1 - Acta Technica Corviniensis

ACTA TECHNICA CORVINIENSIS– BULLETIN of ENGINEERINGis covered by the following indexes:INDEX COPERNICUS – JOURNAL MASTER LISThttp://journals.indexcopernicus.com/ProQuest databasehttp://www.proquest.co.ukGENAMICS JOURNALSEEK DATABASEhttp://journalseek.net/EBSCO Publishinghttp://www.ebscohost.comEVISA databasehttp://www.speciation.net/Chemical Abstracts Service (CAS)http://www.cas.org/GOOGLE SCHOLARhttp://scholar.google.co.in/BASE ‐ Bielefeld Academic Search Enginehttp://base.ub.uni‐bielefeld.de/Open J‐Gate Servicehttp://www.openj‐gate.com/DOAJ ‐ Directory of Open Access Journalshttp://www.doaj.org/getCITED: Academic research listhttp://www.getcited.org/SCIRUS ‐ Elsevierhttp://www.scirus.com/Electronic Journals Libraryhttp://ezb.uni‐regensburg.de“B+” category Journal according to CNCSIS –THE NATIONAL UNIVERSITY RESEARCH COUNCIL’S CLASSIFICATION OF ROMANIAN JOURNALS (POZ. 940)ACTA TECHNICA CORVINIENSIS– BULLETIN of ENGINEERINGISSN: 2067‐3809 [CD‐Rom, online]copyright © UNIVERSITY POLITEHNICA TIMISOARA,FACULTY OF ENGINEERING HUNEDOARA,5, REVOLUTIEI, 331128, HUNEDOARA,ROMANIAhttp://acta.fih.upt.ro

Editorial & Advisory BoardManager & ChairmanROMANIA Imre KISSUniversity Politehnica TIMISOARA,Faculty of Engineering HUNEDOARAAdvisory Board & Steering CommitteeROMANIA Teodor HEPUTUniversity Politehnica TIMISOARA,Faculty of Engineering HUNEDOARADean of the FacultyROMANIA Francisc WEBERUniversity Politehnica TIMISOARA,Faculty of Engineering – HUNEDOARAGeneral Association of Romanian Engineers(AGIR) – branch HUNEDOARAHUNGARY Imre J. RUDASÓbuda University of BUDAPEST,Department of Structural Engineering –BUDAPESTSLOVAKIA Štefan NIZNIKTechnical University of KOŠICE,Faculty of Metallurgy,Department of Materials Science – KOŠICESERBIA Siniša KUZMANOVICUniversity of NOVI SAD,Faculty of Technical Sciences – NOVI SADPOLAND Stanisław LEGUTKOInstitute of Mechanical Technology,Polytechnic University – POZNANPOLAND Andrzej WYCISLIKSilesian University of Technology ‐KATOWICE, Faculty Materials Science &Metallurgy– KATOWICEINDIA Sugata SANYALSchool of Technology & Computer Science,Tata Institute of Fundamental Research –MUMBAIARGENTINA Gregorio PERICHINSKYUniversity of BUENOS AIRES,Faculty of Engineering – BUENOS AIRESHUNGARYROMANIAHUNGARYSLOVAKIASERBIAPORTUGALBULGARIABULGARIAITALYImre DEKÁNYUniversity of SZEGED, Department of ColloidChemistry, president of Hungarian RegionalAcademy Of Sciences – branch of SZEGEDIoan ILCAUniversity Politehnica TIMISOARA,Faculty of Engineering – HUNEDOARAAcademy of Technical Sciences (ASTR) –branch TIMIŞOARABéla ILLÉSUniversity of MISKOLC,Faculty of Mechanical Engineering andInformation Science – MISKOLCKarol VELIŠEKSlovak University of TechnologyBRATISLAVA, Faculty Materials Science &Technology – TRNAVAMirjana VOJINOVIĆ MILORADOVUniversity of NOVI SAD,Faculty of Technical Sciences – NOVI SADJoão Paulo DAVIMUniversity of AVEIRO, Department ofMechanical Engineering – AVEIROKliment Blagoev HADJOVUniversity of Chemical Technology andMetallurgy, Department of AppliedMechanics – SOFIANikolay MIHAILOVAnghel Kanchev University of ROUSSE,Faculty of Electrical and ElectronicEngineering – ROUSSEAlessandro GASPARETTOUniversity of UDINE,Faculty of Engineering – UDINEACTA TECHNICA CORVINIENSIS – BULLETIN of ENGINEERINGISSN: 2067‐3809 [CD‐Rom, online]copyright © UNIVERSITY POLITEHNICA TIMISOARA,FACULTY OF ENGINEERING HUNEDOARA,5, REVOLUTIEI, 331128, HUNEDOARA, ROMANIAhttp://acta.fih.upt.ro© copyright FACULTY of ENGINEERING ‐ HUNEDOARA, ROMANIA 5

ACTA TECHNICA CORVINIENSIS – Bulletin of EngineeringReview process & Editorial PolicyACTA TECHNICA CORVINIENSIS – Bulletin of Engineering is dedicated to publishing material of the highest engineeringinterest, and to this end we have assembled a distinguished Editorial Board and Scientific Committee of academics,professors and researchers.ACTA TECHNICA CORVINIENSIS – Bulletin of Engineering publishes invited review papers covering the full spectrum ofengineering. The reviews, both experimental and theoretical, provide general background information as well as a criticalassessment on topics in a state of flux. We are primarily interested in those contributions which bring new insights, andpapers will be selected on the basis of the importance of the new knowledge they provide.The editorial policy of ACTA TECHNICA CORVINIENSIS – Bulletin of Engineering is to serve its readership in two ways. Firstly,it provides a critical overview of the current issues in a well‐defined area of immediate interest to materials scientists.Secondly, each review contains an extensive list of references thus providing an invaluable pointer to the primary researchliterature available on the topic. This policy is implemented by the Editorial Board which consists of outstanding scientists intheir respective disciplines. The Board identifies the topics of interest and subsequently invites qualified authors. In order toensure speedy publication, each material will be report to authors, separately, thought Report of the Scientific Committee.For an overview of recent dispatched issues, see the ACTA TECHNICA CORVINIENSIS – Bulletin of Engineering issues.ACTA TECHNICA CORVINIENSIS – Bulletin of Engineering encourages the submission of comments on papers publishedparticularly in our journal. The journal publishes articles focused on topics of current interest within the scope of the journaland coordinated by invited guest editors. Interested authors are invited to contact one of the Editors for further details.The members of the Editorial Board may serve as reviewers. The reports of the referees and the Decision of the Editorsregarding the publication will be sent to the corresponding authors.The evaluated paper may be recommended for: Acceptance without any changes – in that case the authors will be asked to send the paper electronically in the required.doc format according to authors' instructions; Acceptance with minor changes – if the authors follow the conditions imposed by referees the paper will be sent in therequired .doc format; Acceptance with major changes – if the authors follow completely the conditions imposed by referees the paper will besent in the required .doc format;Rejection – in that case the reasons for rejection will be transmitted to authors along with some suggestions for futureimprovements (if that will be considered necessary).The manuscript accepted for publication will be published in the next issue of ACTA TECHNICA CORVINIENSIS – Bulletin ofEngineering after the acceptance date.All rights are reserved by ACTA TECHNICA CORVINIENSIS – Bulletin of Engineering. The publication, reproduction ordissemination of the published paper is permitted only be written consent of one of the Managing Editors.ACTA TECHNICA CORVINIENSIS – Bulletin of Engineering accept for publication unpublished manuscripts on theunderstanding that the same manuscript is not under simultaneous consideration of other journals. Publication of a part ofthe data as the abstract of conference proceedings is exempted.All the authors and the corresponding author in particular take the responsibility to ensure that the text of the article doesnot contain portions copied from any other published material which amounts to plagiarism. We also request the authorsto familiarize themselves with the good publication ethics principles before finalizing their manuscripts.Manuscripts submitted (original articles, technical notes, brief communications and case studies) will be subject to peerreview by the members of the Editorial Board or by qualified outside reviewers. Only papers of high scientific quality will beaccepted for publication. Manuscripts are accepted for review only when they report unpublished work that is not beingconsidered for publication elsewhere.ACTA TECHNICA CORVINIENSIS – BULLETIN of ENGINEERINGISSN: 2067‐3809 [CD‐Rom, online]copyright © UNIVERSITY POLITEHNICA TIMISOARA,FACULTY OF ENGINEERING HUNEDOARA,5, REVOLUTIEI, 331128, HUNEDOARA, ROMANIAhttp://acta.fih.upt.ro62012. Fascicule 3 [July–September]

Aims & ScopeGeneral Aims:ACTA TECHNICA CORVINIENSIS – BULLETIN OF ENGINEERING is an international and interdisciplinary journal which reportson scientific and technical contributions.ACTA TECHNICA CORVINIENSIS – BULLETIN OF ENGINEERING publishes invited review papers covering the full spectrum ofengineering. The reviews, both experimental and theoretical, provide general background information as well as acritical assessment on topics in a state of flux. We are primarily interested in those contributions which bring newinsights, and papers will be selected on the basis of the importance of the new knowledge they provide.Topical reviews in materials science and engineering, each including: surveys of work accomplished to date current trends in research and applications future prospects.As an open‐access journal ACTA TECHNICA CORVINIENSIS – Bulletin of Engineering will serve the whole engineeringresearch community, offering a stimulating combination of the following: Research Papers ‐ concise, high impact original research articles,Scientific Papers ‐ concise, high impact original theoretical articles,Perspectives ‐ commissioned commentaries highlighting the impact and wider implications of research appearing inthe journal.ACTA TECHNICA CORVINIENSIS – BULLETIN OF ENGINEERING encourages the submission of comments on papers publishedparticularly in our journal. The journal publishes articles focused on topics of current interest within the scope of thejournal and coordinated by invited guest editors. Interested authors are invited to contact one of the Editors for furtherdetails.Every year, in three issues, ACTA TECHNICA CORVINIENSIS – BULLETIN OF ENGINEERING publishes a series of reviewscovering the most exciting and developing areas of engineering. Each issue contains papers reviewed by internationalresearchers who are experts in their fields. The result is a journal that gives the scientists and engineers the opportunityto keep informed of all the current developments in their own, and related, areas of research, ensuring the new ideasacross an increasingly the interdisciplinary field.ACTA TECHNICA CORVINIENSIS – BULLETIN OF ENGINEERING exchange similar publications with similar institutions of ourcountry and from abroad.Audience:Scientists and engineers with an interest in the respective interfaces of engineering fields, technology and materials,information processes, research in various industrial applications. It publishes articles of interest to researchers andengineers and to other scientists involved with materials phenomena and computational modeling.About us:ACTA TECHNICA CORVINIENSIS – Bulletin of Engineering is an international and interdisciplinary journal which reports onscientific and technical contributions and publishes invited review papers covering the full spectrum of engineering.Every year, in four online issues (fascicules 1 ‐ 4), ACTA TECHNICA CORVINIENSIS – Bulletin of Engineering [e‐ISSN: 2067‐3809] publishes a series of reviews covering the most exciting and developing areas of engineering. Each issue containspapers reviewed by international researchers who are experts in their fields. The result is a journal that gives thescientists and engineers the opportunity to keep informed of all the current developments in their own, and related,areas of research, ensuring the new ideas across an increasingly the interdisciplinary field.ACTA TECHNICA CORVINIENSIS – Bulletin of Engineering has been published since 2008, as an online supplement of theANNALS OF FACULTY ENGINEERING HUNEDOARA – INTERNATIONAL JOURNAL OF ENGINEERING.Now, the ACTA TECHNICA CORVINIENSIS – Bulletin of Engineering is a free‐access, online, international andmultidisciplinary publication of the Faculty of Engineering Hunedoara.Coverage:ACTA TECHNICA CORVINIENSIS – Bulletin of Engineering is a good opportunity for the researchers to exchangeinformation and to present the results of their research activity. Scientists and engineers with an interest in therespective interfaces of engineering fields, technology and materials, information processes, research in variousindustrial applications are the target and audience of ACTA TECHNICA CORVINIENSIS – Bulletin of Engineering. It publishesarticles of interest to researchers and engineers and to other scientists involved with materials phenomena andcomputational modeling.The journal's coverage will reflect the increasingly interdisciplinary nature of engineering, recognizing wide‐rangingcontributions to the development of methods, tools and evaluation strategies relevant to the field. Numerical modelingor simulation, as well as theoretical and experimental approaches to engineering will form the core of ACTA TECHNICACORVINIENSIS – Bulletin of Engineering's content, however approaches from a range of environmental science andeconomics are strongly encouraged.ACTA TECHNICA CORVINIENSIS – Bulletin of Engineering appear in four issues per year and is open to the reviews, papers,short communications and breakings news inserted as Scientific Events, in the field of engineering.© copyright FACULTY of ENGINEERING ‐ HUNEDOARA, ROMANIA 3

ACTA TECHNICA CORVINIENSIS – Bulletin of EngineeringGeneral Topics:ENGINEERING• MECHANICAL ENGINEERING• METALLURGICAL ENGINEERING• AGRICULTURAL ENGINEERING• CONTROL ENGINEERING• ELECTRICAL ENGINEERING• CIVIL ENGINEERING• BIOMEDICAL ENGINEERING• TRANSPORT ENGINEERINGECONOMICS• AGRICULTURAL ECONOMICS• DEVELOPMENT ECONOMICS• ENVIRONMENTAL ECONOMICS• INDUSTRIAL ORGANIZATION• MATHEMATICAL ECONOMICS• MONETARY ECONOMICS• RESOURCE ECONOMICS• TRANSPORT ECONOMICS• GENERAL MANAGEMENT• MANAGERIAL ECONOMICS• LOGISTICSCOMPUTER AND INFORMATION SCIENCES• COMPUTER SCIENCE• INFORMATION SCIENCEAGRICULTURE• AGRICULTURAL & BIOLOGICAL ENGINEERING• FOOD SCIENCE & ENGINEERING• HORTICULTURECHEMISTRY• ANALYTICAL CHEMISTRY• INORGANIC CHEMISTRY• MATERIALS SCIENCE & METALLOGRAPHY• POLYMER CHEMISTRY• SPECTROSCOPY• THERMO‐CHEMISTRYEARTH SCIENCES• GEODESY• GEOLOGY• HYDROLOGY• SEISMOLOGY• SOIL SCIENCEENVIRONMENTAL• ENVIRONMENTAL CHEMISTRY• ENVIRONMENTAL SCIENCE & ECOLOGY• ENVIRONMENTAL SOIL SCIENCE• ENVIRONMENTAL HEALTHBIOMECHANICS & BIOTECHNOLOGY• BIOMECHANICS• BIOTECHNOLOGY• BIOMATERIALSMATHEMATICS• APPLIED MATHEMATICS• MODELING & OPTIMIZATION• FOUNDATIONS & METHODSInvitation:We are looking forward to a fruitful collaboration and we welcome you to publish in our ACTA TECHNICA CORVINIENSIS –Bulletin of Engineering. You are invited to contribute review or research papers as well as opinion in the fields of scienceand technology including engineering. We accept contributions (full papers) in the fields of applied sciences andtechnology including all branches of engineering and management.Submission of a paper implies that the work described has not been published previously (except in the form of anabstract or as part of a published lecture or academic thesis) that it is not under consideration for publication elsewhere.It is not accepted to submit materials which in any way violate copyrights of third persons or law rights. An author is fullyresponsible ethically and legally for breaking given conditions or misleading the Editor or the Publisher.ACTA TECHNICA CORVINIENSIS – BULLETIN of ENGINEERINGISSN: 2067‐3809 [CD‐Rom, online]copyright © UNIVERSITY POLITEHNICA TIMISOARA,FACULTY OF ENGINEERING HUNEDOARA,5, REVOLUTIEI, 331128, HUNEDOARA, ROMANIAhttp://acta.fih.upt.ro42012. Fascicule 3 [July–September]

Regional Associate Editors & CollaboratorsEditors from ROMANIAVasile George CIOATĂUniversity Politehnica TIMIŞOARA, Faculty of Engineering – HUNEDOARAVasile ALEXAUniversity Politehnica TIMIŞOARA, Faculty of Engineering – HUNEDOARASorin Aurel RAȚIUUniversity Politehnica TIMIŞOARA, Faculty of Engineering – HUNEDOARASorin Tiberiu BUNGESCUBanat’s University TIMIŞOARA – Department of Agricultural Machines – TIMIŞOARASimona DZIȚACUniversity of ORADEA, Faculty of Energy Engineering – ORADEAMirela SOHACIUUniversity Politehnica BUCUREŞTI, Faculty of Materials Science and Engineering – BUCUREŞTIEndre IANOSIUniversity Politehnica TIMIŞOARA, Faculty of Mechanical Engineering – TIMIŞOARAValentin VLĂDUȚNational Institute of Research ‐ Development for Machines and Installations (INMA) – BUCUREŞTIRegional Editors from HUNGARYTamás HARTVÁNYISzéchenyi István University in GYŐR, Department of Logistics & Forwarding – GYŐRGyörgy KOVÁCSUniversity of MISKOLC, Faculty of Mechanical Engineering and Information Science – MISKOLCZsolt Csaba JOHANYÁKCollege of KECSKEMÉT, Faculty of Mechanical Engineering and Automation – KECSKEMÉTPéter TELEKUniversity of MISKOLC, Faculty of Mechanical Engineering and Information Science – MISKOLCJózsef SÁROSIUniversity of SZEGED, Faculty of Engineering – SZEGEDGergely DEZSŐCollege of NYÍREGYHÁZA, Engineering and Agriculture Faculty – NYÍREGYHÁZASándor BESZÉDESUniversity of SZEGED, Faculty of Engineering – SZEGEDKrisztián LAMÁRÓbuda University BUDAPEST, Kálmán Kandó Faculty of Electrical Engineering – BUDAPESTPéter FÖLDESISzéchenyi István University in GYŐR, Department of Logistics & Forwarding – GYŐRRegional Editors from SERBIAZoran ANIŠICUniversity of NOVI SAD, Faculty of Technical Sciences – NOVI SADMilan RACKOVUniversity of NOVI SAD, Faculty of Technical Sciences – NOVI SADMaša BUKUROVUniversity of NOVI SAD, Faculty of Technical Sciences – NOVI SADSiniša BIKICUniversity of NOVI SAD, Faculty of Technical Sciences – NOVI SADSlobodan TAŠINUniversity of NOVI SAD, Faculty of Technical Sciences – NOVI SADMilan BANICUniversity of NIŠ, Mechanical Engineering Faculty – NIŠMaja TURK‐SEKULICUniversity of NOVI SAD, Faculty of Technical Sciences – NOVI SADAna LANGOVIC MILICEVICGraduate School of Business Studies, Megatrend University – BELGRADIgor FÜRSTNERSUBOTICA Tech, College of Applied Sciences – SUBOTICAImre NEMEDISUBOTICA Tech, College of Applied Sciences – SUBOTICARegional Editor from AUSTRALIAJaromir AUDYEdith Cowan University ‐ PERTH, Faculty of Regional Professional Studies – BUNBURYRegional Editors from BULGARIAKrasimir Ivanov TUJAROV"Angel Kanchev " University of ROUSSE, Faculty of Agricultural Mechanization – ROUSSEVania GARBEVATechnical University SOFIA – branch PLOVDIV, Department of Control Systems – PLOVDIVAngel ZUMBILEVTechnical University of SOFIA, Department of Material Science and Technology – PLOVDIVRegional Editors from BOSNIA & HERZEGOVINASabahudin JASAREVICUniversity of ZENICA, Faculty of Mechanical Engineering – ZENICA© copyright FACULTY of ENGINEERING ‐ HUNEDOARA, ROMANIA 7

Regional Editors from MALAYSIAAbdelnaser OMRANSchool of Housing, Building and Planning, Universiti Sains Malaysia – PULAU PINANGPandian VASANTUniversity Technology Petronas, Department of Electrical & Electronic Engineering – PERAKRegional Editors from CROATIAGordana BARICUniversity of ZAGREB, Faculty of Mechanical Engineering and Naval Architecture – ZAGREBGoran DUKICUniversity of ZAGREB, Faculty of Mechanical Engineering and Naval Architecture – ZAGREBRegional Editors from SLOVAKIAPeter KOŠTÁLSlovak University of Technology – BRATISLAVA, Faculty Materials Science & Technology – TRNAVATibor KRENICKÝTechnical University of KOŠICE, Faculty of Manufacturing Technologies – PREŠOVMarian FLIMELTechnical University of KOŠICE, Faculty of Manufacturing Technologies – PREŠOVMária FRANEKOVÁUniversity of ŽILINA, Faculty of Electrical Engineering – ŽILINAJozef DOBRANSKYTechnical University of KOŠICE, Faculty of Manufacturing Technologies – PREŠOVBeata HRICOVÁTechnical University of KOŠICE, Faculty of Mechanical Engineering – KOŠICEMiriam MATUŠOVASlovak University of Technology – BRATISLAVA, Faculty Materials Science & Technology – TRNAVAJán KMECTechnical University of KOŠICE, Faculty of Mechanical Engineering – KOŠICERegional Editor from TUNISIAMohamed Najeh LAKHOUAInstitute of Applied Science and Technology of Mateur – MATEURRegional Editor from CYPRUSLouca CHARALAMBOSAmericanos College – NICOSIAACTA TECHNICA CORVINIENSIS – Bulletin of EngineeringThe Editor and editorial board members do not receive any remuneration. These positions are voluntary.We are very pleased to inform that our journal ACTA TECHNICA CORVINIENSIS – BULLETIN of ENGINEERING is going tocomplete its four years of publication successfully. In a very short period it has acquired global presence and scholars fromall over the world have taken it with great enthusiasm. We are extremely grateful and heartily acknowledge the kind ofsupport and encouragement from you.ACTA TECHNICA CORVINIENSIS – BULLETIN of ENGINEERING is seeking qualified researchers as members of the editorialteam. Like our other journals, ACTA TECHNICA CORVINIENSIS – BULLETIN of ENGINEERING will serve as a great resource forresearchers and students across the globe. We ask you to support this initiative by joining our editorial team. If you areinterested in serving as a member of the editorial team, kindly send us your resume to redactie@fih.upt.ro.ACTA TECHNICA CORVINIENSIS – BULLETIN of ENGINEERINGISSN: 2067‐3809 [CD‐Rom, online]copyright © UNIVERSITY POLITEHNICA TIMISOARA,FACULTY OF ENGINEERING HUNEDOARA,5, REVOLUTIEI, 331128, HUNEDOARA, ROMANIAhttp://acta.fih.upt.ro82012. Fascicule 3 [July–September]

Members from SLOVAKIAŠtefan NIZNIKTechnical University of KOŠICE, Faculty of Metallurgy, Department of Materials Science – KOŠICEKarol VELIŠEKSlovak University of Technology BRATISLAVA, Faculty Materials Science & Technology – TRNAVAPeter KOŠTÁLSlovak University of Technology – BRATISLAVA, Faculty Materials Science & Technology – TRNAVAJuraj ŠPALEKUniversity of ZILINA, Faculty of Electrical Engineering – ZILINAVladimir MODRAKTechnical University of KOSICE, Faculty of Manufacturing Technologies – PRESOVMichal HAVRILATechnical University of KOSICE, Faculty of Manufacturing Technologies – PRESOVJozef NOVAK‐MARČINCINTechnical University of KOSICE, Faculty of Manufacturing Technologies – PRESOVĽubomir ŠOOŠSlovak University of Technology in BRATISLAVA, Faculty of Mechanical Engineering – BRATISLAVAMiroslav BADIDATechnical University of KOŠICE, Faculty of Mechanical Engineering – KOŠICEErvin LUMNITZERTechnical University of KOŠICE, Faculty of Mechanical Engineering – KOŠICETibor KVAČKAJTechnical University KOŠICE, Faculty of Metallurgy – KOŠICEStanislav FABIANTechnical University of KOŠICE, Faculty of Manufacturing Technologies – PREŠOVĽudovít KOLLÁTHSlovak University of Technology in BRATISLAVA, Manufacturing Systems Institute – BRATISLAVAVojtech ANNADepartment of Environmental Engineering & Control Processing, Technical University – KOSICELadislav GULANSlovak University of Technology, Institute of Transport Technology & Designing – BRATISLAVADušan HUSKASlovak Agricultural University, Faculty of European studies & Regional Development – NITRAMiroslav VEREŠSlovak University of Technology in BRATISLAVA, Faculty of Mechanical Engineering – BRATISLAVAMilan SAGAUniversity of ŽILINA, Faculty of Mechanical Engineering – ŽILINAImrich KISSInstitute of Economic &Environmental Security, University of Security Management – KOŠICEMiroslav RIMÁRTechnical University of KOŠICE, Faculty of Manufacturing Technologies – PREŠOVFrantišek PALČÁKSlovak University of Technology in BRATISLAVA, Faculty of Mechanical Engineering – BRATISLAVAKarol BALOGSlovak University of Technology BRATISLAVA, Faculty Materials Science & Technology – TRNAVAFrantišek PECHÁČEKSlovak University of Technology BRATISLAVA, Faculty Materials Science & Technology – TRNAVAOtakav BOKŮVKAUniversity of ŽILINA, Faculty of Mechanical Engineering – ŽILINAMichal CEHLÁRTechnical University KOSICE, Faculty of Mining, Ecology, Process Control & Geotechnologies – KOSICEPavel NEČASArmed Forces Academy of General Milan Rastislav Stefanik – LIPTOVSKÝ MIKULÁŠMilan DADOUniversity of ŽILINA, Faculty of Electrical Engineering – ŽILINAPavol RAFAJDUSUniversity of ŽILINA, Faculty of Electrical Engineering – ŽILINAMembers from HUNGARYImre DEKÁNYUniversity of SZEGED, Department, of Colloid Chemistry – SZEGEDBéla ILLÉSUniversity of MISKOLC, Faculty of Mechanical Engineering and Information Science – MISKOLCImre J. RUDASÓbuda University of BUDAPEST, Department of Structural Engineering – BUDAPESTTamás KISSUniversity of SZEGED, Department of Inorganic and Analytical Chemistry – SZEGEDCecilia HODÚRUniversity of SZEGED, College Faculty of Food Engineering – SZEGEDArpád FERENCZCollege of KECSKEMÉT, Faculty of Horticulture, Department of Economics – KECSKEMÉTAndrás BAKÓSzéchenyi István University in GYŐR, Department of Logistics & Forwarding – GYŐRScientific Committee & Reviewers© copyright FACULTY of ENGINEERING ‐ HUNEDOARA, ROMANIA 9

Imre TIMÁRUniversity of Pannonia, Department of Silicate and Materials Engineering – VESZPRÉMKristóf KOVÁCSUniversity of Pannonia, Department of Silicate and Materials Engineering – VESZPRÉMTibor BERCSEYCollege of KECSKEMÉT, Faculty of Mechanical Engineering and Automation – KECSKEMÉTGyula MESTERUniversity of SZEGED, Department of Informatics – SZEGEDIstván MATIJEVICSUniversity of SZEGED, Department of Informatics – SZEGEDÁdám DÖBRÖCZÖNIUniversity of MISKOLC, Faculty of Mechanical Engineering and Information Science – MISKOLCGyörgy SZEIDLUniversity of MISKOLC, Faculty of Mechanical Engineering and Information Science – MISKOLCIstván PÁCZELTUniversity of MISKOLC, Department of Mechanics – MISKOLCJózsef GÁLUniversity of SZEGED, Faculty of Engineering – SZEGEDDénes BERÉNYIUniversity of DEBRECEN, Hungarian Academy of Sciences – DEBRECENLajos BORBÁSBUDAPEST University of Technology and Economics, Department of Vehicle Parts and Drives – BUDAPESTJános NÉMETHUniversity of MISKOLC, Faculty of Mechanical Engineering and Information Science – MISKOLCGyörgy KAPTAYUniversity of MISKOLC, Faculty of Materials Science and Engineering – MISKOLCIstván J. JÓRIBUDAPEST University of Technology & Economics, Machine & Product Design – BUDAPESTMiklós TISZAUniversity of MISKOLC, Department of Mechanical Engineering – MISKOLCIstván BIRÓUniversity of SZEGED, Faculty of Engineering – SZEGEDAndrás ERDŐHELYIUniversity of SZEGED, Institute of Solid State and Radiochemistry – SZEGEDGyula VARGAUniversity of MISKOLC, Faculty of Mechanical Engineering & Information Science – MISKOLCZsolt TIBAUniversity of DEBRECEN, Department of Mechanical Engineering College – DEBRECENTamás HARTVÁNYISzéchenyi István University in GYŐR, Department of Logistics & Forwarding – GYŐRMárta NÓTÁRICollege of KECSKEMÉT, Faculty of Horticulture, Department of Economics – KECSKEMÉTCsaba BALÁZSITechnical Physics & Materials Science Research Institute, Ceramics & Nanocomposites – BUDAPESTMembers from SERBIASinisa KUZMANOVICUniversity of NOVI SAD, Faculty of Technical Sciences – NOVI SADMirjana VOJINOVIĆ MILORADOVUniversity of NOVI SAD, Faculty of Technical Sciences – NOVI SADVladimir KATICUniversity of NOVI SAD, Faculty of Technical Sciences – NOVI SADMiroslav PLANČAKUniversity of NOVI SAD, Faculty of Technical Sciences – NOVI SADMilosav GEORGIJEVICUniversity of NOVI SAD, Faculty of Engineering – NOVI SADVojislav MILTENOVICUniversity of NIŠ, Mechanical Engineering Faculty – NIŠAleksandar RODIĆRobotics Laboratory, “Mihajlo Pupin” Institute – BELGRADEIlija ĆOSIĆUniversity of NOVI SAD, Faculty of Technical Sciences – NOVI SADJanko HODOLIČUniversity of Novi Sad, Faculty of Technical Science – NOVI SADDraginja PERIČINUniversity of NOVI SAD, Faculty of Technology, Department of Biochemistry – NOVI SADPavel KOVACUniversity of NOVI SAD, Faculty of Technical Science – NOVI SADMilan PAVLOVICUniversity of NOVI SAD, Technical Faculty “Mihajlo Pupin” – ZRENJANINZoran STEVICUniversity in BELGRADE, Technical Faculty – BORFerenc F. GAÁLUniversity of NOVI SAD, Institute of Chemistry, Faculty of Sciences – NOVI SADZoran ANIŠICUniversity of NOVI SAD, Faculty of Technical Sciences – NOVI SADDamir KAKASUniversity of NOVI SAD, Faculty of Technical Sciences – NOVI SADJelena KIURSKIUniversity of NOVI SAD, Faculty of Technical Sciences – NOVI SADDjordje VUKELICUniversity of NOVI SAD, Faculty of Technical Science – NOVI SADErne KIŠUniversity of NOVI SAD, Faculty of Technology – NOVI SADACTA TECHNICA CORVINIENSIS – Bulletin of Engineering102012. Fascicule 3 [July–September]

ACTA TECHNICA CORVINIENSIS – Bulletin of EngineeringAna LANGOVIC MILICEVICGraduate School of Business Studies, Megatrend University – BELGRADZlatko LANGOVICGraduate School of Business Studies, Megatrend University – BELGRADNatasa CVETKOVICGraduate School of Business Studies, Megatrend University – BELGRADRadomir SLAVKOVIĆDepartment of Mehatronics, University of KRAGUJEVAC, Technical Faculty – CACAKZvonimir JUGOVIĆDepartment of Mehatronics, University of KRAGUJEVAC, Technical Faculty – CACAKMilica GVOZDENOVIĆUniversity of Belgrade, Faculty of Technology and Metallurgy – BELGRADBranimir JUGOVIĆInstitute of Technical Science, Serbian Academy of Science and Arts – BELGRADEMiomir JOVANOVICUniversity of NIŠ, Faculty of Mechanical Engineering – NIŠEva PATAKISUBOTICA Tech, College of Applied Sciences – SUBOTICAStevan FIRSTNERSUBOTICA Tech, College of Applied Sciences – SUBOTICAVidosav MAJSTOROVICUniversity of Belgrade, Mechanical Engineering Faculty – BELGRADEBranislav BOROVACUniversity of NOVI SAD, Faculty of Technical Science – NOVI SADDragan ŠEŠLIJAUniversity of NOVI SAD, Faculty of Technical Science – NOVI SADMembers from ROMANIATeodor HEPUȚUniversity Politehnica TIMIŞOARA, Faculty of Engineering HUNEDOARAStefan MAKSAYUniversity Politehnica TIMIŞOARA, Faculty of Engineering HUNEDOARAFrancisc WEBERUniversity Politehnica TIMIŞOARA, Faculty of Engineering – HUNEDOARAIoan MĂRGINEANUniversity Politehnica BUCUREŞTI, Faculty of Materials Science and Engineering – BUCUREŞTIIulian RIPOŞANUniversity Politehnica BUCUREŞTI, Faculty of Materials Science and Engineering – BUCUREŞTIVictor BUDĂUUniversity Politehnica TIMIŞOARA, Faculty of Mechanical Engineering – TIMIŞOARAIoan LAZAUniversity Politehnica TIMIŞOARA, Faculty of Mechanical Engineering – TIMIŞOARAMihai CHIŞAMERAUniversity Politehnica BUCUREŞTI, Faculty of Materials Science and Engineering – BUCUREŞTIAurel CRIŞANUniversity Transilvania of BRAŞOV, Faculty of Material Science and Engineering – BRAŞOVMircea BEJANTehnical University of CLUJ‐NAPOCA, Faculty of Mechanical Engineering – CLUJ‐NAPOCAIoan VIDA‐SIMITITechnical University of CLUJ‐NAPOCA, Faculty of Materials Science & Engineering – CLUJ‐NAPOCANicolae FARBAŞAssociation for Multidisciplinary Research of the West Zone of Romania (ACM‐V) – TIMIŞOARACaius PĂNOIUUniversity Politehnica TIMIŞOARA, Faculty of Engineering – HUNEDOARAVasile MIREAUniversity Politehnica BUCUREŞTI, Faculty of Materials Science and Engineering – BUCUREŞTICristian PREDESCUUniversity Politehnica BUCUREŞTI, Faculty of Materials Science and Engineering – BUCUREŞTICarmen ALICUniversity Politehnica TIMIŞOARA, Faculty of Engineering – HUNEDOARACsaba GYENGETechnical University of CLUJ‐NAPOCA, Machine Building Faculty – CLUJ‐NAPOCAAdalbert KOVÁCSUniversity Politehnica TIMIŞOARA, Department of Mathematics – TIMISOARAOctavian LIPOVANUniversity Politehnica TIMIŞOARA, Department of Mathematics – TIMIŞOARAWilhelm KECSUniversity of PETROŞANI, Department of Mathematics–Informatics – PETROŞANITitus PETRILAUniversity of CLUJ‐NAPOCA, Department of Mathematics – CLUJ‐NAPOCAManuela PĂNOIUUniversity Politehnica TIMIŞOARA, Faculty of Engineering – HUNEDOARASorin DEACONUUniversity Politehnica TIMIŞOARA, Faculty of Engineering – HUNEDOARATibor BEDŐUniversity Transilvania of BRAŞOV, Faculty of Material Science and Engineering – BRAŞOVGallia BUTNARUFaculty of Horticulture, Banatul Agricultural Sciences & Veterinary Medicine University – TIMIŞOARATeodor VASIUUniversity Politehnica TIMIŞOARA, Faculty of Engineering – HUNEDOARALaurențiu POPPERUniversity of ORADEA, Faculty of Energy Engineering – ORADEASava IANICI“Eftimie Murgu” University of REŞIȚA, Faculty of Engineering – REŞIȚA2012. Fascicule 3 [July–September] 11

Ioan MILOŞANTransilvania University of BRAŞOV, Faculty of Materials Science and Engineering – BRAŞOVLiviu MIHONUniversity Politehnica TIMIŞOARA, Faculty of Mechanical Engineering – TIMIŞOARAMembers from POLANDLeszek A. DOBRZANSKIInstitute of Engineering Materials and Biomaterials, Silesian University of Technology – GLIWICEStanisław LEGUTKOInstitute of Mechanical Technology, Polytechnic University – POZNANAndrzej WYCISLIKSilesian University of Technology ‐ KATOWICE, Faculty Materials Science & Metallurgy– KATOWICEWładysław GĄSIORInstitute of Metallurgy and Materials Science, Polish Academy of Sciences – KRAKÓWAntoni ŚWIĆLUBLIN University of Technology, Institute of Technological Systems of Information – LUBLINMarian Marek JANCZAREKLUBLIN University of Technology, Institute of Technological Systems of Information – LUBLINMichał WIECZOROWSKIPoznan University of Technology, Institute of Mechanical Technology – POZNANMembers from PORTUGALJoão Paulo DAVIMUniversity of AVEIRO, Department of Mechanical Engineering – AVEIROPaulo BÁRTOLOPolytechnique Institute – LEIRIA, School of Technology and Management – LEIRIAValdemar FERNANDESUniversity of COIMBRA, Department of Mechanical Engineering – COIMBRAJ. Norberto PIRESUniversity of COIMBRA, Department of Mechanical Engineering – COIMBRAA. M. GONÇALVES‐COELHOThe New University of LISBON, Faculty of Science and Technology – CAPARICAMembers from BULGARIANikolay MIHAILOVAnghel Kanchev University of ROUSSE, Faculty of Electrical and Electronic Engineering – ROUSSEKrassimir GEORGIEVInstitute of Mechanics, Bulgarian Academy of Sciences – SOFIAHristo BELOEVAnghel Kanchev University of ROUSSE, Faculty of Electrical and Electronic Engineering – ROUSSEVelizara IVANOVA PENCHEVAAnghel Kanchev University, Faculty of Electrical and Electronic Engineering – ROUSSEKliment Blagoev HADJOVUniversity of Chemical Technology and Metallurgy, Department of Applied Mechanics – SOFIAOgnyan ALIPIEVUniversity of ROUSSE, Department Theory of Mechanisms and Machines – ROUSSEGencho POPOVAnghel Kanchev University of ROUSSE, Faculty of Agricultural Mechanization – ROUSSEPetar RUSSEVAnghel Kanchev University of ROUSSE, Faculty of Agricultural Mechanization – ROUSSEIvan KOLEVAnghel Kanchev University of ROUSSE, Department of Machine Tools & Manufacturing – ROUSSEIvanka ZHELEVAAnghel Kanchev University of ROUSSE, Department of Termotechnics & Manufacturing – ROUSSEMembers from FRANCEBernard GRUZZAUniversite Blaise Pascal, Institut des Sciences de L'Ingenieur (CUST) – CLERMONT‐FERRANDAbdelhamid BOUCHAIRUniversite Blaise Pascal, Institut des Sciences de L'Ingenieur (CUST) – CLERMONT‐FERRANDKhalil EL KHAMLICHI DRISSIUniversite Blaise Pascal, Institut des Sciences de L'Ingenieur (CUST) – CLERMONT‐FERRANDMohamed GUEDDAUniversité de Picardie Jules Verne, Unité de Formation et de Recherche des Sciences – AMIENSAhmed RACHIDUniversité de Picardie Jules Verne, Unité de Formation et de Recherche des Sciences – AMIENSYves DELMASUniversity of REIMS, Technological Institute of CHALONS‐CHARLEVILLE – REIMSMembers from CROATIADrazan KOZAKJosip Juraj Strossmayer University of OSIJEK, Mechanical Engineering Faculty – SLAVONKI BRODMilan KLJAJINJosip Juraj Strossmayer University of OSIJEK, Mechanical Engineering Faculty – SLAVONKI BRODPredrag COSICUniversity of ZAGREB, Faculty of Mechanical Engineering and Naval Architecture – ZAGREBMiroslav CARUniversity of ZAGREB, Faculty of Mechanical Engineering and Naval Architecture – ZAGREBGordana BARICUniversity of ZAGREB, Faculty of Mechanical Engineering and Naval Architecture – ZAGREBAntun STOIĆJosip Juraj Strossmayer University of OSIJEK, Mechanical Engineering Faculty – SLAVONKI BRODGoran DUKICUniversity of ZAGREB, Faculty of Mechanical Engineering and Naval Architecture – ZAGREBMember from CUBANorge I. COELLO MACHADOUniversidad Central “Marta Abreu” LAS VILLAS, Faculty of Mechanical Engineering – SANTA CLARAACTA TECHNICA CORVINIENSIS – Bulletin of Engineering122012. Fascicule 3 [July–September]

ACTA TECHNICA CORVINIENSIS – Bulletin of EngineeringMembers from INDIASugata SANYALSchool of Technology & Computer Science, Tata Institute of Fundamental Research – MUMBAIBijoy BANDYOPADHYAYUniversity of CALCUTTA, Department of Radio Physics & Electronics – CALCUTTANatesh KAPILANNagarjuna College of Engineering & Technology, Mechanical Engineering Department – DEVANAHALLISiby ABRAHAMUniversity of MUMBAI, Guru Nanak Khalsa College – MUMBAITirumala Seshadri SEKHARDr. Sammuel George Institute of Engineering & Technology – MARKAPURAMNabendu CHAKIDepartment Computer Science & Engineering, University of Calcutta – KOLKATAAmit CHAUDHRYUniversity Institute of Engineering and Technology, Panjab University – CHANDIGARHAnjan KUMAR KUNDUUniversity of CALCUTTA, Institute of Radiophysics & Electronics – KOLKATAMembers from CZECH REPUBLICVladimir ZEMANDepartment of Mechanics, Faculty of Applied Sciences, University of West Bohemia – PILSENImrich LUKOVICSDepartment of Production Engineering, Faculty of Technology, Tomas Bata University – ZLÍNJan VIMMRDepartment of Mechanics, Faculty of Applied Sciences, University of West Bohemia – PILSENIvo SCHINDLERTechnical University of OSTRAVA, Faculty of Metallurgy and Materials Engineering – OSTRAVAPavel DRABEKUniversity of West Bohemia in PILSEN, Faculty of Electrical Engineering – PILSENJan KRETTechnical University of OSTRAVA, Faculty of Metallurgy and Materials Engineering – OSTRAVAMiroslav PISKAUniversity of Technology in BRNO, Faculty of Engineering Technology – BRNOJan MÁDLCzech Technical University in PRAGUE, Faculty of Mechanical Engineering – PRAHAMembers from ARGENTINAGregorio PERICHINSKYUniversity of BUENOS AIRES, Faculty of Engineering – BUENOS AIRESAtilio GALLITELLIInstitute of Technology, Centro de desarrollo en Gestión Tecnológica Y Operación – BUENOS AIRESCarlos F. MOSQUERAUniversity of BUENOS AIRES, School of Engineering, Laser Laboratory – BUENOS AIRESJorge Antonio SIKORANational University of MAR DEL PLATA, Engineering Department – MAR DEL PLATAElizabeth Myriam Jimenez REYUniversity of BUENOS AIRES, Faculty of Engineering, Department of Computer Science – BUENOS AIRESArturo Carlos SERVETTOUniversity of BUENOS AIRES, Faculty of Engineering, Department of Computer Science – BUENOS AIRESMembers from ITALYAlessandro GASPARETTOUniversity of UDINE, Faculty of Engineering – UDINEAlessandro RUGGIEROUniversity of SALERNO, Department of Mechanical Engineering – SALERNOAdolfo SENATOREUniversity of SALERNO, Department of Mechanical Engineering – SALERNOMembers from BRAZILAlexandro Mendes ABRÃOUniversidade Federal de MINAS GERAIS, Escola de Engenharia – BELO HORIZONTEMárcio Bacci da SILVAUniversidade Federal de UBERLÂNDIA, Engenharia Mecânica – UBERLÂNDIASergio Tonini BUTTONUniversidade Estadual de CAMPINAS, Faculdade de Engenharia Mecânica – CAMPINASLeonardo Roberto da SILVACentro Federal de Educação Tecnológica de MINAS GERAIS (CEFET) – BELO HORIZONTEJuan Campos RUBIOMetal Cutting & Automation Laboratory, Universidade Federal de MINAS GERAIS – BELO HORIZONTEMembers from BOSNIA & HERZEGOVINATihomir LATINOVICUniversity in BANJA LUKA, Faculty of Mechanical Engineering – BANJA LUKAIsak KARABEGOVICUniversity of BIHAĆ, Faculty of Technical Engineering – BIHAĆSabahudin EKINOVIÇUniversity of ZENICA, Faculty of Mechanical Engineering – ZENICASafet BRDAREVIĆUniversity of ZENICA, Faculty of Mechanical Engineering – ZENICASabahudin JASAREVICUniversity of ZENICA, Faculty of Mechanical Engineering – ZENICAMembers from MOROCCOSaad BAKKALIAbdelmalek Essaâdi University, Faculty of Sciences and Techniques – TANGIERMahacine AMRANIAbdelmalek Essaâdi University, Faculty of Sciences and Techniques – TANGIER2012. Fascicule 3 [July–September] 13

Member from GREECENicolaos VAXEVANIDISUniversity of THESSALY, Department of Mechanical & Industrial Engineering – VOLOSVassilis MOUSTAKISTechnical University of Crete – CHANIAMember from AUSTRIABranko KATALINICVIENNA University of Technology, Institute of Production Engineering – VIENNAViktorio MALISATechnikum WIEN, University of Applied Sciences – VIENNAMembers from MACEDONIAValentina GECEVSKAUniversity "St. Cyril and Methodius" SKOPJE, Faculty of Mechanical Engineering – SKOPJEZoran PANDILOVUniversity "St. Cyril and Methodius" SKOPJE, Faculty of Mechanical Engineering – SKOPJERadmil POLENAKOVIKUniversity "St. Cyril and Methodius" SKOPJE, Faculty of Mechanical Engineering – SKOPJEAleksandra BUŽAROVSKA‐POPOVAUniversity "St. Cyril and Methodius" SKOPJE, Faculty of Technology and Metallurgy – SKOPJERobert MINOVSKIUniversity "St. Cyril and Methodius" SKOPJE, Faculty of Mechanical Engineering – SKOPJEMembers from ISRAELAbraham TALUniversity TEL‐AVIV, Space and Remote Sensing Division ICTAF – TEL‐AVIVAmnon EINAVUniversity TEL‐AVIV, Space and Remote Sensing Division ICTAF – TEL‐AVIVMember from SWEEDENIngvar L. SVENSSONJÖNKÖPING University, School of Engineering Mechanical Engineering – JÖNKÖPINGMembers from UKRAINESergiy G. DZHURADONETSK National Technical University – DONETSKMember from USADavid HUIUniversity of NEW ORLEANS, Department of Mechanical Engineering – NEW ORLEANSMember from SPAINPatricio FRANCOUniversidad Politécnica of CARTAGENA, Ingeniería de Materiales y Fabricación – CARTAGENALuis Norberto LOPEZ De LACALLEUniversity of Basque Country, Faculty of Engineering – BILBAOAitzol Lamikiz MENTXAKAUniversity of Basque Country, Faculty of Engineering – BILBAOMember from SLOVENIAJanez GRUMUniversity of LJUBLJANA, Faculty of Mechanical Engineering – LJUBLJANAMember from GERMANYErich HAHNEUniversity of STUTTGART, Institute of Thermodynamics and Heat Transfer – STUTTGARTKeil REINERTechnical University DRESDEN, Faculty Transportation & Traffic Sciences Friedrich List – DRESDENMember from FINLANDAntti Samuli KORHONENHELSINKI University of Technology, Department of Materials Science & Engineering – HELSINKIHeikki MARTIKKACEO Himtech Oy Engineering – JOUTSENOPentti KARJALAINENUniversity of OULU, Department of Mechanical Engineering, Centre for Advanced Steels Research – OULUACTA TECHNICA CORVINIENSIS – Bulletin of EngineeringThe Scientific Committee members and Reviewers do not receive any remuneration. These positions are voluntary.We are very pleased to inform that our journal ACTA TECHNICA CORVINIENSIS – BULLETIN of ENGINEERING is going tocomplete its four years of publication successfully. In a very short period it has acquired global presence and scholars fromall over the world have taken it with great enthusiasm. We are extremely grateful and heartily acknowledge the kind ofsupport and encouragement from you.ACTA TECHNICA CORVINIENSIS – BULLETIN of ENGINEERINGISSN: 2067‐3809 [CD‐Rom, online]copyright © UNIVERSITY POLITEHNICA TIMISOARA,FACULTY OF ENGINEERING HUNEDOARA,5, REVOLUTIEI, 331128, HUNEDOARA, ROMANIAhttp://acta.fih.upt.ro142012. Fascicule 3 [July–September]

Content of FASCICULE 3 [JULY–SEPTEMBER]1. K. SONI PRIYA, T. DURGABHAVANI, K. MOUNIKA,M. NAGESWARI, P. POLURAJU – INDIANON‐LINEAR PUSHOVER ANALYSIS OF FLATSLAB BUILDING BY USING SAP2000(STRUCTURAL ANALYSIS PROGRAM) 21ABSTRACT: Recent earthquakes in which many concrete structures have been severely damaged or collapsed,have indicated the need for evaluating the seismic adequacy of existing buildings. About 60% of the land areaof our country is susceptible to damaging levels of seismic hazard. We can’t avoid future earthquakes, butpreparedness and safe building construction practices can certainly reduce the extent of damage and loss. Inorder to strengthen and resist the buildings for future earthquakes, some procedures have to be adopted.One of the procedures is the static pushover analysis which is becoming a popular tool for seismicperformance evaluation of existing and new structures. By conducting this push over analysis, we can knowthe weak zones in the structure and then we will decide whether the particular part is retrofitted orrehabilitated according to the requirement. In this paper we are performing the push over analysis on flatslabs by using most common software SAP2000.Many existing flat slab buildings may not have been designedfor seismic forces. Hence it is important to study their response under seismic conditions and to evaluateseismic retrofit schemes. But when compared to beam‐column connections, flat slabs are becoming popularand gaining importance as they are economical.2. Jozef MAŠČENIK – SLOVAKIATHE EVACUATION OF PRESSURE MOULDS AS PROGRESSIVE DEVELOPMENTS OF DIECASTING PROCESS 25ABSTRACT: In these days in foundry branch there is a rapid development of sectors of special castingtechnology with the aim to increase the quality and the efficiency of pressure casting production. In theproduction of castings cast under pressure there is an increased attention to the internal homogeneity ofcastings, where in accordance with the specifics of this technology are the most common casting errorsinternal cavities (bubbles, pores). Internal homogeneity of pressure casting, characterized by the extent ofporosity can be affected by the setup of technological parameters of pressure casting and last but not least byvacuuming the molds, that means to exhaust air and gases from the mold cavity.3. Iosif POPA, Gabriel Nicolae POPA, Sorin DEACONU – ROMANIATHE DETERMINATION OF THE ELECTRIC MOTOR POWER THAT DRIVES THE BELTTRANSPORT CONVEYERS 27ABSTRACT: The paper introduces an analytical method to determine the electric motor power that driveshorizontal and inclination belt transport conveyers, with and without deviation drums. To compute theelectric motor power we used the permitted load, the proper weight of the belt, the advancing strengthintroduced by the support rolls and the supplementary inclination determinate by the winding on the returndrum. The algorithm for electric motor power that drives the belt transport conveyors it was establish in thepaper. The paper introduces on the base of studying spatiality literature may be present the method ofcalculation for motor power that drives the belt transport conveyers with slow and medium capacity.4. Árpád FERENCZ, Márta NÓTÁRI – HUNGARYMANAGEMENT OF RURAL DEVELOPMENT IN COLLAGE OF KECSKEMÉT 31ABSTRACT: Taking all these challenges into consideration, training of farmers is a strategic task regarding thefuture of the country's future, to which College of Kecskemét is also willing to contribute actively. Beyond thebasic training our goal is to provide further professional training for the farmers in order to make themacquire economic, management, regional and knowledge, and use it as a skill. The goal is to make them beable to accomplish management of production processes, organization, professional administration andconsultancy tasks. With their advanced knowledge they need to be able to interpret the EU ruraldevelopment policy, to plan and carry out programs.5. Harshavardhan KAYARKAR, Sugata SANYAL – INDIAA SURVEY ON VARIOUS DATA HIDING TECHNIQUES AND THEIR COMPARATIVE ANALYSIS 35ABSTRACT: With the explosive growth of internet and the fast communication techniques in recent years thesecurity and the confidentiality of the sensitive data has become of prime and supreme importance andconcern. To protect this data from unauthorized access and tampering various methods for data hiding likecryptography, hashing, authentication have been developed and are in practice today. In this paper we will bediscussing one such data hiding technique called Steganography. Steganography is the process of concealingsensitive information in any media to transfer it securely over the underlying unreliable andunsecuredcommunication network. Our paper presents a survey on various data hiding techniques in steganographythat are in practice today along with the comparative analysis of these techniques.© copyright FACULTY of ENGINEERING ‐ HUNEDOARA, ROMANIA 15

ACTA TECHNICA CORVINIENSIS – Bulletin of Engineering6. Peter PENIAK – SLOVAKIACAN BASED APPLICATION PROTOCOLS FOR EMBEDDED DEVICES 41ABSTRACT: Embedded systems are generally designed to perform the dedicated tasks with respect to devicefunctions. Applications that are used in embedded systems are characterized by significant diversity with thedifferent requirements for communication services. The interpretation of application data and controlcommands can be essentially different in interconnected embedded subsystems. The paper deals with CANbased application protocols that can be used for an interconnection of embedded devices via CAN fieldbusnetwork. It is focused on selection of open application protocols that could be potentially used for deviceintegration of different suppliers via CAN bus.7. Róbert SÁNTA – SERBIAINVESTIGATION OF THE REFRIGERANTS CHARACTERISTICS IN VAPOR COMPRESSIONSYSTEMS 45ABSTRACT: The energy efficiency improvement of the refrigeration system to improve the operation qualitymakes it unavoidable to strive for the refrigeration system operation. Nevertheless, the processes takingplace in it should be as accurate as possible to describe the underlying physical and mathematical modeldevelopment and refinement. The experimental investigation of any refrigeration system is usually verycomplicated, mainly due to the financial costs and the large number of variables involved. The use ofnumerical models can reduce the costs and also facilitate understanding the phenomena related to theproblem. The article aims to present and analyze the behavior components of the vapor‐compressionrefrigeration system in case of various refrigerants. Refrigerants included in the present analysis areR22/R134a/R407C/R410A. The simulation program is based upon steady state mathematical models of therefrigeration circuit including the compressor, heat exchangers and thermostatic expansion valve. Thesimulation results have been presented in a graphic.8. Sorina ŞERBAN – ROMANIAANALYSIS AND DESIGN OF INFORMATION SYSTEMS 49ABSTRACT: Systems analysis and design work in chemistry is the result of a complex application called ChimUnivin the creation and operation of relational databases, the implementation of applications dedicated toChemistry. The paper is addressed to students and all those who want to build applications using the skills andhabits of Chemistry, Microsoft Access solution to offer. Fundamental theoretical notions database are missingfrom the scientific approach of this paper. In this paper we intend to highlight issues concerning theorganization of elements in the periodic table, arranging them in groups and periods depending on theirchemical properties.9. László SZABÓ, Rudolf SZABÓ – HUNGARYTHE CARBON AGE – CHARACTERISTICS OF THE CARBON FIBERS 53ABSTRACT: In the various areas, quantities of the materials and goods used by mankind show rapid growth,whereas its form, rate of use is significantly varying. Today requirements and expectations concerning thevarious materials are wide ranging, so the properties of these materials are developed in accordance to thedemands. Presently the carbon fiber is being used more and more frequently in those areas which requirespecial demands. This is explainable by its outstanding properties, namely high tenacity, stiffness, low heatdilation, conductivity etc. From composites, lightweight structures may be produced to meet higher levelapplications. Carbon fiber reinforced composites – in the areas demanding high mechanical usage, will be ofdetermining importance in the future.10. Juliana LITECKA, Slavko PAVLENKO – SLOVAKIAMATHEMATICAL MODELLING OF GEAR HOB SURFACE WITH BASIC PROFILE 57ABSTRACT: Gear production is very important area of manufacturing industries because gears are the widestcomponents in the machines and machine equipments. Mode of production and used tools are importantelements of economical and quality part of production. Nowadays, there are developed the newconstructional solutions of gear hobs which save time and money. For the hob which would produce precisioninvolute gear there is possibility of finding profile which would provide this requirement. For the finding ofthe profile it is needed to have a good mathematical knowledge kinematic and geometrical propertiesinvestigated objects. The paper deals with mathematical description of basic hob surface with straight profilewhich is initial theorem for the determining of accurate profile of gear hob.11. Keyvan Asefpour VAKILIAN, Jafar MASSAH – IRANPERFORMANCE EVALUATION OF CCD AND CMOS CAMERAS IN IMAGE TEXTURALFEATURES EXTRACTION 61ABSTRACT: The first stage of any vision system is the image acquisition stage. If the image has not beenacquired satisfactorily, then the intended tasks for image processing and image classification may not beproperly achievable. In this study, a machine vision system was developed to evaluate the performance of CCDand CMOS cameras for real‐time monitoring of cucumber growth in a greenhouse by extracting imagetextural features. The leaf samples of cucumber crops were brought to the laboratory from the greenhousesto measure the textural features. Laboratory was consisted of a digital camera for taking the images, a LDRarray for providing a uniform lightening and a computer for measuring the textural parameters from theobtained images. The objective of the current study was to select which type of camera is ideal for real‐timeplant health and growth monitoring systems. The effect of distance between camera and leaves for threevalues (30, 40 and 50cm) and the type of camera (CMOS and CCD) on the uniformity of resulted data wereconsidered in this article. Results showed that data for 40cm distance between camera and leaves with a CCDcamera had an acceptable trend for extracting image textural features.12. Imre Zsolt MIKLOS, Cristina Carmen MIKLOS, Carmen Inge ALIC – ROMANIACAM PROFILE COMPUTER AIDED DESIGN PLOTTING 65ABSTRACT: This paper shows how to plotting the profile of a plane rotating cam and a follower in thetranslational move, using Matlab program. Are shown how input the variables, kinematic analysis, speedshodograph in graphical form, respectively plane cam profile designed, with a choice of several options for thebest solutions.162012. Fascicule 3 [July–September]

