12,643 research outputs found

    Close-packed structures and phase diagram of soft spheres in cylindrical pores

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    It is shown for a model system consisting of spherical particles confined in cylindrical pores that the first ten close-packed phases are in one-to-one correspondence with the first ten ways of folding a triangular lattice, each being characterized by a roll-up vector like the single-walled carbon nanotube. Phase diagrams in pressure-diameter and temperature-diameter planes are obtained by inherent-structure calculation and molecular dynamics simulation. The phase boundaries dividing two adjacent phases are infinitely sharp in the low-temperature limit but are blurred as temperature is increased. Existence of such phase boundaries explains rich, diameter-sensitive phase behavior unique for cylindrically confined systems

    Near-infrared spectroscopy of the very low mass companion to the hot DA white dwarf PG1234+482

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    We present a near-infrared spectrum of the hot (TeffT_{\rm eff} ≈\approx 55,000 K) DA white dwarf PG 1234+482. We confirm that a very low mass companion is responsible for the previously recognised infrared photometric excess. We compare spectra of M and L dwarfs, combined with an appropriate white dwarf model, to the data to constrain the spectral type of the secondary. We find that uncertainties in the 2MASS HKHK photometry of the white dwarf prevent us from distinguishing whether the secondary is stellar or substellar, and assign a spectral type of L0±\pm1 (M9-L1).Therefore, this is the hottest and youngest (≈106\approx 10^6 yr) DA white dwarf with a possible brown dwarf companion.Comment: 5 pages, 2 figures, accepted by MNRA

    Are we Bridging the Divide in IWO Psychology?

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    This paper examines the knowledge transfer process within the profession of work and organisational psychology. In consonance with the theme of the 2011 congress, it considers the extent to which proposed ‘bridging mechanisms’ can provide useful vehicles for operationalising the pursuit of the dual goal of improving both the well-being of individuals and the effectiveness of work organizations. It considers the way in which the profession attempts to ground its concepts in a sound evidence base and then successfully mobilise this knowledge at the interface of research and practice. It does so by critically examining the scientist-practitioner model and the ways in which this model can be operationalised by practitioners and researchers. The criticism which is aimed at academics is that their research is irrelevant; it explores narrow concepts too often with student samples. Practitioners, on the other hand, are accused of too infrequently bringing scientific findings from the research literature to their practice. The problem has been cast in terms of both one of knowledge production and also knowledge transfer and is typified, at least in one direction – the impact of research upon practice, by what has in other professions, most notably medicine and more recently management, been called evidence-based practice. Denise Rousseau, in her 2005 presidential address to the American Academy of Management defined evidence-based management (EBM) as “translating principles based on best evidence into organizational practices” and there have been a number of attempts to invoke a similar model of evidence-based practice in the field of work and organisational psychology. In 2007 Anderson described the academic-practitioner divide as ‘natural’, suggesting the way forward was to focus on ‘bridging mechanisms’ describing six which had been proposed at the 1995 SIOP conference. What is the situation over decade later? To what extent have these bridges been built? This paper explores the nature and extent of these bridges by presenting case studies and findings from a UK survey of IWO psychologists
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