1. Dept. of Chemical Engineering; Graduate School of Engineering, Hiroshima University; 1-4-1 Kagamiyama Higashi Hiroshima 739-8527 Japan
2. Dept. Kimia; Fakultas Pendidikan Matematika dan Ilmu Pengetahuan Alam; Universitas Pendidikan Indonesia; Jl. Dr. Setiabudhi No. 229 Bandung 40154 Indonesia
3. Dept. of Physics; Institut Teknologi Bandung; Jl. Ganesha No. 10 Bandung 40132 Indonesia