3d segmentation of rodent brain structures using active volume model with shape priors; conference paper (open access)

3d segmentation of rodent brain structures using active volume model with shape priors; conference paper

N/A
Date: March 20, 2011
Creator: Zhang, Shaoting; Huang, J.; Uzunbas, M.; Shen, T.; Delis, F.; Volkow, N. D. et al.
Object Type: Article
System: The UNT Digital Library
Aerosol Mass Spectrometry via Laser-Induced Incandescence Particle Vaporization Final Report (open access)

Aerosol Mass Spectrometry via Laser-Induced Incandescence Particle Vaporization Final Report

We have successfully developed and commercialized a soot particle aerosol mass spectrometer (SP-AMS) instrument to measure mass, size, and chemical information of soot particles in ambient environments. The SP-AMS instrument has been calibrated and extensively tested in the laboratory and during initial field studies. The first instrument paper describing the SP-AMS has been submitted for publication in a peer reviewed journal and there are several related papers covering initial field studies and laboratory studies that are in preparation. We have currently sold 5 SP-AMS instruments (either as complete systems or as SP modules to existing AMS instrument operators).
Date: October 20, 2011
Creator: Onasch, Timothy B.
Object Type: Report
System: The UNT Digital Library
ALTERED STRUCTURE OF THE MN4CA CLUSTER IN THE OXYGEN EVOLVING COMPLEX OF PHOTOSYSTEM II BY A HISTIDINE LIGAND MUTATION (open access)

ALTERED STRUCTURE OF THE MN4CA CLUSTER IN THE OXYGEN EVOLVING COMPLEX OF PHOTOSYSTEM II BY A HISTIDINE LIGAND MUTATION

None
Date: January 20, 2011
Creator: Yano, Junko; Walker, Lee; Service, Rachel; Yachandra, Vittal & Debus, Richard
Object Type: Article
System: The UNT Digital Library
Amplitudes and Ultraviolet Behavior of N = 8 Supergravity (open access)

Amplitudes and Ultraviolet Behavior of N = 8 Supergravity

In this contribution we describe computational tools that permit the evaluation of multi-loop scattering amplitudes in N = 8 supergravity, in terms of amplitudes in N = 4 super-Yang-Mills theory. We also discuss the remarkable ultraviolet behavior of N = 8 supergravity, which follows from these amplitudes, and is as good as that of N = 4 super-Yang-Mills theory through at least four loops.
Date: May 20, 2011
Creator: Bern, Zvi; Carrasco, John Joseph; Dixon, Lance J.; Johansson, Henrik & Roiban, Radu
Object Type: Article
System: The UNT Digital Library
Analysis of Casualty Risk per Police-Reported Crash for Model Year 2000 to 2004 Vehicles, using Crash Data from Five States (open access)

Analysis of Casualty Risk per Police-Reported Crash for Model Year 2000 to 2004 Vehicles, using Crash Data from Five States

In this report we compare two measures of driver risks: fatality risk per vehicle registration-year, and casualty (fatality plus serious injury) risk per police-reported crash. Our analysis is based on three sets of data from five states (Florida, Illinois, Maryland, Missouri, and Pennsylvania): data on all police-reported crashes involving model year 2000 to 2004 vehicles; 2005 county-level vehicle registration data by vehicle model year and make/model; and odometer readings from vehicle emission inspection and maintenance (I/M) programs conducted in urban areas of four of the five states (Florida does not have an I/M program). The two measures of risk could differ for three reasons: casualty risks are different from fatality risk; risks per vehicle registration-year are different from risks per crash; and risks estimated from national data are different from risks from the five states analyzed here. We also examined the effect of driver behavior, crash location, and general vehicle design on risk, as well as sources of potential bias in using the crash data from five states.
Date: March 20, 2011
Creator: Wenzel, Tom
Object Type: Report
System: The UNT Digital Library
Analysis of Conductor Impedances Accounting for Skin Effect and Nonlinear Permeability (open access)

Analysis of Conductor Impedances Accounting for Skin Effect and Nonlinear Permeability

