Application of automated deduction to the search for single axioms for exponent groups (open access)

Application of automated deduction to the search for single axioms for exponent groups

We present new results in axiomatic group theory obtained by using automated deduction programs. The results include single axioms, some with the identity and others without, for groups of exponents 3, 4, 5 and 7, and a general form for single axioms for groups of odd exponent. The results were obtained by using the programs in three separate ways: as a symbolic calculator, to search for proofs,and to search for couterexamples. We also touch on relations between logic programming and automated reasoning.
Date: February 11, 1992
Creator: McCune, W. & Wos, L.
Object Type: Article
System: The UNT Digital Library
Low-exposure tritium radiotoxicity in mammals (open access)

Low-exposure tritium radiotoxicity in mammals

Studies of tritium radiotoxicity involving chronic /sup 3/H0H exposures in mammals demonstrate in both mice and monkeys that biological effects can be measured following remarkably low levels of exposure - levels in the range of serious practical interest to radiation protection. These studies demonstrate also that deleterious effects of /sup 3/H beta radiation do not differ significantly from those of gamma radiation at high exposures. In contrast, however, at low exposures tritium is significantly more effective than gamma rays, rad for rad, by a factor approaching 3. This is important for hazard evaluation and radiation protection because knowledge concerning biological effects of chronic low-level radiation exposure has come mainly from gamma-ray data; and predictions based on gamma-ray data will underestimate tritium effects - especially at low exposures - unless the RBE is fully taken into account.
Date: February 11, 1982
Creator: Dobson, R.L.
Object Type: Article
System: The UNT Digital Library
International energy R and D: a picture compiled from open sources (open access)

International energy R and D: a picture compiled from open sources

None
Date: February 11, 1975
Creator: Green, E.A.
Object Type: Report
System: The UNT Digital Library
Mechanical model for ductility loss (open access)

Mechanical model for ductility loss

A mechanical model was constructed to probe into the mechanism of ductility loss. Fracture criterion based on critical localized deformation was undertaken. Two microstructure variables were considered in the model. Namely, the strength ratio of grain boundary affected area to the matrix, ..cap omega.., and the linear fraction, x, of grain boundary affected area. A parametrical study was carried out. The study shows that the ductility is very sensitive to those microstructure parameters. The functional dependence of ductility to temperature as well as strain-rate, suggested by the model, is demonstrated to be consistent with the observation.
Date: February 11, 1980
Creator: Hu, W.L.
Object Type: Article
System: The UNT Digital Library
Detection and sizing of underbead cracks using ultrasonic nondestructive examination (open access)

Detection and sizing of underbead cracks using ultrasonic nondestructive examination

Ultrasonic nondestructive examination (NDE) will detect three mil deep underbead cracks in welds joining thin walled iridium hemishells. A correlation was developed to relate the amplitude of the signal reflected from the crack with crack wall area. The observed cracks occur in the weld underbead in the arc taper area during encapsulation of /sup 238/PuO/sub 2/ pellets for thermoelectric generators used in deep space exploration.
Date: February 11, 1982
Creator: Scarbrough, J.D. & Wierzbicki, W.M.
Object Type: Report
System: The UNT Digital Library
Technical Risk Rating of DOE Environmental Projects - 9153 (open access)

Technical Risk Rating of DOE Environmental Projects - 9153

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. The scope of work is diverse, with projects ranging from single acquisitions to collections of projects and operations that span several decades and costs from hundreds of millions to billions US$. The need to be able to manage and understand the technical risks from the project to senior management level has been recognized as an enabler to successfully completing the mission. In 2008, DOE-EM developed the Technical Risk Rating as a new method to assist in managing technical risk based on specific criteria. The Technical Risk Rating, and the criteria used to determine the rating, provides a mechanism to foster open, meaningful communication between the Federal Project Directors and DOE-EM management concerning project technical risks. Four indicators (technical maturity, risk urgency, handling difficulty and resolution path) are used to focus attention on the issues and key aspects related to the risks. Pressing risk issues are brought to the forefront, keeping DOE-EM management informed and engaged such that they fully understand risk impact. Use of the Technical Risk Rating and criteria during reviews …
Date: February 11, 2009
Creator: Cercy, Michael; Fayfich, Ronald & Schneider, Steven
Object Type: Article
System: The UNT Digital Library
Heterogeneous processes at the intersection of chemistry and biology: A computational approach (open access)

