1,344 research outputs found

    Experimental study of a generic high-speed civil transport

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    An experimental study of generic high-speed civil transport was conducted in the NASA Langley 8-ft Transonic Pressure Tunnel. The data base was obtained for the purpose of assessing the accuracy of various levels of computational analysis. Two models differing only in wingtip geometry were tested with and without flow-through nacelles. The baseline model has a curved or crescent wingtip shape, while the second model has a more conventional straight wingtip shape. The study was conducted at Mach numbers from 0.30 to 1.19. Force data were obtained on both the straight wingtip model and the curved wingtip model. Only the curved wingtip model was instrumented for measuring pressures. Selected longitudinal, lateral, and directional data are presented for both models. Selected pressure distributions for the curved wingtip model are also presented

    Identifying Genes of Interest through Clustering and Outlier Analysis of Genomic Time Series Data

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    Using scenarios to forecast outcomes of a refugee crisis

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    The Syrian civil war has led to millions of Syrians fleeing the country, and has resulted in a humanitarian crisis. By considering how such socio-political events may unfold, scenarios can lead to informed forecasts that can be used for decision-making. We examined the relationship between scenarios and forecasts in the context of the Syrian refugee crisis. Forty Turkish students trained to use a brainstorming technique generated scenarios that might follow within six months of the Turkish government banning Syrian refugees from entering the country. Participants generated from 3-6 scenarios. Over half were rated as ‘high’ quality in terms of completeness, relevance/pertinence, plausibility, coherence, and transparency (order effects). Scenario quality was unaffected by scenario quantity. Even though no forecasts were requested, participants’ first scenarios contained from 0-17 forecasts. Mean forecast accuracy was 45% and this was unaffected by forecast quantity. Therefore, brainstorming can offer a simple and quick way of generating scenarios and forecasts that can potentially help decision-makers tackle humanitarian crises

    Lunar maria and related deposits: Preliminary Galileo imaging results

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    During the Earth-Moon flyby the Galileo Solid State Imaging system obtained new information on lunar media. Imaging data in spectral bands from 0.4 to 1.0 micron wavelength provide color data for deposits on the western limb. General objectives were to determine the composition and stratigraphy of mare and related deposits for areas not previously seen well in color, and to compare the results with well-studied nearside maria. Initial results from images reduced with preliminary calibrations show that Galileo spectral reflectance data are consistent with previous earthbased observations

    The Increasing Rotation Period of Comet 10P/Tempel 2

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    We imaged comet 10P/Tempel 2 on 32 nights from 1999 April through 2000 March. R-band lightcurves were obtained on 11 of these nights from 1999 April through 1999 June, prior to both the onset of significant coma activity and perihelion. Phasing of the data yields a double-peaked lightcurve and indicates a nucleus rotational period of 8.941 +/- 0.002 hr with a peak-to-peak amplitude of ~0.75 mag. Our data are sufficient to rule out all other possible double-peaked solutions as well as the single- and triple- peaked solutions. This rotation period agrees with one of five possible solutions found in post-perihelion data from 1994 by Mueller and Ferrin (1996, Icarus, 123, 463-477), and unambiguously eliminates their remaining four solutions. We applied our same techniques to published lightcurves from 1988 which were obtained at an equivalent orbital position and viewing geometry as in 1999. We found a rotation period of 8.932 +/- 0.001 hr in 1988, consistent with the findings of previous authors and incompatible with our 1999 solution. This reveals that Tempel 2 spun-down by ~32 s between 1988 and 1999 (two intervening perihelion passages). If the spin-down is due to a systematic torque, then the rotation period prior to perihelion during the 2010 apparition is expected to be an additional 32 s longer than in 1999.Comment: Accepted by The Astronomical Journal; 22 pages of text, 3 tables, 6 figure

    AssessingOpportunities and Barriers to Reducing the Environmental Footprint of Natural GasDevelopment in Utah’s Uintah Basin

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    Development of natural gas resources in the United States has increased dramatically over the past two decades, a boom driven by favorable prices, new technological developments, and growing interest in domestic sources of energy with a smaller carbon footprint than coal or oil. Most of the expansion in U.S. natural gas production has been from so-called ‘unconventional’ reserves in which extensive natural gas resources trapped in continuous sandstone and shale formations can now be extracted using modern directional drilling and hydraulic fracturing technologies. The Uintah Basin in northeastern Utah has been one of several areas in the U.S. where major tight sands and shale gas plays have been the focus of recent natural gas exploration and development

    Resilience: Protective Factors for Depression and Post Traumatic Stress Disorder among African American Women?

