Afshin J. Ghajar is Regents Professor and John Brammer Professor in the School of Mechanical and Aerospace Engineering at Oklahoma State University, Stillwater, Oklahoma, USA and a Honorary Professor of Xi'an Jiaotong University, Xi'an, China. He received his B.S., M.S., and Ph.D. all in Mechanical Engineering from Oklahoma State University. His expertise is in experimental heat transfer/fluid mechanics and development of practical engineering correlations. Dr. Ghajar has made significant contributions to the field of thermal sciences through his experimental, empirical, and numerical works in heat transfer and stratification in sensible heat storage systems, heat transfer to non-Newtonian fluids, heat transfer in the transition region, and non-boiling heat transfer in two-phase flow. His current research is in two-phase flow heat transfer/ pressure drop studies in pipes with different orientations, heat transfer/pressure drop in mini/micro tubes, and mixed convective heat transfer/pressure drop in the transition region (plain and enhanced tubes). Dr. Ghajar has been a Summer Research Fellow at Wright Patterson AFB (Dayton, Ohio) and Dow Chemical Company (Freeport, Texas). He and his co-workers have published over 200 reviewed research papers and 10 book/handbook chapters. He has delivered numerous keynote and invited lectures at major technical conferences and institutions. He has received several outstanding teaching, research, advising, and service awards from College of Engineering at Oklahoma State University. His latest significant awards are the 75thAnniversary Medal of the ASME Heat Transfer Division "in recognition of his service to the heat transfer community and contributions to the field", awarded in 2013 and the ASME ICNMM 2016 Outstanding Leadership Award, this award recognizes a person whose service within the ICNMM (International Conference on Nanochannels, Microchannels, and Minichannels) is exemplary; the recipient of the award contributed significantly to the lasting success of the conference. Dr. Ghajar is a Fellow of the American Society of Mechanical Engineers (ASME), Heat Transfer Series Editor for CRC Press/Taylor & Francis (he has edited nine books to date), and Editor-in-Chief of Heat Transfer Engineering, an international journal published twenty times per year by Taylor and Francis. Heat Transfer Engineering is aimed at practicing engineers and specialists in heat transfer. Dr. Ghajar is also the co-author of the 5th Edition of Cengel and Ghajar, Heat and Mass Transfer – Fundamentals and Applications, McGraw-Hill, 2015.