1. Department of Physics The University of Jordan Amman 11942 Jordan
2. Department of Chemistry Faculty of Science The Hashemite University, P.O. Box 330127 Zarqa 13133 Jordan
3. Department of Chemistry Yarmouk University Irbid 21163 Jordan
4. Department of Chemistry Faculty of Science Al-Balqa Applied University Al-Salt 19117 Jordan
5. Dr. Baker Jawabrah Al Hourani Bethel University Department of Chemistry 3900 Bethel Drive MSC 2338 Saint Paul MN 55112 USA