51,794 research outputs found

    Derivation of transformation formulas between geocentric and geodetic coordinates for nonzero altitudes

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    Four formulas, for the nonzero altitude transformation from geodetic coordinates (geodetic latitude and altitude) to geocentric coordinates (geocentric latitude and geocentric distance) and vice versa, are derived. The set of four formulas is expressed in each of the three useful forms: series expansion in powers of the earth's flattening; series expansion in powers of the earth's eccentricity; and Fourier series expansion in terms of the geodetic latitude or the geocentric latitude. The error incurred in these series expansions is of the order of one part in 3 x 10 to the 7th power

    Effects of various experimental parameters on errors in triangulation solution of elongated object in space

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    The effects of various experimental parameters on the displacement errors in the triangulation solution of an elongated object in space due to pointing uncertainties in the lines of sight have been determined. These parameters were the number and location of observation stations, the object's location in latitude and longitude, and the spacing of the input data points on the azimuth-elevation image traces. The displacement errors due to uncertainties in the coordinates of a moving station have been determined as functions of the number and location of the stations. The effects of incorporating the input data from additional cameras at one of the stations were also investigated

    Spectroscopic analysis of radiation-generated changes in tensile properties of a polyetherimide film

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    The effects of electron radiation on Ultem, a polyetherimide were studied for doses from 2 x 10 to the 9th power to 6 x 10 to the 9th power rad. Specimens were studied for tensile property testing and for electron paramagnetic resonance and infrared spectroscopic measurements of molecular structure. A Faraday cup design and a method for remote temperature measurement were developed. The spectroscopic data show that radiation caused dehydrogenation of methyl groups, rupture of main-chain ether linkage, and opening of imide rings, all to form radicals and indicate that the so-formed atomic hydrogen attached to phenyl radicals, but not to phenoxyl radicals, which would have formed hydroxyls. The observed decays of the radiation-generated phenoxyl, gem-dimethyl, and carbonyl radicals were interpreted as a combining of the radicals to form crosslinking. This crosslinking is the probable cause of the major reduction in the elongation of the tensile specimens after irradiation. Subsequent classical solubility tests indicate that the irradiation caused massive crosslinking

    A simplified holographic-interferometry technique for real-time flow visualization and analysis

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    A holographic-interferometry technique for flow visualization and analysis that produces real-time moire fringes is described from both experimental and application considerations. It has three chief advantages: real-time data for continuous observation and photography, ease of optical adjustment, and capability of using ordinary-glass test-section windows without affecting the results. A theoretical discussion is presented describing the formation of the fringes in holographic terms and then comparing this result to that which is obtained from a conventional moire approach. A discussion on obtaining density information from the fringe pattern is also included

    Systematic Review of the Literature on Black and Minority Ethnic Communities in Sport and Physical Recreation

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    The Carnegie Research Institute was commissioned by Sporting Equals and the Sports Councils to conduct an independent systematic review of the literature on participation in sport and recreation by Black and minority ethnic (BME) communities. The brief was to focus on UK material from the past ten years, to compile an electronic, bibliographic database and use that evidence to assess the policy significance of existing knowledge in the drive to widen and increase participation. Although the field might still be considered under-researched over 300 items were identified. Judgements were made on the quality of the research on the basis of the methodological and theoretical soundness and the credibility of the link between the conclusions and the data. The various items were collated in an electronic, bibliographic database and coded as: substantive research of good quality; related public statistics and policy documents; and other related materials of interest. The research, policy and practice contained in this body of work is set within an expanding national and international framework of policy and legislation concerned with human rights and principles of equality. The Sports Councils and Sporting Equals have played a significant part in this through initiatives like the Equality Standard. They have not been acting in isolation, but have received support from other sports bodies with initiatives both to challenge discrimination and inequality and to promote participation and inclusion. Nonetheless, there still seems to be a measure of disconnection between research, sports policies and equality policies. Indeed, sports policies are sometimes based on limited representations of racism and so are inhibited in the way they address racial equality

    Spin symmetry in Dirac negative energy spectrum in density-dependent relativistic Hartree-Fock theory

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    The spin symmetry in the Dirac negative energy spectrum and its origin are investigated for the first time within the density-dependent relativistic Hartree-Fock (DDRHF) theory. Taking the nucleus 16^{16}O as an example, the spin symmetry in the negative energy spectrum is found to be a good approximation and the dominant components of the Dirac wave functions for the spin doublets are nearly identical. In comparison with the relativistic Hartree approximation where the origin of spin symmetry lies in the equality of the scalar and vector potentials, in DDRHF the cancellation between the Hartree and Fock terms is responsible for the better spin symmetry properties and determines the subtle spin-orbit splitting. These conclusions hold even in the case when significant deviations from the G-parity values of the meson-antinucleon couplings occur.Comment: 13 pages, 7 figures, 1 table, accepted by Eur. Phys. J.
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