Heterogeneous processes at the intersection of chemistry and biology: A computational approach

Heterogeneous processes hold the key to understanding many problems in biology and atmospheric science. In particular, recent experiments have shown that heterogeneous chemistry at the surface of sea-salt aerosols plays a large role in important atmospheric processes with far reaching implications towards understanding of the fate and transport of aerosolized chemical weapons (i.e. organophosphates such as sarin and VX). Unfortunately, the precise mechanistic details of the simplest surface enhanced chemical reactions remain unknown. Understanding heterogeneous processes also has implications in the biological sciences. Traditionally, it is accepted that enzymes catalyze reactions by stabilizing the transition state, thereby lowering the free energy barrier. However, recent findings have shown that a multitude of phenomena likely contribute to the efficiency of enzymes, such as coupled protein motion, quantum mechanical tunneling, or strong electrostatic binding. The objective of this project was to develop and validate a single computational framework based on first principles simulations using tera-scale computational resources to answer fundamental scientific questions about heterogeneous chemical processes relevant to atmospheric chemistry and biological sciences.
Date: February 11, 2008
Creator: Kuo, I W & Mundy, C J
Object Type: Report
System: The UNT Digital Library
CLOMP: Accurately Characterizing OpenMP Application Overheads (open access)

CLOMP: Accurately Characterizing OpenMP Application Overheads

Despite its ease of use, OpenMP has failed to gain widespread use on large scale systems, largely due to its failure to deliver sufficient performance. Our experience indicates that the cost of initiating OpenMP regions is simply too high for the desired OpenMP usage scenario of many applications. In this paper, we introduce CLOMP, a new benchmark to characterize this aspect of OpenMP implementations accurately. CLOMP complements the existing EPCC benchmark suite to provide simple, easy to understand measurements of OpenMP overheads in the context of application usage scenarios. Our results for several OpenMP implementations demonstrate that CLOMP identifies the amount of work required to compensate for the overheads observed with EPCC. Further, we show that CLOMP also captures limitations for OpenMP parallelization on NUMA systems.
Date: February 11, 2008
Creator: Bronevetsky, G; Gyllenhaal, J & de Supinski, B
Object Type: Article
System: The UNT Digital Library
The Soils and Groundwater – EM-20 S&T Roadmap Quality Assurance Project Plan (open access)

The Soils and Groundwater – EM-20 S&T Roadmap Quality Assurance Project Plan

The Soils and Groundwater – EM-20 Science and Technology Roadmap Project is a U.S. Department of Energy, Office of Environmental Management-funded initiative designed to develop new methods, strategies and technology for characterizing, modeling, remediating, and monitoring soils and groundwater contaminated with metals, radionuclides, and chlorinated organics. This Quality Assurance Project Plan provides the quality assurance requirements and processes that will be followed by EM-20 Roadmap Project staff.
Date: February 11, 2008
Creator: Fix, N. J.
Object Type: Report
System: The UNT Digital Library
Demonstartion of density dependence of x-ray flux in a laser-driven hohlraum (open access)

Demonstartion of density dependence of x-ray flux in a laser-driven hohlraum

Experiments have been conducted using laser-driven cylindrical hohlraums whose walls are machined from Ta{sub 2}O{sub 5} foams of 100 mg/cc and 4 g/cc densities. Measurements of the radiation temperature demonstrate that the lower density walls produce higher radiation temperatures than the high density walls. This is the first experimental demonstration of the prediction that this would occur [M. D. Rosen and J. H. Hammer, Phys. Rev. E 72, 056403 (2005)]. For high density walls, the radiation front propagates subsonically, and part of the absorbed energy is wasted by the flow kinetic energy. For the lower wall density, the front velocity is supersonic and can devote almost all of the absorbed energy to heating the wall.
Date: February 11, 2008
Creator: Young, P E; Rosen, M D; Hammer, J H; Hsing, W S; Glendinning, S G; Turner, R E et al.
Object Type: Article
System: The UNT Digital Library
Thermal Cycling on Fatigue Failure of the Plutonium Vitrification Melter (open access)

