Resource Type

153 Matching Results

Results open in a new window/tab.

Feasibility of PROMIS using computerized adaptive testing during inpatient rehabilitation (open access)

Feasibility of PROMIS using computerized adaptive testing during inpatient rehabilitation

Article describes how there has been an increased significance on patient-reported outcomes in clinical settings. The authors aimed to evaluate the feasibility of administering patient-reported outcome measures by computerized adaptive testing (CAT) using a tablet computer with rehabilitation inpatients, assess workload demands on staff, and estimate the extent to which rehabilitation inpatients have elevated T-scores on six Patient Reported Outcomes Measurement Information System (PROMIS) measures.
Date: May 10, 2023
Creator: Rafiq, Riyad Bin; Yount, Susan; Jerousek, Sara; Roth, Elliot J.; Cella, David; Albert, Mark et al.
System: The UNT Digital Library
Effects of Low-Intensity Aerobic Exercise on Neurophysiological and Behavioral Correlates of Cognitive Function (open access)

Effects of Low-Intensity Aerobic Exercise on Neurophysiological and Behavioral Correlates of Cognitive Function

Article asserts that acute aerobic exercise exerts a small beneficial effect on cognition. Previous research primarily examines cognitive changes following a bout of exercise, while little is currently known about changes in cognitive performance during exercise. Authors state that the primary purpose of this study was to examine the effects of low-intensity cycling on cognitive function indexed by behavioral (response accuracy; reaction time) and neurocognitive (P3 mean amplitude; P3 centroid latency) responses.
Date: May 10, 2023
Creator: Olson, Ryan L.; Cleveland, David J. & Materia, Melissa
System: The UNT Digital Library
[Literary and Media Stars] (open access)

[Literary and Media Stars]

Article about Michelle Valles' charitable contributions and her work as a reporter in El Paso and Austin, Texas.
Date: May 10, 2006
Creator: Holloway, Diane
System: The UNT Digital Library
Literary and Media Stars: People who wrote the book on the literary and media scenes (open access)

Literary and Media Stars: People who wrote the book on the literary and media scenes

Article about Michelle Valles' charitable contributions and her work as a reporter in El Paso and Austin, Texas.
Date: May 10, 2006
Creator: Holloway, Diane
System: The UNT Digital Library
Biosynthesis of 6-Hydroxymellein Requires a Collaborating Polyketide Synthase-like Enzyme (open access)

Biosynthesis of 6-Hydroxymellein Requires a Collaborating Polyketide Synthase-like Enzyme

This article investigates a new architecture for iterative Type I polyketide synthases (PKS) from fungi.
Date: May 10, 2021
Creator: Kahlert, Lukas; Villanueva, Miranda; Cox, Russell J. & Skellam, Elizabeth
System: The UNT Digital Library
Actinide tetra-N-heterocyclic carbene ‘sandwiches’ (open access)

Actinide tetra-N-heterocyclic carbene ‘sandwiches’

Article preparing highly-symmetrical, thorium and uranium octakis-carbene ‘sandwich’ complexes by ‘sandwiching’ the An(IV) cations between two anionic macrocyclic tetra-NHC ligands. The complexes are characterized by a range of experimental methods and DFT calculations.
Date: May 10, 2021
Creator: DeJesus, Joseph F.; Kerr, Ryan W. F.; Penchoff, Deborah A.; Carroll, Xian B.; Peterson, Charles C.; Arnold, Polly L. et al.
System: The UNT Digital Library
Body shape differences in a pair of closely related Malawi cichlids and their hybrids: Effects of genetic variation, phenotypic plasticity, and transgressive segregation (open access)

Body shape differences in a pair of closely related Malawi cichlids and their hybrids: Effects of genetic variation, phenotypic plasticity, and transgressive segregation

