965 research outputs found

    On the calculation of three dimensional laminar boundary layer flows

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    An approximation which reduces the computation of three dimensional, laminar, compressible, boundary layer equations to the problem of solving two dimensional type boundary layer equations is presented. A comparison of this method with a fully three dimensional boundary layer calculation is provided

    Finite difference solution to the three-dimensional, incompressible thermal energy boundary-layer equation

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    An implicit numerical method has been adopted for the solution to the three-dimensional, energy boundary-layer equation. The energy equation is written in terms of a dimensionless temperature function, the relative stagnation-enthalpy difference, and transformed by the introduction of a Blasius-type transformation of coordinates as well as dimensionless stream functions. The method is applied to the problem consisting of an infinite cylinder joined with its axis perpendicular to a thin, flat, heated plate. A Prandtl number equal to one is simply considered

    Apollo experience report: Real-time display system

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    The real time display system used in the Apollo Program is described; the systematic organization of the system, which resulted from hardware/software trade-offs and the establishment of system criteria, is emphasized. Each basic requirement of the real time display system was met by a separate subsystem. The computer input multiplexer subsystem, the plotting display subsystem, the digital display subsystem, and the digital television subsystem are described. Also described are the automated display design and the generation of precision photographic reference slides required for the three display subsystems

    Youth opinions matter: retaining human capital in Coos County

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    As Coos County youth age, their attachment to their communities may deteriorate. This brief presents new data from the Coos Youth Study. This research indicates efforts to keep young people in Coos may benefit from efforts to show students that their views matter to adults in their communities

    Plio-Quaternary exhumation history of the central Nepalese Himalaya: 1. Apatite and zircon fission track and apatite [U-Th]/He analyses

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    New apatite and zircon fission track and (U-Th)/He analyses serve to document the bedrock cooling history of the central Nepalese Himalaya near the Annapurna Range. We have obtained 82 apatite fission track (AFT), 7 zircon fission track (ZFT), and 7 apatite (U-Th)/He (AHe) ages from samples collected along the Marsyandi drainage, including eight vertical relief profiles from ridges on either side of the river averaging more than 2 km in elevation range. In addition, three profiles were sampled along ridge crests that also lie ∼2 km above the adjacent valleys, and a transect of >20 valley bottom samples spans from the Lesser Himalaya across the Greater Himalaya and into the Tethyan strata. As a consequence, these data provide one of the more comprehensive low-temperature thermochronologic studies within the Himalaya. Conversely, the youthfulness of this orogen is pushing the limits of these dating techniques. AFT ages range from >3.8 to 0 Ma, ZFT ages from 1.9 to 0.8 Ma, and AHe ages from 0.9 to 0.3 Ma. Most ridges have maximum ages of 1.3–0.8 Ma at 2 km above the valley bottom. Only one ridge crest (in the south central zone of the field area) yielded significantly older ZFT and AFT ages of ∼2 Ma; we infer that a splay of the Main Central Thrust separates this ridge from the rest of the Greater Himalaya. ZFT and AFT ages from a vertical transect along this ridge indicate exhumation rates of ∼1.5 km Myr−1 (r2 > 0.7) from ∼2 to 0.6–0.8 Ma, whereas AHe ages indicate a faster exhumation rate of ∼2.6 km Myr−1 (r2 = 0.9) over the last 0.8 Myr. Exhumation rates calculated for six of the remaining seven vertical profiles ranged from 1.5 to 12 km Myr−1 (all with low r2 values of <0.6) for the time period from ∼1.2 to 0.3 Ma, with no discernible patterns in south to north exhumation rates evident. The absence of a trend in exhumation rates, despite a strong spatial gradient in rainfall, argues against a correlation of long-term exhumation rates with modern patterns of rainfall. AFT ages in the Tethyan strata are, on average, older than in the Greater Himalaya and may be a response to a drier climate, slip on the South Tibetan Detachment, or a gentler dip of the underlying thrust ramp. These data are further evaluated with thermokinematic modeling in the companion paper by Whipp et al

    The Frames Behind the Games: Player's Perceptions of Prisoner's Dilemma, Chicken, Dictator, and Ultimatum Games

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    The tension between cooperative and competitive impulses is an eternal issue for every society. But how is this problem perceived by individual participants in the context of a behavioral games experiment? We first assess individual differences in players’ propensity to cooperate in a series of experimental games. We then use openended interviews with a subset of those players to investigate the various concepts (or ‘frames’) they used when thinking about self-interested and cooperative actions. More generally, we hope to raise awareness of player’s perceptions of experimental environments to inform both the design and interpretation of experiments and experimental data.Laboratory Experiment, Frames, Selfishness, Cooperation

    Current and future management of the young child with early onset wheezing

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    In this review, we discuss current thinking in relation to available guidelines for the care of preschool-aged children with recurrent wheezing, while highlighting the gaps in our knowledge and discussing changes that could occur over the next 5 years. The Asthma Predictive Index as well as allergen-specific IgE, peripheral eosinophil count and exhaled nitric oxide are perhaps underutilized sources of information that can assist in predicting progression to asthma and response to therapies. Inhaled corticosteroids and leukotriene receptor antagonists decrease impairment and exacerbation frequency in wheezing children but are not disease modifying. Macrolides may be useful during acute wheezing episodes for preventing progression to more severe symptoms. Monoclonal antibodies targeting IgE and TH2 cytokines have been successful in trials of adults and older children with asthma, but trials in younger children are needed. Establishing the phenotype and endotype of young wheezing children can be useful for prognostication of future asthma risk as well as for selection of the most appropriate treatment. Primary asthma prevention strategies are needed during the critical developmental window in early life prior to the onset of irrecoverable loss of lung function

    Caring for Lesbian, Gay, Bisexual, and Transsexual Parents and their Children

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    Estimates indicate that about 1% of all households are headed by gay and lesbian parents and that about 19.4% of these households report having children under the age of 18 years at home. There are a number of social, legal, and health care issues faced by lesbian, gay, bisexual and transgender (LGBT) families and their children. The purpose of this article is to provide information to health care professionals that can help them to better address the health care needs of LGBT families. Included are resources that nurses can use to understand the complex issues facing LGBT families
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