Electrical resistance tomography using steel cased boreholes as electrodes (open access)

Electrical resistance tomography using steel cased boreholes as electrodes

Electrical resistance tomography (ERT) using multiple electrodes installed in boreholes has been shown to be useful for both site characterization and process monitoring. In some cases, however, installing multiple downhole electrodes is too costly (e.g., deep targets) or risky (e.g., contaminated sites). For these cases we have examined the possibility of using the steel casings of existing boreholes as electrodes. The first case we investigated used an array of steel casings as electrodes. This results in very few data and thus requires additional constraints to limit the domain of possible inverse solutions. Simulations indicate that the spatial resolution and sensitivity are understandably low but it is possible to coarsely map the lateral extent of subsurface processes such as steam floods. A hybrid case uses traditional point electrode arrays combined with long-conductor electrodes (steel casings). Although this arrangement provides more data, in many cases it results in poor reconstructions of test targets. Results indicate that this method may hold promise for low resolution imaging where steel casings can be used as electrodes.
Date: March 22, 1999
Creator: Newmark, R. L.; Daily, W. & Ramirez, A.
Object Type: Article
System: The UNT Digital Library
Identifying the Proteins that Mediate the Ionizing Radiation Resistance of Deinococcus Radiodurans R1 (open access)

Identifying the Proteins that Mediate the Ionizing Radiation Resistance of Deinococcus Radiodurans R1

The primary objectives of this proposal was to define the subset of proteins required for the ionizing radiation (IR) resistance of Deinococcus radiodurans R1, characterize the activities of those proteins, and apply what was learned to problems of interest to the Department of Energy.
Date: February 22, 2010
Creator: Battista, John R
Object Type: Report
System: The UNT Digital Library
Workshop on environmental aspects of geothermal resources development (open access)

Workshop on environmental aspects of geothermal resources development

The workshop is divided into the following subjects: water quality, air quality, biological impact, hazards, environmental impact evaluation, and land use and socio-economic impact. Individual problems in each subject area are evaluated by the following criteria: probability of occurrence, seriousness of consequences, resource applicability, time urgency for new research, and researchability for new research. Recommended approaches to solution are given for each problem. Minority statements are given in some cases. (MHR)
Date: November 22, 1974
Creator: Anderson, D. N. & Bowen, R. G.
Object Type: Article
System: The UNT Digital Library
Light duty utility arm equipment qualification test procedure (open access)

Light duty utility arm equipment qualification test procedure

The Equipment Qualification Test described in this test procedure document is the acceptance test procedure (ATP) for the LDUA Baseline System. It verifies that the equipment is complete and in working order, and demonstrates its readiness for being deployed into an actual underground storage tank.
Date: July 22, 1996
Creator: Kiebel, G.R.
Object Type: Report
System: The UNT Digital Library
Bifurcation Theory of the Transition to Collisionless Ion-temperature-gradient-driven Plasma Turbulence (open access)

Bifurcation Theory of the Transition to Collisionless Ion-temperature-gradient-driven Plasma Turbulence

The collisionless limit of the transition to ion-temperature-gradient-driven plasma turbulence is considered with a dynamical-systems approach. The importance of systematic analysis for understanding the differences in the bifurcations and dynamics of linearly damped and undamped systems is emphasized. A model with ten degrees of freedom is studied as a concrete example. A four-dimensional center manifold (CM) is analyzed, and fixed points of its dynamics are identified and used to predict a ''Dimits shift'' of the threshold for turbulence due to the excitation of zonal flows. The exact value of that shift in terms of physical parameters is established for the model; the effects of higher-order truncations on the dynamics are noted. Multiple-scale analysis of the CM equations is used to discuss possible effects of modulational instability on scenarios for the transition to turbulence in both collisional and collisionless cases.
Date: September 22, 2005
Creator: Kolesnikov, R. A. & Krommes, J. A.
Object Type: Report
System: The UNT Digital Library
Operating data for thoria wafer dissolution samples (open access)

Operating data for thoria wafer dissolution samples

None
Date: May 22, 1969
Creator: Schmidt, J. P.
Object Type: Report
System: The UNT Digital Library
The Fernald wet records recovery project: A case history (open access)

