3,943 research outputs found
Sudakov Logarithm Resummation in Transverse Momentum Space for Electroweak Boson Production at Hadron Colliders
A complete description of W and Z boson production at high-energy hadron
colliders requires the resummation of large Sudakov double logarithms which
dominate the transverse momentum (q_T) distribution at small q_T. We compare
different prescriptions for performing this resummation, in particular implicit
impact parameter space resummation versus explicit transverse momentum space
resummation. We argue that the latter method can be formulated so as to retain
the advantages of the former, while at the same time allowing a smooth
transition to finite order dominance at high q_T.Comment: 32 pages, Latex, epsfig, 17 figure
Modifying monolayer behaviour by incorporating subphase additives and improving Langmuir–Blodgett thin film deposition on optical fibres
Experiments showing the possibility of modifying the behaviour of calix[4]resorcinarene monolayers at the air–water interface and optimising the deposition of multilayer coatings onto optical fibres are presented. The nature of the subphase is fundamental to the behaviour of monolayers and their utility in coating and sensing applications. Here we show initial studies exploring the modification of the calix[4]resorcinarene monolayer–water interaction through the introduction of dipole altering alcohol additives to the aqueous subphase. We explored the effect of this modification for three small alcohols. The resulting isotherms of the materials showed a reduction in the surface pressure and area per molecule required in order for the monolayer to reach its point of collapse. Incorporation of alcohols shifted the point of collapse, leading to the application of ethanol being successful in improving the transfer of material via Langmuir–Blodgett coating onto optical fibres at lower pressures. This method may prove useful in allowing greater control over future sensor surface coatings
Managerial Ownership And Dividend Policy In The U.S. Banking Industry
This paper examines a sample of U.S. Bank Holding Companies (BHCs) to determine if there is a relationship between managerial equity ownership (insider holdings) and the level of dividends paid out by the BHC. Given the findings of prior research, the analysis is performed using Two-Stage Least Squares (2SLS) regression with three equations. The three dependent variables are DIVPAY (dividend payout), DEBT (total liabilities over total consolidated assets) and INSIDER (percentage of common stock held by officers and directors). This study finds that insider holdings has a non-linear relation with dividend payout. Initially, there is a significant negative relation between the level of insider holdings and the level of dividends paid. However, higher levels of insider holdings show a positive relation with the level of dividends paid
Observing the Symmetry of Attractors
We show how the symmetry of attractors of equivariant dynamical systems can
be observed by equivariant projections of the phase space. Equivariant
projections have long been used, but they can give misleading results if used
improperly and have been considered untrustworthy. We find conditions under
which an equivariant projection generically shows the correct symmetry of the
attractor.Comment: 28 page LaTeX document with 9 ps figures included. Supplementary
color figures available at http://odin.math.nau.edu/~jws
Mathematical modelling for the transmission dynamics of Rift Valley fever virus with human host
Rift Valley Fever (RVF) is a viral zoonosis spread primarily by mosquitos that primarily affects livestock but has the potential to affect humans. Because of its potential to spread quickly and become an epidemic, it has become a public concern. In this article, the transmission dynamics of RVF with mosquito, livestock and human host using a compartmental model is studied and analyzed. The basic reproduction number R0 is computed using next generation matrix and the disease-free equilibrium state is found to be locally asymptotically stable if R0 1 which implies that rift valley fever could be put under control in a population where the reproduction number is less than 1. The numerical simulations give insightful results to further explore the dynamics of the disease based on the effect of three interventions; efficacy of vaccination, culling of livestock and trapping of mosquitoes introduced in the model
Education and Manpower in the Omaha SMSA
This report is a compilation of statistics having to do with education and manpower in the Omaha Standard Metropolitan Statistical Area (SMSA). The SMSA consists of Douglas and Sarpy Counties in Nebraska and Pottawattamie County in Iowa
Packaging, deployment, and panel design concepts for a truss-stiffened 7-panel precision deployable reflector with feed boom
A concept is presented for achieving a remotely deployable truss-stiffened reflector consisting of seven integrated sandwich panels that form the reflective surface, and an integrated feed boom. The concept has potential for meeting aperture size and surface precision requirements for some high-frequency microwave remote sensing applications. The packaged reflector/feed boom configuration is a self-contained unit that can be conveniently attached to a spacecraft bus. The package has a cylindrical envelope compatible with typical launch vehicle shrouds. Dynamic behavior of a deployed configuration having a 216-inch focal length and consisting of 80-inch-diameter, two-inch-thick panels is examined through finite-element analysis. Results show that the feed boom and spacecraft bus can have a large impact on the fundamental frequency of the deployed configuration. Two candidate rib-stiffened sandwich panel configurations for this application are described, and analytical results for panel mass and stiffness are presented. Results show that the addition of only a few rib stiffeners, if sufficiently deep, can efficiently improve sandwich panel stiffness
CyberKnife with Tumor Tracking: An Effective Treatment for High-Risk Surgical Patients with Single Peripheral Lung Metastases
Standard treatment for operable patients with single peripheral lung metastases is metastasectomy. We report mature CyberKnife outcomes for high-risk surgical patients with biopsy proven single peripheral lung metastases. Twenty-four patients (median age 73 years) with a mean maximum tumor diameter of 2.5 cm (range, 0.8–4.5 cm) were treated over a 6-year period extending from September 2004 to September 2010 and followed for a minimum of 1 year or until death. A mean dose of 52 Gy (range, 45–60 Gy) was delivered to the prescription isodose line in three fractions over a 3–11 day period (mean, 7 days). At a median follow-up of 20 months, the 2-year Kaplan–Meier local control and overall survival rates were 87 and 50%, respectively. CyberKnife with fiducial tracking is an effective treatment for high-risk surgical patients with single small peripheral lung metastases. Trials comparing CyberKnife with metastasectomy for operable patients are necessary to confirm equivalence
Entangled Bessel beams
Orbital angular momentum (OAM) entanglement is investigated in the
Bessel-Gauss (BG) basis. Having a readily adjustable radial scale, BG modes
provide a more favourable basis for OAM entanglement over Laguerre-Gaussian
(LG) modes. The OAM bandwidth in terms of BG modes can be increased by
selection of particular radial modes and leads to a flattening of the spectrum.
The flattening of the spectrum allows for higher entanglement. We demonstrate
increased entanglement in terms of BG modes by performing a Bell-type
experiment and violating the appropriate Clauser Horne Shimony Holt (CHSH)
inequality. In addition, we reconstruct the quantum state of BG modes entangled
in high-dimensions.Comment: 8 pages, 4 figure
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