40 Matching Results

Search Results

Results: 1 - 24 next
open access

Medicare Physician Fee Schedule: CMS Needs a Plan for Updating Practice Expense Component

Description: A letter report issued by the Government Accountability Office with an abstract that begins "Medicare's payments for the costs physicians incur in operating their practices are based on two sets of estimates: total practice expenses and resource estimates for individual services. Total practice expense estimates were derived from American Medical Association (AMA) physician surveys, which the Centers for Medicare & Medicaid Services (CMS) refines with supplemental data submitted by medical spec… more
Date: December 13, 2004
Creator: United States. Government Accountability Office.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

The Effect of Small-Size Habitat Disturbances on Population Density and Time to Extinction of the Prairie Vole

Description: We present a study, based on simulations with SERDYCA, a spatially-explicit individual-based model of rodent dynamics, on the relation between population persistence and the presence of numerous isolated disturbances in the habitat. We are specifically interested in the effect of disturbances that do not fragment the environment on population persistence. Our results suggest that the presence of disturbances in the absence of fragmentation can actually increase the average time to extinction of… more
Date: December 13, 2004
Creator: Kostova, T & Carlsen, T
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Femtosecond laser writing of waveguide structures in sodium calcium silicate glasses

Description: Waveguides were written in soda lime silicate glasses with a composition of xNa{sub 2}O xCaO (1-2x)SiO{sub 2}, where x = 15 and 20, using an amplified femtosecond laser. The waveguides formed around, not inside the exposed regions. This is similar to the waveguide behavior our group first observed in a phosphate glass, Schott IOG-1, and is distinctly different from fused silica in which the waveguides are inside the exposed regions. This data supports the rapid quenching theory, i.e. that the e… more
Date: December 13, 2004
Creator: Reichman, W J; Click, C A & Krol, D M
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Error Sources in the ETA Energy Analyzer Measurement

Description: At present the ETA beam energy as measured by the ETA energy analyzer and the DARHT spectrometer differ by {approx}12%. This discrepancy is due to two sources, an overestimate of the effective length of the ETA energy analyzer bending-field, and data reduction methods that are not valid. The discrepancy can be eliminated if we return to the original process of measuring the angular deflection of the beam and use a value of 43.2cm for the effective length of the axial field profile.
Date: December 13, 2004
Creator: Nexsen, W E
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

A Progressive Subdivision Paradigm (PSP)

Description: The increasing rate of growth in size of currently available datasets is a well known issue. The possibility of developing fast and easy to implement frameworks able to visualize at least part of a tera-sized volume is a challenging task. Subdivision methods in recent years have been one of the most successful techniques applied to the multiresolution representation and visualization of surface meshes. Extensions of these techniques to the volumetric case presents positive effects and major cha… more
Date: December 13, 2004
Creator: Borgo, R.; Scopigno, R.; Cignoni, P. & Pascucci, V.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Input to the NSF Study on Computational Requirements in Geosciences

Description: The Computational Physics Group of the Earth Sciences Division focuses much of its effort on improving current understanding of the response of geologic media to strong shock waves, and on the interaction of those waves with underground structures. Two codes have been developed and used to achieve these objectives: LDEC and GEODYN. Both codes are three-dimensional and massively parallel, and they have both been used on LLNLs high performance computing platforms to advance the state of the art i… more
Date: December 13, 2004
Creator: Antoun, T; Lomov, I & Morris, J
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Stem Cell Research

Description: This report provides background on the research and potential applications of research that uses embryonic and adult stem cells. It also provides information about the current federal and state regulatory landscape, related Congressional and international actions, and relevant ethical concerns.
Date: December 13, 2004
Creator: Johnson, Judith A. & Williams, Erin
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

"Coulomb Glasses"

Description: This is a final report on DE-FG03-00ER45843 entitled ''Coulomb Glasses''. The work is continuing under grant DE-FG02-04ER46107 under the DOE Chicago Operations office. During the award period from August 15, 2000 to December 31, 2003, they studied the following: (1) 1/f Noise in Coulomb Glasses; (2) Coulomb glass phase transitions as a function of positional disorder; (3) a new structural probe of the structural glass transition; and (4) frequency dependence and equilibration of the specific he… more
Date: December 13, 2004
Creator: Yu, Clare
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Unconventional Magnetic Behavior in Multicomponent Compounds

Description: This funding supported investigations of the behavior of complex materials. Very often the chosen materials were structurally complex, since in such cases more and new degrees of freedom that lead to more complicated interactions and more variable behavior. We summarize the most successful parts of that research: (1) implementation of Wannier functions to obtain magnetic coupling constants in magnetic insulators; (2) quasiparticle (single-particle excitation) studies of LiH under high pressure;… more
Date: December 13, 2004
Creator: Pickett, Warren E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Miniature Chemical Sensor

Description: A new chemical detection technology has been realized that addresses DOE environmental management needs. The new technology is based on a variant of the sensitive optical absorption technique, cavity ring-down spectroscopy (CRDS). Termed evanescent-wave cavity ring-down spectroscopy (EW-CRDS), the technology employs a miniature solid-state optical resonator having an extremely high Q-factor as the sensing element, where the high-Q is achieved by using ultra-low-attenuation optical materials, ul… more
Date: December 13, 2004
Creator: Pipino, Andrew C. R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Two-Phase Frictional Pressure Drop Multipliers for SUVA R-134a Flowing in a Rectangular Duct