Thermal Cycling on Fatigue Failure of the Plutonium Vitrification Melter

One method for disposition of excess plutonium is vitrification into cylindrical wasteforms. Due to the hazards of working with plutonium, the vitrification process must be carried out remotely in a shielded environment. Thus, the equipment must be easily maintained. With their simple design, induction melters satisfy this criterion, making them ideal candidates for plutonium vitrification. However, due to repeated heating and cooling cycles and differences in coefficients of thermal expansion of contacting materials fatigue failure of the induction melter is of concern. Due to the cost of the melter, the number of cycles to failure is critical. This paper presents a method for determining the cycles to failure for an induction melter by using the results from thermal and structural analyses as input to a fatigue failure model.
Date: February 11, 2009
Creator: Jordan, Jeffrey & Gorczyca, Jennifer
Object Type: Article
System: The UNT Digital Library
FY07 LDRD Final Report Comparative Analysis of Genome Composition with Respect to Genotype-to-Phenotype Mapping and Metabolic Capability (open access)

FY07 LDRD Final Report Comparative Analysis of Genome Composition with Respect to Genotype-to-Phenotype Mapping and Metabolic Capability

None
Date: February 11, 2008
Creator: D'haeseleer, P
Object Type: Report
System: The UNT Digital Library
Asymmetric injection of cathodic arc plasma into a macroparticlefilter (open access)

Asymmetric injection of cathodic arc plasma into a macroparticlefilter

The cathodic arc plasmas produced by cathode spots usuallyinclude macroparticles, which is undesirable for many applications. Acommon way of removing macroparticles is to use curved solenoid filterswhich guide the plasma from the source to the substrate. In this work, anarc source with relatively small cathode is used, limiting the possiblelocations of plasma production. The relative position of cathodic arcsource and macroparticle filtered was systematically varied and thefiltered plasma current was recorded. It was found that axis-symmetricplasma injection leads to maximum throughput only if an anode aperturewas used, which limited the plasma to near-axis flow by scraping offplasma at larger angles to the axis. When the anode aperture was removed,more plasma could enter the filter. In this case, maximum filtered ioncurrent was achieved when the plasma was injected off-axis, namely offsetin the direction where the filter is curved. Such behavior wasanticipated because the plasma column in the filter is known to beshifted by ExB and centrifugal drift as well as by non-axis-symmetriccomponents of the magnetic field in the filter entrance and exit plane.The data have implications for plasma transport variations caused bydifferent spot locations on cathodes that are not small compared to thefilter cross section.
Date: February 11, 2004
Creator: Anders, Andre & MacGill, Robert A.
Object Type: Article
System: The UNT Digital Library
Report on Toyota Prius Motor Thermal Management (open access)

Report on Toyota Prius Motor Thermal Management

In the current hybrid vehicle market, the Toyota Prius drive system is considered the leader in electrical, mechanical, and manufacturing innovations. It is a significant accomplishment that Toyota is able to manufacture and sell the vehicle for a profit. The Toyota Prius traction motor design approach for reducing manufacturing costs and the motor s torque capability have been studied and tested. The findings were presented in two previous Oak Ridge National Laboratory (ORNL) reports. The conclusions from this report reveal, through temperature rise tests, that the 2004 Toyota Prius (THSII) motor is applicable only for use in a hybrid automobile. It would be significantly undersized if used in a fuel cell vehicle application. The power rating of the Prius motor is limited by the permissible temperature rise of the motor winding (170 C) and the motor cooling oil (158 C). The continuous ratings at base speed (1200 rpm) with different coolant temperatures are projected from test data at 900 rpm. They are approximately 15 kW with 105 C coolant and 21 kW with 35 C coolant. These continuous ratings are much lower than the 30 kW specified as a technical motor target of the U.S. Department of Energy FreedomCAR Program. …
Date: February 11, 2005
Creator: Hsu, J.S.
Object Type: Report
System: The UNT Digital Library
Enhanced Chemical Cleaning: A New Process for Chemically Cleaning Savannah River Waste Tanks (open access)

