178 research outputs found

    Farmers\u27 Elevators in the Spring Wheat Area of South Dakota; Business Operations, 1921-22 to 1930-31

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    The object of the study is to find possibilities of lowering costs and improving operating practices in order that prices paid to farmers for grain might be as high as possible and elevator margins adequate for maintaining the business. Expenses; net income and economic profit, all in terms of per dollar sales or per bushel handled, are used as measures of operating effectiveness by which to analyze variations in elevator business units

    Product architecture development enabling integrated re-design of mechanical products

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    Global competition forces companies to increase their competitive advantage. The design process represents an interesting area to improve the overall business performance. There are two topics involved in improving the design process. The first one is the integration of constraints from the product life cycle in the design process. The second one is the improvement of the ability to judge the influence of a certain design decision quickly. Both topics are dealt with in this paper by describing the new concept of the Product Configuration Structure (PCS). The PCS is used to represent different product configurations with respect to functions, means, components and production methods in a structured way. The product configuration structure serves as a product information backbone in an integrated re-design tool called PROFIDT. To create a better integration of the flow-based function structure and the hierarchical component structure a new concept of connection functions is introduced

    Two-point function of strangeness-carrying vector-currents in two-loop Chiral Perturbation Theory

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    We calculate the correlator between two external vector-currents having the quantum-numbers of a charged kaon. We give the renormalized expression to two loops in standard chiral perturbation theory in the isospin limit, which, as a physical result, is finite and scale-independent. Applications include a low energy theorem, valid at two loop order, of a flavor breaking combination of vector current correlators as well as a determination of the phenomenologically relevant finite O(p6)O(p^6)-counterterm combination QVQ_V by means of inverse moment finite energy sum rules. This determination is less sensitive to isospin-breaking effects than previous attempts.Comment: 24 pages, revtex, 4 figures, 2 tables, revised version, one ref. adde

    Analysis of the vector form factors fKπ+(Q2)f^+_{K\pi}(Q^2) and fKπ(Q2)f^-_{K\pi}(Q^2) with light-cone QCD sum rules

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    In this article, we calculate the vector form factors fKπ+(Q2)f^+_{K\pi}(Q^2) and fKπ(Q2)f^-_{K\pi}(Q^2) within the framework of the light-cone QCD sum rules approach. The numerical values of the fKπ+(Q2)f^+_{K\pi}(Q^2) are compatible with the existing theoretical calculations, the central value of the fKπ+(0)f^+_{K\pi}(0), fKπ+(0)=0.97f^+_{K\pi}(0)=0.97, is in excellent agreement with the values from the chiral perturbation theory and lattice QCD. The values of the fKπ(0)|f^-_{K\pi}(0)| are very large comparing with the theoretical calculations and experimental data, and can not give any reliable predictions. At large momentum transfers with Q2>5GeV2Q^2> 5GeV^2, the form factors fKπ+(Q2)f^+_{K\pi}(Q^2) and fKπ(Q2)|f^-_{K\pi}(Q^2)| can either take up the asymptotic behavior of 1Q2\frac{1}{Q^2} or decrease more quickly than 1Q2\frac{1}{Q^2}, more experimental data are needed to select the ideal sum rules.Comment: 22 pages, 16 figures, revised version, to appear in Eur. Phys. J.

    eta-prime Meson Production in Nucleon-Nucleon Collisions Near The Threshold

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    The production of η\eta' mesons in the reactions ppppηpp\to pp\eta' and pnpnηpn\to pn\eta' at threshold-near energies is analyzed within a covariant effective meson-nucleon theory. The description of cross section and angular distributions of the available data in this kinematical region in the pppp channel is accomplished by including meson currents and nucleon currents with the resonances S11(1650)S_{11}(1650), P11(1710)P_{11}(1710) and P13(1720)P_{13}(1720). Predictions for the pnpn channel are given. The di-electron production from subsequent η\eta' Dalitz decay ηγγγe+e\eta' \to \gamma \gamma^* \to\gamma e^+e^- is also calculated and numerical results are presented for intermediate energy and kinematics of possible experiments with HADES, CLAS and KEK-PS

    THE RATE OF BINARY BLACK HOLE MERGERS INFERRED FROM ADVANCED LIGO OBSERVATIONS SURROUNDING GW150914

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    A transient gravitational-wave signal, GW150914, was identi fi ed in the twin Advanced LIGO detectors on 2015 September 2015 at 09:50:45 UTC. To asse ss the implications of this discovery, the detectors remained in operation with unchanged con fi gurations over a period of 39 days around the time of t he signal. At the detection statistic threshold corresponding to that observed for GW150914, our search of the 16 days of simultaneous two-detector observational data is estimated to have a false-alarm rate ( FAR ) of < ́ -- 4.9 10 yr 61 , yielding a p -value for GW150914 of < ́ - 210 7 . Parameter estimation follo w-up on this trigger identi fi es its source as a binary black hole ( BBH ) merger with component masses ( )( ) = - + - + mm M ,36,29 12 4 5 4 4 at redshift = - + z 0.09 0.04 0.03 ( median and 90% credible range ) . Here, we report on the constraints these observations place on the rate of BBH coalescences. Considering only GW150914, assuming that all BBHs in the universe have the same masses and spins as this event, imposing a search FAR threshold of 1 per 100 years, and assuming that the BBH merger rate is constant in the comoving frame, we infer a 90% credible range of merger rates between – -- 2 53 Gpc yr 31 ( comoving frame ) . Incorporating all search triggers that pass a much lower threshold while accounting for the uncerta inty in the astrophysical origin of each trigger, we estimate a higher rate, ranging from – -- 13 600 Gpc yr 31 depending on assumptions about the BBH mass distribution. All together, our various rate estimat es fall in the conservative range – -- 2 600 Gpc yr 31
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