1,156 research outputs found

    Mapping Digital Media: Digital Media and Investigative Reporting

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    Analyzes how digital media are changing the reporting, composition, and distribution of investigative news; audience expectations; content providers' roles; and the ethical criteria for journalism, from objectivity to transparency about motives

    Application of laser Doppler velocimeter to chemical vapor laser system

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    A laser Doppler velocimeter (LDV) system was used to measure iodide vapor flow fields inside two different-sized tubes. Typical velocity profiles across the laser tubes were obtained with an estimated +/-1 percent bias and +/-0.3 to 0.5 percent random uncertainty in the mean values and +/-2.5 percent random uncertainty in the turbulence-intensity values. Centerline velocities and turbulence intensities for various longitudinal locations ranged from 13 to 17.5 m/sec and 6 to 20 percent, respectively. In view of these findings, the effects of turbulence should be considered for flow field modeling. The LDV system provided calibration data for pressure and mass flow systems used routinely to monitor the research laser gas flow velocity

    X-rays from Blue Compact Dwarf Galaxies

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    We measured the X-ray fluxes from an optically-selected sample of blue compact dwarf galaxies (BCDs) with metallicities <0.07 and solar distances less than 15 Mpc. Four X-ray point sources were observed in three galaxies, with five galaxies having no detectable X-ray emission. Comparing X-ray luminosity and star formation rate, we find that the total X-ray luminosity of the sample is more than 10 times greater than expected if X-ray luminosity scales with star formation rate according to the relation found for normal-metallicity star-forming galaxies. However, due to the low number of sources detected, one can exclude the hypothesis that the relation of the X-ray binaries to SFR in low-metalicity BCDs is identical to that in normal galaxies only at the 96.6% confidence level. It has recently been proposed that X-ray binaries were an important source of heating and reionization of the intergalactic medium at the epoch of reionization. If BCDs are analogs to unevolved galaxies in the early universe, then enhanced X-ray binary production in BCDs would suggest an enhanced impact of X-ray binaries on the early thermal history of the universe.Comment: 4 pages, to appear in Ap

    Synthesis and Antimicrobial Activity of 1,2-Benzothiazine Derivatives

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    © 2016 by the authors; licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC-BY) license (http://creativecommons.org/licenses/by/4.0/).A number of 1,2-benzothiazines have been synthesized in a three-step process. Nine chalcones 1-9 bearing methyl, fluoro, chloro and bromo substituents were chlorosulfonated with chlorosulfonic acid to generate the chalcone sulfonyl chlorides 10-18. These were converted to the dibromo compounds 19-27 through reaction with bromine in glacial acetic acid. Compounds 19-27 were reacted with ammonia, methylamine, ethylamine, aniline and benzylamine to generate a library of forty-five 1,2-benzothiazines 28-72. Compounds 28-72 were evaluated for their antimicrobial activity using broth micro dilution techniques against two Gram-positive bacteria (Bacillus subtilis and Staphylococcus aureus), and two Gram-negative bacteria (Proteus vulgaris and Salmonella typhimurium). The results demonstrated that none of the compounds showed any activity against Gram-negative bacteria, P. vulgaris and S. typhimurium, however compounds 31, 33, 38, 43, 45, 50, 53, 55, 58, 60, 63 and 68 showed activity against Gram-positive bacteria, Bacillus subtilis and Staphylococcous aureus. The range of MIC and MBC was 25-600µg/ml; though some of the MIC and MBC concentrations were high indicating weak activity. Structure activity relationship studies revealed that the compounds with a hydrogen atom or an ethyl group on the nitrogen of the thiazine ring exerted antibacterial activity against Gram-positive bacteria. The results also showed that the compounds where the benzene ring of the benzoyl moiety contained a methyl group or chlorine or bromine atom in the para position showed higher antimicrobial activity. Similar influences were identified where either a bromine or chlorine atom was in the meta position.Peer reviewedFinal Published versio

    MVP Implementation Interviews : Final Report

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    This report presents evidence from a small-scale qualitative research project which took place between January 2021 and November 2021. The project was designed to investigate the facilitators and barriers to implementing the Mentors in Violence Prevention (MVP) Scotland. This report provides some background on these issues before reporting on the main results and drawing conclusions
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