1. University of Wisconsin, 1500 Engineering Dr., Madison, WI 53706, U.S.A
2. Consultant, Fliederweg 3, D 76351 Linkenheim-Hochstetten, Germany
3. Oak Ridge National Laboratory, P.O.Box 2008, Oak Ridge, TN 37831, U.S.A
4. Consultant, 10 Worcester Ct., O’Fallon, MO, U.S.A