913 research outputs found

    Development of a Contingency Capillary Wastewater Management Device

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    The Personal Body .Attached Liquid Liquidator (PBALL) is conceived as a passive, capillary driven contingency wastewater disposal device. In this contingency scenario, the airflow system on the NASA Crew Exploration Vehicle (CEV) is assumed to have failed, leaving only passive hardware and vacuum vent to dispose of the wastewater. To meet these needs, the PBALL was conceived to rely on capillary action and urine wetting design considerations. The PBALL is designed to accommodate a range of wetting conditions, from 0deg < (theta)adv approx. 90deg, be adaptable for both male and female use, collect and retain up to a liter of urine, minimize splash-back, and allow continuous drain of the wastewater to vacuum while minimizing cabin air loss. A sub-scale PBALL test article was demonstrated on NASA's reduced gravity aircraft in April, 2010

    Externally Dispersed Interferometry for Precision Radial Velocimetry

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    Externally Dispersed Interferometry (EDI) is the series combination of a fixed-delay field-widened Michelson interferometer with a dispersive spectrograph. This combination boosts the spectrograph performance for both Doppler velocimetry and high resolution spectroscopy. The interferometer creates a periodic spectral comb that multiplies against the input spectrum to create moire fringes, which are recorded in combination with the regular spectrum. The moire pattern shifts in phase in response to a Doppler shift. Moire patterns are broader than the underlying spectral features and more easily survive spectrograph blurring and common distortions. Thus, the EDI technique allows lower resolution spectrographs having relaxed optical tolerances (and therefore higher throughput) to return high precision velocity measurements, which otherwise would be imprecise for the spectrograph alone.Comment: 7 Pages, White paper submitted to the AAAC Exoplanet Task Forc

    The mass-radius-luminosity-rotation relationship for M dwarf stars

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    NASA's future Transiting Exoplanet Survey Satellite (TESS) mission is expected to discover hundreds of terrestrial exoplanets orbiting around M dwarf stars, which will be nearby and amenable to detailed characterization. To accurately measure radii and equilibrium temperatures of these exoplanets, we need to know the host star properties, specifically mass, radius and luminosity, to equal accuracy. However, relationships for M dwarf stellar properties are poorly constrained, which leaves us unprepared to characterize exoplanets to be discovered by the TESS mission. The best way to determine relationships for M dwarf stars is to study mutually eclipsing binaries because the photometric and spectroscopic data empirically determine the physical parameters of the stars. We are conducting an on-going survey to measure infrared eclipses and individual spectra of carefully selected M dwarf eclipsing binary targets. We are using Mimir, a near-infrared wide-field imager, on the 72-inch Perkins Telescope near Flagstaff, Arizona, to determine the J, H, and K band magnitudes of the individual stars, and we are using Keck HIRES to measure the radial velocities of each component. Combining the observations, we determine the masses, radii and the semi-major axes of each component to an accuracy of 1%. We are also using measured parallaxes to determine the individual components' absolute infrared magnitudes and bolometric luminosities. The ultimate goal is to combine the measurements to determine the mass-radius-luminosity-rotation relationship for M dwarf stars. The relationship is critical for choosing the best TESS M dwarf exoplanets for detailed characterization.http://adsabs.harvard.edu/abs/2016AAS...22714221HPublished versio

    Failure of interpolation in the intuitionistic logic of constant domains

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    This paper shows that the interpolation theorem fails in the intuitionistic logic of constant domains. This result refutes two previously published claims that the interpolation property holds.Comment: 13 pages, 0 figures. Overlaps with arXiv 1202.1195 removed, the text thouroughly reworked in terms of notation and style, historical notes as well as some other minor details adde

    On the recovery of stellar parameters from eclipsing binary data

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    We present the results of a series of simulations designed to determine the observing parameters that can reliably allow for the recovery of stellar masses and radii to better than 1% from double-line spectroscopic eclipsing binaries. This is a critical step in an ongoing program to characterize a large sample of low-mass eclipsing systems discovered by the Kepler Space Telescope using follow-up data from several ground based facilities.http://adsabs.harvard.edu/abs/2016AAS...22734515KPublished versio

    Raman spectral shifts in naturally faulted rocks

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    Acknowledgements. We thank Colin Taylor at UoA for help in sample preparation.This study was supported by the School of Geosciences at the University of Aberdeen and in part by the NERC Centre for Doctoral Training in Oil & Gas (Grant Number: NE/R01051x/1).Peer reviewedPublisher PD

    Quantum Dynamics of a Bose Superfluid Vortex

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    We derive a fully quantum-mechanical equation of motion for a vortex in a 2-dimensional Bose superfluid, in the temperature regime where the normal fluid density ρn(T)\rho_n(T) is small. The coupling between the vortex "zero mode" and the quasiparticles has no term linear in the quasiparticle variables -- the lowest-order coupling is quadratic. We find that as a function of the dimensionless frequency Ω~=Ω/kBT\tilde \Omega = \hbar \Omega/k_BT, the standard Hall-Vinen/Iordanskii equations are valid when Ω~1\tilde \Omega \ll 1 (the "classical regime"), but elsewhere, the equations of motion become highly retarded, with significant experimental implications when Ω~1\tilde \Omega \gtrsim 1.Comment: 12 pages (4 pages + supp info), 2 figures, accepted to PR

    Mortality and cancer incidence following occupational radiation exposure: third analysis of the National Registry for Radiation Workers

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    Mortality and cancer incidence were studied in the National Registry for Radiation Workers in, relative to earlier analyses, an enlarged cohort of 174 541 persons, with longer follow-up (to 2001) and, for the first time, cancer registration data. SMRs for all causes and all malignant neoplasms were 81 and 84 respectively, demonstrating a ‘healthy worker effect'. Within the cohort, mortality and incidence from both leukaemia excluding CLL and the grouping of all malignant neoplasms excluding leukaemia increased to a statistically significant extent with increasing radiation dose. Estimates of the trend in risk with dose were similar to those for the Japanese A-bomb survivors, with 90% confidence intervals that excluded both risks more than 2–3 times greater than the A-bomb values and no raised risk. Some evidence of an increasing trend with dose in mortality from all circulatory diseases may, at least partly, be due to confounding by smoking. This analysis provides the most precise estimates to date of mortality and cancer risks following occupational radiation exposure and strengthens the evidence for raised risks from these exposures. The cancer risk estimates are consistent with values used to set radiation protection standards

    Raman Spectroscopy : an effective thermal marker in low temperature carbonaceous fold-thrust belts

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    Special Publication title- Fold and Thrust Belts: Structural Style, Evolution and Exploration Acknowledgments Z. Crawford and A. Marpino were funded through the University of Aberdeen, School of Geosciences for MGeol and MSc project work. Bond, Butler and Watkins were supported through the Fold-Thrust Research Group, sponsored by Oil Search, Santos and Interoil.Peer reviewedPostprintPostprintPostprintPostprintPostprintPostprintPostprintPostprin
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