1. School of Materials, Energy, Water and Environmental Sciences (MEWES), Nelson Mandela African Institution of Science and Technology (NM-AIST), P.O. Box, 447 Arusha 23311, Tanzania
2. Tanzania Commission for Science and Technology (COSTECH), P.O. Box, 4302 Dar es Salaam 14113, Tanzania
3. School of Business Studies and Humanities (BuSH), Nelson Mandela African Institution of Science and Technology (NM-AIST), P.O. Box, 447 Arusha 63210, Tanzania
4. Department of Mechanical Engineering, Arusha Technical College (ATC), P.O. Box, 296 Arusha 23105, Tanzania