Compression and Diffusion: A Joint Approach to Detect Complexity (open access)

Compression and Diffusion: A Joint Approach to Detect Complexity

Article discussing a joint approach to detect complexity by combining the Compression Algorithm Sensitive To Regularity (CASToRe) and Complex Analysis of Sequences via Scaling AND Randomness Assessment (CASSANDRA) procedures.
Date: February 1, 2003
Creator: Allegrini, Paolo; Benci, V. (Vieri); Grigolini, Paolo; Hamilton, P.; Ignaccolo, Massimiliano; Menconi, Giulia et al.
System: The UNT Digital Library
Radiological Characterization Methodology of INEEL Stored RH-TRU Waste from ANL-E (open access)

Radiological Characterization Methodology of INEEL Stored RH-TRU Waste from ANL-E

An Acceptable Knowledge (AK)-based radiological characterization methodology is being developed for RH TRU waste generated from ANL-E hot cell operations performed on fuel elements irradiated in the EBR-II reactor. The methodology relies on AK for composition of the fresh fuel elements, their irradiation history, and the waste generation and collection processes. Radiological characterization of the waste involves the estimates of the quantities of significant fission products and transuranic isotopes in the waste. Methods based on reactor and physics principles are used to achieve these estimates. Because of the availability of AK and the robustness of the calculation methods, the AK-based characterization methodology offers a superior alternative to traditional waste assay techniques. Using this methodology, it is shown that the radiological parameters of a test batch of ANL-E waste is well within the proposed WIPP Waste Acceptance Criteria limits.
Date: February 1, 2003
Creator: Bhatt, Rajiv N.
System: The UNT Digital Library
Alternative Flowsheets for the Sulfur-Iodine Thermochemical Hydrogen Cycle (open access)

Alternative Flowsheets for the Sulfur-Iodine Thermochemical Hydrogen Cycle

OAK-B135 A hydrogen economy will need significant new sources of hydrogen. Unless large-scale carbon sequestration can be economically implemented, use of hydrogen reduces greenhouse gases only if the hydrogen is produced with non-fossil energy sources. Nuclear energy is one of the limited options available. One of the promising approaches to produce large quantities of hydrogen from nuclear energy efficiently is the Sulfur-Iodine (S-I) thermochemical water-splitting cycle, driven by high temperature heat from a helium Gas-Cooled Reactor. They have completed a study of nuclear-driven thermochemical water-splitting processes. The final task of this study was the development of a flowsheet for a prototype S-I production plant. An important element of this effort was the evaluation of alternative flowsheets and selection of the reference design.
Date: February 1, 2003
Creator: Brown, L. C.; Lentsch, R. D.; Besenbruch, G. E.; Schultz, K. R. & Funk, J. E.
System: The UNT Digital Library
Microstructure of Titanium Welds (open access)

Microstructure of Titanium Welds

Plates of commercially pure titanium were welded and microscopically analyzed to understand the influence of joining variables on weld microstructure.
Date: February 1, 2003
Creator: Danielson, Paul; Wilson, Rick D. & Alman, David E.
System: The UNT Digital Library
Measurement of vacuum-assisted photoionization at 1 GeV for Au and Ag targets (open access)

Measurement of vacuum-assisted photoionization at 1 GeV for Au and Ag targets

None
Date: February 1, 2003
Creator: Dauvergne, D.; Belkacem, A.; Barrue, F.; Bocquet, J.P.; Chevallier, M.; Feinberg, B. et al.
System: The UNT Digital Library
International Technical Working Group Round Robin Tests (open access)

International Technical Working Group Round Robin Tests

The goal of nuclear forensics is to develop a preferred approach to support illicit trafficking investigations. This approach must be widely understood and accepted as credible. The principal objectives of the Round Robin Tests are to prioritize forensic techniques and methods, evaluate attribution capabilities, and examine the utility of database. The HEU (Highly Enriched Uranium) Round Robin, and previous Plutonium Round Robin, have made tremendous contributions to fulfilling these goals through a collaborative learning experience that resulted from the outstanding efforts of the nine participating internal laboratories. A prioritized list of techniques and methods has been developed based on this exercise. Current work is focused on the extent to which the techniques and methods can be generalized. The HEU Round Robin demonstrated a rather high level of capability to determine the important characteristics of the materials and processes using analytical methods. When this capability is combined with the appropriate knowledge/database, it results in a significant capability to attribute the source of the materials to a specific process or facility. A number of shortfalls were also identified in the current capabilities including procedures for non-nuclear forensics and the lack of a comprehensive network of data/knowledge bases. The results of the Round …
Date: February 1, 2003
Creator: Dudder, Gordon B.; Hanlen, Richard C. & Herbillion, Georges M.
System: The UNT Digital Library
Automating the selection of fenestration systems to best meet daylighting performance goals (open access)

