1. Cluster for Polymer Composites, Science and Engineering Research Centre, Engineering Campus; Universiti Sains Malaysia; Nibong Tebal 14300 Penang Malaysia
2. Physics of Geological Processes, Department of Physics; University of Oslo; P.O. Box 1048 Blindern Oslo 0316 Norway
3. Department of Industrial Engineering; University of Trento; Trento 38123 Italy
4. School of Materials and Mineral Resources Engineering; Universiti Sains Malaysia; Nibong Tebal 14300 Penang Malaysia