit button is blunt after very few impacts the hammer will
become useless because of plastic deformation. The bit which has the shortest span of all the three
main components will last in the order of 120 million cycles and the main cause of the failure is wear
(Chiang and Elias, 2000) and as the bit buttons wear out more fines are likely to be generated. The
objective of this paper therefore, are to use blast-hole cuttings as a measure of bit wear rate as well
correlate the weight retained at 75µm sieve size in order to establish their relationship.
Materials and Method
The materials for this work includes: blast-hole cuttings collected from 45 holes from three Nigeria
quarries and drill bit
Method
The grain size of 45 blast-holes drill cuttings collected from three selected quarries were determined
using standard method of America Society for Testing and Materials (ASTM) D 2487 and sieve of the
following mesh sizes: 850 µm, 600µm, 425µm, 300µm, 212µm, 150µm, 75µm, and 63µm were used
the results are presented in Table 1-45 and The wear of the gauge buttons were measured at regular
interval this correlated with weight retained on 75µm sieve size.
Result and Discussion
Tables 1-46 present the size distribution of the blast-hole cutting, it is observe that as number of hole
drill and wear increases the weight blast-hole cuttings retained on 850 µm decreases the weight of
blast-hole cuttings retained on the 75µm sieve size increases. All these point to the fact that it is likely
that as bit button is blunt, regrinding of blast-hole occurs.
Figure 1 shows the correlation between bit gauge button wear rate and weight of blast-hole
cuttings retained on 75µm sieve size cuttings from Geovertrag Quarry, Ado-Ekiti. The polynomial
relationship between Gauge button wear rate and weight of blast-hole cuttings retained on 75µm sieve
size is expressed by equation 2 which is an equation of order 2 and R 2 = 0.957.
Gw = -3E-05wt 2 + 0.003x - 0.099, R² = 0.957 (2)
Where Gw is gauge wear rate and wt is the weight of blast-hole cuttings retained on 75µm
sieve size. Figure 2 presents the correlation between bit gauge button wear rate and weight of blast-

723 Z.O. Opafunso and B. Adebayo
hole cuttings retained at 75µm sieve size cuttings from Johnson Quarry, Akure. The power relationship
between Gauge button wear rate and weight of blast-hole cuttings retained at 75µm sieve size is
expressed by equation 3
Gw = 3E-09wt 3.418 R² = 0.777 (3)
Where Gw is gauge wear rate and wt is the weight of blast-hole cuttings retained at 75µm sieve
size. Figure 3 shows the correlation between bit gauge button wear rate and weight of blast-hole
cuttings retained at 75µm sieve size cuttings from Sonel Boneh Quarry, Ibadan. The polynomial
relationship between Gauge button wear rate and weight of blast-hole cuttings retained on 75µm sieve
size is expressed by equation 4 which is an equation of order 3 and R 2 = 0.729.
Gw = -1E-06wt 3 +0.000wt 2 - 0.021wt + 0.544, R² = 0.729 (4)
Where Gw is gauge wear rate and wt is the weight of blast-hole cuttings retained on 75µm
sieve size.
Figure 1: Plot of Wear Rate against Weight of Blast-hole Cuttings Retained for Geovertrag Quarry, Ado –
Ekiti.

Blast-Hole Cuttings: An Indicator of Drill Bit Wear in Quarries 724
Figure 2: Plot of Wear Rate against Weight of Blast-hole Cuttings Retained for Johnson Quarry, Akure.
Figure 3: Plot of Wear Rate against Weight of Blast-hole Cuttings Retained for Sonel Boneh Quarry, Ibadan.
Table 1: Sieve Analysis of Drill Cuttings from Blast-hole One (Geovertrag Quarry, Ado- Ekiti)
Sieve Size (µm) MeanSieve
Size (µm)
Wt
Retained(g)
%Wt
Retained%
Cum Wt
Retained(g)
Cum Wt
Passing(g)
Cum %
Retained
Cum %
Passing
850 850 140.64 35.16 400.00 0 100.00 0
-850 + 600 600 49.60 12.40 259.36 140.64 64.84 35.16
-600 + 425 425 45.20 11.30 209.76 190.24 52.44 47.56
-425 + 300 300 48.96 12.24 164.56 235.44 41.14 58.86
-300 + 212 212 28.40 7.10 115.60 284.40 28.90 71.10
-212 + 150 150 24.80 6.20 87.20 312.80 21.80 78.20
-150 + 75 75 62.40 15.60 62.40 337.60 15.60 84.40
-75 + 63 63 0 0 0 400.00 0 100.00

725 Z.O. Opafunso and B. Adebayo
Table 2: Sieve Analysis of Drill Cuttings from Blast-hole Two (Govertrag Quarry, Ado- Ekiti)
Sieve Size (µm) MeanSieve
Size (µm)
Wt
Retained(g)
%Wt
Retained%
Cum Wt
Retained(g)
Cum Wt
Passing(g)
Cum %
Retained
Cum %
Passing
850 850 140.36 35.09 400.00 0 100.00 0
-850 + 600 600 45.60 11.40 259.64 140.36 64.91 35.09
-600 + 425 425 41.20 10.30 214.04 185.96 53.51 46.49
-425 + 300 300 44.96 11.24 172.84 227.16 43.21 56.79
-300 + 212 212 32.40 8.10 127.88 272.12 31.97 68.03
-212 + 150 150 28.80 7.20 95.48 304.52 23.87 76.13
-150 + 75 75 66.68 16.67 66.68 333.32 16.67 83.33
-75 + 63 63 0 0 0 400.00 0 100.00
Table 3: Sieve Analysis of Drill Cuttings from Blast-hole Three (Govertrag Quarry, Ado- Ekiti)
Sieve Size (µm) MeanSieve
Size (µm)
Wt
Retained(g)
%Wt
Retained%
Cum Wt
Retained(g)
Cum Wt
Passing(g)
Cum %
Retained
Cum %
Passing
850 850 140.36 35.09 400.00 0 100.00 0
-850 + 600 600 41.60 10.40 259.64 140.36 64.91 35.09
-600 + 425 425 37.20 9.30 218.04 181.96 54.51 45.49
-425 + 300 300 40.96 10.24 180.84 219.16 45.21 54.79
-300 + 212 212 36.40 9.10 139.88 260.12 34.97 65.03
-212 + 150 150 32.80 8.20 103.48 296.52 25.87 74.13
-150 + 75 75 70.68 17.67 70.68 329.32 17.67 82.33
-75 + 63 63 0 0 0 400.00 0 100.00
Table 4: Sieve Analysis of Drill Cuttings from Blast-hole Four (Govertrag Quarry, Ado- Ekiti)
Sieve Size (µm) MeanSieve
Size (µm)
Wt
Retained(g)
%Wt
Retained%
Cum Wt
Retained(g)
Cum Wt
Passing(g)
Cum %
Retained
Cum %
Passing
850 850 138.00 34.50 400.00 0 100.00 0
-850 + 600 600 37.60 9.40 262.00 138.00 65.50 34.50
-600 + 425 425 33.20 8.30 224.40 175.00 56.10 43.90
-425 + 300 300 40.96 10.24 191.20 208.80 47.80 52.20
-300 + 212 212 40.40 10.10 150.24 249.76 37.56 62.44
-212 + 150 150 36.80 9.20 109.84 290.16 27.46 72.54
-150 + 75 75 73.04 18.26 73.04 326.96 18.26 81.74
-75 + 63 63 0 0 0 400.00 0 100.00
Table 5: Sieve Analysis of Drill Cuttings from Blast-hole Five (Govertrag Quarry, Ado- Ekiti)
Sieve Size (µm) MeanSieve
Size (µm)
Wt
Retained(g)
%Wt
Retained%
Cum Wt
Retained(g)
Cum Wt
Passing(g)
Cum %
Retained
Cum %
Passing
850 850 128.00 32.00 399.99 0.01 99.99 0.01
-850 + 600 600 33.60 8.40 272.00 128.00 67.99 32.01
-600 + 425 425 32.40 8.10 238.40 161.62 59.59 40.41
-425 + 300 300 42.16 10.54 206.00 194.00 51.49 48.50
-300 + 212 212 44.26 11.06 163.84 236.68 40.95 59.05
-212 + 150 150 42.00 10.50 119.58 280.42 29.89 70.01
-150 + 75 75 77.58 19.39 77.59 322.40 19.39 80.60
-75 + 63 63 0 0 0.01 399.99 0.01 99.99

Blast-Hole Cuttings: An Indicator of Drill Bit Wear in Quarries 726
Table 6: Sieve Analysis of Drill Cuttings from Blast-hole Six (Govertrag Quarry, Ado- Ekiti)
Sieve Size (µm) MeanSieve
Size (µm)
Wt
Retained(g)
%Wt
Retained%
Cum Wt
Retained(g)
Cum Wt
Passing(g)
Cum %
Retained
Cum %
Passing
850 850 128.00 32.00 400.00 0 100.00 0
-850 + 600 600 32.40 8.10 272.00 128.00 68.00 32.00
-600 + 425 425 32.08 8.02 239.60 160.40 59.90 40.10
-425 + 300 300 41.04 10.26 207.52 192.48 51.88 48.12
-300 + 212 212 47.04 11.76 166.48 233.52 41.62 58.38
-212 + 150 150 40.44 10.11 119.44 280.56 29.86 70.14
-150 + 75 75 79.00 19.75 79.00 321.00 19.75 80.25
-75 + 63 63 0 0 0 400.00 0 100.00
Table 7: Sieve Analysis of Drill Cuttings from Blast-hole Seven (Geovertrag Quarry, Ado- Ekiti)
Sieve Size (µm)
MeanSieve
Size (µm)
Wt
Retained(g)
%Wt
Retained%
Cum Wt
Retained(g)
Cum Wt
Passing(g)
Cum %
Retained
Cum %
Passing
850 850 118.40 29.60 400.00 0 100.00 0
-850 + 600 600 31.60 7.90 281.60 118.40 70.40 29.60
-600 + 425 425 31.44 7.86 250.00 150.00 62.50 37.50
-425 + 300 300 41.84 10.46 218.56 181.44 54.64 45.36
-300 + 212 212 47.32 11.83 176.72 223.28 44.18 55.82
-212 + 150 150 46.96 11.74 129.40 270.60 32.35 67.65
-150 + 75 75 82.44 20.61 82.44 317.56 20.61 79.39
-75 + 63 63 0 0 0 400.00 0 100.00
Table 8: Sieve Analysis of Drill Cuttings from Blast-hole Eight (Geovertrag Quarry,Ado- Ekiti)
Sieve Size (µm) MeanSieve
Size (µm)
Wt
Retained(g)
%Wt
Retained%
Cum Wt
Retained(g)
Cum Wt
Passing(g)
Cum %
Retained
Cum %
Passing
850 850 114.00 28.50 400.00 0 100.00 0
-850 + 600 600 30.00 7.50 286.00 114.00 71.50 28.50
-600 + 425 425 29.84 7.46 256.00 144.00 64.00 36.00
-425 + 300 300 41.04 10.26 226.16 173.84 56.54 43.46
-300 + 212 212 47.32 11.83 185.12 214.88 46.28 53.72
-212 + 150 150 50.16 12.54 137.80 262.20 34.45 65.55
-150 + 75 75 87.64 21.91 87.64 312.36 21.91 78.09
-75 + 63 63 0 0 0 400.00 0 100.00
Table 9: Sieve Analysis of Drill Cuttings from Blast-hole Nine (Geovertrag Quarry, Ado- Ekiti)
Sieve Size (µm) MeanSieve
Size (µm)
Wt
Retained(g)
%Wt
Retained%
Cum Wt
Retained(g)
Cum Wt
Passing(g)
Cum %
Retained
Cum %
Passing
850 850 113.20 28.30 400.00 0 100.00 0
-850 + 600 600 28.40 7.10 286.80 113.20 71.70 28.30
-600 + 425 425 28.64 7.16 258.40 141.60 64.64 35.40
-425 + 300 300 40.64 10.16 229.76 170.24 57.44 42.56
-300 + 212 212 48.92 12.23 189.12 210.88 47.28 52.72
-212 + 150 150 52.56 13.14 140.20 259.80 35.05 64.95
-150 + 75 75 87.64 21.91 87.64 312.36 21.91 78.09
-75 + 63 63 0 0 0 400.00 0 100.00

727 Z.O. Opafunso and B. Adebayo
Table 10: Sieve Analysis of Drill Cuttings from Blast-hole Ten (Geovertrag Quarry, Ado- Ekiti)
Sieve Size (µm) MeanSieve
Size (µm)
Wt
Retained(g)
%Wt
Retained%
Cum Wt
Retained(g)
Cum Wt
Passing(g)
Cum %
Retained
Cum %
Passing
850 850 112.68 28.17 400.00 0 100.00 0
-850 + 600 600 20.40 5.10 287.52 112.68 71.83 28.17
-600 + 425 425 22.64 5.66 266.92 133.08 66.73 33.27
-425 + 300 300 43.60 10.90 244.28 155.72 61.07 38.93
-300 + 212 212 52.92 13.23 200.68 199.32 50.17 49.83
-212 + 150 150 53.36 13.34 147.76 252.24 36.94 63.06
-150 + 75 75 94.40 23.60 94.40 305.60 23.60 76.40
-75 + 63 63 0 0 0 400.00 0 100.00
Table 11: Sieve Analysis of Drill Cuttings from Blast-hole Eleven (Geovertrag Quarry, Ado- Ekiti)
Sieve Size (µm) MeanSieve
Size (µm)
Wt
Retained(g)
%Wt
Retained%
Cum Wt
Retained(g)
Cum Wt
Passing(g)
Cum %
Retained
Cum %
Passing
850 850 112.28 28.07 400.00 0 100 0
-850 + 600 600 20.80 5.20 287.72 112.80 71.93 28.07
-600 + 425 425 22.64 5.66 266.92 133.08 66.73 33.27
-425 + 300 300 43.60 10.90 244.28 155.72 61.07 38.93
-300 + 212 212 52.92 13.23 200.68 199.32 50.17 49.83
-212 + 150 150 53.36 13.34 147.76 252.24 36.94 63.06
-150 + 75 75 94.40 23.60 94.40 305.60 23.60 76.40
-75 + 63 63 0 0 0 400.00 0 100.00
Table 12: Sieve Analysis of Drill Cuttings from Blast-hole Twelve (Geovertrag Quarry, Ado- Ekiti)
Sieve Size (µm) MeanSieve
Size (µm)
Wt
Retained(g)
%Wt
Retained%
Cum Wt
Retained(g)
Cum Wt
Passing(g)
Cum %
Retained
Cum %
Passing
850 850 112.28 28.07 400.00 0 100 0
-850 + 600 600 20.80 5.20 287.72 112.80 71.93 28.07
-600 + 425 425 22.64 5.66 266.92 133.08 66.73 33.27
-425 + 300 300 43.60 10.90 244.28 155.72 61.07 38.93
-300 + 212 212 52.92 13.23 200.68 199.32 50.17 49.83
-212 + 150 150 53.36 13.34 147.76 252.24 36.94 63.06
-150 + 75 75 94.40 23.60 94.40 305.60 23.60 76.40
-75 + 63 63 0 0 0 400.00 0 100.00
Table 13: Sieve Analysis of Drill Cuttings from Blast-hole Thirteen (Geovertrag Quarry, Ado- Ekiti)
Sieve Size (µm) MeanSieve
Size (µm)
Wt
Retained(g)
%Wt
Retained%
Cum Wt
Retained(g)
Cum Wt
Passing(g)
Cum %
Retained
Cum %
Passing
850 850 112.00 28.00 400.00 0 100.00 0
-850 + 600 600 20.80 5.20 288.00 112.00 72.00 28.00
-600 + 425 425 22.40 5.60 267.20 132.80 66.80 33.20
-425 + 300 300 43.20 10.80 244.80 155.20 61.20 38.80
-300 + 212 212 52.80 13.20 201.60 198.40 50.40 49.60
-212 + 150 150 52.96 13.24 148.80 251.20 37.20 62.80
-150 + 75 75 95.84 23.96 95.84 304.16 23.96 76.04
-75 + 63 63 0 0 0 400.00 0 100.00

Blast-Hole Cuttings: An Indicator of Drill Bit Wear in Quarries 728
Table 14: Sieve Analysis of Drill Cuttings from Blast-hole Fourteen (Geovertrag Quarry, Ado- Ekiti)
Sieve Size (µm) MeanSieve
Size (µm)
Wt
Retained(g)
%Wt
Retained%
Cum Wt
Retained(g)
Cum Wt
Passing(g)
Cum %
Retained
Cum %
Passing
850 850 112.00 28.00 400.00 0 100.00 0
-850 + 600 600 20.80 5.20 288.00 112.00 72.00 28.00
-600 + 425 425 22.40 5.60 267.20 132.80 66.80 33.20
-425 + 300 300 43.20 10.80 244.80 155.20 61.20 38.80
-300 + 212 212 52.80 13.20 201.60 198.40 50.40 49.60
-212 + 150 150 52.96 13.24 148.80 251.20 37.20 62.80
-150 + 75 75 95.84 23.96 95.84 304.16 23.96 76.04
-75 + 63 63 0 0 0 400.00 0 100.00
Table 15: Sieve Analysis of Drill Cuttings from Blast-hole Fifteen (Geovertrag Quarry, Ado- Ekiti)
Sieve Size (µm) MeanSieve
Size (µm)
Wt
Retained(g)
%Wt
Retained%
Cum Wt
Retained(g)
Cum Wt
Passing(g)
Cum %
Retained
Cum %
Passing
850 850 107.44 26.86 400.00 0 100.00 0
-850 + 600 600 20.80 5.20 292.56 107.44 73.14 26.86
-600 + 425 425 22.40 5.60 271.76 128.24 67.94 32.06
-425 + 300 300 43.20 10.80 249.36 150.64 62.34 37.66
-300 + 212 212 52.80 13.20 206.16 193.84 51.54 48.46
-212 + 150 150 52.96 13.24 153.36 246.64 38.34 61.66
-150 + 75 75 100.40 25.10 100.40 299.60 25.10 74.90
-75 + 63 63 0 0 0 400.00 0 100.00
Table 16: Sieve Analysis of Drill Cuttings from Blast-hole Sixteen (Geovertrag Quarry, Ado- Ekiti)
Sieve Size (µm) MeanSieve
Size (µm)
Wt
Retained(g)
%Wt
Retained%
Cum Wt
Retained(g)
Cum Wt
Passing(g)
Cum %
Retained
Cum %
Passing
850 850 107.44 26.86 400.00 0 100.00 0
-850 + 600 600 20.80 5.20 292.56 107.44 73.14 26.86
-600 + 425 425 22.40 5.60 271.76 128.24 67.94 32.06
-425 + 300 300 43.20 10.80 249.36 150.64 62.34 37.66
-300 + 212 212 52.80 13.20 206.16 193.84 51.54 48.46
-212 + 150 150 52.96 13.24 153.36 246.64 38.34 61.66
-150 + 75 75 100.40 25.10 100.40 299.60 25.10 74.90
-75 + 63 63 0 0 0 400.00 0 100.00
Table 17: Sieve Analysis of Drill Cuttings from Blast-hole One (Johnson Construction Ltd, Quarry, Akure)
Sieve Size (µm) MeanSieve
Size (µm)
Wt
Retained(g)
%Wt
Retained%
Cum Wt
Retained(g)
Cum Wt
Passing(g)
Cum %
Retained
Cum %
Passing
850 850 140.40 35.10 400.00 0 100.00 0
-850 + 600 600 41.60 10.40 259.60 191.20 64.90 35.10
-600 + 425 425 38.40 9.60 218.00 182.00 54.50 45.50
-425 + 300 300 44.96 11.24 179.60 220.40 44.90 55.10
-300 + 212 212 37.56 9.39 134.64 265.36 33.66 66.34
-212 + 150 150 34.40 8.60 97.08 302.92 24.27 75.73
-150 + 75 75 62.68 15.67 62.68 337.32 15.67 84.33
-75 + 63 63 0 0 0 400.00 0 100.00

729 Z.O. Opafunso and B. Adebayo
Table 18: Sieve Analysis of Drill Cuttings from Blast-hole Two (Johnson Construction Ltd, Quarry, Akure)
Sieve Size (µm) MeanSieve
Size (µm)
Wt
Retained(g)
%Wt
Retained%
Cum Wt
Retained(g)
Cum Wt
Passing(g)
Cum %
Retained
Cum %
Passing
850 850 136.68 34.17 400.00 0 100.00 0
-850 + 600 600 40.80 10.20 263.32 136.68 65.83 34.17
-600 + 425 425 34.24 8.56 222.52 177.48 55.63 44.37
-425 + 300 300 43.32 10.83 188.28 211.72 47.07 52.93
-300 + 212 212 41.00 10.25 144.28 255.04 36.24 63.76
-212 + 150 150 39.12 9.78 103.96 296.04 25.99 74.01
-150 + 75 75 64.84 16.21 64.84 335.16 16.21 83.79
-75 + 63 63 0 0 0 400.00 0 100.00
Table 19: Sieve Analysis of Drill Cuttings from Blast-hole Three (Johnson Construction Ltd, Quarry, Akure)
Sieve Size (µm) MeanSieve
Size (µm)
Wt
Retained(g)
%Wt
Retained%
Cum Wt
Retained(g)
Cum Wt
Passing(g)
Cum %
Retained
Cum %
Passing
850 850 132.80 33.20 400.00 0 100.00 0
-850 + 600 600 38.40 9.60 267.20 132.8 66.80 33.20
-600 + 425 425 34.80 8.70 228.80 171.20 57.20 42.80
-425 + 300 300 39.36 9.84 194.00 206.00 48.50 51.50
-300 + 212 212 40.80 10.20 154.64 245.36 38.66 61.34
-212 + 150 150 36.40 9.10 113.84 286.16 28.46 71.54
-150 + 75 75 77.44 19.36 77.44 322.56 19.36 80.64
-75 + 63 63 0 0 0 400.00 0 100.00
Table 20: Sieve Analysis of Drill Cuttings from Blast-hole Four (Johnson Construction Ltd, Quarry, Akure)
Sieve Size (µm) MeanSieve
Size (µm)
Wt
Retained(g)
%Wt
Retained
Cum Wt
Retained(g)
Cum wt
Passing(g)
Cum %
Retained
Cum %
Passing
850 850 128.00 32.00 400.00 0 100.00 0
-850 +600 600 35.60 8.90 272.00 128.00 68.00 32.00
-600+ 425 425 32.00 8.00 236.40 163.60 59.10 40.90
-425 +300 300 40.72 10.18 204.40 195.60 51.10 48.90
-300 +212 212 42.72 10.68 163.68 236.32 40.92 59.08
-212 +150 150 38.00 9.50 120.96 279.04 30.24 69.76
-150 + 75 75 82.96 20.74 82.96 317.04 20.74 79.26
-75 + 63 63 0 0 0 400.00 0 100.00
Table 21: Sieve Analysis of Drill Cuttings from Blast-hole Five (Johnson Construction Ltd, Quarry, Akure)
Sieve Size (µm) MeanSieve
Size (µm)
Wt
Retained(g)
%Wt
Retained%
Cum Wt
Retained(g)
Cum Wt
Passing(g)
Cum %
Retained
Cum %
Passing
850 850 126.00 31.50 400.00 0 100.00 0
-850 + 600 600 34.00 8.50 274.00 126.00 68.50 31.50
-600 + 425 425 32.00 8.00 240.00 160.00 60.00 40.00
-425 + 300 300 40.32 10.08 208.00 192.00 52.00 48.00
-300 + 212 212 43.52 10.88 167.68 232.32 41.92 58.08
-212 + 150 150 39.20 9.80 124.16 275.84 31.04 68.96
-150 + 75 75 84.96 21.24 84.96 315.04 21.24 78.76
-75 + 63 63 0 0 0 400.00 0 100.00

Blast-Hole Cuttings: An Indicator of Drill Bit Wear in Quarries 730
Table 22: Sieve Analysis of Drill Cuttings from Blast-hole Six (Johnson Construction Ltd, Quarry, Akure)
Sieve Size (µm) MeanSieve
Size (µm)
Wt
Retained(g)
%Wt
Retained%
Cum Wt
Retained(g)
Cum Wt
Passing(g)
Cum %
Retained
Cum %
Passing
850 850 121.20 30.30 400.00 0 100.00 0
-850 + 600 600 32.40 8.10 278.80 121.20 69.70 30.30
-600 + 425 425 32.00 8.00 246.40 153.60 61.60 38.40
-425 + 300 300 40.96 10.24 214.40 185.60 53.60 46.40
-300 + 212 212 41.04 10.26 173.44 226.56 43.36 56.64
-212 + 150 150 43.20 10.80 132.40 267.60 33.10 66.90
-150 + 75 75 89.20 22.30 89.20 310.80 22.30 77.70
-75 + 63 63 0 0 0 400.00 0 100.00
Table 23: Sieve Analysis of Drill Cuttings from Blast-hole Seven (Johnson Construction Ltd, Quarry, Akure)
Sieve Size (µm) MeanSieve
Size (µm)
Wt
Retained(g)
%Wt
Retained%
Cum Wt
Retained(g)
Cum Wt
Passing(g)
Cum %
Retained
Cum %
Passing
850 850 116.80 29.20 400.00 0 100.00 0
-850 + 600 600 30.40 7.60 383.20 116.80 70.80 29.20
-600 + 425 425 31.68 7.92 252.80 147.20 63.20 36.80
-425 + 300 300 40.64 10.16 221.12 178.86 55.28 44.72
-300 + 212 212 41.84 10.46 180.48 219.52 45.12 54.88
-212 + 150 150 44.40 11.10 138.64 261.36 34.66 65.34
-150 + 75 75 94.24 23.56 94.24 305.76 23.56 76.44
-75 + 63 63 0 0 0 400.00 0 100.00
Table 24: Sieve Analysis of Drill Cuttings from Blast-hole Eight (Johnson Construction Ltd, Quarry, Akure)
Sieve Size (µm) MeanSieve
Size (µm)
Wt
Retained(g)
%Wt
Retained%
Cum Wt
Retained(g)
Cum Wt
Passing(g)
Cum %
Retained
Cum %
Passing
850 850 112.60 28.15 400.00 0 100.00 0
-850 + 600 600 29.60 7.40 287.40 112.60 71.85 28.15
-600 + 425 425 30.08 7.52 257.80 142.20 64.45 35.55
-425 + 300 300 39.28 9.82 227.72 172.26 56.93 43.07
-300 + 212 212 43.44 10.86 188.44 211.56 47.11 52.89
-212 + 150 150 47.36 11.84 145.00 255.00 36.25 63.75
-150 + 75 75 97.64 24.41 97.64 302.36 24.41 75.59
-75 + 63 63 0 0 0 400.00 0 100.00
Table 25: Sieve Analysis of Drill Cuttings from Blast-hole Nine (Johnson Construction Ltd, Quarry, Akure)
Sieve Size(µm)
MeanSieve
Size (µm)
Wt
Retained(g)
%Wt
Retained%
Cum Wt
Retained(g)
Cum Wt
Passing(g)
Cum %
Retained
Cum %
Passing
850 850 106.40 26.60 400.00 0 100.00 0
-850 + 600 600 28.60 7.15 293.60 106.40 73.40 26.60
-600 + 425 425 29.28 7.32 265.00 135.00 66.25 33.75
-425 + 300 300 42.20 10.55 235.72 164.28 58.93 41.07
-300 + 212 212 45.04 11.26 193.52 206.48 48.38 51.62
-212 + 150 150 47.44 11.86 148.48 251.52 37.12 62.88
-150 + 75 75 101.04 25.26 101.04 298.96 25.26 74.74
-75 + 63 63 0 0 0 400.00 0 100

731 Z.O. Opafunso and B. Adebayo
Table 26: Sieve Analysis of Drill Cuttings from Blast-hole Ten (Johnson Construction Ltd, Quarry, Akure)
Sieve Size (µm) MeanSieve
Size (µm)
Wt
Retained(g)
%Wt
Retained%
Cum Wt
Retained(g)
Cum Wt
Passing(g)
Cum %
Retained
Cum %
Passing
850 850 99.20 24.80 400.00 0 100.00 0
-850 + 600 600 28.40 7.10 300.80 99.20 75.20 24.80
-600 + 425 425 28.64 7.16 272.40 127.80 68.10 31.90
-425 + 300 300 36.64 9.16 243.76 156.24 60.94 39.06
-300 + 212 212 48.93 12.23 207.12 192.88 51.78 48.22
-212 + 150 150 49.36 12.34 158.20 241.80 39.55 60.45
-150 + 75 75 108.84 27.21 108.84 291.16 27.21 72.79
-75 + 63 63 0 0 0 400.00 0 100.00
Table 27: Sieve Analysis of Drill Cuttings from Blast-hole Eleven (Johnson Construction Ltd, Quarry, Akure)
Sieve Size (µm) MeanSieve
Size (µm)
Wt
Retained(g)
%Wt
Retained%
Cum Wt
Retained(g)
Cum Wt
Passing(g)
Cum %
Retained
Cum %
Passing
850 850 98.40 24.60 400.00 0 100.00 0
-850 + 600 600 28.80 7.20 301.60 98.40 75.40 24.60
-600 + 425 425 29.04 7.26 272.80 127.20 68.20 31.80
-425 + 300 300 36.64 9.16 243.76 156.24 60.94 39.06
-300 + 212 212 48.92 12.23 207.12 192.88 51.78 48.22
-212 + 150 150 49.36 12.34 158.20 241.80 39.55 60.45
-150 + 75 75 108.84 27.21 108.84 291.16 27.21 72.79
-75 + 63 63 0 0 0 400.00 0 100.00
Table 28: Sieve Analysis of Drill Cuttings from Blast-hole Twelve (Johnson Construction Ltd, Quarry, Akure)
Sieve Size (µm)
MeanSieve
Size (µm)
Wt
Retained(g)
%Wt
Retained%
Cum Wt
Retained(g)
Cum Wt
Passing(g)
Cum %
Retained
Cum %
Passing
850 850 98.40 24.60 400.00 0 100.00 0
-850 + 600 600 28.80 7.20 301.60 98.40 75.40 24.60
-600 + 425 425 29.04 7.26 272.80 127.20 68.20 31.80
-425 + 300 300 36.64 9.16 243.76 156.24 60.94 39.06
-300 + 212 212 48.92 12.23 207.12 192.88 51.78 48.22
-212 + 150 150 49.36 12.34 158.20 241.80 39.55 60.45
-150 + 75 75 108.84 27.21 108.84 291.16 27.21 72.79
-75 + 63 63 0 0 0 400.00 0 100.00
Table 29: Sieve Analysis of Drill Cuttings from Blast-hole Thirteen (Johnson Construction Ltd, Quarry,
Akure)
Sieve Size (µm) MeanSieve
Size (µm)
Wt
Retained(g)
%Wt
Retained%
Cum Wt
Retained(g)
Cum Wt
Passing(g)
Cum %
Retained
Cum %
Passing
850 850 98.04 24.51 400.00 0 100.00 0
-850 + 600 600 28.60 7.15 301.96 98.04 75.49 24.51
-600 + 425 425 28.80 7.20 273.36 126.64 68.34 31.66
-425 + 300 300 36.88 9.22 244.56 155.44 61.14 38.86
-300 + 212 212 49.00 12.25 207.68 192.32 51.92 48.08
-212 + 150 150 49.44 12.36 158.68 241.32 39.67 60.33
-150 + 75 75 109.24 27.31 109.24 290.76 27.31 72.69
-75 + 63 63 0 0 0 400.00 0 100.00

Blast-Hole Cuttings: An Indicator of Drill Bit Wear in Quarries 732
Table 30: Sieve Analysis of Drill Cuttings from Blast-hole Fourteen (Johnson Construction Ltd, Quarry,
Akure)
Sieve Size (µm) MeanSieve
Size (µm)
Wt
Retained(g)
%Wt
Retained%
Cum Wt
Retained(g)
Cum Wt
Passing(g)
Cum %
Retained
Cum %
Passing
850 850 98.04 24.51 400.00 0 100.00 0
-850 + 600 600 28.60 7.15 301.96 98.04 75.49 24.51
-600 + 425 425 28.80 7.20 273.36 126.64 68.34 31.66
-425 + 300 300 36.88 9.22 244.56 155.44 61.14 38.86
-300 + 212 212 49.00 12.25 207.68 192.32 51.92 48.08
-212 + 150 150 49.44 12.36 158.68 241.32 39.67 60.33
-150 + 75 75 109.24 27.31 109.24 290.76 27.31 72.69
-75 + 63 63 0 0 0 400.00 0 100.00
Table 31: Sieve Analysis of Drill Cuttings from Blast-hole Fifteen (Johnson Construction Ltd, Quarry, Akure)
Sieve Size (µm) MeanSieve
Size (µm)
Wt
Retained(g)
%Wt
Retained%
Cum Wt
Retained(g)
Cum Wt
Passing(g)
Cum %
Retained
Cum %
Passing
850 850 97.64 24.41 400.00 0 100.00 0
-850 + 600 600 28.60 7.15 302.36 97.64 75.59 24.41
-600 + 425 425 28.80 7.20 273.76 126.24 68.44 31.56
-425 + 300 300 37.00 9.25 244.96 155.04 61.24 38.76
-300 + 212 212 49.00 12.25 207.96 192.04 51.99 48.01
-212 + 150 150 49.44 112.36 158.96 141.04 39.74 60.26
-150 + 75 75 109.52 27.38 109.52 290.48 27.38 72.62
-75 + 63 63 0 0 0 400.00 0 100.00
Table 32: Sieve Analysis of Drill Cuttings from Blast-hole One (Sonel Boneh, Quarry, Ibadan)
Sieve Size (µm) MeanSieve
Size (µm)
Wt
Retained(g)
%Wt
Retained%
Cum Wt
Retained(g)
Cum Wt
Passing(g)
Cum %
Retained
Cum %
Passing
850 850 144.68 36.17 399.98 0.02 99.98 0
-850 + 600 600 46.46 11.60 255.32 144.68 63.81 0.01
-600 + 425 425 41.32 10.33 208.86 191.14 52.21 36.19
-425 + 300 300 47.64 11.91 167.54 232.46 41.88 47.79
-300 + 212 212 33.40 8.35 119.90 280.10 29.97 58.12
-212 + 150 150 28.88 7.22 86.50 313.90 21.62 70.03
-150 + 75 75 57.60 14.40 57.62 342.38 14.40 78.38
-75 + 63 63 0 0 0.02 399.98 0 85.60
Table 33: Sieve Analysis of Drill Cuttings from Blast-hole Two (Sonel Boneh, Quarry, Ibadan)
Sieve Size (µm) MeanSieve
Size (µm)
Wt
Retained(g)
%Wt
Retained%
Cum Wt
Retained(g)
Cum Wt
Passing(g)
Cum %
Retained
Cum %
Passing
850 850 140.80 35.20 400.00 0 100.00 0
-850 + 600 600 41.60 10.40 259.20 140.80 64.80 35.20
-600 + 425 425 38.40 9.60 217.60 182.40 54.40 45.60
-425 + 300 300 44.96 11.24 179.20 220.80 44.80 55.20
-300 + 212 212 37.56 9.39 134.24 265.76 33.56 66.44
-212 + 150 150 34.40 8.60 96.68 303.32 24.17 75.83
-150 + 75 75 62.28 15.57 62.28 337.72 15.57 84.43
-75 + 63 63 0 0 0 400.00 0 100.00

733 Z.O. Opafunso and B. Adebayo
Table 34: Sieve Analysis of Drill Cuttings from Blast-hole Three (Sonel Boneh, Quarry, Ibadan)
Sieve Size (µm) MeanSieve
Size (µm)
Wt
Retained(g)
%Wt
Retained%
Cum Wt
Retained(g)
Cum Wt
Passing(g)
Cum %
Retained
Cum %
Passing
850 850 140.80 35.20 400.00 0 100.00 0
-850 + 600 600 38.40 9.60 259.20 140.80 64.80 35.20
-600 + 425 425 34.80 8.70 220.80 179.20 55.20 44.80
-425 + 300 300 39.36 9.84 186.00 214.00 46.50 53.50
-300 + 212 212 40.80 10.20 146.64 253.36 36.66 63.34
-212 + 150 150 40.40 10.10 105.84 294.16 26.46 73.54
-150 + 75 75 65.44 16.36 65.44 334.56 16.36 83.64
-75 + 63 63 0 0 0 400.00 0 100.00
Table 35: Sieve Analysis of Drill Cuttings from Blast-hole Four (Sonel Boneh, Quarry, Ibadan)
Sieve Size (µm) MeanSieve
Size (µm)
Wt
Retained(g)
%Wt
Retained%
Cum Wt
Retained(g)
Cum Wt
Passing(g)
Cum %
Retained
Cum %
Passing
850 850 140.00 35.00 400.00 0 100.00 0
-850 + 600 600 34.00 8.50 260.00 140.00 65.00 35.00
-600 + 425 425 32.00 8.00 226.00 174.00 56.50 43.50
-425 + 300 300 40.32 10.08 194.00 206.00 48.50 51.50
-300 + 212 212 43.52 10.88 153.68 246.32 38.42 61.58
-212 + 150 150 39.20 9.80 110.16 289.84 27.54 72.46
-150 + 75 75 70.96 17.74 70.96 329.04 17.74 82.26
-75 + 63 63 0 0 0 400.00 0 100.00
Table 36: Sieve Analysis of Drill Cuttings from Blast-hole Five (Sonel Boneh, Quarry, Ibadan)
Sieve Size (µm) MeanSieve
Size (µm)
Wt
Retained(g)
%Wt
Retained%
Cum Wt
Retained(g)
Cum Wt
Passing(g)
Cum %
Retained
Cum %
Passing
850 850 133.60 33.40 400.00 0 100.00 0
-850 + 600 600 30.80 7.70 266.40 133.60 66.60 33.40
-600 + 425 425 29.60 7.40 235.60 164.40 58.90 41.10
-425 + 300 300 40.16 10.04 206.00 194.00 51.50 48.50
-300 + 212 212 47.44 11.86 165.84 234.16 41.46 58.54
-212 + 150 150 46.40 11.60 118.40 281.60 29.60 70.40
-150 + 75 75 72.00 18.00 72.00 328.00 18.00 82.00
-75 + 63 63 0 0 0 400.00 0 100.00
Table 37: Sieve Analysis of Drill Cuttings from Blast-hole Six (Sonel Boneh, Quarry, Ibadan)
Sieve Size (µm) MeanSieve
Size (µm)
Wt
Retained(g)
%Wt
Retained%
Cum Wt
Retained(g)
Cum Wt
Passing(g)
Cum %
Retained
Cum %
Passing
850 850 129.20 32.30 400.00 0.02 99.95 0.01
-850 + 600 600 29.20 7.30 270.80 129.20 67.65 32.39
-600 + 425 425 29.28 7.32 241.60 158.40 60.35 39.65
-425 + 300 300 38.48 9.62 212.32 187.66 53.03 46.97
-300 + 212 212 48.42 12.06 173.84 226.18 43.41 56.59
-212 + 150 150 48.56 12.14 125.42 274.58 31.35 68.65
-150 + 75 75 76.84 19.21 76.86 323.14 19.21 80.79
-75 + 63 63 0 0 0.02 399.98 0 99.99

Blast-Hole Cuttings: An Indicator of Drill Bit Wear in Quarries 734
Table 38: Sieve Analysis of Drill Cuttings from Blast-hole Seven (Sonel Boneh, Quarry, Ibadan)
Sieve Size (µm) MeanSieve
Size (µm)
Wt
Retained(g)
%Wt
Retained%
Cum Wt
Retained(g)
Cum Wt
Passing(g)
Cum %
Retained
Cum %
Passing
850 850 121.60 30.40 400.00 0 100.00 0
-850 + 600 600 28.40 7.10 278.40 121.80 69.60 30.40
-600 + 425 425 28.64 7.16 250.00 150.00 62.50 37.50
-425 + 300 300 38.64 9.66 221.36 178.64 55.34 44.66
-300 + 212 212 50.92 12.73 182.72 217.28 45.68 54.32
-212 + 150 150 54.16 13.54 131.80 268.20 32.95 67.05
-150 + 75 75 77.64 19.41 77.64 322.38 19.41 80.59
-75 + 63 63 0 0 0 400.00 0 100.00
Table 39: Sieve Analysis of Drill Cuttings from Blast-hole Eight (Sonel Boneh, Quarry, Ibadan)
Sieve Size (µm) MeanSieve
Size (µm)
Wt
Retained(g)
%Wt
Retained%
Cum Wt
Retained(g)
Cum Wt
Passing(g)
Cum %
Retained
Cum %
Passing
850 850 110.40 27.60 400.00 0 100.00 0
-850 + 600 600 28.00 7.00 289.60 110.40 72.40 27.60
-600 + 425 425 31.44 7.86 261.60 138.40 65.40 34.60
-425 + 300 300 38.24 9.56 230.16 169.84 57.54 42.46
-300 + 212 212 51.72 12.93 191.92 208.08 47.98 52.02
-212 + 150 150 56.16 14.04 140.20 259.80 35.05 64.99
-150 + 75 75 84.04 21.01 84.04 315.96 21.01 79.99
-75 + 63 63 0 0 0 400.00 0 100.00
Table 40: Sieve Analysis of Drill Cuttings from Blast-hole Nine (Sonel Boneh, Quarry, Ibadan)
Sieve Size (µm) MeanSieve
Size (µm)
Wt
Retained(g)
%Wt
Retained%
Cum Wt
Retained(g)
Cum Wt
Passing(g)
Cum %
Retained
Cum %
Passing
850 850 101.68 25.42 400.00 0 100.00 0
-850 + 600 600 25.60 6.40 298.32 131.68 74.58 25.42
-600 + 425 425 25.84 6.46 272.72 127.28 68.18 31.82
-425 + 300 300 38.56 9.64 246.88 153.12 61.72 38.28
-300 + 212 212 56.12 14.03 208.32 371.68 52.08 47.92
-212 + 150 150 57.36 14.34 152.20 247.60 38.05 61.95
-150 + 75 75 94.84 23.71 94.84 305.16 23.71 76.29
-75 + 63 63 0 0 0 400.00 0 100.00
Table 41: Sieve Analysis of Drill Cuttings from Blast-hole Ten (Sonel Boneh, Quarry, Ibadan)
Sieve Size (µm) MeanSieve
Size (µm)
Wt
Retained(g)
%Wt
Retained%
Cum Wt
Retained(g)
Cum Wt
Passing(g)
Cum %
Retained
Cum %
Passing
850 850 96.00 24.00 400.00 0 100.00 0
-850 + 600 600 20.00 5.00 304.00 96.00 76.00 24.00
-600 + 425 425 20.24 5.06 284.00 116.00 71.00 29.00
-425 + 300 300 40.28 10.07 263.76 136.24 65.94 34.06
-300 + 212 212 59.32 14.83 223.48 176.52 55.87 44.13
-212 + 150 150 59.76 14.94 164.16 235.84 41.04 58.96
-150 + 75 75 104.40 26.10 104.40 295.60 26.10 73.90
-75 + 63 63 0 0 0 400.00 0 100.00

735 Z.O. Opafunso and B. Adebayo
Table 42: Sieve Analysis of Drill Cuttings from Blast-hole Eleven (Sonel Boneh, Quarry, Ibadan)
Sieve Size (µm) MeanSieve
Size (µm)
Wt
Retained(g)
%Wt
Retained%
Cum Wt
Retained(g)
Cum Wt
Passing(g)
Cum %
Retained
Cum %
Passing
850 850 95.60 23.90 400.00 0 100.00 0
-850 + 600 600 19.60 4.90 304.40 95.60 76.10 23.90
-600 + 425 425 19.84 4.96 284.80 115.20 71.20 28.80
-425 + 300 300 40.28 10.07 264.96 135.04 66.24 33.76
-300 + 212 212 59.72 14.93 224.68 175.32 56.17 43.83
-212 + 150 150 60.16 15.04 164.96 235.04 41.24 58.76
-150 + 75 75 104.80 26.20 104.80 295.20 26.20 73.80
-75 + 63 63 0 0 0 400.00 0 100.00
Table 43: Sieve Analysis of Drill Cuttings from Blast-hole Twelve (Sonel Boneh, Quarry, Ibadan)
Sieve Size (µm) MeanSieve
Size (µm)
Wt
Retained(g)
%Wt
Retained%
Cum Wt
Retained(g)
Cum Wt
Passing(g)
Cum %
Retained
Cum %
Passing
850 850 95.60 23.90 400.00 0 100.00 0
-850 + 600 600 19.60 4.90 304.40 95.60 76.10 23.90
-600 + 425 425 19.84 4.96 284.80 115.20 71.20 28.80
-425 + 300 300 40.28 10.07 264.96 135.04 66.24 33.76
-300 + 212 212 59.72 14.93 224.68 175.32 56.17 43.83
-212 + 150 150 60.16 15.04 164.96 235.04 41.24 58.76
-150 + 75 75 104.80 26.20 104.80 295.20 26.20 73.80
-75 + 63 63 0 0 0 400.00 0 100.00
Table 44: Sieve Analysis of Drill Cuttings from Blast-hole Thirteen (Sonel Boneh, Quarry, Ibadan)
Sieve Size (µm) MeanSieve
Size (µm)
Wt
Retained(g)
%Wt
Retained%
Cum Wt
Retained(g)
Cum Wt
Passing(g)
Cum %
Retained
Cum %
Passing
850 850 95.20 23.80 400.00 0 100.00 0
-850 + 600 600 19.60 4.90 304.80 95.20 76.20 23.80
-600 + 425 425 19.44 4.86 285.20 114.80 71.30 28.70
-425 + 300 300 39.88 9.97 265.76 134.24 66.44 33.56
-300 + 212 212 60.12 15.03 225.88 174.12 56.47 43.53
-212 + 150 150 60.56 15.14 165.76 234.24 41.44 58.56
-150 + 75 75 105.20 26.30 105.20 294.80 26.30 73.70
-75 + 63 63 0 0 0 400.00 0 100.00
Table 45: Sieve Analysis of Drill Cuttings from Blast-hole Fourteen (Sonel Boneh, Quarry, Ibadan)
Sieve Size (µm) MeanSieve
Size (µm)
Wt
Retained(g)
%Wt
Retained%
Cum Wt
Retained(g)
Cum Wt
Passing(g)
Cum %
Retained
Cum %
Passing
850 850 95.20 23.80 400.00 0 100.00 0
-850 + 600 600 19.60 4.90 304.80 95.20 76.20 23.80
-600 + 425 425 19.44 4.86 285.20 114.80 71.30 28.70
-425 + 300 300 39.88 9.97 265.76 134.24 66.44 33.56
-300 + 212 212 60.12 15.03 225.88 174.12 56.47 43.53
-212 + 150 150 60.56 15.14 165.76 234.24 41.44 58.56
-150 + 75 75 105.20 26.30 105.20 294.80 26.30 73.70
-75 + 63 63 0 0 0 400.00 0 100.00

Blast-Hole Cuttings: An Indicator of Drill Bit Wear in Quarries 736
Table 46: Sieve Analysis of Drill Cuttings from Blast-hole Fifteen (Sonel Boneh, Quarry, Ibadan)
Sieve Size (µm) MeanSieve
Size (µm)
Wt
Retained(g)
%Wt
Retained%
Cum Wt
Retained(g)
Cum Wt
Passing(g)
Cum %
Retained
Cum %
Passing
850 850 94.80 23.70 400.00 0 100.00 0
-850 + 600 600 19.60 4.90 305.20 94.80 76.30 23.70
-600 + 425 425 19.44 4.86 228.50 114.40 71.40 28.60
-425 + 300 300 39.88 9.97 266.16 133.84 66.54 33.46
-300 + 212 212 60.52 15.13 226.28 173.72 56.57 43.43
-212 + 150 150 60.56 15.14 165.76 234.24 41.44 58.56
-150 + 75 75 105.20 26.30 105.20 294.80 26.30 73.70
-75 + 63 63 0 0 0 400.00 0 100.00
Conclusion
The paper has examined the relationship between gauge button wear rate and blast-hole cuttings
retained on 75µm sieve size. It was observed as bit buttons wear blast-hole cuttings become finer this is
due to regrinding instead of penetrating the rock mass. Strong relationship exists between gauge bit
button wear rate and weight of blast-hole cuttings retained on 75µm sieve size for the three selected
quarries.
References
[1] Beste, U. (2004): On Nature of Cemented Carbide Wear in Rock Drilling, Doctorial Thesis,
Department of Engineering Science,Uppsala University Uppsala, Sweden.
[2] Chiang, L.E. and Elias, D.A. (2000): Modelling Impact in Down-the-Hole Rock drilling,
International Journal of Rock Mechanics and Mining sciences, 37 (2000), pp 599-613.
[3] Gokhale, B.V. (2004): Flushing of Blast-hole, http://rockproducts.com pp 1-4
[4] Hetenyi, M. (1966): Hand book of Experimental Stress Analysis, Wiley New-York, and 115
pp.
[5] Howarth, D.F., Adamson, W.R. and Berndt, T.R. (1986): Correlation of Model Tunnel
Boring and Drilling Machine Performance with Rock Properties, International Journal of Rock
Mechanics and Mining sciences, 23, pp 171-175 [Technical Note].
[6] Morley, A. (1944): Strength of Materials, Longman London, 35pp.
[7] Shah, K.R. and Wong, T.F. (1997): Fracturing at Contact Surfaces Subjected to Normal and
Tangential Load, International Journal of Rock Mechanics, Mining sciences and
Geomechanics, 1997; 3(5), pp 727-739.
[8] Thuro, K. (1997): Drillability Prediction - Geological Influences in Hard Rock Drill and Blast
Tunneling, Geol. Rundsch 86, pp. 426 – 437.

European Journal of Scientific Research
ISSN 1450-216X Vol.20 No.4 (2008), pp.737-745
© EuroJournals Publishing, Inc. 2008
http://www.eurojournals.com/ejsr.htm
Assessment of Micro-Credit Supply by Country Women
Association of Nigeria (Cowan) to Rural Women in
Ondo State, Nigeria
M.G. Olujide
Department of Agricultural Extension & Rural Development
University of Ibadan, Ibadan, Nigeria
E-mail: gbengaolujide@yahoo.com, mg.olujide@ui.mail.edu.ng
Abstract
Most Nigerian rural farmers are small scale farmers who require small amount of
loan to help them improve their production. One of the avenue by which the rural women
obtain loan is through the Country Women Association of Nigeria (COWAN).
This paper assessed the micro credit supply by COWAN to rural women in Ondo
State, Nigeria and specifically find out demographic characteristics of respondents,
examine the conditions for granting loan, attitude of the rural women towards COWAN
micro credit scheme, ascertain amount of micro-credit provided, ways by which rural
women utilizes the micro-credit, the timeliness of micro-credits and examine the
constraints facing rural women towards getting the micro credit.
One hundred and six rural women was selected in four Local Government areas of
Ondo state, using multi-stage random sampling technique.
The result revealed that majority (64.1%) of the rural women had age ranges
between 21 and 40 years, 76.4% of them are married, 9.4% were single, 10.4% were
divorced and the remaining 3.8% of them were divorced. Majority (78.3%) were
Christians, had adult literacy 5.7%, 27.4% had primary education, 17% had secondary
education, 16% of them had no formal education and 8.5% of them had higher education.
On the attitude of rural women, 16% of the respondents fall into the Low attitude
score towards COWAN micro credit. The majority (84%) of them fall into high attitude
score.
The result further revealed that 42.5% of the respondents obtained the sum of
N5,000:00 – N10,000:00 as micro credit and 43.4% of them obtained the sum of
N11,000:00 – N16,000:00 micro credit while 14.1% obtained above N16,000:00 as micro
credit from COWAN.
The respondents used the micro credit obtained from COWAN for farming (85.5%)
and remaining 14.5% of them for trading.
The constraints identified by respondents include lack of funds (37.7%), short
period of repayment (28.7%) and Loan defaulters 16% as their major constraints. The
benefits derived from COWAN micro credit include increase in production (75.5%).
The study revealed that marital status, age, position among husbands wife, number
of children, educational level and religion have no significant relationship with the micro
credit received from COWAN group while the occupation of the respondents has a
significant relationship with the micro credit received.

Assessment of Micro-Credit Supply by Country Women Association of
Nigeria (Cowan) to Rural Women in Ondo State, Nigeria 738
Based on the findings of the study, it is recommended that lump sum of money
should be granted to rural women to enhance their productivity so as to change their living
status.
Keywords: Micro-Credit, Supply, COWAN and Rural Women.
Introduction
Credit is the process of obtaining control over the use of money, good and services in the present in
exchange for a promise to pay at a future date (Adegeye and Dittoh, 1985). It is a capital resources
used in production that is a monetary resources, which can take the form of money in cash or bank
draft or in kind as a firm of biological and physical purchased and supplied to producers.
The purpose of any saving and credit programme is to enable people gain access on reasonable
terms to assets, which they can use to improve their livelihood. Virtually all societies, households and
individual save and borrow money, saving take place during periods when income exceeds
expenditure.
The micro credit scheme was an evolutionary process of merging and refining traditional and
other practices which are indigenous to our people, an adapted to their most felt needs and experience.
These traditional credit systems usually involve: a group of people pooling resources together;
voluntary membership and consensus based on decision making; regular monetary contribution; and
access to credit from group on rotational and interest-free basis.
Micro-credit programmes however extend small loan to people for employment project that
generate income, allowing them to care for themselves and their family. In Nigeria, micro-credit
programmes offer a combination of services and resources to their client in addition to credit. These
often include saving facilities, training, networking and peer support (McKean, C.S. 1989).
According to Williams (1993) rural women are major contributors to subsistence agriculture as
producers and marketers, they also engaged in keeping poultry, small animals such as sheep, goats,
rabbits and dairy cattle. However, inspite of their prominent feature in agricultural production, they are
usually under remunerated in terms of financial gains, social acceptability, appreciation and time taken
off when compared with men (Aweto, 1996).
The basic assumption is that rural women are usually resource poor, lack necessary information
to take vital decisions to improve their conditions of living and consequently do not have access to the
government organs or agencies set up to ameliorate their hardship since rural women are known to be
hard working, it is assumed that if their attitude are changed through training and they become exposed
to the wherewithal by which they can improve their conditions, they will be motivated to engage more
in enterprise development and consequently increase their income to enhance their standard of living
(Brown, 1979). Hence, they will be able to decide on who to approach, for what, when and what to
engage in. Therefore, COWAN intends to provide this vital linkage with resource input and equip rural
women with the management skill required for successfully managing their income generating
activities (Ogunleye, 2000).
The issue of micro-credit has been taking a centre stage of discussions on rural development
and poverty alleviation, Non-governmental organization, governments, the people have discovered that
for effective rural development to thrive, issues of micro credit should form a cardinal programme.
Emerging trends have pointed to the fact that the role of micro-credit has became far from what is used
to be considered as poverty alleviation strategies and as a vehicle for providing financial services to the
poor (Olujide, 1999).
Micro-credit as it is often referred to has been adjudged as a catalyst for sustainable
development. It goes beyond just a programme of economic empowerment that target saver and
provision of credit transaction for low income and underprivileged groups to actual capacity building

739 M.G. Olujide
through the provision of technical assistance to the most vulnerable group with the classification of the
poor (Imam, 1998).
The roles of micro-credit as a poverty alleviation strategy and a vehicle for providing financial
services to the poor have continued to gain prominence in the society. The connect is not far fetched,
this is because developing a broad based of micro-entrepreneurs in any economy is consequential to
the sustenance of its growth and development process (Olujide, 1999).
The Country Women Association of Nigeria (COWAN) is an apex non-governmental
organization for recognition and advancement of rural women in agriculture, economic and decision
making for a total utilization and development of the nations vital human and natural resources and
talent for self-reliance. It is COWANs vision to have a society free from indignity and oppression of
peoples knowledge, elimination of hunger and poverty, economic injustice and inferiority complex,
upholding peoples dignity, sense of belonging and ownership, designing with people a development
process which embraces building self-sufficiency and sustainable development.
COWAN established in Ondo State in 1982, has consistently work hard to develop powerful
tools to increase economic independence of rural women in Nigeria. These tools include a micro credit
system which values, updates and combines indigenous micro-credit practices with aspects of modern
banking system in a way that makes the resulting system deliver credit and related services to rural
villages in a user-friendly way (COWAN, 2000). A unique characteristic of the micro-credit
programme in the ownership of the financial institution by borrowers themselves.
COWAN has additionally organized rural women, updated their production skills, regularly
advised them of economic opportunities and mobilize funds to expose its members to various national,
regional and international workshops and conferences in an effort to update their knowledge and
increase their networks (Ogunleye, 2000). COWAN, a non-governmental organization was set up with
the primary concern of alleviating poverty among the rural women and to increase the economic
independence of rural women in Nigeria (Ogunleye, 1997, Olujide 1999).
The micro credit supplied by COWAN has greatly increase the economic competence of rural
women and has mobilized the traditional strength of Nigerian rural women to promote their
participation in the development of human and natural sources for sustainable livelihood in rural and
urban advocate for women economic and social empowerment.
Women feature in small-scale enterprises and this account for the smallness of their loans. The
provision of credit to people with low income and poor educational background is generally not
acceptable to formal institutions because of higher administrative costs and getting access to finance
has not been easy for rural women.
Research had shown that women have very limited access to land, capital, gainful employment
and positions of decision making (Christine, 1993 and Olawoye,2002). These constraints have drawn
women to the informal sector to source for capital. This informal sector includes family, friends,
private money-lenders, Esusu, cooperative societies. Apart from these sources, Non-governmental
organizations and donor agencies have given out millions as grants to micro finance organizations to
be given out as revolving loans to their members.
It is against the background that the following questions are posed in the study.
1. What are the demographic characteristics (age, marital status, religion, educational level,
occupation) of rural women?
2. What are the conditions for granting micro-credit to rural women?
3. What is the attitude of rural women towards the micro-credit programme?
4. What is the amount granted to micro-credit to rural women?
5. What purposes are the micro-credit utilized?
6. Is the provision of Micro-Credit to rural women by COWAN timely?
7. What are the constraints facing the rural women under the micro-credit programme?

Assessment of Micro-Credit Supply by Country Women Association of
Nigeria (Cowan) to Rural Women in Ondo State, Nigeria 740
Objective of the Study
The general objective of the study was to assess the micro-credit supply of COWAN to the rural
women in Ondo State, Nigeria.
The specific objective include:
1. identify the demographic characteristics (such as age, marital status, religion, educational
level, occupation) of rural women.
2. examine the conditions for granting micro credit to rural women by COWAN.
3. examine the attitude of rural women towards micro credit programme.
4. ascertain if the amount of micro credit provided by COWAN is enough for rural women.
5. identify the ways by which rural women utilizes the Micro-credit.
6. ascertain the timeliness of micro-credit of COWAN,
7. examine the constraints faced by rural women towards getting the micro credit.
Methodology
Area of the Study
The study was carried out in Ondo State of Nigeria. The State has eighteen (18) local government areas
and is located in the South Western area of Nigeria and lies between latitude 7º’N and 4º 47’E
longitude. The state experience two major seasons, dry and wet seasons which favour the growth of
varieties of food and cash crops. The major economics activities of the people was farming and the
major crops grown are yam, cassava, maize and vegetables while the cash crops include cocoa, oil
palm, rubber and kolanut.
Population and Sampling Procedure
The population for this study are rural women in Ondo State who are members of COWAN group.
Multi-stage sampling was employed for the study. The state was divided into four geographical zones
with the eighteen local government areas. The first stage of the sampling involves selection of six
Local Governmnt Areas from each zone Each of the geographical zone has an average of six local
government areas which was randomly selected. In each local government area selected, there are four
groups of COWAN with hundreds (100) members. Forty members were selected for the study
representing 10% the population, making one hundred and six respondents as shown in table 1.
Table 1: Analysis of Sample Selection
Selected Local Government Area
Number of
Programmes
Number of
Programme
Selected
Number of
Respondents in
Local Government
Sampled
Respondents
1. Ondo West Local Government 4 1 150 30
2. Ilaje Local Government 3 1 100 25
3. Akure North Local Government 4 1 160 30
4. Akoko Southeast Local Government 4 1 150 21
Total 15 4 560 106
*Membership strength as contained in COWAN register.
Source: Field Survey, 2006.
Data Collection
Both primary and secondary data were used during the study. Respondents were interviewed using
their responses as primary data, secondary data was obtained from records provided by COWAN,
published articles and relevant texts.

