5,357 research outputs found
Black Holes with Yang-Mills Hair
In Einstein-Maxwell theory black holes are uniquely determined by their mass,
their charge and their angular momentum. This is no longer true in
Einstein-Yang-Mills theory. We discuss sequences of neutral and charged SU(N)
Einstein-Yang-Mills black holes, which are static spherically symmetric and
asymptotically flat, and which carry Yang-Mills hair. Furthermore, in
Einstein-Maxwell theory static black holes are spherically symmetric. We
demonstrate that, in contrast, SU(2) Einstein-Yang-Mills theory possesses a
sequence of black holes, which are static and only axially symmetric.Comment: LaTeX using epsf, aipproc, 10 pages including 9 ps figures, Talk held
by Jutta Kunz at the Conference on Particles, Fields and Gravitation in Lodz,
Poland, April 199
Moderate temperature detector development
P-side backside reflecting constant, photodiode characterization, and photodiode diffusion and G-R currents were investigated in an effort to develop an 8 m to 12 m infrared quantum detector using mercury cadmium telluride. Anodization, phosphorus implantation, and the graded band gap concept were approaches considered for backside formation. Variable thickness diodes were fabricated with a back surface anodic oxide to investigate the effect of this surface preparation on the diffusion limited zero bias impedance. A modeling technique was refined to thoroughly model diode characteristics. Values for the surface recombination velocity in the depletion region were obtained. These values were improved by implementing better surface damage removal techniques
Isospin effects in the disappearance of flow as a function of colliding geometry
We study the effect of isospin degree of freedom on the balance energy
(E) as well as its mass dependence throughout the mass range 48-270 for
two sets of isobaric systems with N/Z = 1 and 1.4 at different colliding
geometries ranging from central to peripheral ones. Our findings reveal the
dominance of Coulomb repulsion in isospin effects on E as well as its
mass dependence throughout the range of the colliding geometry. Our results
also indicate that the effect of symmetry energy and nucleon-nucleon cross
section on E is uniform throughout the mass range and throughout the
colliding geometry. We also present the counter balancing of nucleon-nucleon
collisions and mean field by reducing the Coulomb and the counter balancing of
Coulomb and mean filed by removing the nucleon-nucleon collisions.Comment: 15 pages, 5 figure
Sensitivity of the transverse flow towards symmetry energy
We study the sensitivity of transverse flow towards symmetry energy in the
Fermi energy region as well as at high energies. We find that transverse flow
is sensitive to symmetry energy as well as its density dependence in the Fermi
energy region. We also show that the transverse flow can address the symmetry
energy at densities about twice the saturation density, however it shows the
insensitivity towards the symmetry energy at densities 2.
The mechanism for the sensitivity of transverse flow towards symmetry energy as
well as its density dependence is also discussed.Comment: Phys. Rev. C (in press)2011 14 pages, 6 figure
Does How Much and How You Pay Matter? Evidence from the Inpatient Rehabilitation Facility Prospective Payment System
We use the implementation of a new prospective payment system (PPS) for inpatient rehabilitation facilities (IRFs) to investigate the effect of changes in marginal and average reimbursement on costs. The results show that the IRF PPS led to a significant decline in costs and length of stay. Changes in marginal reimbursement associated with the move from a cost based system to a PPS led to a 7 to 11% reduction in costs. The elasticity of costs with respect average reimbursement ranged from 0.26 to 0.34. Finally, the IRF PPS had little or no impact on costs in other sites of care, mortality, or the rate of return to community residence.
Moderate temperature detector development
The development of (Hg, Cd)Te detectors for 8 to 12 micrometer wavelength regions capable of achieving significantly improved sensitivity at noncryogenic temperatures is discussed
Large-amplitude chirped coherent phonons in tellurium mediated by ultrafast photoexcited carrier diffusion
We report femtosecond time-resolved reflectivity measurements of coherent
phonons in tellurium performed over a wide range of temperatures (3K to 296K)
and pump laser intensities. A totally symmetric A coherent phonon at 3.6
THz responsible for the oscillations in the reflectivity data is observed to be
strongly positively chirped (i.e, phonon time period decreases at longer
pump-probe delay times) with increasing photoexcited carrier density, more so
at lower temperatures. We show for the first time that the temperature
dependence of the coherent phonon frequency is anomalous (i.e, increasing with
increasing temperature) at high photoexcited carrier density due to
electron-phonon interaction. At the highest photoexcited carrier density of
1.4 10cm and the sample temperature of 3K, the
lattice displacement of the coherent phonon mode is estimated to be as high as
0.24 \AA. Numerical simulations based on coupled effects of optical
absorption and carrier diffusion reveal that the diffusion of carriers
dominates the non-oscillatory electronic part of the time-resolved
reflectivity. Finally, using the pump-probe experiments at low carrier density
of 6 10 cm, we separate the phonon anharmonicity to
obtain the electron-phonon coupling contribution to the phonon frequency and
linewidth.Comment: 22 pages, 6 figures, submitted to PR
Stability of the fragments and thermalization at peak center-of-mass energy
We simulate the central reactions of nearly symmetric, and asymmetric
systems, for the energies at which the maximum production of IMFs occurs
(E).This study is carried out by using hard EOS along with
cugnon cross section and employing MSTB method for clusterization. We study the
various properties of fragments. The stability of fragments is checked through
persistence coefficient and gain term. The information about the thermalization
and stopping in heavy-ion collisions is obtained via relative momentum,
anisotropy ratio, and rapidity distribution. We find that for a complete
stopping of incoming nuclei very heavy systems are required. The mass
dependence of various quantities (such as average and maximum central density,
collision dynamics as well as the time zone for hot and dense nuclear matter)
is also presented. In all cases (i.e., average and maximum central density,
collision dynamics as well as the time zone for hot and dense nuclear matter) a
power law dependence is obtained.Comment: 21 Pages, 8 Figure
Multimodal Magnetic Resonance and Near-Infrared-Fluorescent Imaging of Intraperitoneal Ovarian Cancer Using a Dual-Mode-Dual-Gadolinium Liposomal Contrast Agent.
The degree of tumor removal at surgery is a major factor in predicting outcome for ovarian cancer. A single multimodality agent that can be used with magnetic resonance (MR) for staging and pre-surgical planning, and with optical imaging to aid surgical removal of tumors, would present a new paradigm for ovarian cancer. We assessed whether a dual-mode, dual-Gadolinium (DM-Dual-Gd-ICG) contrast agent can be used to visualize ovarian tumors in the peritoneal cavity by multimodal MR and near infra-red imaging (NIR). Intraperitoneal ovarian tumors (Hey-A8 or OVCAR3) in mice enhanced on MR two days after intravenous DM-Dual Gd-ICG injection compared to controls (SNR, CNR, p < 0.05, n = 6). As seen on open abdomen and excised tumors views and confirmed by optical radiant efficiency measurement, Hey-A8 or OVCAR3 tumors from animals injected with DM-Dual Gd-ICG had increased fluorescence (p < 0.05, n = 6). This suggests clinical potential to localize ovarian tumors by MR for staging and surgical planning, and, by NIR at surgery for resection
- …