Depths of equivalent dipole polarizability resolution for some transmitter receiver configurations (open access)

Depths of equivalent dipole polarizability resolution for some transmitter receiver configurations

Equivalent dipole polarizability matrices and equivalent dipole location are a convenient way to summarize magnetic induction data arising from currents induced in isolated conductive objects. The uncertainties in polarizability estimates and in equivalent dipole location provide a quantitative measure of the performance of different configurations of transmitters and receivers. Uncertainties in equivalent dipole polarizability matrices and equivalent dipole position are estimated using a linearized inversion. For a number of systems of rectangular loop transmitters and dipole receivers sited on a horizontal grid, equivalent dipole depth is determined to 10% approximately 20% deeper, than the polarizability matrix elements can be determined to the same precision. Systems that have a lower product of rms polarizability uncertainty and square root of their number of transmitter-receiver pairs are considered more effective for their number of transmitter-receiver pairs. Among the systems studied, a system with three orthogonal transmitter loops and a three component receiver is the most effective, for objects shallower than 0.6 times the instrument siting grid spacing, yielding an rms polarizability uncertainty 0.04 times that of a single transmitter single receiver system. At intermediate depths, a system with two vertical component receivers on the diagonal of a horizontal transmitter loop is most effective …
Date: June 6, 2002
Creator: Smith, J. Torquil; Morrison, H. Frank & Becker, Alex
Object Type: Article
System: The UNT Digital Library
INSIGNIFICANCE OF RADIOTOXICITY OF SPALLATION PRODUCTS IN AN ACCELERATOR-DRIVEN TRANSMUTATION SYSTEM. (open access)

INSIGNIFICANCE OF RADIOTOXICITY OF SPALLATION PRODUCTS IN AN ACCELERATOR-DRIVEN TRANSMUTATION SYSTEM.

One of the concerns facing accelerator-driven transmutation systems (ADSs) is whether the radiotoxicity of materials produced during the transmutation process poses more of a concern than does the radiotoxicity of the spent nuclear fuel (SNF) itself. Most of the common fission products (or FPs) are emitters of beta radiation, but additionally, some of the radionuclides generated during spallation are alpha emitters. Thus, both ingestion and inhalation radiotoxicity of the materials produced during spallation could be significant. Typically, ingestion is considered to be more significant than inhalation radiotoxicity for long-term storage/disposal (such as in a repository) because the greatest potential biological hazard to humans occurs when the isotope is absorbed in nearby ground water or brine and transported from the repository to drinking water. Nonetheless, inhalation radiotoxicity is also important to analyze in case of a breach of containment inside the accelerator facility and/or for short-term (i.e., above-ground) storage concerns. Thus, this study calculated the radiotoxicity of spallation products (or SPs) from three different targets: lead-bismuth eutectic (LBE), LBE-cooled tungsten, and LBE-cooled lead.
Date: June 6, 2002
Creator: TRELLUE, HOLLY R & PITCHER, ERIC J
Object Type: Article
System: The UNT Digital Library
Prostate Cancer Specific Adenoviral Vectors to Increase the Therapeutic Index of Targeted Radiotherapy (open access)

Prostate Cancer Specific Adenoviral Vectors to Increase the Therapeutic Index of Targeted Radiotherapy

The goal of this proposal was to construct and evaluate adenoviral vectors encoding for the human somatostatin receptor subtype 2 (SSTr2) in the context of human prostate cancer.
Date: June 6, 2002
Creator: Rogers, B. E.
Object Type: Report
System: The UNT Digital Library
Octupole effects at super and normal deformation. (open access)

Octupole effects at super and normal deformation.

This presentation deals with recent results on the onset of octupole collectivity in superdeformed nuclei of the A {approx} 190 and A {approx} 150 regions as well as in actinide nuclei at normal deformation. It is shown that most of the properties of these negative parity sequences can be understood in terms of Random Phase Approximation (RPA) calculations, although the observations in some Pu isotopes continue to be a challenge to interpret.
Date: June 6, 2002
Creator: Janssens, R. V. F.
Object Type: Article
System: The UNT Digital Library
Post-Closure Monitoring Report for Corrective Action Unit 329: Area 22 Desert Rock Airstrip Fuel Spill, Nevada Test Site, Nevada (Rev. No.: 0, June 2002) (open access)

