7,760 research outputs found
Vector boson production in association with KK modes of the ADD model to NLO in QCD at LHC
Next-to-leading order QCD corrections to the associated production of vector
boson (Z/W) with the the Kaluza-Klein modes of the graviton in large extra
dimensional model at the LHC, are presented. We have obtained various kinematic
distributions using a Monte Carlo code which is based on the two cut off phase
space slicing method that handles soft and collinear singularities appearing at
NLO level. We estimate the impact of the QCD corrections on various observables
and find that they are significant. We also show the reduction in factorization
scale uncertainty when QCD corrections are included.Comment: 12 pages, 5 figure
High Temperature Thermal Expansion Studies of Pure UO2, Gd2O3 & of UO2-1.5 w/o Gd2O3 Solid Solution
1096-109
Quantum oscillator and Kepler-Coulomb problems in curved spaces: deformed shape invariance, point canonical transformations, and rational extensions
The quantum oscillator and Kepler-Coulomb problems in -dimensional spaces
with constant curvature are analyzed from several viewpoints. In a deformed
supersymmetric framework, the corresponding nonlinear potentials are shown to
exhibit a deformed shape invariance property. By using the point canonical
transformation method, the two deformed Schr\"odinger equations are mapped onto
conventional ones corresponding to some shape-invariant potentials, whose
rational extensions are well known. The inverse point canonical transformations
then provide some rational extensions of the oscillator and Kepler-Coulomb
potentials in curved space. The oscillator on the sphere and the Kepler-Coulomb
potential in a hyperbolic space are studied in detail and their extensions are
proved to be consistent with already known ones in Euclidean space. The
partnership between nonextended and extended potentials is interpreted in a
deformed supersymmetric framework. Those extended potentials that are
isospectral to some nonextended ones are shown to display deformed shape
invariance, which in the Kepler-Coulomb case is enlarged by also translating
the degree of the polynomial arising in the rational part denominator.Comment: 32 pages, no figure; published versio
The sensitivity of a syndromic management approach in detecting sexually transmitted diseases in patients at a public health clinic in Cape Town
Objectives. To evaluate the sensitivity of a syndromic diagnostic procedure in detecting and treating sexually transmitted diseases (STDs) and genital tract infections (GTIs).Methods. All new patients presenting at an STD clinic were sampled systematically by gender over a 6-week period. After the patient's clinical consultation, the clinical records were reviewed. Thereafter all patients were given a thorough genital examination by the research physician, and specimens were collected for laboratory investigations. In a retrospective simulation clinicians' syndromic diagnoses were validated against the laboratory findings, or for genital ulcer syndrome against the findings of the research physician.Results. 170 men and 161 women were included in the sample. Ninety-five per cent of patients were black and the median age was 22 years for women and 26 years for men. In this setting, the Western Cape syndromic diagnostic procedure achieved reasonable levels of sensitivity in detecting Neisseria gonorrhoeae and Chlamydia trachornatis ID men and women, and in detecting Trichomonas vaginalis and bacterial vaginosis ID women. However, it was estimated to be only 36.4% sensitive in detecting genital ulcers ID women, and between 0% and 12.3% sensitive in detecting Candida albicans. With syndromic management 8.2% of men and 32.9% of women would leave the clinic with at least one infection inadequately treated.Conclusions. Despite the introduction of syndromic protocols, it is likely that a proportion of STDs and GTIs are not being detected and treated owing to the high prevalence of multiple syndromes and mixed infections, both symptomatic and asymptomatic
Coherent States for the Non-Linear Harmonic Oscillator
Wave packets for the Quantum Non-Linear Oscillator are considered in the
Generalized Coherent State framerwork. To first order in the non-linearity
parameter the Coherent State behaves very similarly to its classical
counterpart. The position expectation value oscillates in a simple harmonic
manner. The energy-momentum uncertainty relation is time independent as in a
harmonic oscillator. Various features, (such as the Squeezed State nature), of
the Coherent State have been discussed
NLO-QCD Corrections to Dilepton Production in the Randall-Sundrum Model
The dilepton production process at hadron colliders in the Randall-Sundrum
(RS) model is studied at next-to-leading order in QCD. The NLO-QCD corrections
have been computed for the virtual graviton exchange process in the RS model,
in addition to the usual gamma, Z-mediated processes of standard Drell-Yan.
K-factors for the cross-sections at the LHC and Tevatron for differential in
the invariant mass, Q, and the rapidity, Y, of the lepton pair are presented.
We find the K-factors are large over substantial regions of the phase space.Comment: 24 pages, 12 figure
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Si photocathode with Ag-supported dendritic Cu catalyst for CO2 reduction
Si photocathodes integrated with Ag-supported dendritic Cu catalysts are used to perform light-driven reduction of CO2 to C2 and C3 products in aqueous solution. A back illumination geometry with an n-type Si absorber was used to permit the use of absorbing metallic catalysts. Selective carrier collection was accomplished by a p+ implantation on the illumination side and an n+ implantation followed by atomic layer deposition of TiO2 on the electrolyte site. The Ag-supported dendritic Cu CO2 reduction catalyst was formed by evaporation of Ag followed by high-rate electrodeposition of Cu to form a high surface area structure. Under simulated 1 sun illumination in 0.1 M CsHCO3 saturated with CO2, the photovoltage generated by the Si (∼600 mV) enables C2 and C3 products to be produced at -0.4 vs. RHE. Texturing of both sides of the Si increases the light-limited current density, due to reduced reflection on the illumination side, and also deceases the onset potential. Under simulated diurnal illumination conditions photocathodes maintain over 60% faradaic efficiency to hydrocarbon and oxygenate products (mainly ethylene, ethanol, propanol) for several days. After 10 days of testing, contamination from the counter electrode is observed, which causes an increase in hydrogen production. This effect is mitigated by a regeneration procedure which restores the original catalyst selectivity. A tandem, self-powered CO2 reduction device was formed by coupling a Si photocathode with two series-connected semitransparent CH3NH3PbI3 perovskite solar cells, achieving an efficiency for the conversion of sunlight to hydrocarbons and oxygenates of 1.5% (3.5% for all products)
Eigen modes for the problem of anomalous light transmission through subwavelength holes
We show that the wide-spread concept of optical eigen modes in lossless
waveguide structures, which assumes the separation on propagating and
evanescent modes, fails in the case of metal-dielectric structures, including
photonic crystals. In addition to these modes, there is a sequence of new
eigen-states with complex values of the propagation constant and non-vanishing
circulating energy flow. The whole eigen-problem ceases to be hermitian because
of changing sign of the optical dielectric constant. The new anomalous modes
are shown to be of prime importance for the description of the anomalous light
transmission through subwavelength holes.Comment: 5 pages, 4 figure
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