2,252 research outputs found

    Local Density of States in a Dirty Normal Metal connected to a Superconductor

    Full text link
    A superconductor in contact with a normal metal not only induces superconducting correlations, known as proximity effect, but also modifies the density of states at some distance from the interface. These modifications can be resolved experimentally in microstructured systems. We, therefore, study the local density of states N(E,x)N(E,x) of a superconductor - normal metal heterostructure. We find a suppression of N(E,x)N(E,x) at small energies, which persists to large distances. If the normal metal forms a thin layer of thickness LnL_n, a minigap in the density of states appears which is of the order of the Thouless energy D/Ln2\sim \hbar D/L_n^2. A magnetic field suppresses the features. We find good agreement with recent experiments of Gu\'eron {\it et al.}Comment: 5 pages, RevTeX, 7 Figures (included), Submitted to PRB. Revised version: One figure changed, missprints correcte

    Manned geosynchronous mission requirements and systems analysis study add-on

    Get PDF
    An MOTV mission model was constructed in order to establish the baseline condition for SOC basing. A mission model to reflect satellite servicing was extended. Yearly traffic was projected. Driver missions were categorized. Cost trades and sensitivity to traffic rates were performed and service equipment needs were identified

    Analysis of failed contacts from methode connector, FD-744-3S-SF

    Get PDF
    Methode contact cracking failure and subsequent production quality contro

    Entropy-driven enhanced self-diffusion in confined reentrant supernematics

    Full text link
    We present a molecular dynamics study of reentrant nematic phases using the Gay-Berne-Kihara model of a liquid crystal in nanoconfinement. At densities above those characteristic of smectic A phases, reentrant nematic phases form that are characterized by a large value of the nematic order parameter S1S\simeq1. Along the nematic director these "supernematic" phases exhibit a remarkably high self-diffusivity which exceeds that for ordinary, lower-density nematic phases by an order of magnitude. Enhancement of self-diffusivity is attributed to a decrease of rotational configurational entropy in confinement. Recent developments in the pulsed field gradient NMR technique are shown to provide favorable conditions for an experimental confirmation of our simulations.Comment: 10 pages, 5 figure

    Modeling Vegetation Effects on Barrier Island Evolution

    Get PDF
    Barrier islands play a significant role in protecting coastlines and harboring coastal habitats. In an effort to study and better understand the evolution of barrier island systems, a cellular model capturing various meteorological and environmental processes is proposed. Erosion due to wind, gravity, and marine processes are coupled with plant population effects. We demonstrate the inhibition of plant cover on sediment mobility, island migration, and erosion in the presence of sea level rise

    Blackfish-ing for Buzz: The Rhetoric of the Real in Theme Parks and Documentary

    Get PDF
    In 2014, a year of record tourism in the state of Florida, SeaWorld saw a drop of one million visitors to its theme park in Orlando. The decline followed Gabriela Cowperthwaite’s 2013 documentary film Blackfish, which presented the circumstances of orcas, or “killer whales,” held in captivity at parks like SeaWorld as cruel to the animals and dangerous to their trainers. In 2016, SeaWorld announced it will stop breeding orcas, and phase out its orca theatrical shows by 2019, a move widely attributed in the press to the impact of Cowperthwaite’s film. This article examines the film Blackfish as a rhetorical alignment of the symbolic functions of theme parks and documentaries, analyzing the work of the film’s discourse to influence audiences and challenge to SeaWorld’s use of captive orcas to entertain tourists

    Identity and Scene: Alterity and Authenticity in Taxicab Confessions

    Get PDF
    This essay examines the visual rhetoric of HBOs reality TV program Taxicab Confessions, New York, New York (2005). Drawing on Burke’s rhetorical understanding of scene and Straw’s approach to scene as a category for the analysis of urban culture, I argue that the taxicab interior and nighttime street images of New York City structure a scene of indeterminacy, intimacy, and “reality,” thus framing the passengers’ self-presentations within a context of “authenticity.” The program’s visual structure locates passengers simultaneously outside of and within social norms and reinforces hegemonic notions of race, gender, and sexuality. Passengers are situated within a scene that positions them as both eccentric and ordinary, while audiences are provided with a symbolic other that works to contain stretched-but-not-broken norms and thus anchor the normality of the viewer

    The role of string-like, supramolecular assemblies in reentrant supernematic liquid crystals

    Full text link
    Using a combination of isothermal-isobaric Monte Carlo and microcanonical molecular dynamics we investigate the relation between structure and self-diffusion in various phases of a model liquid crystal using the Gay-Berne-Kihara potential. These molecules are confined to a mesoscopic slit-pore with atomically smooth substrate surfaces. As reported recently [see M. G. Mazza {\em et al.}, Phys. Rev. Lett. {\bf 105}, 227802 (2010)], a reentrant nematic (RN) phase may form at sufficiently high pressures/densities. This phase is characterized by a high degree of nematic order and a substantially enhanced self-diffusivity in the direction of the director n^\hat{\bm{n}} which exceeds that of the lower-density nematic and an intermittent smectic A phase by about an order of magnitude. Here we demonstrate that the unique transport behavior in the RN phase may be linked to a confinement-induced packing effect which causes the formation of supramolecular, string-like conformations. The strings consist of several individual molecules that are capable of travelling in the direction of n^\hat{\bm{n}} as individual "trains" consisting of chains of molecular "cars". Individual trains run in parallel and may pass each other at sufficiently high pressures.Comment: 24 page

    Black Holes with Zero Mass

    Full text link
    We consider the spacetimes corresponding to static Global Monopoles with interior boundaries corresponding to a Black Hole Horizon and analyze the behavior of the appropriate ADM mass as a function of the horizon radius r_H. We find that for small enough r_H, this mass is negative as in the case of the regular global monopoles, but that for large enough r_H the mass becomes positive encountering an intermediate value for which we have a Black Hole with zero ADM mass.Comment: 10 pages, 2 ps figures, REVTeX, some minor change
    corecore