It is often necessary to protect sensitive electrical equipment from pulsed electric and magnetic fields. To accomplish this electromagnetic shielding structures similar to Faraday Cages are often implemented. If the equipment is inside a facility that has been reinforced with rebar, the rebar can be used as part of a lighting protection system. Unfortunately, such shields are not perfect and allow electromagnetic fields to be created inside due to discontinuities in the structure, penetrations, and finite conductivity of the shield. In order to perform an analysis of such a structure it is important to first determine the effect of the finite impedance of the conductors used in the shield. In this paper we will discuss the impedances of different cylindrical conductors in the time domain. For a time varying pulse the currents created in the conductor will have different spectral components, which will affect the current density due to skin effects. Many construction materials use iron and different types of steels that have a nonlinear permeability. The nonlinear material can have an effect on the impedance of the conductor depending on the B-H curve. Although closed form solutions exist for the impedances of cylindrical conductors made of linear materials, computational …
Date: July 20, 2011
Creator: Perkins, M. P.; Ong, M. M.; Brown, C. G. & Speer, R. D.
Object Type: Article
System: The UNT Digital Library
ANALYSIS OF THE LEACHING EFFICIENCY OF INHIBITED WATER AND TANK SIMULANT IN REMOVING RESIDUES ON THERMOWELL PIPES (open access)

ANALYSIS OF THE LEACHING EFFICIENCY OF INHIBITED WATER AND TANK SIMULANT IN REMOVING RESIDUES ON THERMOWELL PIPES

A key component for the accelerated implementation and operation of the Salt Waste Processing Facility (SWPF) is the recovery of Tank 48H. Tank 48H is a type IIIA tank with a maximum capacity of 1.3 million gallons. Video inspection of the tank showed that a film of solid material adhered to the tank internal walls and structures between 69 inch and 150 inch levels. From the video inspection, the solid film thickness was estimated to be 1mm, which corresponds to {approx}33 kg of TPB salts (as 20 wt% insoluble solids) (1). This film material is expected to be easily removed by single-rinse, slurry pump operation during Tank 48H TPB disposition via aggregation processing. A similar success was achieved for Tank 49H TPB dispositioning, with slurry pumps operating almost continuously for approximately 6 months, after which time the tank was inspected and the film was found to be removed. The major components of the Tank 49H film were soluble solids - Na{sub 3}H(CO{sub 3}){sub 2} (Hydrated Sodium Carbonate, aka: Trona), Al(OH){sub 3} (Aluminum Hydroxide, aka: Gibbsite), NaTPB (Sodium Tetraphenylborate), NaNO{sub 3} (Sodium Nitrate) and NaNO{sub 2} (Sodium Nitrite) (2). Although the Tank 48H film is expected to be primarily soluble solids, …
Date: October 20, 2011
Creator: Fondeur, F.; White, T.; Oji, L.; Martino, C. & Wilmarth, B.
Object Type: Article
System: The UNT Digital Library
Annual Illness and Injury Surveillance Report: Kansas City Plan, 2010 (open access)

Annual Illness and Injury Surveillance Report: Kansas City Plan, 2010

The U.S. Department of Energy's (DOE) commitment to assuring the health and safety of its workers includes the conduct of illness and injury surveillance activities that provide an early warning system to detect health problems among workers. The Illness and Injury Surveillance Program monitors illnesses and health conditions that result in an absence, occupational injuries and illnesses, and disabilities and deaths among current workers.
Date: June 20, 2011
Creator: United States. Department of Energy. Office of Health, Safety, and Security.
Object Type: Report
System: The UNT Digital Library
Automated Chemical Analysis of Internally Mixed Aerosol Particles Using X-ray Spectromicroscopy at the Carbon K-Edge (open access)

Automated Chemical Analysis of Internally Mixed Aerosol Particles Using X-ray Spectromicroscopy at the Carbon K-Edge

