1. Department of Mechanical Engineering Science, University of Johannesburg, Corner Kingsway and University Rd., Auckland Park, 2006 South Africa
2. Department of Mechanical Engineering, Dedan Kimathi University of Technology, Nyeri-Mweiga Rd., Nyeri, Kenya (Corresponding author), e-mail: fredrick.mwema@dkut.ac.ke, https://orcid.org/0000-0001-6116-5587
3. Department of Chemical, Materials and Metallurgical Engineering, Botswana International University of Science & Technology, Plot 10071 Boseja, Palapye, Botswana