Post-Closure Monitoring Report for Corrective Action Unit 329: Area 22 Desert Rock Airstrip Fuel Spill, Nevada Test Site, Nevada (Rev. No.: 0, June 2002)

There was an increase in total petroleum hydrocarbons (TPH) concentrations at all three depths within Borehole DRA-0. The oxygen concentration at 40 ft below ground surface (bgs) decreased. There was also an increase in carbon dioxide concentration at that depth. The decrease in oxygen concentrations and the increase in carbon dioxide concentration at the 40 ft bgs level could be possible indicators of natural attenuation. It is not possible to determine trends or biodegradation rates with the limited amount of data collected from the site. The sample results from this first monitoring period did not correlate with the baseline results collected in August 2000. Additional samples will be collected and the results will be compared to previously collected samples to determine if the site was at equilibrium in August 2000. Continued annual monitoring will be conducted as specified in the Closure Report to determine trends at the site. As natural attenuation occurs, the TPH concentrations should decrease. The TPH concentrations will be compared over successive monitoring events to determine trends and approximate rates. As natural attenuation occurs, oxygen will be consumed and carbon dioxide will be produced. The oxygen, nitrogen, and carbon dioxide concentrations will also be evaluated to determine …
Date: June 6, 2002
Creator: United States. National Nuclear Security Administration. Nevada Operations Office.
Object Type: Report
System: The UNT Digital Library
DEVELOPMENT OF A CANDLE FILTER FAILURE SAFEGUARD DEVICE (open access)

DEVELOPMENT OF A CANDLE FILTER FAILURE SAFEGUARD DEVICE

Development, testing and optimization of advanced metal and ceramic, barrier and fiber safeguard devices (SGDs) is described. Metal barrier devices are found prone to manufacturing defects and premature blinding. Fiber devices are found to be satisfactory if fine fibers are used. Durable alloys are identified for both oxidation and gasification conditions. Ceramic honeycomb SGDs were found to perform as excellent barrier devices. Optimization has shown such devices to be durable. Field testing of ceramic honeycomb SGDs from two different manufacturers is being pursued.
Date: June 6, 2002
Creator: Bruck, G.J.; Smeltzer, E.E. & Sanjana, Z.N.
Object Type: Report
System: The UNT Digital Library
Cutting Costs by Locating High Production Wells: A Test of the Volcano seismic Approach to Finding ''Blind'' Resources (open access)

Cutting Costs by Locating High Production Wells: A Test of the Volcano seismic Approach to Finding ''Blind'' Resources

In the summer of 2000, Duke University and the Kenyan power generation company, KenGen, conducted a microearthquake monitoring experiment at Longonot volcano in Kenya. Longonot is one of several major late Quaternary trachyte volcanoes in the Kenya Rift. They study was aimed at developing seismic methods for locating buried hydrothermal areas in the Rift on the basis of their microearthquake activity and wave propagation effects. A comparison of microearthquake records from 4.5 Hz, 2 Hz, and broadband seismometers revealed strong high-frequency site and wave-propagation effects. The lower frequency seismometers were needed to detect and record individual phases. Two-dozen 3-component 2- Hz L22 seismographs and PASSCAL loggers were then distributed around Longonot. Recordings from this network located one seismically active area on Longonot's southwest flank. The events from this area were emergent, shallow (<3 km), small (M<1), and spatially restricted. Evidently, the hydrothermal system in this area is not currently very extensive or active. To establish the nature of the site effects, the data were analyzed using three spectral techniques that reduce source effects. The data were also compared to a simple forward model. The results show that, in certain frequency ranges, the technique of dividing the horizontal motion by the …
Date: June 6, 2002
Creator: Shalev, Eylon; Malin, Peter E. & McCausland, Wendy
Object Type: Report
System: The UNT Digital Library
Flexibility and Robustness Calculations for NCSX (open access)

Flexibility and Robustness Calculations for NCSX

The National Compact Stellarator Experiment (NCSX) will study the physics of low aspect ratio, high beta quasi-axisymmetric stellarators. In order to achieve the scientific goals of the NCSX mission, the device must be capable of supporting a wide range of variations in plasma configuration about a reference equilibrium. Numerical experiments are presented which demonstrate this capability.
Date: June 6, 2002
Creator: Pomphrey, N.; Hatcher, R.; Hirshman, S. P.; Hudson, S.; Ku, L. P.; Lazarus, E. A. et al.
Object Type: Report
System: The UNT Digital Library