We have developed an automated data analysis method for atmospheric particles using scanning transmission X-ray microscopy coupled with near edge X-ray fine structure spectroscopy (STXM/NEXAFS). This method is applied to complex internally mixed submicrometer particles containing organic and inorganic material. Several algorithms were developed to exploit NEXAFS spectral features in the energy range from 278 to 320 eV for quantitative mapping of the spatial distribution of elemental carbon, organic carbon, potassium, and noncarbonaceous elements in particles of mixed composition. This energy range encompasses the carbon K-edge and potassium L2 and L3 edges. STXM/NEXAFS maps of different chemical components were complemented with a subsequent analysis using elemental maps obtained by scanning electron microscopy coupled with energy dispersive X-ray analysis (SEM/EDX). We demonstrate the application of the automated mapping algorithms for data analysis and the statistical classification of particles.
Date: January 20, 2011
Creator: Gilles, Mary K.; Moffet, R. C.; Henn, T. & Laskin, A.
Object Type: Article
System: The UNT Digital Library
Autonomous Monitoring of Control Hardware to Predict Off-Normal Conditions Using NIF Automatic Alignment Systems (open access)

Autonomous Monitoring of Control Hardware to Predict Off-Normal Conditions Using NIF Automatic Alignment Systems

The National Ignition Facility (NIF) is a high power laser system capable of supporting high-energy-density experimentation as a user facility for the next 30 years. In order to maximize the facility availability, preventive maintenance enhancements are being introduced into the system. An example of such an enhancement is a camera-based health monitoring system, integrated into the automated alignment system, which provides an opportunity to monitor trends in measurements such as average beam intensity, size of the beam, and pixel saturation. The monitoring system will generate alerts based on observed trends in measurements to allow scheduled pro-active maintenance before routine off-normal detection stops system operations requiring unscheduled intervention.
Date: July 20, 2011
Creator: Awwal, A.; Wilhelmsen, K.; Leach, R.; Kamm, V. M.; Burkhart, S.; Lowe-Webb, R. et al.
Object Type: Article
System: The UNT Digital Library
Biofuel Production Initiative at Claflin University Final Report (open access)

Biofuel Production Initiative at Claflin University Final Report

For US transportation fuel independence or reduced dependence on foreign oil, the Federal Government has mandated that the country produce 36 billion gallons (bg) of renewable transportation fuel per year for its transportation fuel supply by 2022. This can be achieved only if development of efficient technology for second generation biofuel from ligno-cellulosic sources is feasible. To be successful in this area, development of a widely available, renewable, cost-effective ligno-cellulosic biomass feedstock that can be easily and efficiently converted biochemically by bacteria or other fast-growing organisms is required. Moreover, if the biofuel type is butanol, then the existing infrastructure to deliver fuel to the customer can be used without additional costs and retrofits. The Claflin Biofuel Initiative project is focused on helping the US meet the above-mentioned targets. With support from this grant, Claflin University (CU) scientists have created over 50 new strains of microorganisms that are producing butanol from complex carbohydrates and cellulosic compounds. Laboratory analysis shows that a number of these strains are producing higher percentages of butanol than other methods currently in use. All of these recombinant bacterial strains are producing relatively high concentrations of acetone and numerous other byproducts as well. Therefore, we are carrying out …
Date: July 20, 2011
Creator: Chowdhury, Kamal
Object Type: Report
System: The UNT Digital Library
Block-Structured Adaptive Mesh Refinement Algorithms for Vlasov Simulation (open access)

Block-Structured Adaptive Mesh Refinement Algorithms for Vlasov Simulation

None
Date: November 20, 2011
Creator: Hittinger, J A & Banks, J W
Object Type: Article
System: The UNT Digital Library
Building a Better mSUGRA: WIMP Dark Matter Without Flavor Violation (open access)

Building a Better mSUGRA: WIMP Dark Matter Without Flavor Violation

None
Date: June 20, 2011
Creator: Craig, Nathaniel J.; /Stanford U., Phys. Dept.; Green, Daniel & /SLAC /Stanford U., Phys. Dept.
Object Type: Article
System: The UNT Digital Library
Characteristics of Turbulence-driven Plasma Flow and Origin of Experimental Empirical Scalings of Intrinsic Rotation (open access)

Characteristics of Turbulence-driven Plasma Flow and Origin of Experimental Empirical Scalings of Intrinsic Rotation