741 M.G. Olujide
Analytical Techniques
The data obtained from interview schedule was subject to descriptive and inferential statistical
analysis. Descriptive statistics for this study include frequency, percentages and means and the
hypothesis was tested using chi-square.
Result and Discussions
The respondents were requested to describe their demographic characteristics, such as age, marital
status, religion, level of education and occupation as presented in Table 2.
Table 2: Frequency Distribution of rural women according to demographic characteristics (such as age,
marital status, religion, level of education and occupation)
Variables Frequency Percentage
(a) Age (yrs)
21-30 27 25.4
31-40 41 38.7
41-50 22 20.8
51-60 16 15.1
Total 106 100.0
(b) Marital Status
Single 10 9.4
Married 81 76.4
Divorced 11 10.4
Widowed 4 3.8
Total 106 100.0
(c) Religion
Christianity 83 78.3
Islam 17 16.0
Traditional 6 5.7
Total 106 100.0
(d) Level of Education
1. No formal education 26 16.0
2. Primary education 29 27.4
3. Higher education 18 17.0
4. Adult Literacy Education 33 5.7
Total 106 100
(e) Occupation
Farming 35 33.1
Clerk/Typist 26 24.5
Teaching 19 17.6
Trading 26 24.5
Total 106 100
The above table 2 showed that 21 to 30 years old rural women were 25.4 percent, 31-40 years
were 38.7 percent. 41-50 years old respondents were 20.8 percent while 51-60 years old respondents
were 15.1 percent. The result showed that majority of the rural women are neither too young nor too
old, they are in active stage of life. They will be able to put into good use the credit received from
COWAN.
On marital status, the result indicates that 76.4 percent of the rural women were married, 11.3
percent were divorced, 9.4 percent were single and 2.8 percent were widowed. Since majority (76.4%)
of respondents were married, they are responsible. It can be inferred that married applicants are more
favoured than unmarried during application for membership.
On the religion, the result showed that majority of the rural women (78.3%) are Christians,
while 16.0 percent are Muslims and 5.7 are traditionalists. The educational level of the respondents
showed that 5.7% of the rural women had adult literacy education, 27.4 percent had primary education,

Assessment of Micro-Credit Supply by Country Women Association of
Nigeria (Cowan) to Rural Women in Ondo State, Nigeria 742
17.0 percent had secondary education, 16.0 percent of them had no formal education and 8.5 percent
respondents had higher education.
On the occupation of the rural women, the result showed that 33.0 percent of the rural women
major occupation was farming, 24.5 percent of them are clerk/typists, 17.9 percent of the respondents
are teachers and 24.5 percent respondents are traders. This indicates that COWAN takes care of various
activities of women.
Conditions for Giving Loan to Rural Women by Cowan
The conditions for giving loan to rural women by COWAN include the following:
1. You must be a registered COWAN member
2. Intending borrowers must be registered with COWAN organization in their community for
a period of 6 months and must apply for credit through their group.
3. Members must attend meeting regularly and pay monthly due of N100.00.
4. The duration for repaying monetary credit is one year and the interest rate was 10%.
The attitude of rural women towards micro credit received from COWAN micro-credit was
categorized as unfavourable and favourable using attitudinal scores as shown in Table 3.
Table 3: Frequency Distribution of rural women according to attitude towards COWAN Micro Credit
Attitude of Respondents toward COWAN micro-credit Frequency Percentages
Unfavourable 17 16.0
Favourable 89 84.0
Total 106 100.0
Table 3 showed that 16.0 percent of the respondents fall into the low attitude score towards
COWAN micro credit. Also, the majority (84.0%) falls into high attitude score. This therefore, implies
that the rural women had favourable attitude towards the micro credits received from COWAN.
The amount of Micro Credit received as credit from COWAN was presented in Table 4.
Table 4: Frequency Distribution of rural women according to the amount received as credit from COWAN
Amount (N) Frequency Percentage
5,000 – 10,000 45 42.5
11,000 – 16,000 46 43.4
Above 16,000 15 14.1
Total 106 100.0
Table 4 showed that 42.5 percent of the respondents obtained the sum of N5,000 – N10,000 as
micro-credit and 43.4 percent of the respondents obtained the sum of N11,000 – N16,000 micro-credit
while 14.1 percent obtained above N16,000 as micro-credit from COWAN.
Utilization of Micro Credit Received from COWAN
The micro credit given to rural women can be put into various use depending on the occupation of the
beneficiaries as shown in table 5:

743 M.G. Olujide
Table 5: Frequency distribution of respondents according to utilization of micro credit received from
COWAN.
Occupation Frequency Percentage
Farming 91 85.5
Trading 15 14.5
Local Crafts - -
Total 106 100.0
The result showed that majority (85.5 percent) of the respondents used the micro credit
obtained from COWAN organization for farming, 14.5 percent of them used for trading. The
implication of this is that majority of the respondents utilizes the micro credit obtained for their
occupation.
Constraints Faced by Rural Women in Obtaining Micro Credit from constraints faced by rural
women in obtaining micro-credit as shown in Table 6.
Table 6: Frequency Distribution of Respondents According to Constraints Faced by Rural Women
Identified Constraints Frequency Percentages
Lack of funds 40 37.7
Mismanagement of funds 10 9.5
Short period of repayment 30 28.3
Loan defaulters 17 16.0
Lack of incentive from the government 9 8.5
Total 106 100.0
Table 6 indicates that 37.7 percent of the respondents agreed that lack of funds from COWAN
is their major constraints while 28.3 percent agreed that short period of repayment of micro credits
granted was their constraints and 16.0 percents opined that loan defaulters are the major constraints,
and 9.5 percents claimed that mismanagement of funds is the major constraints they faced from
COWAN and 8.5 percent opined that lack of incentives from government is their major constraints.
Benefit Derived from Micro Credit Obtained by Rural Women from COWAN
Benefit derived from micro-credit obtained by rural women were presented in Table 6.
Table 7: Frequency Distribution of Respondents According to the Benefits erived from COWAN Credit
Benefits Derived Frequency Percentages
Increase in Production 70 75.5
Procure more farm inputs 10 9.4
Input 16 15.1
No response 8 7.5
Total 106 100.0
Table 7 indicates that majority of the respondents 75.5 percent obtained the micro-credit to
increase their production while 9.4 percent respondents received it to procure more farm inputs, while
15.1 percent respondents obtained it during the money seasons.

Assessment of Micro-Credit Supply by Country Women Association of
Nigeria (Cowan) to Rural Women in Ondo State, Nigeria 744
Table 8: Chi-square tests of relationship between demographic characteristics of respondents and microcredit
received from COWAN
Demographic Characteristics of
the Respondents
Df
X 2 tabulated
value
X 2 calculated
value
Significance
Level
Decision
Age 3 7.82 4.36 0.05 NS
Marital Status 3 7.82 5.29 0.05 NS
Position among husband’s wife 2 5.99 1.26 0.05 NS
Number of children 3 7.82 4.49 0.05 NS
Educational attainment 4 9.49 6.82 0.05 NS
Religion 2 5.99 1.10 0.05 NS
Occupation 3 7.82 11.0 0.05 S
As shown in table 8, age is tested as related to micro credit received, chi-square of 4.36 was
observed comparing the figure with x 2 tabular that is 7.82, showed that there is no significant
relationship between the age and micro credit received. Consequently, the null hypothesis were
accepted, that in these in no significant relationship between age and micro credit received from
COWAN, chi square value of 4.36 was observed when compare with the x 2 tabulated that is, 7.82. The
null hypothesis was therefore accepted, that is there is no significant relationship between beneficiaries
material status and micro credit received.
The chi-square analysis was used in the contingency table to determine the relationship
between the level of education of respondent and micro credit received. Chi square value of 6.82 was
observed. When compared with the x 2 tabulated that is 9.49. The null hypothesis is accepted implying
that the level of education is not significantly related to the micro credit received. The position of
respondents among husband’s wife and micro credit received was tested. The result shows that chisquare
calculated is 1.26 while X 2 , the null hypothesis is accepted, that is there is no significant
relationship between respondents position among husband’s wife and micro credit received.
For number of children for respondents and micro received, chi-square value 7.82. Therefore
the null hypothesis is accepted which state that there is no significant relationship between the number
of respondents’ children and micro credit received.
Religion of the respondents and micro credit received from COWAN was compared using X 2
statistic. Comparing the X 2 calculated value of 1.10 and X 2 tabulated value of 5.99, the hypothesis is
accepted. That is there is no significant relationship between the respondents’ religions and micro
credit received.
The occupation of the respondents and the micro credit received was analysed using chi-square
statistics. Comparing the X 2 calculated value of 7.82 and X 2 tabulated value of 7.82. The null
hypothesis is accepted that is there is a significant relationship between occupation of the respondents
and micro credit received. The significant relationship is explained by contingency coefficient of 0.31.
This implies age, marital status, education attainment, position among husband’s wife number
of children of respondents and religions of the respondents do not significantly affect the micro credit
received from COWAN but the occupation of the respondents has a significant relationship with the
micro credit received.
Conclusion and Recommendation
This study assesed the micro-credit given to rural women by COWAN in Ondo State. Questionnaire
was used to collect data from the respondents. For the purpose of the study, 106 respondents
representing four local government areas in Ondo State were selected, using the list of registered
COWAN members as sampling frame.
The respondents attitude towards COWAN credit, majority (84 percent) had favourable attitude
towards micro-credit while 16 percent had unfavourable attitude towards micro-credit. On the

745 M.G. Olujide
respondents benefit derived from the micro credit, majority (75.5 percent) of the respondents obtained
the micro-credit to increase their production while 9 percent received it to procure more farm inputs
and 15 percent did not respond to the variable.
On the constraints encountered by COWAN members 37.7 percent had inadequate funding as
constraint, while 28.3 percent had constraint of short period of repayment of loan, 16 percent is
attributed to loan defaulters, 9.5 percent is attributed to mismanagement of funds and 8.5 percent is
attributed to lack of incentives from the government.
Based on the findings in this study, one can realize the COWAN is still bringing improvement
to the living conditions of rural women. The rural women had benefited from the micro-credits granted
to them by COWAN. It can be inferred that COWAN micro-credits had made impact among the rural
women in the studied area.
References
[1] Adegeye and Ditto (1985). “Essential of Agricultural Economics”, Ibadan. Inpac Publisher
Limited, pp. 10-12.
[2] Aweto, R.A. (1996). Agricultural Cooperatives. Stand and Printers. Builds Limited Ibadan. Pp.
141 – 142.
[3] Brown, C.K. (1979). The participation of Women in Rural Development Programmes in
Kaduna State of Nigeria. C.S.E.R Research Pages 5, ABU, Zaria. Pp. 13.
[4] Christine, Y. (1993). Investment Finance Off Limits for Women in Women and Economics
Policy. 0x 7am U.K. Edited by Barbara, pp. 16.
[5] Imam. H. (1998): The role of Micro Credit in Development. Guardian Newspaper Vol. 4, No.
1237 pp. 10.
[6] McKean, C.S. (1989). Training and Technical Assistance for Small and Micro business. A
review of their effectiveness and Implications for Women. Pp. 10 – 15.
[7] Ogunleye, B. (2000). Innovation for Poverty Eradication. Country Women Association of
Nigeria. Presented at Micro-Credit Seminar. Washington DC, pp. 6-8.
[8] Olawoye J.E(2002) Gender informed approaches to sustainable human development.Paper
presented at Workshop on gender issues in economic development,Organised by Nigerian
centre for Economic Management and Administration(NCEMA)held at Ibadan.pp1-4
[9] Olujide, M.G. (1999). “Activities of Selected Non-Governmental Organisations (NGOs) in
Rural Development in South West Nigeria (Ph.D. Thesis), Department of Agricultural
Extension and Rural Development, University of Ibadan, Ibadan, pp. 104-110.
[10] Williams, C.E. (1982). The Status and Tasks of Rural Women In Nigeria: A Case Study of
Allagba Village, Oyo State. Pp. 1 – 2.

European Journal of Scientific Research
ISSN 1450-216X Vol.20 No.4 (2008), pp.746-758
© EuroJournals Publishing, Inc. 2008
http://www.eurojournals.com/ejsr.htm
Comparative Analysis of Pictorial Coverage of Events by
Pakistan’s English Press
Muhammad Nawaz Mahsud
Chairman, Department of Communication Studies
University of Sargodha, Pakistan
Muhammad Khalid
Professor, Department of Communication Studies
University of Sargodha, Pakistan
Firasat Jabeen
Lecturer, Department of Communication Studies
University of Sargodha, Pakistan
Abstract
This study describes the leading English dailies ‘Dawn’ and ‘The Nation’ all pages
pictorial coverage of events of international, national, provincial, and regional importance.
Sixty newspapers containing 30 issues of each of the selected papers are analyzed. Results
of the study show that daily ‘Dawn’ has significantly published more pictures and also
spared significant space to developmental affairs, education, festival, disaster, accident, and
crimes events compared to the number of pictures and space given to the same issues by
daily “The Nation’ for the same period. Conversely daily ‘The Nation’ has published
significantly more pictures and also given more space to the issues of politics, economics,
technology, showbiz, health, war against terrorism, and sports than the number of pictures
and space devoted to the same set of events by daily ‘Dawn.’ The results show no
significant difference between both the papers’ coverage given to the events of
environment, nature, weather, and others. The comparison of overall number of published
pictures on events and space given to those pictures by the selected dailies shows
significant difference. The Nation has published more number of pictures (930) and also
spared significant space (223434) in centimeter compared to the Dawn number of pictures
(712) and the space given to them (112669). It is also observed that both the papers have
published significantly more pictures and also spared more space to the events of
international importance than their number of pictures and space given to events of
national, provincial, and regional importance.
Significance
“One picture tells as much as 1000 words” (www.shipshapewsiebiz.com/NewsRoom.asp-20k). Human
mind understands the language of pictures. Whatever we think, our mind creates pictures, and words
transcend them into reality, making our ideas understandable. Most of the knowledge we perceive is
through our sense of sight. “It is sense of sight that is dominant in human knowledge of the world,
nature and life. Man actually receives two third of his knowledge through vision for what he sees is
memorized easier. This is exactly why photography plays an important role in acquainting us with

Comparative Analysis of Pictorial Coverage of Events by Pakistan’s English Press 747
reality” (Hasan, 2005). Visuals are more effective, influential and memorable compared to the
narration that is why most newspaper editors intend to accompany most of the news stories with
pictures and special attention is given to the pictorial coverage of events so that the real picture of the
event can be presented before the reader. There’s nothing like a photograph to give a newspaper
motion and emotion. Photo journalism lies at the very heart of newspaper design” (Harrower, 2004).
Today’s reader urges to see something unique, appealing, snappy, easy to grasp and that can appeal the
reader’s aesthetic sense. ‘Every picture tells a story and every story deserves a picture. Today’s readers
are so spoiled by TV and magazines that they now expect color photos, yet to accompany nearly every
story they read’ (p.4).
Today’s media is entangled in competitive environment. Print media, newspaper in particular
has to combat television staged with glamour, radio for its access, interactive media for its speed and
glazing magazines. ‘Pictures are one of the key elements of a page. It is a picture that draws a reader
into a page and helps to guide him or her through the page and the material on it’ (Frost, 2002).
Therefore a right picture, at right place in right time plays pivotal role in making newspaper eye
catching and can compete its other technological rivals. ‘It is one of the peculiar characteristics of the
photo that it isolates single moments in time. The TV camera does not’ (McLuhan, 2002). It wouldn’t
be wrong to say that pictures displayed in newspaper significantly attract more readerships. ‘The
convincing power of the verbal comment in turn is strengthened by the photographic image, which
multiplies the emotional elements’ (Hasan, 2005). This study aims to explore the coverage and
importance given to the pictorial coverage by English dailies.
History of pictorial journalism is not so old. A French inventor named Niepce produced the first
permanent photograph in 1826. The historian of photography associated with the rediscovery of
Niepce’s early work was Helmut Gernsheim, whose History of Photography (published in 1995 and
1969) helped shape, for better or worse, the way that developments in the science are understood (Price
1998). Technological advancement in photographic equipments opened new doors of innovation, and it
became possible to capture an event within a camera. The first newspaper photograph was published in
1880. News photos didn’t become common, however, until the early 1900s. Gradually photographs
began to become important elements of newspaper design. Full color photos became common in the
early’80s, thus ushering the modern era of newspaper design (Harrower, 2002). In Pakistan, during
1950s English newspapers followed this trend by giving occasional photographic coverage to
important events. It took some time for Urdu newspaper to give attention to photography. However, in
1953, an Urdu daily ‘Kohistan’ was the first Urdu newspaper that started giving photographic coverage
to the events since then the Urdu press is far ahead in the production of photographs (Hasan and
Khurshid, 1987).
Pictures have a major part to play in setting the emotional agenda of a piece. Whether they are
pictures of widows weeping at a pithead mining disaster or the triumphant smile of the sports victor or
the mouth-twisting absorption of a picture- painting toddler, they all add something to the reader’s
perception of what has happened. The Poynter Institute’s Eye-trac research shows that readers are
drawn into a page by the picture or pictures (Garcia and Stark 1991). The picture is therefore important
to a page design and usually becomes the page’s entry point, drawing the reader in and then directing
them to the start of the main article. Newspapers and magazines are a potent mix of text and image
designed to grab the reader’s attention and hold it, making the experience of reading the news easy and
enjoyable and, more importantly for some, to tempt readers to carry on shelling out a reasonable
amount of precious cash to pay for it. The aim of a magazine front cover or a newspaper front page is
solely to invite the reader to buy, to tempt them into picking up the publication and become engrossed
in its content. The aim of inside is to continue that experience by offering information, education and
entertainment (Frost, 2003).
People have been interested in pictures for a long time. This interest has two related aspects: (a)
our interest in the picture of reality provided us in bits and pieces by our visual and gross body
orienting systems-and their technological enhancements. Indeed, Western science has provided us with
ever-clearer pictures of reality through the extension of our senses by specialized instruments, and (b)

748 Muhammad Nawaz Mahsud, Muhammad Khalid and Firasat Jabeen
we also have an interest in pictures for communication, pictures to transmit information among
ourselves as well as between our increasingly sophisticated information-processing machines and us.
The challenge in the design of a picture is the decision what to preserve and what to discard
(http://human-factors.arc.nasa.gov/ihh/spatial/papers/pdfs_se/pcpsu/Ellis-1993-pictorialcommunication.htm/).
To understand the medium of the photograph is quite impossible, then, without
grasping its relations to other media, both old and new. The photo and visual worlds are secure areas of
anesthesia. A picture of a group of persons of any hue whatever is a picture of people, not of “colored
people.” The logic of the photograph is neither verbal nor syntactical, a condition that renders literary
culture quite helpless to cope with the photograph. By the same token, the complete transformation of
human sense-awareness by this form involves a development of self-consciousness that alters facial
expression and cosmetic makeup as immediately as it does our bodily stance, in public or in private
(McLuhan, 2002).
The photograph is just as useful for collective, as for individual, postures and gestures, whereas
written and printed language is biased toward the private and individual posture. It was in 1839 that
William Henry Fox Talbot read a paper to the Royal Society which had a title: “Some Account of the
Art of Photogenic Drawing, or the process by which natural objects may be made to delineate
themselves without the aid of the artist’s pencil.” He was quite aware of photography as a kind of
automation that eliminated the syntactical procedures of pen and pencil. He was probably less aware
that he had brought the pictorial world into line with the new industrial procedures. It was this allimportant
quality of uniformity and repeatability that had made the Gutenberg breaks between the
Middle Ages and the Renaissance (p. 204). Historical pictorial collections can range from thousands to
millions of images, most of which are originals and many of which are also of unique art factual value.
Most collections, encompassing photographs and works on paper, include documentary photographs,
fine and popular prints and drawings, posters, and architectural and engineering drawings. Among the
many media included are glass-plate and film negatives; daguerreotypes, ambrotypes, and tintypes;
silver gelatin prints and color transparencies; lithographs, woodcuts, and etchings; and pen-and-ink,
watercolor, and chalk drawing (http://www.clir.Org/pubs/reports/ostrow/pub71.htm/).
As Evan (1999) explains it, a still image, such as a photograph of a woman, is less the
equivalent of “woman” than it is a series of disconnected descriptions: “an older woman, seen in the
distance wearing a green coat, watching the traffic, as she crosses the road.” She also tells us that
pictures have no tense, and thus no clear location in time. He reveals how many photographs, which
make an impact on the consciousness of the public, photographs that seem to symbolize something
about the human condition, have been obtained with less than scrupulous honesty. It presents us, says
Evans, with an object as a fait accompli. Visual images are inevitably ambiguous and polysemic, but
they also have certain advantages over words. One is their greater denotative power when used
deliberately and effectively. Another is their capacity to become icons – directly representing some
concept with clarity, impact and wide recognition. This gives them considerable potential for skilful
communication in certain contexts (McQuail, 2005, p. 349).
Sontag (1978) states that ‘the images that have virtually unlimited authority in a modern society
is mainly photographic images.’ A painting is ‘never more than the stating of an interpretation’, while a
photograph: ‘is never less than the registering of an emanation (light waves reflected by objects) –
material vestige of its subject in a way that no painting can be. The image/photograph is not the reality
itself, but, ‘at least … its perfect analogon.’ So, in the first place, the photograph is supposed to
transmit literal reality. In the second, it is an analogon: it is exactly similar to the reality it transmits.
Photographs have most usually been described as ‘icons’, because of their apparent ability to reproduce
some elements of reality. Since the photograph appears, at first sight, to be extremely close to the thing
it represents, the many claims made for its ability to transmit ‘the literal reality’ seem convincing (pp.
3). Photography has taught people a new way of seeing the world. There are quite extensive moral
implications which arise from this code: ‘In teaching us a new visual code, photographs alter and
enlarge our notions of what is worth looking at and what we have a right to observe. She believed that:
‘photographed images… now provide most of the knowledge people have about the look of the past

Comparative Analysis of Pictorial Coverage of Events by Pakistan’s English Press 749
and the reach of the present.’ If this is the case, then photographs exercise considerable power over
how we see the world (p.4).
McQuail (2005) says that there are serious shortcomings to this argument; it is the nature of this
reduction from the object to the image; it is the nature of this reduction, which is important. The
absence in the photograph of a number of elements found in the real world shows clearly how reality is
not simply reduced or altered, but actually transformed by photography. Reality and its photographic
image are in fact much farther apart that leads us to believe that the photograph signifies the actual
scene, object or person in the real world, without needing to be explained through the codes of a
specific culture. The important point about a photograph is that it is open to variety of different
interpretations. Photographs are here imagined to be powerful manipulators of human perception,
precisely because they seem to give us a direct access to the real world (pp. 348). If a photograph is
seen in a person’s family album, then it takes on the domestic and semi private connotations of
personal history. Seen in a mass-circulation newspaper, however, the case is very different. In a
newspaper, a photograph carries an impact for two reasons: first, it has been selected to represent or
reinforce the essence of a story, secondly, because it achieves widespread exposure in terms of the
numbers of people who see the image. The news photo is supposed to lend itself widespread
reproduction and must act as a visual ‘key’ to the story. The news photo will be given, in turn, its own
interpretative caption (p.349).
According to this view, the photographic image is able to mislead us because it is a special,
‘direct’ form of the iconic. Webster (1980) acknowledges the fact that photographs ‘can develop
quickly into symbols.’ Photographs tend to suggest a variety of meanings beyond their simple
resemblance to the real world. For example, a photograph of Marilyn Monroe, shown to a variety of
people who share, broadly, the same culture, may bring out a number of responses in its audience, and
is likely to signify a great deal more than just ‘young female.’ A whole range of meanings connected
with sexuality, the Hollywood star system, early death, and so on, will be brought to mind and will
seem to be combined in the image. It is difficult to produce new meanings from a photograph, which
has already become symbolic of some idea or force in society (p. 172). Types of photograph will also
tend to acquire a number of meanings, which will depend on an audience’s knowledge of the image
under study. They are made as part of continuous process, in which the news values held by the media
institutions and by the journalists who work in these institutions help to determine what the images are
sought in the first place. News photographs are designed to be accessible to large numbers of people,
and are often thought to be instrumental in changing or reinforcing opinion (p. 173).
News photographs are designed to be accessible to large numbers of people, and are often
thought to be instrumental in changing or reinforcing opinion. Rothstein (1974) claims that: ‘the
photographic image speaks directly to the mind and transcends the barriers of language and
nationality.’ The idea of the ‘universal’ ability of the image to speak directly to people across all
national and cultural boundaries is common to many studies of photography. Photographic image and
photojournalism are at least very widespread since they are ‘encountered by each of us virtually every
day of our lives … [and hold] a special place in the way we see the world’ (15-16). Today, no one
thinks of the news as words alone. For the most part, however, television, online news, newspapers and
magazines all depend heavily upon video, still photos, graphics or combinations of the three. The
reason is simple: Images can tell some stories better than pure prose. They vividly convey the emotion
and drama of human events, capturing moments in all their power and detail. Well-chosen words can
describe the moment of victory or defeat in a sporting event so that readers can share it through an act
of imagination (Price, 1998). Pictures, however, can take the viewer directly there, showing the
exhilaration or disappointment on an athlete’s face. Notice how the best television sportscasters fall
silent at the end of a dramatic contest-the moment of celebration after the last pitch of the World
Series, for example, or the meeting at the net when a championship tennis match ends. They know to
hold the commentary for a moment and let the pictures speak for themselves (pp.202-04). Some editors
tend to think of photographs only in terms of their emotional impact, but visual images can do much
more. Pictures also make the abstract concrete and humanize distant events and disasters in a powerful

750 Muhammad Nawaz Mahsud, Muhammad Khalid and Firasat Jabeen
ways. Visual images are among the media’s most potent resources, there is a silver of truth in the
warnings of those 1920s editors who feared photos might lower journalistic standards. Modern news
audiences expect to see photos, and they often count on the images to help decide what is worth their
time and attention. Those photos and their Cutlines then draw readers deeper into the page and lead
them to the accompanying stories. (Cutlines, used synonymously with the term captions by most
journalists, are short blocks of text that explain pictures in terms of who is shown, what is happening,
and when, where and why the photo was taken, pp. 205).
Many studies have focused on the concept of “attitudes”, or peoples’ general predisposition’s to
evaluate other people, objects, and issues favorably or unfavorably. The attitude construct achieved its
pre-eminent position in research on social influence because of the assumption that a person’s attitude
is information, on the one hand, and behavioral change, on the other (Peterson and Thurstone, 1933).
Over the past 50 years numerous theories of attitude change and models of knowledge- attitude-
behavior relationships have been developed (Eagly and Chaiken, 1993; McGuire, 198; Petty, Unnava,
and Strathman, 1991). Although the person ability to learn and recall new information was often
thought to be an important casual determinant of and prerequisite to attitude and behaviours change.
Little empirical evidence has accumulated to support the view that message learning is a necessary step
(Greenwald, 1968; McGuire, 1985; Petty and Cacioppo, 1981). The message comprehension and
learning can occur in the absence of attitude change, and that a person’s attitude can change without
learning the specific information in the communication that is, a person might be able to comprehend
all of the intended information perfectly, but not be persuaded either because the information is counter
argued or seen as personally irrelevant. On the other hand a person might get information all wrong
(scoring zero on a knowledge test) but think about it a manner that produces the intended change. This
analysis helps to why previous research on mass media effects has sometimes found that message
learning and changes in knowledge occur in the absence of attitude change and vice-versa (Petty,
Baker and Gleicher 1991).
The attitude change process involves considerable cognitive work does not mean that the
attitude formed will be rational or “accurate one”. However the important point is that a rather
thoughtful process in which people attend carefully the issue relevant information presented changes
sometimes attitudes. Examine this information in the light of their relevant experiences and knowledge
and evaluate the information along with the dimensions they perceive central to the merits of the issue.
People engaged in this effortful cognitive actively have been characterized as engaging in “systematic”
(Chaiken, Ciberman, and Eagly, 189), “mindful” (Palmerio et al. 1984), and “piecemeal” (Fiske and
Pavelchak, 1986) processing. Different media sources have an impact on peoples’ ability to think about
message specially people are generally better able to process messages that appear in the print media
than those that are controlled externally (e.g., radio and television; Chaiken and Eagly, 1976; Wright,
1981).
This study entails critical and comparative analysis of the pictorial coverage given by two
leading English dailies ‘Dawn’ and ‘The Nation’ to know what events, celebrities, festivals etc are
given importance for pictorial coverage, what are the priorities regarding pictorial display in terms of
the number and the space devoted to the pictures. This study will help to make pictures that are
published in newspapers more effective, theme centered and influential. Because, there is no denying
of the fact that pictorial display plays very important role in making a newspaper recognized.
Methodology
The present study focuses on the print media. “Newspapers and magazines are still the easiest media to
access on the train or bus” (Frost, 2003). Two English elite newspapers ‘Dawn’ and The Nation’ are
selected due to their credibility and value of permanence. All the issues of the said papers published
form January 1 st , 07 to March 31 st , 07 are the universe of the study. Pictures of events and personnel—
international, national, provincial, and regional importance—published by all the selected newspapers’
pages in the prescribed period are taken as unit of analysis. The reason is simply to learn about the
recent trends of pictorial coverage given by both the selected newspapers. Moreover the selected time

Comparative Analysis of Pictorial Coverage of Events by Pakistan’s English Press 751
period will also help to know the innovations the New Year has brought for the readers. Considering
the requirement of the present study and for meaningful inferences and deductions, the researcher has
done systematic sampling. Every third newspaper of the month is selected for the sample. In this way
total ten newspapers of one month and thirty newspapers for the whole period were selected, totaling
sixty.
Categories Selection
There are real advantages for a researcher to use a category system that has been used in other studies.
First, the researcher must know that it is a workable system. If the researcher needs to create his/her
own set of categories, the decision to create own set of categories instead of using an existing set
should be based primarily on the objectives of the study under consideration. It is mostly of limiting
the number of categories. Once coder is familiar with the set of categories, he/she should be able to
operate without frequent reference back to the list and definitions. To scientifically handle the problem
of data collection and data reduction, a coding sheet containing nine columns is created as shown
under:
Coding sheet
International National Provincial Regional
Categories* # of Space in # of Space in # of Space in # of Space in
photos cm photos cm photos cm photos cm
*: Politics, developmental affairs, economics, education, festival, technology, environment, disaster, accident, nature, war, crime, showbiz, health, weather,
protests, event, sports and others
The first column of coding sheet indicates categories; columns 2 nd and 3 rd show the number of
photographs, and the space given to events and personnel of international importance; columns 4 th and
5 th show the number of photographs and the space to events and personnel of national importance;
columns 6 th and 7 th indicate the number of photographs and space to events and personnel of provincial
importance: and columns 8 th and 9 th show the number of photographs to events and personnel of
regional importance.
Pilot Study
Pilot study is made to check how reliable the coding process is (Hansen, A. et al., 1998). Reliability in
content analysis is essentially about consistency: consistency between different coders (inter-coder
reliability), and consistency of the individual coder’s coding practice over time (intra-coder reliability).
There are several different ways of checking or measuring reliability in content analysis, from a simple
check on the percentage of coding decisions which coders agree, to more complex formulae which take
into account the degree to which a certain level of agreement would occur simply by chance in a set
number of coding decisions (pp.120-21). After developing a standardized coding sheet, initially twelve
selected newspapers are deeply observed and coded the materials in the light of the coding sheet. Four
coders (2 female and 2 male students) were properly trained and facilitated to check the authenticity of
the coding sheet and the consistency among the dimensions of the study’s main concepts. Higher
percentage of inter-coder reliability was observed. In this way, finally the required data from the
selected 60 newspapers was collected.
Findings
The results of the study reveal that both the selected leading newspapers have spared significant space
by almost all their pages the pictures of events and personnel of international, national, provincial, and
regional importance for the whole period of three months. The daily ‘Dawn’ exclusive pictorial
coverage given to the issues listed in the table 1.1 reveals that the paper has given significant
importance by both number of pictures (26) and space (2474) in centimeters to international political
events compared to its number of pictures and space devoted national, provincial and regional issues.
Significant difference is observed between the paper pictorial coverage of the events of developmental

752 Muhammad Nawaz Mahsud, Muhammad Khalid and Firasat Jabeen
affairs. The paper has spared significant space to the events of national (7023 cm) and regional
(7328cm) importance than its space given to international, and provincial developmental issues.
The findings further illustrate that the paper has spared significant space (3078cm) to the
pictures on economics’ events of national importance than the observed space given to the pictures of
the same events of international, provincial and regional level. The pictorial coverage of the education
events shows somewhat difference position. International education events are given more space
(2351cm) than the space coverage given to education’ pictures of national or regional level. The results
reveal very little but not significant difference between the number of pictures and space devoted to the
events of international and national festivals. The analytical review of the findings does not indicate
significant difference between the paper coverage to technology, disasters and other events. The paper
has given more space to the pictures on regional environmental issues for the prescribed three months
period. It is also observed that the paper has published more pictures on the events of international
accidents but given more space to the pictures on the events of regional accidents. It is also evident
from the findings of table 1.1 that the paper has spared significant space to the pictures of the events of
national crimes (2975cm) and showbiz (3283cm) compared to international events of crime (1263cm)
and showbiz 2743cm). The empirical results show significant difference regarding the paper space
coverage given to the events of protests, war against terrorism and sports. National protests’ events are
given more space (4086cm) than the event of international protests (2365cm), while the paper has
spared significantly more space (5873 cm) to the international events of war against terrorism and
sports (13419cm) than the national events of war against terrorism (3484cm) and sports (2509).
Table 1.1: Pictorial coverage by ‘Dawn’ for the selected period
International National Provincial Regional
# of Space In # of Space in # of Space in # of SpaceIn
Categories
photos cm photos cm photos cm photos cm
Politics 26 2474 8 915 5 805 1 21
Developmental Affairs 7 896 46 7023 1 190 37 7328
Economics 7 777 30 3078 0 0 2 446
Education 23 2351 8 1299 4 644 2 228
Festivals 16 3151 13 2800 0 0 7 1405
Technology 9 1457 6 690 0 0 0 0
Environment 0 0 3 553 0 0 6 1165
Disaster 2 437 0 0 0 0 3 563
Accident 12 89 1 206 0 0 5 1139
Nature 10 2166 11 2145 2 82 4 456
Crime 7 1263 13 2975 0 0 8 1509
Showbiz 31 2743 25 3283 0 0 0 0
Health 2 470 6 578 0 0 1 115
Weather 1 138 1 213 0 0 6 1234
Protest 12 2365 20 40 96 6 1390 15 3129
War Events 35 5973 20 3494 2 252 8 1412
Sports 86 13419 20 2509 0 0 2 585
Others 9 1766 10 1557 0 0 8 1908
Total 298 44112 241 37417 20 3364 115 22643
Conclusion
As it is evident from the figures of table 1.1 that daily ‘Dawn’ has significantly published more
pictures (298) and spared more space (44112) in centimeter to the events of international importance
than its number of pictures and space given to the events of national (241 pictures, 37417 space),
provincial (20 pictures, 3364 space), and regional (115 pictures, 22643 space) importance.
The study’s another paper ‘The Nation’ pictorial coverage to the same set of issues for the same
period shows that the paper has significantly spared more space (5259cm) to the pictures on
international political events than the pictures on national (1598cm), provincial (1771cm), and regional
(1553cm) political events. The results show that the paper has devoted significant space (5198cm) to

Comparative Analysis of Pictorial Coverage of Events by Pakistan’s English Press 753
the pictures on the regional development issues compared to the spaces given to international, national,
and provincial developmental issues (table 1.2) The review of the results further shows that pictures on
international economics affairs are given highly significant space (7042cm) than the observed spaces
given to the pictures on national, provincial, and regional economic events. Little but not significant
difference is observed between the space given to education events. Picture on regional educational
matters are given little more space compared to the space devoted to international, national, and
provincial education matters. The review of the space given to festival matters reveals somewhat
difference. Pictures on the national festival events are given little more space (1819cm) than the space
(1155cm) given to international festival events.
Table 1.2: Pictorial coverage by ‘The Nation’ for selected time period
International National Provincial Regional
Categories
# of photos
Space
in cm
# of photos Space
in cm
# of photos
Space
in cm
# of Photos Space
In cm
Politics 91 5259 28 1598 13 1771 21 1553
Developmental Affairs 8 1375 8 777 0 0 39 5198
Economics 42 7042 15 963 1 103 15 615
Education 6 590 11 319 5 442 10 981
Festival 9 1155 12 1819 0 0 1 59
Technology 32 3444 1 60 0 0 0 0
Environment 1 14 0 0 0 0 7 924
Disaster 1 226 1 192 0 0 0 0
Accident 2 280 0 0 0 0 2 195
Nature 14 636 10 2566 0 0 3 355
Crime 11 852 3 274 0 0 10 1579
Showbiz 99 7985 21 1857 0 0 0 0
Health 6 227 4 487 0 0 3 144
Weather 4 166 1 166 0 0 3 782
Demonstration 16 3302 14 2011 0 0 21 2917
War Events 25 3570 30 2928 9 695 50 6667
Sports 124 19092 46 4940 0 0 15 564
Others 16 1213 5 972 0 0 6 883
Total e 518 58131 210 21934 28 3012 206 23421
The results further show highly significant difference between the number of pictures and space
given to the events of technology. The paper has devoted very significant space (3444cm) to
international technological events than its space (60cm) given to national technological events. The
study’ findings don’t reveal significant difference between the paper’s number of pictures and space
spared to the events of environment, disaster, crime, health, accident, and weather. While, a big
difference is observed between the paper number of pictures and space spared to the events of nature.
Highly significant space (2566cm) is given to the pictures published on national events of nature than
the space (636cm) devoted to the nature events of international importance.
The results shown by table 1.2 further show significant differences between the number of
pictures and space devoted by the same paper to the events of showbiz, demonstration, war against
terrorism, and sports. The paper has given high significant space to the pictures of the events of
international showbiz (7985cm), demonstration (3302cm), war against terrorism (3570cm), and sports
(19092cm) than the space devoted to the same set of events of national level. However, the observed
findings reveal that the paper has spared high significant space (6667cm) to the pictures on war against
terrorism events of regional importance compared to the space given to the war events of national and
international importance.

754 Muhammad Nawaz Mahsud, Muhammad Khalid and Firasat Jabeen
Conclusion
As it is evident from the figures of table 1.2 that daily ‘The Nation’ has significantly published more
pictures (518) and spared more space (58131) in centimeter to the events of international importance
than its number of pictures and space given to the events of national (210 pictures, 21934 space),
provincial (28 pictures, 3012 space), and regional (206 pictures, 23421 space) importance.
The graphic presentation of the daily ‘Dawn’ shows that the paper has given more space to the
pictures on the events of international and national importance compared to their space given to the
events of provincial and regional importance (figure 1.1). Conversely, daily ‘The Nation’ space
coverage devoted to the pictures published on the events of international, national, provincial, and
regional matters of importance shows different position. The paper as shown by figure 1.2 has given
significant space to the pictures on the events of regional importance than the events of international,
national, and provincial importance. The comparison of both the papers number of pictures shows that
daily ‘The Nation’ has published more pictures on international events than the national, provincial,
and regional events (figure 1.3). While daily the ‘Dawn” has published more pictures on the events of
international and national importance compared to its pictures on the events of provincial and regional
importance (figure 1.4).
Figure 1.1: Dawn pictorial coverage
50000
40000
30000
20000
10000
0
International
National
Provincial
Regional
Figure 1.2: The Nation pictorial coverage
10000
8000
6000
4000
2000
0
International
National
Provincial
Regional
Figure 1.3: Picture Coverage by The Nation
206 International
28
210
518
National
Provincial
Regional

Comparative Analysis of Pictorial Coverage of Events by Pakistan’s English Press 755
Figure 1.4: Picture coverage by Dawn
20
115
241
298
International
National
Provincial
The empirical findings regarding both the dailies space coverage given to pictures published on
the events for the whole three months period show that both the newspapers have spared significant
space to the events of international importance than the events of national, provincial, and regional
importance (figures 1.5 & 1.6). However, daily the ‘Dawn’ has given significantly more space to
events of national level compared to the space given by daily ‘The Nation’ to the same events for same
period.
Regional
Figure 1.5: Space coverage by The Nation
Regional
21%
Province
3%
National
27%
Internati
onal
49%
Figure 1.6: Space coverage by Dawn
Regional
21%
Province
3%
National
35%
Internati
onal
41%
Results of the study shown by table 1.3 illustrate the comparison of number of pictures and
space given to the selected categories by both the papers for the whole stipulated period. As it is
evident from the findings that daily ‘Dawn’ has significantly published more pictures and also spared
significant space to developmental affairs, education, festival, disaster, accident, and crimes events of
international, national, provincial, and regional importance compared to the number of pictures and
space given by daily ‘The Nation’ to the same events for the same period. Conversely daily ‘The
Nation’ published significantly more pictures and also given more space to the issues of politics,
economics, technology, showbiz, health, war against terrorism, and sports of international, national,
provincial, and regional importance. The results show no significant difference between both the
papers’ coverage given to the events of environment, nature, weather, and others. In the light of the
above findings it can be concluded that ‘The Nation’ has not published more pictures but also spared
significant space to the listed set of issues compared to number of pictures and space devoted by
‘Dawn’ to the same events for the whole stipulated period.

756 Muhammad Nawaz Mahsud, Muhammad Khalid and Firasat Jabeen
Table 1.3: Both the papers’ Pictorial coverage Comparison
Dawn The Nation
Categories
# of photos Space in cm # of photos Space in cm
Politics 40 4215 153 10181
Developmental Affairs 91 15437 55 7349
Economics 39 4300 73 8723
Education 37 4521 32 2332
Festival 36 7356 22 3033
Technology 15 2148 33 3504
Environment 9 1718 8 937
Disaster 5 9910 2 418
Accident 18 2243 4 475
Nature 27 4849 27 3557
Crime 28 5747 24 2705
Showbiz 56 6026 120 9842
Health 9 1163 13 858
Weather 8 1586 8 1115
Demonstration 53 10981 51 8230
War Events 65 11131 114 138510
Sports 108 16513 185 24597
Others 27 5230 27 3068
Total 712 112669 930 223 434
Conclusion
The data in this review article mainly focused on many previous studies (Straubhaar & LaRose, 2004;
Entman,1993; McQuail, 2005; and Bandura, 1986). Straubhaar & LaRose write that important events
and figures can help to shape media content. Entman (1993) says that When information is supplied to
news media by source then it arrives with a built in frame that suit the purpose of source and is unlikely
to be purely objective. McQuail (2005) says that photographs are imagined to be powerful
manipulators of human perception, precisely because they seem to give us a direct access to the real
world. These have been selected to represent or reinforce the essence of a story, and to achieve
widespread exposure in terms of the numbers of people who see the image. Bandura’s (1986) model
posits four basic processes of social learning that occur in sequence: attention; retention; production;
and motivation. Our attention is directed at media content of potential relevance to our lives and
personal needs and interests.
Keeping in view the received empirical findings, first and perhaps most obviously, it can be
noted that both the selected newspapers had spared significant space by almost all their pages to
photographs on important events and figures of international, national, provincial, and regional
importance. However, significant difference between the findings of the national leading dailies was
observed. Daily the ‘Dawn’ had given more importance to developmental affairs, education, festival,
disaster, accident, and crimes events compared to the space given by ‘The Nation’ to the same events.
‘The Nation’ conversely, had given significantly more space to the issues of politics, economics,
technology, showbiz, health, war against terrorism, and sports than the space spared to the same events
by daily ‘Dawn.’ The analytical review of the comparison of overall number of pictures and space by
both the newspapers’ pages showed that international events and figures were given more importance
than the events and figures national, provincial, and regional levels (ref. tables 1.1 and 1.2). It was also
observed that both the papers had given significant importance to sports, showbiz, and war against
terrorism’s events and personnel of international importance. A big difference was further traced out
between Overall coverage of the papers had showed that ‘The Nation’ had published more number of
pictures and spared significant space compared to the ‘Dawn’ number of pictures and space for the
whole stipulated period (ref. table 1.3) This position had extended support to the research hypothesis

Comparative Analysis of Pictorial Coverage of Events by Pakistan’s English Press 757
that ‘The Nation publishes more pictures and gives more to the issues international, national, and
regional importance than daily Dawn.’
The daily ‘Dawn’ had given more focus on issues of international and national importance,
while ‘The Nation’ had paid little more focus on issues of regional importance (ref. figures 1.1 & 1.2).
Finally the study’s results did not reveal significant difference between both the papers’ coverage given
to the events of environment, nature, weather, and others. In the light of the above findings it can be
concluded that ‘The Nation’ has not published more pictures but also spared significant space to
compared to number of pictures and space by ‘Dawn’ for the whole stipulated period of three months.
References
[1] Bandura, A (1986). Social Foundations of thought and Actions: a Social Cognitive Theory.
Englewood Cliffs, NJ: Prentice-Hall.
[2] Chaiken, S., Liberman, A., & Eagly. A.H (1989). “Heuristic and systematic within and Beyond
The Persuation Context”, in J. Bargh (ed.), Unintended Thought, pp. 212-252, New York:
Guilford Press.
[3] Eagly, A.H., & Chaiken, S (1993). The Psychology of Attitudes, Fort Worth, TX: Harcourt,
Brace, and Movanovich.
[4] Entman, R.M (1993). ‘Framing: Towards Clarification of a Fractured Paradigm’, Journal of
Communication, 43(4): 51-8. http://www.clir.Org/pubs/reports/ostrow/pub71.htm/.
[5] Evans, H. (1978) Pictures on a Page, Heinemann, p. 216.
[6] Evans, J (1999). ‘cultures of the visual’, in J. Evans and S. Hall (eds), Visual culture: a Reader,
(London: sage) p. 12.
[7] Fiske, S.T., & Pavelchak, M.A (1986). “Category-based versus Piecemeal-based Affective
Responses: Development in Schematriggered Affect”. In R.M. Sorrentino & E.t. Higgings
(eds.), Handbook of Motivation and Cognition: Foundation of Social Behaviour, New York:
Guilford Press pp. 167-203,
[8] Friend, C., Challenger, D., & McAdams, K.C (2005). Contemporary Editing (The McGraw-
Hill) pp.323-5.
[9] Frost, Chris (2003). Designing for newspapers and magazines. pp. 01, 02, 03, 115, 117, and
127.
[10] Goldsmith, A. (1979) The Camera and Its images (Ridge Press/Newsweek Books) pp. 166-7.
[11] Greenwald, A.G (1968). “Cognitive Learning, Cognitive Response to Persuation, and Attitude
Change”, in A. Greenwald, t. Ostrom (Eds.) Psychological foundations of attitudes, New York
Academic Press, pp. 147-170,
[12] Harrower, Tim (2002). The Newspaper Designer’s Handbook (McGraw-Hill), p. 4.
[13] Hasan, Mehdi and Khursheed, A. S (1987). Journalism for All (Etisam Publishers, Lahore), pp.
185, 186.
[14] Hansen, A., Siman, C. Ralph, N. & Chris, N (1998). Mass Communication Research Methods,
Palgrave, New York, N. Y. 10010.
[15] McQuail, Denis (2005). Mass Communication Theory (Vistaar Publications, New Delhi), pp.
348-49.
[16] McQuail, D, & Wendahl, S (1993). Communication Models; for the Study of Mass
Communication. (3 rd Ed.) New York: Longman Publishing.
[17] McLuhan, Marshall (2002). Understanding Media (TJ international Ltd, Padstow, Cornwall,
Great Britain), pp. 204, 206, 210, 214, 217, 218, 219.
[18] Ostrow. S.E (1998). Digitizing Historical Pictorial Collections for the Internet.
http://www.clir.Org/pubs/reports/ostrow/pub71.htm/
[19] Palmerino, M., Linger, E., & McGillis, D (1984). “Attitudes and Attitude Change:
Mindlessness-mindfulness Perspective”, in J.R. Eisre (ed.) Attitudinal Judgment, New York:
Springer-Verlag, pp. S179-195,

758 Muhammad Nawaz Mahsud, Muhammad Khalid and Firasat Jabeen
[20] Peterson, R.E. & Thurstone, L (1933). Motion Pictures and Social Attitudes of Children, New
York: MacMillan.
[21] Petty, R.E. & Cacioppo, U.T (1981). Attitude and Persuation: Classic and Contemporary
Approaches, Dubuque: Wm. C. Brown.
[22] Petty, R.E., Baker, S.M., & Gleicher, F (1991). “Attitudes and Drug Abuse Prevention:
Implications of the Elaboration Likelihood Model of Persuation”, in L. Donohew, H.E. Syper,
& W.J. Bukoski (eds.), Persuasive Communication and Drug Abuse Prevention, Hillsdale, NJ:
Lawrence Erlbaum Associates, pp. 71-90.
[23] Petty, R.E, Unnava, R., & Strathman, A (1991). “Theories of Attitude Change”, in H.
Kassarjain & T. Robertson (eds.), Handbook of Consumer Theory and Research, Englewood
Cliffs, NJ: Prentice-Hall, pp. 241-280,
[24] Price, Stuart (1998). Media Studies, (Singapore through Addison Wesley Longman China Ltd),
pp. 202-210, 213-14, and 217.
[25] Rothstein, A (1974). Photojournalism (Amphoto) pp. 15, 21.
[26] Sontag, S (1978). On Photography (Penguin Books) pp. 3- 4, and 153-54.
[27] Straubhaar,J & LaRose R (2004) Media Now:Understanding Media,Culture, and Technology
Thomson: Wadsworth.
[28] Watson, J (1998). Media Communication. An Introduction to Theory and Process, London:
Macmillan Press Ltd.
[29] Webster, C (1980). The New Photography (John Calder) pp. 172-73.
[30] Wilder D.A. (1990). “Some Determinants of the Persuasive Power”.
www.shipshapewsiebiz.com/NewsRoom.asp-20k

European Journal of Scientific Research
ISSN 1450-216X Vol.20 No.4 (2008), pp.759-771
© EuroJournals Publishing, Inc. 2008
http://www.eurojournals.com/ejsr.htm
Design Space Exploration of Regular NoC Architectures: A
Multi-Objective Evolutionary Algorithm Approach
Rabindra Ku. Jena
Faculty of IT, Institute of Management Technology, Nagpur, India
E-mail: rk_jena2@rediffmail.com
Musbah M. Aqel
Faculty of IT, Middle East University for Graduate Studies
Ammam, Jordan
E-mail: Aqelm06@yahoo.com
Gopal K. Sharma
Department of IT
ABV-Indian Institute of Information Technology & Management, Gwalior, India
E-mail: gksharma@yahoo.com
Prabhat K. Mahanti
Department of CSAS, University of New Brunswick, Saint John, Canada
E-mail: pkmahanti@yahoo.co.in
Abstract
In this paper, we address the problem of topological mapping of intellectual
properties (IPs) on the tile of a mesh-based NoC to minimize energy and maximum
bandwidth requirement. As the stated problem is NP-hard in nature, we proposed a
heuristic technique based on multi-objective genetic algorithm to obtain an optimal
approximation of the pareto-optimal. We have considered “many-many” mapping between
switch and cores (IPs) instead of “one-one” mapping. The evaluation performed on
randomly generated benchmarks and a real application (a M-JPEG encoder), showed the
efficiency, accuracy and scalability of our proposed approach.
Keywords: NoC optimization, energy, performance, system level synthesis, Genetic
algorithm.
1. Introduction
Network on Chip (NoC) has been proposed as a solution for the communication challenges like
propagation delays, scalability, infeasibility of synchronous communication etc. in a nano scale regime
(Zitzler and Thiele, 1999; Hu and Marculescu, 2003). To meet these challenges under the strong timeto-market
pressure, it is essential to increase the reusability of components and system architectures in
a plug and play fashion (Hu and Marculescu, 2003). Simultaneously, the volume of data and control
traffic among the cores grows. So, it is essential to address the communication-architecture synthesis

Design Space Exploration of Regular NoC Architectures: A
Multi-Objective Evolutionary Algorithm Approach 760
problem through mapping of cores onto the communication architecture (Lahiri, Raghunathan, and
Dey, 2000).
Regular tile-based network-on-chip (NoC) architecture was proposed to mitigate these complex
on-chip communication problems (Zitzler and Thiele, 1999; Jena et al, 2006; Hu and Marculescu,
2003). As shown in Figure 1, such a chip consists of a grid of regular tiles where each tile can be the
resources/core like a general-purpose processor, a DSP, a memory subsystem, etc. A router is
embedded within each tile with the objective of connecting it to its neighboring tiles. Thus, instead of
routing design-specific global on-chip wires, the inter-tile communication can be achieved by routing
packets.
Figure 1: Regular Tile-based NoC.
2
1
0
0
02
1
2
12 22
C C C
01 11 21
C C C
00 10
20
C C C
Three key concepts come together to make this tile-based architecture very promising:
1) Structured network wiring
2) Modularity
3) Standard interfaces
More precisely, since the network wires are structured and wired beforehand, their electrical
parameters can be very well controlled and optimized. In turn, these controlled electrical parameters
make it possible to use aggressively signaling circuits that help reduce the power dissipation and
propagation delay significantly. Modularity and standard network interfaces facilitate reusability and
interoperability of the modules. Moreover, since the network platform can be designed in advance and
later reused directly with many applications, it makes sense to highly optimize this platform as its
development cost can be easily amortized across many applications.
On the other hand, the regular tile-based architecture may lead to significant area overhead if
applied to applications whose IPs’ sizes vary significantly. In order to achieve the best performance/
cost tradeoff, the designer needs to select the right NoC platform (e.g., the platform with the right size
of tiles, routing strategies, buffer sizes, etc.) and further customize it according to the characteristics of
the application under design. For most applications, the area cost overhead is fully compensated by the
design time savings and performance gains because of the regular NoC architecture.
The advantages of using the regular NoC approach can be further increased if the IPs in the
library are developed with regularity (in terms of size) taken into consideration as well. Moreover,
partitioning the application with regularity in mind can also help in reducing the cost overhead. Finally,
the region-based design (Kumar et al, 2002) can be used to further reduce the area overhead by
embedding irregular regions inside the NoC, which can be insulated from the network. From the design
perspective, given a target application described as a set of concurrent tasks which have been assigned
and scheduled, to exploit the architecture in Figure 1. More precisely, in order to get the best
energy/performance tradeoff, the designer needs to determine the topological placement of this IPs
onto different tiles.

761 Rabindra Ku. Jena, Musbah M. Aqel, Gopal K. Sharma and Prabhat K. Mahanti
Therefore this paper focuses on both computation and communication synthesis to minimize
the energy consumption and communication delay by minimizing maximum link bandwidth using
many-many mapping between resources and switches. The proposed communication synthesis task has
been solved in two phases as shown in Figure 1. The first phase (P-1) is called computational
synthesis. The input to P-I of is a task graph. The task graph consists up tasks as vertices and direct
edges represent volume of data flowing between two vertices and their data dependencies. The output
of P-I is a core communication graph (CCG) characterized by library of interconnection network
elements and performance constraints. The core communication graph consists of processing and
memory elements are shown by P/M in the Figure 2.
Figure 2: Mappings for NoC synthesis problems.
The directed edges between two blocks represent the communication trace. The communication
trace characterized by bandwidth (bsd) and volume (vsd) of data flowing between different cores. The
second phase (P-II) is basically called as communication synthesis. The input to the communication
synthesis problem is the CCG. The output of the P-II is the energy and throughput synthesizes NoC
back bone architecture as shown in Figure 2.
In this paper we address the problem of mapping the core onto NoC architecture to minimize
energy consumption and maximum link bandwidth. Both of the above stated objectives are inversely
proportional to each other. The above stated problem is an NP-hard problem (Garey and Johnson,
1979). So, genetic algorithm is a suitable candidate for solving the multi-objective problem (Benini and
Micheli, 2002). The optimal solution obtained by our approach saves (10-70) % of energy and around
(5-20) % of the maximum link bandwidth (on average) in compare to different existing approaches.
Experimental result shows that our proposed model is superior in terms of quality of result and
execution time in compare to other approaches.
The paper is organized as follows. We review the related work in Section 2. Sections 3 and 4
describe the problem definition and the energy model assumed in this paper respectively. Section 5
represents the multi-objective genetic algorithm formulation for the problem. Section 6 discusses the
basic idea and problem formulation for the proposed approach. Experimental results are discussed in
section 7. Finally, a conclusion is given in section 8.

Design Space Exploration of Regular NoC Architectures: A
Multi-Objective Evolutionary Algorithm Approach 762
2. Related Work
The problem of synthesis in mesh-based NoC architectures has been addressed by different
authors.(Hu and Marculescu, 2003) present a branch and bound algorithm for mapping IPs/cores on a
mesh-based NoC architecture that minimizes the total amount of power consumed in communications.
(De Micheli, 2004) addresses the problem under the bandwidth constraint with the aim of minimizing
communication delay by exploiting the possibility of splitting traffic among various paths. (Lei and
Kumar, 2003) present an approach that uses genetic algorithms to map an application on a mesh-based
NoC architecture. The algorithm finds a mapping of the vertices of the task graph on the available
cores so as to minimize the execution time. However these papers do not solve certain important
issues. The first relates to the evaluation model used. In most of the approaches the exploration model
decides the mapping to explore the design space without taking important dynamic effects of the
system into consideration. Again in the above mentioned works, in fact, the application to be mapped
is described using task graphs, as in (Lei and Kumar, 2003), or simple variations such as the core graph
in (Murali and Micheli, 2004) or the application characterization graph (APCG) in (Hu and
Marculescu, 2003). These formalisms do not, however, capture important dynamics of communication
traffic. The second problem relates to the optimization method used. It refers in all cases to a single
performance index (power in (Hu and Marculescu, 2003), performance in (Murali and Micheli, 2004;
Lei and Kumar, 2003). So the optimization of one performance index may lead to unacceptable values
for another performance index (e.g. high performance levels but unacceptable power consumption).
Recently, (Jena and sharma, 2006) proposed a model that consider “many-many” mapping between
core and tiles using multi-objective genetic algorithm. But they used core communication graph as the
input to their model.
We therefore think that the problem of mapping can be more usefully solved in a multiobjective
environment starting from the higher level of input (Task Graph) as compared to the model
discussed in (Jena and sharma, 2006). The contribution we intend to make in this paper is to propose a
multi-objective approach to solving the synthesis problem on a mesh-based NoC architecture, where
we take the task graph as input. The approach will use evolutionary computing techniques based on
genetic algorithm to explore the mapping space with the goal to optimize maximum link bandwidth
and energy consumption (both computation and communication).
3. Problem Definition
3.1. A Task Graph (TG)
Is a digraph, G (V, E), where each vertex v Є V represent task and each edge e Є E is a weighted edge,
where weight signifies the volume of data flowing through the edge. Every edge also represents the
data dependency between the connecting vertices.
3.2. A Core Communication Graph (CCG)
Is a digraph, G(V, E), where each vertex v Є V represent core and e Є E is a communication edge
having two attributes, denoted by bsd and vsd are the required bandwidth and total volume of
communication respectively.
3.3. Communication Structure
The 2-D mesh communication architecture has been considered for its several desire properties like
regularity, concurrent data transmission and controlled electrical parameters (Hu and Marculescu,
2003; Kumar et al, 2002). Figure 3 shows how a Tile (T) is binding with its surrounding switches(S) in
a 2-D mesh NoC architecture. Each tile is a square surrounded by ‘4’ switches and links. A resource in
a tile can be connected to maximum ‘4’ switches as shown in the Figure 3. Each switch is connected to

763 Rabindra Ku. Jena, Musbah M. Aqel, Gopal K. Sharma and Prabhat K. Mahanti
its neighboring switches via two unidirectional links. To prevent the packet loss due to the multiple
packets approaching to the same output port, each switch has small buffers (registers) to temporarily
store the packets. Each resource has ‘4’ Resource Network Interfaces (RNIs) to connect to the network
via switches. RNIs are responsible for packetizing and depacketizing the communication data.
Core
Core
NI
NI
NI NI
Figure 3: Communication Structure.
Core
Core
S1 S2
We implement static XY wormhole routing in this paper because:
i) it is easy to implement in switch.
ii) it doesn’t required packet ordering buffer at the destination. It is free of deadlock and live
lock (Banerjee et al, 2004; Murali and Micheli, 2004).
4. Energy Model
Energy minimization is the one of the major challenging task in NoC design. In (Ye et al, 2002), Ye et
al. first define the bit energy metric of a router as the energy consumed when a single bit of data goes
through the router. In (Hu et al, 2003) modify the bit energy model so that it is suitable for 2D mesh
NoC architecture. They derives mathematical expression for bit energy consume, when data transfer
from switch ‘i’ to switch ‘j’ is given by
Ei,j bit = (hij+1) ESbit + hij ELbit
(1)
Where ESbit and ELbit are the energy consumed in the switches and links respectively. The
variable hij represent the number of links on the shortest path. As per the expression, the energy
consumption is depend on the hop distance (hij) between switch ‘i’ and ‘j’ because ESbit and ELbit
constant. Note ESbit is the energy consumption due to switches is depending on the number of ports in
the switches. But in our case the total energy is the sum of communication and computation energy, i.e
E i, j bit = (hij + 1) ESbit + hij ELbit + ECom
(2)
EComp is the computational energy consumption. The following sections discuss the basic ideas
of problem formulation using multi-objective optimization paradigm.
5. Multi-Objective Optimization
Definition
A general multi-objective optimization problem is defined as:
Minimize f (x) = (f1(x),….., fk(x)) subject to x Є X, where x represents a solution and X is a set of
feasible solutions. The objective function vector f (x) maps a solution vector ‘x’ in decision space to a
point in objective space.
In general, in a multi-objective optimization problem, it is not possible to find a single solution
that minimizes all objectives, simultaneously. Therefore, one is interested to explore a set of solutions,
called the pareto optimal set, which are not dominated by any other solution in the feasible set. The
corresponding objective vectors of these Pareto optimal points, named efficient points, form the Pareto
front on the objective space.
S4
S3

Design Space Exploration of Regular NoC Architectures: A
Multi-Objective Evolutionary Algorithm Approach 764
Definition
We say x dominates x* iff i Є {1,……,k}
fi(x) ≤ fi(x*) and there exists at least one i Є {1,…., k} such that fi(x) < fi(x*).
The most traditional approach to solve a multi-objective optimization problem is to aggregate
the objectives into a single objective by using a weighting mean. However this approach has major
drawbacks. It is not possible to locate the non-convex parts of the pareto front and it requires several
consecutive runs of the optimization program with different weights. Recently, there has been an
increasing interest in evolutionary multi-objective optimization. This is because of the fact that
evolutionary algorithms (EAs) seem well-suited for this type of problems (Coello et al, 2002), as they
deal simultaneously with a set of possible solutions called population. This allows us to find several
members of the pareto optimal set in a single run of the algorithm. To solve the synthesis problem as
discussed in section 4, we used the multi-objective genetic algorithm principle.
5.1. A Multi-Objective Genetic Algorithm
In order to deal with the multi-objective nature of NoC problem we have developed genetic algorithms
at different phases in our model. The algorithm starts with a set of randomly generated solutions
(population). The population’s size remains constant throughout the GA. Each iteration, solutions are
selected, according to their fitness quality (ranking) to form new solutions (offspring). Offspring are
generated through a reproduction process (Crossover, Mutation). In a multi-objective optimization, we
are looking for all the solutions of best compromise, best solutions encountered over generations are
fled into a secondary population called the “Pareto Archive”. In the selection process, solutions can be
selected from this “Pareto Archive” (elitism). A part of the offspring solutions replace their parents
according to the replacement strategy. In our study, we used elitist non-dominated sorting genetic
algorithm NSGA-II by (Deb et al, 2002). The following section outlined the working principle of
NSGA-II.
5.1.1. NSGA-II
In this section we discuss how the elitist selection occurs in NSGA-II by the classification of the
population into different fronts based on non dominated sorting ranks.
Figure 4: NAGA-II working principle.
In NSGA-II, as shown in Figure 4 the offspring population Qt is first created by using the
parent population Pt. However, instead of finding the non dominated front of Qt only, first the two
populations are combined together to form Rt of size 2N. Then a non – dominated sorting is used to
classify the entire population Rt. Although this requires more effort compared to performing a nondominating
sorting on Qt alone, it allows a global non-domination check among the offspring and
parent solutions. Once the non-dominated sorting is over, the new population is filled by solutions of
different non-dominated fronts, one at a time. The filling starts with the best non-dominated front and

765 Rabindra Ku. Jena, Musbah M. Aqel, Gopal K. Sharma and Prabhat K. Mahanti
continues with solutions of the second non-dominated front, followed by the third non-dominated front
and so on. Since the overall population size of Rt is 2N, not all fronts may be accommodated in N slots
available in the new population. All fronts which could not be accommodated are simply deleted.
When the last allowed front is being considered, there may exist more solutions in the last front than
the remaining slots in the new population. This scenario is illustrated in Figure 4. Instead of arbitrarily
discarding some members of the last front, it would be wise to use a niching strategy to choose the
members of the last front, which reside in the least crowded region in that front. But we will not go into
too much detail on that. For more details refer to (Deb, 2002).
6. Problem Formulation
6.1. Basic Idea
Like other algorithms in area of design automation, the algorithm of NoC communication architecture
is a hard problem. Our attempt is to develop an algorithm that can give near optimal solution within
reasonable time. Genetic algorithms have shown the potential to achieve the dual goal quite well (Jena
et al, 2006; Lahiri et al, 2000; Srinivasan and Chatha, 2005).
As shown in Figure 5 and discussed in section 1, the problem is solved in two phases. The first
phase (P-I) is basically a task assignment problem (TA-GA). The input to the problem is a TG. We
assume that all the edge delays are a constant and equal to Average Edge Delay (AED) (Banerjee et al,
2004).The output of the first phase is a Core Communication Graph (CCG).
The main task of the second phase (P-II) is communication synthesis which basically deals with
mapping of cores to the tiles of the NoC backbone using multi objective genetic algorithm. The next
section discusses each phases in detail.
Figure 5: An overall design flow.
TA-GA
CTA-GA
CTS-GA
NoC Architecture Description
Task Graph
Task Assignment
Evaluation
Core Communication Graph
Core Tile Mapping
Evaluation
Core Tile Switch Mapping
Evaluation
Optimize NoC
6.1.1. Task Assignment Problem (TA-GA)
Given a task graph TG with all edge delay are constant and equal to average edge delay and IPs with
specifications matrix containing cost and computational energy. The main objectives of this phase are
to assign the tasks from the task graph to the available IPs in order to:
(i) minimize the computational energy by reducing the power consumption.
P-I
P-II

Design Space Exploration of Regular NoC Architectures: A
Multi-Objective Evolutionary Algorithm Approach 766
(ii) Minimize the total cost of the resources. The above said problem is a NP-hard multi-objective
problem. We proposed a multi-objective genetic algorithm based on principle of NSGA-II as
discussed in subsection 5.1.1.
Generally, in genetic algorithm, the chromosome is the representation of solution to the
problem. In this case length of each chromosome is proportional to the number of nodes in a task
graph. The i-th gene in the chromosome identifies the IP which is assigning the i-th node in the task
graph. One example of chromosome encoding is given in Figure 5. Each gene (node in TG) in the
chromosome contains an integer which represents a IP. Each IP is chosen from the list of permissible
IPs for that task. As shown in the Figure 6 the task number ‘2’ in the task graph is assign to IP number
‘7’ which is chosen from set of IPs {7, 8, and 17}. We consider a single point crossover to generate the
offspring’s. As for mutation operation, we consider the mutation by substitution i.e. at a time a gene in
a chromosome is chosen with some random probability and the value in the gene is substitute by one of
the best permissible value (i.e the index value of an IP) for the gene. The aim is to assign more tasks to
a particular IP to reduce the communication between IPs. (i.e., to minimize the number of IPs used for
a task graph.)
Figure 6: Chromosome encoding for task assignment.
Chromosome
6.1.2. Core-Tile Mapping (CTM)
After optimal assignment of tasks to the IPs, we get a Core Communication Graph (CCG) as shown in
the Figure 5. The input to this mapping task CT-GA is a CCG and a structure of NoC back bone. In our
case it is a n×m mesh. The objectives of the mapping are (i) to reduce the average communication
distance between the cores (i.e., to reduce number of switches in the communication path). (ii) to
maximize throughput(i.e., minimize the maximum link bandwidth) under the communication
constraint. The task of CTM is solved in two steps:
(a) Core-Tile assignment (CTA-GA)
(b) Core-Tile-Switch assignment (CTS-GA)
6.1.2.1. Core-tile Assignment (CTA-GA)
Core-tile assignment is a multi-objective mapping which maps the cores from CCG to the tiles of the
NoC structure. So the multi-objective genetic algorithm based on NSGA-II is a best candidate for the
above said mapping problem. Here the chromosome is the representation of the solution to the
problem, which in this case describe by the mapping.
The inputs to CTA-GA are the CCG and NoC backbone structure. In this case the Noc
backbone is a 2D mesh. Each tile in mesh has an associated gene which identified the core mapped to
the tile. In n×m mesh, for example the chromosome is formed by n×m genes. The i-th gene identified
the core in the tiles in row (⎡(i/n)⎤) and column (i % n).
The crossover and mutation operators for this mapping have been defined suitably as follows:
Crossover
The crossover between two chromosomes C1 and C2 is generated a new chromosome C3 as follows.
The dominant mapping between C1 and C2 is chosen. Its hot core (the hot core is the IP in CCG

767 Rabindra Ku. Jena, Musbah M. Aqel, Gopal K. Sharma and Prabhat K. Mahanti
required maximum communication) is remapped to a random tile in the mesh, resulting a new
chromosome C3.
Algorithm Crossover (C1, C2)
{
If (C1 dominate C2)
C3 = C1;
else
C3 = C2;
Swap (C3, Hot (C3), random({1,2,3,…….m×n}));
Return (C3);
}
The function Swap(C, i, j) exchange the i-th gene with j-th gene in the chromosome C.
Mutation:
The mutation operator acts on a single chromosome (C) to obtained a muted chromosome C 0 as
follows. A tile Ts from chromosome C is chosen at random. Indicating the core in the tile Ts as cs and ct
as the core with which cs communicates most frequently, cs is remapped on a tile adjacent to Ts so as to
reduce the distance between cs and ct thus obtaining the mutated chromosome C 0 . Algorithm, given
below describes the mutation operator. The RandomTile(C) function gives a tile chosen at random
from chromosome C. The MaxCommunication(c) function gives the core, with which c communicates
most frequently. The Row(C, T) and Col(C, T) functions respectively give the row and column of the
tile T in chromosome C. Finally, the Upper, Lower, Left, Right(C, T) functions give the tile to the
north, south, east and west of the tile T in chromosome C.
Mutate (C)
{
Chromosome C 0 = C;
Tile Ts = Random Tile (C 0 );
Core cs = C 0-1 (Ts);
Core ct = MaxCommunication (cs);
Tile Tt = C 0 (ct);
i f (Row(C 0 , Ts) < Row(C, Tt))
T 0 s = Upper (C 0 , Ts);
else if (Row(C 0 , Ts) > Row(C 0 , Tt))
T 0 s = Lower(C 0 , Ts);
else if (Col(C 0 , Ts) < Col(C 0 , Tt))
T 0 s = Left(C 0 , Ts);
else
T 0 s = Right(C 0 , Ts);
Swap (C 0 , Ts, T 0 s);
Return (C 0 );
}
6.1.2.2. Core-Tile-Switch assignment (CTS-GA)
The CTS-GA is a crucial step in the whole optimization process. This step is followed by CTA-GA as
discussed in the previous section. The input to CTS-GA is the best chromosomes from CTA-GA and
CCG. The best chromosome derived from CTA-GA shows the efficient placement of core in the tiles
of a 2D-mesh. As we discussed in section 1, our mapping is a many-many mapping from tiles to
switches i.e. a tile can bind to more than one switch (maximum 4) and a switch can connected to more
than one tiles (maximum 4). The aim of the many-many mapping is to reduce
(1) The hop distance between source and destination, and
(2) The congestions at NI to increase the throughput.

