11,983 research outputs found

    Special Propeller Protractor

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    A special protractor was designed and built with a view towards supplying a simple, inexpensive, practical, portable instrument for making measurements to detect propeller warpage under practically all conditions, without the use of auxiliary equipment, and without having to remove the propeller from the airplane. A detailed description is given of the protractor. Techniques for measuring are described. Directions are given on how to use the protractor to set detachable blade-type propellers on an airplane

    Polynominals related to powers of the Dedekind eta function

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    The vanishing properties of Fourier coefficients of integral powers of the Dedekind eta function correspond to the existence of integral roots of integer-valued polynomials Pn(x) introduced by M. Newman. In this paper we study the derivatives of these polynomials. We obtain non-vanishing results at integral points. As an application we prove that integral roots are simple if the index n of the polynomial is equal to a prime power pm or to pm + 1. We obtain a formula for the derivative of Pn(x) involving the polynomials of lower degree

    Recursive formulation of Madelung continuity equation leads to propagation equation

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    We apply a recursive approach to the continuity equation of the Madelung fluid resulting in a propagation equation for particle probability densities. This propagation equation can be used to propagate particle distributions in the presence of a Madelung pressure field. We show that the derived propagation equation goes over into the guidance equation of the de Broglie-Bohm theory in the limit of well located single particles. As an example, we propagate particles that enter the lower slit of a double-slit experiment, while the Madelung fluid enters both slits.Comment: Article replaced because: Reformulated from a mathematical point of vie

    NNLL resummation for s-channel single top quark production

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    I present the next-to-next-to-leading-logarithm (NNLL) resummation of soft and collinear gluon corrections to single top quark production in the s channel. Attaining NNLL accuracy involves the calculation of the two-loop soft anomalous dimension for the partonic subprocesses. Finite-order expansions of the resummed cross section are calculated through next-to-next-to-leading order (NNLO). Numerical results are presented for s-channel single top quark production at the Tevatron and the LHC, including the dependence of the cross sections on the top quark mass and the uncertainties in the theoretical prediction. The higher-order corrections are significant for energies at both colliders and they decrease the theoretical uncertainty.Comment: 17 pages, 12 figures; added figures and discussio

    Importing Corruption Culture from Overseas: Evidence from Corporate Tax Evasion in the United States

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    This paper studies how cultural norms and enforcement policies influence illicit corporate activities. Using confidential IRS audit data, we show that corporations with owners from countries with higher corruption norms engage in higher amounts of tax evasion in the U.S. This effect is strong for small corporations and decreases as the size of the corporation increases. In the mid-2000s, the United States implemented several enforcement measures which significantly increased tax compliance. However, we find that these enforcement efforts were less effective in reducing tax evasion by corporations whose owners are from countries with higher corruption norms. This suggests that cultural norms can be a challenge to legal enforcement.

    Ferromagnetic planar Josephson junction with transparent interfaces: a {\phi} junction proposal

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    We calculate the current phase relation of a planar Josephson junction with a ferromagnetic weak link located on top of a thin normal metal film. Following experimental observations we assume transparent superconductor-ferromagnet interfaces. This provides the best interlayer coupling and a low suppression of the superconducting correlations penetrating from the superconducting electrodes into the ferromagnetic layer. We show that this Josephson junction is a promising candidate for an experimental {\phi} junction realization.Comment: References update

    Molecular Dynamics Simulations of Detonation Instability

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    After making modifications to the Reactive Empirical Bond Order potential for Molecular Dynamics (MD) of Brenner et al. in order to make the model behave in a more conventional manner, we discover that the new model exhibits detonation instability, a first for MD. The instability is analyzed in terms of the accepted theory.Comment: 7 pages, 6 figures. Submitted to Phys. Rev. E Minor edits. Removed parenthetical statement about P^\nu from conclusion
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