4,973 research outputs found

    A comparative study of the nonuniqueness problem of the potential equation

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    The nonuniqueness problem occurring at transonic speeds with the conservative potential equation is investigated numerically. The study indicates that the problem is not an inviscid phenomenon, but results from approximate treatment of shock waves inherent in the conservative potential model. A new bound on the limit of validity of the conservative potential model is proposed

    Alien Registration- Jameson, Gertrude E. (Brewer, Penobscot County)

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    https://digitalmaine.com/alien_docs/10850/thumbnail.jp

    An improved viscid/inviscid interaction procedure for transonic flow over airfoils

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    A new interacting boundary layer approach for computing the viscous transonic flow over airfoils is described. The theory includes a complete treatment of viscous interaction effects induced by the wake and accounts for normal pressure gradient effects across the boundary layer near trailing edges. The method is based on systematic expansions of the full Reynolds equation of turbulent flow in the limit of Reynolds numbers, Reynolds infinity. Procedures are developed for incorporating the local trailing edge solution into the numerical solution of the coupled full potential and integral boundary layer equations. Although the theory is strictly applicable to airfoils with cusped or nearly cusped trailing edges and to turbulent boundary layers that remain fully attached to the airfoil surface, the method was successfully applied to more general airfoils and to flows with small separation zones. Comparisons of theoretical solutions with wind tunnel data indicate the present method can accurately predict the section characteristics of airfoils including the absolute levels of drag

    Design, development and evaluation of Stanford/Ames Extra-Vehicular Activity (EVA) prehensors

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    A summary is given of progress to date on work proposed in 1983 and continued in 1985, including design iterations on three different types of manually powered prehensors, construction of functional mockups of each and culminating in detailed drawings and specifications for suit-compatible sealed units for testing under realistic conditions

    Impact of Shape Parameterisation on Aerodynamic Optimisation of Benchmark Problem

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    Putting into Question the Imaginary of Recovery: A Dialectical Reading of the Global Financial Crisis and its Aftermath

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    In this article we put into question the discourses that emerged during the Global Financial Crisis (GFC) and that coalesced around a particular socio-economic imaginary of ?recovery? over the period 2009-2012. Our reading of these discourses is very much guided by the notion of the dialectic as developed by Fredric Jameson, and as such this paper can be read as attempt to put his theoretical ideas to work. Through our dialectical reading we aim to create a certain estrangement effect that makes the imaginary of recovery seem very odd and unnatural. In order to achieve such an effect we postulate four theses which are deliberately antagonistic: first, that there has been no ?crisis of capitalism?; second, that we must change the valence of the GFC from negative to positive; third, that the relationship between finance capitalism and ?free markets? is deeply contradictory; and fourth, that we must resist the regulation discourse

    Spatial knowledge management and participatory governance: rethinking the trajectories of urban, socio-economic and environmental change and the politics of 'sustainability' in southern cities

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    This paper presents the analytical framework developed iteratively by the research team of the Chance2Sustain (C2S) research project between 2010 and July 2014, in order to answer the main research question which was posed at the outset of the research, namely : how can spatial knowledge management (SKM) and participatory governance contribute to sustainable urban development ? To answer this question, the C2S project was designed to undertake comparative empirical research in 10 cities in four fast-growing countries of the South to understand the role of SKM and participatory processes in facing the challenges in a number of strategic domains of urban development ; those of economic growth, social inequality and vulnerability, and environmental governance. In each city, there were researchers from both the North and South working together in the five domains of economic growth through megaprojects ; social mobilisation and social exclusion in sub-standard settlements ; environmental governance with the focus on water-related issues ; spatial knowledge management; and fiscal decentralisation and participatory city budgeting

    Borda Meets Pascal

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    Every so often (especially in mathematics), unforeseen connections between different ideas arise and beg explanation. This happened to us when, in an effort to generalize the voting procedure known as the Borda count, we began to see vectors of the form (-1, 1), (1, -2, 1), (-1, 3, -3, 1), (1, -4, 6, -4, 1), and so on. As you might imagine, we were instantly intrigued by this unanticipated relationship with Pascal\u27s triangle, and we quickly set out to find an explanation. This article describes some of our initial findings

    Brown Dwarfs in the Pleiades Cluster. III. A deep IZ survey

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    We present the results of a deep CCD-based IZ photometric survey of a ~1 sq. deg area in the central region of the Pleiades Galactic open cluster. The magnitude coverage of our survey (from I~17.5 down to 22) allows us to detect substellar candidates with masses between 0.075 and 0.03 Msol. Details of the photometric reduction and selection criteria are given. Finder charts prepared from the I-band images are provided.Comment: 11 pages with 8 figures, 4 of them are finder charts given in gif format. Accepted for publication in A&AS. Also available at http://www.iac.es/publicaciones/preprints.htm
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