Mohamed Anwar K. Abdelhalim Prof. Dr. Biomedical Physics Department of Physics and Astronomy, College of Science, King Saud University P.O. 2455, Riyadh 11451 E-mail: abdelhalimmak@yahoo.com mabdulhleem@ksu.edu.sa Mobile No. 009660509649633Home Office No. 009660114676451 Office Room No. 1A49 Page: http://faculty.ksu.edu.sa/72438/Pages/Home.aspx