1. Freshmen Engineering Department, Potti Sriramulu Chalavadi Mallikarjuna Rao College of Engineering and Technology, Vijayawada, Andhra Pradesh, India
2. Department of Physics, Acharya Nagarjuna University, Nagarjunanagar, Andhra Pradesh, India
3. Department of Physics, SPW Degree College, Tirupati, Andhra Pradesh, India and
4. Department of Humanities and Science, Malla Reddy Engineering College (A), Secunderabad, Telangana, India