842 research outputs found

    On Court Reoganization

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    Observations of near-bottom flow in a wave-dominated nearshore environment

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    To provide observational data for analysis of near-bottom, wave-induced flows, a downward-looking laser Doppler velocimeter (LDV) was deployed to profile the near-bed velocity structure of a six meter water column at a site just outside the surfzone off the coast of North Carolina. 90 second "snap-shots" of the velocity at six elevations below 20 cm above bottom were measured at 25 Hz, while pressure was concurrently measured at 126 cm above bottom. The near-bottom data were supplemented with a benthic acoustic stress sensor (BASS) at approximately 20 cm above bottom which concurrently measured velocity components at 10 Hz. The purposes of this report are to document the collection, processing and archival of these data and to present the profiles for evaluation.Funding was provided by the Coastal Sciences Program of the Office of Naval Research under Grant N00014-92-J-12300

    Water levels and artesian pressure in wells in Las Vegas Valley and in other valleys in Nevada, 1913-1945

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    The rock formations of the earth are great natural reservoirs in which a part of the water derived from rain and snow is stored. Water levels and artesian pressure in wells register the stages of these natural reservoirs. The changes in water levels or artesian pressure are indicative of the depletion or replenishment of the natural reservoirs. Systematic and periodic measurements of water levels and artesian pressure in wells have been made in Nevada, by State and Federal agencies from time to time. However, only a few of these measurements have ever been published. Under the cooperative arrangement between the State Engineer of Nevada and the Director of the U.S. Geological Survey, Department of the Interior, beginning in July 1944, a considerable effort was made to assemble and compile the authentic available records of measurements for publication. Such a compilation provides a permanent record, readily available, for future reference. The result of this compilation is set forth in this report. It is the third in the series of Nevada Water Resources Bulletins prepared by the U. S. Department of Interior, Geological Survey, in cooperation with the State Engineer

    Multi-Fidelity Design Optimization of a Long-Range Blended Wing Body Aircraft with New Airframe Technologies

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    The German Cluster of Excellence SE²A (Sustainable and Energy Efficient Aviation) is established in order to investigate the influence of game-changing technologies on the energy efficiency of future transport aircraft. In this paper, the preliminary investigation of the four game-changing technologies active flow control, active load alleviation, boundary layer ingestion, and novel materials and structure concepts on the performance of a long-range Blended Wing Body (BWB) aircraft is presented. The BWB that was equipped with the mentioned technologies was designed and optimized using the multi-fidelity aircraft design code SUAVE with a connection to the Computational Fluid Dynamics (CFD) code SU2. The conceptual design of the BWB aircraft is performed within the SUAVE framework, where the influence of the new technologies is investigated. In the second step, the initially designed BWB aircraft is improved by an aerodynamic shape optimization while using the SU2 CFD code. In the third step, the performance of the optimized aircraft is evaluated again using the SUAVE code. The results showed more than 60% reduction in the aircraft fuel burn when compared to the Boeing 77

    Benefits of Hybrid-Electric Propulsion to Achieve 4x Increase in Cruise Efficiency for a VTOL Aircraft

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    Electric propulsion enables radical new vehicle concepts, particularly for Vertical Takeoff and Landing (VTOL) aircraft because of their significant mismatch between takeoff and cruise power conditions. However, electric propulsion does not merely provide the ability to normalize the power required across the phases of flight, in the way that automobiles also use hybrid electric technologies. The ability to distribute the thrust across the airframe, without mechanical complexity and with a scale-free propulsion system, is a new degree of freedom for aircraft designers. Electric propulsion is scale-free in terms of being able to achieve highly similar levels of motor power to weight and efficiency across a dramatic scaling range. Applying these combined principles of electric propulsion across a VTOL aircraft permits an improvement in aerodynamic efficiency that is approximately four times the state of the art of conventional helicopter configurations. Helicopters typically achieve a lift to drag ratio (L/D) of between 4 and 5, while the VTOL aircraft designed and developed in this research were designed to achieve an L/D of approximately 20. Fundamentally, the ability to eliminate the problem of advancing and retreating rotor blades is shown, without resorting to unacceptable prior solutions such as tail-sitters. This combination of concept and technology also enables a four times increase in range and endurance while maintaining the full VTOL and hover capability provided by a helicopter. Also important is the ability to achieve low disc-loading for low ground impingement velocities, low noise and hover power minimization (thus reducing energy consumption in VTOL phases). This combination of low noise and electric propulsion (i.e. zero emissions) will produce a much more community-friendly class of vehicles. This research provides a review of the concept brainstorming, configuration aerodynamic and mission analysis, as well as subscale prototype construction and flight testing that verifies transition flight control. A final down-selected vehicle is also presented

    A systematic review of parent and family functioning in pediatric solid organ transplant populations

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    The process of pediatric solid organ transplantation (SOT) places new and increased stressors on patients and family members. Measures of family functioning may predict psychological and health outcomes for pediatric patients and their families, and provide opportunity for targeted intervention. This systematic review investigated parent and family functioning and factors associated with poorer functioning in the pediatric SOT population. Thirty‐seven studies were identified and reviewed. Studies featured a range of organ populations (eg, heart, liver, kidney, lung, intestine) at various stages in the transplant process. Findings highlighted that parents of pediatric SOT populations commonly report increased stress and mental health symptoms, including posttraumatic stress disorder. Pediatric SOT is also associated with increased family stress and burden throughout the transplant process. Measures of parent and family functioning were associated with several important health‐related factors, such as medication adherence, readiness for discharge, and number of hospitalizations. Overall, findings suggest that family stress and burden persists post‐transplant, and parent and family functioning is associated with health‐related factors in SOT, highlighting family‐level functioning as an important target for future intervention.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/136483/1/petr12900.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136483/2/petr12900_am.pd

    Building an Ecosystem of Support: An Evaluation of North Dakota’s Community School Programs

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    Community school programs respond to students’ nonacademic needs so that they can focus on their learning. This session highlights a collaboration of organizations across North Dakota as they implement two community school programs. A shared evaluation plan supports the implementation of the two programs and will provide data to improve services provided to students

    The impact of parent-created motivational climate on adolescent athletes' perceptions of physical self-concept

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    This is a preliminary version of this article. The official published version can be obtained from the link below.Grounded in expectancy-value model (Eccles, 1993) and achievement goal theory (Nicholls, 1989), this study examined the perceived parental climate and its impact on athletes' perceptions of competence and ability. Hierarchical regression analyses with a sample of 237 British adolescent athletes revealed that mothers and fathers' task- and ego-involving climate predicted their son's physical self-concept; the father in particular is the strongest influence in shaping a son's physical self-concept positively and negatively. It was also found that the self-concept of the young adolescent athlete is more strongly affected by the perceived parental-created motivational climate (both task and ego) than the older adolescent athlete's self-concept. These findings support the expectancy-value model assumptions related to the role of parents as important socializing agents, the existence of gender-stereotyping, and the heavy reliance younger children place on parents' feedback
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