433 research outputs found

    Security Interest in Aircraft

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    Quasinormal Modes and Choptuik Scaling in the Near Extremal Reissner-Nordstr{\"o} Black Hole

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    We study quasinormal modes of massless scalar and fermion fields in the near extremal Reissner-Nordstr{\"o}m black hole, and relate them to Choptuik scaling form following a recently proposed analytic approach. For both massless cases, quasinormal modes are shown to be proportional to the black hole horizon and the Hawking temperature, and the critical exponents are the same, although for the fermionic case there are two possible discrete quasinormal modes. In addition, the critical exponent of the massive boson is also equivalent to that of the massless case. Finally, we discuss quasinormal modes and critical exponents in the other models, and obtain some different critical exponents between massless boson and massive one.Comment: 13 pages, Refs. and comments are added. To appear in Phys. Lett.

    Dilaton driven Hawking radiation in AdS2_2 black hole

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    A recent study shows that Hawking radiation of the massless scalar field does not appear on the two-dimensional AdS2_2 black hole background. We study this issue by investigating absorption and reflection coefficients under dilaton coupling with the matter field. If the scalar field does not couple to the dilaton, then it is fully absorbed into the black hole without any outgoing mode. On the other hand, once it couples to the dilaton field, the outgoing mode of the massless scalar field exists and the nontrivial Hawking radiation is obtained. Finally, we comment on this dilaton dependence of Hawking radiation in connection with a three-dimensional black hole.Comment: 13 pages, revtex, no figures, version to appear in Phys. Lett.

    Historicising intervention: Strategy and synchronicity in British intervention 1815-50

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    Copyright @ 2013 British International Studies Association.This article identifies three key themes in British intervention for purposes of liberal reordering in the period 1815–50, namely the ‘opening-up’ of new market spaces (discussed in relation to Uruguay/the Argentine Confederation in the 1840s), a cosmopolitan humanitarianism evident in the campaign for the abolition of the Atlantic slave trade that ran throughout this period, and the political-ideological contest between constitutionalist and absolutist forces and represented here by intervention in the Iberian Peninsula in the late 1820s to1830s. In developing a strategic perspective upon military/naval intervention the analysis shows its utility to have been subordinate to more fundamental sociopolitical, cultural, and institutional determinants. With regard to understanding the outcomes of specific intervention the analysis shows the importance of systematically evaluating developments in the domestic political environments of both intervening and target state as well as the military campaign itself and the need for sufficient general alignment or synchronisation in the timeline of developments in each of these three domains. This model helps to explain that whilst liberal interventions are not necessarily bound to fail, they frequently prove more difficult, complex, and protracted than the interveners expect

    Decay Rate and Low-Energy Near-Horizon Dynamics of Acoustic Black Holes

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    We study the low-energy dynamics of an acoustic black hole near the sonic horizon. For the experimental test of black hole evaporation in the laboratory, the decay rate (greybody factor) of the acoustic black hole (sonic hole) can be calculated by the usual low-energy perturbation method. As a consequence, we obtain the decay rate of the sonic horizon from the absorption and the reflection coefficients. Moreover, we show that the thermal emission from the sonic horizon is only proportional to a control parameter which describes the velocity of the fluid.Comment: 13pages, 3figures, RevTeX3, some minors corrected. version to appear in PL

    Urban assets and the financialisation fix: land tenure, renewal and path dependency in the city of Birmingham

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    Cities are places of incremental decision-making involving complex negotiations that produce accumulations of urban assets and path dependency. The ownership, control and co-ordination of urban land and its transformation into an investment asset is a key link between economic interests and urban activities that come together in site-based “financialisation fixes”. A financialisation fix combines a development solution for a specific site with a financial model creating a locally embedded asset. This article examines how land tenure (freehold versus leasehold rights) influences the transformation of a city and the role a local authority plays in the financial management of land assets. This includes an analysis of the application of financialisation to urban assets and the first tax increment financing scheme of 1875

    Absorption cross section and Hawking radiation in two-dimensional AdS black hole

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    We calculate the absorption coefficient of scalar field on the background of the two-dimensional AdS black hole, which is of relevance to Hawking radiation. For the massless scalar field, we find that there does not exist any massless radiation.Comment: 6 pages, revtex, no figure

    Using the Pathways Community HUB Care Coordination Model to Address Chronic Illnesses: A Case Study

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    Background/Objectives: Ohio communities are developing and expanding care coordination initiatives to integrate care for low-income pregnant women. Some of these initiatives are guided by the Pathways Community HUB model, which uses community healthworkers to address health, social, and behavioral risks for at-risk populations. This study documents the development, challenges andmanagement responses, and lessons learned from implementing a Pathways Community HUB care coordination program for anotherpopulation -- low-income adults with chronic disease risks.Methods: The study utilizes data extracted from the Care Coordination Systems (CCS) database used in Lucas County, Ohio between2015 and 2017 and interviews with program managers. Based on CCS data and insights from those interviewed, we describe the development and accomplishments of a Pathways Community HUB program for adults with chronic illnesses and identify challenges and lessons learned.Results: The Toledo/Lucas County program addressed more than half of 3,515 identified health and behavioral risks for 651 low-income adults in the program during its first two years of operation. Key challenges included building community support, establishing capacities to coordinate care, and sustaining the program over time. Establishing community networks to support program services and developing multiple funding sources are key lessons for long-term program sustainability.Conclusions: Documenting challenges and successes of existing programs and extracting lessons to guide implementation of similarpublic health efforts can potentially improve delivery of interventions. The Pathways Community HUB model has demonstrated success in addressing risks among at-risk adults. However, more comprehensive assessments of the model across different populations are warranted
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