How did life come to be on the surface of the earth? Darwin himself recognized that his basic idea of evolution by variation and natural selection must be a continuous process extending backward in time through that period in which the first living things arose and into the period of 'Chemical Evolution' which preceded it. We are approaching the examination of these events by two routes. One is to seek for evidence in the ancient rocks of the earth which were laid down prior to that time in which organisms capable of leaving their skeletons in the rocks to be fossilized were in existence. This period is sometime prior to approximately 600 million years ago. The earth is believed to have taken its present form approximately 4700 million years ago. We have found in rocks whose age is about 1000 million years certain organic molecules which are closely related to the green pigment of plants, chlorophyll. This seems to establish that green plants were already fluorishing prior to that time. We have now found in rocks of still greater age, namely, 2500 million years, the same kinds of molecules mentioned above which can be attributed to the presence of living …

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This report discusses research and development programs of the Irradiation Processing Department in FY-1965.

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Declassified 24 Sep 1973. Two detailed, conceptual process, equipment, and plant designs were prepared for facilities for recovering spent Rover fuel (highly enriched uranium-graphite) at the Idaho Chemical Processing Plart. The results of the study indicate that the fluoridevolatility process is preferred on both economic and technical grounds. Both processes employ a comnion fuel shipping, storage, and charging system and use continuous, fluidized-bed oxidation of the fuel as the first step of the head-end operation. Subsequent operations in the aqueous process include batch leaching the ash with 5 M HF--10 M HNO/sub 3/ in two parallel lines of Teflon-lined leaching and feed-preparation equipment, followed by solvent extraction to decontaminate and recover the uranium as uranyl nitrate. Post-burning operations in the fluoride-volatiiity process include the continuous fluidized-bed and moving-bed fluorination of the ash followed by partial condensation to remove niobium pentafluoride and passage of the UF/sub 6/ through heated sodium fluoride pellets to completely decontaminate the uranium. The uranium is recovered as uranium hexafluoride. (auth)

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Daily newspaper from Cuero, Texas that includes local, state and national news along with advertising.

Daily newspaper from Baytown, Texas that includes local, state, and national news along with advertising.

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