Toroidal plasma flow driven by turbulent torque associated with nonlinear residual stress generation is shown to recover the observed key features of intrinsic rotation in experiments. Specifically, the turbulence-driven intrinsic rotation scales close to linearly with plasma gradients and the inverse of the plasma current, qualitatively reproducing empirical scalings obtained from a large experimental data base. The effect of magnetic shear on the symmetry breaking in the parallel wavenumber spectrum is identified. The origin of the current scaling is found to be the enhanced kll#3; symmetry breaking induced by increased radial variation of the safety factor as the current decreases. The physics origin for the linear dependence of intrinsic rotation on the pressure gradient comes from the fact that both turbulence intensity and the zonal flow shear, which are two key ingredients for driving the residual stress, are increased with the strength of the turbulence drives, which are R/LTe and R/Lne for the collisionless trapped electron mode (CTEM). Highlighted results also include robust radial pinches in toroidal flow, heat and particle transport driven by CTEM turbulence, which emerge "in phase", and are shown to play important roles in determining plasma profiles. Also discussed are experimental tests proposed to validate findings …
Date: March 20, 2011
Creator: W.X. Wang, T.S. Hahm, S. Ethier, G. Rewoldt, W.M. Tang, W.W. Lee and P.H. Diamond
Object Type: Report
System: The UNT Digital Library
THE CHEMICAL AND RADIATION RESISTANCE OF POLYPHENYLENE SULFIDE AS ENCOUNTERED IN THE NUCLEAR WASTE CLEANING PROCESSES (open access)

THE CHEMICAL AND RADIATION RESISTANCE OF POLYPHENYLENE SULFIDE AS ENCOUNTERED IN THE NUCLEAR WASTE CLEANING PROCESSES

Polyphenylene sulfide (PPS) is extremely resistant to gamma irradiation, caustic solution, and dilute nitric acid. PPS is the material of construction for the coalescers used in the Modular Caustic-Side Solvent Extraction Unit (MCU). After applying the equivalent of 16 years of gamma irradiation and several months of exposures to caustic solution, no dimensional changes nor chemical changes were detected in PPS whether the PPS was in fiber form or in a composite with E-glass fibers. However, PPS acts as a media for heterogeneous nucleation. In particular, PPS appears to favor aluminosilicate formation in saturated solutions of aluminum and silicon in caustic environments. Parallel testing, in progress, is examining the stability of PPS when exposed to the new solvent formulation under development for MCU. Preliminary data, after two months of exposure, PPS is remarkably stable to the new solvent.
Date: October 20, 2011
Creator: Fondeur, F.
Object Type: Article
System: The UNT Digital Library
Comparison of CAISO-run Plexos output with LLNL-run Plexos output (open access)

Comparison of CAISO-run Plexos output with LLNL-run Plexos output

In this report we compare the output of the California Independent System Operator (CAISO) 33% RPS Plexos model when run on various computing systems. Specifically, we compare the output resulting from running the model on CAISO's computers (Windows) and LLNL's computers (both Windows and Linux). We conclude that the differences between the three results are negligible in the context of the entire system and likely attributed to minor differences in Plexos version numbers as well as the MIP solver used in each case.
Date: December 20, 2011
Creator: Schmidt, A.; Meyers, C. & Smith, S.
Object Type: Report
System: The UNT Digital Library
A comparison of geospatially modeled fire behavior and potential application to fire and fuels management for the Savannah River Site. (open access)

A comparison of geospatially modeled fire behavior and potential application to fire and fuels management for the Savannah River Site.

This study evaluates modeled fire behavior for the Savannah River Site in the Atlantic Coastal Plain of the southeastern U.S. using three data sources: FCCS, LANDFIRE, and SWRA. The Fuel Characteristic Classification System (FCCS) was used to build fuelbeds from intensive field sampling of 629 plots. Custom fire behavior fuel models were derived from these fuelbeds. LANDFIRE developed surface fire behavior fuel models and canopy attributes for the U.S. using satellite imagery informed by field data. The Southern Wildfire Risk Assessment (SWRA) developed surface fire behavior fuel models and canopy cover for the southeastern U.S. using satellite imagery.
Date: December 20, 2011
Creator: Kurth, Laurie; Hollingsworth, LaWen & Shea, Dan
Object Type: Report
System: The UNT Digital Library
Conceptual Design of a 100 MWe Modular Molten Salt Power Tower Plant (open access)

