10,152 research outputs found

    Water separator

    Get PDF
    An apparatus for separating liquids from gases or gaseous fluids is described. Features of the apparatus include: (1) the collection and removal of the moisture in the fluid is not dependent upon, or affected by gravity; (2) all the collected water is cyclically drained from the apparatus irrespective of the attitude of the separator; and (3) a fluid actuator is utilized to remove the collected water from the separator

    Planar Detonation Wave Initiation in Large-Aspect-Ratio Channels

    Get PDF
    In this study, two initiator designs are presented that are able to form planar detonations with low input energy in large-aspect-ratio channels over distances corresponding to only a few channel heights. The initiators use a single spark and an array of small channels to shape the detonation wave. The first design, referred to as the static initiator, is simple to construct as it consists of straight channels which connect at right angles. However, it is only able to create planar waves using mixtures that can reliably detonate in its small-width channels. An improved design, referred to as the dynamic initiator, is capable of detonating insensitive mixtures using an oxyacetylene gas slug injected into the initiator shortly before ignition, but is more complex to construct. The two versions are presented next, including an overview of their design and operation. Design drawings of each initiator are available elsewhere [7]. Finally, photographs and pressure traces of the resulting planar waves generated by each device are shown

    Vibration and stress analysis of soft-bonded shuttle insulation tiles. Modal analysis with compact widely space stringers

    Get PDF
    An efficient iterative procedure is described for the vibration and modal stress analysis of reusable surface insulation (RSI) of multi-tiled space shuttle panels. The method, which is quite general, is rapidly convergent and highly useful for this application. A user-oriented computer program based upon this procedure and titled RESIST (REusable Surface Insulation Stresses) has been prepared for the analysis of compact, widely spaced, stringer-stiffened panels. RESIST, which uses finite element methods, obtains three dimensional tile stresses in the isolator, arrestor (if any) and RSI materials. Two dimensional stresses are obtained in the tile coating and the stringer-stiffened primary structure plate. A special feature of the program is that all the usual detailed finite element grid data is generated internally from a minimum of input data. The program can accommodate tile idealizations with up to 850 nodes (2550 degrees-of-freedom) and primary structure idealizations with a maximum of 10,000 degrees-of-freedom. The primary structure vibration capability is achieved through the development of a new rapid eigenvalue program named ALARM (Automatic LArge Reduction of Matrices to tridiagonal form)

    Thermal stress analysis of reusable surface insulation for shuttle

    Get PDF
    An iterative procedure for accurately determining tile stresses associated with static mechanical and thermally induced internal loads is presented. The necessary conditions for convergence of the method are derived. An user-oriented computer program based upon the present method of analysis was developed. The program is capable of analyzing multi-tiled panels and determining the associated stresses. Typical numerical results from this computer program are presented

    Kant, Morality, and Hell

    Get PDF
    In this paper I argue that, although Kant argues that morality is independent of God (and hence, agrees with the Euthyphro), and rejects Divine Command Theory (or Theological Voluntarism), he believes that all moral duties are also the commands of God, who is a moral being, and who is morally required to punish those who transgress the moral law: "God’s justice is the precise allocation of punishments and rewards in accordance with men’s good or bad behavior." However, since we lack a strict proof of God's existence, we can still fulfill our duties from the motive of duty. if we did know that God exists, then this would undermine our pure moral motivation to do our duty, since we would have an even stronger interest in pleasing God through our good conduct. The effect of undermining our pure moral motivation would be to make us less eligible for divine reward, since God rewards us for doing our duty from the motive of duty

    Population change and fiscal stress in Missouri's third class counties

    Get PDF
    "During the recent recession, local governments struggled to manage budgets as revenues dropped. Because the recession was deeper and longer than any in the past half-century, with a slower recovery, reserve funds were not sufficient. With lower revenue, the majority of local governments struggled to meet the needs and expectations of citizens. Since the Great Recession of 2008-2009, the budgets of local governments have not recovered at the same pace as the economy as a whole. The recession may have created greater demands for government services, and tax bases may have been affected by more cautious spending by businesses and consumers. Slow local budget recovery also may be due to state government decisions, such as changes in tax laws, stagnant or lower state aid, taxation constraints and increasing state mandated services (Aldag et al., 2017). An example of a state tax constraint is Missouri's Hancock Amendment, which limits both state and local governments' abilities to raise taxes. Elected local officials cannot raise taxes without voter approval (Kevin-Myers and Hembree, 2012). Finally, local governments' decisions on taxes and tax incentives have major impacts on their own revenues (White, 2017)."--Page 1.Written by Judith I. Stallman (Professor Emeritus, Agricultural and Applied Economics and Public Affairs), Austin Sanders (Master's student in Agricultural and Applied Economics)New 10/19Includes bibliographical reference

    Security, uncertainty, and urban futures: a conversation with Austin Zeiderman

    Get PDF
    How has the opposition between “civilized” urbanity and “barbaric” rurality conditioned future imaginaries in Latin America? What are the historical links between urbanization and attempts to establish social and spatial order during colonization, after independence, and in other political conjunctures? In the following conversation, anthropologist Austin Zeiderman reviews historical perspectives on Latin American cities with a focus on the future. With an interest in the genealogy of urban imaginaries, he sheds light on contemporary preoccupations with future uncertainty and the specific role that security plays therein. Ever since the conquistadors set foot on the continent, he argues, the future has exerted affective power via hopes, threats, and visions of both utopian and dystopian possibilities

    Semi-analytical dark matter halos and the Jeans equation

    Full text link
    Although N-body studies of dark matter halos show that the density profiles, rho(r), are not simple power-laws, the quantity rho/sigma^3, where sigma(r) is the velocity dispersion, is in fact a featureless power-law over ~3 decades in radius. In the first part of the paper we demonstrate, using the semi-analytic Extended Secondary Infall Model (ESIM), that the nearly scale-free nature of rho/sigma^3 is a robust feature of virialized halos in equilibrium. By examining the processes in common between numerical N-body and semi-analytic approaches, we argue that the scale-free nature of rho/sigma^3 cannot be the result of hierarchical merging, rather it must be an outcome of violent relaxation. The empirical results of the first part of the paper motivate the analytical work of the second part of the paper, where we use rho/sigma^3 proportional to r^{-alpha} as an additional constraint in the isotropic Jeans equation of hydrostatic equilibrium. Our analysis shows that the constrained Jeans equation has different types of solutions, and in particular, it admits a unique ``periodic'' solution with alpha=1.9444. We derive the analytic expression for this density profile, which asymptotes to inner and outer profiles of rho ~ r^{-0.78}, and rho ~ r^{-3.44}, respectively.Comment: 37 pg, 14 fig. Accepted to ApJ: added two figures and extended discussion. Note that an earlier related paper (conference proceedings) astro-ph/0412442 has a mistake in eq.(2.2); the correct version is eq.(5) of the present submissio

    Spacecraft applications of advanced global positioning system technology

    Get PDF
    The purpose of this study was to evaluate potential uses of Global Positioning System (GPS) in spacecraft applications in the following areas: attitude control and tracking; structural control; traffic control; and time base definition (synchronization). Each of these functions are addressed. Also addressed are the hardware related issues concerning the application of GPS technology and comparisons are provided with alternative instrumentation methods for specific functions required for an advanced low earth orbit spacecraft

    Shielding against design flaws with field repairable control logic

    Get PDF
    • 

    corecore