Prof. Dr. Alexander Yakovelich Malkin is the Principal Research Fellow at the Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences, Moscow. He has written five monographs and more than 100 papers in English, including three books on the subject of rheology. He has also taken part as an invited plenary or keynote speaker at numerous international conferences and meetings on rheology, polymer processing and physics. Prof. Dr. Avraam I. Isayev is a Distinguished Professor Emeritus in the Department of Polymer Engineering at the University of Akron, USA. He has been a member of the Society of Rheology since 1981, and a Senior Member of the Society of Plastics Engineers since 1984. His interests include polymer processing, rheology of polymers, and the injection, co-injection, transfer, compression and gas-assisted injection molding of polymers.