Automating the selection of fenestration systems to best meet daylighting performance goals

None
Date: February 1, 2003
Creator: Fernandes, Luis & Papamichael, Konstantinos
System: The UNT Digital Library
Neutron Scattering Studies of Nanomagnetism and Artificially Structured Materials (open access)

Neutron Scattering Studies of Nanomagnetism and Artificially Structured Materials

Nanostructured magnetic materials are intensively studied due to their unusual properties and promise for possible applications. The key issues in these materials relate to the connection between their physical properties (transport, magnetism, mechanical, etc.) and their chemical-physical structure. In principle, a detailed knowledge of the chemical and physical structure allows calculation of their physical properties. Theoretical and computational methods are rapidly evolving so that magnetic properties of nanostructured materials might soon be predicted. Success in this endeavor requires detailed quantitative understanding of the magnetic structure and properties.
Date: February 1, 2003
Creator: Fitzsimmons, M. R.; Bader, S. D.; Borchers, J. A.; Felcher, G. P.; Furdyna, J. K.; Hoffmann, A. et al.
System: The UNT Digital Library
A New System to Monitor Data Analyses and Results of Physics Data Validation Between Pulses at Diii-D (open access)

A New System to Monitor Data Analyses and Results of Physics Data Validation Between Pulses at Diii-D

A Data Analysis Monitoring (DAM) system has been developed to monitor between pulse physics analysis at the DIII-D National Fusion Facility (http://nssrv1.gat.com:8000/dam). The system allows for rapid detection of discrepancies in diagnostic measurements or the results from physics analysis codes. This enables problems to be detected and possibly fixed between pulses as opposed to after the experimental run has concluded thus increasing the efficiency of experimental time. An example of a consistency check is comparing the experimentally measured neutron rate and the expected neutron emission, RDD0D. A significant difference between these two values could indicate a problem with one or more diagnostics, or the presence of unanticipated phenomena in the plasma. This new system also tracks the progress of MDSplus dispatched data analysis software and the loading of analyzed data into MDSplus. DAM uses a Java Servlet to receive messages, CLIPS to implement expert system logic, and displays its results to multiple web clients via HTML. If an error is detected by DAM, users can view more detailed information so that steps can be taken to eliminate the error for the next pulse.
Date: February 1, 2003
Creator: Flanagan, A.; Schachter, J. M. & Schissel, D. P.
System: The UNT Digital Library
Heavy ion fusion sources (open access)

Heavy ion fusion sources

In Heavy-Fusion and in other applications, there is a need for high brightness sources with both high current and low emittance. The traditional design with a single monolithic source, while very successful, has significant constraints on it when going to higher currents. With the Child-Langmuir current-density limit, geometric aberration limits, and voltage breakdown limits, the area of the source becomes a high power of the current, A {approx} I{sup 8/3}. We are examining a multi-beamlet source, avoiding the constraints by having many beamlets each with low current and small area. The beamlets are created and initially accelerated separately and then merged to form a single beam. This design offers a number of potential advantages over a monolithic source, such as a smaller transverse footprint, more control over the shaping and aiming of the beam, and more flexibility in the choice of ion sources. A potential drawback, however, is the emittance that results from the merging of the beamlets. We have designed injectors using simulation that have acceptably low emittance and are beginning to examine them experimentally.
Date: February 1, 2003
Creator: Grote, D. P.; Kwan, J. & Westenskow, G.
System: The UNT Digital Library
Hydrogen Gas Generation Model for Fuel Based Remote Handled TRU Waste Stored at INEEL (open access)

Hydrogen Gas Generation Model for Fuel Based Remote Handled TRU Waste Stored at INEEL

