Stephen Hall graduated from the University of Pennsylvania with a Bachelor of Science degree in Chemical Engineering (1974). His career in the chemical process industries includes jobs for manufacturers and engineering contractors, where he has designed portions of more than 100 projects. Much of his work has been for food, pharmaceutical, or specialty chemical (i.e., batch chemical process) clients, but he has also designed systems for heavy chemical and petrochemical installations. He has published several articles on chemical engineering topics, and writes computer software (www.pipesizingsoftware.com).