Design Space Exploration of Regular NoC Architectures: A
Multi-Objective Evolutionary Algorithm Approach 768
For the above stated optimization problem, we considered multi-objective genetic algorithm
based on NSGA-II. Here each gene in the chromosome is representing an edge in the CCG, which
includes source and destination. So the number of genes in each chromosome is the number of edges in
the CCG. Each tile in each gene position can be bind at most four switches as shown in Figure 7.
Figure 7: Chromosome representation for CTS-GA.
i th gene
7. Experimental Results
This section presents the results of our multi-objective genetic formulation (MGA). The final results i.e
the result obtained after completion of CTM are compared with PBB algorithm (Hu and Marculescu,
2003) and MGAP algorithm (Jena et al, 2006). For TA-GA, we consider NSGA-II multi-objective
evolutionary algorithm technique with crossover probability 0.98 and mutation probability 0.01. For
CTA-GA, we consider NSGA-II with our introduced new crossover and mutation operator. For CTS-
GA, again we consider NSGA-II with uniform crossover with probability 0.98 and single point
mutation with probability 0.01.Table 1 shows the bit-energy value of a link and a switch (4×4)
assuming 0.18 µm technology.
Table 1: Bit energy values for switch and link.
ELbit
ESbit
5.445pJ 0.43pJ
The value of ELbit is calculated from the following parameters:
(1) length of link (2mm)
(2) capacitance of wire (0.5fF/ µm)
(3) voltage swing (3.3V).
In our experiment, we consider three random task graphs, each consisting of 9, 14 and 18 nodes
respectively. After P-I, we found that the CCG of all three benchmarks consists up less than 9 cores.
So, which can be mapped on to a 3×3 mesh NoC architecture. But for performance comparison
between “many-many” and “one-one” binding between core and switch, we consider more complex
task graphs. We considered that the required bandwidth of an edge connect two different nodes is
uniformly distributed over the range [0, 150Mbytes].The traffic volume of an edge also has been
uniformly distributed over the range [0, 1Gbits]. Figure 8 shows the maximum link bandwidth
utilization of three benchmarks. It is clear from the figure that our approach (MGA) saves more than
5% link bandwidth as compare to MGAP and around 15% in compare to PBB. Figure-9 shows that our
approach saves more than 70% of energy consumptions in compare to PBB (on average) and around
10% in compare to MGAP.
The real time application is a modified Motion-JPEG (M-JPEG) encoder. Which differs from
traditional encoders in three ways: (i) it only supports lossy encoding while traditional encoders
support both lossless and lossy encodings.(ii) it can operate on YUV and RGB video data whereas
traditional encoders usually operate on the YUV format, and (iii) it can change quantization and

769 Rabindra Ku. Jena, Musbah M. Aqel, Gopal K. Sharma and Prabhat K. Mahanti
Huffman tables dynamically while the traditional encoders have no such behavior. We omit giving
further details on the M-JPEG encoder as they are not crucial for the experiments performed here.
Interested readers may refer to (Pimentel et al, 2002). Figure 10 shows the bandwidth requirements and
energy consumptions for M-JPEG encoder application. From the figure it is clear that our approach out
perform other approaches. Figure 11 shows the behavior of NSGA-II with respect to number of
generations.
Figure 12 shows a important performance comparison “many-many” mapping versus “oneone”
mapping between core and switch. The figure shows that “many-many” mapping saves up to (70-
72) % of energy consumption and up to 20% of maximum link bandwidth in compare to “one-one”
mapping. Further the figure shows that the saving factor increases with increase of the dimension of
NoC architecture for more complex applications.
Figure 8: Maximum Link Bandwidth comparisons for three random benchmarks.
Maximum Link
Bandwidth(MB/s)
120
100
80
60
40
20
0
MGA PBB MGAP
1 2
Benchmarks
3
Figure 9: Energy comparisons for three random benchmarks.
Enargy
Consumptions(mJ)
250
200
150
100
50
0
MGA PBB MGAP
1 2
Benchmarks
3

Design Space Exploration of Regular NoC Architectures: A
Multi-Objective Evolutionary Algorithm Approach 770
Figure 10: Maximum Link Bandwidth and Energy comparisons for M-JPEG.
Normalized Values
1
0.8
0.6
0.4
0.2
0
MGA PBB MGAP
Energy Max. Link
Bandwidth
Performance Matrices
Figure 11: M-JPEG Encoder performance using NSGA-II.
Figure 12: ‘Many-Many’ Vs ‘One-One’ performance comparison.
8. Conclusion
In this paper we have proposed a model for topological mapping of IPs/cores in a mesh-based NoC
architecture with many- many mappings between core to switches. The approach uses heuristics based
on multi-objective genetic algorithms (NSGA-II) to explore the mapping space and find the pareto
mappings that optimize Maximum link bandwidth and performance and power consumption. The
experiments carried out with randomly generated benchmarks and a real application (M-JPEG encoder
system) confirms the efficiency, accuracy and scalability of the proposed approach. Future
developments will mainly address the definition of more efficient genetic operators to improve the
precision and convergence speed of the algorithm Evaluation will also be made of the possibility of

771 Rabindra Ku. Jena, Musbah M. Aqel, Gopal K. Sharma and Prabhat K. Mahanti
optimizing mapping by acting on other architectural parameters such as routing strategies, switch
buffer sizes, etc.
References
[1] A. D. Pimentel, S. Polstra, F. Terpstra, A. W. van Halderen, J. E. Coffland, and L.
O.Hertzberger (2002) Towards efficient design space exploration of heterogeneous embedded
media systems. E. Deprettere, J. Teich, and S. Vassiliadis, editors, Embedded Processor Design
Challenges: Systems, Architectures, Modeling, and Simulation, volume 2268 of LNCS,
Springer-Verlag, pp.7–73.
[2] C. A. Coello, D. A. Van Veldhuizen, and G. B. Lamont (2002) Evolutionary Algorithms for
Solving Multi-Objective Problems. Kluwer Academic Publishers, New York.
[3] C. J. Glass and L. M. Ni (1992) The Turn Model for Adaptive Routing, Proc.19 th Ann. Int’l
Symp. Computer Architecture, pp. 278-287.
[4] Deb, K. (2002) Multi-Objective Optimization using Evolutionary Algorithms, John Wiley and
Sons Ltd, pp. 245-253.
[5] E. Zitzler and L. Thiele (1999) Multi-objective evolutionary algorithms: A comparative case
study and the strength pareto approach, IEEE Transactions on Evolutionary Computation, 4(3),
pp.257–271.
[6] J. Hu and R. Marculescu (2003) Energy-aware mapping for tile-based NoC architectures under
performance constraints, Asia & South Pacific Design Automation Conference.
[7] J. Hu and R. Marculescu (2003) Exploiting the Routing Flexibility for Energy/Performance
Aware Mapping of Regular NoC Architectures, Proc. DATE’03, pp. 688-693.
[8] Jena R. K., Sharma, G.K, (2006) A multi-objective Optimization Model for Energy and
Performance Aware Synthesis of NoC architecture, Proceedings of IP/SoC, Decmber 6-7, pp
477-482.
[9] K. Lahiri, A. Raghunathan, and S. Dey (2000) Efficient Exploration of the SoC Communication
Architecture Design Space, Proc. IEEE/ACM ICCAD’00, pp. 424-430.
[10] K. Srinivasan and Karam S. Chatha (2005) ISIS: A Genetic Algorithm based Technique for
Custom On-Chip Interconnection Network Synthesis, Proceedings of the 18 th International
Conference on VLSI Design (VLSID’05).
[11] Luca Benini and Giovanni De Micheli (2002) Networks on Chips: A New SoC Paradigm, IEEE
Computer, pp. 70–78.
[12] M. R. Garey and D. S. Johnson (1979) Intractability: a guide to the theory of NP-completeness,
Freeman and Company.
[13] N. Banerjee, P. Vellanki, and K. S. Chatha (2004) A power and performance model for
network-on-chip architectures, Design, Automation and Test in Europe, pp. 1250–1255.
[14] S. Kumar et al. (2002) A Network on Chip Architecture and Design Methodology, Proc.
ISVLSI’02, April 2002, pp. 105-112.
[15] S. Murali and G. D. Micheli (2004) Bandwidth-constrained mapping of cores onto NoC
architectures, Design, Automation, and Test, Europe IEEE Computer Society, pp. 896–901.
[16] T. Lei and S. Kumar (2003) A two-step genetic algorithm for mapping task graphs to a network
on chip architecture, Euro micro Symposium on Digital Systems Design, Sept. 1–6.
[17] T. T. Ye, L. Benini, and G. D. Micheli (2002) Analysis of Power Consumption on Switch
Fabrics in Network Routers, Proc. DAC’02, pp.524-529.
[18] William J. Dally and Brian Towles (2002) Route Packet, Not Wires: On-Chip Interconnection
Networks, Proceedings of DAC.

European Journal of Scientific Research
ISSN 1450-216X Vol.20 No.4 (2008), pp.772-787
© EuroJournals Publishing, Inc. 2008
http://www.eurojournals.com/ejsr.htm
Etude Comparative des Méthodes D’évaluation de la
Vulnérabilité à la Pollution des Aquifères en
Milieu Poreux: Application Aux Eaux Souterraines du
District D’abidjan (Sud de la Côte D’ivoire)
Kouamé Kan Jean
Laboratoire des Sciences et Techniques de l’eau et de l’Environnement (LSTEE)
UFR des Sciences de la Terre et des Ressources Minières
Université de Cocody Abidjan (UCA), 22 BP 582 Abidjan 22
Jourda Jean Patrice
Laboratoire des Sciences et Techniques de l’eau et de l’Environnement (LSTEE)
UFR des Sciences de la Terre et des Ressources Minières
Université de Cocody Abidjan (UCA), 22 BP 582 Abidjan 22
Centre Universitaire de Recherche et d’Application en Télédétection (CURAT)
UFR des Sciences de la Terre et des Ressources Minières, 22 BP 801 Abidjan 22
Adja Miessan Germain
Laboratoire des Sciences et Techniques de l’eau et de l’Environnement (LSTEE)
UFR des Sciences de la Terre et des Ressources Minières
Université de Cocody Abidjan (UCA), 22 BP 582 Abidjan 22
Deh Serges Kouakou
Laboratoire des Sciences et Techniques de l’eau et de l’Environnement (LSTEE)
UFR des Sciences de la Terre et des Ressources Minières
Université de Cocody Abidjan (UCA), 22 BP 582 Abidjan 22
Anani Abenan Tawa
Laboratoire des Sciences et Techniques de l’eau et de l’Environnement (LSTEE)
UFR des Sciences de la Terre et des Ressources Minières
Université de Cocody Abidjan (UCA), 22 BP 582 Abidjan 22
Effini Adiow Thérèse
Laboratoire des Sciences et Techniques de l’eau et de l’Environnement (LSTEE)
UFR des Sciences de la Terre et des Ressources Minières
Université de Cocody Abidjan (UCA), 22 BP 582 Abidjan 22
Biémi Jean
Laboratoire des Sciences et Techniques de l’eau et de l’Environnement (LSTEE)
UFR des Sciences de la Terre et des Ressources Minières
Université de Cocody Abidjan (UCA), 22 BP 582 Abidjan 22
Centre Universitaire de Recherche et d’Application en Télédétection (CURAT)
UFR des Sciences de la Terre et des Ressources Minières, 22 BP 801 Abidjan 22

Etude Comparative des Méthodes D’évaluation de la Vulnérabilité à la
Pollution des Aquifères en Milieu Poreux: 773
Abstract
Supply drinking water of Abidjan District population is dependent of groundwater
and water quality is unceasingly threatened to various potential sources of pollution. This
study aims to determine the most relevant method in the evaluation of Abidjan District
groundwater vulnerability to pollution in order to protect them. Application of DRASTIC
and GOD methods in this study allowed evaluating intrinsic vulnerability of groundwater
to pollution of Abidjan District. A comparative study starting from Kappa test and
statistical analysis of surfaces, were thus carried out. Statistical analysis of different
vulnerability maps to pollution reveals that vulnerability is concentrated between
"moderate and high” classes with 88.37 and 88.18 percent of study area respectively for
DRASTIC and GOD methods. Comparative study showed that DRASTIC and GOD
methods have a moderate agreement (Kappa coefficient is 41 percent) but GOD tends to
overestimate the vulnerability of an index compared to DRASTIC. Also, vulnerability map
to pollution resulting from DRASTIC method was retained for the evaluation of Abidjan
District groundwater vulnerability to pollution.
Keywords: Evaluation, Vulnerability, groundwater Pollution, Abidjan District, Côte
d'Ivoire
1. Introduction
La protection des eaux souterraines est une question de plus en plus préoccupante tant au niveau de
l’exploitation de la ressource qu’à celui des impacts sur la santé humaine. La préservation de la qualité
de l’eau souterraine est d’autant plus importante du fait que cette ressource, une fois contaminée, est
difficile à être réhabilitée (Banton et Bangoy, 1997). De plus, certains contaminants peuvent persister
durant des dizaines ou des centaines d’années, du fait des processus d’atténuation (adsorption,
dégradation) limités en milieu aquifère (Banton et Bangoy, 1997). Le problème devient plus grave pour
les pays à ressources en eau limitées comme c’est le cas du District d’Abidjan où la population est
tributaire des eaux souterraines (Jourda et al., 2003). La qualité de cette eau est sans cesse menacée par
les diverses sources potentielles de pollution du District d’Abidjan (Kouadio et al., 1998; Jourda et al.,
2006a). L'insuffisance ou l'absence de stations d'épuration dans les zones d'activités domestiques et
industrielles permet d'appréhender l'ampleur de la catastrophe qui menace les eaux souterraines (Jourda
et al., 2006a; Kouamé, 2007). Ces carences font que, le plus souvent, la pollution de ces eaux est
constatée après ses méfaits, c'est-à-dire après qu'elle ait migré de sa zone initiale et atteint par recharge
les eaux souterraines. Etant donné les coûts importants engendrés par la restauration des aquifères
contaminés, la protection des eaux souterraines du District d’Abidjan devient alors primordiale afin de
sauvegarder, à moyen et à long terme, sa qualité (Jourda et al., 2006b). Une des approches d’aide à la
protection et à la prévention contre la pollution des eaux souterraines est la cartographie des zones
vulnérables à la pollution (Champagne et Chapuis, 1993). Cette étude a été entreprise dans le but
d'identifier les zones à haut risque de contamination, indépendamment du type de polluant et de
déterminer la méthode qui permet de mieux évaluer la vulnérabilité. Elle devrait en principe
conditionner les plans d'occupation des sols ou, du moins, permettre de cibler les zones où des mesures
rigoureuses de protection devraient être adoptées.
2. Présentation de la Zone D’étude
Le District d’Abidjan (Figure 1) sur lequel porte cette étude, est situé au Sud de la Côte d’Ivoire et
regroupe les dix communes de la ville d’Abidjan plus trois Sous-préfectures (Bingerville, Songon et
Anyama). D’une superficie de 2 119 Km 2 avec un taux de croissance de 3,7% et une densité de

774 Kouamé kan Jean, Jourda Jean Patrice, Adja Miessan Germain, Deh Serges
Kouakou, Anani Abenan Tawa, Effini Adiow Thérèse and Biémi Jean
population de 1 475 hbts/Km 2 , ce District regroupe une population estimée à environ 3 125 890
habitants en 1998 (INS, 2001). Cette population s’est accrue aujourd’hui d’une manière considérable
pour atteindre les 5 millions d’habitants en 2006 à cause de la crise socio-politique que connaît la Côte
d’Ivoire depuis septembre 2002 (MPD, 2006).
Figure 1: Localisation de la zone d’étude
Sur le plan géologique, le District d’Abidjan appartient au bassin sédimentaire côtier d’âge
Crétacé à Quaternaire ne représentant que 2,5% de la superficie du pays (Tastet, 1979; Aghui et Biémi,
1984). Il s’étend sur 400 Km de long et sur 40 Km de large de Fresco (Côte d’Ivoire) à la limite du
Ghana. Ce bassin contient trois niveaux aquifères d’inégale importance, dont l’aquifère du Continental
Terminal est exploité pour l’alimentation en eau potable de la population abidjanaise. Le District
d’Abidjan est bien arrosé avec une hauteur moyenne annuelle estimée à 1 600 mm.

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3. Matériel et Méthodes
3.1. Matériel
Pour l’élaboration des paramètres physiques de la nappe, les données suivantes de la zone d’étude ont
été utilisées:
• les cartes géologique et géotechnique de la région d’Abidjan;
• les cartes topographiques;
• la carte du réseau hydrographique;
• les données de pluie, de température, de piézomètre et de puits;
• les coupes de forage.
Pour le traitement et l’élaboration des couches, les logiciels MapInfo 5.0, ArcView 3.2 et EVC
ont été utilisés.
Toutes les cartes utilisées sont au 1/50 000 et ont été scannées et numérisées sous MapInfo dans
le système de coordonnées UTM WGS 84, zone 30, hémisphère nord.
3.2. Méthodes
L’évaluation de la vulnérabilité intrinsèque a été réalisée à partir de deux méthodes. Il s’agit des
méthodes DRASTIC et GOD.
Méthode DRASTIC
La méthode DRASTIC, développée en 1987 aux Etats-Unis par l’Agence américaine de la Protection
de l’Environnement (EPA), permet de cartographier les zones vulnérables à la pollution (Aller et al.,
1987; Vrba et Zaporozec, 1994). C’est une méthode standardisée d’évaluation et de cartographie de la
vulnérabilité des eaux souterraines indépendamment du type de polluant. Elle prend en compte la
majeure partie des facteurs hydrogéologiques qui affectent et contrôlent l’écoulement des eaux
souterraines (Mohamed, 2001). Elle permet de visualiser le degré relatif de vulnérabilité des eaux
souterraines de la zone d’étude, car basée sur sept paramètres de vulnérabilité (Bézélgues et al., 2002).
Ce sont:
• la profondeur de l’eau (D);
• la recharge efficace (R);
• les matériaux de l’aquifère (A);
• le type de sol (S);
• la topographie ou la pente (T);
• l’impact de la zone non saturée ou zone aérée (I);
• la perméabilité ou la conductivité hydraulique de l’aquifère (C).
L’évaluation de la vulnérabilité par la méthode DRASTIC s’effectue par le calcul de l’Indice
DRASTIC (ID) selon l’équation (1) où les indices c et p désignent respectivement la "cote"et le
"poids" du paramètre.
ID = Dc×
Dp + Rc×
Rp + Ac×
Ap + Sc×
Sp + Tc×
Tp + Ic×
Ip + Cc×
Cp (1)
L’indice (ID) ainsi calculé représente une mesure du niveau de risque de contamination de
l’unité hydrogéologique à laquelle il se rattache. Ce risque augmente avec la valeur de l’indice. Après
le calcul de l’indice (IDRASTIC), on fait correspondre des classes de vulnérabilité aux différentes plages
d’indices calculés. Les classes proposées par la méthode DRASTIC sont consignées dans le table I-.

776 Kouamé kan Jean, Jourda Jean Patrice, Adja Miessan Germain, Deh Serges
Kouakou, Anani Abenan Tawa, Effini Adiow Thérèse and Biémi Jean
Table I: Intervalles des valeurs des ID et classes correspondantes (Aller et al., 1987)
Intervalles Classe DRASTIC
23 – 80 Vulnérabilité très faible
80 – 100 Vulnérabilité faible
100 – 140 Vulnérabilité modérée
140 – 180 Vulnérabilité forte
180 – 226 Vulnérabilité extrême
La classification de la carte des indices en fonction des plages définies par la méthode, a permis
d’élaborer la carte de vulnérabilité à la pollution des eaux souterraines du District d’Abidjan.
Méthode GOD
Comme la méthode DRASTIC, GOD est une méthode des systèmes paramétriques, conçue en
Angleterre en 1987 par Foster. Elle utilise également une approche empirique où la vulnérabilité des
aquifères est définie en fonction de l’inaccessibilité de la zone saturée, au sens de la pénétration du
polluant, et de la capacité d’atténuation que présente la couche sus-jacente à la zone saturée. La
méthode GOD permet de réaliser une estimation rapide de la vulnérabilité d’un aquifère (Bézelgues et
al., 2002). Elle diffère de la méthode DRASTIC dans le sens où le nombre de paramètres de
vulnérabilité n’est que de trois pour l’évaluation de la vulnérabilité intrinsèque des aquifères. Le
premier réside dans l’identification du type d’aquifère en fonction de son degré de confinement (Ca).
Le deuxième correspond à la profondeur à la nappe (Cd) et le troisième est défini par la lithologie de
l’aquifère (Cl) (Murat et al., 2003). L’indice GOD (IGOD) qui permet d’évaluer la vulnérabilité de
l’aquifère à la pollution est obtenu par la multiplication de ces trois paramètres. L’indice GOD (IGOD)
se détermine selon l’équation (2), avec C, la cote du paramètre (Murat et al., 2000):
IG = Ca × Cl × Cd
(2)
Après le calcul de l’indice, on fait correspondre des classes de vulnérabilité aux différentes
plages d’indices obtenues. D’une manière générale, les indices GOD sont répartis en cinq classes de
vulnérabilité allant du "très faible" à "extrême"(Table II). Le degré de vulnérabilité augmente avec
l’indice GOD.
Table II: Intervalles des valeurs de IGOD et classes correspondantes (Murat et al., 2003)
Intervalle Classe GOD
0 – 0,1 Vulnérabilité très faible
0,1 – 0,3 Vulnérabilité faible
0,3 – 0,5 Vulnérabilité modérée
0,5 – 0,7 Vulnérabilité forte
0,7 – 1 Vulnérabilité extrême
Les différentes classes des indices de vulnérabilité GOD permettent l’élaboration de la carte de
vulnérabilité à la pollution des eaux souterraines au niveau du District d’Abidjan.
Les cartes de vulnérabilité étant des outils importants d’aide à la prise de décision en matière de
gestion d’aménagement du territoire, elles doivent refléter la réalité d’où la nécessité de leur validité.
Méthode de validation des méthodes de cartographie de la de vulnérabilité à la pollution
La détérioration de la qualité de l’eau souterraine est appréciée par mesures des paramètres physicochimiques
et bactériologiques. Plusieurs auteurs (Isabel et al., 1990; Champagne et Chapuis, 1993;
Mohamed, 2001; Jourda et al., 2003; Kouamé, 2003; Douagui, 2004; Fofana, 2005; Jourda, 2005;
Jourda et al., 2005; Anani, 2006 et Jourda et al., 2006b) ont vérifié la validité des méthodes
d’évaluation de la vulnérabilité à la pollution en se basant sur des données chimiques des eaux

Etude Comparative des Méthodes D’évaluation de la Vulnérabilité à la
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souterraines. Dans la validation des cartes de vulnérabilité, les zones réellement contaminées doivent
correspondre à celles où les indices de vulnérabilité sont les plus élevés. Une zone vulnérable peut
également avoir un faible indice de vulnérabilité du fait que la notion de vulnérabilité n’est pas
synonyme d’une pollution actuelle, mais plutôt d’une prédisposition de ces zones à une contamination
éventuelle, si rien n’est entrepris pour les protéger (Kouamé, 2007). La validation des cartes de
vulnérabilité a porté sur l’analyse du taux de nitrates contenu dans les eaux souterraines du District
d’Abidjan. Les données de nitrate utilisées couvrent que la ville d’Abidjan et datent de 2001.
Une étude comparative des deux méthodes utilisées s’avère indispensable en vue de déterminer
celle qui permet de mieux évaluer la vulnérabilité à la pollution des eaux souterraines du District
d’Abidjan.
Etude comparative des méthodes d’évaluation de la vulnérabilité
Dans cette étude comparative, la méthode DRASTIC est celle qui servira de référence pour déterminer
les variations d’évaluation de la vulnérabilité. Deux méthodes statistiques ont été utilisées pour faire
cette comparaison:
• le test de conformité (coefficient de kappa)
Le coefficient de Kappa (K) représente l'indice statistique qui mesure le degré de concordance
ou d’accord d'une évaluation entre deux ou plusieurs méthodes ayant à juger un même phénomène. Un
guide d'interprétation, suggéré par Landis et Koch (1977), permet d’apprécier le degré d’accord en
fonction de la valeur observée du coefficient Kappa.
• l’analyse statistique des surfaces
L’analyse statistique des surfaces permettra de savoir si la méthode GOD sous-évalue, surévalue
ou évaluation identiquement la vulnérabilité par rapport à la méthode DRASTIC prise comme
référence. Les données utilisées par ces méthodes de comparaison sont les deux cartes de vulnérabilité
produites par les méthodes DRASTIC et GOD, et le nombre de pixels par classe de vulnérabilité.
4. Résultats et Discussion
L’établissement des différents paramètres et leur combinaison ont permis de réaliser les cartes de
vulnérabilité à la pollution selon les deux méthodes.
4.1. Carte de vulnérabilité à la pollution à partir de la méthode DRASTIC
Dans le cas de la méthode DRASTIC, les valeurs des indices DRASTIC (IDRASTIC) calculés oscillent
entre 113 et 192. La vulnérabilité à la pollution augmente avec l’indice obtenu. En tenant compte du
fait que les valeurs limites des intervalles des indices DRASTIC sont relatives, une autre classification
adaptée à l’étude a donc été effectuée. Cette autre classification permet de fixer les limites des
intervalles des indices calculés et de faire correspondre des classes de vulnérabilité à ces indices. Ce fut
le cas des travaux réalisés par Lynch et al. (1993), Lobo-Ferreira et al. (1995), Navalur et Engel
(1997), Murat et al. (2000), Kimmeier (2001), Mohamed (2001), Murat et al. (2003), Jourda (2005) et
Kouamé (2007). Les classes de vulnérabilité élaborées à partir de ces travaux en tenant compte des
valeurs des IDRASTIC, varient entre "Faible” et "Très forte”, et sont résumées dans le tableau III. Une
telle classification tient compte des valeurs minimum et maximum d’indices obtenus et non des classes
standard définies par Aller et al. (1987).

778 Kouamé kan Jean, Jourda Jean Patrice, Adja Miessan Germain, Deh Serges
Kouakou, Anani Abenan Tawa, Effini Adiow Thérèse and Biémi Jean
Table III: Classification des degrés de vulnérabilité en fonction des IDRASTIC calculés
Intervalles des IDRASTIC
Classe de vulnérabilité
IDRASTIC < 129 Vulnérabilité "Faible"
130 < IDRASTIC < 149 Vulnérabilité "Moyenne"
150 < IDRASTIC < 169 Vulnérabilité "Forte"
IDRASTIC > 170 Vulnérabilité "Très forte"
La carte issue de cette classification est illustrée à la figure 2 et indique les degrés de
vulnérabilité à la pollution des eaux souterraines du District d’Abidjan.
Figure 2: Carte de vulnérabilité à la pollution des eaux souterraines du District d’Abidjan à partir de la
méthode DRASTIC
Cette carte de vulnérabilité (Figure 2) est constituée de quatre (4) classes réparties de la manière
suivante:
• la classe «Faible» traduit une vulnérabilité faible à la pollution et représente 0,21% des zones
cartographiées (Figure 3). Le faible indice de vulnérabilité observé peut s’expliquer par le fait que
l’aquifère possède dans cette partie l’argile-sableuse comme zone vadose.
• la classe «Moyenne» se rencontre à l’Ouest, au Sud-Ouest, au Sud et dans une partie de l’Est de la
zone d’étude. Elle garantit une pollution moins sévère et représente 47,33% de la zone d’étude. Le
degré de vulnérabilité moyen, peut s’expliquer par le fait que la zone vadose est constituée en
majorité de couche sablo-argileuse et cette couche est associée à une conductivité hydraulique
moyenne (29 – 41 m/j) et à une recharge annuelle moyenne oscillant entre 110 et 480 mm/an dans
cette partie;

Etude Comparative des Méthodes D’évaluation de la Vulnérabilité à la
Pollution des Aquifères en Milieu Poreux: 779
Figure 3: Répartition spatiale des degrés de vulnérabilité à la pollution selon DRASTIC
• la classe «Forte» occupe l’Est, le Nord-Est et le Centre du District d’Abidjan. Elle représente une
proportion moins importante que la classe précédente soit 41,04%. Le degré fort de vulnérabilité
peut s’expliquer par le fait que la conductivité hydraulique est élevée (41-81 m/j) et la recharge
annuelle est aussi forte (480 à 760 mm/an);
• la classe «Très forte» se rencontre plus au Sud de la zone d’étude. Toute la zone sud d’Abidjan
(Treichville, Marcory, Koumassi, Port-Bouët) est concernée par cette classe. L’indice très fort de
vulnérabilité peut être dû au type d’aquifère (sable grossier) associé à une infiltration importante
(760–850 mm/an), à une conductivité hydraulique élevée (49–56 m/j) et à une faible profondeur de
la nappe (1-11 m). Tous ces paramètres rendent les eaux souterraines très vulnérables dans cette
partie du District d’Abidjan. La progression de cette classe vers le Centre de la zone d’étude est
aussi remarquable dans le cas d’une contamination.
4.2. Carte de vulnérabilité à la pollution à partir de la méthode GOD
Pour la méthode GOD, l’indice de vulnérabilité (IGOD) calculé s’échelonne de 0,14 à 0,29. Les valeurs
extrêmes des indices GOD sont 0 et 1. Le processus de classification de la carte des indices en fonction
des classes de vulnérabilité est le même que celui décrit au niveau de la méthode DRASTIC. La
classification adoptée dans cette étude tient compte des indices GOD obtenus. Ainsi, les plages de
vulnérabilité élaborées à partir des indices GOD varient du "Faible" au "Très forte" et sont résumé dans
le tableau IV. La carte issue de cette classification est illustrée à la figure 4.
Table IV: Classification des degrés de vulnérabilité en fonction des IGOD calculés
Intervalles des IGOD
Classe de vulnérabilité
IGOD < 0,15 Vulnérabilité "Faible"
0,15 < IGOD < 0,20 Vulnérabilité "Moyenne"
0,20 < IGOD < 0,25 Vulnérabilité "Forte"
IGOD > 0,25 Vulnérabilité "Très forte"

780 Kouamé kan Jean, Jourda Jean Patrice, Adja Miessan Germain, Deh Serges
Kouakou, Anani Abenan Tawa, Effini Adiow Thérèse and Biémi Jean
Figure 4: Carte de vulnérabilité à la pollution des eaux souterraines du District d’Abidjan à partir de la
méthode GOD
L’analyse de cette carte de vulnérabilité (Figure 4) révèle quatre degrés de vulnérabilité. Ces
degrés constituent les quatre classes qui se présentent de la manière suivante:
• la classe «Faible» est représentée par un espace localisé à Abobo et occupe 0,29% des zones
cartographiées (Figure 5). Elle traduit une vulnérabilité faible à la pollution. Le faible indice de
vulnérabilité observé peut s’expliquer par le fait que, de l’argile sableuse est présente dans cette
partie de l’aquifère.
Figure 5: Répartition spatiale des degrés de vulnérabilité à la pollution selon GOD
• la classe «Moyenne» se rencontre à l’Ouest, au Sud-Ouest, au Centre, à l’Est et au Nord-Est et
représente 66,21% de la zone d’étude. Elle garantit une pollution moins sévère dans le cas d’une
contamination. Le degré de vulnérabilité moyen, peut être lié à la profondeur moyenne de la nappe
dans ces zones (entre 20 et 60 m);

Etude Comparative des Méthodes D’évaluation de la Vulnérabilité à la
Pollution des Aquifères en Milieu Poreux: 781
• la classe «Forte» occupe une partie du Nord et du Centre de la zone d’étude. Elle représente une
proportion moins importante que la classe précédente soit 21,97%. Le degré fort de vulnérabilité
peut s’expliquer par le fait que les eaux se trouvent à une faible profondeur (entre 10 et 20 m);
• la classe «Très forte» se rencontre plus au Sud de la zone d’étude. Elle progresse vers le Centre
d’Abidjan et représente 11,53% de la zone d’étude. L’indice très fort de vulnérabilité peut être dû à
la localisation des eaux à une profondeur très faible (entre 2 et 5 m). Tous les autres paramètres
sont presque égaux en terme de vulnérabilité à la pollution des eaux souterraines du District
d’Abidjan.
Les cartes de vulnérabilité obtenues par les méthodes DRASTIC et GOD ont révélé que le Sud
de la zone d’étude est plus vulnérable. Cette vulnérabilité progresse du Sud vers le Nord. Les cartes de
vulnérabilité à la pollution sont des outils d’aide à décision et leur validation par des paramètres
n’ayant pas servi à leur réalisation s’avère nécessaire.
Validation des cartes de vulnérabilité à la pollution
Les taux de nitrates contenus dans les eaux souterraines sont compris entre 3 et 100 mg/L. La carte
issue de ces données (Figure 6) montre une répartition spatiale de la concentration de nitrate au niveau
d’Abidjan.
Figure 6: Carte de la répartition spatiale de la concentration en nitrates en 2001
Elle révèle que toute la partie sud d’Abidjan a un taux de nitrates supérieur à 50 mg/L. Cette
forte concentration en nitrates (> 50 mg/L) est aussi observée dans les communes du Plateau,
Attécoubé, Adjamé et une partie des communes de Yopougon, Abobo et Cocody. Nous pouvons
déduire de cette observation que la pollution progresse dans le sens sud-nord avec un nouveau pôle de
pollution à l’Ouest.

782 Kouamé kan Jean, Jourda Jean Patrice, Adja Miessan Germain, Deh Serges
Kouakou, Anani Abenan Tawa, Effini Adiow Thérèse and Biémi Jean
Les cartes de vulnérabilité produites par les deux méthodes ont montré qu’on assiste à une
progression de la vulnérabilité du Sud au Nord. Les zones à fort taux de nitrates (> 50 mg/L),
progressant également du Sud vers le Nord, se superposent aux zones de très forte à forte vulnérabilité
à la pollution. La superposition de ces deux types de zones (vulnérabilité forte et taux de nitrate élevé)
permet de dire que la carte établie par ces méthodes reflète la réalité du terrain. Cette analyse ne permet
pas de déceler la méthode la plus efficace dans l’évaluation de la vulnérabilité à la pollution des eaux
souterraines du District d’Abidjan, d’où l’intérêt de l’étude comparative.
4.3. Comparaison des méthodes d’évaluation de la vulnérabilité
Pour faciliter la comparaison des méthodes, le nombre de pixels obtenu par classe et par méthode est
consigné dans le tableau V. Les pixels par classe sont les éléments de base utilisés par les 2 méthodes
de comparaison: test de kappa et. analyse statistique de surface.
Table V: Répartition des nombres de pixels par classe et par méthode
Drastic God
Faible 151 207
Moyenne 34 283 47 965
Forte 29 733 15 919
Très forte 8 273 8 349
Total 72 440 72 440
Test de Kappa
Le coefficient Kappa (K) a été calculé à partir des nombres de pixels des différentes classes et de la
formule de Cohen (1970) (Tableau VI).
Table VI: Matrice des résultats de proportion d’accord Ho et du coefficient Kappa
Drastic God
Ho Coefficient K Ho Coefficient K
Drastic 1 1
God 0,650 0,418 1 1
Le calcul du coefficient de Kappa révèle que le test de Kappa est fiable puisque la valeur du
coefficient de Kappa (K) est positive donc interprétable. Le coefficient K vaut 0,418 et selon le guide
établi par Landis et Koch (1977), il s’agit d’un degré d’accord "modéré" entre ces deux méthodes. En
faisant référence à l’indice Ho (proportion évaluée avec le même indice de vulnérabilité), l’accord est
bon avec Ho égal à 0,650. Nous pouvons donc noter qu’il y’a une concordance «acceptable»
d’évaluation de la vulnérabilité à la pollution entre les méthodes GOD et DRASTIC. Cette
concordance peut s’explique par le fait que ces deux méthodes évaluent la vulnérabilité intrinsèque,
c'est-à-dire que les paramètres utilisées par ces méthodes sont directement liés à la nappe.
Pour connaître la méthode qui évalue le mieux la vulnérabilité, le seul test de Kappa ne suffit
pas, il faut aussi une analyse statistique des surfaces cartographiées par les méthodes pour pouvoir se
prononcer.
Analyse statistique des surfaces cartographiées
Afin de comparer les cartes de la vulnérabilité à la pollution résultant des deux méthodes, quatre
classes identiques de vulnérabilité ont été choisies. En outre, la surface occupée par chaque classe a été
calculée et transformée en pourcentage (Tableau VII).

Etude Comparative des Méthodes D’évaluation de la Vulnérabilité à la
Pollution des Aquifères en Milieu Poreux: 783
Table VII: Pourcentage des surfaces selon le degré de vulnérabilité par les méthodes DRASTIC et GOD
Classes de vulnérabilité Drastic God
Faible 0,21% 0,29%
Moyenne 47,33% 66,21%
Forte 41,04ù 21,97%
Très forte 11,42% 11,53%
Total 100%
De l’analyse du tableau VII, nous tirons les remarques suivantes:
• la vulnérabilité par la méthode DRASTIC est concentrée entre les classes « moyenne » et «
forte » (88,37%) avec 47,33% pour la classe « moyenne » et 41,04% pour la « forte »;
• la méthode GOD aussi a la vulnérabilité concentrée entre les classes « moyenne » et « forte
» (88,18%) avec 66,21% pour la classe « moyenne » et 21,97% pour la « forte »;
Les méthodes DRASTIC et GOD ont évalué une vulnérabilité concentrée entre les classes «
moyenne » et « forte »; mais, la méthode DRASTIC est plus concentrée sur la classe « forte » avec
41,04% que la méthode GOD (21,97%). Le tableau VII révèle néanmoins que la classe « faible » est
peu représentée par les méthodes DRASTIC (0,21%) et GOD (0,29%).
Le résultat du croisement (soustraction entre les indices de vulnérabilité) des deux cartes de
vulnérabilité est résumé à la figure 7. L’analyse de cette figure indique que les classes 3 et 2 ont un
pourcentage nul et la différence d’indice « 0 » regroupe la proportion la plus importante (65%). Les
méthodes DRASTIC et GOD présentent donc un équilibre sur les 2/3 de la zone d’étude car les indices
de vulnérabilité sont identiques sur ces zones. Elles représentent 65% de la zone d’étude. Il y a donc
une parfaite association entre ces méthodes, confirmée par la valeur de H0 (65%) obtenue par le test de
kappa.
Figure 7: Histogramme de la variation d’indice entre DRASTIC et GOD
Bien que 65% de la zone d’étude soient évalués avec des indices identiques, il y a tout de même
quelques variations. Les variations d’indices se situent entre une sous-évaluation (8%) et une surévaluation
(27%) d’un indice de la méthode DRASTIC par rapport à la méthode GOD. La tendance de
la sur ou sous-évaluation de la vulnérabilité par la méthode DRASTIC n’est pas très importante car ces
deux méthodes n’utilisent que des paramètres intrinsèques. Les deux cartes de vulnérabilité sont donc
presque semblables. Il y a alors une parfaite association entre les méthodes DRASTIC et GOD malgré
ces quelques différences d’un indice. L’association entre ces méthodes a été confirmée par Murat

784 Kouamé kan Jean, Jourda Jean Patrice, Adja Miessan Germain, Deh Serges
Kouakou, Anani Abenan Tawa, Effini Adiow Thérèse and Biémi Jean
(2000), Kimmeier (2001), Fofana (2005) et Anani (2006). Au regard des résultats de l’étude
comparative, nous retenons que la méthode DRASTIC est la mieux indiquée dans la cartographie de la
vulnérabilité à la pollution des eaux souterraines du District d’Abidjan.
5. Conclusion
L’application des méthodes DRASTIC et GOD a permis d’évaluer la vulnérabilité intrinsèque à la
pollution des eaux souterraines du District d’Abidjan. L’analyse des différentes cartes de vulnérabilité
à la pollution a montré que la vulnérabilité par les méthodes DRASTIC et GOD est concentrée entre
les classes moyenne et forte. La comparaison des cartes de vulnérabilité à partir du test de Kappa a
montré qu’il existe un accord modéré entre ces méthodes (le coefficient Kappa vaut 0,418). L’analyse
des fréquences de surface des cartes de vulnérabilité a révélé que les méthodes (DRASTIC et GOD)
ont un parfait accord (65%), mais la méthode GOD a tendance à sur-évaluer la vulnérabilité d’un
indice par rapport à DRASTIC.
La carte de vulnérabilité établie par les deux méthodes a été validée avec la carte de répartition
spatiale du taux de nitrates de 2001. En effet, les deux méthodes utilisées ont montré qu’on assiste à
une progression de la vulnérabilité du Sud vers le Nord. Les zones à fort taux de nitrates (> 50 mg/L)
progressant également dans le même sens se superposent parfaitement aux zones de très forte à forte
vulnérabilité. La superposition de ces deux types de zones (vulnérabilité forte et taux de nitrates élevé)
permet de dire que la carte établie par ces méthodes reflète la réalité du terrain. Mais la carte de
vulnérabilité réalisée à partir de la méthode DRASTIC reflète le mieux la réalité de la pollution des
eaux souterraines du District d’Abidjan

Etude Comparative des Méthodes D’évaluation de la Vulnérabilité à la
Pollution des Aquifères en Milieu Poreux: 785
References
[1] Aghui N. et Biémi J. (1984). Géologie et hydrogéologie des nappes de la région d’Abidjan et
risques de contamination. Annales de l’Université Nationale de Côte d’Ivoire, série c tome 20,
pp.331-347.
[2] Aller L., Bennett T., Lehr J.H., Petty R. J. et Hackett G. (1987). DRASTIC: A standardised
system for evaluating ground water pollution potential using hydrogeologic settings. EPA, Ada,
Oklahoma, 622 p.
[3] Anani A. T. épse Kouakou (2006). Evaluation et cartographie des zones vulnérables à la
pollution des eaux souterraines au niveau du District d’Abidjan (Sud de la Côte d’Ivoire) par
les méthodes DRASTIC et GOD. Mémoire de DEA, Université de Cocody, 71 p.
[4] Banton O. et Bangoy L. (1997). Hydrogéologie: Multiscience environnementale des eaux
souterraines. Presse de l’Université du Québec, AUPELF, pp. 375 – 389
[5] Bézelgues S., Des Garets E., Mardhel V. et Dörfliger N. (2002). Cartographie de la
vulnérabilité de Grand-Terre et de Marie-Galatie (Guadeloupe). Phase 1: méthodologie de
détermination de la vulnérabilité, 45 p.
[6] Champagne L. et Chapuis R. P. (1993). Évaluation de la vulnérabilité à la pollution des
formations aquifères de la MRC de Montcalm selon la méthode Drastic. Rev. Sc. Tech. Eau;
26; pp. 76 -169.
[7] Cohen J. (1970). A coefficient of agreement for nominal scales, Educ. Psychol. Meas, pp. 27-
46.
[8] Douagui A. (2004). Evaluation de la vulnérabilité à la pollution de la nappe du Quaternaire du
secteur "Canal de Vridi" – Grand-Bassam par la méthode DRASTIC. Mémoire de DEA,
Université d’Abobo-Adjamé, 71 p.
[9] Fofana F. (2005). Evaluation et cartographie de la vulnérabilité à la pollution de la nappe
d’Abidjan selon les méthodes DRASTIC et GOD. Mémoire de DEA, Université d’Abobo-
Adjamé, 68 p.
[10] Foster S.S.D. (1987). Fundamental concepts in aquifer vulnerability, pollution risk and
protection strategy. Atti Int. Conf. Vulnerability of soil and Groundwater to Pollutants, RIVM
Proc. and Inf. 38. pp. 69-86.
[11] INS (2001). Recensement Général de la Population et de l’Habitation (RGPH) 1998. Données
socio-démographiques et économiques des localités, résultats définitifs par localités, région des
lagunes, vol.III, tome 1, 43 p.
[12] Isabel D., Gelinas P. et Aubre F. (1990). Cartographie de la vulnérabilité des eaux
souterraines au Québec. Rev. Sc. Tech. Eau, 23 p.
[13] Jourda J. P. (2005). Méthodologie d’application des techniques de Télédétection et des
systèmes d’information géographique à l’étude des aquifères fissurés d’Afrique de l’Ouest.
Concept de l’hydrotechniquespatiale: cas des zones tests de la Côte d’Ivoire. Thèse de Doctorat
d’Etat, Université de Cocody, 430 p.
[14] Jourda J. P., Kouamé K. F., Soro N., Kouamé K. J., Kouadio B. H., Saley M. B., Kouamé
K et Ahoussi E. (2003). Gestion et protection des eaux souterraines urbaines: apports d’un
système d’information géographique à la réalisation de la carte de vulnérabilité de la nappe du
continental terminal au niveau de l’agglomération d’Abidjan. Dans les Actes de la conférence
francophone SIG 2003, Paris, octobre 2003, 18 p.
[15] Jourda J. P., Saley M. B., Kouamé K. J., Kouadio B. H, Biémi J. et Razack M. (2005).
Gestion et protection des ressources en eaux souterraines: contribution d’un SIG à la réalisation
de la carte de vulnérabilité à la pollution des aquifères fissurés de Korhogo (nord de la Côte
d’Ivoire) selon la méthode DRASTIC. Dans les Actes de la Conférence francophone SIG 2005,
du 5 au 6 octobre 2005, Paris, 16 p.
[16] Jourda J. P.; Kouamé K. J., Saley M. B., Kouadio B.H. et Oga Y.S. (2006a): Contamination
of the Abidjan aquifer by sewage: An assessment of extent and strategies for protection. In:

786 Kouamé kan Jean, Jourda Jean Patrice, Adja Miessan Germain, Deh Serges
Kouakou, Anani Abenan Tawa, Effini Adiow Thérèse and Biémi Jean
Groundwater pollution in Africa (Edited by Yongxin X. and Brent U.), pp. 293-302, Taylor &
Francis/Balkema, Great-Britain
[17] Jourda J. P., Kouamé K. J.; Saley M. B., Kouamé K. F., Kouadio B. H. et Kouamé K.
(2006b). A new cartographic approach to determine the groundwater vulnerability of the
Abidjan aquifer. In: Groundwater pollution in Africa (Edited by Yongxin X. and Brent U.), pp.
103-114, Taylor & Francis/Balkema, Great-Britain
[18] Kimmeier F. (2001). 3-D Groundwater flow modelling in heterogeneous geologic media:
Integrated approach using spatial and temporal database, geostatistics and GIS. Thesis
presented to the faculty of sciences of the Neuchâtel University, 223 p.
[19] Kouadio L., Abdoulaye S., Jourda P., Loba M. et Rambaud A. (1998). Conséquences de la
pollution urbaine sur la distribution d’eau d’alimentation publique à Abidjan. Dans: Cahiers de
l’Association Scientifique Européenne pour l’Eau et la Santé, vol.3, n°1, pp. 61 – 75.
[20] Kouamé K. J. (2003). Apports d’un système d’information géographique à la réalisation de la
carte de vulnérabilité de la nappe du Continental terminal au niveau de l’agglomération
d’Abidjan. Mémoire de DEA des Sciences de la Terre option hydrogéologie, Université de
Cocody, 63 p.
[21] Kouamé K. J. (2007). Contribution à la Gestion Intégrée des Ressources en Eaux (GIRE) du
District d’Abidjan (Sud de la Côte d’Ivoire): Outils d’aide à la décision pour la prévention et la
protection des eaux souterraines contre la pollution. Thèse de Doctorat de l’Université de
Cocody, 226 p.
[22] Landis J. R. et Koch G. G. (1977). The measurement of observer for categorical data,
Biometrics, pp. 159-179.
[23] Lobo-Ferreira J. P., Novo E. M. et Oliveira M. M. (1995). Groundwater vulnerability
mapping: Application to the Minho watershed in Northern Portugal’s Celtic Region.
Laboratorio Nacional de Engenharia Civil, Lisbon, Portugal, 7 p.
[24] Lynch S. D., Reynders A. G. et Schulz R. (1993). Preparing input data for a national-scale
groundwater vulnerability map of Southern Africa in 6 th National Hydrological Symposium,
SANCIAHS, September 1993 and water S.A. (1994) 20, pp. 239 – 246.
[25] Ministère du Plan et du Développement (MPD) (2006). Rapport national de l’Etat et le
devenir de la population de la Côte d’Ivoire (REPCI). Population et développement: défis et
perspectives pour la Côte d’Ivoire. UNFPA, août 2006.
[26] Mohamed R. M. (2001). Evaluation et cartographie de la vulnérabilité à la pollution de
l’aquifère alluvionnaire de la plaine d’El Madher, Nord-Est algérien, selon la méthode
DRASTIC. Sciences et changement planétaires / sécheresse, vol. 12, n°2, pp. 95-101.
[27] Murat V. (2000). Etude comparative des méthodes d’évaluation de la vulnérabilité intrinsèque
des aquifères à la pollution: Application aux aquifères granulaires du Piémont LAURENTIEN.
Mémoire de maîtrise, INRS – Géosciences, Québec, 127 p.
[28] Murat V., Martel R., Michaud Y. et Therrien R. (2000). Etude comparative des méthodes
d’évaluation de la vulnérabilité des aquifères à la pollution: Application aux aquifères
granulaires du Piémont LAURENTIEN, Québec, AIH-CNC et SCG, pp. 411-418.
[29] Murat V., Paradis D., Savard M. M., Nastev M., Bourque E., Hamel A., Lefebvre R. et
Martel R. (2003). Vulnérabilité à la nappe des aquifères fracturés du sud-ouest du Québec:
Evaluation par les méthodes DRASTIC et GOD. Ressources naturelles Canada, Commission
Géologique, 16 p.
[30] Navalur k. C. S. et Engel B. A. (1997). Predicting spatial distribution of vulnerability of
Indiana State Aquifer system to nitrate leaching using a GIS. 18 p.
[31] Tastet J. P. (1979). Environnements sédimentaires et structuraux quaternaires du littoral du
Golfe de guinée (Côte d’Ivoire, Togo, Bénin). Thèse de Doctorat d’Etat ès sciences, Université
de Bordeaux 1, 181 p.

Etude Comparative des Méthodes D’évaluation de la Vulnérabilité à la
Pollution des Aquifères en Milieu Poreux: 787
[32] Vrba J. et Zaporozec A. (1994). Guidebook on mapping groundwater vulnerability.
International association of hydrgeologists, vol.16, 131 p.

European Journal of Scientific Research
ISSN 1450-216X Vol.20 No.4 (2008), pp.788-795
© EuroJournals Publishing, Inc. 2008
http://www.eurojournals.com/ejsr.htm
Development of an Integrated Poultry/Fishery Husbandry for
Optimal Agricultural Production
F.R. Falayi
Agricultural Engineering Department, The Federal University of Technology
P.M.B. 704, Akure, Ondo State, Nigeria
A.S. Ogunlowo
Agricultural Engineering Department, The Federal University of Technology
P.M.B. 704, Akure, Ondo State, Nigeria
M.O. Alatise
Agricultural Engineering Department, The Federal University of Technology
P.M.B. 704, Akure, Ondo State, Nigeria
Abstract
The need to find alternative but productive means of managing animal waste in the
modern day agriculture waste cannot be over emphasised. One important means of
managing these wastes is through conversion to important use either as animal feeds or as
manures.
An integrated poultry/fishery housing unit was designed and constructed such that
poultry droppings were made to drop into the ponds directly and used as feed for clarias
gariepinus. The set-up was made of four concrete ponds on which three wooden battery
cages were mounted except the fourth pond which served as the control. The ponds were
stocked with twenty (20) juvenile clarias garipinus each. Fish in pond 1, two and three were
fed with droppings from one broiler, two broilers and three broilers respectively. While fish
in ponds 4 were fed with the fish concentrate. A total of 6 birds (4 weeks old) and 80
juvenile clarias gariepinus were used. This experiment lasted for 6 months. During this
period of study, the environmental parameters were monitored and the effect of poultry
waste on the development of the fish was analysed.
There was an increase in weight of the fish in all ponds through out the period of
the study. The weight gained by the fish in pond 1 increased at an increasing rate of 10.85
g/week up to the 15 th week after stocking. Thereafter, the weight gained started increasing
at a constant rate of 86.8g/week up to the 20 th week after stocking and thereafter a weight
increase at a deceasing rate of 136.56 g/week up to harvest period. In pond 2, the weight of
the fish increased at an increasing rate of 7.47 g/week up to 8 th week. Thereafter, the
weight gain increased at a constant rate of 24.88 g/week to 16 th week and increasing at a
decreasing rate of 42.75 g/week to harvest. The same trend was observed in pond 3 but the
weight gain increased at an increasing rate of 8.06 g/week up to the 4 th week and then
increasing at a constant rate of 10.89 g/week to the 16 th week. Thereafter, there was weight
increase at a decreasing rate of 32.36 g/week to harvest. Pond 4, which was the control,
showed a different trend in the development of the fish, in this case, there was a weight
gain at an increasing rate of 12.90 g up to the 18 th week after stocking. Thereafter there was
a weight gain at a decreasing rate of 147.22 g/week up to harvest period.