Conceptual Design of a 100 MWe Modular Molten Salt Power Tower Plant

A conceptual design of a 100 MWe modular molten salt solar power tower plant has been developed which can provide capacity factors in the range of 35 to 75%. Compared to single tower plants, the modular design provides a higher degree of flexibility in achieving the desired customer's capacity factor and is obtained simply by adjusting the number of standard modules. Each module consists of a standard size heliostat field and receiver system, hence reengineering and associated unacceptable performance uncertainties due to scaling are eliminated. The modular approach with multiple towers also improves plant availability. Heliostat field components, receivers and towers are shop assembled allowing for high quality and minimal field assembly. A centralized thermal-storage system stores hot salt from the receivers, allowing nearly continuous power production, independent of solar energy collection, and improved parity with the grid. A molten salt steam generator converts the stored thermal energy into steam, which powers a steam turbine generator to produce electricity. This paper describes the conceptual design of the plant, the advantages of modularity, expected performance, pathways to cost reductions, and environmental impact.
Date: September 20, 2011
Creator: Pacheco, James E. & Carter Moursund, Dale Rogers, David Wasyluk
Object Type: Article
System: The UNT Digital Library
Deglacial radiocarbon history of tropical Atlantic thermocline waters: absence of CO2 reservoir purging signal (open access)

Deglacial radiocarbon history of tropical Atlantic thermocline waters: absence of CO2 reservoir purging signal

None
Date: May 20, 2011
Creator: Cleroux, C.; deMenocal, P. B. & Guilderson, T. P.
Object Type: Article
System: The UNT Digital Library
Design of Benchmark Imagery for Validating Facility Annotation Algorithms (open access)

Design of Benchmark Imagery for Validating Facility Annotation Algorithms

None
Date: April 20, 2011
Creator: Roberts, R S; Pope, P A; Vatsavai, R R; Jiang, M; Arrowood, L F; Trucano, T G et al.
Object Type: Article
System: The UNT Digital Library
Development of K-Basin High-Strength Homogeneous Sludge Simulants and Correlations Between Unconfined Compressive Strength and Shear Strength (open access)

Development of K-Basin High-Strength Homogeneous Sludge Simulants and Correlations Between Unconfined Compressive Strength and Shear Strength

K-Basin sludge will be stored in the Sludge Transport and Storage Containers (STSCs) at an interim storage location on Central Plateau before being treated and packaged for disposal. During the storage period, sludge in the STSCs may consolidate/agglomerate, potentially resulting in high-shear-strength material. The Sludge Treatment Project (STP) plans to use water jets to retrieve K-Basin sludge after the interim storage. STP has identified shear strength to be a key parameter that should be bounded to verify the operability and performance of sludge retrieval systems. Determining the range of sludge shear strength is important to gain high confidence that a water-jet retrieval system can mobilize stored K-Basin sludge from the STSCs. The shear strength measurements will provide a basis for bounding sludge properties for mobilization and erosion. Thus, it is also important to develop potential simulants to investigate these phenomena. Long-term sludge storage tests conducted by Pacific Northwest National Laboratory (PNNL) show that high-uranium-content K-Basin sludge can self-cement and form a strong sludge with a bulk shear strength of up to 65 kPa. Some of this sludge has 'paste' and 'chunks' with shear strengths of approximately 3-5 kPa and 380-770 kPa, respectively. High-uranium-content sludge samples subjected to hydrothermal testing (e.g., …
Date: February 20, 2011
Creator: Onishi, Yasuo; Baer, Ellen BK; Chun, Jaehun; Yokuda, Satoru T.; Schmidt, Andrew J.; Sande, Susan et al.
Object Type: Report
System: The UNT Digital Library
Dielectric Wakefield Accelerator to drive the future FEL Light Source. (open access)

Dielectric Wakefield Accelerator to drive the future FEL Light Source.

