6,093 research outputs found

    Dense gas in the dust lane of Centaurus A

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    The interstellar medium of Centaurus A (NGC 5128) has been studied extensively in recent years, using mostly molecular lines tracing low to medium density gas (500 to several 10310^3 cm−3^{-3}). The amount and distribution of the dense molecular gas was largely unknown. Here we present new millimeter data of the HCN(1-0), CS(2-1), and CS(3-2) rotational transitions towards the nearby radio galaxy Centaurus A observed with the SEST on La Silla, Chile. We obtained spectra of the HCN(1-0) emission which traces dense 104^4 cm−3^{-3} molecular gas at the center and along the prominent dust lane at offset positions ±60′′\pm60^{\prime \prime} and ±100′′\pm100^{\prime \prime}. We also obtained a few spectra of CS(2-1) and (3-2) tracing densities of ∼105\sim10^5 cm−3^{-3}. The emission in these lines is weak and reaches a few mK at the available angular resolutions of 54′′^{\prime \prime} - 36′′^{\prime \prime}. At the central position, the integrated intensity ratio I(HCN)/I(CO) peaks at 0.064, and decreases to ∼\sim0.02 to 0.04 in the dust lane.Comment: 7 pages, 5 figures, accepted by A.&A. 04. May 200

    A report on the sea otter, Enhydra lutris L., in California

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    This report discusses in detail findings and observations of 5 years of research on the sea otter population and its relationship to the nearshore marine environment in California. Initial efforts were directed at providing some relief to the commercial abalone fishery in the Cambria - Point Estero area north of Morro Bay. This fishery has subsequently collapsed along with other commercial and sport abalone and sport crab fisheries throughout the sea otter's range due to continued sea otter foraging. Capturing, tagging and translocation studies, censusing studies, examination of sea otter remains, habitat surveys, food habits observations and studies on otters in captivity provide a broad base of information on the expanding sea otter population in California and its effects on resources utilized by man. Recommendations for sea otter management consistent with esthetic, recreational, and commercial uses of marine resources are included in this report. (95pp.

    A transient digitiser for fast air shower events

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    Air shower structure are often measured on time scales of a few nanoseconds. Longitudinal disk structure near the core is of the order of meters in dimension, air Cerenkov pulses have full widths at half maximum of the order of tens of nanoseconds, and fast timing over typical arrays is usually measured to nanosecond accuracy. oscilloscopes can be used but have very limited dynamic range and are expensive if measurements down to a few nanoseconds are to be made. For the fast Cerenkov work, an instrument with better dynamic range than an oscilloscope and with a time resolution sufficient to allow measurements limited only by system risetime of a few nanoseconds is needed. A 16/32 channel, 8 bit, fast transient digitizer was designed and built which runs at sample intervals down to approx. 1 nanosecond per channel

    Dungeness crab research program

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    In 1974, the California State Legislature, recognizing the problem of low yields from the Dungeness crab resource of central California, directed the Department of Fish and Game to conduct an investigation into the causes of the decline. The Operations Research Branch of the Department has conducted preliminary studies and field operations necessary to formulate the Dungeness Crab Research Program. The objectives, research design, and work plans are presented for a 4-year program from July 1, 1975 through August 31, 1979. (38pp.

    Integrating Case-Based Reasoning with Adaptive Process Management

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    The need for more flexiblity of process-aware information systems (PAIS) has been discussed for several years and different approaches for adaptive process management have emerged. Only few of them provide support for both changes of individual process instances and the propagation of process type changes to a collection of related process instances. The knowledge about changes has not yet been exploited by any of these systems. To overcome this practical limitation, PAIS must capture the whole process life cycle and all kinds of changes in an integrated way. They must allow users to deviate from the predefined process in exceptional situations, and assist them in retrieving and reusing knowledge about previously performed changes. In this report we present a proof-of concept implementation of a learning adaptive PAIS. The prototype combines the ADEPT2 framework for dynamic process changes with concepts and methods provided by case-based reasoning(CBR) technology

    Antitrust and the Securities Industry Lessons from the Shipping Industry

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    Criminal Jurisdiction Over United States Civilians Accompanying the Armed Forces Abroard

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    Antitrust and the Securities Industry Lessons from the Shipping Industry

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    Dungeness crab research program: Report for the Year 1976

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    All larval stages of the 1976 year class, with the exception of the 5th zoeal stage, were found in Gu1f waters January through March. The first post-larval stage was collected in San Pablo Bay in May. Fifty percent of 1976 year class crabs entered the Bay complex as compared to nearly 80% in 1975. The 1976 year class appears relatively weak. No electrophoretic polymorphism was found in Cancer magister to be of value in Dungeness crab population determinations. Multi-variate correlations comparing crab landings with an array of oceanographic parameters and the crab density dependent factor were computer-run for both northern and central California. The most significant correlating factors at the time late stage larvae prevail were sea level and atmospheric pressure for central California and, for northern California, the density dependent factor and sea surface temperature. Female crabs held at controlled temperatures indicated gonad maturation and spawning may be induced by increased temperature. Analyses of crab tissues revealed burdens of petroleum hydrocarbons, silver, selenium, cadmium, and PCB's higher in central California crabs, while DDE was found in higher amounts in northern California crab tissue. Thru-flow culture systems were developed which should yield about 163 megalopae of Dungeness crabs in 63 days from 1,200 laboratory hatched zoeae.(46pp.

    Criminal Jurisdiction Over United States Civilians Accompanying the Armed Forces Abroard

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