Abstract
Dr. Don Sheer, Consulting Scientist for the Analytical Division of Millipore Corporation, was aboard Swiss Air Flight SR111 when it crashed off the Nova Scotia coast on September 2, 1998. He was accompanied by his wife, Diane. Don's technical expertise, dedication, voracious curiosity, and relationships with technologists across many fields led to new products and applications throughout his professional career. The paper he co-authored for this issue is among his last publications. The sudden loss of Don and Diane remains difficult for colleagues and friends alike to comprehend.