1,624 research outputs found

    A design handbook for phase change thermal control and energy storage devices

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    Comprehensive survey is given of the thermal aspects of phase change material devices. Fundamental mechanisms of heat transfer within the phase change device are discussed. Performance in zero-g and one-g fields are examined as it relates to such a device. Computer models for phase change materials, with metal fillers, undergoing conductive and convective processes are detailed. Using these models, extensive parametric data are presented for a hypothetical configuration with a rectangular phase change housing, using straight fins as the filler, and paraffin as the phase change material. These data are generated over a range of realistic sizes, material properties, and thermal boundary conditions. A number of illustrative examples are given to demonstrate use of the parametric data. Also, a complete listing of phase change material property data are reproduced herein as an aid to the reader

    Determination of aerosol content in the atmosphere from ERTS-1 data

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    The author has identified the following significant results. Significant results, relating the radiance over water surfaces to the atmospheric aerosol content, have been obtained. The results indicate that the MSS channels 4, 5, and 6 centered at 0.55, 0.65, and 0.75 microns have comparable sensitivity, and that the aerosol content can be determined within + or - 10% with the assumed measurement errors of the MSS. The fourth channel, MSS 7, is not useful for aerosol determination due to the water radiance values from this channel generally being less than the instrument noise. The accuracy of the aerosol content measurement could be increased by using an instrument specifically designed for this purpose. This radiance-aerosol content relationship can possibly provide a basis for monitoring the atmospheric aerosol content on a global basis, allowing a base-line value of aerosols to be established. The contrast-aerosol content investigation shows useful linear relationships in MSS channels 4 and 5, allowing the aerosol content to be determined within + or - 10%. MSS 7 is not useful due to the low accuracy in the water radiance, and MSS 6 is found to be too insensitive. These results rely on several assumptions due to the lack of ground truth data, but do serve to indicate which channels are most useful

    Interstate Water Litigation in the West: A Fifty-Year Retrospective

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    The Political Cultures of Irrigation and the Proxy Battles of Interstate Water Litigation

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    Groundwater depletion ignores the political boundaries of western states, the legal boundaries of western water codes, and the jurisdictional boundaries of western water federalism. In the wake of the groundwater revolution, it is becoming apparent that certain interstate lawsuits derive essentially from deeper conflicts rooted in the clash between surface-water and groundwater irrigation communities—and their respective political cultures. The interstate divide may be yielding to the hydrological divide. This article attends to that deeper relationship between irrigation agriculture and political culture across the Great Plains. Part I provides a brief history of its surface-water irrigation communities, to compose a recognizable image of their political culture: one that is rooted in classical western water law and cooperative water federalism, and depends upon interstate compacts and federal irrigation projects. Part II surveys the groundwater revolution and the distinct political culture it has generated: one that doubts the merits of classical western water law, and suspects the power of western water federalism. Part III describes a revealing theater of the conflict between these political cultures: the Republican River Basin. On the surface, the conflict is a legal casus belli between sovereign states. But beneath that conflict lies a deeper and more intractable conflict, where interstate litigation becomes recognizable as a proxy battle between surface-water and groundwater irrigation communities. How the states and the United States resolve this deeper conflict may determine the future of water federalism across the Great Plains—and the fate of the rivers upon which its communities depend

    Beyond Drought: Water Rights in the Age of Permanent Depletion

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    This is the published version

    Pharmacologic inhibition of RGD-binding integrins ameliorates fibrosis and improves function following kidney injury

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    Fibrosis is a final common pathway for many causes of progressive chronic kidney disease (CKD). Arginine-glycine-aspartic acid (RGD)-binding integrins are important mediators of the pro-fibrotic response by activating latent TGF-β at sites of injury and by providing myofibroblasts information about the composition and stiffness of the extracellular matrix. Therefore, blockade of RGD-binding integrins may have therapeutic potential for CKD. To test this idea, we used small-molecule peptidomimetics that potently inhibit a subset of RGD-binding integrins in a murine model of kidney fibrosis. Acute kidney injury leading to fibrosis was induced by administration of aristolochic acid. Continuous subcutaneous administration of CWHM-12, an RGD integrin antagonist, for 28 days improved kidney function as measured by serum creatinine. CWHM-12 significantly reduced Collagen 1 (Col1a1) mRNA expression and scar collagen deposition in the kidney. Protein and gene expression markers of activated myofibroblasts, a major source of extracellular matrix deposition in kidney fibrosis, were diminished by treatment. RNA sequencing revealed that inhibition of RGD integrins influenced multiple pathways that determine the outcome of the response to injury and of repair processes. A second RGD integrin antagonist, CWHM-680, administered once daily by oral gavage was also effective in ameliorating fibrosis. We conclude that targeting RGD integrins with such small-molecule antagonists is a promising therapeutic approach in fibrotic kidney disease

    The Interaction of Management with Botanical Composition of Irrigated Grass-Legume Pasture Mixtures in the Intermountain West USA

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    Beef produced on semi-arid range and milk produced in confinement are the main agricultural commodities in the semi-arid western USA. The studies reported here were undertaken to determine the suitability of irrigated pasture as an alternative to traditional beef and dairy production systems. The clipping and grazing studies were not run concurrently or within the same field, but were successive steps in selecting mixtures best-suited for rotational stocking of irrigated pastures in the Intermountain West. Summaries of productivity data have been reported elsewhere (MacAdam, 2002; MacAdam et al., 2004)

    Mediterranean radiocarbon offsets and calendar dates for prehistory

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    A single Northern Hemisphere calibration curve has formed the basis of radiocarbon dating in Europe and the Mediterranean for five decades, setting the time frame for prehistory. However, as measurement precision increases, there is mounting evidence for some small but substantive regional (partly growing season) offsets in same-year radiocarbon levels. Controlling for interlaboratory variation, we compare radiocarbon data from Europe and the Mediterranean in the second to earlier first millennia BCE. Consistent with recent findings in the second millennium CE, these data suggest that some small, but critical, periods of variation for Mediterranean radiocarbon levels exist, especially associated with major reversals or plateaus in the atmospheric radiocarbon record. At high precision, these variations potentially affect calendar dates for prehistory by up to a few decades, including, for example, Egyptian history and the much-debated Thera/Santorini volcanic eruption
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