872 research outputs found

    Reducing Hardships: Student Motivations, Educational Workflows, and Technology Choices in Academic Settings

    Get PDF
    Objective – This study examines The University of Manitoba student attitudes toward technology’s role in University study spaces and in their own educational workflows. Methods - A series of semi-structured group interviews were conducted with current undergraduate and graduate students at The University of Manitoba. Three group interviews were conducted with questions about individual technology and space use while studying in the library, and three group interviews were conducted with questions about group collaboration using technologies and tools in group study spaces. Transcripts were coded iteratively and separately by the researchers, analyzed for interrater reliability, categorized, and reviewed using axial coding to identify major themes. Through continued examination of these themes, a single theory emerged. Results - The participants expressed a strong need for independence and feelings of control over their workflows, technological tools, and environments. They discussed how interpersonal concerns and anxieties motivated their workflow choices and acknowledged the (often conflicting) motivational forces of personal necessity and personal preference. When examining the motivations behind the selection of technologies and work practices, it became clear that the respondents make technology and workflow decisions in an attempt to minimize their experience of perceived hardships. These perceived hardships could be social, emotional, educational, environmental, or temporal in nature, and the weight of any one hardship on decision making varied according to the individual. Conclusions - Libraries should be aware of this foundational user motivation and make choices accordingly - identifying and minimizing hardships whenever possible, unless they are necessary to achieve learning or service-specific goals. Additional research is required to help articulate the nuances experienced by particular student demographics. Librarians and future researchers should also consider investigating the potential disconnect between librarian and user attitudes toward technology, the prioritization of user-centered decision-making, and whether or not systematically disadvantaged social groups have different attitudes toward technology and its place in library spaces and academic work.https://journal.lib.uoguelph.ca/index.php/perj/article/view/545

    Fast Variations of Gamma-Ray Emission in Blazars

    Get PDF
    The largest group of sources identified by EGRET are Blazars. This sub-class of AGN is well known to vary in flux in all energy bands on time-scales ranging from a few minutes (in the optical and X-ray bands) up to decades (radio and optical regimes). In addition to variations of the gamma-ray flux between different viewing periods, the brightest of these sources showed a few remarkable gamma-ray flares on time-scales of about one day, confirming the extension of the ``Intraday-Variability (IDV)'' phenomenon into the GeV range. We present first results of a systematic approach to study fast variability with EGRET data. This statistical approach confirms the existence of IDV even during epochs when no strong flares are detected. This provides additional constraints on the site of the gamma-ray emission and allows cross-correlation analyses with light curves obtained at other frequencies even during periods of low flux. We also find that some stronger sources have fluxes systematically above threshold even during quiescent states. Despite the low count rates this allows explicit comparisons of flare amplitudes with other energy bands.Comment: 5 pages including figures, LaTex, uses aipproc.sty, to appear in the proceedings of the 4th Compton Symposium at Williamsburg, V

    An Infrared Study of the Circumstellar Material Associated with the Carbon Star R Sculptoris

    Get PDF
    The asymptotic giant branch (AGB) star R Sculptoris (R Scl) is one of the most extensively studied stars on the AGB. R Scl is a carbon star with a massive circumstellar shell (Mshell∌7.3×10−3 M⊙M_{shell}\sim 7.3\times10^{-3}~M_{\odot}) which is thought to have been produced during a thermal pulse event ∌2200\sim2200 years ago. To study the thermal dust emission associated with its circumstellar material, observations were taken with the Faint Object InfraRed CAMera for the SOFIA Telescope (FORCAST) at 19.7, 25.2, 31.5, 34.8, and 37.1 ÎŒ\mum. Maps of the infrared emission at these wavelengths were used to study the morphology and temperature structure of the spatially extended dust emission. Using the radiative transfer code DUSTY and fitting the spatial profile of the emission, we find that a geometrically thin dust shell cannot reproduce the observed spatially resolved emission. Instead, a second dust component in addition to the shell is needed to reproduce the observed emission. This component, which lies interior to the dust shell, traces the circumstellar envelope of R Scl. It is best fit by a density profile with n∝rαn \propto r^{\alpha} where α=0.75−0.25+0.45\alpha=0.75^{+0.45}_{-0.25} and dust mass of Md=9.0−4.1+2.3×10−6 M⊙M_d=9.0^{+2.3}_{-4.1}\times10^{-6}~M_{\odot}. The strong departure from an r−2r^{-2} law indicates that the mass-loss rate of R Scl has not been constant. This result is consistent with a slow decline in the post-pulse mass-loss which has been inferred from observations of the molecular gas.Comment: 10 pages, 10 figures, accepted to Ap

