8,278 research outputs found

    New computer program solves wide variety of heat flow problems

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    Boeing Engineering Thermal Analyzer /BETA/ computer program uses numerical methods to provide accurate heat transfer solutions to a wide variety of heat flow problems. The program solves steady-state and transient problems in almost any situation that can be represented by a resistance-capacitance network

    Low-profile and wearable energy harvester based on plucked piezoelectric cantilevers

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    The Pizzicato Energy Harvester (EH) introduced the technique of frequency up-conversion to piezoelectric EHs wearable on the lateral side of the knee-joint. The operation principle is to pluck the piezoelectric bimorphs with plectra so that they produce electrical energy during the ensuing mechanical vibrations. The device presented in this work is, in some ways, an evolution of the earlier Pizzicato: it is a significantly more compact and lighter device; the central hub holds 16 piezoelectric bimorphs shaped as trapezoids, which permits a sleek design and potentially increased energy output for the same bimorph area. Plectra were formed by Photochemical Machining of a 100-μm-thick steel sheet. To avoid the risk of short-circuiting, the plectra were electrically passivated by sputtering a 100 nm layer of ZrO2. Bench tests with the steel plectra showed a very large energy generation. Polyimide plectra were also manufactured with a cutting plotter from a 125μm-thick film. Besides bench tests, a volunteer wore the device while walking on flat ground or climbing stairs, with a measured energy output of approximately 0.8 mJ per step. Whereas most of the tests were performed by the traditional method of discharging the rectified output from the EH onto a resistive load, tests were performed also with a circuit offering a stabilised 3.3 V supply. The circuit produced a stable 0.1 mA supply during running gait with kapton plectra

    A preliminary training guide for utilizing high-altitude, color-infrared photography in compiling soil maps

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    Instruction for acquiring and analytically processing small-scale color-infrared photography to perform a soil resources inventory over forests of the southern U.S. is provided. Planning the project; acquiring aerial photography, materials, equipment and supplemental data; and preparing the photography for analysis are discussed. The procedures for preparing ancillary and primary component overlays are discussed. The use of correlation charts and dichotomous keys for mountain landforms, water regime, and vegetation is explained

    Second Skin: Investigating the Production of Contoured Patterns for the Theatrical Costume Industry

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    This paper discusses research into pattern cutting via mould-making techniques for body conscious, contoured clothing used in the theatrical costume industry (film, television and theatre). With their considerable experience as costume makers, the authors recognized a gap in knowledge and documentation for this approach to pattern cutting. The intentions were to expand the range of techniques available for theatrical costume professionals, allowing practitioners to draw complex style lines directly onto the body shape and onto inanimate objects. The research explored different approaches through a series of three-dimensional experiments, which included contouring the body with moulds to achieve sculptural or abstract forms and discovering the capabilities, advantages and restrictions of the technique. The enquiry includes a variety of methodologies, which investigated the practical, technical and historical background to contoured pattern cutting. Object-based research considered the design and manufacture of body conscious garments. Action-based research and semi-structured interviews with practitioners, considered the skills costume makers use to produce contoured clothing and the ethics connected with drawing styles directly onto the human body. In order to contextualize the practical investigations, a review of the literature revealed the limited extent of contemporary and historical research dedicated to contoured pattern cutting

    Navigating Into the New Safe Harbor : Model Interest Surveys as a New Tool for Title IX Compliance Programs

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    The policy debate and the divergent views expressed in the mainstream media have provided little practical advice regarding the Additional Clarification or the Model Survey to the well-intentioned academic institution seeking to comply with Title IX in a cost-effective manner. This Article is intended to be a source of such practical advice. This Article discusses the Additional Clarification from the perspective of the academic institution and seeks to help it evaluate whether to implement the OCR\u27s recommendations, including the Model Survey, as part of its Title IX compliance program. The Article does not engage in the policy debate regarding the Additional Clarification or Title IX enforcement policy generally. Section I of this Article discusses Prong Three from a historical perspective, to place the Additional Clarification in context. Section II summarizes the contributions of the Additional Clarification to the Title IX compliance landscape and explains the OCR\u27s recommendations for using the Model Survey. Section III discusses possible advantages and disadvantages of using the Model Survey. Section IV suggests an approach to using the Model Survey as an ongoing component of a Title IX compliance monitoring program

    After Midnight: A Regression Discontinuity Design in Length of Postpartum Hospital Stays

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    Patients who receive more hospital treatment tend to have worse underlying health, confounding estimates of the returns to such care. This paper compares the costs and benefits of extending the length of hospital stay following delivery using a discontinuity in stay length for infants born close to midnight. Third-party reimbursement rules in California entitle newborns to a minimum number of hospital "days," counted as the number of midnights in care. A newborn delivered at 12:05 a.m. will have an extra night of reimbursable care compared to an infant born minutes earlier. We use a dataset of all California births from 1991-2002, including nearly 100,000 births within 20 minutes of midnight, and find that children born just prior to midnight have significantly shorter lengths of stay than those born just after midnight, despite similar observable characteristics. Furthermore, a law change in 1997 entitled newborns to a minimum of 2 days in care. The midnight discontinuity can therefore be used to consider two distinct treatments: increasing stay length from one to two nights (prior to the law change) and from two to three nights (following the law change). On both margins, we find no effect of stay length on readmissions or mortality for either the infant or the mother, and the estimates are precise. The results suggest that for uncomplicated births, longer hospitals stays incur substantial costs without apparent health benefits.
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