Article describes study which investigated the contributions of both genetic and plastic components for differences in body shape in two species of Lake Malawi cichlids using wild‐caught specimens and a common garden experiment.
Date: May 10, 2017
Creator: Husemann, Martin; Tobler, Michael; McCauley, Cagney; Ding, Baoqing & Danley, Patrick D.
System: The UNT Digital Library
EMP protection technology interchange (open access)

EMP protection technology interchange

Investigation and assessment of the potential degrading and destructive effects associated with the nuclear electromagnetic (EMP) phenomena has created a large technological base. This base is indeed quite broad owing to the unique and system-pervasive character of the EMP. One of the aims of an emerging discipline, such as that associated with EMP, is to provide for adequate transfer and integration of the developing technology into the overall engineering community. The needs of the community and how EMP hardening and protection information can be transferred or exchanged are reviewed. Many of the current and generally available sources of information are listed, examples of interchange methods are provided, and problems of developing specifications, standards, and suitable guidelines for design and incorporation of protection are also discussed.
Date: May 10, 1977
Creator: Martin, L. C.
System: The UNT Digital Library
Diffusion due to a single wave in a magnetized plasma (open access)

Diffusion due to a single wave in a magnetized plasma

Hamiltonian methods are used to study the motion of a particle in the field BZ and a single electrostatic wave. The particle motion is studied by numerically integrating the equations of motion. Diagrams of various particle trajectories are given. (MOW)
Date: May 10, 1976
Creator: Smith, G. R. & Kaufman, A. N.
System: The UNT Digital Library
Hadron collisions at TEV energies (open access)

Hadron collisions at TEV energies

This paper discusses the need for higher energy accelerators to probe the mysteries of the subatomic universe. Intermediate vector bosons are discussed as well as symmetry breaking and the standard model. (LSP)
Date: May 10, 1988
Creator: Cahn, R. N.
System: The UNT Digital Library
Visualizations in Hostile Rapid Scan Forensics (open access)

Visualizations in Hostile Rapid Scan Forensics

None
Date: May 10, 2004
Creator: Bartoletti, T
System: The UNT Digital Library
Transverse Beam Instability in a Compact Dielectric Wall Induction Accelerator (open access)

Transverse Beam Instability in a Compact Dielectric Wall Induction Accelerator

Using the dielectric wall accelerator technology, they are developing a compact induction accelerator system primarily intended for pulsed radiography. Unlike the typical induction accelerator cell that is long compared with its accelerating gap width, the proposed dielectric wall induction accelerator cell is short and its accelerating gap width is comparable with the cell length. In this geometry, the RF modes may be coupled from one cell to the next. They will present recent results of RF modeling of the cells and a prediction of the transverse beam instability on a 2-kA, 8-MeV beam.
Date: May 10, 2005
Creator: Chen, Y.; McCarrick, J. F. & Nelson, S. D.
System: The UNT Digital Library
Nuclear Structure of Radioactive Neutron-Rich Nuclei with 4pi Detector Arrays (open access)

Nuclear Structure of Radioactive Neutron-Rich Nuclei with 4pi Detector Arrays

In-beam studies of {gamma}-ray spectroscopy of radioactive neutron-rich nuclei using the 4{pi} TIGRESS array at TRIUMF requires a ''tag'' to improve the selectivity of the detected {gamma} rays in the high {gamma}-ray background produced by radioactive beams and the need for Doppler-shift correction. We propose development of two types of large solid angle auxiliary charged particle detectors to be used in conjunction with TRIGRESS in order to provide the required tag. The initial phase of detector development will focus on research involving light-mass radioactive beams with Z {le} 20. Gas avalanche detectors, such as CHICO, are not the ideal detector for lighter ions. Therefore, a new detector system, called Bambino, is being developed that is based on commercially available CD type position-sensitive silicon detectors. Three CD-S2 detectors, with a thickness of 140 {micro}m, have been ordered from Micron Semiconductor Ltd. A split spherical target chamber will be built in Rochester to accommodate two of those CD detectors in both forward and backward directions. These detectors will be placed 3 cm from the target, providing an angular coverage from 20.1{sup o} to 49.4{sup o} for the forward hemisphere and from 130.6{sup o} to 159.9{sup o} for the backward hemisphere. The detectors …
Date: May 10, 2005
Creator: Wu, C. Y.; Becker, J. A. & Cline, D.
System: The UNT Digital Library
A Rapid Compression Machine Modelling Study of the Heptane Isomers (open access)

