R. Rajasekar, PhD, professor and head of the Department of Mechanical Engineering, Kongu Engineering College (An Autonomous Institution under Anna University), Tamilnadu, India. He obtained his PhD from the Indian Institute of Technology, Kharagpur, and specializes in materials science and engineering, renewable energy, surface coating on solar cells, and tribological performance of carbide inserts. He has published more than 130 research articles in reputed international journals, as well as more than 30 book chapters. C. Moganapriya, PhD, is a post-doctoral researcher, Department of Mining Engineering, Indian Institute of Technology Kharagpur, West Bengal, India. She completed her PhD in 2019 and her current research area includes surface engineering of solar cells for performance enhancement of power conversion efficiency and tribological performance of cutting tool inserts by adopting several hard coating materials. She has published 40 research articles and 15 book chapters with international publishers. P. Sathish Kumar, PhD, is a research associate, Department of Mining Engineering, Indian Institute of Technology Kharagpur, West Bengal, India. His main research areas are in tribological studies of mining bits, thin film coating, natural fiber composites, and renewable energy.