ACTA TECHNICA CORVINIENSIS – Bulletin of Engineering13. A.G. VIJAYA KUMAR, S.V.K. VARMA, Y. RAJASHEKARA GOUD, K. RAGHUNATH – INDIATHERMAL DIFFUSION AND RADIATION EFFECTS ON UNSTEADY MHD FLOW PAST ALINEARLY ACCELERATED VERTICAL PLATE WITH VARIABLE TEMPERATURE AND MASSDIFFUSION 67ABSTRACT: The objective of the present study is to investigate thermal diffusion and radiation effects onunsteady MHD flow past a linearly accelerated vertical plate with variable temperature and mass diffusionunder the influence of applied transverse magnetic field. The fluid considered here is a gray, absorbing/emitting radiation but a non‐scattering medium. At time t>0, the plate is linearly accelerated with a velocity u= u 0 t in its own plane. And at the same time, plate temperature and concentration levels near the plate raisedlinearly with time t. The dimensionless governing equations involved in the present analysis are solved usingthe Laplace transform technique. The velocity, temperature, concentration, Skin‐friction, the rate or heattransfer and the rate of mass transfer are studied through graphs and tables in terms of different physicalparameters like magnetic field parameter (M), radiation parameter (R), Schmidt parameter (Sc), soretnumber (So), Prandtl number (Pr), thermal Grashof number (Gr), mass Grashof number (Gm) and time (t).14. Angela IAGĂR, Gabriel Nicolae POPA, Corina Maria DINIŞ – ROMANIAANALYSIS OF EVENTS IN ELECTRIC STATIONS USING FOCUS FOR WINDOWS PROGRAM 75ABSTRACT: The continuous development of the energetic system and the necessity to increase the safety inoperation and the quality of the supplied electric power imposes increasingly severe conditions to theprotection and control systems. Among the most important components of SCADA systems used for theelectric stations control and protection are the equipments for disturbances recording and analysis, such asthe Compact Digital Recorder (CDR). The data stored in the internal CDR memory can be extracted on a PC byCDR Link for Windows program. This paper presents Focus for Windows program, designated forvisualization, analysis, interpretation and printing the recordings performed in electric stations with CDRequipments.15. Mohamed ZELLAGUI, Abdelaziz CHAGHI – ALGERIAMEASURED IMPEDANCE BY MHO DISTANCE PROTECTION FOR PHASE TO EARTH FAULT INPRESENCE GCSC 81ABSTRACT: This paper presents the impact study of GTO Controlled Series Capacitor (GCSC) parameters on MHOdistance relays measured impedance for 220 kV protected electrical transmission line in the presence of phaseto earth fault with fault resistance. The study deals with a 220 kV electrical transmission line of EasternAlgerian transmission networks at Group Sonelgaz (Algerian Company of Electrical and Gas), compensated byseries Flexible AC Transmission System (FACTS) i.e. GCSC connected at midpoint of the line. The transmittedactive and reactive powers are controlled by three GCSC’s. The effects of maximum reactive power injected aswell as injected maximum voltage by GCSC on measured impedance by distance relays is treated. Thesimulations results investigate the impact of GCSC injected parameters (reactance, voltage and reactivepower) on measured resistance and reactance in the presence of earth fault with resistance fault for differentcases study.16. Emil RAGAN, Marcel FEDÁK, Pavol SEMANČO – SLOVAKIAHEATING PROCESS MODELING FOR DIE‐CASTING JETS ON THE MACHINES WITH HOTCHAMBER 87ABSTRACT: In general the application of die‐casting technology in foundries that are focused on non ferrousmetals allows producing cast parts with specific properties. Another advantage of pressure die‐castingtechnology with hot chamber is the possibility of production of precision cast parts in low dimensionaltolerances, often without further machining. Castings have got smooth surface, good mechanical properties,and they also may have complex construction workability. Required qualitative properties of castingsproduced with the pressure die‐casting technology with hot chamber are dependent on several parameters,which include holding stable temperature of the die‐casting nozzle. Therefore in this paper we proposed themathematical model as one of the method how to control heating die‐casting nozzle of the hot chamberpressure die‐casting machine using a gas torch.17. Sergei TARASOV, Valery RUBTSOV – RUSSIAFLOW WEAR BY SHEAR INSTABILITY IN SLIDING 91ABSTRACT: Inhomogeneous character of deformation in subsurface layers of metals in sliding resulted ingeneration of a nanocrystalline layer. Specificity of its deformation behavior is a hydrodynamic flow patterndeveloping due to shear instability under conditions of thermal softening. Macroscopic analysis of plasticdeformation carried out on the assumption that deformation behavior of the nanocrystalline subsurface layeris similar to that of the parallel‐plane viscous Newtonian flow. It was shown that velocity tangentialdiscontinuity surfaces may exist inside the deforming subsurface layer. These surfaces are particular cases ofHelmholtz instability and may serve as potential sites where turbulences may nucleate. The objective of thiswork is to estimate macroscopic conditions for generation of the eddy‐like flow instability in sliding on thebasis of hydrodynamic approach including previously obtained both experimental and numerical simulationresults.18. Vasile ALEXA – ROMANIASIMULATION OF HYDRAULIC LOAD LOSSES IN PIPES, USING THE WORKING MEDIUM“ADINA” 97ABSTRACT: The fluid analysis module of the program is fluid solver for compressible and incompressible fluidprovides a world‐class finite element solutions and the ability to control the flow, fluid can contain freesurface and fluid, as well as fluid flow and structure of the interface between. This paper presents a method ofsimulation and presentation of the load losses in a fluid flowing through a pipe. It also presents a study on thealgorithm for calculating these losses depending on the flow regime & pipe type, and the determination of thelongitudinal load loss coefficient. The theory and numerical methods used in the program for laminar andturbulent flow are summarized and then the solutions of various problems are presented.2012. Fascicule 3 [July–September] 17

ACTA TECHNICA CORVINIENSIS – Bulletin of Engineering19. Preetida VINAYAKRAY‐JANI, Sugata SANYAL – INDIAROUTING PROTOCOLS FOR MOBILE AND VEHICULAR AD HOC NETWORKS: ACOMPARATIVE ANALYSIS 101ABSTRACT: We present comparative analysis of MANET (Mobile Ad‐Hoc Network) and VANET (Vehicular Ad‐HocNetwork) routing protocols, in this paper. The analysis is based on various design factors. The traditionalrouting protocols of AODV (Ad hoc On‐Demand Distance Vector), DSR (Dynamic Source Routing), and DSDV(Destination‐Sequenced Distance‐Vector) of MANET are utilizing node centric routing which leads to frequentbreaking of routes, causing instability in routing. Usage of these protocols in high mobility environment likeVANET may eventually cause many packets to drop. Route repairs and failures notification overheads increasesignificantly leading to low throughput and long delays. Such phenomenon is not suitable for Vehicular Ad hocNetworks (VANET) due to high mobility of nodes where network can be dense or sparse. Researchers haveproposed various routing algorithms or mechanism for MANET and VANET. This paper describes the relevantprotocols, associated algorithm and the strength and weakness of these routing protocols.20. Vladimir KULIK, Ján PAŠKO – SLOVAKIATHE STRUCTURAL DESIGN AND STRENGTH CALCULATION WORM EXTRUSION MACHINESFOR PRODUCING PLASTIC PROFILES 107ABSTRACT: The most practical and the most widely used technology of plastic profile extrusion technology isworm extruder. The contribution deals with the design and stress analysis of a single worm extruder.Extrusion technology is one of the leading production technology for processing thermoplastics, as well aselastomers (rubber). The introduction is given substance and principle of extrusion technology. In other partsof the paper is processed with design and stress analysis of a single worm.21. Koros NEKOUFAR – IRANNEW MODELING OF THERMAL DIVISION IN TURBULENT TUBES 111ABSTRACT: Turbulent Ranque effect is a typical macro–quantum phenomenon, which cannot be described byclassical theory. About a century of unsuccessful experience in defining this phenomenon on the basis ofclassical methods testifies to this. The basic idea of non–local thermodynamics is to use quantum entropy,with every quantum defined as equal to Boltzman constant. This hypothesis will allow applyingthermodynamic energy. Further, correlations of quantum mechanics are used. In this article, the process ofgasses’ thermal division in turbulent tubes is described on the basis of thermodynamic theory according toNewtonian time.22. Igor LAZAREV – MACEDONIAKarl KUZMAN – SLOVENIAJovan MICKOVSKI, Jovan LAZAREV, Jasmina CALOSKA, Atanas KOCHOV – MACEDONIAMETAL MATRIX COMPOSITES AS TOOLS MATERIAL FOR THE DEEP DRAWING 115ABSTRACT: In order to improve the strength and high‐temperature properties of sintered iron, metal matrixiron‐ Alumina (Al 2 O 3 ) composite material has been studied. In the present investigation, iron powder added by0‐8 Wgt % Al 2 O 3 powder where selected for the study. Powders where mixed, compacted and subsequentlysintered at 1150 o C in laboratory tube furnace, under an endo gas atmosphere. Composite material propertieswere evaluated. The outcome results is that 4 vol % Al 2 O 3 is the optimal percentage of the Alumina to obtainsuperior properties of the metal matrix composite. The deep drawing die and punch have been designed byusing metal matrix composite and experimentally tested.23. Georgeta Emilia MOCUȚA, Mihaela POPESCU, Ioan Dănuț DAN – ROMANIATHE BEST WAY OF WORKING SPACE ROBOT WHICH EQUIPS A FLEXIBLE MANUFACTURINGCELL COMPONENT OF WELDED IN RAIL FIELD 119ABSTRACT: The industrial robot acts on its operating space under different shapes, namely by manipulatingparts, by executing processing technological operations, by measuring specific parameters of products oreven of the operating space etc. Many applications and functions performed by a robot reveal an essentialcharacteristic, namely their versatility. Studying the movement of a robot consists of a single well‐definedproblem but a collection of several problems that are more or less than one other option. Exemplification wasperformed using MSC NASTRAN program.24. Martin PETRUF, Ján KOLESÁR – SLOVAKIALOGISTIC AND ACQUISITION 123ABSTRACT: Acquisition of the most modern technical systems and their logistical support requires innovativeapproaches to be adopted in design, manufacturing and providing logistical services for their operation. Thearticle aims to be a contribution to the acquisitional approach termed as CALS, i.e. to a modern, computerbasedlogistics. Integrated logistical support provided through electronization of design and operationaldocumentation linked with standardization and continuous upgrade is yielding surprising benefits.Implementation of computer systems in logistics for modern trends in military and industrial branches is ofvital importance, particularly for the purpose of obtaining higher quality from the aspect of systemcharacteristics, both in view of the methods applied – concurrent engineering, limiting the variability ofmanufacturing and the like.25. Rajdeep BORGOHAIN – INDIADATA HIDING TECHNIQUES USING NUMBER DECOMPOSITIONS 127ABSTRACT: Data hiding is the art of embedding data into digital media in a way such that the existence of dataremains concealed from everyone except the intended recipient. In this paper, we discuss the various LeastSignificant Bit (LSB) data hiding techniques. We first look at the classical LSB data hiding technique and themethod to embed secret data into cover media by bit manipulation. We also take a look at the data hidingtechnique by bit plane decomposition based on Fibonacci numbers. This method generates more bit planeswhich allows users to embed more data into the cover image without causing significant distortion. We alsodiscuss the data hiding technique based on bit plane decomposition by prime numbers and natural numbers.These methods are based on mapping the sequence of image bit size to the decomposed bit number to hidethe intended information. Finally we present a comparative analysis of these data hiding techniques.182012. Fascicule 3 [July–September]

ACTA TECHNICA CORVINIENSIS – Bulletin of EngineeringSCIENTIFIC EVENTS IN 2012 133 20 th ANNUAL INTERNATIONAL CONFERENCE on COMPOSITES, NANO OR METALS ENGINEERING – ICCE‐2022 – 28 July 2012, Beijing, CHINA THE 6 th INTERNATIONAL CONFERENCE ON INDUSTRIAL ENGINEERING AND MANAGEMENT – IEM201210 – 12 August, 2012, Zhengzhou, CHINA THE 9 th INTERNATIONAL CONGRESS “MACHINES, TECHNOLOGIES, MATERIALS – INNOVATIONS FOR THEINDUSTRY” – MTM'1219 – 21 September, 2012, Varna, BULGARIA THE 4 th INTERNATIONAL CONFERENCE ON MATERIALS SCIENCE AND TECHNOLOGIES – ROMAT 201217 – 19 October, 2012, Bucuresti, ROMANIA FEDERATED CONFERENCE ON COMPUTER SCIENCE AND INFORMATION SYSTEMS – FedCSIS 20129 – 12 September, 2012, Wrocław, POLAND THE 5 th INTERNATIONAL CONFERENCE ON MASS CUSTOMIZATION AND PERSONALIZATION IN CENTRALEUROPE (MCP – CE 2012) – CUSTOMER CO‐CREATION IN CENTRAL EUROPE19 – 21 September, 2012, Novi Sad, SERBIA THE 18 th EUNICE CONFERENCE ON INFORMATION AND COMMUNICATIONS TECHNOLOGIES29 – 31 August, 2012, Budapest, HUNGARY MACHINE‐BUILDING AND TECHNOSPHERE OF THE XXI CENTURY17 – 22 September, 2012, Sevastopol, UKRAINE INTERNATIONAL CONFERENCE on MATHEMATICAL MODELING IN PHYSICAL SCIENCES – IC‐MSQUARE20123 – 7 September, 2012, Budapest, HUNGARY 11 th INTERNATIONAL SCIENTIFIC CONFERENCE – MMA 2012 – ADVANCED PRODUCTION TECHNOLOGIES20 – 21 September, 2012, Novi Sad, SERBIA 4 th INTERNATIONAL SCIENTIFIC AND EXPERT CONFERENCE – TEAM 2012 (Technique, Education,Agriculture & Management)17 – 19 October, 2012, Slavonski Brod, CROATIA 1 st INTERNATIONAL SCIENTIFIC CONFERENCE – COMETa 2012 – CONFERENCE on MECHANICALENGINEERING TECHNOLOGIES AND APPLICATIONS28 – 30 November, 2012, Jahorina, BOSNIA&HERZEGOVINA 4 th INTERNATIONAL CONFERENCE ON MATERIALS SCIENCE AND TECHNOLOGIES ‐ ROMAT 201217 – 19 October, 2012, Bucharest, ROMANIA 2 nd INTERNATIONAL CONFERENCE ON CIVIL ENGINEERING AND BUILDING MATERIAL – CEBM 201217 – 18 November, 2012, Hong Kong 7 th INTERNATIONAL ICQME CONFERENCE (Quality, Management, Environment, Education, Engineering)19 – 21 September, 2012, Tivat, MONTENEGRO INTERNATIONAL CONFERENCE ON NEW ENERGY, BIOLOGICAL ENGINEERING AND FOOD SECURITY ‐NEBEFS 20124 – 5 September, 2012, Hong Kong INTERNATIONAL CONFERENCE ON MANUFACTURING – MANUFACTURING 201214 – 15 November, Macau, CHINA 2 nd INTERNATIONAL CONFERENCE ON INTEGRATED INFORMATION – IC‐ININFO 201230 August – 3 September, 2012, Budapest, HUNGARY INTERNATIONAL CONFERENCE ON MANUFACTURING ENGINEERING AND TECHNOLOGY FORMANUFACTURING GROWTH – METMG 20121 – 2 November,2012, San Degio, USA INTERNATIONAL CONFERENCE ON APPLIED PHYSICS AND MATERIALS SCIENCE – APMS 20125 – 6 October, 2012, Dalian, CHINAGENERAL GUIDELINES FOR PREPARING THE MANUSCRIPTS 137ACTA TECHNICA CORVINIENSIS – BULLETIN of ENGINEERINGISSN: 2067‐3809 [CD‐Rom, online]copyright © UNIVERSITY POLITEHNICA TIMISOARA,FACULTY OF ENGINEERING HUNEDOARA,5, REVOLUTIEI, 331128, HUNEDOARA, ROMANIAhttp://acta.fih.upt.ro2012. Fascicule 3 [July–September] 19

ACTA TECHNICA CORVINIENSIS – Bulletin of EngineeringACTA TECHNICA CORVINIENSIS – Bulletin of Engineering, Fascicule 3 [July–September] includes original papers submitted tothe Editorial Board, directly by authors or by the regional collaborators of the Journal. In this sense, ACTA TECHNICACORVINIENSIS – Bulletin of Engineering, Fascicule 3 [July–September] includes 25 scientific originals papers.ACTA TECHNICA CORVINIENSIS – Bulletin of Engineering is an international and interdisciplinary journal which reports onscientific and technical contributions. The ACTA TECHNICA CORVINIENSIS – Bulletin of Engineering advances theunderstanding of both the fundamentals of engineering science and its application to the solution of challenges andproblems in engineering and management, dedicated to the publication of high quality papers on all aspects of theengineering sciences and the management.You are invited to contribute review or research papers as well as opinion in the fields of science and technology includingengineering. We accept contributions (full papers) in the fields of applied sciences and technology including all branches ofengineering and management.Submission of a paper implies that the work described has not been published previously (except in the form of an abstractor as part of a published lecture or academic thesis) that it is not under consideration for publication elsewhere. It is notaccepted to submit materials which in any way violate copyrights of third persons or law rights. An author is fullyresponsible ethically and legally for breaking given conditions or misleading the Editor or the Publisher.The Editor reserves the right to return papers that do not conform to the instructions for paper preparation and templateas well as papers that do not fit the scope of the journal, prior to refereeing. The Editor reserves the right not to accept thepaper for print in the case of a negative review made by reviewers and also in the case of not paying the required fees ifsuch will be fixed and in the case time of waiting for the publication of the paper would extend the period fixed by theEditor as a result of too big number of papers waiting for print. The decision of the Editor in that matter is irrevocable andtheir aim is care about the high content‐related level of that journal.The general mission of the ACTA TECHNICA CORVINIENSIS – Bulletin of Engineering is to disseminate academic knowledgeacross the scientific realms and to provide applied research knowledge to the appropriate stakeholders. We are keen toreceive original contributions from researchers representing any Science related field.We strongly believe that the open access model will spur research across the world especially as researchers gainunrestricted access to high quality research articles. Being an Open Access Publisher, Academic Journals does not receivepayment for subscription as the journals are freely accessible over the internet.ACTA TECHNICA CORVINIENSIS – BULLETIN of ENGINEERINGISSN: 2067‐3809 [CD‐Rom, online]copyright © UNIVERSITY POLITEHNICA TIMISOARA,FACULTY OF ENGINEERING HUNEDOARA,5, REVOLUTIEI, 331128, HUNEDOARA, ROMANIAhttp://acta.fih.upt.ro202012. Fascicule 3 [July–September]

1. K. SONI PRIYA, 2. T. DURGABHAVANI, 3. K. MOUNIKA, 4. M. NAGESWARI, 5. P. POLURAJUNON‐LINEAR PUSHOVER ANALYSIS OF FLATSLAB BUILDING BYUSING SAP2000 (STRUCTURAL ANALYSIS PROGRAM)1‐5.DEPARTMENT OF CIVIL ENGINEERING, KLCE, VADDESWARAM, GUNTUR DIST‐522502, INDIAABSTRACT: Recent earthquakes in which many concrete structures have been severely damaged or collapsed, have indicatedthe need for evaluating the seismic adequacy of existing buildings. About 60% of the land area of our country is susceptibleto damaging levels of seismic hazard. We can’t avoid future earthquakes, but preparedness and safe building constructionpractices can certainly reduce the extent of damage and loss. In order to strengthen and resist the buildings for futureearthquakes, some procedures have to be adopted. One of the procedures is the static pushover analysis which is becominga popular tool for seismic performance evaluation of existing and new structures. By conducting this push over analysis, wecan know the weak zones in the structure and then we will decide whether the particular part is retrofitted or rehabilitatedaccording to the requirement. In this paper we are performing the push over analysis on flat slabs by using most commonsoftware SAP2000.Many existing flat slab buildings may not have been designed for seismic forces. Hence it is important tostudy their response under seismic conditions and to evaluate seismic retrofit schemes. But when compared to beamcolumnconnections, flat slabs are becoming popular and gaining importance as they are economical.KEYWORDS: Pushover analysis, Retrofitting, Rehabilitation, Column jacketing, Response Spectrum, Demand curve, Capacitycurve, Plastic hingeINTRODUCTIONThe static pushover analysis is becoming a populartool for seismic performance evaluation of existingand new structures. The pushover analysis of astructure is a static non‐linear analysis underpermanent vertical loads and gradually increasinglateral loads. The purpose of pushover analysis is toevaluate the expected performance of structuralsystems by estimating performance of a structuralsystem by estimating its strength and deformationdemands in design earthquakes by means of staticinelastic analysis, and comparing these demands toavailable capacities at the performance levels ofinterest.TYPES OF ANALYSISDifferent types of analysis are as follows:1. Linear Static Analysis.2. Linear Dynamic Modal Response SpectrumAnalysis.3. Linear Dynamic Modal Response History Analysis.4. Linear Dynamic Explicit Response History AnalysisAmong all the analyses, deformation can be predictedin nonlinear static and dynamic analysis. Twodimensionalnonlinear push‐over analysis is carried outon a typical flat slab building.Flat slab is an American development, originated byTurner in 1906. It is a concrete slab reinforced in twoor more directions so as to bring its load to supportingcolumns, generally without the help of any beams orgirders. Failure of RC flat slab farming systems duringsevere earthquakes have led to widespread rejectionof flat slab as a viable system in regions of highseismicity. Many existing buildings do not have beendesigned for seismic forces. It is important to studytheir response under seismic conditions and toevaluate seismic retrofit schemes. A plot of the totalbase shear versus top displacement in a structure isobtained by this analysis that would indicate anypremature failure or weakness. By conducting thispush over analysis we can know the weak zones in theflat slab then the particular part is retrofitted. Theretrofitting can be done by:a) Column jacketingb) Addition of beams at floorc) Column jacketing and addition of beamsThe retrofitting of ground storey by column jacketingis a good cost effective technique but is adequate onlywhen seismic deficiency is small.The beam retrofitting reduces the sagging hingingsignificantly. Increasing the number of storey ofretrofitting by either column retrofitting alone orbeam retrofitting alone does not improve thebehavior significantly.When column jacketing and addition of beam areadopted simultaneously on more number of stories,large increase in lateral strength and stiffness can beachieved.PUSH OVER ANALYSISThe pushover analysis of a structure is a static nonlinearanalysis under permanent vertical loads andgradually increasing lateral loads. The equivalentstatic lateral loads approximately representearthquake induced forces. A plot of the total baseshear versus top displacement in a structure isobtained by this analysis that would indicate anypremature failure or weakness. The analysis is carriedout up to failure, thus it enables determination ofcollapse load and ductility capacity. This type ofanalysis enables weakness in the structure to beidentified. The decision to retrofit can be taken in suchstudies.NECESSITY OF NON‐LINEAR STATIC PUSHOVER ANALYSISThe existing building can become seismically deficientsince seismic design code requirements are constantlyupgraded and advancement in engineeringknowledge. Further, Indian buildings built over past© copyright FACULTY of ENGINEERING ‐ HUNEDOARA, ROMANIA 21

two decades are seismically deficient because of lackof awareness regarding seismic behavior of structures.The widespread damage especially to RC buildingsduring earthquakes exposed the constructionpractices being adopted around the world, andgenerated a great demand for seismic evaluation andretrofitting of existing building stocks.PURPOSE OF NON‐LINEAR STATIC PUSH‐OVER ANALYSISThe purpose of pushover analysis is to evaluate theexpected performance of structural systems byestimating performance of a structural system byestimating its strength and deformation demands indesign earthquakes by means of static inelasticanalysis, and comparing these demands to availablecapacities at the performance levels of interest. Theevaluation is based on an assessment of importantperformance parameters, including global drift, interstory drift, inelastic element deformations (eitherabsolute or normalized with respect to a yield value),deformations between elements, and elementconnection forces (for elements and connections thatcannot sustain inelastic deformations). The inelasticstatic pushover analysis can be viewed as a method forpredicting seismic force and deformation demands,which accounts in an approximate manner for theredistribution of internal forces that no longer can beresisted within the elastic range of structuralbehavior.PUSHOVER METHODOLOGYA pushover analysis is performed by subjecting astructure to a monotonically increasing pattern oflateral loads, representing the inertial forces whichwould be experienced by the structure whensubjected to ground shaking.Under incrementally increasing loads variousstructural elements may yield sequentially.Consequently, at each event, the structureexperiences a loss in stiffness. Using a pushoveranalysis, a characteristic non linear force displacementrelationship can be determined.Main steps involved in pushover methodology1. Definition of plastic hinges: In SAP2000, nonlinearbehavior is assumed to occur within a structure atconcentrated plastic hinges. The default typesinclude an uncoupled moment hinges, anuncoupled axial hinges, an uncoupled shear hingesand a coupled axial force and biaxial bendingmoment hinges.2. Definition of the control node: control node is thenode used to monitor displacements of thestructure. Its displacement versus the base‐shearforms the capacity (pushover) curve of thestructure.3. Developing the pushover curve which includes theevaluation of the force distributions. To have adisplacement similar or close to the actualdisplacement due to earthquake, it is important toconsider a force displacement equivalent to theexpected distribution of the inertial forces.Different forces distributions can be used torepresent the earthquake load intensity22ACTA TECHNICA CORVINIENSIS – Bulletin of Engineering4. Estimation of the displacement demand: This is acrucial step when using pushover analysis. Thecontrol is pushed to reach the demanddisplacement which represents the maximumexpected displacement resulting from theearthquake intensity under consideration.5. Evaluation of the performance level: Performanceevaluation is the main objective of a performancebased design. A component or action is consideredsatisfactory if it meets a prescribed performance.The main output of a pushover analysis is in terms ofresponse demand versus capacity. If the demandcurve intersects the capacity envelope near the elasticrange, Fig.1a, then the structure has a good resistance.If the demand curve intersects the capacity curve withlittle reserve of strength and deformation capacity,Fig.1b, then it can be concluded that the structure willbehave poorly during the imposed seismic excitationand need to be retrofitted to avoid future majordamage or collapse.(a)safe design (b)unsafe designFig.1 Typical seismic demand versus capacityDepending on the weak zones that are obtained in thepushover analysis, we have to decide whether to doperform seismic retrofitting or rehabilitation.SEISMIC RETROFITTINGSeismic retrofitting is the modification of existingstructures to make them more resistant to seismicactivity, ground motion, or soil failure due toearthquakes.Various repair/retrofit options available today includecrack injection, shortcreting, steel jacketing, steelplate bonding, CFRP/GFRP jacketing, RC jacketing,addition of new structural elements (braces, walls,etc.), incorporation of passive energy dissipationdevices, and provision of base isolation.Types of Retrofitting:1. Local techniquea) Column jacketingb) Addition of beams at floorThe retrofitting of ground storey by column jacketingis a good cost effective technique but is adequate onlywhen seismic deficiency is small.The beam retrofitting reduces the sagging hingingsignificantly. Increasing the number of storey ofretrofitting by either column retrofitting alone orbeam retrofitting alone does not improve thebehavior significantly.2. Global techniqueThis can be typically done by the addition of crossbraces or new structural walls.REHABILITATIONRehabilitation or reconstruction or replacementincludes work to restore the original capacity to meet2012. Fascicule 3 [July–September]

ACTA TECHNICA CORVINIENSIS – Bulletin of Engineeringtypical service loads by reconstructing the effectedparts in a structure.Rehabilitation Options:1. Addition of new concrete shear walls2. Use of Fiber Reinforced Polymer laminates tostrengthen masonry, unreinforced clay tile, orconcrete members.3. Add steel bracing4. Improve connection capacities5. Reduce structure mass6. Global stiffeningslab is 200 mm and no shear reinforcement is providedin the slabs. The columns are 250 mm square insection.Figure 3. 3‐D ViewFigure 2. Lateral load Vs DeformationA plot is drawn between base shear and roofdisplacement. Performance point and location ofhinges in various stages can be obtained frompushover curve as shown in figure 2. The range AB iselastic range, B to IO is the range of immediateoccupancy IO to LS is the range of life safety and LS toCP is the range of collapse prevention. If all the hingesare within the CP limit then the structure is said to besafe. However, depending upon the importance ofstructure the hinges after IO range may also need tobe retrofitted.DESIGN OF FLAT SLABA typical flat slab with two stories is considered in thepresent study.It has not been detailed for earthquakeloads but have been designed for wind loads.Theheight of the each storey is 3m.For the purpose of design, linear structural analysis ofthe building is carried out by the computer programSAP2000 (Structural Analysis Program, Version 12.00).The slab of the building is assumed to be acting like arigid floor diaphragm. The building is designed as perIS: 456‐1978 using limit state method of design. Theload combinations used are as follows:1.5 DL+1.5 LL1.5 DL+1.5 LL+1.2 WLFor the purpose of wind load calculations, thestructure is assumed to be situated in Vijayawada.The wind loads are calculated as per the IS: 875(Part3)‐1987:V z =V b k 1 k 2 k 3where V z =design wind speed at any height z inm/s,V b =basic wind speed in m/s(=50 m/s for building inVijayawada).The design wind pressure(p z ) iscalculated as follows:P z =0.6V z2From the above equations, the total design windspeed on the building was obtained as 1.5 kN/m 2 actingalong X‐direction.The materials used are M 20 gradeconcrete and Fe 415 grade steel. The thickness of theFigure 2. Deformed shape (DEAD)Figure 3. Response spectrumTable1: Centre Of Masses At Different LevelsHeight in m Mass in kN‐s 2 /m3 30.326 30.329 28.03Table2: Pushover Loads(IS1893)Height in mQ i (kN)9 125.256 125.253 27.36Figure 4. Pushover curve2012. Fascicule 3 [July–September] 23

ACTA TECHNICA CORVINIENSIS – Bulletin of EngineeringFigure 5. Framed hingesRESULTS AND DISCUSSIONSThe resulting pushover curve for the G+2 building isshown in Figure 4. The curve is initially linear but startto deviate from linearity as the columns undergoinelastic actions. When the building is pushed well intothe inelastic range, the curve become linear again butwith a smaller slope. The curve could be approximatedby a bilinear relationship.Plastic hinges formation for the building mechanismshave been obtained at different displacement levels.The hinging patterns are plotted at different levels infigures 8 to16. Plastic hinges formation starts at basecolumns of lower stories, then propagates to upperstories and continue with yielding of interiorintermediate columns in the upper stories.Figure 6. Deformed shape at step 0Figure 7. Deformed shape at step 1Figure 9. Deformed shape at step 3Figure 10. Deformed shape at step 4CONCLUSIONSUnder the pressure of recent developments, seismiccodes have begun to explicitly require theidentification of sources of inelasticity in structuralresponse, together with the quantification of theirenergy absorption capacity. Many existing buildingsdo not have been designed for seismic forces. It isimportant to study their response under seismicconditions and to evaluate seismic retrofit schemes.Hence push over analysis has been gaining importancefor the strengthening and evaluation of the existingstructures. By conducting the pushover analysis onflat slabs, pushover curve and demand curve can beobtained. Then, based on the results we need todecide whether to perform rehabilitation orretrofitting depending upon the seismic zone of theexisting structures.REFERENCES[1] Push over analysis on shear critical frames, SerhanGuner and Frank J. Vecchio[2] Seismic retrofit of columns in buildings for flexureusing concrete jacket.Gnanasekaran Kaliyaperumal andAmlan Kumar Sengupta[3] Pushover analysis of reinforced concrete framestructures. A. kadid and A. boumrkik department ofcivil engineering, university of Batna, Algeria[4] ISET Journal of Earthquake Technology, Paper No. 505,Vol. 46, No. 2, June 2009, pp. 77–107[5] Asian Journal of civil engineering (Building andHousing)Vol. 9, No. 1 (2008) Pages 75‐83[6] CI Structural Journal/January‐February 2010 by SerhanGuner and Frank J. VecchioACTA TECHNICA CORVINIENSIS – BULLETIN of ENGINEERINGISSN: 2067‐3809 [CD‐Rom, online]Figure 8. Deformed shape at step 2copyright © UNIVERSITY POLITEHNICA TIMISOARA,FACULTY OF ENGINEERING HUNEDOARA,5, REVOLUTIEI, 331128, HUNEDOARA, ROMANIAhttp://acta.fih.upt.ro242012. Fascicule 3 [July–September]

THE EVACUATION OF PRESSURE MOULDS AS PROGRESSIVEDEVELOPMENTS OF DIE CASTING PROCESS1.Jozef MAŠČENIK1.TECHNICAL UNIVERSITY OF KOŠICE, FACULTY OF MANUFACTURING TECHNOLOGIES, DEPT. OF TECHNICAL DEVICES DESIGN, PRESOV, SLOVAKIAABSTRACT: In these days in foundry branch there is a rapid development of sectors of special casting technology with the aimto increase the quality and the efficiency of pressure casting production. In the production of castings cast under pressurethere is an increased attention to the internal homogeneity of castings, where in accordance with the specifics of thistechnology are the most common casting errors internal cavities (bubbles, pores). Internal homogeneity of pressurecasting, characterized by the extent of porosity can be affected by the setup of technological parameters of pressurecasting and last but not least by vacuuming the molds, that means to exhaust air and gases from the mold cavity.KEYWORDS: die casting, vacuum, porosity, quality of castingINTRODUCTIONTechnology of casting metal in a vacuum was beingput into the production process already in the middleof last century in the U.S., where three systems weredeveloped (NELMAR, OHSE, Morton). From the pointof then state of the techniques its practical use was atone point (closing of exhaust valve) insufficiently met.This technology was introduced to mass production in80s in Japan. Today, the world leader in metal castingin a vacuum is vacuum systems developed by the SwissFONDAREX.Figure 1. Comparison of conventionaland vacuum pressure casting metalare not fully taken by venting form system. Dependingon the nature of the vent system and pistoncompression force in the filling chamber, the pressurein the mold cavity is increasing during the first stageof compression to the value of 0.3 MPa. In otherphases of compression, these values may be doubledor even tripled.(fig. 1a) Venting the mold cavity by gasand air diversion gas using vacuum causes a reductionin back pressure in the mold cavity. In this wayantipressure rarely exceeds 0.02 MPa [1,2].The principle design of degassing pressure form isshown schematically in Fig. 2, where with the help ofvalve the valve suction device is formed, which has towithin a few milliseconds, when the casting processtakes place, drain away air and gases from the moldcavity. Exhaustion lasts throughout the molding cycle[3].THE METHODOLOGY OF EXPERIMENTS AND EQUIPMENTFor the realization of experiments the compressedcasting machine FRECH DAW125F was used, designedfor casting non‐ferrous metals with a verticallyarranged filling chamber and degassing of thepressure casting mold was realized by a vacuumdevice FONDAREX. Analysis of the impact of degassingthe pressure molds on casting porosity has beenobserved on the cast on Figure 3.Figure 2. Scheme of vacuuming process [4]By the conventional method of casting during themolding phase in the inlet system and the mold cavity,anti‐ pressure of gases and vapors is formed whichduring the short period of time sufficient compressionFigure 3. Analyzed CastingThe tested analyzed casting is made from an alloyZnAl4Cu1, whose chemical composition responded toEN 1774 and is listed in the table 1.© copyright FACULTY of ENGINEERING ‐ HUNEDOARA, ROMANIA 25

ACTA TECHNICA CORVINIENSIS – Bulletin of EngineeringTable 1. Chemical Composition ofthe Experimental Cast of the Applied AlloyChemical composition of the experimental cast of theapplied alloy ‐ % of elements contentAl Cu Mg Cr Ti Pb3,9 0,8 0,05 ‐ ‐ 0,001according to EN 17743,8 – 4,2 0,7 ‐ 1,10,0035‐ 0,6‐ ‐max.0,003Chemical composition of the experimental cast of theapplied alloy ‐ % of elements contentCb Sn Fe Ni Si Zn0,002 0,001 0,001 0,001 0,01 95,225according to EN 1774max.0,003max.0,001max.0,02max.0,001max.0,02therestPorosity analysis was performed by the indirectmethod of verification and the volume density of thesamples. For this analysis was used Mettler Toledoscales PG203‐S. The measured values were thencalculated density cast by the relation:mρ = (1)Vρ – density [kg.m ‐3 ], m – mass [kg], V – volume [m 3 ].Subsequently, the calculated density values weredetermined by casting % porosity castings analyzedaccording to the relation:densityofthealloy ‐ measured densityofthealloyporosity= *100% (2)densityofthealloyDuring the casting process in a vacuum and withoutvacuum there were constant technologicalparameters on the pressure casting machine FRECHDAW125F: time of increase pressure: 1,5 s, increase pressure: 16 MPa, temperature of alloy: 434 °C, velocity of I. phase: 0,12 m.s ‐1 velocity of II. phase: 1,2 m.s ‐1ANALYSIS OF THE ACHIEVED RESULTSThe measured values of the analyzed samples porositycast without degassing and with vacuuming ofpressure molds are shown in Table 2. Graphical processof the porosity dependence of the samples cast in avacuum and without vacuum is illustrated in Figure 4.No.Table 2. The measured mass and densityand calculated porosityWithoutvacuumWithvacuumWithoutvacuumWithvacuumWithoutvacuumWithvacuumMass [g] Density [kg/dm 3 ] Porosity [%]1 23,776 23,918 6,458 6,531 3,612 2,5222 23,948 23,991 6,463 6,559 3,537 2,1043 23,901 23,951 6,498 6,56 3,015 2,0904 23,830 23,942 6,485 6,555 3,209 2,1645 23,842 23,931 6,494 6,534 3,075 2,4786 23,782 23,981 6,477 6,523 3,328 2,6427 23,837 23,958 6,496 6,547 3,045 2,2848 23,816 23,910 6,481 6,525 3,269 2,6129 23,806 23,935 6,486 6,535 3,194 2,46310 23,854 23,952 6,478 6,527 3,313 2,582Min. 23,776 23,910 6,458 6,523 3,015 2,090Max. 23,948 23,991 6,498 6,560 3,612 2,642Average 23,839 23,946 6,481 6,539 3,259 2,394CONCLUSIONSThe distribution of total volume of pores in the crosssection of the casting depends on the conditions ofimplementation of the mold cavity. By the turbulenceof the melt, air and gases are entrained fromlubricants and mold forms system, they are notsufficiently vented and subsequently they are beingclosed to the wall casting. By the application ofdegassing pressure form are air and gases vented intothe vacuum tank unit with a positive impact onminimizing the porosity of castings.REFERENCES[1.] Gašpár, Š., Paško, J.: Technologické faktory tlakovéholiatia a ich vplyv na mechanické vlastnosti odliatkov zosilumínu. In: Strojírenská technologie. Vol. 14 (2010), p.53‐56. ISSN 1211‐4162[2.] Gašpár, Š., Paško, J., Malik, J.: Elimination of porosityof die casting by increased pressure function. In:Výrobné inžinierstvo. Vol. 10, No. 2 (2011), p. 21‐23. ISSN1335‐7972[3.] Paško, J., Malik, J., Gašpár, Š., Novák‐Marcinčin, J.:Influence of technological parameters of die castningon qualitative properties of castings. In:Manufacturing engineering and technology. No. 1(2010), p. 3‐6. ISSN 1312‐0859[4.] www. iron‐foundry.com[5.] www.subtech.comACTA TECHNICA CORVINIENSIS – BULLETIN of ENGINEERINGISSN: 2067‐3809 [CD‐Rom, online]Figure 4. Graph of Porosity Valuescopyright © UNIVERSITY POLITEHNICA TIMISOARA,FACULTY OF ENGINEERING HUNEDOARA,5, REVOLUTIEI, 331128, HUNEDOARA, ROMANIAhttp://acta.fih.upt.ro262012. Fascicule 3 [July–September]

1.Iosif POPA, 2. Gabriel Nicolae POPA, 3. Sorin DEACONUTHE DETERMINATION OF THE ELECTRIC MOTOR POWER THATDRIVES THE BELT TRANSPORT CONVEYERS1‐3.DEPARTMENT OF ELECTROTECHNICAL ENGINEERING AND INDUSTRIAL INFORMATICS, FACULTY OF ENGINEERING HUNEDOARA,POLITECHNICA UNIVERSITY TIMIŞOARA, STR. REVOLUȚIEI, NO.5, HUNEDOARA, ROMANIAABSTRACT: The paper introduces an analytical method to determine the electric motor power that drives horizontal andinclination belt transport conveyers, with and without deviation drums. To compute the electric motor power we used thepermitted load, the proper weight of the belt, the advancing strength introduced by the support rolls and thesupplementary inclination determinate by the winding on the return drum. The algorithm for electric motor power thatdrives the belt transport conveyors it was establish in the paper. The paper introduces on the base of studying spatialityliterature may be present the method of calculation for motor power that drives the belt transport conveyers with slowand medium capacity.KEYWORDS: electric motor power, belt transport conveyers, analytical method, algorithmINTRODUCTIONThe paper introduces on the base of studyingspatiality literature [1‐4] may be present the methodof calculation for motor power that drives the belttransport conveyers with slow and medium capacity.For this, it can do from mechanical tensions from thebelt of transport conveyor, in the case of conveyerswith and without deviation drums, after which it maydetermine the reduced resistant moments to shafts ofdrive motors, and then may be calculate the necessarypower for motors. It may be considered that the belttransport conveyers are drive with triphasic cageinduction motors [5‐7].THE DETERMINATION OF REDUCED RESISTANT MOMENTS ATMOTOR SHAFTThe tensions in the belt, for inclined transportconveyer with β>0, without deviation drum (fig.1), inpoints 1, …, 4 are:S 1 = S x [N] (1)( q + q ) ⋅L⋅w⋅cosβ−q⋅L⋅sinβS2 = Sx+ b rgb[N] (2)S3 k î ⋅S 2= [N] (3)( q + q + q ) ⋅L⋅w⋅cosβ+ ( q + q ) ⋅L⋅sinβS 4 = S 3 +[N] (4)b î rpb îIn these relations, the tension S x in point of banddetach from motor drum does not know, q rp [N/m]and q rg [N/m] are uniform distribute weights formobile parts of the superior train rolls, respective forthe inferior, w[‐] it is the specific resistance tomovement of the band (w=0,03…0,05 for the piperolls) and k î [‐] it is a coefficient which put in theevidence the contribution of return and deviationdrums, at modify the band tensions.The uniform charge weights q rp şi q rg may be calculatewith:Grpqrp = (5)l 1Grgqrg = (6)l 2Fig.1. Belt inclinator transport conveyerwithout deviation drumwhere G rp [N] and G rg [N] are the weight of movementparts of superior train rolls, respective of inferior trainrolls.The coeficient k î takes values by 1,05…1,07 for thewrap up angles by 180 0 , and 1,03…1,05 for the wrapup angles by 90 0 , and 1,02…1,03 the wrap up anglessmaller than 90 0 .© copyright FACULTY of ENGINEERING ‐ HUNEDOARA, ROMANIA 27

The Euler ecuation about the condition of unslip of theband on motor drum is:28μ ⋅αk f ⋅ S 4 = S 1 ⋅ e [N] (7)where k f [‐] is the safety coefficient for unslip onmotor drum (k f =1,2…1,3), e is the base of naturalslogarithms, μ [‐] is the friction coefficient between theband and the driven drum (μ=0,25…0,35) and α[rad]it is the angle of wrap up for the band on motor drum.With relations (1),…, (4) and (6) may be get:⋅[ qb⋅( 1+kî) + kî⋅qrg+ qî+ qrp][ q ⋅( 1−k) + q ]⎧w⋅cosβ⎫kf⋅L⋅⎨⎬sin b î îS⎩+β ⋅⎭1 = [N] (8)μ⋅αe −k⋅kSS +fic4 = k î ⋅S1[N] (9)k fThe reduce resistant moments for motor shaft may beobtioned with:( S −S)4 1 DTMrr= ⋅ [Nm] (10)η ⋅i2Rwhere the tensions in band S 1 and S 2 are fromexpressions (8) and (9).For horizontal transport conveyers, without deviationdrums when β=0 and from expressions (8) and (9)result:k f ⋅L⋅w⋅[ q b ⋅( 1+k î ) + k î ⋅q rg + q î + q rp ]S1 =[N] (11)eμ ⋅α− k f ⋅k î( 1+k )⎪⎧⎡qb⋅ î ⎤⎪⎫S4 = L ⋅⎨kî ⋅S1+ w ⋅ ⎢⎥⎬[N] (12)⎪⎩ ⎣+ kî⋅qrg+ qî+ qrp⎦⎪⎭The reduce resistance moments at motor shaft, maybe determinate with the formula (10) where S 1 and S 2are given by expression (11) and (12).The reduce resistance moments at shaft of drivenmotor, may be determinate for the belt transportconveyer with deviation drum is presented in fig.2.Fig.2. Belt inclinated transport conveyerwith deviation drumACTA TECHNICA CORVINIENSIS – Bulletin of EngineeringThe tensions in band, in points 1,…,8, for β>0 are:S 1 = S x [N] (13)SS 2 ≈ S 1 [N] (14)3 k î 1 ⋅ S 2= [N] (15)( q + q )S4= S3+ b rg ⋅L2⋅w⋅cosβ[N] (16)−q⋅L⋅sinβS = S +87b2S = î ⋅ [N] (17)5 k 1 S4S 6 ≈ S 5 [N] (18)S = î ⋅ [N] (19)7 k 2 S6( q + q + q )+b( q + q ) ⋅L⋅sinβbîîrp1⋅L1⋅wcos⋅ β[N] (20)where k î1 [‐] it is the band loading coefficient becausethe band passing over deviation drums (k î1 =1,02…1,03)and k î2 [‐] it is the band loading coefficient over returndrum (k î2 =1,07…1,09).The band loading that passing over deviation drumshave some coefficients values, because the angles ofwrap up of band on these drums are equal.The condition by unslip of band on motor drum is:μ ⋅αk f ⋅ S 8 = S 1 ⋅e(21)With these expressions (13),…,(21) may be get thenext ecuations:Sk f ⋅S A1 =e⋅α−k2⋅k î ⋅k î 1 2 fμ [N] (22)S = 28 S1⋅ k î 1 ⋅ k î 2 + S A [N] (23)where S A has this formula:⎛qb⋅( L1+ kî1⋅kî2 ⋅L2) ⎞SA= w⋅cosβ⋅⎜⎟qrgkî1kî2 L2L1( qîqrp)⎝+ ⋅ ⋅ ⋅ + ⋅ +⎠ (24)+ sinβ⋅ L ⋅ q + q −k⋅k⋅q⋅L( ( ))1bîî1For horizontal transport conveyer (β=0) with banddeviation drums, the tensions S 1 and S 8 from the bandare:k f ⋅SBS1 = [N] (25)μ ⋅α2e − k ⋅k⋅kî1î2bî 2S = 2S1⋅ k î 1 ⋅ k î 2 + S B8 [N] (26)where S B may be calculate with:S B⎡⎤⎢q b ⋅( L1+ k î 1⋅k î 2 ⋅L2)= w ⋅ ⎢ + q rg ⋅k î 1⋅k î 2 ⋅L2⎢(27)⎣+ L1⋅2( ) ⎥ ⎥⎥ q î + q rp ⎦For these two situations (β>0 and β=0) the reducedresistant moments at motor shaft may be computewith:( S8− S1) DTMrr= ⋅ [Nm] (28)η ⋅i2Rf2012. Fascicule 3 [July–September]

ACTA TECHNICA CORVINIENSIS – Bulletin of EngineeringIn the relations (10) and (28) i is the transmition ratioof reduction devices:Ωmi = (29)ΩTwhere Ω m [s ‐1 ] and Ω T [s ‐1 ] are the angular speeds of themotor and the driven drum.THE NECESSARY POWER CALCULATION FOR DRIVING THE BELTTRANSPORT CONVEYERSThe necessary power for driving the belt transportconveyer may be calculate with:− 3P = M ⋅ Ω ⋅ 10 ;PPTTT==MMrrrrrr⋅ i ⋅m⋅ i ⋅ ΩvRbTT⋅ 10⋅ 10− 3− 3; [kW] (30)where v b [m/s] is the band speed and R T [m] is the rayof driven drum.May be choise a motor which has the nominal speed n n[rot/min]:30⋅Ω nmn ≥ (31)πand the power:Pn ≥ P T(32)In continuation it is checking if the starting motormoment M p [Nm] is bigger than the reduced resistantmoment M rr [Nm] at shaft of driven motor. For this,from the motor catalog, it is determining the variationof the motor moment in function with the slip s[‐].The motor moment is giving by simplification ecuationof Kloss:⋅MkM = 2 s s(33)k+skswhere: M k [Nm] is the critical motor moment, s k [‐] ‐the slip at the critical moment and s[‐] is the motorslip. These size are calculating with:M = λ ⋅ M ;ssskkk= sMMkknPn= λ ⋅Ωn30 ⋅P= λ ⋅nkπ ⋅nn2n ⋅( λ + λ − 1 );n0− n=n0nΩ 0 − Ω n=Ω0n0− ns = ;n⋅;2( λ + λ − 1 );2⋅( λ + λ − 1 )0Ω 0 − Ωs =Ω0(34)(35)(36)n0− nnsn= ;n0(37)Ω 0 − Ω nsn=Ω 0In this relations:λ[‐] is the motor overload coefficient gave it in themotor catalog,P n [W] is the motor nominal power,n 0 [rot/min] and Ω 0 [s ‐1 ] are the syncronic speed,respective the angular speed proper at this speed,n n [rot/min] and Ω n [s ‐1 ] are the nominal speed,respective the angular speed,n [rot/min] and Ω [s ‐1 ] are the momentan speed,respective the angular speed ands k [‐], s n [‐] and s[‐] are the slip proper for the criticalmoment M k , nominal moment M n and currentmoment M.The motor starting moment M p [Nm] are calculatingwith sympliphicate formula of Kloss for s=1:Mp⋅M⋅s= 2 (38)1+k k2skThe motor may win the dynamic moment M d [Nm] if:M p >M rr (39)If this condition is not carries out, may be choise amotor with bigger power.CONCLUSIONSThis paper introduces on the base of investigationdone it on spatiality literature [1‐7], a quick calculationof necessary power for drive with triphasic cageinduction motors the inclined or horizontal belttransport conveyer, with and without deviationdrums.For inclined or horizontal belt transport conveyerwithout deviation drums, the necessary power ofdriven motor are calculating with (30), (8), (9), (11),(12) and (10), and for inclined or horizontal transportconveyer with deviation drums, the necessary powerof driven motor are calculating with (30), (28), (24),(22), (23) or (27), (26), (25) and (28) with carry out ofinequality (39), for these two constructive types.In this work may be establish the algorithm and thecomputing program of power driven motor for belttransport conveyer with small and medium capacity.REFERENCES[1.] N.V. Boțan ‐ The Base of Computing Electrical Drives(in Romanian), Technical House, Bucharest, Romania,1970 (Bazele calculului acționărilor electrice, EdituraTehnică, Bucureşti, România, 1970).[2.] Al. Fransua, C. Saal, and I. Țopa ‐ Electrical Drives (inRomanian), Didactical and Pedagogical House,Bucharest, Romania, 1975 (Acționări electrice, EdituraDidactică şi Pedagogică, Bucureşti, România, 1975).2012. Fascicule 3 [July–September] 29

ACTA TECHNICA CORVINIENSIS – Bulletin of Engineering[3.] A.S. Ostrovski, A.O. Spivakovski, M.G. Potapov, andM.A. Kotov ‐ Electrical Drive of Belt TransportConveyers, Technical House, Bucharest, Romania, 1968(in Romanian, translate from Russian), (Acționareaelectrică a benzilor transportoare, Editura Tehnică,Bucureşti, România, 1968).[4.] I. Popa, and G.N. Popa ‐ Electronic Device with Wiringand Programmable Structure, for Low‐Voltage Three‐Phase Induction Motors (in Romanian), Mirton House,Timişoara, Romania, 2000 (Dispozitive electronice custructură cablată şi programată, de protecție amotoarelor asincrone trifazate de joasă tensiune,Editura Mirton, Timişoara, România, 2000).[5.] J. Rodriguez, J. Pontt, N. Becker, and A. Weinstein ‐Regenerative drives in the megawatt range for highperformancedownhill belt conveyors, IEEETransaction on Industry Applications, vol.38, no.1,January/February 2002, pp. 203‐210.[6.] M.A. Abdel‐halim, M.A. Badr, and A.I. Alolah ‐ Smoothstarting of slip ring induction motors, IEEE Transactionon Industry Applications, vol.12, no.4, December 1997,pp. 317‐322.[7.] L. Hewitson, M. Brown, and B. Ramesh ‐ PracticalPower Systems Protection, Linacre House, Jordan Hill,Oxford, U.K., 2004ACTA TECHNICA CORVINIENSIS – BULLETIN of ENGINEERINGISSN: 2067‐3809 [CD‐Rom, online]copyright © UNIVERSITY POLITEHNICA TIMISOARA,FACULTY OF ENGINEERING HUNEDOARA,5, REVOLUTIEI, 331128, HUNEDOARA, ROMANIAhttp://acta.fih.upt.ro302012. Fascicule 3 [July–September]

1.Árpád FERENCZ, 2. Márta NÓTÁRIMANAGEMENT OF RURAL DEVELOPMENT IN COLLAGE OFKECSKEMÉT1‐2.COLLEGE OF KECSKEMÉT, HORTICULTURAL FACULTY, HUNGARYABSTRACT: Taking all these challenges into consideration, training of farmers is a strategic task regarding the future of thecountry's future, to which College of Kecskemét is also willing to contribute actively. Beyond the basic training our goal is toprovide further professional training for the farmers in order to make them acquire economic, management, regional andknowledge, and use it as a skill. The goal is to make them be able to accomplish management of production processes,organization, professional administration and consultancy tasks. With their advanced knowledge they need to be able tointerpret the EU rural development policy, to plan and carry out programs.KEYWORDS: rural development, basic training, goals, programsINTRODUCTIONAs Hungary is a member of the EU, it is important tomeet the EU requirements and legislation. During theaccession negotiations, one of the most critical areaswas the environmental protection and specializedagricultural administration which proved to be asignificant gap to be overcome. To do so the existenceof a significant number of well‐trained professionals,who are capable to take appropriate actions, carry outa high level achievements according to the EuropeanUnion directives and requirements, is outstandinglyimportant and highly necessary.The most significant challenges of the sand ridge towhich the College of Kecskemét Horticultural Facultyhas to find an educational strategy are drying andwater scarcity. The most urgent tasks are summarizedbelow: the county's agricultural and rural developmentconcept should be based on a strategy which hasbeen elaborated to deal with drying‐upon the ridge area further production extension,agro‐environmental program expansion in abroader range, an appropriate adjustment of landutilisation to the conditions (stop the forestation,prefer the cultivated farms). utilize the dry‐agriculture in its maximumpotential, disperse drought‐resistant species andvarieties, and support related (applied) researchand development functions, the priority development of animal husbandry, retention and development of large‐scalecultivation, dissemination of the concept and means ofprecision agriculturefrom the side of wider economy, it is recommended todevelop three sectors: environmental industry, foodprocessing, rural tourism.MATERIAL AND METHODS. Agricultural training inHorticulture FacultyThe College of Kecskemét Horticultural Faculty doesextended research nationally and internationally,especially in applied research fields which are in closerelationship with our educational profile.The research of Faculty fields are ornamental plant‐,vegetable‐, fruit‐ and vine‐growing, processing,machinery, economics, marketing, informatics andenvironmental protection. Three inventions andseveral innovations mark our research results. Fromamong the inventions developed at the Faculty theframeless foil early growing method developed by theVegetable Growing Institute is worth mentioning. It isused in more than 3000 hectare nationally.The present projects of Faculty are on organic controlproducts, developing environmentally friendlygrowing technologies, modelling sustainabledevelopment on the sand table‐land between theRivers Danube and Tisza, bio‐ethanol‐based utilisationof agricultural products. We intend to publish ourresults widely in national and international literature,at scientific conferences and discussions.The Faculty organizes several professional conferencesand exhibitions. The students of faculty also take partin the research projects of the institutions. Local andnational student researchers’ conferences provide agreat opportunity for discussing and presenting theirresearch results.For post‐graduates in college education we offerdifferent specialist engineering further educationalcourses such as Specialised Engineer of IntegratedFruit Growing, Specialised Engineer of Agro‐Environment, Vini‐ and Viticulture SpecialisedEngineer, Rural Development Manager, SpecialisedEngineer of Greenery Farming, Specialised Engineer ofVegetable Forcing and Mushroom Growing.The Faculty has regular further education courses forpeople with basic, secondary and higher educationqualifications in Flower arrangement, Park keeping,Pruning, Plant protection, soil protection, fruit andvegetable storing, vine‐growing, wine‐making andother fields. Silver spike farmer, Gold spike farmer,Agricultural entrepreneur training courses (which areon the national vocational training list) are alsopopular. Besides the training courses, our faculty is an© copyright FACULTY of ENGINEERING ‐ HUNEDOARA, ROMANIA 31

examination centre of the Hungarian vocationaltraining.INCLUDING RURAL DEVELOPMENT ACTIVITIESThe value of the region) is increasing, its unique(environmentally friendly, bio‐) agriculture is getting anew chance, and it becomes possible to renew thefarmsteads areas. Accordingly, the tasks are: to improve professional organization of the ruralarea development, there is a need for integrated rural developmentprofessionals with comprehensive knowledge,(education), It requires common, multi‐disciplinary researches(applications) individual farm‐specific modelling is neededRESULTS AND DISCUSSION. The multifunctionalagriculture and sustainable agricultureThe concept of multifunctional agriculture andsustainable agriculture must be applied in everydaypractice. Primary concern is the environmental,economic and social sustainability. These correlationsare summarized in Fig 1.NatureGLOBALClimate EU Economy SocietyChangingDrought, System of The decline Urbanization,drying agricultural of local alienation,water subsidies farms homogenizationscarcityExtremeWeatherECO-The challenges andSOCIETYNOMYconflicts of agriculture inBács-Kiskun County(institutionalsystem)System The crisis of Migration, Unstable Lack of FoodChange the aging, land use, economic safety,Effects agriculture poverty soil erosion, planning, rural affordableunemployment food, lackof visionNATIONALLOCALPolitics Economy Society Environment Economy SocietySETTLEMENT(Infrastructure)Figure 1: The impacts on rural developmentFARMERS PROFESSIONAL DEVELOPMENT IN COLLAGE OFKECSKEMÉTThe Regional Advisory Centre providing continuousfurther education for farmers has been operating atthe Horticultural College Faculty since 2007. Withregular further training courses ‐ like farmerentrepreneur, bio cultivator, park keeper, winegrower,winemaker, vineyardist courses ‐ we enhancefarmers’ theoretical and practical skills andcompetences in their profession. In addition, at thefaculty we provide service with the accredited PlantExamination Laboratory of Soil for planters, which wewill expand with environment, food andmicrobiological experiments and testing of rawmaterials.32ACTA TECHNICA CORVINIENSIS – Bulletin of EngineeringThe Regional Professional Advisory Centre assists thework of the accredited Plant Examination Laboratoryof Soil to a significant extent, because the binding soilsamples of contractual partners of 2008‐2009 areanalyzed here.The Fig 2‐3 give information about the farmers takingparticipation in the training.distribution100%80%60%40%20%0%percentagewomenmengenderFigure 2. The gender proportion of trainees100%80%60%40%20%0%collegepost-highvocationalelementaryeducational levelFigure 3. The educational level of traineesAssessing the figures we can state that the 60% ofparticipants are male, regarding the education levelthe primary/elementary school education is dominantamong the participants, followed by the highereducational graduates. The reason why most peopletake part in the training is their obligations to meetand fulfil the expectations of grants they have won.Examining the scope of their activities we canconclude that nearly 90% of the participants work asactive farmers. The aim of the Kecskemét CollegeFaculty of Horticulture is that after the furthertraining course farmers will be able to carry out: improvement measures regarding the standard ofliving of people living in rural areas, problem and development analysis of rural areas,prepare a business plan, continuous updating and improvement of themanagement structure, meeting the expectations of internationalstandards of rural development management,how to write and coordinate rural developmentprojectsCONCLUSIONS, SUGGESTIONSThe Faculty must strive for developing theinfrastructural conditions in order to educate thediscipline of theoretical and practical ruraldevelopment in a most modern way. The training canbe organized on three levels: basic full time courses(BSc) (bachelor degree program of economic and rural12012. Fascicule 3 [July–September]

ACTA TECHNICA CORVINIENSIS – Bulletin of Engineeringdevelopment), vocational training in ruraldevelopment, and MSc courses after the successfulaccreditation. Particular emphasis should be put oncourses giving professional qualifications, most ofwhich are subsidized by the state. As a result, wemanage to develop close professional relationshipswith farmers, which partly serve as the practicalcriteria of the education as well.In close cooperation with farmers we try to provideservices beyond education and further trainingincluding both laboratory tests (soil and plantexamination, food, raw materials testing,microbiological testing), and purchasing specializedbooksREFERENCES[1.] Csatári, B. (2010): the common future of thecountryside. Dialogue in the countryside, II. grade, 1No. pp. 6‐9[2.] Glatz, F. (2009): The future of farms and the future offarm research. National Rural Forum. Dialogue in thecountryside, Vol 1. No.1. pp. 16‐17[3.] 3rd F. Glatz (2009): The Present and Future of Farms.II. National Rural Forum. Dialogue in the countryside,Vol 1. No. 3. pp. 3‐5[4.] Koponicsné Gy. D. ‐Varga, Gy. (2009): Learning andeducation opportunities in rural areas. The vision foragriculture and rural areas. West Hungarian Universityof Agriculture and Food Science, Mosonmagyaróvár,Conference Proceedings, Vol. 1. pp. 120‐130[5.] Kozar, J. – Toth, K. (2009): Regional aspects of theconsultancy. The vision for agriculture and rural areas.West Hungarian University of Agriculture and FoodScience, Mosonmagyaróvár, Conference Proceedings,Vol. 1. pp. 30‐36[6.] Stark A. (2009): Rural development funding in 2008‐2010. II. National Rural Forum. Dialogue in thecountryside, Vol.1. No. 3. pp. 12‐15ACTA TECHNICA CORVINIENSIS – BULLETIN of ENGINEERINGISSN: 2067‐3809 [CD‐Rom, online]copyright © UNIVERSITY POLITEHNICA TIMISOARA,FACULTY OF ENGINEERING HUNEDOARA,5, REVOLUTIEI, 331128, HUNEDOARA, ROMANIAhttp://acta.fih.upt.roACTA TECHNICA CORVINIENSIS – BULLETIN of ENGINEERINGISSN: 2067‐3809 [CD‐Rom, online]copyright © UNIVERSITY POLITEHNICA TIMISOARA,FACULTY OF ENGINEERING HUNEDOARA,5, REVOLUTIEI, 331128, HUNEDOARA, ROMANIAhttp://acta.fih.upt.ro2012. Fascicule 3 [July–September] 33

