1. Department of Mechanical Engineering Science, University of Johannesburg, Auckland Park Kingsway Campus, Johannesburg 2006, South Africa
2. Department of Mechanical Engineering, University of Ilorin, P.M.B. 1515, Ilorin, Kwara State, Nigeria e-mail: and
3. Department of Mechanical Engineering Science, University of Johannesburg, Auckland Park Kingsway Campus, Johannesburg 2006, South Africa e-mail:
4. Department of Mechanical Engineering Technology, University of Johannesburg, Doornfontein Campus, Johannesburg 2006, South Africa
5. Department of Mechanical Engineering, MNNIT Allahabad, Uttar Pradesh 211004, India e-mail:
6. National Laser Centre, Council for Scientific and Industrial Research (CSIR), Pretoria 0001, South Africa e-mail: