PAKISTAN ACADEMY OF SCIENCESFounded 1953President:Secretary General:Treasurer:Pr<strong>of</strong>. Dr. Atta-ur-Rahman, FRS, N.I., H.I., S.I.,T.I.Pr<strong>of</strong>. Dr. G.A. Miana, S.IPr<strong>of</strong>. Dr. Shahzad A. MuftiPROCEEDINGS OF THE PAKISTAN ACADEMY OF SCIENCES, published since 1964, is quarterly journal<strong>of</strong> the <strong>Academy</strong>. It publishes original research papers and reviews in basic and applied sciences. All papers arerefereed externally. Authors are not required to be Fellows or Members <strong>of</strong> the <strong>Academy</strong>, or citizens <strong>of</strong> <strong>Pakistan</strong>.EDITOR-IN-CHIEFDr. Abdul Rashid<strong>Pakistan</strong> <strong>Academy</strong> <strong>of</strong> <strong>Sciences</strong>3-Constitution Avenue, Islamabad, <strong>Pakistan</strong>E-mail: pas.editor@gmail.comEngineering <strong>Sciences</strong> & TechnologyPr<strong>of</strong>. Dr. Abdul Raouf, S.I.36-P, Model Town ExtensionLahore, <strong>Pakistan</strong>E-mail: abdulraouf@umt.edu.pkMedical <strong>Sciences</strong>Pr<strong>of</strong>. Dr. M. Salim Akhtar, S.I.725, Shadman HouseShadman Colony ILahore – 54000E-mail: msakhter47@yahoo.comEDITORSLife <strong>Sciences</strong>Pr<strong>of</strong>. Dr. Kauser A. Malik, H.I., S.I.,T.I.Forman Christian CollegeFerozepur Road, LahoreE-mail: kauser45@gmail.comPhysical <strong>Sciences</strong>Pr<strong>of</strong>. Dr. M. Aslam Baig, H.I.. S.I.,T.I.Department <strong>of</strong> PhysicsQuaid-i-Azam UniversityIslamabadE-mail: baig@qau.edu.pkEDITORIAL BOARDLocal Advisory BoardPr<strong>of</strong>. Dr. M. ArslanDr. N.M. ButtPr<strong>of</strong>. Dr. M. Qasim JanPr<strong>of</strong>. Dr. M. Ajmal KhanDr. Anwar NasimPr<strong>of</strong>. Dr. Asghar QadirPr<strong>of</strong>. Dr. M. QaisarPr<strong>of</strong>. Dr. RiazuddinInternational Advisory BoardPr<strong>of</strong>. Dr. A.K. Cheetham, USAPr<strong>of</strong>. Dr. P.K. Khabibullaev, UzbekistanPr<strong>of</strong>. Dr. S.N. Kharin, KazakhstanPr<strong>of</strong>. Dr. H.W. Korf, GermanyPr<strong>of</strong>. Dr. Tony Plant, USAPr<strong>of</strong>. Dr. S.G. Ponnambalam, MalaysiaPr<strong>of</strong>. Dr. E. Nieschlag, GermanyPr<strong>of</strong>. Dr. D.L.G. Noakes, CanadaPr<strong>of</strong>. Dr. M.S. Ying, ChinaAnnual Subscription for 2011: <strong>Pakistan</strong>: Institutions, Rupees 2000/-; Individuals, Rupees 1000/-Other countries: US$ 100.00 (Price includes air-lifted overseas delivery)© Copyright. Reproduction <strong>of</strong> paper abstracts is permitted provided the source is acknowledged. Permission toreproduce any other material may be obtained in writing from the Editor-in-Chief.The articles published in the Proceedings contain data and opinions <strong>of</strong> the author(s) only. The <strong>Pakistan</strong> <strong>Academy</strong> <strong>of</strong><strong>Sciences</strong> and the Editors accept no responsibility whatsoever in this regard.HEC Recognized, Category XPublished by <strong>Pakistan</strong> <strong>Academy</strong> <strong>of</strong> <strong>Sciences</strong>, 3 Constitution Avenue, G-5/2, Islamabad, <strong>Pakistan</strong>Tel: 92-5 1-9207140 & 9215478; Fax: 92-51-9206770; Website: www.paspk.orgPrinted at PanGraphics (Pvt) Ltd., No. 1, I & T Centre, G-7/l, Islamabad, <strong>Pakistan</strong>Tel: 92-51-2202272, 2202449 Fax: 92-51-2202450 E-mail: pangraph@gmail.com