747 research outputs found

    Picosecond photofragment spectroscopy. I. Microcanonical state-to-state rates of the reaction NCNO→CN+NO

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    This paper, the first in a series of three papers, gives a detailed account of our studies on picosecond photofragment spectroscopy. The unimolecular reaction NCNO→CN+NO is examined in detail here. Microcanonical state‐to‐state rates are measured in molecular beams at different energies in the reagent NCNO using pump–probe techniques: one picosecond pulse initiates the reaction from an initial (v,J) state and a second pulse, delayed in time, monitors the CN radical product in a specific rovibrational state, or the reagent NCNO (transient absorption). The threshold energy for reaction is determined to be 17 083 cm^(−1) (bond energy=48.8 kcal/mol). Measured rates are found to be sharply dependent on the total energy of the reagent, but independent of the rotational quantum state of product CN. Results of transient absorption measurements are used to argue that the ground statepotential energy surface dominates the reaction in the range of excess energies studied. The energy dependence of the rates, k_(MC)(E), is compared with that predicted by statistical theories. Both standard RRKM (tight transition state) and phase space theory (loose transition state) fail to reproduce the data over the full range of energies studied, even though nascent product state distributions are known to be in accord with PST at these energies. Furthermore, k_(MC)(E) is not a strictly monotonically increasing function of energy but exhibits some structure which cannot be explained by simple statistical theories. We advance some explanations for this structure and deviations from statistical theories

    Enhancing Nursing Education with the World Wide Web

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    Distance learning in nursing is a relatively new phenomenon. The rapidly changing health care environment, the diversity of students entering nursing, and curriculum changes calling for more student-centered, interactive teaching methods are a few of the reasons why the time is right to explore Web based distance learning (WBDL). In this article the authors discuss reasons to incorporate Web based distance learning into nursing education

    The analogue strikes back: Star Wars, star authenticity, and cinematic anachronism

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    As if responding to the widespread condemnation of George Lucas's 'CGI-heavy' prequel Star Wars trilogy, J.J Abrams’s 2015 'reboot' The Force Awakens displays an extreme reliance upon star presence and authentic practical effects, to an extent that produces significant textual effects at a variety of levels. We here show how the film is premised upon and preoccupied with the authentic and authenticating presence of the main stars of the first wave of Star Wars productions (1977-83). However, on this outing we also expand what traditionally counts as a star 'actor' beyond the likes of Carrie Fisher and Harrison Ford courtesy of actor-network theory and recent 'media archaeology' trends. Indeed, Abrams proclaimed that his Star Wars film would hark back to a more 'authentic' aesthetic, by employing Panavision cameras and vintage Kodak stock, among other things, to capture images of the legacy stars, and other practical and animatronic effects. Consideration of these non-human 'actors' here helps us to re-perceive the role of 'zombie media' forms that move into composition with human stars to enhance the marketing and enjoyment of an authentic Star Wars experience

    Magneto-superconductivity of 100-atm O2-annealed RuSr2Gd1.5Ce0.5Cu2O10

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    Studied 100-atm O2-annealed RuSr2Gd1.5Ce0.5Cu2O10 (Ru-1222) compound crystallized in a tetragonal I4/mmm space group crystal structure. Thermo-gravemetric (TG) analysis of the compound showed the release of oxygen and breaking to metallic constituents in two distinct steps at around 350 and 500 0C. The DC magnetization data (M vs. T) revealed magnetic transition at 100 K followed by superconducting transition at 40 K. Low field M vs. H hysteresis loop showed a lower critical field (Hc1) value of around 25 Oe. Ferromagnetic component is evidenced at 5, 10, 20 and 40 K. Near saturation field of above 5 Tesla is observed at 5 K. Zero-field returning moment (Mr) and zero-moment coercive field (Hc) values at 5 K are 0.35mB and 250 Oe. The resistance vs. temperature (R vs. T) behaviour of the sample confirmed superconductivity at around 43 K. Superconductivity transition (Tc) is broadened under magnetic field with strong granularity like steps.Comment: 16 pages including text and six figure

    Contextual cropping and scaling of TV productions

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    This is the author's accepted manuscript. The final publication is available at Springer via http://dx.doi.org/10.1007/s11042-011-0804-3. Copyright @ Springer Science+Business Media, LLC 2011.In this paper, an application is presented which automatically adapts SDTV (Standard Definition Television) sports productions to smaller displays through intelligent cropping and scaling. It crops regions of interest of sports productions based on a smart combination of production metadata and systematic video analysis methods. This approach allows a context-based composition of cropped images. It provides a differentiation between the original SD version of the production and the processed one adapted to the requirements for mobile TV. The system has been comprehensively evaluated by comparing the outcome of the proposed method with manually and statically cropped versions, as well as with non-cropped versions. Envisaged is the integration of the tool in post-production and live workflows
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