34,873 research outputs found

    Development of an optimized intumescent coating

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    Intumescent coatings for small diameter air launched missiles were studied. An aerodynamically smooth, moderately flexible coating, with excellent thermal efficiency was developed

    Culture Rules: The Foundations of the Rule of Law and Other Norms of Governance

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    This study presents evidence about relations between national culture and social institutions. We operationalize culture with data on cultural dimensions for over 50 nations adopted from cross-cultural psychology and generate testable hypotheses about three basic social norms of governance: the rule of law, corruption, and accountability. These norms correlate systematically and strongly with national scores on cultural dimensions and also differ across cultural regions of the world. Regressions indicate that quantitative measures of national culture are alone remarkably predictive of governance, that economic inequality and British heritage add to predictive power, but that economic development and other factors add little. The results suggest a framework for understanding the relations between fundamental institutions of social order as well as policy implications for reform programs in transition economies.http://deepblue.lib.umich.edu/bitstream/2027.42/39991/3/wp605.pd

    Development of thermal stratification and destratification scaling concepts. Volume 1: Definition of thermal stratification scaling parameters and experimental investigations

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    The dimensionless parameters associated with the thermal stratification and pressure history of a heated container of liquid and its vapor were examined. The Modified Grashof number, the Fourier number, and an Interface number were parameterized using a single test liquid, Freon 113. Cylindrical test tanks with spherical dome end caps were built. Blanket heaters covered the tanks and thermocouples monitored the temperatures of the liquid, the ullage, the tank walls, and the foam insulation encapsulating the tank. A centrifuge was used for the 6 inch tank to preserve the same scaling parameter values between it and the larger tanks. Tests were conducted over a range of Gr* values and the degree of scaling was checked by comparing the dimensionless pressures and temperatures for each scaled pair of tests. Results indicate that the bulk liquid temperature, the surface temperature of the liquid, and the tank pressure can be scaled with the three dimensionless parameters. Some deviation was, however, found in the detailed temperature profiles between the scaled pairs of tests

    Constructing Gravitational Dimensions

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    It would be extremely useful to know whether a particular low energy effective theory might have come from a compactification of a higher dimensional space. Here, this problem is approached from the ground up by considering theories with multiple interacting massive gravitons. It is actually very difficult to construct discrete gravitational dimensions which have a local continuum limit. In fact, any model with only nearest neighbor interactions is doomed. If we could find a non-linear extension for the Fierz-Pauli Lagrangian for a graviton of mass mg which does not break down until the scale Lambda_2=(mg Mpl)^(1/2), this could be used to construct a large class of models whose continuum limit is local in the extra dimension. But this is shown to be impossible: a theory with a single graviton must break down by Lambda_3 = (mg^2 Mpl)^(1/3). Next, we look at how the discretization prescribed by the truncation of the KK tower of an honest extra diemsinon rasies the scale of strong coupling. It dictates an intricate set of interactions among various fields which conspire to soften the strongest scattering amplitudes and allow for a local continuum limit. A number of canditate symmetries associated with locality in the discretized dimension are also discussed.Comment: 21 pages, 6 diagrams, 1 figur

    Forest structure, stand composition, and climate-growth response in montane forests of Jiuzhaigou National Nature Reserve, China.

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    Montane forests of western China provide an opportunity to establish baseline studies for climate change. The region is being impacted by climate change, air pollution, and significant human impacts from tourism. We analyzed forest stand structure and climate-growth relationships from Jiuzhaigou National Nature Reserve in northwestern Sichuan province, along the eastern edge of the Tibetan plateau. We conducted a survey to characterize forest stand diversity and structure in plots occurring between 2050 and 3350 m in elevation. We also evaluated seedling and sapling recruitment and tree-ring data from four conifer species to assess: 1) whether the forest appears in transition toward increased hardwood composition; 2) if conifers appear stressed by recent climate change relative to hardwoods; and 3) how growth of four dominant species responds to recent climate. Our study is complicated by clear evidence of 20(th) century timber extraction. Focusing on regions lacking evidence of logging, we found a diverse suite of conifers (Pinus, Abies, Juniperus, Picea, and Larix) strongly dominate the forest overstory. We found population size structures for most conifer tree species to be consistent with self-replacement and not providing evidence of shifting composition toward hardwoods. Climate-growth analyses indicate increased growth with cool temperatures in summer and fall. Warmer temperatures during the growing season could negatively impact conifer growth, indicating possible seasonal climate water deficit as a constraint on growth. In contrast, however, we found little relationship to seasonal precipitation. Projected warming does not yet have a discernible signal on trends in tree growth rates, but slower growth with warmer growing season climates suggests reduced potential future forest growth

    Culture Rules: The Foundations of the Rule of Law and Other Norms of Governance

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    This study presents evidence about relations between national culture and social institutions. We operationalize culture with data on cultural dimensions for over 50 nations adopted from cross-cultural psychology and generate testable hypotheses about three basic social norms of governance: the rule of law, corruption, and accountability. These norms correlate systematically and strongly with national scores on cultural dimensions and also differ across cultural regions of the world. Regressions indicate that quantitative measures of national culture are alone remarkably predictive of governance, that economic inequality and British heritage add to predictive power, but that economic development and other factors add little. The results suggest a framework for understanding the relations between fundamental institutions of social order as well as policy implications for reform programs in transition economies.Rule of Law, Corruption, Accountability, Culture, Governance, Economic Inequality, Economic Development

    A new estimate on Evans' Weak KAM approach

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    We consider a recent formulation of weak KAM theory proposed by Evans. As well as for classical integrability, for one dimensional mechanical Hamiltonian systems all the computations can be explicitly done. This allows us on the one hand to illustrate the geometric content of the theory, on the other hand to prove new lower bounds which extend also to the generic n degrees of freedom case
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