13,548 research outputs found

    Verification test of the MSFC solar simulator using a Honeywell double-covered liquid solar collector

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    Additional verification data to support the utilization of the MSFC Solar Simulator for testing solar collectors was obtained. The Honeywell double-covered liquid solar collector number 2 for which thermal performance data under natural outdoor conditions had been previously obtained was installed on the Solar Simulator and subjected to a series of eight tests under various conditions of wind flow rate. Although these test conditions were not absolutely identical to those of the outdoor tests, they are considered to be sufficiently representative to provide a basis for an accurate comparative analysis of the data recorded for both test programs

    Indoor thermal performance evaluation of Daystar solar collector

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    The test procedures used and results obtained from a test program to obtain thermal performance data on a Daystar Model 21B, S/N 02210, Unit 2, liquid solar collector under simulated conditions are described. The test article is a flat plate solar collector using liquid as a heat transfer medium. The absorber plate is copper and coated with black paint. Between the tempered low iron glass and absorber plate is a polycarbonate trap used to suppress convective heat loss. The collector incorporates a convector heat dump panel to limit temperature excursions during stagnation. The following tests were conducted: (1) collector thermal efficiency; (2) collector time constant; (3) collector incident angle modifier; (4) collector heat loss coefficient; and (5) collector stagnation

    Bayesian approaches to technology assessment and decision making

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    Until the mid-1980s, most economic analyses of healthcare technologies were based on decision theory and used decision-analytic models. The goal was to synthesize all relevant clinical and economic evidence for the purpose of assisting decision makers to efficiently allocate society's scarce resources. This was true of virtually all the early cost-effectiveness evaluations sponsored and/or published by the U.S. Congressional Office of Technology Assessment (OTA) (15), Centers of Disease Control and Prevention (CDC), the National Cancer Institute, other elements of the U.S. Public Health Service, and of healthcare technology assessors in Europe and elsewhere around the world. Methodologists routinely espoused, or at minimum assumed, that these economic analyses were based on decision theory (8;24;25). Since decision theory is rooted in—in fact, an informal application of—Bayesian statistical theory, these analysts were conducting studies to assist healthcare decision making by appealing to a Bayesian rather than a classical, or frequentist, inference approach. But their efforts were not so labeled. Oddly, the statistical training of these decision analysts was invariably classical, not Bayesian. Many were not—and still are not—conversant with Bayesian statistical approaches

    Health Care Opinion Leaders' Views on Health Care Delivery System Reform

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    Presents findings of a survey of experts on reforming delivery systems -- organized delivery systems, patient-centered medical homes, and retail clinics -- and recommended policy strategies, such as improving the primary care system

    Health Care Opinion Leaders' Views on the Quality and Safety of Health Care in the United States

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    Presents findings from an annual survey of a diverse group of experts on strategies to improve the quality and safety of health care in the United States

    Health Care Opinion Leaders' Views on the Transparency of Health Care Quality and Price Information in the United States

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    Presents findings from a survey of experts on collecting and reporting public information on the quality and price of healthcare services; the role of transparency in improving quality, efficiency, and cost-effectiveness; and obstacles

    Environmental nanomaterials for pollution control and decontamination technology

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    postprintThe 2009 International Conference on Nanotechnology and Advanced Materials (ICNAM 2009), Hong Kong, 6-8 May 2009.國際納米技術暨先進材料會議, 香港, 2009年5月6-8日

    Incinerating Hong Kong water treatment sludge: the potential of ash reuse and recycling

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    Symposium PaperSymposium Theme: How Sustainable Development Matters: The Search for Joined-up DisciplinesAt present, landfilling is the only means to dispose of nearly 900 tonnes of dewatered waste sludge generated in Hong Kong everyday. The Environmental Protection Department of Hong Kong has chosen sludge incineration to resolve this issue, but it should be further noticed that this approach still results in residual ashes that require proper stabilization prior to be landfilled. A sustainable solution in waste management should develop a closed-loop for material flow by reusing and recycling. Current focuses on sludge incineration planning are largely the stringency of emission standards and the impact on the facility surrounding areas. However, potential reuse and recycling strategies for incineration ash should also be taken into account to be part of the sustainable waste management plan. This paper introduces the different types of sludge generated in Hong Kong; predicts the characteristics of their ashes after incineration; and evaluates the potential of ash reuse and recycling strategies, e.g. land applications and construction materials, in according to their unique nature and application goals. Although both scientific principles and engineering feasibility are core consideration factors for beneficial uses of incineration ash, rigorous campaign for the public acceptance will be essential toward the success of such implementation.postprin

    A Cost-Index Approach to Valuing Investment In "Far Into The Future" Environmental Technology

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    Governments investing in long-lead technology development programs face considerable uncertainty as to whether the investment eventually will “pay off” for the taxpayer. This paper offers a framework to inform long-lead technology investment. We extend the theory of quality-adjusted cost indices to develop a conceptually rigorous, but data parsimonious, means of estimating consumer benefits from a new technology. We apply this model to a possible future electricity generation technology, space solar power (SSP). The United States, Japan, and other governments have begun investing in SSP but lack the benefit of a relevant economic context for informed decisions. We frame and analyze the economic relationship between SSP and competing electricity generation technologies with respect to direct costs, environmental externalities, and reliability. We also explicitly incorporate uncertainty and consider differences in the resource endowments available to electricity markets by considering four distinct world geographic regions.energy, environment, technological change, cost indices, space technology

    Geometry modeling and multi-block grid generation for turbomachinery configurations

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    An interactive 3D grid generation code, Turbomachinery Interactive Grid genERation (TIGER), was developed for general turbomachinery configurations. TIGER features the automatic generation of multi-block structured grids around multiple blade rows for either internal, external, or internal-external turbomachinery flow fields. Utilization of the Bezier's curves achieves a smooth grid and better orthogonality. TIGER generates the algebraic grid automatically based on geometric information provided by its built-in pseudo-AI algorithm. However, due to the large variation of turbomachinery configurations, this initial grid may not always be as good as desired. TIGER therefore provides graphical user interactions during the process which allow the user to design, modify, as well as manipulate the grid, including the capability of elliptic surface grid generation
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