Enhanced Chemical Cleaning: A New Process for Chemically Cleaning Savannah River Waste Tanks

At the Savannah River Site (SRS) there are 49 High Level Waste (HLW) tanks that eventually must be emptied, cleaned, and closed. The current method of chemically cleaning SRS HLW tanks, commonly referred to as Bulk Oxalic Acid Cleaning (BOAC), requires about a half million liters (130,000 gallons) of 8 weight percent (wt%) oxalic acid to clean a single tank. During the cleaning, the oxalic acid acts as the solvent to digest sludge solids and insoluble salt solids, such that they can be suspended and pumped out of the tank. Because of the volume and concentration of acid used, a significant quantity of oxalate is added to the HLW process. This added oxalate significantly impacts downstream processing. In addition to the oxalate, the volume of liquid added competes for the limited available tank space. A search, therefore, was initiated for a new cleaning process. Using TRIZ (Teoriya Resheniya Izobretatelskikh Zadatch or roughly translated as the Theory of Inventive Problem Solving), Chemical Oxidation Reduction Decontamination with Ultraviolet Light (CORD-UV{reg_sign}), a mature technology used in the commercial nuclear power industry was identified as an alternate technology. Similar to BOAC, CORD-UV{reg_sign} also uses oxalic acid as the solvent to dissolve the metal (hydr)oxide …
Date: February 11, 2009
Creator: Ketusky, Edward; Spires, Renee & Davis, Neil
Object Type: Article
System: The UNT Digital Library
Residual stress measurement and microstructural characterization of thick beryllium films (open access)

Residual stress measurement and microstructural characterization of thick beryllium films

Beryllium films are synthesized by a magnetron sputtering technique incorporating in-situ residual stress measurement. Monitoring the stress evolution in real time provides quantitative through-thickness information on the effects of various processing parameters, including sputtering gas pressure and substrate biasing. Specimens produced over a wide range of stress states are characterized via transmission and scanning electron microscopy, and atomic force microscopy, in order to correlate the stress data with microstructure. A columnar grain structure is observed for all specimens, and surface morphology is found to be strongly dependent on processing conditions. Analytical models of stress generation are reviewed and discussed in terms of the observed microstructure.
Date: February 11, 2008
Creator: Detor, A.; Wang, M.; Hodge, A. M.; Chason, E.; Walton, C.; Hamza, A. V. et al.
Object Type: Report
System: The UNT Digital Library
Sludge Batch 5 Slurry Fed Melt Rate Furnace Test with Frits 418 and 550 (open access)

Sludge Batch 5 Slurry Fed Melt Rate Furnace Test with Frits 418 and 550

Based on Melt Rate Furnace (MRF) testing for the Sludge Batch 5 (SB5) projected composition and assessments of the potential frits with reasonable operating windows, the Savannah River National Laboratory (SRNL) recommended Slurry Fed Melt Rate Furnace (SMRF) testing with Frits 418 and 550. DWPF is currently using Frit 418 with SB5 based on SRNL's recommendation due to its ability to accommodate significant sodium variation in the sludge composition. However, experience with high boron containing frits in DWPF indicated a potential advantage for Frit 550 might exist. Therefore, SRNL performed SMRF testing to assess Frit 550's potential advantages. The results of SMRF testing with SB5 simulant indicate that there is no appreciable difference in melt rate between Frit 418 and Frit 550 at a targeted 34 weight % waste loading. Both batches exhibited comparable behavior when delivered through the feed tube by the peristaltic pump. Limited observation of the cold cap during both runs showed no indication of major cold cap mounding. MRF testing, performed after the SMRF runs due to time constraints, with the same two Slurry Mix Evaporator (SME) dried products led to the same conclusion. Although visual observations of the cross-sectioned MRF beakers indicated differences in the …
Date: February 11, 2009
Creator: Miller, Donald & Pickenheim, Bradley
Object Type: Report
System: The UNT Digital Library
Tank 26 Evaporator Feed Pump Transfer Analysis (open access)

