1. Faculty of Engineering and Green Technology, Universiti Tunku Abdul Rahman, Jalan Universiti; Bandar Barat, 31900 Kampar Perak Malaysia
2. Department of Chemical Engineering; Faculty of Engineering; Universiti Teknologi Petronas 32610 Bandar Seri Iskandar Perak Darul Ridzuan
3. School of Materials and Mineral Resources Engineering, Universiti Sains Malaysia, Engineering Campus; 14300 Nibong Tebal Penang Malaysia
4. Center of Excellence Geopolymer and Green Technology, School of Materials Engineering, Universiti Malaysia Perlis (UniMAP); P. O. Box 77, D/A Pejabat Pos Besar, 01000 Kangar Perlis Malaysia