1. Faculty of Science, Department of Chemistry, University of Malaya; Kuala Lumpur Malaysia
2. Faculty of Engineering, Department of Electrical Engineering, University of Malaya; 50603 Kuala Lumpur Malaysia
3. Faculty of Applied Sciences, Department of Physical Science, Tunku Abdul Rahman University College; Jalan Genting Kelang, Setapak 53300 Kuala Lumpur Malaysia