4,268 research outputs found

    Analytic slowing-down distributions as modified by turbulent transport

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    The effect of electrostatic microturbulence on fast particles rapidly decreases at high energy, but can be significant at moderate energy. Previous studies found that, in addition to changes in the energetic particle density, this results in nontrivial changes to the equilibrium velocity distribution. These effects have implications for plasma heating and the stability of Alfv\'en eigenmodes, but make multiscale simulations much more difficult without further approximations. Here, several related analytic model distribution functions are derived from first principles with reasonable approximations. A single dimensionless parameter characterizes the relative strength of turbulence relative to collisions, and this parameter appears as an exponent in the model distribution functions. Even the most simple of these models reproduces key features of the numerical phase-space transport solution and provides a useful a priori heuristic for determining how strong the effect of turbulence is on the redistribution of energetic particles in toroidal plasmas.Comment: 13 pages; 6 figure

    Mercerization of Cotton for Strength with Special Reference to Aircraft Cloth

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    The object of the present investigation was to determine the conditions for mercerizing cotton yarn to obtain the maximum strength for a given weight. Apparatus for controlling the variables was built and yarns were mercerized with it under systematically varied conditions of tension, time, temperature, and concentration of caustic soda. The strongest conclusion to be drawn from this work is that the strongest mercerized yarn of a given count from a given quality of cotton is obtained under the following conditions: 1. use of low-twist yarn obtained with twist multipliers from 2.2 to 3; 2. thorough pretreatment of the yarn to remove all extraneous materials; 3. mercerization at a temperature of 0 C or lower; 4. use of sufficient tension during mercerization to prevent the yarn from contracting more than 3 percent. 5. Use of caustic solution having a concentration of 10 percent or higher; 6. the time of mercerization to be 5 minutes. The resulting yarn should be 40 to 100 percent stronger than the original yarn of the same weight

    Asymptomatic Hypertrophic Cardiomyopathy: Diagnosis and Therapy

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    Locally Polynomially Bounded Structures

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    We prove a theorem which provides a method for constructing points on varieties defined by certain smooth functions. We require that the functions are definable in a definably complete expansion of a real closed field and are locally definable in a fixed o-minimal and polynomially bounded reduct. As an application we show that in certain o-minimal structures definable functions are piecewise implicitly defined over the basic functions in the language.Comment: Change of titl

    Sequencing Lifeline Repairs After an Earthquake: An Economic Approach

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    Recoveries after recent earthquakes in the U.S. and Japan have shown that large welfare gains can be achieved by reshaping current emergency plans as incentive-compatible contracts. We apply tools from the mechanisms design literature to show ways to integrate economic incentives into the management of natural disasters and discuss issues related to the application to seismic event recovery. The focus is on restoring lifeline services such as the water, gas, transportation, and electric power networks. We put forward decisional procedures that an uninformed planner could employ to set repair priorities and help to coordinate lifeline firms in the post-earthquake reconstruction.utilities, inter-temporal decisions, natural disasters, mechanism design, network externalities

    Exact norm-conserving stochastic time-dependent Hartree-Fock

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    We derive an exact single-body decomposition of the time-dependent Schroedinger equation for N pairwise-interacting fermions. Each fermion obeys a stochastic time-dependent norm-preserving wave equation. As a first test of the method we calculate the low energy spectrum of Helium. An extension of the method to bosons is outlined.Comment: 21 pages, 3 figures, LaTeX fil

    A Strategy for the Design of Flame Retardants: Cross-linking Processes

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    Cross-linking is identified as an effective means for flame retardation of polymers and schemes for the cross-linking of poly(ethylene terephthalate) and poly(methyl methacrylate) are presented. For poly(ethylene terephthalate) the scheme involves polymerization of the initially produced vinyl ester. This is followed by chain-stripping, producing a polyene, and cyclization of this polyene. For poly(methyl methacrylate) the scheme entails the formation of anhydride linkages between adjacent polymer strands. Evidence is presented to show the efficacy of these processes and information is produced to aid in the identification of new flame retardants

    Implementation of Arbitration Decisions in Domestic Law

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    Arbitration, even if it seems simply providing for the possibility of arbitration, is increasingly attracting attention as a possible means to discipline the resolution of otherwise potentially intractable international tax controversies concerning the allocation of taxing rights under tax treaties.While perceived, though not without reservation, to be a potential welcome addition to a typical mutual agreement procedure (MAP) patterned on article 25 (“the MAP article”) of the OECD Model Tax Convention on Income and Capital(“the OECD Model”) in the form of article 25(5), other provisions of article 25, notably its “interpretive” and “application,”and “legislative”,aspects and contemplated recourse to a “joint commission”reflect a long-standing awareness, even possibly a latent expectation, that objective interveners and alternative or supplementary means or other extensions of the MAP beyond the typical limits of a “specific case”may help the MAP to achieve its full potential. In fact, one author, in a thoughtful and wide-ranging analysis of arbitration in the tax context, has essentially presumed its usefulness but, in a fashion to which these comments are sensitive, has referred to “mandatory arbitration” as “a solution in search of a problem”. These comments express a point of view as a contribution to the discussions framed by this book. They proceed on the assumption, for the most part, that an otherwise legally effective arbitration decision can be reached and that what remains is to give it fair effect in relation to states’ assessments of taxpayers under their laws. No assumptions are made about the specific features or peculiarities of particular states’ laws. Ultimately, of course these matter
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