633 research outputs found

    The force of gravity in Schwarzschild and Gullstrand-Painlev\'e coordinates

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    We derive the exact equations of motion (in Newtonian, F=ma, form) for test masses in Schwarzschild and Gullstrand-Painlev\'e coordinates. These equations of motion are simpler than the usual geodesic equations obtained from Christoffel tensors in that the affine parameter is eliminated. The various terms can be compared against tests of gravity. In force form, gravity can be interpreted as resulting from a flux of superluminal particles (gravitons). We show that the first order relativistic correction to Newton's gravity results from a two graviton interaction.Comment: 6 pages, Honorable mention in 2009 Gravity Essay Competition, submitted IJMPD, added reference

    The Americans with Disabilities Act: What it Means to Small Business Owners

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    Small Business owners  with as few as 15 employees came under the provisions  of the Americans With Disabilities Act on July 26, 1994. A small business not affected in the employment   area  may  need  to  provide   the  disabled   customer   access  to   the  business. Successful small business strategies for the future should  systematically  incorporate not only the philosophy of accommodation for the disabled , but realistic attention to details of compliance and competitiveness. This paper reviews terms and conditions that will aid the business compliance owner in planning  for  compliance  with the ADA.  Additional  sources of  help are also provided

    Thomas Coram: the life and times of a research unit at the Institute of Education (London)

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    For nearly 50 years, the Thomas Coram Research Unit (TCRU) has been integral to the IOE (Institute of Education), UCL’s Faculty of Education and Society (University College London, UK). This article is written from the perspectives of four researchers who have served in the TCRU’s formative years and over its lifetime. It chronicles the TCRU’s history and meaning, situating these reflections within the wider and much changed context of academia, politics and society. It begins with an overview of the TCRU’s origins as a dedicated government-funded research unit in 1973, the rationale and aims of its founder and first director, Jack Tizard, and the TCRU’s subsequent evolution, and its work in the fields of childhood, families and children’s services. This is followed by a consideration of some important features of the TCRU, which have created its distinct identity, for example multidisciplinarity, working with mixed methods, international collaborations, a convivial and collegiate environment and a continuing capacity to generate new ideas and directions for research. The article also reflects on some of the challenges faced by the TCRU and how it has responded to them. The article concludes by considering whether there is still a place today for a dedicated, university-based social research unit with a long-term and strategic orientation

    Taxation of farms in Missouri

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    Publication authorized September 18, 1926.Digitized 2007 AES.Includes bibliographical references

    Generational research: between historical and sociological imaginations

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    This paper reflects on Julia Brannen’s contribution to the development of theory and methods for intergenerational research. The discussion is contextualised within a contemporary ‘turn to time’ within sociology, involving tensions and synergies between sociological and historical imagination. These questions are informed by a juxtaposition of Brannen’s four-generation study of family change and social historian Angela Davis’s exploration women and the family in England between 1945 and 2000. These two studies give rise to complementary findings, yet have distinctive orientations towards the status and treatment of sources, the role of geography in research design and limits of generalisatio

    Criminal Justice

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    Economics of Laying Flocks in Texas.

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    8 p

    Scientific mindfulness: a foundation for future themes in international business

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    We conceptualize new ways to qualify what themes should dominate the future IB research agenda by examining three questions: Whom should we ask? What should we ask and which selection criteria should we apply? What are the contextual forces? We propose scientific mindfulness as the way forward for generating themes in IB research

    On the Application of a Monolithic Array for Detecting Intensity-Correlated Photons Emitted by Different Source Types

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    It is not widely appreciated that many subtleties are involved in the accurate measurement of intensity-correlated photons; even for the original experiments of Hanbury Brown and Twiss (HBT). Using a monolithic 4x4 array of single-photon avalanche diodes (SPADs), together with an off-chip algorithm for processing streaming data, we investigate the difficulties of measuring second-order photon correlations g2 in a wide variety of light fields that exhibit dramatically different correlation statistics: a multimode He-Ne laser, an incoherent intensity-modulated lamp-light source and a thermal light source. Our off-chip algorithm treats multiple photon-arrivals at pixel-array pairs, in any observation interval, with photon fluxes limited by detector saturation, in such a way that a correctly normalized g2 function is guaranteed. The impact of detector background correlations between SPAD pixels and afterpulsing effects on second-order coherence measurements is discussed. These results demonstrate that our monolithic SPAD array enables access to effects that are otherwise impossible to measure with stand-alone detectors.Comment: 17 pages, 6 figure
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