1. Guest Editor, Duke Energy Distinguished Professor of Environmental Engineering and Science, Professor of Earth Science and Director, Global Institute for Energy and Environmental Systems (GIEES), Univ. of North Carolina, Charlotte, N.C. E-mail: hiinyang@uncc.edu
2. Guest Editor, Professor and Quenon Chair in Mining Engineering, Univ. of Missouri-Rolla, Rolla, MO. E-mail: frimpong@umr.edu