1,997 research outputs found
Local Density of States in a Dirty Normal Metal connected to a Superconductor
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 of a superconductor - normal metal
heterostructure. We find a suppression of at small energies, which
persists to large distances. If the normal metal forms a thin layer of
thickness , a minigap in the density of states appears which is of the
order of the Thouless energy . 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
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
Entropy-driven enhanced self-diffusion in confined reentrant supernematics
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
. 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
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
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
Black Holes with Zero Mass
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
- …