Dr. Stephen Idem is a professor in the Department of Mechanical Engineering at Tennessee Tech University. He received his Ph.D. in Mechanical Engineering from Purdue University, and has more than 32 years of experience in the areas of fluid flow measurement, scale model testing, and thermal modeling. He participated in many studies related to the measurement of air flow and pressure loss characteristics of typical residential and commercial duct systems. He has created a numerical model of downdraft evaporative cooling tower performance, which was verified experimentally. He has extensive experience performing flow and pressure measurements on scale models of primary and secondary air supply ducts, windboxes, and exhaust stacks of coal-fired power plants in order to improve their thermal performance. He has developed an on-line cleanliness factor model of the convection passes in coal-fired power plants, and has likewise created numerical models of steady and transient heat exchanger performance. Dr. Idem recently completed a project to determine the absolute roughness of phenolic ducts with a four-bolt flange joint. Currently he is performing experimental and finite element modeling investigations of unreinforced and reinforced galvanized steel spiral flat oval duct deformation when subjected to positive or negative gauge pressures. He is also participating in a study to model rectangular duct deflection due to applied pressure.