Tank 26 Evaporator Feed Pump Transfer Analysis

The transfer of liquid salt solution from Tank 26 to an evaporator is to be accomplished by activating the evaporator feed pump, located approximately 72 inches above the sludge layer, while simultaneously turning on the downcomer. Previously, activation of the evaporator feed pump was an isolated event without any other components running at the same time. An analysis of the dissolved solution transfer has been performed using computational fluid dynamics methods to determine the amount of entrained sludge solids pumped out of the tank to the evaporator with the downcomer turned on. The analysis results showed that, for the maximum and minimum supernate levels in Tank 26 (252.5 and 72 inches above the sludge layer, respectively), the evaporator feed pump will entrain between 0.03 and 0.1 wt% sludge undissolved solids weight fraction into the eductor, respectively, and therefore are an order of magnitude less than the 1.0 wt% undissolved solids loading criteria to feed the evaporator. Lower tank liquid levels, with respect to the sludge layer, result in higher amounts of sludge entrainment due to the increased velocity of the plunging jets from the downcomer and evaporator feed pump bypass as well as decreased dissipation depth. Revision 1 clarifies the …
Date: February 11, 2009
Creator: Tamburello, David; Dimenna, Richard & Lee, Si
Object Type: Report
System: The UNT Digital Library
The Prospect of using Three-Dimensional Earth Models To Improve Nuclear Explosion Monitoring and Ground Motion Hazard Assessment (open access)

The Prospect of using Three-Dimensional Earth Models To Improve Nuclear Explosion Monitoring and Ground Motion Hazard Assessment

The last ten years have brought rapid growth in the development and use of three-dimensional (3D) seismic models of earth structure at crustal, regional and global scales. In order to explore the potential for 3D seismic models to contribute to important societal applications, Lawrence Livermore National Laboratory (LLNL) hosted a 'Workshop on Multi-Resolution 3D Earth Models to Predict Key Observables in Seismic Monitoring and Related Fields' on June 6 and 7, 2007 in Berkeley, California. The workshop brought together academic, government and industry leaders in the research programs developing 3D seismic models and methods for the nuclear explosion monitoring and seismic ground motion hazard communities. The workshop was designed to assess the current state of work in 3D seismology and to discuss a path forward for determining if and how 3D earth models and techniques can be used to achieve measurable increases in our capabilities for monitoring underground nuclear explosions and characterizing seismic ground motion hazards. This paper highlights some of the presentations, issues, and discussions at the workshop and proposes a path by which to begin quantifying the potential contribution of progressively refined 3D seismic models in critical applied arenas.
Date: February 11, 2008
Creator: Antoun, T.; Harris, D.; Lay, T.; Myers, S. C.; Pasyanos, M. E.; Richards, P. et al.
Object Type: Report
System: The UNT Digital Library
Radial-Gap Permanent Magnet Motor and Drive Research FY 2004 (open access)

