1. Bayer Thai Company Limited; No.4-4/1, I-8 Road, Map Ta Phut Industrial Estate; Map Ta Phut, Muang Rayong 21150 Thailand
2. Julius Kruttschnitt Mineral Research Centre, Sustainable Minerals Institute; University of Queensland; 40 Isles Road, Indooroopilly Brisbane Qld 4068 Australia
3. Department of Chemical Engineering, Faculty of Engineering; Burapha University; 169 Long-Hard Bangsaen Road, Saen Sook, Muang Chonburi 20131 Thailand