The Idaho National Environmental and Engineering Laboratory (INEEL) initiated efforts to calculate the hydrogen gas generation in remote-handled transuranic (RH-TRU) containers in order to evaluate continued storage of unvented RH-TRU containers in vaults and to identify any potential problems during retrieval and aboveground storage. A computer code is developed to calculate the hydrogen concentration in the stored RH-TRU waste drums for known configuration, waste matrix, and radionuclide inventories as a function of time.
Date: February 1, 2003
Creator: Khericha, Soli T.; Bhatt, Rajiv N. & Liekhus, Kevin
System: The UNT Digital Library
Equilibrium in heavy ion collisions (open access)

Equilibrium in heavy ion collisions

We discuss the question of equilibration in heavy ion collisions and how it can be addressed in experiment.
Date: February 1, 2003
Creator: Koch, Volker & Majumder, Abhijit
System: The UNT Digital Library
INEEL Lead Recycling in a Moratorium Environment (open access)

INEEL Lead Recycling in a Moratorium Environment

Since 1999, the Idaho National Engineering and Environmental Laboratory (INEEL) Lead Project successfully recycled over 700,000 pounds of excess INEEL lead to the private sector. On February 14, 2000, the Secretary of Energy, Bill Richardson, formalized the January 12, 2000, moratorium on recycling radioactive scrap metal that prevented the unrestricted release of recycled scrap metals to the private sector. This moratorium created significant problems for the INEEL lead recycling program and associated plans; however, through the cooperative efforts of the INEEL and Idaho State University as well as innovative planning and creative thinking the recycling issues were resolved. This collaboration has recycled over 160,000 pounds of excess lead to Idaho State University with a cost savings of over $.5M.
Date: February 1, 2003
Creator: Kooda, Kevin Evan; Mc Cray, Casey William; Aitken, Darren William & Galloway, Kelly
System: The UNT Digital Library
Multi-criteria decision analysis: Limitations, pitfalls, and practical difficulties (open access)

Multi-criteria decision analysis: Limitations, pitfalls, and practical difficulties

The 2002 Winter Olympics women's figure skating competition is used as a case study to illustrate some of the limitations, pitfalls, and practical difficulties of Multi-Criteria Decision Analysis (MCDA). The paper compares several widely used models for synthesizing the multiple attributes into a single aggregate value. The various MCDA models can provide conflicting rankings of the alternatives for a common set of information even under states of certainty. Analysts involved in MCDA need to deal with the following challenging tasks: (1) selecting an appropriate analysis method, and (2) properly interpreting the results. An additional trap is the availability of software tools that implement specific MCDA models that can beguile the user with quantitative scores. These conclusions are independent of the decision domain and they should help foster better MCDA practices in many fields including systems engineering trade studies.
Date: February 1, 2003
Creator: Kujawski, Edouard
System: The UNT Digital Library
The renewables portfolio standard in Texas: An early assessment (open access)

The renewables portfolio standard in Texas: An early assessment

None
Date: February 1, 2003
Creator: Langniss, Ole & Wiser, Ryan
System: The UNT Digital Library
Microtopography for Ductile Fracture Process Characterization - Part 1: Theory and Methodology (open access)

Microtopography for Ductile Fracture Process Characterization - Part 1: Theory and Methodology

The mechanics of ductile fracture is receiving increased focus as the importance of integrity of structures constructed from ductile materials is increasing. The non-linear, irreversible mechanical response of ductile materials makes generalized models of ductile cracking very difficult to develop. Therefore, research and testing of ductile fracture have taken a path leading to deformation-based parameters such as crack tip opening displacement (CTOD) and crack tip opening angle (CTOA). Constrained by conventional test techniques and instrumentation, physical values (e.g. crack mouth opening displacement, CMOD, and CTOA angles) are measured on the test specimen exterior and a single through-thickness "average" interior value is inferred. Because of three-dimensional issues such as crack curvature, constraint variation, and material inhomogeneity, inference of average parameter values may introduce errors. The microtopography methodology described here measures and maps three-dimensional fracture surfaces. The analyses of these data provide direct extraction of the parameters of interest at any location within the specimen interior, and at any desired increment of crack opening or extension. A single test specimen can provide all necessary information for the analysis of a particular material and geometry combination.
Date: February 1, 2003
Creator: Lloyd, Wilson Randolph
System: The UNT Digital Library
Microtopography for Ductile Fracture Process Characterization - Part 2: Application for CTOA Analysis (open access)

Microtopography for Ductile Fracture Process Characterization - Part 2: Application for CTOA Analysis

