98 research outputs found

    Near infrared spectroscopy of the type IIn SN 2010jl: evidence for high velocity ejecta

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    The Type IIn supernova SN 2010jl was relatively nearby and luminous, allowing detailed studies of the near-infrared (NIR) emission. We present 1 - 2.4 micron spectroscopy over the age range of 36 - 565 days from the earliest detection of the supernova. On day 36, the H lines show an unresolved narrow emission component along with a symmetric broad component that can be modeled as the result of electron scattering by a thermal distribution of electrons. Over the next hundreds of days, the broad components of the H lines shift to the blue by 700 km/s, as is also observed in optical lines. The narrow lines do not show a shift, indicating they originate in a different region. He I 1.0830 and 2.0587 micron lines both show an asymmetric broad emission component, with a shoulder on the blue side that varies in prominence and velocity from -5500 km/s on day 108 to -4000 km/s on day 219. This component may be associated with the higher velocity flow indicated by X-ray observations of the supernova. The absence of the feature in the H lines suggests that this is from a He rich ejecta flow. The He I 1.0830 micron feature has a narrow P Cygni line, with absorption extending to ~100 km/s and strengthening over the first 200 days, and an emission component which weakens with time. At day 403, the continuum emission becomes dominated by a blackbody spectrum with a temperature of ~1900 K, suggestive of dust emission.Comment: 17 pages, 18 figure

    The Future of Textiles: Disruption and Collaboration

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    The textile field, while not “local” in the geographic sense, is a community: a group of people with a shared language, history, and practices that date back thousands of years. As deeply-rooted as those materials and practices are, textiles is also an area that has historically experienced enormous disruptions due to changing technology and globalization. In the 21st century, we are undergoing something like a second Industrial Revolution. Advances in digital and robotic technologies and shifting labor markets are driving a revolution in where and how things are made. Global climate change, lack of food security for much of the world’s population, and concern about overwhelming quantities of waste and toxic pollution are altering our priorities for land and resource management. These challenges are bringing together the formerly opposed approaches of handcraft and high-tech, organic and artificial in new and unexpected ways. Venturing into the field of textiles today is taking a bold step into a constellation of disciplines that, on the surface, may not appear to have much in common with the history of cloth. But the future of textiles will rely on cross-collaborations in areas of science, medicine, engineering, technology, agriculture, waste management, and other specialties, as well as an understanding of the balance required for environmentally and economically sustainable textile production. The panel will discuss the changes that are taking place in the textile field and will present new and burgeoning areas in the textile industry including commercially viable smart textiles, non-petroleum synthesized fibers, waterless dyeing, alternative manufacturing strategies, and sustainable practices. It will celebrate positive disruptions and cross-disciplinary collaborations that will enlarge and enrich the textile community, and demonstrate once again the resiliency of its social fabric

    Performance of Three LED-Based Fluorescence Microscopy Systems for Detection of Tuberculosis in Uganda

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    BACKGROUND: Direct smear microscopy using Ziehl-Neelsen (ZN) staining is the mainstay of tuberculosis (TB) diagnosis in most high burden countries, but is limited by low sensitivity in routine practice, particularly in high human immunodeficiency virus (HIV) prevalence settings. METHODS: We compared the performance of three commercial light emitting diode (LED)-based microscopy systems (Primostar™ iLED, Lumin™ and AFTER®) for fluorescent detection of Mycobacterium tuberculosis with ZN microscopy on slides prepared from sputum of TB suspects. Examination time for LED-based fluorescent microscopy (LED FM) and ZN slides was also compared, and a qualitative user appraisal of the LED FM systems was carried out. RESULTS: LED FM was between 5.6 and 9.4% more sensitive than ZN microscopy, although the difference was not statistically significant. There was no significant difference in the sensitivity or specificity of the three LED FM systems, although the specificity of Fraen AFTER was somewhat lower than the other LED FM methods. Examination time for LED FM was 2 and 4 times less than for ZN microscopy. LED FM was highly acceptable to Ugandan technologists, although differences in operational performance of the three systems were reported. CONCLUSIONS: LED FM compares favourably with ZN microscopy, with equivalent specificity and a modest increase in sensitivity. Screening of slides was substantially quicker using LED FM than ZN, and LED FM was rated highly by laboratory technologists. Available commercial systems have different operational characteristics which should be considered prior to programmatic implementation

    Determinants of social media adoption by B2B organizations

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    This study contributes to the current dearth of knowledge on the potential of social media as a marketing tool in industrial settings, by focusing on factors that determine social media adoption by B2B organizations. A conceptual model, which draws on the technology acceptance model and resource-based theory, is developed and tested using quantitative data from B2B organizations in the UK. Findings suggest that perceived usefulness of social media within B2B organizational contexts is determined by image, perceived ease of use and perceived barriers. Additionally, the results show that adoption of social media is significantly affected by organizational innovativeness and perceived usefulness. The moderating role of organizational innovativeness is also tested but no support is found. The findings of the study are further validated via nine qualitative interviews with B2B senior managers, yielding additional interesting and in-depth insights into the drivers of social media adoption by B2B organizations

    SDSS-III: Massive Spectroscopic Surveys of the Distant Universe, the Milky Way Galaxy, and Extra-Solar Planetary Systems

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    Building on the legacy of the Sloan Digital Sky Survey (SDSS-I and II), SDSS-III is a program of four spectroscopic surveys on three scientific themes: dark energy and cosmological parameters, the history and structure of the Milky Way, and the population of giant planets around other stars. In keeping with SDSS tradition, SDSS-III will provide regular public releases of all its data, beginning with SDSS DR8 (which occurred in Jan 2011). This paper presents an overview of the four SDSS-III surveys. BOSS will measure redshifts of 1.5 million massive galaxies and Lya forest spectra of 150,000 quasars, using the BAO feature of large scale structure to obtain percent-level determinations of the distance scale and Hubble expansion rate at z<0.7 and at z~2.5. SEGUE-2, which is now completed, measured medium-resolution (R=1800) optical spectra of 118,000 stars in a variety of target categories, probing chemical evolution, stellar kinematics and substructure, and the mass profile of the dark matter halo from the solar neighborhood to distances of 100 kpc. APOGEE will obtain high-resolution (R~30,000), high signal-to-noise (S/N>100 per resolution element), H-band (1.51-1.70 micron) spectra of 10^5 evolved, late-type stars, measuring separate abundances for ~15 elements per star and creating the first high-precision spectroscopic survey of all Galactic stellar populations (bulge, bar, disks, halo) with a uniform set of stellar tracers and spectral diagnostics. MARVELS will monitor radial velocities of more than 8000 FGK stars with the sensitivity and cadence (10-40 m/s, ~24 visits per star) needed to detect giant planets with periods up to two years, providing an unprecedented data set for understanding the formation and dynamical evolution of giant planet systems. (Abridged)Comment: Revised to version published in The Astronomical Journa

    Reflections on the Study of Transformational Leadership

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    Streaming audio requires RealPlayer.The University Archives has determined that this item is of continuing value to OSU's history.Ohio State University. Mershon Center for International Security StudiesStreaming audio, phot
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