1. Academic Development Unit, Faculty of Engineering and the Built Environment, University of the Witwatersrand, 1 Jan Smuts Avenue, Johannesburg 2001, South Africa
2. School of Chemical and Metallurgical Engineering, University of the Witwatersrand, 1 Jan Smuts Avenue, Johannesburg 2001, South Africa
3. Department of Materials Engineering, Sunyani Technical University, Sunyani P.O. Box 206, Ghana
4. Department of Civil Engineering, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA 01609, USA
5. Department of Mechanical Engineering, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA 01609, USA