Development of an Interated Poultry/Fishery Husbandry for Optimal Agricultural Production 789
Keywords: Integrated, fishery, poultry, droppings, pond
Introduction
In many parts of the world, fish have provided an important part of people’s diet for centuries. The
increasing per capita consumption of fish is partially due to consumer demand for healthy diet and the
growing recognition that the fatty acid content of fish provides health benefit to man. The growth rate
of the world’s human population has called for increased harvest of fish and fisheries products from
marine and inland waters (Woynarovich 1979). Chandrasoma (1988) observed that during the last
hundred years, fish catches have increased rapidly due to improved technologies. Despite the fact that
growth in fish catches stopped some 15 years ago, over fishing had already caused the worldwide
decrease in stock to become a real problem. The need to increase fish production by fish farming is
urgent. Fish farming is an agricultural activity that can deeply improve the already existing farming
system. As in agriculture, fish farming techniques include the removal of unwanted plants and animals,
their replacement by desirable species, the improvement of these species by crossbreeding and
selection, and the improvement of food availability by the use of fertilizer. Fish farming can benefit
from agricultural by-products generated by other activities, as these activities can be used to increase
the quality of plankton, that is, the natural food of fish (Chakrabarty and Hettiarachchi 1982). Fish
farming can be combined with poultry, animal husbandry and irrigation practices, which can lead to
higher production and net profits. This practice is called integrated fish farming or integrated
aquaculture. The integration of animal husbandry, especially poultry, with fish farming in a small scale
results in the production of organic manure for the fertilization of the fish pond to increase the
production of the natural food organism (planktonic algae) to be eaten by the fish. In some cases, the
poultry wastes are used as direct food by some fish without supplementary feedings, such species
include Nile Tilapia (FAO, 1996).
There are various methods of integrating poultry with fish farming. Some designs give room for
the poultry house to be sited on a land near the pond and the poultry waste/ manure is transferred into
the pond manually. While another design sites the poultry directly on the pond. Literature regarding
poultry/fish integration generally relates to battery or deep litter in which the birds are typically fed on
complete diets in pelleted or mash form and the manure used as feed (Little and Muir, 1987). Manure
is packed into the pond to fertilize it for the fish to feed. Not all fish are carnivores; therefore, not all
can feed on manure. The herbivores rather pick waste supplemental feeds from the birds’ meal only.
Integrated fish farming is regarded by aquaculturists of most countries as a model farming system for
full utilization of local resources, for waste recycling and energy saving, and for maintaining ecological
balance and circulation. Besides increasing the supply of fish, meat and eggs, and employment
opportunities, it also reduces the cost of fish production through utilization of local farm products as
fish feeds and fertilizers and reorganization of farm labour for effective output (De Silva 1991).
Although this technology is highly productive in certain regions in China and parts of Asia,
Sharma 1981, reported that it is now recognized that large-scale technology transfer to most other
regions, both inside and outside China, is dependent on a clearer scientific understanding of the
physical, chemical and biological processes involved.
In developing countries like Nigeria, many are not informed about integrated fish farming and
its attendant benefits. There is virtually no reliable data concerning the feasibility and adoption of the
system. Adesulu (2001) stated that integrated fish farming is not a common practise in Nigeria. Thus
this study was carried out in order to intensify our efforts on integrated agricultural production.
2. Methodology
Model poultry housing unit and concrete fishponds were designed and constructed using locally
available materials. Three wooden battery cages were mounted on the fish ponds. The set-up was made

790 F.R. Falayi, A.S. Ogunlowo and M.O. Alatise
of four concrete ponds on which three wooden battery cages were mounted except the fourth pond
which served as the control. The ponds were stocked with twenty (20) juvenile clarias garipinus each.
Fish in pond 1, 2 and 3 were fed with droppings from one broiler, two broilers and three broilers
respectively. While fish in ponds 4 were fed with the fish concentrate as shown in table 1.
A total of 6 birds (4 weeks old) and 80 juvenile clarias garipinus were used. This experiment
lasted for 6 months. During this period, the environmental parameters were monitored and the effect of
poultry waste on the fish development was noticed. Data collected were subjected to appropriate
statistical analysis.
2.1. Measurements
Bird’s development was determined by measuring the feed consumed and the weight gained on weekly
basis. Grower’s mash was used to feed the broiler chickens throughout the period of the experiment
while fish weight and numbers of fish in the ponds were measured every two weeks. Fish were
harvested at the end of sixth month and the weight and number of fish harvested were also recorded.
2.2. Integrated Poultry Housing Husbandry Description
The pond was designed mainly to give an enabling aquacultural environment for catfish. The pond was
made of hollow block of 150mm (6 inches). The pond was constructed on simple strip concrete
foundation and was divided into three cells of 1m each for different treatments. The wall was
adequately plastered with appropriate mixture of cement, sand and water and adequate precaution
against under cuts by water. One important characteristic of a modern fishpond is that it must be
drainable; this means that it should be possible to empty the pond down to the last drop of water hence
the floor of the pond was constructed at a slope of 0.2 for proper drainage.The ponds were supplied
with well water and drained through gate valves of 37mm (1 ½ inches).
The poultry-housing unit was designed to give appropriate ventilation system for good
performance of the birds. The floor dimension was 4.50m by 2.54m and total height of the building
was 3.14m. The poultry-housing unit was constructed using timber and steel, which are readily
available materials with good strength and minimum cost. The roof was made of galvanized corrugated
roofing sheet. The cage was constructed using wood and wire mesh for the cage floor. The height of
the cage was 0.47m, length of 0.5m and width of 0.4m. The complete housing unit is as shown in plate
1
Table 1: Feeding Table for Catfish Grow-out
Average weight (grams) Feeding level (%body weight) Pellet size (mm)
5-10 5.5-6.0 2.0
10-25 4.5-5.5 2.0
25-70 4.0-4.5 3.0
100-250 3.0-4.0 4.5
500-750 1.5-2.0 4.5
750-1000 1.1-1.5 4.5 or 6.0
1000-1250 0.9-1.1 4.5 or 6.0
1250-1500 0.8-1.0 4.5 or 6.0
1500-2000 0.7-0.9 4.5 or 6.0

Development of an Interated Poultry/Fishery Husbandry for Optimal Agricultural Production 791
3.0. Results and Discussion
3.1. Fish Development
Plate 1: Experimental set up of the integrated unit
The general development of the fish in the various ponds is as shown in Fig. 1. There was an increase
in weight of the fish through out the period of study. It could be observed from the graph that the
weight gained by the fish in pond 1 increased at an increasing rate of 10.85 g/week up to the 15 th week
after stocking. Thereafter, the weight gained started increasing at a constant rate of 86.8g/week up to
the 20 th week after stocking and then there was weight increase at a deceasing rate of 136.56 g/week up
to harvest period as shown in Fig. 2. In pond 2, the weight of the fish started increasing at an increasing
rate of 7.47 g/week up to 8 th week. Thereafter, the weight gain was increasing at a constant rate of
24.88 g/week to 16 th week and increasing at a decreasing rate of 42.75 g/week to harvest. The same
trend was observed in pond 3 but the weight gain increased at an increasing rate of 8.06 g/week up to
the 4 th week and increasing at a constant rate of 10.89 g/week to the 16 th week. Thereafter, there was
weight increase at a decreasing rate of 32.36 g/week to harvest. Pond 4 which was the control showed a
different trend in the development of the fish, there was a weight gain at an increasing rate of 12.90 g
up to the 18 th week after stocking. Thereafter there was a weight gain at a decreasing rate of 147.22
g/week to harvest period as shown in Fig.2.
However an analysis of the variance of the collected data showed that there was no significant
difference in the weight of the fish in the various ponds up to 6 th week after stocking as shown in table
2 (Fcritical>Fcalculated at 0.05 level). However as from the 6 th week to the 24 th week, there was a significant
difference in the weight of the fish in the various ponds (Fcritical

792 F.R. Falayi, A.S. Ogunlowo and M.O. Alatise
stocking. It is obvious from fig 1 that the fish in pond 1 fed with droppings from only one bird
compared favourably with pond 4 which was the control. This was followed by the fish in pond 2 fed
from droppings of two birds and lastly the fish in pond 3 fed with droppings of three birds.
A regression analysis was carried out to predict the weight of fish in the various ponds when
compared with the control pond. The regression of pond 1 on pond 4 is as shown in fig.3 which
showed a high correlation (R 2 =0.9985) and polynomial of the third degree best described the
relationship ie y = 3E-07x 3 - 0.001x 2 + 1.2585x - 20.261. A regression of pond 2 on pond4 (Fig. 4)
showed an equation y = 2E-07x 3 - 0.0007x 2 + 0.8721x - 7.1101 with a correlation of 0.99(R 2 =. 0.99)
while the regression of pond 3 on pond 4 was fitted with the polynomial equation y = 1E-07x 3 -
0.0005x 2 + 0.6725x + 1.8387 with high correlation (R 2 = 0.9988) as shown in Fig 5. Mortality rate of
20% was recorded in pond3 during the experiment. However, no mortality rate was recorded for pond
2 and pond 1. The experiment did not allow for sorting of the fish as development progressed hence
slight cannibalism of less than 5% was recorded in all the ponds
Figure 1: Average Weight of Fish Against Weeks after Stocking
Figure 2: Comparison of the Growth Fish Rate/week in the Various Ponds

Development of an Interated Poultry/Fishery Husbandry for Optimal Agricultural Production 793
Figure 3: Regression of pond1 on control pond
Figure 4: Regression of pond2 on control pond
Figure 5: Regression pf pond3 on control pond

794 F.R. Falayi, A.S. Ogunlowo and M.O. Alatise
Table 2: ANOVA of Fish Developments in the 6 th Week after Stocking
Source of Variation SS df MS F P-value F crit
Between Groups 353.6875 3 117.8958 0.429721 0.73546 3.4903
Within Groups 3292.25 12 274.3542
Total 3645.938 15
Table 3: ANOVA of Fish Development 24 Weeks after Stocking
Source of Variation SS df MS F P-value F crit
Between Groups 789956.4 3 263318.8 6.280948 0.000633 2.703594
Within Groups 3856954 92 41923.42
Total 4646911 95
3.2. Development of the Birds
The birds recorded an increasing weight gain throughout the period of the study. The average weight
during stocking to the end of the study varied from 0.7kg to about 9kg. There was no significant
difference at 5% level in the average weight of the birds in the various cages as shown in Fig.6 and this
implied that the development of birds in the cages was equal throughout the period of the study. Zero
mortality was recorded throughout the period of study and this confirmed that the environmental
conditions of the housing unit were suitable for poultry production
Figure 6: Relationship between the average weight of birds in different cages and weeks after Stocking
10000
9000
8000
7000
6000
5000
4000
3000
2000
1000
0
cage1
cage2
cage3
0 2 4 6 8 12 14 16 18 20 22 24
Weeks af ter stocking
Conclusions
A relatively new technology of vertical integration of poultry and fishery system is been developed.
The system has been tested and confirmed that a five weeks old broiler can produce droppings capable
of feeding twenty juvenile clarias gueripinus to about six months to an average weight of about 0.75
Kg. Although, the average weight of fish fed with concentrates at the same period was about 1 Kg but
the comparative cost of raising fish with concentrates which is expensive and raising fish with poultry
waste justified the study.

Development of an Interated Poultry/Fishery Husbandry for Optimal Agricultural Production 795
References
[1] Adesulu E.A. (2001). Pisciculture. External communication limited 1 st edition, pp 65-67
[2] Chandrasoma J. (1988). Observations on Marketing of fish produced in seasonal tanks', Jour
Inland Fish Sri Lanka, 4: 63–67.
[3] Chakrabarty R. D. & A. Hettiarachchi (1982). ‘Preliminary Observations on Fish Polyculture
cum Duck raising in a Farm Pond in Sri Lanka’, Jour Inland Fish. Sri Lanka, Vol 1. 54–61.
[4] De Silva K. G. H. M. (1991). ‘The Predicament of the Freshwater Fisheries and Aquaculture of
Sri Lanka’, NAGA, The ICLARM Quarterly, Jan. 1991, pp. 6–7.
[5] FAO (1996). Management for Freshwater Fish Culture. Ponds and water practices. FAO
Publication, 21/1, 233pp.
[6] Ivor H. Seeley and Roger .W (1996). Building quantities explain: 5 th Edition. Macmillan press
Limited, London. Page 87.
[7] Little. D. and Muir, J. (1987). A guide to Integrated warm water aquaculture. published by the
Inst. Aquaculture, University of Stirring. Stirring Scotland.
[8] Sharma B. K. (1981). Fish Culture Integrated with Livestock Raising; Summer Institute on
Farming System integrating agriculture, livestock and fish culture, 6 July - 4 August, Central
Inland Fisheries Research Institute, Barackpore, West Bengal, pp. 128–142.
[9] Woynarovich E. (1979). The feasibility of combining animal husbandry with fish farming, with
special reference to duck and pig production. In: Advanced in Aquaculture, T. V. R. Pillay and
W. A. Dill (eds.). Fishing News Books Ltd. Farnham, Surrey, England, pp. 203–208.

European Journal of Scientific Research
ISSN 1450-216X Vol.20 No.4 (2008), pp.796-804
© EuroJournals Publishing, Inc. 2008
http://www.eurojournals.com/ejsr.htm
Robust Control of a Doubly Fed Asynchronous Machine of a
Wind Turbine System
S. Gherbi
S. Yahmedi
M. Sedraoui
Abstract
In these last years, there is a growing interest to use the wind turbines systems to
produce the electricity (see [1]) because it uses a renewable and non polluted energy which
is the wind. There is different challenges in the control of the wind energy systems and we
have to take in a count a several parameters that perturb the system as: the wind speed
variation, the consumption variation of the electricity energy and the kind of the power
consumed (active or reactive) ...etc. In this paper, we present a method to synthesize a
robust controller for a wind turbine system based in a model equipped with doubly fed
asynchronous machine which is the most used model in this last years [2] and we used the
H ∞ robust control method with the recent method based on the use of the linear matrix
inequalities (LMI’s): Gahinet-Akparian [4], the results show the stability and the
performance robustness of the system in spite of the perturbations mentioned before.
Keywords: Doubly fed asynchronous machine, robust control, H ∞ controller design
method, linear matrix inequality LMI
I. Introduction
From all the renewable energy electricity production systems, the wind turbine systems are the most
used specially the doubly fed asynchronous machine based systems, the control of theses systems is
particularly difficult because all of the uncertainties introduced such as: the wind speed variations, the
electrical energy consumption variation, the system parameters variations, in this paper we focus on the
robust control ( H ∞ controller design method) of the doubly fed asynchronous machine which is the
most used in the wind turbine system due to its low cost, simplicity of construction and maintenance
[1]. This paper is organised as follow: section 2 presents the wind turbine systems equipped with the
doubly fed asynchronous machine and the mathematical electrical equations are presented, then a
model (in the state space form) are deducted, in the section 3 we present the H ∞ robust controller
design method used to control our system, the section 4 present a numerical application and the results
in both the frequency and time plan are presented and conclusion is given in section 5.
II. System Presentation and Modelling
The wind turbines system is represented by the following figure:

Robust Control of a Doubly Fed Asynchronous Machine of a Wind Turbine System 797
Figure 1: Wind turbine system representation
The system use the wind power to drag the double fed asynchronous machine who acts as a
generator, the output power produced must have the same high quality when it enters the electrical
network, i.e: 220 volts amplitude and 60 Hz frequency and the harmonics held to a low level in spite of
wind speed changes and electrical energy consumption in active or reactive power form. References
[5], [6], [7] describe detailed models of wind turbines for simulations, we use the model equipped with
the doubly fed induction generators (asynchronous machine) (for more details see [8]), the system
electrical equations are given in ( d, q)
frame orientation, then:
The stator voltage differential equations are:
d
Vds = Rs.
I ds + Φ ds − ws
⋅Φ
qs
(1)
dt
d
Vqs = Rs.
I qs + Φ qs + ws
⋅Φ
ds
(2)
dt
The rotor voltage differential equations are:
d
Vdr = Rr
. Idr
+ Φdr
− wr
⋅Φ
qr
(3)
dt
d
Vqr = Rr
. Iqr
+ Φ qr + wr
⋅Φ
dr
(4)
dt
The stator flux vectors equations are:
Φ ds = L s.
Ids
+ M.
Idr
(5)
Φ qs = L s.
I qs + M . I qr
The rotor flux vectors equations:
(6)
Φ dr = L r . I dr + M.
I ds
(7)
Φ qr = L r.
Iqr
+ M . Iqs
(8)
The electromagnetic couple flux equation :
M
Cem p.
( Φ ds.
I qr −Φ
qs . I dr )
L
= (9)
s
The electromagnetic couple mecanic equation:
dΩ
= C + J + f . Ω
dt
Cem r
(10)
Where:
V , : Statoric voltage vector components in ‘d’ and ‘q’ axes respectively.
ds Vqs
V dr , Vqr
: Rotoric voltage vector components in ‘d’ and ‘q’ axes respectively.
I ds , I qs : Statoric current vector components in ‘d’ and ‘q’ axes respectively.
I dr , I qr : Rotoric current vector components in ‘d’ and ‘q’ axes respectively.
Φ ds , Φ qs : Statoric flux vector components in ‘d’ and ‘q’ axes respectively.
Φ , : Rotoric flux vector components in ‘d’ and ‘q’ axes respectively.
dr qr Φ

798 S. Gherbi, S. Yahmedi and M. Sedraoui
s r R R , : Stator and rotor resistances (of one phase) respectively.
s r L L , : Stator and rotor cyclic inductances respectively.
w s , wr
: Statoric and rotoric current pulsations respectively.
M : Cyclic mutual inductance.
p : Number of pair of the machine poles.
C r : Resistant torque.
f : Viscous rubbing coefficient.
J : Inertia moment.
2.1. State space Model
In order to apply the robust controller design method, we have to put the system model in the state
space from; we consider the rotoric voltage V dr , Vqr
as the inputs and the statoric voltage V ds , Vqs
as
the outputs, i.e. we have to design a controller who acts on the rotoric voltages to keep the output
statoric voltages at 220 volts and 50Hz frequency in spite of the electric network perturbations (demand
variations … etc) and the wind speed variations (see fig.2).
Figure 2: A Doubly fed wind turbine system control configuration
Where: u , y and e are the rotoric voltage vector (control vector), statoric output voltage vector
and the error signal between the input reference and the output system respectively. K , G are the
controller, wind turbine system respectively. R is the statoric voltage references vector and
ons
perturbati are the electric energy demand variations, wind speed variations …etc.
• Let us consider [ ] T
x = Φ Φ as a state vector, and [ ] T
I I V V
dr qr
u = ds qs ds qs as the command
vector, the stator flux vector is oriented in d axis of Parks reference frame then : Φ qs = 0 and
I ds , I qs are considered constant in the steady state ie: I�
ds = I�
qs = 0 .
• We use the folowing doubly fed asynchronous machine parameters:
R = 5Ω
; R = 1.
0113Ω
; M = 0.
1346H
= 0.
3409H
; = 0.
605H
; = 146.
6Hz
; = 2π ⋅50Hz
s
r
L
M
Let w = ws
− wr
and σ = 1−
.
2
s r L ⋅
L s
• The state space (11) can be obtained by the combining of the equations (1) to (8) as follow:
⎧x�
= A⋅
x + B ⋅ u
⎨
⎩y
= C ⋅ x + D ⋅ u
(11)
Where:
x = φ φ , [ ] T
u = I I V V , [ ] T
V y = and :
[ ] T
dr
⎡−
R
⎢
L
= ⎢ r
⎢−
w
⎢
⎣
r
r
qr
A ,
ds
qs
⎤ ⎡ Rr.
M
wr
⎥ ⎢
L
⎥ B
= ⎢ r
− Rr
⎥ ⎢ 0
L ⎥
r ⎦
⎢
⎣
dr
0
qr
Rr.
M
L
r
1
0
L r
⎤
0⎥
⎥
1⎥
⎥
⎦
ds qs V
w r
w s

Robust Control of a Doubly Fed Asynchronous Machine of a Wind Turbine System 799
⎡ Rr
M ⎢
L
= − ⋅ ⎢ r
Lr
⎢ w
⎢
⎣
⎤
w ⎥
⎥
Rr
− ⎥
L ⎥ r ⎦
C ,
⎡ 2
M
⎢Rs
+ ⋅ R
2
= ⎢ L
D
r
⎢
⎢ σ ⋅ Ls.
W
⎢⎣
r
− σ ⋅ L . W
M
Rs
+
L
III. The H∞ Controller Design Method
It is necessary to recall the basics of a control loop (fig.3), with: Δ m : is the system uncertainty, K: the
controller , G: the nominal system.
s
2
2
r
⋅ R
r
M
L
r
0
⎤
0 ⎥
⎥
M ⎥
⎥
Lr
⎥⎦
Figure 3: The control loop with the output multiplicative uncertainties
The multiplicative uncertainties at the process output which include all the perturbations that
' −1
act in the system are then : Δm = ( G − G).
G , with G′ = G(
I + Δ m ) : is the perturbed system, (Fig.3) show
the singular values plot at the frequency plan of Δ m , we can see that the uncertainties are smaller at
low frequencies and grow at the medium and high frequencies, this mean a strong perturbation at high
frequencies (the transient phase), we also note a pick at the pulsation: ω = 260rad / sec due to the fact
that the system is highly coupled at this pulsation.
We can bound the system uncertainties by the following weighting matrix function:
⎡ 0.
55(
0.
02 jw + 1)
⎢
( 1 + 0.
0001 jw)
( jw)
= ⎢
⎢ 0
⎢⎣
⎤
0 ⎥
⎥
0.
55(
0.
02 jw + 1)
⎥
( 1 + 0.
0001 jw)
⎥⎦
W t (12)
The robust stability condition [11] is then:
σ [ T ( jw)
⋅Wt
( jw)
] ≺ 1
(13)
Or: [ ( ) ] [ ( ) ] 1 −
σ T jw < σ Wt
jw
(14)
Where: T ( jw)
is the nominal closed loop transfer matrix defined by:
( ) ( ) ( ) [ ( ) ( ) ] 1 −
T jw = G jw ⋅ K jw ⋅ I + G jw ⋅ K jw
(15)
The equations (13) allow us to guaranty the stability robustness, in other hand we most
guaranty satisfying performances (no overshoot, satisfying time response …etc) in the closed loop
(performances robustness), this can by done by the performance robustness condition [12]:
σ [ S( jw)
⋅W
p ( jw)
] ≺ 1
(16)
Or: [ ( ) ] [ ( ) ] 1 −
σ S jw < σ Wp
jw
(17)
Where:
• S ( jw)
is the sensitivity matrix given by:
( ) [ ( ) ( ) ] 1 −
S jw = I + G jw ⋅ K jw
(18)
• WP ( jw)
is a weighting matrix function designed to meet the performance specifications desired
in the frequency plan, we choose the following matrix function:

800 S. Gherbi, S. Yahmedi and M. Sedraoui
W p
⎡ ( 0.
005 jw + 1)
⎤
⎢
0
0.
05 jw
⎥
( jw)
= ⎢
⎥
(19)
⎢
( 0.
005 jw + 1)
0
⎥
⎢⎣
0.
05 jw ⎥⎦
• The fig.6 represent the singular values of WP ( jw)
in the frequency plan, one notice that the
specifications on the performances are bigger in low frequencies (integrator frequency
behaviour), this guaranty no static error.
Then the standard problem of H∞ Control theory is then:
T(
jw)
⋅Wt
( jw)
min (20)
K stabili sin g S(
jw)
⋅W
p ( jw)
∞
i.e.: to find a stabilising controller K that minimise the norm (20).
IV. Application
The minimisation problem (20) is solved by using two Riccati equations [10] or with the linear matrix
inequalities approach [4]. For our system, we use the linear matrix inequalities solution with the
Matlab instruction lmi
hinf available at ‘LMI/ Toolbox’ of Matlab ® Mathworks inc (for more details
see [12]).
The controller obtained (in the state space form) is presented in appendix.
• The fig.7. and the fig.8. show the satisfaction of the stability and performances robustness
•
(conditions (14) and (17)).
We choose the desired outputs R = ( Vds
_ ref
and V qs of the nominal case.
= 1
0
Vqs
_ ref = 0 ) , and the fig.9.show the outputs V
1
ds
Singular values
10 -0.1
10 -0.2
10 -0.3
10 -0.4
10 -0.5
10 -0.6
10 -4
Figure 4: The system uncertainties maximum singular values
10 -3
10 -2
σ
[ Δ ( jw)
]
m
10 -1
10 0
Pulsations
10 1
10 2
10 3
10 4

Robust Control of a Doubly Fed Asynchronous Machine of a Wind Turbine System 801
Figure 5: Maximum singular values of the system uncertainties m
Singular values
Singular values
10 3
10 2
10 1
10 0
10 -1
10 1
10 0
10 -1
10 -2
10 -3
10 -4
10 -5
10 -6
10 -4
10 -4
10 -3
10 -2
10 -1
10 0
Pulsations rad/sec
Δ bounded by the singular values of ( jw)
σ
[ ( jw)
]
Figure 6: Singular Values of the weighting performance specification
10 -3
10 -2
10 -1
10 0
Pulsations rad/sec
10 1
10 1
W t
10 2
10 2
σ
[ Δ ( jw)
]
m
10 3
10 3
10 4
10 4
W t
.

802 S. Gherbi, S. Yahmedi and M. Sedraoui
Singular values
Singular values
10 1
10 0
10 -1
10 -2
10 -3
10 -4
10 -5
10 1
10 0
10 -1
10 -2
10 -3
10 -4
10 -5
10 -4
10 -4
10 -6
10 -3
10 -3
Figure 7: Stability robustness condition
10 -2
10 -1
σ
[ T ( jw)
]
10 0
Pulsations rad/sec
10 1
Figure 8: Performances robustness condition
10 -2
10 -1
σ
[ ] 1 −
( jw)
W p
10 0
Pulsations rad/sec
10 1
10 2
σ
10 2
σ
[ ] 1 −
( jw)
W t
[ S(
jw)
]
10 3
10 3
10 4
10 4

Robust Control of a Doubly Fed Asynchronous Machine of a Wind Turbine System 803
Outputs
Outputs
1
0.8
0.6
0.4
0.2
0
1
0.8
0.6
0.4
0.2
0
Figure 9: Step response of the controlled closed loop nominal system
0 0.05 0.1 0.15 0.2 0.25
Time (sec)
0 0.05 0.1 0.15 0.2 0.25
Time (sec)
The fig.9 show the step responses of the closed loop controlled nominal system; we note no
overshoot and a satisfying time response.
V. Conclusion
In this paper we deal with the control problem of a wind turbine equipped with a doubly fed
asynchronous machine subject to various perturbations and system uncertainties (wind speed
variations, electrical energy consumption, system parameters variations ...etc), we show that the H∞
controller design method can be successfully applied to this kind of systems keeping stability and good
performances in spite of the perturbations and system uncertainties.
Vds
Vqs
Vqs
Vds

804 S. Gherbi, S. Yahmedi and M. Sedraoui
References
[1] G. L. Johnson, ‘ Wind energy systems : Electronic Edition’, Manhattan, KS, October 10, 2006.
[2] ‘AWEA Electrical Guide to Utility Scale Wind Turbines’, The American Wind Energy
Association, March 2005, available at http://www.awea.org.
[3] J. C. Doyle, K. Glover, P. P. Khargonekar and Bruce A. Francis, ‘ State-Space Solution to
Standard H2 and H∞ Control Problems’, IEEE Transactions on Automatic Control, Vol. 34, N°.
8, August 1989.
[4] P. Gahinet, P. Akparian. ‘A linear Matrix Inequality Approch to H∞ Control ‘, Int. J. of Robust
& Nonlinear Control“, vol. 4, pp. 421-448, 1994.
[5] J. Soens, J. Driesen, R. Belmans, ‘ Equivalent Transfer Function for a Variable-speed Wind
Turbine in Power System Dynamic Simulations ‘, International Journal of Distributed Energy
Resources, Vol.1 N°2, April-June, 2005; pp. 111-133.
[6] ‘Dynamic Modelling of Doubly-Fed Induction Machine Wind-Generators’, DigSilent GmbH
Technical Documentation, 2003, available at http://www.digsilent.de.
[7] J. Soens, J. Driesen, R. Belmans, ‘ Wind turbine modelling approaches for dynamic power
system simulations ‘, IEEE Young Researchers Symposium in Electrical Power Engineering -
Intelligent Energy Conversion, (CD-Rom), Delft, The Netherlands, March 18-19, 2004.
[8] J. Soens, V. Van Thong, J. Driesen, R. Belmans , ‘ Modelling wind turbine generators for
power system simulations ‘, European Wind Energy Conference EWEC, Madrid, 16 – 19 June
2003.
[9] Sigurd Skogestad, Ian Postlethwaite, ‘Multivariable Feedback Control Analysis and Design’,
John Wiley and Sons, 1996. pp: 72 to 75
[10] J . C. Doyle, K. Glover, P. P. Khargonekar and Bruce A. Francis, ‘State-Space Solution to
Standard 2 H and H ∞ Control Problems’, IEEE Transactions on Automatic Control, Vol. 34,
N°. 8, August 1989.
[11] D.-W. Gu, P. Hr. Petkov and M. M. Konstantinov, ‘Robust Control Design with MATLAB ® ’,
© Springer-Verlag London Limited 2005.pp:27 to 29
[12] P. Gahinet, A. Nemirovski, A. J. Laub, M. Chilali. “LMI Control Toolbox For Use with
MATLAB ® ”, User’s Guide Version 1, The MathWorks, Inc. 1995.

European Journal of Scientific Research
ISSN 1450-216X Vol.20 No.4 (2008), pp.805-816
© EuroJournals Publishing, Inc. 2008
http://www.eurojournals.com/ejsr.htm
Effects of Enviromental Variables on
Poultry Performance and Pond Water Quality in
an Integrated Poultry/Fishery Farming
F.R. Falayi
Agricultural Engineering Department, The Federal University of Technology
P.M.B. 704, Akure, Ondo State, Nigeria
A.S. Ogunlowo
Agricultural Engineering Department, The Federal University of Technology
P.M.B. 704, Akure, Ondo State, Nigeria
M.O. Alatise
Agricultural Engineering Department, The Federal University of Technology
P.M.B. 704, Akure, Ondo State, Nigeria
Abstract
The need to find alternative but productive means of managing animal waste in the
modern day agriculture waste cannot be over emphasised. One important means of
managing these wastes is through conversion to important use either as animal feeds or as
manures. Fish farming can be combined with poultry, animal husbandry and irrigation
practices, which can lead to higher production and net profits. This practice is called
integrated fish farming or integrated aquaculture. The integration of animal husbandry,
especially poultry, with fish farming in a small scale results in the production of organic
manure for the fertilization of the fish pond to increase the production of the natural food
organism (planktonic algae) to be eaten by the fish. In some cases, the poultry wastes are
used as direct food by some fish without supplementary feedings, such species include Nile
Tilapia and catfish
An integrated poultry/fishery housing unit was designed and constructed such that
poultry droppings were made to drop into the ponds directly and used as feed for clarias
gariepinus. The set-up was made of four concrete ponds on which three wooden battery
cages were mounted except the fourth pond which served as the control. The ponds were
stocked with twenty (20) juvenile clarias garipinus each. There were four treatments and 3
replicates, fish in pond 1, two and three were fed with droppings from one broiler, two
broilers and three broilers respectively. While fish in ponds 4 were fed with the fish
concentrate. A total of 6 birds (4 weeks old) and 80 juvenile clarias gariepinus were used.
This experiment lasted for 6 months. During this period, the environmental parameters
were monitored and the effect of poultry waste on the development of the fish was
analysed.
There were remarkable differences in the microclimate inside and outside the
building. The birds were well protected from harsh environmental conditions and a uniform
development was recorded. Pollution resulting from the use of poultry droppings adversely
affected the development of the fish. Increase in the volume of droppings led to increase in
the Bio-Chemical oxygen demand and Chemical Oxygen demand of the pond water which

Effects of Enviromental Variables on Poultry Performance and Pond Water Quality in an
Integrated Poultry/Fishery Farming 806
consequently led to a decrease in the dissolved oxygen. Water turbidity also increased with
increased droppings. Other water parameters like conductivity, chloride and pH values
were within acceptable values suggested in literatures.
The system has shown the possibility of effective poultry waste management
technique which ensured that nothing is wasted and waste handling problem is grossly
reduced.
Keywords: Integrated, fishery, poultry, droppings, pond
1. Introduction
In many parts of the world, fish have provided an important part of people’s diet for centuries. The
increasing per capita consumption of fish is partially due to consumer demand for healthy diet and the
growing recognition that the fatty acid content of fish provides health benefit to man. The growth rate
of the world’s human population has called for increased harvest of fish and fisheries products from
marine and inland waters (Woynarovich 1979). Chandrasoma (1988) observed that during the last
hundred years, fish catches have increased rapidly due to improved technologies. The need to increase
fish production by fish farming is urgent. Fish farming is an agricultural activity that can deeply
improve the already existing farming system. As in agriculture, fish farming techniques include the
removal of unwanted plants and animals, their replacement by desirable species, the improvement of
these species by crossbreeding and selection, and the improvement of food availability by the use of
fertilizer. Fish farming can benefit from agricultural by-products generated by other activities, as these
activities can be used to increase the quality of plankton, that is, the natural food of fish (Chakrabarty
and Hettiarachchi 1982). Fish farming can be combined with poultry, animal husbandry and irrigation
practices, which can lead to higher production and net profits. This practice is called integrated fish
farming or integrated aquaculture. The integration of animal husbandry, especially poultry, with fish
farming in a small scale results in the production of organic manure for the fertilization of the fish pond
to increase the production of the natural food organism (planktonic algae) to be eaten by the fish. In
some cases, the poultry wastes are used as direct food by some fish without supplementary feedings,
such species include Nile Tilapia (FAO, 1996).
Intensive livestock housing such as livestock-fish farming employs an environmental control
system to maintain animal health and welfare and raise production efficiency. The thermal
environment within an animal house can be defined in terms of air temperature, relative humidity,
thermal radiation and air velocity. Air temperature and sometimes relative humidity, are commonly
used as the criteria by which the rate of ventilation is controlled (Charles 1994).
Adverse environments can affect the incidence and severity of certain endemic diseases. For
example, a poor indoor microclimate, which is characterized by an inadequate thermal environment,
poor ventilation and high burden of aerial pollutants, can play a major role in the aetiology of enzootic
bronchopneumonia of calves and weaner pigs (Eikmeier and Mayer 1965).
Several authors have discussed and reported the effect of temperature on the milk yield of dairy
cow, the performance of fattening pigs and the egg yield of laying hens. The lower critical temperature
(LCT) defines the lower limit of the range of optimal temperature: the upper limit is given by the upper
critical temperature (UCT). LCT is affected by factors such as age, sex, breed, food energy level and
intake, feathering, stocking density, bedding system, etc. UCT values are rarely exceeded for housed
livestock in temperate climates but a serious problem in the tropical humid climate like Nigeria. The
CIGR commission recommended maximum and minimum values of relative humidity (RH) as a
function of indoor temperature, for example an RH of 50-90% at 0ºC followed by a steady decrease of
RH to a tolerable range of 40-60% at 30ºC.

807 F.R. Falayi, A.S. Ogunlowo and M.O. Alatise
The object of this study was to investigate the effect micro-climate parameters like temperature
and relative humidity in an integrated husbandry with respect to physiological, growth and health
aspects. The development of the fish and birds have been reported elsewhere.
Materials and Methods
Model poultry housing unit and concrete fishponds were designed and constructed using locally
available materials. Three wooden battery cages were mounted on the fish ponds. The set-up was made
of four concrete ponds on which three wooden battery cages were mounted except the fourth pond
which served as the control. The ponds were stocked with twenty (20) juvenile clarias garipinus each.
Fish in pond 1, 2 and 3 were fed with droppings from one broiler, two broilers and three broilers
respectively. While fish in ponds 4 were fed with the fish concentrate as shown in table 1.
Table 1: Feeding Table for Catfish Grow-out
Average weight (grams) Feeding level (%body weight) Pellet size (mm)
5-10 5.5-6.0 2.0
10-25 4.5-5.5 2.0
25-70 4.0-4.5 3.0
100-250 3.0-4.0 4.5
500-750 1.5-2.0 4.5
750-1000 1.1-1.5 4.5 or 6.0
1000-1250 0.9-1.1 4.5 or 6.0
1250-1500 0.8-1.0 4.5 or 6.0
1500-2000 0.7-0.9 4.5 or 6.0
A total of 6 birds (4 weeks old) and 80 juvenile clarias garipinus were used. This experiment
lasted for 6 months. During this period, the environmental parameters were monitored and the effect of
poultry waste on the fish development was observed.
Air temperature and humidity inside the husbandry were measured using a combined thermistor
and capacitive sensor with a range of 5 to 60ºC and 0-100% RH, respectively. The accuracy at 25ºC
was ± 0.5ºC and ± 2% RH. Data collected were stored using a data logger. The procedure is similar to
Seedorf et al 1998. The relationship between external and internal temperatures was analysed.
Direct analysis was used to determine water temperature (0C), Turbidity (NTU), pH,
Conductivity (μscm-1), Dissolved oxygen (mg/l) and Salinity (%) using Horiba U 10 portable water
analyser, while chemical analysis was used to determine chemical components which include; Nitrite,
Ammonia, colour, Biochemical oxygen demand (BOD), Chloride, Chemical oxygen demand (COD),
Dissolved oxygen (DO).
3. Integrated Poultry Housing Husbandry Description
The pond was designed mainly to give an enabling aquacultural environment for catfish. The pond was
made of hollow block of 150mm (6 inches). The pond was constructed on simple strip concrete
foundation and was divided into three cells of 1m each for different treatments. The wall was
adequately plastered with appropriate mixture of cement, sand and water and adequate precaution
against under cuts by water. One important characteristic of a modern fishpond is that it must be
drainable; this means that it should be possible to empty the pond down to the last drop of water hence
the floor of the pond was constructed at a slope of 0.2 for proper drainage. The ponds were supplied
with well water and drained through gate valves of 37mm (1 ½ inches).
The poultry-housing unit was designed to give appropriate ventilation system for good
performance of the birds. The floor dimension was 4.50m by 2.54m and total height of the building
was 3.14m. The poultry-housing unit was constructed using timber and steel, which are readily

Effects of Enviromental Variables on Poultry Performance and Pond Water Quality in an
Integrated Poultry/Fishery Farming 808
available materials with good strength and minimum cost. The roof was made of galvanized corrugated
roofing sheet. The cage was constructed using wood and wire mesh for the cage floor. The height of
the cage was 0.47m, length of 0.5m and width of 0.4m. The complete housing unit is as shown in
Fig.1.
Figure 1: Experimental set up of the integrated unit
4. Results and Discussion
Variation in pH level in the ponds
The pH value of the water in the various ponds through out the experiment varied between 5.9 and 7.0
in pond 1, 6.3 to 7.7 in pond2 and 6.6 to 7.8 in pond3. There were fluctuations in the values of the pH
in the ponds as shown in Fig 2. However the values of pH recorded in the ponds were within the
acceptable limit necessary for optimum growth of cat fish. The value of pH recorded at the control
pond was slightly higher than that obtained in pond 1. This must have been as a result of the
ingredients used in the preparation of the fish concentrates.
Figure 2: p H Values of water in the various ponds against weeks after stocking

809 F.R. Falayi, A.S. Ogunlowo and M.O. Alatise
Variation in the turbidity level in the ponds
The turbidity level in the various pond water throughout the period of the experiment is as shown in
Fig.3. The turbidity of the pond water increased through out the experiment. Highest value of turbidity
was recorded in pond3, followed by pond2 and pond1. The least value of turbidity was recorded in
control pond. This trend must have been as a result of the increased quantity of droppings into the
ponds. A linear relationship was established between turbidity of water in the ponds against the number
of weeks after stocking which showed a high correlation of 0.99. (R2 =0.99) as shown in Fig. 3.
Figure 3: Variations in the Turbidity against weeks after stocking
Variation in dissolved oxygen level in the ponds
The total dissolved oxygen (DO) in the various ponds throughout the experiment is as shown in Fig.4.
The value decreased significantly towards the end of the experiment in all the ponds. This development
might be as result of increase in the weight of the fish bringing about an increase in the quantity of
droppings from the birds. The poultry droppings is an organic material which has high BOD and
capable of utilising the oxygen in the water. Dissolved oxygen depletion was highest in pond3
followed by pond2 and pond1 and least oxygen depletion was recorded in control pond. When
compared with the tolerable (DO) standard level, the values of dissolved oxygen in ponds 1 and 2 were
within the limit suitable for fish culture but the DO level recorded in pond3 towards the end of the
experiment was below the standard required for effective catfish production and must have been
responsible for the retarded growth of fish in the pond.
Figure 4: Variations in the Dissolved oxygen in the water against weeks after stocking

Effects of Enviromental Variables on Poultry Performance and Pond Water Quality in an
Integrated Poultry/Fishery Farming 810
Variation in the chemical oxygen demand (COD) level in the ponds
The chemical oxygen demand (COD) increased in all the ponds from stocking to the end of the
experiment as shown in Fig.5. The COD level recorded in pond 3 was highest. This was expected
because of the quantity of droppings into the pond which increased with age of the birds. The COD test
was used to determine the oxygen equivalent of the organic matter that can be oxidised by a strong
chemical oxidising agent. Also as expected, the COD values in the ponds were greater than the BOD
values because more compounds could be oxidised chemically than could be oxidised biologically.
However, the value of COD recorded in control pond was the least.
Figure 5: Variations of COD in the pond water against Weeks After Stocking
Variation in the conductivity level in the ponds
Conductivity ranges in value from 0.42 to 0.82 μscm-1 through out the period of experiment as shown
in Fig. 6. It was observed that the conductivity level was unstable through out the period of the
experiment. A highest value of conductivity was noticed in pond3 and the least in control pond. The
high value of conductivity might be connected with the droppings into the ponds.
Variation in Colour of water
Figure 6: Variations in the conductivity against Weeks After Stocking
The colour of water in the various ponds is as shown in Fig.7. As expected, the highest value of colour
of water was recorded in pond3 and the least in control pond. The increased colour change in the ponds
corresponded with the quantity of droppings from the poultry birds and the age of the birds.

811 F.R. Falayi, A.S. Ogunlowo and M.O. Alatise
Figure 7: Variations in the colour of water against Weeks After Stocking
Variation in Bio-chemical oxygen demand (BOD) level in the ponds
The variation in the BOD level in the various ponds throughout the period of the experiment is as
shown in Fig.8. As expected, highest value of BOD was recorded in pond3 and least value was
recorded in pond1. The introduction of oxygen – demanding material like poultry droppings into pond
would expectedly caused the depletion of the dissolved oxygen in the water. This might pose a threat
or affect the development of the fish if the concentration falls below a critical point. A linear
relationship was established between the BOD level and weeks after stocking with a high correlation
(R2=0.98).
Figure 8: Variations in the Bio-chemical-oxygen - Demand of the water against Weeks after Stocking
Variation in chloride level in the ponds
Chloride level in the various ponds during the period of experiment is as shown in Fig.9. A highest
chloride level was observed in pond3 while the last was recorded in pond1. The value of chloride
recorded in pond 2 was more than that of control pond. The reason for this variation is not yet obvious
but might be due to the composition of the poultry feed. However the chloride level was considered
suitable for the growth of the fish when compared to the standard chloride level for fish (not less than
20 mg/l).

Effects of Enviromental Variables on Poultry Performance and Pond Water Quality in an
Integrated Poultry/Fishery Farming 812
Figure 9: Relationship between the chloride levels in the various ponds and Weeks After Stocking
Development of the Birds
The birds recorded an increasing weight gain throughout the period of the study. The average weight
during stocking to the end of the study varied from 0.7kg to about 9kg. There was no significant
difference at 5% level in the average weight of the birds in the various cages as shown in the ANOVA
table shown in table 7.1 and Fig.10 and this implied that the development of birds in the cages was
equal throughout the period of the study.
Figure 10: Relationship between the average weight of birds in different cages and weeks after Stocking
10000
9000
8000
7000
6000
5000
4000
3000
2000
1000
0
cage1
cage2
cage3
0 2 4 6 8 12 14 16 18 2 0 2 2 2 4
Weeks after stocking
Zero mortality was recorded throughout the period of study and this confirmed that the
environmental conditions of the housing unit were suitable for poultry production. A log-log plot of the
weight of birds and time is shown in Fig. 11. This graph is a straight line which relates the growth of
weight of birds as a power of time and similar to the observations of Kettlewell, P. J. and Moran, P.
(1992) and Aerts et-al (2000).

813 F.R. Falayi, A.S. Ogunlowo and M.O. Alatise
logM
Figure 11: LogM versus Logt
y = 0.8772x - 0.3361
R 2 1.2
1
0.8
0.6
0.4
0.2
0
= 0.9237
-0.2
-0.4
-0.6
0 0.5 1 1.5
logt
logM
Linear (logM )
Monitoring of Environmental Parameters
Environmental parameters such as humidity and temperature outside and inside the husbandry were
monitored as these would affect the welfare of the birds.
Relative Humidity Variations
The relative humidity within and outside the integrated aquaculture in the morning, afternoon and
evening is as shown in the graphs in Fig.12, 13, and 14. The graphs indicated that the relative humidity
within the integrated aquaculture in most cases was higher than that of the outside. In the morning
there was a marked difference between the indoor and outdoor relative humidity. The relative humidity
outside varies from 77.7% to 96.8% while the relative humidity inside varies from 83.6% to 98.8%.
The increase in relative humidity resulted from evaporation of water from the pond surface. This is a
very high relative humidity and could influence the growth of disease causing micro-organisms, which
could adversely affect the well being of the birds. However, no incidence of disease was recorded
throughout the period of the experiment because of lower temperature and increased management
practices. Since a battery cage system was used for the birds, it was not possible for the birds to
contaminate the feed and the water.
Figure 12: Relative humidity Outside and Inside the Building in the Morning
Relative hmidity 0 C
100
95
90
85
80
75
0 5 10 15 20 25 30 35 40 45 50 55
No of Days
Rhout
RHin

Effects of Enviromental Variables on Poultry Performance and Pond Water Quality in an
Integrated Poultry/Fishery Farming 814
Figure 13: Relationship between relative humidity inside and outside in the Afternoon
Relative Humidity (%)
80
70
60
50
40
30
20
0 20 40 60
No of Days
Figure 14: Relationship between relative humidity inside and outside the building in the evening
Relative Humidity(%)
100
90
80
70
60
50
40
RHin
30
0 20 40 60
No of Days
In the afternoon, the relative humidity outside and inside the building followed the same pattern
and no clear difference was observed. This might be as a result of an increase in wind movement. The
relative humidity inside varies from 43.2% to 81.5% while the relative humidity outside varies from
40% to 82.7%.
In the evening, the pattern was not different from that of the morning, which implied that the
relative humidity conditions inside, the building was slightly higher than that of outside. The relative
humidity inside varied from 57% to 89.3% while the relative humidity outside varies from 56.6% to
87.6%, which was normal and within the comfort zone as stated by Seedorf, et al (1998).
Temperature Variations
The indoor and outdoor temperature varied with the periods of the day. In the morning the indoor
temperature was usually greater than that of outdoor temperature but in the afternoon the outdoor
temperature was a slightly higher than the indoor temperature. The indoor temperature in the morning
varied from 21.2 ºC to 27.1 ºC while the outdoor temperature varies from 21.7 ºC to 27.3 ºC as shown
in Fig.15. In the afternoon, the indoor temperature varied 26.1ºC to 34.6ºC while the outdoor
temperature varied from 26.9ºC to 36.3ºC as shown in Fig.16. In the evening, outside and inside
temperatures followed the same pattern as shown in Fig 17. The outdoor temperature varied from
25.2ºC to 33ºC while the inside temperature varied from 25.2ºC to 32.7ºC. This is considered normal
and within the thermo neutral or comfort zone of the birds (Van Kampen, 1997).
Rhout
RHin
Rhout

815 F.R. Falayi, A.S. Ogunlowo and M.O. Alatise
Figure 15: Temperature Outside and Inside the Building in the Morning
Temperatures
28
27
26
25
24
23
22
21
20
0 5 10 15 20 25 30 35 40 45 50 55
No of Days
Figure 16: Relationship between outside and inside temperatures in the afternoon
Figure 17: Relationship between temperatures outside and inside the building in the Evening
Temperatures ( 0 C)
35
30
25
20
15
0 20
No of Days
40 60
Conclusions
An integration of Poultry and Fishery system has been developed for the purpose of optimal
productivity and the following conclusions can be drawn from the research study; it has been possible
to integrate poultry and fishery husbandry and the waste generated by the poultry serving as a feed for
the fish. Droppings from a broiler that was given unlimited access to feed and water was capable of
feeding twenty clarias gariepinus to an average weight of about six hundred grammes (0.6 Kg) without
using any other feed. The system has shown the possibility of effective poultry waste management
technique which ensured that nothing is wasted and waste handling problem is grossly reduced.
Tout
Tin
Tout
Tin

Effects of Enviromental Variables on Poultry Performance and Pond Water Quality in an
Integrated Poultry/Fishery Farming 816
Pollution resulting from the use of poultry droppings adversely affected the development of the
fish. Increase in the volume of droppings led to increase in the Bio-Chemical oxygen demand and
Chemical Oxygen demand of the pond water which consequently led to a decrease in the dissolved
oxygen. Water turbidity also increased with increased droppings. Other water parameters like
conductivity, chloride and pH values were within acceptable values suggested in literatures.
References
[1] Chakrabarty R. D. & A. Hettiarachchi (1982). ‘Preliminary Observations on Fish Polyculture
cum Duck raising in a Farm Pond in Sri Lanka’, Jour Inland Fish. Sri Lanka, Vol 1. 54–61.
[2] Chandrasoma J. (1988). Observations on Marketing of fish produced in seasonal tanks', Jour
Inland Fish Sri Lanka, 4: 63–67.
[3] Charles D.R. (1994). Comparative climatic requirements. In: Livestock Housing (Wathes C.M;
Carles D.R. eds) CAB international.pp. 3-24.
[4] CIGR (1984). Climatisation of animal houses. Report of working group. Scottish Farm building
Investigation Unit, cribastone, Aberdeen, Scotland.
[5] Eikmeier H., Mayer H. (1965). The economic importance of the enzootic pneumonia of pigs.
Berliner Munchener Tierartliche Wochenschrift. 78, 449-450.
[6] Seedorf J.; Hartung J; Schroder M; Linkert K.H.; Petersen S; Takai H; Johnson J.O.; Metz
J.H.M; Groot P.W.G.; Uenk G.H.; Philips V.R.; Holden M.R.; Sneath R.W. Short J.L.; White
R.P. and Wathes C.M.A (1998) Temperature and Moisture conditions in Livestock Buildings in
Northern Europe. J. agric Engng Res 70, 49-57
[7] Woynarovich E. (1979). The feasibility of combining animal husbandry with fish farming, with
special reference to duck and pig production. In: Advanced in Aquaculture, T. V. R. Pillay and
W. A. Dill (eds.). Fishing News Books Ltd. Farnham, Surrey, England, pp. 203–208

European Journal of Scientific Research
ISSN 1450-216X Vol.20 No.4 (2008), pp.817-827
© EuroJournals Publishing, Inc. 2008
http://www.eurojournals.com/ejsr.htm
Spatial Distribution and Characterisation of the Sediments of
the Estuary of Comoe River (Grand-Bassam, Côte D’ivoire)
Adopo Kouassi Laurent
Laboratoire de Géologie Marine, Sédimentologie et Environnement
Centre de Recherche en Ecologie, Université d’Abobo-Adjamé
01 BP 10588 Abidjan 01 (Côte d’Ivoire)
E-mail: l_adopo@yahoo.fr
Tel: (225) 21 25 73 36/08 49 61 00; Fax. (225) 21 24 01 91
Kouassi Kouakou Lazare
Laboratoire de Géologie Marine, Sédimentologie et Environnement
Centre de Recherche en Ecologie, Université d’Abobo-Adjamé
01 BP 10588 Abidjan 01 (Côte d’Ivoire)
E-mail: k_lazare@yahoo.fr
Tel: (225) 21 25 73 36/05 61 23 06; Fax. (225) 21 24 01 91
Wognin Ama Valérie Irma
Laboratoire de Géologie Marine et Sédimentologie
UFR-Sciences de la Terre et des Ressources Minières
Université de Cocody, 22 BP 582 Abidjan 22 (Côte d’Ivoire)
E-mail: ama_valerie@yahoo.fr
Tel: (225) 22 48 38 02/07 90 49 62
Monde Sylvain
Laboratoire de Géologie Marine et Sédimentologie
UFR-Sciences de la Terre et des Ressources Minières
Université de Cocody, 22 BP 582 Abidjan 22 (Côte d’Ivoire)
E-mail: ama_valerie@yahoo.fr
Tel: (225) 22 48 38 02/08 76 75 77
Meledje N’Diaye Hermann
Laboratoire de Géologie Marine, Sédimentologie et Environnement
Centre de Recherche en Ecologie, Université d’Abobo-Adjamé
01 BP 10588 Abidjan 01 (Côte d’Ivoire)
E-mail: meledjendiay@yahoo.fr
Tel: (225) 21 25 73 36/09 93 96 17; Fax. (225) 21 24 01 91
Aka Kouamé
Laboratoire de Géologie Marine et Sédimentologie
UFR-Sciences de la Terre et des Ressources Minières
Université de Cocody, 22 BP 582 Abidjan 22 (Côte d’Ivoire)
E-mail: akaraphael@yahoo.fr
Tel: (225) 22 48 38 02/08 87 30 97

Spatial Distribution and Characterisation of the Sediments of the Estuary of
Comoe River (Grand-Bassam, Côte D’ivoire) 818
Abstract
A sedimentological study was carried out at the estuary of Comoe river with the
perpose of determining, using the granulometric and mineralogical characteristics, the
origin, the transport process and the space distribution of sediments. In the estuary of
Comoe river, one distinguishes in the downstream sector a prevalence of mud and fine
sands. In the upstream sector sands are mainly middle to coarse in size. The muds are
localised in the vicinities of the banks while sands are in the principal channel of the river.
The mineral found in the sediments is characterised by heavy minerals (the
amphibole, tourmaline, diopside and epidote) and light minerals (quartz and feldspaths).
The morphoscopy of the quartzs revealed the prevalence of rounded and bright
particles, representing a fluviatile transport at a relatively long distance.
Keywords: sediment, sand, estuary, Comoe, Grand-Bassam, Côte d’Ivoire
1. Introduction
Les estuaires, zones de rencontre entre le fleuve et la mer, présentent une dynamique assez complexe
(LE NORMANT, 1995). En effet, les dépôts des particules transportées par les eaux fluviales et
marines façonnent la morpho-structure des paysages estuariens.
En Côte d’Ivoire, ABE (1995) et WOGNIN (2004) ont mis en évidence les conséquences de la
dynamique de l’embouchure du fleuve Bandama. Celles-ci se traduisent par un déplacement progressif
de cette embouchure vers l’Ouest.
Au niveau de l’embouchure de la Comoé à Grand-Bassam, zone de rencontre entre l’Océan
Atlantique, la lagune Ebrié et le fleuve Comoé, la dynamique hydrosédimentaire est encore plus
spectaculaire si bien que les dépôts successifs de sédiments donnent naissance à un banc de sables qui
rompt le contact naturel entre le fleuve et l’océan (KOFFI et al., 1991). Des travaux de dragage ont été
effectués pour ouvrir cette embouchure qui s’est toujours refermée quelques années plus tard
(TASTET, 1979; ABE et al., 1996; ABE, 2005). Ainsi, des opérations d’ouverture ont respectivement
eu lieu en 1987, 1990 et 2005 après les colmatages observés en 1975, 1989 et 2003. Aujourd’hui, cette
embouchure reste toujours fermée et entraîne le confinement du milieu estuarien, la surcharge des eaux
fluvio-lagunaires et l’envahissement des plans d’eau par les végétaux flottants (SANKARE et ETIEN,
1991; SANKARE et al., 1991). Ces travaux de dragage se sont soldés par des échecs à cause de la non
maîtrise de la dynamique sédimentaire qui contrôle le fonctionnement de cette embouchure. Les
travaux de ABE et al. (1996) ont révélé que le caractère irrégulier des débits du fleuve Comoé pourrait
expliquer, en partie, cette fermeture. En effet, selon ces auteurs, la réduction significative des débits de
ce cours d’eau pendant les périodes d’étiage, notamment au cours de ces dernières décennies du fait de
l’influence des fluctuations climatiques, favorise les phénomènes de sédimentation. La conjugaison des
dépôts fluviatiles et du transit littoral occasionne le colmatage rapide de l’embouchure du fleuve
Comoé.
Cependant, ces études ne mettent ni l’accent sur la caractérisation des sédiments du fond au
niveau de l’embouchure ni sur la dynamique sédimentaire. Or, l’approche géologique permet de
comprendre les multiples variations historiques et de reconstruire les étapes d’évolution de
l’environnement (AMEY et al., 2007).
L’objectif de cette étude est de caractériser les sédiments déposés à l’estuaire du fleuve Comoé
afin de connaître leur origine, leur mode de transport et leur répartition spatiale.

819 Adopo Kouassi Laurent, Kouassi Kouakou Lazare, Wognin Ama Valérie Irma
Monde Sylvain, Meledje N’Diaye Hermann and Aka Kouamé
2. Site et Méthodes
2.1. Site D’étude
Le secteur estuarien du fleuve Comoé est à l’extrémité orientale de la lagune Ebrié. Il est situé entre
5°12’ et 5°14’ de latitude Nord et 3°42’ et 3°44’ de longitude Ouest. Cette zone constitue le plus vaste
estuaire du littoral ivoirien (KOFFI et al., 1991). La zone d’étude couvre les environs de l’île Morin au
Nord, le pont de Moossou à la confluence du fleuve Comoé et de la lagune Ebrié, l’île Bouet et le
cordon littoral au Sud. Elle inclue le bras du cours du fleuve Comoé jusqu’au village de Yaou au Nord-
Est (Figure 1). La zone estuarienne est alimentée par le Comoé qui draine tout l’arrière pays et couvre
une superficie de 78000 km 2 .
Figure 1: Localisation de la zone d’étude
Libéria
Mali
Bassin de
la Comoé
Océan
Atlantique
Banc de sable
Burkina-Faso
La grande partie du bassin versant de la Comoé est située sur le socle appartenant au vieux
bouclier précambrien de l’Afrique de l’Ouest (AVENARD, 1971). Le sous-bassement de cette partie
du bassin est composé de différents types de roche-mères dont les principales sont les granites, les
migmatites et les roches métamorphiques. La zone de Grand-Bassam se localise dans la zone centrale
du bassin sédimentaire où on observe des formations miopliocène à quaternaire (TASTET, 1979;
DELOR, 1992).
Ghana

Spatial Distribution and Characterisation of the Sediments of the Estuary of
Comoe River (Grand-Bassam, Côte D’ivoire) 820
Les travaux de PERRAUD (1971) ont permis de distinguer différents types de sols sur le bassin
de la Comoé. Les formations pédologiques les plus prépondérantes sont les sols ferrallitiques parsemés
de quelques lambeaux de sols bruns eutrophes tropicaux dérivés de roches basiques.
Le régime hydrologique du fleuve Comoé est caractérisé par le régime tropical de transition au
Nord, le régime tropical de transition atténué au Centre et le régime équatorial de transition au Sud. Les
écoulements observés au Sud du bassin de la Comoé sont fortement influencés par le régime tropical
de transition du Nord. Ce régime comporte généralement une seule période de hautes eaux (aoûtseptembre-octobre),
suivie d’un tarissement rapide de novembre à décembre.
2.2. Méthodes D’étude
Pour déterminer les caractéristiques granulométriques des sables de l’estuaire du fleuve Comoé, 24
échantillons de sédiments ont été prélevés sur huit (8) radiales allant d’une berge à une autre à l’aide
d’une benne Van Veen (voir figure 1).
Les sédiments ont été traités selon la technique décrite par SAAIDI (1991). Les matières
organiques et les débris coquilliers ont été éliminés respectivement à l’aide de l’eau oxygénée 30% et
de l’acide chlorhydrique 50%. Après élimination de la fraction inférieure à 63 μm, chaque échantillon
de sable a subi une analyse granulométrique à sec sur une colonne de 16 tamis (série AFNOR). Les
sables de l’estuaire ont été caractérisés à travers la moyenne granulométrique (Mz), le skwness (Sk) et
l’indice de classement (So), déterminés à l'aide des méthodes de FRIEDMAN (1967) et FOLK (1974).
Les cartes sédimentologiques et les cartes de positionnement ont été réalisées à l’aide des
logiciels ArcView 3.3 et SURFER 8.2.
3. Résultats et Discussion
3.1. Description et cartographie des faciès sédimentaires superficiels
3.1.1. Description des faciès sédimentaires
L’analyse granulométrique des sédiments superficiels de l’estuaire du fleuve Comoé met en évidence
trois faciès lithologiques. Il s’agit des sables, des vases et des sédiments "mixtes" (Tableau I).

821 Adopo Kouassi Laurent, Kouassi Kouakou Lazare, Wognin Ama Valérie Irma
Monde Sylvain, Meledje N’Diaye Hermann and Aka Kouamé
Table I: Granulométrie et description des sables de l’estuaire du fleuve Comoé
Ech.
Positions
Longitude Latitude
Faciès sédimentaires Mz (µm) Sk So
1* 429324 581026 Vase fluide noirâtre; très riche en matières organiques < 63 (-) (-)
2 429324 580827 Sables grossiers, jaune roux, modérément classés 765 0,66 0,95
3 429324 580477 Sables très fins de couleur grise; modérément classés à mal classés 115 0,82 0,23
4* 425629 580028 Vase fluide noirâtre; très riche en matières organiques < 63 (-) (-)
5 425629 579728 Sable grossiers, jaune roux, modérément classés 625 0,75 0,55
6 425629 579479 Sables fins de couleur grise; modérément classés à mal classés 135 0,85 0,25
7 421485 578181
Vases sableuses de couleur grise olive à noire olive; modérément
classée à mal classée
73 0,81 0,29
8 421485 577981
Sables moyens, jaune roux à grisâtre; modérément classés; présence de
quelques débris coquilliers
482 0,68 0,45
9 421485 577731 Sables fins de couleur grise; modérément classés à mal classés. 240 0,85 0,26
10* 419885 577132
Crème de vase de couleur verdâtre; présence de débris végétaux et
coquilliers
< 63 (-) (-)
11* 420085 577132 Vase fluide verdâtre; riche en matières organiques < 63 (-) (-)
12 420387 577132
Vase sableuse de couleur gris olive à noire olive; modérément classée
à mal classée
68 0.83 0,27
13* 419638 577931 Vase fluide noirâtre; très riche en matières organiques < 63 (-) (-)
14 420636 577931
Sables moyens, jaune roux à grisâtre; modérément classés; présence de
quelques débris coquilliers
412 0.76 0,50
15 420037 577931
Vase sableuse de couleur grise olive à noire olive modérément classée
à mal classée
67 0,84 0,29
16 419438 576384
Sables moyens, jaune roux à grisâtre avec quelques débris coquilliers;
modérément classée
358 0,66 0,52
17 420087 576384
Sables moyens, jaune roux à grisâtre; modérément classés; présence de
quelques débris coquilliers
459 0,78 0,55
18 420489 576384
Sables moyens, jaune roux à grisâtre; modérément classés; présence de
quelques débris coquilliers
476 0,77 0,48
19* 419138 575584 Crème de vase grisâtre; riche en matières organiques < 63 (-) (-)
20* 419488 575584 Crème de vase grisâtre; présence de débris végétaux et coquilliers < 63 (-) (-)
21* 419788 575584 Vases fluides noirâtre; très riche en matières organiques < 63 (-) (-)
22 419388 574836 Sables fins de couleur grise; modérément classés à mal classés 158 0,86 0,30
23 419588 574836 Sables fins de couleur grise; modérément classés à mal classés 213 0,80 0,31
24 419887 574836 Sable très fin de couleur grise; modérément classés à mal classés 120 0,82 0,28
Ech. Echantillon; * Station à proximité de la rive; (-) paramètres non identifiés
La granulométrie des sables contenus dans les sédiments prélevés révèle que les grains sont très
fins à grossiers (Ech. 2, 3, 5, 6, 8, 9, 16, 17; 18, 23, 24). La couleur des sables est brun-jaunâtre à degré
variable. On trouve dans les sédiments quelques débris végétaux et coquilliers. La granulométrie de ces
sables augmente lorsqu’on tend vers lit du cours d’eau. Par ailleurs, les sables sont plus grossiers en
amont qu’en aval.
Les vases sont de couleur variable et se localisent aux voisinages des berges (Ech. 1, 4, 10, 11,
13, 19, 20, 21). Les vases fluides sont noirâtres et très riches en matières organiques. La crème de vase
présente une couleur grisâtre et est riches en matières organiques.
Les sédiments "mixtes" (Ech. 7, 12, 15) sont constitués de sables vaseux et de vases sableuses.
Leur coloration varie du noir olive au gris olive. Ils contiennent à la fois des débris végétaux et
coquilliers.
3.1.2. Répartition spatiale des teneurs en fractions granulométriques
Sur le plan spatial, la distribution des sédiments n’est pas homogène à l’estuaire du fleuve Comoé
(Figure 2). Les sables moyens à grossiers se rencontrent dans le lit principal du fleuve. Leur
granulométrie diminue de l’amont vers aval. La moyenne granulométrique des sables est comprise
entre 240 et 765 µm. Les indices de classement se situent entre 0,58 et 1,12 avec une moyenne de 0,85.
Ceci indique que les sables dans l’estuaire sont modérément classés à mal classés. Les indices
d’asymétrie (skewness) s’étendent de 0,06 à 0,25 indiquant une forte asymétrie vers les petites tailles.

