Sandip Kunar, PhD, is an assistant professor in the Department of Mechanical Engineering, Aditya Engineering College, A.P., India. He has published more than 50 research papers in various reputed international journals, national and international conference proceedings, 16 book chapters, and nine books, as well as two patents. His research interests include non-conventional machining processes, micromachining processes, advanced manufacturing technology, and industrial engineering. Gurudas Mandal, PhD, is an assistant professor in the Department of Metallurgical Engineering at Kazi Nazrul University, West Bengal, India. He has 20 technical research publications in reputed international journals, eight conference proceedings, nine book chapters, and one patent. He also serves as a reviewer for several reputed journals and has organized and chaired numerous national and international conferences. His research interests include alloy steel, cast iron, composite materials, magnetic materials, hydrogen energy, and archaeometallurgy.