7,265 research outputs found

    Good Stuff to Read This Year

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    (Excerpt) Reading: the very word is like a bell/that tolls me back from thee to my sole self. Actually, Keats wrote Forlorn, but where I wrote Reading on the first line of this clean yellow sheet, the rest of Keats\u27 line came unbidden, and since I\u27m not by nature one to ignore the unbidden, I thought I\u27d better write it down. Now, why did it come? Well, I\u27ll go with \u27\u27words like bells -and I can think of all kinds of bells: reading\u27s a school hell-as in I\u27ve got to get the reading done or in That was a great book we read in class ; it\u27s an alarm, a wake-up call; it\u27s a telephone bell, a door bell, some guest come calling, invited or not; it\u27s a chapel bell, something holy happening, something that engages us full-length, then pulls us beyond supposition. For Keats, forlorn was a funeral bell, tolling to him; for me reading\u27s something I need to do to keep from some kinds of dying. I suspect that\u27s so for you, too

    Finite element formulation for transient heat treat problems

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    The macrothermomechanical behavior of materials subjected to rapid thermal or mechanical loading such as occurs in most heat treatments is described. The equations are developed for Lagrangian, Eulerian, and intermediary kinematic descriptions and are independent of the constitutive laws and the equation of state; they can be solved numerically for a specified material and boundary conditions. The coupled transport effects between dissipation and energy are included. The conventional linearized stability approach indicates the numerical procedure to be stable, with certain restriction on the time step size

    IUS solid rocket motor contamination prediction methods

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    A series of computer codes were developed to predict solid rocket motor produced contamination to spacecraft sensitive surfaces. Subscale and flight test data have confirmed some of the analytical results. Application of the analysis tools to a typical spacecraft has provided early identification of potential spacecraft contamination problems and provided insight into their solution; e.g., flight plan modifications, plume or outgassing shields and/or contamination covers

    Pricing-to-market in NSW rice export markets

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    The Ricegrowers’ Cooperative Limited is a single‐desk seller of NSW Japonica rice on the export market. Confidential monthly price data supplied by the Cooperative were used to examine ‘pricing‐to‐market’ in four of its major export markets. The hypothesis of a competitive market was rejected. The Cooperative has been able to vary mark‐ups over different markets and with respect to the importer’s currency in each market. The exchange rate results in particular suggest that the Cooperative has been able to exercise market power to obtain price premiums.Crop Production/Industries, International Relations/Trade,

    Residual stress in plasma sprayed ceramic turbine tip and gas path seal specimens

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    The residual stresses in a ceramic sheet material used for turbine blade tip gas path seals, were estimated. These stresses result from the plasma spraying process which leaves the surface of the sheet in tension. To determine the properties of plasma sprayed ZrO2-Y2O3 sheet material, its load deflection characteristics were measured. Estimates of the mechanical properties for sheet materials were found to differ from those reported for plasma sprayed bulk materials

    Analysis of the transient behavior of rubbing components

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    Finite element equations are developed for studying deformations and temperatures resulting from frictional heating in sliding system. The formulation is done for linear steady state motion in two dimensions. The equations include the effect of the velocity on the moving components. This gives spurious oscillations in their solutions by Galerkin finite element methods. A method called streamline upwind scheme is used to try to deal with this deficiency. The finite element program is then used to investigate the friction of heating in gas path seal

    Experimental study of bubble cavities attached to a rotating shaft in a reservoir

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    Bubble cavities formed by air entrainment and attached to a rotating shaft in an oil reservoir were studied. The cavities appear to the unaided eye as toroidal. High speed photography, however, reveals the individuality of the bubble cavities and their near solid body rotational characteristics. The cavities are distorted by the rotation effects but remain attached and tend to merge because of edge effects in the axial direction. The flow field within the reservoir is influenced by the unusual character of the two phase fluid found there; the vorticity is readily visualized. Other examples of vapor entrapment at the inlet of an eccentric rotor are also discussed. A simplified analytical method is provided, and a numerical analysis is being investigated. Vapor (void) entrainment and generation can significantly alter leakage rates and stability of seals, bearings, and dampers. Recognition of these effects in the component design systems will result only after detailed studies of the above phenomena

    The influence of weight and fat on lamb prices revisited

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    Previous research has found inconsistencies in the valuation of weight and fat characteristics of lamb carcasses between the saleyard and wholesale markets. In this paper, recent New South Wales saleyard and wholesale price data on different classes of lamb are analysed using hedonic methods to determine the relative influence of weight and fat on prices received. Fat score 2 lambs are heavily discounted relative to fat score 3 lambs, and there are significant seasonal price differentials, but there are no significant premiums or discounts for weight or other fat characteristics. These results hold for both the saleyard and wholesale markets. The implication is that the efficiency of price discovery in the Australian lamb market has improved a little in recent years in the sense that premiums and discounts are now consistent across market levels. However consumers’ stated preferences for large lean lambs are not being reflected in price incentives generated in the live lamb and lamb carcass markets.lamb, marketing, hedonic models, carcass characteristics, Demand and Price Analysis, Livestock Production/Industries, Marketing,
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