1. Petroleum Applications Department , Egyptian Petroleum Research Institute , Nasr City, P.B. 11727 , Cairo , Egypt , Tel.: +20 2 22745902, Fax: +20 2 22747433
2. Analysis and Evaluation Department , Egyptian Petroleum Research Institute , Nasr City, P.B. 11727 , Cairo , Egypt
3. Physical Chemistry Department, Electrochemistry and Corrosion laboratory , National Research Centre , El-Bohouth St. 33, Dokki, P.O. 12622 , Giza , Egypt