1. Singh Simutech Pvt. Ltd., Bharatpur, Rajasthan 321201, India
2. Department of Physics, Shri Venkateshwara University, Gajraula, Amroha, Uttar Pradesh 244236, India
3. Department of Physics, Multani Mal Modi College Modinagar, C.C.S. University, Meerut, Uttar Pradesh 201204, India