    Externally Dispersed Interferometry for Precision Radial Velocimetry

    Get PDF
    Externally Dispersed Interferometry (EDI) is the series combination of a fixed-delay field-widened Michelson interferometer with a dispersive spectrograph. This combination boosts the spectrograph performance for both Doppler velocimetry and high resolution spectroscopy. The interferometer creates a periodic spectral comb that multiplies against the input spectrum to create moire fringes, which are recorded in combination with the regular spectrum. The moire pattern shifts in phase in response to a Doppler shift. Moire patterns are broader than the underlying spectral features and more easily survive spectrograph blurring and common distortions. Thus, the EDI technique allows lower resolution spectrographs having relaxed optical tolerances (and therefore higher throughput) to return high precision velocity measurements, which otherwise would be imprecise for the spectrograph alone.Comment: 7 Pages, White paper submitted to the AAAC Exoplanet Task Forc

    Detection of sulphur in the galactic center

    Get PDF
    A strong detection at the (SIII) 18.71 micron line is reported for the Galactic Center region, Sgr A West. A line flux of 1.7 + or - 0.2x10 to the -17th power W cm(-2) is found for a 20-arc second beam-size measurement centered on IRS 1. A preliminary analysis indicates that the SIII abundance relative to hydrogen is consistent with the cosmic abundance of sulfur, 1.6x10 to the -5th power, if a filling factor of unity within the known clumps is assumed. However, the sulfur abundance in the Galactic Center may be as much as a factor of 3 overabundant if a filling factor of 0.03 is adopted, a value found to hold for some galactic HII regions

    Umidade ponderal em tecidos de pereira durante o perĂ­odo de dormĂȘncia sob condiçÔes de inverno ameno.

    Get PDF
    O objetivo deste trabalho foi avaliar a umidade ponderal (UP) em diferentes tecidos das cultivares de pereira Kieffer (Pyrus communis) e Housui (Pyrus pyrifolia), durante a dormĂȘncia, em condiçÔes de inverno ameno. Foram avaliadas plantas do pomar experimental da Embrapa Clima Temperado, Pelotas, RS. Utilizouse o delineamento experimental inteiramente casualizado, em esquema fatorial 3x4x5, que consistiu em trĂȘs tecidos (gema, casca e lenho), quatro porçÔes de ramos (terminal, mediana, axial e esporĂ”es) e cinco datas de coleta, em 2005 (1/7, 3/8, 6/9, 23/9 e 13/10), com parcelas subdivididas e trĂȘs repetiçÔes. Houve aumento na UP do lenho na cultivar Kieffer atĂ© a metade da dormĂȘncia, com subsequente redução a partir desta fase, o que pode ser atribuĂ­do ao aumento na UP observado nas gemas apĂłs satisfação da exigĂȘncia em frio e superação de dormĂȘncia. Na cultivar Housui, a insatisfação da exigĂȘncia em frio, associada Ă  ocorrĂȘncia de altas temperaturas durante o inverno, refletiu-se na redução da UP e na desidratação das gemas durante a dormĂȘncia. A dinĂąmica da ĂĄgua em tecidos de pereira Ă© diretamente influenciada pelo acĂșmulo de frio hibernal e depende da exigĂȘncia em frio de cada cultivar
    • 

    corecore