2,014 research outputs found
Interstate educational programs: Are we ready?
During the past 15 years, Utah State University and other institutions have vigorously investigated the possibility of sharing educational resources across state lines. This concept, while very important to higher education\u27s future, has not been fully realized. The most obvious barriers have been lack of financial resources and working models. This paper outlines models and procedures that could benefit institutions in the development of cooperative degrees
Suppression of Bremsstrahlung at Non-Zero Temperature
The first-order bremsstrahlung emission spectrum is
at zero temperature. If the radiation is emitted into a region that contains a
thermal distribution of photons, then the rate is increased by a factor
where is the Bose-Einstein function. The stimulated
emission changes the spectrum to for . If this were correct, an infinite amount of energy would be radiated in the
low frequency modes. This unphysical result indicates a breakdown of
perturbation theory. The paper computes the bremsstrahlung rate to all orders
of perturbation theory, neglecting the recoil of the charged particle. When the
perturbation series is summed, it has a different low-energy behavior. For
, the spectrum is independent of and has a value
proportional to .Comment: 16 pages (plain TeX), figures available on reques
Knowledge Sharing Through MS SharePoint
Microsoft SharePoint is being used in Government, private, public and association offices throughout the United States. SharePoint was created to increase accountability for projects within a team environment. How could SharePoint help increase accountability in information management? This article will review SharePoint’s positive and negative characteristics in the hopes of helping information professionals understand what SharePoint really is in the information world and how it can be applied to libraries and other information management organizations
Light-front Schwinger Model at Finite Temperature
We study the light-front Schwinger model at finite temperature following the
recent proposal in \cite{alves}. We show that the calculations are carried out
efficiently by working with the full propagator for the fermion, which also
avoids subtleties that arise with light-front regularizations. We demonstrate
this with the calculation of the zero temperature anomaly. We show that
temperature dependent corrections to the anomaly vanish, consistent with the
results from the calculations in the conventional quantization. The gauge
self-energy is seen to have the expected non-analytic behavior at finite
temperature, but does not quite coincide with the conventional results.
However, the two structures are exactly the same on-shell. We show that
temperature does not modify the bound state equations and that the fermion
condensate has the same behavior at finite temperature as that obtained in the
conventional quantization.Comment: 10 pages, one figure, version to be published in Phys. Rev.
On the Role of Chaos in the AdS/CFT Connection
The question of how infalling matter in a pure state forms a Schwarzschild
black hole that appears to be at non-zero temperature is discussed in the
context of the AdS/CFT connection. It is argued that the phenomenon of
self-thermalization in non-linear (chaotic) systems can be invoked to explain
how the boundary theory, initially at zero temperature self thermalizes and
acquires a finite temperature. Yang-Mills theory is known to be chaotic
(classically) and the imaginary part of the gluon self-energy (damping rate of
the gluon plasma) is expected to give the Lyapunov exponent. We explain how the
imaginary part would arise in the corresponding supergravity calculation due to
absorption at the horizon of the black hole.Comment: 18 pages. Latex file. Minor changes. Final version to appear in
Modern Physics Letters
Skyrmions, Hadrons and isospin chemical potential
Using the Hamiltonian formulation, in terms of collective variables, we
explore the evolution of different skyrmionic parameters as function of the
isospin chemical potential (), such as the energy density, the charge
density, the isoscalar radius and the isoscalar magnetic radius. We found that
the radii start to grow very fast for MeV, suggesting the
occurrence of a phase transition.Comment: 10 pages, 5 figure
Nickel in Non-ferrous General Engineering Alloys
ALTHOUGH nickel in its wrought forms has important applications as an engineering material, particularly in the chemical and electronic industries, the major usage of the metal, in both ferrous and non-ferrous metallurgy, is as an alloying
element.
Nickel-base alloys can be broadly divided into the
nickel-chromium -base " Superalloys" for high-temperature
service , and materials , such as nickel-copper and nickel-chromium- iron alloys, which are used for more general engineering purposes, particularly where resist-ance to corrosion is involved.
The technology of the former type of material tends
to be rather specialized, since it is concerned very
largely with high-temperature properties, and it is not
proposed to discuss these high-temperature alloys in
this paper but to describe some recent developments in the nickel-base alloys of general engineering interest and in the nickel-containing copper-base and aluminiumbase
alloys
Skyrme model and Isospin Chemical Potential
We discuss the stability of the Skyrmion solution in the presence of a finite
isospin chemical potential . Solving numerically the mass of the Skyrmion
as function of , we find a critical value MeV where the
Skyrmion mass vanishes. We compare the exact numerical treatment with an
analytical discussion based on a special shape for the profile of the Skyrmion
due to Atiyah and Manton. The extension of this ansatz for finite works
quite well for MeV. Then, for small values of , where the
analytical approach is valid, we consider the possibility of having an angular
deformation for the Skyrmionic profile, which is possible for finite values of
. This is however, a small effect. Finally we introduce finite temperature
corrections, which strength the instability induced by the chemical potential,
finding the dependence of the critical temperature on .Comment: 13 pages, 7 figure
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