Dr. Dexter Perkins received his Ph. D. from the University of Michigan in 1979. He has published over 80 papers and three books. He has had research appointments at the University of Chicago and the Universite Blaise Pascal and has been a regular faculty member in the Department of Geology and Geological Engineering at the University of North Dakota for more than 20 years. His current research is focused on mineral equilibria and science education reform. Kevin R. Henke received his Ph. D. in geology from the University of North Dakota in 1997. He has had research and postdoctoral appointments at Oak Ridge National Laboratory in the Chemistry Department at North Dakota State University and in the Chemistry Department at the University of Kentucky. He has also taught in the Department of Geological Sciences at the University of Kentucky. Currently he is researching the chemistry and environmental impacts of mercury and other heavy metals as an employee of the Center for Applied Energy Research at the University of Kentucky Lexington. . Language: English