A Rapid Compression Machine Modelling Study of the Heptane Isomers

Previously we have reported on the combustion behavior of all nine isomers of heptane in a rapid compression machine (RCM) with stoichiometric fuel and ''air'' mixtures at a compressed gas pressure of 15 atm. The dependence of autoignition delay times on molecular structure was illustrated. Here, we report some additional experimental work that was performed in order to address unusual results regarding significant differences in the ignition delay times recorded at the same fuel and oxygen composition, but with different fractions of nitrogen and argon diluent gases. Moreover, we have begun to simulate these experiments with detailed chemical kinetic mechanisms. These mechanisms are based on previous studies of other alkane molecules, in particular, n-heptane and iso-octane. We have focused our attention on n-heptane in order to systematically redevelop the chemistry and thermochemistry for this C{sub 7} isomer with the intention of extending our greater knowledge gained to the other eight isomers. The addition of new reaction types, that were not included previously, has had a significant impact on the simulations, particularly at low temperatures.
Date: May 10, 2005
Creator: Silke, E J; Curran, H J; Simmie, J M; Pitz, W J & Westbrook, C K
System: The UNT Digital Library
The High Current Experiment: First Results (open access)

The High Current Experiment: First Results

The High Current Experiment (HCX) is being assembled at Lawrence Berkeley National Laboratory as part of the U.S. program to explore heavy ion beam transport at a scale representative of the low-energy end of an induction linac driver for fusion energy production. The primary mission of this experiment is to investigate aperture fill factors acceptable for the transport of space-charge dominated heavy ion beams at high space-charge intensity (line-charge density {approx}0.2{micro}C/m) over long pulse durations (>4 {micro}s). This machine will test transport issues at a driver-relevant scale resulting from nonlinear space-charge effects and collective modes, beam centroid alignment and beam steering, matching, image charges, halo, lost-particle induced electron effects, and longitudinal bunch control. We present the first experimental results carried out with the coasting K{sup +} ion beam transported through the first 10 electrostatic transport quadrupoles and associated diagnostics. Later phases of the experiment will include more electrostatic lattice periods to allow more sensitive tests of emittance growth, and also magnetic quadrupoles to explore similar issues in magnetic channels with a full driver scale beam.
Date: May 10, 2004
Creator: Seidl, P; Baca, D; Bieniosek, F; Faltens, A; Lund, S; Molvik, A et al.
System: The UNT Digital Library
Comparison of Average Transport and Dispersion Among a Gaussian Model, a Two-Dimensional Model and a Three-Dimensional Model (open access)

Comparison of Average Transport and Dispersion Among a Gaussian Model, a Two-Dimensional Model and a Three-Dimensional Model

The Nuclear Regulatory Commission uses MACCS2 (MELCOR Accident Consequence Code System, Version 2) for regulatory purposes such as planning for emergencies and cost-benefit analyses. MACCS2 uses a straight-line Gaussian model for atmospheric transport and dispersion. This model has been criticized as being overly simplistic, although only expected values of metrics of interest are used in the regulatory arena. To test the assumption that averaging numerous weather results adequately compensates for the loss of structure in the meteorology that occurs away from the point of release, average MACCS2 results have been compared with average results from a state-of-the-art, 3-dimensional LODI (Lagrangian Operational Dispersion Integrator)/ADAPT (Atmospheric Data Assimilation and Parameterization Technique) and a Lagrangian trajectory, Gaussian puff transport and dispersion model from RASCAL (Radiological Assessment System for consequence Analysis). The weather sample included 610 weather trials representing conditions for a hypothetical release at the Central Facility of the Department of Energy's Atmospheric Radiation Measurement site. The values compared were average ground concentrations and average surface-level air concentrations at several distances out to 100 miles (160.9 km) from the assumed release site.
Date: May 10, 2004
Creator: Mitchell, J. A.; Molenkamp, C. R.; Bixler, N. E.; Morrow, C. W. & Ramsdell, J. V. Jr.
System: The UNT Digital Library
Dispersion Analysis of the Pulseline Accelerator (open access)

