62 research outputs found

    Interaction of Hydrogen with Graphitic Surfaces, Clean and Doped with Metal Clusters

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    ProducciĂłn CientĂ­ficaHydrogen is viewed as a possible alternative to the fossil fuels in transportation. The technology of fuel-cell engines is fully developed, and the outstanding remaining problem is the storage of hydrogen in the vehicle. Porous materials, in which hydrogen is adsorbed on the pore walls, and in particular nanoporous carbons, have been investigated as potential onboard containers. Furthermore, metallic nanoparticles embedded in porous carbons catalyze the dissociation of hydrogen in the anode of the fuel cells. For these reasons the interaction of hydrogen with the surfaces of carbon materials is a topic of high technological interest. Computational modeling and the density functional formalism (DFT) are helping in the task of discovering the basic mechanisms of the interaction of hydrogen with clean and doped carbon surfaces. Planar and curved graphene provide good models for the walls of porous carbons. We first review work on the interaction of molecular and atomic hydrogen with graphene and graphene nanoribbons, and next we address the effects due to the presence of metal clusters on the surface because of the evidence of their role in enhancing hydrogen storage.Ministerio de EconomĂ­a, Industria y Competitividad (Grant MAT2014-54378-R

    Probing the heart and mind of the viewer: scientific studies of film and theatre spectators in the Soviet Union, 1917-1936

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    A vast array of research institutes and cultural organizations began to study the viewer of Soviet cinema and theatre in the years following the October Revolution. These investigations called on the techniques of sociology, psychology, and physiology to make Soviet cultural production more “efficient” and “rational.” Belying the conventional assumption that the cultural revolution of 1928–1932 brought empirical research in aesthetics to an abrupt end, this paper traces the continuation and redefinition of studies of the viewer in the Soviet Union after the “Great Break.” My analysis of the work of the “Scientific Research Sector” at the State Institute of Cinematography (VGIK) between 1933 and 1936 outlines how Stalin-era researchers shifted their gaze from viewers’ tastes and attitudes to questions of perceptual management and effectiveness. Exploring the VGIK researchers’ attempts to determine the “laws” of aesthetic perception and optimize intelligibility, the article brings to light the developments in scientific knowledge underwriting Soviet culture's transition to a form “accessible to the millions.

    A QCD analysis of ZEUS diffractive data

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    Deep inelastic scattering with leading protons or large rapidity gaps at HERA

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    Measurement of D+- and D0 production in deep inelastic scattering using a lifetime tag at HERA

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    The production of D-+/-- and D-0-mesons has been measured with the ZEUS detector at HERA using an integrated luminosity of 133.6 pb(-1). The measurements cover the kinematic range 5 < Q(2) < 1000 GeV2, 0.02 < y < 0.7, 1.5 < p(T)(D) < 15 GeV and |eta(D)| < 1.6. Combinatorial background to the D-meson signals is reduced by using the ZEUS microvertex detector to reconstruct displaced secondary vertices. Production cross sections are compared with the predictions of next-to-leading-order QCD, which is found to describe the data well. Measurements are extrapolated to the full kinematic phase space in order to obtain the open-charm contribution, F-2(c (c) over bar), to the proton structure function, F-2
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