1. Department of Physics and Astronomy, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia
2. Faculty of Medicine, Ain Shams University, El-Khalyfa El-Mamoun Street, Abbassia, Cairo 11774, Egypt
3. Chrono-Environnement Laboratory, UMR CNRS 6249, Bourgogne, Franche-Comté University, CEDEX, F-25030 Besançon, France
4. Faculty of Medicine, Ibn Sina University, Aljerif West Block (88), Khartoum 11115, Sudan