About the Author NANCY J. SELL, is Professor of Natural and Applied Sciences at the University of Wisconsin-- Green Bay, as well as President of N.J. Sell & Associates, an engineering consulting firm. She is a member of TAPPI, ASTM, National Society of Professional Engineers, the American Chemical Society, and other professional organizations. Among her nearly 75 published efforts are two other books and numerous journal articles, technical papers, reports, teaching manuals, and chapters in technical books and encyclopedias. Dr. Sell is co-holder of two patents and has made numerous presentati...