1. Dep. of Physics, Faculty of Sciences, Palestine Technical University, Tulkarm, P.O. Box 7, Palestine
2. Dep. of Physics, College of Sciences, Mutah University, Karak, Jordan
3. Applied Physics Department, Faculty of Science, Tafila Technical University, P.O. Box 179, Tafila 66110, Jordan
4. General Studies Dep., Yanbu Industrial College, P.O. Box 30436, Yanbu Industrial City, KSA
5. Dep. of Physics, Jordan University, Amman 11942, Jordan