1,468 research outputs found

    Anthropological Investigations of late heathen graves in Upernavik District.

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    The Eskimos came to Greenland in several waves, each group carrying with it its own culture. Skeletal materials are however only available from the lnugsuk Culture, the latest culture period. As already mentioned, the investigations of the skeletal materials described above primarily concern the lnugsuk people as they were like shortly after immigrating to Greenland. Their contact with white men essentially takes place during the last two centuries, and coincides with the introduction of Christianity. Thus, by analyzing the skeletal remains of the last heathen Greenlanders, one arrives at a picture of the development of the Inugsuk people throughout half a millenium in Greenland, and at the same time has a basis of comparison between the last pure Eskimos and the present-day Greenlanders. Several investigations of the physical anthropology of these immigrated peoples have already been published ( JØRGENSEN, 1954; LAUGHLIN & JØRGENSEN, 1956; SKELLER, 1954; GESSAIN, 1960).The Eskimos came to Greenland in several waves, each group carrying with it its own culture. Skeletal materials are however only available from the lnugsuk Culture, the latest culture period. As already mentioned, the investigations of the skeletal materials described above primarily concern the lnugsuk people as they were like shortly after immigrating to Greenland. Their contact with white men essentially takes place during the last two centuries, and coincides with the introduction of Christianity. Thus, by analyzing the skeletal remains of the last heathen Greenlanders, one arrives at a picture of the development of the Inugsuk people throughout half a millenium in Greenland, and at the same time has a basis of comparison between the last pure Eskimos and the present-day Greenlanders. Several investigations of the physical anthropology of these immigrated peoples have already been published ( JØRGENSEN, 1954; LAUGHLIN & JØRGENSEN, 1956; SKELLER, 1954; GESSAIN, 1960).The Eskimos came to Greenland in several waves, each group carrying with it its own culture. Skeletal materials are however only available from the lnugsuk Culture, the latest culture period. As already mentioned, the investigations of the skeletal materials described above primarily concern the lnugsuk people as they were like shortly after immigrating to Greenland. Their contact with white men essentially takes place during the last two centuries, and coincides with the introduction of Christianity. Thus, by analyzing the skeletal remains of the last heathen Greenlanders, one arrives at a picture of the development of the Inugsuk people throughout half a millenium in Greenland, and at the same time has a basis of comparison between the last pure Eskimos and the present-day Greenlanders. Several investigations of the physical anthropology of these immigrated peoples have already been published ( JØRGENSEN, 1954; LAUGHLIN & JØRGENSEN, 1956; SKELLER, 1954; GESSAIN, 1960)

    Virtues and Flaws of the Pauli Potential

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    Quantum simulations of complex fermionic systems suffer from a variety of challenging problems. In an effort to circumvent these challenges, simpler ``semi-classical'' approaches have been used to mimic fermionic correlations through a fictitious ``Pauli potential''. In this contribution we examine two issues. First, we address some of the inherent difficulties in a widely used version of the Pauli potential. Second, we refine such a potential in a manner consistent with the most basic properties of a cold Fermi gas, such as its momentum distribution and its two-body correlation function.Comment: 16 pages, 6 figure

    Using Dissolved Organic Carbon Concentration and Character Data to Assess Land Use Change Effects on Coastal Waters

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    2016 South Carolina Water Resources Conference South Carolina Water Resources at a Crossroads: Response, Readiness and Recover

    Creating Open Digital Library Using XML: Implementation of OAi-PMH Protocol at CERN

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    This article describes the implementation of the OAi-PMH protocol within the CERN Document Server (CDS). In terms of the protocol, CERN acts both as a data provider and service provider and the two core applications are described. The application of XML Schema and XSLT technology is emphasized

    Cooperative Dynamics in Unentangled Polymer Fluids

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    We present a Generalized Langevin Equation for the dynamics of interacting semiflexible polymer chains, undergoing slow cooperative dynamics. The calculated Gaussian intermolecular center-of-mass and monomer potentials, wich enter the GLE, are in quantitative agreement with computer simulation data. The experimentally observed, short-time subdiffusive regime of the polymer mean-square displacements, emerges here from the competition between the intramolecular and the intermolecular mean-force potentials.Comment: 9 pages, latex, 3 figure

    Proton fraction in the inner neutron-star crust

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    Monte Carlo simulations of neutron-rich matter of relevance to the inner neutron-star crust are performed for a system of A=5,000 nucleons. To determine the proton fraction in the inner crust, numerical simulations are carried out for a variety of densities and proton fractions. We conclude---as others have before us using different techniques---that the proton fraction in the inner stellar crust is very small. Given that the purported "nuclear pasta" phase in stellar crusts develops as a consequence of the long-range Coulomb interaction among protons, we question whether pasta formation is possible in such proton-poor environments. To answer this question, we search for physical observables sensitive to the transition between spherical nuclei and exotic pasta structures. Of particular relevance is the static structure factor S(k)---an observable sensitive to density fluctuations. However, no dramatic behavior was observed in S(k). We regard the identification of physical observables sensitive to the existence---or lack-thereof---of a pasta phase in proton-poor environments as an open problem of critical importance.Comment: 24 pages and 7 figure

    Nonuniform Neutron-Rich Matter and Coherent Neutrino Scattering

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    Nonuniform neutron-rich matter present in both core-collapse supernovae and neutron-star crusts is described in terms of a semiclassical model that reproduces nuclear-matter properties and includes long-range Coulomb interactions. The neutron-neutron correlation function and the corresponding static structure factor are calculated from molecular dynamics simulations involving 40,000 to 100,000 nucleons. The static structure factor describes coherent neutrino scattering which is expected to dominate the neutrino opacity. At low momentum transfers the static structure factor is found to be small because of ion screening. In contrast, at intermediate momentum transfers the static structure factor displays a large peak due to coherent scattering from all the neutrons in a cluster. This peak moves to higher momentum transfers and decreases in amplitude as the density increases. A large static structure factor at zero momentum transfer, indicative of large density fluctuations during a first-order phase transition, may increase the neutrino opacity. However, no evidence of such an increase has been found. Therefore, it is unlikely that the system undergoes a simple first-order phase transition. It is found that corrections to the commonly used single heavy nucleus approximation first appear at a density of the order of 101310^{13} g/cm3^3 and increase rapidly with increasing density. Thus, neutrino opacities are overestimated in the single heavy nucleus approximation relative to the complete molecular dynamics simulations.Comment: 17 pages, 23 included ps figure

    All-electron GW calculation based on the LAPW method: application to wurtzite ZnO

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    We present a new, all-electron implementation of the GW approximation and apply it to wurtzite ZnO. Eigenfunctions computed in the local-density approximation (LDA) by the full-potential linearized augmented-plane-wave (LAPW) or the linearized muffin-tin-orbital (LMTO) method supply the input for generating the Green function G and the screened Coulomb interaction W. A mixed basis is used for the expansion of W, consisting of plane waves in the interstitial region and augmented-wavefunction products in the augmentation-sphere regions. The frequency-dependence of the dielectric function is computed within the random-phase approximation (RPA), without a plasmon-pole approximation. The Zn 3d orbitals are treated as valence states within the LDA; both core and valence states are included in the self-energy calculation. The calculated bandgap is smaller than experiment by about 1eV, in contrast to previously reported GW results. Self-energy corrections are orbital-dependent, and push down the deep O 2s and Zn 3d levels by about 1eV relative to the LDA. The d level shifts closer to experiment but the size of shift is underestimated, suggesting that the RPA overscreens localized states.Comment: 10 pages, 3 figures, submitted to Phys. Rev.
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