Yahya Elsayed Ibrahim,
Department of propylene production, Egyptian Propylene and Polypropylene Company, Portsaid, Egypt.
Nadia Ali ElSayed, Saeed Mohamed Abdallah,
Refining and Petrochemical Department, Faculty of Petroleum and Mining Engineering, Suez University, Suez 43512, Egypt.
Mohamed ElSokary,
Egyptian Petroleum Research Institute, Nasr City, Cairo 11759, Egypt.