[en] This book presents information on the following topics: analysis of oil shale products and effluents using a multitechnique approach; nuclear methods for trace elements in petroleum and petroleum products; uranium content of petroleum by fission; fast neutron activation analysis of fossil fuels and liquefaction products; determination of trace element forms in solvent refined coal products; an automated multidetector system for instrumental neutron activation analysis of geological and environmental materials; on-line nuclear analysis of coal and its uses; investigation of coal hydrogenation using deuterium as an isotopic tracer; the natural permeability reduction in porous media due to the presence of kaolinite; the application of photon induced x-ray fluorescence for the simultaneous determinations of cobalt, nickel and molybdenum in hydrodesulfurization catalysts; and applications of nuclear magnetic resonance of oil shale evaluation and processing