The Fernald wet records recovery project: A case history

This paper discusses a project performed to recover wet records discovered in January 1995 at the Fernald Environmental Management Project (FEMP). This paper discusses the emergency and record recovery phases of the project, the technical options considered for records recovery, and special measures which were required due to radiological contamination of the records. Also, the root causes and lessons learned from the incident, and path forward for future records management operations at Fernald, are discussed.
Date: June 22, 1995
Creator: Sterling, Harry J.; Devir, Brian R.; Hawley, Robert A. & Freesmeyer, Mary T.
Object Type: Article
System: The UNT Digital Library
Thermodynamic Factors Affecting UC<sub>1-x</sub>N<sub>x</sub>Irradiation and Synthesis (open access)

Thermodynamic Factors Affecting UC<sub>1-x</sub>N<sub>x</sub>Irradiation and Synthesis

There is interest in attempting to synthesize nearly pure uranium nitride (UN) kernels for high-temperature gas-cooled reactor (HTGR) fuel. Because the proposed process involves carbothermic conversion of a urania-carbon mixture in nitrogen and because there is a complete ideal solution of uranium carbide (UC) and UN, which is written as UC{sub 1-x}N{sub x}, the practical value of x for fuel irradiation needs to be determined. Insight is to be gained by relevant thermodynamic calculations of carbide-nitride equilibria for the fuel and fission product systems. The equilibria are readily compared on the nitrogen-based Ellingham diagram, which, in turn, provides guidance in interpreting past irradiations and in synthesis of the UC{sub 1-x}N{sub x} kernels.
Date: April 22, 2005
Creator: Lindemer, T. B.
Object Type: Report
System: The UNT Digital Library
First principles calculations for litiated manganese oxides (open access)

First principles calculations for litiated manganese oxides

First principles calculations using the local-spin-density-functional theory are presented of densities of electronic states for MnO, LiMnO{sub 2} in the monoclinic and orthorhombic structures, cubic LiMn{sub 2}O{sub 4} spinel, and {lambda}-MnO{sub 2} (delithiated spinel), all in antiferromagnetic spin configurations. The changes in energy spectra as the Mn oxidation state varies between 2+ and 4+ are illustrated. Preliminary calculations for Co-doped LiMnO{sub 2} are presented, and the destabilization of a monoclinic relative to a rhombohedral structure is discussed.
Date: December 22, 1998
Creator: Benedek, R.; Prasad, R.; Thackeray, M. M.; Wills, J. M. & Yang, L. H.
Object Type: Article
System: The UNT Digital Library
Study of Chemical Changes in Uranium Oxyfluoride Particles Progress Report March - October 2009 (open access)

Study of Chemical Changes in Uranium Oxyfluoride Particles Progress Report March - October 2009

Nuclear forensics relies on the analysis of certain sample characteristics to determine the origin and history of a nuclear material. In the specific case of uranium enrichment facilities, it is the release of trace amounts of uranium hexafluoride (UF{sub 6}) gas - used for the enrichment of uranium - that leaves a process-characteristic fingerprint. When UF{sub 6} gas interacts with atmospheric moisture, uranium oxyfluoride particles or particle agglomerates are formed with sizes ranging from several microns down to a few tens of nanometers. These particles are routinely collected by safeguards organizations, such as the International Atomic Energy Agency (IAEA), allowing them to verify whether a facility is compliant with its declarations. Spectrometric analysis of uranium particles from UF{sub 6} hydrolysis has revealed the presence of both particles that contain fluorine, and particles that do not. It is therefore assumed that uranium oxyfluoride is unstable, and decomposes to form uranium oxide. Understanding the rate of fluorine loss in uranium oxyfluoride particles, and the parameters that control it, may therefore contribute to placing boundaries on the particle's exposure time in the environment. Expressly for the purpose of this study, we prepared a set of uranium oxyfluoride particles at the Institute for Reference …
Date: November 22, 2009
Creator: Kips, R.; Kristo, M. & Hutcheon, I.
Object Type: Report
System: The UNT Digital Library
Thick Liquid-Walled, Field-Reversed Configuration (open access)

