434 research outputs found

    Joining the Team: A Case Study Identifying and Assessing Critical Factors Influencing NCAA Division III Student-Athlete Matriculation

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    This research sought to understand what factors influence how first-year student-athletes at a National Collegiate Athletic Association (NCAA) Division III institution chose the school to attend in light of the heuristic perspective of bounded rationality, which posits that decision makers are rational in some but not all elements of the decision-making process. Data were assessed for the entire respondent group as well as subgroups based on gender and by amount of non-loan financial aid received by using the principal component analysis and the Mann-Whitney U test. The analysis showed athletic variables such as conference affiliation, quality of opponents, recruiting materials, and quality of the athletic website were important determining factors for the entire population group. This research provides the basis for a model for coaches to use to contact and encourage desired prospects to apply and matriculate

    Experimental aerodynamic characteristics of a generic hypersonic accelerator configuration at Mach numbers 1.5 and 2.0

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    An experimental investigation of the static longitudinal and lateral-directional aerodynamic characteristics of a generic hypersonic research vehicle was conducted in the Langley Unitary Plan Wind Tunnel (UPWT). A parametric study was performed to determine the interference effects of various model components. Configuration variables included delta and trapezoidal canards; large and small centerline-mounted vertical tails, along with a set of wing-mounted vertical tails; and a set of model noses with different degrees of bluntness. Wing position was varied by changing the longitudinal location and the incidence angle. The test Mach numbers were 1.5 and 2.0 at Reynolds numbers of 1 x 10(exp 6) per foot, 2 x 10(exp 6) per foot, and 4 x 10(exp 6) per foot. Angle of attack was varied from -4 degrees to 27 degrees, and sideslip angle was varied from -8 degrees to 8 degrees. Generally, the effect of Reynolds number did not deviate from conventional trends. The longitudinal stability and lift-curve slope decreased with increasing Mach number. As the wing was shifted rearward, the lift-curve slope decreased and the longitudinal stability increased. Also, the wing-mounted vertical tails resulted in a more longitudinally stable configuration. In general, the lift-drag ratio was not significantly affected by vertical-tail arrangement. The best lateral-directional stability was achieved with the large centerline-mounted tail, although the wing-mounted vertical tails exhibited the most favorable characteristics at the higher angles of attack

    Air entrapment and residual stresses in rolls wound with a rider roll

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    Air is entrained during the process of winding webs. Rider rolls are often employed in an effort to reduce the amount of air which enters the wound roll. This paper presents the results of an experiment which allows the entrained air to be measured. With knowledge of the levels of entrapped air an algorithm was chosen to predict the amount of entrained air for various operating conditions. Finally the air entrapment algorithm was incorporated into a wound roll model such that the effect of the entrained air on the residual pressures within the wound roll could be studied.Mechanical and Aerospace Engineerin

    Simulation and Analyses of Stage Separation of Two-Stage Reusable Launch Vehicles

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    NASA has initiated the development of methodologies, techniques and tools needed for analysis and simulation of stage separation of next generation reusable launch vehicles. As a part of this activity, ConSep simulation tool is being developed which is a MATLAB-based front-and-back-end to the commercially available ADAMS(Registerd TradeMark) solver, an industry standard package for solving multi-body dynamic problems. This paper discusses the application of ConSep to the simulation and analysis of staging maneuvers of two-stage-to-orbit (TSTO) Bimese reusable launch vehicles, one staging at Mach 3 and the other at Mach 6. The proximity and isolated aerodynamic database were assembled using the data from wind tunnel tests conducted at NASA Langley Research Center. The effects of parametric variations in mass, inertia, flight path angle, altitude from their nominal values at staging were evaluated. Monte Carlo runs were performed for Mach 3 staging to evaluate the sensitivity to uncertainties in aerodynamic coefficients

    Continuity and change - The planning and management of long distance walking routes in Scotland

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    In recent years a number of changes have taken place in Scotland in respect of issues of land management, access and the natural environment. These include the creation of Scotland’s first National Parks in 2002 and the introduction of the Land Reform (Scotland) Act 2003, which has enshrined in legislation the principle of responsible access in the countryside. The aim of this study was to consider the implications of these changes for a specific type of recreational land use in Scotland, Long Distance (Walking) Routes (LDRs). Using semi-structured interviews with representatives of a number of agencies and with other individuals closely involved with LDRs, the research considered the extent to which these changes have or may alter the rationale for the provision of LDRs, their funding and their management. The research indicates a need and a willingness to build on existing stakeholder approaches to management with a view to engaging a broader range of communities of interest. The main challenge for those involved with LDRs is how to fund future development of these routes. One aim of a more participatory stakeholder management approach is to help route managers to use public funds to lever funds from other source

    Role of Secondary Motifs in Fast Folding Polymers: A Dynamical Variational Principle

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    A fascinating and open question challenging biochemistry, physics and even geometry is the presence of highly regular motifs such as alpha-helices in the folded state of biopolymers and proteins. Stimulating explanations ranging from chemical propensity to simple geometrical reasoning have been invoked to rationalize the existence of such secondary structures. We formulate a dynamical variational principle for selection in conformation space based on the requirement that the backbone of the native state of biologically viable polymers be rapidly accessible from the denatured state. The variational principle is shown to result in the emergence of helical order in compact structures.Comment: 4 pages, RevTex, 4 eps figure

    Protein structures and optimal folding emerging from a geometrical variational principle

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    Novel numerical techniques, validated by an analysis of barnase and chymotrypsin inhibitor, are used to elucidate the paramount role played by the geometry of the protein backbone in steering the folding to the correct native state. It is found that, irrespective of the sequence, the native state of a protein has exceedingly large number of conformations with a given amount of structural overlap compared to other compact artificial backbones; moreover the conformational entropies of unrelated proteins of the same length are nearly equal at any given stage of folding. These results are suggestive of an extremality principle underlying protein evolution, which, in turn, is shown to be associated with the emergence of secondary structures.Comment: Revtex, 5 pages, 5 postscript figure

    The potential determinants of young people's sense of justice: an international study

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    This paper uses reports from 13,000 Grade Nine pupils in five countries to examine issues such as whether they were treated fairly at school, trust their teachers and adults in wider society, are willing to sacrifice teacher attention to help others, and support the cultural integration of recent immigrants. Using such reports as ‘outcomes’ in a multi‐stage regression model, it is clear that they are largely unrelated to school‐level pupil mix variables. To some extent, these outcomes are stratified by pupil and family background in the same way for all countries. However, the largest association is with pupil‐reported experience of interactions with their teachers. Teachers appear to be a major influence on young people's sense of justice and the principles they apply in deciding whether something is fair. The paper concludes by suggesting ways in which schools and teachers could take advantage of this finding
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