12,427 research outputs found

    The measurement of the winds near the ocean surface with a radiometer-scatterometer on Skylab

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    The author has identified the following significant results. There were a total of twenty-six passes in the ZLV mode that yielded useful data. Six were in the in-track noncontiguous mode; all others were in the cross-track noncontiguous mode. The wind speed and direction, as effectively determined in a neutral atmosphere at 19.5 m above the sea surface, were found for each cell scanned by S193. It is shown how the passive microwave measurements were used both to compute the attenuation of the radar beam and to determine those cells where the backscatter measurement was suspect. Given the direction of the wind from some independent source, with the typical accuracy of measurement by available meteorological methods, a backscatter measurement at a nadir angle of 50, 43, or 32 deg can be used to compute the speed of the wind averaged over the illuminated area

    Community based rehabilitation after severe traumatic brain injury: a randomised controlled trial

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    Objective: Evaluation of multidisciplinary community based outreach rehabilitation after severe traumatic brain injury (TBI). Methods: A randomised controlled trial compared outreach treatment (mean of two sessions a week for 27.3 (SD 19.1) weeks) in community settings such as participants' homes, day centres, or workplaces, with provision of written information detailing alternative resources. Follow up for an average of 24.8 months after initial allocation was by a blinded independent assessor. Participants were aged 16–65, had sustained severe TBI between 3 months and 20 years previously, and had no other neurological conditions. Of 110 initially allocated, 48 outreach and 46 information participants were successfully followed up. Primary outcome measures (Barthel index (BI) and the brain injury community rehabilitation outcome-39 (BICRO-39)) focused on levels of activity and participation. Secondary measures were the functional independence measure and the functional assessment measure (FIM+FAM) and, in a subgroup of 46 participants, the hospital anxiety and depression scale. Analyses were non-parametric. Results: outreach participants were significantly more likely to show gains on the BI and the BICRO-39 total score and self organisation and psychological wellbeing subscales. There were likewise strong trends (p<0.10) for BICRO personal care and mobility, and on the FIM+FAM for personal care and cognitive functions. Differential improvements were not seen for indices of socialising, productive employment, anxiety, or depression. Median changes on individual subscales were small, reflecting the diversity of the clinical population; however, 40% of outreach but only 20% of information participants made a clinically significant improvement of 2+ points on at least one BICRO-39 scale. Time since injury was unrelated to the magnitude of gains. Conclusions: This is the first RCT of multidisciplinary community rehabilitation after severe TBI, and suggests that even years after injury it can yield benefits which outlive the active treatment period

    Pre-Hawking Radiation from a Collapsing Shell

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    We investigate the effect of induced massive radiation given off during the time of collapse of a massive spherically symmetric domain wall in the context of the functional Schr\"odinger formalism. Here we find that the introduction of mass suppresses the occupation number in the infrared regime of the induced radiation during the collapse. The suppression factor is found to be given by eβme^{-\beta m}, which is in agreement with the expected Planckian distribution of induced radiation. Thus a massive collapsing domain wall will radiate mostly (if not exclusively) massless scalar fields, making it difficult for the domain wall to shed any global quantum numbers and evaporate before the horizon is formed.Comment: 10 pages, 3 figures. We updated the acknowledgments as well as added a statement clarifying that we are following the methods first laid out in Phys. Rev. D 76, 024005 (2007

    Derivation of Internally-Consistent Thermodynamic Data by the Technique of Mathematical Programming: a Review with Application the System MgO-SiO2-H2O

