JOHN A. TYRELL, PhD, is Visiting Scientist in the Department of Chemistry and Bio-chemistry at the University of North Carolina Wilmington, where he teaches Fundamentals of Heterocyclic Chemistry among other courses. Dr. Tyrell holds sixty-eight patents and has more than twenty years of industrial research experience, much of it focused on heterocyclic chemistry research at Lederle Laboratories, General Electric Plastics, and OxyChem.