ACTA TECHNICA CORVINIENSIS – Bulletin of EngineeringACTA TECHNICA CORVINIENSIS – BULLETIN of ENGINEERINGISSN: 2067‐3809 [CD‐Rom, online]copyright © UNIVERSITY POLITEHNICA TIMISOARA,FACULTY OF ENGINEERING HUNEDOARA,5, REVOLUTIEI, 331128, HUNEDOARA, ROMANIAhttp://acta.fih.upt.roACTA TECHNICA CORVINIENSIS – BULLETIN of ENGINEERINGISSN: 2067‐3809 [CD‐Rom, online]copyright © UNIVERSITY POLITEHNICA TIMISOARA,FACULTY OF ENGINEERING HUNEDOARA,5, REVOLUTIEI, 331128, HUNEDOARA, ROMANIAhttp://acta.fih.upt.ro© copyright FACULTY of ENGINEERING ‐ HUNEDOARA, ROMANIA 34

1.Harshavardhan KAYARKAR, 2. Sugata SANYALA SURVEY ON VARIOUS DATA HIDING TECHNIQUES AND THEIRCOMPARATIVE ANALYSIS1.M.G.M’S COLLEGE OF ENGINEERING AND TECHNOLOGY, NAVI MUMBAI, INDIA2.SCHOOL OF TECHNOLOGY AND COMPUTER SCIENCE, TATA INSTITUTE OF FUNDAMENTAL RESEARCH, MUMBAI, INDIAABSTRACT: With the explosive growth of internet and the fast communication techniques in recent years the security and theconfidentiality of the sensitive data has become of prime and supreme importance and concern. To protect this data fromunauthorized access and tampering various methods for data hiding like cryptography, hashing, authentication have beendeveloped and are in practice today. In this paper we will be discussing one such data hiding technique calledSteganography. Steganography is the process of concealing sensitive information in any media to transfer it securely overthe underlying unreliable andunsecured communication network. Our paper presents a survey on various data hidingtechniques in steganography that are in practice today along with the comparative analysis of these techniques.KEYWORDS: DataHiding, Cover Media, Steganography, SteganalysisINTRODUCTIONInternet came into existence in the late 1960s and1970s out of the need to exchange research dataamong the researchers across different universitiesand also to enable communication in the battlefield toconvey vital information which could proveadvantageous in the war situations. Since theinception of the internet, the security and theconfidentiality of the sensitive information have beenof utmost importance and top priority.The reason for this security and confidentiality isbecause the underlying communication network overwhich the transfer of sensitive information is carriedout is unreliable and unsecured. Anybody with theproper knowledge and right applications caneavesdrop and learn of the communication andintercept the data transfer which could be verydangerous and even life threatening in somesituations.Ideally the internet and the communication networkand the routing protocols should exhibit the followingthe properties: Security: Security is an important property of theinternet. The internet should provide and preservethe confidential and sensitive information thatflows through it. The security should be such thatonly the intended recipient of the informationshould gain access to it. Distributed Operation: The internet should bedistributed rather than only residing on somecentralized server. In the event of the crash theinternet should not lose its functionality andcontinue performing efficiently. Reliability: Reliable communication is one of thevital properties of the internet. The internet shouldguarantee the reliable delivery of the informationto the intended recipient. Fault‐Tolerance: Fault‐tolerance means the abilityof the system to operate normally even in theevents of failure. Internet should exhibit faulttoleranceso that it keeps on functioning evenwhen there is failure in some part of the internet. Quality of Service Support: Quality of Service(QoS) is one of the crucial properties in terms ofcommunication. Inter should provide QoS supportto various applications and sensitive data andshould prioritize them depending on the nature ofthe data. Robustness: Internet should be robust in the sensethat it should continue functioning normally evenin the presence of errors and unexpected situationslike invalid input.All the above mentioned properties are ideal andcannot be practically implemented in the structureand functioning of the internet as it comprises ofmany networks, different infrastructures: wired,wireless, ad hoc and various mobility models [1] [2] [3][4] [5]. One such property that cannot be guaranteedin the internet is Security.Due to the inability to guarantee security, variousvulnerabilities exist in the network that can beexploited and gives rise to several security attacks.Some of the common security attacks are listedbelow. Impersonation or Spoofing: The main goal of thisattack is to assume the identity of the person andconvince the sender that it is communicating withthe intended recipient. Man in the Middle attack: In this attack, theattacker makes independent connections with thetwo parties across the network making them© copyright FACULTY of ENGINEERING ‐ HUNEDOARA, ROMANIA 35

elieve that they are communicating privately,when in fact the communication is controlled andintercepted by the attacker. Traffic Analysis: In this process the attacker listensto the chatter on the communication networkbetween two parties without interacting betweenthem and tries to learn the information that theyare sharing.To mitigate these security vulnerabilities and facilitateseamless and safe transfer of data over thecommunication channel, techniques likecryptography, hashing, authentication, authorization,steganography are developed.Our paper illustrates various data hiding techniques insteganography to enable the safe transfer of criticaldata over the unsecure network.Steganography is sometimes erroneously confusedwith cryptography, but there are some notable anddistinctive differences between the two. In somesituations steganography is often preferred tocryptography because in cryptography the cipher textis a scrambled output of the plaintext and theattacker can guess that encryption has beenperformed and hence can employ decryptiontechniques to acquire the hidden data. Also,cryptography techniques often require highcomputing power to perform encryption which maypose a serious hindrance for small devices that lackenough computing resources to implementencryption.On the contrary, steganography is the process ofmasking the sensitive data in any cover media like stillimages, audio, video over the internet. This way theattacker does not realize that the data is beingtransmitted since it is hidden to the naked eye andimpossible to distinguish from the original media.Steganography involves 4 steps:a. Selection of the cover media in which the data willbe hidden.b. The secret message or information that is neededto be masked in the cover image.c. A function that will be used to hide the data in thecover media and its inverse to retrieve the hiddendata.d. An optional key or the password to authenticateor to hide and unhide the data.In this paper we present a survey on various datahiding techniques in steganography along with theircomparative analysis.The rest of the paper is organized as follows: Section 2presents the survey on various data hiding techniquesand related work. Section 3 performs the ComparativeAnalysis of the techniques discussed in Section 2.Finally Section 4 draws the Conclusion of the paper.ACTA TECHNICA CORVINIENSIS – Bulletin of EngineeringVARIOUS DATA HIDING TECHNIQUES – Data HidingTechniques in Still ImagesIn this section we will be presenting the survey onvarious data hiding techniques in steganography tofacilitate secure data transmission over the underlyingcommunication network.Nosrati et al. [6] introduced a method that embedsthe secret message in RGB 24 bit color image. This isachieved by applying the concept of the linked listdata structures to link the secret messages in theimages. First, the secret message that is to betransmitted is embedded in the LSB’s of 24 bit RGBcolor space. Next, like the linked list where each nodeis placed randomly in the memory and every nodepoints to every other node in list, the secret messagebytes are embedded in the color image erratically andrandomly and every message contains a link or apointer to the address of the next message in the list.Also, a few bytes of the address of the first secretmessage are used as the stego‐key to authenticate themessage. Using this technique makes the retrieval andthe detection of the secret message in the imagedifficult for the attacker.Kuo et al. [7],[8],[9] and [10] presented a reversibletechnique that is based on the block division toconceal the data in the image. In this approach thecover image is divided into several equal blocks andthen the histogram is generated for each of theseblocks. Maximum and minimum points are computedfor these histograms so that the embedding space canbe generated to hide the data at the same timeincreasing the embedding capacity of the image. A onebit change is used to record the change of theminimum points.Das et al. have listed different techniques to hide data[11] [12]. The authors have mainly focused on howsteganography can be used and combined withcryptography to hide sensitive data. In this approachthey have explained and listed various methods likePlaintext Steganography, Still ImagerySteganography, Audio/Video Steganography and IPDatagram Steganography which can be used to hidedata. The authors have also elucidated theSteganalysis process which is used to detect ifsteganography is used for data hiding.Naseem et al. [13] presented an Optimized Bit PlaneSplicing algorithm to hide the data in the images. Thismethod incorporates a different approach than thetraditional bit plane splicing technique. In thisapproach instead of just hiding the data pixel by pixeland plane by plane, the procedure involves hiding thedata based on the intensity of the pixels. The intensityof the pixels in categorized into different ranges anddepending on the intensity of the pixel, the number ofbits are chosen that will be used to hide data in that362012. Fascicule 3 [July–September]

ACTA TECHNICA CORVINIENSIS – Bulletin of Engineeringparticular plane. Also, the bits are hidden randomly inthe plane instead of hiding them adjacent to eachother and the planes are transmitted sporadically thusmaking it difficult to guess and intercept thetransmitted data.Fu et al. presented some novel methods for datahiding in halftone images [14], [15]. The proposedmethod enables to hide huge amounts of data evenwhen the original multitone images are unavailable byforced pair‐toggling. The resulting stego‐images havehigh quality and virtually are indistinguishable fromthe original image.Dey et al. [16] have proposed a novel approach to hidedata in stego‐images which is an improvement overthe Fibonacci decomposition method. In this methodthe authors have exploited Prime Numbers to hidedata in the images. The main agenda is to increase thenumber of bit planes of the image so that not only theLSB planes but even the higher bit planes can be usedto hide to data. This is done by converting the originalbit planes to some other binary number system usingprime numbers as the weighted function so that thenumber of bits to represent each pixel increases whichin turn can be used hide data in higher bit planes. Theauthors have also performed a comparison of theFibonacci decomposition method with the traditionalLSB data hiding technique showing that the formeroutperforms the latter method and comparingFibonacci Decomposition method with the proposedmethod which outclasses the former method. Also,the proposed method generates the stego‐imagewhich is virtually indistinguishable from the originalimage.Data Hiding Techniques in Audio SignalsKekreetal proposed two novel methods to transfersecret data over the network by hiding them in theaudio signals, thus generating a stego‐audio signal [17][18]. In the first method the authors hide the secretdata in the LSB of audio by considering the parity ofthe sample, i.e. instead of directly replacing thedigitized sample of the audio with the secret message,first the parity of the sample is checked and then thesecret data is embedded into the LSB. This way itbecomes even more difficult for the intruders to guessthe bit or the data that is being transmitted. In thesecond approach, XORing of the LSB’s is performed.The LSB’s are XORed and depending on the outcomeof this operation and the secret data that is to beimplanted, the LSB of the sample data is changed orleft unchanged. A different approach is followed byKondo. Kondo [19] proposed a data hiding algorithmto embed data in stereo audio signals. The algorithmuses polarity of reverberations which is added to thehigh frequency signals. In this method the highfrequency signals are replaced by one middle channeland then the data is embedded. The polarity ofreverberations that is added to each channel isperformed to adjust the coherence between thesechannels. The detection of the embedded data is doneby employing the correlation between the sum anddifference of the stereo signal. Also, original signal isnot required to extract the hidden data by using thisalgorithm.Data Hiding Techniques in IPv4 HeaderTo securely transmit the data over the network theVasudevan et al. [20] used the analogy of the jigsawpuzzle. They insinuate to fragment the data intovariable sizes instead of fixed size like the jigsawpuzzle and append each fragment of data with a presharedmessage authentication code (MAC) and asequence number so that the receiver canauthenticate and combine the received fragments intoa single message. At the sender side every datafragment is prefixed and suffixed with a binary ‘1’ andthen XOR’ed with a Random number called the onetimepad and transmitted over the network. When thereceiver receives the message it performs the exactopposite process of that to the sender and retrievesthe intended message.Ahsan and Kundurpresented two novel approachesthat exploit the redundancy in the IPv4 header of theTCP/IP protocol suite to convey the secret messageover the communication channel without detection[21], [22], [23], [24]. In the first method, the FLAGSfield containing the fragmentation information is usedto conceal the data and transmit over the network. Inthe second technique 16‐bit identification field of theheader through chaotic mixing and the generation ofsequence numbers is used to hide the data and conveythe information to the recipient.Data Hiding Techniques in Video SequencesLi et al. [25] and [26] suggested a data hidingtechnique based on the video sequences. This methodimplements an adaptive embedding algorithm toselect the embed point where the sensitive data is tobe concealed. The scheme functions by adopting 4x4DCT residual blocks and determining a predefinedthreshold. The blocks are scanned in an inverse zigzagfashion until the first non‐zero coefficient isencountered. The value of this coefficient is comparedwith predefined threshold and if it is greater than thethreshold then that pixel is chosen to embed the data.Data Hiding Techniques using DNA SequencesAbbasy et al. [27] and [28] introduced a scheme toenable secure sharing of resource in cloud computingenvironments. The proposed method employs DNAsequences to hide data. The process consists of twosteps. In the first step a DNA sequence is selected andthe binary data is converted into this DNA sequence byapplying the pairing rules. This step, apart from2012. Fascicule 3 [July–September] 37

converting the data also increases the complexity byapplying the complementary rules and then indexingthe garbled sequence. The second step involves theextraction of the hidden data from the DNA sequencewhere in exactly a reverse operation is performed tothe first step.COMPARATIVE ANALYSIS OF VARIOUS DATA HIDINGTECHNIQUESIn this section a comparative analysis of different datahiding schemes in steganography is presented.The authors in [6], [7], [13], [14] and [16] have allpresented techniques to hide data in the still imagesand generated stego‐images as the output. In [6] theauthors embed the data in RGB 24 bit color image byusing the linked data structures where in, the datahidden in the image is linked with other data.The advantage of this method is that hiding the datarandomly than sequential will make it difficult for theattacker to locate it and also without theauthentication key the attacker will not be able toaccess the next piece of data in the image. Instead ofusing the whole image as the cover image, the authorsin [7] have proposed a method that segments theimage into blocks of equal sizes. Also, the processinvolved in this method is reversible hence there is noloss of hidden data. The approach followed in thisscheme to conceal data is quite different. In thistechnique the histograms of the blocks of images istaken and they are shifted to minimum point of thehistogram and then the data is hidden between thesepoints. The improvement of this technique is that itprovides higher capacity to hide data than theprevious method.In [13] optimized bit plane splicing method isimplemented. In this method the intensity value of thepixel is divided into different planes and rather thanusing the traditional method of hiding the data intoLSB of the pixel and plane by plane, the data in thisapproach is hidden based on the intensity of thepixels. The pixels are grouped based on the intensityand then number of pixels used to represent the datais chosen depending on the intensities. Also, ratherthan hiding the data sequentially in the planes, thedata is hidden randomly and during the transmissionof the data the planes are transferred randomly tomake it difficult to intercept the data. The advantageof this technique is that by grouping the pixelsaccording to the intensity more number of bits isavailable to represent the hidden data than just theLSB of the pixel. In [16] to increase and utilize thehigher bit planes to hide the data a different approachfrom the one discussed earlier is employed. This isachieved by converting the original bit planes intosome other binary number system using the primeACTA TECHNICA CORVINIENSIS – Bulletin of Engineeringnumbers as the weighted function. This enables to usemore number of bits to represent the hidden data.The authors in [17] and [19] use audio signals as thecover media to hide the sensitive data. In [17] theauthors present two techniques to hide data in theaudio signals. In the first method before hiding thedata in the LSB of the sample of the audio signal theparity of the sample checked. This method makes theattacker difficult to guess the transmitted data. In thesecond approach, the LSB’s are XOR’ed and dependingon the result of this operation and the hidden data theLSB of the sample data is decided to be changed orleft unchanged. In [19] a separate approach isfollowed where in the stereo audio signals are used toembed the data. In the proposed algorithm thepolarity of reverberations is applied to the highfrequency signals which are then replaced by onemiddle channel to embed the critical data.Jigsaw‐based approach [20] is used to transfer dataover the communication channel securely. In thisscheme the data is fragmented in block of variablesizes and a message authentication code (MAC) is usedto authenticate each and every piece of data. Also,every message is prefixed and suffixed with a binary 1along with XOR‐ing the data with the randomlygenerated one‐time pad.By fragmenting the data theattacker is unable to make sense of the data at thesame time he cannot access the data unless he possessthe authentication code for the data. A diverseapproach is followed by the authors in [21]. In thisscheme the redundant fields in the IPv4 header isexploited to mask the data. The fragment bit of FLAGSand the 16‐bit identification fields are utilized to passthe delicate data over the communication network.TABLE I below provides a brief summary of the datahiding techniques in steganography with theiradvantages.CONCLUSIONSIn this paper we discussed about steganography andpresented some notable differences betweensteganography and cryptography. We also surveyedvarious data hiding techniques in steganography andprovided a comparative analysis of these techniques.In the Introduction section we discussed about varioussecurity flaws and vulnerabilities in internet.We also discussed about various techniques to enablethe secure transfer of data with the help of methodslike cryptography, steganography, hashing, andauthentication. In the next section we presentedvarious techniques to conceal data in steganography.Comparative Analysis has been presented in Section 3,followed by the Conclusion.382012. Fascicule 3 [July–September]

ACTA TECHNICA CORVINIENSIS – Bulletin of EngineeringTable Ia: A brief summary of various data hidingtechniques in steganography ‐ Data HidingTechniques ProposedCover Media1. StillImage2. AudioSignal3. IPv4HeaderData Hiding Techniques Proposed1. In [6] the authors implementeda scheme that uses the conceptlinked list of randomlyembedding the data in theimage and linking themtogether.2. The method proposed in [7]divided the images into equalblock sizes and then useshistogram to embed the data.3. Optimized Bit Plane splicingalgorithm [13] is implementedwhere in the pixels are groupedbased on their intensity andthen the number of bits are torepresent the hidden data arechosen.4. In [16] higher bit planes aregenerated by converting thepixels into different binaryformat using prime numbers asthe weighted function.1. In [17] the authors proposedtwo methods to use the audiosignals to hide the data. In thefirst method, the parity of thesample is checked beforereplacing the LSB of thesample. In the second approachXOR‐ing is carried out.2. In [19] polarity of thereverberations is added to thehigh frequency channels andthese high frequency channelsare used hide the data.1. In [21] the authors haveexploited the redundant fieldslike fragmentation bit and the16‐bit identification field of theIPv4 header to covertly transferthe data over thecommunication network.ACTA TECHNICA CORVINIENSIS – BULLETIN of ENGINEERINGTable Ib: A brief summary of various data hidingtechniques in steganography ‐ Advantage(s)Cover Media Advantage(s)1. StillImage1. The attacker is unable to guessthe next message as the data isnot hidden sequentially. Also,without the password it is notpossible to access the hiddendata.2. Rather than sending a singleimage containing all the hiddendata, blocks of images can besent in out of order to confusethe attacker.3. Since data is hidden in thehistogram it is difficult tolocate the data along with theincrease in capacity to concealdata.4. As the bits are grouped basedon the intensity of the pixels,more number of darkerintensity pixels can be used torepresent the hidden data thanjust the LSB2. AudioSignal3. IPv4Header5. Higher bit planes can now beused to hide the data insteadof just the lower bit planes.1. It is difficult to determine thedata in the audio signalsbecause the data is not hiddendirectly in the sample but theparity is checked beforeinserting the data.2. 1. As the polarity of thereverberations is used to hidethe data in the high frequencysignals, the stego‐audio signalsgenerated are more robust andresistant to errors duringtransmission.1. As the inherent fields of IPv4header are utilized to transferthe data, it is extremelydifficult to detect these covertchannels. Hence, the sensitivedata can be communicatedeasily by using this technique.ISSN: 2067‐3809 [CD‐Rom, online]copyright © UNIVERSITY POLITEHNICA TIMISOARA,FACULTY OF ENGINEERING HUNEDOARA,5, REVOLUTIEI, 331128, HUNEDOARA, ROMANIAhttp://acta.fih.upt.ro2012. Fascicule 3 [July–September] 39

REFERENCES[1.] Bhavyesh Divecha, Ajith Abraham, Crina Grosan andSugata Sanyal, “Analysis of Dynamic Source Routingand Destination‐Sequenced Distance‐VectorProtocols for Different Mobility models”, First AsiaInternational Conference on Modeling andSimulation, AMS2007, 27‐30 March, 2007, Phuket,Thailand. Publisher: IEEE Press, pp. 224‐229.[2.] S. Gowrishankar, S. Sarkar, T. G. Basavaraju,"Simulation Based Performance Comparison ofCommunity Model, GFMM, RPGM, Manhattan Modeland RWP‐SS Mobility Models in MANET," FirstInternational Conference onNetworks andCommunications (NETCOM '09), 27‐29 Dec. 2009,pp.408‐413.[3.] Jonghyun Kim, Vinay Sridhara, Stephan Bohacek,“Realistic mobility simulation of urban meshnetworks”, Journal of Ad Hoc Networks, Vol. 7, Issue2, March 2009, Publisher: Elsevier,pp. 411‐430.[4.] Liu Tie‐yuan, Chang Liang, Gu Tian‐long, "Analyzingthe Impact of Entity Mobility Models on thePerformance of Routing Protocols in the MANET”,3rd International Conference onGenetic andEvolutionary Computing, 14‐17 Oct. 2009, pp.56‐59.[5.] M.F. Sjaugi, M. Othman, M.F.A. Rasid, "Mobilitymodels towards the performance of geographicalbasedroute maintenance strategy in DSR", IEEEInternational Symposium on InformationTechnology, ITsim 2008 ,Vol. 3, 2008, pp. 1‐5.[6.] M. Nosrati, R. Karimi, H. Nosrati, and A. Nosrati,“Embedding stego‐text in cover images using linkedlist concepts and LSB technique”, Journal ofAmerican Science, Vol. 7, No. 6, 2011, pp. 97‐100.[7.] Wen‐Chung Kuo, Dong‐Jin Jiang, Yu‐Chih Huang, “AReversible Data Hiding Scheme Based on BlockDivision”, Congress onImage and Signal Processing,Vol. 1, 27‐30 May 2008, pp.365‐369[8.] Yih‐Chuan Lin, Tzung‐Shian Li, Yao‐Tang Chang,Chuen‐Ching Wang, Wen‐TzuChen, “A Subsamplingand Interpolation Technique for ReversibleHistogram Shift Data Hiding”, Image and SignalProcessing,Lecture Notes in Computer Science, Vol.6134, 2010, Publisher: Springer Berlin/Heidelberg, pp.384‐393.[9.] Chyuan‐Huei Thomas Yang, Chun‐Hao Hsu, “A HighQuality Reversible Data Hiding Method UsingInterpolation Technique, "IEEE Fifth InternationalConference onInformation Assurance andSecurity,Vol. 2, 18‐20 Aug. 2009, pp.603‐606.[10.] Che‐Wei Lee and Wen‐Hsiang Tsai, “A Lossless DataHiding Method by Histogram Shifting Based on anAdaptive Block Division Scheme”, PatternRecognition and Machine Vision, River Publishers,Aalborg, Denmark, pp. 1–14.[11.] Soumyendu Das, Subhendu Das, BijoyBandyopadhyay, Sugata Sanyal, “Steganography andSteganalysis: Different Approaches”, InternationalJournal of Computers, Information Technology andEngineering (IJCITAE), Vol. 2, No 1, June, 2008, SerialPublications, pp. 1‐11.[12.] Abbas Cheddad, Joan Condell, Kevin Curran, Paul McKevitt, “Digital image steganography: Survey andanalysis of current methods”, Journal of SignalProcessing, Elsevier, Volume 90, Issue 3, March 2010,pp.727‐752.[13.] M. Naseem, Ibrahim M. Hussain, M. Kamran Khan,Aisha Ajmal, “An Optimum Modified Bit PlaneSplicing LSB Algorithm for Secret Data Hiding”,International Journal of Computer Applications, Vol.29, No. 12, 2011. Foundation of Computer Science,New York, USA, pp. 36‐43.ACTA TECHNICA CORVINIENSIS – Bulletin of Engineering[14.] Ming Sun Fu and O.C. Au, “Data hiding watermarkingfor halftone images", IEEE Transactions onImageProcessing, Vol.11, No.4,Apr. 2002, pp.477‐484.[15.] Soo‐Chang Pei and J.M. Guo, “Hybrid pixel‐baseddata hiding and block‐based watermarking for errordiffusedhalftone images", IEEE TransactionsonCircuits and Systems for Video Technology,Vol.13,No.8, Aug. 2003, pp. 867‐ 884.[16.] Sandipan Dey, Ajith Abraham, Sugata Sanyal, “AnLSB Data Hiding Technique Using Prime Numbers”,IEEEThird International Symposium on InformationAssurance and Security,Manchester, UnitedKingdom, IEEE Computer Society press, USA,29‐31Aug. 2007, pp.101‐106.[17.] H.B. Kekre, Archana Athawale, Archana Athawale,Uttara Athawale, “Information Hiding in AudioSignals”, International Journal of ComputerApplications IJCA, Vol. 7, No. 9,Foundation ofComputer Science, New York, USA, pp. 14‐19.[18.] B. Santhi, G. Radhika and S. Ruthra Reka,“Information Security using Audio Steganography‐ASurvey”, Research Journal of Applied Sciences,Engineering and Technology, Vol. 4, No. 14, pp. 2255‐2258.[19.] K. Kondo, “A Data Hiding Method for Stereo AudioSignals Using the Polarity of the Inter‐ChannelDecorrelator”,IEEEFifth International ConferenceonIntelligent Information Hiding and MultimediaSignal Processing,IIH‐MSP'09.12‐14 Sept. 2009,pp.86‐89.[20.] Rangarajan A. Vasudevan, Sugata Sanyal, AjithAbraham, Dharma P. Agrawal, “Jigsaw‐based securedata transfer over computer networks”, Proceedingsof International Conference onInformationTechnology: Coding and Computing,Las Vegas,Nevada,Vol. 1, 5‐7 April 2004, pp. 2‐ 6.[21.] Kamran Ahsan, Deepa Kundur, “Practical data hidingin TCP/IP”, Proceedings of ACM Workshop onMultimedia Security, Vol. 2002, pp. 7‐19.[22.] Steven J. Murdoch and Stephen Lewis, “Embeddingcovert channels into TCP/IP”, Information Hiding,Lecture Notes in Computer Science, vol. 3727,Springer Berlin / Heidelberg, 2005, pp. 247‐261.[23.] Sebastian Zander, Grenville Armitage, and PhilipBranch, “A survey of covert channels andcountermeasures in computer network protocols”,IEEE Communications Surveys & Tutorials, Vol. 9, No.3, 2007, pp. 44‐57.[24.] Wojciech Mazurczyk and Krzysztof Szczypiorski,“Steganography of VoIP streams”, On the Move toMeaningful Internet Systems,OTM 2008, Springer,Vol. 5332, pp. 1001‐1018.[25.] Yu Li, He‐xin Chen, Yan Zhao, “A new method of datahiding based on H.264 encoded video sequences”,IEEE 10th International Conference onSignalProcessing(ICSP), 24‐28 Oct. 2010, pp.1833‐1836.[26.] Xiaoyin Qi, Xiaoni Li, Mianshu Chen,Hexin Chen,“Research on CAVLC audio‐video synchronizationcoding approach based on H.264”,IEEEInternationalConference on Uncertainty Reasoning andKnowledge Engineering (URKE), Vol. 2, 4‐7 Aug. 2011,pp.123‐126.[27.] Mohammad Reza Abbasy, BharanidharanShanmugam, “Enabling Data Hiding for ResourceSharing in Cloud Computing Environments Based onDNA Sequences”, IEEE World Congress on Services(SERVICES), 4‐9 July 2011, pp. 385‐390.[28.] H.J. Shiu, K.L. Ng, J.F. Fang, R.C.T. Lee, C.H. Huang,“Data hiding methods based upon DNA sequences”,Information Sciences, Elsevier, Vol. 180, Issue 11, 1June 2010, pp. 2196‐2208.402012. Fascicule 3 [July–September]

1.Peter PENIAKCAN BASED APPLICATION PROTOCOLS FOR EMBEDDED DEVICES1.UNIVERSITY OF ŽILINA, FACULTY OF ELECTRICAL ENGINEERING, DEPARTMENT OF CONTROL AND INFORMATION SYSTEMS, ŽILINA, SLOVAKIAABSTRACT: Embedded systems are generally designed to perform the dedicated tasks with respect to device functions.Applications that are used in embedded systems are characterized by significant diversity with the different requirementsfor communication services. The interpretation of application data and control commands can be essentially different ininterconnected embedded subsystems. The paper deals with CAN based application protocols that can be used for aninterconnection of embedded devices via CAN fieldbus network. It is focused on selection of open application protocolsthat could be potentially used for device integration of different suppliers via CAN bus.KEYWORDS: CAN, CAL, CIP, ZAL, ZCL, APS, NWM, API, ODVA, CiAINTRODUCTIONEmbedded systems are generally designed to performthe dedicated tasks with respect to device functions.The small, computerized parts within a larger devicethen could serve for more general purpose andprovide variety of functions within overall subsystem.These devices can be implemented either asstandalone devices without necessity to interconnectwith the other systems, or have to cooperate in realtimeperformance constraints.Applications that are used in embedded systems arecharacterized by significant diversity with thedifferent requirements for communication services.The interpretation of application data and controlcommands can be essentially different ininterconnected embedded subsystems. Thereforeusing of the common open application protocols,which are independent on proprietary solutions of theparticular vendors, is a key factor for a success. Theparticular manufacturers tend to support variousopen communication protocols, such as CAN,DeviceNet, Ethernet/IP and ZigBee. Usually, there areno problems when using devices of the samemanufacturers for there is a good chance to use thesame applications and their proprietary applicationprotocols.An example of CAN as an internal interface forinterconnection of the embedded devices withinprinter subsystem is shown in Figure 1. The differentsubsystems are connected via CAN bus and cancooperate with using selected application protocol.Although CAN itself has not been used by all providersand we can still find a high technologicalheterogeneity in available products, due to itspopularity and widespread deployment in automotiveindustry, we will focus on the possible openapplication protocols for CAN based embeddedsystems.Figure 1. CAN internal interfacefor embedded printer subsystemsHowever, if there is a need to interconnect the devicesof various manufacturers, the problems can occurdespite using the same communication protocols. Avehicle control system can be used as a very goodexample as shown in Figure 2. CAN bus is very oftenimplemented as integration layer for the devices ofdifferent vendors so that they can be interconnectedwith car’s control system and on‐board computer.Although a common application protocol has to beselected for their full integration.Figure 2. Vehicle control system with CANCAN APPLICATION PROTOCOLSCAN application layer has to support implicit, explicitmessages and provide mapping of CAN identifiers tothe defined messages, or devices.© copyright FACULTY of ENGINEERING ‐ HUNEDOARA, ROMANIA 41

In addition, API (Application Programming Interface)is necessary for applications as well, providing thedefined device profiles and necessary applicationobjects. Device profiles and application objectsrepresent virtual model of the defined devices and areused to identify capabilities of devices, map physicalbehavior to the variables and access applicationobjects from applications.Implicit and explicit application protocol messageswith assigned CAN identifiers are encapsulated to theCAN frames and sent via CAN network. The networkarchitecture and structure of the common applicationlayer of CAN networks is shown in Table 1[1].Table 1. CAN application layerRM-OSI LayerAPI7 Implicitmessages(I/O)Network architecture(CAN based)Aplication objectsDevice profiles5, 6 (Encapsulation)432 CAN v.21 ISOExplicitmessages(I/O)The application protocols used for embedded deviceshave not been unified yet. Individual vendors still tryto use their proprietary architectures, however, thereis an effort to create alliances of producers, such asODVA, Fieldbus Foundation in order to promote acommon standard for application layer [2,3]. Thevendor independent standard CAL (CAN ApplicationLayer) is supported by association CiA (CAN inAutomation), while CIP (The Common IndustrialProtocol) protocol for industrial automationapplications is promoted by ODVA (Open DeviceNetAssociation).As an alternative solution, ZigBee protocols ZAL(ZigBee Application Layer)/ ZCL (ZigBee ClusterLibrary) that are used in mobile applications andwireless networks, could be used as a potentialsolution for future as well. However, there have beenno ZAL/ZCL implementations so far, except TCP/UDPencapsulation of ZAL/ZCL protocol messages [4].Typical CAN/CAL application protocols that can beused with the CAN link layer services are shown inTable 2 [1]. ZigBee protocols are added as well, as apotential solution for integration with mobile devices.Table 2. CAN based application protocolsRM-OSI LayerRM-OSI LayerCAN/CAL protocolsAPI CAL CIP ZAL/ZCL75, 6 (Encapsulation)432 CAN v.21 ISOACTA TECHNICA CORVINIENSIS – Bulletin of EngineeringCANOpen/CAL protocolCAL provides a vendor independent applicationprotocol for an object‐oriented environment, whichcan be used for the integration of the variousembedded devices. CAL protocol model is shown inTable 3.Table 3. CAL application protocolsLayerProtocolDevice profiles Profile A Profile B Profile C ………..7 CAL/CANopen (CiA)NMT DBT LMT CMS-2 CAN 2.01 CAN ISO 11898The protocol introduces a number of methods fortransmitting and receiving messages through the socalledcommunication objects. CAL uses the followingtypes of messages: AM (Administration Messages) SDM/SDO(Service Data Messages/Objects ) PDM / PDO (Process Data Messages / Objects) PM (Pre‐defined Messages)PDO object is used for exchange of the implicitmessages between applications. The objects arerepresented as variables, events (events), or dataareas (domains), which are mapped to thecorresponding PDO messages/objects in devicedirectory. Always, the transmission is initiated by theclient. SDO object is used for communication viaexplicit messages and supports communication inpeer‐to‐peer mode. It can be used for non‐fragmentedmessages with size 4B. Protocol is able to read andwrite data to object directory, transmit large volumesof data via fragmentation protocol.Assignment of CAN identifiers is a key factor in thenetwork architecture. CAN is able to control thepriority of messages and provides a common list ofidentifiers (Poll), which are dynamically allocated tothe end devices by object distributor (DMT). There isdedicated number of network identifiers (1260)available for objects (CMO) and only a small part isblocked for internal purpose.CAL provides centralized management with networkmanagement server NMT, which basic task is thesupervision of individual nodes in the network ("NMTGuarding"). NMT server maintains a list of activenodes and their status is periodically tested bymessage "Guard Request", as shown in Table 3. Deviceprofiles are used for modeling of various networkdevices. CAL defines a common network directory forobjects "Object Dictionary", in which every object isaddressable by 16‐bit index and 16‐bit sub‐index. Theremaining CAL sub‐protocols (DMT, CMS, LMT) will notbe mentioned [1].422012. Fascicule 3 [July–September]

ACTA TECHNICA CORVINIENSIS – Bulletin of EngineeringCIP PROTOCOLCIP is object‐oriented protocol for heterogeneousdevices and networks (CAN, ControlNet, Ethernet/IP).The object model is applied for applications (API), butalso in internal protocol architecture. It provides awide range of communication services for embeddeddevices and supports the specific requirements ofindustrial and control applications [1].CIP uses hierarchical model of communication anddevice addressing. Each device has assigned a uniqueidentifier called MAC address (MAC ID #). The nodesare connected to the sub‐networks interconnected tothe CIP domain. CIP domain is seen as a logical area inwhich all nodes can be interconnected. To supportspecific communication requirements, the differentdomains can be established with assignedcommunication mode for each group independently(peer‐to‐peer, master‐slave (cyclic), producerconsumer).There are two basic services: Explicit messages ‐for writing and reading of theobject attributes, connection settings and filetransfers Implicit Messaging – for exchange of /O processdata in real time.ZigBee APPLICATION PROTOCOL (ZAL)The ZAL protocol describes a set of structuredcommunication primitives for an exchange ofapplication data among mobile devices. ZAL protocolwas designed for wireless communication of mobiledevices via IEEE 802.15.4 link layer. The primary designgoal of the ZAL was to support wirelesscommunication of embedded systems, running onmicrocontrollers with limited amount of code, RAMand low network bandwidth. Therefore a compactlow‐traffic message format was developed withadditional services, such as a device binding, servicediscovery and security protocol.As a result, the ZigBee protocols became very popularand well‐suited for a structured communicationamong networked embedded systems. There is apossibility that ZAL could be used as a commonapplication protocol for CAN devices as well. Althoughthe ZigBee Application Layer was originally designedto operate only over IEEE 802.15.4 wireless networks[6], an adaptation of the ZigBee Application Layer forCAN bus is generally possible. Figure 5 illustrates thepossible use case. Mobile devices connected naturallyuse ZAL protocol for an internal communication viaZigBee. For a device integration, a dedicated gatewayhas to be used to link CAN devices with ZigBee ones. Inaddition, ZCL and APS (Application Support Sub‐layer)application protocols are to be supported in CANdevices in order to enable full interoperability of theembedded devices.Figure 3. CIP addressing of CAL objectsThe example of communication between twoembedded devices via CAN and protocol CIP isillustrated by Figure 4. The format of CIP explicitmessages is shown in Figure 10.CIP Explicit MessageIDDATA11 b 8 B0 GID S –MAC ID1 0 MAC ID GID1 1 GID S-MAC ID1 1 1 1 1 GIDGM GID MACID F XID MAC ID FT FC R/R SC A2 b 3 b 6 b 1 b 3 b 6 b 2 b 6 b 1 b nCIP headerIDGMGIDMAC IDS-MAC IDFTIDFTFCR/RSCAIdentifierGroup MessageGroup Message IDMAC addressS MAC addressFragment bitTransaction IDFragment TypeFragment CountRequest/ResponseService CodeArgumentsGroup 1Group 2Group 3Group 4Figure 4. Format of explicit CIP messagesFigure 5. Integration of WPAN (ZigBee) and CAN devicesThe integration approach has at least three majorparts: ZigBee/CAN gateway for network integration Encapsulation of ZCL/APS messages via CAN busprotocol Mapping of addresses to CAN‐ID identifiersFigure 6 shows a model of ZigBee/CAN gateway. Thegateway has physical interfaces for the both data linklayers (CAN 2.0, IEEE 802.15.4).In addition, the network layer protocol (NWM) isneeded for ZigBee devices [5]. Finally, the mainintegration is to be covered by an additionalapplication sub‐layer (7+). Z‐CAP protocol (ZigBee CANAdaptation Protocol), responsible for addressmapping and ZAL message encapsulation, is proposedto address the integration challenge.2012. Fascicule 3 [July–September] 43

The new protocol has to be implemented inZigBee/CAN gateway and each CAN node (Fig. 6 b).However, ZigBee devices do not require anyadaptation (Fig. 6 a).Figure 6. Protocol model of ZigBee/CAN integrationwith Z‐CAP protocolZ‐CAP protocol offers two major services. Firstly, themapping of ZigBee addresses to CAN‐IDs is to beimplemented. This process is based on Z‐CAP bindingtable with assigned pairs of addresses (ZigBee, CAN).ZigBee devices would communicate with CAN devicesas they would belong to ZigBee network. CANapplications would also use primarily ZigBeeaddresses. Z‐CAP protocol just translates addresses toCAN‐id and enables transfer of application messagesamong end nodes.Secondly, an encapsulation of ZAL/ASP messages viaCAN. Although an encapsulation is known technique,CAN propose very limited transport service with just8B data left for a payload. It means, we cannotencapsulate the complete ZCL/APS messages (~70B)within one CAN frame (8B). Instead, ZAL message hasto be divided to the several CAN frames and overalldata integrity is to be managed by a fragmentationprocedure. Z‐CAP protocol therefore offers 1B ofpayload for fragmentation to identify all CAN framesbelonging to 1 ZAL/ASP message (1B ‐ FR=fragment id +FRC=fragment offset), as shown in Figure 7.ACTA TECHNICA CORVINIENSIS – Bulletin of Engineeringon selection of open application protocols that couldbe used for integration of devices, with taking intoconsideration restriction to CAN link layer fortransport of application protocol packets/messages.Besides the standard application protocols such asCAL and CIP, there is a new challenge with ZibBeeapplication protocols that are much more popular andaccepted by various vendors for mobilecommunication (WPAN). Therefore therecommendation is to focus on encapsulation ofZibBee protocols (ZAL, ZCS) via CAN messages in thesame way as 6LoWPAN [RFC4944]. This would enablea simple integration with mobile embedded devicesand could simplify overall network architecture ofapplication layer for embedded devices.REFERENCES[1.] Franeková, M.‐ Kállay, F.‐ Peniak, P. Vestenický, P.(2007): Komunikačná bezpečnosť priemyselných sietí.ŽU Žilina, ISBN 978‐80‐8070‐715‐6 1.[2.] Mahalik, N. P (2003).: Fieldbus technology, Industrialnetwork standard for Real – Time Distributed Control,Springer, 2003[3.] Kállay, F.‐ Peniak, P. (2003): Počítačové sítě LAN MANWAN a jejich aplikace. Monografia, Grada Publishing2003, ISBN 80‐247‐0545‐1[4.] Tolle G.(2008): A UDP/IP Adaptation of the ZigBeeApplication Protocol, October 2008, [WWW],http://tools.ietf.org/html/draft‐tolle‐cap‐00[5.] ZigBee specification, ZigBee alliance, January 17 2008,http://www.zigbee.org/Products/TechnicalDocumentsDownload/tabid/237/Default.aspx[6.] IEEE 802 working group, Part 15.4: Wireless MediumAccess Control (MAC) and Physical Layer (PHY),Specifications for Low‐Rate Wireless Personal AreaNetworks (WPANs), IEEE Computer Society, Standardspecification,http://standards.ieee.org/getieee802/download/802.15.4‐2006.pdfACTA TECHNICA CORVINIENSIS – BULLETIN of ENGINEERINGFigure 7. Encapsulation/Fragmentationof ZCL/APS messages via CANCONCLUSIONSThe paper dealt with CAN based application protocolsthat can be used for an interconnection of embeddeddevices via CAN fieldbus network. The main focus wasISSN: 2067‐3809 [CD‐Rom, online]copyright © UNIVERSITY POLITEHNICA TIMISOARA,FACULTY OF ENGINEERING HUNEDOARA,5, REVOLUTIEI, 331128, HUNEDOARA, ROMANIAhttp://acta.fih.upt.ro442012. Fascicule 3 [July–September]

INVESTIGATION OF THE REFRIGERANTS CHARACTERISTICS INVAPOR COMPRESSION SYSTEMS1.Róbert SÁNTA1.COLLEGE OF APPLIED SCIENCES – SUBOTICA TECH/ DEPARTMENT OF ENERGY AND ENVIRONMENT, MARKA ORESKOVICA 16, 24000 SUBOTICA,SERBIAABSTRACT: The energy efficiency improvement of the refrigeration system to improve the operation quality makes itunavoidable to strive for the refrigeration system operation. Nevertheless, the processes taking place in it should be asaccurate as possible to describe the underlying physical and mathematical model development and refinement. Theexperimental investigation of any refrigeration system is usually very complicated, mainly due to the financial costs and thelarge number of variables involved. The use of numerical models can reduce the costs and also facilitate understanding thephenomena related to the problem. The article aims to present and analyze the behavior components of the vaporcompressionrefrigeration system in case of various refrigerants. Refrigerants included in the present analysis areR22/R134a/R407C/R410A. The simulation program is based upon steady state mathematical models of the refrigerationcircuit including the compressor, heat exchangers and thermostatic expansion valve. The simulation results have beenpresented in a graphic.KEYWORDS: Refrigeration system, Refrigeration, Mathematical model, Simulation, COPINTRODUCTIONThe European Commission accepts a proposal package[1] of future indicators at the beginning of 2008. Theaim of this is to decrease the rapidly increasinggreenhouse gas emissions based on the 2007 data.Furthermore to increase the renewable energysources in the total energy consumption in theproportion of 20% by the year 2020.The utilization of renewable energy sources isinfluenced by several factors. Besides the naturalenvironment, the economic conditions are also majorfactors affecting the case of renewable energies. Thefossil fuel prices and conditions of other energy costsare significantly determined by the demand forrenewable as well as the amount of state aid andgovernment fiscal policy application.The energy efficiency improvement of therefrigeration system to improve the operation qualitymakes it unavoidable to strive for the refrigerationsystem operation. Nevertheless, the processes takingplace in it should be as accurate as possible to describethe underlying physical and mathematical modeldevelopment and refinement.In addition to the structural design and dimensions ofcomponents of the refigeration system, therefrigerant is also a major influencing factor. Therefrigerant disposes of a lot of thermodynamiccharacteristics which differ among themselvessubstantially. The thermodynamic characteristics aremajor contributors to the suitable choice ofrefrigerant, the choice of components of therefrigeration and cooling system, the refrigerant maybe necessary when replacing.The experimental investigation of any refrigerationsystem is usually very complicated, mainly due to thefinancial costs and the large number of variablesinvolved. The use of numerical models can reduce thecosts and also facilitate understanding thephenomena related to the problem.Many researchers dealt with the description of thesteady state behavior of a vapor compressionrefrigeration system such as Koury et al. [2] proposeda model for a refrigeration system with distributedparameter model for heat exchanger, Jong Won Choiet al.[3], Bellman et al.[4], Yang Zhao et al.[5] and S. A.Klein et al.[6].DESCRIPTION OF PHYSICAL SYSTEMThe vapor‐compression refrigeration cycles consists ofthe four main components: evaporator, compressor,condenser and expansion valves. The refrigerant is theworking fluid of the refrigeration system.Figure 1. Energy flow diagram of the refrigeration systemIn the evaporator, the refrigerant takes over the heatfrom the low‐temperature primary fluid byvaporization. In the evaporator, the refrigerant issuperheated and vapor is sucked in by compressor.With the invested mechanical work, it is broughthigher level of energy. On the discharge side of the© copyright FACULTY of ENGINEERING ‐ HUNEDOARA, ROMANIA 45

compressor, the now hot and highly pressurized vaporis cooled in the condenser.In the condenser, vapor provides the heat to thesecondary fluid and then the refrigeration condenses.Condensation in horizontal tubes may involve partialor total condensation of the vapor. Depending on theapplication, the inlet vapor may be superheated, equalto 1.0 or below 1.0.Superheated vapor enters the horizontal tube, whichhas a temperature below the saturation temperatureof the vapor. The flow at this point in the tube issingle‐phase vapor flow. After the vapor cools andbecomes saturated, condensation starts to occur onthe inner wall of the tube.Near the outlet of the horizontal tube, the vaporquality reduces to zero and the flow in the tubebecomes single‐phase liquid flow.The condensed refrigerant then passes through apressure‐lowering expansion device.The expansion device is to reduce the pressure and toregulate the refrigerant mass flow rate. The widelyutilized expansion device is the thermostaticexpansion valves. The thermostatic expansion is avalve for controlling the refrigerant flow by a sensorbulb placed in the evaporator discharge line and hencecontrols the mass rate by the degree of superheat.The low pressure, refrigerant leaving the expansiondevice enters the evaporator, in which the refrigerantabsorbs heat and boils. The refrigerant then returns tothe compressor and the cycle is repeated.The observed heat exchangers are counter‐cross flow,shell and tube type. Tubes are made of copper andhave a staggered layout. In the current case, therefrigerant flows through in finned tube bundle ofheat exchangers, while primary and secondary fluidflow in the shell across the tube bundle.In this case, the compression occurs on the principle ofdisplacement reciprocating compressor. While thethrottle is isenthalpic and occurs with variable crosssectionof expansion valve.MATHEMATICAL MODEL OF REFRIGERATION SYSTEM. HeatexchangersThe evaporation and the condenser are approached ina similar manner from the modeling point of view.Both are divided into regions associated to the phaseof the refrigerant.In the case of the condenser the superheated vapor,and the condensation are considered, whereas theevaporator is divided into the evaporating aresuperheated vapor regions.For the each region, the overall heat transfercoefficients is evaluated by assuming that thermalresistance due to wall conduction, contact and foulingare negligibly small.Heat exchanger energy balances:Water sideQ = m ⋅ ⋅c pw ⋅ΔT w(1)Refrigerant sideCondensing region46Q = ⋅ ⋅Δ(2)mref i lvACTA TECHNICA CORVINIENSIS – Bulletin of EngineeringEvaporating regionQSingle phase regions( i −i)= m⋅ ref⋅v i(3)Q = m⋅ ref⋅cpref⋅ΔTref(4)Overall Heat ExchangersQ = A⋅U⋅LMTD(5)CondenserQ C = Qdesuperheated+ Qcondensing(6)EvaporatorQ o= Qevaporating+ Qdesuperheating(7)LMTD is the logarithmic mean temperature differencedefined by:ΔT2− ΔT1LMTD = (8)ΔT2lnΔT1The heat transfer correlation can be written as:1 Ao 1= +(9)U Ai⋅αwηo⋅αrWhere is the finned heat transfer surface effiencygiven by the well known correlation:⎛ Af⎞ηo = 1−⎜ ⋅( 1−ηf)A⎟(10)⎝ o ⎠The heat transfer coefficient of single‐phaserefrigerant vapor was calculated by the Dittus‐Boeltercorrelation [7]αvap⋅di⎛ G⋅dcin⎞ ⎛ μ ⋅ p ⎞= 0.023⋅⎜⎟ ⋅⎜⎟ (11)λ ⎝ μ ⎠ ⎝ λ ⎠Water‐side heat transfer coefficient for staggeredhorizontal tubes is given by [7]αw⋅dcout⎛ G⋅dout⎞ ⎛ μ ⋅ p ⎞= C ⋅⎜⎟ ⋅⎜⎟λ ⎝ μ ⎠ ⎝ λ ⎠(12)Kandlikar correlation [8] was used for the predictionof the heat transfer coefficient in flow boiling. Thefinal correlation consists of two sets of constants. Onefor the convective evaporation dominated regime andthe other for the nucleate boiling dominated regime.The correlation is:Cα ( C ( Co) C2( 25 Fr )C5C ( Bo)4kf =α f ⋅ 1 ⋅ ⋅ ⋅ f + 3 ⋅ ⋅Fn)(13)and the constants are given in the table below.Table 1: Constants in Kandlikar (1990) correlationconstant Convective evaporation Nucleate boilingC 1 1.1360 0.6683C 2 ‐0.9 ‐0.2C 3 667.2 1058C 4 0.7 0.7C 5 0.3 0.3The correlation is calculated twice using each set ofconstants and the greater of the two values is used asthe heat transfer coefficient.α = maxααc(14)For the two phase regions, in the condenser, Shahcorrelation [9] was selected to proposed heat transfercoefficient. The Shah correlation is a modified versiontp n,0.80.60.330.332012. Fascicule 3 [July–September]

ACTA TECHNICA CORVINIENSIS – Bulletin of Engineeringof Dittus‐Boelter single‐phase heat transfercorrelation. The two‐phase model the reducedpressure refrigerant takes into account.0.76 0.04⎡0.8 3.8⋅x⋅( )( 1−x)⎤α kf = α f ⋅⎢1−x +*0. 38 ⎥ (15)⎣p ⎦Where the reduced pressure is:∗p =pp critIn Eqs. (11) the single phase heat transfer coefficientsare determined by the Dittus‐Boelter correlation.Compressor modelRefrigerant mass flow rate through the compressor isa function of compression ratio, refrigerant densityand compressor speed, that is,. ⎛ p ⎞⎜cm = f , ρ sz , N⎟(16)⎝ pe⎠The relationship between compressor exit and inlettemperatures is given by:k−1⎡ ⎤⎢⎛p ⎞ knyT⎥ny = Tsz⋅⎢⎜⎟ − 1⎥(17)⎢⎝psz⎠⎣ ⎥⎦Neglecting the thermal inertia effects, the indicatedwork is given by:k−1⎡ ⎤k ⎢⎛p ⎞ knyW = ⋅p⎥sz ⋅vsz⋅⎢⎜⎟ − 1k − 1⎥(18)⎢⎝psz⎠⎣ ⎥⎦Isentropic effiencies [10] is correlated as a function ofthe pressure ratio between condensation pressureand evaporation pressure.2η = A +⋅B⋅τ+ C ⋅τ(19)where A, B and C are the regression coefficients.THERMOSTATIC EXPANSION VALVE MODEL AND REFRIGERANTThermostatic expansion valve is the valve thatcontrols the refrigerants mass flow rate by sensing thedegree of suction vapor superheat temperature. Theenthalpy is assumed to be constant. The refrigerantmass flow is calculated by the following equation.( p − p )m = C ⋅ 2ρ ⋅(20)where C is the characteristic constant of the valve.The refrigerants used in this study are the R22, R134a,R407C, R410A. Calculation of the refrigerants andtransport properties is performed by correlationswritten as computer code function, usingthermodynamic properties coming from SOLKANEdatabase [11]. The effect of the circulation of oil is nottaken into account in the model.INITIAL CONDITION AND VALUESThe mathematical models are simulated by the use ofthe software tool Solkane.The initial conditions and values for the simulation: Refrigerant: R22, R134a, R407C, R410A Refrigerating capacity: Q = 2kWo Temperature of evaporator: T o = 0 C Pressure drop in evaporator: Δ p =0.4bar Superheating temperature: Δ T = 5Kce Temperature of condenser: T c = 45 C Pressure drop in condenser: Δ p = 0.1bar Isentropic efficiency of compressor: η =0. 8SIMULATION RESULT AND DISCUSSIONRefrigerants:Figure 2. The coefficient of performance of the refrigeratorRefrigerantsFigure 3. Performance of the compressorRefrigerants:Figure 4. Specific latent heat of the refrigerantsRefrigerants:Figure 5. Volume capacity of the refrigerantsRefrigerants:Figure 6.Volume flow of the refrigerantsRefrigerants:Figure 8. Pressure differenceo2012. Fascicule 3 [July–September] 47

Figure 7. Pressure ratio of evaporator & condenser pressure48Figure 9. Discharge temperatureFigure 11. Inlet temperature of refrigerant in evaporatorFigure 10. Discharge pressureRefrigerantsRefrigerants:Refrigerants:Refrigerants:Refrigerants:Figure 12. Inlet pressure of refrigerant in evaporatorCONCLUSIONS The performance coefficient of the vaporrefrigerant system of the refrigerant R22 is thehighest of the investigated refrigerants since thisone possesses the smallest refrigerant compressorpower requirement and its latent heat is high.However, the applicability of the R22 refrigerant isof finite time, since it contains Cl its release isceased until 2010, so it can be stated that R134arefrigerant dispose the best properties in terms ofefficiency. Too high pressure is not favorable in the operationprocess of the equipment.The high partial pressurefrom the aspects of strength is unfavorable, itACTA TECHNICA CORVINIENSIS – Bulletin of Engineeringrequires wall thickness contributing in costsincrease. The pressure ratio in the condenser and theevaporator resulting positively of the pistoncompressors, while of the centrifugal compressorsthe small pressure difference between partialpressure is positive. The increase of pressure ratioin the piston compressor reduces volumetricefficiency of the compressor. When using reciprocating compressors it isadvantageous if the volumetric capacity is highbecause that way the transportable volumetricflow and thus the machine sizes decrease. In theprocesses of turbo‐compressors the highvolumetric flow, low volumetric capacity isespecially favorable. In the heat exchanger, the heat transfer isfavorable, if the thermal conductivity coefficient ishigh,while the vapor,the liquid viscosity andsurface tension of refrigerant is low. The refrigerant that meets all the requirementsfully is non‐existent. In each case the conditionsand requirements must be examined in order tochoose the most suitable and favorable refrigerant.REFERENCES[1.] Combating climate change The EU leads the way 2008Edition, Catalogue number: NA‐AB‐08‐128‐EN‐C.[2.] R.N.N. Koury, L. Machado, K.A.R. Ismail: Numericalsimulation of a variable speed refrigeration system,International Journal of Refrigeration 24 (2001) 192‐200, PII: S0140‐7007(00)00014‐1.[3.] Jong Won Choi, Gilbong Lee, Min Soo Kim: Numericalstudy on the steady state and transient performanceof a multi‐type heat pump system, InternationalJournal of Refrigeration 34 (2011) 1157‐1172,doi:10.1016/j.ijrefrig.2010.09.021.[4.] Belman, J. M., Navarro‐Esbrí, J., Ginestar, D. and MilianV., Steady‐state model of a variable speed vaporcompression system using R134a as working fluid.International Journal of Energy Research, 34: 933–945.(2010) doi: 10.1002/er.1606.[5.] Yang Zhao, Zhao Haibo, Fang Zheng: Modeling anddynamic control simulation of unitary gas engine heatpump, Energy Conversion and Management 48 (2007)3146‐3153,[6.] S. A. Klein, D. T. Reindl, and K. Brownell, RefrigerationSystem Performance using Liquid‐Suction HeatExchangers, International Journal of Refrigeration,Vol. 23, Part 8, pp. 588‐596 (2000).[7.] John R. Thome, Engineering Data Book III, Single‐PhaseShell‐Side Flows and Heat Transfer, Chapter 3, SwissFederal Institute of Technology Lausanne CH‐1015Lausanne, 2004, Switzerland.[8.] Satish G. Kandlikar, Heat transfer and fluid low inminichannels and microchannels, MechanicalEngineering Department, Rochester Institute ofTechnology, Elsevier Science (2005), ISBN: 0‐0804‐4527‐6 , USA.[9.] M.M. Shah. A general correlation for heat transferduring film condensation in tubes. InternationalJournal of Heat and Mass Transfer, 22(4):547–556,1979.[10.] Verein Detscher Ingenieure VDI – Warmeatlas (VDIHeat Atlas), Chapter HBB, VDI – GesellschaftVerfahrrenstechnik und Chemieingenieurwesen (GVC),Düsseldorf, 1993.[11.] Solvay Chemicals Rue de Ransbeek 310 –1120 Bruxelles– Belgium2012. Fascicule 3 [July–September]

1.Sorina ŞERBANANALYSIS AND DESIGN OF INFORMATION SYSTEMS1.UNIVERSITY POLITEHNICA TIMISOARA, FACULTY OF ENGINEERING HUNEDOARA, HUNEDOARA, ROMANIAABSTRACT: Systems analysis and design work in chemistry is the result of a complex application called ChimUniv in thecreation and operation of relational databases, the implementation of applications dedicated to Chemistry. The paper isaddressed to students and all those who want to build applications using the skills and habits of Chemistry, MicrosoftAccess solution to offer. Fundamental theoretical notions database are missing from the scientific approach of this paper.In this paper we intend to highlight issues concerning the organization of elements in the periodic table, arranging them ingroups and periods depending on their chemical properties.KEYWORDS: applications, implementation, information system, computer system, databaseINTRODUCTIONIn our everyday life, computers are commonplace andeven essential in some cases. One could say rightlythat we live in a computerized society. It should benoted that computer is actually a machine thatprocesses a series of information that we give them.Information is an essential element in this entire chain.In fact, in practice meet, among others, two relatedconcepts, namely the information system andcomputer system.The information system includes all elements involvedin the collection, transmission, processing, etc..information, so the role of information system is totransmit information.The set of all elements involved in the process ofprocessing and transmitting data electronically makeup a computer system. In a computer system can get:computer, data transmission systems, otherhardware, software, data processing, etc..It can be said therefore that the information system isincluded in the computer system, the latter being anessential component of the first.In the last fifty years, the production and use ofcomputer ‐ hardware and software ‐ has grownbeyond imagination. With the emergence ofcomputers, programmers have the ability to designproducts faster and cheaper software for datamaintenance and distribution.The model used for data storage is a relationaldatabase. In database systems, data defining separateapplication programs, users saw only the externaldefinition of an object, without knowing how it isdefined and how it works.In this way, the definition of the object can bechanged without affecting its users if it does notchange the external definition. For example, if you arenew or changed data of Structural existing ones,where application programs are not affected, if notdirectly dependent on what is changing.In databases there is a data query, meaning that morefiles are seen as a whole, eliminating redundantinformation as possible. It also allows simultaneousaccess to the same data, located in the same place ormore spatially distributed users, each with personalwork style. Software system that allows theconstruction of databases, input information intodatabases called management system database. [4]A management system database enables a user toaccess data using a high‐level language close to theusual way of expression, to obtain information,making abstraction of user selection algorithms applythe data involved and mode of storage them. DBMS isan interface between operating system users.Access is a special type of database called RelationalDatabase. A relational database shares information indistinct subsets. Each subset groups the informationon a particular topic. In Access, these subsets of dataresiding in individual tables. Access allows us to createrelationships between tables. These relationships arebased on a common field in two tables.When you create a database, we want to make surethat it is designed not only to meet our requirementsrelated to data entry, but corresponds to viewing andreporting requirements of the data stored in varioustables that form the database.APPLICATION SUBMISSIONOne of the features is an information explosion inrecent years. Huge volume of information can not beused effectively through traditional methods.Automatic processing of information using electroniccomputing systems has become a necessity for allfields. Thus, the most advanced method of organizinginformation for a meeting of automatic processingdatabases.Figure 1. Relationships between tables© copyright FACULTY of ENGINEERING ‐ HUNEDOARA, ROMANIA 49