Dispersion Analysis of the Pulseline Accelerator

The authors analyze the sheath helix model of the pulseline accelerator. They find the dispersion relation for a shielded helix with a dielectric material between the shield and the helix and compare it against the results from 3-D electromagnetic simulations. Expressions for the fields near the beam axis are obtained. A scheme to taper the properties of the helix to maintain synchronism with the accelerated ions is described. An approximate circuit model of the system that includes beam loading is derived.
Date: May 10, 2005
Creator: Caporaso, G J; Briggs, R J; Poole, B R & Nelson, S D
System: The UNT Digital Library
Handling Irreducible Loops: Optimized Node Splitting vs. DJ-Graphs (open access)

Handling Irreducible Loops: Optimized Node Splitting vs. DJ-Graphs

This paper addresses the question of how to handle irreducible regions during optimization, which has become even more relevant for contemporary processors since recent VLIW-like architectures highly rely on instruction scheduling. The contributions of this paper are twofold. First, a method of optimized node splitting to transform irreducible regions of control flow into reducible regions is derived. This method is superior to approaches previously published since it reduces the number of replicated nodes by comparison. Second, three methods that handle regions of irreducible control flow are evaluated with respect to their impact on compiler optimizations: traditional and optimized node splitting as well as loop analysis through DJ graphs. Measurements show improvements of 1-40% for these methods of handling irreducible loop over the unoptimized case.
Date: May 10, 2001
Creator: Unger, Sebastian & Mueller, Frank
System: The UNT Digital Library
Effect of Activation Cross Section Uncertainties on the Radiological Assessment of the MFE/DEMO First Wall (open access)

Effect of Activation Cross Section Uncertainties on the Radiological Assessment of the MFE/DEMO First Wall

A Monte Carlo procedure has been applied in this work in order to address the impact of activation cross sections (XS) uncertainties on contact dose rate and decay heat calculations for the outboard first wall (FW) of a magnetic fusion energy (MFE) demonstration (DEMO) reactor. The XSs inducing the major uncertainty in the prediction of activation related quantities have been identified. Results have shown that for times corresponding to maintenance activities the uncertainties effect is insignificant since the dominant XSs involved in these calculations are based on accurate experimental data evaluations. However, for times corresponding to waste management/recycling activities, the errors induced by the XSs uncertainties, which in this case are evaluated using systematic models, must be considered. It has been found that two particular isotopes, {sup 60}Co and {sup 94}Nb, are key contributors to the global DEMO FW activation uncertainty results. In these cases, the benefit from further improvements in the accuracy of the critical reaction XSs is discussed.
Date: May 10, 2005
Creator: Cabellos, O; Reyes, S; Sanz, J; Rodriguez, A; Youssef, M & Sawan, M
System: The UNT Digital Library
Developing High Brightness and High Current Beams for HIF Injectors (open access)