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    The problem of deriving an optimal set of thermodynamic properties of minerals from a diverse experimental data base is reviewed and a preferred methodology proposed. Mathematical pro-gramming(MAP) methods extend the linear programming (LIP) approach first presented by Gordon (1973), and make it possible to account for the type of information conveyed, and the uncertainties attending both phase equilibrium data and direct measurements of phase properties. For phase equilibrium data which are (in most cases) characterized by non-normal error distributions across experimental brackets, the midpoint of a bracket is no more probable than other points, and the data are best treated by considering the inequality in the change in Gibbs free energy of reaction at each half-bracket. Direct measurements of phase properties can be assumed to have approximately normal error distributions, and the MAP technique optimizes agreement with these values by using the principles of least squares in the definition of an objective function. The structure of this problem, treatment of uncertainties in various types of experimental data, and method of optimizing final solutions are discussed in some detail. The method is applied to experimental data in the MgO-SiO2-H2O system, where inconsistencies among the data are resolved and an optimal set of thermodynamic properties is presented. The derived standard state entropies and volumes agree with all direct measurements (within their uncertainties), as do enthalpies of formation from the elements except for those of talc (+16 kJ mol−1), anthophyllite (+ 14 kJ mol−1), and brucite (−1 kJ mol−1). Stable phase relations in the system have the topology predicted by Greenwood (1963, 1971), with quartz- and forsterite-absent invariant points at 683 °C-6-4 kb and 797 °C-12 kb respectively, repeating at 552 °C-120 b and 550 °C-55 b. The thermodynamic analysis indicates little remaining flexibility in the phase relations, which, when combined with suitable activity models for solid solution, should allow for accurate determination of the conditions of metamorphism of ultramafic rock

    H2O contents and hydrogen isotopic composition of apatite crystals from L, LL5-6 ordinary chondrites.

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    第3回極域科学シンポジウム/第35回南極隕石シンポジウム 11月30日(金) 国立国語研究所 2階講

    Local free-fall temperature of a RN-AdS black hole

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    We use the global embedding Minkowski space (GEMS) geometries of a (3+1)-dimensional curved Reissner-Nordstr\"om(RN)-AdS black hole spacetime into a (5+2)-dimensional flat spacetime to define a proper local temperature, which remains finite at the event horizon, for freely falling observers outside a static black hole. Our extended results include the known limiting cases of the RN, Schwarzschild--AdS, and Schwarzschild black holes.Comment: 18 pages, 11 figures, version to appear in Int. J. Mod. Phys.

    Circuit enhances vertical resolution in raster scanning systems

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    Circuit enhances vertical resolution in electron beam, raster scanning systems exhibiting aperture distortion in the vertical direction. A sensitized area /image/ produces a video output when the scan beam nears it, which causes vertical elongation in the reconstructed images of all sensitized areas on the surface

    The reaction of Escherichia coli cytochrome bo with H202: Evidence for the formation of an oxyferryl species by two distinct routes

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    AbstractWe have re-examined the reaction of fast oxidised cytochrome bo with H2O2 in a stopped-flow spectrophotometer. Monitoring the reaction at 582 nm allows us to observe the formation and decay of a spectroscopically distinct intermediate which accumulates transiently prior to the formation of an oxyferryl species previously characterised in this laboratory (Watmough, N.J., Cheesman, M.R., Greenwood, C. and Thomson, A.J. (1994) Biochem. J. 300, 469–475 [1]). The reaction shows three distinct phases of which the fast and intermediate phases are bimolecular and show a marked pH dependence. Initially these results appeared incompatible with the report that only one equivalent of H2O2 is required to generate the oxyferryl species (Moody, A.J. and Rich, P.R. (1994) Eur. J. Biochem. 226, 731–737 [2]). However, these data can be reconciled by a branched reaction mechanism whose contributions differ according to the peroxide concentration used

    Large sulfur isotope fractionations in Martian sediments at Gale crater

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    Variability in the sulfur isotopic composition in sediments can reflect atmospheric, geologic and biological processes. Evidence for ancient fluvio-lacustrine environments at Gale crater on Mars and a lack of efficient crustal recycling mechanisms on the planet suggests a surface environment that was once warm enough to allow the presence of liquid water, at least for discrete periods of time, and implies a greenhouse effect that may have been influenced by sulfur-bearing volcanic gases. Here we report in situ analyses of the sulfur isotopic compositions of SO2 volatilized from ten sediment samples acquired by NASA’s Curiosity rover along a 13 km traverse of Gale crater. We find large variations in sulfur isotopic composition that exceed those measured for Martian meteorites and show both depletion and enrichment in 34S. Measured values of δ34S range from −47 ± 14‰ to 28 ± 7‰, similar to the range typical of terrestrial environments. Although limited geochronological constraints on the stratigraphy traversed by Curiosity are available, we propose that the observed sulfur isotopic signatures at Gale crater can be explained by equilibrium fractionation between sulfate and sulfide in an impact-driven hydrothermal system and atmospheric processing of sulfur-bearing gases during transient warm periods
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