1. Department of Chemical, Metallurgical and Materials Engineering, Tshwane University of Technology, Staatsartillerie Rd., Phillip Nel Park, Pretoria West, Private Bag X680, Pretoria, South Africa
2. Department of Electrical Engineering, Tshwane University of Technology, Staatsartillerie Rd., Phillip Nel Park, Pretoria West, Private Bag X680, Pretoria, South Africa
3. Department of Metallurgical and Materials Engineering, University of Nigeria, Nsukka, University Market Rd., Private Bag 0004, Nsukka, Enugu State, Nigeria; and Department of Chemical, Metallurgical and Materials Engineering, Tshwane University of Technology, Staatsartillerie Rd., Phillip Nel Park, Pretoria West, Private Bag X680, Pretoria, South Africa (Corresponding author), e-mail: victor.aigbodion@unn.edu.ng, https://orcid.org/0000-0001-5550-5522