Developing High Brightness and High Current Beams for HIF Injectors

The US Heavy Ion Fusion Virtual National Laboratory is continuing research into ion sources and injectors that simultaneously provide high current (0.5-1.0 Amps) and high brightness (normalized emittance better than 1.0 {pi}-mm-mr). The central issue of focus is whether to carry on the traditional approach of large surface ionization sources or to adopt a multi-aperture approach that transports many smaller ''beamlets'' separately at low energies before allowing them to merge. For the large surface source, the recent commissioning of the 2-MeV injector for the High Current experiment has increased our understanding of the beam quality limitations for these sources. We have also improved our techniques for fabricating large diameter aluminosilicate sources to improve lifetime and emission uniformity. For the multi-aperture approach we are continuing to study the feasibility of small surface sources and a RF induced plasma source in preparation for beamlet merging experiments, while continuing to run computer simulations for better understanding of this alternate concept. Experiments into both architectures will be performed on a newly commissioned ion source test stand at LLNL called the STS-500. This stand test provides a platform for testing a variety of ion sources and accelerating structures with 500 kV, 17-microsecond pulses. Recent progress …
Date: May 10, 2002
Creator: Ahle, L & Kwan, J W
System: The UNT Digital Library
Development of M-shell x-ray sepctroscopy and spectropolarimetry of Z-pinch tungsten plasmas (open access)

Development of M-shell x-ray sepctroscopy and spectropolarimetry of Z-pinch tungsten plasmas

None
Date: May 10, 2004
Creator: Shlyaptseva, A; Fedin, D; Hamasha, S; Harris, C; Kantsyrev, V; Neill, P et al.
System: The UNT Digital Library
Overview of Virtual National Labratory Objectives, Plans, and Projects (open access)

Overview of Virtual National Labratory Objectives, Plans, and Projects

Significant experimental and theoretical progress has been made in the U.S. heavy ion fusion program on high-current sources, transport, and focusing. Currents over 200 mA have been transported through a matching section and 10 half-lattice periods with electric quadrupoles. An experiment shows control of high beam current with an aperture, while avoiding secondary electrons. New theory and simulations of the neutralization of intense beam space charge with plasma in various focusing chamber configurations predict that near-emittance-limited beam focal spot sizes can be obtained even with beam perveance (ratio of beam space potential to ion energy) >10 x higher than in earlier HIF focusing experiments. Progress in a new focusing experiment with plasma neutralization up to 10{sup -3} perveance, and designs for a next-step experiment to study beam brightness evolution from source to target are described.
Date: May 10, 2004
Creator: Logan, B.; Celata, C.; Kwan, J.; Lee, E.; Leitner, M.; Seidl, P. et al.
System: The UNT Digital Library
Ribbon Fiber Laser-Theory and Experiment (open access)

Ribbon Fiber Laser-Theory and Experiment

A scalable fiber laser approach is described based on phase-locking multiple gain cores in an antiguided structure. The waveguide is comprised of periodic sequences of gain- and no-gain-loaded segments having uniform index, within the cladding region. Initial experimental results are presented.
Date: May 10, 2002
Creator: Beach, R J; Feit, M D; Brasure, L D & Payne, S A
System: The UNT Digital Library
Shock Initiation of Heterogeneous Explosives (open access)

Shock Initiation of Heterogeneous Explosives

The fundamental picture that shock initiation in heterogeneous explosives is caused by the linking of hot spots formed at inhomogeneities was put forward by several researchers in the 1950's and 1960's, and more recently. Our work uses the computer hardware and software developed in the Advanced Simulation and Computing (ASC) program of the U.S. Department of Energy to explicitly include heterogeneities at the scale of the explosive grains and to calculate the consequences of realistic although approximate models of explosive behavior. Our simulations are performed with ALE-3D, a three-dimensional, elastic-plastic-hydrodynamic Arbitrary Lagrange-Euler finite-difference program, which includes chemical kinetics and heat transfer, and which is under development at this laboratory. We developed the parameter values for a reactive-flow model to describe the non-ideal detonation behavior of an HMX-based explosive from the results of grain-scale simulations. In doing so, we reduced the number of free parameters that are inferred from comparison with experiment to a single one - the characteristic defect dimension. We also performed simulations of the run to detonation in small volumes of explosive. These simulations illustrate the development of the reaction zone and the acceleration of the shock front as the flame fronts start from hot spots, grow, and …
Date: May 10, 2004
Creator: Reaugh, J E
System: The UNT Digital Library