Thick Liquid-Walled, Field-Reversed Configuration

A thick flowing layer of liquid (e.g., flibe--a molten salt, or Sn{sub 80}Li{sub 20}--a liquid metal) protects the structural walls of the field-reversed configuration (FRC) so that they can last the life of the plant even with intense 14 MeV neutron bombardment from the D-T fusion reaction. The surface temperature of the liquid rises as it passes from the inlet nozzles to the exit or receiver nozzles due to absorption of line and bremsstrahlung radiation, and neutrons. The surface temperature can be reduced by enhancement of convection near the surface to transport hot surface liquid into the cooler interior. This surface temperature must be compatible with a practical heat transport and energy recovery system. The evaporative flux from the wall driven by the surface temperature must also result in an acceptable impurity level in the core plasma. The shielding of the core by the edge plasma is modeled with a 2D transport code for the resulting impurity ions; these ions are either swept out to the distant end tanks, or diffuse to the hot plasma core. An auxiliary plasma between the edge plasma and the liquid wall can further attenuate evaporating flux of atoms and molecules by ionization. The current …
Date: September 22, 2000
Creator: Moir, R. W.; Bulmer, R. H.; Gulec, K.; Fogarty, P.; Nelson, B.; Ohnishi, M. et al.
Object Type: Article
System: The UNT Digital Library
Cure shrinkage effects in epoxy and polycyanate matrix composites (open access)

Cure shrinkage effects in epoxy and polycyanate matrix composites

A relatively new advanced composite matrix, polycyanate ester, was evaluated for cure shrinkage. The chemical cure shrinkage of composites is difficult to model but a number of clever experimental techniques are available to the investigator. In this work the method of curing a prepreg layup on top of a previously cured laminate of identical ply composition is utilized. The polymeric matrices used in advanced composites have been primarily epoxies and therefore a common system of this type, Fiberite 3501-6, was used as a base case material. Three polycyanate matrix systems were selected for the study. These are: Fiberite 954-2A, YLA RS-3, and Bryte Technology BTCy-1. The first three of these systems were unidirectional prepreg with carbon fiber reinforcement. The Bryte Technology material was reinforced with E-glass fabric. The technique used to evaluate cure shrinkage results in distortion of the flatness of an otherwise symmetric laminate. The first laminate is cured in a conventional fashion. An identical layup is cured on this first laminate. During the second cure all constituents are exposed to the same thermal cycles. However, only the new portion of the laminate will experience volumetric changes associate with matrix cure. The additional strain of cure shrinkage results in …
Date: December 22, 1995
Creator: Spellman, Gordon P.
Object Type: Report
System: The UNT Digital Library
Sensor systems for the Altair Lunar Lander: (open access)

Sensor systems for the Altair Lunar Lander:

The Altair Lunar Lander will enable astronauts to learn to live and work on the moon for extended periods of time, providing the experience needed to expand human exploration farther into the solar system. My overriding recommendation: Use independent and complementary [sometimes referred to as 'orthogonal'] techniques to disambiguate confounding/interfering signals. E.g.: a mass spectrometer ['MS'], which currently serves as a Majority Constituent Analyzer ['MCA'] can be very valuable in detecting the presence of a gaseous specie, so long as it falls on a mass-to-charge ratio ['m/z'] that is not already occupied by a majority constituent of cabin air. Consider the toxic gas, CO. Both N{sub 2} and CO have parent peaks of m/z = 28, and CO{sub 2} has a fragment peak at m/z = 28 [and at 16 and 12], so the N{sub 2} and CO{sub 2} m/z=28 signals could mask low, but potentially-dangerous levels of CO. However there are numerous surface-sensitive CO detectors, as well as tunable-diode-laser-based CO sensors that could provide independent monitoring of CO. Also, by appending a gas chromatograph ['GC'] as the front-end sample processer, prior to the inlet of the MS, one can rely upon the GC to separate CO from N{sub 2} …
Date: December 22, 2009
Creator: Mariella, Raymond, Jr.
Object Type: Report
System: The UNT Digital Library
Development of a Commercial Process for the Production of Silicon Carbide Fibrils (open access)

Development of a Commercial Process for the Production of Silicon Carbide Fibrils

