For pioneering research in disturbance and landscape ecology and in modeling of land-use change with its implications for global changes, which have influenced environmental decision making on a worldwide scale.
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 application of chemical and engineering principles to the development of nuclear fuel processing; separation science and technology; and innovative biomedical and bioprocessing concepts for environmental protection, energy production and conservation, and resource recovery
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