11,723 research outputs found

    Book Review: Microscopic anatomy of invertebrates

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    Book Review: Microscopic anatomy of invertebrates, VoL 11, A, B, C, Insecta. Harrison, Frederick W. (editor), and Michael Locke. New York: Wiley-Liss, voL 11A, xxii+381 [+index 1-74], voL 11B, xxii+385-840 [+index 1-74 (repeated)], voL 3, xxii+843-1296 [incL 74 page index]. Cloth: $675.00. [ISBN 0-471-15955-7 (set).

    Crystalline-silicon reliability lessons for thin-film modules

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    The reliability of crystalline silicon modules has been brought to a high level with lifetimes approaching 20 years, and excellent industry credibility and user satisfaction. The transition from crystalline modules to thin film modules is comparable to the transition from discrete transistors to integrated circuits. New cell materials and monolithic structures will require new device processing techniques, but the package function and design will evolve to a lesser extent. Although there will be new encapsulants optimized to take advantage of the mechanical flexibility and low temperature processing features of thin films, the reliability and life degradation stresses and mechanisms will remain mostly unchanged. Key reliability technologies in common between crystalline and thin film modules include hot spot heating, galvanic and electrochemical corrosion, hail impact stresses, glass breakage, mechanical fatigue, photothermal degradation of encapsulants, operating temperature, moisture sorption, circuit design strategies, product safety issues, and the process required to achieve a reliable product from a laboratory prototype

    An Algorithm for Synthesizing Mass and Stiffness Matrices from Experimental Vibration Modes

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    An algorithm is described for synthesizing the mass and stiffness matrices from experimentally derived modal data in a way that preserves the physical significance of the individual mass and stiffness elements. The mass and stiffness matrices are derived for a rollup solar array example, and are then used to define the modal response of a modified array

    Magellan/Galileo solder joint failure analysis and recommendations

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    On or about November 10, 1988 an open circuit solder joint was discovered in the Magellan Radar digital unit (DFU) during integration testing at Kennedy Space Center (KSC). A detailed analysis of the cause of the failure was conducted at the Jet Propulsion Laboratory leading to the successful repair of many pieces of affected electronic hardware on both the Magellan and Galileo spacecraft. The problem was caused by the presence of high thermal coefficient of expansion heat sink and conformal coating materials located in the large (0.055 inch) gap between Dual Inline Packages (DIPS) and the printed wiring board. The details of the observed problems are described and recommendations are made for improved design and testing activities in the future

    Long-term stability of amorphous-silicon modules

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    The Jet Propulsion Laboratory (JPL) program of developing qualification tests necessary for amorphous silicon modules, including appropriate accelerated environmental tests reveal degradation due to illumination. Data were given which showed the results of temperature-controlled field tests and accelerated tests in an environmental chamber

    Phillips and the Natural Gas Act

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    RUSAP: A computer program for the calculation of Roll-Up Solar Array Performance characteristics

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    RUSAP is a FORTRAN 4 computer program designed to determine the performance characteristics (power-to-weight ratio, blanket tension, structural member section dimensions, and resonant frequencies) of large-area, roll-up solar arrays of the single-boom, tensioned-substrate design. The program includes the determination of the size and weight of the base structure supporting the boom and blanket and the determination of the blanket tension and deployable boom stiffness needed to achieve the minimum-weight design for a specified frequency for the first mode of vibration. A complete listing of the program, a description of the theoretical background, and all information necessary to use the program are provided

    Parametric study of the performance characteristics and weight variations of large-area roll-up solar arrays

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    Performance characteristics and weight variations of large area, roll-up, solar array

    Reforming finance in transitional socialist economies : avoiding the path from shell money to shell games

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    In the late 1980s, transitional socialist economies (TSEs) in Central and Eastern Europe were only somewhat more sophisticated than shell money systems: savings books or currency had to be used for most transactions and there was no risk assessment, information monitoring and acquisition, or portfolio management. The TSEs have moved toward a two-tiered banking system but they lag in the development of competitive, market-based financial systems. In several TSEs the financial system seems to be part of a shell game to hide the losses of the real economy. The authors argue that rapid, successful economic reform requires putting the shell game to an end. They review several contentious issues of financial reform in the TSEs, especially issues involving macrofinance, corporate finance, the internal debt problems, and the need to build efficient banks. The authors contend that the banks should be"cleaned up"when they are privatized, to prevent the quick reemergence of debt problems. They believe that either of the proposed alternatives for shaping financial systems in the TSEs - very highly capitalized banking or narrow banking - would minimize the need for future support. Either alternative would reduce leverage in the TSEs and provide more financial stability. But taking concerns about moral hazard to an extreme - prohibiting debt finance - could starve new firms for credit and limit economic growth.Economic Theory&Research,Financial Crisis Management&Restructuring,Environmental Economics&Policies,Banks&Banking Reform,Financial Intermediation

    Electricity from photovoltaic solar cells: Flat-Plate Solar Array Project final report. Volume VI: Engineering sciences and reliability

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    The Flat-Plate Solar Array (FSA) Project, funded by the U.S. Government and managed by the Jet Propulsion Laboratory, was formed in 1975 to develop the module/array technology needed to attain widespread terrestrial use of photovoltaics by 1985. To accomplish this, the FSA Project established and managed an Industry, University, and Federal Government Team to perform the needed research and development. This volume of the series of final reports documenting the FSA Project deals with the Project's activities directed at developing the engineering technology base required to achieve modules that meet the functional, safety and reliability requirements of large-scale terrestrial photovoltaic systems applications. These activities included: (1) development of functional, safety, and reliability requirements for such applications; (2) development of the engineering analytical approaches, test techniques, and design solutions required to meet the requirements; (3) synthesis and procurement of candidate designs for test and evaluation; and (4) performance of extensive testing, evaluation, and failure analysis to define design shortfalls and, thus, areas requiring additional research and development. During the life of the FSA Project, these activities were known by and included a variety of evolving organizational titles: Design and Test, Large-Scale Procurements, Engineering, Engineering Sciences, Operations, Module Performance and Failure Analysis, and at the end of the Project, Reliability and Engineering Sciences. This volume provides both a summary of the approach and technical outcome of these activities and provides a complete Bibliography (Appendix A) of the published documentation covering the detailed accomplishments and technologies developed
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