1. a School of Materials and Mineral Resources Engineering, Universiti Sains Malaysia, 14300 Seberang Perai Selatan, Pulau Pinang, Malaysia
2. b School of Materials and Mineral Resources Engineering, Universiti Sains Malaysia, 14300 Seberang Perai Selatan, Pulau Pinang, Malaysia;, Email: hazizan@eng.usm.my
3. c School of Materials and Mineral Resources Engineering, Universiti Sains Malaysia, 14300 Seberang Perai Selatan, Pulau Pinang, Malaysia