Evaluation of the 2008 Lexus LS 600H Hybrid Synergy Drive System (open access)

Evaluation of the 2008 Lexus LS 600H Hybrid Synergy Drive System

Subsystems of the 2008 Lexus 600h hybrid electric vehicle (HEV) were studied and tested as part of an intensive benchmarking effort carried out to produce detailed information concerning the current state of nondomestic alternative vehicle technologies. Feedback provided by benchmarking efforts is particularly useful to partners of the Vehicle Technologies collaborative research program as it is essential in establishing reasonable yet challenging programmatic goals which facilitate development of competitive technologies. The competitive nature set forth by the Vehicle Technologies program not only promotes energy independence and economic stability, it also advocates the advancement of alternative vehicle technologies in an overall global perspective. These technologies greatly facilitate the potential to reduce dependency on depleting natural resources and mitigate harmful impacts of transportation upon the environment.
Date: January 15, 2009
Creator: Burress, T. A.; Coomer, C. L.; Campbell, S. L.; Wereszczak, A. A.; Cunningham, J. P.; Marlino, L. D. et al.
Object Type: Report
System: The UNT Digital Library
Voro++: a three-dimensional Voronoi cell library in C++ (open access)

Voro++: a three-dimensional Voronoi cell library in C++

Voro++ is a free software library for the computation of three dimensional Voronoi cells. It is primarily designed for applications in physics and materials science, where the Voronoi tessellation can be a useful tool in the analysis of densely-packed particle systems, such as granular materials or glasses. The software comprises of several C++ classes that can be modified and incorporated into other programs. A command-line utility is also provided that can use most features of the code. Voro++ makes use of a direct cell-by-cell construction, which is particularly suited to handling special boundary conditions and walls. It employs algorithms which are tolerant for numerical precision errors, and it has been successfully employed on very large particle systems.
Date: January 15, 2009
Creator: Rycroft, Chris
Object Type: Report
System: The UNT Digital Library
Removal of Solids From Highly Enriched Uranium Solutions Using the H-Canyon Centrifuge (open access)

Removal of Solids From Highly Enriched Uranium Solutions Using the H-Canyon Centrifuge

Prior to the dissolution of Pu-containing materials in HB-Line, highly enriched uranium (HEU) solutions stored in Tanks 11.1 and 12.2 of H-Canyon must be transferred to provide storage space. The proposed plan is to centrifuge the solutions to remove solids which may present downstream criticality concerns or cause operational problems with the 1st Cycle solvent extraction due to the formation of stable emulsions. An evaluation of the efficiency of the H-Canyon centrifuge concluded that a sufficient amount (> 90%) of the solids in the Tank 11.1 and 12.2 solutions will be removed to prevent any problems. We based this conclusion on the particle size distribution of the solids isolated from samples of the solutions and the calculation of particle settling times in the centrifuge. The particle size distributions were calculated from images generated by scanning electron microscopy (SEM). The mean particle diameters for the distributions were 1-3 {micro}m. A significant fraction (30-50%) of the particles had diameters which were < 1 {micro}m; however, the mass of these solids is insignificant (< 1% of the total solids mass) when compared to particles with larger diameters. It is also probable that the number of submicron particles was overestimated by the software used …
Date: January 15, 2009
Creator: Rudisill, T. & Fernando Fondeur, F.
Object Type: Report
System: The UNT Digital Library
Searches for Fractionally Charged Particles: What Should Be Done Next? (open access)

Searches for Fractionally Charged Particles: What Should Be Done Next?

Since the initial measurements of the electron charge a century ago, experimenters have faced the persistent question as to whether elementary particles exist that have charges that are fractional multiples of the electron charge. I concisely review the results of the last 50 years of searching for fractional charge particles with no confirmed positive results. I discuss the question of whether more searching is worthwhile?
Date: January 15, 2009
Creator: Perl, Martin L.
Object Type: Article
System: The UNT Digital Library
Alloys for 1000 degree C service in the Next Generation Nuclear Plant NERI 05-0191 (open access)

Alloys for 1000 degree C service in the Next Generation Nuclear Plant NERI 05-0191

