1. Malaysian Palm Oil Board, Kajang, Malaysia
2. Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, Serdang, Malaysia
3. Faculty of Defence Science and Technology, Universiti Pertahanan Nasional Malaysia, Kuala Lumpur, Malaysia
4. Department of Mechanical and Manufacturing Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, Bangi, Malaysia