1. Faculty of Industrial Sciences & Technology, Universiti Malaysia Pahang, Gambang, Kuantan 26300, Malaysia
2. Chemistry Department, Faculty of Science, Al−Azhar University, Assiut 71524, Egypt
3. Department of Physics, Faculty of Sciences, King Khalid University, P. O. Box 9004, Abha 61413, Saudi Arabia
4. Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, UPM Serdang, Selangor 43400, Malaysia