For internationally recognized contributions in distributed and cluster computing, including the development of the Parallel Virtual Machine and the Message Passing Interface standard now widely used in science to solve computational problems in biology, physics, chemistry, and materials science.
For innovative and fundamental contributions to the understanding of the interactions and transport of electrons in gases and liquids, negative ion processes, the interfacing of the gaseous and condensed phases of matter, and the use of fundamental knowledge in the development of gaseous dielectrics, radiation detectors, and pulsed power
For fundamental studies in radiation physics, radiation dosimetry, and surface physics and for pioneering theoretical work on collective electron modes, surface electromagnetic waves in solids, and elucidation of the interaction of charged particles with matter.
For original studies of the genetic effects of radiation in mammals. A world authority on mammalian mutagenesis, he and co-workers provided the experimental basis for estimating the genetic hazards of radiation to man and for the corresponding recommendations of national and international standards bodies