Norman J. Wagner holds the Unidel Robert L. Pigford Chair in Chemical and Biomolecular Engineering at the University of Delaware. Internationally recognized for his research and applications of colloidal suspensions, he received the Bingham medal and was elected to both the National Academy of Engineering and National Academy of Inventors. Jan Mewis is Emeritus Professor of the Chemical Engineering Department at the Katholieke Universiteit Leuven. He has lectured worldwide and was chairman of the International Committee on Rheology. He received the Bingham medal in the US, as well as the Gold medal of the British Society of Rheology.