17,830 research outputs found

    Saturn orbiter mission study

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    A preliminary analysis of the important aspects of missions orbiting the planet Saturn is provided. Orbital missions to Saturn is given serious consideration for the 1980's, or after flybys by Pioneer 10/G and Mariner Jupiter-Saturn 1977. An attempt is made to characterize Saturn orbiters in detail so that comparisons with Jupiter missions can be made. The scientific objectives of Saturn exploration are grouped under four topics: (1) the atmosphere, (2) the magnetosphere, (3) the rings, and (4) the satellites

    Iterative methods for plasma sheath calculations: Application to spherical probe

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    The computer cost of a Poisson-Vlasov iteration procedure for the numerical solution of a steady-state collisionless plasma-sheath problem depends on: (1) the nature of the chosen iterative algorithm, (2) the position of the outer boundary of the grid, and (3) the nature of the boundary condition applied to simulate a condition at infinity (as in three-dimensional probe or satellite-wake problems). Two iterative algorithms, in conjunction with three types of boundary conditions, are analyzed theoretically and applied to the computation of current-voltage characteristics of a spherical electrostatic probe. The first algorithm was commonly used by physicists, and its computer costs depend primarily on the boundary conditions and are only slightly affected by the mesh interval. The second algorithm is not commonly used, and its costs depend primarily on the mesh interval and slightly on the boundary conditions

    Impact of disorder on the 5/2 fractional quantum Hall state

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    We compare the energy gap of the \nu=5/2 fractional quantum Hall effect state obtained in conventional high mobility modulation doped quantum well samples with those obtained in high quality GaAs transistors (heterojunction insulated gate field-effect transistors). We are able to identify the different roles that long range and short range disorders play in the 5/2 state and observe that the long range potential fluctuations are more detrimental to the strength of the 5/2 state than short-range potential disorder.Comment: PRL 106, 206806 (2011

    A Survey of Horse Training in New England

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    New England no longer has a significant horse training industry. It has many small operations with no obvious and overlapping training philosophies or practices. Show and competition programs are intense and competitive at regional, national and even international levels leading to the observation that techniques employed are equally strategic and tediously designed in order to encourage the exemplary results in the show ring. This study aimed to examine the methods, routines, and strategies that are used by top tier trainers in the New England region of the United States. This information was collected both in survey form and in interview form, to maximize collection and indications of how each particular trainer, breeder, or owner was most easily contacted. The data was then compiled, analyzed for trends, outliers, and other points of interest with the end goal of giving a basic but thorough view of the methods and strategies used by trainers of prestige in the New England area. Results of this study will hold relevance both to those interested in this luxury hobby and to economy minded individuals, as horses are still a substantial percentage of livestock in the New England area. Future studies in the New England area could target a larger group of trainers and stables, while future studies could also be performed in other regions of the United States

    Saturated hydrocarbon polymeric binder for advanced solid propellant and hybrid solid grains Quarterly report no. 2, 1 Feb. - 30 Apr. 1966

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    Synthesis and analysis of ethylene-neohexene copolymers with other non ketene-imine group free radicals for solid and hybrid grain propellant saturated hydrocarbon binder progra

    Understanding single-top-quark production and jets at hadron colliders

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    I present an analysis of fully differential single-top-quark production plus jets at next-to-leading order. I describe the effects of jet definitions, top-quark mass, and higher orders on the shapes and normalizations of the kinematic distributions, and quantify all theoretical uncertainties. I explain how to interpret next-to-leading-order jet calculations, and compare them to showering event generators. Using the program ZTOP, I show that HERWIG and PYTHIA significantly underestimate both s-channel and t-channel single-top-quark production, and propose a scheme to match the relevant samples to the next-to-leading-order predictions.Comment: 40 pgs., revtex4, 35 ps figs; added Fig. 4, 1 Ref., minor clarifications, to appear in Phys. Rev.
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