Varanasi (UP), April 26 (IANS) Noted physicist Prof. Onkar Nath Srivastava, Emeritus Professor, Banaras Hindu University (BHU), who was awarded the Padma Shri in 2016 for his research on hydrogen energy and nanotechnology, died of Covid at BHU hospital. The cremation was held on Sunday. He was 79 and was on ventilator support at Sir Sunderlal Hospital after testing positive for Covid-19 on April 20. Prof Srivastava, was a material physicist and vice president for India and South Asia of the International Association for Hydrogen Energy. After doing his post-doctoral research at Cornell University, USA, he returned to India to start his career as a lecturer at BHU, where he served as a reader, professor, head of the department of physics and the coordinator of the Centre of Advance Studies - Hydrogen Energy Centre.