Yunus A. Çengel is Professor Emeritus of Mechanical Engineering at the University of Nevada, Reno. He received his B.S. in mechanical engineering from Istanbul Technical University and his M.S. and Ph.D. in mechanical engineering from North Carolina State University. His areas of interest are renewable energy, energy efficiency, energy policies, heat transfer enhancement, and engineering education. He served as the director of the Industrial Assessment Center (IAC) at the University of Nevada, Reno, from 1996 to 2000.

John M. Cimbala is Professor of Mechanical Engineering at The Pennsyl¬vania State University (Penn State), University Park, PA. He received his B.S. in Aerospace Engi-neering from Penn State and his M.S. in Aeronautics from the California Institute of Technology (CalTech). He received his Ph.D. in Aeronautics from CalTech in 1984.

Mehmet Kanoğlu is Professor of Mechanical Engineering at University of Gaziantep. He received his B.S. in mechanical engineering from Istanbul Technical University and his M.S. and Ph.D. in mechanical engineering from University of Nevada, Reno. His research areas include renewable energy systems, energy efficiency, refrigeration systems, gas liquefaction, hydrogen production and liquefaction, geothermal energy, and cogeneration. He is the author or coauthor of dozens of jour¬nal and conference papers.

John M. Cimbala is Professor of Mechanical Engineering at The Pennsyl¬vania State University (Penn State), University Park, PA. He received his B.S. in Aerospace Engi-neering from Penn State and his M.S. in Aeronautics from the California Institute of Technology (CalTech). He received his Ph.D. in Aeronautics from CalTech in 1984.