1. Department of Basic Sciences, Preparatory Year College, Hail University, Saudi Arabia
2. Nottingham College, Science Faculty, UK
3. Department of Physics, College of Science and Humanities, Imam Abdulrahman Bin, Faisal University, P.O. Box 12020, Jubail, Saudi Arabia
4. Physics Department, Rabigh College of Science and Art, King Abdulaziz University, Rabigh 21911, Saudi Arabia