376,917 research outputs found

    X-ray Variability and Emission Process of the Radio Jet in M87

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    We monitored the M87 jet with the ACIS-S detector on Chandra with 5 observations between 2002 Jan and 2002 Jul. Our goal was to determine the presence and degree of variability in morphology, intensity, and spectral parameters. We find strong variability of the core and HST-1, the knot lying 0.8" from the core. These observations were designed to constrain the X-ray emission process: whereas synchrotron emission would necessitate the presence of extremely high energy electrons with a halflife of a few years or less, inverse Compton emission from a relativistic jet would arise from low energy electrons with very long halflives. Currently, all indications point to a synchrotron process for the X-ray emission from the M87 jet. We give key parameters for a ``modest beaming'' synchrotron model.Comment: 4 pages with 2 embedded figures (1 in color). To be published in the proceedings of the Bologna Jet Workshop "The Physics of Relativistic Jets in the CHANDRA and XMM Era", 23-27 September 2002, Brunetti, Harris, Sambruna, and Setti, editors. 2003, New Ast. Re

    A System Exhibiting Toroidal Order

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    A two dimensional system of discs upon which a triangle of spins are mounted is shown to undergo a sequence of interesting phase transitions as the temperature is lowered. We are mainly concerned with the `solid' phase in which bond orientational order but not positional order is long ranged. As the temperature is lowered in the `solid' phase, the first phase transition involving the orientation or toroidal charge of the discs is into a `gauge toroid' phase in which the product of a magnetic toroidal parameter and an orientation variable (for the discs) orders but due to a local gauge symmetry these variables themselves do not individually order. Finally, in the lowest temperature phase the gauge symmetry is broken and toroidal order and orientational order both develop. In the `gauge toroidal' phase time reversal invariance is broken and in the lowest temperature phase inversion symmetry is also broken. In none of these phases is there long range order in any Fourier component of the average spin. A definition of the toroidal magnetic moment TiT_i of the iith plaquette is proposed such that the magnetostatic interaction between plaquettes ii and jj is proportional to TiTjT_iT_j. Symmetry considerations are used to construct the magnetoelectric free energy and thereby to deduce which coefficients of the linear magnetoelectric tensor are allowed to be nonzero. In none of the phases does symmetry permit a spontaneous polarization.Comment: 9 pages, 6 figure

    New g'r'i'z' Photometry of the NGC 5128 Globular Cluster System

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    We present new photometry for 323 of the globular clusters in NGC 5128 (Centaurus A), measured for the first time in the grizg'r'i'z' filter system. The color indices are calibrated directly to standard stars in the grizg'r'i'z' system and are used to establish the fiducial mean colors for the blue and red (low and high metallicity) globular cluster sequences. We also use spectroscopically measured abundances to establish the conversion between the most metallicity-sensitive colors ((gr)0(g'-r')_0, (gi)0(g'-i')_0) and metallicity, [Fe/H].Comment: 14 pages, 9 figures, accepted in A

    (Global) Hip Hop Studies Bibliography

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    This bibliography documents Hip Hop scholarship outside of America, including scholarly works that may be US centric, yet expands its analysis to other parts of the world. Hip Hop Studies outside the boundaries of the United States stretches as far and wide as Hip Hop itself. This scholarship started in 1984, and the amount of scholarship beyond American boundaries has continued to grow up through present day. The first wave, before Mitchell\u27s Global Noise (2001), includes a wider range of scholarly works such as conference presentations and books written by journalists, in addition to traditional academic sources such as books and journal articles. I included the variety of scholarly works in the first wave that I do not include in the second wave because the earlier works can function as primary sources and document how the field has grown

    John Hansen

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    Profile of John Hansen (High Court judge in New Zealand) interviewed at the time of his visit to IALS as part of a project to research attitudes and approaches to case management in Britain. He explains some of the approaches his country has taken to judicial reform. Published in the Profile section of Amicus Curiae - Journal of the Institute of Advanced Legal Studies and its Society for Advanced Legal Studies. The Journal is produced by the Society for Advanced Legal Studies at the Institute of Advanced Legal Studies, University of London

    The Internal Effects of Corporate Social Responsibility on Firm Performance

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    The purpose of this thesis is to identify the internal effects of corporate social responsibility on firm performance. It also examines the definition of corporate social responsibility and two varying theories about the topic. This thesis explores the human resource, quality and financial aspects of firm performance and how those aspects of a company are affected by adopting significant corporate social responsibility programs. This research seeks to answer the claim that corporate social responsibility programs do not have a positive effect on the actual performance of an organization. It will examine the effect of CSR on employee attitudes, moral and overall satisfaction, seeking to determine if it affects employees in such a way that would affect their performance. This thesis will also examine the effect of implementing CSR programs on the quality of the company’s service or products. Finally, it will investigate the financial effects of implementing CSR programs on an organization

    Socrates or Muhammad? Joseph Ratzinger on the Destiny of Reason

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    Science and democracy reconsidered

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    To what extent is the normative commitment of STS to the democratization of science a product of the democratic contexts where it is most often produced? STS scholars have historically offered a powerful critical lens through which to understand the social construction of science, and seminal contributions in this area have outlined ways in which citizens have improved both the conduct of science and its outcomes. Yet, with few exceptions, it remains that most STS scholarship has eschewed study of more problematic cases of public engagement of science in rich, supposedly mature Western democracies, as well as examination of science-making in poorer, sometimes non-democratic contexts. How might research on problematic cases and dissimilar political contexts traditionally neglected by STS scholars push the field forward in new ways? This paper responds to themes that came out of papers from two Eastern Sociological Society Presidential Panels on Science and Technology Studies in an Era of Anti-Science. It considers implications of the normative commitment by sociologists working in the STS tradition to the democratization of science.https://estsjournal.org/index.php/ests/article/view/383Published versio
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