The current work continues a project completed in 1999 by ReMaxCo Technologies in which a novel, microwave based, VLS Silicon Carbide Fibrils concept was verified. This project continues the process development of a pilot scale commercial reactor. Success will lead to sufficient quantities of fibrils to expand work by ORNL and others on heat exchanger tube development. A semicontinuous, microwave heated, vacuum reactor was designed, fabricated and tested in these experiments. Cylindrical aluminum oxide reaction boats are coated, on the inner surface, with a catalyst and placed into the reactor under a light vacuum. A series of reaction boats are then moved, one at a time, through the reactor. Each boat is first preheated with resistance heaters to 850 C to 900 C. Each reaction boat is then moved, in turn, to the microwave heated section. The catalyst is heated to the required temperature of 1200 C to 1300 C while a mixture of MTS (methyl trichlorosilane) and hydrogen are introduced into the annulus of the boat. The MTS is dissociated to allow the carbon and silicon components to be dissolved into the catalyst. The catalyst saturates and precipitates silicon carbide onto the surface of the reaction boat to grow …
Date: April 22, 2003
Creator: Nixdorf, Richard D.
Object Type: Article
System: The UNT Digital Library
Performance-Driven Interface Contract Enforcement for Scientific Components (open access)

Performance-Driven Interface Contract Enforcement for Scientific Components

Several performance-driven approaches to selectively enforce interface contracts for scientific components are investigated. The goal is to facilitate debugging deployed applications built from plug-and-play components while keeping the cost of enforcement within acceptable overhead limits. This paper describes a study of global enforcement using a priori execution cost estimates obtained from traces. Thirteen trials are formed from five, single-component programs. Enforcement experiments conducted using twenty-three enforcement policies are used to determine the nature of exercised contracts and the impact of a variety of sampling strategies. Performance-driven enforcement appears to be best suited to programs that exercise moderately expensive contracts.
Date: February 22, 2007
Creator: Dahlgren, Tamara L.
Object Type: Article
System: The UNT Digital Library
OHVT Technology Roadmap (open access)

OHVT Technology Roadmap

The U.S. Department of Energy (DOE) Office of Heavy Vehicle Technologies (OHVT) was created in March 1996 to address the public-interest transportation-energy aspects of a set of customers who at that time had been largely unrecognized, namely, the manufacturers, suppliers, and users of heavy transport vehicles (trucks, buses, rail, and inland marine). Previously, the DOE had focused its attention on meeting the needs of the personal-transport-vehicle customer (automobile manufacturers, suppliers, and users). Those of us who were of driving age at the time of the 1973 oil embargo and the 1979 oil price escalation vividly recall the inconvenience and irritation of having to wait in long lines for gasoline to fuel our cars. However, most of us, other than professional truck owners or drivers, were unaware of the impacts that these disruptions in the fuel supply had on those whose livelihoods depend upon the transport of goods. Recognizing the importance of heavy vehicles to the national economic health, the DOE created OHVT with a mission to conduct, in collaboration with its industry partners and their suppliers, a customer-focused national program to research and develop technologies that will enable trucks and other heavy vehicles to be more energy-efficient and able to …
Date: October 22, 2001
Creator: Bradley, R. A.
Object Type: Report
System: The UNT Digital Library
User's manual for the OIL codes (open access)

User's manual for the OIL codes

None
Date: October 22, 1974
Creator: Cunningham, M. E.
Object Type: Report
System: The UNT Digital Library
Internal wave signal processing: A model-based approach (open access)

Internal wave signal processing: A model-based approach

A model-based approach is proposed to solve the oceanic internal wave signal processing problem that is based on state-space representations of the normal-mode vertical velocity and plane wave horizontal velocity propagation models. It is shown that these representations can be utilized to spatially propagate the modal (depth) vertical velocity functions given the basic parameters (wave numbers, Brunt-Vaisala frequency profile etc.) developed from the solution of the associated boundary value problem as well as the horizontal velocity components. These models are then generalized to the stochastic case where an approximate Gauss-Markov theory applies. The resulting Gauss-Markov representation, in principle, allows the inclusion of stochastic phenomena such as noise and modeling errors in a consistent manner. Based on this framework, investigations are made of model-based solutions to the signal enhancement problem for internal waves. In particular, a processor is designed that allows in situ recursive estimation of the required velocity functions. Finally, it is shown that the associated residual or so-called innovation sequence that ensues from the recursive nature of this formulation can be employed to monitor the model`s fit to the data.
Date: February 22, 1995
Creator: Candy, J. V. & Chambers, D. H.
Object Type: Article
System: The UNT Digital Library
River Protection Project (RPP) Immobilized High Level Waste (HLW) Interim Storage Plan (open access)

