1. Department of Physics; R.T.M. Nagpur University; Nagpur 440033 India
2. Department of Chemistry; Sevadal Mahila Mahavidhyalaya; Nagpur 440009 India
3. N. H. College Bramhapuri; Gondwana University; Gadchiroli 442605 India
4. Department of Chemical Engineering; Konkuk University; Seoul 143701 South Korea