The objective of the proposed research is to define strategies for the improvement of alloys for structural components, such as the intermediate heat exchanger and primary-to-secondary piping, for service at 1000 degree C in the He environment of the NGNP. Specifically, we will investigate the oxidation/carburization behavior and microstructure stability and how these processes affect creep. While generating this data, the project will also develop a fundamental understanding of how impurities in the He environment affect these degradation processes and how this understanding can be used to develop more useful life prediction methodologies.
Date: January 15, 2009
Creator: Was, Gary S.; Jones, J.W. & Pollock, T.
Object Type: Report
System: The UNT Digital Library
ACRF Instrumentation Status: New, Current, and Future - December 2008 (open access)

ACRF Instrumentation Status: New, Current, and Future - December 2008

The purpose of this report is to provide a concise but comprehensive overview of Atmospheric Radiation Measurement Climate Research Facility instrumentation status. The report is divided into the following five sections: (1) new instrumentation in the process of being acquired and deployed, (2) field campaigns, (3) existing instrumentation and progress on improvements or upgrades, (4) proposed future instrumentation, and (5) Small Business Innovation Research instrument development.
Date: January 15, 2009
Creator: Voyles, J. W.
Object Type: Report
System: The UNT Digital Library
Risk Reduction Through Use of External Technical Reviews, Technology Readiness Assessments and Technical Risk Ratings - 9174 (open access)

Risk Reduction Through Use of External Technical Reviews, Technology Readiness Assessments and Technical Risk Ratings - 9174

The U.S. Department of Energy's Office of Environmental Management (DOE-EM) was established to achieve the safe and compliant disposition of legacy wastes and facilities from defense nuclear applications. A large majority of these wastes and facilities are 'one-of-a-kind' and unique to DOE. Many of the programs to treat these wastes have been 'first-of-a-kind' and unprecedented in scope and complexity. This has meant that many of the technologies needed to successfully disposition these wastes were not yet developed or required significant re-engineering to be adapted for DOE-EM's needs. The DOE-EM program believes strongly in reducing the technical risk of its projects and has initiated several efforts to reduce those risks: (1) Technology Readiness Assessments to reduce the risks of deployment of new technologies; (2) External Technical Reviews as one of several steps to ensure the timely resolution of engineering and technology issues; and (3) Technical Risk Ratings as a means to monitor and communicate information about technical risks. This paper will present examples of how Technology Readiness Assessments, External Technical Reviews, and Technical Risk Ratings are being used by DOE-EM to reduce technical risks.
Date: January 15, 2009
Creator: Cercy, M.; Steven, P.; Schneider, S.; Kurt, D. & Gerdes, K.
Object Type: Article
System: The UNT Digital Library
300 Area D4 Project Fiscal Year 2008 Building Completion Report (open access)

300 Area D4 Project Fiscal Year 2008 Building Completion Report

This report documents the deactivation, decontamination, decommissioning, and demolition (D4) of eighteen buildings in the 300 Area of the Hanford Site that were demolished in Fiscal Year 2008. The D4 of these facilties included characterization, engineering, removal of hazardous and radiologically contaminated materials, equipment removal, utility disconnection, deactivation, decontamination, demolition of the structure, and stabilization or removal of the remaining slab and foundation, as appropriate.
Date: January 15, 2009
Creator: Westberg, R. A.
Object Type: Report
System: The UNT Digital Library
Compliance of SLAC_s Laser Safety Program with OSHA Requirements for the Control of Hazardous Energy (open access)

Compliance of SLAC_s Laser Safety Program with OSHA Requirements for the Control of Hazardous Energy

SLAC's COHE program requires compliance with OSHA Regulation 29CFR1910.147, 'The control of hazardous energy (lockout/tagout)'. This regulation specifies lockout/tagout requirements during service and maintenance of equipment in which the unexpected energization or start up of the equipment, or release of stored energy, could cause injury to workers. Class 3B and Class 4 laser radiation must be considered as hazardous energy (as well as electrical energy in associated equipment, and other non-beam energy hazards) in laser facilities, and therefore requires careful COHE consideration. This paper describes how COHE is achieved at SLAC to protect workers against unexpected Class 3B or Class 4 laser radiation, independent of whether the mode of operation is normal, service, or maintenance.
Date: January 15, 2009
Creator: Woods, Michael
Object Type: Article
System: The UNT Digital Library
Laser Safety for the Experimental Halls at SLAC_s Linac Coherent Light Source (LCLS) (open access)

