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Medicare Advantage: Required Audits of Limited Value

Description: A letter report issued by the Government Accountability Office with an abstract that begins "In fiscal year 2006, the Centers for Medicare & Medicaid Services (CMS) spent over $51 billion on the Medicare Advantage program, which serves as an alternative to the traditional fee-for-service program. Under the Medicare Advantage program, companies wishing to participate must annually submit bids (effective with contract year 2006) that identify the health services the company will provide to Medica… more
Date: July 30, 2007
Creator: United States. Government Accountability Office.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Sensitivity study of reliable, high-throughput resolution metricsfor photoresists

Description: The resolution of chemically amplified resists is becoming an increasing concern, especially for lithography in the extreme ultraviolet (EUV) regime. Large-scale screening and performance-based down-selection is currently underway to identify resist platforms that can support shrinking feature sizes. Resist screening efforts, however, are hampered by the absence of reliable resolution metrics that can objectively quantify resist resolution in a high-throughput fashion. Here we examine two high-… more
Date: July 30, 2007
Creator: Anderson, Christopher N. & Naulleau, Patrick P.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Patterns and Implications of Gene Gain and Loss in the Evolution of Prochlorococcus

Description: Prochlorococcus is a marine cyanobacterium that numerically dominates the mid-latitude oceans and is the smallest known oxygenic phototroph. Numerous isolatesfrom diverse areas of the world's oceans have been studied and shown to be physiologically and genetically distinct. All isolates described thus far can be assigned to either a tightly clustered high-light (HL)-adapted clade, or a more divergent low-light (LL)-adapted group. The 16S rRNA sequences of the entire Prochlorococcus group differ… more
Date: July 30, 2007
Creator: Lapidus, Alla; Kettler, Gregory C.; Martiny, Adam C.; Huang, Katherine; Zucker, Jeremy; Coleman, Maureen L. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

STOUT SMEARING FOR TWISTED FERMIONS.

Description: The effect of Stout smearing is investigated in numerical simulations with twisted mass Wilson quarks. The phase transition near zero quark mass is studied on 12{sup 3} x 24, 16{sup 3} x 32 and 24{sup 3} x 48 lattices at lattice spacings a {approx_equal} 0.1-0.125 fm. The phase structure of Wilson fermions with twisted mass ({mu}) has been investigated in [1,2]. As it is explained there, the observed first order phase transition limits the minimal pion mass which can be reached in simulations a… more
Date: July 30, 2007
Creator: SCHOLZ,W.; JANSEN, K.; McNEILE, C.; MONTVAY, I.; RICHARDS, C.; URBACH, C. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Spectral Properties of Quarks in the Quark-Gluon Plasma

Description: We analyze the spectral properties of the quark propagator above the critical temperature for the deconfinement phase transition in quenched lattice QCD using clover improved Wilson fermions. The bare quark mass dependence of the quark spectral function is analyzed by varying the hopping parameter {kappa} in Landau gauge. We assume a two-pole structure for the quark spectral function, which is numerically found to work quite well for any value of {kappa}. It is shown that in the chiral limit th… more
Date: July 30, 2007
Creator: Karsch, F. & Kitazawa, M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Extensive Set of Low-Fidelity Covariances in Fast Neutron Region.

Description: An extensive set of covariances for neutron cross sections has been developed to provide initial, low-fidelity but consistent uncertainty data for nuclear criticality safety applications. The methodology for the determination of such covariances in fast neutron region is presented. It combines the nuclear reaction code EMPIRE, which calculates sensitivity to nuclear reaction model parameters and the Bayesian code KALMAN to propagate uncertainty of the model parameters onto cross sections. Takin… more
Date: July 30, 2007
Creator: Pigni, M. T.; Herman, M.; Oblozinsky, P. & Rochman, D.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

PHASE STRUCTURE OF TWISTED EGUCHI-KAWAI MODEL.

