1. Centre for Advanced Manufacturing and Material Processing Faculty of Eangineering University of Malaya 50603 Kuala Lumpur Malaysia
2. Department of Chemistry Faculty of Science University of Malaya 50603 Kuala Lumpur Malaysia
3. Department of Chemical Engineering Faculty of Engineering University of Malaya 50603 Kuala Lumpur Malaysia
4. Department of Electrical Engineering Faculty of Engineering University of Malaya 50603 Kuala Lumpur Malaysia