Physical data model (MFD) is obtained by the logicalrepresentation of data in a data description languageclosely related to a DBMS, in this case Access. [4].Basically, he will use the physical data model in orderto ensure a consistent processing cycle consists mainlyof operations for creating, updating, mining, printing,reorganization, rescue, protection.ChimUniv database application shows the followingstructure:The objective is to create operating interface of thedatabase. After creating database, tables andestablishing relationships between tables, thedatabase is:ACTA TECHNICA CORVINIENSIS – Bulletin of EngineeringFigure 5. Base structureTHE STRUCTURE ANALYSESpeaking at the click of a button, it will open forms.For most forms I used background images can addthem using the forms properties window. Thus, theownership Pictures give the file path will be thewallpaper, choose an embedded type (encapsulated),for it was not dependent on whether the image onthat computer's hard disk, but to one embedded inour database And the forms are larger than the imagestretch instead choose Clip property, because theimage to expand across the entire form.Figure 2. Performance AnalyzerThe data elements contained in the table followingform:Figure 3. Table ELEMENTSIt then creates forms. Forms are an effective way fordisplaying, entering and editing information in thedatabase. You can create interactive forms of tables.Home ELEMENT query query is used as shown below:Figure 6. Periodic System FormPeriodic System form is made up of several buttonsthat we have the name and symbol of each element inthe periodic table. The action on each of the buttonswill open a form, the same for all buttons, open a formelement, they will be displayed all the properties ofelements. We notice the existence and Structure ofthe image, which is an OLE object in our database.Figure 4. Query ELEMENTThis query is used to implement sufficiently detailedform that describes the main features of a chemicalelement. Parameter is the item for which we want tomake the description. The use of this query do asdescribed below.Queries allow us to manipulate data in databasetables. Queries are questions of fact. We use queriesto get the answers we need, from informationcontained in the database.50Figure 7. Form ElementsElectronic Configuration button opens a form where itshows the electronic shell structure for each elementby simply selecting the desired item from the list.2012. Fascicule 3 [July–September]

ACTA TECHNICA CORVINIENSIS – Bulletin of EngineeringFigure 8. Electronic Configuration FormThe graphics button actuation, opens the graphics arepresented and described the chemical properties involute depending on atomic number of each chemicalelement. Observe the right of the form features of thisproperty, which has corresponding text field in a tablecolumn of type memo Charts.Figure 12. Shape variation of boiling point depending on theatomic numberFigure 9. Shape variation dependingon the atomic number densityFigure 13. Shape variation of the melting temperatureaccording to atomic numberAs can be seen and buttons representing metals,alkaline earth metals, transition metals, rare gases,which are forms representing the OLE object type.Figure10. Shape variation dependingon the number of atomic electronegativityFigure 11. Shape variation of ionization energyaccording to atomic numberFigure 14. Forms for submission of metals and nonmetalsAfter achieving the necessary components of ourdatabase, integrate applications in a project using theApplication Wizard. It can automatically generate anapplication project via File / New / Project / Wizard,executing the following steps:1. has created a new directory;2. or copied files on the project ChimUniv;3. wizard to launch the Application Wizard4. or defined project attributes.2012. Fascicule 3 [July–September] 51

The new project which now includes all formsgenerated, so that will be generated and tested theapplication executable. [1]CONCLUSIONSThe study computer applications to achieve this, wecan say that the use of databases in education can be atool more attractive to users, this computer inteaching‐learning process causing us to find solutionsand modern interactive approach to class. Made usingas an example I tried to demonstrate effectiveimplementation of computers in teaching certainsubjects. Using databases leads to increasedcompetence and creativity, to growth and higheraverage educational attainment, the increased use ofinformation technologies in different fields. [3]REFERENCES[1.] Ionel MUSCALAGIU, Teodora PETRAŞ, DATABASEVisual FoxPro DBMS software, Mirton PublishingHouse, Timisoara 2002[2.] DRĂGĂNESCU, Mihai, Computers and Society,Technical Publishing House, Bucharest 1986[3.] ADĂSCĂLIȚEI A., Computer Assisted Training, IAC.Multimedia Information Systems Design, Internetsource http://www.ee.tuiasi.ro/~aadascal/[4.] Eduard KOLLER, Monica ROŞCULEȚ, Programming inAccess 97 , Theory, Bucharest 2002[5.] S. ŞERBAN, Computer Training in Chemistry: Strengthsand Weaknesses, ACTA TECHNICA CORVINIENSIS –Bulletin of Engineering – Fascicule 2 – Tome III – 2010.[6.] S. ŞERBAN, Educational soft for chemistry, ANNALS OFTHE FACULTY OF ENGINEERING HUNEDOARA, 2006,Tome IV, Fascicule 3[7.] Grupul BDSEIG, Baze de date. Fundamente teoretice şipractice, Editura InfoMega, 2001[8.] Thomas CONNOLLY, Carolyn BEGG, Anne STRACHAN –Baze de date. Proiectare. Implementare. Gestionare,Editura TEORA, 2001[9.] M.D. POPOVICI, Virtual Reality: Technologycomponents, Politehnica University, Bucureşti, 2002[10.] Sorina ŞERBAN, Vasile ALEXA, About the concept ofeducational software and the implementation in theUniversity educational System, 1 st Regional Conference‐ Mechatronics in Practice and Education MECH ‐ CONF2011, Subotica, SERBIA, 357‐362[11.] Vasile ALEXA, Imre KISS, Sorin Aurel RATIU, VasileGeorge CIOATĂ, E‐Learning Practice in Performing theLaboratory Works Specific to the Pneumatic Drives, 1 stACTA TECHNICA CORVINIENSIS – Bulletin of EngineeringRegional Conference ‐ Mechatronics in Practice andEducation MECH ‐ CONF 2011, Subotica, SERBIA, 34‐38[12.] Sorin Aurel RATIU, Vasile ALEXA, Imre KISS, AnaJOSAN, Virtual Didactic Laboratory for the InteractiveStudy of an Internal Combustion Engine ManagementSystem, 1 st Regional Conference ‐ Mechatronics inPractice and Education MECH ‐ CONF 2011, Subotica,SERBIA, 316‐320[13.] I. CERGHIT, Teaching methods, Polirom PublishingHouse, Iaşi, 2006[14.] I. JINGA, E. ISTRATE, Training and computer‐assistedassessment, ALL Publishing House, Bucuresti, 2006[15.] F. MOLDOVEANU, Z. RACOVITA, S. PETRESCU, G. HERA,Computer graphics, Teora Publishing House, 1996[16.] B. J. REISER, I. TABAK, W. A. SANDOVAL, B. SMITH, F.STEINMULLER, T. J. LEONE: BGuILE – Stategic andConceptual Scaffolds for Scientific Inquiry in BiologyClassrooms, Cognition and Instruction: Twenty fiveyears of progress, Mahvah, NJ: Erlbaum, 2001[17.] BAEK, Young K., LAYNE, Benjamin H., Color, graphics,and animation in a computer‐assisted learning tutoriallesson, Journal of Computer‐Based Instruction, Vol15(4), 1988, 131‐135[18.] Roger P. GLADWIN, Don MARGERISON, Steve M.WALKER, Computer‐assisted learning in chemistry,Computers & Education, 19, I1–2, 1992, 17‐25[19.] I.D. BENEST, Computer‐Assisted Learning usingdynamic electronic books, Computers & Education, 15,1–3, 1990, 195‐203[20.] A. JONES, E. SCANLON, C. TOSUNOGLU, E. MORRIS, S.ROSS, P. BUTCHER, J. GREENBERG, Contexts forevaluating educational software, Interacting withComputers, 11, 5, 1999, 499‐516[21.] Dee BALDWIN, Joyce JOHNSON, Peggy HILL, Studentsatisfaction with classroom use of computer‐assistedinstruction, Nursing Outlook, 42, 4, 1994, 188‐192[22.] Hossein MAHDIZADEH, Harm BIEMANS, MartinMULDER, Determining factors of the use of e‐learningenvironments by university teachers, Computers &Education, 51, 1, 2008, 142‐154[23.] ROŞCA, Ioan Gh., ZAMFIR, Gabriel, APOSTOL,Constantin‐Gelu; BODEA, Constanța‐Nicoleta,Informatica instruirii, Editura Economică, Bucureşti,2002[24.] ZAMFIR, Gabriel, Integrarea aplicațiilor în instruireaasistată, Editura Economică, Bucureşti, 2001ACTA TECHNICA CORVINIENSIS – BULLETIN of ENGINEERINGISSN: 2067‐3809 [CD‐Rom, online]copyright © UNIVERSITY POLITEHNICA TIMISOARA,FACULTY OF ENGINEERING HUNEDOARA,5, REVOLUTIEI, 331128, HUNEDOARA, ROMANIAhttp://acta.fih.upt.ro522012. Fascicule 3 [July–September]

1.László SZABÓ, 2. Rudolf SZABÓTHE CARBON AGE – CHARACTERISTICS OF THE CARBON FIBERS1‐2. ENVIRONMENTAL PROTECTION ENGINEERING INSTITUTE, REJTŐ SÁNDOR FACULTY OF LIGHT INDUSTRY AND ENVIRONMENTAL PROTECTIONENGINEERING, ÓBUDA UNIVERSITY,1034 BUDAPEST, DOBERDÓ U. 6, HUNGARYABSTRACT: In the various areas, quantities of the materials and goods used by mankind show rapid growth, whereas its form,rate of use is significantly varying. Today requirements and expectations concerning the various materials are wide ranging,so the properties of these materials are developed in accordance to the demands. Presently the carbon fiber is being usedmore and more frequently in those areas which require special demands. This is explainable by its outstanding properties,namely high tenacity, stiffness, low heat dilation, conductivity etc. From composites, lightweight structures may beproduced to meet higher level applications. Carbon fiber reinforced composites – in the areas demanding high mechanicalusage, will be of determining importance in the future.KEYWORDS: carbon fiber fabrication, properties, applicationINTRODUCTIONPresently Carbon Fiber is being used more and morefrequently in those areas which require specialdemands. This is explainable by its outstandingproperties, namely, (high tenacity, stiffness, low heatdilation, conductivity etc.). Carbon Fiber is rigid,brittle and because of this, its processing requiresparticular care, special handling. With thedevelopment of the manufacturing, and processingtechnologies and the decrease of its price, carbonfibers expectedly and in the future will play a key rolein the field of high demanding composites.DISCUSSIONSIn the various areas, quantities of the materials andgoods used by mankind show rapid growth, whereasits form, rate of use is significantly varying (Figure 1).In the second half of the 20 th Century, concerning thehigh ratio of metal usage, a change and shift towardspolymers, composites and ceramics can be observed,and their usage is increasing significantly. Todayrequirements and expectations concerning the variousmaterials are wide ranging, so the properties of thesematerials are developed in accordance to thedemands.sources for research are readily available. Demandsare emerging in more and more areas for using thethusly developed materials and structures, and withthe further development of processing technologies,along with mass production, their prices aredecreasing making them available for use in a widerange.In 1879, Edison made the first Carbon Fiber bycarbonizing bamboo fiber to use it as incandescentfilament in light bulbs. Carbon Fiber, because of itsexcellent properties and high price was first made inthe 1960’s from regenerated fibers, and then bycarbonizing PAN fiber. It began to be applied in theAerospace industry. This was followed by theexpensive and valuable sport goods, and currentlymachinery parts (Figure 2).Figure 1. Relative importance of material developmentthrough historyIn the development of new materials, a decisive role isplayed by Space Research and the Military Industry inwhich for developing special material properties, theFigure 2. Trend and forecast in carbon fibres shipmentFrom composites, lightweight structures may beproduced to meet higher level applications. Themechanical properties of fibers, textiles used forreinforcing composites, related to weight arecharacterized by high tenacity, low elongation andhigh elasticity modulus. Amongst the plasticreinforcementfibrous materials, the properties ofcarbon fiber „Black Magic” are especially outstanding.Carbon fiber reinforced composites – in the areasdemanding high mechanical usage, will be ofdetermining importance in the future (Figure3).© copyright FACULTY of ENGINEERING ‐ HUNEDOARA, ROMANIA 53

Figure 3. Materials evolutionThe properties and price of carbon fibers alsoencompass a broad territory. With the pricedecreasing of the higher filament numbered (higherthan 24K), carbon tows produced for commercialusage, the greater volume and the wider industrialusage came to prominence and this tendency,expectedly, will continue.The Carbon Fiber is made mostly (approx; 95 %) from asynthetic fiber well known in the textile industry,namely PAN (Polyacrylonitrile), and it is so calledprecursor fiber (Figure 4), whereas the raw material ofthe remaining 5 % is either tar or regenerated fibers.ACTA TECHNICA CORVINIENSIS – Bulletin of Engineeringfrom the fiber, while its chemical structure changes.The OPAN fiber (approximate with 62% of carboncontent) formed after oxidation, becomes a textilematerial having excellent heat, flame and fire resistantproperties, which after various textile industryoperations (Stretch ‐ Breaking, Carding, Spinning,Weaving, Knitting, or in Tow / Staple fiber form usingnon‐woven methods) may be further processed.Products’ made from OPAN do not melt, have a highLOI value (40‐60), its heat resistance is above (300 ⁰C),and because of this, they are mainly used in areaswhere heat, fire resistance, heat insulation (weldingblankets, protective clothing, etc.) is required. Duringthe oxidation process, a crust forms on the surface ofthe OPAN fiber, and because of this, its loop tenacity islow (8‐15% of the tensile strength), thusly the fiber isbrittle. By increasing of the temperature andprocessing time, the density of OPAN fiber (ρ=1.35‐1.42g/cm³) can also be increased, and with this, heatresistance of the material can be augmented, but thefiber will be more rigid. Although OPAN and carbonfibers are both black, their other properties arebasically different (Figure 6.).Figure 4. Manufacturing processof carbon fibers (PAN‐based)The PAN precursor based oxidized fiber (OPAN),carbon and graphite fiber production process is welldepicted in Figure 5.Figure 6. Properties of OPAN and carbon fibersOPAN products processed by textile industry methodsand then carbonized can be used in a variety of uniqueapplications.In the hydrogen driven electrical transformer, thecarbon membrane allows the protons to pass throughwhile by separating the electrons, electric current isgenerated.In the case of sodium‐sulphur electrical energy storing,the sulphur is stored in the carbonized OPANmembrane sponge.In the C‐C composite technology, the thick felt madefrom OPAN is carbonized at high temperature and theC is diffused into the material. From the thuslycreated, compact structured CandC compositematerial, high temperature 1000 ⁰C bearing, aircraftand racing car brake discs and brake pads are made.In the manufacturing of carbon fiber, by leading thepre‐tensioned fibers exiting from the oxidation oveninto high temperature (800‐1500 ⁰C) nitrogen gasblanketed ovens, the structure of the carbon fiber isformed (Figure 7).Figure 5. The oxidation, carbonizationand graphitisation processThe OPAN fiber is produced by oxidizing themoderately stretched PAN fiber at 220‐250 ⁰C. In theprocess of the oxidation, taking several hours, most ofthe burnable gases and toxic materials are exhausted54Figure 7. Structure of carbon fiber2012. Fascicule 3 [July–September]

ACTA TECHNICA CORVINIENSIS – Bulletin of EngineeringTo forward chemical bonding with the matrix materialof the composite, after exiting from the ovens, thesurface of the fibers is activated and sizing is alsocarried on to their surface.In the course of graphite production the pre‐tensionedfibers are further led through high temperature(2000‐3000 ⁰C) nitrogen gas blanketed ovens. The rawmaterial, production technology parameters(tensioning zones, stressing level, temperatures,surface treatment etc.) all have deciding effect on theproperties of the fiber (by increasing the temperature,rigidity of the fiber also increases), thusly tenacity andstiffness properties of the carbon fibers encompass awide range.The carbon fiber, without twisting is wound onto 5‐12kg‐ spools. To avoid twisting, the tow is unwoundtangentially from the rotating spool. The diameter ofthe carbon fiber is around 5‐7 μm (approx. 0.4 – 0.7dtex). The thickness of the carbon tow is defined bythe number of single filaments it contains, where(K=1000) (1K, 2K, 6K, 12K, 24K, 50K, 60K, 300K, etc.).The tows may also be used in the following forms: Milled powder (less than one mm long) form, orcompacted into chips / pellet form. Chopped (3‐10 mm), As tow, by direct extruding. Laid, spreaded tow, wound or, Using various textile technical methods, variouslystructured sheet forms (UD, BD, MD or 3D may beattained). Impregnated (pre‐pregs) or using thedry infusion process, embedded in matrixmaterial, they can be used as compositereinforcement (Figure 8).Figure 8. Product forms of carbon fibersFrom further processing point of the carbon fiber, it isimportant that the filaments in the tow be orientedand parallel. It is expedient to guide the carbon fiber –similarly to the Kevlar – on orange peel formed towguiding elements.At unwinding of the tows, tow forces should beidentical, minimal and independent from changes inthe diameter of the spool, in short, it must beconstant. At the unwinding creel, when positioningthe tow spools at the lateral guiding of the tows, onemust strive to minimize any breaks and that towsarrive parallel to the positioning reed. During theguiding, contact between the tows must be reducedto the minimum, overlapping of the tows is notallowed.In the 50K, 6‐10 mm wide tow, there are 35‐60filament layers on top of each other. During sheetformation, it is important that the tow filaments bespread homogenously, without gaps in the plane ofthe fabric. Namely, uniform penetration of the matrixinto the thick filament layers is not ensured andbecause of this, the tows, by spreading them, arewidened and thinned out. An important aim, is theformation of homogenous, gap free, thin, low areadensity (80‐120 g/m²) filaments, which make it possibleto form light, selective and valuable compositestructures (Figure 9).Figure 9. Spreading carbon tow and fabricTable 1. The mechanical properties of metalsC – HTHighTenacityC – IMIntermediateModulusDichte ρ g/cc 1.74 1.80Elongation at break % 1.50 1.93Tensile strength, σ MPa 3600 5600Specific tensile strength σ*cN/tex (km)206 301Tensile modulus E GPa 240 290Specific tensile modulus E*cN/tex (km)13800 16100Long time heat resistance ⁰C 500 500Coefficient of Liner ThermalExpansion, α 10−⁶/ ⁰C‐0.91 ‐0.91Fiber diameter, d, μm 7 5Melting / Sublimation ⁰C 3600 3600C – HMHighModulusC – HMSHigh ModulusStrengthE ‐GlassAluminumSteel1.83 1.85 2.55 2.70 7.850.57 0.63 2.5 1.82300 3600 2470 70‐700 2880125194 95 36400 550 70 70 2002185029730 2700 2500500 500‐0.91‐0.91 4‐9 22.2 136.5 5 7‐133600 3600 840 660 1500Spreading of the tow can be intensified by eliminatingtwists, reducing sizing, ensuring long free guiding,heating, vibrating and by blowing air on it.Carbon fiber is a high tenacity, high modulus brittlematerial, and because of this, in its processing, specialhandling is required. Since the density of carbon fiber(ρ≈1.8 g/cm³) and fiber reinforced composites (ρ≈1.4g/cm³) is small, their tenacity, in relation to the weightof the material (σ* = σ/ρg) and their elasticity modulus(E* = E/ρg) values considerably surpass the mechanicalproperties of metals (Table 1).Tensile strength of the various materials, in generalengineering practice is expressed to cross section2012. Fascicule 3 [July–September] 55

(GPa) and weight used in the textile industry (cN/tex,km) as shown in Figure 10.ACTA TECHNICA CORVINIENSIS – Bulletin of EngineeringIt can be seen that the greatest increase of carbonfiber usage is expected to be in industrial applications.According to the latest forecasts, by 2020, the yearlycarbon fiber demand is estimated to be 340 000 tons.CONCLUSIONSLight tows are used in the aircraft industry, forsporting goods and for fine machinery components,whereas the coarse, heavier (above 24K) tows areused for bracing large wind blades (blade lengthabove 40 m), automobiles, high pressure tanks,pipelines, offshore drilling, mooring lines, ship hulls,buildings reinforcement (Figure 11).Figure 10. Tensile strength of the various materials,expressed to engineering (cross section)and weight use systemCharacteristics of carbon fiber: Excellent specific strength and excellent specificmodulus Low density (ρ=1.7‐1.8 gcc) High dimensional stability High toughness Fatigue resistance Good vibration damping Self lubrication Low coefficient of thermal expansion Conductivity and thermal stability Electrical conductivity X‐ray permeability Electromagnetic protection Biological inertness Chemical inertness Imperviousness to corrosion (high resistance toalkalis, acid and organic solutions).The light (up to 24K) and heavy (above 24K) carbonfiber producers, and their development capacities areshown in Table 2.For the main areas of applications of the carbon fiberdemands are shown in Table 3.Figure 11. The main application areasof carbon fiber and trendsCarbon fiber – especially in cases where greatmechanical requirements need to be met – is acomposite reinforcer of key importance. The usage ofthe carbon fibers will expectedly have widerperspectives in the future.REFERENCES[1.] Kolkmann A. –Gries T. Scheser M. – Dilthey U.:Innovative Yarn Structures and Coating for Textil –Reinforced Concrete Techtextil Symposion 2005 ‐Buildtech[2.] Tálos G.: Kompozitok a textil szemszögéből TMTETexPlat kiadvány 2009.[3.] Szabó D. – Szabó L.: Textil erősítésű építőanyagokMagyar Textiltechnika 2008/6. p. 159‐162.[4.] Kollár L. –Kiss R.: Szálerősítésű műanyagok(kompozitok) az építőiparban Közúti és mélyépítésiszemle 1998/9. p. 331‐338.[5.] Zsigmond B. – Szabó R: Oxidized and Carbon Fiber asRaw Material of Technical Textiles Budapest, DanubiusHotel Gellért 2010. on 23. September[6.] Solan J.: Carbon fiber market: Cautious optimism High‐Performance Composites March 2011.[7.] Borbély B. – Szabó R.: Black Magic; The Present and theFuture Application of Carbon Fibers 1‐st RegionConferenc – Mechatronics in Practice and EducationSzabadka 8‐10. December 2011.[8.] Szabó R.: Carbon Fibers and Weaving of TechnicalTextiles Seminar in Corlu Tr. 10. Juni 2011.[9.] Szabó R.: Textil termékek szerepe a kompozitgyártásában 19. Műszaki Textil Fórum Tolna, 2011. 10.27.[10.] Szabó R.: Kompozitok Innovatív textil‐ és ruhaiparitermékek a gazdaság minden területén NemzetköziKonferencia BKIK Székház Budapest, 2011. okt. 6[11.] Szabó R.: Műanyag erősítő textilanyagok és –szerkezetek, ERŐSÍTETT MŰANYAGOK 2010Nemzetközi BALATON Konferencia 2010. május 18‐20.Keszthely, Hotel Helikon[12.] Spreading and spread‐tow Weaving Machines HarmoniIndustry Co.562012. Fascicule 3 [July–September]

1.Juliana LITECKA, 2. Slavko PAVLENKOMATHEMATICAL MODELLING OF GEAR HOB SURFACE WITH BASICPROFILE1,2 DEPARTMENT OF TECHNOLOGICAL DEVICES DESIGN, FACULTY OF MANUFACTURING TECHNOLOGIES OF TECHNICAL UNIVERSITY IN KOŠICE WITH ASEAT IN PREŠOV, ŠTÚROVA 31, PREŠOV, SLOVAKIAABSTRACT: Gear production is very important area of manufacturing industries because gears are the widest components inthe machines and machine equipments. Mode of production and used tools are important elements of economical andquality part of production. Nowadays, there are developed the new constructional solutions of gear hobs which save timeand money. For the hob which would produce precision involute gear there is possibility of finding profile which wouldprovide this requirement. For the finding of the profile it is needed to have a good mathematical knowledge kinematic andgeometrical properties investigated objects. The paper deals with mathematical description of basic hob surface withstraight profile which is initial theorem for the determining of accurate profile of gear hob.KEYWORDS: gear hob, hob profile, hob surface, mathematical description, parametric equationsINTRODUCTIONGear hobbing is a continuous rolling method. The bodyenveloping is a cylindrical involute worm. Tool andworkpiece rotate during the generating motion whilethe milling cutter executes the cutting motion as itcircles around.To manufacture spur gears, milling cutter andworkpiece are shifted in relation to each other in thedirection of the workpiece axis, and the generatingmotion is carried out at the same time. [1]Gear hobs, shows on Figure 1. (a), are very productivecutting tools used for machining of gear wheel andother different components like spline shafts, chainwheels, ratchet gearing and parts with screw surface.Gear hobs are universal tools because with the samemodule we can machine gear wheels with differentnumber of teeth, tooth inclination, corrected oruncorrected gear and worm wheels.The characteristic element for the calculating anddesign of hob is basic surface of tool (Figure 1. (b)).Figure1. (a) Constructional solution of solid gear hob (b)Basic surface of gear hob with straight profileFor the investigation of a basic tool surface we will usetheory of three‐dimensional curves and helix surfaces.PRINCIPLES OF GEOMETRICAL THEORYFor investigate a case of hob we need to appear fromthree basic geometric definition: curve, surface,movement.a. The curveThe curve is a geometrical concept, of which an exactand at the same time quite general definition presentsconsiderable difficulties and is carried out differentlyin different branches of geometry.In elementary geometry the concept of a curve is notclearly defined and is sometimes defined as "lengthwithout width" or as the "boundary of a surface" . Inelementary geometry the study of a curve essentiallyreduces to consideration of examples (a straight line,an interval, a polygon, a circle, etc.).Since it does not have general methods at its disposal,elementary geometry has gone quite deeply into thestudy of properties of specific curves (conic sections,certain algebraic curves of higher orders andtranscendental curves), using special methods in eachcase. In analytic geometry a curve in a plane is definedas a set of points whose coordinates satisfy anequation F(x,y)=0.Restrictions must be imposed on the function F sothat, on the one hand, the equation should have aninfinite set of solutions and, on the other hand, so thatthis set of solutions does not fill "a piece of theplane" .An important class of curves comprises those forwhich the function F(x,y) is a polynomial in the twovariables; in this case the curve defined by theequation F(x,y)=0 is said to be algebraic. Algebraiccurves specified by an equation of the first degree arestraight lines. [2]© copyright FACULTY of ENGINEERING ‐ HUNEDOARA, ROMANIA 57

ACTA TECHNICA CORVINIENSIS – Bulletin of Engineeringb. The surfaceIn geometry, a two‐dimensional collection of points(flat surface), a three‐dimensional collection of pointswhose cross section is a curve (curved surface), or theboundary of any three‐dimensional solid.In general, a surface is a continuous boundary dividinga three‐dimensional space into two regions.c. The movementThe movement is unlimited set of geometricaltransformation the same type (e.g. set of rotationsaround axis, or set of translations along straight line)or unlimited set of geometrical affinetransformations, which are analytical represented bytransposed matrix:⎡a11(u)a12(u)a13(u)a14(u)⎤⎢⎥= ⎢a21(u)a22(u) a23(u)a24(u)T(u)⎥ (1)⎢a(u) a (u) a (u) a (u) ⎥31 32 33 34⎢⎥⎣ 0 0 0 1 ⎦where functions a ij are function of one real variable, alldefined, linear and least once differentiable oninterval I.For the describing of surface in the extensive Euclidspace there will be equations:F{x, y,z,1} = F{x(t), y(t),z(t),1}. T(u) for u∈I (2)where F{x(t),y(t),z(t),1} is function of generatingcurve.The equation (2) we may to write by parametricequations:x = x(t).a (u) + y(t).a (u) + z(t).a (u) + a (u)y = x(t).az = x(t).a112131(u) + y(t).a(u) + y(t).a122232(u) + z(t).a(u) + z(t).a13233314(u) + a(u) + a2434(u)(u)for each u∈I and t∈J.ANALYTICAL DESCRIPTION OF HOB SURFACE GEOMETRYFor the investigation of surface geometry of hob wewill use the geometry of helix surface S which iscreated by helix movement of curve k. The curve k is agenerating curve of a helix surface S. A set of allposition of generating curve k for helix movement,which define helix surface S, is one system of curveswhich models the surface S. The helix surface S is oneparametricsystem of curves ‐ all position k u ofgenerating curve k for helix movement which definesurface S.Each point P of helix surface S is situated on someposition k u of generating curve k (Figure 2.).This fact we may formulate so that one‐parametricvariable of point P will be variable u. Position of thispoint P on curve k u we describe by second parametricvariable t (Figure 3.). The helix surface S is twoparametricsystem of points P(t,u) in the threedimensional space with coordinates (x,y,z).(3)Figure 2. The generating of helix surface by curve kFigure 3. The generating of curve k by point PPoint P of generating curve k creates by helixmovement the defining helix surface S ‐ helicoid whichis a curve on this helix surface.Set of all helicoids which are created by each point ofgenerating curve k is second system of curves whichmodels helix surface S. All these helicoids have unitaxis z, all they are clockwise or anticlockwise and theyhave the same size of convolution:p = π .m(4)where m is module of hob.On Figure 2 there is illustrated model of helix surfacewhich is created by curve k by helix movement in thecoordinate system (x,y,z) where axis z is axis ofhelixoid. Two systems of curves, it means systemposition curve k and system of helicoid created pointsof curve k, create model of helix surface.For the mathematical descriptiom of helix surface wewill use parametric equations of curve k, wherek:{x=x(t), y=y(t), z=z(t), t∈}, which is straightline of basic hob profile. Their parametric equationswe may describe on based of Figure 3.:582012. Fascicule 3 [July–September]

ACTA TECHNICA CORVINIENSIS – Bulletin of Engineeringx(t) = ty(t) = 0 t∈ rff , r af(5)z(t) = z0 −t.tg(α )whereπ .mz0 = + rf.tg( α )(6)4r f is a radius of hob pitch circler af is a radius of hob addendum circler ff is a radius of hob dedendum circle.In the case of hob we consider, helix surface which iscreated by curve k, clockwise and convolution is p. Thetransposed matrix of movement of curve k will berepresented:⎡cos(u)− sin(u) 0 0 ⎤⎢⎥⎢sin(u) cos(u) 0 0⎥T(u)= ⎢π .m.u0 0 1 ⎥ (7)⎢360 ⎥⎢⎥⎣ 0 0 0 1 ⎦After the writing the equations (5),(6),(7) to equation(2) we get final parametric equations of hob surface inthe coordinates (x,y,z).x = t.cos(u)t∈rff,rafy = t.sin(u)(8)u∈2iπ ,2(i + 1)ππ .m π .m.uz = + rftg(α ) +4360where i is number of convolutions.CONCLUSIONSIn the case of investigation of surface geometry ofgear hob we was based on transformation ofmovement straight line curve which rotates aroundaxis z and at the same time translates along the sameaxis z. The describing of the movement was realizedby 4x4 transposed matrix and the results wererepresented by parametric equations of the surface.By these parametric equations we may investigate thehob movement in depends of gear movement for gearproduction in the next part of research of influencethe hob profile to gear production. By analysis ofresults of the research we may to design new profileof gear hob which will be machine gear with higheraccuracy.REFERENCES[1.] Tschätsch, H.:Applied Machinig Technology, SpringerDordrecht Heildelberg London New York, pp. 398,2009.[2.] Hazewinkel, M.: Encyclopaedia of Mathematics,Supplement III, Springer, pp. 568, 2007.[3.] Maščenik, J., Batešková, E.: Design and computing ofgearing with Autodesk Inventor. In: MOSIS '09. ‐Ostrava, P. 227‐230., 2009[4.] Pavlenko, S., Haľko, J., Maščenik, J., Nováková, M.:Časti strojov II, 1. edition ‐ Prešov: FVT TU, 2008.[5.] Pavlenko, S.: K profilovaniu odvaľovacích fréz, FVT TU,Prešov, pp. 106, 2006, ISBN 80‐8073‐493‐3[6.] Pavlenko, S., Haľko, J., Paško, J.: Impact of spur‐gearhobdiameter on tooth profile accuracy, In: ScientificBulletin. Vol. 20, serie C (2006), p. 321‐324, 2006,[7.] Litvin, L. F., Fuentes A.: Gear geometry and appliedtheory, Cambridge University Press, 2004[8.] Lawrence, D. J. : A catalog of special plane curves,Dover Publications. pp. 168,171–173., 1972, ISBN 0‐486‐60288‐5.[9.] Jüttler, B. , Piene, R., Dokken, T.: Geometric modelingand algebraic geometry, Springer, pp. 231, 2008, ISBN978‐3‐540‐72184‐0[10.] Radzevich, S. P. : Kinematic geometry of surfacemachining, CRC Press, pp. 508, 2007ACTA TECHNICA CORVINIENSIS – BULLETIN of ENGINEERINGISSN: 2067‐3809 [CD‐Rom, online]copyright © UNIVERSITY POLITEHNICA TIMISOARA,FACULTY OF ENGINEERING HUNEDOARA,5, REVOLUTIEI, 331128, HUNEDOARA, ROMANIAhttp://acta.fih.upt.ro2012. Fascicule 3 [July–September] 59

ACTA TECHNICA CORVINIENSIS – Bulletin of EngineeringACTA TECHNICA CORVINIENSIS – BULLETIN of ENGINEERINGISSN: 2067‐3809 [CD‐Rom, online]copyright © UNIVERSITY POLITEHNICA TIMISOARA,FACULTY OF ENGINEERING HUNEDOARA,5, REVOLUTIEI, 331128, HUNEDOARA, ROMANIAhttp://acta.fih.upt.roACTA TECHNICA CORVINIENSIS – BULLETIN of ENGINEERINGISSN: 2067‐3809 [CD‐Rom, online]copyright © UNIVERSITY POLITEHNICA TIMISOARA,FACULTY OF ENGINEERING HUNEDOARA,5, REVOLUTIEI, 331128, HUNEDOARA, ROMANIAhttp://acta.fih.upt.ro© copyright FACULTY of ENGINEERING ‐ HUNEDOARA, ROMANIA 60

1.Keyvan Asefpour VAKILIAN, 2. Jafar MASSAHPERFORMANCE EVALUATION OF CCD AND CMOS CAMERAS INIMAGE TEXTURAL FEATURES EXTRACTION1‐2.DEPARTMENT OF AGROTECHNOLOGY, COLLEGE OF ABOURAIHAN, UNIVERSITY OF TEHRAN, TEHRAN, IRANABSTRACT: The first stage of any vision system is the image acquisition stage. If the image has not been acquiredsatisfactorily, then the intended tasks for image processing and image classification may not be properly achievable. In thisstudy, a machine vision system was developed to evaluate the performance of CCD and CMOS cameras for real‐timemonitoring of cucumber growth in a greenhouse by extracting image textural features. The leaf samples of cucumber cropswere brought to the laboratory from the greenhouses to measure the textural features. Laboratory was consisted of adigital camera for taking the images, a LDR array for providing a uniform lightening and a computer for measuring thetextural parameters from the obtained images. The objective of the current study was to select which type of camera isideal for real‐time plant health and growth monitoring systems. The effect of distance between camera and leaves for threevalues (30, 40 and 50cm) and the type of camera (CMOS and CCD) on the uniformity of resulted data were considered in thisarticle. Results showed that data for 40cm distance between camera and leaves with a CCD camera had an acceptable trendfor extracting image textural features.KEYWORDS: CCD Camera, CMOS Camera, Image Processing, Pattern Recognition, Textural FeaturesINTRODUCTIONThe first stage of any vision system is the imageacquisition stage [1]. After the image has beenobtained, various methods of processing can beapplied to the image to perform the many differentvision tasks required today. However, if the image hasnot been acquired satisfactorily then the intendedtasks may not be achievable, even with the aid ofsome form of image enhancement [5].Cameras are usually used for image acquisition stage.Charge Coupled Device (CCD) and ComplementaryMetal Oxide Semiconductor (CMOS) image sensors aretwo different technologies for capturing imagesdigitally. Each type has certain strengths andweaknesses giving advantages in differentapplications. The current situation and outlook forboth technologies is vibrant, but a new frameworkexists for considering the relative strengths andopportunities of CCD and CMOS imagers [4].Both types of imagers convert light into electriccharge and process it into electronic signals. In a CCDsensor, every pixel’s charge is transferred through avery limited number of output nodes (often just one)to be converted to voltage, buffered, and sent off‐chipas an analogue signal.All of the pixel can be devoted to light capture, andthe output’s uniformity (a key factor in image quality)is high. In a CMOS sensor, each pixel has its owncharge‐to‐voltage conversion, and the sensor oftenalso includes amplifiers, noise‐correction, anddigitization circuits, so that the chip outputs digitalbits. These other functions increase the designcomplexity and reduce the area available for lightcapture. With each pixel doing its own conversion,uniformity is lower. But the chip can be built torequire less off‐chip circuitry for basic operation [13].Developing high quality cameras based on CCD andCMOS sensors and image processing techniques havecreated a large number of machine vision applicationsin precision agriculture. Computer programs haveincreased the ability of image processing for sortingand grading fruits and other agricultural products.Calculating image textural parameters such asentropy, energy, homogeneity and contrast is one ofthe principle methods for determining the situation ofimage objects.Some of the machine vision applications needed fornon‐contact monitoring of agricultural productsconditions have already been developed. In a research,images of plants’ leaves were taken digitally by a CCDcamera. Then, spectral and morphologicalcharacteristics of these leaves were used to detectnutrient deficiency. This research also suggested thepossibility of using machine vision systems that coulddetermine plant status and indicate deficiencies [8].In a research, a CCD camera was used to take theimages from greenhouse grown grass and broadleafplants. CO‐OCCURRENCE MATRICES WERE utilized on agray‐scale image to compute texture features such asinertia and angular second moment to classifygreenhouse plants [9].By using a CMOS camera, co‐occurrence matrices wasmade for the hue saturation and intensity colourspace to obtain an overall classification accuracy of91% on images of seven common cultivars of nurserystock. Computation time was an important factor andsuggested using a smaller set of texture features [11].© copyright FACULTY of ENGINEERING ‐ HUNEDOARA, ROMANIA 61

A machine vision‐guided plant sensing and monitoringsystem was used to detect calcium deficiency inlettuce crops grown in greenhouse conditions. Imageswere taken by a CCD colour camera and then, themachine vision system extracted plant features todetermine overall plant growth and health status. Themethodology developed was capable of identifyingcalcium‐deficient lettuce plants one day prior to visualstress detection by human vision [12].In a study, researchers designed an automatic robotwith real time image processing system to detectnitrogen deficiency in greenhouse cucumber crops.Images were taken digitally by a CMOS camera andimage textural features were extracted for calculatingthree textural parameters: entropy, energy andhomogeneity [2]. They also used a CCD camera to takethe images and measured entropy and homogeneityvalues for greenhouse crop leaves’ image with acomputer image processing method in an experiment.The objective of their study was growth modelingwith a machine vision system for tomato, cucumberand eggplant crops [3].The objective of the current study was to select whichtype of camera is ideal for real‐time plant health andgrowth monitoring systems. This could be achieved bya multi‐sensing systems (including CCD and CMOScameras) equipped with an artificial light source forextracting image textural features.MATERIALS AND METHODS – Experimental setup forgrowing greenhouse cropThe plant‐production system was constructed in aresearch center located at the Controlled EnvironmentAgricultural Center at the College of Abouraihan(University of Tehran, Iran). A hydroponic greenhouseof cucumber crop was chosen to collect data. Tworows were selected near the center of greenhouse in atime of one month after two‐leaf stage. 100 leaveswere picked randomly from each row every three daysin 12:00 am and were brought to the laboratory. Thegreenhouses were covered with a doublepolycarbonate glazing and equipped with a Pad andFan evaporative cooling system.Desired climate set points were maintained by anautomatic climate control system. Environmentalparameters were collected by a data logger(Pardazesh Tamkar, Iran). Connected to the datalogger, for each of two rows, four temperaturesensors (LM35, National Semiconductor, Japan), tworelative humidity sensors (083E, Met One Instruments,USA) and one carbon dioxide sensor (TGS4161,FIGARO, Japan) were hung from the greenhouse roof,2m above the ground level. The distances betweentemperature sensors and relative humidity sensors inthe rows were approximately 2m and 4m,respectively. During the experiment, the greenhouse62ACTA TECHNICA CORVINIENSIS – Bulletin of Engineeringtemperature was set to 25°C for the day (14 h) and20°C for the night (10 h). Root‐zone environmentswere maintained at a pH of 6.2, EC of 2.0 dSm −1 , and atemperature of 20°C. Nutrient solutions were changedevery 7 days to maintain proper nutrient levels in theroot zone.Image acquisition systemAfter picking the leaves, they were brought to a darkroom for taking pictures. A CCD color camera (Canon,Powershot, G12, Japan) and a CMOS color camera(Canon, Powershot, SX40 HS, Japan) were used totake pictures from the leaves. Distance betweenCamera and the Leaves (DBCL) was set as a variablewith three values of 30, 40 and 50 cm. A 200‐LEDsarray with view angle of 70° was used above thecamera to increase the light uniformity for the regionof interest. Distance between LDR and the leaves wasset as a 20 cm (Figure 1).Figure1. Image acquisition system for plants’ leavesTwo sequential images were taken by each camerafrom each plant leave with a certain DBCL. Imageswere transferred to the computer and then, imageaveraging was used for analysis to reduce the effect ofrandom electronic noise and to reduce disturbancesby factors that would cause the leaves to move. Thecaptured images dimension was 1600 × 1200 pixels andwas analyzed as a raw bitmap image. The program forthe plant growth monitoring system was written withMathWorks MATLAB R2010b using Image ProcessingToolbox.Image processing and pattern recognitionFrom each retrieved image, the region of interest (theplant’s leaf) was extracted through an imagesegmentation process [3,12]. This focused leaf imagewas used to calculate the colour features of the leaf.Gray‐Level Co‐occurrence Matrix (GLCM) was used tocapture the spatial dependence of gray‐level featuresof the image [6,7]. Each matrix was run throughprobability‐density functions to calculate differenttextural parameters. After analyzing the colourfeatures of the focused image, the textural features2012. Fascicule 3 [July–September]

ACTA TECHNICA CORVINIENSIS – Bulletin of Engineeringwere extracted. In one review, 21 textural parameterswere identified [15]. However, another reportindicated that only three textural parameters wereuseful in identifying plant health—entropy, energy,and homogeneity [12,14].In this research, two textural parameters were used inidentifying plant quality—entropy and homogeneity.After calculating textural parameters from eachimage, the values of parameters were averaged toobtain a dimensionless number to expose a parameterin an interval.RESULTS AND DISCUSSIONThe experiment ran for a total of 90 days. Figure 2 andFigure 3 illustrate the timeline of the extractedentropy at 12:00 am as averaged values obtained fromcucumber crops.It was assumed that changes in the plant texture andsurface structure are external symptoms of the plant’sinternal physiological status [10].Figure 3. Timeline of the extracted entropy at 12:00 am asaveraged values obtained from cucumber crops by CCDcamera when DBCL is: (a) 30cm, (b) 40cm, and (c) 50cmFigure 2. Timeline of the extracted entropy at 12:00 am asaveraged values obtained from cucumber crops by CMOScamera when DBCL is: (a) 30cm, (b) 40cm, and (c) 50cmIn comparison with younger leaves, older plants’leaves are more colourful with different levels ofgreen colour. This is usually detected by higher levelsof entropy values from the images of older plants [3].In this study, textural features were examined byprobability‐density functions on GLCM.Figure 4. Timeline of the extracted homogeneity at 12:00 amas averaged values obtained from cucumber crops by CMOScamera when DBCL is: (a) 30cm, (b) 40cm, and (c) 50cm2012. Fascicule 3 [July–September] 63

During the experiment, non‐uniform data with nocertain trends was obtained by using CMOS camera inthree values of DBCL to extract entropy.Results of using CCD camera were also not reliable forDCBL 30cm and 50cm, but data for DCBL 40cm had anacceptable trend for extracting entropy feature.Figure 4 and Figure 5 illustrate the timeline of theextracted homogeneity at 12:00 am as averagedvalues obtained from the cucumber crops.Figure 5. Timeline of the extracted homogeneity at 12:00 amas averaged values obtained from cucumber crops by CCDcamera when DBCL is: (a) 30cm, (b) 40cm, and (c) 50cmAs older plants’ leaves are more colourful withdifferent shades of green, the related gray‐level pixeldistribution (homogeneity) decreases over time.Conversely, the younger plants, being more unified incolour, have higher homogeneity values [3]. Duringthe experiment, non‐uniform data with no certaintrends was obtained by using CMOS camera in threevalues of DBCL to extract homogeneity. Results ofusing CCD camera were also not reliable for DCBL 30cmand 50cm, but data for DCBL 40cm had an acceptabletrend for extracting homogeneity feature.CONCLUSIONSIn this study, a machine vision system was developedto evaluate the performance of CCD and CMOScameras for real‐time monitoring of plant growth in agreenhouse. Entropy and homogeneity weremeasured as textural features for greenhouse plantleaves’ image in an experiment for cucumber crops.The leaf samples were brought to the laboratory fromthe greenhouses to measure the textural features. The64ACTA TECHNICA CORVINIENSIS – Bulletin of Engineeringeffect of Distance between Camera and Leaves (DBCL)for three values (30, 40 and 50cm) and the type ofcamera (CMOS and CCD) on the uniformity of resulteddata were considered in this article.Results showed that non‐uniform data with no certaintrends was obtained by using CMOS and CCD camera intwo values of DBCL (30cm and 50cm) to extractentropy. Data for DCBL 40cm with a CCD camera hadan acceptable trend for extracting both of entropyand homogeneity features.ACKNOWLEDGEMENTThe authors would like to thank the University of Tehran forsupport of this research project.REFERENCES[1.] Asefpour Vakilian, A. and Asefpour Vakilian, K., A NewSatellite Image Segmentation Enhancement TechniqueFor Weak Image Boundaries, Annals of FacultyEngineering Hunedoara ‐ International Journal ofEngineering, X(2), 2012.[2.] Asefpour Vakilian, K. and Massah, J., Design,Development and Performance Evaluation of a Robotto Early Detection of Nitrogen Deficiency inGreenhouse Cucumber (Cucumis sativus) with MachineVision, International Journal of Agriculture: Research &Review, 2(4), 2012.[3.] Asefpour Vakilian, K. and Massah, J., Non‐linear GrowthModeling of Greenhouse Crops with Image TexturalFeatures Analysis, International Research Journal ofApplied and Basic Science, 3(1), 2012.[4.] Boyle, W.S. and Smith, G.E., Charge CoupledSemiconductor Devices. Bell System and TechnologyJournal, 49(4), 1970.[5.] Gonzalez, R. and Woods, R, Digital image processing.Addison‐Wesley, New Jersey, 2002.[6.] Haralick, R.M., Shanmugam, K., Dinstein, I., Texturalfeatures for Image Classification, IEEE Transactions onSystems, Man, and Cyberentics, 3(6), 1973.[7.] Jain, R., Kasturi, R. and Schunck, B.G., Machine Vision.McGraw‐Hill, 1995.[8.] Ling, P.P, Giacomelli, G.A. and Russell, T.P., Monitoringof plant development in controlled environment withmachine vision, Adv. in Space Research, 18(4‐5), 1996.[9.] Meyer, G.E., Troyer, W.W., Fitzgerald, J.B. andPaparozzi, E.T., Leaf nitrogen analysis of poinsettia(Euphorbia Pulcherrima Will D.) using spectralproperties in natural and controlled lighting. AppliedEngineering in Agriculture, 8(5), 1992.[10.] Penuelas, J. and Filella, I., Visible and near‐infraredreflectance techniques for diagnosing plantphysiological status, Trends in Plant Science, 3, 1998.[11.] Shearer, S.A. and Holmes, R.G., Plant identificationusing colour co‐occurrence matrices, Transactions onASAE, 33(6), 1990.[12.] Story, D., Kacira, M., Kubota, C., Akoglu, A., An, L.,Lettuce calcium deficiency detection with machinevision computed plant features in controlledenvironments, Computers and Electronics inAgriculture, 74, 2010.[13.] Tompsett, M.F., Amelio, G.F., Bertram, W.J., Buckley,R.R., McNamara, W.J., Mikkelsen, J.C. and Sealer, D.A.,Charge‐coupled imaging devices: Experimental results,IEEE Transactions on Electronic Devices. 18(11) 1971.[14.] Ushada, D., Murase, H. and Fukuda, H., Non‐destructivesensing and its inverse model for canopy parametersusing texture analysis and artificial neural network,Computers and Electronics in Agriculture, 57, 2007.[15.] Zheng, C., Sun, D.W. and Zheng, L., Recent applicationsof image texture for evaluation of food qualities‐areview Trends in Food Science and Technology, 17,2006.2012. Fascicule 3 [July–September]

1.Imre Zsolt MIKLOS, 2. Cristina Carmen MIKLOS, 3. Carmen Inge ALICCAM PROFILE COMPUTER AIDED DESIGN PLOTTING1.UNIVERSITY „POLITEHNICA” TIMIŞOARA, FACULTY OF ENGINEERING HUNEDOARA, ROMANIAABSTRACT: This paper shows how to plotting the profile of a plane rotating cam and a follower in the translational move,using Matlab program. Are shown how input the variables, kinematic analysis, speeds hodograph in graphical form,respectively plane cam profile designed, with a choice of several options for the best solutions.KEYWORDS: Cam, follower, cam profileINTRODUCTIONThe transformation of one of the simple motions, suchas rotation, into any other motions is oftenconveniently accomplished by means of a cammechanism A cam mechanism usually consists of twomoving elements, the cam and the follower, mountedon a fixed frame. Cam devices are versatile, andalmost any arbitrarily‐specified motion can beobtained. In some instances, they offer the simplestand most compact way to transform motions.A cam may be defined as a machine element having acurved outline or a curved groove, which, by itsoscillation or rotation motion, gives a predeterminedspecified motion to another element calledthe follower. The cam has a very important function inthe operation of many classes of machines, especiallythose of the automatic type, such as printing presses,shoe machinery, textile machinery, gear‐cuttingmachines, and screw machines. In any class ofmachinery in which automatic control and accuratetiming are paramount, the cam is an indispensablepart of mechanism.Cam mechanisms design, respectively profileobtaining, may be realize by many methods. The firstdesign methods for cam mechanisms war graphical.These methods require many graphical constructionswith low precision. With the new entry calculationsystems, have develop analytical methods to obtaincam profile by software writing (Basic, C++, Matlab,MathCAD, etc). These methods are faster, giving tothe plant designer varieties data results and charts.Plotting a plane cam profile requires knowledge ofsome initial elements of calculation. These are: The motion phases based on the technologicalprocess data, defined by the anglesof lifting, high stationary, going down and downstationary, respectively follower race (lineardisplacement respectively oscillating) Law of motion, which is chosed by thedesigner according to the angles values thatdefine motion phases and by the value of theangular velocity of the cam. In most cases law ofmotion is chosen depending on the maximumacceleration of the follower (for the reasons ofinertia forces equilibration), respectivelyon the acceleration jump from one phase toanother. Maximum pressure angle (between the followerand cam) Motion (linear or oscillating) and follower form Follower roller radius (if necessary), according tothe minimum radius of basic circle Expansion joints (if necessary)Plotting a plane cam profile can be made by graphicalmethods and analytical method. In both cases thedesign involves the following steps: Kinematic analysis of a cam mechanism,respectively the graphical representation ofdisplacement variation and follower low speeddepending on the cam rotational angle Velocities hodograph building Determination of minimum radius of curvature ofthe cam Checking the contact pressure Entering in calculations the expansion joints (ifnecessary) Establishing minimum radius of the cam basecircle, respectively the radius of the roller follower(if necessary) Cam profile constructionPROGRAM AND RESULTS PRESENTATIONPlane rotating cam plotting profile, with follower intranslation moving, was made with mathematicalformulas provided by analytical methods [2], using acomputer program designed and written in Matlabprogramming environment.For the case study was considered a cam mechanismhaving the follower parabolic law ofmotion, respectively the following input data definedby the technological process requirements: Follower lift: h = 50 mm Uplift angle: ϕ 1 = 150 grade Upper stationary angle: ϕ 2 = 30 grade Down angle: ϕ 3 = 150 grade Pressure angle allowed: δ = 30 grade Eccentricity: e = 10 mmWhen the computer program is launching appear adialog box with the user, from which will beintroduced the input data (dialog box defined withthe input procedure). This is shown in Figure 1.Based on input data (defined by the technologicalprocess) computer program make graphicrepresentation of displacement and follower lowspeed depending on cam rotation angle (Fig. 2),© copyright FACULTY of ENGINEERING ‐ HUNEDOARA, ROMANIA 65

espectively velocities hodograph (velocity anddisplacement graphic dependence of the follower)(figure 3).ACTA TECHNICA CORVINIENSIS – Bulletin of Engineering5045Fig.1. Initial dates inputFig. 4. Choosing the minimum radius of basic circleFurther, the program performs roll follower radiuscalculation, follower and cam contact verification,respectively determines by graphic representationcam profile (based on user input data) Fig. 5.150120906560304035s180 030s[mm]2521033020vr[mm/s]s[mm]1510500 1 2 3 4 5 6 7fi[ ra d ]403020100-1 0-2 0-3 0v-4 00 1 2 3 4 5 6 7fi[ra d ]50454035302520Fig.2. Cam mechanism kinematic analysis240270Fig. 5. Cam profile with parabolic motion lawCONCLUSIONSThe presented calculation program is very easy touse by the designer, through introduction of initialdata, given by the technological process; in a veryshort time it can get the cam profile, respectivelykinematics on cam mechanism graphicrepresentations.REFERENCES[1.] Artobolevski, I. Teoria mecanismelor şi a maşinilor,Editura Tehnică, Bucureşti, 1955[2.] Chen, F. Y., Mechanics and Design of Cam Mechanisms,Pergamon Press, New York, 1982[3.] Ghinea, M., Firețeanu, V., Matlab, calcul numeric,grafică, aplicații, Editura Teora, Bucureşti 1997[4.] Kovacs, Fr., ş.a., Mecanisme, Litografia U.P. Timişoara,1992.[5.] Manolescu, N., ş.a., Teoria mecanismelor şi a maşinilor,Editura Didactică şi Pedagogică, Bucureşti, 1972.[6.] Miklos, Zs., Mecanisme. Analiza mecanismelor, EdituraMirton, Timişoara. 2005[7.] Miklos, I. Mecanisme şi organe de maşini,Universitatea Politehnica Timişoara, 1995.[8.] Simionescu, I., Moise, V. ,Mecanisme, Editura Tehnică,Bucureşti, 1999.300151050-40 -30 -20 -10 0 10 20 30 40vr[m /s]Fig.3. Velocity hodographIt is known that on synthesis graphicalmethod of cam mechanisms, the velocitieshodograph is used to determine minimum radius ongraphical method of basic circle. In case of analyticalmethods based on known relations [2], computerprogram determines the minimum value of basiccircle, showing more options, the userentering through an input procedure, the chosenvalue, fig.4.ACTA TECHNICA CORVINIENSIS – BULLETIN of ENGINEERINGISSN: 2067‐3809 [CD‐Rom, online]copyright © UNIVERSITY POLITEHNICA TIMISOARA,FACULTY OF ENGINEERING HUNEDOARA,5, REVOLUTIEI, 331128, HUNEDOARA, ROMANIAhttp://acta.fih.upt.ro662012. Fascicule 3 [July–September]

1.A.G. VIJAYA KUMAR, 2. S.V.K. VARMA, 3. Y. RAJASHEKARA GOUD, 4. K. RAGHUNATHTHERMAL DIFFUSION AND RADIATION EFFECTS ON UNSTEADYMHD FLOW PAST A LINEARLY ACCELERATED VERTICAL PLATE WITHVARIABLE TEMPERATURE AND MASS DIFFUSION1. DEPARTMENT OF MATHEMATICS, MVJ COLLEGE OF ENGINEERING, BANGLORE, KARNATAKA, INDIA2.DEPARTMENT OF MATHEMATICS, S.V.UNIVERSITY, TIRUPATI, A.P, INDIA3. DEPARTMENT OF HUMANITIES AND SCIENCES, G. PULLAREDDY ENGINEERING COLLEGE, KURNOOL, A.P, INDIA4.DEPARTMENT OF MATHEMATICS, BHEEMA INSTITUTE OF TECHNOLOGY AND SCINECE, ADONI, KURNOOL, A.P. INDIAABSTRACT: The objective of the present study is to investigate thermal diffusion and radiation effects on unsteady MHD flowpast a linearly accelerated vertical plate with variable temperature and mass diffusion under the influence of appliedtransverse magnetic field. The fluid considered here is a gray, absorbing/ emitting radiation but a non‐scattering medium.At time t>0, the plate is linearly accelerated with a velocity u = u 0 t in its own plane. And at the same time, platetemperature and concentration levels near the plate raised linearly with time t. The dimensionless governing equationsinvolved in the present analysis are solved using the Laplace transform technique. The velocity, temperature,concentration, Skin‐friction, the rate or heat transfer and the rate of mass transfer are studied through graphs and tables interms of different physical parameters like magnetic field parameter (M), radiation parameter (R), Schmidt parameter (Sc),soret number (So), Prandtl number (Pr), thermal Grashof number (Gr), mass Grashof number (Gm) and time (t).KEYWORDS: magnetic field, radiation, thermal diffusion, vertical plate, porous mediumINTRODUCTIONThe study of magneto hydro‐dynamics with mass andheat transfer in the presence of radiation anddiffusion has attracted the attention of a largenumber of scholars due to diverse applications. Inastrophysics and geophysics, it is applied to study thestellar and solar structures, radio propagationthrough the ionosphere, etc. In engineering we find itsapplications like in MHD pumps, MHD bearings, etc.The phenomenon of mass transfer is also verycommon in theory of stellar structure and observableeffects are detectable on the solar surface. In freeconvection flow the study of effects of magnetic fieldplay a major rule in liquid metals, electrolytes andionized gases. In power engineering, the thermalphysics of hydro magnetic problems with masstransfer have enormous applications. Radiative flowsare encountered in many industrial and environmentprocesses, e.g. heating and cooling chambers, fossilfuel combustion energy processes, evaporation fromlarge open water reservoirs, astrophysical flows, solarpower technology and space vehicle re‐entry.MHD effects on impulsively started vertical infiniteplate with variable temperature in the presence oftransverse magnetic field were studied bySoundalgekar et al. [12]. The effects of transverselyapplied magnetic field, on the flow of an electricallyconducting fluid past an impulsively started infiniteisothermal vertical plate were also studied bySoundalgekar et al. [11]. The dimensionless governingequations were solved using Laplace transformtechnique. Kumari and nath [8] studied thedevelopment of the asymmetric flow of a viscouselectrically conducting fluid in the forward stagnationpoint region of a two‐dimensional body and over astretching surface was set into impulsive motion fromthe rest. The governing equations were solved usingfinite difference scheme. The radiative free convectionflow of an optically thin gray‐gas past semi‐infinitevertical plate studied by Soundalgekar and Takhar[13]. Hossain and Takhar have considered radiationeffects on mixed convection along an isothermalvertical plate [5]. In all above studies the stationaryvertical plate considered. Raptis and Perdikis [10]studied the effects of thermal‐radiation and freeconvection flow past a moving vertical plate. Thegoverning equations were solved analytically. Das et al[4] have considered radiation effects on flow past animpulsively started infinite isothermal vertical plate.The governing equations were solved by the Laplacetransform technique. Muthucumaraswamy andJanakiraman [9] have studied MHD and radiationeffects on moving isothermal vertical plate withvariable mass diffusion.Alam and Sattar [3] have analyzed the thermaldiffusioneffect on MHD free convection and masstransfer flow. Jha and Singh [6] have studied theimportance of the effects of thermal‐diffusion (massdiffusion due to temperature gradient). Alam et al [1]studied the thermal‐diffusion effect on unsteady MHDfree convection and mass transfer flow past animpulsively started vertical porous plate. Recently,Alam et al [2] studied combined free convection andmass transfer flow past a vertical plate with heat© copyright FACULTY of ENGINEERING ‐ HUNEDOARA, ROMANIA 67

generation and thermal‐diffusion through porousmedium.This paper deals with the effects of thermal‐diffusionand radiation on unsteady MHD flow past animpulsively started linearly accelerated infinitevertical plate with variable temperature and massdiffusion in the presence of transverse appliedmagnetic field. The dimensionless governingequations involved in the present analysis are solvedusing Laplace transform technique. The solutions areexpressed in terms of exponential and complementaryerror functions.MATHEMATICAL ANALYSISThermal‐diffusion and radiation effects on unsteadyMHD flow past of a viscous incompressible,electrically conducting, radiating fluid past animpulsively started linearly accelerated infinitevertical plate with variable temperature and massdiffusion in the presence of transverse appliedmagnetic field are studied. The plate is takenalong x′− ‐axis in vertically upward direction andy′−axis is taken normal to the plate. Initially it isassumed that the plate and fluid are at the sametemperature T ′ ∞ and concentration level C ′ ∞ instationary condition for all the points. At timet ′ > 0 , the plate is linearly accelerated with a velocityu = u0 t ′ in the vertical upward direction against tothe gravitational field. And at the same time theplate temperature is raised linearly with time tand also the mass is diffused from the plate tothe fluid is linearly with time. A transversemagnetic field of uniform strength B 0 is assumedto be applied normal to the plate. The viscousdissipation and induced magnetic field are assumedto be negligible. The fluid considered here is gray,absorbing/emitting radiation but a non‐scatteringmedium. Then under by usual Boussinesq’sapproximation, the unsteady flow is governed bythe following equations:2 2∂u′* ∂ u′σβ0u′= gβ( T′−T∞ ′ ) + gβ( C′− C′∞ ) + v − (1)2∂t′∂y′ρ2∂T′∂ T′∂qrρ cp= κ −(2)2∂t′∂y′∂y′22∂C′∂ C′⎛ ∂ T′⎞= D + D ⎜ ⎟2 1∂ ′ ∂ ′2(3)t y ⎝ ∂y′⎠With the following initial and boundary conditionst ≤ 0 : u′= 0, T′= T′, C′= C′, forall y′and′∞ ∞t′> 0 : u′= u0t′,T′= T∞′ +C′= C′+∞( Tw′− T∞′) At′,( C′− C′) At′at y′= 0w∞ACTA TECHNICA CORVINIENSIS – Bulletin of Engineeringu = 0, T′→ T′, C′→ C′as y′→ ∞ (4)′∞∞2u0where A =vThe local radiant for the case of an optically thin graygas is expressed by∂qr* 4 4= −4aσ ( T∞′−T′)(5)∂y′It is assumed that the temperature differences within4the flow are sufficiently small and that T′ may beexpressed as a linear function of the temperature. This4is obtained by expanding T′ in a Taylor series aboutT and neglecting the higher order terms, thus we get∞ ′4 3 4′ ≅ 4T∞ ′ T′−3T∞′(6)TFrom equations (5) and (6), equation (2) reduces to2∂T′∂ T′* 3ρ C p = κ + 16a σT′( T′−T′)2∞ ∞(7)∂t′∂y′On introducing the following non‐dimensionalquantities2u′t′u0y′u0T′−T∞′u = , t = , y = , θ = ,u0v v Tw′−T∞′C′− C′∞ a′v ω′vC = , a = , ω =22C′− C′w∞u 0 u 0g• v C′w −CG ′ ∞m3u0g v( TwT∞ )= β ′ − ′( ) ,,Gr3u0μCρPr= βD1(Tw′−T∞′)= ,S0= κ v(C′w −C′∞ )22 3v σB0v16a• v σT∞S c = , M = , R =′22D ρu0ku0(8)we get the following governing equations which aredimensionless.2∂u∂ u= Grθ + GmC+ − Mu, (9)2∂t∂y2∂θ1 ∂ θ R= − θ , (10)2∂tPr ∂yPr∂C1 ∂ C ∂ θ= + S2 o(11)2∂tSc ∂y∂yThe initial and boundary conditions in dimensionlessform are as follows:t′ ≤0: u = 0,θ = 0,C = 0 for all y,t > 0 : u = t, θ = t, C = t at y = 0, andu → 0, c → 0 as y → ∞.(12)The appeared physical parameters are defined in thenomenclature. The dimensionless governing equationsfrom (9) to (11), with respect to the boundaryconditions (12) are solved by usual Laplace transformtechnique and the solutions for hydro magnetic flowin the presence of radiation and thermal diffusionthrough are obtained as follows.22682012. Fascicule 3 [July–September]

