1. Department of Chemical, Metallurgical and Materials Engineering, Tshwane University of Technology (TUT) , Pretoria 0183, South Africa
2. Centre for Energy and Electric power (CEEP), Tshwane University of Technology (TUT) , Pretoria 0183, South Africa
3. Department of Materials Science and Engineering, Obafemi Awolowo University (OAU) , Ile-Ife 220002, Nigeria
4. Department of Industrial and Systems Engineering, University of Pretoria (UP) , Hatfield 00028, South Africa