4,704 research outputs found

    You Get What You Pay For?: Rethinking U.S. Organ Procurement Policy in Light of Foreign Models

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    The U.S. organ transplant system is in crisis due to the paucity of transplantable organs. Such a shortage exists because otherwise viable organs are too often buried along with the bodies in which they reside. Organs are wasted because the existing U.S. organ transplant system sets up barriers to organ donation--chiefly the legal presumption of unwillingness to donate ( voluntary donation\u27) and the National Organ Transplant Act\u27s ban on the transfer of organs for valuable consideration. This Note surveys the qualified successes of Austria, Belgium, Brazil, and France with their various presumed consent models of organ procurement. It also considers other proposals, including monetary and non-monetary incentives for organ donation. In light of the limitations of these proposals, this Note concludes with two recommendations: (1) the creation of a trial program of regulated open markets for cadaveric organs in one or several states; and (2) the implementation of a national donor registry with a system of priority based on willingness to donate. These measures would best address the organ shortage within the existing U.S. legal and ethical framework

    Enhancement of reliability in condition monitoring techniques in wind turbines

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    The majority of electrical failures in wind turbines occur in the semiconductor components (IGBTs) of converters. To increase reliability and decrease the maintenance costs associated with this component, several health-monitoring methods have been proposed in the literature. Many laboratory-based tests have been conducted to detect the failure mechanisms of the IGBT in their early stages through monitoring the variations of thermo-sensitive electrical parameters. The methods are generally proposed and validated with a single-phase converter with an air-cored inductive or resistive load. However, limited work has been carried out considering limitations associated with measurement and processing of these parameters in a three-phase converter. Furthermore, looking at just variations of the module junction temperature will most likely lead to unreliable health monitoring as different failure mechanisms have their own individual effects on temperature variations of some, or all, of the electrical parameters. A reliable health monitoring system is necessary to determine whether the temperature variations are due to the presence of a premature failure or from normal converter operation. To address this issue, a temperature measurement approach should be independent from the failure mechanisms. In this paper, temperature is estimated by monitoring an electrical parameter particularly affected by different failure types. Early bond wire lift-off is detected by another electrical parameter that is sensitive to the progress of the failure. Considering two separate electrical parameters, one for estimation of temperature (switching off time) and another to detect the premature bond wire lift-off (collector emitter on-state voltage) enhance the reliability of an IGBT could increase the accuracy of the temperature estimation as well as premature failure detection
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