X-ray free-electron lasers (FELs) are expensive instruments and a large part of the cost of the entire facility is driven by the accelerator. Using a high-energy gain dielectric wake-field accelerator (DWA) instead of the conventional accelerator may provide a significant cost saving and reduction of the facility size. In this article, we investigate using a collinear dielectric wakefield accelerator to provide a high repetition rate, high current, high energy beam to drive a future FEL x-ray light source. As an initial case study, a {approx}100 MV/m loaded gradient, 850 GHz quartz dielectric based 2-stage, wakefield accelerator is proposed to generate a main electron beam of 8 GeV, 50 pC/bunch, {approx}1.2 kA of peak current, 10 x 10 kHz (10 beamlines) in just 100 meters with the fill factor and beam loading considered. This scheme provides 10 parallel main beams with one 100 kHz drive beam. A drive-to-main beam efficiency {approx}38.5% can be achieved with an advanced transformer ratio enhancement technique. rf power dissipation in the structure is only 5 W/cm{sup 2} in the high repetition rate, high gradient operation mode, which is in the range of advanced water cooling capability. Details of study presented in the article include the overall …
Date: April 20, 2011
Creator: Jing, C.; Power, J. & Zholents, A.
Object Type: Report
System: The UNT Digital Library
The DNA repair endonuclease XPG interacts directly and functionally with the WRN helicase defective in Werner syndrome (open access)

The DNA repair endonuclease XPG interacts directly and functionally with the WRN helicase defective in Werner syndrome

XPG is a structure-specific endonuclease required for nucleotide excision repair (NER). XPG incision defects result in the cancer-prone syndrome xeroderma pigmentosum, whereas truncating mutations of XPG cause the severe postnatal progeroid developmental disorder Cockayne syndrome. We show that XPG interacts directly with WRN protein, which is defective in the premature aging disorder Werner syndrome, and that the two proteins undergo similar sub-nuclear redistribution in S-phase and co-localize in nuclear foci. The co-localization was observed in mid- to late-S-phase, when WRN moves from nucleoli to nuclear foci that have been shown to contain protein markers of both stalled replication forks and telomeric proteins. We mapped the interaction between XPG and WRN to the C-terminal domains of each and show that interaction with the C-terminal domain of XPG strongly stimulates WRN helicase activity. WRN also possesses a competing DNA single-strand annealing activity that, combined with unwinding, has been shown to coordinate regression of model replication forks to form Holliday junction/chicken foot intermediate structures. We tested whether XPG stimulated WRN annealing activity and found that XPG itself has intrinsic strand annealing activity that requires the unstructured R- and C-terminal domains, but not the conserved catalytic core or endonuclease activity. Annealing by XPG is …
Date: April 20, 2011
Creator: Trego, Kelly S.; Chernikova, Sophia B.; Davalos, Albert R.; Perry, J. Jefferson P.; Finger, L. David; Ng, Cliff et al.
Object Type: Article
System: The UNT Digital Library
Dual and Triple Ion-Beam Irradiations of Fe, Fe(Cr) and Fe(Cr)-ODS Final Report: IAEA SMoRE CRP (open access)

Dual and Triple Ion-Beam Irradiations of Fe, Fe(Cr) and Fe(Cr)-ODS Final Report: IAEA SMoRE CRP

Structures of nanoparticles in Fe-16Cr-4.5Al-0.3Ti-2W-0.37Y2O3 (K3) and Fe-20Cr-4.5Al-0.34Ti-0.5Y2O3 (MA956) oxide dispersion strengthened (ODS) ferritic steels produced by mechanical alloying (MA) and followed by hot extrusion have been studied using high-resolution transmission electron microscopy (HRTEM) techniques to gain insight about the formation mechanism of nanoparticles in MA/ODS steels. The observations of Y-Al-O complex-oxide nanoparticles in both ODS steels imply that decomposition of Y2O3 in association with internal oxidation of Al occurred during mechanical alloying. While the majority of oxide nanoparticles formed in both steels is Y4Al2O9, a few oxide particles of YAlO3 are also occasionally observed. These results reveal that Ti (0.3 wt %) plays an insignificant role in forming oxide nanoparticles in the presence of Al (4.5 wt %). HRTEM observations of crystalline nanoparticles larger than {approx}2 nm and amorphous or disordered cluster domains smaller than {approx}2 nm provide an insight into the formation mechanism of oxide nanoparticle in MA/ODS steels, which we believe from our observations involves a solid-state amorphous precursor followed by recrystallization. Dual ion-beam irradiations using He{sup +} + Fe{sup +8} ions were employed to gain more detailed insight about the role of nanoparticles in suppressing radiation-induced swelling. This is elaborated through TEM examinations of cavity distributions …
Date: November 20, 2011
Creator: Fluss, M. J.; Hsiung, L. L. & Marian, J.
Object Type: Report
System: The UNT Digital Library