2,433 research outputs found

    Relative potentials of concentrating and two-axis tracking flat-plate photovoltaic arrays for central-station applications

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    The purpose of this study is to assess the relative economic potentials of concenrating and two-axis tracking flat-plate photovoltaic arrays for central-station applications in the mid-1990's. Specific objectives of this study are to provide information on concentrator photovoltaic collector probabilistic price and efficiency levels to illustrate critical areas of R&D for concentrator cells and collectors, and to compare concentrator and flat-plate PV price and efficiency alternatives for several locations, based on their implied costs of energy. To deal with the uncertainties surrounding research and development activities in general, a probabilistic assessment of commercially achievable concentrator photovoltaic collector efficiencies and prices (at the factory loading dock) is performed. The results of this projection of concentrator photovoltaic technology are then compared with a previous flat-plate module price analysis (performed early in 1983). To focus this analysis on specific collector alternatives and their implied energy costs for different locations, similar two-axis tracking designs are assumed for both concentrator and flat-plate options

    Respiratory System

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    The Way Will Open: A Study of the Presidency of Jack Niemeyer at Bank Street College of Education

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    A biography of John H. Niemeyer who served as president of Bank Street College of Education from 1955 through 1973.https://educate.bankstreet.edu/faculty-staff/1012/thumbnail.jp

    Taut-Wire, Sun azimuth Traverses

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    The Challenge of Measuring Performance

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    The value of residential photovoltaic systems: A comprehensive assessment

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    Utility-interactive photovoltaic (PV) arrays on residential rooftops appear to be a potentially attractive, large-scale application of PV technology. Results of a comprehensive assessment of the value (i.e., break-even cost) of utility-grid connected residential photovoltaic power systems under a variety of technological and economic assumptions are presented. A wide range of allowable PV system costs are calculated for small (4.34 kW (p) sub ac) residential PV systems in various locales across the United States. Primary factor in this variation are differences in local weather conditions, utility-specific electric generation capacity, fuel types, and customer-load profiles that effect purchase and sell-back rates, and non-uniform state tax considerations. Additional results from this analysis are: locations having the highest insolation values are not necessary the most economically attractive sites; residential PV systems connected in parallel to the utility demonstrate high percentages of energy sold back to the grid, and owner financial and tax assumptions cause large variations in break-even costs. Significant cost reduction and aggressive resolution of potential institutional impediments (e.g., liability, standards, metering, and technical integration) are required for a residential PV marker to become a major electric-grid-connected energy-generation source

    Stand-alone flat-plate photovoltaic power systems: System sizing and life-cycle costing methodology for Federal agencies

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    A simple methodology to estimate photovoltaic system size and life-cycle costs in stand-alone applications is presented. It is designed to assist engineers at Government agencies in determining the feasibility of using small stand-alone photovoltaic systems to supply ac or dc power to the load. Photovoltaic system design considerations are presented as well as the equations for sizing the flat-plate array and the battery storage to meet the required load. Cost effectiveness of a candidate photovoltaic system is based on comparison with the life-cycle cost of alternative systems. Examples of alternative systems addressed are batteries, diesel generators, the utility grid, and other renewable energy systems

    SYSTEM AND METHODS FOR VENTILATION THROUGH A BODY CAVITY

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    A system and methods for the delivery of oxygen through a body cavity of a subject using oxygen microbubbles . Through circulation of oxygen microbubbles through the body cavity , oxygen and carbon dioxide exchange may occur . Overall improvement in extending survival rate time during emergency situations caused by pulmonary or similar oxygen - intake restricting injury and / or failure may be achieved through use of the invented system and methods

    EP4: ALLERGY PREVALENCE, COST AND PRODUCTIVITY LOSS IN AN INSURED EMPLOYEE POPULATION

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    Centripetal Forces: Multidistrict Litigation and Its Parts

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    The article focuses on various issues related to multidistrict litigation (MDL). Topics discussed include the regulation of MDL proceedings under the Multidistrict Litigation Act of 1968, the role of the U.S. lawyers in centralized proceedings of tag-along cases, and the role of panel of judges in adjudicating MDL
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