1. Manonmaniam Sundaranar University, Tirunelveli, India
2. Department of Physics, Research Centre, Nesamony Memorial Christian College, Marthandam, India
3. Department of Physics, Centre for Molecular and Biophysics Research, Mar Ivanios College, Thiruvanathapuram, India
4. Department of Chemistry, NSS College Ottapalam, Palakad, India