29,435 research outputs found

    Low-temperture electrostatic silicon-to-silicon seals using sputtered borosilicate glass

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    Silicon members are hermetically sealed to each other. Process produces no measurable deformation of silicon surfaces and is compatible with package designs of tight tolerance. Seals have been made with glass coatings in 10-mm to 20-mm thickness range without any prior annealing of coated silicon substrates

    A case study of asthma care in school age children using nurse-coordinated multidisciplinary collaborative practices

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    Aim: To describe the role of school nursing in leading and coordinating a multidisciplinary networked system of support for children with asthma, and to analyze the strengths and challenges of undertaking and supporting multiagency interprofessional practice. Background: The growth of networked and interprofessional collaborations arises from the recognition that a number of the most pressing public health problems cannot be addressed by single-discipline or -agency interventions. This paper identifies the potential of school nursing to provide the vision and multiagency leadership required to coordinate multidisciplinary collaboration. Method: A mixed-method single-case study design using Yin’s approach, including focus groups, interviews, and analysis of policy documents and public health reports. Results: A model that explains the integrated population approach to managing school-age asthma is described; the role of the lead school nurse coordinator was seen as critical to the development and sustainability of the model. Conclusion: School nurses can provide strategic multidisciplinary leadership to address pressing public health issues. Health service managers and commissioners need to understand how to support clinicians working across multiagency boundaries and to identify how to develop leadership skills for collaborative interprofessional practice so that the capacity for nursing and other health care professionals to address public health issues does not rely on individual motivation. In England, this will be of particular importance to the commissioning of public health services by local authorities from 2015

    The Fluctuations of lake Victoria

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    Design and experimental evaluation of a swept supercritical Laminar Flow Control (LFC) airfoil

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    A large chord swept supercritical laminar flow control (LFC) airfoil was designed, constructed, and tested in the NASA Langley 8-ft Transonic Pressure Tunnel (TPT). The LFC airfoil experiment was established to provide basic information concerning the design and compatibility of high-performance supercritical airfoils with suction boundary layer control achieved through discrete fine slots or porous surface concepts. It was aimed at validating prediction techniques and establishing a technology base for future transport designs and drag reduction. Good agreement was obtained between measured and theoretically designed shockless pressure distributions. Suction laminarization was maintained over an extensive supercritical zone up to high Reynolds numbers before transition gradually moved forward. Full-chord laminar flow was maintained on the upper and lower surfaces at M sub infinity = 0.82 up to R sub c is less than or equal to 12 x 10 to the 6th power. When accounting for both the suction and wake drag, the total drag could be reducted by at least one-half of that for an equivalent turbulent airfoil. Specific objectives for the LFC experiment are given

    Water resource problems of energy projects in the Colorado River Basin

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    The successful development of western coal and oil shale deposits is dependent, to a significant degree, on the availability of adequate water supplies. EQL is involved in a study of the aggregate effects of various energy activities in the upper Colorado River Basin on downstream water quantity and quality. These activities will tend to reduce the available water in the river, and could increase its salinity, which is already so high as to interfere with downstream domestic and agricultural use

    Beyond A/B Testing: Sequential Randomization for Developing Interventions in Scaled Digital Learning Environments

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    Randomized experiments ensure robust causal inference that are critical to effective learning analytics research and practice. However, traditional randomized experiments, like A/B tests, are limiting in large scale digital learning environments. While traditional experiments can accurately compare two treatment options, they are less able to inform how to adapt interventions to continually meet learners' diverse needs. In this work, we introduce a trial design for developing adaptive interventions in scaled digital learning environments -- the sequential randomized trial (SRT). With the goal of improving learner experience and developing interventions that benefit all learners at all times, SRTs inform how to sequence, time, and personalize interventions. In this paper, we provide an overview of SRTs, and we illustrate the advantages they hold compared to traditional experiments. We describe a novel SRT run in a large scale data science MOOC. The trial results contextualize how learner engagement can be addressed through inclusive culturally targeted reminder emails. We also provide practical advice for researchers who aim to run their own SRTs to develop adaptive interventions in scaled digital learning environments

    Warm and Cold Denaturation in the Phase Diagram of a Protein Lattice Model

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    Studying the properties of the solvent around proteins, we propose a much more sophisticated model of solvation than temperature-independent pairwise interactions between monomers, as is used commonly in lattice representations. We applied our model of solvation to a 16-monomer chain constrained on a two-dimensional lattice. We compute a phase diagram function of the temperature and a solvent parameter which is related to the pH of the solution. It exhibits a native state in which the chain coalesces into a unique compact conformation as well as a denatured state. Under certain solvation conditions, both warm and cold denaturations occur between the native and the denatured states. A good agreement is found with the data obtained from calorimetric experiments, thereby validating the proposed model.Comment: 7 pages, 2 figure

    Development of a carbon fibre composite active mirror: Design and testing

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    Carbon fibre composite technology for lightweight mirrors is gaining increasing interest in the space- and ground-based astronomical communities for its low weight, ease of manufacturing, excellent thermal qualities and robustness. We present here first results of a project to design and produce a 27 cm diameter deformable carbon fibre composite mirror. The aim was to produce a high surface form accuracy as well as low surface roughness. As part of this programme, a passive mirror was developed to investigate stability and coating issues. Results from the manufacturing and polishing process are reported here. We also present results of a mechanical and thermal finite element analysis, as well as early experimental findings of the deformable mirror. Possible applications and future work are discussed.Comment: Accepted by Optical Engineering. Figures 1-7 on http://www.star.ucl.ac.uk/~sk/OEpaper_files

    Re-entrant magnetic field induced charge and spin gaps in the coupled dual-chain quasi-one dimensional organic conductor Perylene2_2[Pt(mnt)2_2]

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    An inductive method is used to follow the magnetic field-dependent susceptibility of the coupled charge density wave (CDW) and spin-Peierls (SP) ordered state behavior in the dual chain organic conductor Perylene2_2[Pt(mnt)2_2]. In addition to the coexisting SP-CDW state phase below 8 K and 20 T, the measurements show that a second spin-gapped phase appears above 20 T that coincides with a field-induced insulating phase. The results support a strong coupling of the CDW and SP order parameters even in high magnetic fields, and provide new insight into the nature of the magnetic susceptibility of dual-chain spin and charge systems.Comment: 6 pages, 6 figure

    Magnetic order in the quasi-one-dimensional spin 1/2 chain, copper pyrazine dinitrate

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    We present the first evidence of magnetic order in the quasi-one-dimensional spin 1/2 molecular chain compound, copper pyrazine dinitrate Cu(C4H4N2)(NO3)2}. Zero field muon-spin relaxation measurements made at dilution refrigerator temperatures show oscillations in the measured asymmetry, characteristic of a quasistatic magnetic field at the muon sites. Our measurements provide convincing evidence for long range magnetic order below a temperature T_N=107(1) mK. This leads to an estimate of the interchain coupling constant of |J'|/k_B=0.046 K and to a ratio |J'/J| = 4.4 x 10^-3.Comment: 4 pages, 3 figures. Submitted to Physical Review Letter
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