33,103 research outputs found

    Fluid injection device for high-pressure systems

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    Screw activated device, consisting of a compressor, shielded replaceable ampules, a multiple-element rubber gland, and a specially constructed fluid line fitting, injects measured amounts of fluids into a pressurized system. It is sturdy and easily manipulated

    Relationships among Prices across Alternative Marketing Arrangements for Fed Cattle and Hogs

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    Reduced reliance on cash market prices for fed cattle and hogs raise questions about the role of cash prices in price discovery. We use seven years of weekly data from mandatory price reports to determine whether or not cash market prices are cointegrated with other procurement prices and then test for causality among the price series. Cash prices were cointegrated with all but one procurement price series. Cash market prices Granger cause all other procurement prices. Bidirectional causality was found in some but not all cases. Thus, cash market prices remain of central importance in price discovery for fed cattle and hogs.cattle, cointegration, causality, hogs, Johansen, marketing, prices, Stock-Watson, vector error correction, Livestock Production/Industries, Marketing, Q13(of Q18),

    Calculating photonic Green's functions using a non-orthogonal finite difference time domain method

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    In this paper we shall propose a simple scheme for calculating Green's functions for photons propagating in complex structured dielectrics or other photonic systems. The method is based on an extension of the finite difference time domain (FDTD) method, originally proposed by Yee, also known as the Order-N method, which has recently become a popular way of calculating photonic band structures. We give a new, transparent derivation of the Order-N method which, in turn, enables us to give a simple yet rigorous derivation of the criterion for numerical stability as well as statements of charge and energy conservation which are exact even on the discrete lattice. We implement this using a general, non-orthogonal co-ordinate system without incurring the computational overheads normally associated with non-orthogonal FDTD. We present results for local densities of states calculated using this method for a number of systems. Firstly, we consider a simple one dimensional dielectric multilayer, identifying the suppression in the state density caused by the photonic band gap and then observing the effect of introducing a defect layer into the periodic structure. Secondly, we tackle a more realistic example by treating a defect in a crystal of dielectric spheres on a diamond lattice. This could have application to the design of super-efficient laser devices utilising defects in photonic crystals as laser cavities.Comment: RevTex file. 10 pages with 8 postscript figures. Submitted to Phys Rev

    SUCCESS FACTORS FOR VALUE ADDED NEW GENERATION COOPERATIVES

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    Two surveys of New Generation Cooperative (NGC) managers were carried out to ascertain the factors most important to their success. Factors in the Planning and Development as well as the Financing and Cost categories were most important, and NGCs with more employees and more members' equity are most successful.Agribusiness,

    Success Factors for New Generation Cooperatives

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    The goal of this research was to determine success factors for New Generation Cooperatives (NGCs). A self-explicated approach was used to assess the importance of various factors grouped in broad categories using data collected from a mailout survey of NGC managers. Results suggest that factors in the "Planning and Development" and "Financing and Costs" categories are considered to be critically important by NGC managers, though differences in factor rankings exist between managers of enterprises involved in the processing of different commodities.New Generation Cooperative, self-explication, Agribusiness,

    Quantum Corrections to Newton's Law

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    We present a new approach to quantum gravity starting from Feynman's formulation for the simplest example, that of a scalar field as the representative matter. We show that we extend his treatment to a calculable framework using resummation techniques already well-tested in other problems. Phenomenological consequences for Newton's law are described.Comment: 7 pages, 1 figure; improved fig., refs;improved discussion;more discussion; proo

    Observations of the 51.8 micron (O III) emission line in Orion

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    The 51.8 micron fine structure transition P2:3P2 3P1 for doubly ionized oxygen was observed in the Orion nebula. The observed line strength is of 5 plus or minus 3 times 10 to the minus 15th power watt/sq cm is in good agreement with theoretical predictions. Observations are consistent with the newly predicted 51.8 micron line position. The line lies close to an atmospheric water vapor feature at 51.7 micron, but is sufficiently distant so that corrections for this feature are straightforward. Observations of the 51.8 (O III) line are particularly important since the previously discovered 88 micron line from the same ion also is strong. This pair of lines should, therefore, yield new data about densities in observed H II regions; or else, if density data already are available from radio or other observations, the lines can be used to determine the differential dust absorption between 52 and 88 micron in front of heavily obscured regions

    Optical Lenses for Atomic Beams

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    Superpositions of paraxial laser beam modes to generate atom-optical lenses based on the optical dipole force are investigated theoretically. Thin, wide, parabolic, cylindrical and circular atom lenses with numerical apertures much greater than those reported in the literature to date can be synthesized. This superposition approach promises to make high quality atom beam imaging and nano-deposition feasible.Comment: 10 figure
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