58,220 research outputs found

    Development of fuel cell electrodes Semiannual report, 30 Jun. 1966 - 30 Dec. 1966

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    Fuel cell using circulating liquid electrolyte and water removal by transpiration through porous electrode

    Interim prediction method for low frequency core engine noise

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    A literature survey on low-frequency core engine noise is presented. Possible sources of low frequency internally generated noise in core engines are discussed with emphasis on combustion and component scrubbing noise. An interim method is recommended for predicting low frequency core engine noise that is dominant when jet velocities are low. Suggestions are made for future research on low frequency core engine noise that will aid in improving the prediction method and help define possible additional internal noise sources

    Decrease in the high energy X-ray flux from Cen XR-2. Search for X-rays from the large and small Magellanic clouds

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    High energy X ray sky survey data on decreased intensity of Cen XR-2, and X ray energy flux from Magellanic clouds - Mildura, Australia, October 15 and 24, 196

    Measured and predicted noise of the Avco-Lycoming YF-102 turbofan noise

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    Acoustic testing of the AVCO-Lycoming YF-102 turbofan engine was done on a static test stand in support of the quiet short-haul research aircraft acoustic design. Overall noise levels were dominated by the fan noise emanating from the exhaust duct, except at high power settings when combination tones were generated in the fan inlet. Component noise levels, calculated by noise prediction methods were in reasonable agreement with the measured results. Far-field microphones placed at ground level were found superior to those at engine centerline height, even at high frequencies

    Interim prediction method for externally blown flap noise

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    An interim procedure for predicting externally blown flap (EBF) noise spectra anywhere below a powered lift aircraft is presented. Both engine-under-the-wing and engine-over-the-wing EBF systems are included. The method uses data correlations for the overall sound pressure level based on nozzle exit area and exhaust velocity along with OASPL directivity curves and normalized one-third-octave spectra. Aircraft motion effects are included by taking into account the relative motion of the source with respect to the observer and the relative velocity effects on source strength

    A role for doctors in assisted dying? An analysis of legal regulations and medical professional positions in six European countries

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    An extensive debate about assisted suicide and euthanasia has been taking place in westernized countries during the last twenty years. Traditionally, the medical profession has maintained a clear distance from euthanasia and assisted suicide, but this distance can no longer be justified by simply referring to the law. This paper analyses the legal and, in particular, medical professional positions with respect to the doctor’s role in assisted dying in certain Western European countries (Belgium, Germany, Netherlands, Norway, Switzerland, United Kingdom) and discusses their implications for doctors

    Space Trumps Time When Talking About Objects

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    The nature of the relationship between the concepts of space and time in the human mind is much debated. Some claim that space is primary and that it structures time (cf. Lakoff & Johnson, 1980) while others (cf. Walsh, 2003) maintain no difference in status between them. Using fully immersive virtual reality (VR), we examined the influence of object distance and time of appearance on choice of demonstratives (this and that) to refer to objects. Critically, demonstratives can be used spatially (this/that red triangle) and temporally (this/that month). Experiment 1 showed a pattern of demonstrative usage in VR that is consistent with results found in real‐world studies. Experiments 2, 3, and 4 manipulated both when and where objects appeared, providing scenarios where participants were free to use demonstratives in either a temporal or spatial sense. Although we find evidence for time of presentation affecting object mention, the experiments found that demonstrative choice was affected only by distance. These results support the view that spatial uses of demonstratives are privileged over temporal uses

    Strong Correlations in Actinide Redox Reactions

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    Reduction-oxidation (redox) reactions of the redox couples An(VI)/An(V), An(V)/An(IV), and An(IV)/An(III), where An is an element in the family of early actinides (U, Np, and Pu), as well as Am(VI)/Am(V) and Am(V)/Am(III), are modeled by combining density functional theory with a generalized Anderson impurity model that accounts for the strong correlations between the 5f electrons. Diagonalization of the Anderson impurity model yields improved estimates for the redox potentials and the propensity of the actinide complexes to disproportionate.Comment: 17 pages, 10 figure, 3 tables. Corrections and clarifications; this version has been accepted for publication in The Journal of Chemical Physic

    Improvements and modifications to the NASA microwave signature acquisition system

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    A user oriented description of the modified and upgraded Microwave Signature Acquisition System is provided. The present configuration of the sensor system and its operating characteristics are documented and a step-by-step operating procedure provides instruction for mounting the antenna truss assembly, readying the system for data acquisition, and for controlling the system during the data collection sequence. The resulting data products are also identified
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