Radial-Gap Permanent Magnet Motor and Drive Research FY 2004

The objective of this task was to study permanent magnet (PM) radial-gap traction drive systems that could meet the U.S. Department of Energy FreedomCAR Program's 2010 goals to expose weaknesses or identify strengths. Initially, the approach was to compare attributes such as physical deformations during operation, performance (torque, power, efficiency versus speed), material requirements (strength), material costs, manufacturability, weight, power density, specific power, reliability, and drivability for specific motors. Three motors selected were the commercially available 60-kW radial-gap surface-mounted PM motor manufactured by UQM Technologies, Inc.; a hypothetical PM motor with rotor-supported magnets similar to the Honda MCF-21; and Delphi's automotive electric machine drive motor, whose rotor is a ferromagnetic cylinder, held at one end by a shaft that supports the magnets on its inner surface. Potential problems have appeared related to PM motors, such as (1) high no-load spin losses and high operational power losses, probably from eddy current losses in the rotor; (2) the undemonstrated dual mode inverter control (DMIC) for driving a brushless dc motor (BDCM) (UQM and Delphi motors); (3) uncertainty about the potential for reducing current with DMIC; and (4) uncertainty about the relation between material requirements and maximum rotor speed. Therefore, the approach was …
Date: February 11, 2005
Creator: McKeever, J.W.
Object Type: Report
System: The UNT Digital Library
Damage Detection System with Sub-microsecond Resolution (open access)

Damage Detection System with Sub-microsecond Resolution

Fiber optic grating sensors have been used to measure multi-dimensional strain, pressure, temperature, corrosion and moisture. This paper presents a method of using fiber grating sensors to measure the position and velocity of a very fast event associated with a blast wave. A chirped fiber grating of 50 mm length is placed in a highly energetic material. The action of the shock wave is to destroy the fiber grating as it propagates along it. By using a spectral filter such as a chirped fiber grating in combination with high speed detectors the position and velocity of the shock wave may be determined. A layout of a system used to experimentally verify this technique is described and results presented for two different highly energetic materials.
Date: February 11, 2008
Creator: Udd, E & Benterou, J
Object Type: Article
System: The UNT Digital Library
Science Priorities for Mars Sample Return (open access)

Science Priorities for Mars Sample Return

None
Date: February 11, 2008
Creator: Borg, L.; Des Marais, D. & Beaty, D.
Object Type: Report
System: The UNT Digital Library
Salt Processing Through Ion Exchange at the Savannah River Site Selection of Exchange Media and Column Configuration - 9198 (open access)

Salt Processing Through Ion Exchange at the Savannah River Site Selection of Exchange Media and Column Configuration - 9198

The Department of Energy (DOE) has developed, modeled, and tested several different ion exchange media and column designs for cesium removal. One elutable resin and one non-elutable resin were considered for this salt processing application. Deployment of non-elutable Crystalline Silicotitanate and elutable Resorcinol Formaldehyde in several different column configurations were assessed in a formal Systems Engineering Evaluation (SEE). Salt solutions were selected that would allow a grouping of non-compliant tanks to be closed. Tests were run with the elutable resin to determine compatibility with the resin configuration required for an in-tank ion exchange system. Models were run to estimate the ion exchange cycles required with the two resins in several column configurations. Material balance calculations were performed to estimate the impact on the High Level Waste (HLW) system at the Savannah River Site (SRS). Conceptual process diagrams were used to support the hazard analysis. Data from the hazard analysis was used to determine the relative impact on safety. This report will discuss the technical inputs, SEE methods, results and path forward to complete the technical maturation of ion exchange.
Date: February 11, 2009
Creator: Spires, Renee; Punch, Timothy & McCabe, Daniel
Object Type: Article
System: The UNT Digital Library
Spheromak Energy Transport Studies via Neutral Beam Injection (open access)

Spheromak Energy Transport Studies via Neutral Beam Injection

Results from the SSPX spheromak experiment provide strong motivation to add neutral beam injection (NBI) heating. Such auxiliary heating would significantly advance the capability to study the physics of energy transport and pressure limits for the spheromak. This LDRD project develops the physics basis for using NBI to heat spheromak plasmas in SSPX. The work encompasses three activities: (1) numerical simulation to make quantitative predictions of the effect of adding beams to SSPX, (2) using the SSPX spheromak and theory/modeling to develop potential target plasmas suitable for future application of neutral beam heating, and (3) developing diagnostics to provide the measurements needed for transport calculations. These activities are reported in several publications.
Date: February 11, 2008
Creator: McLean, H. S.; Hill, D. N.; Wood, R. D.; Jayakumar, J. & Pearlstein, L. D.
Object Type: Report
System: The UNT Digital Library