机译:
School of Materials Science and Engineering Jimma Institute of Technology Jimma University Jimma P.O.Box 378 Ethiopia;
Defense Engineering College Bishoftu P.O.Box 1041 Ethiopia;
The Ministry of Mines Petroleum and Natural Gas Addis Ababa P.O.Box 486 Ethiopia;
School of Chemical Engineering Jimma Institute of Technology Jimma University Jimma P.O.Box 378 Ethiopia;