ACTA TECHNICA CORVINIENSIS – Bulletin of Engineering2012. Fascicule 3 [July–September] 69( ) ( )( ) ⎟ ⎟ ⎠⎞⎜⎜⎝⎛−−⎟⎟⎠⎞⎜⎜⎝⎛−+⎟⎟⎠⎞⎜⎜⎝⎛+⎟⎟⎠⎞⎜⎜⎝⎛+=PrRtt2PryerfcRyexpR4yPr2tPrRtt2PryerfcRyexpR4yPr2ty,tθ(13)( )⎟⎟⎠⎞⎜⎜⎝⎛⎟⎠⎞⎜⎝⎛−+⎥⎥⎥⎥⎥⎦⎤⎢⎢⎢⎢⎢⎣⎡⎟⎟⎠⎞⎜⎜⎝⎛ −−⎟ ⎟ ⎠⎞⎜⎜⎝⎛⎟⎟⎠⎞⎜⎜⎝⎛ ++=t2Scyerfccbd4tScyexptScyt2Scyerfc2Scytb1C( y ,t )22π( )( ) ⎥ ⎥⎥⎥⎥ ⎦⎤⎢⎢⎢⎢⎢⎣⎡⎟⎟⎠⎞⎜⎜⎝⎛−−−−+⎟⎟⎠⎞⎜⎜⎝⎛−+−−⎟⎠⎞⎜⎝⎛ −−ctt2ScyerfccScyexpctt2ScyerfccScexp yct)exp(cbd21⎥⎥⎥⎥⎥⎦⎤⎢⎢⎢⎢⎢⎣⎡⎟⎟⎠⎞⎜⎜⎝⎛−−+⎟⎟⎠⎞⎜⎜⎝⎛+⎟⎠⎞⎜⎝⎛−−PrRtt2PryR )erfcyexp(PrRtt2PryR )erfcexp( ycbd21⎥⎥⎥⎥⎥⎦⎤⎢⎢⎢⎢⎢⎣⎡⎟⎟⎠⎞⎜⎜⎝⎛−−⎟⎟⎠⎞⎜⎜⎝⎛−+⎟⎟⎠⎞⎜⎜⎝⎛+⎟⎟⎠⎞⎜⎜⎝⎛+−PrRtt2PryR )erfcyexp(R4yPr2tPrRtt2PryR )erfcexp(yR4yPr2tb( )( )⎥⎥⎥⎥⎥⎥⎥⎥⎥⎥⎥⎥⎦⎤⎢⎢⎢⎢⎢⎢⎢⎢⎢⎢⎢⎢⎣⎡⎟⎟⎟⎟⎟⎠⎞⎜⎜⎜⎜⎜⎝⎛⎟⎠⎞⎜⎝⎛−−−−+⎟⎟⎟⎟⎟⎠⎞⎜⎜⎜⎜⎜⎝⎛⎟⎠⎞⎜⎝⎛−+−−⎟⎠⎞⎜⎝⎛ −+ tcPrRt2PryerfccPrRyexptcPrRt2PryerfccPrRexpyct)exp(cbd21(14)( )( )( ) ⎥ ⎥⎥⎥⎥ ⎦⎤⎢⎢⎢⎢⎢⎣⎡⎟⎟⎠⎞⎜⎜⎝⎛−−⎟⎟⎠⎞⎜⎜⎝⎛−+⎟⎟⎠⎞⎜⎜⎝⎛+⎟⎟⎠⎞⎜⎜⎝⎛+=PrRtt2PryR erfcyexpR4yPr2tPrRtt2PryR erfcexpyR4yPr2tAy,tu 1⎥⎥⎦⎤⎢⎢⎣⎡⎟⎟⎠⎞⎜⎜⎝⎛ −−⎟⎟⎠⎞⎜⎜⎝⎛⎟⎟⎠⎞⎜⎜⎝⎛ ++ t4ScyexptScyt2Scyerfc2ScytA222π( )⎥⎥⎥⎥⎥⎦⎤⎢⎢⎢⎢⎢⎣⎡⎟⎠⎞⎜⎝⎛−−⎟⎟⎠⎞⎜⎜⎝⎛−+⎟⎠⎞⎜⎝⎛+⎟⎟⎠⎞⎜⎜⎝⎛+−−+Mtt2yM)erfcyexp(M4y2tMtt2yM)erfcexp(yM4y2tAA1 21( )( )⎥⎥⎥⎥⎥⎥⎦⎤⎢⎢⎢⎢⎢⎢⎣⎡⎟⎟⎠⎞⎜⎜⎝⎛⎟⎠⎞⎜⎝⎛−−−−+⎟⎟⎠⎞⎜⎜⎝⎛⎟⎠⎞⎜⎝⎛−+−−+tcPrRt2PryerfccPrRyexptcPrRt2PryerfccPrRexpyct)exp(2A 3 ( )( ) ⎥ ⎥⎥⎥⎥ ⎦⎤⎢⎢⎢⎢⎢⎣⎡⎟⎟⎠⎞⎜⎜⎝⎛−−−−+⎟⎟⎠⎞⎜⎜⎝⎛−+−−+ctt2ScyerfccScyexpctt2ScyerfccScexp yct)exp(2A 4 ( ) ( )( ) ( )⎥⎥⎥⎥⎥⎦⎤⎢⎢⎢⎢⎢⎣⎡⎟⎠⎞⎜⎝⎛−−−−+⎟⎠⎞⎜⎝⎛−+−−+tlMt2yerfclMyexptlMt2yerfclMexp ylt)exp(2A 5 ( )( )⎥⎥⎥⎥⎥⎥⎦⎤⎢⎢⎢⎢⎢⎢⎣⎡⎟⎟⎠⎞⎜⎜⎝⎛⎟⎠⎞⎜⎝⎛−−−−+⎟⎟⎠⎞⎜⎜⎝⎛⎟⎠⎞⎜⎝⎛−+−−−tlPrRt2PryerfclPrRyexptlPrRt2PryerfclPrRexp ylt)exp(2A 5 ( ) ( )( ) ( )⎥⎥⎥⎥⎥⎦⎤⎢⎢⎢⎢⎢⎣⎡⎟⎠⎞⎜⎝⎛+−+−+⎟⎠⎞⎜⎝⎛++++tnMt2yerfcnMyexptnMt2yerfcnMexp yexp(nt)2A 6 ( )( ) ⎥ ⎥⎥⎥⎥ ⎦⎤⎢⎢⎢⎢⎢⎣⎡⎟⎟⎠⎞⎜⎜⎝⎛−−+⎟⎟⎠⎞⎜⎜⎝⎛+−ntt2ScyerfcnScyexpntt2ScyerfcnScexp yexp(nt)2A 6( )( )⎟⎟⎠⎞⎜⎜⎝⎛+⎥⎥⎥⎥⎥⎦⎤⎢⎢⎢⎢⎢⎣⎡⎟⎟⎠⎞⎜⎜⎝⎛−−++⎟⎟⎠⎞⎜⎜⎝⎛++t2ScyerfcAPrRtt2PryerfcRyexpPrRtt2PryerfcRyexp2A87( )⎥⎥⎥⎥⎥⎦⎤⎢⎢⎢⎢⎢⎣⎡⎟⎠⎞⎜⎝⎛++⎟⎠⎞⎜⎝⎛++−Mtt2yM)erfcexp(yMtt2yM )erfcexp(yAA2187 (15)where,1ScMn,1ScMR,lRbPrd,ScPrRcSc ,Sb 0−=−−==−==,Mb)Gm(1,AMRGrbGmA 21+=−−=

70(Pr−1)=bGm( R −cPr)( − M+c −cPr)A3=,cR RbGm(R −cPr)A4=,cR(R − M+c −cPr)[ RGr(R−M+c −cPr)+ Gmbc(MPr−R)]A52Gm(Sc−1)=A62A7R(R −M)(R−M+c −cPr)[ M(R + bcPr) + cR(1+b)(Sc −1)]M R(M−c+ cSc)cR(Pr−1)(Gr−bGm)+ Gmb(R −M)(cPr−R)=2cR(R −M)[ −1)+ MPr bc −bR(M+c −cSc)]Gm cR(ScA8=2cM RTHE RATE OF HEAT TRANSFERFrom temperature field, now we study Nusseltnumber (rate of change of heat transfer)it is given innon‐dimensional form as⎡∂θ⎤Nu = −⎢⎥(17)⎣ ∂y⎦y=0From equations (13) and (17), we get Nusselt numberas follows⎡ Rt tPr ⎛ Rt ⎞ Pr Rt ⎤Nu = ⎢tRerf + exp⎜− ⎟ + erf ⎥⎣ Pr π ⎝ Pr ⎠ 2 R Pr ⎦THE RATE OF MASS TRANSFERFrom the concentration field, we now study Sherwoodnumber (rate of change of mass transfer) it is given innon‐dimensional form as follows⎡∂C⎤Sh = −⎢⎥(18)⎣ ∂y⎦ y=0From equations (14) and (18), we getSh = 2(1+b)tSc ⎛+ ⎜d−π ⎝b ⎞⎟c ⎠⎡ Sc⎤⎛ b ⎞ ⎢ exp(ct) ⎥−⎜d− ⎟exp(−ct)⎢ πt⎥⎝ c ⎠⎢⎥⎣+− cScerf −ct⎦⎡ Pr ⎛ Rt ⎞⎤⎢ exp⎜− ⎟⎥⎛ b ⎞⎢πt⎝ Pr ⎠−⎜d− ⎟⎥⎝ c ⎠⎢Rt ⎥⎢+Rerf ⎥⎣ Pr ⎦⎡⎢tRerf− b⎢⎢ Pr⎢+erf⎣ 2 RRtPr+RtPrtPr ⎛exp⎜−π ⎝RtPrScπt⎡ Pr ⎛ Rt ⎞ ⎤⎢ exp⎜− + ct⎟⎥⎛ b ⎞ ⎢ πt⎝ Pr ⎠+⎥⎜d− ⎟exp(−ct)⎝ c ⎠ ⎢⎥⎢⎛ R ⎞+ R − cPrerf ⎜ − c⎟t⎥⎢⎣⎝ Pr ⎠ ⎥⎦⎞⎤⎟⎥⎠⎥⎥⎥⎦ACTA TECHNICA CORVINIENSIS – Bulletin of EngineeringGRAPHSIn order to get the physical insight into the problem,we have plotted velocity, temperature, concentration,the rate of heat transfer and the rate of mass transferfor different values of the physical parameters likeRadiation parameter (R), Magnetic parameter(M),Soret number(So), Schmidt number (Sc), ThermalGrashof number (Gr), Mass Grashof number (Gm),time (t) and Prandtl number (Pr) in figures 1 to 14 forthe cases of heating (Gr < 0, Gm < 0) and cooling (Gr >0, Gm > 0) of the plate at time t = 0.4. The heating andcooling take place by setting up free‐convectioncurrent due to temperature and concentrationgradient.VelocityVelocityVelocity1.210.80.60.40.20-0.2-0.4-0.6M=1, Gr=15, Gm=10M=3, Gr=15, Gm=10M=5, Gr=15, Gm=10M=7, Gr=15, Gm=10M=1, Gr=-15, Gm=-10M=3, Gr=-15, Gm=-10M=5, Gr=1-5, Gm=-10M=7, Gr=-15, Gm=-10-0.80 0.5 1 1.5 2 2.5y43210-1-2-3Figure 1: Velocity profiles when so=5, Sc=2.01,Pr=0.71, R=15 and t=0.4-40 0.5 1 1.5 2 2.5y10.80.60.40.20-0.2-0.4-0.6So=1, Gr=15, Gm=10So=5, Gr=15, Gm=10So=10,Gr=15, Gm=10So=15, Gr=15, Gm=10So=20, Gr=15, Gm=10So=25, Gr=15, Gm=10Figure 2: Velocity profiles when M=3, Sc=2.01,Pr=0.71, R=15 and t=0.4-0.80 0.5 1 1.5 2 2.5ySo=1, Gr=-15, Gm=-10So=5, Gr=-15, Gm=-10So=10, Gr=-15, Gm=-10So=15, Gr=-15, Gm=-10So=20, Gr=-15, Gm=-10So=25, Gr=-15, Gm=-10R=5, Gr=15, Gm=10R=10, Gr=15, Gm=10R=15, Gr=15, Gm=10R=20, Gr=15, Gm=10R=25, Gr=15, Gm=10R=5, Gr=15, Gm=10R=10, Gr=-15, Gm=-10R=15, Gr=-15, Gm=-10R=20, Gr=-15, Gm=-10R=25, Gr=-15, Gm=-10Figure 3: Velocity profiles when so=5, Sc=2.01, M=3, Pr=0.71and t=0.42012. Fascicule 3 [July–September]

ACTA TECHNICA CORVINIENSIS – Bulletin of Engineering1.5Sc=2, Gr=15, Gm=10Sc=4, Gr=15, Gm=101Sc=6, Gr=15, Gm=10Sc=8, Gr=15, Gm=10Sc=2, Gr=-15, Gm=-100.5Sc=4, Gr=-15, Gm=-10Sc=6, Gr=-15, Gm=-10VelocitySc=8, Gr=-15, Gm=-100-0.5Velocity43210-10 0.5 1 1.5 2 2.5yFigure 4: Velocity profiles when so=5, M=3,Pr=0.71, R=15 and t=0.4t=0.2, Gr=15, Gm=10t=0.4, Gr=15, Gm=10t=0.6, Gr=15, Gm=10t=0.8, Gr=15, Gm=10t=0.2, Gr=-15, Gm=-10t=0.4, Gr=-15, Gm=-10t=0.6, Gr=-15, Gm=-10t=0.8, Gr=-15, Gm=-10Figure 8: Concentration profiles when R=5,Sc=2.01 and Pr=0.71-1-2-30 0.5 1 1.5 2 2.5 3Figure 5: Velocity profiles when so=5, Sc=2.01,M=3, Pr=0.71, R=15Figure 9: Concentration profiles when So=10,Pr=0.71 and R=5Figure 6: Temperature profiles when Pr=0.71Figure 10: Concentration profiles for different Rwhen So=5, Sc=2.01 and Pr=0.71Figure 7: Temperature profiles when R=10Figure 11: Nusselt number2012. Fascicule 3 [July–September] 71

72Figure 12: Sherwood Number for different ScFigure 13: Sherwood Number for different SoFigure 14: Sherwood Number for different RDISCUSSION AND RESULTSFigure (1) displays the influences of M (magneticparameter) on the velocity field in cases ofcooling and heating of the plate. It is found thatthe velocity decreases with increasing of magneticparameter M in case of cooling, while it increases inthe case of heating of the plate. It is seen that fromFigure (2) the velocity increases with increase in So( Soret number ) in the case cooling of the platebut a reverse effect is identified in the case ofheating of the plate. From figure (3) and (4) it isobserved that with the increase of radiationparameter R or Schmidt number Sc, the velocityincreases up to certain y value (distance from theplate) and decreases later for the case of coolingof the plate. But a reverse effect is observed in theACTA TECHNICA CORVINIENSIS – Bulletin of Engineeringcase of heating of the plate. The velocity profilesfor different values of time t are shown in Figure (5), itis seen that as time t increases the velocity increasesgradually in the case of cooling of the plate and thetrend is just reversed in the case of heating of theplate.The temperature of the flow field is mainly affected bythe flow parameters, namely, Radiation parameter (R)and the prandtl number (Pr). The effects of theseparameters on temperature of the flow field areshown in figures 6 & 7 respectively. Figure 6 depictsthe temperature profiles against y (distance from theplate) for various values of radiation parameter (R) attime t=0.2 & 0.4 keeping Prandtl number (Pr) asconstant. It is observed that as radiation parameter Rincreases the temperature of the flow field decreasesat all the points.Figure 7 shows the plot of temperature of the flowfield against for different values of Prandtl number(Pr) at time t = 0.2 & t =0.4 taking radiation parameter(R) as constant. It is observed that the temperature ofthe flow field decreases in magnitude as Pr increases.It is also observed that the temperature for air(Pr=0.71) is greater than that of water (Pr=7.0). This isdue to the fact that thermal conductivity of fluiddecreases with increasing Pr, resulting decreases inthermal boundary layer.The concentration distributions of the flow field aredisplayed through figures 8, 9 &10. It is affected bythree flow parameters, namely Soret number (So),Schmidt number (Sc) and radiation parameter(R)respectively. From figure 8 it is clear that theconcentration increases with an increase in So (soretnumber). Figure 8 & 10 reveal the effect of Sc and R onthe concentration distribution of the flow field. Theconcentration distribution is found to increase fasterup to certain y value (distance from the plate) anddecreases later as the Schmidt parameter (Sc) orRadiation parameter (R) become heavier.Nusselt number is presented in Figure 11 against timet. From this figure the Nusselt number is observed toincrease with increase in R for both water (Pr=7.0) andair (Pr=0.71). It is also observed that Nusselt numberfor water is higher than that of air (Pr=0.71). Thereason is that smaller values of Pr are equivalent toincreasing the thermal conductivities and thereforeheat is able to diffuse away from the plate morerapidly than higher values of Pr, hence the rate of heattransfer is reduced. Figure 12, 13 & 14 representSherwood number against time t. And it is observedthat the Sherwood number decreases with increase inSc (Schmidt number), So (soret number) and R(radiation parameter).Nomenclaturea* Absorption coefficienta Accelerated parameter2012. Fascicule 3 [July–September]

ACTA TECHNICA CORVINIENSIS – Bulletin of EngineeringB0 External magnetic fieldC’ Species concentrationC’ w Concentration of the plateC’ ∞ Concentration of the fluid far away from the plateC Dimensionless concentrationCp Specific heat at constant pressureD Chemical molecular diffusivityD 1 Coefficient of thermal diffusivityg Acceleration due to gravityGr Thermal Grashof numberGm Mass Grashof numberM Magnetic field parameterNu Nusselt numberPr Prandtl numberq r Radiative heat flux in the y‐ directionR Radiative parameterSc Schmidt numberS0 Soret numberSh Sherwood numberT Temperature of the fluid near the plateT’ w Temperature of the plateT’ ∞ Temperature of the fluid far away from the platet Timet Dimensionless timeu’ Velocity of the fluid in the x’ ‐ directionu0 Velocity of the plateu Dimensionless velocityy’ Co‐ordinate axis normal to the platey Dimensionless co‐ordinate axis normal to the plateGreek symbolsк Thermal conductivity of the fluid∝ Thermal diffusivityβ Volumetric coefficient of thermal expansionβ* Volumetric coefficient of expansion with concentrationμ Coefficient of viscosityν Kinematic viscosityρ Density of the fluidσ Electric conductivityθ Dimensionless temperatureerf Error functionerfc Complementary error functionSubscriptsω Conditions on the wall∞ Free stream conditionsREFERENCES[1.] M.S.Alam, M.M. Rahman and M.A. Maleque, Localsimilarity solutions for unsteady MHD freeconvection and mass transfer flow past animpulsively started vertical porous plate with Dufourand Soret effects, Thammasat int.j.sci.tech. 10(3)(2005),1‐8.[2.] M.S.Alam, M.M.Rahman and M.A. Samad, Numericalstudy of the combined free‐forced convection andmass transfer flow past a vertical porous plate in aporous medium with heat generation and thermaldiffusion , Nonlin. Anal.Model. Control 11(4) (2006),331‐343[3.] M.M. Alam and M. A. Sattar, Transient MHD heat andmass transfer flow with thermal diffusion in arotating system, J. Energy Heat Mass trans. 21(1999)m 9‐21.[4.] U . N. Das, R.K. Deka and V.M. Soundalgekar ,Radiation effects on flow past an impulsively startedvertical infinite plate, J. heo. Mech. 1(1996), 111‐115.[5.] M. A. Hossain and H. S. Takhar, Radiation effect onmixed convection along a vertical plate with uniformsurface temperature, Heat Mass Trans. 31(1996), 243‐248.[6.] B. K. Jha and A. K. Singh, Soret effects on freeconvectionand mass transfer flow in the Stokesproblem for a infinite vertical plate, Astrophys.SpaceSci. 173(2) (1990).[7.] N. G. Kafoussias, MHD thermal –diffusion effects onfree convective and mass transfer flow over aninfinite vertical moving plate. Astrophys.Space Sci.192(1) (1992), 11‐19.[8.] M. Kumari and G. Nath , Development of twodimensionalboundary layer with an appliedmagnetic field due to an impulsive motion, Indian J.pure Appl. Math. 30 (1999), 695‐708.[9.] R. Muthucumaraswamy and B. Janakiraman, MHDand radiation effects on moving isothermal verticalplate with variable mass diffusion, Theo. Appl. Mech.33(1) (2006), 17‐29.[10.] A. Raptis and C. Perdikis, Radiation and freeconvection flow past a moving plate, Int. J.ApplMech. Eng. 4(1999), 817‐821.[11.] V.M. Soundalgekar , S.K. Gupta and N.S. Birajdar,Effects of mass transfer and free convection currentson MHD Stokes problem for a vertical plate, NuclearEng. Des. 53(1979), 339‐346.[12.] V.M.Soundalgekar, M.R.Patil and M.D. Jahagirdar,MHD Stokes problem for a vertical plate withvariable temperature, Nuclear Eng. Des. 64(1981), 39‐42.[13.] V.M. Soundalgekar and H.S. Takhar, Radiation effectson free convection flow past a semi‐infinite verticalplate , Model. Measure.Comrol (1993), 31‐40.ACTA TECHNICA CORVINIENSIS – BULLETIN of ENGINEERINGISSN: 2067‐3809 [CD‐Rom, online]copyright © UNIVERSITY POLITEHNICA TIMISOARA,FACULTY OF ENGINEERING HUNEDOARA,5, REVOLUTIEI, 331128, HUNEDOARA, ROMANIAhttp://acta.fih.upt.ro2012. Fascicule 3 [July–September] 73

ACTA TECHNICA CORVINIENSIS – Bulletin of EngineeringACTA TECHNICA CORVINIENSIS – BULLETIN of ENGINEERINGISSN: 2067‐3809 [CD‐Rom, online]copyright © UNIVERSITY POLITEHNICA TIMISOARA,FACULTY OF ENGINEERING HUNEDOARA,5, REVOLUTIEI, 331128, HUNEDOARA, ROMANIAhttp://acta.fih.upt.roACTA TECHNICA CORVINIENSIS – BULLETIN of ENGINEERINGISSN: 2067‐3809 [CD‐Rom, online]copyright © UNIVERSITY POLITEHNICA TIMISOARA,FACULTY OF ENGINEERING HUNEDOARA,5, REVOLUTIEI, 331128, HUNEDOARA, ROMANIAhttp://acta.fih.upt.ro© copyright FACULTY of ENGINEERING ‐ HUNEDOARA, ROMANIA 74

1. Angela IAGĂR, 2. Gabriel Nicolae POPA, 3. Corina Maria DINIŞANALYSIS OF EVENTS IN ELECTRIC STATIONS USING FOCUS FORWINDOWS PROGRAM1‐3. DEPARTMENT OF ELECTROTECHNICAL ENGINEERING & INDUSTRIAL INFORMATICS, FACULTY OF ENGINEERING HUNEDOARA,UNIVERSITY POLITEHNICA TIMIŞOARA, STR. REVOLUȚIEI, NO.5, HUNEDOARA, ROMANIAABSTRACT: The continuous development of the energetic system and the necessity to increase the safety in operation andthe quality of the supplied electric power imposes increasingly severe conditions to the protection and control systems.Among the most important components of SCADA systems used for the electric stations control and protection are theequipments for disturbances recording and analysis, such as the Compact Digital Recorder (CDR). The data stored in theinternal CDR memory can be extracted on a PC by CDR Link for Windows program. This paper presents Focus for Windowsprogram, designated for visualization, analysis, interpretation and printing the recordings performed in electric stationswith CDR equipments.KEYWORDS: energetic system, safety in operation, Compact Digital Recorder (CDR), SCADA systemsINTRODUCTIONIn Romania, according to TRANSELECTRICA strategy(Romanian Transmission and System Operator), formanaging the electric transport and distribution gridis used an EMS/SCADA system (Energy Managementand Supervisory Control and Data Acquisition). Thissystem has a hierarchical, decentralized, distributedand redundant architecture.An EMS/SCADA system contains [1, 2]:a. measuring components (for electric grids aremeasured the voltages, currents, active andreactive powers, frequency, as well as the activeand reactive energy);b. drive and automation components (for electricgrids: switches, circuit breakers, disconnectorsetc.);c. hardware components: computers, printers,plotters, monitors, synoptic displays, processmanagement modules, PLC control modules,storing units (discs and/or magnetic tapes) etc;d. software components: operation systems (in realtime, or not), data collecting systems, databasemanagement systems, simulation programs,communication programs, archiving/datarestoration programs;e. communication components: LAN networks (Local Area Network: coaxial cables,UTP, fiber optic cables, network cards); telephone lines; terrestrial radio communication equipment(emission‐reception stations, transmission relays); communication equipment.The measuring components could be simpletransducers connected to an analogue‐digitalconversion unit, or can be instruments with digitaloutput.The digital value of measurement is taken by a RTU(Remote Terminal Unit), which evaluates themeasurement result (is made a verification to framewithin the pre‐established measuring limits); for someusual cases RTU initiates the performance of somecontrols and communicates the measurement resultsto the processing central system.Figure 1. Principle diagram of an EMS/SCADA systemOne of the most important components ofEMS/SCADA systems is the database managementsystem.The drive and automation components are connectedto the RTU tele‐transmission terminal units or to PLCs,which, based on the evaluation results, or based onthe controls arrived from the processing centralsystem control the performance of some operations.RTUs are local decisional modules that can initiatesome critical or routine operations.© copyright FACULTY of ENGINEERING ‐ HUNEDOARA, ROMANIA 75

The hardware components offer the processing,storing, enter, display and data printing support.From safety considerations are used redundantelements to prevent the data loss or operationsinterruption.The software components allow the data monitoring,visualizing and processing. Some of these componentscan initiate physical operations, such as controlling ofsome drive and automation elements.The communication programs, beside the electroniccommunication support, ensure the connectionsbetween different system elements. Provided that thecommunications ensure the system’s vital data flux,are used redundant means to prevent the system’spartial or total drop.EMS/SCADA functions within the energetic system are: data acquisitions and exchange; chronological recording of events; data automatic processing; post fault analysis; real‐time database updating; maintaining thedatabase with historical information regarding thesystem operation; tele‐control; warnings and alarms; user interface [3‐7].When a disturbance occurs in electric stations, it takesplace a variation of the analogue and binaryparameters. This variation is recorded by theacquisition (scanning) equipments, from whichcategory is also the Compact Disturbance Recorderproduced by TELECOMM Bucharest [8].ACTA TECHNICA CORVINIENSIS – Bulletin of EngineeringFocus for Windows [9] is a program designated forvisualization, analysis, interpretation and printing therecordings performed in electric stations withequipments of digital perturbograph type.Each parameter is associated with a logic channel, aset of value segments (pre and post‐fault) andauxiliary information. These are components of afocus document. Focus program provides a summaryof the fault analysis through a disturbance report.The quantities (analogue and numerical) acquired byCDR can be graphically visualized with Focus forWindows program.The program provides, also, the phasor diagrams ofvoltages and currents, and their harmonic analysis.There are two types of menus used within theprogram: static menus and contextual menus. Thestatic menus provide general (global) optionsregarding the focus documents.The contextual menu allows the obtaining ofinformation about a channel (about a visible quantity)as well as performing of specific operations on therespective channel (amplification on abscise, onordinate, color setting, graph line thickness settingetc.).SUMMARY OF A FAULT REPORT GENERATED BY FOCUSPROGRAMFurther is presented a summary of the fault reportgenerated by Focus program in case of a single‐phaseshort‐circuit with ground on the 400 kV overheadtransmission line (OTL) Sibiu, in Mintia station.A. Values of Pre‐fault QuantitiesThe total time allocated to record the pre‐faultquantities was 99.96 ms. Figure 3 show the phasordiagrams of voltages and currents at time moment t=‐60 ms. The differences betweens the RMS values ofphase voltages, respectively phase currents are verysmall: UL1=239.2 kV, UL2=240.6 kV, UL3=239.5 kV,IL1=365 A, IL2=374.6 A, IL3=369.5 A.Figure 2. Logic operational diagram of the acquisition,extraction and analysis system of the events from anelectric stationCDR records the disturbance data and events duringthe time period:t recording = t Pre + t Fault + t Post , (1)where: t Pre represents the pre‐fault recording time,t Fault is the fault recording time, and t Post is the postfaultrecording time.Figure 3. Marker 1: t=‐60 ms (pre‐fault).Phasor diagrams of voltages and currents762012. Fascicule 3 [July–September]

ACTA TECHNICA CORVINIENSIS – Bulletin of EngineeringPhase difference between voltages is approximately120°. Also, the phase currents are shiftedsymmetrically by approximately 120°. One can noticethat the phasors U and I are slightly dephased. Thehomopolar voltage and the homopolar current havelow RMS values: U0=5.159 kV, I0=42.23 A. All theseindicate a normal operation of the electric line at themoment t=‐60 ms.In Figure 4, at t=‐30 ms, the phase differences betweenthe phase voltages are a little modified against thenormal operation.B. Values of Fault QuantitiesThe values measured at the moment t=17 ms (Figure 5)are framed within the fault period of the recording. Atthis moment is recorded a maximum value of thecurrent on phase 2 (IL2=2.93 kA) and a voltagedecrease on phase 2 (UL2=70.02 kV).One can notice a significant increase of the homopolarquantities (I0=3.597 kA, U0=294 kV), up to the limitwhen the high‐voltage breaker’s protections of OTLSibiu are triggered.At t=34 ms (Figure 6) is noticed the disappearance ofthe phase fault current (IL2=44.49 A) and homopolarcurrent (I0=312.6 A).Analogue quantities in the time period t= ‐60 ...34 msare presented in Figure 7. Numerical quantities in thetime period t= ‐60 ...34 ms are presented in Figure 8.Figure 4. Marker 2: t=‐30 ms (pre‐fault).Phasor diagrams of voltages and currentsIs noticed a slight decrease of the voltage on phase 2(UL2=218.2 kV) compared with the voltages on theother phases (UL1=236.4 kV, UL3=240.8 kV). Thecurrent on phase 2 (IL2=1.314 kA) has a higher value(IL1=331.2 A, IL3=401.2 A). The homopolar voltage andthe homopolar current have high values (U0=111.8 kV,I0=1.344 kA).Marker 2 (at t=‐30 ms) catches the incipient stage of aphase‐to‐ground fault on phase 2 (L2).Figure 6. Marker 5: t=34 ms (fault).Phasor diagrams of voltages and currentsFigure 5. Marker 4: t=17 ms (fault).Phasor diagrams of voltages and currentsFigure 7. Analogue quantitiesin the time period t= ‐60 ...34 ms2012. Fascicule 3 [July–September] 77

Markers 1 (t=‐60 ms) and 2 (t=‐30 ms) show that theOTL protections are in stand‐by (pre‐fault period).Marker 3 (t=‐8 ms) is close the trigger limit.In Figure 8, marker 5 (t=34 ms) indicates: PLC REC CH0:1 – trigger impulse issued by the distance protectionREL 521 of the teleprotection channel that sends atrigger impulse to the high‐voltage breaker of Sibiustation.In Figure 8, marker 4 (t=17 ms) indicates the start ofdistance protections: START L2 RE 1:1 – start for group1 of protections through the line distance protectionterminal REL 521, phase L2; GEN. START 1:1 – generalstart of distance protection REL 521; GEN. TRIP R1:1 –trigger impulse sent by the distance protection REL 521to the high‐voltage breaker of OTL Sibiu, in Mintiastation; DIST. TRIP 1:1 – trigger of distance protectionREL 521; START L2 LZ 1:1 – start for group 2 ofprotections through the digital relay LZ96a, phase L2;GEN. START 1:1 – general start of digital relay LZ96a;DIST. TRIP 1:1 – trigger of digital relay LZ96a.ACTA TECHNICA CORVINIENSIS – Bulletin of EngineeringIn Sibiu station the distance protection frames thesingle‐phase‐to‐ground fault in triggering step two,and the protection from the Sibiu station starts; thetwo breakers of high‐voltage OTL, from Mintia,respectively Sibiu, trigger simultaneously.In Figure 9, marker 6 (t=165 ms) presents the revert ofthe distance protection from initial state.Fault locator of REL 521 terminal use for the distanceto fault calculation a line modelling algorithm, thattakes into account the sources at both ends of theline. Taking into account the RMS values of the phasecurrents and voltages, the distance is quantified fromthe place where the protection is mounted up to thefault place, and is equal by 24.2 km.In Figure 10, marker 7 (t=1065 ms) indicates AR ONREL/R 1:1, with the following functions: sending of a reclosing impulse to the Sibiu OTL’sbreaker in Mintia; sending of a reclosing impulse to the Mintia OTL’sbreaker in Sibiu, by emitting a high‐frequencyimpulse through teleprotection (this being acommon channel).Figure 9. Marker 6 (t=165 ms): revert of distance protectionfrom initial stateFigure 10. Marker 7 (t=1065 ms): reclosing impulses to thebreakersMarker 8 (in Figure 10) indicates the time momentt=1083 ms, when the Sibiu OTL’ breaker is in closingprogress.Marker 9 (in Figure 10) indicates the moment t=1125ms, when the Sibiu OTL breaker is closed.C. Values of Post‐fault QuantitiesAt the moment t=1184 ms (Figure 11) small differencesbetween RMS values of the phase voltages (UL1=239.6kV, UL2=242.5 kV, UL3=239.9 kV) and RMS values ofthe phase currents (IL1=375.8 A, IL2=394.3 A, IL3=369.5 A) are noticed. The RMS value of the homopolarquantities are low (U0=37.58 kV, I0=42.23 A).This figure presents the end of the successful reclosing(+).Figure 8. Numerical quantities in the time periodt= ‐60 ...34 ms. Start of distance protections782012. Fascicule 3 [July–September]

ACTA TECHNICA CORVINIENSIS – Bulletin of EngineeringFigure 11. Marker 10: t=1184 ms (post‐fault). Phasordiagrams of voltages and currentsCONCLUSIONSThe EMS/SCADA functions within the energetic systemare: data acquisitions and exchange; chronologicrecording of events; data automatic processing; postfaultanalysis; real‐time database update;maintenance with historic information regarding thesystem’s operation; tele‐control; warnings and alarms;user interface.The Compact Digital Recorder (CDR) allows therecording of events that appear in electric stationsoperation.Focus for Windows is a program designated forvisualization, analysis, interpretation and printing therecordings performed in electric stations withequipments of digital perturbograph type. Eachparameter is associated with a logic channel, a set ofvalue segments (pre and post‐fault) and auxiliaryinformation. These are components of a focusdocument.Focus program provides a summary of the faultanalysis through a disturbance report. Are noticedespecially the facilities offered by Focus program inanalyzing the analogue and numerical quantities; thevisualization of RMS values, phasor diagrams andharmonic analysis are in real time. Focus programallows the harmonic analysis of the voltages andcurrents up to 10‐th order.Further the analysis of the disturbance report issuedby the Focus program, can be determined the causes,amplitude and consequences of the appeareddisturbance.REFERENCES[1.] Bailey, D and Wrigh, E: Practical SCADA for Industry,Elsevier, 2002.[2.] Brand, K et al: Substation Automation Handbook,Utility Automation Consulting Lohmann, 2003.[3.] Brand, K: The Standard IEC 61850 as Prerequisite forIntelligent Applications in Substations, IEEE/PESGeneral Meeting, USA, 2004.[4.] Matz, V; Radil, T; Ramos, P and Serra, A. C:Automated Power Quality Monitoring System for onlineDetection and Classification of Disturbances, IEEEIMTC 2007 – Instrumentation and MeasurementTechnology Conference, Warsaw, Poland, May 2007.[5.] Mohamed, E.A; Talaat, H. A and Khamis, E.A: FaultDiagnosis System for Tapped Power TransmissionLines, Electric Power Systems Research, vol. 80, pp.599–613, 2010.[6.] Terzija, V and Radojevic, Z: Numerical Algorithm forAdaptive Autoreclosure and Protection of Medium‐Voltage Overhead Lines, IEEE Trans. Power Deliv, vol.12 (2), pp. 554‐559, 2004.[7.] Dobriceanu, M; Bitoleanu, A; Popescu, M and Vlăduț,G: Practical Aspects Concerning the Monitoring ofthe Electrical Stations, WSEAS Transactions onInformation Science and Applications, issue 11, vol. 2,pp. 1897‐1904, 2005.[8.] *** Compact Disturbance Recorder, TELECOMM,2000.[9.] *** Focus for Windows v2.0, TELECOMM, 2000ACTA TECHNICA CORVINIENSIS – BULLETIN of ENGINEERINGISSN: 2067‐3809 [CD‐Rom, online]copyright © UNIVERSITY POLITEHNICA TIMISOARA,FACULTY OF ENGINEERING HUNEDOARA,5, REVOLUTIEI, 331128, HUNEDOARA, ROMANIAhttp://acta.fih.upt.ro2012. Fascicule 3 [July–September] 79

ACTA TECHNICA CORVINIENSIS – Bulletin of EngineeringACTA TECHNICA CORVINIENSIS – BULLETIN of ENGINEERINGISSN: 2067‐3809 [CD‐Rom, online]copyright © UNIVERSITY POLITEHNICA TIMISOARA,FACULTY OF ENGINEERING HUNEDOARA,5, REVOLUTIEI, 331128, HUNEDOARA, ROMANIAhttp://acta.fih.upt.roACTA TECHNICA CORVINIENSIS – BULLETIN of ENGINEERINGISSN: 2067‐3809 [CD‐Rom, online]copyright © UNIVERSITY POLITEHNICA TIMISOARA,FACULTY OF ENGINEERING HUNEDOARA,5, REVOLUTIEI, 331128, HUNEDOARA, ROMANIAhttp://acta.fih.upt.ro© copyright FACULTY of ENGINEERING ‐ HUNEDOARA, ROMANIA 80

1.Mohamed ZELLAGUI, 2. Abdelaziz CHAGHIMEASURED IMPEDANCE BY MHO DISTANCE PROTECTION FORPHASE TO EARTH FAULT IN PRESENCE GCSC1‐ 2 LSP‐IE RESEARCH LABORATORY, FACULTY OF TECHNOLOGY, DEPARTMENT OF ELECTRICAL ENGINEERING, UNIVERSITY OF BATNA, ALGERIAABSTRACT: This paper presents the impact study of GTO Controlled Series Capacitor (GCSC) parameters on MHO distancerelays measured impedance for 220 kV protected electrical transmission line in the presence of phase to earth fault withfault resistance. The study deals with a 220 kV electrical transmission line of Eastern Algerian transmission networks atGroup Sonelgaz (Algerian Company of Electrical and Gas), compensated by series Flexible AC Transmission System (FACTS)i.e. GCSC connected at midpoint of the line. The transmitted active and reactive powers are controlled by three GCSC’s. Theeffects of maximum reactive power injected as well as injected maximum voltage by GCSC on measured impedance bydistance relays is treated. The simulations results investigate the impact of GCSC injected parameters (reactance, voltageand reactive power) on measured resistance and reactance in the presence of earth fault with resistance fault for differentcases study.KEYWORDS: GCSC, electrical transmission line, earth fault, symmetrical components; MHO distance relay, measuredimpedanceINTRODUCTIONFault currents have an important influence on thedesign and operation of equipment and powersystems. In Algerian Company of Electrical and Gas,more than 80% of the occurred faults on 220 and 400kV overhead transmission networks are single phaseto ground type. However, phase to phase faults arethe most common fault type after single phase toground faults.Distance protection relays have been widely applied asthe primary protection in high voltage transmissionlines due to their simple operating principle andcapability to work independently under mostcircumstances [1‐2]. The basic operation principle ofdistance relay is based on the fact that the lineimpedance is fairly constant with respect to the linelength. However, the implementation of FACTSControllers in power system transmission forenhancing the power system controllability andstability have introduced new power system issues inthe field of power system protection that must beconsidered and analyzed [3]. Some of the concernsinclude the rapid changes in line impedance and thetransients introduced by the fault occurrence with theassociated control action of the FACTS Controllers.The presence of the FACTS devices in the faulted loopintroduces changes to the line parameters seen by thedistance relay. The effect of FACTS device would affectboth the steady state and transient trajectory of theapparent impedance seen by distance relays due tothe fast response time of FACTS Controllers withrespect to that of the protective devices. The impactof FACTS devices on distance protection variesdepending on the type of FACTS device used, theapplication for which it is applied and the location ofthe FACTS device in the power system.The effect of different types of series FACTS devices ondistance protection of transmission lines has beenreported: for Thyristor Controlled Series Capacitor(TCSC) in [4‐7] and for Static Synchronous SeriesCompensator (SSSC) in [8‐9], for shunt FACTS devicesthe type Static Synchronous Compensators(STATCOM) is study in [10‐12] and for Static VarCompensators (SVC) in [13‐14]. However, the authorshave not come across any reported work onmitigation of the impact of midpoint series FACTScompensated transmission lines on distanceprotection.In this paper we report the impact of variation ofmaximum reactive power injected by GCSC for threecase study in the presence phase to earth faults(phase A) at the end of the transmission line withresistance fault (R F ). The GCSC is located on 220 kVmidline of the Algerian transmission line betweensubstations Ain M’lila and Khenchela which isprotected by MHO distance relay installed at busbar A.The study concerns the impact of injected parameters(X GCSC , V GCSC and Q GCSC ) of the GCSC on the measuredimpedance by distance relay R seen and X seen forprotected transmission line in presence of resistancefault which varies between 5 to 50 Ω.REACTIVE POWER ON TRANSMISSION LINE IN PRESENCE GCSCThe compensator GCSC mounted on figure 1.a is thefirst that appears in the family of series compensators.It consists of a capacitance (C) connected in serieswith the electrical transmission line and controlled bya valve‐type GTO thyristors mounted in anti‐paralleland controlled by an extinction angle (γ) variedbetween 0° and 180° [15‐17]. Controlled series© copyright FACULTY of ENGINEERING ‐ HUNEDOARA, ROMANIA 81

compensation, apply dynamic control of the degree ofseries compensation in a long line.(a)(b)Figure 1. Transmission line in presence of GCSC system.a). Control principle, b). Apparent reactance.Figure 2 shows typical current and voltage waveformsfor the GCSC of Figure 1, for a given blocking angle γ.[16]. It is assumed that the transmission line current(I L ), is sinusoidal.Figure 2. GCSC current, voltage waveformsand switch controlThis compensator injected in the transmission line ABbetween busbar A (source) and B (load) a variablecapacitive reactance (X GCSC ). From figure 1.b thiscapacitive reactance is defined by the followingequation [18‐19]:⎡ 2 1 ⎤XGCSC( γ ) = XC.Max ⎢1− γ − sin(2 π)⎣ π π ⎥(1)⎦where, X = 1CMax .CGCSC. ω(2)The conduction angle (β) which varies between 0 to90°, is defined by next relation:⎛π⎞β = π − 2γ = 2⎜−γ⎟(3)⎝ 2 ⎠From equation (3), the equation (2) becomes:⎡ ⎛π−β⎞ 1⎤XGCSC( β) = XC.Max ⎢1−⎜⎟− sin ( π( π −β))π π⎥(4)⎣ ⎝ ⎠⎦ACTA TECHNICA CORVINIENSIS – Bulletin of Engineeringwhere, the relation of injected voltage is:⎡ ⎛π−β⎞1⎤VGCSC( β) = VGCSC −Max⎢1−⎜⎟− sin ( π( π−β))π π⎥ (5)⎣ ⎝ ⎠⎦The reactive injected power by GCSC is:2VGCSC( β)QGCSC( β)= (6)XGCSC( β)The active and reactive power at busbar B with GCSC isdefined by following equations:VA.VBPB( δ ) =sin( δ ) (7)RAB− XGCSC2VB VA.VBQB( δ ) = PB( δ) = − cos( δ)(8)ZAB −XGCSC ZAB −XGCSCwhere,⎧VB = VBW .+ VGCSC⎨(9)⎩ VBW.= VAW.−ΔVThe V A.W and V B.W represent voltages at busbar A and Brespectively without GCSC.IMPEDANCE MEASURED BY MHO DISTANCE RELAYDistance protection has been widely used in theprotection of EHV and HV transmission lines. The basicprinciple of MHO distance protection involves thedivision of the voltage at the relaying point by themeasured current [1], [29]. The apparent impedanceso calculated is compared with the reach pointimpedance. If the measured impedance (Z seen ) is lessthan the reach point impedance, it is assumed that afault exists on the line between the relay and thereach point.The basic principle of operation of distance protectionis shown in figure 3. The input to the relay point isthe phase voltages and line currents transformedwith the help of voltage transformer (VT) and currenttransformers (CT).Figure 3. Principle of MHO distance protectionin presence phase to earth fault.The voltage would fall towards zero at the point ofthe fault. The impedance measured by MHO distancerelay (Z seen ) in presence phase (A) to earth fault iscalculate by flowing equation [20‐21]:VAVRelay IA+Ko.IoZseen = = = Rseen + j.X (10)seenI KRelayZ822012. Fascicule 3 [July–September]

ACTA TECHNICA CORVINIENSIS – Bulletin of EngineeringZo− Z1KCTwhere, Ko= and KZ= (11)3. ZK1PHASE TO EARTH FAULT CURRENT CALCULATION ONPRESENCE GCSCFigure 4 is shows the equivalent circuit fortransmission line en presence single phase (phase A)to ground fault with fault resistance (R F ) at busbar Bwith GCSC inserted on midline.Figure 4. The equivalent circuit with GCSCThe total transmission line (Z AB‐GCSC ) impedance withGCSC inserted on midline is given by:ZAB GCSC AB [ ( )−= R + j XAB − XGCSC β ] (12)Regarding reference [22], the basic equation for thisfault is:I = I = 0(13)bcV . 0a= V1+ V2+ V0 = RF Ia≠ (14)The coefficients Z AB‐T and Z GCSC‐T are defined forsimplicity is:ZAB− T= ZAB.1 + ZAB.2 + ZAB.0(15)XGCSC− T= XGCSC.1 + XGCSC.2 + XGCSC.0(16)From figure 4, the symmetrical currents componentsare:VS+ VGCSCI1= I2 = I0= (17)⎛ ZAB−T ⎞ ⎛ ZAB−T ⎞⎜ ⎟+ XGCSC −T+ ⎜ ⎟+3. RF⎝ 2 ⎠ ⎝ 2 ⎠I Awhere, I1+ I2+ I0= (18)3From equations (17) and (18), the current in phase A is:3.( VS+ VGCSC)IA= (19)⎛ ZAB−T ⎞ ⎛ ZAB−T ⎞⎜ ⎟+ XGCSC −T+ ⎜ ⎟+3. RF⎝ 2 ⎠ ⎝ 2 ⎠VTThe symmetrical components of voltages are:⎡V0⎤ ⎡1 1 1⎤⎡VA⎤⎢ 1 2V⎥1=⎢ 1 a a⎥⎢ V⎥ (20)⎢ ⎥ B3 ⎢ ⎥⎢ ⎥2⎢⎣V⎥2⎦⎢⎣ 1 a a⎥⎦⎣⎢V⎥C ⎦From equation (14) and matrix (20), the voltage atphase A is:3. RF.( VS + VGCSC)VA= (21)⎛ ZAB−T ⎞ ⎛ ZAB−T ⎞⎜ ⎟+ XGCSC −T+ ⎜ ⎟+3. RF⎝ 2 ⎠ ⎝ 2 ⎠From equations (10), (17), (19) and (21), the measuredimpedance Z seen by distance relay is only related to: Parameters of transmission line : U n , l L , R AB ,and X AB , Current and voltage transformer ratios: K CTand K VT , Parameters of GCSC installed: V GCSC and X GCSC ,Fault conditions: location n F and resistance R F .CASE STUDY AND SIMULATION RESULTSThe electrical network 220 kV, 50 Hz studied in thispaper [23], is the eastern Algerian electricaltransmission networks at Sonelgaz group (Algeriancompany of Electrical and Gas) is shows in figure 5.The MHO distance relay is located on the busbar at AinM’lila in Oum El Bouaghi to protect the singletransmission line between busbar A and busbar B atKhenchela substation HV/MV.Figure. 5. Algerian electrical networks studyThe GCSC system is installed in the midpoint of theprotected line by a MHO distance relay. Theinvestigation were carried out for three case studiesrespectively for 30, 50 and 70 MVar of injectedreactive power as well as for 10, 20 and 30 kV injectedvoltage. The parameters of transmission line and theinstalled GCSC are summarized in the appendix.2012. Fascicule 3 [July–September] 83

A. Impact on transmission line protectedThe figures 6.a and 6.b represent the variation ofreactive power (Q B ) and active power (P B ) at the loadbusbar B respectively as a function of injected X GCSC bydifferent GCSC.ACTA TECHNICA CORVINIENSIS – Bulletin of Engineering(b)Figure 7. Distance relay measured impedance Variation Z seen .a). R seen = f (X GCSC ), b). X seen = f (X GCSC ).(a)C. Impact of V GCSC on impedance measured by relayFigures 8.a and 8.b represent the variation of R seen andX seen respectively as a function R F for different injectedvoltage V GCSC by different GCSC study.(b)Figure 6. Powers Variation with respect to injectedreactance. a). Q B = f (X GCSC ), b). P B = f (X GCSC )B. Impact of X GCSC on the impedance measured by relayThe figures 7.a and 7.b represent the variation of theresistance R seen and reactance X seen respectively as afunction of injected X GCSC by different GCSC in thepresence R F .(a)(b)Figure 8. Distance relay measured impedance Variation Z seen .a). R seen = f (V GCSC ), b). X seen = f (V GCSC ).(a)D. Impact of Q GCSC on impedance measured by relayFigures 9.a and 9.b represent the variation of R seen andX seen as a function R F for different injected Q GCSCinjected by different GCSC study.842012. Fascicule 3 [July–September]

ACTA TECHNICA CORVINIENSIS – Bulletin of Engineering(a)(b)Figure 9. Variation of impedance Z seen by distance relay.a). R seen = f (Q GCSC ), b). X seen = f (Q GCSC ).CONCLUSIONSThe results are presented in relation to a typical 220 kVsingle electrical transmission system employingdifferent GCSC (10 MVar/10 kV, 50 MVar/20 kV and 70MVar/30 kV). The compensator is connected at themidpoint of a protected transmission line by distancerelay. The simulation results show the direct impacton the total impedance of a protected line fordifferent injected variable parameters X GCSC , V GCSC andQ GCSC of the compensator. As can be seen theresistance R seen and reactance X seen respectively in thepresence of GCSC and in case of earth fault withresistance fault R F varied between 5 to 50 Ω at the endof the line are affected.Therefore distance relay tripping characteristicdepends on many factors including the power systemstructural and the pre‐fault condition, the earth faultresistance, and parameters of reactance injected byGCSC based the maximum reactive power injected onelectrical transmission line. So, it is necessary tomodify the setting protection zones in order toprevent circuit breaker nuisance tripping and improvethe performances of MHO distance relay protection.AppendixA. Power source:U s = 11 kV, f n = 50 Hz.B. Power transformer:U TR = 11/220 kV, S TR = 200 MVA, X TR1 = j 0,213 Ω,X TR0 = j 0,710 Ω,C. Electrical transmission line:U L = 220 kV, Length = 117 km, Z 1 = 0,1213 + j 0,4227 Ω/km,Z 0 = 0,3639 + j 1,2681 Ω/k.D. GCSC study:Case 1. Q Max = 30 MVar, V Max = 10 kV, X C.Max = 3,333 Ω,Case 2. Q Max = 50 MVar, V Max = 20 kV, X C.Max = 8,000 Ω,Case 3. Q Max = 70 MVar, V Max = 30 kV, X C.Max = 12,857 Ω.REFERENCES[1.] G. Zigler, Numerical Distance Protection : Principlesand Applications, 3 rd edition, Publics CorporatePublishing, Germany, June 2008.[2.] AREVA, Network Protection & Automation Guide, 2 ndEdition, Published by AREVA, Paris, France, January2010.[3.] K.K. Sen and M.L. Sen, "Introduction to FACTSControllers: Theory, Modeling and Applications", JohnWiley & Sons, Inc., and IEEE Press, New Jersey, USA,2009.[4.] A.N. Abdel‐Latief, A.F. Abdel‐Gawad and M.E.Mandour, "Mitigation the Effect of TCSC on theTransmission Lines Protection Devices", The 42 ndInternational Universities Power EngineeringConference (UPEC), Brighton, UK, 4‐6 September 2007.[5.] M. Khederzadeh and T.S. Sidhu, "Impact of TCSC onthe Protection of Transmission Lines", IEEETransactions on Power Delivery, Vol. 21, No. 1, pp. 80‐87, January 2006.[6.] T.S. Sidhu, and M. Khederzadeh, "TCSC impact onCommunication‐aided Distance Protection Schemesand its Mitigation", IEE Proceedings on Generation,Transmission and Distribution, Vol. 152, Issue 5, pp. 714‐728, September 2006.[7.] M. Zellagui and A. Chaghi, "A Comparative Study ofGCSC and TCSC Effects on MHO Distance Relay Settingin Algerian Transmission Line", International Journal ofEngineering and Technology (IJET), Vol. 2, No. 2, pp.220‐228, February 2012.[8.] S. Jamali and H. Shateri, "Locus of ApparentImpedance of Distance Protection in the Presence ofSSSC", European Transaction on Electrical Power(ETEP), Vol. 21, No.1, pp. 398‐412, January 2011.[9.] Shojaei and S.M. Madani, "Analysis of MeasuredImpedance by Distance Relay in Presence of SSSC", 5 thIET International Conference on Power Electronics,Machines and Drives (PEMD’10), Brighton, UK, 19‐21April 2010.[10.] M.V. Sham, and K. Panduranga Vittal, "SimulationStudies on the Distance Relay Performance in thePresence of STATCOM", Journal of ElectricalEngineering (JEE), Vol. 11, No. 3, March 2011.[11.] Q. Liu, Z. Wang and Y. Zhang, "Study on a NovelMethod of Distance Protection in Transmission Linewith STATCOM", Power and Energy EngineeringConference (APPEEC’10), China, 28‐31 March, 2010.2012. Fascicule 3 [July–September] 85

[12.] W.H. Zhang, S.J. Lee, M.S. Choi and S. Oda,"Considerations on Distance Relay Setting forTransmission Line with STATCOM", 2010 IEEE, Powerand Energy Society General Meeting, USA, 25‐29 July2010.[13.] F.A. Albasri, T.S. Sidhu and R.K. Varma, "PerformanceComparison of Distance Protection Schemes for Shunt‐FACTS Compensated Transmission Lines", IEEETransactions on Power Delivery, Vol. 22, No. 4, pp.2116‐2125, October 2007.[14.] S. Jamali, A. Kazemi and H. Shateri, "MeasuredImpedance by Distance Relay for Inter Phase Faults inthe Presence of SVC on Double‐circuit Lines", IET 11 thConference on Developments in Power SystemProtection (DPSP’12), Birmingham, UK, 23 ‐ 26 April2012.[15.] J. G. Agrawal and K.D. Joshi, "Experimental Study ofSome Variable Impedance Type FACTS Devices", 4 thInternational Conference on Emerging Trends inEngineering & Technology (ICETET’11), Nagpur, India,18‐20 November, 2011.[16.] L. F. W. de S o w E. H. Watanabe and M. Aredes, "GTOControlled Series Capacitors: Multi‐module and MultipulseArrangements", IEEE Transaction on PowerDelivery, Vol. 15, No. 2. pp. 725‐731, April 2000.[17.] K.K. Sen and M.L. Sen, Introduction to FACTSControllers: Theory, Modeling and Applications, JohnWiley & Sons, Inc., and IEEE Press, New Jersey, USA,2009.[18.] M. Zellagui and A. Chaghi, "MHO Distance Relay ofTransmission Line High Voltage using SeriesCompensation in Algerian Networks", Journal of ACTAElectrotehnica, Vol. 52, No. 3, pp. 126‐133, October 2011.[19.] L. Gérin‐Lajoie, "A MHO Distance Relay Device in EMTPWorks", Electric Power Systems Research (EPSR), Vol.79, No. 3, pp. 484‐49, March 2009.[20.] D. Sweeting, "Applying IEC 60909, Short‐circuitCurrent Calculations", 58 th Annual IEEE, 2011 Record ofConference Papers Industry Applications Society, 19‐21September 2011.[21.] Ha Heng Xu and Zhang BaoHui, "Study on ReactanceRelays for Single Phase to Earth Fault on EHVTransmission Lines", International Conference onPower System Technology (PowerCon’04), 21‐24November 2004.[22.] S. Jamali and H. Shateri, "Impedance Based FaultLocation Method for Single Phase to Earth Faults inTransmission Systems", 10 th IET InternationalConference on Developments in Power SystemProtection (DPSP’10), 29 March ‐ 1 April, 2010.[23.] Sonelgaz Group,"Electrical Networks High Voltage 220kV", Company of Electrical Transmission, GRTE, Alger,Algeria, 30 December 2011.ACTA TECHNICA CORVINIENSIS – Bulletin of EngineeringACTA TECHNICA CORVINIENSIS – BULLETIN of ENGINEERINGISSN: 2067‐3809 [CD‐Rom, online]copyright © UNIVERSITY POLITEHNICA TIMISOARA,FACULTY OF ENGINEERING HUNEDOARA,5, REVOLUTIEI, 331128, HUNEDOARA, ROMANIAhttp://acta.fih.upt.ro862012. Fascicule 3 [July–September]

