1. Department of Mechanical Engineering, Dedan Kimathi University of Technology, Nyeri-Mweiga Rd., 10143 Nyeri, Kenya (Corresponding author), e-mail: fredrick.mwema@dkut.ac.ke, https://orcid.org/0000-0001-6116-5587
2. Department of Mechanical Engineering Science, University of Johannesburg, Corner Kingsway and University Rd., Auckland Park 2006, South Africa
3. Department of Physics, Brno University of Technology, Technická 2848/8, 61600 Brno, Czech Republic; Department of Environmental Chemistry and Tech, Dagestan State University, Ulitsa Batyraya, 4а, Makhachkala, Republic of Dagestan 367008, Russia; and Central European Institute of Technology, Brno University of Technology, Purkyňova 123, Brno 61200, Czech Republic
4. Pan African University of Life and Earth Sciences Institute, Oduduwa Rod., 900001 Ibadan, Nigeria