1. University of Ha'il Department of Chemical Engineering, College of Engineering P.O. Box 2440 81441 Ha'il Saudi Arabia
2. King Saud University Geology & Geophysics Department P.O. Box 2455 11451 Riyadh Saudi Arabia
3. Chemical and Environmental Engineering Department of Civil via Opera Pia 15 16145 Genoa Italy
4. Al Neelain University Department of Chemical Engineering, Faculty of Engineering P.O. Box 12702 1121 Khartoum Sudan
5. Elmergib University Department of Chemical and Petroleum Engineering Alkhums Libya