1. Department of Physics; Anand Institute of Higher Technology; Kazhipattur, 603 103, Chennai Tamilnadu India
2. Department of Physics; Presidency College; Chennai 600 005 Tamilnadu India
3. Departmentof Physics; Hindustan Institute of Technology and Science; Padur, 603 103, Chennai Tamilnadu India
4. Department of Chemical Engineering; Membrane Filtration Lab, National Taiwan University; Taipei 10617 Taiwan, Republic of China