1. Emil RAGAN, 2. Marcel FEDÁK, 3. Pavol SEMANČOHEATING PROCESS MODELING FOR DIE‐CASTING JETS ON THEMACHINES WITH HOT CHAMBER1. FACULTY OF MANUFACTURING TECHNOLOGIES OF TECHNICAL UNIVERSITY OF KOŠICE WITH A SEAT IN PREŠOV, DEPARTAMENT OF TECHNOLOGICALSYSTEMS OPERATION, PREŠOV, SLOVAKIA2‐3. FACULTY OF MANUFACTURING TECHNOLOGIES OF TECHNICAL UNIVERSITY OF KOŠICE WITH A SEAT IN PREŠOV, DEPARTMENT OF MANUFACTURINGMANAGEMENT, PREŠOV, SLOVAKIAABSTRACT: In general the application of die‐casting technology in foundries that are focused on non ferrous metals allowsproducing cast parts with specific properties. Another advantage of pressure die‐casting technology with hot chamber isthe possibility of production of precision cast parts in low dimensional tolerances, often without further machining.Castings have got smooth surface, good mechanical properties, and they also may have complex construction workability.Required qualitative properties of castings produced with the pressure die‐casting technology with hot chamber aredependent on several parameters, which include holding stable temperature of the die‐casting nozzle. Therefore in thispaper we proposed the mathematical model as one of the method how to control heating die‐casting nozzle of the hotchamber pressure die‐casting machine using a gas torch.KEYWORDS: Pressure die‐casting, die‐casting nozzle, hot chamber pressure die‐casting machineINTRODUCTIONHigh pressure die‐casting technology in foundriesprocessing non‐ferrous molten metal metals allowsproducing casting of various shapes with specificproperties. The advantages of applying the technologyof high pressure die casting using hot chamber is thepossibility of precision castings in low dimensionaltolerance [1,2] .These castings have a smooth surface often withoutany further machining, and they also have goodmechanical properties [3]. This technology mayproduce castings with complex construction. Thequality of the castings depends on several parameters.One of the important parameter is control andregulation of temperature stability of nozzle [4,5].During the operation of pressure die‐casting machineswith hot chamber dynamic changes occur mainly intemperature time casting nozzle according to thecasting machine cycle. It is needed to hold thetemperature of casting nozzle at optimum valuetherefore it is necessary to eliminate dynamic changes.Given the operation consuming conditions during thedie‐casting process the nozzle is regulated bycontrolled gas torch. For regulation of nozzletemperature, there are several types of regulation[2,6].In this paper we focus on the compilation of modelwith simple control loop with a mathematicaldescription of the regulated system, and also on thecreation of transitional characteristic with regulatorydesign. Simple control‐loop that is formed by thetorch that heats the nozzle of pressure die‐castingmachine uses the proposed proportional regulatory.EQUATION MODEL DEFINITION OF REGULATORY SYSTEMFor appropriateness of the solutions it is firstlynecessary to derive an equation describing thedependence of torch gas flow on temperature ofcasting nozzle as the equation of the regulatorysystem. In the regulatory system the gas flow of thegas torch is referred as input value q and thetemperature difference of the nozzle expressed as T‐T 0 and surroundings temperature is an output variable[4].For the casting nozzle we can determine equation forthermal balance:nQ = Q +(1)1 2 Q3where: Q 1 ‐ amount of the heat per time unitgenerated by burning gas in torch, nQ 1 ‐ amount of theheat per time unit generated by burning gas in torchthat crossed into nozzle, Q 2 ‐ amount of the heat pertime unit generated by burning gas in torch that heatsnozzle, Q 3 ‐ heat loss per time unit.Variable Q 1 can be expressed as:Q 1 = ql(2)where: q ‐ gas flow of the torch, l ‐ calorific value ofthe gas.Variable Q 2 is expressed as:dTQ 2 = cm(3)dtwhere: c ‐ specific heat of the nozzle, m ‐ weight of thenozzle, T ‐ nozzle temperature, t ‐ time.Q = kSp ( T − T 0 )(4)where: k ‐ heat transfer coefficient from the nozzleinto the surroundings, S p ‐ surface area of the nozzle,T 0 ‐ surroundings temperature.© copyright FACULTY of ENGINEERING ‐ HUNEDOARA, ROMANIA 87

Substituting equations (2), (3), (4) into equation (1)with subsequent adjustment we determine equationof regulatory system:mc d( T − T ) kSp( T − T )0 0q = . +(1.1)nl dt nlThe input quantity of the regulatory system is the gasflow q and output is the temperature difference of thenozzle T‐T 0 together with the temperature ofsurroundings.In operator’s shape:⎛ mcp+kSp⎞q = ⎜ ( T −T0)nl⎟(1.2)⎝ ⎠The transmission of the system S is represented byratio of output to input quantity.T − T0nlS = =(5)q mcp + kSTRANISTIONAL CHARACTERISTICBased on the establishment of the transmission of thesystem we described transitional characteristics forstep unit change of input variable and also forparticular value q.Transitional characteristic of the system can beexpressed as follows (see figure. 1a):⎛kSpnl − t ⎞T − T = ⎜ −mc ⎟0 1⎜e(6)kS ⎟p⎝ ⎠q[m -3 .s -1 ]T-T0[ºC]nlkS pq[m -3 .s -1 ]T-T 0 [ºC]qnlkSp1nckS pnckSpqpt[s]t[s]t[s]t[s]Figure 1. Transitional characteristic, a) with stepb) with step qa)b)ACTA TECHNICA CORVINIENSIS – Bulletin of EngineeringIf the step of the input variable is not unity, but entersparticuler value q the course of the temperaturedifference of the nozzle and surroundings is describedby the equation (figure. 1b):⎛kSpnlq − t ⎞T − T = ⎜ −mc ⎟0 1⎜e(6.1)kS ⎟p⎝ ⎠MODEL OF REGULATORY SYSTEMThe initiation of the temperature change of the nozzletowards surroundings can be realized by regulating ofthe gas flow q that enters the torch. To control thegas flow a proportional regulator can be selected.Transfer of a proportional regulator is formulated asfollows:R = KP(7)Regulatory circuit can be depicted by block diagram asin figure 2.q q-nT-T 0 q 1S (p)R (p)T-T 0 -WT-T 0Figure 2. Block scheme of regulatory circuitTransmission of the action variable is expressed byfollowing equation:nlS mcp + kSpnlFa= ==(8)1 + RS KnlP1 +mcp + kSp+ KPnlmcp + kSFigure 3 depicts amplitude and phase characteristicsand figure 4 depicts transitional characteristic for K=1and P=1. Circuit is characterized by stability andirregularity.The transmission of the disturbance:1 1 mcp + kSpFPor= ==(9)1 + RS KnlP1 +mcp + kSp+ KPnlmcp + kSAmplitude and phase characteristic is depicted infigure 5 and figure 6 depicts transitional characteristicfor K=1 and P=1.The transmission of the control is:knlPRS mcp + kSpKnlPFr= ==(10)1 + RS KnlP1 +mcp + kSp+ KPnlmcp + kSpppW882012. Fascicule 3 [July–September]

ACTA TECHNICA CORVINIENSIS – Bulletin of EngineeringA(jω)[dB]40q[m 3 .s -1 ]-A(jω)[dB]+φ0-401 10 1001000log ωT-T 0 [ºC]1t[s]+π/20log ω-π/2-φFigure 3. Amplitude and phase characteristicsq[m -3 .s -1 ]T-T 0 [ºC]mckS − Pnlp1nlkS − pPnlt[s]-A(jω)[dB] +A(jω)[dB-A(jω)[dB]+φ5050+π/2-π/2-φ0Figure 4. Transitional characteristic0,0010,010,1t[s]1 10 100 1000log ωlog ω1nckS Pnlp +t[s]Figure 6. Transitional characteristicCONCLUSIONS AND DISCUSIONFor simple regulatory circuit formed by the torch thatheats the nozzle the proportional regulator was used.On the basis of the proposed model of regulatorysystem the amplitude, phase and transitionalcharacteristics of the action variable were determined(Figure 4 ‐ 6). The control of the regulatory circuit wasdesigned by equation of the transmission (10). Fromthese characteristics, it is known that the regulatorycircuit is stable and irregular. From transmissionequation of disturbance (9) and based on theamplitude, phase and transitional characteristics forthe failure of the circuit it is evident that the defect inthe regulatory circuit is quickly diminishing. It can beconcluded that heating the nozzle by gas torch inpressure die‐casting machines with hot chambertogether with proportional regulator is easy to controland it has relatively good regulatory characteristics.REFERENCES[1.] MALIK, J., GAŠPÁR, Š., PAŠKO, J.: Technologickéfaktory vplývajúce na kvalitu tlakovoliatychodliatkov zo zliatin hliníka, In: Výrobné inžinierstvo.Roč. 9, č. 1 (2010), s. 32‐34, 38. ‐ ISSN 1335‐7972[2.] RAGAN, E.: Liatie kovov pod tlakom, FVT TU Košice sosídlom v Prešove, Prešov, 2007, 381s ISBN 978‐80‐8073‐979‐9[3.] MALÍK, J. a kol.: Vplyv podmienok tlakového liatia namechanické vlastnosti tlakovo liatych odliatkov,Slévárenství 2007, č. 7, s. 311 – 315, ISSN 47 325[4.] RAGAN, E.: Proces liatia pod tlakom, FVT TU Košice sosídlom v Prešove, Prešov, 1997[5.] PAŠKO, J., MALIK, J., GAŠPÁR, Š., NOVÁK‐MARCINČIN,J.: Influence of technological parameters of diecastning on qualitative properties of castings, n:Manufacturing engineering and technology. No.1(2010), p. 3‐6. ‐ ISSN 1312‐0859[6.] KRENICKÝ, T.: Monitoring prevádzky technickýchsystémov s využitím virtuálnej inštrumentácie.Strojárstvo extra 5, 2010, p. 25/1‐2, ISSN 1335‐2938Figure 5. Amplitude and phase characteristics2012. Fascicule 3 [July–September] 89

ACTA TECHNICA CORVINIENSIS – Bulletin of EngineeringACTA TECHNICA CORVINIENSIS – BULLETIN of ENGINEERINGISSN: 2067‐3809 [CD‐Rom, online]copyright © UNIVERSITY POLITEHNICA TIMISOARA,FACULTY OF ENGINEERING HUNEDOARA,5, REVOLUTIEI, 331128, HUNEDOARA, ROMANIAhttp://acta.fih.upt.roACTA TECHNICA CORVINIENSIS – BULLETIN of ENGINEERINGISSN: 2067‐3809 [CD‐Rom, online]copyright © UNIVERSITY POLITEHNICA TIMISOARA,FACULTY OF ENGINEERING HUNEDOARA,5, REVOLUTIEI, 331128, HUNEDOARA, ROMANIAhttp://acta.fih.upt.ro© copyright FACULTY of ENGINEERING ‐ HUNEDOARA, ROMANIA 90

FLOW WEAR BY SHEAR INSTABILITY IN SLIDING1‐2.INSTITUTE OF STRENGTH PHYSICS AND MATERIALS SCIENCES SB RAS, TOMSK, RUSSIA1.Sergei TARASOV, 2. Valery RUBTSOVABSTRACT: Inhomogeneous character of deformation in subsurface layers of metals in sliding resulted in generation of ananocrystalline layer. Specificity of its deformation behavior is a hydrodynamic flow pattern developing due to shearinstability under conditions of thermal softening. Macroscopic analysis of plastic deformation carried out on theassumption that deformation behavior of the nanocrystalline subsurface layer is similar to that of the parallel‐plane viscousNewtonian flow. It was shown that velocity tangential discontinuity surfaces may exist inside the deforming subsurfacelayer. These surfaces are particular cases of Helmholtz instability and may serve as potential sites where turbulences maynucleate.KEYWORDS: shear instability, nanocrystalline layer, sliding, wearINTRODUCTIONNow there is an interest in studying high‐straindeformation behavior of nanocrystalline materials.The well‐known fact is that inhomogeneousdeformation in subsurface layers of metals in highloadsliding results in generation and flow of ananocrystalline layer [1]. Specificity of its deformationbehavior is a hydrodynamic flow pattern developingdue to shear instability under conditions of thermalsoftening. The nature of shear instability here is acrossover from common shear deformation mode tothe grain rotation governed either by grain boundaryslipping mechanism (GBS) or rotationalrecrystallization mechanism [2] or disclinationmechanism [3] under condition of submicron sizegrain structure formation and dynamicrecrystallization. All these proposed deformationmechanisms might be discussed in studyingdeformation in nanocrystalline materials. However,GBS is the most studied and well‐documentedmechanism, which may serve a basis for analyzing theshear instability. Phenomenon of the shear instabilityin sliding is considered as a product of deep structuremodification, which is a common finding in metalssubjected to high strain rate impact test whenadiabatic shear bands are generated [4].Shear instability of a special type described as a Kelvin‐Helmholtz instability is observed when metal (copper,beryllium or aluminum) plates collide each other in aglancing manner at 2 to 8 mm/μs velocity and smallangle [5, 6]. Wave‐like patterns or eddies are oftenfound at the interface between the plates and areinherent in the said instability. Generation of thispattern may be suppressed by depositing eithergalvanic or electron beam coatings on the surface ofsamples. Such an effect of stabilization is explained bysuppression of shear band generation due to refiningsource metal grains [6]. Judging by this explanationwe may suggest that the developments of shearinstability and shear bands are interrelated.It is reported [7] that generation of eddy‐likestructures during high velocity impact might be bystrain localization zones formed at the previousdeformation stages. Once generated these zonesbecome then involved in a vortex‐like flow [7]. In ouropinion these zones are the results of shear instabilitylike those observed in impact welding, i.e. under highvelocityimpact shear deformation.Eddy‐like structures of another nature may be foundon the worn surfaces of soft Al–Sn and Cu–Pb alloysafter testing at low sliding speeds [8]. It wassuggested [8] that they might nucleate and growunder thermodynamic instability conditions with theiraxes being parallel to the sliding direction. However,the most feasible mechanism for formation of thesestructures may be mechanical mixing as follows frompioneering works of D.A. Rigney.Dynamic high‐speed sliding of aluminum/steel pair wasreported [9]. It was shown that both eddy‐like flowand intermixing occurred at the worn surfaces andresulted in formation of a mechanically mixednanocrystalline layer (MML).The objective of this work is to estimate macroscopicconditions for generation of the eddy‐like flowinstability in sliding on the basis of hydrodynamicapproach including previously obtained bothexperimental and numerical simulation results.EXPERIMENTAL CONDITIONSModern literature sources offer models for gradualformation of nanocrystalline layer in sliding test [9].These models are based traditionally either ondeformation rate or wear debris intermixing withinthe contact zone.However, the nanocrystalline layer structure is verymuch alike the structure of adiabatic shear bandsobtained in explosion loading [10]. It is possible with© copyright FACULTY of ENGINEERING ‐ HUNEDOARA, ROMANIA 91

the tribological experiment to simulate conditionsclose to both approaches depending on the slidingspeed and the size of a real contact area. In connectionwith this, we carried out tribological experimentsunder conditions when friction coefficient changedsharply due to adhesive interaction between thesamples’ surfaces’.Such an approach allowed obtaining fast changes inthe contact geometry and thus provoked theoccurrence of shear instability. Preliminaryexperiments allowed us to determine needed testregimes and sample dimensions.Samples in the form of ∅5 mm and 20 mm length pinswere cut off the ∅5 mm commercial copper rods usinga lathe tool. End surfaces were ground manually andgently to remove lathe grooves and then used in weartest. After testing, the sample was fixed inside a steelnut using Wood’s metal. The abrasive wheel rotatingat1000 RPM with water cooling was used only forinitial rough metal removal in the longitudinal crosssectionso that it in no way could produce any artifactnanocrystalline layer at the end surface of the pin. Allfurther polishing was carried out manually. A crosssectionof a typical pin after preparation but beforesliding looked like as having no plastic deformationtraces.Vertical pin‐on‐disk sliding tester 2169 UMT‐1(Tochpribor, Ivanovo) was used to test three samplessimultaneously against a counterface of ∅320 mm 64HRc tool steel disk. These samples were brought in anunlubricated sliding contact and then tested at 0.5MPa, 0.6 m/s and 0.1 MPa, 1 m/s. It was shown bypreliminary experiments that combination of lowsliding speed and high contact stress is the mostsevere wear test mode for copper samples.Microstructure of the worn samples was characterizedusing both an optical and a differential‐interferential(DIC) contrast microscope Axiovert 200 MAT (CarlZeiss). More details on the experiment andcharacterization are given in [15].RESULTSThe result of experimenting was a realization of shearinstability conditions (0.6 m/s, 0.5 MPa) andgeneration of a nanocrystalline layer having a clearboundary with the low‐lying plastically deformedmaterial (see Fig.1). This clear boundary may beevidence of shear mechanism of the nanocrystallinelayer formation, which is similar to that of a shearband formation. Structurally, this layer may be dividedinto four zones as follows: plastic deformation and texturized grain zone I; intense fragmentation zone II; “turbulent” flow zone III and finally, “laminar” flow zone IV.ACTA TECHNICA CORVINIENSIS – Bulletin of EngineeringZones I and II may be called also by usual deformationzones whereas both III and IV are the viscous flowzones [15]. One may see that both strain andfragmentation gradually grow starting from thedeepest layers of zone I to the fragmentation zone IIuntil an interface between zones II and IV (III) isformed as a result of shear instability.Zone I is characterized by crystallographic rotation ofthe grains with respect to shear stress while zone II is aplace of intense structural fragmentation.More details on structure and mechanicalcharacteristics of this layer are given elsewhere [15].Figure 1. Microstructure of plastic deformation zones in acopper sample after sliding test at 0,6 m/s, 0,5 MPa). I –plastic deformation and texture zone ; II – fragmentationzone; III‐ flow instability zone; IV – stability low zone.Figure 2. Turbulent flow zone III.Morphological specificity of zones III and IV is thatthey are composed mainly of fine grains arranged in ~1μm thickness sublayers which are elongated with thesliding direction.922012. Fascicule 3 [July–September]

ACTA TECHNICA CORVINIENSIS – Bulletin of EngineeringAnother important morphological feature is zone IIIwithin which one may see eddy‐like flow of materialwhich is very much alike the fluid turbulent flowpatterns (see Fig.2). It is necessary to note here thatthose eddies are often found on the worn surfaces [8]as a result of mechanical intermixing. In our case, wefound them generated at some depth below the wornsurface, which may be related to the specificity ofshear instability mechanism of nanocrystalline layerformation. Furthermore, the vortex flow may befound within zone IV which is composed of 1 μm thicksublayers [15].DISCUSSIONIt was shown in the first part of this work that plasticdeformation patterns of nanocrystalline layer aresimilar to those of a flowing fluid. The zone IV sublayerinterfaces denote shear direction in the materials andlook similar to the flowing fluid laminar layers,whereas zone III rotation mode zones look like eddiesinitiated in turbulent mode flow. Let us assume thatthe basic deformation mechanism for nanocrystallinemetals is by grain boundary slipping. Then, thenanocrystalline layer generated in sliding wear testsbecomes even more alike a fluid since its structuralelements are nanograins which are capable both oftranslational and rotational movements.As noted [11], the polycrystalline material grainsdeforming in accordance with the diffusionaccommodated grain boundary slipping mechanismreveal a behavior patterns very much alike if theypossessed the Newtonian viscosity. Therefore, we cannumerically evaluate a possibility of turbulent modeoccurrence in a subsurface layer from a standpoint ofhydrodynamics by drawing an analogy with a viscousfluid flowing in a space between two parallel plates,one of which is fixed while the other is moving relativeto the first one (Couette flow) (see Fig.3).Figure 3. Plastic deformation of subsurface layerin the form of Couette flow.The type of a flow regime is characterized by theReynolds number:ρLVRe = m(1)ηwhere ρ is density, L is characteristic size, Vm is meanflow velocity , η ‐ viscosity. In theory, the Couette flowis assumed to be absolutely stable againstinfinitesimal perturbances [12] whereas in practice acrossover from laminar to turbulent regime may beobserved for Reynolds number in the order 10 3 . Toestimate the Reynolds number, we assume that themaximum mean flow velocity V m is equal to thecounterbody’s velocity V c ≈1 m/s and the characteristicsize coincides with the experimentally obtainednanocrystalline layer’s thickness L≈500 μm [15].Figure 4. Subsurface layer velocity distribution vs. depthbelow the worn surface. Curves 1 to 5 correspond todifferent moments of time [15].Both CBS deformation and, therefore, the viscosity ofthe nanocrystaline layer are controlled by the grainboundary diffusion. We are going to estimate thenanocrystalline layer’s viscosity on the assumptionthat the nanocrystalline layer suffers a throughthicknessflow. Assuming this, we can use the Coble’sdiffusion creep equation considered in detailselsewhere [11] to determine the viscosity as follows:31 d kTηB = , (2)C1δDBΩwhere d is a mean grain size, k is the Boltzmannconstant, T is temperature, δ is a grain boundarywidth, Ω is atomic volume, D B is a grain boundarydiffusion coefficient, С 1 is a dimensionless coefficientwhich is ≈10 2 for equiaxial grains [11].The mean grain size is assumed to be ≈100 nm. Thegrain boundary width was 0.5 to 10 nm to estimateboth maximum and minimum viscosity levels.2012. Fascicule 3 [July–September] 93

It is difficult to determine temperature in the vicinityof worn surface; therefore, we believe it is not below200°C since we found it experimentally to be at thelevel of ≈160°C at the 1 mm depth below the wornsurface [13]. Also, we believe the temperature was inthe range of 300 to 400 °C.The grain boundary diffusion coefficient D Bdetermined by the Arrhenius equation both fromdiffusivity factor and activation energy [14] fornanocrystalline copper in the 200 to 400 °Ctemperature interval of interest is in the range 10 ‐12 to10 ‐10 m 2 /s. Substituting corresponding temperature aswell as diffusion coefficient in expression (2), weobtain the viscosity to be within 1⋅10 6 to 5⋅10 4 Pa⋅srange.The result of dry sliding wear process simulation on acopper sample showed that plastic strain rate γ&reached 10 3 s ‐1 for applied shear stress τ ≈ 200 MPa [15].Using this result, we can determine the viscosity of aNewtonian fluid from a ratio between the shear stressand shear strain rate:τηγ&Substituting the above found values of both τ and γ&= (3)in (3) we obtain the viscosity ≈2⋅10 5 Pa⋅s, which fallswithin the above determined range 1⋅10 6 to 5⋅10 4 Pa⋅s.The Reynolds number determined using expression (1)from these viscosities will be in the order of 10 ‐5 . Fromthe standpoint of hydrodynamics, that low Reynoldsnumbers correspond only to nonperturbed laminarplastic flow of the nanocrystalline subsurface layer[12].The Reynolds theory works correctly only forinfinitesimal perturbances whereas the polycrystallinestructure of materials implies the inhomogeneity of itscharacteristics in itself. Moreover, sliding testconditions serve to produce extra mechanical andthermal inhomogeneities in the material. It was shownby numerical simulations on a macroscopic onedimensionmodel that plastic shear in subsurface layerof copper sample is developed nonstationary in timeand inhomogeneously through the depth below theworn surface [15]. This process generates a velocityfield characterized by its non‐linear profilecontrastingly to that of the Couette flow (see Fig.4). Itfollows from Fig.4 those two types of velocity zonescould exist in the deforming material. High velocitygradient zones (slope curve portions) correspond toshear instability zones developing under plasticdeformation. Other zones of zero velocity gradients(horizontal curve portions shown in rectangles) aremoving in parallel to the worn surface at the samevelocity and carrying only elastic deformation.ACTA TECHNICA CORVINIENSIS – Bulletin of EngineeringTherefore, the surfaces with the velocity tangentialdiscontinuities may exist inside the subsurface layer indifferent moments of time and different depths belowthe worn surface. From the hydrodynamicsstandpoint, the absolute instability is of occurrence onthese surfaces. This instability may be interpreted as asimplest case of the Helmholtz instability which is aspecial type of an instability occurring at theinterfaces between the flows of either the same ordifferent fluids but under condition of havingdifferent flow rates [12].Another example of a surface on which the Helmholtzinstability may develop is a boundary between thesubsurface layer and elastically deforming low‐lyingbase metal.Taking into account the results of numericalsimulations, we may describe the process ofdeformation in the subsurface layer as follows. Duringany moment of time elastic deformation zones aregenerated together with one or even several shearinstability zones where intense plastic shear occurs(see Fig.5), i.e. there is at least one interface on whichthe turbulence may develop.To evaluate the feasibility of such a case, we invokeagain the Reynolds number but now we apply it tosome smaller structure scale of the subsurface layer,namely, to relative movement of 1 μm‐ thick sublayerswhich compose the subsurface layer [15].Figure 5. Schematic of the subsurface layerdeformation in slidingReynolds himself defined his criterion as follows [16]:VhRe =(4)cλwhere V is the flow velocity, h is the characteristic sizeof flow, с is the mean velocity of molecules, λ is themean run of molecules. In our situation, V and h is themean velocity of movement and the subsurface layerthickness, respectively.942012. Fascicule 3 [July–September]

ACTA TECHNICA CORVINIENSIS – Bulletin of EngineeringWithin the framework of our model [15], anelementary strain carrier is a 1 μm‐ thickness sublayerof material, therefore, parameters c and λ may beinterpreted respectively as the velocity anddisplacement of this sublayer for a time during whichit stays in the shear instability zone. Numericalmodeling enabled the values of these parameters tobe as follows: V ≈ 2⋅10 ‐2 m/s, h ≈ 3⋅10 ‐4 m, с ≈ 1⋅10 ‐2 ‐ 4⋅10 ‐2 m/s, λ ≈ 1⋅10 ‐8 ‐ 8⋅10 ‐8 m [15]. Substituting this numbersin expression (4), we obtain the Reynolds number tobe in the range 1875 to 30000.The system of parallel‐plane flows as simulated in [15]and which describes deformation in a subsurface layerof metal in sliding becomes instable at that highReynolds numbers and any infinitesimal perturbancemay bring it to the turbulence regime.CONCLUSIONSShear instability conditions were realized in the courseof tribological experiment. A nanocrystalline 500 μmthickness subsurface layer was obtained as a result ofshear instability (see Figs. 1, 2). Plastic deformationpattern of this layer gives evidence of a deformationmechanism much alike a viscous fluid flow. One ofdistinctive structural features of this layer is theoccurrence of eddies both inside the layer and at theinterface with the base low‐lying material.Macroscopic analysis of plastic deformation wascarried out on assumption that the deformationbehavior of the nanocrystalline subsurface layer issimilar to that of the parallel‐plane viscous Newtonianflow. Specificity of deformation mechanisms was notconsidered explicitly. From the standpoint ofhydrodynamics, plastic flow of copper subsurfacelayer under existing experimental conditions shouldbe absolutely stable, i.e laminar.Situation becomes quite opposite when we take intoconsideration earlier revealed nonstationary andinhomogeneous shear deformation pattern. In thiscase, one or more velocity tangential discontinuitysurfaces may exist inside the deforming subsurfacelayer at different moments of time and depths belowthe worn surface. These surfaces are particular casesof Helmholtz instability and may serve as potentialsites where turbulences may nucleate. The feasibilityof eddy‐like structure in such zones was supported byestimating Reynolds number values.ACKNOWLEDGEMENTThe reported here work was carried out under ProjectIII.20.2.4. «Study of friction mechanisms and subsurfacestructure development in metals, alloys and compositesunder different conditions of friction contact and on a basisof multi‐level approach» of Program III.20.2. «Scientificfoundations for development of materials and coatings ofnon‐equilibrium structural and phase states on a basis ofmulti‐level approach» as well as with financial support fromRussian Fund for Basic Research (grant No 10‐08‐00629‐a).REFERENCES[1.] S.Yu. Tarassov and A.V. Kolubaev. Effect of frictionon subsurface layer microstructure in austenitic andmartensitic steels// Wear ‐ 1999.‐V.231. 228‐234.[2.] M.A. Meyers and H.R.Pak. Observation of anadiabatic shear band in titanium by high‐voltagetransmission electron microscopy. Acta Metall. 34,2493 (1986).[3.] S.V. Bobylev, A.K.Mukherjee and I.A. Ovid’koTransition from plastic shear into rotationdeformation mode in nanocrystalline metals andceramics Rev.Adv.Mater. Sci. 19 (2009) 103‐113.[4.] S. Yu. Tarasov, A.V. Kolubaev. Generation of shearbands in subsurface layers of metals in sliding.Physics of solid state, 2008. Vol.50.No 5. P.844‐847.[5.] O.B. Drennov. On development of shear instability inmetals. Journal of technical physics 69, (1999). 38‐43[6.] A.L Mikhailov Hydrodynamic instabilities in strengthmedia – from object to tool. Physicalmesomechanics V.10, No.5 (2007) 53‐62.[7.] V.G. Morozov, S.A. Saveliev, Yu.I. Mescheryakov, N.I.Zhigacheva, B.K. Barakhtin. Vortex model of elasticplasticflow under impact loading. Physics andmechanics of materials 8, 8 (2009).[8.] R. Schouwenaars, V.H. Jacobo, A. OrtizMicrostructural aspects of wear in soft tribologicalalloys Wear 263 (2007) 727–735.[9.] D. A. Rigney, Hong‐Jin Kim, A. Emge, R. E. Winter, P.T. Keightley, Woo‐kyun Kim; M. L. Falk.Nanostructures generated by explosively‐drivenfriction‐experiments and MD simulations. ActaMaterialia, (2009) V. 57, No 17, Pages 5270‐5282.[10.] Y. Xu, H.J. Yang, M.A. Meyers. Dynamicrecrystallization in the shear bands of Fe–Cr–Nimonocrystal: Electron backscatter diffractioncharacterization Scripta Mater. 58, (2008) 691‐694.[11.] R.Raj and M.F.Ashby On Grain Boundary Sliding andDiffusional Creep / Metallurgical Transactions. –Vol.2. – April 1971. – P.1113 –1127.[12.] Monin A.S., Yaglom A.M. Statistical hydromechanics.V.1., M.:Nauka, 1967. 640с.[13.] S.Yu. Tarasov. Structural changes in metallicmaterials in adhesion sliding wear. Thes. Doct. of Sci.‐ Tomsk.‐ 2008.‐ 282 с.[14.] Yu. R. Kolobov, R.Z. Valiev, G.P. Grabovetskaya et all.Grain boundary diffusion and properties ofnanostructured materials. Novosibirsk: Nauka, 2001.‐ 232 p.[15.] S. Tarasov, V. Rubtsov, A. Kolubaev Subsurface shearinstability and nanostructuring of metals in slidingWear 268 (2010) 59–66.[16.] Problems of turbulence. Book of translated papers.Ed. by M.A.Velikanov and N.T. Shveikovsky. M.‐L,ONTI, 1936, 332 с.ACTA TECHNICA CORVINIENSIS – BULLETIN of ENGINEERINGISSN: 2067‐3809 [CD‐Rom, online]copyright © UNIVERSITY POLITEHNICA TIMISOARA,FACULTY OF ENGINEERING HUNEDOARA,5, REVOLUTIEI, 331128, HUNEDOARA, ROMANIAhttp://acta.fih.upt.ro2012. Fascicule 3 [July–September] 95

ACTA TECHNICA CORVINIENSIS – Bulletin of EngineeringACTA TECHNICA CORVINIENSIS – BULLETIN of ENGINEERINGISSN: 2067‐3809 [CD‐Rom, online]copyright © UNIVERSITY POLITEHNICA TIMISOARA,FACULTY OF ENGINEERING HUNEDOARA,5, REVOLUTIEI, 331128, HUNEDOARA, ROMANIAhttp://acta.fih.upt.roACTA TECHNICA CORVINIENSIS – BULLETIN of ENGINEERINGISSN: 2067‐3809 [CD‐Rom, online]copyright © UNIVERSITY POLITEHNICA TIMISOARA,FACULTY OF ENGINEERING HUNEDOARA,5, REVOLUTIEI, 331128, HUNEDOARA, ROMANIAhttp://acta.fih.upt.ro© copyright FACULTY of ENGINEERING ‐ HUNEDOARA, ROMANIA 96

1.Vasile ALEXASIMULATION OF HYDRAULIC LOAD LOSSES IN PIPES, USING THEWORKING MEDIUM “ADINA”1.UNIVERSITY POLITEHNICA TIMISOARA, FACULTY OF ENGINEERING HUNEDOARA, HUNEDOARA, ROMANIAABSTRACT: The fluid analysis module of the program is fluid solver for compressible and incompressible fluid provides aworld‐class finite element solutions and the ability to control the flow, fluid can contain free surface and fluid, as well asfluid flow and structure of the interface between. This paper presents a method of simulation and presentation of the loadlosses in a fluid flowing through a pipe. It also presents a study on the algorithm for calculating these losses depending onthe flow regime & pipe type, and the determination of the longitudinal load loss coefficient. The theory and numericalmethods used in the program for laminar and turbulent flow are summarized and then the solutions of various problemsare presented.KEYWORDS: hydraulic load losses, pipes, simulation, Adina programINTRODUCTIONADINA has a wide range of simulation capabilities inmechanical field and has applications in such areas.ADINA program is the basic structure of the solver forsolid, truss, beam, pipe, metal plate, shell and cranniesprovide diversification and general finite elementanalysis capabilities.ADINA is based on the finite element and finite volumediscrete map, with a very comprehensive and efficientsolution to address all of arbitrary geometry flows.The fluid analysis module of the program is fluid solverfor compressible and incompressible fluid provides aworld‐class finite element solutions and the ability tocontrol the flow, fluid can contain free surface andfluid, as well as fluid flow and structure of theinterface between.Besides being used widely in industries, the ADINASystem is also used effectively in teaching andresearch at universities all around the world. ADINAoffers many attractive capabilities for use as ateaching and research tool.Figure 1. Fluid structure interaction [1]Fluid‐structure interaction (FSI) occurs when fluid flowcauses deformation of the structure. Thisdeformation, in turn, changes the boundaryconditions of the fluid flow.The above presented figure showed the fluidstructureinteraction analysis of a membrane valve.Here, the fluid pressure deforms the membrane whichchanges the boundary conditions of the flow [1].When the real fluids flow through pipes, two types ofhydraulic losses occur: Linear losses h pd , (longitudinal or distributed),mathematically expressed by the Darcy's formula:2l vhpd= λ(1)d 2g Local losses h pl , mathematically expressed by theWeisbach's formula:2vhpl= ξ(2)2gwhere:m ; l ‐ lenght of pipe [ ] d ‐ diameter pipe [ m; ]⎡m ⎤ v ‐ average speed section⎢⎣ s ⎥ ;⎦⎡ m ⎤ g ‐ acceleration of gravity⎢ 2⎣s⎥ ;⎦ λ ‐ linear coefficient of hydraulic losses; ξ ‐ local hydraulic loss coefficients to differenttypes of hydraulic resistance.The flow regime in pipes is characterised by theReynolds similarity criterion value, Re, in relation to itscritical value:vdRe = (3)ν© copyright FACULTY of ENGINEERING ‐ HUNEDOARA, ROMANIA 97

where: “ν ” represents the constitutive coefficient ofthe kinematics’ viscosity.The flow regime can be: laminar: Re < Recrt = 2320 ; turbulent: Re > Recrt = 2320 .The problem of determining the λ coefficient is thefundamental problem of pipe calculation. Nikuradse isthe first who undertook a systematic study of thiscoefficient, establishing its relationship with the flowregime and the relative roughness, and drawing thediagram that bears his name [2].An American engineer Lewis F Moody (1880‐1953)prepared the diagram shown in figure 1 for use withordinary commercial pipes. Today, the Moodydiagram is still widely used and is the best meansavailable for estimating the friction factor.The fact that λ depends both on the Reynoldsnumber and the wall roughness, makes it difficult touse unique formulas to calculate it, assuming that l,ν , d, v and k (equivalent roughness) are known [2].ACTA TECHNICA CORVINIENSIS – Bulletin of Engineering5Blasius ‐ for Re < 101λ =(6)4100Re5Prandtl ‐ for 10 < Re < 3⋅101= 2lg Re λ i −0,λ66( ) 8(7) Konakov ‐ for 3 ⋅ 10 < Re < 101= 1,8lg Re−1,5(8)λb.2. The pipe is under transition from hydraulicallysmooth to hydraulically rough 9.4 < CRIT < 200, thelinear loss coefficient depends on the flow regime, butalso on the equivalent roughness of the pipekλ = λ(Re, ) , being applicable the relation ofdColebrook‐White:1 ⎛⎞⎜ 2.51 k= −2lg+ ⎟ (9)λ ⎜⎟⎝ Re λ i3.71d⎠b.3. Hydraulically rough pipe – CRIT > 200, the linearloss coefficient depends only on the equivalent⎛ k ⎞roughness of the pipe λ = λ⎜⎟ , being applicable the⎝ d ⎠relation of Karman‐Nikuradse:1 ⎛ k ⎞= 2lg⎜⎟+ 1.14(10)λ ⎝ d ⎠798Figure 2. Moody diagrama) If Re < Recrt = 2320 (the flow regim laminar), forcalculation of the Hagen‐Poiseuille ’ s relationshipusing:64λ =(4)Reb) If Re > Recrt = 2320 (the flow regim turbulent),using Moody ’ s criterion:kCRIT = Re λi(5)dTo assess this criterion, we approximate λ, admittingthat its value is within the range:λ i = (0.02‐0.04).Depending on the value of this criterion, whichdescribes the nature of the pipe, we shall apply one ofthe relations:b.1. Hydraulically smooth pipe – CRIT < 9.4, the linearloss coefficient depends only on the flow regimeλ=λ(Re). Therefore, we shall apply one of the relations:Figure 3. Algorithm to determinatethe linear loss cofficient λHaving the λ coefficient calculated with one of theabove relations (case of the turbulent regime), we willcheck the value of Moody's criterion, which mustcorrespond to the initially admitted domain.Otherwise, “λ” shall be recalculated applying theformula of the new value of the criterion, i.e. of thenew hydraulic character of the pipe.SIMULATION OF LINEAR LOAD LOSSES, USING THE WORKINGMEDIUM “ADINA”The ADINA CFD program provides state‐of‐the‐artfinite element and control volume capabilities forincompressible and compressible flows. The flows maycontain free surfaces and moving interfaces betweenfluids, and between fluids and structures.The procedure used in ADINA CFD is based on finiteelement and finite volume discretization schemes,2012. Fascicule 3 [July–September]

ACTA TECHNICA CORVINIENSIS – Bulletin of Engineeringwith a most general and efficient solution approach.General flow conditions in arbitrary geometries can besolved.The steps taken to realise the simulations, using theCFD‐3D model, were as follows:a) Establishing the scope of analysis – From the pointof connection in the basement to the first consumerwho lives on the ground floor, the length is 3.5 meters,and the other consumers are placed vertically, threemeters apart from each other.3−3⎡m⎤The maximum circulated flow is 1.25⋅10⎢ ⎥⎣ s ⎦(Figure 4).c) Establishing the properties of the material –thermo‐physical properties of the material and fluid,respectively;d) Establishing the loads – as loads, we have the 5 barpressuree) Finite element discretisation of the analysisdomain. After generating the discretisation network,we obtained 979 nodes and 4800 finite elements.Etaj IV3500 3000 3000 3000 3000QEtaj IIIEtaj IIEtaj IPFigure 7. Finite element discretisationof the analysis domainf) Establishing the conditions on the outline – thepipe was assimilated as a wall with 1.4 µm roughnessand 0.03 m diameter.Figure 4. Case studiedb) Establishing the flow parameters – To determinethe linear loss coefficient, we will consider the verticalwater column (pipe) of a block P+4 (ground floor + 4floors), which has the diameter d = 0.03 [m] and theroughness k = 0.0014 m.Figure 5. Establishing the flow parametersFigure 8. Establishing the conditions on the outlineCONCLUSION AND RESULTS OF NUMERICAL SIMULATIONSThe theory and numerical methods used in theprogram for laminar and turbulent flow aresummarized and then the solutions of variousproblems are presented.In this paper we presented the methodology fordetermining the linear pressure loss coefficient andpressure fluctuation in the pipe, using the workingmedium “ADINA”.The pressure variation in the pipe:Figure 6. Establishing the loads (5 bar)Figure 9. The pressure variation in the pipeThe velocity field in different planes:2012. Fascicule 3 [July–September] 99

Figure 10. The velocity field in a plane perpendicularto the X‐axisFigure 11. The velocity field in a plane perpendicularto the Y‐axisFigure 12. The velocity field in a plane perpendicularto the Z‐axisFluid–structure interaction (FSI) can be simulated thevelocity field in different planes and the pressurevariation in the pipe.REFERENCES[1.] Mark A. Robinson, Paul R. Sparrow, Chris Clegg, KamalBirdi, Design engineering competencies: futurerequirements and predicted changes in theforthcoming decade, Design Studies, Volume 26, Issue2, March 2005, Pages 123‐153[2.] V. Braibant, G. Sander, Optimization techniques:Synthesis of design and analysis, Finite Elements inAnalysis and Design, Volume 3, Issue 1, April 1987,Pages 57‐78[3.] H.W. Wagener, K.J. Pahl, Energy flow, energy lossesand efficiency of the hydraulic press system, Journalof Mechanical Working Technology, Volume 17, August1988, Pages 93‐102[4.] P. Doron, D. Barnea, Flow pattern maps for solid‐liquidflow in pipes, International Journal of MultiphaseFlow, Volume 22, Issue 2, April 1996, Pages 273‐283[5.] T. Kaya, R. Pérez, C. Gregori, A. Torres, Numericalsimulation of transient operation of loop heat pipes,Applied Thermal Engineering, Volume 28, Issues 8–9,June 2008, Pages 967‐974ACTA TECHNICA CORVINIENSIS – Bulletin of Engineering[6.] K. Dasgupta, A. Chattapadhyay, S.K. Mondal,Selection of fire resistant hydraulic fluids throughsystem modeling and simulation, SimulationModelling Practice and Theory, Volume 13, Issue 1,January 2005, Pages 1‐20[7.] W. Borutzky, B. Barnard, J. Thoma, An orifice flowmodel for laminar and turbulent conditions,Simulation Modelling Practice and Theory, Volume 10,Issues 3–4, 15 November 2002, Pages 141‐152[8.] Dídia Covas, Iva N. Stoianov, Joao F. Mano, HelenaRamos, Nigel Graham, Cedo Maksimovic, The dynamiceffect of pipe‐wall viscoelasticity in hydraulictransients. Part II—model development, calibrationand verification, Journal of Hydraulic Research,Volume 43, Issue 1, 2005, pages 56‐70[9.] Valentin Heller, Scale effects in physical hydraulicengineering models, Journal of Hydraulic Research,Volume 49, Issue 3, 2011, pages 293‐306[10.] Michael B. Abbott, Karsten Havn, Sten Lindberg, Thefourth generation of numerical modelling inhydraulics, Journal of Hydraulic Research, Volume 29,Issue 5, 1991, pages 581‐600[11.] Hricová, B., Nakatová, H., Badida, M., Lumnitzer, E..(2009) Aplication of ecodesign and life cycleassessment in evaluation of machine products, MMA2009, Novi Sad, Serbia, p. 250‐253[12.] Hricová, B., Nakatová, H., Badida, M., Lumnitzer, E..(2009) Utilisation of tools of environmentalmanagement in evaluation of environmental profile ofproducts, MTeM 2009, Cluj‐Napoca , Romania, p. 317‐320[13.] Košťál, P., Mudriková, A., Velíšek, K. (2008). Materialflow in flexible manufacturing. 4th InternationalScientific Conference of the Military Technical College.The 13th International Conference on AppliedMechanics and Mechanical Engineering, Arab Republicof Egypt, Cairo[14.] Lamár, K. (2004), Digital Control of Permanent MagnetSynchronous Motors, Proceedings of the BudapestTech Jubilee Conference, Budapest, Hungary, pp. 213‐228[15.] Antal, G., Lamár, K. (2002), Modern Solutions toIntegrated Building Automation Systems, Proceedingsof the International Conference ”Kandó 2002”,Budapest, Hungary, p.5‐10[16.] Neszveda, J. (2009). Safety Lifecycle of IntermittentlyOperated Device, Academic and Applied Research inMilitary Science, Vol.8, Issue 2, pp. 203–211[17.] Anagnostopoulos, J. (2003), Discretization oftransport equations on 2D Cartesian unstructuredgrids using data from remote cells for the convectionterms. International Journal for Numerical Methods inFluids 42(3), 297 – 32[18.] Choudhary, K., Mazumdar, Dipak, (1995).Mathematical modeling of fluid flow, heat transferand solidification phenomena in continuous casting ofsteel, Steel Research, 66, No. 5[19.] F. Stella, M. Giangi, F. Paglia, A. Casata, D. Simone, P.Gaudenzi, A numerical simulation of fluid–structureinteraction in internal flows, Numerical Heat Transfer,Part B: Fundamentals: An International Journal ofComputation and Methodology, Volume 47, Issue 5,2005, pages 403‐418[20.] Peter Beater, Modeling and Digital Simulation ofHydraulic Systems in Design and EngineeringEducation using Modelica and HyLib, ModelicaWorkshop 2000, 2000, Lund, Sweden[21.] W. Borutzky, B. Barnard, J. Thoma, An orifice flowmodel for laminar and turbulent conditions,Simulation Modelling Practice and Theory, Volume 10,Issues 3–4, 15 November 2002, Pages 141–1521002012. Fascicule 3 [July–September]

1.Preetida VINAYAKRAY‐JANI, 2. Sugata SANYALROUTING PROTOCOLS FOR MOBILE AND VEHICULAR AD HOCNETWORKS: A COMPARATIVE ANALYSIS1.DA_IICT, GANDHINAGAR, INDIA2.TATA INSTITUTE OF FUNDAMENTAL RESEARCH, MUMBAI, INDIAABSTRACT: We present comparative analysis of MANET (Mobile Ad‐Hoc Network) and VANET (Vehicular Ad‐Hoc Network)routing protocols, in this paper. The analysis is based on various design factors. The traditional routing protocols of AODV(Ad hoc On‐Demand Distance Vector), DSR (Dynamic Source Routing), and DSDV (Destination‐Sequenced Distance‐Vector)of MANET are utilizing node centric routing which leads to frequent breaking of routes, causing instability in routing. Usageof these protocols in high mobility environment like VANET may eventually cause many packets to drop. Route repairs andfailures notification overheads increase significantly leading to low throughput and long delays. Such phenomenon is notsuitable for Vehicular Ad hoc Networks (VANET) due to high mobility of nodes where network can be dense or sparse.Researchers have proposed various routing algorithms or mechanism for MANET and VANET. This paper describes therelevant protocols, associated algorithm and the strength and weakness of these routing protocols.KEYWORDS: Mobile Ad‐Hoc Network, Vehicular Ad‐Hoc Network, Routing Protocols, Geographic Source Routing (GSR),Spatially Aware packet Routing (SAR), Anchor‐based Street and Traffic (A‐STAR) aware routing, Connectivity AwareRoutingINTRODUCTIONAn emerging Mobile Ad hoc Networks (MANET) andVehicular Mobile Networks (VANET) are expected toform network centric communications. Large numberof mobile nodes communicates through single ormulti‐hop routing protocols. Although VANET is one ofthe classified scenarios of MANET, VANET nodes formhighly dynamic network where node density could beeither dense or sparse. Besides vehicle radios havevery limited radio range and must communicate withone another by multi‐hop routing protocols.Apparently, widely varying mobility characteristics ofmobile or vehicular nodes are expected to have asignificant impact on the performance of routingprotocols. Therefore even though researchers havedeveloped routing protocols like Ad hoc On‐demandVector (AODV), Dynamic Source Routing (DSR),Destination Sequence Distance Vector (DSDV) etc. forMANET [2], these protocols cannot be directlyadopted in VANETs, efficiently, because of the rapidvariation in link connectivity, high speed andextremely varied density of vehicular nodes in VANET.Researchers have developed special routing protocolsfor VANET [3], and these are aimed to adapt rapidlychanging mobility pattern of the vehicular nodes.Although such mobility characteristics exhibit spatialor temporal dependency of nodes, they areinsufficient to capture some important mobilitycharacteristics of scenarios in which MANETs may bedeployed, i.e. the mobility characteristics generateprotocol independent metrics [18]. But eventually thisprotocol independent metrics significantly influencesthe routing protocol performance. Attempt is made tocategorize and summarize the routing protocols, asper the design factors, that influence the mobilityperformance.This paper attempts to provide design factors thataffect MANET and VANETs in section II. Subsections IIalso provide classification and qualitative comparisonof MANET and VANET routing protocols. Finallysection III discusses conclusion and open issues ofdeveloped or proposed routing protocols.DESIGN FACTORS THAT AFFECTS THE ROUTING PROTOCOLSIn general, routing protocols designed for MANET andVANET are categorized from topology point, these areeither flat, hierarchical or position based;Communication paradigm (uni‐cast or multicast orbroadcast), Delay tolerance, Quality of service, Clusterbased routingA. TopologyFlat topology: MANET routing protocols OptimizedLink State Routing (OLSR), DSDV, Wireless RoutingProtocol (WRP), Global State Routing (GSR), FisheyeState Routing (FSR), Source Tree Adaptive Routing(STAR) [7], Distance Routing Effect Algorithm forMobility (DREAM) represents flat topology whereroute updates are periodically performed thatconstantly updates the network topology. Thisperiodic updates are, regardless of network load,bandwidth or scalability. Such protocols are proactiveand do not provide power saving as router updatesare made periodicallyAlternatively researchers have also developed thereare reactive protocols in like AODV, Label‐basedMultipath Routing (LMR), Temporally‐OrderedRouting Algorithm (TORA), Location Aided Routing(LAR), Zone Routing Protocol (ZRP), Flow OrientedRouting Protocol (FORP) where routing update is© copyright FACULTY of ENGINEERING ‐ HUNEDOARA, ROMANIA 101

made on demand. In this type of protocol designactive routes between sender and receiver nodes isdetermined by making route discovery. Routediscovery is made by flooding network with routerequest and receiving route response packets innetwork. Such phenomena, helps nodes to conservepower as there are no periodic signals to respond.These MANET protocols are not suitable for VANET, asdiscovering routing path is time consuming asvehicular node’s speed is high.Hierarchical or Hybrid: In MANET routing protocol likeZRP [4], represent this category that uses the hybridapproach to improve scalability of routing protocol.By considering proactive and reactive mechanisms,ZRP divides network in intra and inter zones, whereintra‐zone protocols are proactive and inter‐zoneprotocols are reactive. Although this protocolimproves scalability, lack of implementation feasibilitymakes this routing aspect unsuitable for VANET.Position‐based: Position based routing protocols useslocation aided approach for MANET.In VANET vehicular nodes either communicate withanother vehicle (V2V) or road side vehicle (V2R). Inexisting infrastructure and ad hoc nodes of IEEE 802.11wireless standard the time required to authenticateand associate with Basic Service Set (BSS) is too longto be considered by VANET. Therefore 802.11pstandard will provide wireless devices with ability tocommunicate through short‐duration messages,necessary to communicate between a high speedvehicle and a stationary roadside unit (V2R) includinghigh speed vehicle (V2V). This mode of operation isknown as Wireless Access in Vehicular Environment(WAVE) [19].Although this V2V communication decentralized, it isrobust and supports the low data transport times foremergency [10] warning, Such thing is not feasiblewith roadside cellular base station as they are oftenoverwhelmed by calls in emergency, due to lack ofload balancing mechanism to avoid congestion innetwork [5].In MANET the proposed routing protocol LAR, usesinformation about location through geographiccoordinates or relative position of nodes to generateroute information thus by reducing overhead oftraditional flooding mechanism. Moreover locationservice may be built into nodes or distributed locationservices may be utilized [12, 5].The position based routing approach was designed forMANET routing protocol called Greedy PerimeterStateless Routing (GPSR) [25]. In this greedyforwarding strategy is used to forward messagestoward known destination. However if at one or multihop, there are no nodes in direction of destinationthen it uses the perimeter mode. Usage of suchACTA TECHNICA CORVINIENSIS – Bulletin of Engineeringrouting strategy in VANET is not efficient as in urbanarea radio obstruction restricts the effective routeand usage of perimeter mode is often required.During obstruction this perimeter mode uses thecreated planner graph that causes the message to bedelivered immediate node instead of farthestreachable node. Thus more nodes will carry messages,eventually increasing delays. Such inefficiency can alsocause messages to be delivered in wrong directionwhen node moves from communication range of onenode to another.As a result VANET uses Geographic Source Routing(GSR) [11]. This particular routing mechanism usesDijkstra’s shortest path algorithm to find shortestpath between source and destination. Using staticstreet map in piror and location information abouteach node, source forwards the message todestination and computes route to destination usingDijkstra’s shortest path algorithm. The sourcemessage computes the sequence of intersection thatmust be traversed in order to reach destination.Although this algorithm is VANET specific it does notconsider vehicle density, however authorsacknowledges this and can see a potential to improvethis routing mechanism.Another position based routing protocol calledSpatially Aware packet Routing (SAR) [16], tries toprevent limitations of recovery strategy used by GPSRof MANET. It is similar to GSR, but relies upon theexternal service such as Geographical InformationService (GIS) to extract street map and construct‘spatial model’ to calculate shortest path to routepacket to a destination. When shortest path isdecided, unlike GSR, it determines the geographicallocations that need to be travelled in embedded inpacket header. When node needs to forward packet ituses this immobile physical location information toroute packet to next geographic location. Thus itavoids the greedy strategy like GSR towarddestination. Author does provide recovery strategy ifforwarding node cannot find next location specified inpacket header. In one method it suggests the usage ofsuspension buffer to store information till node findssuitable location. In another method node greedilyforwards packet to destination. Usage of suspensionbuffer provides the high packet delivery ratio withexpense of delay compare to no recovery strategy inSAR.Unlike GSR, Anchor‐based Street and Traffic (A‐STAR)[20] aware routing uses bus routes to find routes withhigh probability for packet delivery. It uses thegeographic forwarding points to route packet todestination, including route information to determinetraffic density. However this static approach is less1022012. Fascicule 3 [July–September]

ACTA TECHNICA CORVINIENSIS – Bulletin of Engineeringoptimal compare to dynamic approach that utilizeslatest traffic condition information.In VANET, Connectivity Aware Routing (CAR) [15]maintains the cache of successful routes betweenvarious source and destination pairs. Nodes using CARperiodically sends HELLO beacons indicating the“velocity vector” information. On receiving thisinformation receiving node will update its neighbourtable and calculates its own velocity vector andvelocity vectors of its neighbours. The entries in tableexpire after two HELLO intervals. However this HELLObeacon interval adapts as per traffic density, byincreasing its frequency when traffic is sparse and bydecreasing when traffic is dense. To maintain routingpaths as the vehicle changes its position, guards areutilized to avoid the repetition of discovery phase ofroute. If the node at a route end point changes itsdirection then node activates guard with old and newvelocity vectors. The node that is aware of a guard canuse guard table information to ensure the delivery ofmessages to destination node that has moved. Onceguard aware node receives a message addressed tothe relocated node, it will add the guard coordinatesas an anchor point to the message. Then it estimatesthe new position of the destination and forwards themessage. Protocol also suggests two recoverystrategies like “timeout algorithm with active cycle”and “walk around error recovery” to rectify therouting error incurred due to communication gapsbetween two anchor points or guards that are notmaintained due to low traffic. Without making usageof map of location services, this protocol shows theability to create the virtual infrastructure through‘guards’. Protocols also provide the street and trafficawareness during discovery phase and maintains theroute and adapts to traffic densities.B. Communication ParadigmIn general communication paradigm include unicast,multicast, geocast, anycast, geographical anycastcommunication. Unicast communication provides oneto‐onecommunication where target node location isknown precisely or it is in the communication rangethrough single or multi hop distance. Multicast orbroadcast communication provides one‐to‐manycommunication where many single node cancommunicate with group of target nodes identified bycommon destination address. Multicasting isinterpreted for group oriented communication. Thistype of communication paradigm is more suitable forapplications that will require dissemination ofmessages to many different nodes in the network.The specialized form of multicast group is also calledgeocast where nodes are within particular geographiclocation relative to source able to receive geocastmessages. In addition to this there is also anotherspecialized form of multicast called anycast where anode sends message to any destination node in agroup of nodes. This anycast also provides dataacquisition feature where a nodes sends messages tocertain geographic area to request data from anynode found in that geographic location, calledgeographical anycast.Many multicasting protocols have been proposed forMANET as well as for VANET. Designed and developedMANET based routing protocols are either using treestructure or mesh structure. Within the MANETworking group at IETF two proposed multicast routingfor ad hoc networks are Multicast Ad‐hoc On‐demandDistance Vector (MAODV) [26] and On‐demandMulticast Routing Protocol (ODMRP) [27].MAODV uses the shared bi‐directional multicast treewhile ODMRP maintains the tree topology. In MOADVwith hard state of connected links, any link breakageforce actions to repair the tree. Group leader inmulticast tree maintains the up to date informationabout multicast tree by periodically sending grouphello message and receiver unicasts the reply back tosource. But if intermediate node on route path moveaway, the reply is lost, eventually route is lost.Unlike MAODV, ODMRP being mesh topology,alternative path is feasible where link failure need nottrigger the re‐computation of the mesh. Any brokenlink eventually time out and route information forsource and receiver is periodically refreshed by thesource. The broadcasted route refreshes from everysource could result in scalability issue if intermediatenodes are not part of multicast group, resulting inextra processing overhead. This makes tree basedMAODV topology more efficient as it avoids sendingduplicate packets to receivers. However in highmobility environment where topology changes veryfast, tree‐based MAODV is not suitable as unicast replyback to source is unable to reach if intermediate nodein route path moves away. However in mesh basedODMRP alternative routes updates are broadcastedfrom receiver to source, making more robust againstlink failure with expense of associated overhead.Therefore compared to tree based topology, meshbased topology outperforms in high mobilityenvironment.C. Delay Tolerance NetworkSparse MANETs are a class of ad hoc networks wherenode density is low and contacts between the nodes innetwork occurs infrequently. As a result, the networkgraph is rarely, if ever, connected where messagedelivery must be delay tolerant. However traditionalMANET routing Protocols make the assumption thatthe network graph is fully connected and fail to routemessages if there is no complete route from source todestination at the time of sending. For this reason2012. Fascicule 3 [July–September] 103

traditional MANET routing protocol cannot be used insparse MANETs. A key challenge is to find a route thatcan provide good delivery performance and low endto‐enddelay in a disconnected graph where nodesmay move freely.To overcome this issue, node mobility is exploited tophysically carry messages between disconnected partsof network. The scheme that exploits the nodemobility, referred to as mobility assisted routing thatemploys the store‐carry‐and‐forward model is used.Mobility assisted routing consists of each nodeindependently making forwarding decisions that takeplace when two nodes meet.In VANET, when few vehicles are equipped withwireless transceivers, network will be sparse; delaytolerant routing algorithms are needed. The proposedMotion Vector Algorithm (MOVE) [8] for V2R VANETconsiders sparse network where prior prediction mustbe made for rare opportunistic routing. It is assumedthat every node has knowledge of its own positionand heading, where destination is a fixed globallyknown location. From this current vehicular nodefinds closest distance between vehicle and messagedestination along its trajectory. Current vehicularnode periodically sends HELLO message. Neighbouringnodes sends RESPONSE message to make itself knownto current vehicular node. Given the direction ofwhere neighbouring node is heading; current nodedetermines the shortest distance to destination alongthe trajectory of neighbouring node. The current nodethen makes decision to forward the message whiledetermining the each vehicle’s current distance fromdestination. This algorithm where data delivery rate ishigher for sparse network, compared to greedy,position based routing and uses less system bufferspace. With resulted performance evaluation, authorshave noted that if routes are consistent and uniform,greedy position based routing performs better thanMOVE.In line with MOVE algorithm another algorithm calledScalable Knowledge based Vehicular Routing (SKVR)[1], also makes the usage of the predictable routes andvehicle schedules. It divides the network in interdomainand intra‐domain. In inter‐domain routingsource and destination belong to different routeswhereas in intra‐domain source and destinationbelong to same route. In inter‐domain algorithm,message is forwarded to a vehicle travelling indestination domain and once destination domain isreached intra‐domain message delivery procedure willbe followed. In intra‐domain messages are sent inforward or reverse directions, depending on theentires of contact list. If the sending vehicle contactlist does not contain any vehicle in the destination’sdomain, then messages are delivered to the otherACTA TECHNICA CORVINIENSIS – Bulletin of Engineeringvehicles in contact list. When vehicles along the sameroute encounter one another, a node carrying amessage must decide whether to continue bufferingthe message, or to forward it, based on the directioninformation of the vehicle.Using strategy called ‘carry‐and‐forward’ VehicleAssisted Data Delivery (VADD) [17] algorithm allowspackets to be carried by vehicles in sparse networkand eventually relaying it to appropriate node when itenters in broadcasting range. Each node in VADDknows its own position and also requires externalstreet map that includes traffic statistics. Selection ofthe candidate node, to which message need to beforwarded, is encountered through different selectioncriteria. However such criteria are either not scalableor consumes more bandwidth through duplication ofpackets. Authors have observed while using VADD,network becomes unstable as vehicle densitydecreased, because optimal paths were not availableand because algorithm relies upon probabilistic trafficdensity information.Unlike VADD, Static Node Assisted Adaptive Vehicularrouting (SADV) [6] where static node has capability tostore a message until it can forward the message to anode travelling on the optimal path. Algorithm alsodynamically adapts to varying traffic densities innetwork, so that every node can measure the amountof time required to deliver message. However like any‘store‐and‐forward’ this algorithm requires theefficient buffer management. By using ‘Least DelayIncrease’ strategy, where static node checks whichpaths are currently available and eliminates packetswhich will not significantly increase their deliverydelay.Routing called Geographical Opportunistic (GeOpps)[9] routing in delay tolerant network is usingopportunistic routing with carry‐and‐forwardapproach to route messages. Algorithm assumes thatvehicle is using GPS and Navigation system that helpsto route and locate static road site unit.D. Quality of Service (QoS)QoS routing strategy is not followed by any traditionalMANET routing protocols. However there are researchattempt to integrate such strategies within MANETrouting protocols.Multi‐hop Routing Protocols for Urban VANET (MURU)[13], estimates quality factors of a route based onvehicle position, speed and trajectories. Based on thisquality factors MURU introduces new metric called‘Expected Disconnection Degree’ (EDD). Hence MURUnodes need to know its own position and haveexternal street map including presence of efficientlocation service. This new metric value considered tobe low as EDD, is an estimation of probability thatdetermines the breakability of route during given time1042012. Fascicule 3 [July–September]