Spatial Distribution and Characterisation of the Sediments of the Estuary of
Comoe River (Grand-Bassam, Côte D’ivoire) 822
Aux voisinages des îles Bouet et Morin ainsi qu’à la confluence de la lagune Ouladine, les
sables sont fins à très fins (67 < Mz < 120).
Au niveau des berges, zones occupées par les végétaux flottants depuis la fermeture de
l’embouchure, on rencontre uniquement des vases fluides et de la crème de vase, riches en matières
organiques. Aussi, à proximité de l’embouchure, trouvent-on, en abondance (plus de 80% des
sédiments) des vases fluides de couleur noire olive. Cette zone constitue ainsi une vasière interne en
relation avec les apports du fleuve Comoé.
Dans le bras de la lagune Ebrié, le faciès granulométrique est caractérisé par des sables vaseux.
Les sédiments sont très bien classés et témoignent de l’extrême turbulence de cette zone même pendant
la phase d’accumulation sableuse.
585000
580000
575000
Figure 2: Répartition des faciès de surface des sédiments dans l’estuaire du fleuve Comoé
Lagune
Ouladine
Lagune Ebrié
415000 420000 425000 430000
3.2. Mode de transport des sédiments
Embouchure fermée
Fleuve Comoé
0 4km
Moyenne
granulométrique (µm)
Légende
< 63
63 -250
250 - 500
> 500
Ile morin
Ile bouet
Banc de sable
Les courbes granulométriques des sables du fleuve Comoé présentent plusieurs allures (Figure 3).
L'application du test de VISHER (1969) aux sédiments de l’estuaire du fleuve Comoé indique que les
sables sont transportés majoritairement par saltation (environ 75%). Le transport par charriage qui
vient au second plan représente une proportion relativement faible (environ 15%), de même que le
transport en suspension qui ne représente qu'environ 10%.
Océan

823 Adopo Kouassi Laurent, Kouassi Kouakou Lazare, Wognin Ama Valérie Irma
Monde Sylvain, Meledje N’Diaye Hermann and Aka Kouamé
Figure 3: Courbes granulométriques de quelques échantillons de sables de l’estuaire du fleuve Comoé
Suspension
Saltation
Charriage
10000 1000
100 diamètre( µm)
%
100
95
90
85
80
75
70
65
60
55
50
45
40
35
30
25
20
15
10
5
0
10
3.3. Morphoscopie et minéralogie des sables
3.3.1. Morphoscopie du quartz
L’observation à la loupe binoculaire des différents échantillons a permis de constater que la plupart des
grains de sables observés sont ronds, luisants et anguleux luisants (Figure 4). Les grains ronds luisants
sont dominants dans l’ensemble des stations (79 %). Cependant, autour des îles, les grains anguleux
luisants sont dominants dans les sables (en moyenne 80 %).
L’aspect anguleux luisants des grains de quartz dans la plupart des échantillons indique leur
origine allochtone.
Figure 4: Aspect des minéraux de l’estuaire du fleuve Comoé
Grains ronds luisants Grains anguleux luisants
st1
st2
st3
st4
st5
st6
st7
st8

Spatial Distribution and Characterisation of the Sediments of the Estuary of
Comoe River (Grand-Bassam, Côte D’ivoire) 824
3.3.2. Morphométrie du quartz
La plupart des grains de sable de l’estuaire ont des indices d’aplatissement et des indices de
dissymétrie relativement voisins, à l’exception de la radiale 5 ou on enregistre des valeurs plus élevées
(Tableau II).
Table II: Description de la morphométrie du quartz de l’estuaire du fleuve Comoé
Position
Longitude Latitude
Indice d’aplatissement Indice de dissymétrie Origine des grains
Radiale 1 429324 581026 1,05 0,58 lointaine
Radiale 2 425629 580028 1,10 0,65 lointaine
Radiale 3 421485 577981 1,11 0,45 lointaine
Radiale 4 420085 577132 1,10 0,56 lointaine
Radiale 5 420636 577931 2,30 0,89 proche
Radiale 6 420087 576384 1,98 0,55 lointaine
Radiale 7 419488 575584 1,15 0,55 lointaine
Radiale 8 419887 574836 1,15 0,35 lointaine
3.3.3. Minéralogie
L’analyse minéralogique des échantillons de sables de l’estuaire du fleuve Comoé fait ressortir un
spectre minéralogique caractérisé par un ensemble de minéraux lourds et de minéraux légers (Figure
5). Les minéraux lourds rencontrés dans la fraction sableuse sont essentiellement des nésosilicates
grenat (2%), on trouve aussi des inosilicates représentés par l’amphibole (2%) et le pyroxène (4%), du
cyclosilicate représenté par la tourmaline jaune (3%) et du sorosilicate représenté par l’épidote (2%).
Parmi les minéraux légers, on retrouve des tectosilicates représentés par le quartz (77%) et le
feldspath (3%). On rencontre aussi du phyllosilicate représenté par le micas (7%).
Figure 5: Cortège minéralogique de sédiment de l’estuaire du fleuve Comoé
Tourmaline
3%
Pyroxène
4%
Micas
7%
Feldspath
3%
Grenat
2%
Amphibole
2%
Epidote
2%
Quartz
77%

825 Adopo Kouassi Laurent, Kouassi Kouakou Lazare, Wognin Ama Valérie Irma
Monde Sylvain, Meledje N’Diaye Hermann and Aka Kouamé
4. Discussion
Les analyses granulométriques et minéralogiques montrent que la distribution des sédiments n’est pas
homogène dans l’estuaire de la Comoé. Les vases et les sables fins se localisent aux voisinages des îles
et des berges, zones fortement colonisées par les végétaux aquatiques envahissants. La présence de
vases sur les berges peut s’expliquer par la décomposition suivie de la sédimentation des végétaux
aquatiques et de la végétation en bordure du cours d’eau. Par ailleurs, les vitesses des courants qui sont
relativement faibles sur les berges favorisent la décantation des matières organiques.
La localisation des sables moyens et grossiers dans le lit du fleuve Comoé peut s'expliquer par
l'énergie du courant qui paraît relativement plus importante dans cet axe dont la pente est plus
accentuée que les autres parties du fleuve. Dans la partie amont de l’estuaire et notamment dans le bras
du fleuve (vers yaou), les sables sont plus grossiers qu’en aval (vers l’embouchure). En effet, la
fermeture de l’embouchure crée un plan d’eau où les actions hydrodynamiques sont relativement
faibles. KOUASSI (2007) et KOUASSI et al. (2007) rapportent qu’à l’entrée des plans d’eau les
éléments grossiers se déposent à la suite d’une diminution de la compétence du transport des cours
d’eau.
L’analyse minéralogique des sables révèle la présence de minéraux lourds tels l’amphibole
(actinote, hornblende), le rutile, la limonite, le diopside et le zircon. La présence de minéraux légers,
notamment le quartz et les feldspaths, dans chaque sédiment est aussi remarquable. Ces minéraux font
partie de ceux décrits par BROCHE et al. (1977) dans la partie supérieure du bassin versant du fleuve
Comoé. La répartition des minéraux révèle une origine continentale détritique issue des formations de
l'arrière-pays.
L’examen morphoscopique montre l’omniprésence des grains arrondis luisants dans l’ensemble
de l’estuaire. Ce qui met en évidence l’influence du transport par l’eau des sédiments et de la
dynamique fluviale. Les valeurs des différents indices d’aplatissement et de dissymétrie montrent que
les grains de sables rencontrés dans l’estuaire ont subi un transport fluviatile sur une longue distance.
Ce qui confirme les résultats de l’étude morphoscopique. Toutefois, les échantillons prélevés aux
voisinages de l’île Morin (radiale 5) sont anguleux et ont leurs indices d’aplatissement et de
dissymétrie élevés. Ce qui montre ces sables sont issus de l’altération des roches en place.
5. Conclusion
Les analyses granulométrique et minéralogique ont montré que les sédiments rencontrés dans l’estuaire
du fleuve Comoé sont constitués de vases, de sables fins, de sables moyens et de sables grossiers. Ces
sables sont majoritairement moyens à grossiers en amont de l’estuaire et fins à très fins vers
l’embouchure.
L’aspect arrondi et luisant des grains de sables dans la plupart des échantillons prélevés montre
que les sables rencontrés dans l’estuaire proviennent de la partie amont du bassin et ont été transportés
sur une distance relativement longue par l’eau.
Le cortège minéralogique renferme à la fois des minéraux lourds tels que l’amphibole (actinote,
hornblende), la tourmaline, le diopside et l’épidote et des minéraux légers parmi lesquels le quartz est
le plus abondant. Cette étude a montré que la distribution des sédiments n’est pas homogène dans
l’estuaire du fleuve Comoé. Les vases et les sables fins se retrouvent du aux voisinages des berges et
près de l’île Bouet représentant les zones fortement occupées par les végétaux aquatiques envahissants.
Les travaux se poursuivent dans le but d’étudier les facteurs influençant la répartition spatiale
des sédiments dans l’estuaire du fleuve Comoé et prévoir l’évolution, à moyen et long terme, des
phénomènes de sédimentation. Les résultats devraient permettre de simuler, à terme, le fonctionnement
hydrosédimentaire de l’embouchure du fleuve Comoé.

Spatial Distribution and Characterisation of the Sediments of the Estuary of
Comoe River (Grand-Bassam, Côte D’ivoire) 826
6. Remerciements
Cette recherche a fait l’objet d’un soutien financier et logistique de la Fondation Internationale pour la
Science (IFS, Suède). Nous adressons nos sincères remerciements à cette institution pour sa
contribution à nos travaux.
References
[1] ABE J. (1995). Etude comparative de la dynamique sédimentaire aux embouchures des fleuves
du littoral ivoirien. Proc. Int. Conf. “Costal change 95“ Bordomer-IOC, Bordeaux: 347-363.
[2] ABE J. (2005). Contribution à la connaissance de la morphologie et de la dynamique
sédimentaire du littoral Ivoirien (cas du littoral d’Abidjan): Essais de modélisation en vue d’une
gestion rationnelle, Thèse de doctorat d’Etat Sc. Nat. Abidjan. 309p.
[3] ABE J., BAKAYORO S., BAMBA S., CISSOKO S. (1996). L’hydrologie de l’estuaire du
Comoé à Grand-Bassam (Côte d’Ivoire) Agronomie Africaine. Journal ivoirien d’océanologie
et de liminologie. 8 (3): 201-212.
[4] AMEY K. B., BEDJA K., NEGLO K. (2007). Distribution longitudinale de la granulométrie du
sable littorale togolais: grain moyen, sorting index et skewness. Journal des Sciences pour
l’Ingénieur. N°8: 1 - 8.
[5] AVENARD J.M. (1971). Aspect de la géomorphologie. in: "Le milieu naturel de Côte
d’Ivoire", mém. ORSTOM, Paris, n° 50: 1-72.
[6] BROCHE., CASSANOVA R., LOUP G. (1977). Atlas des minéraux en grain Identification par
photographies en couleurs, 171 pp.
[7] DELOR C., DIABY et TASTET J-P. (1992). Notice explicative de la carte géologique de la
Côte d’Ivoire à 1/200.000, feuille Grand-Bassam, mémoire de la Direction de la géologie de
Côte d’Ivoire, n°4, Abidjan Côte d’Ivoire.
[8] FOLK R. L. (1974). Petrology of sedimentary rocks. Austin, Texas: Hemphills, 182 P.
[9] FRIEDMAN G. M. (1967). Dynamic processes and statistical parameters compared for size
frequency distribution of beach and river sands. Journal of Sedimentary petrology 37(2): 327-
354.
[10] KOFFI. K & ABE J. (1991). Contribution à l’étude des modifications hydro-sédimentaires
consécutives à la réouverture artificielle de l’embouchure du Comoé à Grand-Bassam. Journal
Ivoirien d’Océanologie et Limnologie: Vol. 1, n°2, 47-60.
[11] KOUASSI K. L. 2007. Hydrologie, transport solide et modélisation de la sédimentation dans
les lacs des barrages hydro-électriques de Côte d’Ivoire: cas du lac de Taabo (Côte d’Ivoire).
Thèse de doctorat, Univ. d’Abobo-Adjamé, 209p.
[12] KOUASSI K. L., Wognin A. V. I., Gnagne T., N’go Y. A., Courivaud J-R, Kassy P., Demé M.
& Aka K., 2007. Caractérisation des sables et morphologie du fond du lac du barrage
hydroélectrique de Taabo (Côte d’Ivoire). Science & Nature, 4(1): 93-103.
[13] LE NORMANT C. (1995). Modélisation numérique tridimensionnelle des processus de
transport des sédiments cohésifs en environnement estuarien. Thèse de doctorat, Institut
National Polytechnique de Toulouse; spécialité physique et chimie de l’environnement.
N°1002, 253p.
[14] PERRAUD A. (1971). Les sols. in: "Le milieu naturel de Côte d’Ivoire". Mém. ORSTOM,
Paris, n°50: 265-391.
[15] SAAIDI E. (1991). Traité de sédimentologie. Pétrographie, environnements sédimentaires.
Edition Ellipes, 393p.
[16] SANKARE Y., ETIEN N. (1991). Analyse des effets de l’ouverture du chenal de Grand
Bassam (estuaire du fleuve Comoé, Lagune Ebrié) sur la macrofaune benthique lagunaire.
Journal Ivoirien d’Océanologie et Limnologie, 1 (2): 81-90.

827 Adopo Kouassi Laurent, Kouassi Kouakou Lazare, Wognin Ama Valérie Irma
Monde Sylvain, Meledje N’Diaye Hermann and Aka Kouamé
[17] SANKARE Y., KOTHIAS A. J-B., KONAN A. A. (1991). Les effets de la réouverture de
l’embouchure du fleuve Comoé sur la végétation littorale lagunaire (Lagune Ebrié – Côte
d’Ivoire). Journal Ivoirien d’Océanologie et Limnologie, 1 (2): 71-79.
[18] TASTET J. P. (1979): Environnements sédimentaires et structuraux quaternaires du littoral du
Golfe de Guinée (Côte d’Ivoire, Togo et Bénin). Thèse de doctorat, Univ. Bordeaux I, n°621,
175p.
[19] VISHER G.S. (1969). Grain-size distributions and depositional processes. Journal of
Sedimentary Petrology 39(3): 1074-1106.
[20] WOGNIN A. V. I. (2004). Caractérisation hydrologique et sédimentologique de l’embouchure
du fleuve Bandama. Thèse de doctorat, Univ. de Cocody, 198p.

European Journal of Scientific Research
ISSN 1450-216X Vol.20 No.4 (2008), pp.828-835
© EuroJournals Publishing, Inc. 2008
http://www.eurojournals.com/ejsr.htm
Blind SIMO GSM Channel Identification
Taba Mohamed Tahar
LAIG Laboratory, Guelma University, Algeria
E-mail: mttaba@yahoo.fr
S. Femmame
LACSC Laboratory, ECE Paris, France
D. Mossadeg
Electronic Department, Annaba University, Algeria
Abstract
The bandwidth efficiency of many communication systems could be improved if
the transmission channel was estimated blindly, i.e. without resort to training sequences.
GMSK is a spectrum-efficient modulation scheme, and it is adopted as the modulation
standard of GSM systems. However, because of its phase modulation, Gaussian filtering,
and partial response signalling properties, GMSK is not a linear modulation. Linear
approximation of the GMSK signal makes the blind equalization system model applicable
for GSM. In this paper, we present a linear approximation of GMSK signals and we
propose a blind GSM channel identification algorithm based on the cross relation method.
Keywords: GMSK modulation, blind identification, GSM channels, SIMO system.
1. Introduction
The Pan-European cellular standard of GSM uses a time division multiple access (TDMA) scheme,
where each frequency band is shared by 8 users allocated with 8 time slots. During each time slot
(approximately 0.577ms), a 142-bit burst is transmitted, in which two 58-bit streams of information
data are separated by a training midamble. The 26-bit training midamble can be used by receivers to
identify the unknown linear channel impulse response that includes transmitter filter, physical channel,
and receiver filter. This training sequence represents a sizable overhead that reduces the overall system
efficiency. If blind /semi-blind equalization [5] can eliminate part of the entire training overhead while
maintaining the system performance at an acceptable level, it can significantly improve the system
efficiency.
In this study, we first present a new blind channel identification algorithm based on the cross
relation method [1]. We note that blind channel identification algorithms based on SOS are sensitive to
channel order mismatch [2], which is very common in wireless environment.
The rest of our paper is organized as follows. Section 2 describes an approximated linear model
for the nonlinear Gaussian shift keying modulation (GMSK) used in GSM. In section 3, we expose
method of extracting channel diversity from linear GMSK system. In section 4, we introduce the blind
channel identification algorithm based on the cross relation. And in section 5, simulation results are
presented.

Blind SIMO GSM Channel Identification 829
2. GMSK Approximation
The impulse response of the Gaussian LPF h(t) is:
2
σ ⎛ − σ 2 ⎞
h(
t)
= exp ⎜ t ⎟
B 2π
⎝ 2 ⎠
Where
(1)
σ = 2πB ln 2 , with BT = 0.3 for GSM.
B is the 3 dB bandwidth of the filter. The square pulse response g(t) of the Gaussian LPF is:
⎛ t ⎞
g ( t)
= h(
t)
* rect⎜
⎟
⎝ T ⎠
Where the rectangular function rect(x) is defined by:
⎧
⎛ t ⎞ ⎪1
,
rect⎜
⎟ = ⎨ T
⎝ T ⎠ ⎪
⎩0,
T
for t <
2
Otherwise
The pulse response g(t) can be written as
1 ⎡ ⎛ ⎞ ⎛ ⎞⎤
⎢ ⎜
t −T
2
⎟ ⎜
t + T 2
g( t)
= Q 2π
BT −Q
2πBT
⎟⎥
2T
⎢
⎜ ⎟ ⎜ ⎟
⎣ ⎝ T ln( 2)
⎠ ⎝ T ln( 2)
⎠⎥⎦
Where Q (t) is the Q-function
(2)
Q(
t)
=
∞
2
1 ⎛
∫ exp⎜
τ
π ⎜
−
2
2
t ⎝
⎞
⎟
dτ
⎠
(3)
Consequently, the continuous phase modulation (CPM) pulse is the integral
t
∫ ∞
−
ψ ( t) = g(
τ − 2T
) dτ
(4)
In GSM system, the GMSK parameter BT=0.3 is chosen so that:
⎧0,
t ≤ 0;
ψ ( t)
≈ ⎨
(5)
⎩1,
t ≥ 4T.
The baseband signal of GMSK modulation is:
⎡
⎤
= ⎢ ∑ − ⎥
⎣
⎦
∞ π
s ( t)
exp j ( t nT)
n 2 α ψ
(6)
n=
−∞
In witch α = ± 1 is the binary data for transmission. Because, existing blind equalization
n
algorithm rely on linear system models, linear approximation of the GMSK signal becomes the
necessary first step. Following the approach used in [1] for linear QAM approximation of the GMSK
signal used in GSM, we take the first approximation step:
⎡
⎤
= ⎢ ∑ − ⎥
⎣
⎦
∞ π n−4
n
s ( t)
exp j ψ ( t nT)
⎛ π ⎞ ⎡ π
⎤
n 2 α ≈ exp⎜ j ∑ ⎟ ∏ exp
⎢
j ( t − kT )
k
k ⎥
n=
−∞
⎝ 2 α ψ
k = −∞ ⎠k
= n−3
⎣ 2α
(7)
⎦
t Є [nT, (n+1)T).
Equation (7) becomes the basis of linear approximation. It can be seen that there are 16
different terms in the product expansion of (7). Among the 16 different linear pulses, however, only
two pulses are significant while the others are nearly all zero. Retaining these two most significant
pulses, the linear approximate model for GMSK with BT = 0.3 is:
∞
∞
s( t)
= ∑a
( t nT )
( t nT )
0,
h − +
n 0 ∑a1
, nh
−
(8)
1
n=
−∞
n=
−∞
Where

830 Taba Mohamed Tahar, S. Femmame and D. Mossadeg
⎡
π
0
n
exp j
⎣ 2 n=
−∞
= −α
nα n−1a
0,
n−2
⎦
−1
a = j
, n ⎢ ∑α n⎥
= α na
0,
n
⎡
π
a = j
j
, n α n ⎢ ∑α = n⎥
α na
0,
n
j exp 1 −2
2 n=
−∞
n
⎤
⎤
⎣ ⎦
In other words, the GMSK signal can be approximated with almost no error by the sum of two
QAM signals with pulse shapes h0(t) and h1(t). These two pulses in the linear approximation [3], are
shown in figure 1.
For the case L = 4, BT=0.3,
h0 ( t)
= β ( t − 4T
) β ( t − 3T
) β ( t − 2T
) β ( t − T )
0 ≤ t≤ 5T
(9)
h 1(
t)
= β ( t − T)
β ( t − 2T
) β ( t − 4T
) β ( t + T)
0 ≤ t ≤ 3T
With,
(10)
⎧sin[
πh
−πhψ
( t)]
⎪
,
sin( πh)
⎪
β ( t) = ⎨β
( −t),
⎪
0,
⎪
⎩
With h=0.5 β(t) becomes:
tε
[ 0,
LT )
tε
( LT , 0]
t ≥ 0
(11)
π ⎧cos(
2 g(
t))
⎪
β ( t) = ⎨β
( −t),
⎪
⎩0,
tε
[ 0,
LT )
1 t1Q
( σ t1)
−t2Q
( σ t2)
ψ(
t)
= +
−...
tε
( LT , 0]
2 2Tp
2 2
2 2
exp( −σ
/ 2)
t exp( σ / 2)
t ≥ 0
1 − − t2
−
2Tσ
2π
(12)
Tp
Tp
t1 = t − 2 , t 2 t + 2 , σ =
Tp: sampling period.
2πB = ln 2
Figure 1: Represents two pulse shapes in the GMSK linear approximation. The power in h1(t) is 0.48% of the
power in h0(t).
h 1(t)
Because the majority (99.5%) of signal energy in GMSK signal s(t) is contained in the first
pulse approximation h0(t) figure 1, we can further simplify s(t) into a single QAM transmission
∞
= ∑ ( t − nT ), a =
0
n j na
n
n 1
n=
−∞
s( t)
a h
α (13)
−
It can be noted that the approximation error may be viewed as an additive interference.
Therefore, even in noiseless channels, the maximum signal-to-noise ratio (SNR) of this approximation
h 0(t)
p

Blind SIMO GSM Channel Identification 831
is at 23dB [2].with this linear QAM quaternary phase shift keying (QPSK) approximation, existing
blind equalization methods can be applied.
For a physical channel impulse response hc(t) the combined linear approximation pulse is
simply:
as
Figure 2: The composite channel response h(t) for equalizers.
h(t) = hc(t) * h0(t). (14)
The received GMSK signal is approximately:
x(
t)
h(
t − kT ) s(
k)
+ n(
t)
= ∑ +∞
k = −∞
Where n(t) is channel noise. The baud rate sampled discrete signals and responses are defined
xi = x(
iT ), hi
= h(
iT ), ni
= n(
iT )
The channel output sequence is thus a stationary sequence:
L
x h a + n
n = ∑
k = 0
k
n−k
n
3. Channel Diversity
For the single QPSK approximation of the GMSK signal, only sampling at higher than the baud rate
will not generate the necessary channel diversity needed in all SOS methods for blind equalization due
to the lack of excess bandwidth in the approximate pulse shape h0(t). Naturally, one can create channel
diversity by adding antennas. Unfortunately, additional antenna unit requires extra RF receiver and
significantly increases the hardware cost. Here we show how to reduce hardware cost by processing the
received data so that two channel outputs can be extracted from a single received GMSK signal [6].
We observe that an = jαnan-1 in the linear QPSK approximation of GMSK. However, the
relationship actually indicates that at any given time, an can only select two values instead of four.
Hence, an is a pseudo-QPSK and is realized by rotating a BPSK signal.
( ∏ )( )
− + M L 1
n−k
an− k = j
n−l
M + L−n
α n−M
−L
j
l=
k −3
Without loss of generality, let ( M + L−n
j )
(15)
(16)
α (17)
α n−M
−L
be purely real (or imaginary). Then
n−k
a ~ ~
n−k
= j an−
k , an−
k = ± 1,
(18)
k = 0,...,
M + L −1
To extract channel diversity from the single-channel system (16), signal pre-processing based
on special characteristics of the pseudo-QPSK input is necessary. Equation (16) can be transformed as:

832 Taba Mohamed Tahar, S. Femmame and D. Mossadeg
L
n = ∑
k = 0
k
L
n−k
a~
n−k
n−k
+ n = ∑ [ hk j ] an−
k + ω n
k = 0
x h j ω
As a result, we can obtain a new (derotated) sequence:
~ x = x
−n
j
n
=
n
L
∑
k = 0
−k
n
[ hk
j ] a~
−
n−k
+ j ω n
~ (19)
Derotation not only changes the GMSK detection into a simpler BPSK detection problem, it
can also create channel diversity useful in blind equalization [1]
Since { }
n
1
n
a ~ is real-valued sequence, we can induce two sub-channel outputs from (20):
L
{ ~
−k
−n
x } = Re[
h j ] a~
+ Re[
j ]
n
∑
k=
0
x = Re ω
x
2
n
k
n−k
L
{ ~
−k
−n
x } = Im[
h j ] a~
+ Im[
j ]
∑
k=
0
n−k
n
= Im ω (21)
n
k
n
Where the common input is a BPSK signal, i.e.
~ = = ± 1.
−
a n
n
j an
From the BPSK input data sequence, two sub-channels can be generated without over-sampling
and extra antenna,
{ } { } { } { } k
1
−k
hk
= Re( hk
j ) and
2
−
hk
= Im( hk
j
We hence arrive at the familiar equation in SIMO [7] (Single Input / Multiple Output) models:
X[k] = Hã[k] + n[k]
Where:
{ }
[ ]
{ [ ] } ,
⎡Re
x[
k]
⎤ { }
x k = ⎢
Im
⎥
⎣ x k ⎦ { } ,
⎡Re
H ⎤ { }
H = ⎢
Im
⎥ []
⎣ H ⎦ { [] } .
⎡Re
n[
k]
⎤
n k = ⎢
Im
⎥
⎣ n k ⎦
(22)
Re(
k
)
k
Im( h
− share no common zeros [2].
H will have full column rank if { } h − and { }
4. Cross-Relation Method
Consider a SIMO system of q outputs given by:
= ∑
=
M
k 0
k j
y(
l)
h(
k)
s(
l − k)
+ n(
l)
(23)
The noise free outputs yi(k), 1≤ i≤ q are given by:
yi(k) = hi(k) * s(k), 1≤ i≤ q (24)
where “*” denotes convolution. Using commutativity of convolution, it follows:
hj(k) * yi(k) = hi(k) * yj(k), 1≤ i

Blind SIMO GSM Channel Identification 833
⎡
⎢
⎢
Y(
l)
Y ⎢ l =
⎢
⎢
⎢
⎣ 0
•
Y(
l−1)
•
0
Y(
l)
0 ⎤
− Y
⎥
( 1)
⎥
• ⎥
⎥
• ⎥
− Y ⎥
( l−1)
⎦
(27)
With l = 3,…,q and:
⎡ yl
( M )
⎢
⎢
•
Y ⎢ ( l ) = •
⎢
⎢ •
⎢
⎣y
l ( N −1)
•
•
•
•
•
•
yl
( 0)
⎤
•
⎥
⎥
• ⎥
⎥
• ⎥
y ( N − M −1)
⎥
l ⎦
(28)
In the presence of noise, equation (26) can be naturally solved in the least- square (LS) [4]
sense according to:
ˆ
H H
= argminh
Y Y h
(29)
hCR q q
h = 1
5. Simultion Results
We now present simulation results of GSM blind identification. A GMSK pulse of four symbols was
generated and bandwidth BT=0.3. The bit rate is 27 kb/s.
Figure 3: Estimation of propagation channel.
s(t): transmitted signal BPSK
n(t): additive noise
h(t): combined filter [h(t)=h0(t)*hc(t)]
Figure 3 represents the estimated impulse response of the propagation channel for COST-207
[6]. Figure 4 represents the relative error estimation for training method and blind method.

834 Taba Mohamed Tahar, S. Femmame and D. Mossadeg
Figure 4: Impulse response of channels COST-207 Mobil canal model for TYPICAL URBAN and RURAL
AREA
Figure 5: Relative error for canal estimation
6. Conclusion
In this paper, we have addressed the problem of blind channel equalization, based on the Cross-
Relation method with the exploitation of the linearization of the GMSK signal used in GSM systems.
The simulation results show great potential of blind identification algorithms in GSM, since we have
used no extra antenna or over-sampling the received signal. This method is of great importance since
we can use the 10 bits in the midamble of the burst GSM signal to transmit information.

Blind SIMO GSM Channel Identification 835
References
[1] Karim Abed-Meraim, Wanzhi Qiu, and Yingbo Hua, “Blind System Identification”,
Proceedings of the IEEE, pp. 1310:1322, AUGUST 1997
[2] Zhi Ding and Ge Li, “Single Channel Blind Equalization for GSM Cellular Systems,” IEEE
Journal on Selected Areas in Communications, Vol. 16, No. 8, Oct. 1998.
[3] Ghassan Kawas Kaleh, “Simple Coherent Receivers for Partial Response Continuous Phase
Modulation,” IEEE Journal on Selected Areas in Communications, vol. 7, NO. 9, December
1989
[4] A. Aïssa-El-Bey, M. Grebici, K. Abed-Meraim and A. Belouchrani, “Blind System
Identification Using Cross-Relation Methods: Further Results And Developments,” 7 th
International Symposium on Signal Processing and its Applications (ISSPA), vol. 1, pp. 649-
652, Paris, France, July, 2003.
[5] CICHOCKI Andrzej, AMARI Shun-ichi, “Adaptive Blind Signal and Image Processing:
Learning Algorithms and Applications”, Willey 2001.
[6] P. Hoeher, “A Statistical Discrete-Time Model for the WSSUS Multipath Channel,” IEEE
Transactions on Vehicle Technology, vol.41, pp. 461-468, Nov. 1992.
[7] Jingdong Chen; Nteng Huang; Benesty, J, “An adaptive blind SIMO identification approach to
joint multichannel time delay estimation”, Acoustics, Speech, and Signal Processing, 2004.
Volume 4, Issue, 17-21 May 2004

European Journal of Scientific Research
ISSN 1450-216X Vol.20 No.4 (2008), pp.836-843
© EuroJournals Publishing, Inc. 2008
http://www.eurojournals.com/ejsr.htm
The Chemical Control of the Pests in the Truck Farming and the
Quality of Vegetables in African Urban Cities: The Health
Hazards and Security of Consumers
Dembele Ardjouma
Laboratoire Central d’Agrochimie et d’Ecotoxicologie, Lanada 04 BP 612
Abidjan 04 Cote D’ivoir
E-mail: ardjouma@yahoo.fr, labeco@aviso.ci
Tel: 00 225 05 95 95 72/ 00225 20 22 5838; Fax: 00 225 22 52 31 61
Oumarou Badini
Washington State University 206 Bryan Hall PO Box 645121
Pullman, WA 99164-5121
Traore Sory Karim
UFR des Sciences et Gestion de l’Environnement, Université d’Abobo-Adjamé 02 B.P
801 Abidjan 02 (Côte d’Ivoire)
Mamadou Koné
UFR des Sciences et Gestion de l’Environnement, Université d’Abobo-Adjamé 02 B.P
801 Abidjan 02 (Côte d’Ivoire)
Coulibaly D. Ténébé
UFR des Sciences de la Nature/Protection des Végétaux et de l’Environnement
Université d’Abobo - Adjamé, 02 B.P. 801 Abidjan 02/Cote D’ivoire
A. Abba Toure
Département Environnement et Santé, Institut Pasteur, B.P. V 34 Abidjan
Abstract
The truck farming vegetables such as lettuce, spinach and turnip are attacked by
several pests, making the use agrochemicals necessary to get a good quality and high
production. The Spraying of pesticides such as Deltamethrin, Cypermethrin, Acephate and
Maneb allow the control of almost all insect pests and fungus diseases. The quality of the
production can be compromised by the microbial contamination of these vegetables from
irrigated water and accumulation of pesticides in residues, because producers don’t respect
good agricultural practices.
There is a need for the truck farming sector to comply with current phytosanitary
regulations and quality control of marketed vegetables in order to protect consumers from
health hazards.
Keywords: Agrochemicals, biotechnology, phytosanitary, regulation, residues.

The Chemical Control of the Pests in the Truck Farming and the Quality of
Vegetables in African Urban Cities: The Health Hazards and Security of Consumers 837
Introduction
Horticulture is a vital economic sector for most African countries. In Côte d’Ivoire, this sector is
confronted to pests’ attacks and phytosanitary problems. It needs to comply to the pesticides
regulations and the quality control (traceability) which are now required by most industrials and export
countries. The study was conducted in the “M’POUTO village” on the surroundings of the Ebrié
lagoon in Abidjan, the economic capital of Côte d’Ivoire. The main objective of this study is to assess
the impact of pest on truck farming Lettuce, Spinach, and Turnip, and the application of agrochemicals
for plant protection, and the quality of irrigation water. The specific objectives are (1) to evaluate the
impact of agrochemicals application on plants pests, (2) to determine their economic incidence, (3) to
monitor irrigation water quality, and (4) to control some essential production factors which are
indicators of a good standard quality production.
Materials And Methods
Plant material
The Lettuce, Lactuca sativa L. (Asteraceae or Compositaceae) is the more consumed vegetable in
the world. There are approximately 149 varieties worldwide [1]. There are two main classes of lettuce:
non-head forming lettuces such as the “celtuce” or “lettuce - asparagus” and the head-forming lettuces
such as the “Batavia” or “curly” cabbage lettuce.
Seeds germination is normal between 0°C and 25°C, and sunlight plays a major role in the
growth and the development process.
Lettuce has a high water demand [2], and grows well in different types of soils presenting a
steady structure with good water holding capacity. In general, lettuce is a moderately heavy consumer
of nutrients. Seedlings of lettuce are planted at 2 to 4 leaf-stage in well-prepared seedbeds (trays of
earth) ploughed at depth and mixed to manure. The application of fertilizer (NPKS) is often necessary
and must be incorporated in the soil before planting. The growth cycle is very variable (45 to 100 days)
depending on the variety. Agrochemicals applications (insecticides and fungicides) on the lettuce
cultures against the pest attacks are often done in the middle and end of cultural cycle.
The spinach, Spinacia oleracea L. (Chénopodiaceae), is named “the prince of vegetables”. It
is an annual plant generally cultivated as biennial in the vegetable exploitations gardens. The plant
develops initially, on a very short axis, a rosette constituted of fifteen (15) to twenty (20) leaves. These
leaves are lengthily petiolate with full limb more or less blighted. Mineral fertilization (NPK) is often
necessary according to expected yields. But the poultry’s liquid manures and dejections abundantly
brought are very largely sufficient to face exports of mineral elements. Watering must be sufficiently
abundant to satisfy the water needs of the plant. The diseases and pest management of the plants must
be carefully and frequently controlled so [3], the weedings are very important and a thinning can be
practiced in case of a very dense germination and seedlings. Spinach usually matures in 35 to 45 days.
The plant may be harvested from the time there are 5-6 leaves on the plant right before the seed stalk
develops. The phytosanitary protection of the plants intervenes in middle and end of cycle.
The turnip, Brassica rapa L. var. rapa, (Brassicaceae) is produced in specialized market
gardening. The plant is normally bi-annual. In its vegetative stage it is constituted of a basal rosette
made of about fifteen leaves with real green limb and bristling with rough hairs.
According to the varietal type, it has a tuberous root of flattened, conical or cylindrical form
and of variable color (white, yellow, black or two-tone).
One notes about thirty varieties but the range of the varieties currently cultivated is rather
restricted (Tokyo hybridizes F1, Chinese turnip). Turnips are primarily cultivated in full field by direct
seeding on fertile well-prepared seedbeds is also possible. The needs in mineral elements are important
and sustained fertilization (NPK) is needed before planting and during the growth cycle.

838 Dembele Ardjouma, Oumarou Badini, Traore Sory Karim,
Mamadou Koné, Coulibaly D. Ténébé, A. Abba Toure
The application of manure must be done on the precedent crop. The growth cycle is 40 - 70
days dependent on climatic conditions and varieties. Turnips are harvested as young roots by
successive thinnings. The diseases control and protection of turnips must be regular due to frequent
pest attacks.
Agrochemicals material[4]
Deltamethrin: Trade name DECIS (K -OTHRINE)
Molecular formula: C22H19Br2NO3
(S)- α-cyano-3-phenoxybenzyl (1R,3R)-3-(2,2-dibromovinyl)-2,2-dimethylcyclopropane
carboxylate (IUPAC)
structural formula:
Decis 25 EC is an emulsifiable concentrate of formulation (25g/l). It is approved for a wide
variety of insects including acarina, thysanoptera and arthropods pests of the horticultural plants.
We made a first application on the salad lettuce at the stage 27 days with an amount of
treatment of 0.042 g/l (25 l of Decis in 15 l of water) for 400 m 2 .
The stage 39 days: corresponds to the second treatment by Deltamethrin with the same
concentration of 0,042 g/l and by Maneb with the concentration of 5 g/l representing 93,75 grams of
CALLIMAN 80 WP for the sprayer of 15 liters for 400 m 2 .
The stage 45 days: corresponds to the third treatment by Maneb with the same concentration of
5 g/l.
For turnip, at the stage 18 days we have done the first treatment by Deltamethrin with the
concentration of 0,025 g/l (15 milliliters of DECIS 25 EC in 15 liters of water) for 400 m 2 .
The Stage 30 days: corresponds to the second treatment by Deltamethrin with the same
concentration of 0,025 g/l and by Maneb with the concentration of 5 g/l representing 93,75 grams of
CALLIMAN 80 WP for the sprayer of 15 liters. The Stage 38 days of turnips received the same
treatment as the stage 30 days.
Cypermethrin: Trade name Cypercal 50 EC
Molecular formula: C22H19C12NO3
(RS)-I-cyano-3-phenoxybenzyl (1RS)-cis-trans-3-
(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate (IUPAC)
Structural formula:
Cypermethrin 50 EC is an emulsifiable concentrate of formulation (50 g/l). It is approved for a
broad spectrum of harmful insects (Caterpillars, Thrips, Heliothis and white flies). We carried out the
first application on spinaches at the stage 18 days, the amount of application is of 0.133 g/l (40 ml of
CYPERCAL 50 EC. in 15l of water) for 400 m 2 . At the stage 30 days the spinaches received an

The Chemical Control of the Pests in the Truck Farming and the Quality of
Vegetables in African Urban Cities: The Health Hazards and Security of Consumers 839
amount of treatment of 0,133 g/l in addition to 5 g/l of maneb (93.75g of CALLIMAN 80 WP in 15 l
of water) for 400 m 2 .
Acephate : Trade name Orthen 75 SP
Molecular formula : C4H10NO3PS
O,S-dimethyl acetylphosphoramidothioate (IUPAC)
Structural formula:
Orthen 75 SP is a water-soluble powder of formulation 75% acephate. It is a systemic pesticide.
Methadomiphos (C2H8O2NPS) is a metabolite of acephate and it is also systemic.
Structural formula: O
"
CH3OPSCH3
'
NH2
O,S,-dimethyl phosphoramidothioate (IUPAC)
These two organophosphorous pesticides are both effective against a broad range of insect pests
(sucking, biting, and mining insects) on such vegetable and crops as cabbages, cotton, tobacco, sugar
beet, head lettuce. It is used as a pre-harvest spray at 0.5-1.5 kg/ha. With this amount, protection
against the insects vermin is obtained from 7 to 21 days.
The first application on lettuce is done at at stage 27 days with the amount of 2 g/l (40 g of
Orthen 75 SP in 15 l of water) for 400m 2 .
At the stage 39 days the amount of treatment of lettuce is 2 g/l in addition to 5 g/l of maneb for
400 m 2 .
Maneb: Trade name Calliman 80 WP
Molecular formula: C4H6N2S4Mn
Manganese ethylene-1,2-bisdithiocarbamate (IUPAC)
Structural formula:
Calliman 80 WP is a wettable powder of formulation 80% of maneb (dithiocarbamate), an
effective protective fungicide against the main foliar diseases(Anthracnose, Mildew, Alternaria,
Rhizoctonia, cercospora, Sclerotinia and Septoria).
It should be applied before and after seeding on all three vegetables at amount of 5 g/l.
Moreover the salad lettuce received a treatment at the stage of 45 days.
Plants phytopathology and pests monitoring
After each treatment, every two (2) days we proceed:
• to the description of the general characteristics of the plants, especially the leaves, and we look
out for visible signs of attacks and diseased plants.
• to the counting of the insects captured in the traps for follow-up of the dynamics of the
recolonisation following the various treatments[5].

840 Dembele Ardjouma, Oumarou Badini, Traore Sory Karim,
Mamadou Koné, Coulibaly D. Ténébé, A. Abba Toure
The final identification of the fungus was made after observation of the samples under a
microscope (enlarged to a size 400 times) and according to known keys of identification[6,7].
Irrigated water monitoring
We sowed under the fume hood raw water of boring in the Petri glass, on culture medium sterilized..
The analysis consisted of identifying thermotolerant Coliform and faecal Streptococci and counting of
the colonies of red or pink coloring of 2 to 3 millimeters (mm) in diameter. The criterion of assessment
is fixed to 2x10 3 .
Results and Discussion
Pests Numbers (N)
14
12
10
8
6
4
2
0
Coleoptera
Graphic 1: Pests control on lettuce
PESTS POPULATION ASSESSMENT ON LETTUCE
Hymenoptera
Diptera
Hemiptera
Lepidoptera
Orthoptera
Graphic 2: Pests conrol on spinach
Spray Parcel (PT)
No Spray Parcel (PnT)
We counted 79% of pests in the untreated lettuce plots against 69% in the deltamethrin treated
plots with the Hemiptera representing the most important group.of devastators pests. The pests
recolonisation of the field plots was done 12 days after the first application of acephate against 8 days
with deltamethhrin.
The agrochemicals application makes it possible to reduce by 50% the losses of production of
the salad.

The Chemical Control of the Pests in the Truck Farming and the Quality of
Vegetables in African Urban Cities: The Health Hazards and Security of Consumers 841
We obseved 84% of pests in untreated plots against 57% in plots treated with the cypermethrin,
with the Hemiptera representing the most important group. The recolonisation by the pests was done
10 days after the first application of cypermethrin. The agrochemicals application makes it possible to
reduce by 25% the losses of production of the spinaches.
Pests Numbers (N)
12
10
8
6
4
2
0
Coleoptera
Graphic 3: Pests Control on turnip
PESTS POPULATION ASSESSMENT ON TURNIP
Hymenoptera
Diptera
Hemipte ra
Lepidoptera
Orthoptera
Spray Parcel(PT)
No Sp ray Pa rcel (Pn T)
We observed 91% of pests in untreated plots against 62% on the plots treated with
deltarmethrin, and the Hemiptera also set up the most important group of pests. The pests
recolonisation was done 8 days after the first application of deltarmethrin.
The first application of agrochemicals makes it possible to reduce by 42% the losses of turnip
production.
We identified only one pathogenic fungus on the lettuce (9 % of production). It is
Cladosporium sp of:
Division of Amastigomycota
Group of Deuteromycetes
Class of Hyphomycetes
Gender of Cladosporium.
which is the agent responsible of Cladosporium gray mold but the preventive spraying of Maneb gives
efficient protection on the lettuce.
Table 1: Microbiology Monitoring of Irrigated Water
Bacteria Resultats Criteria
Thermotolerant Coliform/g 3.10 5 2.10 3
Faecal Streptococci/g 10 6 10 3
The presence of micro-organisms such as Thermotolerant Coliform and the faecal Streptococci
is respectively hundred fifty (150) times and one thousand (1000) times
higher than the criteria for international standard allowed for irrigation water quality in
agricultural fields.
Generally the application of Agrochemicals significantly reduced the number and the varieties
of pests on the treated plots. The Coleoptera and the Hymenoptera contain the main species of the
predatory and natural enemies thus auxiliary of plants protection, having a significant impact on the
dynamics of the populations of pests. The preservation of these different auxiliaries is necessary for a
sustainable management of natural resources. Deltamethrin has a good level of selectivity and it is a

842 Dembele Ardjouma, Oumarou Badini, Traore Sory Karim,
Mamadou Koné, Coulibaly D. Ténébé, A. Abba Toure
considerable advantage for the management of pests and the environment management than the
Acephate which, has a low selectivity but a wide range of effectiveness against insect pest and good
residual activity.
The preservation of the auxiliaries of culture in spite of the chemical treatment is essential
considering the important role that they play in the maintenance of agro-ecological balances.
The Lepidoptera (larva), Orthoptera and Hemiptera represent the most important group of
insect pests, which attack and cause the highest damage in truck farming lettuce, spinach and turnip.
However, the considerable differences in number of captured insects and pests found between the
treated and untreated field plots show that a targeted application of agrochemicals against these groups
of pests is efficient.
The majority of the groups of pests which attach and cause important damage on turnip,
spinach and lettuce can be controlled by the application of agrochemical products according to good
agricultural practices (GAP) compatible with the protection of the environment and the preservation of
non-target organisms.
However, one of the biggest problems encountered by vegetable producers is their lack of
sufficient knowledge about how to use safely the agrochemicals. They are not sufficiently aware of the
risks of pesticides accumulation in vegetables, and the possible health problems for consumers being
exposed to these risks. They are also often confronted with the problems of accessibility to agricultural
credits.
The microbiological analysis of the irrigation water highlighted an overload of thermotolerant
Coliforms and fecal Streptococci. These bacteria which are not normally pathogenic, are usually used
to indicate the possible presence of pathogenic microfauna organisms. Thus their very high number
compared to the threshold recommended shows a low water quality.
The strong presence of these indicating bacteria suggests a probable presence in the irrigation
water of very dangerous pathogenic parasites that could develop and cause very important damages to
the plants, farmers and the consumers.
The contaminated vegetables can cause a certain number of diseases. Particularly, the
contaminated salads are sources of bacterial diseases such as the typhoid and paratyphoid fevers
(Salmonella typhi/paratyphi) whose origin comes from the excrements of the patients or healthy
carriers [8]. Other bacteria of the Salmonella species can also cause collective intoxications. The
periodically endemic Cholera in the tropical countries, maybe transmitted by soiled salads. Also the
bacterial dysentery (Shigella dysenteriae) can be transmitted by soiled vegetables believed
contaminated by the excrements.
The preventive protection against these diseases is often done by vaccination. But the use of
hygienic measures like disinfections with chloramphenicol, bleach into the water or the potassium
permanganate (KMnO4) are of primary importance.
Conclusion
The insecticides of biological origin represent an asset but their major disadvantage in addition to their
high costs, is their instability with storage. They quickly lose their effectiveness and consequently any
competitiveness [9]. But the need for both safe and natural food products while respecting nature and
maintaining a healthy environment is a very important concept to be considered in Integrated Pest
Management (IPM). IPM can be defined as a combination and the reasoned use of all the methods
which makes it possible to control or to maintain the populations of pests to a threshold economically
bearable [10].
If the consumers estimate that the products are of the first rate quality, they will not hesitate to
pay for the full price. Finally, one can reach a great effectiveness in the improvement of plants
protection by associating the conservation of auxiliary insects with the application of agrochemicals
and biotechnology. Our developing countries will be able certainly to benefit from this progress.

The Chemical Control of the Pests in the Truck Farming and the Quality of
Vegetables in African Urban Cities: The Health Hazards and Security of Consumers 843
References
[1] CHAUX C. & FOURY C. (1994), Productions légumières: Tome 2: Légumes-feuilles, Tiges,
Fleurs, Racines, Bulbes. Editions Lavoisier, Paris-France. 639p.
[2] E.J. RYDER & WHITAKER T.W. (1976), Lettuce. In “Evolution of crop plants”. N.W.
Simmonds edit., Longmann-London. 215p.
[3] MATTHEWS G.A. (1984), Pest management. Longman, London & New York. 231p.
[4] DEMBELE A. (2000), Cours de Chimie des Pesticides. Université d’Abobo Adjamé, Année
académique 2000-2001. 1p.
[5] DELVARE G. & ABERLENC H. P. (1989), Les insectes d’Afrique et d’Amérique tropicale:
Clés pour la reconnaissance des familles. Prifas Cirad dépt. Gerdat, Montpellier-France. 302p.
[6] KIFFER E. & MORELET M. (1997), Les Deutéromycètes: Classification et clés
d’identification générique. INRA, Paris-France. p161-169.
[7] BOTTON B. & Al (1990), Moisissures utiles et nuisibles. Importance industrielle: 2e édition.
Masson Collection Biotechnologies, Paris-Milan-Barcelone-Mexico. 498p
[8] MESSIAEN C.M. (1989), Le potager tropical: 2e édition entièrement refondue. Presses
Universitaires de France (PUF) & ACCT, Paris. 580p.
[9] LAVABRE E.M. (1992), Ravageurs des cultures tropicales. G-P Maisonneuve et Larose &
ACCT, Paris.178p.
[10] H. SIMON & Al (1994), La protection des cultures. Editions Lavoisier-Tec & Doc, Paris.
351p.

European Journal of Scientific Research
ISSN 1450-216X Vol.20 No.4 (2008), pp.844-851
© EuroJournals Publishing, Inc. 2008
http://www.eurojournals.com/ejsr.htm
Database Interfacing using Natural Language Processing
Imran Sarwar Bajwa
Department of Computer Science and IT, The Islamia University of Bahawalpur
E-mail: imransbajwa@gmail.com
Shahzad Mumtaz
Department of Computer Science and IT, The Islamia University of Bahawalpur
E-mail: shahzadz22@hotmail.com
M. Shahid Naweed
Department of Computer Science and IT, The Islamia University of Bahawalpur
E-mail: shahid_naweed@hotmail.com
Abstract
To write technically correct SQL queries is a complex and skill requiring task
especially for a novel user. This situation becomes more complex when a low skilled
person has to use a database management system for a specific business purpose. S/He has
to write some quires at his own and perform various tasks. This scenario requires more
expertise and skills in terms of understanding and writing the accurate and functional
queries. The task of the novel user can be simplified by providing an easy interface that is
well known to that user. In order to resolve all such issues, automated software is needed,
which facilitates both users and software engineers. User writes the requirements in simple
English in a few statements and the designed system has the ability to analyze the given
script. After composite analysis and mining of associated information, the designed system
generates the intended SQL queries that can be run directly. The paper describes a system
that can create SQL queries automatically. The designed system provides a quick and
reliable way to generate SQL queries to save time and budget of both the user and system
analyst.
Keywords: Information extraction, Automatic Query Generation, Knowledge Retrieval,
Natural language processing.
1.0. Introduction
Relational databases are the premier way of storing common data repositories. After storing the data
contents in a database, an interfacing mechanism is required to talk with the prearranged repository of
the confined data. The conventional way of communicating with a database is to fist build a connection
stream and then adding, deleting or updating the data contents in the database by using a standardized
interfacing mechanism [1]. Simple command shells are typically used and they are often incorporated
within every distinct database product. These command shells are typically simple filters which helps a
use to log on to the database, execute particular commands and receive output. These command shells
provide access to the database from the machine on which the database is actually running [2]. After
hooking to a particular database a user or a programmer requires an interface and typically that

Database Interfacing using Natural Language Processing 845
interface is provided by some technical languages. These languages are called query languages and are
constituted of the database commands typically used for asking questions to a distinctive database and
getting intended response. SQL [3] (Structured Query Language) is the most popular query language
which is actually the defacto language of databases today. SQL is an orthodox tool of database
querying. Different database management systems implement this standardized language with trivial
alterations and adjustments. However, in spite of these proprietary extensions by the vendors, the core
of this querying language is the same in all of the environments.
From an application programmer's point of view, the major novelty in the relational database is
that one uses a declarative query language, SQL. Most computer languages are procedural. The
programmer tells the computer what to do, step by step, specifying a procedure. Using SQL interface,
the programmer defines his requirements and questions and the RDBMS query planner figures out how
to get it [5]. There are two compensations of using a declarative language. The first is that the queries
no longer depend on the data depiction. The RDBMS is free to store data according to its own design
requirements [6]. The second major factor is improved software dependability. For various web-based
and stand-alone applications the generic SQL is used to make the things simple and straightforward.
Besides these praising compensations occupied by SQL, it’s technical and trifle interface makes this
language monotonous and difficult to learn and use. It is quite intricate to remember these SQL
commands and use them accurately and precisely.
In order to resolve all such issues, an automated software is needed, which facilitates both users
and software engineers. As far as this software is concerns the time, it takes to explore all the facilities
and services, should be quite less than a minute and this information is quite useful for the users.
2.0. Problem Description
Modern software engineering requires quick and automated solutions which may have ability to create
the accurate and precise SQL queries automatically. For complex queries an expert programmer also
requires assistance in terms of automatic query generation. He can use these queries after making
appropriate adjustments and alterations in the automated generated queries with less effort in less time
as compared to the traditional approaches.
The task of the novel user can be simplified by providing an easy interface that is more familiar
and well known to that user. In order to resolve all such issues, an automated software is needed, which
facilitates both users and software engineers. User writes the requirements in simple English in a few
statements and the designed system has obvious ability to analyze the given script. After composite
analysis and mining of associated information, the designed system generates the intended SQL queries
that can be run directly. The designed system has robust ability to create code automatically without
external environment. The designed system provides a quick and reliable way to generate SQL queries
to save the time and budget of both the user and system analyst
3.0. Used Methodology
The understanding and multi-aspect processing of the natural languages that are also termed as "speech
languages", is actually one of the arguments of greater interest in the field artificial intelligence field
[8]. The natural languages are irregular and asymmetrical. Traditionally, natural languages are based
on un-formal grammars. There are the geographical, psychological and sociological factors which
influence the behaviours of natural languages [12]. There are undefined set of words and they also
change and vary area to area and time to time.Due to these variations and inconsistencies, the natural
languages have different flavours as English language has more than half dozen renowned flavours all
over the world [14]. These flavours have different accents, set of vocabularies and phonological
aspects. These ominous and menacing discrepancies and inconsistencies in natural languages make it a
difficult task to process them as compared to the formal languages [13].

846 Imran Sarwar Bajwa, Shahzad Mumtaz and M. Shahid Naweed
The English language statements are effortlessly converted into a SQL query by using the
newly designed rule based algorithm. Select query is the common query used to choose a set of values
from a table [4]. An example of a college database has been used in the conducted research. Student’s
data will be retrieved, inserted and deleted by automatically generated queries from simple English
text.
3.1. SELECT Query
First of all the ‘SELECT’ query has been processed. ‘SELECT’ query has four parts as following:
SELECT * FROM Students
Keyword Required Set keyword Table Name
‘SELECT’ query can easily be generated from the provided input string of as there are two
keywords ‘SELECT’ and ‘FROM’. Other two required values are ‘Required Set’ and ‘Table Name’.
To process the speech language text and find ‘Required Set’ and ‘Table Name’ the conventional norms
of the English language and grammatical rule are used. The conventional structure of simple English
sentence is the key rule of comprehending and analyzing the natural language text [13] as in the
following example:
“I need names of all students.”
Following is the complete analysis of this simple sentence.
Table 01: Generating SELCET Query from text
Lexicons Phase-I Phase –II
I Noun ----------
need Verb ----------
names Noun Field Name
of preposition ----------
all Noun *
students Noun Table Name
In this example the ‘Required Set’ field is filled by the ‘Filed Name’ attribute and the ‘Table
Name’ filed is filled by the ‘Table Name’ attribute as following:
Select * from Students
Here the table Name is searched from the array of available all tables in the database. From all
available tables, the nearest table name is picked that ‘students’ in this example.
3.2. INSERT Query
After ‘SELECT’ query ‘INSERT’ query has been processed. ‘INSERT’ query has five fragments as
following:
INSERT INTO Students VALUES (5, ‘Ali’)
Keyword keyword Table Name Keyword Record
‘INSERT’ query can also produced from the given statement as there are three keywords
‘INSERT’, ‘INTO’ and ‘VALUES’ [6]. Other two required parameters are ‘Table Name’ and
‘Record’. Using same rule based algorithm ‘Table Name’ and ‘Record’ are extracted. As in the
following example:
“I want to insert a student whose Roll No. is 5 and Name is Ali.”
Following is the complete analysis of this simple sentence.

Database Interfacing using Natural Language Processing 847
Table 02: Generating INSERT Query from text
Lexicons Phase-I Phase –II
I Noun -----------
want Verb -----------
to Preposition -----------
insert Verb Action
a article -----------
student Noun Table Name
whose Conjunction -----------
Roll No Noun Attribute
is Helping Verb ------------
5 Noun Value
and Conjunction ------------
Name Noun Attribute
is Helping Verb ------------
Ali Noun Value
In this example the ‘Required Set’ field is filled by the ‘Filed Name’ attribute and the ‘Table
Name’ filed is filled by the ‘Table Name’ attribute. Here the table Name is searched from the array of
available all table sin the database. From all available tables, the nearest table name is picked that
‘students’ in this example.
3.3. DELETE Query
Same like ‘SELECT’ and ‘INSERT’ queries ‘DELETE’ query can also be easily processed. ‘DELETE’
query has five parts as following:
DELETE FROM Students WHERE Age > 25
Keyword Keyword Table Name Keyword Condition
The ‘DELETE’ query typically consists of three keywords as ‘DELETE’, ‘FROM’ and
‘WHERE’. Other two required values are ‘Table Name’ and ‘Condition’. To find ‘Table Name’ and
‘Condition’ parameters the English language defined grammatical rule are used as in the following
example:
“I want to delete the students more than 25 years age.”
Following is the complete analysis of this simple sentence.
Table 03: Generating DELETE Query from text
Lexicons Phase-I Phase –II
I Noun ---------
want Verb ---------
to preposition ---------
delete verb Action
the article ---------
students Noun Table Name
more preposition Condition
than Noun ----------
25 Noun Value
years Noun -----------
age Noun Parameter
For ‘DELETE’ query, first the condition is defined. In this example Parameter and Value are
combined with Condition parameters. In this example table Name is also retrieved from the array of
available all tables in the database.

848 Imran Sarwar Bajwa, Shahzad Mumtaz and M. Shahid Naweed
4.0. Work Flow of Designed System
The designed system “Computational Linguistics based System for Automatic Database Query
Generation” is adequately capable of automatically generating queries. This designed system performs
its function in multi-phase procedure. There are five modules in total that are Text input acquisition,
text comprehension, Information retrieval and ultimately generation of SQL Queries. Following is the
brief detail of all these phases.
4.1. Text input Acquisition
This module helps to acquire input text scenario. User provides the business scenario in from of strings
of the text. This module reads the input text in the form characters and generates the words by
concatenating the input characters. This module is the implementation of the lexical phase. Lexicons
and tokens are generated in this module. After the lexicons generation further processing can be
performed on the input text.
4.2. Text Comprehension
Figure 01: Lexical analysis of input text string
This module reads the input from module one in the form of words or lexicons. These words are
categorized into various classes as verbs, helping verbs, nouns, pronouns, adjectives, prepositions,
conjunctions, etc. These classes are further used to understand the various parts of the given sentence.
4.3. Information Retrieval
Figure 02: Parts of speech tagging of input text
This module, extracts key words of the SQL queries as Select, Insert, Delete, From, Into, Where, etc.
Keywords are found by matching the tokens with the given array of al possible keywords. These key

Database Interfacing using Natural Language Processing 849
words are further used to generate the respective queries. The information like table name, field name,
number of attributes and logical conditions are also extracted in this phase.
4.4. SQL Queries generation
Figure 03: Query information extraction
This module combines the keywords and other required parameters for a particular query. SQL query
is ultimately generated here according to the given rules in the designed algorithm. As separate
scenario will be provided for various types of queries, the separate functions have been implemented
for particular query.
Figure 04: Generation of SQL Query
5.0. Results and Analysis
After designing and coding the query generating system, its accuracy and efficiency was tested. For
testing purpose of the queries generated by the designed system simple and complex level queries were
generated. Each query from each category as Select, Insert, Delete was checked.
15 sample queries were generated and the intended results have been shown in the following
table.

