38 research outputs found

    Analysis and Experimental Tests of a High-Performance Evacuated Tubular Collector

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    A high-performance collector based on the use of all-glass, evacuated tubular collector elements is described and analyzed, and supporting experimental data presented. The collector operated with excellent efficiency at temperatures high enough to drive existing air conditioning units, and showed good performance under diffuse light and low insolation conditions. Collector efficiency was insensitive to operating temperature, ambient temperature, and wind speed. In addition, air, as well as liquid, can be used as the heat transfer fluid, with no significant performance penalty. While the equations governing the useful energy produced can be cast in a form similar to that for flat plate collectors, several important parameters were unique in a number of respects. The loss coefficient was unusually low, while the flow factor and effective insolation were unusually high

    The NASA Exoplanet Archive: Data and Tools for Exoplanet Research

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    We describe the contents and functionality of the NASA Exoplanet Archive, a database and tool set funded by NASA to support astronomers in the exoplanet community. The current content of the database includes interactive tables containing properties of all published exoplanets, Kepler planet candidates, threshold-crossing events, data validation reports and target stellar parameters, light curves from the Kepler and CoRoT missions and from several ground-based surveys, and spectra and radial velocity measurements from the literature. Tools provided to work with these data include a transit ephemeris predictor, both for single planets and for observing locations, light curve viewing and normalization utilities, and a periodogram and phased light curve service. The archive can be accessed at http://exoplanetarchive.ipac.caltech.edu.Comment: Accepted for publication in the Publications of the Astronomical Society of the Pacific, 4 figure

    Vampires in the village Žrnovo on the island of Korčula: following an archival document from the 18th century

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    Središnja tema rada usmjerena je na raščlambu spisa pohranjenog u Državnom arhivu u Mlecima (fond: Capi del Consiglio de’ Dieci: Lettere di Rettori e di altre cariche) koji se odnosi na događaj iz 1748. godine u korčulanskom selu Žrnovo, kada su mještani – vjerujući da su se pojavili vampiri – oskvrnuli nekoliko mjesnih grobova. U radu se podrobno iznose osnovni podaci iz spisa te rečeni događaj analizira u širem društvenom kontekstu i prate se lokalna vjerovanja.The main interest of this essay is the analysis of the document from the State Archive in Venice (file: Capi del Consiglio de’ Dieci: Lettere di Rettori e di altre cariche) which is connected with the episode from 1748 when the inhabitants of the village Žrnove on the island of Korčula in Croatia opened tombs on the local cemetery in the fear of the vampires treating. This essay try to show some social circumstances connected with this event as well as a local vernacular tradition concerning superstitions

    A Preliminary Comparison of Three Tourniquet Instructions for Just-in-Time Guidance of a Simulated Tourniquet Application

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    The American College of Surgeons (ACS) and the Department of Homeland Security (DHS) encourage the use of tourniquets as part of the “Stop the Bleed” campaign. Both have provided instructions for layperson tourniquet application in order to save the life of a hemorrhaging trauma victim. This study sought to compare the impact of using ACS and DHS instructions with manufacturer-provided instructions for the completion of simulated tourniquet application steps. Thirty surgical trainees completed a simulated tourniquet application with one of the three instruction sets. Their completion time and success for each step were measured. Participants that received ACS instructions failed the fewest number of steps (p < 0.01) and completed the task faster (Mean (SD) = 70 (33) seconds) compared to those with the manufacturer-provided instructions (p < 0.01). Tourniquet instruction sets need to be refined in order to optimize the success rate of just-in-time guidance for tourniquet application

    Sooting Tendencies of Aromatic Hydrocarbons with Oxygen-Containing Side-Chains

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    <p>Paper presented at the 2018 Spring Technical Meeting of the Eastern States Section of the Combustion Institute, March 4-7 2018, State College PA.</p> <p><br></p> <p>Yield Sooting Index (YSI) was determined for 13 oxygen-containing aromatic compounds by measuring line-of-sight spectral radiance (LSSR) in a laminar non-premixed methane/air flame doped with 1000 ppm of each compound. The compounds included anisole (methoxybenzene), other aromatic ethers, and phenols. The presence of oxygen greatly reduced soot formation in some cases, but increased it in others. Thus oxygenated aromatics are potentially valuable as fuel components with intrinsically low particulate emissions, but the specific structure is important. Compounds containing an aromatic ring with an adjacent oxygen atom tended to have a lower sooting tendency than did compounds with oxygen atoms elsewhere in the side chain. This observation was quantitatively explored using Density Functional Theory (DFT) calculations. The bond dissociation energies for nine aromatic hydrocarbons and oxygenates were calculated using GGA B3LYP density functions with 6-31G(d) basis sets. When possible, unimolecular dissociation to phenoxy radical was favored and resulted in much lower YSIs than similar compounds where the oxygen atom was not adjacent to the aromatic ring. Structures that dissociated to benzyl radical had much higher sooting tendencies, sometimes by over a factor of two in comparison to phenoxy-forming compounds.</p
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