[1] Nelson Mandela African Inst Sci & Technol, Sch Mat Energy Water & Environm Sci MEWES, POB 447, Arusha, Tanzania
[2] Nelson Mandela African Inst Sci & Technol, Water Infrastruct & Sustainable Energy Futures WIS, Arusha, Tanzania
[3] Nelson Mandela African Inst Sci & Technol, Struct Mat & Engn Res Grp, Arusha, Tanzania
[4] Wollega Univ, Dept Civil Engn, Nekemte, Ethiopia