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    There is a great need to carefully examine issues that may elevate one’s risk for mental illness and develop strategies to mitigate risk and cultivate resilience.  African Americans, specifically African American women (AAW), are disproportionately affected by mental illness, including depression and post-traumatic stress disorder (PTSD).  Higher rates of PTSD among AAW may be explained by significant rates of trauma exposure.  Higher resiliency in individuals with mental illnesses is associated with better treatment response/outcomes.  An examination of two (2) promising psycho-educational curricula for AAW at risk for depression and PTSD supports consideration of resilience as a protective factor among this population.  Strengthening psychological resilience among diverse AAW at risk for depression and/or PTSD may serve as a protective factor for symptom severity.  Multidimensional prevention and intervention strategies should incorporate culturally-centered, gender-specific, and strengths-based (resilience) models of care to help encourage mental health help-seeking and promotion of wellness for AAW

    Book Reviews

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    Book Reviews ================ Equal Employment Policy for Women: Strategies for Implementation in the United States, Canada, and Western Europe Ronnie Steinberg Ratner, ed. Philadelphia, Pennsylvania: Temple University Press. Pp. xxii, 520 Reviewed by Robert Belton ------------------------------------- The Host State of Transnational Corporations Juha Kuusi England: Saxon House. 1978. Pp. 117. 25.25ReviewedbyDr.NasrollahS.Fatemi−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−TheEnclosureofOceanResources:EconomicsandtheLawoftheSeaRossD.EckertStanford:HooverInstitution.1979.Pp.xvi,390.25.25 Reviewed by Dr. Nasrollah S. Fatemi ---------------------------------- The Enclosure of Ocean Resources: Economics and the Law of the Sea Ross D. Eckert Stanford: Hoover Institution. 1979.Pp. xvi, 390. 16.95 Reviewed by Ann L. Hollic

    Spitzer Space Telescope Observations of the Nucleus of Comet 103P/Hartley 2

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    We have used the Spitzer Space Telescope InfraRed Spectrograph (IRS) 22-μm peakup array to observe thermal emission from the nucleus and trail of comet 103P/Hartley 2, the target of NASA’s Deep Impact Extended Investigation (DIXI). The comet was observed on UT 2008 August 12 and 13, while 5.5 AU from the Sun. We obtained two 200 frame sets of photometric imaging over a 2.7 hr period. To within the errors of the measurement, we find no detection of any temporal variation between the two images. The comet showed extended emission beyond a point source in the form of a faint trail directed along the comet’s antivelocity vector. After modeling and removing the trail emission, a NEATM model for the nuclear emission with beaming parameter of 0.95 ± 0.20 indicates a small effective radius for the nucleus of 0.57 ± 0.08 km and low geometric albedo 0.028 ± 0.009 (1σ). With this nucleus size and a water production rate of 3 × 10^(28) molecules s^(-1) at perihelion, we estimate that ~100% of the surface area is actively emitting volatile material at perihelion. Reports of emission activity out to ~5 AU support our finding of a highly active nuclear surface. Compared to Deep Impact’s first target, comet 9P/Tempel 1, Hartley 2’s nucleus is one-fifth as wide (and about one-hundredth the mass) while producing a similar amount of outgassing at perihelion with about 13 times the active surface fraction. Unlike Tempel 1, comet Hartley 2 should be highly susceptible to jet driven spin-up torques, and so could be rotating at a much higher frequency. Since the amplitude of nongravitational forces are surprisingly similar for both comets, close to the ensemble average for ecliptic comets, we conclude that comet Hartley 2 must have a much more isotropic pattern of time-averaged outgassing from its nuclear surface. Barring a catastrophic breakup or major fragmentation event, the comet should be able to survive up to another 100 apparitions (~700 yr) at its current rate of mass loss
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