850 Imran Sarwar Bajwa, Shahzad Mumtaz and M. Shahid Naweed
Table 04: Accuracy ratio of various types of queries
Types Simple Complex Total
SELECT 14 13 90%
INSERT 13 11 80%
DELETE 14 12 87%
Total Accuracy = 86%
A matrix representing accuracy of query generation test (%) for simple level and complex level
queries has been constructed. Overall diagrams accuracy for all types of queries is determined by
adding total accuracy of all categories and calculating its average that is 86% in this case.
Figure 05: Graphical representation of the results
14
12
10
8
6
4
2
0
SELECT INSERT DELETE
The graph above is showing the accuracy ratio of various SELECT, INSERT & DELETE
queries in terms of simple and complex queries parameters.
6.0. Conclusion
The designed system “Computational Linguistics based System for Automatic Database Query
Generation” facilitates both users and software engineers in terms of generating SQL queries
automatically. The task of the novel user can be simplified by providing an easy interface that is more
familiar and well known to that user. In order to resolve all such issues, an automated software is
needed, which facilitates both users and software engineers. User writes the requirements in simple
English in a few statements and the designed system has obvious ability to analyze the given script.
After composite analysis and mining of associated information, the designed system generates the
intended SQL queries that can be run directly. The designed system has robust ability to create code
automatically without external environment. The designed system provides a quick and reliable way to
generate SQL queries to save the time and budget of both the user and system analyst. An elegant
graphical user interface has also been provided to the user for entering the Input scenario in a proper
way and generating UML diagrams.
7.0. Future Work
There is also some margin of improvements in the algorithms for generating the intended SQL queries.
Current accuracy of generating diagrams is about 80% to 85%. It can be enhanced up to 95% by
improving the algorithms and inducing the ability of learning in the system. In this research only three
types of queries has been addressed as SELECT, INSERT, and DELETE query. There are still other
types of queries that require some sufficient solution.
Simple
Complex

Database Interfacing using Natural Language Processing 851
References
[1] Allen,J. (1994) Natural Language Understanding. Benjamin- Cummings Publishing Company,
New York.
[2] Biber, D., Conrad, S., & Reppen, R. (1998). Corpus Linguistics: Investigating Language
Structure and Use. Cambridge Univ. Press, Cambridge, U.K.
[3] D. DeHaan, D. Toman, M. P. Consens, and T. Ozsu. (2003) A Comprehensive XQuery to SQL
Translation using Dynamic Interval Encoding. In SIGMOD.
[4] C. A. Thompson, R. J. Mooney and L. R. Tang, Learning to parse natural language database
queries into logical form, in: Workshop on Automata Induction, Grammatical Inference and
Language Acquisition (1997).
[5] Salton, G., & McGill, M. (1983). Introduction to Modern Information Retrieval. McGraw-Hill,
New York.
[6] A. Rosenthal. D. Reiner, Extending the Algebraic Framework of Query Processing to Handle
Outer joins, Proc. VLDB Singa- pore 1984. pp. 334-343.
[7] Fagan, J. L. (1989). The effectiveness of a non-syntactic approach to automatic phrase indexing
for document retrieval. Journal of the American Society for Information Science, 40 (2), 115–
132.
[8] J. M. Zelle and R. J. Mooney, Learning semantic grammars with constructive inductive logic
programming, in: Proceedings of the 11th National Conference on Arti_cial Intelligence
(AAAI Press/MIT Press, Washington, D.C., 1993), pp. 817ñ822.
[9] Kowalski, G. (1998). Information Retrieval Systems: Theory and Implementation. Kluwer,
Boston.
[10] Krovetz, R., & Croft, W. B. (1992). Lexical ambiguity and information retrieval. ACM
Transactions on Information Systems, 10, 115–141.
[11] Losee, R. M. (1988). Parameter estimation for probabilistic document retrieval models. Journal
of the American Society for Information Science, 39(1), 8–16.
[12] Losee, R. M. (1996a). Learning syntactic rules and tags with genetic algorithms for information
retrieval and filtering: An empirical basis for grammatical rules. Information Processing and
Management, 32(2), 185–197.
[13] Manning, C. D., & Schutze, H. (1999). Foundations of Statistical Natural Language
Processing. MIT Press, Cambridge, Mass.
[14] Partee, B. H., Meulen, A. t., &Wall, R. E. (1990). Mathematical Methods in Linguistics.
Kluwer, Dordrecht, The Netherlands.

European Journal of Scientific Research
ISSN 1450-216X Vol.20 No.4 (2008), pp.852-862
© EuroJournals Publishing, Inc. 2008
http://www.eurojournals.com/ejsr.htm
Role of Trade, External Debt, Labor Force and Education in
Economic Growth Empirical Evidence from Pakistan by using
ARDL Approach
Arshad Hasan
Muhammad Ali Jinnah University Islamabad
E-mail: Aarshad.hasan@gmail.com
Safdar Butt
Dean faculty of Business Administration and Social Sciences
Mohammad Ali Jinnah University
Abstract
This paper examines the determinants of economic growth for Pakistan over a
period of 1975-2005, using Autoregressive Regressive Distributed Lag (ARDL) approach
to Cointegration. The relation ship between economic growth, trade, external debt, labor
force and education has been discussed in long term and short term. And it is found that
labor force and trade have significant impact on economic growth whereas external debt
has no association with economic growth in long term or short term indicating that it has
not been used efficiently and productively. An appropriate policy to educate and develop
the human resources of the country coupled with export oriented policies can help in
accelerating the process of economic development and growth and that in turn can have
multidimensional positive effects on the economy and economic conditions of common
man.
Keywords: Pakistan, exports, human capital, causality, ARDL
JEL Classification Codes: C12, C22
1. Introduction
Pakistan’s economy has shown various ups and downs during last 30 years. This study explores the
various factors that have impact on the long-term economic growth of the country. Some of the factors
that affect the economic growth of a country include human capital, total trade external debt and
education. An examination of the role of said factors in economic growth is more important for
developing countries like Pakistan that are fighting against poverty.
Human capital has been considered as one of the primary engines of economic growth and
development. Economic theory suggests that human capital is an important determinant of growth.
Various theoretical models include human capital as a factor of production and consider the
accumulation of human capital as an element of the growth process and empirical evidence for number
of countries also confirms this relationship. Thus we can say that human resource development and its
efficient management plays vital role in the economic growth of economy.
In emerging economies like Pakistan export can play a pivotal role in accelerating the process
of economic growth. The export led hypothesis assumes that export expansion leads to better resource

Role of Trade, External Debt, Labor Force and Education in
Economic Growth Empirical Evidence from Pakistan by using ARDL Approach 853
allocation and improves production efficiency. This is possible through technological development,
new capital formation and employment creation which are pre requisites for accelerated economic
growth. During last few decades, Pakistan has shifted from import substitution policy to export
oriented policy. Economic reforms in the last five years have done much to boost Pakistan’s
merchandise trade/GDP ratio. Evidence on relationship between trade and economic growth is mixed
Capital is an important factor of production. Capital inflows in the form of external debt can
play a vital role in increasing the national output. However, excess use of such capital may have
negative impact as it increases the debt servicing costs and can effect balance of payments. Empirical
evidence suggests bidirectional causality between external debt and growth. Higher external debt
lowers growth but at the same time low growth increases indebtedness. Higher debt operates through a
strong negative effect on physical capital accumulation and on total factor productivity. Lower growth
reduces revenues and primary surpluses. If these are not addressed and adjusted timely these can affect
debt ratios. Reducing debt levels would therefore, contribute to growth by boosting both capital
accumulation and productivity growth.
This study analyzes the relationship between economic growth, human capital, trade and
external debt and education for the period 1995-2005. The paper is organized as follows.
The section II provides an overview of the existing literature about the relationship between
economic growth, exports, human capital external debt and education. The data employed and
methodology adopted has been explained in section III. Empirical results have been discussed in
section IV. Section V deals with conclusion and policy implications
2. Literature Review
2.1. Human Capital and Economic Growth
Lucas (1993) argues that accumulation of human capital serves as an engine of growth. Human capital
accumulation takes place in schools, in research organizations, and in the course of producing goods
and engaging in trade.He investigates the reasons of diversity in the quality of life among nations and
finds that major source of difference is the dissimilarity in human capital. Mankiw (1992) further
extends the theory and considers human capital as an additional accumulate able factor. He provides
evidence that changes in human capital ultimately translates into significant changes of growth rates.
Relationship between economic growth and human capital has been examined extensively.
Many theoretical models of economic growth exists which include Nelson and Phelps (1966), Lucas
(1988), Becker, Murphy, and Tamura (1990), Rebelo (1992), and Mulligan and Sala-i-Martin (1992).
Many empirical researchers which include Romer(1990), Barro(1991),Benhabib and Spiegel(1994)
provide evidence that economic growth and schooling are correlated across countries and time.
Studies that examine the relationship between economic growth and human capital
accumulation are divided into two broader categories. First group of studies uses growth accounting
framework. The growth accounting framework assumes that education, increases the human capital
stock of individuals that improves their productivity and ultimately contributes to growth. This group
includes the studies of Baumol(1986), Barro(1991), Barro and Lee(1993). Other group of studies
employs endogenous growth model. The endogenous growth models assume that human capital creates
new ideas which is transformed into scientific knowledge and ultimately leads to accelerate the process
of economic growth. This group includes Lucas (1988), Romer(1990), Grossman (1991).
Barro(1991), Barro and Lee(1993),Benhabib and Spiegel(1994)provide evidence that human
capital accumulation promotes economic growth). Bils and Klenow (2000) take up the matter
differently and find that levels of schooling are positively correlated with growth rates. But they find
that direction of relation is debatable. Here question arises whether increased schooling results in
accelerated economic growth or accelerated economic growth leads to attainment of higher schooling
due to better allocation of resources for education in the country. However, relatively few studies have

854 Arshad Hasan and Safdar Butt
tested for causality between human capital formation and economic growth. Studies which test for
causality between human capital and growth within a bivariate framework are De Meulemeester and
Rochat (1995), In and Doucouliagos (1997) and Asteriou and Agiomirgianakis (2001).
2.2. Trade and Economic Growth
Relationship between trade and economic growth has been examined extensively. There are number of
studies that empirically investigate the relationship between exports and growth. These studies either
use correlation analysis or employ causality techniques. The empirical evidence on the export growth
nexus is mixed with no clear consensus. Ahmad (2001) reviews approximately 40 studies conducted
during 1970-1990 and finds that empirical support for the export led growth in developing and
developed countries is considerably weaker in more recent studies. Results for studies that use
cointegration and causality analysis are significantly different from those studies which are based on
correlation analysis. Summers (1997) examines the relationship between total trade and growth for
Australian and Canadian market and finds that imports and exports trade play different roles on
economic growth. Summers finds that import trade has a significance role in Canada. However no
evidence of in support of export led growth is found for Australian economy. Strydom (2003) studies
the role of foreign sector in economy and finds that international trade does not play a significant role
in economic growth .One possible reason for this ambiguity is the lack of understanding of the
diffusion system that links trade with economic growth. The evidence shows that the channels through
which trade generates growth have asymmetric growth effects. Therefore economic policies should be
structured to eliminate the impeding effects for such channels and to augment the efficiency of less
efficient mechanism.
Human capital accumulation increases the quality of labor, which in turn, enhances the
productivity of the workforce and stimulates further exports and economic growth (Chuang 2000).
Hanson and Harrison (1995), Stokey(1996) and many other Empirical studies suggest that trade
promotes human capital accumulation and vice-versa. Support for said argument is wide spread
covering range of countries and time periods.
2.3. External Debt and Economic Growth
External debt serves as catalyst to mobilize other factors of production. In many countries, external
debt has been used as main source of capital investment for development of the physical infrastructure.
However, there has been a concern regarding the proper utilization of external debt in poverty
alleviation and overall economic growth of the country.
The relationship between external debt and economic growth has been examined extensively in
recent years. These studies have largely focused on the harmful effects of a country’s “debt overhang”.
It is meant that debt is accumulated to such a high level that becomes a threat for the borrower country
and it faces problems in servicing the debts. The empirical findings suggest that debt overhang
depresses growth by increasing investors’ uncertainty about actions the government might take to meet
its onerous debt-servicing obligations. Debt overhang may also affect the efforts of the government to
carry out structural and fiscal reforms which are necessary to accelerate the economic growth process
of the country. Governments also feel pressures to retire foreign debts. Pakistan’s external debt
situation of the 1990s is consistent with the findings of the recent literature on the relationship between
debt and economic growth. If take an overview of the last decade we find that large current account
deficit (almost 5.0percent of GDP) for an extended period of one decade, the irresponsible use of
borrowed funds, mounting real cost of borrowing and stagnant exports have contributed significantly
in quick accumulation of external debt.
A number of studies have examined the relationship between external debt and economic
growth. The majority of these studies have found that debt variables are significantly and negatively
correlated with growth. Maureen (2001) analyses the magnitude and structure of Kenya's external debt
and examines its impact on economic growth and private investment using time series data for the

Role of Trade, External Debt, Labor Force and Education in
Economic Growth Empirical Evidence from Pakistan by using ARDL Approach 855
period 1970- 1995. The empirical results show that external debt accumulation has a negative impact
on economic growth of Kenya. Karagol (1999) examines the relationship between economic growth,
external debt service and capital inflow using the time series data for Turkey and employing
simultaneous equations. The result suggests that the rise in the debt-servicing ratio adversely affects
economic growth, whereas the decrease in the rate of growth reduces the ability of an economy to
service its debt. This study further provides that the direct impact of external debt on the economic
growth is negative. However favorable indirect effects of it exceed the direct effects. Chowdhury
(1994) investigates the direct, indirect of the external debt on economic growth of seven countries by
using panel data for the period of 1970-1988. These countries include Bangladesh, Indonesia,
Malaysia, Philippines, South Korea, Sri Lanka and Thailand. Results suggest that the external debt of
developing countries is not a primary cause of economic slow down. Schclarek (2004) examines the
probability of existence of both linear and nonlinear relationship between debt and economic growth
for developing and industrial countries. Evidence here is mixed. In case of developing countries, a
significant negative relationship has been observed between external debt and economic growth.
However, no such relationship has been observed in case of industrial countries.
The literature survey shows that a number of studies have examined the role of external debt,
labor force and trade in economic growth separately. But there is no single study examining the role of
these variables in the economy in an integrated way. In this regard, this study attempts to bridge this
gap.
3. Data Description and Methodology
3.1. Data Description and Definition of Variables
This study examines the relationship between economic growth, trade, external debt, human capital
and education. Data on all variables is taken from various publications of State Bank of Pakistan,
Bureau of Statistics, Economic Survey of Pakistan and Lee and Barro’s database on human capital
measures. The study uses annual data that cover the period from 1975 -2005.
3.2. Dependent variable
The economic growth is used as the dependent variable in the model. Gross domestic product (GDP) is
employed as the proxy of the economic growth
3.3. Independent variables
The independent variables are Education, Total Trade, External Debt and Labor Force.
Education
A review empirical work on the relationship between human capital and growth reveals that various
proxies have been used to measure the human capital stock. Alternative proxies for human capital
includes school enrolment ratios, adult literacy rates, levels of education attainment and average years
of schooling, monetary value of human capital stock and international test scores of students. These are
very diversified but all have limitations in one way or other.
School enrolment ratios, adult literacy rates are extensively used in growth regressions due to
their easy availability and broad coverage. Adult literacy rates ignore most of the investments made in
human capital as they do not include qualifications obtained above the basic levels of education so it
seems to be a poor measure of human capital available for current production. Enrolment ratios are
flow variables, and the children currently enrolled in schools are not yet part of the labor force.
Therefore, enrolment ratios do not accurately represent changes in human capital stock. Levels of
education and average years of schooling are most popular and commonly used measures today. This

856 Arshad Hasan and Safdar Butt
study uses average years of schooling of the working age population as a proxy for Education .It is
hypothesized that there exists a positive relationship between education and economic growth.
Total Trade
Trade plays an important role in increasing the production of goods and services. Total trade is the sum
of total exports and imports. All data has been converted into Pakistani rupees and it is transformed at
constant prices of 2000 to adjust the impact of exchange rate variations. It is hypothesized that there
exists a positive relationship between trade and economic growth.
External Debt
External debt is one of the major sources of financing the development programs. These programs
generally focus on infrastructure development that is necessary to lay down the foundations of
sustainable economic growth. It is hypothesized that there exists a positive relationship between
external debt and economic growth. For this study External debt has been translated into Pakistani
rupees at constant prices of 2000 and then logarithm of External debt is taken to construct the variable.
It is hypothesized that there exists a negative relationship between external debt and economic growth.
Labor Force
Labor force is directly involved in the production process and large labor force can help to enhance
production of goods and services. For purpose of this study Labor force of the age between 15 and 64
has been taken from Economic Survey of Pakistan. It is hypothesized that there exists a positive
relationship between labor force and economic growth.
3.4. Methodology
To examine the impact of human capital, trade, external debt and education on economic growth
following model has been tested
Ln GDPt = β0+ β1 lnTT t+ β2 lnLF t + β3 lnTD t + β4 Edu t+μt
(1)
Where
GDP= gross domestic product (in constant terms for year 2000)
TT = total trade
LF= labor force in the age range of 15-64
TD = total debt at constant Rate
Education = average year of schooling
Existence of the long run equilibrium relationship among chronological variables can be
investigated by using several methods. The most widely used methods include Engle and Granger
(1987) test, fully modified OLS procedure of Phillips and Hansen’s (1990), maximum likelihood based
Johansen (1988, 1991) and Johansen-Juselius (1990) tests. All these methods require that the variables
in the system are integrated of order one I (1). Futher, these methods are considered as weak as these
methods do not provide robust results for small samples or structural breaks. Due to these problems, a
newly developed autoregressive distributed lag (ARDL) approach to cointegration has become popular
in recent years.
The ARDL modeling approach was originally introduced by Pesaran and Shin (1999) and
further extended by Pesaran (2001). This approach has numerous econometric advantages in
comparison to other Cointegration methods. One major advantage of ARDL approach is that it can be
applied irrespective of degree of integration. Secondly, ARDL approach provides robust results in
small sample sizes and estimates of the long-run coefficients are well consistent in small sample sizes(
Pesaran and Shin 1999).
Furthermore, a dynamic error correction model (ECM) can be derived from ARDL that
integrates the short-run dynamic with the long-run equilibrium without losing long run information. In
view of the above advantages, we use ARDL approach for cointegration analysis and the resulting
ECM.

Role of Trade, External Debt, Labor Force and Education in
Economic Growth Empirical Evidence from Pakistan by using ARDL Approach 857
An ARDL representation of above equation is as below:
Δ Ln GDPt = β0+ Σ βiΔ Ln GDPt -i+ Σ βi Δ lnTT t-i + Σ βi Δ lnLF t-i + Σ βi Δ lnTD t-i +
Σ βi Δ Edu t-i +μ t Where i ranges from 1 to p (2)
The ARDL method estimates number of regressions to determine the optimal lag length for
each variable. The appropriate lag length for each variable is selected using Schwartz-Bayesian Criteria
(SBC).
The underlying assumption of ARDL procedure is that each variable should be integrated of
orders zero or one i.e. I(0) or I(1). If any variable is integrated of higher order then the procedure is not
applicable. Therefore first step is to perform unit root tests to ensure that none of the variable in
equation (1) is I (2) or higher order.
In the second step of ARDL model, the long-run relationship and the resulting error correction
model is estimated. A general error correction representation of equation (2) is given below:
Δ Ln GDPt = β0+ Σ βiΔ Ln GDPt -i+ Σ λi Δ lnTT t-i + Σ δiΔ lnLF t-i+ Σ φ i Δ lnTD t-i+
Σ ηi Δ Edu t-i + ECM +μt
As external debt, total trade and labor force and education are expected to have a positive
effect on economic growth, the coefficients β, δ and φ are expected to be positive, i.e. β > 0, λ > 0 δ >
0, φ > 0 and η > 0.
Finally, we examine the stability of short-run and long-run coefficients by using cumulative
(CUSUM) and cumulative sum of squares (CUSUMSQ) tests. The CUSUM and CUSUMSQ statistics
are updated recursively and plotted against the break points. If the plots of CUSUM and CUSUMSQ
statistics stay with in the critical bonds of 5% level of significance, the null hypothesis of all
coefficients in the given regression are stable can not be rejected.
4. Empirical Results
Table 1 exhibits the results of unit-root test .Augmented Dickey-Fuller (ADF) and Phillip Parren
procedures have been used to test the stationarity of time series. ADF test assumes that time series is
independently and identically distributed which may not be the case for some of the data so PP- Test
has also been applied which permits the data to be heterogeneously distributed.
Table 1: Unit Root Test
ADF-level ADF-Ist Diff PP-level PP-Ist Diff
Ln GDP 0.2578 -5.6013 0.5908 -5.981
Ln TT -0.1582 -3.0468 -0.5617 -5.7437
Ln ED -1.0521 -3.3468 -1.0521 -3.1421
Edu -1.7318 -3.0972 -2.7568 -4.4379
Ln LF -0.43 -3.5870 -0.7625 -5.2623
Critical. Value 5% -2.9640 -2.9678 -2.9640 -2.9678
Results presented in above table indicate that variables are integrated of order one or lower, so
ARDL methodology can be used to investigate the presence of long term relationship among variables.
The first step in the ARDL procedure is to estimate equation (2)
(3)

858 Arshad Hasan and Safdar Butt
Table 2a: Autoregressive Distributed Lag Estimates
ARDL(1,1,0,0,0) selected based on Schwarz Bayesian Criterion
Independent variables Coefficient S. E t Statistics P value
Ln GDPt-I 0.5487 0.2005 2.7363 0.01
lnTTt 0.2830 0.1500 1.8862 0.07
lnTTt-1 - 0.2688 0.1190 -2.2584 0.03
lnTDt -0.0810 0.1931 -0.4643 0.65
Edut 0.0032 0.0405 0.0785 0.94
lnLFt 1.2120 0.4637 2.6141 0.01
C 1.2949 0.8583
Table 2b:
R-Squared 0.99
R-Bar-Squared 0.98
S.E. of Regression 0.06
S.D. of Dependent Variable 0.51
DW-statistic 2.37
F-stat. F(6, 22) 306.95
significance [.000]
Table 2 (a & b) indicates that total trade and labor force has significant relationship with
economic growth whereas total debt and education have insignificant relationship. The value of R-Bar-
Squared is 0.98 which indicates a high degree of correlation among variables. F statistics is also
significant at 1% which indicates overall goodness of fit. The test for the presence of long-run
relationship amongst the variables of equation (1) highlights the following results. Bahmani-Oskooee
and Bohal (2000) have shown that the results of this first step are sensitive to lag length selected in
equation (2). As we are using annual data so a shorter lag length is considered.
Table 3: ARDL (1,1,0,0,0) Model Long Run Results Dependent variable log (GDP)
Independent variables Coefficient Standard Error t value P value
LTT 0.0313 0.2344 0.1333 0.89
LLF 2.6859 0.8924 3.0098 0.00
LED -0.1987 0.4316 -0.4603 0.65
Edu 0.0070 0.0894 0.0786 0.93
C 2.8694 1.6401 1.7495 0.09
A careful examination of results in Table 3 reveals that Labor Force has significant long term
relationship with economic growth. External debt has insignificant negative association with economic
growth. Similarly total trade and education have no significant impact in economic growth. Short-run
dynamics of the relationship has also been examined by employing ARDL error correction
representation. Estimates of error correction representation of ARDL model are given table below

Role of Trade, External Debt, Labor Force and Education in
Economic Growth Empirical Evidence from Pakistan by using ARDL Approach 859
Table 4: Error Correction Representation for the ARDL Model ARDL (1,1,0,0,0)
Independent variables Coefficient S .E t Statistics P value
Δ lnTT 0.2829 0.1500 1.8862 0.07
Δ lnLF 1.2120 0.4636 2.6141 0.02
Δ lnTD -0.8966 0.1931 0.4643 0.64
Δ Edu 0.0031 0.0405 0.0784 0.93
ECM(-1) -0.4512 0.2005 2.2502 0.03
R-Squared .39
S.E. of Regression .06
S.D. of Dependent Variable .07
DW-statistic 2.37
F-stat. F(5, 23) 2.87
significance [.037]
The ECM equation is given as
ECM = Ln GDPt -.031266* lnTT t +0.19869* lnTD t + 0.0070366* Edu t -2.6859* lnLF t -
2.8694*C
Examination of error correction model in Table 4 shows that labor force has the strongest effect
on economic growth in the short run which is followed by total trade. The short-run effect of total
external debt on economic growth in Pakistan is weak and statistically insignificant at even 10% level
of significance. The coefficient of ECM term has correct sign and significant at 10 %. It confirms the
presence of relationship between the variables. The Coefficient of the ECM term suggests that
adjustment process is quite fast and 45% of the previous year’s disequilibrium in economic growth
from its equilibrium path will be corrected in the current year. Thus, the evidence presented in this
section suggests that economic growth in Pakistan is mainly determined by fluctuations in labor force ,
and trade both in the short run and the long run. Total debt is not an important determinant of economic
growth either in the short-run or the long-run.
The CUSUM and CUSUMSQ plots to check the stability of short run and long run coefficients
in the ARDL error correction model are given below in figure 1:
1.5
1.0
0.5
0.0
Figure 1:
Plot of Cumulative Sum of Squares of
Recursive Residuals
-0.5
1977 1982 1987 1992 1997 2002 2005
The straight lines represent critical bounds at 5% significance level

860 Arshad Hasan and Safdar Butt
Plot of Cumulative Sum of Recursive
Residuals
15
10
5
0
-5
-10
-15
1977 1982 1987 1992 1997 2002 2005
The straight lines represent critical bounds at 5% significance level
Figure 1 shows that both statistics CUSUM and CUSUMSQ are with in the critical bounds of 5
% indicating that the model is structurally stable.
5. Conclusion
This paper attempts to examine the determinants of economic growth for Pakistan over the period of
1975-2005, using ARDL approach to Cointegration. The results indicate that labor force and trade are
important determinant of economic growth in short run and long run. The results indicate a positive
relationship between labour force and economic growth which in line with the general assertion that
the labour force is a key factor of production and hence it is positively associated with the economic
growth of a nation. The external debt is found to not to have any relationship with economic growth.
This result indicates that the external debt has not been used productively and efficiently in Pakistan
which may be one of the reasons behind the slow economic growth. An appropriate combination of a
suitable flow of external debt, an educated and highly productive labor force and a properly balanced
external trade can lead to economic development and accelerate the growth process. An integrated
policy covering human resource development frame work and export friendly trade strategy can have
multidimensional positive effects on the nation’s march towards growth and prosperity.

Role of Trade, External Debt, Labor Force and Education in
Economic Growth Empirical Evidence from Pakistan by using ARDL Approach 861
References
[1] Bahmani-Oskooee, M. and Bohl, M. T., “German monetary unification and the stability of
German M3 money demand function” Economic Letters, Vol.66, 2000, pp.203-208.
[2] Engle, R. and Granger, C., “Cointegration and error and testing”, Econometrica, 55, 1987,
pp.251-276.
[3] Johansen, S., “Statistical analysis of cointegrating vectors”, Journal of Economic Dynamics and
Control, Vol.12, 1988, pp.231-254
[4] Johansen, S. and Juselius, K., “Maximum likelihood estimation and inference on cointegration
–with application to the demand for money” Oxford Bulletin of Economics and Statistics, Vol.
52, 1990, pp.169-210.
[5] Peseran, M. H. and Shin, Y., An Autoregressive Distributed Lag Modelling Approach to
Cointegration Analysis. Chapter 11 in Econometrics and Economic Theory in 20th Century:
The Ragnar Frisch Centennial Symposium, Strom, S. (ed.). (Cambridge University Press:
Cambridge, 1999)
[6] Pesaran, M. H. and B. Pesaran, B., Microfit 4.0 Interactive Econometric Analysis (Oxford
University Press, Oxford, 1997).
[7] Chowdhury, Khorshed (1994). "A Structural Analysis of External Debt and Economic Growth:
Some Evidence from Selected Countries in Asia and the Pacific." Applied Economics 26: 1121-
1131.
[8] Kalima, Barbara (2002). "Gender and Debt". African Forum and Network on Debt &
Development, pp: 6-7.
[9] Maureen Were (2001). "The Impact of External Debt on Economic Growth and Private
Investment in Kenya." Kenya Institute for Public Policy Research and Analysis, pp: 28-30
[10] Shrestha, Min B. and Khorshed Chowdhury (2005). "A Sequential Procedure for Testing Unit
Roots in the Presence of Structural Break in Time Series Data". International Journal of
Applied Econometrics and Quantitative Studies, 2, pp: 1-15.
[11] Strydom, P.D.F. (2003). International trade and economic growth in South Africa, The
Economic Society of South Africa.
[12] Summers, Peter M. (1997). "Trade and Growth in Settle Economies: Australian and Canadian
Comparisons", Melbourne Institute Working Papers 9/97 pp.6
[13] Barro, R., (1991), “Economic Growth in a Cross Section of Countries,” Quarterly Journal of
Economics, 106, 407-33.
[14] Barro, R. and J.-W. Lee, (1993), “International Comparisons of Educational Attainment,”
Journal of monetary Economics, 32, 363-94.
[15] Ramesh Paudel and Min B Shrestha (2006),” The Role of External Debt, Total Trade and
Labour Force in Economic Growth: The case of Nepal” ,The Business Review, Cambridge;
Summer 2006; 5, 2; ABI/INFORM Global pg. 130
[16] De Meulemeester, J. L. and D. Rochat, (1995), “A Causality Analysis of the Link Between
Higher Education and Development,” Economics of Education Review, 14, 351-61
[17] Chuang, (2000), " Human Capital, Exports, and Economic Growth: A Causality Analysis for
Taiwan, 1952-1995" . Review of International Economics, Vol. 8, pp. 712-720, November
[18] In, F. and C. Doucouliagos, (1997), “Human Capital Formation and US Economic Growth: A
Causality Analysis,” Applied Economics Letters, 4, 329-31.
[19] Lucas, R E(1988). "On the Mechanics of Development Planning." Journal of Monetary
Economics, 22. pp. 3-42.
[20] Romer, P. (1990), “Human Capital and Growth: Theory and Evidence,” Carnegie-Rochester
Conference Series on Public Policy, 32, 251-285.
[21] Grossman. G M. and E Helpman (1991), “Innovation and growth in global ~Cam briddge,
Massachusetts M.I.T. Press.

862 Arshad Hasan and Safdar Butt
[22] Benhabib, J. and M. Spiegel, (1994), “The Role of Human Capital in Economic Development:
Evidence from Cross-Country Data,” Journal of Monetary Economics, 34, 143-73.
[23] Asteriou, D. and G. M. Agiomirgianakis, (2001), “Human Capital and Economic Growth: Time
Series Evidence from Greece,” Journal of Policy Modeling, 23, 481-89.
[24] Barro, R., (1991), “Economic Growth in a Cross Section of Countries,” Quarterly Journal of
Economics, 106, 407-33.
[25] Barro, R. and J.-W. Lee, (1993), “International Comparisons of Educational Attainment,”
Journal of monetary Economics, 32, 363-94.
[26] Pesaran, M. H., Y. Shin, and R. Smith (2001). “Bounds Testing Approaches to the Analysis of
Level Relationships,” Journal of Applied Econometrics, 16(3), 289
[27] Barro, R. J. and X. Sala-i-Martin (1999), Economic Growth. New York: McGraw-Hill.
[28] Pesaran, M. H. and B. Pesaran.(1997),”Working with Microfit 4.0: Interactive Econometric
Analysis”, Oxford: Oxford University Press.
[29] Ahmad, J. (2001), “Causality Between Exports and Economic Growth: What Do the
Econometric Studies Tell Us?” , Pacific Economic Review, 6(1), 147-167.
[30] Bils, M. and P. Klenow. (2000), “Does Schooling Cause Growth?” American Economic
Review, 90(5), 1160-1183.

European Journal of Scientific Research
ISSN 1450-216X Vol.20 No.4 (2008), pp.863-870
© EuroJournals Publishing, Inc. 2008
http://www.eurojournals.com/ejsr.htm
Development of Mechanical Prosthetic Hand System for BCI
Application
N. A Abu Osman
Department of Biomedical Engineering, Faculty of Engineering
University of Malaya, 50603, Kuala Lumpur, Malaysia
S. Yahud
Department of Biomedical Engineering, Faculty of Engineering
University of Malaya, 50603, Kuala Lumpur, Malaysia
S. Y Goh
Department of Biomedical Engineering, Faculty of Engineering
University of Malaya, 50603, Kuala Lumpur, Malaysia
Abstract
The study is to develop a prosthetic hand that can be controlled by Brain-Computer
Interface (BCI). The proposed prosthetic hand consists of palm and 5 fingers. The hand
was designed to perform the 4 predetermined essential tasks in BCI applications;
cylindrical grasp, key pinch, pulp to pulp pinch and tripod pinch. The phalanges of the
finger was modeled as three link open chain joined at the metacarpal joint (MCP), proximal
joint (PIP) and distal joint (DIP). Each segment denote as phalanx was made from two
parallel aluminum plates and connected to the other segment using a bolted spacer acting as
hinge joint. Length of each segment was made such that it will form an equiangular motion
path during trajectory. Each joint is actuated by its individual actuator. Two mechanisms
were proposed in this study. The first mechanism is the tendon drive; used terelyne string
to pull each segment to flexion. The second mechanism is a spring return; a stored resistive
force in torsion spring will kick the segment to its initial position. The hand was equipped
with potentiometers and pressure sensors for control purposes. The prototype was tested
with BCI system, in order to meet its initial objective and additional tests were carried out
to evaluate its performance. An experiment to test the performance of the prosthetic hand
was carried out successfully. Strength of each tendon was measured using a proof ring
method and motion images were captured using video camera and analyzed using Peak
Motus Performance 2000 Motion Analysis software.
1.0. Introduction
Brain-Computer interface
A brain-computer interface (BCI) is a communication system in which messages or commands convey
from an individual to external device without passing through a brain's normal output pathways of
peripheral nerves and muscles. A BCI use the recorded electroencephalogram (EEG) rhythms from the
electrodes on scalp and translated to the external device. The BCI application is useful for people with
severe motor disabilities and in worst case for a completely paralyzed or “locked-in” patient that
unable to communicate by any way. BCI application is wide and can be varied depending on the need

Development of Mechanical Prosthetic Hand System for BCI Application 864
of the user such as communication, controlling the environment, or moving prosthetic limb [1].
Wolpaw et. al has used BCI to restore communication for locked-in subject by moving a cursor in one
or two dimension to choices on computer screen [2]. Birch and Mason [3] has used the LF-ASD to
allow user to navigate a maze by making, turning decisions at intersection which could be implement
for wheelchair control. Graz-BCI [4] is used by tetraplegic patient to control the opening or closing of
a hand orthosis.
In this study, the BCI is used to control a prosthetic hand. Figure 1 shows the block diagram of
the BCI proposed in this study.
Prosthetic hand
Figure 1: Block diagram showing the components of BCI
Development of prosthetic hand is inspired by the beauty and complexity of the human hand. Human
hand is a very complex and malleable tool connected to the most powerful and complicated controller,
the brain. Hand is made up from wrist, palm and fingers. First finger is the thumb followed by index,
middle, ring and little finger. Skeleton of the hand can be divided into three segments; the carpus or
bones of the wrist, the metacarpus or bones of the palm and the phalanges or bones of the finger.
Prostheses can be classified into; body powered and externally powered. Most of the ancient belowelbow
prosthetics known are body powered and apparently relied on the contralateral hand or relative
motion between the shoulder, upper arm and forearm for the operation.
Body powered below-elbow prosthetics usually consist of split hook or five fingers, socket and
harness. This type of prosthetic hand only provide open and close hand action, and due to this
limitation study are carried out to overcome it by switching to the externally powered prosthetic hand.
The current trend in prosthetic hands is externally powered. An externally powered prosthetic hand is
actuated by external actuators such as DC motors, ultrasonic motors, pneumatic cylinder, hydraulic
cylinder and shape memory alloy material (SMA). Robotic technology has been helpful in improving
the control and design of prosthetic hand. There are close relationship between robotics and prosthetic
hand since both provide human like motion and prehension. In robotic hand the main focus is to imitate
the human hand and enhance the performance. Thus, in robotic application two fingers are sufficient,

865 N. A Abu Osman, S. Yahud and S. Y Goh
however three fingers are needed to perform dexterous tasks in an unstructured environment and to
achieve full grasp of two-dimensional object [5]. Whereas, prosthetic hands are inspired by the need to
replace the function of the human hand and try the best to resemble the human hand both functionally
and structurally. In general prosthetic hands have benefited from the development of the robotic
technologies. Brain-computer interface (BCI) project developed by University of Malaya is a project
consists of signal processing part, BCI box and the device, as shown in figure 1. The device is
composed of prosthetic hand and fuzzy controller. The objective of the study is to develop a prosthetic
hand that able to perform the four basic tasks required by human hand: cylindrical grasps, key pinch,
pulp to pulp pinch and tripod pinch.
2.0. Methodology
In this study the primary concern is to develop a prosthetic hand that able to perform the four essential
tasks using a BCI system. In order for the hand to perform the four tasks, the hand should possess the
maximum number of the DOFs. As a result, the proposed design should yield a total of 16 DOFs with
each finger has 3 DOFs and thumb has 4 DOFs. The design of the finger has the following
characteristics; (i) each finger has a total of three joints with three DOFs, (ii) thumb has similarly three
joints but with four DOFs, (iii) each DOF is actuated by one actuator, (iv) each joint has installed a
torsion spring within it for return mechanism, and (v) each joint is equipped with potentiometer for
control. For every DOF of movements, it is driven by its individual actuator, thus the hand used up to
16 units of actuator. Actuator used in this design is DC micromotors type 1331 with gearhead
reduction series 14/1 manufactured by Faulhaber Group. The actuator is then connected to its
respective segment using a terelyne string. The string will pulled the segment as the actuator rotates,
the angle and speed of the flexion is depending on the output of the actuator. Flexion of each segment
is accomplished when the string being pulled by the actuator and reset to its original position when
string releases. The reset mechanism is, attain with the used of torsion spring at the joint. The stored
resistive force on the torsion spring will reset segment to its original position. The string will act as a
flexor digitorum profundus tendon of the human hand. The basic unit of the prosthetic hand is the
prosthetic finger. Each prosthetic finger is said to maintain the same anatomical structure and
dimensional proportion, regardless of their size. The three phalanx; distal, middle and proximal
phalanges are denoted as L3, L2 and L1 accordingly as shown in figure 2 and connected to form a
finger as shown in figure 3.
Figure 2: Different size and shape of phalanx

Development of Mechanical Prosthetic Hand System for BCI Application 866
Figure 3: Prosthetic finger
Each phalanx is made from 2-parallel aluminum plate of 1.5mm thickness and join using a
brass spacer bolted with 2mm diameter stainless steel screw. DC motors with the combination of
reduced gear heads are used to actuate finger segments. Process of determining the length of the
phalanx acquired the implementation of the Fibonacci sequence. Fibonacci sequence in application to
the human hand stated that; the difference between the length of the next phalanx and the sum length of
the two prior phalanges must equal to zero. The sum of the distal phalanx and the middle phalanx
should be equal to the length of the proximal phalanx. However, Park et al [6] in his work has showed
that the bone lengths of the finger does not follow the Fibonacci relationship but the motion paths of
the digits still form an equiangular spiral path. Therefore to achieve the equiangular spiral motion path
the respective length that representing each segment should include the absolute bone length and
functional length (radius of the joint). Length of each segment was referred to author’s hand herself
and using the Hamilton’s ratio [7] to verify that the chosen length is sufficient to form an equiangular
spiral motion.
All the fabrication and machining process was done in the mechanical workshop in the
Department of Mechanical Engineering, University of Malaya, Malaysia. The precise machining was
carried out using a CNC (computer numerical control) wire EDM (electrical discharge machining)
machine Sodick, available in the Department of Manufacturing and Design, University of Malaya,
Malaysia.
3.0. Result
A prototype of prosthetic hand was successfully fabricated and tested for functionality, performance
and strength. Figure 4 shows the flow diagram of a BCI system to control prosthetic hand developed by
Biomedical Engineering BCI group, University of Malaya. A fuzzy controller is used to control the
prosthetic hand. Input for controller is fed from the BCI box. EEG signals acquired from subject is
amplified and converted to digital signal. The signal is further process and classified before send to
fuzzy controller.

867 N. A Abu Osman, S. Yahud and S. Y Goh
Figure 4: A BCI system developed for control of prosthetic hand.
The prosthetic hand then acted according to the subject intent. The proposed BCI system was
effectively controlled the prosthetic hand. The prosthetic hand is capable of performing the four
essential tasks: cylindrical grasps, key pinch, pulp to pulp pinch and tripod pinch as shown in figure 5.
Figure 5: The four pre-determined tasks for the prosthetic hand
Strength for each joint was measured using proof ring method. Maximum loads used for
calibration of the proof ring is 1.2 kg. Figure 6 shows the graph obtained form the proof ring
calibration test. A LabVIEW program was developed to capture voltage changes as the ring
experienced tension. In the test the ring was placed between actuator and measured joint of the

Development of Mechanical Prosthetic Hand System for BCI Application 868
prosthetic finger. LabVIEW program will capture value of strain gages during flexion and steady state.
Each joint was tested for flexion angle ranging from 10° to 90°. The collected results shows that the
value do not exceed the calibration range, (0-6.5V). Value acquired for each potentiometer shows
degree of flexion made from respective joint. The reading was taken at chosen angle; 10°, 45° and 90°
in fuzzy GUI (graphical user interface) controller box. Figure 7 shows a sample of collected data for
three potentiometers on index finger at; metacarpal joint (MCP), proximal joint (PIP), and distal joint
(DIP) accordingly.
Figure 6: Calibration graph of Proof Ring used in strength test.
Figure 7: Potentiometers reading at MCP, PIP and DIP joints of middle finger
4.0. Discussion
Design of prosthetic hand emphasize on simple mechanism and robustness. The prototype employed
simple pulling tendon mechanism for flexion and resistive torsion spring for return mechanism.
Structural design of the prosthetic hand is made simple for easy assemble and dissemble without
destructing any of components. Ample area in every phalanx of the finger provides space for future
modification. Selection of material based on availability, cost and strength. Design and mechanism of
the hand is simple if compared with other available prosthetic hands [8][9][10][11]. However, size and

869 N. A Abu Osman, S. Yahud and S. Y Goh
weight of the prosthetic hand could be reduced and skin could be added into the design to give more
humanlike impression.
Functional strength on each joint is depending on the tendon’s material. Terelyne string is used
as tendon and able to withstand a maximum functional weight of 45 kg. Therefore, the prosthetic hand
is capable of handling functional weight more than required by human hand [12]. The path of fingertip
trajectory for each prosthetic finger is similar to Guo’s trajectory [13]. Maximum flexion angles for
each joint are varied but approaching the value suggested by Thakor et. al [14]. The prosthetic hand is
able to pose the four desired tasks without reaching a maximum angle of each joint. The four tasks
focused in the study are basic functional activities commonly performed by human hand. The selection
of hand tasks can be observed in experiment to investigate functional strength of the hand by Chao et.
al [12].
The proposed BCI system is able to control the prosthetic hand, during online experiment.
Subject however has to be trained in order for him/her to control the prosthetic hand. Performance of
prosthetic hand in BCI environment is very much depending on factors such as subject’s EEG control
ability, system performance, feedback delay and 50 Hz interference. As far as the author is concern,
there is no experimental work done to demonstrate the actual performance of BCI controlling a
prosthetic hand.
5.0. Conclusion
The prototype of a prosthetic hand has fulfilled the objective of the study. A total 16 DOFs is
considered sufficient however it can be increase for better dexterity. Increasing the number of DOFs
could result in different and complicated mechanism. Thus it will add complexity to the design and
controller. The major contributor to the total weight of current prosthetic hand is DC motors. In future
build in actuators could be considered to replace DC motors. he prosthetic hand in this study was
developed specifically for BCI application. Application of BCI technology in controlling a prosthetic
hand is a promising method to restore communication of “locked-in” with external environment. To
date, experiment to test ability to control prosthetic hand was carried out on healthy subject. The
possibility of implementing the technology to “locked-in” patient is yet to be discovered.
Acknowledgement
I would like to thank the UM-BCI group for great teamwork and sharing knowledge in completing the
project. Thank you to all technicians in mechanical workshop, University of Malaya for their help and
advice during fabrication and machining processes.

Development of Mechanical Prosthetic Hand System for BCI Application 870
References
[1] Melody M. Moore. 2003. Real-World Applications for Brain-Computer Interface Technology.
IEEE Trans. on Neural Systems and Rehab. Eng., vol. 11, No.2, 162-165.
[2] J.R. Wolpaw, D.J. McFraland, T.M. Vaughan, G. Schalk. 2003. The Wordsworth Center Brain-
Computer Interface (BCI) Research and Development Program. IEEE Trans. on Neural
Systems and Rehab. Eng. vol.11, No.2, 204-207.
[3] G.E. Birch, S.G. Mason. 2000. Brain-Computer Interface Research at the Neil Squire
Foundation. IEEE Trans. on Rehab. Eng. vol. 8, No.2, 193-195.
[4] C. Guger, W. Harkam, C. Hertnaes, and G. Pfurtscheller. 1999. Prosthetic control by an EEGbased
brain-computer interface (BCI). Proc. AAATE 5th European Conference for the
Advancement of Assistive Technology.
[5] S. Nahavandi and A.Z. Kouzani. 2001. Artificial Hand – From a Robotic Perspective. Seventh
Australian and New Zealand Intelligent Info. Sys. Conf. 37-42,
[6] Andrew E. Park, MD, John J. Fernandez, MD, Chicago, IL, Karl Schmedders, PhD, Evanston,
IL, Mark S. Cohen, MD, Chicago, IL. 2003. The Fibonacci Sequence: Relationship to the
Human Hand. The Journal of Hand Surgery, vol. 28A No. 1. 157-160.
[7] R. Hamilton, R. A. Dunsmuir. 2002. Radiographic Assessment of the Relative Lengths of the
Bones of the Fingers of the Human Hand. The Journal of Hand Surgery, vol. 27B No. 6, 546 -
548
[8] R. Tomovic and G. Boni. 1962. An Adaptive Artificial Hand. IRE Trans. on Automatic
Control, vol. 7, issue 3, 3-10.
[9] Peter J. Kyberd. Colin Light, Paul H. Chappell, Jim M. Nightingale, Dave Whatley and Mervyn
Evans. 2001. The design of anthropomorphic prosthetic hands: A study of the Southampton
Hand. Robotica (2001) Vol. 9, 563-600
[10] S. Schulz, C. Plyatiuk and G. Bretthauer. 2001. A New Ultralight Anthrpomorphic Hand. Proc.
of the IEEE Int. Conf. on Robotics and Auto. vol. 3, 2437-2441
[11] M. Carozza, B. Massa, S. Micera, R. Lazzarini, M. Zecca and P. Dario. 2002. The development
of a novel prosthetic hand – ongoing research and preliminary results. IEEE/ASME Trans. on
Mechatronics, vol. 7, no. 2, 109-114
[12] Chao, E.Y. 1989. Biomechanics of the hand: a basic research study. World Scientific, 1989.
[13] Gongliang Guo, William A. Gruver, and Xikang Qian. 1992. A new Design for a Dextrous
Robotic Hand Mechanism. IEEE Int. Conf. on Systems, Man, and Cybernetics, 35-38
[14] Becker, J.C., Thakor, N.V. 1988. A study of the Range of Motion of Human Fingers with
Application to Anthropomorphic Designs. IEEE Trans. on Biomedical Engineering, vol. 35,
No.2, 110-117

European Journal of Scientific Research
ISSN 1450-216X Vol.20 No.4 (2008), pp.871-881
© EuroJournals Publishing, Inc. 2008
http://www.eurojournals.com/ejsr.htm
Toxicity of Arsenic in the Ground Water of
Comarca-Lagunera (Mexico)
Faten Semadi
Laboratoire d’Optimisation de la Conception d’Ingénierie et d’Environnement (LOCIE)
73376 Le bourget du lac Cedex France
E-mail: fsemadi@yahoo.fr
Vincent Valles
Laboratoire d'hydrogéologie d'Avignon
E-mail: vincent.valles@univ-avignon.fr
Jose Luis Gonzalez Barrios
Centro Nacional de Investigación Disciplinaria
en Relaciones Agua-Suelo-Planta-Atmósfera (INIFAP-Mexico)
E-mail: gonzalez.barrios@inifap.gob.mx
Abstract
Nowadays, ecosystems are menaced by toxic pollutants causing environmental
disturbances and human health risk. Many researchers are working over the world on this
subject.
This paper shows a study on arsenic as a trace element provoking human health risk
and environmental problems with an approach on this pollution origin.
In the first part, the statistical approach associated with geochemical methods lets
explain the sources of variability of arsenic content that could be associated to three main
points: the first is related with climate aridity as a responsible of water evaporation and
concentration; the second point is related to geological variability especially in the upper
part of the studied watershed. The third point is linked with aeration conditions which
influence the toxicity of arsenic forms. Pentavalent forms of arsenic are dominant in the
upper part of the watershed while trivalent forms are more important downstream where
arsenic toxicity increases.
The second part of this work presents a very high human health risk assessed for
watershed population concluding that it is very urgent to react to this problem.
Keywords: Arsenic, human health, risk, Mexico, environment, geochemistry
Introduction
The population exposure to arsenic is mainly by food with an average uptake of 40 µg daily, but with a
high spatial variability depending on geographical situation and sea food consumption. Arsenic is a
trace element widespread in the Earth's crust. Some soils have a high arsenic content under mineral
compounds that are very toxic. In certain areas of the world, the groundwater consumed by people has
a very high content of arsenic under inorganic compounds. On the other hand, the organic forms of

Toxicity of Arsenic in the Ground Water of Comarca-Lagunera (Mexico) 872
arsenic have a lower toxicity (like Arsenocholine and arsenobetaine) and they are present into fish and
other seafood (Dolique, 1968).
Water can be polluted by arsenic compounds with industrial waste discharges or industrial dust
carried down by rain or snow. Polluting dust may come from fuel oxidation (especially coal),
metallurgic activities (for gold production or other metals extractions), by agricultural practices (use of
pesticides and food additives for animal production) or by waste incineration.
Arsenic is a poison well known since antiquity. The presence of even weak concentrations into
the municipal drink water is a good reason for people worry.
The human exposure to arsenic by handling or inhalation may causes:
• acute intoxication at the end of seven days
• subacute intoxication at the end of 90 days
• cancerous affections at the end of 40 years
In the last years, several works on arsenic were carried in the United States, Russia, Chile and
Madagascar. This work is devoted to the Mexican arid zone called Comarca Lagunera where
observations suggest that arsenic could be related to human health problems. Physicochemical studies
on hidro-chemistry were made recently on this area focusing the environmental impact of groundwater
salinity and major elements on irrigated soils (Gonzalez-Barrios, 1992).
This work has two parts:
• the human health risk assessment related to the polluted drink water with inorganic
arsenic compounds.
• the arsenic content observed and its variability according with a geographical distribution
Studied Area
The environment of the studied area is strongly marked by geological features combining volcanic
rocks with sedimentary and marine rocks. The climate is arid and continental causing salt
concentration and evaporitic formations in soils. Topography designs two great watersheds: the Nazas
and the Aguanaval rivers basins that finish their hydrological courses in an endorreic plane at 1000
meters over the sea. This plane called Comarca Lagunera on the Mexican Altiplano, is surrounded by
mountains: the "Sierra Madre Oriental" and the "Sierra Madre Occidental" which have an altitude
between 1800 and 2800 meters (figure 1). It should be noted that Comarca lagunera is the endorreic
bottom (approximately 48000 km 2 ) of a bigger hydrological region of 92000 km 2 .
On this endorreic bottom there are not marshy or humid zones because groundwater table is
generally more than one hundred of meters depth.
Figure 1: The studied area

873 Faten Semadi, Vincent Valles and Jose Luis Gonzalez Barrios
Materials and methods
ACP
The analysis of principal components (ACP) is a multivariable method for statistical analysis. It could
be useful for quantify and order with hierarchical basis the mechanisms responsible of water quality. In
this work, it is calculated starting from a matrix of correlation. The variables are then centred and
reduced, making possible the solution of unit changes restrictions. Thus, a parameter such as the
electric conductivity expressed in dS m -1 will be treated like a concentration value expressed in M L -1 .
The ACP makes possible to find the factorial axes with linear combinations of parameters,
because all of them are not playing the same roll. In hydrochemistry, the experience shows that a
factorial axis usually represents a process or a source of variability.
It is important to say that the factorial axes are orthogonal, it means independent; they represent
mechanisms between them. For the ACP, the processes do not interfere between them. It makes
possible to group different chemical parameters by their behaviour, it means that it makes a behaviour
typology for the chemical parameters observed. The ACP let also group the water samples with similar
characteristics within all observed parameters.
Monte Carlo Method
It is a simulation method based on the distribution laws of all the parameters. This operation is repeated
hundreds or thousands of times, making possible the calculation of an average value and its standard
deviation.
Calculations of speciation: modeling thermodynamic of chemical balances
When water contacts soil minerals, a great number of chemical reactions take place into the aqueous
phase and within solution and minerals. According to the case, the ions content in the solution
increases or decrease like a "source" or a "sink" in a forecasting model of the solution transfers.
Geochemical models were developed in this work with the purpose of present briefly:
Modelling thermodynamic balances
It consists of studying three tools of current use in geochemistry: the interactions of water - rocks by
thermodynamic balances. The majority of natural solutions contain a great number of chemical species
distributed in different phases (liquid, solid and gaseous) ready to interact between them. That is why
the study of balances between solutions and minerals leads to the estimation of activities of dissolved
chemical species from the solute concentrations. Knowing the activities, it is possible to calculate the
saturation state of the solutions related to minerals present in the environment by its solubility product
(generally reported on thermodynamic data bases).
Analyze of concentration diagrams
The second approach is the study of solute concentration evolution in aqueous solutions while
solutions are concentrated (Al-Droubi, 1976; Gac, 1980; Fritz, 1981, Vallès, 1987, Ribolzi and Al,
1993). This method is based on the examination of concentration diagrams and is adapted to
groundwater concentration by evaporation (Mediterranean and, arid climates). The development of
these diagrams requires data of measurement (Al-Droubi, 1976; Gac, 1980; Vallès, 1987; Barbiéro,
1994) or the calculation of the concentration factor in solutions by a reference tracer (Gac, 1980;
Gonzalez-Barrios, 1992; Ribolzi et al, 1993; Barbiéro, 1994).

Toxicity of Arsenic in the Ground Water of Comarca-Lagunera (Mexico) 874
Generalized residual alkalinity
Residual alkalinity (Van Beek and Van Breemen, 1973), resulting from the concept of residual
carbonate (Eaton, 1950), it is obtained by difference between carbonated alkalinity (Alcc) and the total
concentrations of the divalent cations in solution:
AR = Alcc-2(Ca 2+) T-2(Mg 2+ )T (1)
It is expressed in equivalents per litter of solution. The evolution way of the solution
concentrations under evaporation conditions can be predicted according to the sign of the residual
alkalinity. This concept was generalized with successive precipitation of some minerals such as
calcite-gypsum sequence (Al-Droubi, 1976; Valles, 1987; Valles and al, 1989; Valles and al, 1991). It
corresponds to a ionic balance which let foreseen the main geochemical interactions.
Until little time ago, this method was used to foreseen the way of evolution of a concentrating
solution or to precise the geochemical group of solutions. Since not so far time ago, the conservative
character of residual alkalinity was theoretically predicted (Valles and al, 1991) and was showed on
field conditions (Ribolzi and al., 1993). Consequently this concept can be used in the applications to
quantitative purpose such as the decomposition of a flood flow hydrogram (Giusti and Neal, 1993;
Ribolzi and al, 1996). It was largely used by Gonzalez Barrios (1992) to explain the behaviour of
major chemical elements in the groundwater of the Comarca Lagunera. The results of this study are
synthesized in the following part.
Results and discussion
The arsenic content of 52 groundwater samples was taken from Gonzalez Barrios (1992) as well as the
major chemical elements. The groundwater data bases are reported in appendix 1.1 and 1.2.
Statistical study of arsenic concentrations and other elements
This part focused the danger of toxicity by mineral arsenic. The groundwater analysis was made in
Mexico at the laboratory of INIFAP CENID-RASPA in 1989, with traditional procedures:
thermoelectric atomic absorption method.
Table 1: Statistics on arsenic and other chemical elements concentrations
Variable Average Minimum Maximum Variance
Standar
deviation
Variation
Coefficient
Unit
Carbonated Alkalinity 2,86E-03 1,30E-03 6,40E-03 1,28E-06 1,13E-03 3,95E-01 Eq L -1
H 3,02E-05 5,01E-06 1,00E-04 6,07E-13 2,46E-05 8,15E-01 mg L -1
Na 1,84E+02 4,60E+01 8,14E+02 1,16E+00 1,63E+02 8,90E-01 mg L -1
Ca 1,11E+02 2,00E+01 5,49E+02 2,66E-01 1,03E+02 9,28E-01 mg L -1
Mg 2,80E+01 1,22E+00 2,15E+02 7,19E-02 4,18E+01 1,50E+00 mg L -1
Cl 8,15E+01 1,06E+01 2,66E+02 1,23E-01 6,59E+01 8,09E-01 mg L -1
SO4 5,24E+02 5,28E+01 2,88E+03 3,19E+00 5,53E+02 1,06E+00 mg L -1
Pb 2,49E-02 2,07E-04 2,30E-01 1,26E-08 5,12E-02 2,06E+00 mg L -1
Zn 2,16E-02 6,54E-05 6,00E-01 1,12E-07 8,56E-02 3,96E+00 mg L -1
Cu 5,13E-04 6,35E-05 1,70E-02 9,34E-11 2,43E-03 4,75E+00 mg L -1
As 9,96E-02 1,00E-02 5,50E-01 2,29E-07 1,31E-01 1,32E+00 mg L -1
EC 1,59E+00 3,67E-01 6,40E+00 1,44E+00 1,20E+00 7,55E-01 dS cm -1

875 Faten Semadi, Vincent Valles and Jose Luis Gonzalez Barrios
Figure 2: Arsenic concentration compared with the statistical and norm values
Table 2: Arsenic statistical and norm values and ratios
Minimum K1 Average K2 Maximum Norm K3
0.01 1/5 0.096 1.9 0.55 0.05 11
K1 = Minimum / norm values ratio
K2 = Average / norm values ratio
K3 = Maximum / norm values ratio
According with table 1 and 2, as well as figure 2, the arsenic content in groundwater exceeds
the effective norm; the minimal value remains lower than norm value average arsenic value is almost
two times greater the norm value (K2 = 1.9). The maximum value exceeds eleven times the norm value
(K3 = 11).
Seeking natural mechanisms for explain the observed arsenic contents
Chemical types of water and theirs evolutions
Figure 3: chemical types of groundwaters and their evolution
The PIPER diagrams are useful for characterising chemical solutions. They provide rich and
practical information for the qualitative description of water. They make possible to visualize the
relative contents of cations and anions expressed as a percentage, and help to determine the
geochemical type of water with the diagram subdivisions on triangles and a rhombus.

Toxicity of Arsenic in the Ground Water of Comarca-Lagunera (Mexico) 876
The points observed show a high dispersion. The most diluted waters are characterized by a
calcic carbonated type. When water concentrates, it evolves to a sodic sulphated type. The general
evolution corresponds to a neutral saline type.
Statistical Approach on chemical variability
The convenience of separate treatment for each watershed will be demonstrated in the next discussion.
Statistical approach will take into account of this choice.
ACP
The first factorial plan of the ACP analysis represents more than the half (59%) of the data information
with the following highlights:
The first axis determines the maximum of inertia (41%). In this axis the electric conductivity, is
opposed to low soluble and low controlled elements. This result is usual in arid and salt environments.
The arsenic as well as sodium and sulphate concentrate while water evaporates in arid climate; water
increases mineral content. This partially explains the high arsenic concentration in water.
The arsenic in solution is low controlled and has a geochemical behaviour like soluble salt.
Chloride and sodium as well as pH are in an intermediate position (figure 4).
The second axis, opposes arsenic to sulphate with alkalinity. It acts of an axis translating the
importance of mineralisations of major origin (sulphides, arsenides) in lithology. The abundance of
arsenic is associated that of the SO4. The deterioration of sulphides produces acidity which consumes
alkalinity from where the Alc opposition/SO4 + As (figure 5).
As regards principal component analysis applied to the second line flow, i.e. strong arsenic
contents, the first axis of this representation determines the maximum of inertia (48.4%). As for the
other line of flow, it acts of a climatic axis which opposes to conductivity opposes a very located
group: arsenic, sulphates, sodium, calcium and electric conductivity with copper, lead, zinc and
alkalinity. Arsenic is not controlled, it behaves like a soluble salt (a behavior of a tracer), it
concentrates with the evaporation of water.
For this line of flow, the importance of the climatic aridity on the quality of water is a little
stronger than for the other line of flow. Axis 2 opposes to lead, arsenic, sulphates with pH. As for the
other line of flow, it acts of an effect of lithology.
For this line of flow, the importance of the climatic aridity on the quality of water is a little
stronger than for the other line of flow.
Metals, arsenic and SO4 have the same origin, i.e. a major origin probably related to the
mineral increase associated volcanicity.
As regards the ACP STATE applied to the globality of the samples of water, i.e. for the two
lines of flow confused, the results are comparable, but the inertia of the climatic axis decreases with the
profile of the lithological axis. This result shows that the two lines of flow are thus characterized by a
lithology the different upstream which generates at the beginning of the different contents arsenic, then
evaporation concentrates arsenic in the two lines of flow.

877 Faten Semadi, Vincent Valles and Jose Luis Gonzalez Barrios
Figure 4: Analyzes factorial correspondences of the various elements (First line of flow)
Figure 5: Analyzes factorial correspondences of the various elements (Second line of flow)
Figure 6: Distribution of the frequencies of the two arsenic pennies groups of the As/SO4 report/ratio
Sulphate seems to be the most mobile element and nearest to electric conductivity. It could be
used as a concentration tracer.