Laser Safety for the Experimental Halls at SLAC_s Linac Coherent Light Source (LCLS)

The LCLS at the SLAC National Accelerator Laboratory will be the world's first source of an intense hard x-ray laser beam, generating x-rays with wavelengths of 1nm and pulse durations less than 100fs. The ultrafast x-ray pulses will be used in pump-probe experiments to take stop-motion pictures of atoms and molecules in motion, with pulses powerful enough to take diffraction images of single molecules, enabling scientists to elucidate fundamental processes of chemistry and biology. Ultrafast conventional lasers will be used as the pump. In 2009, LCLS will deliver beam to the Atomic Molecular and Optical (AMO) Experiment, located in one of 3 x-ray Hutches in the Near Experimental Hall (NEH). The NEH includes a centralized Laser Hall, containing up to three Class 4 laser systems, three x-ray Hutches for experiments and vacuum transport tubes for delivering laser beams to the Hutches. The main components of the NEH laser systems are a Ti:sapphire oscillator, a regen amplifier, green pump lasers for the oscillator and regen, a pulse compressor and a harmonics conversion unit. Laser safety considerations and controls for the ultrafast laser beams, multiple laser controlled areas, and user facility issues are discussed.
Date: January 15, 2009
Creator: Woods, Michael; Anthony, Perry; Barat, Ken; Gilevich, Sasha; Hays, Greg & White, William E.
Object Type: Article
System: The UNT Digital Library
Physical test of a particle simulation model in a sheared granular system (open access)

Physical test of a particle simulation model in a sheared granular system

We report a detailed comparison of a slow gravity driven sheared granular flow with a computational model performed with the Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS). To our knowledge, this is the first thorough test of the LAMMPS model with a laboratory granular flow. In the experiments, grains flow inside a silo with a rectangular cross-section, and are sheared by a rough boundary on one side and smooth boundaries on the other sides. Individual grain position and motion are measured using a particle index matching imaging technique where a fluorescent dye is added to the interstitial liquid which has the same refractive index as the glass beads. The boundary imposes a packing order, and the grains are observed to flow in layers which get progressively more disordered with distance from the walls. The computations use a Cundall--Strack contact model between the grains, using contact parameters that have been used in many other previous studies, and ignore the hydrodynamic effects of the interstitial liquid. Computations are performed to understand the effect of particle coefficient of friction, elasticity, contact model, and polydispersity on mean flow properties. After appropriate scaling, we find that the mean velocity of the grains and the number density …
Date: January 15, 2009
Creator: Rycroft, Chris; Orpe, Ashish & Kudrolli, Arshad
Object Type: Article
System: The UNT Digital Library
HANFORD DOUBLE SHELL TANK THERMAL AND SEISMIC PROJECT SUMMARY OF COMBINED THERMAL AND OPERATING LOADS WITH SEISMIC ANALYSIS (open access)

HANFORD DOUBLE SHELL TANK THERMAL AND SEISMIC PROJECT SUMMARY OF COMBINED THERMAL AND OPERATING LOADS WITH SEISMIC ANALYSIS

This report summarizes the results of the Double-Shell Tank Thermal and Operating Loads Analysis (TaLA) combined with the Seismic Analysis. This combined analysis provides a thorough, defensible, and documented analysis that will become a part of the overall analysis of record for the Hanford double-shell tanks (DSTs). The bases of the analytical work presented herein are two ANSYS{reg_sign} finite element models that were developed to represent a bounding-case tank. The TaLA model includes the effects of temperature on material properties, creep, concrete cracking, and various waste and annulus pressure-loading conditions. The seismic model considers the interaction of the tanks with the surrounding soil including a range of soil properties, and the effects of the waste contents during a seismic event. The structural evaluations completed with the representative tank models do not reveal any structural deficiencies with the integrity of the DSTs. The analyses represent 60 years of use, which extends well beyond the current date. In addition, the temperature loads imposed on the model are significantly more severe than any service to date or proposed for the future. Bounding material properties were also selected to provide the most severe combinations. While the focus of the analyses was a bounding-case tank, …
Date: January 15, 2009
Creator: TC, MACKEY; JE, DEIBLER; MW, RINKER; KI, JOHNSON; FG, ABATT; NK, KARRI et al.
Object Type: Report
System: The UNT Digital Library
Mechanical properties of granular materials: A variational approach to grain-scale simulations (open access)