Description: We study the phase structure of the four-dimensional twisted Eguchi-Kawai model using numerical simulations. This model is an effective tool for studying SU(N) gauge theory in the large-N limit and provides a nonperturbative formulation of the gauge theory on noncommutative spaces. Recently it was found that its Z{sub n}{sup 4} symmetry, which is crucial for the validity of this model, can break spontaneously in the intermediate coupling region. We investigate in detail the symmetry breaking po… more
Date: July 30, 2007
Creator: Ishikawa, T.; Azeyanagi, T.; Hanada, M. & Hirata, T.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Estimate of the 9Be(n,el) Cross-section Uncertainties for the ENDL99 and ENDF/B-VII Evaluations

Description: Uncertainties for the ENDL99 and ENDF/B-VII evaluations of the {sup 9}Be (n, el) cross section have been estimated for incident neutron energies up to 20 MeV. The uncertainties were obtained by extracting the spread of the experimental data about the evaluations, using a sophisticated procedure to ensure smoothness of the uncertainty as a function of energy. The technique used to obtain the uncertainties is described briefly in this report, and the resulting error bands are given for the two ev… more
Date: July 30, 2007
Creator: Younes, W & Pruet, J
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

First principles calculation of point defects and mobility degradation in bulk AlSb for radiation detection application

Description: The development of high resolution, room temperature semiconductor radiation detectors requires the introduction of materials with increased carrier mobility-lifetime ({mu}{tau}) product, while having a band gap in the 1.4-2.2 eV range. AlSb is a promising material for this application. However, systematic improvements in the material quality are necessary to achieve an adequate {mu}{tau} product. We are using a combination of simulation and experiment to develop a fundamental understanding of … more
Date: July 30, 2007
Creator: Lordi, V; Aberg, D; Erhart, P & Wu, K J
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

BULK THERMODYNAMICS AND CHARGE FLUCTUATIONS AT NON-VANISHING BARYON DENSITY.

Description: We present results on bulk thermodynamic quantities as well as net baryon number, strangeness and electric charge fluctuations in QCD at non-zero density and temperature obtained from lattice calculations with almost physical quark masses for two values of the lattice cut-off aT = 1/4 and 1/6. We show that with our improved p4fa3-action the cut-off effects are under control when using lattices with a temporal extent of 6 or larger and that the contribution to the equation of state, which is due… more
Date: July 30, 2007
Creator: MIAO,C. & SCHMIDT, C.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Combined Estimation of Hydrogeologic Conceptual Model, Parameter, and Scenario Uncertainty with Application to Uranium Transport at the Hanford Site 300 Area

Description: This report to the Nuclear Regulatory Commission (NRC) describes the development and application of a methodology to systematically and quantitatively assess predictive uncertainty in groundwater flow and transport modeling that considers the combined impact of hydrogeologic uncertainties associated with the conceptual-mathematical basis of a model, model parameters, and the scenario to which the model is applied. The methodology is based on a n extension of a Maximum Likelihood implementation … more
Date: July 30, 2007
Creator: Meyer, Philip D.; Ye, Ming; Rockhold, Mark L.; Neuman, Shlomo P. & Cantrell, Kirk J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Chiral Limit and Light Quark Masses in 2+1 Flavor Domain Wall Qcd.

Description: We present results for meson masses and decay constants measured on 24{sup 3} x 64 lattices using the domain wall fermion formulation with an extension of the fifth dimension of L{sub s} = 16 for N{sub f} 2 + 1 dynamical quark flavors. The lightest dynamical meson mass in our set-up is around 331MeV. while partially quenched mesons reach masses as low as 250MeV. The applicability of SU(3) x SU(3) and SU(2) x SU(2) (partially quenched) chiral perturbation theory will be compared and we quote val… more
Date: July 30, 2007
Creator: Scholz, E. & Lin, M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Nuclear Reaction Data from Surrogate Measurements: A Consideration of (n,f) Cross Sections

Description: A brief summary of the Surrogate reaction method, an indirect approach for determining compound-nuclear reaction cross sections, is presented. The possibilities for obtaining accurate (n,f) cross sections from Surrogate measurements that are analyzed in the Weisskopf-Ewing and Ratio approximations are considered. Theoretical studies and benchmark experiments that provide new insights into the validity and limitations of the Surrogate approach, are discussed.
Date: July 30, 2007
Creator: Escher, J E; Bernstein, L A; Burke, J T; Dietrich, F S & Lyles, B F
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

MODEL STUDY OF THE SIGN PROBLEM IN A MEAN-FIELD APPROXIMATION.

