1. Dept. of Elec. Eng., Bu-Ali Sina University, Mahdieh Street, Hamedan 65178-38695, Iran
2. Dept. of Chem. Eng. and Oil Refining, Basrah University for Oil and Gas, Basrah 61004, Iraq
3. Dept. of Oil and Gas Eng., Basrah University for Oil and Gas, Basrah 61004, Iraq