659 research outputs found
An Evaluation of Uranium-Series Dating of Fossil Echinoids from Southern California Pleistocene Marine Terraces
Fossil sea urchins (Strongylocentrotus) from Pleistocene marine terraces on the southern California Channel Islands have been dated by the uranium-series method in order to test the suitability of echinoids for dating marine terraces. Results indicate that urchin plates and spines do not behave as closed systems with respect to both uranium and thorium. Calculated ages based on these data do not agree with uranium-series ages (120,000 and 127,000 yrs) obtained previously from corals from the same localities. Thus, fossil sea urchins (Strongylocentrotus) are not considered suitable for uranium-series dating of Pleistocene marine terrace deposits
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Thermal analysis of Perforated Metal Air Transportable Package (PMATP) prototype.
Sandia National Laboratories (SNL) has designed a crash-resistant container, the Perforated Metal Air Transportable Package (PMATP), capable of surviving a worst-case plane crash, including both impact and subsequent fire, for the air transport of plutonium. This report presents thermal analyses of the full-scale PMATP in its undamaged (pre-test) condition and in bounding post-accident states. The goal of these thermal simulations was to evaluate the performance of the package in a worst-case post-crash fire. The full-scale package is approximately 1.6 m long by 0.8 m diameter. The thermal analyses were performed with the FLEX finite element code. This analysis clearly predicts that the PMATP provides acceptable thermal response characteristics, both for the post-accident fire of a one-hour duration and the after-fire heat-soak condition. All predicted temperatures for the primary containment vessel are well within design limits for safety
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