Toxicity of Arsenic in the Ground Water of Comarca-Lagunera (Mexico) 878
Geochemical approach
Concentration diagrams: the aridity effect
The concentration diagrams let classify water by increasing concentrations. When an element
concentrates proportionally to the solution volume reduction, the slope of its dots is 1. This behaviour
like a chemical tracer has not reaction between mineral and liquid phases. In this study case, the
sulphate ion as well as sodium, chloride, magnesium and arsenic ions looks like tracers in a first
approximation (fig.7). The arsenic content evolves mainly by concentration; it seems that there are not
mineral precipitations limiting its concentration increasing; this can be related to the climate aridity.
However the slope concentrations for chloride and sodium are lower than 1. This means that, from
weak concentrations, the increasing concentrations for sodium are not completely proportional to the
variation of the solution concentration factor; this mechanism implies probably ADSORPTION by
clays. This phenomenon is very frequent in this salt environment studied by Gonzalez Barrios (1992).
It is accompanied by a magnesium ADSORPTION process. The chloride behaviour can be related to
its formation of iron oxi-hydroxides (green rusts) with partial substitution of OH- ions (Trolard, F et
al., 1996, Condom, N. 2000). However, the intensity of this control is light.
In this group of chemical elements, magnesium and arsenic present a strong dispersion of
observed points around the average tendency. Concerning arsenic, it was possible to treat separately
two groups of points based on As/SO4 ratios which can be separated statistically. The bimodal
character of the As/SO4 ratio frequencies (fig 6) makes possible to separate these two sub-groups.

879 Faten Semadi, Vincent Valles and Jose Luis Gonzalez Barrios
Figure 7: Diagrams of concentration of the various elements
The data treatment on concentration diagrams (fig. 7), shows two groups of points with a
similar slope value (next to 1) and a weak dispersion around the regression line. This result suggests
the existence of at least two lines of hydro-chemical flows under aridity conditions, with different
initial arsenic content. The increasing coefficient of correlation in these two groups supports this
interpretation (R² goes from 0.6 to 0.81 and 0.59).
Thus, alkalinity remains stable and calcium concentration increases but less than tracer
concentrations (Fig.7).
This evolution can be explained by the calcite precipitation. According to the generalized
residual alkalinity law (presented in the materials and methods), this mineral precipitates while water
are concentrating. Alkalinity decreases or steel stable, and the calcium concentration increases, but less

Toxicity of Arsenic in the Ground Water of Comarca-Lagunera (Mexico) 880
than the concentration factor. This is in conformity with the results obtained. The precipitation of
calcite will be confirmed with the balance diagram of solution/calcite.
With constant CO2 content the reduction of alkalinity should increase the pH, by a reduction of
the H + content. In deed the mol concentration of this element increases with water concentration. It
should be explained by a gradual concentration of CO2 in water which reflecting a space variability of
the water tables. Indeed, when the medium is under water the gases exchanges are reduced. It results a
weak content of O2 and a high content of CO2.
The data concerning metals like Zn, Pb, Cd and Cu are limited and interpretation will be related
primarily to Zn and Pb that are elements better know (Fig.7). The lead concentrations are remarkably
stables, the slope of the fitted points is close to 0, reflecting a mechanism of strong chemical control of
Pb concentrations. It is probably the result of a mineral precipitation (oxyde/hydroxyde or sulphate
kind). The study of balance diagrams will let to identify the kind of this mineral precipitation.
Concerning the zinc, its variability is more important than Pb and its concentration tendency is less
stable. This must be due to mineral precipitation as well, but less systematic than lead.
The concentration diagrams show the global concentration of water from upstream to
downstream into hydrological flows. Chemical mechanisms of mineral precipitations are suggested but
they must be confirmed by the balance diagrams.
Conclusion
This work is based on the analysis of 51 groundwater samples of the Comarca Lagunera region of
northern arid of Mexico exposed to a health risk because of high arsenic concentration in groundwater
used for irrigation and some of them for drinking water under rural and marginal conditions.
The methods used from statistics to chemical equilibrium modelling and sanitary risk
assessment, allow to quantify the health risk and its variability.
The origin of arsenic pollution seems to be from dissolution of deep volcanic rocks in the
mountains. The importance of this dissolution is variable according to lithological characteristics of the
catchments. This induces geographical differences for the health risk assessment. Moreover the climate
aridity causes water evaporation and concentration of soluble salts such as arsenic. The statistical
approach shows that climate aridity is the main process related to high arsenic contents observed in this
area. This is reflected in a health risk that increases from upstream to downstream where low areas are
located.
When groundwater goes from upstream to downstream it transit by different ventilation
conditions: good conditions upstream and bad conditions downstream. This causes a differential
expression of dissolved arsenic forms. Trivalent forms are more toxics than pentavalent forms and
become dominants downstream where the highest arsenic concentrations are observed.
In summary, it was possible to identify the origin of arsenic pollution, the main process
responsible for its variability and the induced risk on the catchments area. Health risk related to arsenic
is different upon the catchments area. However, the lack of referenced data concerning specific toxicity
of arsenic forms, beyond the simple distinction between pentavalent and trivalent forms, does not let to
validate the accurate health risk assessment obtained with thermodynamic models. This point could be
a research line for the continuation of this work.

881 Faten Semadi, Vincent Valles and Jose Luis Gonzalez Barrios
References
[1] Al-Droubi, A., 1976. Geochemistry of salts and the solutions concentrated by evaporation -
Model thermodynamic of simulation application on the salted ground of Chad, Th Doc. Sci.,
Univ. Of Strasbourg, France, 177 pages.
[2] Condom, N. 2000. Study and modeling of the transfers of water and aqueous solutions in the
sodic grounds and the tablecloths of the Office of Niger to Mali. Thesis ENSAM, 180 pages.
Dolique, R. 123PP. 1968-L' arsenic and its compounds. Published by the university presses of
France.
[3] Gonzalez-Barrios, J.L., 1992. Water of irrigation and salinity of the grounds in Mexican arid
region: example in "Comarca Lagunera", Th Doc. Sci., University of Montpellier II, France,
316 pages.
[4] Ribolzi, O, Valles, V and Bariac, T, 1996. Comparison of hydrograph deconvolutions using
residual alcalinity, chloride and oxygen 18 aces hydrochemical tracers. Resour Toilets. LMBO,
32, 4, 1051-1059.
[5] Trolard F, Génin J.M.R., Abdelmoula Mr., Bourrié G, Humbert B and Herbillon A. (1997)
Identification of green rust in A reductomorphic soil by Romance Mössbaner and
spectroscopiés. Géochimica and Casmochimica Acta, 61, 1107-1111.
[6] Valles V and A.M. of Cockborne - 1992- Development of a software of geochemistry applied
to the study cde the quality of water. Seminar "Deterioration and restoration of the quality of
inland waters" Port-Leucate October 1-2, 1992, 20-23.
[7] Valles V, M Rezagui, L Auque, A Semadi, L Roger, H. Zougari, 1997. Geochemistry of
saltworks slois in two arid zones of the Mediterranean basin. Geochemistry of the Chott
Melghir-Mehrouane watershed in Algeria. Arid Soil Research and Rehabilitation (the USA):
11:71-84.

European Journal of Scientific Research
ISSN 1450-216X Vol.20 No.4 (2008), pp.882-890
© EuroJournals Publishing, Inc. 2008
http://www.eurojournals.com/ejsr.htm
Modeling and Temperature Controller Design for
Yazd Solar Power Plant
Aref Shahmansoorian
Islamic Azad University of IEslamshahr
E-mail: a_shahmansoorian@iiau.ac.ir
Abdolvahed Saidi
National Iranian Oil Company-OGPC Department
E-mail: saidi@nioc.org
Abstract
The Yazd Integrated Solar Combined Cycle (ISCC) Power Plant consists of two gas
turbines that are generating power synchronous to Iranian national electrical network. One
steam turbine will be supplied by gas units, while a parabolic through solar field is
integrated with the system, as a combined cycle. In this paper an integrated model of the
solar field with the purpose is presented, and a multivariable generalized predictive
temperature controller is proposed for the system. As it is illustrated in the simulation
results, such a control strategy can robustly regulate both the temperature of outlet oil, and
the temperature of outlet steam water of the solar boiler, despite the variation of the
inherent time delays of the system and external disturbances.
Keywords: ISCC power plant, Solar Field, heat exchanger, modeling, multivariable GPC.
I. Introduction
The feasibility studies and technical specification of an integrated solar combined cycle power plant
has been recently completed, and this type of power plant will be constructed in the city of Yazd in
near future [15]. This power plant is designed with two steam turbines, two gas turbines and a solar
field which supplies excess steam for steam turbines. The solar field consist of parabolic through
collectors, solar boiler, pumps, control valves and an expansion vessel. The solar field itself possess 84
loops with eight collectors in each loop[16]. The collector has parabolic mirrors which focus the sun
beams directly on the oil pipe, and the solar collectors are equipped with a sun tracker system. The oil
enters the solar field with the temperature of 230ºC and depart from it with the temperature of 391ºC.
The outlet oil from solar field enters a special heat exchanger named solar boiler, in which the
accumulated heat in the solar field exchanges the supplied water into superheated steam[17].
The solar boiler consist of three exchangers that preheating, evaporating and superheating the
water in three stage. The oil enters the superheater stage at 391ºC/15bar and depart from preheater
stage at 293ºC/11bar. The supplied water enters the preheater with 235ºC/105bar and depart the
superheater with 380ºC/102 bar. The inverse direction heat exchanger is chosen in order to increase the
rate of heat transfer. The necessary pressure for oil is provided with 3 pumps, which one of them is
standby. The type of tank in the solar field is an expansion vessel that the inlet pressure is fixed with

Modeling and Temperature Controller Design for Yazd Solar Power Plant 883
nitrogen. The control valves are regulating the oil flow for temperature control. Figure (1) illustrates
the schematics of an ISCC power plant [12].
Figure 1: Integrated Solar Combined Cycle Power Plant
II. Solar Field Modeling
In order to have a tractable and complete model of the solar field it is necessary to model the heat
exchanger and the solar collectors in detail [1]. In this section the proposed models for these
components are studied.
A. Solar Collector Model
The designed solar collector consists of double steel/glass pipe with vacuum insulation. The collector
mirrors absorb a fraction of solar beam energy, and focuses the rest on the aforementioned oil pipes at
the center of parabolic through. The heat energy is transferred to the oil through convection,
conduction and radiation [14].
Figure 2: circuit model of heat transfer
Since the radiation heat transfer relates the rate of heat transfer to the fourth power of the
temperature, in order to compensate for the temperature losses, a global coefficient of thermal losses is
defined as below:
Qloss
Hl
= (1)
( Ts
−Tamb)
In which T s and T are the oil pipe surface and the ambient temperatures, respectively. The
amb
Heat loss factor, H can be obtained from calibration experiments, and can be assumed constant with a
l
sufficient degree of accuracy. Considering the heat loss in the collectors as elaborated, the dynamic
equation of solar field heat transfer is given as following [4]:
∂Ts
ρ η IG H G T T ) LH ( T T )
(2)
Cs As
= opt − l ( s − amb − t s − f
∂t
s
This equation contains the absorbed energy of the oil pipe, the transferred energy to the oil and
the heat loss to ambient. The left hand side of the equation determines the temperature variation of the
metal pipe surface, in the condition while the thermal equilibrium has not been reached. The first term

884 Faten Semadi, Vincent Valles and Jose Luis Gonzalez Barrios
in the right hand side determines the volume of radiation energy that oil pipe has received, the second
term shows the ambient heat loss, and the third term evaluates the oil absorbed energy. The amount oil
absorbed energy can be determined by the following [4]:
∂T f
∂T
• f
ρ f C f A f + ρ f C f q = LH t ( Ts
− T f )
(3)
∂t
∂x
In this equation the first term in LHS governs the temperature variation of the oil with respect
to time, and the second term governs the temperature variation with respect to the movement of oil.
Since the governing heat transfer equations are partial differential equations, for the purpose of control
they are discretized with the assumption of the temperature being fixed along each collector, using
finite element method.
ΔT
η s =
Δt
ρ
opt . G K
1
I − ( Ts
−Tamb
sC
s As
ρ sC
s As
s s s
• ΔT
f m
LH t
= ( T f −T
− ) + ( Ts
−T
f )
f
Δt
ρ A
ρ C A
B. Heat Exchanger Model
f
f
f
f
f
K
) − ( Ts
−T
f )
ρ C A
In order to model the heat exchanger, the inlet pressure is assumed to be constant [12,14]. The
governing equations can then be classified into two set of equations for temperature variations and
phase variations. It is assumed that in the preheater and superheater stages, there are no phase change,
and hence, the governing equations are due to the temperature variation. In the preheater there is only
temperature rise in water, while in superheater the temperature increase occurs on the steam [17]. The
boiler design conditions guarantees that the water is entering the preheater with the temperature of
293ºC and will depart it with the temperature of 314ºC. In steam generator water exchange to steam
with the temperature of 314ºC and in superheater saturated steam is heated to the temperature of
380ºC. Note that the governing equation of heat exchanger is also in the form of partial differential
equation. For control purpose the governing equations are discretized using finite element method with
three nodes. The governing equation of oil behavior in each node is as follows [13, 18]:
dToil
ρoilVoilCoil = ρoilCoilFoil
( Toil( out) −Toil(
in)
)
dt
K ⎡
⎣( Toil( out) −Twater( out) ) −( Toil( in) −Twater(
in)
) ⎤
⎦
(5)
−
⎛Toil( out) −T
⎞
water( out)
Ln ⎜
⎟
T −T
⎟
⎝ oil ( in) water( in)
⎠
the left side term of the above equation showes the temperature variation of oil in time, the first term of
right, show the temperature variation of oil in effect of moving oil between pipes of energy absorber in
any stage. The second term of right side shows the rate of heat transfer from oil to water. The equation
that gives the thermodynamical behavior of water (steam) in pre heater and super heater is shown as
equation (6).
In which it is assumed that the temperature in those stages are fixed and only temperature
variations occurs at the transient of one stage to another. Similarly, the equation that gives the
thermodynamical behavior of water (steam) in preheater and superheater in this case, is [13, 18]:
dTwater
ρwaterVwaterCwater =−ρwaterCwater Fwater( Twater ( out ) −Twater(
in)
)
dt
K⎡( T
+
−T ) −( T −T
) ⎤
⎣ oil ( out ) water ( out) oil( in) water ( in)
⎦
⎛Toil ( out ) −T
⎞
water( out)
Ln ⎜
⎟
Toil ( in) T ⎟
⎝ − water ( in)
⎠
In the equation (6) we assume that temperature in each section is fixed (temperature is variation
just in cross from section to another section). It should be considered that in this equation, the physical
characteristic of water in pre heater has been assumed fixed because of the small variation in these
parameters.
(4)
(6)

Modeling and Temperature Controller Design for Yazd Solar Power Plant 885
In this equation the physical properties of the water is assumed to be fixed in the preheater.
Whereas, the physical properties of steam in the superheater show larger variation, and hence, must be
taken into account. To include this variation into the system dynamics the changes of C, ρ (density and
specific thermal capacity) is considered by the following equations into the model. (For a detail
discussion on the modeling refer to [6].
P
R
ρ steam =
R =
RT
18
(7)
kN . m
R = 8.
3145 ( )
kmol . K
0.
25
0.
5
C = 143.
05−183.
54θ
+ 82.
751θ
− 3.
6989θ
(8)
C
C steam =
18 . 015
(9)
θ = T ( Kelvin ) / 100
The equation that gives the thermo-dynamical behavior of saturated steam in steam generator is
shown in the equation (10):
[ ]
( ) •
• •
K2
( TH1
−TC
2)
−(
TH
2 −Tc1
)
= moho
−mi
hi
+ mcvu
(10)
TH1
−Tc
2
Ln(
)
TH
2 −Tc1
• • •
m o = mi
− m cv
• •
In this equation m i , m o , m cv
•
are flow of inlet water, flow of outlet water and variation of
control value respectively. h is enthalpy of steam and u is energy of mass unit. The left side term of
above equation is rate of heat transfer from oil to water. The first two terms of right, showes the
variation of thermal power of saturated steam in cross of control value, and the last term showes the
variation of energy in control volume [9, 10].
III. Controller Synthesis
The solar field is a nonlinear, multivariable system possessing long and varying time delays. For this
class of systems the predictive control methods are suitable. These types of controller are the most
attractive controllers for process control practitioners, after common PID controllers [3, 7]. In this
paper a multivariable GPC routine is proposed for temperature control of the system. The time delay in
the system is caused by the installation distance ( x ) between the actuators and the sensors in the
system. Hence, the time delay is related to the fluid speed and distance between the sensor and pump,
as follows:
x
τ =
ν
•
•
m
m = ρQ
= ρAv
⇒ν
=
ρA
ρAx
ρV
⇒τ
= = =
• •
m m
∑
ρ V
m
A. System Identification and parameter estimation
i
•
i
The solar field is a two-input two output system, from a control point of view. The system inputs are
the oil and water flow rates and its outputs are the oil and water temperatures. From the well known
identification techniques, the transfer matrix of the system can be obtained from simulated input output
pairs of the system. The identified model of the system has been derived as following:
(11)

886 Faten Semadi, Vincent Valles and Jose Luis Gonzalez Barrios
−1
⎡ k11z
−d
0 ⎤
11
⎢ z −1
⎥
−1
⎢1+
T11z
G ' ( z ) =
⎥
(12)
−1
−1
⎢ k 21z
k
−
− ⎥
21 22 z
d
d 22
⎢ z
z
−1
−1
⎥
⎣1+
T 1+
T
21z
22 z ⎦
As it is clear from the structure of the identified model, the water temperature is almost not
related to the outlet oil temperature (G12=0), and this weak relation can be modeled as a disturbance to
the system. The other components are simply modeled with a first order system with a time varying
time delay. This structure of the model can be used for the GPC synthesis.
B. Design of multivariable GPC controller
The controller design consists of three steps. A) prediction model determination. B) Objective function
assignment and C) control law calculation. The prediction model for the system can be derived from
the equation (12), in which the model is rewritten in the form of :
− 1
−1
e(
t)
A ( q ) y(
t)
= B(
q ) u(
t −1)
+
(13)
Δ
In which u (t)
is control signal and y (t)
is the process output as the vector of oil and water
−1
−1
−1
temperatures. Moreover, e (t)
is measurement noise with zero mean and Δ = 1−
q . A ( q ) , B ( q ) are the
polynomial matrices with degree n A and n B respectively. The Objective function to be minimized has
the form of :
∑ ∑[
] ∑[
]
= = =
⎭ ⎬⎫
m N ⎧ 2
N u
2
2
(14)
J = ⎨ri
y i ( t + j)
− wi
( t + j)
+ λ Δu(
t + j −1)
i 1 ⎩ j 1
j 1
Or in matrix form:
T
T
J = y − w R y − w + λ Δu
Δ
(15)
[ ] [ ] u
In which N is the maximum of prediction horizon and 2
N is the control horizon. λ is the
u
penalty coefficient and R is the weighting matrix of errror signal. In order to generate the control
signal, the future outputs of the system is predicted by the following equation:
ˆy = GΔ u+ f
(16)
In which, f is the free response of the system and G includes the step response parameters.
The optimal solution for the control signal to minimize the cost function (15), while preserving closed
loop stability is calculated from the following equation.
[ ]
T
1
T
λ −
Δ u= I 0 � 0 ⎡
⎣G RG+ I⎤ ⎦ RG ( w− f)
(17)
C. Parameter Tuning in Multivariable GPC
The tuning of the controller parameters is mostly based on experience, and the simulation of the closed
loop response. The designer has the freedom to tune either the cost function weighting, or change the
disturbance dynamics, observer dynamics, the desired trajectory and finally the prediction and control
Horizons. More penalizing λ on the control effort and R on the tracking error will reduce the control
effort. The structure of the model is fixed in this method and only the noise levels can be assigned to
−1
−1
−1
tune the performance. However, from the inherent integrator form of D ( z ) = ( 1 − z ) A(
z ) forces the
error of the closed loop system to a step disturbane to converge asymptotically to zero [8, 11].
IV. Closed-Loop Simulation Result
The designed controller for the system has the parameters 1 2
functions are tuned through the simulation to:
N = 6, N = 37, N = 3 and the weighting
u

Modeling and Temperature Controller Design for Yazd Solar Power Plant 887
Q
i
⎡1
= ⎢
⎣0
0 ⎤
⎥,
1⎦
R
i
⎡3.
5
= ⎢
⎣0
0⎤
0.
2
⎥
⎦
Moreover, the time delays for the oil and water is calculated from the design condition
(NDI=900 w/m 2 ) and the system pipe length to constant values of 35 and 50 times the sampling time,
respectively. The time constant of the system model is identified to be ten seconds. The closed loop
response of the system using GPC controller is compared to that using PI controller with the controller
gains: kp = 0.04, ki
= 0.007 . The variation of solar radiation is considered as a constant disturbance and
illustrated in figure (3). In this simulation the solar radiation is changed from 900 to 800 w/m 2 and its
effect on the oil and water temperature is illustrated in figure (3). Due to the larger time delays in oil
path compared to that in the water path, the water temperature output shows a faster response.
However, both oil and water temperatures are rejecting the effect of disturbance with PI and GPC
controllers. Although the overall performance of two controllers are relatively desirable the coupling of
two quantities have greater impact on the PI controller compared to that on GPC design.
Figure 3: The effect of solar radiation on the response
405
400
395
390
385
380
375
370
PI
Effect of Variation in NDI
365
100 120 140 160 180 200
time
220 240 260 280
In figure (4) the effect of measurement noise is illustrated on the response. GPC controller is
effectively rejecting the noise effect, due to its predictive nature. Figure (5) illustrates the effect of
leakage in oil and water pipes. In this case it is assumed that the oil leakage occurs on the path before
entering the solar field and the water leakage occurs before entering the heat exchanger. Due to this
failure in the system the temperature of oil and water is observed just after the leakage happens.
However, the controller is able to regulate the temperature, in spite of the failure.
GPC

888 Faten Semadi, Vincent Valles and Jose Luis Gonzalez Barrios
Figure 4: The effect of measurement noise on the response
430
420
410
400
390
380
370
360
350
Effect of Noise
50 100 150 200 250
time
Real Temperature of Oil
Real Temperature of Steam
Temperature of Oil(after mesurment)
Temperature of Steam(after mesurment)
The superior performance of the GPC controller is also observed in this simulation. Figure (6)
illustrates the change in the system delay as a result of flow rate change due to the leakage. It is
observed that the system delay increases as the flow rates increased, as expected.
Figure 5: The effect of leakage on oil and steam temperature
V. Conclusions
In this paper a multivariable predictive control algorithm is proposed for the solar power plant. It is
shown that due to the existance of large and variable time delays in the temperature outputs of the heat
exchanger of the power plant, and the coupling between the oil and water temperature of it, a
multivariable GPC controller is effectively regulating the system outputs, despite disturbances,
measurement noise, and leakage. The predictive structure of the controller make it less sensitive to the
varying time delays. The proposed controller is able to not only preserve the stability of the system, but
also the performance of the system with the presence of disturbance and measurement noise.

Modeling and Temperature Controller Design for Yazd Solar Power Plant 889
VI. Nomenclature
Figure 6: The Variation of delay in effect of flow variation
ρ s Density of oil pipe (kg/m 3 )
•
q Oil flow (m 3 /s)
Cs Specific thermal capacity of oil pipe (J/kg ºC)
G Width of collector (m)
As Area of metal pipe (m 2 )
Ht Heat transfer coefficient from pipe to oil (W/m 2 ºC)
ρ f
3
Density of oil (kg/m )
L Inner diameter of oil pipe (m)
C Specific thermal capacity of oil (J/kg ºC)
f
I Sun direct radiation (W/ m 2 )
V Volume of fluid path (m 3 )
•
m Mass flow of fluid(kg/s)
Af Inner cross area of oil pipe (m 2 )
Tf
Tf
Oil temperature along one collector (ºC)
- Oil temperature along previous collector (ºC)
Ts Temperature of oil pipe (ºC)
η Optical efficiency of mirrors
opt
x Distance of sensor from control valve (m)
HL Thermal loss coefficient (W/m 2 ºC)
v Oil velocity (m/s)
ρ Fluid density(kg/m 3 )
Flow (m 3 /s)
Q
A cross area of fluid pipe (m 2 )

890 Faten Semadi, Vincent Valles and Jose Luis Gonzalez Barrios
References
[1] A.W. ordys – A.W. pike - M. A. Johnson – R.M.katebi and M.J.Grimble.“Modeling and
simulation of Power Generation Plants” Springer-verlag 1994
[2] A.Saidi “Solar Field Modeling and Temperature Control of Yazd ISCC Power Plant” Master
thesses, K.N.Toosi,University of technology,2002
[3] Donna M.Schneider “Control of Process with Time Delays” IEEE Transactions on Industry
Applications Vol.24No.2,March/Appril-1988
[4] E.F Comacho – M. Berenguel and F.R. Rubio. “Advanced Control of Solar Plant” Springerverlag
1997
[5] E.F.Camacho and C.Bordons “Model Predictive Control in the Process Industry” Springer-
Verlag,1995
[6] Gordon van wylen- Richard Sonntag- claus Borgnakke “Fundamentals of Classical
Thermodynamics” fourth Edition
[7] J.E. Marshall “Control of time – delay systems.” Institution of Electrical Engineers 1979
[8] J.M.Maciejowski “Predictive Control with constraint” Prentice Hall-2002
[9] Jonas Eborn and Karel Johan Astrom. “Modeling of a Boiler Pipe with Two-Phase Flow
Instabilities” www.control.lth.sel~kja/rodpaper.pdf
[10] K.J Astrom – R.D. Bell. “Drum – Boiler Dynamics”1998 www.control.lth.sel~kja/rodpaper.pdf
[11] O.Bego,N.Peric “Decoupling Multivariable GPC with Reference Observation” 10 th
Mediterranean Electrical Conference, MeleCon 2000,Vol. II
[12] Pilkington (Solar International) “Status Report on Solar Thermal Power Plants”. www.
Pilkington .com
[13] Pierre Bélanger “Control engineering: a modern approach” Saunders College Pub.1995.
[14] Sandia Co. “Test Results SEGS LS-2 Solar Collector” Technical Report www.Sandia.gov.
1994
[15] S.R.Hosseini “Report of feasibility study (Technical and Economical) of yazd solar thermal
power plant” NRI.2000
[16] S.R.Hosseini “Report of solar field design in yazd solar thermal power plant” NRI.2000
[17] S.R.Hosseini “Report of solar boiler design in yazd solar therma power plant” NRI 2000
[18] V.Ganapathy “Steam Plant Calculation Manual.” Marcel Dekker1984

European Journal of Scientific Research
ISSN 1450-216X Vol.20 No.4 (2008), pp.891-904
© EuroJournals Publishing, Inc. 2008
http://www.eurojournals.com/ejsr.htm
A Predictive Current Control Technique on Fuel Cell Based
Distributed Generation in a Standalone AC Power Supply
K. G. Firouzjah
Faculty of Electrical & Computer Engineering, Noshirvani University of Technology
Shariati Street, Babol, Iran, P. O. Box 47135-484
E-mail: kgorgani@stu.nit.ac.ir
Tel: +98-111-323-9214; Fax: +98-111-323-9214
H. Eshaghtabar
Faculty of Electrical & Computer Engineering, Noshirvani University of Technology
Shariati Street, Babol, Iran, P. O. Box 47135-484
Tel: +98-111-323-9214; Fax: +98-111-323-9214
A. Sheikholeslami
Faculty of Electrical & Computer Engineering, Noshirvani University of Technology
Shariati Street, Babol, Iran, P. O. Box 47135-484
Tel: +98-111-323-9214; Fax: +98-111-323-9214
S. Lesan
Faculty of Electrical & Computer Engineering, Noshirvani University of Technology
Shariati Street, Babol, Iran, P. O. Box 47135-484
Tel: +98-111-323-9214; Fax: +98-111-323-9214
Abstract
This research presents a new method based on predictive current control (PCC) of
fuel cell based distributed generation systems (DGS) in a standalone AC power supply. To
boost low output DC voltage of the fuel cell to high DC voltage and compensate for its
slow response during the transient, two full-bridge DC to DC converters are adopted and
their controllers are designed based on PCC. The proposed method produces the reference
current by using of the DC link capacitor voltage. Thereupon the method determines the
portion of fuel cell and backup battery to feed load and capacitor. The analysis results
presented in this research demonstrate that the suggested method is capable to increase
transient performance of adopted system in load and fuel cell output voltage variations.
Simulations with MATLAB have been carried out to verify the proposed predictive current
controller in mentioned application and the results are discussed in this research.
Keywords: Fuel Cell, Distributed Generation, Predictive Current Control, DC-DC
Converters, Backup Battery

A Predictive Current Control Technique on Fuel Cell Based Distributed
Generation in a Standalone AC Power Supply 892
1. Introduction
Previous empirical research provides contradictory and inconclusive evidence on the value relevance
of comprehensive income disclosures promulgated in different countries. Thus, present study using
comprehensive income of Iranian firm's data shed more lights on the issue.
Fuel cells are devices capable of converting chemical energy into heat and dc electrical energy
by means of the oxidation of a fuel, usually hydrogen (Padulles et al, 2000). Distributed generation
(DG) technologies can provide energy solutions to some customers that are more cost-effective, more
environmentally friendly, or provide higher power quality or reliability than conventional solutions.
The voltage of fuel cell stack decreases largely as the load current increase, and the voltage increases
as the temperature increase at the same current. Thus DGS should be interfaced with Power Electronic
systems such as DC to DC or/and DC to AC power converters to obtain a sinusoidal AC output voltage
with fixed frequency from variable or high-frequency AC voltage sources or DC voltage sources
(Haiping et al, 2005). So the DC-DC converter plays a key role in making the fuel cell DC power
available for stand-alone applications.
To boost low output DC voltage of the fuel cell to high DC voltage, a forward DC to DC boost
converter, a push-pull DC to DC boost converter or an isolated full-bridge DC to DC power converter
can be selected. In addition, various topologies such as the H-bridge series resonant buck and boost
converters have been presented in (Blaabjerg et al, 2004). Anderson et al, (2002) present a current fed
push-pull converter. This topology decreases the conduction losses in the switches due to the low fuel
cell voltage. Nergaard et al, (2002) suggest an interleaved front-end boost converter. This topology
considerably reduces the current ripple flowing into the fuel cell. A dual loop control strategy (current
and voltage loop) has been used for the interleaved converter. Jung et al, (2005;2005) introduce a Zsource
converter. This is a new concept in which a shoot-through vector directly steps up the DC
source voltage without using a boost DC-DC converter. The boost voltage rate depends on the total
duration of the shoot-through zero vectors over one switching period Jung et al, (2005). Also, In
reference (Wang and Nehrir, 2006) a non-isolated boost converter with a conventional PI controller has
been used for the converter control. Akkinapragada (2007) had been employed a non-isolated buckboost
DC-DC converter with a closed loop PWM (pulse width modulation) control strategy as
described in Reference (Mohan et al, ). The reference (Duran-Gomez et al, 2006) had been presented
an approach to convert the generated dc output voltage of a PV cell array into a higher regulated dc
voltage. The approach employs a series-combined connected boost and buck boost dc-dc converter for
power conditioning of the dc voltage provided by a photo-voltaic array. Chandrasekaran and Gokdere
(2004) introduce a novel composite integrated magnetic (IM) core structure, which minimizes inductor
current ripple. Their subject is a compact, IM core structure for a three-phase interleaved, DC-DC
boost converter that feeds off the fuel cell output and can provide a programmable, regulated, high
voltage DC bus for the distributed power system.
In recent years, the higher efficiency and the more advanced power conversion, energy
utilization equipment, a variety of circuit topologies of the soft-switching DC-DC power converter are
urgently required. The reference (Ogura et al, 2003) has introduced a boost type ZVS-PWM chopperfed
DC-DC power converter with a single active auxiliary resonant snubber in the load side for the
power interface of solar photovoltaic and fuel cell power conditioners. The character of this boost type
ZVS-PWM chopper-fed DC-DC power converter is feasible. Also, a unidirectional isolated full-bridge
DC to DC power converter can be used to boost low fuel cell voltage (Bendre et al, 2003; Aydemir,
2002; Kim et al, 1997; Jain et al, 2002; Brunoro and Vieira, 1999; Jeon and Cho, 2001). In addition, a
bidirectional full-bridge DC to DC power converter can be used for stepping up low battery voltage or
stepping down high-voltage-side DC link according to battery discharge or recharge mode (Peng et al,
2004; Jiang and Dougal, 2003). Among the presented power converters, two phase-shifted full-bridge
DC to DC converters, which are one of the most attractive topologies for high power generation are
adopted as described in (Jung, 2005; Keyhani and Jung, 2004) with a unidirectional full-bridge DC to
DC boost converter for the fuel cell and a bidirectional full-bridge DC to DC boost/buck converter for

893 K. G. Firouzjah, H. Eshaghtabar, A. Sheikholeslami and S. Lesan
battery. This research develops a circuit model and controllers of fuel cell based distributed generation
systems (DGS) in a standalone AC power supply. Dynamic model of the fuel cell is considered. To
boost low output DC voltage of the fuel cell to high DC voltage and compensate for its slow response
during the transient, two full-bridge DC to DC converters are adopted and their controllers are
designed. Furthermore, (Suzuoka et al, 2003) presents a novel circuit topology of a voltage source type
zero voltage soft-switching full bridge inverter DC-DC power converter with an isolated highfrequency
transformer link this power converter incorporates zero current soft-switching (ZCS) mode
phrase-shifted PWM active power switches in series with diode into two diode arms of full-bridge
rectifier or center-tapped rectifier in transformer secondary-side.
In spite of desirable performance of the mentioned methods, a novel method based on
predictive current control has been proposed to control the fuel cell and backup battery on the
presented structure in (Jung, 2005; Keyhani and Jung, 2004). The proposed method produces the
reference current by using of the DC link capacitor voltage. In other word, the presented algorithm
calculates the required current of load and capacitor to regulate and control DC output at a desired
voltage level. Thereupon the method determines the portion of fuel cell and backup battery to feed load
and capacitor. In this research, the predictive current control strategy as described in References
(Rodriguez, 2007; Rodriguez, 2004; Wen and Zheng, 2006; Premrudeepreechacharn and
Poapornsawan, 2000) has been employed.
2. System Structure
The adopted structure of fuel cell, backup battery and the interfaced converters are based on the
reference (Jung, 2005; Keyhani and Jung, 2004) as described in Fig. 1. In this system, a low voltage
DC output of fuel cell is used along with unidirectional boost converter to prevent reliability
deterioration by stacking a number of series cells. A low DC voltage battery for backup is connected in
parallel with the high side DC link through a bidirectional buck/boost converter because difficulties in
battery management can be significantly reduced. Furthermore, an isolated full-bridge DC to DC
power converter is adopted to boost low output DC voltage of fuel cell because its topology is suitable
for high power applications. To boost low output DC voltage of the fuel cell to high DC voltage, a
forward, a push-pull or an isolated full-bridge DC to DC power converter is selected. Among these
power converters, two phase-shifted full-bridge DC to DC converters are consist of a unidirectional
full-bridge DC to DC boost converter for fuel cell and a bidirectional full-bridge DC to DC boost/buck
converter for the battery. In Fig. 1, the unidirectional power converter system for the fuel cell consists
of a fuel cell, an input filter (L1, C1), a full-bridge power converter (F1 to F4), a high frequency
transformer (N1:N2), a bridge-diode (DF1 to DF4), and an output filter (L2, C2), while the bidirectional
power converter system for the battery consists of a battery, a static switch (SB), two full-bridge power
converters (B1 to B4, B11 to B44), and a high frequency transformer (n1:n2) (Jung, 2005).

A Predictive Current Control Technique on Fuel Cell Based Distributed
Generation in a Standalone AC Power Supply 894
Figure 1: Unidirectional/bidirectional DC to DC power converters (Jung, 2005).
Fig. 2 shows power flows of DC to DC power converters for battery discharge and battery
recharge. As shown in Fig. 2, the unidirectional full-bridge DC to DC boost converter permits only one
directional power flow from the fuel cell to the load because a reverse current can damage the fuel cell.
In addition, response speed of the power converter should be slow enough to meet slow dynamic
response of the fuel cell. On the other hand, the bidirectional full-bridge DC to DC power converter
allows both directional power flows for battery discharge and recharge, and its response also should be
fast to compensate for the slow dynamics of fuel cell during start-up or sudden load changes. For
battery discharge mode illustrated in Fig. 2 (a), which occurs when a startup or a sudden load increase,
the fuel cell starts delivering electric power to the load and the battery instantly provides power until
the fuel cell reaches a full operation state. After transient operation, only the fuel cell feeds electric
power to the load. For battery recharge mode shown in Fig. 2 (b), the battery absorbs the energy
overflowed from the fuel cell to prevent DC-link voltage VDC from being overcharged during a sudden
load decrease, and then the battery is recharged by the fuel cell in a steady-state until it reaches a
nominal voltage (Jung, 2005). The adopted model of the load (RL) is a three-phase DC to AC inverter
with PWM bipolar switching strategy that is shown in Fig. 3.
Figure 2: Power flows of DC to DC power converters (Jung, 2005)
(a): Battery discharge (b): Battery recharge

895 K. G. Firouzjah, H. Eshaghtabar, A. Sheikholeslami and S. Lesan
Figure 3: Three-phase DC to AC inverter with Three-phase load.
3. Predictive Current Control (PCC) in Single Phase Converter
Fig. 4 shows the topology of single phase full-bridge converter with nonlinear Inductive-Resistive
load. Nonlinear treatment of load is modeled in the form of (e) potential. According to the Fig. 4, the
current direction is being selected conventionally in a fix direction. If switching of converter selected
as bipolar control, the switching states will be:
State 1 → S 1,S 4: on S 2,S 3:
off
State 2 → S 2,S 3: on S 1,S 4:
off
Therefore, the duty cycle of S1,S4 switches (D) can be defined. While S1,S4 and S2,S3 are ON,
the load voltage will be equal to Vd and -Vd respectively.
Ton1,4
D =
T
(1)
Ton is the time that S1,S4 are ON in a period (T). So, in a sample the mean value of load voltage
is equal to 2D-1, that:
di
(2D − 1) Vd= Ri + L + e
dt
(2)
While S2,S3 are ON, the duty cycle is D'. According to the bipolar switching technique of single
phase converter:
D= 1−
D′
(3)
By rewriting these equations in discrete time domain we have:
( i( n+ 1) i(
n)
)
(2D( n) -1) V d Ri( n) L e(
n)
T
−
= + +
(4)
D
( n )
( i( n+ 1) i(
n)
)
( n) ( n) d
−
+ + +
Ri L e V
=
T
2 V
d
Figure 4: Single phase full-bridge converter with nonlinear load
(5)

A Predictive Current Control Technique on Fuel Cell Based Distributed
Generation in a Standalone AC Power Supply 896
Figure 5: Tracing of reference current in one period of T
That i(n) and i(n+1) are currents of existing state and the next state, respectively. e(n) is potential of
nonlinear part of load in existing state and D(n) is the existing state of S1,S4 switches in a duty cycle.
According to the Fig. 5 with the reference current iReference and considering this hypothesis that all
calculations are in n-state, if S1,S4 are ON, the load current will increase and if not, will be decrease.
Finally, the reference current can be traced by converter where a proper value of D increases or
decreases the load current. Therefore, duty cycle of D(n) in existing state (time of switching state 1 in a
period T) changes the current from i(n) to i(n+1). According to the PCC, duty cycle of switches
determined in a way that the current i(n) reach to i(n+1). So, i(n+1) can be defined as a reference current
and ON or OFF time of switches can be calculated in a suitable way that current of existing state reach
to reference current.
4. Proposed Switching Technique
A suitable and desired controlling technique in order to supply the required power of load and fix it,
based on (Jung, 2005) recommended configuration is presented in this research. This recommended
controlling algorithm divides into two sections:
1. If the fuel cell be able to supply the load perfectly, no battery will be used and fuel cell will
supply the load, merely. In this situation, battery will be charged by fuel cell.
2. If the fuel cell can not be able to supply the load perfectly, maximum usage of fuel cell is
performed and then battery supplies the remaining required power.
Whereas load DC capacitor’s voltage should remain around 1 p.u., the recommended technique
is follows to fix the voltage of C2 in the desired range.
All the following equations investigated in discrete time state. In the first stage, we assume that
the fuel cell can fully supply the load merely. In the second stage, we assume that the fuel cell can not
perfectly supply the load. The relation between voltage and current of C2, yields the following
expressions:
Continuous time state:
dV
C IC= C2 dt
Discrete time state:
VC( n + 1) −VC(
n)
IC( n) = C2
T
Continuous time state:
I F 2 = IC + I L
Discrete time state:
I F2 ( n) = IC( n) + IL( n)
Continuous time state:
(6)
(7)
(8)
(9)

897 K. G. Firouzjah, H. Eshaghtabar, A. Sheikholeslami and S. Lesan
dI F 2
V AB 2 = L2 + VC
dt
Discrete time state:
(10)
IF2( n + 1) −IF2(
n)
V AB 2( n) = L2 + VC( n)
T
where:
(11)
VC( n + 1) = VC Ref
= 1 pu . .
Also, the average voltage of VAB1, based on bipolar switching technique of full bridge power
converter (F1 to F4), is as follow:
V AB1 = (2D −1)
V Fdc
(12)
dI ′ 2
V AB1 = LT + RTI′ 2 + V ′ AB 2
dt
That RT and LT are the transformer’s impedances.
(13)
N 1 V ′ AB 2 = V AB 2
N 2
(14)
N 2 I′ 2 = I 2
N 1
In discrete form we have:
(15)
(2 D ( n) − 1) V FCdc = LT I′ 2( n + 1) −I′
2(
n)
+ RTI′ 2( n) + V ′ A B 2(
n)
T
(16)
Where, subscript (n) in (11) and (16) represents the present time values that can be easily
measured. Consequently, by having these values from (11), we will obtain IF2(n+1) that is the required
reference current of next situation. We can obtain the duty cycle of D(n) by considering IF2=I2 (Fuel cell
can supply the load merely).
N 2 N 2 T
I1( n + 1) = I2( n + 1) = ( V AB 2( n) + IF2(
n)
)
N1 N1 L2
(17)
I1( n + 1) −I1(
n)
LT + RTI1( n) + V ′ AB 2(
n) + V FCdc
D( n)
= T
2 V FCdc
(18)
If the resultant D is less than 1, fuel cell would have the capability of supplying the load by
desired duty cycle. Thus, the battery is not needed. But, if D>1, Fuel cell would have not that
capability and therefore, we should calculate the maximum power of fuel cell at the first step by
considering D=1, and in the second step, supplying the remain power by using battery with DB, which
is related with its converter.
If D=1, then we would have:
V AB1= V FCdc
(19)
dI 1
V ′ AB 2 = V FCdc −LT−RTI1 dt
That in discrete time situation:
(20)
I1( n + 1) −I1(
n)
V ′ AB 2( n) = V FCdc −LT −RTI1(
n)
T
By having the values of current state we can obtain I1(n+1) with D=1 as:
(21)
T
I 1( n + 1 ) =
LT
[ V FCdc −RTI1( n) − V ′ A B 2( n) ] + I1( n)
(22)
I1(n+1) is the maximum value of fuel cell produced current with D=1 that:
N 1
I Max _FC= I1( n + 1)
N 2
(23)

A Predictive Current Control Technique on Fuel Cell Based Distributed
Generation in a Standalone AC Power Supply 898
by considering the required current of IF2(n+1) in (17), we achieve the remaining required current of load
as:
I B 2( n + 1) = I F 2( n + 1) −I
Max _FC
(24)
By having the value of IB2(n+1), we can get DB(n) with the way presented before as:
n2
I B1( n + 1) = IB 2(
n + 1)
n1
(25)
n1
V ′ ab 2 = Vab
2
n2
(26)
I ( n + 1) −I
( n)
L + R I ( n) + V ′ ( n) + V
DB( n)
= T
2 V
B1 B1
t t B 1 ab 2 battery
battery
(27)
That, Lt and Rt are the transformer’s impedances.
According to the mentioned above, we can extract the recommended algorithm as Fig. 6. The
illustrated flowchart shows the performance of suggested algorithm so well. Consequently, after
employing this algorithm and also by fixing the capacitor’s voltage in 1 p.u., we would be able to feed
the power of three phase loads by a three phase converter, with PWM switching technique (such as
Fig. 3).
Figure 6: DC link capacitor's voltage controlling flowchart with fuel cell and backup battery.

899 K. G. Firouzjah, H. Eshaghtabar, A. Sheikholeslami and S. Lesan
5. Simulation Results
In this research, simulations are carried out based on employing the suggested algorithm on adopted
system as shown in Fig. 6 and Fig. 1, respectively. MATLAB simulation results show the capability of
proposed algorithm to control the switching modes of the fuel cell and backup battery in transient
states. Simulations are carried out in the following:
5.1. Fuel Cell's Output Voltage Drops and there is no Backup
In this section, supposed that the boosted output voltage of fuel cell drops below its steady-state value
(into 0.5 p.u.). As shown in Fig. 7, FC's voltage dropped and recovered at 0.2 and 1 second
respectively. In the other word, a failure occurred during 0.2 through 1 second for the fuel cell.
According to Fig. 7, while backup battery is not existed, the DC link capacitor's voltage drops. Also,
the voltage and current of three phase load is decreased.
5.2. Fuel Cell's Output Voltage Drops, Load Increases and there is no Backup
We expect that by increasing the load in fuel cell failure the output will have a worse condition than is
in section A. Fig. 8 illustrates the verity of this fact. As shown in this figure, a failure occurred during
0.2-1 second for the fuel cell; furthermore the three phase load increased at 0.45 second. These results
remark that the output voltage and current have a bad situation in lack of backup battery.
5.3. Fuel Cell's Output Voltage Drops and Backup Battery Exists
In this section, supposed that the boosted output voltage of fuel cell drops below its steady-state value
(around 0.5 p.u.) and backup battery is employed based on the proposed algorithm in Fig. 6.
Figure 7: Simulation results under fuel cell's failure and no backup existence.

A Predictive Current Control Technique on Fuel Cell Based Distributed
Generation in a Standalone AC Power Supply 900
Figure 8: Simulation results under fuel cell's failure, load increasing and no backup existence.
As shown in Fig. 9, fuel cell's voltage is dropped at 0.2 second and then recovered at 1 second.
To take into consideration of battery as a backup of this system, leads to a regulated DC link voltage
during fuel cell's failure. Therefore, the output current and voltage have no transient and variation.
Figure 9: Simulation results under a fuel cell's fail with backup existence
5.4. Fuel Cell's Output Voltage Not Changes, Load Increases and Backup Battery Exists
As shown in Fig. 10, when load increases (at 0.45 second), backup battery compensates the shortage of
fuel cell's output voltage. Fuel cell and backup battery feed the load together.

901 K. G. Firouzjah, H. Eshaghtabar, A. Sheikholeslami and S. Lesan
Figure 10: Simulation results under load increasing with backup existence
5.5. Fuel Cell's Output Voltage Drops, Load Increases and Backup Battery Exists
The worst state of illustrated system in Fig. 1 is increment of load during fuel cell's failure. The main
objective of this research is improved FC based system in this condition. As a mater of fact, backup
battery has two tasks:
1. DC link capacitor's voltage regulation in desired level.
2. Transient states of system variation reduction.
According to Fig. 11, the output parameters (i.e. DC link capacitor voltage, load voltage and
current) have the desired value and minimum transient state together. However a fail occurs during 0.2-
1 second for the fuel cell, and furthermore the three phase load increases at 0.45 second, backup battery
is capable to reach the above goals.
Figure 11: Simulation results under fuel cell's failure, load increasing and backup existence.
Note that the back up battery operates when fuel cell is not capable to do its task so well. As
shown in Fig. 12, backup battery operates during fuel cell's failure and load increment (0.2-1 second)
whereas SB=1. On the other hand, when fuel cell be able to feed load and DC link capacitor lonely, SB
is set to zero and backup battery will be in charging mode.

A Predictive Current Control Technique on Fuel Cell Based Distributed
Generation in a Standalone AC Power Supply 902
Figure 12: Duty cycle of fuel cell and backup battery's converters
6. Conclusions
In this research it has been presented a new predictive current control based method to convert the
generated dc output voltage of fuel cell into a higher regulated dc voltage. The suggested algorithm
calculates the required current of load and capacitor to regulate and control DC output at a desired
voltage level on the basis of adopted system (Fuel cell in parallel with backup battery and interfaced
converters). Investigated studies illustrate that the worst state of fuel cell based distributed generation
systems in a standalone AC power supply is increment of load during fuel cell's output voltage failures.
The main objective of this research is improved FC based system in critical conditions. Clearly, backup
battery has two tasks:
1. DC link capacitor's voltage regulation in desired level.
2. Transient states of system variation reduction.
According to the simulation results, the output parameters have the desired value and minimum
transient state together. In conclusion, the suggested predictive current control based method is capable
to achieve mentioned goals with good performance of system's interfaced converters. Simulation
results with MATLAB reflect the potentiality of this controller for the fuel cell based DG applications.

903 K. G. Firouzjah, H. Eshaghtabar, A. Sheikholeslami and S. Lesan
References
[1] Akkinapragada, N., 2007. “Dynamic Modeling and Simulations of Solid Oxide Fuel Cells for
Grid-Tied Applications”, Master's Thesis, Electrical Engineering, University of Missouri-Rolla.
[2] Anderson, G. K., C. Klumpner, S. B. Kjaer, and F. Blaabjerg, 2002. “A New Power Inverter for
Fuel Cells”, IEEE Conf. Power Electronics Specialists, 2(2), pp. 727-733.
[3] Aydemir, M. T., A. Bendre, and G. Venkataramanan, 2002. “A critical evaluation of high
power hard and soft switched isolated DC-DC converters”, IEEE IAS'02, 2, pp. 1338-1345.
[4] Bendre, G. Venkataramanan, and D. Divan, 2003. “Dynamic analysis of loss-limited switching
full-bridge DC-DC converter with multimodal control”, IEEE Trans. Industry Applications,
39, pp. 854-863.
[5] Blaabjerg, F., Z. Chen, and S. B. Kjaer, 2004. “Power Electronics as Efficient Interface in
Dispersed Power Generation Systems”, IEEE Trans. Power Electronics, 19(5).
[6] Brunoro, M. and J. L. F. Vieira, 1999. “A high-performance ZVS full-bridge DC-DC 0-50-V/0-
10-A power supply with phase-shift control”, IEEE Trans. Power Electronics, 14, pp. 495-505.
[7] Chandrasekaran, S., and L. U. Gokdere, 2004. “Integrated Magnetics for Interleaved DC-DC
Boost Converter for Fuel Cell Powered Vehicles”, IEEE Conf. PESC 04, 1, pp. 356-361.
[8] Duran-Gomez, J. L., E. Garcia-Cervantes, D. R. Lopez-Flores, P. N. Enjeti, and L. Palma,
2006. “Analysis and Evaluation of a Series-Combined Connected Boost and Buck-Boost DC-
DC Converter for Photovoltaic Application”, IEEE Conf. APEC'06, pp. 1-7.
[9] Haiping, X., Q. Ermin, G. Xin, W. Xuhui, and K. Li, 2005. “Analysis and Design of High
Power Interleaved Boost Converters for Fuel Cell Distributed Generation System”, IEEE Conf.
Power Electronics Specialists, pp. 140–145.
[10] Jain, P. K., Wen Kang, H. Soin, and Youhao Xi, 2002. “Analysis and design considerations of a
load and line independent zero voltage switching full bridge DC/DC converter topology”, IEEE
Trans. Power Electronics, 17, pp. 649-657.
[11] Jeon, S. -J., and G.-H. Cho, 2001. “A zero voltage and zero-current switching full bridge DC-
DC converter with transformer isolation”, IEEE Trans. Power Electronics, 16, pp. 573-580.
[12] Jiang, Z. and R. A. Dougal, 2003. “Control design and testing of a novel fuel-cell-powered
battery-charging”, IEEE APEC'03, 2, pp. 1127-1133.
[13] Jung, J. -W., 2005. “Modeling and Control of Fuel Cell Based Distributed Generation
Systems”, PhD Dissertation, Ohio State University.
[14] Jung, J. -W., M. Dai, and A. Keyhani, 2005. “Modeling and control of a fuel cell based Zsource
converter”, IEEE Conf. APEC 05, 2, pp. 1112-1118.
[15] Keyhani, A. and J. –W. Jung, 2004. “Distributed energy systems”, Journal of Iranian
Association of Electrical and Electronics Engineers, 1(2), pp. 33-40.
[16] Kim, E. –S., K. –Y., Joe, M. –H., Kye, Yoon-Ho Kim, and Byung-Do Yoon, 1997. “An
improved ZVZCS PWM FB DC/DC converter using energy recovery snubber”, IEEE
APEC'97, 2, pp. 1014-1019.
[17] Liu, C., T. Nergaard, L. Leslie, J. Ferrell, X. Huang, T. Shearer, J. Reichl, J. Lai, and J. Bates,
2002. “Power Balance Control and Voltage Conditioning for Fuel Cell Converter with Multiple
Sources”, IEEE Conf. Power Electronics Specialists, 4, pp. 2001-2006.
[18] Mohan, N., T. M. Undeland, and W. P. Robbins, “Power Electronics, Converters, Applications
and Design”, 2nd Edition, John Wiley & Sons.
[19] Ogura, K., S. Chandhaket, T.Ahmed, and M. Nakaoka, 2003. “Non-Isolated ZVS-PWM Boost
Chopper-Fed DC-DC Converter with Auxiliary Edge Resonant Snubber”, IEEE Conf.
IECON'03, 3, pp. 2356–2362.
[20] Padulles, J., G. W. Ault, and J. R. McDonald, 2000. “An Approach to the Dynamic Modeling
of Fuel Cell Characteristics for Distributed Generation Operation”, IEEE- PES Winter Meeting,
1(1), pp. 134-138.
[21] Peng, F. Z., H. Li, G. –J. Su, and J. S. Lawler, 2004. “A new ZVS bidirectional DC-DC
converter for fuel cell and battery application”, IEEE Trans. Power Electronics, 19, pp. 54-65.

A Predictive Current Control Technique on Fuel Cell Based Distributed
Generation in a Standalone AC Power Supply 904
[22] Premrudeepreechacharn, S., and T. Poapornsawan, 2000. “Fuzzy Logic Control of Predictive
Current Control for Grid connected Single Phase Inverter”, IEEE Conf. Photovoltaic Specialists
Conference, pp. 1715-1718.
[23] Rodriguez, J., J. Pontt, C.A. Silva, P. Correa, P. Lezana, P. Cortes, and U. Ammann, 2007.
“Predictive Current Control of a Voltage Source Inverter”, IEEE Trans. Industrial Electronics ,
54, pp. 495 – 503.
[24] Rodriguez, J., J. Pontt, C. Silva, P. Cortes, U. Amman, and S. Rees, 2004. “Predictive current
control of a voltage source inverter”, Power Electronics Specialists Conference, PESC 04, in
Proc. IEEE, 3, pp. 2192 - 2196.
[25] Suzuoka, K., S. Moisseev, L. Gamage, K. Soshin, K. Nishida, and M. Nakaoka, 2003. “Boost
Transformer Linked Full Bridge Soft-Commutation DC-DC Power Converter with Secondary-
Side Phase-Shifted PWM Rectifier Switches”, IEEE Conf. IECON '03, 1, pp. 49-54.
[26] Wang, C., and M. H. Nehrir, 2006. “Control of PEM Fuel Cell Distributed Generation
Systems”, IEEE Trans. Energy Conversion, 21(2), pp. 586-595.
[27] Wang, C., and M. H. Nehrir, 2006. “Short-time Overloading Capability and Distributed
Generation Applications of Solid Oxide Fuel Cells”, accepted for IEEE Trans. Energy
Conversion.
[28] Wen. X., F. Lin, and T. Q. Zheng, 2006. “Dynamic Model and Predictive Current Control of
Voltage Source Converter Based HVDC”, in Proc. IEEE, PowerCon, pp. 1–5.

European Journal of Scientific Research
ISSN 1450-216X Vol.20 No.4 (2008), pp.905-913
© EuroJournals Publishing, Inc. 2008
http://www.eurojournals.com/ejsr.htm
Effects of Ethyl acetate Portion of Syzygium Aromaticum
Flower Bud Extract on Indomethacin-Induced Gastric
Ulceration and Gastric Secretion
Okasha Mohammad Abdul- Halim
Department of Human Physiology, Faculty of Medicine
Ahmadu Bello University, Zaria, Nigeria
Magaji Rabiu Abdussalam
Department of Human Physiology, Faculty of Medicine
Bayero University, Kano, Nigeria
Abubakar Mujtaba Suleiman
Department of Pharmacognosy and Drug Development, Faculty of Pharmaceutical
Sciences, Ahmadu Bello University, Zaria, Nigeria
Fatihu Muhammad Yakasai
Department of Veterinary Pathology and Microbiology, Faculty of Veterinary Medicine
Ahmadu Bello University, Zaria, Nigeria
Abstract
Clove, the dried flower bud of Syzygium aromaticum (Family: Myrtaceae) is one of
the important herbs used as indigenous medicine in India, and in Unani Medicine. It
contains flavonoids and tannins among others that have bee proven to stimulate the
production of prostaglandins which contribute to the maintenance of basal gastric mucosal
blood flow and mucus secretion that enhance the mucosal integrity defense and repair of
injury. In the present work, we investigated the gastric anti-ulcerogenic and antisecretory
effects of the ethyl acetate portion of the ethanolic extract of Syzygium aromaticum
(SaETAC) flower bud in rats, using indomethacin as a necrotizing agent. SaETAC
demonstrated a gastro-protective anti-ulcerogenic effect as well as a marked decrease of
volume, titritable acidity and acid output of gastric secretion in rats. The extract proved to
possess some phytochemicals which may contribute to the observed gastric antiulcerogenic
and anti-secretory activity.
Keywords: Syzygium aromaticum, ethyl acetate, indomethacin, gastric ulcer, gastric
secretion
1. Introduction
Clove is the dried reddish brown flower bud of Syzygium aromaticum (Family: Myrtaceae), an
evergreen tropical tree 10-20 cm in height, indigenous to India, Indonesia, Zanzibar, Mauritius and Sri
Lanka. Sometimes, it is called Eugenia caryophyllata. It is one of the important herbs used as

Effects of Ethyl acetate Portion of Syzygium Aromaticum Flower Bud Extract on
Indomethacin-Induced Gastric Ulceration and Gastric Secretion 906
indigenous medicine in India, and in Unani Medicine. (Trease and Evans, 1972). It is commonly called
“Kanumfari” in Hausa and ‘Kanumfo’ in Yoruba.
Clove is reported as aphrodisiac (Khan, 1893; Tajuddin et al., 2004), stomachic (Nadkarni,
2000; Attar, 1370), carminative, antispasmodic (Khory and Katrak, 1985; Pourgholami et al., 1990). It
is also reported to be useful in conceiving in high doses and acts as a contraceptive in low doses (Ibn
Al-Baytar, 1869) and useful in cataract (Raazi, 1961).
Peptic ulcers are sores or eroded areas that form in the lining mucosa of the stomach,
duodenum, lower esophagus and Merkel’s diverticulum. They affect more than 4 million people each
year in the United States (Graham, 1996). Peptic ulcer is the most common gastrointestinal disorder in
clinical practice. Oxidative stress and free radical-mediated processes have been implicated in the
pathogenesis of gastrointestinal disorders (Salim, 1992).In the absence of non-steroidal anti
inflammatory drugs (NSAIDs) use or acid hypersecretory states such as Zollinger-Ellison Syndrome,
Helicobacter pylori is the causative factor in 75% of all patients with gastric ulcer and 90% of all
patients with duodenal ulcer (Falk, 2000).
Three classes of drugs have been shown to have a direct effect on Helicobacter pylori:
antibiotics, bismuth salts, and proton pump inhibitors. Because Helicobacter pylori is difficult to
eradicate, most treatment regimens combine agents from two or even all three of these cases. In all of
them, patients with active peptic disease should also receive a total of 6 weeks of acid suppression with
an H2 receptor antagonist. Peptic ulcer therapy through this combination of drugs has not been very
effective due to non-compliance to drugs by patients and possible side effects of the drugs being taken
continuously (Peura, 1998).
Considering the several side effects of modern medicine, indigenous drugs with fewer side
effects should be looked for as a better alternative for the treatment of peptic ulcer (Salim, 1992).
Recent studies found that different substances from plant sources not only afford gastroprotection but
also accelerate ulcer healing. They may also possess anti-inflammatory action by suppressing the
neutrophil/cytokine cascade in gastrointestinal tract (GIT) (Alarcon de la Lastra et al., 1995),
promoting tissue repair though expression of various growth factors, exhibiting antioxidant (Kim et al.,
2004) scavenging reactive oxygen species (ROS) (Pastrada-Bonilla et al., 2003; Liu, et al., 2002),
showing anti-nucleolytic, cytochrome P450 2F1 inhibitory, anti-necrotic and anti-carcinogenic
activities (Bagchi et al., 2002).
There are various plant-originated "gastroprotectors" with different composition that have been
used in clinical and folk medicine by many countries due to their beneficial effects on the mucosa of
GIT. In China and Japan, polyphenol extracts such as Sopharadin extracts, containing flavonoids and
its synthetic flavonoid derivative known as Solon are widely employed in peptic ulcer therapy and also
as food additives and nutritional supplements, mainly because of their strong inhibition of
prostaglandin (PG) metabolism and vasoconstrictive leukotriene inhibition (Kyogoku et al., 1979).
This study aims at throwing some lights on the effects of ethyl acetate portion of the ethanolic
extract of Syzigium aromaticum flower bud on indomethacin-induced gastric mucosal damage and
gastric secretion which may help in detection of some gastroprotective properties of this extract.
2. Materials and Methods
2.1. Chemicals and drugs
The following chemicals and drugs were used: Absolute Ethanol (Sigma Aldrich), Ethyl acetate
(ETAC) (Sigma Aldrich), Indomethacin (Chiesi) ampoule was used in a dose of 20 mg/kg S.C. as
reported by Okabe et al. (1977) and Urushidani et al. (1979). Cimetidine (Lek Pharm. Slovenia) was
used in a dose of 50 mg/kg S.C. (Moron et al., 1982) and in a dose of 100 mg/kg S.C. as reported by
Satoh et al. (1983), sodium hydroxide (NaOH) (England), phenolphthalein (E.Merck Darmstadt,
Germany)

907 Okasha Mohammad Abdul- Halim, Magaji Rabiu Abdussalam,
Abubakar Mujtaba Suleiman and Fatihu Muhammad Yakasai
2.2. Preparation of plant material
The flower bud of the Syzygium aromaticum was sourced from ‘Kasuwar Rimi’ market in Kano
Metropolis, Nigeria. It was identified and authenticated at the Herbarium section of the Department of
Biological Sciences, Ahmadu Bello University and given a voucher number 900132 with deposition of
a specimen for further reference. The air dried herb was extracted with aqueous ethanol (70%) in a
soxhlet extractor. The extract after concentration at reduced pressure was suspended in methanol and
partitioned with ethyl acetate to obtain ethyl acetate (ETAC) portion. The portion was concentrated in
vacuum and the residue of the portion was obtained.
2.3. Phytochemical Screening
The extract was screened for the presence of various phytochemicals employing standard screening test
(Trease and Evans. 1983). Conventional protocols for detecting the presence of alkaloids, tannins, etc.
were used.
2.4. Acute Toxicity Test
LD50 determination was conducted using the method of Lorke (1983). In the first phase male and
female mice were divided into three groups of three mice each. After an overnight fasting, the animals
were treated with the extract at doses 1000, 100 and 10mg/kg. In the second phase the animals were
grouped into four of one mouse each and treated with doses of the extract at 200; 400, 800 and 1600
mg/kg. The animals were observed for 24 hours after treatment and the final LD50 was calculated.
2.5. Animals
Swiss male albino rats ranging in weight from 165- 180 grams were used for this study. The animals
were housed under similar conditions of temperature, relative humidity and light/dark cycle with free
access to standard laboratory chow and tap water ad libitum. The animals were fasted for 48 hours
before the commencement of the experiment with only free access to water (Weisher and Thiemer,
1983). This has been proved to be non-ulcerogenic and sufficient for absolute emptying of the stomach
as reported by El-Sokkary et al. (1991). Each of the animals was kept in an individual cage with wide
meshed raised floor to prevent coprophagia. The animals were randomly assigned into three different
groups:
(1) Indomethacin – treated (control) group (10 rats)
Five rats for the study of gastric ulceration and five rats to study gastric secretion.
(2) Extract – treated group (30 rats)
Extract (50, 100, &200mg/kg S.C.) was injected 30 minutes before indomethacin to
study its effect on gastric secretion and gastric mucosal damage induced by
indomethacin.15 rats to study gastric secretion (5rats for each dose) and 15 rats for
gastric ulcer studies (5rats for each dose).
(3) Cimetidine – treated (reference) group (20 rats)
Cimetidine in a dose of 50 and 100 mg/kg S.C. was used to test its effect on
indomethacin – induced gastric ulceration and gastric secretion. Ten rats for gastric
secretion studies (5 rats for each dose of cimetidine) and ten rats to study gastric
mucosal integrity affection (5 rats for each dose).
2.6. Study of Gastric Ulceration
After the 48 hours fasting, the control group was subcutaneously (S.C.) injected with saline.
Experimental groups received SaETAC (50, 100 and 200 mg/kg S.C.) and the reference groups
received cimetidine in a dose of 50 and 100 mg/kg B.W. (Moron et al., 1982; Satoh et al., 1983). After

Effects of Ethyl acetate Portion of Syzygium Aromaticum Flower Bud Extract on
Indomethacin-Induced Gastric Ulceration and Gastric Secretion 908
30 minutes all the groups were administered indomethacin (20mg/kg S.C.).Then, the animals were
deprived of both food and water for seven (7) hours (Urushidani et al., 1979). Later on, the animals
were sacrificed by decapitation (Satoh et al., 1983). The stomachs were opened along the greater
curvature, rinsed slowly with normal saline then stretched out as much as possible on a Whatman’s
filter paper. The ulcerated surface in each stomach was measured with a transparent millimeter scale
rule and the result for each group was expressed in mm of mean ulcer ± S.E. (Ulcer index) (Scepovic
and Radmanovic, 1984). Preventive index (P.I. %) was later calculated according to the method of
Hano et al. (1976) as follows:
U.I. indomethacin – U.I. extract plus indomethacin
P.I. % = X 100
U.I. indomethacin
2.7. Study of Gastric Secretion
Gastric juice was collected after making pyloric ligation according to the technique of Shay et al.
(1954) as modified by Levine (1965) where esophageal ligation was avoided. The animals were fasted
for 48 hours to ensure complete emptying of the stomach, but allowed water ad libitum. The animals
were then weighed at the end of the fasting period. Then, under light anaesthesia, the abdomen was
opened by midline incision and the stomach was identified. A pyloric ligature was made by using a
thread with care to avoid damage of the blood vessels or traction of the stomach. The abdomen was
closed by sutures and cleaned thoroughly with saline. The anaesthesia was discontinued and the
animals were allowed to recover for a period of three (3) hours. After the 3 hours, the animals were
sacrificed and the abdomen of each animal was opened and the esophagus was ligated, then the
stomach was removed and washed with saline and dried. An opening along the greater curvature was
made and the gastric contents were drained into a graduated centrifuge tube then centrifuged at 3000
rpm for 10 minutes.
2.8. Analysis of the Gastric Juice
2.8.1. Volume of gastric juice
After the centrifugation, the supernatant was measured as volume of the gastric juice.
2.8.2. Determination of the Titritable Acidity
A given volume of the gastric juice (0.2 ml) was titrated against 0.01 N NaOH using an end point of
pH 7.0 as determined colorimetrically with phenol red as an indicator (Grossman, 1963). It was
calculated as milliequivalents per liter (mEq/L) which is equal to the number of milliliters (mL) of 0.1
N NaOH required to neutralize 100 ml of the gastric juice
Volume of 0.01N NaOH which neutralizes 1 mL of gastric juice
= X 100
10
(Davenport, 1977).
2.8.3. Determination of acid output
This was calculated as µEq/h by multiplying the volume of gastric secretion (ml/h) of an animal by the
titritable acidity (acid concentration) (mEq/L) of the gastric secretion in that animal (Okabe et al.,
1975).

