904 resultados para Arrester beds.
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North Carolina Department of Transportation, Raleigh
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Federal Highway Administration, Washington, D.C.
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Federal Highway Administration, Washington, D.C.
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West Virginia Department of Highways, Charleston
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Federal Highway Administration, Office of Safety and Traffic Operations Research and Development, McLean, Va.
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Federal Highway Administration, Washington, D.C.
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Federal Highway Administration, Washington, D.C.
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West Virginia Department of Highways, Charleston
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Arizona Department of Transportation, Phoenix
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Federal Highway Administration, Washington, D.C.
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There is considerable public, political and professional debate about the need for additional hospital beds in Australia. However, there is no clarity in regard to the definition, meaning and significance of hospital bed counts. Relative to population, there has been a total decline in bed availability in Australia over the past 15 years of 14.6% (22.9% for public hospital beds). This decline is partly offset by reductions in length of stay and changes to models of care; however, the net effect is increased bed occupancy which has in turn resulted in system-wide congestion. Future bed capability needs to be better planned to meet growing demands while at the same time continuing trends for more efficient use. Future planning should be based in part on weighted bed capability matched to need.
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Dry river beds are common worldwide and are rapidly increasing in extent due to the effects of water management and prolonged drought periods due to climate change. While attention has been given to the responses of aquatic invertebrates to drying rivers, few studies exist on the terrestrial invertebrates colonizing dry river beds. Dry river beds are physically harsh and they often differ substantially in substrate, topography, microclimate and inundation frequency from adjacent riparian zones. Given these differences, we predicted that dry river beds provide a unique habitat for terrestrial invertebrates, and that their assemblage composition differs from that in adjacent riparian zones. Dry river beds and riparian zones in Australia and Italy were sampled for terrestrial invertebrates with pitfall traps. Sites differed in substrate type, climate and flow regime. Dry river beds contained diverse invertebrate assemblages and their composition was consistently different from adjacent riparian zones, irrespective of substrate, climate or hydrology. Although some taxa were shared between dry river beds and riparian zones, 66 of 320 taxa occurred only in dry river beds. Differences were due to species turnover, rather than shifts in abundance, indicating that dry river bed assemblages are not simply subsets of riparian assemblages. Some spatial patterns in invertebrate assemblages were associated with environmental variables (irrespective of habitat type), but these associations were statistically weak. We suggest that dry river beds are unique habitats in their own right. We discuss potential human stressors and management issues regarding dry river beds and provide recommendations for future research.
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Experiments involving row spacing and tillage, originally established in Mackay and Ingham in 2001, were planted to a second cycle of sugarcane in 2006 following a soybean break. Despite large yield differences, economic analysis indicated that there would be little difference in gross margins because of the much higher costs of the tilled system. It is concluded that without GPS guidance, as was the case with these experiments, cane yields are likely to be reduced with no tillage but these problems may well be overcome by implementing minimum strategic tillage to remove compaction from the planting row.
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Abstract is not available.
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The vapor-phase dehydrogenation of 1 -butanol to butyraldehyde was studied in a fixed bed of catalyst from 250° to 360° C. Of all the catalysts studied during preliminary investigation, the one containing 90% copper, 8% chromia, and 2% carbon supported on pumice was best, with high activity and selectivity. The data are expressed in the form of a first-order irreversible reaction rate equation. Single-site surface reaction (hydrogen adsorbed) is the rate-controlling mechanism at all the temperatures studied. The rate data obtained in the entire range of experimental conditions fit the rate equation based on this mechanism with a standard deviation of ± 22.8%.