3,370 research outputs found

    A NASTRAN model of a large flexible swing-wing bomber. Volume 3: NASTRAN model development-wing structure

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    The NASTRAN model plan for the wing structure was expanded in detail to generate the NASTRAN model for this substructure. The grid point coordinates were coded for each element. The material properties and sizing data for each element were specified. The wing substructure model was thoroughly checked out for continuity, connectivity, and constraints. This substructure was processed for structural influence coefficients (SIC) point loadings and the deflections were compared to those computed for the aircraft detail model. Finally, a demonstration and validation processing of this substructure was accomplished using the NASTRAN finite element program. The bulk data deck, stiffness matrices, and SIC output data were delivered

    A NASTRAN model of a large flexible swing-wing bomber. Volume 5: NASTRAN model development-fairing structure

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    The NASTRAN model plan for the fairing structure was expanded in detail to generate the NASTRAN model of this substructure. The grid point coordinates, element definitions, material properties, and sizing data for each element were specified. The fairing model was thoroughly checked out for continuity, connectivity, and constraints. The substructure was processed for structural influence coefficients (SIC) point loadings to determine the deflection characteristics of the fairing model. Finally, a demonstration and validation processing of this substructure was accomplished using the NASTRAN finite element program. The bulk data deck, stiffness matrices, and SIC output data were delivered

    Anisotropy, phonon modes, and lattice anharmonicity from dielectric function tensor analysis of monoclinic cadmium tungstate

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    We determine the frequency dependence of four independent CdWO4_4 Cartesian dielectric function tensor elements by generalized spectroscopic ellipsometry within mid-infrared and far-infrared spectral regions. Single crystal surfaces cut under different angles from a bulk crystal, (010) and (001), are investigated. From the spectral dependencies of the dielectric function tensor and its inverse we determine all long wavelength active transverse and longitudinal optic phonon modes with AuA_u and BuB_u symmetry as well as their eigenvectors within the monoclinic lattice. We thereby demonstrate that such information can be obtained completely without physical model line shape analysis in materials with monoclinic symmetry. We then augment the effect of lattice anharmonicity onto our recently described dielectric function tensor model approach for materials with monoclinic and triclinic crystal symmetries [Phys. Rev. B, 125209 (2016)], and we obtain excellent match between all measured and modeled dielectric function tensor elements. All phonon mode frequency and broadening parameters are determined in our model approach. We also perform density functional theory phonon mode calculations, and we compare our results obtained from theory, from direct dielectric function tensor analysis, and from model lineshape analysis, and we find excellent agreement between all approaches. We also discuss and present static and above reststrahlen spectral range dielectric constants. Our data for CdWO4_4 are in excellent agreement with a recently proposed generalization of the Lyddane-Sachs-Teller relation for materials with low crystal symmetry [Phys. Rev. Lett. 117, 215502 (2016)].Comment: arXiv admin note: text overlap with arXiv:1512.0859

    Evaluation of geophysical parameters measured by the Nimbus-7 microwave radiometer for the TOGA Heat Exchange Project

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    The data distributed by the National Space Science Data Center on the Geophysical parameters of precipitable water, sea surface temperature, and surface-level wind speed, measured by the Scanning Multichannel Microwave Radiometer (SMMR) on Nimbus-7, are evaluated with in situ measurements between Jan. 1980 and Oct. 1983 over the tropical oceans. In tracking annual cycles and the 1982-83 E1 Nino/Southern Oscillation episode, the radiometer measurements are coherent with sea surface temperatures and surface-level wind speeds measured at equatorial buoys and with precipitable water derived from radiosonde soundings at tropical island stations. However, there are differences between SMMR and in situ measurements. Corrections based on radiosonde and ship data were derived supplementing correction formulae suggested in the databook. This study is the initial evaluation of the data for quantitative description of the 1982-83 E1 Nino/Southern Oscillation episode. It paves the way for determination of the ocean-atmosphere moisture and latent heat exchanges, a priority of the Tropical Ocean and Global Atmosphere (TOGA) Heat Exchange Program

    ‘This ain’t no love-in, this ain’t no happenin’: Misfits, Detroit hardcore and the performance of zombie scenarios

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    This article explores the (ever changing) manifestation of the living dead as iconographic metaphor and performance scenario in Detroit’s hardcore punk scene in the early 1980s. Focusing in particular on B-movie references by the Misfits, it will discuss how a shared transamerican vocabulary and image bank was used to respond to a national, cultural and economic landscape that played itself out in diverse ways on local and tribal levels. Here, low-budget atomic age zombie flicks of the 1950s and 1960s were made, as Dick Hebdige suggests they should, ‘to mean and mean again’ as a process of subcultural style. They hysterically re-performed the ‘real’ post-apocalyptic world of unemployment, fuel shortages, nuclear threat, curfews and pollution that was being portrayed contemporaneously in George Romero’s Dawn of the Dead (1978). Although it is commonly argued that zombies, like all monsters, are manifestations of ‘collective nightmares’, for hardcore punks hanging out in Detroit in the early 1980s the performance of zombie scenarios can be better understood as the theatricalization of lived experience and an attempt to work through the fluid relationships between roles and participants

    Anisotropy and phonon modes from analysis of the dielectric function tensor and inverse dielectric function tensor of monoclinic yttrium orthosilicate

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    We determine the frequency dependence of the four independent Cartesian tensor elements of the dielectric function for monoclinic symmetry Y2_2SiO5_5 using generalized spectroscopic ellipsometry from 40-1200 cm−1^{-1}. Three different crystal cuts, each perpendicular to a principle axis, are investigated. We apply our recently described augmentation of lattice anharmonicity onto the eigendielectric displacement vector summation approach [A. Mock et al., Phys. Rev. B 95, 165202 (2017)], and we present and demonstrate the application of an eigendielectric displacement loss vector summation approach with anharmonic broadening. We obtain excellent match between all measured and model calculated dielectric function tensor elements and all dielectric loss function tensor elements. We obtain 23 Au_{\mathrm{u}} and 22 Bu_{\mathrm{u}} symmetry long wavelength active transverse and longitudinal optical mode parameters including their eigenvector orientation within the monoclinic lattice. We perform density functional theory calculations and obtain 23 Au_{\mathrm{u}} symmetry and 22 Bu_{\mathrm{u}} transverse and longitudinal optical mode parameters and their orientation within the monoclincic lattice. We compare our results from ellipsometry and density functional theory and find excellent agreement. We also determine the static and above reststrahlen spectral range dielectric tensor values and find a recently derived generalization of the Lyddane-Sachs-Teller relation for polar phonons in monoclinic symmetry materials satisfied [M. Schubert, Phys. Rev. Lett. 117, 215502 (2016)]

    Resources File on Records of Boston Social Welfare Agencies

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    One of the Healey Library\u27s areas of collection focus is 19th century private social welfare and charitable agencies of the Boston area. This paper reports on the creation of an electronic resource file with entries on every organization, institution, and society that fits that category
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