Allan D. Kraus, PhD, is Professor of Mechanical Engineering at the University of Akron, Ohio, and is principal associate at Allan D. Kraus Associates. He is the author of many works on thermal systems. Abdul Aziz, PhD, is Professor of Mechanical Engineering at Gonzaga University in Spokane, Washington. James Welty, PhD, Professor of Mechanical Engineering at Oregon State University in Corvallis, is co-author of Fundamentals of Momentum, Heat, and Mass Transfer (Wiley).