1. Oil Products Distribution Company (OPDC), Ministry of Oil,Tikrit,Iraq
2. AL-Hawija Technical Institute, Northern Technical University,Al-Hawija,Iraq
3. University of Maine,Department of Chemistry,Orono,ME,USA,04469
4. College of Basic Education Shirqat, Tikrit University,Tikrit,Iraq
5. North Refineries Company Baiji, Ministry of Oil,Baiji,Iraq
6. Uuiversity of Samarra, College of Engineering,Samarra,Iraq
7. University of El Oued,Fac. Technology,El Oued,Algeria,39000