Mechanical properties of granular materials: A variational approach to grain-scale simulations

The mechanical properties of cohesionless granular materials are evaluated from grain-scale simulations. A three-dimensional pack of spherical grains is loaded by incremental displacements of its boundaries. The deformation is described as a sequence of equilibrium configurations. Each configuration is characterized by a minimum of the total potential energy. This minimum is computed using a modification of the conjugate gradient algorithm. Our simulations capture the nonlinear, path-dependent behavior of granular materials observed in experiments. Micromechanical analysis provides valuable insight into phenomena such as hysteresis, strain hardening and stress-induced anisotropy. Estimates of the effective bulk modulus, obtained with no adjustment of material parameters, are in agreement with published experimental data. The model is applied to evaluate the effects of hydrate dissociation in marine sediments. Weakening of the sediment is quantified as a reduction in the effective elastic moduli.
Date: January 15, 2009
Creator: Holtzman, R.; Silin, D.B. & Patzek, T.W.
Object Type: Article
System: The UNT Digital Library
300 Area D4 Project Fiscal Year 2007 Building Completion Report (open access)

300 Area D4 Project Fiscal Year 2007 Building Completion Report

This report documents the deactivation, decontamination, decommissioning, and demolition (D4) of twenty buildings in the 300 Area of the Hanford Site. The D4 of these facilties included characterization, engineering, removal of hazardous and radiologically contaminated materials, equipment removal, utility disconnection, deactivation, decontamination, demolition of the structure, and stabilization or removal of the remaining slab and foundation, as appropriate.
Date: January 15, 2009
Creator: Westberg, R. A.
Object Type: Report
System: The UNT Digital Library
Spectroscopic Study of the Thermal Degradation of PVP-capped Rh and Pt Nanoparticles in H2 and O2 Environments (open access)

Spectroscopic Study of the Thermal Degradation of PVP-capped Rh and Pt Nanoparticles in H2 and O2 Environments

Poly(N-vinylpyrrolidone) (PVP) capped platinum and rhodium nanoparticles (7-12 nm) have been studied with UV-VIS, FTIR and Raman spectroscopy. The absorption bands in the region 190-900 nm are shown to be sensitive to the electronic structure of surface Rh and Pt atoms as well as to the aggregation of the nanoparticles. In-situ FTIR-DRIFT spectroscopy of the thermal decay of PVP stabilized Rh and Pt nanoparticles in H{sub 2} and O{sub 2} atmospheres in temperatures ranging from 30 C-350 C reveal that decomposition of PVP above 200 C, PVP transforms into a 'polyamidpolyene' - like material that is in turn converted into a thin layer of amorphous carbon above 300 C. Adsorbed carbon monoxide was used as a probing molecule to monitor changes of electronic structure of surface Rh and Pt atoms and accessible surface area. The behavior of surface Rh and Pt atoms with ligated CO and amide groups of pyrrolidones resemble that of surface coordination compounds.
Date: September 15, 2009
Creator: Borodko, Yuri; Lee, Hyun Sook; Joo, Sang Hoon; Zhang, Yawen & Somorjai, Gabor A.
Object Type: Article
System: The UNT Digital Library
Energy dependence of transverse momentum fluctuations in Pb+Pb collisions at the CERN Super Proton Synchrotron (SPS) at 20A to 158A GeV (open access)

Energy dependence of transverse momentum fluctuations in Pb+Pb collisions at the CERN Super Proton Synchrotron (SPS) at 20A to 158A GeV