ACTA TECHNICA CORVINIENSIS – Bulletin of Engineeringperiod. Based on destination location and street map,source node calculates the shortest trajectory to thedestination to find route to destination. This shortesttrajectory detail is stored in the packet and is used as adirectional guideline for Route Request (RREQ)message. Node receiving RREQ message calculatesEDD of the link between two subsequent nodes.MURU uses pruning method to improve the scalabilityof RREQ message, where node receiving RREQmessage will wait for backoff delay that is directlyproportional to the EDD between the previousforwarder of RREQ and current one. During thisbackoff interval the node determines whether to dropthe RREQ message or rebroadcast it. Nevertheless, byusing pruning method broadcasting area iterativelybecomes smaller to receive RREQ broadcast.Eventually when destination receives the RREQmessage from different routes, it selects the routewith smallest EDD. This smaller broadcasting area isproblematic if the next hop node is located outside ofbroadcasting range. However with low overhead anddelay, MURU provide quality route with highpercentage of throughput.Another algorithm called Prediction Based Routing(PBR) [14], focussed on providing Internetconnectivity to vehicles. This algorithm assumes thateach vehicle has knowledge of its own position. Thealgorithm takes advantage of the less erratic vehiclemovement patterns on road to predict the durationand expiry of a route from a client vehicle to a mobilegateway vehicle. Just before route failure is predicted,PBR pre‐emptively seeks new route to avoid loss ofservice. However, it is unclear that how gateway willshare bandwidth demand with number of vehicles.E. Clustering based routingClustering is a process that divides the network intointerconnected substructures, called structures. Agroup of nodes identifies themselves to be a part ofcluster and a node designated as cluster head (CH) willbroadcast the packet to cluster. The stability of nodeis the key to create the stable cluster infrastructure.There have been attempts to study cluster‐basedrouting protocols in MANET. VANETs behave in adifferent way than the model that predominate inMANET’s research, are due to driver behaviour,constraints on mobility and high speeds.In MANET, Weighted Clustering Algorithm (WCA) [21]based on the use of weight metric that include severalsystem parameters like the node‐degree, distancewith all its neighbours, node speed and time spent as aCH. Each node obtains the weight value of other nodesand CHs through re‐broadcasting. As a result itinduces overhead. If node moves into region which isnot covered by CH, then once again cluster set‐upprocess gets invoked. Such procedure is timeconsuming as it introduces more overhead to process.The performance of WCA is enhanced by algorithmcalled Distributed Weighted clustering Algorithm(DWCA) [22], which localizes the configuration andreconfiguration of cluster and restricts the powerrequirement on CHs.In VANET, a reactive Location Routing Algorithm withCluster Based Flooding (LORA‐CBF) [23], where eachnode can be CH, gateway or cluster member. For eachcluster there is CH, a node that connects two clusterscalled gateway. The packets are forwarded byprotocol similar to greedy routing. If location ofdestination is not available then source will sentlocation request. This is similar to route request inAODV, but only CH and gateways can disseminates thelocation request and location reply. Performanceresults show the network mobility and size of thenetwork affects the performance of AODV and DSR[2], more significantly than LORA‐CBF.Another VANET routing algorithm called Clustering forOpen IVC Networks (COIN) [24], where CH is based onvehicular dynamics and driver intensions. Performanceshows that COIN represents more stable clusteringstructure of VANET, at the cost of little overhead.CONCLUSIONS AND OPEN ISSUESIn this paper attempt is made to provide comparativeand qualitative analysis of MANET and VANET routingprotocols by categorizing them within five differentdesign factors.Although foundation of MANET and VANET routingprotocols is well established; it is essential to makecomprehensive performance evaluation of variousalgorithms, by implementing them in real‐timescenario.The performance of routing protocols MANET andVANET depends significantly on the mobility modelsand the density of nodes. Therefore it is essential todesign routing protocols specific to given mobilitymodels.REFERENCES[1.] S. Ahmed, S.S. Kanere, “SKVR: Scalable KnowledgebasedRouting Architecture for Public TransportNetworks”, Proceedings of the 3rd InternationalWorkshop on Vehicular Ad hoc Networks (VANET'06),ACM, New York, NY, USA, 2006, pp. 92‐93.[2.] R. Bai, M. Singhal, “DOA: DSR over AODV routing formobile ad hoc networks”, IEEE Transactions on MobileComputing, vol.5, no.10, Oct. 2006, pp.1403‐1416.[3.] E. Fonseca, A. Festag, “A survey of existing approachesfor secure ad hoc routing and their applicability toVANETS”, NEC network laboratories, 28 pages,Version 1.1, March‐ 2006, pp. 1‐28.[4.] Z. J. Haas, M. R. Pearlman, P. Samar, “The ZoneRouting Protocol (ZRP) for Ad hoc Networks”, IETFInternet Draft, July 2002. http://tools.ietf.org/id/draftietf‐manet‐zone‐zrp‐04.txt[5.] J. Bernsen, D. Manivannan, “Unicast Routing Protocolsfor vehicular Ad Hoc Networks: A critical comparison2012. 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and classification,” In Journal of Pervasive and MobileComputing 5, 2009, Elsevier, pp. 1‐18.[6.] Y. Ding, C. Wang, L. Xiao, “A static‐node assistedadaptive routing protocol in vehicular networks”Proceedings of the fourth ACM international workshopon Vehicular ad hoc networks, VANET'07, ACM, NewYork, NY, USA, 2007, pp. 59‐68.[7.] F. Giudici, E. Pagani, “Spatial and Traffic‐AwareRouting (STAR) for Vehicular System.” Proceedings ofFirst International Conference on High PerformanceComputing and Communications, Lecture Notes inComputer Science. Publisher: Springer BerlinHeidelberg, Vol. 3726, 2005, pp. 77‐86[8.] J. LeBrun, C.N. Chuah, D. Ghosal, M. Zhang,“Knowledge‐based opportunistic forwarding invehicular wireless ad hoc networks”, Proceedings ofthe 61st IEEE Vehicular Technology Conference (VTC),vol. 4, 30 May‐1 June 2005, pp. 2289‐ 2293.[9.] I. Leontiadis, C. Mascolo, “GeOpps: GeographicalOpportunistic Routing for Vehicular Networks”, IEEEInternational Symposium on World of Wireless, Mobileand Multimedia Networks, 18‐21 June 2007, Espoo,Finland, pp. 1‐6.[10.] C. Lochert, H. Hartenstein, J. Tian, H. Fussler, D.Hermann, M. Mauve, “A routing strategy for vehicularad hoc networks in city environments”, Proceedings ofthe IEEE Intelligent Vehicles Symposium, 9‐11 June,2003, pp. 156‐161.[11.] C. Lochert, M. Mauve, H. Fussler, H. Hartenstein,“Geographic routing in city scenarios”, ACMSIGMOBILE Mobile Computing and CommunicationsReview, vol. 9, No. 1, January, 2005, pp. 69‐72.[12.] M. Mauve, J. Widmer, H. Hartenstein, “A survey onposition‐based routing in mobile ad hoc networks”,Journal of IEEE Network, vol.15, no.6, Nov/Dec 2001,pp.30‐39.[13.] Z. Mo, H. Zhu, K. Makki, N. Pissinou, “MURU: A Multihoprouting protocol for urban vehicular ad hocnetworks”, Proceedings of the Third IEEE AnnualInternational Conference on Mobile and UbiquitousSystems Workshops, 17‐21 July 2006, pp.1‐8.[14.] V. Namboodiri, L. Gao, “Prediction‐based routing forvehicular ad hoc networks”, IEEE Transactions onVehicular Technology, Vol. 56, No. 4, July 2007, pp.2332‐2345 .[15.] V. Naumov, T. R. Gross, “Connectivity‐aware routing(CAR) in vehicular ad‐hoc networks”, Proceedings ofthe 26th IEEE International Conference on ComputerCommunications, 6‐12 May 2007, pp.1919‐1927.[16.] J. Tian, L. Han, K. Rothermel, “Spatially aware packetrouting for mobile ad hoc inter‐vehicle radionetworks”, Proceeding of the IEEE IntelligentTransportation Systems, Vol. 2, 12‐15 October, 2003,pp. 1546‐ 1551.[17.] J. Zhao, G. Cao, “VADD: Vehicle‐Assisted Data Deliveryin vehicular ad hoc networks”, Proceedings of the 25thIEEE International Conference on ComputerCommunications (INFOCOM), 2006, pp. 1‐12.[18.] Bhavyesh Divecha, Ajith Abraham, Crina Grosan andSugata Sanyal "Analysis of Dynamic Source Routingand Destination‐Sequenced Distance‐Vector Protocolsfor Different Mobility models", First Asia InternationalConference on Modelling and Simulation, 27‐30 March,2007, Phuket, Thailand, pp. 224‐229.ACTA TECHNICA CORVINIENSIS – Bulletin of Engineering[19.] Status of Project IEEE 802.11 task group p, “WirelessAccess in Vehicular Environment” (WAVE)”,http://www.ieee802.org/11/Reports/tgp_update.htm[20.] R.C. Seet, G. Liu, B.S. Lee, C.H Foh, K.J. Wong and K.K.Lee, “A‐STAR: A mobile ad hoc routing strategy formetropolis vehicular Communication”, Performance ofComputer and Communication Networks, Lecturenotes in Computer Science, Vol. 3042, Publisher:Springer Berlin Heidelberg, 2004, pp. 989‐999.[21.] M Chatterjee, S. Das and D. Turgut, “WCA: A WeightedClustering Algorithm for Mobile Ad hoc Networks”,Journal of Cluster Computing (Special Issue on MobileAd Hoc Networks), Vol. 5, No. 2, Springer, pp. 193‐202,2002[22.] W. Choi and M. Woo, “A Distributed WeightedClustering Algorithm for Mobile Ad Hoc Networks”, InProceedings of IEEE Advanced InternationalConference on Telecommunications and InternationalConference on Internet and Web Applications andServices, 2006, pp. 73.[23.] R. A. Santos, A. Edwards, R.M. Edwards and N.L.Seed,“Performance evaluation of routing Protocols inVehicular Ad Hoc Networks,” The International Journalof Ad Hoc and Ubiquitous Computing, Vol. 1, No. 1, pp.80‐91, Inderscience, 2005[24.] J. Blum, A. Eskandarian and L. Hoffman, “MobilityManagement in IVC Networks,” In Proceedings of IEEEIntelligent Vehicles Symposium, 2003, pp. 150‐155.[25.] B. Karp, H.T. Kung, “GPSR: Greedy Perimeter StatelessRouting for Wireless Networks,” In Proceedings of the6 th International Conference on Mobile Computing andNetworking, MobiCom’00, ACM, New York, NY, USA,2000, pp. 243‐254.[26.] E. M Royer, C. E. Perkins, “Multicast Ad hoc OndemandDistance Vector (MAODV) Routing,” InternetDraft, http://tools.ietf.org/html/draft‐ietf‐manetmaodv‐00[27.] Y. Yi, Sung‐Ju Lee, W. Su, M. Gerla, “On‐demandMulticast Routing Protocol (ODMRP) for Ad hocNetworks”, Internet Draft,http://tools.ietf.org/html/draft‐ietf‐manet‐odmrp‐04ACTA TECHNICA CORVINIENSIS – BULLETIN of ENGINEERINGISSN: 2067‐3809 [CD‐Rom, online]copyright © UNIVERSITY POLITEHNICA TIMISOARA,FACULTY OF ENGINEERING HUNEDOARA,5, REVOLUTIEI, 331128, HUNEDOARA, ROMANIAhttp://acta.fih.upt.ro1062012. Fascicule 3 [July–September]

1.Vladimir KULIK, 2. Ján PAŠKOTHE STRUCTURAL DESIGN AND STRENGTH CALCULATION WORMEXTRUSION MACHINES FOR PRODUCING PLASTIC PROFILES1‐2.TECHNICAL UNIVERSITY OF KOŠICE, FACULTY OF MANUFACTURING TECHNOLOGIES, DEPARTMENT TECHNICAL DEVICES DESIGN, PRESOV, SLOVAKIAABSTRACT: The most practical and the most widely used technology of plastic profile extrusion technology is worm extruder.The contribution deals with the design and stress analysis of a single worm extruder. Extrusion technology is one of theleading production technology for processing thermoplastics, as well as elastomers (rubber). The introduction is givensubstance and principle of extrusion technology. In other parts of the paper is processed with design and stress analysis of asingle worm.KEYWORDS: extruders, extrusion, wormINTRODUCTIONExtrusion technology is one of the leading productiontechnology for processing thermoplastics, as well aselastomers (rubber). The essence of this technologylies in the heated feed material (plastic) in the meltingchamber at a temperature of about 200°C (at whichthe plastic in the plastic state), which is also stirred bythe worm and then extruded through the exit portionof a worm into the mold or mold through the hole.After printing, material should be cool for thestabilization of product shapes and sizes. Profileresulting from the extrusion head is continuously pullsand further adjusts depending on the technology. Inthe production of extruded profiles after the moldprocessing there are cooling process continued, whichis in the most cases cooling medium is water. Forextrusion through a hole shaped, this profile which iscreated have to be stabilized by water or air‐cooling.To avoid over cooling the melt extruded profile,change dimensions, there are placed it in the profiledbore gauges, where the profile is cooled to atemperature such as, that the resulting profile wasdimensionally stable. In the case of extrusion rubbermixtures can be extruded profile led directly tovulcanization [4] [7].Figure 1. The principle of a worm extruderTHE STRUCTURAL DESIGN WORM EXTRUDERSWorms are among the main functional parts of theworm extrusion machines, whose constructiondepends on the type of processed material. Animportant variable is the compression ratio, whichexpresses the ratio of the volume profile for a wormpitch of the worm in two places. A change of acompression ratio is usually achieved by varying thethickness profile of the worm. The size depends on thesize of a worm extruder. Worm is determined bydiameter D and length L, which usually refers to theaverage L / D. For extruding thermoplastic extruderworms are used most frequently with a length of 23 to30 D and a compression ratio of 1:1.5 to 1:4,5 andpolymers with narrow melting temperature range istypically processed to worm with a highercompression ratio. When geometry of a worm isselecting, should be taken care of the materialcharacteristic to be processed. Compression ratio forthe machine filled with a preheated mixture rangesfrom 4 to 6, for machines to meet a cold mixture of 10to 18. [4]Save the worm machine is bearings. Worm isconnected to the drive shaft coupling or pen. Inprocessing there are must respect certaintechnological parameters, mainly because power mustbe designed so that the performance was sufficientand the worm speed should normally be continuous orstepped and changeable in a wide range. [7]Worms from the design point of view can be dividedinto:a.) variable angle of climb,b.) long transition zone,c.) double‐acting worm,d.) short transition zone,e.) completed a smooth torpedo,f.) with the driving element degassing and stirringpart.© copyright FACULTY of ENGINEERING ‐ HUNEDOARA, ROMANIA 107

ACTA TECHNICA CORVINIENSIS – Bulletin of EngineeringWorms are loaded with axial force on the pressure orbuckling. It depends on the ratio of worm length andits diameter. It is therefore necessary to calculate theslenderness ratio (λ).Figure 2. Diagram of a simple worm [7]Figure 1 shows a diagram of a simple worm, wherethey are displayed basic geometric parameters too.Total volume of material transported by worm can becalculated from the basic relationship [4]:β ΔPQ = α.n− ⋅η Lwhere:Q – total volume of the worm material per unit time[mm 3 .s ‐1 ],n – rotational speed [s ‐1 ],∆P – pressure gradient in the direction of the wormaxis [MPa],η – viscosity of the polymer [kg.m ‐1 .s ‐1 ],D – worm diameter [mm]STRENGTH CALCULATION OF SIMPLE WORM EXTRUDERSWorms are much stressed functional parts of theworm extruders. They are stored in the bearings,which allow rotational movement of the worm andcapture the axial and radial forces. [3] [7]Figure 3. Load a single wormThe sizes of forces acting on the bearings arecalculated from the following relations:2DFA= π ⋅ p ;4qLFB = 2b;qLF C = ( 1 + 2b)2bwhere:D – worm diameter [mm],p – pressure at the end of the worm [MPa],q – continuous load [N.mm ‐1 ]2L λ = 0iwhere:λ – slenderness ratio [‐],L 0 – reduced length [mm],i – radius of inertia [mm]Worms whose slenderness ratio exceeds 50 (λ> 50)are strained to the bar and worm whose slendernessratio is less than 50 (λ> 50) are stressed by thepressure. When stress is calculated on the pressurereduced stress (σ r ), which must be less than theallowed voltage (σ D ). [6] [7]2max2maxσ r = σ + 4τ≤σDF MσOmax = σ + σ O = + ;S WOMKmaxτ max =Wwhere:σ r – reduced stress [MPa],σ max – maximum normal stress [MPa],τ max – maximum tangential stress [MPa],σ D – maximum possible stress [MPa],F – axial force applied to the worm [N],S – Cross‐section worm [mm 2 ],M O – bending moment [N.mm],W O – selectional module for bend [mm 3 ],M Kmax – maximum torque [N.mm],W K – sectional module for torsion [mm 3 ]The maximum deflection at the end of the worm iscalculated from the relationship:4qLy max = ;8EJ44πD⎡ ⎛ d ⎞ ⎤J = ⎢1− ⎜ ⎟ ⎥64 ⎢⎣⎝ 4 ⎠ ⎥⎦where:y max – maximum deflection [mm],q – continuous load [N.mm ‐1 ],L – worm length [mm],E – Modulus of elasticity [MPa],J – moment of inertia of the cross section of the worm[mm 4 ],D – maximum diameter of the worm [mm],d – minimum diameter of the worm [mm]For reliable operation of these machines is alsoimportant to twist the worm. Twisting the wormshould not exceed 1.5 to 3° degrees [7]. For the truesize of the torsion:K1082012. Fascicule 3 [July–September]

ACTA TECHNICA CORVINIENSIS – Bulletin of Engineering° MKL180ϕ max = ⋅ ≤ϕDGJ πwhere:φ ° max – maximum tortion [°],M K – torque [N.mm ‐1 ],L – worm length [mm],G – modulus of elasticity [MPa],φ D – the maximum possible tortion[°]CONCLUSIONSDesign and calculation of components of themachinery is a creative activity using theoretical andpractical experience. This activity must be gearedmainly to meet the requirements. At present, virtuallyall areas of design activities supported by computertechnology that can be effectively used in the designof machinery components particularly in theconstruction of technical documentation and fieldstrength calculations.REFERENCES[1.] Gašpár, Š.: Implementácia programu AutodeskInventor 2009 pri riešení rovinne zaťažených, statickyurčitých priamych konštrukcií. ERIN 2009: 3. ročníkmedzinárodní konference, Ostrava, VŠB‐TU, 2009,ISBN 978‐80‐248‐1982‐2[2.] Batešková, E. – Maščenik, J. – Haľko, J. – Gašpár, Š:Device for measurement of clamped joints frictiontorque. In: Technological Developments inNetworking, Education and Automation. ‐ Dordrecht:Springer, 2010, p. 417 – 419, ISBN 978‐90‐481‐9150‐5[3.] Horvát, T. – Pavlenko, S. – Palko, A.: Použitieprogramu Autodesk Inventor pri vytváraní adimenzovaní hriadeľov, 2010. In: Vzdelávanie učiteľovstredných odborných škôl v nových európskychnormách : zborník referátov informačno‐tématickéhoseminára : 21. október 2010, Prešov FVT TU, s. 110‐114.,ISBN 978‐80‐553‐0549‐3[4.] Liptáková, T. – Alexy, P. – Gondár, E. – Khunová, V.:Polymérne technické materiály, ŽU Žilina, 2009, 182 s.[5.] Maščenik, J. – Haľko, J.: Proposal and calculation ofworm gear with PC upport /Návrh a výpočet závitovkys podporou PC /, In: ERIN 2009. ‐ Ostrava : VŠB‐TU, ‐ISBN 9788024819822[6.] Pavlenko, S. – Haľko, J. – Maščenik, J. – Nováková,M.:Navrhovanie súčastí strojov s podporou PC, 1. vyd.– Prešov : FVT TU, 2008, 347 s.,ISBN 978‐80‐553‐0166‐2[7.] Ragan, E. a kol.: Vstrekovanie plastických hmôt, FVTTU Prešov, 2008, 548 s., ISBN 978‐80‐553‐0102‐0ACTA TECHNICA CORVINIENSIS – BULLETIN of ENGINEERINGACTA TECHNICA CORVINIENSIS – BULLETIN of ENGINEERINGISSN: 2067‐3809 [CD‐Rom, online]ISSN: 2067‐3809 [CD‐Rom, online]copyright © UNIVERSITY POLITEHNICA TIMISOARA,FACULTY OF ENGINEERING HUNEDOARA,5, REVOLUTIEI, 331128, HUNEDOARA, ROMANIAhttp://acta.fih.upt.ro2012. Fascicule 3 [July–September] 109

ACTA TECHNICA CORVINIENSIS – Bulletin of EngineeringACTA TECHNICA CORVINIENSIS – BULLETIN of ENGINEERINGISSN: 2067‐3809 [CD‐Rom, online]copyright © UNIVERSITY POLITEHNICA TIMISOARA,FACULTY OF ENGINEERING HUNEDOARA,5, REVOLUTIEI, 331128, HUNEDOARA, ROMANIAhttp://acta.fih.upt.roACTA TECHNICA CORVINIENSIS – BULLETIN of ENGINEERINGISSN: 2067‐3809 [CD‐Rom, online]copyright © UNIVERSITY POLITEHNICA TIMISOARA,FACULTY OF ENGINEERING HUNEDOARA,5, REVOLUTIEI, 331128, HUNEDOARA, ROMANIAhttp://acta.fih.upt.ro© copyright FACULTY of ENGINEERING ‐ HUNEDOARA, ROMANIA 110

1.Koros NEKOUFARNEW MODELING OF THERMAL DIVISION IN TURBULENT TUBES1.ISLAMIC AZAD UNIVERSITY, CHALOOS BRANCH, IRANABSTRACT: Turbulent Ranque effect is a typical macro–quantum phenomenon, which cannot be described by classical theory.About a century of unsuccessful experience in defining this phenomenon on the basis of classical methods testifies to this.The basic idea of non–local thermodynamics is to use quantum entropy, with every quantum defined as equal to Boltzmanconstant. This hypothesis will allow to apply thermodynamic energy. Further, correlations of quantum mechanics are used.In this article, the process of gasses’ thermal division in turbulent tubes is described on the basis of thermodynamic theoryaccording to Newtonian time.KEYWORDS: Non‐local thermodynamic, Ranque effect, vortical tubeINTRODUCTIONTurbulent Ranque effect is a typical macro–quantumphenomenon, which cannot be described by classicaltheory. About a century of unsuccessful experience indefining this phenomenon on the basis of classicalmethods testifies to this.Another new approach to solve this problem is usingnon‐local version of thermodynamics, developed inthe Moscow State University of Engineering Ecology[1].The basic idea of non–local thermodynamics is to usequantum entropy, with every quantum defined asequal to Boltzman constant– k. This hypothesis willallow to apply thermodynamic energy – kT. Further,correlations of quantum mechanics are used. Forbrevity purposes, only the relation of energy–time isused here:Δ EΔt= h / 2(1)Using ΔЕ=kT in the relation (1) allows establishing theminimum interval macroscopic processes that dependonly on temperature:hΔ t =(2)2kTIn addition, radius r and volume V in the environmentfor time Δt is:chr = cΔ t =(3)2kTV= (4/3)πr 3 =(π/6)(c h /kT) 3 (4)For example, at T=293K, by using relations (2), (3), (4)we will receive following results:Δt=1.3*10 ‐14 s,r=3.9*10 ‐6 m,V=2.5*10 ‐16 m 3Volume V, calculated using the minimum sizes of ΔЕ,Δt, k on physical sense is the minimum macroscopicvolume. The enclosed area by this volume is namedmacro cell in non–local version of thermodynamics.The macro cell can be considered as shortly living andspecial physical cluster, over the molecular level inhierarchy of macroscopic system.Characteristic of a macro cell as a physical self–reliantobject is that, on the one hand, it is the maximummicroscopic volume and quantum mechanics lawsapply to it, and on the other hand, is the minimummacroscopic volume, to which apply minimumclassical definitions. Hereafter there is a possibility ofsimultaneous existence of Boltzman and Planckconstants at macro level.For example, in the new approach it has been shownthat the ensemble of particles in a macro cell act as aunit and their collective speed at time Δt is υ=(kT/m) 1/2 . In other words, in non‐local version ofthermodynamics, balance is considered as dynamicresilient position and for its maintenance, function ofcertain forces is required which depend ontemperature:Fmm kT= ±(5)ΔtmIt was on this basis that Ranque effect was describedthermodynamically [2].CALCULATIONFor this purpose, we will start with some macroscopicelements in hydrodynamics. In the way that themacroscopic elementary stream will have themaximum section of a macro cell, the connectedsurface stream will have a thickness of 2r, where r ismacro cell radius. Obviously, macroscopic theelementary stream will have a radius of R with themaximum section of a macro cell.Let the ensemble of such elementary streams have amacroscopic and connected surface stream of width band volume V=2brR, but the attached surface streamwith N package will have such volume of V p =2brRN.© copyright FACULTY of ENGINEERING ‐ HUNEDOARA, ROMANIA 111

ACTA TECHNICA CORVINIENSIS – Bulletin of EngineeringThe mass of surface package of stream is calculatedfrom the following relation:112M=2brRNρ (6)where ρ indicates density, and N indicates the numberof elementary surface vortex.In a vortex tube, the centrifugal force arising in amacroscopic vortex (6) operates with angular speedω:F=Mω²R (7)Force F as an external force acts on macro cell of nonlocalversion of thermodynamics in which operatesresilient force (5).As a result, according to the non–local version ofthermodynamics, the macro cell moves from oneequilibrium to another dynamic equilibrium position,observing the equality of centrifugal force andresilient inertial forces in a macro cell.At resilient equilibrium state of this position, the othermacro cell will have a new temperature according tothe relation (5).Equating (5), (7) it results in:Mω²Rm kT= .ΔtmConsidering m=Vρ and (6) we will have:2brω²R²Nρ 1/2 =VΔtkTVAs V =(4/3)πr³, Δ t = h / 2kT, r = ch/ 2kT, it is possibleto have the following ratio:bω²R²Nρ 1/2 =aT (8)here a =πсk(2⁄3πсħ) 1/2 =0.0337 (m.J) 3/2 /s.K (a collectionof constants)Thus, the right side of expression (8) only depends ontemperature and some basic constants. Parameters inthe left part depend on current vortex’s radius R i , andso we can write the following expression:(ω 2 bR 2 N√ρ) i =aT i (9)Later expressions (8), (9) are the main equations fordescribing the regime and structural effect ofparameters of Ranque vortex tube, which areobtained exclusively based on macro quantumparameters.One can easily analyze hydrodynamic vortex attachedto the tube’s internal wall. For this purpose we mayuse linear speed in tube’s entrance of vortex tube’sconnector, which has been calculated on the basis ofentrance section of connector tube’s nozzle andspecific efficiency υ=2πRω.Whence ω=υ⁄2πR and finally, from relation (7) we willget:.υ²bNρ 1/2 =a´T (10)here, a´=4π²a=1.3304 (m.J) 3/2 /s.K., i.e. in the conditionof applying optional linear speed, entrance stream ofRanque effect is determined by dependent packagebN and density ρ.Amount of selection of cold (hot) stream should beconsidered separately. Selection affects hydrodynamicstream. So we will consider the linear speed at tube’swall equal to υ R =2πRω R and υ i =2πR i ω i . Dividing υ R on υ iwe’ll have:υ i =υ R (R i /R)(ω i /ω R ) (11)The ratio of first relation decreases as the radius ofvortex decreases, but the second ratio may increasewhich results in the decrease or increase of externalstream’s temperature. This naturally influencesselection of hot stream.Therefore, selection influence can lead to a minimumof external stream’s temperature and a maximum ofdivision efficiency. If we arrive at the conclusion thatthermodynamic nature of all division processes isidentical, optimum thermodynamic selection will havealways an identical probability without any specialrestrictions, i.e. the ratio of selections of cold and hotstreams should be equal. These facts have beenproved by examinations.RESULTS AND DISCUSSIONSThe analysis of industrial cyclone devices "NIIOGaz"type 15–D×1YP by calculating various entranceparameters according to the obtained mathematicalmodel (10) showed that for a regime, which itstemperature has not exceeded its boiling point, just3–12 macroscopic elementary vortexes of "solid‐state"character are needed.This analysis shows that in order to maintain requiredeffect without exceeding boiling point, we just needto have kept a thin wall layer in dependent vortex ofsolid object. Such a state regarding solid object in theregion of vortex tube in the Gutsol experimental work[3] has been considered based on high–speed filming.Figure 1. Changes of the number of macroscopic vortexesas compared to diameter of vortex tube for the(calculation) devices.2012. Fascicule 3 [July–September]

ACTA TECHNICA CORVINIENSIS – Bulletin of EngineeringTo analyze the mentioned method, experimental dataof PhD thesis of doctorate student of Moscow StateUniversity of Engineering, M.A. Terekhov, which wasdone under supervision of Professor O.A. Troshkin [4],were used.Researches were done on a Ranque tube withseparable box’s diameter of D=18mm; and length ofL=125mm. The experimental stand was equipped bythe modern measurement and control set ofequipments and automation equipments andadvanced integral software programs.Of experimental data, all regime parameters, whichare used in the formula (10), except the number ofmacroscopic elementary dependent vortex, are clearin the package N. Their number was calculated 16 withgeneral thickness of 2rN=0.11mm.For comparison it should be noted that in thisexperiment there are h/2r=513 dependent elementarymacroscopic layer in the opening of entrance tube.CONCLUSIONSDuring processing of experimental data with variousratios of products it has been noticed thatmultiplication of υbN in the formula (10) changesunnoticeably by change of selection of product in theselection region of m=0.5.According to this feature, thermodynamic method ofthe analysis of the vortex equipments was formulated,and following results were obtained accordingly:1– On the basis of regime and structural parameters ofvortex tube, the number of elementarymacroscopic vortex for the regime of vortex tubeN without exceeding of temperature from boilingpoint was calculated:N=4π 2 aTρ 3/4 bh 2 ⁄G 22– The analysis of the received result was carried out.There should be enough macroscopic vortexes sothat the increase of vortex’s width (b) when thestream enters the vortex tube, does not lead todecrease of wave to N

ACTA TECHNICA CORVINIENSIS – Bulletin of EngineeringACTA TECHNICA CORVINIENSIS – BULLETIN of ENGINEERINGISSN: 2067‐3809 [CD‐Rom, online]copyright © UNIVERSITY POLITEHNICA TIMISOARA,FACULTY OF ENGINEERING HUNEDOARA,5, REVOLUTIEI, 331128, HUNEDOARA, ROMANIAhttp://acta.fih.upt.roACTA TECHNICA CORVINIENSIS – BULLETIN of ENGINEERINGISSN: 2067‐3809 [CD‐Rom, online]copyright © UNIVERSITY POLITEHNICA TIMISOARA,FACULTY OF ENGINEERING HUNEDOARA,5, REVOLUTIEI, 331128, HUNEDOARA, ROMANIAhttp://acta.fih.upt.ro© copyright FACULTY of ENGINEERING ‐ HUNEDOARA, ROMANIA 114

1.Igor LAZAREV, 2. Karl KUZMAN, 3. Jovan MICKOVSKI,4.Jovan LAZAREV, 5. Jasmina CALOSKA, 6. Atanas KOCHOVMETAL MATRIX COMPOSITES AS TOOLS MATERIAL FOR THE DEEPDRAWING1. ORBICO MAZIVA, PRVOMAJSKA STR. BB, SKOPJE, R .of MACEDONIA2.FACULTY OF MECHANICAL ENGINEERING, UNIVERSITY OF LJUBLJANA, LJUBLJANA, SLOVENIA3.FACULTY FOR TECHNOLOGY AND METALLURGY, UNIVERSITY “ST CYRIL AND METHODIUS”, SKOPJE, R. of MACEDONIA4‐6.FACULTY OFMECHANICAL ENGINEERING, UNIVERSITY “ST. CYRIL AND METHODIUS”, SKOPJE , R. of MACEDONIAABSTRACT: In order to improve the strength and high‐temperature properties of sintered iron, metal matrix iron‐ Alumina(Al 2 O 3 ) composite material has been studied. In the present investigation, iron powder added by 0‐8 Wgt % Al 2 O 3 powderwhere selected for the study. Powders where mixed, compacted and subsequently sintered at 1150 o C in laboratory tubefurnace, under an endo gas atmosphere. Composite material properties were evaluated. The outcome results is that 4 vol %Al 2 O 3 is the optimal percentage of the Alumina to obtain superior properties of the metal matrix composite. The deepdrawing die and punch have been designed by using metal matrix composite and experimentally tested.KEYWORDS: sintering, compressing, strength, hardness, toolsINTRODUCTIONSintered iron components are used for variouscommercial applications. However, inferior strength isa limitation of sintered straight iron powdermetallurgy products in many applications. Therefore,it is very important to increase the strength ofstraight iron powder metallurgy products. There arereferences [1÷4] for sintered iron and iron‐carbonpremixes. However, sintering often is carried out inthe relatively higher temperature. The purpose of thepresent investigation was to increase the strength ofthe sintered iron by incorporating ceramic particlesand to obtain sintered materials at relatively lowertemperature, than generally used in industry.The Faculty of Mechanical Engineering in Skopje andLjubljana have conducted project which is oriented tothe usage of composite materials as materials for tooland die design and this material meets therequirements for mechanical properties to insure thestrength of the tools for sheet metal forming.The series of numerical and experimental analysis fordefining the material characteristics have beenperformed to optimize the mechanical properties.EXPERIMENTAL PROCEDUREIn order to define a composite material that will bemost suitable for preparation of the working elementsof the tools for deep drawing, which will havesufficient strength to withstand the pressure transmitthe stresses of work, but will also have goodproperties of friction and lubrication, composites iron‐ alumina were examined (Fe‐Al 2 O 3 ).Iron powder is product by Swedish company Hoganas.To determine the optimal composition of usedmaterials for sintering technique and to obtain themaximal deformation strengthening behaviours ofsintered iron‐alumina composites was prepareddifferent mixture.Alumina and iron powder have been mixed by using arotary mill regards of small portions of mixture (100 grmixture). Then, in the mixed powders is added acertain quantity of polyvinyl chloride as a means oflubrication using laboratory mortar, to improve theplasticity of mixture for consolidation of shapes bypressing. Mixed material has been compacted intocylindrical shape (test pieces) with a diameter 12 mmand height about 15 mm by onsite uniaxialcompressing in pressings tool (Fig.1). Compacting wascurry out in a hydraulic press fabricated by Erichsen.For all five mixture are prepared test pieces by usingfour different compaction pressures of 200, 400, 600and 800 MPa, with aim to determine the influence ofpressure to green and sintered density and tooptimising out coming sinter properties of piecesregards to straight and microstructure (optimaldensification) of composite.When the compressing and receiving process havebeen finished, compacts were placed in the furnace,for a very slow warm up to 100 o C, hold 5 hours by thistemperature and warm up to 200 o C with 20 hourshold time, in order to dry and evaporate the polyvinylchloride used as lubricator and bonding mean of thematrix and reinforcement. After drying andevaporation, weight measurement of test pieces wasmade, on the scales with an accuracy of 1 / 1000 gramsand dimensional measurement with an accuracy of 1 /100 mm.The sintering of the green cylindrical compacts wascarried out in a laboratory tube furnace (Fig.2),© copyright FACULTY of ENGINEERING ‐ HUNEDOARA, ROMANIA 115

equipped with tube made from stainless steel, withinput and output of neutral and reduction gas furnaceatmosphere. The sinter atmosphere coexist from 90%Nitrogen and 10% hydrogen.ACTA TECHNICA CORVINIENSIS – Bulletin of Engineeringanother proof that the iron composite containing 4%Al 2 O 3 has the best characteristics compared to othercomposites.Fig.1 ‐ Tool for compacting of test piecesThe whole process is carried out during 5 hours and 40minutes. The sintering was realized by heating 1 hourand 40 minutes to the required temperature 1150°Cand hold time of 1 hour and 40 minutes at thistemperature. Cooling was carried out gradually in theprotective atmosphere of gases. When thetemperature dropped to a temperature of 400°C, testpieces were left to cool to room temperature in thefurnace, without the circulation of gases. If cooling isperformed in air to temperatures up to 480 0 C, thenthe iron can oxidize.Fig.2 ‐ Sintering furnaceAfter sintering, dimensional and weight measurementwas made. Then the hardness is measured by Rockwellmethod, use ball 1/16’’ and force of 100 daNComposite hardnessThe most important characteristic that should havecomposite, since the goal and purpose that he shouldhave this investigation, applying for the processingtools, is the hardness and wear. The aim of thisinvestigation is to determine the most appropriatecomposition of the composite in terms ofrepresentation of Al 2 O 3 , the pressure at which itshould be compressed by forming and consolidationof tools for deep drawing. The influence of sinteringtemperature shout is investigated in future.On the figure 3 can be seen that the compositecontaining 4% Al 2 O 3 has the largest hardness and this isachieved at pressures 600 and 800 MPa. This is116Fig.3 ‐ Hardness diagram at iron composites depending byparticipation of Al 2 O 3 and the compressing pressureMicrostructureMetallographic images were made starting from 100%up to 92%Fe in mixture and for all pressures of themanufactured compact from 200 to 800 MPa, andanalyze the structure of the compact. Figures 4 and 5are showing metallographic some images ofcomposite material with 100% Fe, compressed withpressure 200 and 600 MPa, and figures 6 and 7 showmetallographic images of composite material of 96%Feand 4 % Al 2 O 3 , during same pressures for compressing,as show of microstructure of pressing compacted andsintered specimens. All specimens are sintered ontemperature of 1150 0 C in time of 45 minutes, as werepointed in advance.Microstructure of sintered specimen's of pure Fe,show that is build bond between ferritic grains, with aamount of rest porosity, results from relative highforming porosity. The presence porosity show that thesintering temperature end time was not sufficient toobtain pore's free shape.The build microstructure to specimen doped withAl 2 O 3 show higher porosity as pure sintered Fe. Theporosity increase with amount of added Al 2 O 3 . Fegrains are sintered in claster and between they arepresent Al 2 O 3 . Between Fe‐ and Al 2 O 3 – grains are notenough close phase interface, which should becontribute to better mechanical properties ofmaterial, especialy to increasing of toughness. Theadded Al 2 O 3 is isolated between Fe‐grains or isdepozited in pores. The present Al 2 O 3 grains in themicrostructure should be obstacle for free deformingof Fe grains, resulting to reinforcement of base Fematerial coresponding to their hardness anddeformation resistance. In the present microstructure,Al 2 O 3 isolate grains could be contribute to satisfiedmechanical properties of base Fe material for the goalof employment – as tools material for deep drawing.The presents of relative high porosity contributed tokeep lubricant to surface of tools and drawing goods.2012. Fascicule 3 [July–September]

ACTA TECHNICA CORVINIENSIS – Bulletin of EngineeringTable 2. Characteristics of composite Fe‐Al 2 O 3Fig.4 ‐ Metallographic images of composite 100%Fecompressed by pressure of 200MpaGreendensitySintereddensityStrengthduring 10%strainHardness6,03 g/cm 3 6,188 g/cm 3 200 N/mm 2 115‐130 HRBFrom this composite, two elements for deep drawingtool were made: die and blank holder for second draw(Fig. 9) for cylindrical deep drawn parts with adiameter of 50 mm in cylindrical part with diameter 35mm.For compressing of these parts from compositematerial, special tools are designed andmanufactured. Images are shown on figure 8.Fig.5 ‐ Metallographic image of composite 100%Fecompressed by pressure of 600 MPaFig. 8 ‐ Compressing tool for diea)Fig.6 ‐ 96%Fe‐4% Al 2 O 3 , ‐ 200 MpaFig.7 ‐ 94% Fe‐ 4% Al 2 O 3 – 600 MpaDEEP DRAWING DIE DESIGNThe goal of carry outer investigation, which same ofresults is presented in this paper, is to find the mostsuitable composite Fe‐Al 2 O 3 , according to researchesmade and previously explained the optimal compositeis presented below (Table 1).Table 1. The most suitable composite Fe‐Al 2 O 3Compressing Sintering SinteringFe Al 2 O 3pressure temperature time96 % 4 % 600 MPa 1150 о C 40 min.This composite has the characteristics presented inTable 2.b)Fig.9 ‐ Blank holder (a) and die (b) manufactured bycomposite material 96%Fe and 4% Al 2 O 3 compressed bypressure of 600MPa and sintered on temperature of 1150 0 CThe tool (the die and the blank holder) made of ironcomposite Fe‐Al 2 O 3 is used to deep drawn 105 pieces oflow carbonic sheet metal. Figure 10 shows the drawnpieces including the die and the blank holder. Theresults are shown in form of a diagram in Figure 11.The deep drawing was made of low carbonic sheetsteel thick 1 mm. If we analyze the diagram in Figure 11we can conclude that there is a difference in thestrength of deep drawing. It is a result from the nonhomogeneousstructure of the cold rolled sheet metal.The strength at depth of deep drawing h 1 =38 mm,which is the subject of the analysis is between theminimum 43 kN and the maximum 47 kN. If weconsider the tendency of this strength we can statethat it decreases by increasing the number of drawnpieces (Fig. 11). It is a result of self‐polishing thesurface due to the wear of the radius of the die.2012. Fascicule 3 [July–September] 117

Fig. 10 ‐ The die, the blank holder and deep drawn piecesFig.11 ‐ The tendency of decrease of the deep drawingstrength in the second operaiton of deep drawing wiht toolFe‐Al 2 O 3The tool has successfully endured all the deepdrawings without any damages. In addition to thebatch of 105 pieces around 10 pieces of galvanized lowcarbonic sheet metal have been deep drawn as well.CONCLUSIONSIn this paper is made a substitution of classical toolsteels (OCR12, Mat. No. 1.2080, DIN X210Cr12) withcomposite material for the deep drawing tool,presenting innovation and contribution to thedevelopment of tools production.Moreover the composite material was made ofworking elements of the deep drawing tool, blankholder and die for drawing of cylindrical parts for thesecond operation. Manufacturing the tool elementsfor the second operation of deep drawing processwere chosen with the reason that they are withsmaller size compared with the tools for fist draw. Thepowder material, iron and alumina were supplied fromthe Swedish company Hoganes.First of all researches were made in order todetermine which composition from the powdermaterials will create composite materials with thebest mechanical characteristics (pressure strength andhardness). Mixed material is compressed in sampleswith a diameter 12 mm and height about 15 mm bycompressing in specially developed tool. Thecompressing is performed on Erichsen hydraulicmachine owned by the laboratory of Faculty forMechanical Engineering in Skopje. For all 5 groups ofmixtures, 4 compressing were made with differentpressure of 200,400,600 and 800 MPa. Themanufactured samples were drying and sintering inthe dryer and sintering furnace in the laboratory of118ACTA TECHNICA CORVINIENSIS – Bulletin of EngineeringFaculty for Technology and Metallurgy in Skopje.Sintering furnace has a tube chamber with diameterof 80 mm. Sintering is performing in protectiveatmosphere with nitrogen and hydrogen. Sinteringtime after reaching temperature of 1150 0 C for samplesis 40 minutes and for parts of tool is 1 hour and 20minutes. Thus the sintering of the samples isachieving hardness of 96 HRB, and working elementsof the tool to 120 HRB.Investigation showed that the best mechanicalcharacteristics were achieved with the composition of4% Al2O3 and 96% iron power. In a view of pressure,the best results are achieving under pressure of 800MPa, but because it is very high pressure, it is adoptworking pressure of 600 MPa.The company MK Mold DOO manufactured two toolsfor compressing die and blank holder. With this toolsare manufactured two pieces of die and two pieces ofthe blank holder for drawing of cylindrical parts.Given the porosity of composite material have betterhold on characteristics for the lubricant thereby itreduces the forces and the friction stresses. Besidesthat it does not damage the surface of the deepdrawn parts.The strength of the deep drawing, shows a slighttendency of decrease depending on the number ofdeep drawn parts. It is a result from the fact that thedie and the blank holder have been used directlyfollowing the compacting and sintering, with noadditional mechanical processing. During the workdue to gliding and attrition, there is self‐polishing thesurface of die.ACKNOWLEDGEMENTThe project has been financed by: Ministry of Education & Science of Rep. of Macedonia; Ministry of Height Education & Science of Rep. ofSlovenia.REFERENCES[1.] J. Caloska, I. Lazarev, J. Lazarev, J. Mickoski: Metalnimatricni kompoziti za izrabotka na alati otporni naabenje. Razvojno istrazuvacki proekt sofinansiran odMinisterstvoto za obrazovanie i nauka. Skopje, 2009godina[2.] Lazarev, K.Kuzman J. Mickovski, J.Lazarev, J.Caloska:Sintered Iron‐Alumina Composites as tools material forthe deep drawing. 3rd International Conference″Advanced Composite Materials Engineering ″COMAT2010. 27‐ 29 October 2010, Brasov, Romania[3.] Ј.К. Mickovski, I.Ј. Lazarev, Ј. Lazarev, D. Stoevska‐Gogovska: Microstructure case study of LENStmprocessed cilinder from AISI H13 steel. Journal forTechnology of Plasticity, No 1‐2, 2010, Novi Sad[4.] S. K. Mukherjee, B. Cotterell and Y. W. Mai: Sinterediron‐ceramic composites. Journal of Materials Science,Springer Netherlands, Volume 28, Number 3/ February,1993[5.] J. H. Schneibel, C. A. Carmichael, E. D. Specht and R.Subramanian: Liquid‐phase sintered iron aluminideceramiccomposites. Metals and Ceramics Division, OakRidge National Laboratory, PO Box 2008, Oak Ridge,Tennessee 37831‐6115, USA, 19962012. Fascicule 3 [July–September]

1. Georgeta Emilia MOCUȚA, 2. Mihaela POPESCU, 3. Ioan Dănuț DANTHE BEST WAY OF WORKING SPACE ROBOT WHICH EQUIPS AFLEXIBLE MANUFACTURING CELL COMPONENT OF WELDED IN RAILFIELD1‐2. POLITEHNICA UNIVERSITY OF TIMISOARA, ROMANIA3. SOCIETATEA NAȚIONALĂ TRANSPORT FEROVIAR MARFĂ, "CFR MARFA"‐SA SUCURSALA TIMISOARA, ROMANIAABSTRACT: The industrial robot acts on its operating space under different shapes, namely by manipulating parts, byexecuting processing technological operations, by measuring specific parameters of products or even of the operatingspace etc. Many applications and functions performed by a robot reveal an essential characteristic, namely their versatility.Studying the movement of a robot consists of a single well‐defined problem but a collection of several problems that aremore or less than one other option. Exemplification was performed using MSC NASTRAN program.KEYWORDS: industrial robot, operating space, movement of a robot, exemplificationINTRODUCTIONThe industrial robot acts on its operating space underdifferent shapes, namely by manipulating parts, byexecuting processing technological operations, bymeasuring specific parameters of products or even ofthe operating space etc.Many applications and functions performed by a robotreveal an essential characteristic, namely theirversatility.Versatility defined as the robot's physical ability toperform various functions and to take various actionsin a given technological application is closely related tothe structure and mechanical ability of the robot,which in turn determines the configuration of therobot workspace.Since the workspace of a robot has geometrydepending on components and structure of itsmechanisms, in this space the characteristic point ofthe robot must execute motions on trajectoriesimposed by obstacles to avoid collision. In a firstanalysis of a robot working space should not be dealtwith "obstacles" and can be utilized. "Obstacles" areoperating in the area of warehouses or other exhaustretrofit devices of flexible robotic cell in which allcomponents must interact.Trajectory through "obstacles" can be chosen so thatwe can avoid collisions with maximum probability.THE STUDYStudying the movement of a robot consists of a singlewell‐defined problem but a collection of severalproblems that are more or less than one other option.The robot is becoming a more autonomousmechanical system that increases the need forautomatic trajectory planning in its development.The simplest planning problem assumes that therobot is only moving object in space which does notpossess dynamic properties thus avoiding temporalproblems.It also considers that the robot does not come intocontact with surrounding objects, thus avoidingproblems of mechanical interaction.These considerations turn the physical planningproblem into a purely geometric problem.Furthermore it is considered that the robot is onlymoving rigid solid which is limited only by theobstacles.With these simplifications the basic problem ofplanning robot trajectories can be formulated asfollows: let’s consider A a single solid or rigid (robot) thatmoves in a Euclidean space W, called workspace,represented by Rn, n = 2 or 3; it's movement isnot limited by any restriction on kinematics. let’s consider B1,...,Bq fixed rigid objects(obstacles) distributed in well defined positionsin working space W; knowing the position and orientation, at baseline,the robot, and final finishing position andorientation of this workspace W, generate a pathspecifying a continuous sequence of positions andorientations of A starting from the initialconfiguration (position and orientation), avoidingthe contact with obstacles Bj and finishing in thefinal configuration (position and orientation)final;© copyright FACULTY of ENGINEERING ‐ HUNEDOARA, ROMANIA 119if such a path does not exist, ”error” must bereported.It is obvious that although the basic planning problemis super simplified it is still a difficult problem withmany solutions and direct extensions to morecomplicated issues.Objectively mobile object (the robot the characteristicpoint) in such a matter is referred to in the literatureas ”flying objects”.The basic problem involves the robot path planningthrough exactly the trajectory generated by theplanner. It is also assumed that both the geometryand robotics as well as obstacles positions are knownwith precision. In reality no planning problem meetsthese assumptions. Moreover, they control theirrobots and geometric patterns are not precise. Sincethe robot has no a priori information about the

desktop, it must be based on runtime its sensorysystem for recording information necessary to achievethe task. It must work in exploring space and solve theproblem of planning in the presence of uncertainties.The problem is to calculate the trajectory generationbased on data received from the motion planner sizesorder to ensure passage of the robot through theestablished points.Generation of movement can be made directly in thespace coordinates kinematics couplings, oroperational area.Navigation strategy refers to determining how(methods) to move the robot according to the type oftask performed.Modelling space implies establishing navigation mapsin the considered space.Modelling methods known in literature are [1‐5]: uniform grid method; tree method; heterogeneous grid method; convex polygon method; method of crossing points.Evolution of the robot in the workspace imposes thestatement that the space of configurations SC isintrinsically independent of the choice of referencesystems SA and SW.Trajectory planning problem in the presence ofobstacles can be expressed as: given a workspacepopulated with obstacles known through theirborders, and by moving objects, must determine apath without collisions with obstacles in bringingmobile objects in the final initial configuration.The problem can be approached in two ways global orlocal, hence the two types of planning methods: globaland local.Application of global methods require completeknowledge of the working space ”in advance”,modelling proper clearance, research and selection ofall possible paths of a certain trajectoriescorresponding to a minimum cost criterion. Such amethod guarantees the existence or absence of asolution. Also global planning methods can be easilyadapted to the off‐line programming.Applying a local method requires partial knowledge ofthe workspace.Such a method does not guarantee reaching the finalconfiguration, but the advantage of good real‐timeadjustments.In both cases, solving the planning problem involvessolving geometric problems (pure geometry) orcombine geometry with kinematics and/or dynamics.In such situations often are used the results ofalgorithmic geometry.In general the application of planning methods mustmeet certain restrictions such as: the safest way, theshortest path, etc.ANALYSES, DISCUSSIONS, APPROACHES ANDINTERPRETATIONSAnalyzing the best methods in place of the theoreticaland the application can highlight the road mapmethod, exact cell decomposition method and thepotential field method. Of these potential field120ACTA TECHNICA CORVINIENSIS – Bulletin of Engineeringmethod treats the robot represented as a point inconfiguration space, that as a particle under theinfluence of an artificial potential field U whose localvariations reflects ”structure” of the free space.Potential function is defined as the amount of freespace on an attractive potential, which attracts therobot toward the final configuration, and a repulsivepotential, which removes the robot from obstacles.The method was originally developed as an "on line”method to avoid collisions to be applied when there isno model of obstacles, in advance, but they may referto during the execution of movement. In particular,the procedure can lock in a local minimum of potentialfunction.This deficiency can be corrected by calculating thefinite element method applied to study a potentialfield.Starting from the potential field finite elementmethod we propose, as an effective tool for theanalysis of optimum road space of the robot.Thus we suggest that the workspace of a robot to bemodelled as a homogenous body which is dependenton structure geometry of components and obstacles.In this space to work tasks the robot must go throughthe obstacles imposed trajectories which it has toavoid.The road through the obstacles can be chosen so thatto avoid the maximum probability collisions. If weaccept that two neighbouring obstacles behave astwo sources of the same physical stationary field andconsider that the moving of the characteristic point iscarried on the same potential trajectory as that of theresulting field we can select a family of trajectoriescorresponding to a certain field potential in a giveninterval.In the application illustrated in Figure 1 the workingspace was modelled as a homogeneous body withknown thermal characteristics.YZ Xut Set: MSC/NAST t0.0.0.0.0.0.0.0.0.100.100.100.100.100.100.100.Figure 1 Thermal analysis of a working space modelled ashomogeneous body found in a field where the heat sourcehot / cold data are boundaries of obstacles.Obstacles are considered as being „hot" or "cold"areas/sources on the boundary of the consideredworking space as being a homogenous body on whicha thermal field is applied from the hot/cold sources(modelled obstacles).Applying the finite element method analysis facility onthe thermal model workspace the outcome isisothermal surfaces. From these areas we can define100.93.7587.581.2575.68.7562.556.2550.43.7537.531.2525.18.7512.56.250.2012. Fascicule 3 [July–September]

ACTA TECHNICA CORVINIENSIS – Bulletin of Engineeringcurves obtained by modelling which can betrajectories of the characteristic point.Using the family of isothermal surfaces in the averagetemperature (resulting from thermal finite elementanalysis) on this can reside optimum trajectories to bepassed.So configurations libraries can be built‐up for theworking space and trajectories to pass, respectivelylocated on the average temperature isothermalsurface.Illustrated in Figure 1 is a workspace of a robotmodelled as homogeneous body found in a field whereheat sources hot / cold data are borders of theobstacles that need to avoid in his motion.Thermal finite element analysis on the isothermalmodel gives us the results. The treaty was exemplifiedin the plan but can be generalized in three‐dimensionalspace. Most times one of the 3D motion parameterscan be imposed by the kinematics couplings whichcontrols programming. Applications can be treatedand depending on who is involved in the processrobot. The most complex situation is found in weldingrail vehicle structures.CONCLUSIONSA key issue in the field of industrial robots operation(i.e. programming the optimal path of motion) enjoysthe benefits of programs devoted to finite elementanalysis to allow for applying the ”potential fieldmethod” as an analysis of a stationary thermal field.Exemplification was performed using MSC NASTRANprogram.REFERENCES[1.] Garbea D., Analiză cu elemente finite Editura TehnicăBucuresti 1990[2.] Hubner H. K., "Metoda Elementului Finit PentruIngineri" Departamentul de inginerie mecanică,Laboratorul de cercetari Genenral Motors, Wiley‐Interscience, John Wiley&Sons, New York, London,Sydney, Toronto, 1990[3.] Pires, J. N, Loureiro, A., Bölmsjo, G., Welding Robots ‐Technology, System Issues and Application, 1stEdition., 2006, XVIII, 180 p. 88 illus., Hardcover, ISBN:978‐1‐85233‐953‐1[4.] Staicu, S., Liu, X‐J., Wang, J., Inverse dynamics of theHALF parallel manipulator with revolute actuators,Nonlinear Dynamics, Springer, 50, 1‐2, pp. 1‐12, 2007[5.] Staicu,S., Zhang, D., A novel dynamic modellingapproach for parallel mechanisms analysis, Roboticsand Computer‐Integrated Manufacturing, Elsevier, 24,1, pp. 167‐172, 2008ACTA TECHNICA CORVINIENSIS – BULLETIN of ENGINEERINGISSN: 2067‐3809 [CD‐Rom, online]copyright © UNIVERSITY POLITEHNICA TIMISOARA,FACULTY OF ENGINEERING HUNEDOARA,5, REVOLUTIEI, 331128, HUNEDOARA, ROMANIAhttp://acta.fih.upt.roACTA TECHNICA CORVINIENSIS – BULLETIN of ENGINEERINGISSN: 2067‐3809 [CD‐Rom, online]copyright © UNIVERSITY POLITEHNICA TIMISOARA,FACULTY OF ENGINEERING HUNEDOARA,5, REVOLUTIEI, 331128, HUNEDOARA, ROMANIAhttp://acta.fih.upt.ro2012. Fascicule 3 [July–September] 121

ACTA TECHNICA CORVINIENSIS – Bulletin of EngineeringACTA TECHNICA CORVINIENSIS – BULLETIN of ENGINEERINGISSN: 2067‐3809 [CD‐Rom, online]copyright © UNIVERSITY POLITEHNICA TIMISOARA,FACULTY OF ENGINEERING HUNEDOARA,5, REVOLUTIEI, 331128, HUNEDOARA, ROMANIAhttp://acta.fih.upt.roACTA TECHNICA CORVINIENSIS – BULLETIN of ENGINEERINGISSN: 2067‐3809 [CD‐Rom, online]copyright © UNIVERSITY POLITEHNICA TIMISOARA,FACULTY OF ENGINEERING HUNEDOARA,5, REVOLUTIEI, 331128, HUNEDOARA, ROMANIAhttp://acta.fih.upt.ro© copyright FACULTY of ENGINEERING ‐ HUNEDOARA, ROMANIA 122

