6,751 research outputs found
Compact stars in gravity
In the present paper we generate a set of solutions describing the interior
of a compact star under theory of gravity which admits conformal
motion. We consider the equation of state (EOS) with
for the fluid distribution consisting normal matter,
being the EOS parameter. We therefore explore several aspects of the model
analytically along with graphical representations to check the physical
validity as well as acceptability of it within specified observational
constraint in connection to a dozen of the compact star candidates. It is shown
from the presented model that these objects are nothing but radiating compact
stars.Comment: 16 pages, 6 figures, 1 table, substantial modification based on
referee repor
A van Hemmen-Kondo model for disordered strongly correlated electron systems
We present here a theoretical model in order to describe the competition
between the Kondo effect and the spin glass behavior. The spin glass part of
the starting Hamiltonian contains Ising spins with an intersite exchange
interaction given by the local van Hemmen model, while the Kondo effect is
described as usual by the intrasite exchange . We obtain, for large
values, a Kondo phase and, for smaller values, a succession, with
decreasingComment: 14 pages, 4 figures, accepted for publication in Phys. Rev.
Democratic Political Socialization on University Campuses
This paper intends to contextualize early research on political socialization with recent developments that provide new considerations for the transmission of democratic political learning at a more advanced learning stage. It attempts to demonstrate this literature on political socialization as the foundation for evaluating the continuing research of the Penn Democracy Project in the field of democratic political socialization of undergraduate students. In light of the political socialization literature, this paper reveals the results of the most recent iteration of the Penn Democracy Project research study, which provide insight into the state of citizenship at the University of Pennsylvania. The overarching conclusion of this study supports the notion that while the University of Pennsylvania offers resources and opportunities for undergraduates to foster civic values, through specialized courses; centers; and funding for clubs, it fails to actively cultivate a shared culture of citizenship among its students. Finally, this paper evaluates strategic policy initiatives to effectively increase democratic citizenship education for undergraduate students at the University of Pennsylvania and introduces possible considerations to transplant this “Penn Model” on other university campuses
Robustness of d-Density Wave Order to Nonmagnetic Impurities
Effect of finite density of nonmagnetic impurities on a coexisting phase of
d-density wave (DDW) order and d-wave superconducting (DSC) order is studied
using Bogoliubov-de Gennes (BdG) method. The spatial variation of the
inhomogeneous DDW order due to impurities has a strong correlation with that of
density, which is very different from that of DSC order. The length scale
associated with DDW is found to be of the order of a lattice spacing. The
nontrivial inhomogeneities are shown to make DDW order much more robust to the
impurities, while DSC order becomes very sensitive to them. The effect of
disorder on the density of states is also discussed.Comment: 4 pages, 3 PostScript figure
Reductive Biotransformation of Ethyl Acetoacetate: A Comparative Studies using Free and Immobilized Whole Yeast Cells
Bioreduction of ethyl acetoacetate with free and immobilized yeast whole cell was achieved by using water and sucrose combination. After detachment from immobilized beads under basic condition, the corresponding ethyl(S)-(+)-3-hydroxybutanoate was isolated with 98 to 100% yield. Immobilized beads of yeast whole cell were prepared at different temperature which affects the morphology and physiology of the beads for the diffusion of the enzyme, which shown the maximum conversion of the substrate to products as compared to the free yeast whole cell
Universal linear relations between susceptibility and Tc in cuprates
We developed an experimental method for measuring the intrinsic
susceptibility \chi of powder of cuprate superconductors in the zero field
limit using a DC-magnetometer. The method is tested with lead spheres. Using
this method we determine \chi for a number of cuprate families as a function of
doping. A universal linear (and not proportionality) relation between Tc and
\chi is found. We suggest possible explanations for this phenomenon.Comment: Accepted for publication in PR
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