The crack tip opening angle (CTOA) is seeing increased use to characterize fracture in so-called "low constraint" geometries, such as thin sheet aerospace structures and thin-walled pipes. With this increase in application comes a need to more fully understand and measure actual CTOA behavior. CTOA is a measure of the material response during ductile fracture, a "crack tip response function". In some range of crack extension following growth initiation, a constant value of CTOA is often assumed. However, many questions concerning the use of CTOA as a material response-characterizing parameter remain. For example, when is CTOA truly constant? What three-dimensional effects may be involved (even in thin sheet material)? What are the effects of crack tunneling on general CTOA behavior? How do laboratory specimen measurements of CTOA compare to actual structural behavior? Measurements of CTOA on the outer surface of test specimens reveal little about threedimensional effects in the specimen interior, and the actual measurements themselves are frequently difficult. The Idaho National Engineering and Environmental Laboratory (INEEL) use their microtopography system to collect data from the actual fracture surfaces following a test. Analyses of these data provide full three-dimensional CTOA distributions, at any amount of crack extension. The analysis is …
Date: February 1, 2003
Creator: Lloyd, Wilson Randolph & McClintock, F. A.
System: The UNT Digital Library
Contamination Control During In Situ Jet Grouting for Application in a Buried Transuranic Waste Site (open access)

Contamination Control During In Situ Jet Grouting for Application in a Buried Transuranic Waste Site

Engineers at the Idaho National Engineering and Environmental Laboratory (INEEL) have developed means of contamination control associated with jet-grouting buried radioactive mixed waste sites. Finely divided plutonium/americium oxide particulate can escape as the drill stem of the jet-grouting apparatus exits a waste deposit in preparation for insertion in another injection hole. In studying various options for controlling this potential contamination, engineers found that an elaborate glovebox/drill string shroud system prevents contaminants from spreading. Researchers jet-grouted a pit with nonradioactive tracers to simulate the movement of plutonium fines during an actual application. Data from the testing indicate that the grout immobilizes the tracer material by locking it up in particles large enough to resist aerosolization.
Date: February 1, 2003
Creator: Loomis, Guy George & Jessmore, James Joseph
System: The UNT Digital Library
'Mini'-Roadmapping - Ensuring Timely Sites' Cleanup / Closure by Resolving Science and Technology Issues (open access)

'Mini'-Roadmapping - Ensuring Timely Sites' Cleanup / Closure by Resolving Science and Technology Issues

Roadmapping is a powerful tool to manage technical risks and opportunities associated with complex problems. Roadmapping identifies technical capabilities required for both project- and program-level efforts and provides the basis for plans that ensure the necessary enabling activities will be done when needed. Roadmapping reveals where to focus further development of the path forward by evaluating uncertainties for levels of complexity, impacts, and/or the potential for large payback. Roadmaps can be customized to the application, a “graded approach” if you will. Some roadmaps are less detailed. We have called these less detailed, top-level roadmaps “mini-roadmaps”. These miniroadmaps are created to tie the needed enablers (e.g., technologies, decisions, etc.) to the functions. If it is found during the mini-roadmapping that areas of significant risk exist, then those can be roadmapped further to a lower level of detail. Otherwise, the mini-roadmap may be sufficient to manage the project / program risk. Applying a graded approach to the roadmapping can help keep the costs down. Experience has indicated that it is best to do mini-roadmapping first and then evaluate the risky areas to determine whether to further evaluate those areas. Roadmapping can be especially useful for programs / projects that have participants from …
Date: February 1, 2003
Creator: Luke, Dale & Murphy, James
System: The UNT Digital Library
Anomalies in the Applied Magnetic Fields on Diii-D and Their Implications for the Understanding of Stability Experiments (open access)

Anomalies in the Applied Magnetic Fields on Diii-D and Their Implications for the Understanding of Stability Experiments

