1. Department of Physics, College of Science, Taibah University, Yanbu, Saudi Arabia
2. Departament de Física, Universitat de les Illes Balears, 07122 Palma de Mallorca, Balearic Islands, Spain
3. Faculty of Sciences, Beirut Arab University, Beirut, Lebanon
4. Information Technology Department, Al-Zahra College for Women, P.O.Box 3365, Muscat, Oman