21,727 research outputs found
Dark conductivity of CdS as a function of S-vapor pressure during heat treatment between 500 deg C and 700 deg C
Cadmium sulfide dark conductivity as function of sulfur vapor pressure during heat treatment between 500 and 700 deg
Assessment of the international workshop on CdS solar cells
General problems relating to the basic understanding of CdS/Cu2S solar cell operation, to material aspects of the cell and to manufacturing methods and cell engineering are discussed
X-ray and electron damage, and photochemical reactions in CdS single crystals and layers, and annealing of these defects Final report
X-ray and electron damage and photochemical reactions in CdS single crystals and layers with defect annealin
The influence of strong magnetic fields and instantons on the phase structure of the two-flavor NJL model
Both in heavy-ion collisions as in magnetars very strong magnetic fields are
produced, which has its influence on the phases of matter involved. In this
paper we investigate the effect of strong magnetic fields (B = 5 m_pi^2 /e =
1.7 x 10^19 G) on the chiral symmetry restoring phase transition using the
Nambu-Jona-Lasinio model. It is observed that the pattern of phase transitions
depends on the relative magnitude of the magnetic field and the instanton
interaction strength. We study two specific regimes in the phase diagram, high
chemical potential and zero temperature and vice versa, which are of relevance
for neutron stars and heavy-ion collisions respectively. In order to shed light
on the behavior of the phase transitions we study the dependence of the minima
of the effective potential on the occupation of Landau levels. We observe a
near-degeneracy of multiple minima with differing occupation numbers, of which
some become the global minimum upon changing the magnetic field or the chemical
potential. These minima differ considerably in the amount of chiral symmetry
breaking and in some cases also of isospin breaking.Comment: 11 pages, 8 figures, references added and some minor change
Cancellation of quantum mechanical higher loop contributions to the gravitational chiral anomaly
We give an explicit demonstration, using the rigorous Feynman rules developed
in~\0^{1}, that the regularized trace \tr \gamma_5 e^{-\beta \Dslash^2} for
the gravitational chiral anomaly expressed as an appropriate quantum mechanical
path integral is -independent up to two-loop level. Identities and
diagrammatic notations are developed to facilitate rapid evaluation of graphs
given by these rules.Comment: 10 pages, LaTeX and psfig (many figures
High-velocity gas towards the LMC resides in the Milky Way halo
To explore the origin of high-velocity gas in the direction of the Large
Magellanic Cloud (LMC) we analyze absorption lines in the ultraviolet spectrum
of a Galactic halo star that is located in front of the LMC at d=9.2 kpc
distance. We study the velocity-component structure of low and intermediate
metal ions in the spectrum of RXJ0439.8-6809, as obtained with the Cosmic
Origins Spectrograph (COS) onboard HST, and measure equivalent widths and
column densities for these ions. We supplement our COS data with a
Far-Ultraviolet Spectroscopic Explorer spectrum of the nearby LMC star Sk-69 59
and with HI 21cm data from the Leiden-Argentina-Bonn (LAB) survey. Metal
absorption towards RXJ0439.8-6809 is unambiguously detected in three different
velocity components near v_LSR=0,+60, and +150 km/s. The presence of absorption
proves that all three gas components are situated in front of the star, thus
being located in the disk and inner halo of the Milky Way. For the
high-velocity cloud (HVC) at v_LSR=+150 km/s we derive an oxygen abundance of
[O/H]=-0.63 (~0.2 solar) from the neighbouring Sk-69 59 sightline, in
accordance with previous abundance measurements for this HVC. From the observed
kinematics we infer that the HVC hardly participates in the Galactic rotation.
Our study shows that the HVC towards the LMC represents a Milky Way halo cloud
that traces low-column density gas with relatively low metallicity. It rules
out scenarios in which the HVC represents material close to the LMC that stems
from a LMC outflow.Comment: 4 pages, 3 figures; submitted to A&A Letter
Dark conductivity of CdS as a function of S-vapor pressure during heat treatment between 500 deg and 700 deg C
Dark conductivity, photoconductivity, and luminescence of cadmium sulfide crystals heat treated in sulfur or cadmium vapor
Evidence for a dual population of neutron star mergers from short Gamma-Ray Burst observations
Short duration Gamma-Ray Bursts are thought to originate from the coalescence
of neutron stars in binary systems. They are detected as a brief ( 2s),
intense flash of gamma-ray radiation followed by a weaker, rapidly decreasing
afterglow. They are expected to be detected by Advanced LIGO and Virgo when
their sensitivity will be low enough. In a recent study we identified a
population of short Gamma-Ray Bursts that are intrinsically faint and nearby.
Here we provide evidence in favor of the existence of this new population that
can hardly be reproduced with a model of field neutron star binary
coalescences. We propose that these systems may be produced dynamically in
globular clusters, and may result from the merger of a black hole and a neutron
star. The advanced LIGO and Virgo observation of a high rate of NSBH mergers
compatible with the dynamical formation in globular clusters would be a
confirmation of this hypothesis and would enable for the derivation of the mass
function of black holes inside globular clusters, as well as the luminosity
function of faint short GRBs.Comment: 15 pages, 5 figures, 1 table, submitted to Ap
Production and annealing of intrinsic defects in X-Ray irradiated CdS single crystals
Production and annealing of intrinsic defects in X-ray irradiated cadmium sulfide single crystal
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