1. Department of Petroleum and Chemical Engineering, College of Engineering, Sultan Qaboos University, Post Office Box 33, Muscat 123, Oman
2. Department of Chemistry, College of Science, Sultan Qaboos University, Post Office
Box 36, Muscat 123, Oman
3. Corporate Research and Development Direction, Sonatrach, Avenue du 1er Novembre, 35000 Boumerdes, Algeria