Description: We study the sign problem of the fermion determinant at nonzero baryon chemical potential. For this purpose we apply a simple model derived from Quantum Chromodynamics, in the limit of large chemical potential and mass. For SU(2) color, there is no sign problem and the mean-field approximation is similar to data from the lattice. For SU(3) color the sign problem is unavoidable, even in a mean-field approximation. We apply a phase-reweighting method, combined with the mean-field approximation, t… more
Date: July 30, 2007
Creator: Hidaka, Y.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Quarkonium Correlators at Finite Temperature and Potential Models.

Description: We discuss the calculations of quarkonium spectral functions in potential models and their implications for the interpretation of the lattice data on quarkonium correlators. In particular, we find that melting of different quarkonium states does not lead to significant change in the Euclidean time correlators. The large change of the quarkonium correlators above deconfinement observed in the scalar and axial-vector channels appears to be due to the zero mode contribution.
Date: July 30, 2007
Creator: Mocsy, A. & Petreczky, P.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

STUDY OF THE CRITICAL POINT IN LATTICE QCD AT HIGH TEMPERATURE AND DENSITY.

Description: We propose a method to probe the nature of phase transitions in lattice QCD at finite temperature and density, which is based on the investigation of an effective potential as a function of the average plaquette. We analyze data obtained in a simulation of two-flavor QCD using p4-improved staggered quarks with bare quark mass m/T = 0.4, and find that a first order phase transition line appears in the high density regime for {mu}{sub q}/T {approx}> 2.5. The effective potential as a function o… more
Date: July 30, 2007
Creator: EJIRI,S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

An Event-Driven Hybrid Molecular Dynamics and Direct Simulation Monte Carlo Algorithm

Description: A novel algorithm is developed for the simulation of polymer chains suspended in a solvent. The polymers are represented as chains of hard spheres tethered by square wells and interact with the solvent particles with hard core potentials. The algorithm uses event-driven molecular dynamics (MD) for the simulation of the polymer chain and the interactions between the chain beads and the surrounding solvent particles. The interactions between the solvent particles themselves are not treated determ… more
Date: July 30, 2007
Creator: Donev, A; Garcia, A L & Alder, B J
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

THERMODYNAMICS AND HEAVY-QUARK FREE ENERGIES AT FINITE TEMPERATURE AND DENSITY WITH TWO FLAVORS OF IMPROVED WILSON QUARKS.

Description: Thermodynamics of two-flavor QCD at finite temperature and density is studied on a 16{sup 3} x 4 lattice, using a renormalization group improved gauge action and the clover improved Wilson quark action. In the simulations along lines of constant m{sub PS}/m{sub V}, we calculate the Taylor expansion coefficients of the heavy-quark free energy with respect to the quark chemical potential ({mu}{sub q}) up to the second order. By comparing the expansion coefficients of the free energies between qua… more
Date: July 30, 2007
Creator: Maezawa, Y.; Hatsuda, T.; Aoki, S.; Kanaya, K.; Ejiri, S.; Ishii, N. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Ce-doped single crystal and ceramic garnets for �y ray detection

Description: Ceramic and single crystal Lutetium Aluminum Garnet scintillators exhibit energy resolution with bialkali photomultiplier tube detection as good as 8.6% at 662 keV. Ceramic fabrication allows production of garnets that cannot easily be grown as single crystals, such as Gadolinium Aluminum Garnet and Terbium Aluminum Garnet. Measured scintillation light yields of Cerium-doped ceramic garnets indicate prospects for high energy resolution.
Date: July 30, 2007
Creator: Hull, G.; Roberts, J.; Kuntz, J.; Fisher, S.; Sanner, R.; Tillotson, T. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Barium iodide single-crystal scintillator detectors

Description: We find that the high-Z crystal Barium Iodide is readily growable by the Bridgman growth technique and is less prone to crack compared to Lanthanum Halides. We have grown Barium Iodide crystals: undoped, doped with Ce{sup 3+}, and doped with Eu{sup 2+}. Radioluminescence spectra and time-resolved decay were measured. BaI{sub 2}(Eu) exhibits luminescence from both Eu{sup 2+} at 420 nm ({approx}450 ns decay), and a broad band at 550 nm ({approx}3 {micro}s decay) that we assign to a trapped excito… more
Date: July 30, 2007
Creator: Cherepy, N
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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