1. Department of Mechanical and Industrial EngineeringUniversity of Namibia P.O. Box 3624 ONGWEDIVA, REPUBLIC OF NAMIBIA
2. Department of Mechanical Engineering ScienceUniversity of Johannesburg, Auckland Park Kingsway Campus JOHANNESBURG, REPUBLIC OF SOUTH AFRICA 2006
3. Department of Mining and Metallurgical EngineeringUniversity of Namibia P.O. Box 3624 ONGWEDIVA, REPUBLIC OF NAMIBIA