River Protection Project (RPP) Immobilized High Level Waste (HLW) Interim Storage Plan

This document replaces HNF-1751, Revision 1. It incorporates updates to reflect changes in programmatic direction associated with the vitrification plant contract and associated DOE-ORP guidance. In addition it includes planning associated with failed/used melter and sample handling and disposition work scope. The document also includes format modifications and section numbering update consistent with CH2M HILL Hanford Group, Inc. procedures.
Date: September 22, 2000
Creator: Briggs, M. G.
Object Type: Report
System: The UNT Digital Library
River Protection Project (RPP) Immobilized High Level Waste (IHLW) Storage Plan (open access)

River Protection Project (RPP) Immobilized High Level Waste (IHLW) Storage Plan

None
Date: September 22, 2000
Creator: Briggs, M. G.
Object Type: Report
System: The UNT Digital Library
River Protection Project (RPP) Immobilized Low Activity Waste (ILAW) Disposal Plan (open access)

River Protection Project (RPP) Immobilized Low Activity Waste (ILAW) Disposal Plan

This document replaces HNF-1517, Rev 2 which is deleted. It incorporates updates to reflect changes in programmatic direction associated with the vitrification plant contract change and associated DOE/ORP guidance. In addition it incorporates the cancellation of Project W-465, Grout Facility, and the associated modifications to Project W-520, Immobilized High-Level Waste Disposal Facility. It also includes document format changes and section number modifications consistent with CH2M HILL Hanford Group, Inc. procedures.
Date: September 22, 2000
Creator: Briggs, M. G.
Object Type: Report
System: The UNT Digital Library
TWRS Retrieval and Storage Mission and Immobilized Low Activity Waste (ILAW) Disposal Plan (open access)

TWRS Retrieval and Storage Mission and Immobilized Low Activity Waste (ILAW) Disposal Plan

None
Date: September 22, 2000
Creator: Briggs, M. G.
Object Type: Report
System: The UNT Digital Library
REFRACTORY OXIDE MELTING POINTS (open access)

REFRACTORY OXIDE MELTING POINTS

None
Date: October 22, 1952
Creator: Lambertson, Wingate A. & Gunzel, Fred H., Jr.
Object Type: Report
System: The UNT Digital Library
Novel approaches to the production of higher alcohols from synthesis gas. Quarterly technical progress report No. 11, April 1, 1993--June 30, 1993 (open access)

Novel approaches to the production of higher alcohols from synthesis gas. Quarterly technical progress report No. 11, April 1, 1993--June 30, 1993

This document reports work during this quarter on the project to produce higher alcohols from synthesis gas. A set of four methanol synthesis runs was conducted. Significant catalyst deactivation was experienced, and essentially all of the oil was lost from the reactor over the course of two weeks of operation. Three screening runs of potential high temperature oil were also conducted. However, essentially no oil remained in the reactor after completion of each run. A 1%Rh/1.3%Re/Al{sub 2}O{sub 3} catalyst was prepared from Re and Rh carbonyls with the objective of obtaining intimate contact between Rh and Re atoms. The catalytic activity of this catalyst was explored. Mo was deposited on the catalyst from both molybdenum hexacarbonyl [Mo(CO){sub 6}] and (NH{sub 4}){sub 6}Mo{sub 7}O{sub 24}{center_dot}4H{sub 2}O. The catalytic activity of the molybdenum promoted catalysts was found to be the highest achieved to date under this contract.
Date: November 22, 1993
Creator: Roberts, G. W. & Kow, S.
Object Type: Report
System: The UNT Digital Library