1. Materials and Manufacturing Directorate, Air Force Research Laboratory, MLPJ, 3005 Hobson Way Bldg 651, Wright Patterson Air Force Base, Ohio 45433; UES, Inc., Dayton, Ohio 45432; Anteon Corporation, Dayton, Ohio 45431; Science Applications International Corporation, Dayton, Ohio 45434; and Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania 19104