1.Martin PETRUF, 2. Ján KOLESÁRLOGISTIC AND ACQUISITION1‐2.TECHNICAL UNIVERSITY, FACULTY OF AERONAUTICS, DEPARTMENT OF AVIATION ENGINEERING, RAMPOVÁ 7, 041 21 KOŠICE, SLOVAKIAABSTRACT: Acquisition of the most modern technical systems and their logistical support requires innovative approaches tobe adopted in design, manufacturing and providing logistical services for their operation. The article aims to be acontribution to the acquisitional approach termed as CALS, i.e. to a modern, computer‐based logistics. Integrated logisticalsupport provided through electronization of design and operational documentation linked with standardization andcontinuous upgrade is yielding surprising benefits.KEYWORDS: Logistics Support, Production’s Logistics, Continued Acquisition, Life‐Cycle, Logistical management, SimultedengineeringINTRODUCTIONLong term aspect of life‐cycle at complex and costlysystems in aviation and defence industry isnecessitating continuous and rapid solutions toeconomically demanding upgrades, modernizationand innovation. All that requires knowledge of steadyand more frequent and revolutionary facts fromsciences and technology bound to growing need forcomputer technology, new information and testingtechnologies, etc.Implementation of computer systems in logistics formodern trends in military and industrial branches is ofvital importance, particularly for the purpose ofobtaining higher quality (complex quality) from theaspect of system characteristics (readiness,performance, reliability, safety, viability formanufacturing, maintainability, availability,supportability, partial or overall modernization,recycling, etc.... ), both in view of the methods applied(concurrent engineering, limiting the variability ofmanufacturing and the like).The CALS Initiative (Computer Aided Acquisition andLogistic Support)‐ was incepted in 1985 and startingwith 1994 it has been meant as continuous acquisitionand life cycle support as a means of integratedlogistical support for complex technical systems [1].THE CALS APPROACH AND PRODUCT ACQUISITIONTechnologies based on CALS have been originallydesigned only for information support of logistics.Gradual development, mostly the increasingperformance of information technologies caused CALSto transform into the means of informational supportfor research‐manufacturing–operation and modernlogistical support of complex technical systems (CTS)in all phases of the product life‐cycle, starting withmarket research and ending with its liquidation.Interconnection of design of complex technicalsystems and their manufacturing through informationtechnologies, i.e. Computer Aided Design(CAD), Computer Aided Manufacturing (CAM) isaffected by rapid changes in modernization, facts thatrequire comprehensive revision of the manufacturingprocesses and activities related to both acquisitionand support of logistics.The fundamental thing in managing CTS ismanagement of logistics in terms of acquisitiondisciplines, directed in all the phases of the acquisitionlife‐cycle. The complex effort is covered by the notionof integrated logistical support (ILS) and iscontinuously defining, projecting, upgrading andensuring a comprehensive readiness support of theCTS throughout its entire life‐cycle [2].Fig. 1. Acquisition approach of the CALSCALS is aimed to bring revolutionary changes in thefields of collecting, archiving and transfer of digitaldata as well as unification of information and testingtechnologies. Computer aided design andmanufacturing enables replacement of drawing andcopies by data modelling the new product to bemanufactured taking the form of an integrated© copyright FACULTY of ENGINEERING ‐ HUNEDOARA, ROMANIA 123

database, which makes it possible to design and planboth manufacturing and logistical support in realtime, involving production teams, further contractorsand sub‐contractors. There is thus an integratedProduct Team ‐ the IPT. Such approach is termed asConcurrent Engineering ‐ CE, see illustration in Fig.1.In practice, CALS involves organization of a jointinformation area supported by automated systemsdesigned to ensure efficient solution of engineeringproblems and planning of company resources, as wellas planning of manufacturing, remote approach toinformation and on‐line solutions of supplier‐andcustomerrelations, prognoses development and tasksof prediction. The joint integrated database featuresuniform and standard rules of generating,downloading, upgrading, searching and transferringinformation.Administration of the joint data base is ensured by asystem called PLM (Product Lifecycle Management),either serving as a comprehensive file of computerizedsystems such as CAE/CAD/CAM/PMD and ERP/CRM/SCMfor development, design and integrated logisticsupport of CTS, or as an information system for acompany facilitating interaction with othermanufacturers.ACTA TECHNICA CORVINIENSIS – Bulletin of EngineeringCurrently from the PDM systems is the most famousENOVIA and Smart Team (Dessault System),Teamcenter (Unigraphics Solutions), Winchill (PTC),my SAP PLM (SAP), Baan PDM (PDM), and Russiansystem Pilot: PLM (ASCON), PMD Step Suite (MO“Applied logistics), Party Plus (Pilot Software).Dessault Systems Company a program based onENOVIA PDM (Product Manager) integration modulesCAD/CAM/CAE designed to simulate a product datamanagement, processes and resources at differentstages of life cycle – from conceptual design todisposal. The Smart Team is based on Interbase orOracle with different visualizer – Fig. 2PLM as a system – illustrated in Fig.3 formsfundaments of integrating the information area ofindustrial products and on the basis CALS, it enablesinteraction of a wide spectrum of manufacturersutilizing computerized systems.Fig. 3. Life cycle of industrial manufacturing and thecomputerized systems appliedFig. 2. System Smart TeamLegend:PLM – life‐cycle management, PDM – management ofsystem data, CAD –design, CAE – engineering, CAM –technology and manufacturing, CRM – customer datamanagement , SCADA – dispatching management,MES – managing performances, SCM – managing thesupply chain, ERP – company planning andmanagement, CNC – computer based control of themachinery, MRP‐2 – planning of production resources,ITEM – interactive electronic manuals.The market success of the CTS without the CALStechnology would be in these days a missionimpossible. Standardized data formats of networkservers enable rapid propagation of modern designsavoiding „reinventing the wheel“. Such a modernapproach to design and manufacturing of high‐techproducts consists of:1242012. Fascicule 3 [July–September]

ACTA TECHNICA CORVINIENSIS – Bulletin of Engineering applying computer and modern informationtechnology in all phases of the product life‐cycle, applying a unified methodology to processcontrolling, cooperating with the participants (manufacturers,contractors, operators ...) in compliance with therequirements set out by international standardsregulating such interactions (electronic dataexchange).Implementation of the CALS should be integrated intothe Contracts on delivery of CTS concluded betweenthe manufacturer, contractor and the customer.Higher level of information integration is known as the„Joint CALS Program and the „ Joint Engineering DataManagement of Information Control Systems – JED‐MICS“. Both are considered as revolutionary programsidentifying a range of functional requirements for thelogistical processes of the CTS, such as: Logistical support analysis / LSA /, Logistical support analysis recording / LSAR /,etc....,or supporting the spare parts supply for theequipment repair processes.LOGISTICAL SUPPORT TO MANUFACTURING AND OPERATIONThe introduction of CALS for manufacturing andlogistics was of key importance owing to its single andintegrated databases equally suitable for the supplier,designer, technical manuals, trainers and logisticspecialists as well. Existence of different databasesdesigned and maintained on the part of the supplierand customer raises the need for standardization andcooperation. Then both parts of the logistics,acquisition and maintenance are fused into a single,integrated logistics, which starts before research andends at retiring the item from operation. Most of thelife‐cycle phases, starting with choosing the suppliersof raw materials and components ending with sellingthe product require logistical support, i.e. controllingthe supplier chain to increase the value added to theproduct, to decrease material demand and cut shortthe time of waiting for the product made ready. Themore frequently used approach „ Make or Bay “,particularly at limited manufacturing capacities, oradvantages in completion of standard parts. Most ofthe firms are developing specialized software andhardware for example ‐ commerce and, either theyare providing or using a joint information area, toprovide services, ensure operation for building,manufacturing or delivery the products on order [4].Design and manufacturing of CTS directly on orderwith re‐defined parameters and specifications, whenusing CALS technology, enables minimizing time oncost per order. Coordination of the activities of all thepartner companies making use of the internet and e‐commerce, /electronic data Exchange/ known as thesystem of data administration /CPC/ integratedinformation area enables repeated use of identicalproject documentation in joint projects, an approachthat substantially reduces the time of developing anew product, reduces the costs of the entire designand the cycle of manufacturing as well as simplifyingfunctioning of the systems (Fig. 4).Fig. 4. Virtual company and interaction with subcontractorsMODERN LOGISTIC SYSTEM based on the CALS vision will bea system continuously upgraded and standardized.The standards must be applied in all the participatingcompanies involved in the research, development andmanufacturing of the CTS, on the basis ofinternationally accepted documents for the integratedlogistical support. The synergic effect of implementingthe CALS is remarkable and some of the sourcesdeclare: 30 ‐ 40% acceleration in implementation of researchand development, Up to 30% cuts in cost of purchasing new CTS, Up to 20% cuts in the time of purchasing anddelivering spare parts, As much as the 9th multiple of reducing timeneeded for adaptation of projects [1],[5].In view of the manufacturing, substantial in‐crease inthe quality of products, as much as 50% reduction ofthe time for development and preparation ofmanufacturing, increase in productivity by 75%,savings in inventory management by 60%, increasingreturn of investments by 70% and as high as 50%reduction in the services and stocks.On introducing CALS, the savings presented can beeven higher thanks to its function of maintenance andsub‐function of testing, measurement and diagnostics(TDM – Test Measurement Diagnostic), which enabletransition from the time‐bound maintenance tomaintenance by status quo. Furthermore, CALS isproviding accelerated research and development ofZTS reducing the periods of 6 up 10 years down to 4and rapid implementation of top‐level technology intomanufacturing processes. Researches centres of CALS2012. Fascicule 3 [July–September] 125

technology – „Applied logistics„ are in economicallydeveloped countries (USA, France, Germany, Russia,UK .....) are intensively dealing with research andimplementation of software solutions for high‐techproducts and their in‐formation support. Provision oflogistical services for the implementation of solutionsis conditioned by the joint approach of theparticipating companies at creating integratedinformation products and modern technology‐basedapproaches.INTEGRATED LOGISTICAL SUPPORT (ILP) is ensured by a setof Technologies focused on improving operational andtechnical features of products as well as on cuttinglife‐cycle costs. For example, „Tupolev“ by developingits operational documentation Tu – 204/214 to theinternational standard known as the ASD S 1000 D ismanaging its post‐sale service and increasing itsproduct competitiveness. Key component of thistechnology for monitoring technical status is increating and maintaining electronic form for aircraft,automated data processing, using RFID components,etc. ..., what in their long run provides excellentreliability of aircraft manufactured and passengersafety. The first Russian aircraft designed by means ofthe CALS technology, including the digital analysis oflogistical support (ALP) is the one known as the SSJ –100, an aircraft entirely designed in digitalenvironment, making extensive use of the CAD andPDM technologies.CONCLUSIONSSystems‐based approach in developing integratedinformation systems in support of high‐tech productsand CTS throughout their entire life‐cycle makes itnecessary to adopt continuous improvements ofconcepts, in‐depth study and development of CALStechnologies. Knowledge of top‐level products andprocedures of the CALS enables high‐speedACTA TECHNICA CORVINIENSIS – Bulletin of Engineeringconfiguration of the CTS, integrated logistical supportand its analysis in all phases of the product life‐cycle,re–engineering of company processes in research,manufacturing and operation of high‐tech products.The system of PDM data administration plays adecisive role in an integrated in‐formationenvironment and provides retrieves rationallystructured data for product design, technology,manufacturing and operation as well as operation ofrealization of modern logistical support for complextechnical systems. A new standard ASD S 3000 L isbeing prepared today with participation of worldleaders in research of technologies. Certain modulesfor logistics and safety mostly in aviation technologyare object of development conducted by the AVIS, awell established Slovak company.REFERENCES[1] PETRUF, M.: Logistika OS z pohľadu poznatkov vstrojárske praxi špeciálnej techniky, výzbroje amateriálu. Trenčín: Transfér, 2004. 5strán.[2] JAHELKA, K.: Kontinuálna akvizícia a podpora životnéhocyklu zbraňových systémov. Brno: Zborník VA Brno,1996.[3] MADARASZ,L.,BUČKO,M.,ANDOGA,R.: Integračné aspektytvorby a prevádzky systémov CIM, TUKE FEIKošice, Elfa s.r.o., 2006[4] MADARASZ,L.: Inteligentné technológie a ich aplikácia vzložitých systémoch, TUKE FEI Košice, University PressElfa, 2004[5] MALINDŽAK,D.: Výrobná logistika I.,TUKE F BERG Košice,Vydavateľstvo ŠTROFEK Košice, 1996[6] KYSEĽOVÁ, K., CEHLÁR, M.: Economic characterization ofraw material extration technological processes by computer.Košice : Acta Mettallurgica Slovaca, Roč. 9, č.1(2003), s.55‐62, ISSN 1335‐1532[7] www.cals.ru/collaboration/[8] ru.wikipedia.org/wiki/CALS‐technologieACTA TECHNICA CORVINIENSIS – BULLETIN of ENGINEERINGISSN: 2067‐3809 [CD‐Rom, online]copyright © UNIVERSITY POLITEHNICA TIMISOARA,FACULTY OF ENGINEERING HUNEDOARA,5, REVOLUTIEI, 331128, HUNEDOARA, ROMANIAhttp://acta.fih.upt.ro1262012. Fascicule 3 [July–September]

1.Rajdeep BORGOHAINDATA HIDING TECHNIQUES USING NUMBER DECOMPOSITIONS1.DEPARTMENT OF COMPUTER SCIENCE AND ENGINEERING, DIBRUGARH UNIVERSITY INSTITUTE OF ENGINEERING AND TECHNOLOGY, DIBRUGARH, INDIAABSTRACT: Data hiding is the art of embedding data into digital media in a way such that the existence of data remainsconcealed from everyone except the intended recipient. In this paper, we discuss the various Least Significant Bit (LSB) datahiding techniques. We first look at the classical LSB data hiding technique and the method to embed secret data into covermedia by bit manipulation. We also take a look at the data hiding technique by bit plane decomposition based on Fibonaccinumbers. This method generates more bit planes which allows users to embed more data into the cover image withoutcausing significant distortion. We also discuss the data hiding technique based on bit plane decomposition by primenumbers and natural numbers. These methods are based on mapping the sequence of image bit size to the decomposed bitnumber to hide the intended information. Finally we present a comparative analysis of these data hiding techniques.KEYWORDS: Data Hiding, Least Significant Bit, Steganography, SteganalysisINTRODUCTIONSharing of digital media is one of the main reasons forthe boom of the internet. Users can share betweenthem various information in digital format. But withthe increasing threat of security [14] in the cyberworld, it has become very important that anyimportant information shared through these digitalmedia be concealed in such a way that only theintended recipient will be able to retrieve theinformation. In this context data hiding in the form ofsteganography plays a very important role. The wordsteganography is derived from Greek which means“Concealed Writing” [15]. The intended data isembedded in an image in such a way that no one butthe recipient can extract the hidden message.For data hiding, the requirements [5] are:• A medium to hold the hidden informationwhich is known as cover media.• The secret message which the sender intendsto embed within the cover media.• A steganography function and its inverse.• An optional key (stego‐key) that is used tohide or unhide the data.For hiding the data, the cover media can be any one ofthe following digital media [6]:• Plain Text• Digital Image• Audio• Video• IP DatagramThe process of hiding data, we first take the covermedia which can be of any format as mentionedabove.After that we take the secret information which wewant to hide in the cover media. The secret messagecan be in any form, plain text or cipher text or evenother image file.The cover media and secret message is then passedthrough a steganography function and the message isembedded in the cover media. We can also optionallyuse a key to hide the message and later decode itusing the same key [13].Figure 1. Steganography ProcessFor embedding data in digital media, two domains aregenerally considered, spatial domain [16, 21] and thetransform domain [17, 22]. In the transform domain,the domains considered are Discrete Cosine Transform(DCT) [7], Discrete Fourier Transform (DFT) [23] andDiscrete Wavelet Transform (DWT) [8].Both the spatial and transform embedding schemehas to fulfill three requirements of visibility,robustness and capacity. Visibility is concerned withthe fact that human observers should not be able todetect distortions due to the hidden message in thedigital media. On the other hand, it is very importantthat once a secret message is inserted, it becomesimpossible to delete or manipulate that message. Thisis the requirement for robustness. Moreover, thecapacity of the digital media should be kept inconsideration while inserting the message. Thesethree factors are dependent on each other and abalance must be maintained between them as© copyright FACULTY of ENGINEERING ‐ HUNEDOARA, ROMANIA 127

increase in one of the factors leads to the decrease inother [9].Though, there are many data hiding techniques [2, 3,4], in this paper, we consider the spatial domain ofdata hiding. We discuss the various data hidingtechniques using bit manipulation of the lowestsignificant bit (LSB). We take a look at how the bitplanes can be increased by various numberdecomposition methods without compromising onthe three requirements of visibility, robustness andcapacity.The rest of the paper is organized as follows. InSection 2 we take a look at the classical LSB datahiding technique. Here we discuss how secret text canbe embedded in cover image using LSB manipulation.Section 3 of the paper contains the Fibonacci LSB datahiding technique. Section 4 of the paper contains theLSB data hiding technique using decomposition ofprime numbers. The approach for decompositionusing prime numbers is discussed here. Section 5contains LSB data hiding by natural numbers. Here thedecomposition of bit planes by natural numbers isdiscussed. In Section 6 we present a comparativeanalysis between the various LSB data hidingmethods. Finally, in Section 7, we present theconclusion for the paper.CLASSICAL LSB DATA HIDING TECHNIQUEOne of the simplest implementation of data hidingtechnique is the classical least significant bit datahiding technique [18]. The technique is based onmanipulation of the least significant bits of the carrierimage to accommodate the hidden message.The insertion of LSB varies according to the number ofbits in an image. For an 8 bit image, the value of 8 thbit, which is the least significant bit of each pixel,would be modified and the secret message would beembedded [19].Suppose if we wanted to insert the letter ‘A’ into animage. The binary equivalent of ‘A’ is 10000001. Now ifour sample image of 8 bit has the following pixelvalues:10101010 10001010 11111111 01011010110101010 10101010 10001011 10101111So, embedding the binary equivalent of ‘A’ i.e.10000001would change the pixel values of our sampleimage to:101010101 10001010 111111110 01011010010101010 10101010 10001010 0101111In our sample image the least significant bit value ofpixel 1, 3, 4 and 7 have been changed.Similarly, for an image of 24 bit, we need to changethe RGB (Red Blue Green) color values. Suppose oursample image has the following pixel values,[10010101 10101010 11110101][10001001 10001110 10000010]128ACTA TECHNICA CORVINIENSIS – Bulletin of Engineering[11110101 01001010 10001011]So to accommodate our desired character, ‘A’, wehave to make the following modifications:[10010101 10101010 11110100][10001000 10001110 10000010][11110100 01001010 10001011]So, basically we have changed the values of 3 bit toaccommodate our desired character.Though, classical data hiding is simple to implement, itis vulnerable to image manipulation [15].LSB DATA HIDING USING FIBONACCI NUMBERSBattisti et al. [1] proposed a method of embeddingdata into digital media by decomposition of Fibonaccinumber sequence which allowed different bit planedecomposition when compared to the classical LSBscheme.The Fibonacci sequence, named after Leonardo ofPisa, also known as Fibonacci, is a sequence ofnumbers in the following integer sequence:0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89 …The Fibonacci numbers are defined by a recurrencerelation:F p (0) = F p (1) = 1F p (n) = F p (n – 1) + F p (n – p – 1), ∀ n ≥ 2, n∈NThe bit planes are now decomposed based on theFibonacci sequence. The main drawback of thisapproach is that of redundancy and to counter thatand obtain a unique representation, Zeckendorftheorem [20] is used.To embed the intended message in the cover image, itis decomposed into bit planes by using Fibonacci p‐decomposition. The Zeckendorf condition is checkedfor each bit to be modified. If the condition is fulfilled,the bit is inserted otherwise the bit following it isconsidered.LSB DATA HIDING USING PRIME NUMBERSLSB data hiding using prime numbers is a data hidingtechnique proposed by Dey et.al [10] as animprovement over the Fibonacci numbers data hidingtechnique proposed by Battisti et. al. The main idea ofthe work was to use the prime number decompositionand generate new set of bit planes and embedinformation in these newly generated bit planes withminimal distortion.In this approach, the researchers took an image of mbits and increased the number of bit planes to n,where the value of n was equal or greater than orequal to the number of bit planes of the image. Thiswas achieved by converting the bit planes of theimage to another number system using primenumbers as the weighted function. This resulted in theincrease of number of bits and consequently it couldbe used for hiding data in higher bit planes withminimal distortion.2012. Fascicule 3 [July–September]

ACTA TECHNICA CORVINIENSIS – Bulletin of EngineeringFor decomposition, the weight function was definedas:P (0) = 1, P (i) = p i ∀ i ∈ Z + , p i = i th PrimeIn case of any ambiguity, the lexicographically highernumber is given preference.For embedding the data in the image, a number n ischosen in such a way that all possible pixel values inthe range of [0, 2 k ‐ 1] could be represented using firstn prime number, so that n virtual are achieved afterthe decomposition.The value of n can be found out by the formula,n‐1∑ +p 2i 0 i≥k‐ 1After finding the prime numbers, a k‐bit to n‐bitsequence is mapped, marking all the valid primenumber in the system. Now, for each pixel of theimage, a virtual bit plane is chosen and secret data isembedded is by modifying the corresponding virtualbit plane by the desired information bit by bit. If theresulting sequence of data after embedding the datamatches the k‐bit to n‐bit mapping, the bits are keptotherwise it is discarded. After insertion of the hiddendata, the resultant prime number system is convertedback to the original binary system and the stegoimageis achieved.For extraction, each pixel with the hidden informationis converted into prime decomposition and from thosebit planes, the secret message is extracted. All the bitsare combined together to get the final message.LSB DATA HIDING USING NATURAL NUMBERSThe approach of LSB data hiding by natural numberswas proposed by Dey et.al [11]. In this approach, theresearchers proposed data hiding by decomposition ofa pixel value in sum of natural numbers. This resultedin generation of more bit planes than the Classical LSBdata hiding, Fibonacci LSB data hiding and the Primenumber data hiding [10].For decomposition, the weight function is defined as:W (i) = N (i) = i + 1, ∀ I ∈ Z + ∪ {0}The researchers used the same concept in case ofambiguity which gave higher precedence tolexicographically higher number.For embedding the data into the k‐bit image, anumber n is chosen in a way such that all pixel valuesin the range of [0, 2 k – 1] could be represented usingfirst n numbers, which resulted in generation of nvirtual bit planes .The value of n can be found out by the formula,k + 3‐ 1 ± 2 + 9n ≥2After finding the value of n, a k‐bit to n‐bit map iscreated and all valid representations in naturalnumbers system are marked. Now, for each pixel avirtual bit plane is chosen and the secret data isembedded. If the virtual bit plane matches themapping system, the hidden data is kept otherwise itis discarded. After insertion of the secret message, thenatural number system is converted back to itsoriginal binary form and the stego‐image is achieved.To extract the message from the stego‐image, all thepixels with embedded data bit are converted to thenatural number decomposition, and the secretmessage bits are extracted. Finally, all bits arecombined together to get the embedded hiddenmessage.COMPARISON OF LSB DATA HIDING TECHNIQUESIn the previous section, we have looked at the varioustechniques for data hiding using numberdecomposition. Here, we present a comparativeanalysis between the various data hiding techniquesusing number decomposition.Table 1. Technique used in LSB data hidingClassical LSB data hiding uses thesimplest approach. In classical LSB dataClassical LSB hiding, the least significant bit of a pixelis manipulated in order to embed thedesired image.In Fibonacci approach, the bit planes aredecomposed so as to generate more bitFibonacciplanes and then the secret message isTechniqueembedded on following the Zeckendorftheorem.LSB datahiding byprimenumbersLSB datahiding bynaturalnumbersIn LSB data hiding using prime numbers,the bit planes are decomposed by usingsum of prime numbers. After that thesecret message is embeddedlexicographically.In LSB data hiding using natural numbers,the bit planes are decomposed by usingsum of natural numbers. Here also thesecret message is embeddedlexicographically.Table 2. Embedding Techniques used in LSB data hidingData are inserted in the least significantClassical LSBbit of the cover image.Technique uses Fibonacci P‐sequence forFibonacci generation of bit planes and data isTechnique inserted if it passes the Zeckendorfcondition.LSB datahiding byprimenumbersLSB datahiding bynaturalnumbersA k‐bit to n‐bit map is created where thevalue of n is,n‐1k∑ p 2 ‐ 1i + 0 i≥Data is inserted bit by bit matching the k‐bit to n‐bit mapping sequence.A k‐bit to n‐bit map is created where thevalue of n is,k + 3‐ 1 ± 2 + 9n ≥2Data is inserted bit by bit matching the k‐bit to n‐bit mapping sequence.2012. Fascicule 3 [July–September] 129

ACTA TECHNICA CORVINIENSIS – Bulletin of EngineeringClassical LSBFibonacciTechniqueLSB datahiding byprimenumbersLSB datahiding bynaturalnumbersTable 3. Weight functionsThe least significant bit of the imagepixel is manipulated. In case of 8 bitimage it is the 8 th bit of each byte. For24 bit image the RGB color code arechanged [12].F p (0) = F p (1) = 1F p (n) = F p (n – 1) + F p (n – p – 1),∀ n ≥ 2,n∈NP(0) = 1, P(i) = p i ∀ i ∈ Z + , p i = i th PrimeW (i) = N (i) = i + 1, ∀ I ∈ Z + ∪ {0}Table 4. Number of bit planes generated8 bit planes using gray scale 8bit LenaClassical LSBimage.FibonacciTechniqueLSB datahiding byprimenumbersLSB datahiding bynaturalnumbers12 bit planes using gray scale 8bit Lenaimage.15 bit planes using gray scale 8bit Lenaimage.23 bit planes using gray scale 8bit Lenaimage.CONCLUSIONSIn this paper, we looked at the different approaches ofthe spatial data hiding techniques using LeastSignificant Bit manipulation.We discussed about the classical LSB data hidingtechnique which is based on manipulation of the leastsignificant bit. We took a further look at the differentnumber decomposition techniques by which more bitplanes could be generated to conceal more datawithout causing significant distortion.By comparative analysis, we could see that among thedata hiding techniques, decomposition using naturalnumbers yielded the highest number of bit planeswhich was 23. This was followed by 15, 12 and 8 bit ofPrime number technique [11], Fibonacci Technique andClassical LSB technique respectively.Finally we can say that in this era of internet wherethere is increasing use of digital format to sendvaluable information and data, steganography willplay a very important role in the days to come.REFERENCES[1.] F. Battisti, M. Carli, A. Neri, K. Egiaziarian, “AGeneralized Fibonacci LSB Data Hiding Technique, 3rdInternational Conference on Computers and Devicesfor Communication (CODEC‐06), Institute of RadioPhysics and Electronics, University of Calcutta,December 18‐20, 2006.[2.] Aruna Ambalavanan and Rajarathnam Chandramouli“A Bayesian Image Steganalysis approach to estimatethe embedded secret message,” InternationalMultimedia Conference, Proceedings of the 7thWorkshop on Multimedia and Security, ACM Press,New York, USA, 2005, pp. 33 –38.[3.] Liu Shaohui, Yao Hongxun, Gao Wen, “Neural networkbased steganalysis in still images,” Proceedings of the2003 International Conference on Multimedia andExpo (ICME 2003), vol.2, July 2003, pp. II – 509–512.[4.] Patricia Lafferty, Farid Ahmed “Texture‐basedsteganalysis: results for color images,” Proceedings ofthe SPIE Mathematics of Data/Image Coding,Compression, and Encryption VII, with Applications,vol. 5561, 2004, pp. 145 – 151.[5.] Steganographic Techniques and their use in an Open‐Systems Environment‐Bret Dunbar, The InformationSecurity Reading Room, SANS Institute 2002,http://www.sans.org/readingroom/whitepapers/covert/677.php[6.] Steganography Primer ‐ Ruid, Computer Academicunderground,2004,http://www.dustintrammell.com/presentations/Steganography‐Primer.pdf[7.] J. R. Hernandez, J. M. Rodr´ıguez, and F. P´erez‐Gonz´alez, “Improving the performance of spatialwatermarking of images using channel coding,” SignalProcess. 80(7), pp. 1261–1279, 2000.[8.] F. Battisti, K. Egiazarian, M. Carli, and A.Neri, “Datahiding based on Fibonacci‐Haar transform,” in MobileMultimedia/Image Processing for Military and SecurityApplications, SPIE Defense and Security, Vol. 6579, May2007.[9.] E. Mammia, F. Battisti, M. Carlia, A. Neria, and K.Egiazarianb, “A novel spatial data hiding schemebased on generalized Fibonacci sequences”, MobileMultimedia/Image Processing, Security, andApplications 2008, Proceedings. of SPIE ,Vol. 698269820C, (2008)[10.] Sandipan Dey, Ajith Abraham and Sugata Sanyal "AnLSB Data Hiding Technique Using Prime Numbers",Third International Symposium on InformationAssurance and Security, August 29‐31, 2007,Manchester, United Kingdom, IEEE Computer Societypress, USA, ISBN 0‐7695‐2876‐7, pp. 101‐106, 2007.[11.] Sandipan Dey, Ajith Abraham and Sugata Sanyal "AnLSB Data Hiding Technique Using Natural Numbers",IEEE Third International Conference on IntelligentInformation Hiding and Multimedia Signal Processing,IIHMSP 2007, Nov 26‐28, 2007, Kaohsiung City, Taiwan,IEEE Computer Society press, USA, ISBN 0‐7695‐2994‐1,pp. 473‐476, 2007.1302012. Fascicule 3 [July–September]

ACTA TECHNICA CORVINIENSIS – Bulletin of Engineering[12.] Nani Koduri, “Information Security through ImageSteganography using Least Significant Bit Algorithm”,Master’s Thesis, Information Security and ComputerForensics, University of East London.[13.] Soumyendu Das, Subhendu Das, Bijoy Bandyopadhyayand Sugata Sanyal, "Steganography and Steganalysis:Different Approaches", International Journal ofComputers, Information Technology and Engineering(IJCITAE), Vol. 2, No 1, June, 2008, Serial Publications.[14.] Dhaval Gada, Rajat Gogri, Punit Rathod, Zalak Dedhia,Nirali Mody, Sugata Sanyal and Ajith Abraham, "ADistributed Security Scheme for Ad Hoc Networks",ACM Crossroads, Special Issue on Computer Security.Volume 11, No. 1, September, 2004, pp. 1‐17.[15.] Neil F. Johnson and Sushil Jajodia, “Exploringsteganography: seeing the unseen," IEEE Computer31(2), pp. 26‐34, 1998.[16.] Jessica Fridrich and Miroslav Goljan, “On estimation ofsecret message length in LSB steganography in spatialdomain," in Security, Steganography, andWatermarking of Multimedia Contents VI,Proceedings of SPIE 5306, pp. 23‐34, 2004.[17.] Guorong Xuan, Yun Q. Shi, Zhicheng Ni, “Reversibledata hiding using integer wavelet transform andcompanding technique,” IWDW04, Korea, October2004.[18.] Chi‐Kwong Chan and L. M. Cheng, “Hiding data inimages by simple LSB substitution,” PatternRecognition, pp. 469–474, Mar. 2004.[19.] Walter Bender, Daniel Gruhl, Norishighe Morimoto,and A. Lu, “Techniques for data hiding." I.B.M.Systems Journal, vol. 35, no. 3 & 4, pp. 313{336, 1996.[20.] Verner E. Jr. Hoggatt, “Fibonacci and Lucas Numbers,”The Fibonacci Association, Santa Clara, California, USA,1972.[21.] Raymond B. Wolfgang and Edward J. Delp, “Awatermarking technique for digital imagery: furtherstudies." In International Conference on Imaging,Systems, and Technology, pp. 279{287, IEEE, Las Vegas,Nevada, U.S.A., 30 Jun, 1997[22.] Mauro Barni, Franco Bartolini, VitoCappellini,Alessandro Piva(1998), “A DCT‐domainsystem for robust image watermarking”, SignalProcessing, Vol. 66 (1998), pp.357–372.[23.] Nabin Ghoshal , Jyostna Kumar Mandal, “A NovelTechnique for Image Authentication in FrequencyDomain using Discrete Fourier TransformationTechnique”, Malaysian Journal of Computer Science,ISSN 0127‐9094, Vol. 21, No. 1, pp. 24‐32, 2008.ACTA TECHNICA CORVINIENSIS – BULLETIN of ENGINEERINGISSN: 2067‐3809 [CD‐Rom, online]copyright © UNIVERSITY POLITEHNICA TIMISOARA,FACULTY OF ENGINEERING HUNEDOARA,5, REVOLUTIEI, 331128, HUNEDOARA, ROMANIAhttp://acta.fih.upt.ro2012. Fascicule 3 [July–September] 131

ACTA TECHNICA CORVINIENSIS – Bulletin of EngineeringACTA TECHNICA CORVINIENSIS – BULLETIN of ENGINEERINGISSN: 2067‐3809 [CD‐Rom, online]copyright © UNIVERSITY POLITEHNICA TIMISOARA,FACULTY OF ENGINEERING HUNEDOARA,5, REVOLUTIEI, 331128, HUNEDOARA, ROMANIAhttp://acta.fih.upt.roACTA TECHNICA CORVINIENSIS – BULLETIN of ENGINEERINGISSN: 2067‐3809 [CD‐Rom, online]copyright © UNIVERSITY POLITEHNICA TIMISOARA,FACULTY OF ENGINEERING HUNEDOARA,5, REVOLUTIEI, 331128, HUNEDOARA, ROMANIAhttp://acta.fih.upt.ro© copyright FACULTY of ENGINEERING ‐ HUNEDOARA, ROMANIA 132

Scientific Events in 20121. THE 20 th ANNUAL INTERNATIONAL CONFERENCE ON COMPOSITES, NANO OR METALS ENGINEERING –ICCE‐2022–28 July 2012, Beijing, CHINAThe ICCE conference is unique in that while it is an engineering conference, it has attracted numerous chemists, physicistsand scientists from diverse fields in our efforts to promote interdisciplinary research on composites. Of particular concernis the challenge for materials engineers to understand the wide diversity of length scales ranging from nano to micro tomacro and full scale and to question the validity of the theories or models which are known to be valid only in certainlength scales. The ICCE is among the first composite materials conferences which take a leading vital role to bridge the gapbetween nano‐chemistry and nano‐engineering and attracted hundreds of papers in this existing relatively new field ofnano‐composites engineering.The ICCE conference will provide a forum for the exchange of information and ideas in virtually all areas compositematerials research. The goals of the ICCE conference are: To BRIDGE THE GAP between Materials Science, Mechanics and manufacturing of Composite Materials; To ENCOURAGE INTERDISCIPLINARY research bridging the gap between aerospace technology, bio‐materials,chemistry, electronics, fluid mechanics, infrastructures, magnetic materials, nanotechnology, physics, powdermetallurgy, sensors/actuators, among others and To ENCOURAGE LEVERAGING of composite materials research resources through joint research between participantsand writing joint research proposals.Detailed informations here: www.icce‐nano.org2. THE 6 th INTERNATIONAL CONFERENCE ON INDUSTRIAL ENGINEERING AND MANAGEMENT – IEM201210–12 August, 2012, Zhengzhou, CHINAYou are invited to submit papers in all areas of Industrial Engineering and Management. All papers accepted will beindexed by Ei Compendex and ISTP.Manufacturers and developers of equipment, components, software and services complementing the topics of theconference are invited to display their state‐of‐the‐art products. The exhibition will be placed in the conference area. Forfurther information, potential exhibitors can contact with email: iciem2012@163.com.Detailed informations here: http://www.ieee‐iciem.org3. THE 9 th INTERNATIONAL CONGRESS “MACHINES, TECHNOLOGIES, MATERIALS ‐ INNOVATIONS FOR THEINDUSTRY” – MTM'1219–21 September, 2012, Varna, BULGARIAWe invite you to take part in the 9th International Congress “Machines, Technologies, Materials ‐ Innovations for theIndustry”, which will be held from 19th till 21st September 2012 again in hotel “Aqua Azur” in the sea resort “St.Konstantin and Elena”, region Varna, as a comprehensive scientific‐technical manifestation, which includes three maintopics. The Congress program includes also five special congress sub‐sections which previously were held separately.We believe that and this time the Congress will be a successful international forum in the field of engineering science. Wehope that in this way the Congress MTM'12 will become a bigger innovation mediator between scientific research andindustry and we offer you to take advantage of this opportunity. We believe that you will take this opportunity andcontribute to the success of the Congress with your researches and experience.We would be very grateful to you if you recommend MTM'12 to colleagues of yours, from your country and abroad, whomight have scientific and practical interests in the thematic area of the Congress.Short information about the Congress you may find in the attached file and detailed information is available onhttp://mech‐ing.com/mtm/4. THE 4 th INTERNATIONAL CONFERENCE ON MATERIALS SCIENCE AND TECHNOLOGIES – ROMAT 201217–19 October, 2012, Bucuresti, ROMANIAOn behalf of the Organizing Committee, we are honored to invite you to participate and submit a paper at the 4‐thINTERNATIONAL CONFERENCE ON MATERIALS SCIENCE AND TECHNOLOGIES – ROMAT 2012 organized by POLITEHNICAUniversity of Bucharest ‐ Materials Science and Engineering Faculty in association with Bucharest Chamber of Commerceand Industry.We are convinced that your presence will particularly contribute to a high level of the conference and it is an occasion toachieve an efficient idea and information exchanges for further development of this field.Detailed informations here: http://www.romat2012.eu/5. FEDERATED CONFERENCE ON COMPUTER SCIENCE AND INFORMATION SYSTEMS – FedCSIS 20129–12 September, 2012, Wrocław, POLANDThe 2012 Federated Conference on Computer Science and Information Systems cordially invites you to considercontributing an Event (conference, symposium, workshop, consortium meeting, and special session).Each Event may run over any span of time within the conference dates (from half‐day to three days). The FedCSIS Eventsprovide a platform for bringing together researchers, practitioners, and academia to present and discuss ideas, challengesand potential solutions on established or emerging topics related to research and practice in computer science andinformation systems.The FedCSIS Events provide a platform for bringing together researchers, practitioners, and academia to present anddiscuss ideas, challenges, and potential solutions on established or emerging topics related to research and practice incomputer science and information systems.The Events will be selected based on the scientific/technical interest and/or their relevance to practitioners in their topics,the clarity of the proposal in addressing the requested information, the innovativeness of the Event topics, and thecapacity in the FedCSIS multi‐conference program.Detailed informations here: http://www.fedcsis.org/© copyright FACULTY of ENGINEERING ‐ HUNEDOARA, ROMANIA 133

ACTA TECHNICA CORVINIENSIS – Bulletin of Engineering6. THE 5 th INTERNATIONAL CONFERENCE ON MASS CUSTOMIZATION AND PERSONALIZATION IN CENTRALEUROPE (MCP – CE 2012) – CUSTOMER CO‐CREATION IN CENTRAL EUROPE19 – 21 September, 2012, Novi Sad, SERBIAOn behalf of the Organizational Board and Scientific Committee of the 5th International Conference on MassCustomization and Personalization in Central Europe (MCP – CE 2012), we cordially invite you to participate and to shareyour research ideas, efforts and results with other scientists, entrepreneurs and corporate managers, dedicated to theidea of Mass Customization and Personalization.Organized for the fifth time, the biannual MCP‐CE conference would like to emphasize the role and importance ofCustomer Co‐Creation that offers customers a chance to express their differences, and also an opportunity for innovationsand new business models such as MC and Open Innovation platforms, for sharing designs and developments and benefitsfrom the experiences of others.Detailed informations here: http://www.mcp‐ce.org/7. THE 18 th EUNICE CONFERENCE ON INFORMATION AND COMMUNICATIONS TECHNOLOGIES29–31 August, 2012, Budapest, HUNGARYThe aim of the annual EUNICE conference is to provide a forum that brings together young researchers and scientist fromEurope and neighboring regions to meet and exchange ideas and recent works on all aspect of information andcommunication technologies.For any additional information please consult the conference website: http://tmit.bme.hu/eunice20128. MACHINE‐BUILDING AND TECHNOSPHERE OF THE XXI CENTURY17 – 22 September, 2012, Sevastopol, UKRAINEInternational Union of Machine‐Builders, Donetsk National Technical University and a number of leading companies ofUkraine, Russia, Belarus, Romania, Poland and other countries will host the XIX international science and engineeringconference MACHINE‐BUILDING AND TECHNOSPHERE OF THE XXI CENTURY taking place in the city of Sevastopol onSeptember 17‐22 nd 2012.The aim of the conference is to exchange the science and engineering information, define new engineering andtechnologies development and creation forward‐looking ways develop joint research programmes, establish businesscontacts and commercial links in this area.Detailed informations here: http://donntu.edu.ua/ukr/7/konf/sevastopol/about.htm9. INTERNATIONAL CONFERENCE on MATHEMATICAL MODELING IN PHYSICAL SCIENCES– IC‐MSQUARE 20123 – 7 September, 2012, Budapest, HUNGARYThe conference aims to promote the knowledge and the development of high‐quality research in mathematical fields thathave to do with the applications of other scientific fields and the modern technological trends that appear in them, thesefields being those of Physics, Chemistry, Biology, Medicine, Economics, Sociology, Environmental sciences etc. Some of themain topics are: mathematical modeling in Fundamental Physics: e.g. high‐energy physics, particle physics, nuclear, atomic, andmolecular physics, gravitation, cosmology, astrophysics, plasma physics, electrodynamics, fluid dynamics, condensedmatterphysics, chemical physics, chaos, statistical mechanics etc. evolutionary computation (Genetic algorithms, Evolutionary programming, Eagle strategy, Swarm intelligence, Antcolony optimization, Particle swarm optimization, Differential evolution etc.) mathematical methods and tools for modeling complex physical and technical systems software and computer complexes for experimental data processing methods, algorithms, and software of computer algebra computational chemistry, biology, and biophysics new generation computing tools, distributed scientific computing efficient solvers and nonlinear problems, computational modeling in engineering and science multiscale modeling, multiphysics modeling progress in discretization methodsConference organizers are supporting educational actions during the Conference meeting.You may find details of the Conference visiting the Conference website at http://www.icmsquare.net10. 11 th INTERNATIONAL SCIENTIFIC CONFERENCE – MMA 2012 – ADVANCED PRODUCTION TECHNOLOGIES20 – 21 September, 2012, Novi Sad, SERBIAChair for Metrology, Quality, Fixtures, Tools and Environmental Aspects, Chair for machine tools, technological processes,flexible technological systems and design processes and Chair for Metal Cutting Technologies, within the Department forProduction Engineering, at Faculty of Technical Sciences in Novi Sad, organize 11th International Scientific Conference MMA2012 under the motto ADVANCED PRODUCTION TECHNOLOGIES.By continuing 33‐years tradition of the Conference, it is expected that presented results from the scientific institutions, aswell as from the industrial research departments will contribute to the further development of production processes inthe metal industry. We hereby extend this call to all researchers, scientific workers and industry professionals tocontribute to the International Scientific Conference MMA 2012 by submitting scientific papers, and to the affirmation ofproduction engineering in the region by active participation in its work.The Conference shall be held from September 20‐21, 2012 in Novi Sad, at the Faculty of Technical Sciences, Trg DositejaObradovica 6, Serbia. Information about the programme committee, the organization committee, and other informationrelated to the MMA 2012 conference, can be found on http://www.ftn.uns.ac.rs/mma201211. 4 th INTERNATIONAL SCIENTIFIC AND EXPERT CONFERENCE – TEAM 2012 (Technique, Education,Agriculture & Management)17 – 19 October, 2012, Slavonski Brod, CROATIAThe International TEAM Society in cooperation with Mechanical Engineering Faculty in Slavonski Brod – Josip JurajStrossmayer University of Osijek, is honored to invite you to the 4th International Scientific and Expert Conference TEAM2012. The conference will provide an open forum for scholar students, academicians, researchers or scientists and insurethe exchange of experiences and research results on various aspects and application areas. Conference also gives anexcellent opportunity to establish useful professional and research contacts with foreign colleagues and begin a commoncooperation between universities and research centers.Aim and Scope of the conference: Transfer of Knowledge and Dissemination of Achievements Mobility of Teachers andInternational Cooperation Interdisciplinary Approach on DevelopmentYou may find details of the Conference visiting the Conference website at http://team2012.sfsb.hr1342012. Fascicule 3 [July–September]

ACTA TECHNICA CORVINIENSIS – Bulletin of Engineering12. 1 st INTERNATIONAL SCIENTIFIC CONFERENCE – COMETa 2012 – CONFERENCE on MECHANICALENGINEERING TECHNOLOGIES AND APPLICATIONS28 – 30 November, 2012, Jahorina, BOSNIA&HERZEGOVINAFaculty of Mechanical Engineering University of East Sarajevo initiates first international conference COMETa 2012, withaims to contribute to the implementation of new technologies into production processes as well as achieving bettercooperation between scientific research institutions and enterprises.Basic concept of the Conference: Plenary session (invited papers about global issues), Symposium (oral presentation onthe conference topics) and poster presentation, Workshops. The main goal of this conference is to bring togetherrenowned national and international experts in the field of research and application of new technologies anddevelopment of mechanical systems, for sharing experiences and knowledge. Moreover, public presentations of actualresearches and new construction solutions improve the competitiveness of the economy in region.We have great pleasure to invite all interested scientific research institutions and businesses to actively participate andwith their papers contribute to successfully organizing of this scientific conference. Detailed informations here:http://www.ues.rs.ba/en/university/international‐cooperation/scientific‐conferences‐and‐meetings/cometa‐201213. 4 th INTERNATIONAL CONFERENCE ON MATERIALS SCIENCE AND TECHNOLOGIES ‐ ROMAT 201217 – 19 October, 2012, Bucharest, ROMANIAOn behalf of the Organizing Committee, we are honoured to invite you to participate and submit a paper at the 4‐thINTERNATIONAL CONFERENCE ON MATERIALS SCIENCE AND TECHNOLOGIES ‐ ROMAT 2012 organized by POLITEHNICAUniversity of Bucharest ‐ Materials Science and Engineering Faculty in association with Bucharest Chamber of Commerceand Industry. The Conference topics will cover the following fields:• Advanced materials and technologies: Ferrous and Non‐ferrous Metallurgy; Materials Engineering; Materials Processing;Nanomaterials; Casting‐solidification; Biomaterials and Medical Devices;• Materials Characterization: Characterization of Microstructure and Material Properties; Functional Materials Modeling;Nucleation, Microstructure Evolution and Phase Transition; Interface Dominated Mechanical Properties;Nanostructured Coatings, Surfaces & Films;• Environmental protection in materials industry: Advanced Techniques for Industrial Effluent Treatment; EnvironmentManagement; Instruments under Sustainable Development Requirements; Solutions for Re‐use of By‐products andWastes; Health and Environment;• Economics and management in materials industry: Globalization and Prospects on Regional Metallurgy; TheComplementarity – Definition Criterion for Industrial Strategies; The Competitiveness – Fundamental Component ofIndustrial Policies.Detailed informations here: http://www.romat2012.eu/14. 2 nd INTERNATIONAL CONFERENCE ON CIVIL ENGINEERING AND BUILDING MATERIAL – CEBM 201217 – 18 November, 2012, Hong KongThe 2 nd International Conference on Civil Engineering and Building Material (CEBM 2012) will be held in Hong Kong fromNovember 17‐18, 2012. It is a premium international conference covers all areas related to the Theory, Development,Applications, Experiences and Evaluation of Civil Engineering and Building Materials and gathers fellow students,researchers and practitioners in these fields from all around the world.The conference will continue the excellent tradition of gathering world‐class researchers, engineers and educatorsengaged in the fields of Civil Engineering and Building Materials to meet and present their latest activities. You arecordially invited to attend this interesting event. This conference is co‐sponsored by Asia Civil Engineering Association, theInternational Association for Scientific and High Technology and International Science and Engineering Research Center.Detailed informations here: http://www.iasht.org/cebm/15. 7 th INTERNATIONAL ICQME CONFERENCE (Quality, Management, Environment, Education, Engineering)19 – 21 September, 2012, Tivat, MONTENEGROUniversity of Montenegro, Faculty of mechanical engineering (Podgorica), Centre for quality and Ministry for Economy areorganising 7th International Conference ICQME (Quality, Management, Environment, Education, Engineering) to be held inTivat, September 19‐21, 2012.The idea of Conference has first come to life when a need was felt to have the eleventh traditional National Conference onQuality Management System (SQM) with the international participation evolve into an international conference, with anextension of thematic areas to be covered.National Conference on Quality Management System (SQM) with the international participation has been gatheringprominent experts from the field of quality over the last twelve years. In addition to the local, Montenegro experts, theparticipation lists included a number of well‐known scientists and experts from France, Spain, Canada, England, Italy,Denmark, Slovenia, Serbia, Bosnia‐Herzegovina, Croatia, and 7th International ICQME Conference some of the vital issuesof quality, management, engineering, education, and environmental protection will be discussed, and the participants willbe from both the university and the commercial fields, which will contribute to a more productive exchange of ideas andexperiences.The conference intends to shed further light on the complex and potentially conflicting choices firms take in order toacquire, exchange, and create knowledge in order to improve its performance. This theme relates to quite a wide varietyof aspects relating to the increasing complexity (e.g. economic, management, engineering, sociology) of systems forknowledge creation and innovation. This complexity implies a more intensive and more frequent need to embrace as wellas to connect both internal and external source of knowledge in the search for new technological achievements.Detailed informations here: http://wbc‐inco.net/object/event16. INTERNATIONAL CONFERENCE ON NEW ENERGY, BIOLOGICAL ENGINEERING AND FOOD SECURITY ‐NEBEFS 20124 – 5 September, 2012, Hong Kong2012 International Conference on New Energy, Biological Engineering and Food Security (NEBEFS 2012) will be held onSeptember 4‐5, 2012, Hong Kong.The goal of this conference is to bring together the researchers from academia and industry as well as practitioners toshare ideas, problems and solutions relating to the multifaceted aspects of New Energy, Biological Engineering and FoodSecurity.Detailed informations here: http://www.nebefs‐conf.org2012. Fascicule 3 [July–September] 135

ACTA TECHNICA CORVINIENSIS – Bulletin of Engineering17. INTERNATIONAL CONFERENCE ON MANUFACTURING – MANUFACTURING 201214 – 15 November, Macau, CHINAManufacturing 2012 will be the most comprehensive conference focused on the various aspects of advances inManufacturing and Materials Science. This Conference provides a chance for academic and industry professionals todiscuss recent progress in the area of Manufacturing and Materials Science. Furthermore, we expect that the conferenceand its publications will be a trigger for further related research and technology improvements in this important subject.The goal of this conference is to bring together the researchers from academia and industry as well as practitioners toshare ideas, problems and solutions relating to the multifaceted aspects of Manufacturing and Materials Science.Detailed informations here: http://manufacturing2012.org/index.htm18. 2 nd INTERNATIONAL CONFERENCE ON INTEGRATED INFORMATION – IC‐ININFO 201230 August – 3 September, 2012, Budapest, HUNGARYThe Conference website at http://www.icininfo.net is given to you as a referencefor the aims and scopes of the IC‐ININFO 2012. 5 th Symposium on Dynamic Simulation Models supporting Management Strategies 2 nd Symposium on Evidence‐Based Information in Clinical Practice Information and Knowledge Management Entrepreneurship and the Role of Information 2 nd Symposium on Advances Information for Strategic Management 2 nd symposium on Contemporary issues in Management: Organizational Behavior, Information Technology, Education &Hospital leadership 2 nd Symposium on Integrated Information: Theory, Policies, Tools 2 nd Symposium on Open Access Repositories: Self‐archiving, Metadata, Content Policies, UsageYou are welcomed to propose a session or a symposium for IC‐ININFO 2012.Session organizers will be benefited by a 15% refund of their session.For more information, contact the conference secretariat at secretariat@icininfo.net19. INTERNATIONAL CONFERENCE ON MANUFACTURING ENGINEERING AND TECHNOLOGY FORMANUFACTURING GROWTH – METMG 20121 – 2 November,2012, San Degio, USAMETMG 2012 will be the most comprehensive Conference focused on the various aspects of advances in ManufacturingEngineering and Technology for Manufacturing Growth. Our Conference provides a chance for academic and industryprofessionals to discuss recent progress in the area of Manufacturing Engineering and Technology for ManufacturingGrowth. Topic: Computer Aided Design and Manufacturing and related topics Material Forming Processes and related topics Machining Technology and related topics Welding Technology and related topics Metallurgical Manufacturing Processes and related topics Automation in Manufacturing and related topics Micro and Nano Fabrications and related topicsDetailed informations here: http://metmg‐conf.org/20. INTERNATIONAL CONFERENCE ON APPLIED PHYSICS AND MATERIALS SCIENCE (APMS 2012)5 – 6 October, 2012, Dalian, CHINAAPMS 2012 will be the most comprehensive conference focused on the various aspects of advances in Applied Physics andMaterials Science. Our Conference provides a chance for academic and industry professionals to discuss recent progress inthe area of Information Technology, Applied Physics and Materials Science.The goal of this conference is to bring together the researchers from academia and industry as well as practitioners toshare ideas, problems and solutions relating to the multifaceted aspects of Information Technology, Applied Physics andMaterials Science.Detailed informations here: http://www.apms‐conf.org/index.htmACTA TECHNICA CORVINIENSIS – BULLETIN of ENGINEERINGISSN: 2067‐3809 [CD‐Rom, online]copyright © UNIVERSITY POLITEHNICA TIMISOARA,FACULTY OF ENGINEERING HUNEDOARA,5, REVOLUTIEI, 331128, HUNEDOARA, ROMANIAhttp://acta.fih.upt.ro1362012. Fascicule 3 [July–September]

IndexesACTA TECHNICA CORVINIENSIS – Bulletin of Engineeringis accredited and ranked in the B+ category byCNCSIS – The National University Research Council’s Classification of Romanian Journals,http://www.cncsis.ro/member ofThe Romanian Editorial Platform SCIPIOhttp://www.scipio.roACTA TECHNICA CORVINIENSIS – Bulletin of Engineeringis indexed in the following databases and directories:INDEX COPERNICUS – JOURNAL MASTER LISThttp://journals.indexcopernicus.com/GENAMICS JOURNALSEEK DATABASEhttp://journalseek.net/EVISA databasehttp://www.speciation.net/GOOGLE SCHOLARhttp://scholar.google.co.in/DOAJ ‐ Directory of Open Access Journalshttp://www.doaj.org/© copyright FACULTY of ENGINEERING ‐ HUNEDOARA, ROMANIA 137

ACTA TECHNICA CORVINIENSIS – Bulletin of EngineeringSCIRUS ‐ Elsevierhttp://www.scirus.com/ProQuest databasehttp://www.proquest.co.ukEBSCO Publishinghttp://www.ebscohost.comChemical Abstracts Service (CAS)http://www.cas.org/Open J‐Gatehttp://www.openj‐gate.com/Bielefeld Academic Search Enginehttp://digital.ub.uni‐bielefeld.deElectronic Journals Libraryhttp://ezb.uni‐regensburg.deACTA TECHNICA CORVINIENSIS – BULLETIN of ENGINEERINGISSN: 2067‐3809 [CD‐Rom, online]copyright © UNIVERSITY POLITEHNICA TIMISOARA, FACULTY OF ENGINEERING HUNEDOARA,5, REVOLUTIEI, 331128, HUNEDOARA, ROMANIAhttp://acta.fih.upt.ro1382012. Fascicule 3 [July–September]

MANUSCRIPT PREPARATION– General GuidelinesThese instructions are written in a form that satisfies all of the formatting requirements for the authormanuscript. Please use them as a template in preparing your manuscript. Authors must take special care tofollow these instructions concerning margins. The basic instructions are simple: Manuscript shall be formatted for an A4 size page. The top and left margins shall be 25 mm. The bottom and right margins shall be 25 mm. The text shall have both the left and right margins justified.The original of the technical paper will be sent through e‐mail as attached document (*.doc, Windows 95 orhigher). Manuscripts should be submitted to e‐mail: redactie@fih.upt.ro, with mention “for ACTA TECHNICACORVINIENSIS – Bull. of Eng.”.STRUCTUREThe manuscript should be organized in the following order: Title of the paper, Authors' names and affiliation,Abstract, Key Words, Introduction, Body of the paper (in sequential headings), Conclusion, Acknowledgements(where applicable), References, and Appendices (where applicable).THE TITLEThe title is centred on the page and is CAPITALIZED AND SET IN BOLDFACE (font size 14 pt). It should adequatelydescribe the content of the paper. An abbreviated title of less than 60 characters (including spaces) should alsobe suggested.AUTHOR’S NAME AND AFFILIATIONThe author's name(s) follows the title and is also centred on the page (font size 11 pt). A blank line is requiredbetween the title and the author's name(s). Last names should be spelled out in full and succeeded by author'sinitials. The author's affiliation (in font size 11 pt) is provided below. Phone and fax numbers do not appear.ABSTRACTA nonmathematical abstract, not exceeding 200 words, is required for all papers. It should be an abbreviated,accurate presentation of the contents of the paper. It should contain sufficient information to enable readers todecide whether they should obtain and read the entire paper. Do not cite references in the abstract.KEY WORDSThe author should provide a list of three to five key words that clearly describe the subject matter of the paper.TEXT LAYOUTThe manuscript must be typed single spacing. Use extra line spacing between equations, illustrations, figuresand tables. The body of the text should be prepared using Georgia or Times New Roman. The font size used forpreparation of the manuscript must be 11 points. The first paragraph following a heading should not beindented. The following paragraphs must be indented 10 mm. Note that there is no line spacing betweenparagraphs unless a subheading is used. Symbols for physical quantities in the text should be written in italics.FIGURES AND TABLESFigures (diagrams and photographs) should be numbered consecutively using Arabic numbers. They should beplaced in the text soon after the point where they are referenced. Figures should be centred in a column andshould have a figure caption placed underneath. Captions should be centred in the column, in the format “Figure1” and are in upper and lower case letters.When referring to a figure in the body of the text, the abbreviation "Figure" is used Illustrations must besubmitted in digital format, with a good resolution. Table captions appear centred above the table in upper andlower case letters.When referring to a table in the text, "Table" with the proper number is used. Captions should be centred in thecolumn, in the format “Table 1” and are in upper and lower case letters. Tables are numbered consecutively andindependently of any figures. All figures and tables must be incorporated into the text.© copyright FACULTY of ENGINEERING ‐ HUNEDOARA, ROMANIA 149

ACTA TECHNICA CORVINIENSIS – Bulletin of EngineeringEQUATIONS AND MATHEMATICAL EXPRESSIONSEquation numbers should appear in parentheses and be numbered consecutively. All equation numbers mustappear on the right‐hand side of the equation and should be referred to within the text.CONCLUSIONA conclusion section must be included and should indicate clearly the advantages, limitations and possibleapplications of the paper. Discuss about future work.ACKNOWLEDGEMENTSAn acknowledgement section may be presented after the conclusion, if desired. Individuals or units other thanauthors who were of direct help in the work could be acknowledged by a brief statement following the text.REFERENCESReferences should be listed together at the end of the paper in alphabetical order by author’s surname. List ofreferences indent 10 mm from the second line of each references. Personal communications and unpublisheddata are not acceptable references.Journal Papers: Surname 1, Initials; Surname 2, Initials and Surname3, Initials: Title, Journal Name, volume(number), pages, year.Books: Surname 1, Initials and Surname 2, Initials: Title, Edition (if existent), Place of publication, Publisher, year.Proceedings Papers: Surname 1, Initials; Surname 2, Initials and Surname 3, Initials: Paper title, Proceedings title,pages, year.ACTA TECHNICA CORVINIENSIS – BULLETIN of ENGINEERINGISSN: 2067‐3809 [CD‐Rom, online]copyright © UNIVERSITY POLITEHNICA TIMISOARA,FACULTY OF ENGINEERING HUNEDOARA,5, REVOLUTIEI, 331128, HUNEDOARA, ROMANIAhttp://acta.fih.upt.ro1502012. Fascicule 3 [July–September]

ACTA TECHNICA CORVINIENSIS– BULLETIN of ENGINEERINGACTA TECHNICA CORVINIENSIS– BULLETIN of ENGINEERINGISSN: 2067‐3809 [CD‐Rom, online]copyright © UNIVERSITY POLITEHNICA TIMISOARA, FACULTY OF ENGINEERING HUNEDOARA,5, REVOLUTIEI, 331128, HUNEDOARA,ROMANIAhttp://acta.fih.upt.ro