138,913 research outputs found

    Chromium ion plating studies for enhancement of bearing lifetime

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    Six 440-C hardened stainless steel roller bearing test rods were ion plated with various chromium films of thicknesses from .2 microns to 7 microns. The thinner (approximately .2 microns) coating sample had 3 times the fatigue life of the unplated (standard) specimens. Contrastingly, the samples having thicker coatings (several microns) had short fatigue lives (about 3% of the unplated standard)

    'The Scope for Wisdom’: Early Buddhism on Reasons and Persons

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    The Past and Future of Light Dark Matter Direct Detection

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    We review the status and future of direct searches for light dark matter. We start by answering the question: `Whatever happened to the light dark matter anomalies?' i.e. the fate of the potential dark matter signals observed by the CoGeNT, CRESST-II, CDMS-Si and DAMA/LIBRA experiments. We discuss how the excess events in the first two of these experiments have been explained by previously underestimated backgrounds. For DAMA we summarise the progress and future of mundane explanations for the annual modulation reported in its event rate. Concerning the future of direct detection we focus on the irreducible background from solar neutrinos. We explain broadly how it will affect future searches and summarise efforts to mitigate its effects.Comment: Invited review article for the International Journal of Modern Physics A. 20 pages, 3 figure

    A novel dry coal feeding concept for high-pressure gasifiers

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    A novel dry coal feeding concept was developed for injecting ground coal into high-pressure gasifiers. Significant power savings are projected because the coal is injected directly with a ram and there is no requirement for pumping large volumes of gas or fluid against pressure. A novel feature of the concept is that a new seal zone is formed between the ram and injection tube each cycle. The seal zone comprises a mixture of a small quantity of finely ground coal and a fluid. To demonstrate the feasibility of the concept, coal was injected into a 1000-psi chamber with an experimental device having a 7-1/2-inch-diameter ram and a 28-inch-long stroke

    Commercial property prices and bank performance

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    We seek to assess the effect of changes in commercial property prices on bank behaviour and performance in a range of industrialised economies, extending the existing micro literature on bank performance. The results suggest that, consistent with macro-level studies, commercial property prices have a marked impact on the behaviour and performance of individual banks. The signs found are consistent with a view that commercial property provides important forms of collateral that are perceived by banks to reduce risk and encourage lending. Such an impact exists even when conventional independent variables determining bank performance are included. Moreover, there is evidence that the magnitude of this impact is related to the size of the bank, the direction of commercial property price movements, and regional factors. The results have implications for risk managers, regulators and monetary policy makers. Notably, they underline the crucial relevance of commercial property prices as a macroprudential variable that warrants close scrutiny by the authorities. They also highlight the need to develop indicators of individual bank exposure to the property market that could help to calibrate the potential impact of changes in prices in stress tests

    Glow in the Dark Matter: Observing galactic halos with scattered light

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    We consider the observation of diffuse halos of light around the discs of spiral galaxies, as a probe of the interaction cross section between Dark Matter and photons. Using the galaxy M101 as an example, we show that for a scattering cross section at the level of 10^(-23) x (m/GeV) cm^2 or greater Dark Matter in the halo will scatter light out from the more luminous centre of the disc to larger radii, contributing to an effective increased surface brightness at the edges of the observed area on the sky. This allows us to set an upper limit on the DM-photon cross section using data from the Dragonfly instrument. We then show how to improve this constraint, and the potential for discovery, by combining the radial profile of DM-photon scattering with measurements at multiple wavelengths. Observation of diffuse light presents a new and potentially powerful way to probe the interactions of Dark Matter with photons, which is complimentary to existing searches.Comment: 6 pages, 3 figures: v2 matches version accepted to PRL, with an extended discussion of potential background
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