27,129 research outputs found

    Nonprofit Board Accountability: A Literature Review and Critique

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    Accountability is a buzzword in today’s nonprofit society. The press is full of stories detailing the sordid affairs of nonprofit organizations that have betrayed the confidence and trust of the public. What does accountability mean to a nonprofit organization today? What role does the board play in establishing and maintaining this accountability? The purpose of this essay is to explore the current literature on board accountability and recommend a strategy for boards to follow in maintaining their own system of accountability. Three main areas of accountability will be addressed: financial and legal accountability, moral accountability, and outcomes accountability. Self-assessment tools will be reviewed as a means of identifying areas of accountability that a board may need to work on

    Adhesive for cryogenic temperature applications

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    Adhesive, which bonds a metal liner to a filament wound composite structure used for cryogenic pressure vessels, prevents the metal liner from buckling under depressurization. The adhesive consists of adducts of urethane and epoxy resins

    Battery cell thermal-conductive coating increases efficiency

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    Thin coating of high-temperature epoxy resin provides necessary electrical insulation, as well as good thermal conductivity between battery cells. Insulation increases efficiency of nickel-cadmium battery, as it would any multicell battery assembly in which cell-to-cell thermal balance is critical

    A Decade of Urban History: The Historical Urban Studies Series

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    The first half of the 1990s was a pivotal period in the development and growth of urban history in Europe. In Britain the Urban History Group began to convene again after a decade in abeyance, work commenced on the three-volume Cambridge Urban History of Britain, the Urban History Yearbook became Urban History whilst the European Association of Urban Historians organized their first conference. It was in this climate that Ashgate Publishing commissioned a new monograph series, Historical Urban Studies, under the editorship of Richard Rodger, editor of Urban History, and Jean-Luc Pinol, the leading French urban historian and a key figure in the European Association of Urban Historians (EAUH). The aim of the series was and is to be comparative over both time and space, drawing on multiple locations to explore what is common and what distinctive about the urban experience of diverse towns and nations. The broad agenda for the series was shaped by an overarching concern with the administration and governance of the city which underpinned attempts to manage the social, economic and political challenges wrought by 300 years of urban change. In particular, the editors stress the importance of the comparative element which should allow historians to distinguish ‘which were systematic factors and which were of a purely local nature’. The editors set themselves an ambitious agenda and this essay aims to explore how the series has developed over the ten or so years since it commenced publication; the degree to which it has provided a platform for advancing the sub-discipline of urban history; and to consider some future directions which urban history might take

    Slow, Continuous Beams of Large Gas Phase Molecules

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    Cold, continuous, high flux beams of benzonitrile, fluorobenzine, and anisole have been created. Buffer-gas cooling with a cryogenic gas provides the cooling and slow forward beam velocities. The beam of benzonitrile was measured to have a forward velocity peaked at 67 ±5\pm 5 m s1^{-1}, and a continuous flux of 101510^{15} molecules s1^{-1}. These beams provide a continuous source for high resolution spectroscopy, and provide an attractive starting point for further spatial manipulation of such molecules, including eventual trapping

    Actinometry of Hydrogen Plasmas

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    Optical emission spectroscopy (OES) can be used to map the electron energy distribution of hydrogen plasmas. Using actinometry, a type of OES where trace amounts of noble gases are introduced, the effect of discharge power on the electron temperature of hydrogen plasmas was explored. This was done using argon and krypton as actinometers for low pressure hydrogen plasmas. It was determined that the electron temperature decreased with respect to power supplied to the discharge

    Highly Optimized Tolerance: Robustness and Power Laws in Complex Systems

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    We introduce highly optimized tolerance (HOT), a mechanism that connects evolving structure and power laws in interconnected systems. HOT systems arise, e.g., in biology and engineering, where design and evolution create complex systems sharing common features, including (1) high efficiency, performance, and robustness to designed-for uncertainties, (2) hypersensitivity to design flaws and unanticipated perturbations, (3) nongeneric, specialized, structured configurations, and (4) power laws. We introduce HOT states in the context of percolation, and contrast properties of the high density HOT states with random configurations near the critical point. While both cases exhibit power laws, only HOT states display properties (1-3) associated with design and evolution.Comment: 4 pages, 2 figure

    Highly Optimized Tolerance: Robustness and Design in Complex Systems

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    Highly optimized tolerance (HOT) is a mechanism that relates evolving structure to power laws in interconnected systems. HOT systems arise where design and evolution create complex systems sharing common features, including (1) high efficiency, performance, and robustness to designed-for uncertainties, (2) hypersensitivity to design flaws and unanticipated perturbations, (3) nongeneric, specialized, structured configurations, and (4) power laws. We study the impact of incorporating increasing levels of design and find that even small amounts of design lead to HOT states in percolation

    Power Laws, Highly Optimized Tolerance, and Generalized Source Coding

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    We introduce a family of robust design problems for complex systems in uncertain environments which are based on tradeoffs between resource allocations and losses. Optimized solutions yield the “robust, yet fragile” features of highly optimized tolerance and exhibit power law tails in the distributions of events for all but the special case of Shannon coding for data compression. In addition to data compression, we construct specific solutions for world wide web traffic and forest fires, and obtain excellent agreement with measured data
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