1. Dept. of Polymer Science and Technology; Univ. of Calcutta; 92 A. P. C. Road Kolkata 700 009 West Bengal India
2. Dept. of Chemical and Biological Engineering, Industrial Membrane Research Inst; Univ. of Ottawa; 161 Louis Pasteur St Ottawa ON K1N 6N5 Canada
3. Dept. of Biotechnology; Indian Inst. of Technology Kharagpur; Kharagpur 721302 West Bengal India