Results are presented on event-by-event fluctuations of transverse momenta p{sub T} in central Pb+Pb interactions at 20A, 30A, 40A, 80A, and 158A GeV. The analysis was performed for charged particles at forward center-of-mass rapidity (1.1 < y*{sub {pi}} < 2.6). Three fluctuation measures were studied: the distribution of average transverse momentum M(p{sub T}) in the event, the {phi}{sub p{sub T}} fluctuation measure, and two-particle transverse momentum correlations. Fluctuations of p{sub T} are small and show no significant energy dependence in the energy range of the CERN Super Proton Synchrotron. Results are compared with QCD-inspired predictions for the critical point, and with the UrQMD model. Transverse momentum fluctuations, similar to multiplicity fluctuations, do not show the increase expected for freeze-out near the critical point of QCD.
Date: April 15, 2009
Creator: Collaboration, NA49 & Anticic, T.
Object Type: Article
System: The UNT Digital Library
Hot Electron Generation and Transport Using K(alpha) Emission (open access)

Hot Electron Generation and Transport Using K(alpha) Emission

We have conducted experiments on both the Vulcan and Titan laser facilities to study hot electron generation and transport in the context of fast ignition. Cu wires attached to Al cones were used to investigate the effect on coupling efficiency of plasma surround and the pre-formed plasma inside the cone. We found that with thin cones 15% of laser energy is coupled to the 40{micro}m diameter wire emulating a 40{micro}m fast ignition spot. Thick cone walls, simulating plasma in fast ignition, reduce coupling by x4. An increase of prepulse level inside the cone by a factor of 50 reduces coupling by a factor of 3.
Date: October 15, 2009
Creator: Akli, K. U.; Stephens, R. B.; Key, M. H.; Bartal, T.; Beg, F. N.; Chawla, S. et al.
Object Type: Article
System: The UNT Digital Library
Fermi/LAT Discovery of Gamma-Ray Emission From the Flat-Spectrum Radio Quasar PKS 1454-354 (open access)

Fermi/LAT Discovery of Gamma-Ray Emission From the Flat-Spectrum Radio Quasar PKS 1454-354

None
Date: May 15, 2009
Creator: Abdo, Aous A.; Ackermann, M.; Atwood, W. B.; Axelsson, M.; Baldini, L.; Ballet, J. et al.
Object Type: Article
System: The UNT Digital Library
Fabrication and characterization of submicron polymer waveguides by micro-transfer molding (open access)

Fabrication and characterization of submicron polymer waveguides by micro-transfer molding

Various methods exist for fabrication of micron and submicron sized waveguide structures. However, most of them include expensive and time consuming semiconductor fabrication techniques. An economical method for fabricating waveguide structures is introduced and demonstrated in this thesis. This method is established based on previously well-developed photonic crystal fabrication method called two-polymer microtransfer molding. The waveguide in this work functions by a coupler structure that diffracts the incident light into submicron polymer rods. The light is then guided through the rods. Characterization is done by collecting the light that has been guided through the waveguide and exits the end of these submicron polymer bars. The coupling and waveguiding capabilities are demonstrated using two light sources, a laser and white light.
Date: December 15, 2009
Creator: Wu, Te-Wei
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Ion Drifts in a Snowflake Divertor (open access)

Ion Drifts in a Snowflake Divertor

None
Date: October 15, 2009
Creator: Ryutov, D. D. & Umansky, M. V.
Object Type: Article
System: The UNT Digital Library
Discovery of Pulsed Gamma Rays from the Young Radio Pulsar PSR J1028-5819 with the Fermi Large Area Telescope (open access)

Discovery of Pulsed Gamma Rays from the Young Radio Pulsar PSR J1028-5819 with the Fermi Large Area Telescope

Radio pulsar PSR J1028-5819 was recently discovered in a high-frequency search (at 3.1 GHz) in the error circle of the Energetic Gamma-Ray Experiment Telescope (EGRET) source 3EG J1027-5817. The spin-down power of this young pulsar is great enough to make it very likely the counterpart for the EGRET source. We report here the discovery of {gamma}-ray pulsations from PSR J1028-5819 in early observations by the Large Area Telescope (LAT) on the Fermi Gamma-Ray Space Telescope. The {gamma}-ray light curve shows two sharp peaks having phase separation of 0.460 {+-} 0.004, trailing the very narrow radio pulse by 0.200 {+-} 0.003 in phase, very similar to that of other known {gamma}-ray pulsars. The measured {gamma}-ray flux gives an efficiency for the pulsar of {approx}10-20% (for outer magnetosphere beam models). No evidence of a surrounding pulsar wind nebula is seen in the current Fermi data but limits on associated emission are weak because the source lies in a crowded region with high background emission. However, the improved angular resolution afforded by the LAT enables the disentanglement of the previous COS-B and EGRET source detections into at least two distinct sources, one of which is now identified as PSR J1028-5819.
Date: May 15, 2009
Creator: Abdo, Aous A.; Ackermann, M.; Atwood, W.B.; Baldini, L.; Ballet, J.; Barbiellini, Guido et al.
Object Type: Article
System: The UNT Digital Library
Observation of Strong Resonant Behavior in the Inverse Photoelectron Spectroscopy of Ce Oxide (open access)