909 Okasha Mohammad Abdul- Halim, Magaji Rabiu Abdussalam,
Abubakar Mujtaba Suleiman and Fatihu Muhammad Yakasai
2.9. Statistical Analysis
The experimental data were expressed as the mean ± S.E.M. The significance of the results was
determined using analysis of variance (ANOVA) with later comparison by Dunnett’s t-test and the
results were considered significant if p < 0.05.
3. Results
3.1. Phytochemical Screening
Preliminary phytochemical analysis of the extract revealed the presence of flavonoids, glycosides,
tannins, resins and alkaloids.
3.2. Acute Toxicity Studies
The intraperitoneal LD50 of the extract in mice was found to be 565.7mg/kg.
3.3. Gastric Mucosal Integrity Studies
Indomethacin (20 mg/kg S.C.) produced severe gastric mucosal ulceration restricted to the corpus with
an ulcer index of 33.9 ± 1.2. The ulcers appeared in the form of streaks and/or groups and went deep in
the mucosa with severe necrotic and hemorrhagic bases.
Administration of SaETAC (100 mg/kg) showed a significant (p

Effects of Ethyl acetate Portion of Syzygium Aromaticum Flower Bud Extract on
Indomethacin-Induced Gastric Ulceration and Gastric Secretion 910
Table 2: Showing the different parameters tested on 3 hourly collected gastric secretion for different rat
groups.
Groups Indomethacin Extract + indomethacin Cimetidine ± Indomethacin
(20mg/kg) (50mg/kg) (100mg/kg) (200mglkg) (50mg/kg) (100mg/kg)
Parameters
Volume
(ml/3h)
4.14±0.11 2.36±0.34* 2.62±0.25*** 2.20±0.23* 1.30±0.13*** 1.18±0.13***
Titritable
acidity(mEq/L)
74.50±1.70 36.44±2.1*** 32.24±1.41*** 18.06±1.41*** 12.8±0.8*** 10.6±0.82***
Acid Output
(µEq/h)
102.87±4.0 28.82±4.3*** 27.92±2.4*** 3.25±1.7*** 5.62±0.8*** 4.20±0.6***
Values indicate mean ± S.E.M.
Significant variation against Indomethacin – treated group at * = P < 0.05 and *** = P < 0.001
As regards cimetidine, each of the two doses (50 & 100 mg/kg), when administered 30 minutes
prior to indomethacin, produced an appreciable decrease in the volume, titritable acidity and acid
output of gastric secretion as compared to indomethacin – treated group. It was noticed that the
significant changes in all parameters were dose – dependent as shown in table (2).
4. Discussion
The gastrointestinal side effects of NSAIDs, especially in the stomach, are one of the most serious
complications in patients using these drugs (Hawkey, 2000; Wallace, 1997). Indeed, indomethacin
showed potent ulcerogenic action in experimental animals (Takeuchi et al. 1991; Wallace, 1997).
The antiulcerogenic activity of many plant species is related to their content of flavonoids.
Spartium junceum L., a species used in Turkish folk medicine to treat gastric ulcer, contains
glycosylated flavonoids with antioxidant activity (Yesilada et al., 2000).
There are various plant-originated "gastroprotectors" with different composition that have been
used in clinical and folk medicine in many countries due to their beneficial effects on the mucosa of
GIT. In China and Japan, polyphenol extracts such as Sopharadin extracts, containing flavonoids and
its synthetic flavonoid derivative known as Solon are widely employed in peptic ulcer therapy and also
as food additives and nutritional supplements, mainly because of their strong inhibition of
prostaglandin (PG) metabolism and vasoconstrictive leukotriene inhibition (Kyogoku et al., 1979).
The phytochemical screening of the plant extract of Syzygium aromaticum carried out by
Jenkins et al.(1967), showed that it contains alkaloids, amino acids, flavonoids, proteins, sterols,
reducing sugars, tannins and phenols. Another study by Magaji and Yaro (2006) revealed the presence
of tannins, resins, steroid glycosides, alkaloids and flavonoids.
Flavonoids have anti-inflammatory activity and protect the gastric mucosa against a variety of
ulcerogenic agents in different mammalian species (Harborne and Williams, 2000). As a result, many
studies have examined the antiulcerogenic activities of plants containing flavonoids using either
naturally derived or synthetic compounds. Plants containing flavonoids were found to be effective in
preventing this kind of lesion, mainly because of their antioxidant properties (Cody et al., 1986;
Harborne and Williams, 2000).Recently, the antioxidant activity of flavonoids has attracted interest
because of the strong evidence that oxidation processes are involved in the mechanisms of several
gastric disorders, including ulcerogenesis (La Casa et al., 2000).
The results of the present work revealed that SaETAC extract in the dose level of 100 mg/kg
showed a reduction in ulcer index similar to that produced by cimetidine 50 mg/kg and in turn, the
preventive index was nearly equal. Meanwhile, the larger dose of the extract (200mg/kg) reported an
appreciable decrease in the ulcer index (2.6 ± 1.4) which is much lower than that produced by the big
dose of cimetidine (100 mg/kg). Furthermore, both of the extract and cimetidine have reported a
significant decrease in the volume and acid output of gastric secretion. Besides, it is noticed that the
larger dose of the extract has provided a higher degree of ulcer prevention (92.3%). This
gastroprotective effect may be resulting from the marked decrease in the volume and acid output of

911 Okasha Mohammad Abdul- Halim, Magaji Rabiu Abdussalam,
Abubakar Mujtaba Suleiman and Fatihu Muhammad Yakasai
gastric secretion produced by administration of the SaETAC extract, in addition to the high flavonoids
contained in the extract.
The results of our study are consistent with the results of Giamperi et al. (2004) who reported
that grapefruit seed extract showed good gastroprotective antiulcerogenic activity and they attributed
this effect to the antioxidative activity of citrus flavonoids found in grapefruit. Also, Heggers and his
colleagues (2002) and Reagor et al. (2002) reported that grapefruit flavonoids possess antibacterial,
antiviral and antifungal properties.
It can be concluded by the analysis of the obtained data that the anti ulcer activity of SaETAC
extract against indomethacin – induced gastric mucosal damage includes: the high content of
flavonoids in that extract, its exact mechanism of action remains unclear, but may involve an action on
biosynthesis and metabolism of prostaglandins and mucus in the gastric mucosa (Motilva et al., 1994).
Also, flavonoids has antibacterial, antiviral, antifungal (Heggers et al., 2002) and antioxidative activity
(Giamperi et al., 2004). In addition, the SaETAC extract has decreased the volume and acid output of
gastric secretion, as reported from our study results, an effect which may contributes in its gastric
mucosal protective activity.
References
[1] Alarcon de la Lastra, A.C., Martin, M.J., Motilva, V., et al. (1995). Gastroprotection induced by
silymarin, the hepatoprotective principle of Silybum marianum in ischemia-reperfusion mucosal
injury: role of neutrophils. Planta Med., 61 (20): 116 – 119.
[2] Attar, H.Z. (1370). Qaranful (clove). In: Ikhtiyarat-e-Badiyee (Persian). Edited by Attar, H.Z.
Lucknow, Munshi Nawal Kishore, India, Pp: 381.
[3] Bagchi, D., Ray, S.D., Bagchi, M., Preuss, H.G. and Stohs, S.J. (2002). Mechanistic pathways
of antioxidant cytoprotection by a novel IH636 grape seed proanthocyanidin extract. Indian J.
Exp. Biol., 40(6): 717-726.
[4] Cody, V., Middleton, E. and Harborne, J. B. (1986). Plant Flavonoids in Biology and Medicine.
In: Biochemical, Pharmacological and Structure– Activity Relationships. Alan Liss, New York.
[5] Davenport, H.W. (1977). Gastric secretion. In: Physiology of the Digestive tract. 4 th ed. Year
Book, Medical Publishers Incorporated, USA, Pp: 102-128.
[6] El-Sokkary, M., Mansour, M.M., El-Ficky, M.S., Okasha, M.A.M., Bacyoni, M., El-Sayed,
A.Z. and Abdel-Mottleb, A.M. (1991). Influence of zinc sulphate on gastric ulceration and
secretion in indomethacin-treated male rats. J. Biol. Med. Sci. Ther., 7 (1): 366-385.
[7] Falk, P. (2000). Helicobacter pylori - can the mechanisms of pathogenesis guide us towards
novel strategies for treatment and prevention? J. Intern. Med., 240: 319-332.
[8] Giamperi, L., Fraternale, D., Bucchini, A., Rocco, D. (2004). Antioxidant activity of Citrus
paradise seeds glyceric extract. Fitoterapia, 75(20): 221-224.
[9] Graham, D.Y. (1996). Non-steroidal anti-inflammatory drugs, Helicobacter pylori and Ulcers:
where we stand. Am. J. Gastroenterol., 91 (10): 2086.
[10] Grossman, M.I. (1963). Physiology for Physicians. A monthly publication of the American
Physiological Society, 1 (7): 1-5.
[11] Hano, J., Bugaski, J., Danek, L., and Wantuch, C. (1976). The effect of neuroleptics on the
development of gastric ulcers in rats exposed to restraint and cold stress. Pol. J. Pharmacol.
Pharm., 28: 37-47.
[12] Harborne, J. B. and Williams, C. A. (2000). Advances in flavonoid research since 1992.
Phytochemistry, 55(6): 481-504.
[13] Hawkey, C.J. (2000). Nonsteroidal anti-inflammatory drug gastropathy. Gastroenterology, 119:
521-535.

Effects of Ethyl acetate Portion of Syzygium Aromaticum Flower Bud Extract on
Indomethacin-Induced Gastric Ulceration and Gastric Secretion 912
[14] Heggers, J.P., Cottingham, J., Gusman, J., et al. (2002). The effectiveness of processed
grapefruit seed extract as an antibacterial agent: II. Mechanism of action and in-vitro toxicity. J.
Altern. Complement. Med., 8: 333-340.
[15] Ibn Al – Baytar (1869). Qaranful (clove). In: Al Jame’ Li- Mufradat al advia wal Aghzia
(Arabic). Volume IV. Edited by: Ibn Al – Batyar. Matba Zahiyah, Zaaherah Mutawaffarah,
Cairo, Egypt, Pp: 7-9.
[16] Jenkins, G.L., Knevel, A.M. and Digangi, F.E. (1967). Quantitative Pharmaceutical chemistry.
McGraw Hill Book Company, New York, America, Pp: 455-462.
[17] Khan, M.A. (1893). Qaranful (clove). In: Moheet-e-Azam (Persian). Volume III. Edited by:
Khan M.A., Matba Nizami, Kanpur, India, Pp: 296.
[18] Khory, R.N., and Katrak, N.N. (1985). Eugenia caryophyllata. In: Materia Medica of India and
their therapeutics. Edited by Khory, R.N., Katrak, N.N., Neeraj Publishing House, Delhi, India,
Pp: 264-265.
[19] Kim, S.C., Byun, S.H., Yang, C.H., et al. (2004). Cytoprotective effects of Glycyrrhizae radix
extract and its active component liquiritigenin against cadmium-induced toxicity (effects on
bad translocation and cytochrome c-mediated PARP cleavage). Toxicology, 197(3): 239-251.
[20] Kyogoku, K., Hatayama, K., Yokomori, S., et al. (1979). Anti-ulcer effect of isoprenyl
flavonoids. II.Synthesis and anti-ulcer activity of new chalcones related to sophoradin. Chem.
Pharm. Bull., 27: 2943-2952.
[21] La Casa, C., Villegas, I., Alarcon de la Lastra, C., Motilva, V. and Calero, M. J. M.
(2000).Evidence for protective and anti-oxidant properties of rutine, a natural flavone, against
ethanol-induced gastric lesions. Journal of Ethnopharmacology, 71: 45-53.
[22] Levine, R. J. (1965). Stimulation by saliva of gastric secretion in rat. Life Sciences, 4: 959 –
964.
[23] Liu, C.F., Lin, C.C., Lin, M.H., Lin, Y.S. and Lin, S.C. (2002). Cytoprotection by propolis
ethanol extract of acute absolute ethanol-induced gastric mucosal lesions. Am. J.Chin. Med.,
30(2-3): 245-254.
[24] Lorke, D. (1983). A new approach to practical acute toxicity testing. Arch. Toxicol., 54: 275-
287.
[25] Magaji, R.A. and Yaro, A.H. (2006). Preliminary Phytochemical Screening of the Cold
Aqueous Extract of Syzygium aromaticum. Biological and Environmental Sciences Journal for
the Tropics, 3 (1): 4-6.
[26] Moron, F., Javor, T., Bata, M., Fiegler, M. and Mozsik, G. (1982). The relationship between
indomethacin – induced gastric ulcer, ulcer protection by cimetidine and prostacyclin and the
cAMP system of the gastric fundic mucosa in the rat. Acta Physiol. Acad. Sci. Hung., 60 (3):
149 – 153.
[27] Motilva, V., Alarcon, de la Lastra, C. and Martin, M.J. (1994). Ulcer-protecting effects of
naringenin on gastric lesions induced by ethanol in rat: role of endogenous prostaglandins. J.
Pharm. Pharmacol., 46: 91-94.
[28] Nadkarni, K. M. (2000). Myrtus caryophyllus. In: Materia Medica. Edited by: Nadkarni A.K.,
Popular Prakashan (pvt Ltd), Mumbai, India, Pp: 835-836.
[29] Okabe, S., Honda, K., Takeuchi, K. and Takagi, K. (1975). Inhibitory effect of l-glutamine on
gastric irritation and back diffusion of gastric acid in response to aspirin in the rat. Am. J. Dig.
Dis., 20 (7): 626-631.
[30] Okabe, S., Takeuchi, K., Urushidani, T., and Takagi, K. (1977). Effects of cimetidine, a
histamine H2 – receptor antagonist on various experimental gastric and duodenal ulcers. Am. J.
Dig. Dis., 22: 677 – 684.
[31] Pastrada-Bonilla, E., Akoh, C.C., Sellappan, S. and Krewer, G. (2003). Phenolic content and
antioxidant capacity of muscadine grapes. J. Agric. Food Chem., 51(18): 5497-5503.

913 Okasha Mohammad Abdul- Halim, Magaji Rabiu Abdussalam,
Abubakar Mujtaba Suleiman and Fatihu Muhammad Yakasai
[32] Peura, D. (1998). Helicobacter pylori: Rational Management Options. Am. J. Med., 105: 424 -
430.
[33] Pourgholami, M.H., Kamalinejad, M., Javadi, M., Majzoob, S. and Sayyah, M. (1990).
Evaluation of the anticonvulsant activity of the essential oil of Eugenia caryophyllata in male
mice. J. Ethnopharmacol., 64: 167-171.
[34] Raazi, A.B.M. (1961). Qaranful (clove). In: Kitab al Haawi Fi al Tibb (Arabic). Volume XXI.
Edited by: Raazi A.B.M., Dar al Ma’arif, Hyderabad, India, Pp: 302.
[35] Reagor, L., Gusman, J., McCoy, L., Carino, E. and Heggers, J.P. (2002). The effectiveness of
processed grapefruit-seed extract as an antibacterial agent: I. An in vitro agar assay. J.
Altern. Complement. Med., 8: 325-332.
[36] Salim, A.W.S. (1992). Use of scavenging oxygen derived free radicals to protect rat against
aspirin and ethanol –induced erosive gastritis . J. Pharmaceutical Sci., 81:9.
[37] Satoh, H., Guth, P.H., and Grossman, M.J. (1983). Role of bacteria in gastric ulceration
produced by indomethacin in the rat. Cytoprotective action of antibiotics. Gastroenterology, 84:
483-489.
[38] Scepovic, Z. and Radmanovic, B.Z. (1984). Interaction between reserpine and non-steroidal
anti-inflammatory drugs in producing gastric ulcers in rats. European J. Pharmacol., 98: 445-
448.
[39] Shay, H., Komarov, S., Fells, S.S., Meranz, D., Gruenlein, M. and Siplet, H. (1945). A simple
Method for the Uniform production of gastric ulceration in the Rat. Gastroenterology, 5: 43-61.
[40] Tajuddin, A.S., Ahamd, S., Latif, A. and Qasmi, I.A. (2004). Effect of 50% Ethanolic Extract
of Syzygium aromaticum (L.) Merr. & Perry (Clove) on Sexual Behaviour of Normal male
Rats. Complimentary and Alternative Medicine, 4: 17.
[41] Takeuchi, K., Ueshima, K., Hironaka, Y., Fujioka, Y., Matsumoto, J. and Okabe, S. (1991).
Oxygen free radicals and lipid peroxidation in the pathogenesis of gastric mucosal lesions
induced by indomethacin in rats. Digestion, 49: 175-184.
[42] Trease, G.E. and Evans, W.C. (1972). Eugenia caryophyllata. In: a Text book of
Pharmacognosy. Edited by: Trease, G.E., Evans, W.C., Bailliere Tindall and Cassell, London,
England, Pp: 382.
[43] Trease, G. E. and Evans, W. C. (1983). Textbook of Pharmacology. 12 th edition. Bailliere
Tindall, London, England, Pp: 343 – 383.
[44] Urushidani, T. Kasuya, U. and Okabe S. (1979). The mechanism of aggravation of
indomethacin-induced gastric ulcers by adrenalectomy in the rat. Jpn.J. Pharmacol., 29: 775-
780.
[45] Wallace, J.L. (1997). Nonsteroidal anti-inflammatory drugs and gastroenteropathy: the second
hundred years. Gastroenterology, 112: 1000-1016.
[46] Weischer, C.H. and Thiemer, K. (1983). A method of induction of cold, indomethacin and
restraint ulcers in rats. Meth. and Find. Clin. Pharmacol., 5 (5): 315-319.
[47] Yesilada, E., Tsuchiya, K., Takaishi, Y. and Kazuyoshi, K., J. (2000). Isolation and extraction
of free radical scavenging flavonoid glycosides from the flowers of Spartium junceum by
activity guided fraction. Ethnopharmacology, 73(3): 471-478.

European Journal of Scientific Research
ISSN 1450-216X Vol.20 No.4 (2008), pp.914-923
© EuroJournals Publishing, Inc. 2008
http://www.eurojournals.com/ejsr.htm
Real Digital TV Accessed by Cellular Mobile System
Basil M. Kasasbeh
Faculty of Information Technology, Applied Science University
Amman 11931, Jordan
E-mail: b_kasasbeh@asu.edu.jo
Rafa E. Al-Qutaish
Faculty of Information Technology, Applied Science University
Amman 11931, Jordan
E-mail: rafa@rafa-elayyan.net
Muzhir S. Al-Ani
Faculty of Information Technology, Amman Arab University
Amman 11953, Jordan
E-mail: muzhir@aau.edu.jo
Khalid Al-Sarayreh
Faculty of Information Technology, Applied Science University
Amman 11931, Jordan
E-mail: khalid_sar@yahoo.com
Abstract
Presently, there is a huge revolution through the use of internet and cellular mobile
units, that almost dominant the world by a huge investment in this field. This paper aims at
incorporating the digital live TV video to the cellular mobile system. The next generation
cellular mobile communication system can have the ability to access the video TV with
high resolution. This system is constructed by receiving and multiplexing satellite TV
channels to be standby and accessible.
Keywords: Wireless Communication, Cellular Networks, Mobile Communication, TV
Broadcast, Next Generation Mobile Systems, Multimedia Systems, Video
Transmission.
1. Introduction
Marconi’s invention in 1901 led to start new fields of telecommunications revolution such as radio,
TV, satellite, mobile, wireless networking and cellular technology. Nowadays, wireless
communications and networks play an important part of communications over the world and led a
wonderful growth of market [1].
Wireless and cellular revolution is apparent in the growth of the mobile phone market. In 1990
the mobile phone users were approximately 11 millions but this number is increasing rapidly to 1
billion in 2004. The future predicts billions and billions of users and so of investments. This huge

Real Digital TV Accessed by Cellular Mobile System 915
number of users over the world needs a simple, convenient, standard, compatible, flexible, and wide
variety of services [2].
Last few years the cost associated with mobile telephones have been decreasing. Mobile
telephone prices have dropped since 1996 and they are an economical way to provide phone service to
the population. New types of wireless devices are being introduced that have access to the internet to
achieve the services available on the internet. Modern mobiles units consist of elegant and comfortable
features that lead to new services.
Nowadays, there is a huge revolution through the use of internet and cellular mobile units, that
almost dominant the world by a huge investment in this field. This paper aims at incorporating the
digital live TV video to the cellular mobile system. The next generation cellular mobile communication
system can have the ability to access the video TV with high resolution. This system is constructed by
receiving and multiplexing satellite TV channels to be standby and accessible.
This paper presents an overview the digital TV broadcasting in Section 2 and an overview of
the digital satellite TV in Section 3. Section 4 discusses the digital video broadcasting. In section 5, the
third generation wireless system is discussed. Section 6 describes the next generation wireless system.
Section 7 presents the proposed RD-TV-CM system. Finally, a discussion in Section 8 concludes the
paper.
2. Digital TV Broadcast
Many attempts have been examined to introduce digital TV with higher resolution, but these affect the
huge number of existing old systems. One approach to design a common standard for digital
broadcasting TV goes in parallel with mobile communications systems applying video compression
[3].
In 1993 the aim of development a common digital TV system for Europe were named Digital
Video Broadcasting (DVB) and Digital Audio Broadcasting (DAB). The goal of DVB is to introduce
digital television broadcasting using satellite transmission and terrestrial transmission. Different levels
of quality are integrated in receiver decoder such as [4]:
• Standard Definition TV (SDTV)
• Enhanced Definition TV (EDTV).
• High Definition TV.
• Multimedia PC.
• High Resolution Systems (HRS).
Transmits data using flexible containers are basically using MPEG-2 frames. DVB sends
service information contained in its data stream which specifies the content of a container. The
following contents have been defined:
• Network Information Table (NIT) that lists the services of provider set-top boxes.
• Service Description Table (SDT), that lists names and parameters for each service within an
MPEG multiplexed channel.
• Event Information Table (EIT) that contains status information about the current
transmission and some additional information for set-top boxes.
• Time and Data Table (TDT), that contains update information for set-top boxes.
These different types of data are either contains a single channel for HDTV, multiple channels
for EDTV or SDTV, or multimedia data broadcasting [5].
3. Digital Satellite TV
The invention of Satellite led to a big revolution in communications that have been used in the
following fields: weather forecasting, Radio & TV broadcasting, military applications and navigation.

916 Basil M. Kasasbeh, Rafa E. Al-Qutaish, Muzhir S. Al-Ani and Khalid Al-Sarayreh
Motion Picture Expert Group (MPEG) describes a form of compression for digital moving
images of TV. This format also allows for audio datastreams synchronizing with the video. Analog
satellite TV uses around 27-36 MHz of bandwidth for its FM video and FM audio subcarriers for each
channel. So the operators put some separate channels, via a digital datastream into a similar bandwidth.
The actual compression ratio can be varied with the needs of suppliers of the video information
between Studio needs 12 Mbps, Broadcast needs 8 Mbps and VHS needs 2 Mbps [3].
The Digital data from several channels can be multiplexed into an MPEG Transport Stream
(MPEG-TS) along with various audio channels. A package with several channels modulated onto one
carrier. The lowest compression ratio will occupy the highest bandwidth but will be needed when the
video content requires much detail.
4. Digital Video Broadcast
Digital Video Broadcast (DVB) is another group that is important and interesting in satellite
transmission. DVB or any satellite system must have at least the following features that required for
Integrated Receiver Decoder (IRD) (i.e satellite box) [6]:
1. System Recommended Requirements
• MPEG-2 transport stream is used.
• Service information is based on MPEG-2 program specific information
• Scrambling is defined by CA (Conditional Access) technical group.
• CA uses the MPEG-2 CA-descriptor.
2. Video Recommended Requirements:
• MPEG-2 main profile at main level is used (1.5-15 Mbps).
• The frame rate is 25 Hz.
• Encoded pictures may have either 4:3 or 16:9 aspect ration.
• IRDs will support 4:3 and 16:9 aspect ratio.
• IRDs must support the use of pan and scan vectors to allow 4:3 monitor to give a full screen
display of 16:9 coded picture.
• IRDs must support a full screen display of 720*576 pixels.
• IRDs must provide appropriate up conversion to produce a full screen display of 544*576
pixels and 480*576.
3. Audio Recommended Requirements
• MPEG-2 layer I and layer II must be supported by the IRD.
• The use of layer II is recommended for the encoded bitstream.
• IRDs must support single channel, dual channel joint stereo and extraction of at least a
stereo pair from MPEG-2 compatible multichannel audio.
• IRDs must support sampling rates of 32 kHz, 44.1 kHz and 48 kHz.
5. Third Generation Wireless System
The objective of the third generation (3G) wireless communications is to provide fairly high speed
wireless communications to support multimedia, data, video in addition to voice. The ITU for the year
2000 was developed the IMT-2000 that defined the 3G capabilities as, voice quality, 144 kbps data rate
for high speed vehicles, 384 kbps data rate for slowly moving, 2.048 Mbps for office use, symmetrical
and asymmetrical data transmission rates, support for both packet switched and circuit switched data

Real Digital TV Accessed by Cellular Mobile System 917
services, adaptive interface to the internet, more efficient use, support for wide variety of mobile
equipment and flexibility to allow the introduction of new services and technologies.
Modern communication technology is the trend toward universal personal telecommunications
and universal communications access. One concept refers to the ability of a person to identify easily by
using any communication system in the country. The other concept refers to the capability of one's
terminal in a wide variety of environments to connect to information services. Personal
Communications Services (PCSs) and Personal Communications Networks (PCNs) are some concepts
of wireless communications and objectives of 3G wireless.
European Telecommunications Standards Institute (ETSI) works to develop a Universal Mobile
Telecommunications System (UMTS) as Europe's 3G wireless standard. UMTS includes two
standards; one is Wideband CDMA (W-CDMA) to provide high data rate with efficient use of
bandwidth. The other standard is known as IMT-TC (TD-CDMA) that is a combination of W-CDMA
and TDMA technology [7, 8].
The dominant technology for 3G system is CDMA. Different CDMA schemes share some
common such as bandwidth, chip rate and multirate. Bandwidth is an important design goal for 3G
system is to limit channel usage to 5 MHz. This value of bandwidth or more improves the receiver's
ability to resolve multipath when compared to narrow band. The chip rate depends on desired data rate
and bandwidth limitations. A chip rate of 3 Mcps or more is reasonable. Multirate refers to the
provision of multiple fixed data rate logical channels to a given user, in which different data rates are
provided on different logical channels.
6. Next Generation Wireless System
Multimedia broadcasting and DVB can be also used for high bandwidth asymmetrical internet access.
Different types of service provider can help to provide information to the customers as illustrated in
Figure 1. If the customer wants to download high-volume information, the information provider
transmits this information to the satellite provider via service provider.
TV
broadcasting
Radio
broadcasting
Internet
provider
Figure 1: Mobile internet services.
Next
Generation
Internet
TV Receiver
Radio Receiver
Next
Generation
Mobile
The satellite provider multiplexes a stream of data together with other digital TV channels and
transmits it to the customer via satellite and a satellite receiver. The customer can receive the
information with the help of a DVB adapter inside a multimedia PC. These information can be
encrypted to ensure that the information received by the indicated customer.
The 3G cellular system through the year 2006 is extended over a wide area of the world. The
trend of 4G or Next Generation (NG) of mobile cellular systems may be covering all the
communications and services over the world. The 4G offers the following views: next generation, new
air interface, new network, strict generation, wireless & wireline, technology trends, service providers,
wireless internet, higher bit rate, cost reduction, user services and white space.

918 Basil M. Kasasbeh, Rafa E. Al-Qutaish, Muzhir S. Al-Ani and Khalid Al-Sarayreh
The trends of NG mobile system may be deployed around the year 2010. The aim is to integrate
all type of services in a single frame. NG is not necessary defined by specific features but by
significant advance in system capability beyond what can be achieved with 3G. The NG data
transmission rate are planned to be up to 20 Mbps, which 10 times faster than the 3G. NG will allow
high quality smooth video transmission.
Multimedia network illustrated in Figure 2 to cover a huge number of different types of
services that are compatible and accessible to the next generation mobile system. The suggestion of a
new technologies supported to computers, communications and networking to standardized and merge
all forms of data including audio and video in a multimedia streams. The customer can access any
service via its IP address identification. This form can be standardized and any sub network can
connect via adapted interface to the high speed internet to form a big and huge collection of services
over the world that is the Multimedia Broadcast over a Cellular Network (MBCN). The Fast
Information Channel (FIC) is transmitted using a special modulation scheme that is a Multi Carrier
Modulation (MCM). The last stage before transmitter is the wide band Orthogonal Frequency Division
Multiplexing (OFDM) that is able to compact wide band of information [9].
Audio
Service
Data
Service
Video
Service
Figure 2: Multimedia multiplexing system.
Audio
Encoder
Packet
Encoder
Video
Encoder
Channel
Coder 1
Channel
Coder n
Channel
Coder 1
Channel
Coder n
Channel
Coder 1
Channel
Coder n
Main
Service
Channel
MSC
MUX
Transmitted
Signal
Fast
Information
Channel (FIC)
7. Proposed RD-TV-CM System
Nowadays, we are looking for a tremendous revolution in mobile system services and applications.
Different types of wireless data transmission that applied cellular technology have unsymmetrical
characteristics. In order to integrate these different multimedia systems over a standard network, it
must be capable to adapt these different types of data. Many important features must be standardized to
reach an integrated of all available system. Wide bandwidth, high bit rate and huge amount of capacity
are the most important features to recover all multimedia transmissions as well as some specifications
for cellular mobile to store and display the received data.
Introduction of mobile IP address offers a new technology of mobile access to all internet
services with some retraction of speed. The digital TV channels can be transmitted via satellite and
then received by the customer as requested information.
The consumers, looking for near future, through the introduction of new mobile technologies,
so by using these devices they can be able to access all the services over a separate air interface. The
Transmission
MUX
Transmitter
OFDM

Real Digital TV Accessed by Cellular Mobile System 919
proposed Real Digital TV accessed by Cellular Mobile (RD-TV-CM) may be constructed through
eight items; the next subsections describe these eight items.
7.1. Satellite Configuration
Many configurations can be provided between earth station and satellite antenna, and the suitable one
is being used to provide point to point link between base station transmitter and Base Station Mobile
Center Receiver (BS-MCR) through the satellite as shown in Figure 3.
Multi
Receivers
7.2. Channels Distribution
Satellite 1
Transmitter 1
Figure3: Broadcasting TV satellite.
Multi
Receivers
Multi
Receivers
Satellite 2
Transmitter 2
Multi
Receivers
The construction of BS-MCR is built to receive several satellite sits from different areas over the
world. These multiple receivers are fixed on their specific areas and each sub receiver is concentrated
on a number of channels. This is built through a two set of nested multiplexers, one set for satellite and
the other for channels as shown in Figure 4.
SAT1
SATm
7.3. Image Compression
.
.
.
.
.
.
.
.
.
Figure 4: Multiplexing channel system.
Satellite
Multiplexing
SAT1_CH1
SAT1_CHn
.
.
.
.
.
.
SATm_CHn
Channel
Multiplexing
Selected
Channel
High digital TV image is at least 1024*1024 pixels. So retransmitted this form needed a huge capacity
as well as high speed. The aim is to introduce this image in new form to be adapted with the suggested

920 Basil M. Kasasbeh, Rafa E. Al-Qutaish, Muzhir S. Al-Ani and Khalid Al-Sarayreh
system. The best form of reduction that referred to new mobile technology is to reduce the size by a
factor of 4. This can be implemented by two level of compression to generate a new image size of
265*256 as shown in Figure 5.
0
1
2
3
.
.
.
.
.
1023
7.4. Frame Format
0 1 2 3 . . . . . . . . . .1023
Figure 5: Image compression.
0
1
2
.
.
511
Level_1 compression
0 1 2 . . . . 511
0
1
.
255
Level_2 compression
0 1 . .255
The suggested frame format shown in Figure 6 consists of the following fields :
• Start Frame (SF), 2 bytes length.
• -*Identification Source Address (ISA), 2 bytes length.
• Identification Destination Address (IDA), 2 bytes length.
• Identification Function Frame (IFF), 2 bytes length, identifies the purpose of frame.
• User Data Frame (UDF), 64*3 kbytes length.
• End Frame (EF), 2 bytes length.
S
F
7.5. Rate Specification
I
S
A
I
D
A
Figure 6: Frame format structure.
I
F
F
2 2 2 2 192 k 2 Bytes
The frame length is 16 bytes of synchronization and identification and 64*3 bytes for data. The 64
kbytes comes from 256*256 pixels image size. So the total frame length is 1536128 bits. Acceptable
live TV must be transmitted at least 25 frame per second. The permitted bit rate in this case is
38.403200 Mbps.
U
D
F
E
F

Real Digital TV Accessed by Cellular Mobile System 921
7.6. Handover
The aim of handover in a Cellular system should not cause a cut-off and keep call in best quality,
during the mobility of mobile out of the BTS range or crossing the boundaries of the cell. When a
mobile phone access the satellite TV broadcasting, so it must be adapted to any movement of mobile
phone as well as the satellite movements. This is done by an Intelligent Supervisory System (ISS) to
compare between all the parameters as shown in Figure 7.
7.7. Operation
Handover in Satellite System
Figure 7: Intelligent Handover.
Intelligent Supervisory System
Handover in Mobile System
The company mobile center installed a many receivers to receive a certain satellites. The next
generation mobile unit is built to load and excite TV software. The operation started firstly when a
mobile user requesting a specific satellite TV, that is confirmed by MSC company. Secondly the
mobile user requesting a specific channel, that is also confirmed by MSC. When all the lows are in
order, so the requested service has been in the hand of the mobile user as shown in Figure 8.
Satellite
Center
Figure 8: Transmitting of data.
Mobile
Center
Req. Sat.
Req. Ch.
Ack. Sat.
Ack. Ch.
Data Flow
Mobile
User

922 Basil M. Kasasbeh, Rafa E. Al-Qutaish, Muzhir S. Al-Ani and Khalid Al-Sarayreh
7.8. System structure
The structure of the system can be divided into the following five subsystems:
1. Satellite Antenna (SA),
2. Satellite Receiver (SR),
3. Multiplexing System (MS),
4. Mobile Network (MN), and
5. Mobile Subscriber (MS).
The MS demand a specific satellite then a certain channel by the software executed over the
mobile phone. These informations transmitted to the MS through the MN. The MS pointed to the
indicated satellite and channel and insure a line from the requested channel to the subscriber.
8. Conclusion
Currently, there is a huge revolution through the use of internet and cellular mobile units, that almost
dominant the world by a huge investment in this field. This paper aims at incorporating the digital live
TV video to the cellular mobile system. The next generation cellular mobile communication system
can have the ability to access the video TV with high resolution. This system is constructed by
receiving and multiplexing satellite TV channels to be standby and accessible.
Huge amount of money invested in the market of Wireless telecommunications networks that
leads to new technologies to serve this field. The impaction of all multimedia data in a single channel
can be accessed from mobile unit is a strong and power technology which is an elegant face of the next
generation mobile system. The system is simple and depends on the multiplexing of different
multimedia services that can be accessed by the subscriber. This distribution is flexible and compatible
that permits the customer to access any services from its own mobile unites at any site over the world.
This system must be intelligent to avoid loaded capacity when a huge number of subscribers need to
access the same service. This system can be reach its maximum efficiency, when the next generation
well be reachable and accessible with their adaptable high speed of transmission, high verity of
services, high capacity of channels, high quality and performance of mobile units with high screen
resolution.
Acknowledgement
This work was supported by the Applied Science University, Amman, Jordan.

Real Digital TV Accessed by Cellular Mobile System 923
References
[1] W. H. Al-Sawalmeh and M. S. Al-Ani, “Signal Strength Measurements in GSM”, Asian
Journal of Information Technology, Vol. 3, No. 11, 2004, pp. 1103-1107.
[2] W. Stallings, Wireless Communications and Networks, Prentice Hall, New Jersey, 2002.
[3] W. X. Wang and S. D. Blostein, “Video Image Transmission over Mobile Satellite Channel”,
Elsevier, Signal Processing (Image Communication), Vol. 16, No. 6, 2001, pp. 531-540.
[4] D. E. Comer, Network Systems Deign Using Network Processors, Person Education Inc., 2004.
[5] K. B. Benson and D. G. Fink, HDTV Advanced TV, McGraw Hill, New York 1991.
[6] J. W. Mark and W. Zhuang, Wireless Communications and Networking, Prentice Education,
New Jersey, 2003.
[7] P. M. Heysters, H. Bouma, J. Smit and G. J. M. Smit, “A Reconfigurable Function Array
Architecture for 3G and 4G Wireless Terminals”, in proceedings of the World Wireless
Congress, San Francisco, USA, 2002
[8] J. Schiller, Mobile Communications, Person Education Limited, England, second edition, 2003.
[9] G. J. M. Smit, P. J. M. Havinga, M. Bos, L. T. Smit and P. M. Heysters, “Reconfiguration in
Mobile Multimedia Systems”, in proceedings of Progress Workshop on Embedded Systems,
Utrecht, Netherlands, 2000

European Journal of Scientific Research
ISSN 1450-216X Vol.20 No.4 (2008), pp.924-933
© EuroJournals Publishing, Inc. 2008
http://www.eurojournals.com/ejsr.htm
A Rule-Based Fuzzy Automatic Voltage Regulator for
Power System Stability
Samuel N. Ndubisi
Department of Electrical and Electronic Engineering, Enugu State
University of Science and Technology PMB 01660, Enugu, Nigeria
E-mail: linkdrsam@yahoo.com
Tel.: 2348037046217
Marcel .U. Agu
Department of Electrical Engineering, University of Nigeria Nsukka
Enugu State, Nigeria
Abstract
Conventional automatic voltage regulators (CAVR) are observed to have limited
operational performance as regards to the control of turbo generator terminal voltage and
reactive power during abnormal operating conditions. This is due to its fixed parameters
and linearized models of the power system. This paper presents a rule based fuzzy logic
controller configured in form of proportional integral controller. It showed a very high
improved control of the turbo generator terminal voltage due to very high number of rules
(11×11) used and the plant model is not really being considered. Settling time, over shoot
etc. were equally reduced by the new controller.
Keywords: Conventional automatic voltage regulators; fuzzy logic controller; exciter;
fuzzy rules.
1. Introduction
The primary function of the Automatic Voltage Regulator (AVR) of the turbo generator (TG) is to
control the terminal voltage and reactive power whilst also ensuring proper sharing of the reactive
power amongst parallel connected generators. Load changes and faults always subjects TGs which are
nonlinear systems to terminal voltage and reactive power variations. The AVR design must be robust
enough to cope with both normal load and fault condition of operation. The resultant effect of all these
changes in operating condition is that there will be considerable changes in the TG dynamics. Research
has shown that conventional linear fixed gain AVRs can worsen the performance under this condition.
Response variations in some circumstances causes negative damping, and degrading system stability
[1].
Also the TG model is needed before designing the AVR controller. The idea in this work is to
overcome these problems by developing an exact functional replacement for a conventional AVR, with
machine voltage the only feedback signal. It is based on the fuzzy logic control.
The fuzzy logic concept incorporates an alternative way which allows one to design a controller
using a higher level of abstraction without knowing the plant model [2]. This makes fuzzy logic
controllers very attractive for ill defined systems with uncertain parameters. With the help of fuzzy

A Rule-Based Fuzzy Automatic Voltage Regulator for Power System Stability 925
logic concepts, experts’ knowledge can be used directly to design a controller. Fuzzy logic allows one
to express the knowledge with subjective concepts such as very big, too small, moderate and slighty
deviated, which are mapped to numeric ranges [3].
Fuzzy control implementation of AVR has been reported in a number of publications [4,5,6].
Due to its lower computation burden and its ability to accommodate uncertainties in the plant model,
fuzzy logic PI configured AVR (FAVR) appear to be suitable for implementing AVRs. The
implementation of FAVR is through simple microcomputer with A/D and D/A converters [7]. The
performance of this controller is observed to depend on the operating conditions of the system,
although, it is less sensitive than conventional linear PI controller. In this paper, a rule based fuzzy
logic PI configured controller is developed for excitation and generator terminal voltage control. The
vast rule (11×11) developed for the FAVR made it well suitable for different operating conditions of
the plant. The controller is applied to a mathematical model of the exciter and synchronous generator.
The responses of the machine subject to a fault in the transmission line is obtained by nonlinear
simulations [7]. System responses for three different operating conditions are conducted using FAVR,
conventional PI, and PID controller. All the simulations are carried out using MATLAB software
package. Result shows reduction in overshoot, settling time, rise time and overall responses.
2. Rule – Based Fuzzy Logic AVR
A fuzzy logic controller (FLC) is a special kind of a state variable controller governed by a family of
rules and a fuzzy inference mechanism. The FLC algorithm can be implemented using heuristic
strategies, defined by linguistically described statements. The fuzzy logic control algorithm reflects the
mechanism of control implemented by people, without using any formalized knowledge about the
controlled plant in the form of mathematical models, and without an analytical description of the
control algorithm. The main FLC are fuzzification, rule base, inference mechanism and defuzzification
[8]. Fuzzification is the process of transferring the crisp input variables to corresponding fuzzy
variables. In this work, the error between the desired voltage Vd and the terminal voltage Vt i.e. Ve and
the integral of the error VI are the two inputs. Ve is fuzzified according to the membership functions
shown in fig.1 and is similar to membership function of VI.
For each input variable eleven labels are defined, namely: NV, NL, NB, NM, NS, ZR, PS, PM,
PB, PL and PV which stands for negative very large, negative large, negative big, negative medium,
negative small, zero, positive small, positive medium, positive big, positive large and positive very
large. This numerically stands for (-1, -0.8, -0.6, -0.4, -0.2, 0, 0.2, 0.4, 0.6, 08 and 1). With the two
inputs for this FLC, an (11×11) decision table is constructed as shown in Table 1. Every entity in the
table represents a rule. The antecedent of each rule conjuncts Ve and VI fuzzy set values. An example
of the ith rule is: if Ve is NS and VI is PL then U is PB. This means that if the voltage error is negative
small and integral of voltage error is positive large then the output of controller should be positive big.
Figure 1: Membership functions for input Ve
The procedure for calculating the crisp output of the FLC for some values of input variables is
based on the following three steps [8];

926 Samuel N. Ndubisi and Marcel .U. Agu
STEP 1: Determination of the degree of firing (DOF) of the rules
The (DOF) of the ith rule consequent is a scalar value which equals the minimum of the two antecedent
membership degrees.
Table 1: Decision table of 121 rules
Integral of voltage error VI
Voltage error Ve NV NL NB NM NS ZR PS PM PB PL PV
NV NV NV NV NV NV NV NL NB NM NS ZR
NL NV NV NV NV NV NL NB NM NS ZR PS
NB NV NV NV NV NL NB NM NS ZR PS PM
NM NV NV NV NL NB NM NS ZR PS PM PB
NS NV NV NL NB NM NS ZR PS PM PB PL
ZR NV NL NB NM NS ZR PS PM PB PL PV
PS NL NB NM NS ZR PS PM PB PL PV PV
PM NB NM NS ZR PS PM PB PL PV PV PV
PB NM NS ZR PS PM PB PL PV PV PV PV
PL NS ZR PS PM PB PL PV PV PV PV PV
PV ZR PS PM PB PL PV PV PV PV PV PV
For instance, if Ve is PM with a membership degree of 0.4 and VI is PS with a membership
degree of 0.2 then the degree of firing of this rule is 0.2.
STEP 2: Inference mechanism
The inference mechanism consists of two processes called fuzzy implication and rule aggregation. The
degree of firing of rule interacts with its consequent to provide the output of the rule, which is a fuzzy
subset. The formulation used to determine how the DOF and the consequent fuzzy set interact to form
the rule output is called a fuzzy implication. In fuzzy logic control the most commonly used method for
inferring the rule output is mamdani method [9, 10, 11].
STEP 3: Defuzzification
To obtain a crisp output value from the fuzzy set obtained in the previous step, a mechanism called
defuzzification is used. In this work output u is defuzzified according to the membership functions
shown in fig 2. Centre of area method [7] is used for defuzzification.
Figure 2: Membership functions for output u
Tuning: To achieve a fast response from the controller during faults, the FLC can be tunned with the
parameters g0, g1 and g2 as shown in fig 4.
3. A Power System Dynamic Model
In this paper, simplified dynamic model of a single-machine infinite bus power system is considered
[12]. This model consists of a single synchronous machine connected through a parallel transmission

A Rule-Based Fuzzy Automatic Voltage Regulator for Power System Stability 927
line to a very large network approximated by an infinite bus. The classical third order single–axis
dynamic model of the simple machine infinite bus power system shown in fig 3 has the equations as
follows [12,13]
3.1. Mechanical equations
() t = ω()
-ω
0
� δ t
(1)
ω� () t =
D
ω0
( ω()
t -ω0
) − ( Pe
( t)
− Pm
)
H
2H
(2)
The mechanical input power Pm is assumed to be constant in the excitation controller design.
This implies that the governor action is slow enough not to have any significant impact on the machine
dynamics.
3.2. Electrical generator dynamics
′
1
T ′
( )
() t = E () t − E () t
Eq f q
d 0 (3)
3.3. Electrical equations (assumed X ′ d = X q )
q () t = E′
q () t + ( X d − X ′ d ) I () t
′ f () t = K cU
() t
E′
d ()
() t Vs
sinδ
() t
t =
E d
E f
P
I
I
e
d
q
Q
() t
() t
() t
E′
q
=
X ′ ds
−V
s cosδ
t
X ′
() t ()
Vs
sinδ
=
X ′
E′
q
=
ds
ds
() t
() t V cosδ () t
s
X ′
ds
() t = X I () t
′
E ad f
() t = E′
() t − X ′ I () t
2
s
V
−
X ′
[ ( ) ( () ) ] 2
1
2
2
+ X I t
Vt q d d
d q
ds
(11)
More details of the modeling can be seen in [14]. The definitions of the parameters are as
indicated under symbols and abbreviations.
X = X + X + X
(12)
ds
ds
d
d
T
T
L
L
X ′ = X ′ + X + X
(13)
X =
X + X
s
T
L
(4)
(5)
(6)
(7)
(8)
(9)
(10)

928 Samuel N. Ndubisi and Marcel .U. Agu
3.4. Linear model of SMIB
Figure 3: A single machine infinite bus power system.
By linearizing the above equations about the operating point, we have the state variable model of a
single machine to infinite bus (SMIB) as follows
X � = AX
+ BU
(14)
y = CX
(15)
Where the state variable x is defined by
X = [ Δδ
, Δω,
ΔE′
q ]
In the above system matrix A, B, and C are represented by
(16)
⎡
⎢
⎢
0
1
⎢ ω0
V ′ s E q cosδ
D
A = ⎢−
−
⎢ 2H
X ′ ds 2H
⎢ ( X ′ d − X d ) Vs
sinδ
⎢−
0
⎢⎣
T ′ ′
d 0 X ds
⎤
⎥
0
⎥
ω0
V sin ⎥
s δ
−
⎥
2H
X ′ ds ⎥
1 ( X − ′ ) 1 ⎥
d X d
−
⎥
T ′ ′ ′
d 0 Td
0 X d 0 ⎥⎦
⎡ ⎤
⎢
0
⎥
⎢ ⎥
B = ⎢ 0 ⎥
⎢ ⎥
⎢
K c ⎥
⎢⎣
T ′ ⎥ d 0 ⎦
⎡ E′
q − X d I d
C = ⎢
⎢⎣
Vt
− X ′ d Vs
sinδ
+
X ′ ds
2
X ′ d I q
Vt
⎛ Vs
⎞
⎜
⎟
⎟cosδ
⎝ X ′ ds ⎠
0
E′
− ′ q X d I
Vt
where sub index 0 shows that matrices are calculated at operating point.
( )( ) ( ) ( )
3.5. Simplified voltage and reactive power control loop model (AVR)
0
d
⎛ X ′ ⎤
d ⎞
⎜
⎜1-
⎟ ⎥
⎝ X ′ ds ⎠ ⎥⎦
It is observed from [15] that in an interconnected power system, that the control is made up of load
frequency control loop (LFC) and automatic voltage control loop (AVR). The LFC loop controls
changes in real power due to changes in rotor angle while the AVR loop controls the changes in
reactive power which depends on excitation voltage magnitude. Because the excitation time constant is
much smaller than the prime mover time constant, its transient decay much faster. For this, the crosscompiling
between the LFC loop and AVR loop is negligible and hence the load frequency and
excitation voltage control can be analyzed independently (see fig 4).
0

A Rule-Based Fuzzy Automatic Voltage Regulator for Power System Stability 929
Figure 4: Schematic diagram of LFC and AVR of a synchronous generator
Thus, the AVR in fig 4 is replaced with the FAVR as shown in fig 5 and the nonlinear model
developed as follows. Reference [12] gave different types of exciter and generator models but the
model in fig 4 is a simplified linearized models which took into account the major time constants and
ignores the saturation or other nonlinearities.
Figure 5: FAVR control loop.
From fig 5 Let
V () t = X1
() t , V f = X 2()
t , b = X 3(
t)
Vt
KG
V
()
() t KG
= or V�
t = − + VF
VF
1+
τ GS
τ G τ G
X1
KG
or V () t
X 2
τ G τ G
+ − = �
VF
K F = or
u 1+
τ ES
(17)
VF
K E X 2 K E
VF
() t = − + u = − + − u
τ E τ E τ E τ E
� (18)
∫ V e = b = ∫ ( Vd
−Vt
) = VI
or () 1 X V V V t b� = d
So that
− t = d −
(19)

930 Samuel N. Ndubisi and Marcel .U. Agu
⎡ 1
⎢
−
⎡V�
⎤
G
t ⎡X�
⎤
τ
1 ⎢
⎢ ⎥ ⎢ ⎥ ⎢
F = ⎢V�
F ⎥ = ⎢X�
2⎥
= ⎢ 0
⎢
b�
() t
⎥ ⎢
X�
⎥ ⎢
⎣ ⎦ ⎣ 3 ⎦ ⎢ −1
⎢
⎣
KG
τ G
1 K E − + u
τ E τ E
0
⎤
0
⎥
⎥ ⎡0⎤
⎥
0 +
⎢ ⎥
⎥ ⎢
0
⎥
Vd
⎥ ⎢⎣
1⎥
⎥
⎦
0
⎥
⎦
⎡ 1
F = ⎢−
⎣ τ G
y = CX
K G
× X 1 + × X 2 ;
τ G
1 K
⎤
E
− × X 2 + × u(
index);
Vd
( index)
− X ( 1)
⎥
τ E τ E
⎦
() ( ) ( ) ;
4. Simulation Results
The performance of the FAVR controller is examined through simulation using MATLAB software
package developed based on the exciter and generator models of fig.5.
It is worth noting that the FAVR here considers only the deviations of the terminal voltage for
its set point and the liveliness of the control signal. However, during major disturbances the rotor angle
of the generator with respect to the infinite busbar of the power system is disturbed significantly and
can take sometime to settle down following the event. It is known that conventional AVR (CAVR)
controller can reduce the damping torque of the generator if it uses only the terminal voltage as its
feedback signal resulting to reduction of damping of rotor oscillations. This has to be examined
sufficiently in a later work.
Two set of tests are carried out
A. Voltage v Sudden terminal ariation
With this sudden terminal voltage change, four tests were carried out
1. With CAVR, the amplifier transfer function is given by
K A
(22)
1+
τ AS
and K A = 10 , τ A = 0.
1,
K E = 1,
τ E = 0.
4 , KG = 1 , τG
= 0.
1,
K R = 1,
τ R = 0.
05 has
the response shown below.
Figure 6: Terminal voltage step response for CAVR.
2. A stabilizer is connected between the exciter output and the input summer with a
step input signal. The stabilizer transfer function is
2S
(23)
0.
04S
+ 1
(20)
(21)

A Rule-Based Fuzzy Automatic Voltage Regulator for Power System Stability 931
The response is shown below with its time domain specifications
Figure 7: Terminal Voltage step response of CAVR with stabilizer
3. A PID is connected in series with the amplifier. The PID parameters are
K P = 10 , K I = 0.
25 and K D = 0.
28
.
Figure 8: Terminal voltage step response with PID controller.
4. With the FAVR of fig 4, the response to a step input is shown below with the time
specifications.
Figure 9: (a) Terminal and desired voltage step response with FAVR
(b) Fuzzy input voltage to the generator

932 Samuel N. Ndubisi and Marcel .U. Agu
B. A Three phase fault was applied after 2 seconds and cleared in 4 seconds in fig 4 and
the response of the FAVR is recorded below.
Figure 10: (a) Step response of FAVR to three phase fault.
(b) Fuzzy input voltage to the generator
5. Conclusion
A proportional integral (PI) type fuzzy regulator for terminal voltage and reactive power control of
turbo generators is considered in this work. The result shows that the FAVR performance is very high
as compared to convectional AVR. The overshoot, settling time and rise time are highly reduced
during the two tests conducted. The observed set back is on the steady state error which can be cleared
by automatically tuning the gains g0, g1 and g2 to achieve the required result.
6. List of Symbols and Abbreviations
Symbols
δ () t power angle of the generator, radian.
ω () t rotor speed of the generator, radian/s
P mechanical power, p.u.
m
() t
P e active electrical power delivered by the generator, p.u.
E′ q () t transient EMF in the quadratic axis in the generator, p.u.
E f () t equivalent EMF in the excitation coil, p.u.
Vt () t generator terminal voltage, p.u.
V s infinite bus voltage, p.u.
U f output of the PI fuzzy controller.
H inertia constant
V error voltage
e
V setpoint or reference voltage
d
V exciter output voltage
f
K E exciter gain
K generator model gain
G
τ E exciter time constant
τ generator time constant
G
g , g , g fuzzy gains
1
2
0

A Rule-Based Fuzzy Automatic Voltage Regulator for Power System Stability 933
Abbreviations
AVR automatic voltage regulator
LFC load frequency control
FLC fuzzy logic controller
FAVR fuzzy automatic voltage regulator
CAVR conventional automatic voltage regulator
SMIB single machine infinite bus
PI proportional and integral controller
PID proportional, integral and derivative controller
Acknowledgement
This work was supported by the Power Holdings Company of Nigeria (PHCN), Enugu Distribution
Zone.
References
[1] Hogg B.W, “Representation and control of turbo generators in electric power systems,” Chapter
5 in modeling of dynamical systems vol 2: PP 112 - 149 1981.
[2] Zadeh L.A “Outline of a new approach to the analysis of complex systems and decision
processes,” IEEE Trans. on systems, man and cybernetics, Vol 3, no 1, 1973, PP 28 - 44
[3] Hassan M.A.M, Malik O.P and Hope G.S, “A fuzzy logic based stabilizer for a synchronous
machine,” IEEE Trans. on Energy conversion, vol. 6, no 3, 1991 PP 407- 413.
[4] Weng J.Y, Cheng S.J., Malik O.P. “A Synchronous generator fuzzy excitation controller
optimally designed with a genetic algorithm” IEEE Trans on power systems vol 13, no3, PP
884 884 – 889, August 1998.
[5] Hassan A.R, Sadrul Ula A.H.M “Design and implementation of a fuzzy controller Based
Automatic Voltage Regulator for a Synchronous Generator.” IEEE Trans. on Energy
conversion, Vol 9, No 3, September 1994.
[6] El-Metwally K.A, and Malik O.P, “Fuzzy logic power system stabilizer.” IEE proceedings on
Generation, Transmission and Distribution Vol 142, no 3, May 1995, PP 277 – 281.
[7] Passion K.M and Yurkovich S. “Fuzzy control” Addison Wesley Longman, Inc 1998
[8] Tsoukalas L.H. and Uhrig R.E “Fuzzy and Neural Approach in Engineering.” John Wiley &
Sons, Inc 1997
[9] Mamdani E.H and Assilian S., “An experiment in linguistic synthesis with a fuzzy logic
controller” International Journal of man - machine studies, vol 7, 1975, PP 1-13.
[10] Mamdani E.H; “Advances in the linguistic synthesis of fuzzy controllers,” International Journal
of man - machine studies, vol 8, 1976, PP 669-678.
[11] Mamdani E.H, Ostergaard J.J and Lambessis E., “Use of fuzzy logic for implementing rulebase
control of industrial processes” Fuzzy sets and Decision Analysis, North Holland:
Amsterdam, 1984, PP 429-445
[12] Kundur P, “Power system stability and control,” Mc Graw-Hill, Inc NY 1994.
[13] Wang Y, Hill D. J, Middleton R.H and Gao L. “Transient stability Enhancement and voltage
Regulation for power systems,” IEEE Trans on Power systems, vol 8, PP 620-627, 1993
[14] Guo Y., Hill D.J. and Wary Y, “Global Transient stability and voltage Regulation for power
systems” IEEE Transaction on power systems. Vol 16, No 4, PP 678-688, 2001.