Zahid Amjad, Ph.D., is a visiting professor in the Division of Mathematics and Sciences at Walsh University, North Canton, Ohio. During his more than 30 years at Calgon Corporation, Pittsburgh, Pennsylvania, and Lubrizol Advanced Materials, Inc., Cleveland, Ohio, Dr. Amjad has worked in various fields, including cosmetics, home care, oral care, pharmaceutics, water treatment, water purification, and related fields. His major interests include biological and industrial applications of water-soluble and water-swellable polymers, interactions of polymers with different substrates, crystal growth and dissolution, and adsorption and desorption phenomena in aqueous systems. Dr. Amjad has published more than 160 technical papers, has contributed to numerous book chapters, has edited 6 books, and holds 30 US patents. Dr. Amjad is also the owner of Aqua Science and Technology LLC, Columbus, Ohio, which provides consulting services for industrial water treatment, separation processes, and related technologies.