2,113 research outputs found

    Avalanche Dynamics in Wet Granular Materials

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    We have studied the dynamics of avalanching wet granular media in a rotating drum apparatus. Quantitative measurements of the flow velocity and the granular flux during avalanches allow us to characterize novel avalanche types unique to wet media. We also explore the details of viscoplastic flow (observed at the highest liquid contents) in which there are lasting contacts during flow, leading to coherence across the entire sample. This coherence leads to a velocity independent flow depth at high rotation rates and novel robust pattern formation in the granular surface.Comment: 5 pages, 3 figures in color, REVTeX4, for smaller pdfs see http://angel.elte.hu/~tegzes/condmat.htm

    Does consumer protection enhance disclosure credibility in reward crowdfunding?

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    We study how the interplay of disclosure and regulation shapes capital allocation in reward crowdfunding. Using data from Kickstarter, the largest online reward crowdfunding platform, we show that, even in the absence of clear regulation and enforcement mechanisms, disclosure helps entrepreneurs access capital for their projects and bolsters engagement with potential project backers, consistent with the notion that disclosure mitigates moral hazard. We further document that, subsequent to a change in Kickstarter’s terms of use that increases the threat of consumer litigation, the association between project funding and disclosure becomes stronger. This evidence suggests that consumer protection regulation enhances the perceived credibility of disclosure. We find the effect of the change in terms of use to be more pronounced in states with stricter consumer protection regulations. Taken together, our findings yield important insights on the role of disclosure, as well as on the potential effects of increased regulation on crowdfunding platforms

    Accreditation council for graduate medical education (ACGME) annual anesthesiology residency and fellowship program review: a "report card" model for continuous improvement

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    <p>Abstract</p> <p>Background</p> <p>The Accreditation Council for Graduate Medical Education (ACGME) requires an annual evaluation of all ACGME-accredited residency and fellowship programs to assess program quality. The results of this evaluation must be used to improve the program. This manuscript describes a metric to be used in conducting ACGME-mandated annual program review of ACGME-accredited anesthesiology residencies and fellowships.</p> <p>Methods</p> <p>A variety of metrics to assess anesthesiology residency and fellowship programs are identified by the authors through literature review and considered for use in constructing a program "report card."</p> <p>Results</p> <p>Metrics used to assess program quality include success in achieving American Board of Anesthesiology (ABA) certification, performance on the annual ABA/American Society of Anesthesiology In-Training Examination, performance on mock oral ABA certification examinations, trainee scholarly activities (publications and presentations), accreditation site visit and internal review results, ACGME and alumni survey results, National Resident Matching Program (NRMP) results, exit interview feedback, diversity data and extensive program/rotation/faculty/curriculum evaluations by trainees and faculty. The results are used to construct a "report card" that provides a high-level review of program performance and can be used in a continuous quality improvement process.</p> <p>Conclusions</p> <p>An annual program review is required to assess all ACGME-accredited residency and fellowship programs to monitor and improve program quality. We describe an annual review process based on metrics that can be used to focus attention on areas for improvement and track program performance year-to-year. A "report card" format is described as a high-level tool to track educational outcomes.</p

    Results on Plasma Focusing of High Energy Density Electron and Positron Beams

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    We present results from the SLAC E-150 experiment on plasma focusing of high energy density electron and, for the first time, positron beams. We also discuss measurements on plasma lens-induced synchrotron radiation, longitudinal dynamics of plasma focusing, and laser- and beam-plasma interactions.Comment: LINAC 2000 paper No. THC13, Monterey, CA. Aug.21-25,2000, 3 pages, 2 figure

    Observation of Plasma Focusing of a 28.5 GeV Positron Beam

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    The observation of plasma focusing of a 28.5 GeV positron beam is reported. The plasma was formed by ionizing a nitrogen jet only 3 mm thick. Simultaneous focusing in both transverse dimensions was observed with effective focusing strengths of order Tesla per micron. The minimum area of the beam spot was reduced by a factor of 2.0 +/- 0.3 by the plasma. The longitudinal beam envelope was measured and compared with numerical calculations

    Does the marine biosphere mix the ocean?

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    Author Posting. © Sears Foundation for Marine Research, 2006. This article is posted here by permission of Sears Foundation for Marine Research for personal use, not for redistribution. The definitive version was published in Journal of Marine Research 64 (2006): 541-561, doi:10.1357/002224006778715720.Ocean mixing is thought to control the climatically important oceanic overturning circulation. Here we argue the marine biosphere, by a mechanism like the bioturbation occurring in marine sediments, mixes the oceans as effectively as the winds and tides. This statement is derived ultimately from an estimated 62.7 TeraWatts of chemical power provided to the marine environment in net primary production. Various approaches argue something like 1% (.63 TeraWatts) of this power is invested in aphotic ocean mechanical energy, a rate comparable to wind and tidal inputs
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