16,052 research outputs found

    Tkachenko modes in rotating neutron stars: the effect of compressibility and implications for pulsar timing noise

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    Long wavelength oscillations (Tkachenko waves) of the triangular lattice of quantized vortices in superfluid neutron stars have been suggested as one of the possible explanations for the timing noise observed in many radio pulsars, in particular for the 100-1000 day variations in the spin of PSR B1828-11. Most studies to date have, however, been based on the hydrodynamics developed for superfluid Helium. In this paper we extend the formulation to a two fluid neutron and proton system, relevant for neutron star interiors and include the effect of chemical coupling, compressibility and mutual friction between the components. In particular we find that chemical coupling and compressibility can have a drastic effect on the mode structure. However, for the slower pulsars rotating at 1-10 Hz (such as PSR 1828-11), most choices of parameters in the equation of state lead to Tkachenko oscillations with frequencies in the correct range to explain the timing noise. We also investigate the case of more rapidly rotating pulsars (above 100 Hz) for which we find that there is a vast portion of parameter space in which there are no Tkachenko modes, but only modified sound waves at much higher frequencies

    Data processing large quantities of multispectral information

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    Method is combination of digital and optical techniques. Multispectral data is coded into binary matrix format and then encoded onto photographic film. Film is holographically correlated with spectral signature to generate single-class classification map. Number of maps are optically superimposed to produce full-color, multiclass classification map

    Some Problems With the Uniform Trustees’ Powers Act

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    Evangelical Christians in Canadian National Television News, 1994–2004: A Frame Analysis

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    Recent surveys have shown that most evangelical Christians in Canada believe that the news media treat them unfairly. This study empirically tested the validity of the evangelicals’ charge against the media by examining the frames used in the nightly, national news reports of Global, CBC and CTV television networks. An analysis of all reports featuring evangelicals showed that neutral and positive frames, together, were almost equal in strength and number to negative frames used; this resulted in an overall rating of “balanced” for the coverage. While overall the coverage was balanced, the frequency and exclusivity of certain negative frames elevated their saliency considerably. For example, the “evangelicals as intolerant” frame alone appeared in one quarter of all reports. Regarding topic of the news reports, evangelicals most often received coverage for involvement in politics followed closely by involvement in criminal or immoral actions. Implications of these results are discussed

    Being, doing, and play: A theoretical and clinical exploration

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    This paper explores the metonymy of the following aphorism, delivered by Winnicott in a 1967 lecture: “From being comes doing, but there can be no do before be.” (1970, p. 25, emphasis in original). This aphorism has been little discussed or explored in the literature, but Winnicott articulated similar ideas in his more academic papers (e.g., 1965, 1970). These similar communications about being and doing will be examined alongside more contemporary thinking about the ideas to which Winnicott alludes in this aphorism; works by Benjamin (1988) and Akhtar (2000) in particular will be brought to bear on the subject. Two case studies will then be discussed, in order to examine the clinical implications of the theoretical discussion. Ultimately, such exploration will substantiate the claim that, through the metonymy of being and doing, Winnicott was alluding to a “statement of human nature” that he published just 3 years later (1970, p. 2). Winnicott’s own concept of play will then be posited as a critical, third element comprising “the life of a human being,” which will serve to situate the discussion within a contemporary, relational framework (1970, p. 2)
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