Small non-axisymmetric magnetic fields are known to cause serious loss of stability in tokamaks leading to loss of confinement and abrupt termination of plasma current (disruptions). The best known examples are the locked mode and the resistive wall mode. Understanding of the underlying field anomalies (departures in the hardware-related fields from ideal toroidal and poloidal fields on a single axis) and the interaction of the plasma with them is crucial to tokamak development. Results of both locked mode experiments and resistive wall mode experiments done in DIII-D tokamak plasmas have been interpreted to indicate the presence of a significant anomalous field. New measurements of the magnetic field anomalies of the hardware systems have been made on DIII-D. The measured field anomalies due to the plasma shaping coils in DIII-D are smaller than previously reported. Additional evaluations of systematic errors have been made. New measurements of the anomalous fields of the ohmic heating and toroidal coils have been added. Such detailed in situ measurements of the fields of a tokamak are unique. The anomalous fields from all of the coils are one third of the values indicated from the stability experiments. These results indicate limitations in the understanding of the interaction …
Date: February 1, 2003
Creator: Luxon, J.L.; Schaffer, M.J.; Jackson, G.L.; Leuer, J.A.; Nagy, A.; Scoville, J.T. et al.
System: The UNT Digital Library
On the influence of forests on the overall fate of semivolatile organic contaminants (open access)

On the influence of forests on the overall fate of semivolatile organic contaminants

None
Date: February 1, 2003
Creator: MacLeod, Matthew
System: The UNT Digital Library
Is there a 'forest filter effect' for organic pollutants? (open access)

Is there a 'forest filter effect' for organic pollutants?

None
Date: February 1, 2003
Creator: Maddalena, Randy L.; McKone, Thomas E. & Riley, William J.
System: The UNT Digital Library
Flow heterogeneity following global no-flow ischemia in isolated rabbit heart (open access)

Flow heterogeneity following global no-flow ischemia in isolated rabbit heart

The purpose of this study was to evaluate flow heterogeneity and impaired reflow during reperfusion following 60 min global no-flow ischemia in the isolated rabbit heart. Radiolabeled microspheres were used to measure relative flow in small left ventricular (LV) segments in five ischemia + reperfused hearts and in five non-ischemic controls. Although variable in the post-ischemic hearts, flow heterogeneity was increased relative to pre-ischemia for the whole LV (0.92 plus or minus 0.41 vs. 0.37 plus or minus 0.07, P < 0.05) as well as the subendocardium (Endo) and subepicardium (Epi) considered separately (endo: 1.28 plus or minus 0.74 vs. 0.30 plus or minus 0.09; epi: 0.69 plus or minus 0.22 vs. 0.38 plus or minus 0.08; P < 0.05 for both comparisons) during early reperfusion. There were also segments with abnormally reduced reflow. The number of segments with abnormally reduced reflow increased as flow heterogeneity increased. Abnormally reduced reflow indicates that regional ischemia can persist despite restoration of normal global flow. In addition, the relationship between regional and global flow is altered and venous outflow is derived from regions with continued perfusion and not the whole LV. These observations emphasize the need to quantify regional reflow during reperfusion following …
Date: February 1, 2003
Creator: Marshall, Robert C.; Powers-Risius, Patricia; Reutter, Bryan W.; Schustz, Amy M.; Kuo, Chaincy; Huesman, Michelle K. et al.
System: The UNT Digital Library
Testing, Modeling, and Monitoring to Enable Simpler, Cheaper, Longer-Lived Surface Caps (open access)

Testing, Modeling, and Monitoring to Enable Simpler, Cheaper, Longer-Lived Surface Caps

Society has and will continue to generate hazardous wastes whose risks must be managed. For exceptionally toxic, long-lived, and feared waste, the solution is deep burial, e.g., deep geological disposal at Yucca Mtn. For some waste, recycle or destruction/treatment is possible. The alternative for other wastes is storage at or near the ground level (in someone’s back yard); most of these storage sites include a surface barrier (cap) to prevent downward water migration. Some of the hazards will persist indefinitely. As society and regulators have demanded additional proof that caps are robust against more threats and for longer time periods, the caps have become increasingly complex and expensive. As in other industries, increased complexity will eventually increase the difficulty in estimating performance, in monitoring system/component performance, and in repairing or upgrading barriers as risks are managed. An approach leading to simpler, less expensive, longer-lived, more manageable caps is needed. Our project, which started in April 2002, aims to catalyze a Barrier Improvement Cycle (iterative learning and application) and thus enable Remediation System Performance Management (doing the right maintenance neither too early nor too late). The knowledge gained and the capabilities built will help verify the adequacy of past remedial decisions, …
Date: February 1, 2003
Creator: Piet, Steven James; Breckenridge, Robert Paul & Burns, Douglas Edward
System: The UNT Digital Library