Description: The adiabatic two-phase frictional multipliers for SUVA, R-134a flowing in a rectangular duct (with D{sub H} = 4.8 mm) have been measured for 3 nominal system pressures (0.9 MPa, 1.38 MPa and 2.41 MPa) and 3 nominal mass fluxes (510, 1020 and 2040 kg/m{sup 2}/s). The data is compared with several classical correlations to assess their predictive capabilities. The Lockhart-Martinelli model gives reasonable results at the lowest pressure and mass flux, near the operating range of most refrigerati… more
Date: December 13, 2004
Creator: Vassallo, P & Keller, K
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Probing the Elastic-Plastic, Time-Dependant Response of Test Fasteners using Finite Element Analysis (FEA)

Description: The evolution of global and local stress/strain conditions in test fasteners under test conditions is investigated using elastic-plastic, time-dependent finite element analyses (FEA). For elastic-plastic response, tensile data from multiple specimens, material heats and test temperatures are integrated into a single, normalized flow curve from which temperature dependency is extracted. A primary creep model is calibrated with specimen- and fastener-based thermal relaxation data generated under … more
Date: December 13, 2004
Creator: Renauld, ML & Lien, H
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Comparison of AEO 2005 natural gas price forecast to NYMEX futures prices

Description: On December 9, the reference case projections from ''Annual Energy Outlook 2005 (AEO 2005)'' were posted on the Energy Information Administration's (EIA) web site. As some of you may be aware, we at LBNL have in the past compared the EIA's reference case long-term natural gas price forecasts from the AEO series to contemporaneous natural gas prices that can be locked in through the forward market, with the goal of better understanding fuel price risk and the role that renewables play in mitigat… more
Date: December 13, 2004
Creator: Bolinger, Mark & Wiser, Ryan
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Isotopically Enriched Films and Nanostructures by Ultrafast Pulsed Laser Deposition

Description: This project involved a systematic study to apply newly discovered isotopic enrichment effects in laser ablation plumes to the fabrication of isotopically engineered thin films, superlattices, and nanostructures. The approach to this program involved using ultrafast lasers as a method for generating ablated plasmas that have preferentially structured isotopic content in the body of the ablation plasma plumes. In examining these results we have attempted to interpret the observations in terms of… more
Date: December 13, 2004
Creator: Pronko, Peter
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Distribution of the Tax Burden Across Individuals: An Overview

Description: This report discusses in the first section different philosophies about how the tax burden should be distributed, and what those philosophies imply for the shape of the tax system. In particular, it addresses the question of the justifications for a progressive tax system (one where the share of income collected as a tax rises as income rises). This section is presented for the interested reader, but is not a necessary preliminary to examining the analysis in the second section, which presents … more
Date: December 13, 2004
Creator: Gravelle, Jane G. & Shvedov, Maxim
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Analysis of the Effect of Geometry Generated Turbulence on HCCI Combustion by Multi-Zone Modeling

Description: This paper illustrates the applicability of a sequential fluid mechanics, multi-zone chemical kinetics model to analyze HCCI experimental data for two combustion chamber geometries with different levels of turbulence: a low turbulence disc geometry (flat top piston), and a high turbulence square geometry (piston with a square bowl). The model uses a fluid mechanics code to determine temperature histories in the engine as a function of crank angle. These temperature histories are then fed into a… more
Date: December 13, 2004
Creator: Aceves, S. M.; Flowers, D. L.; Martinez-Frias, J.; Espinosa-Loza, F.; Christensen, M.; Johansson, B. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

A New Vista in Scientific Data Management

Description: This paper examines the use of an in-core database in place of traditional data structures in two ASC codes. Results so far indicate a dramatic reduction in code, coupled with an increase in functionality. Performance impact has been around one percent for the majority of problems tested. Debugging has been the major roadblock thus far, and a portable browser tool has been written that will soon work with a variety of debuggers.
Date: December 13, 2004
Creator: Keasler, J
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Analysis of Next Generation TCP

Description: The Transmission Control Protocol (TCP) has been around for around 30 years, and in that time computer networks have increased in speed and reliability many times over. TCP has done very well to maintain stability and avoid collapse from congestion in the Internet with this incredible increase in speed. But as the speed of networks continues to increase, some assumptions about the underlying network that influenced the design of TCP may no longer hold valid. Additionally, modern networks often … more
Date: December 13, 2004
Creator: Halliday, K; Hurst, A & Nelson, J
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Advantages of Analytical Transformations in Monte Carlo Methods for Radiation Transport

Description: Monte Carlo methods for radiation transport typically attempt to solve an integral by directly sampling analog or weighted particles, which are treated as physical entities. Improvements to the methods involve better sampling, probability games or physical intuition about the problem. We show that significant improvements can be achieved by recasting the equations with an analytical transform to solve for new, non-physical entities or fields. This paper looks at one such transform, the differen… more
Date: December 13, 2004
Creator: McKinley, M. S.; Brooks, E. D., III & Daffin, F.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Progress in the Peeling-Ballooning Model of ELMs: Numerical Studies of 3D Nonlinear ELM Dynamics

Description: Nonlinear simulations with the 3D electromagnetic two-fluid BOUT code are employed to study the dynamics of edge localized modes (ELMs) driven by intermediate wavelength peeling-ballooning modes. It is found that the early behavior of the modes is similar to expectations from linear, ideal peeling-ballooning mode theory, with the modes growing linearly at a fraction of the Alfven frequency. In the non-linear phase, the modes grow explosively, forming a number of extended filaments which propaga… more
Date: December 13, 2004
Creator: Snyder, P. B.; Wilson, H. R. & Xu, X. Q.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
Back to Top of Screen