Observation of Strong Resonant Behavior in the Inverse Photoelectron Spectroscopy of Ce Oxide

X-ray Emission Spectroscopy (XES) and Resonant Inverse Photoelectron Spectroscopy (RIPES) have been used to investigate the photon emission associated with the Ce3d5/2 and Ce3d3/2 thresholds. Strong resonant behavior has been observed in the RIPES of Ce Oxide near the 5/2 and 3/2 edges. Inverse Photoelectron Spectroscopy (IPES) and its high energy variant, Bremstrahlung Isochromat Spectroscopy (BIS), are powerful techniques that permit a direct interrogation of the low-lying unoccupied electronic structure of a variety of materials. Despite being handicapped by counting rates that are approximately four orders of magnitude less that the corresponding electron spectroscopies (Photoelectron Spectroscopy, PES, and X-ray Photoelectron Spectroscopy, XPS) both IPES and BIS have a long history of important contributions. Over time, an additional variant of this technique has appeared, where the kinetic energy (KE) of the incoming electron and photon energy (hv) of the emitted electron are roughly the same magnitude as the binding energy of a core level of the material in question. Under these circumstances and in analogy to Resonant Photoelectron Spectroscopy, a cross section resonance can occur, giving rise to Resonant Inverse Photoelectron Spectroscopy or RIPES. Here, we report the observation of RIPES in an f electron system, specifically the at the 3d{sub …
Date: December 15, 2009
Creator: Tobin, J G; Yu, S W; Chung, B W; Waddill, G D; Damian, E; Duda, L et al.
Object Type: Article
System: The UNT Digital Library
UNCERTAINTY IN THE GLOBAL FORECAST SYSTEM (open access)

UNCERTAINTY IN THE GLOBAL FORECAST SYSTEM

We validated one year of Global Forecast System (GFS) predictions of surface meteorological variables (wind speed, air temperature, dewpoint temperature, air pressure) over the entire planet for forecasts extending from zero hours into the future (an analysis) to 36 hours. Approximately 12,000 surface stations world-wide were included in this analysis. Root-Mean-Square- Errors (RMSE) increased as the forecast period increased from zero to 36 hours, but the initial RMSE were almost as large as the 36 hour forecast RMSE for all variables. Typical RMSE were 3 C for air temperature, 2-3mb for sea-level pressure, 3.5 C for dewpoint temperature and 2.5 m/s for wind speed. Approximately 20-40% of the GFS errors can be attributed to a lack of resolution of local features. We attribute the large initial RMSE for the zero hour forecasts to the inability of the GFS to resolve local terrain features that often dominate local weather conditions, e.g., mountain- valley circulations and sea and land breezes. Since the horizontal resolution of the GFS (about 1{sup o} of latitude and longitude) prevents it from simulating these locally-driven circulations, its performance will not improve until model resolution increases by a factor of 10 or more (from about 100 km to …
Date: April 15, 2009
Creator: Werth, D. & Garrett, A.
Object Type: Article
System: The UNT Digital Library
Effects of physical and geochemical heterogeneities on mineral transformation and biomass accumulation during uranium bioremediation at Rifle, Colorado (open access)

Effects of physical and geochemical heterogeneities on mineral transformation and biomass accumulation during uranium bioremediation at Rifle, Colorado

None
Date: June 15, 2009
Creator: Li, Li; Steefel, C. I.; Hubbard, S. S.; Kowalsky, M. B. & Englert, A.
Object Type: Article
System: The UNT Digital Library