SADHU SINGH, PhD, retired as Professor and Head of Mechanical Engineering Department of G.B. Pant University of Agriculture and Technology, Pantnagar. He is a postgraduate in Mechanical Design and Production Engineering. He obtained his doctorate from Kurukshetra University. He served for 15 years at Regional Engineering College (now NIT Kurukshetra) and then for 19 years at G.B. Pant University of Agriculture and Technology, including a tenure as Dean Faculty of Engineering and Technology. He has also served as the Director (Colleges), Punjab Technical University Jalandhar. He has published 15 books on mechanical engineering and 50 research papers in national and international journals.
P. L. SAH, PhD, is Professor and Head Mechanical Engineering, College of Technology, G.B. Pant University of Agriculture and Technology, Pantnagar. He has long experience of teaching machine drawing and has to his credit many research papers in reputed journals.