1. Thermal Analysis Laboratory, Material Characterization Center, Department of Chemistry, Western Kentucky University, Bowling Green, Kentucky 42101; Southern Clay Products, Inc., 1212 Church Street, Gonzales, Texas 78629; Triton Systems, Inc., 200 Turnpike Road, Chelmsford, Massachusetts 01824; Air Force Research Laboratory/MLBP, Building 654, 2941 P Street, Wright-Patterson Air Force Base, Ohio 45433