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Influence of Clastic Dikes on Vertical Migration of Contaminants in the Vadose Zone at Hanford
The purpose of this study was to examine the hypothesis that clastic dikes could form a preferential flow path through the vadose zone to the water table at the Hanford Site. Clastic dikes are subvertical structures that form within sedimentary sequences after deposition, and cut across the original sedimentary layers. They are common throughout the Hanford Site, often occurring in organized polygonal networks. In the initial phase of the project, we analyzed the large-scale geometry of the clastic dikes and developed an algorithm for simulating their spatial distribution. This result will be useful in providing maps of the potential distribution of clastic dikes in areas where they are not exposed at the surface (e.g., where covered by windblown sand or by construction of facilities like tank farms at the surface). In addition to the study of the large scale distribution of the dikes, a major focus of the project was on field, laboratory, and modeling studies of the hydrogeologic al properties of the clastic dikes and the effect that they have on transport of water through the vadose zone. These studies were performed at two field locations at the Hanford Site. We performed an extensive series of field and laboratory …
Date:
March 14, 2003
Creator:
Murray, Christopher J.; Ward, Anderson L. & Wilson, John L.
Object Type:
Report
System:
The UNT Digital Library
Higher Order Hard Edge End Field Effects.
In most cases, nonlinearities from magnets must be properly included in tracking and analysis to properly compute quantities of interest, in particular chromatic properties and dynamic aperture. One source of nonlinearities in magnets that is often important and cannot be avoided is the nonlinearity arising at the end of a magnet due to the longitudinal variation of the field at the end of the magnet. Part of this effect is independent of the longitudinal of the end. It is lowest order in the body field of the magnet, and is the result of taking a limit as the length over which the field at the end varies approaches zero. This is referred to as a ''hard edge'' end field. This effect has been computed previously to lowest order in the transverse variables. This paper describes a method to compute this effect to arbitrary order in the transverse variables, under certain constraints.
Date:
September 14, 2004
Creator:
Berg, J. S.
Object Type:
Article
System:
The UNT Digital Library
Dynamic Data-Driven Event Reconstruction for Atmospheric Releases
This is a collaborative LDRD Exploratory Research project involving four directorates--Energy & Environment, Engineering, NAI and Computation. The project seeks to answer the following critical questions regarding atmospheric releases--''How much material was released? When? Where? and What are the potential consequences?'' Inaccurate estimation of the source term can lead to gross errors, time delays during a crisis, and even fatalities. We are developing a capability that seamlessly integrates observational data streams with predictive models in order to provide the best possible estimates of unknown source term parameters, as well as optimal and timely situation analyses consistent with both models and data. Our approach utilizes Bayesian inference and stochastic sampling methods (Markov Chain and Sequential Monte Carlo) to reformulate the inverse problem into a solution based on efficient sampling of an ensemble of predictive simulations, guided by statistical comparisons with data. We are developing a flexible and adaptable data-driven event-reconstruction capability for atmospheric releases that provides (1) quantitative probabilistic estimates of the principal source-term parameters (e.g., the time-varying release rate and location); (2) predictions of increasing fidelity as an event progresses and additional data become available; and (3) analysis tools for sensor network design and uncertainty studies. Our computational framework incorporates …
Date:
March 14, 2005
Creator:
Mirin, A; Serban, R & Kosovic, B
Object Type:
Report
System:
The UNT Digital Library
Detection of Pathogens Using a Handheld PCR Thermocycler
None
Date:
May 14, 2001
Creator:
Emanuel, P; Hadfield, T; Koopman, R; Richards, J; Benett, W; Stratton, P et al.
Object Type:
Article
System:
The UNT Digital Library
Updated Volumetric Expansion Factors for K Basin Sludge During Storage
Sludge has accumulated in the K East (KE) and K West (KW) Basins at the Hanford Site. This sludge contains metallic uranium and uranium oxides that will corrode, hydrate, and generate and consume gases during containerized storage. From these corrosion reactions, two sludge expansion mechanisms can be expected: 1) expansion of the volume of the sludge solids from the generation of corrosion oxidation products that occupy more space than the starting-state sludge; and 2) expansion of the bulk sludge volume from the retention of hydrogen gas bubbles. This report provides a review and updated projections of the volumetric expansion occurring due to corrosion and gas retention during the containerized storage of K Basin sludge. New design and safety basis volume expansion values are provided for the following sludge streams: KW Floor, KW North Loadout Pit, KW canister, and fuel piece sludge.
Date:
March 14, 2003
Creator:
Schmidt, Andrew J. (BATTELLE (PACIFIC NW LAB)) & Delegard, Calvin H. (BATTELLE (PACIFIC NW LAB))
Object Type:
Report
System:
The UNT Digital Library
Nuclear structure with accurate chiral perturbation theory nucleon-nucleon potential: Application to 6Li and 10B
The authors calculate properties of A = 6 system using the accurate charge-dependent nucleon-nucleon (NN) potential at fourth order of chiral perturbation theory. By application of the ab initio no-core shell model (NCSM) and a variational calculation in the harmonic oscillator basis with basis size up to 16 {h_bar}{Omega} they obtain the {sup 6}Li binding energy of 28.5(5) MeV and a converged excitation spectrum. Also, they calculate properties of {sup 10}B using the same NN potential in a basis space of up to 8 {h_bar}{Omega}. The results are consistent with results obtained by standard accurate NN potentials and demonstrate a deficiency of Hamiltonians consisting of only two-body terms. At this order of chiral perturbation theory three-body terms appear. It is expected that inclusion of such terms in the Hamiltonian will improve agreement with experiment.
Date:
October 14, 2003
Creator:
Navratil, P & Caurier, E
Object Type:
Report
System:
The UNT Digital Library
Evaluation of Nevada Test Site Ground Motion and Rock Property Data to Bound Ground Motions at the Yucca Mountain Repository
Yucca Mountain licensing will require estimation of ground motions from probabilistic seismic hazard analyses (PSHA) with annual probabilities of exceedance on the order of 10{sup -6} to 10{sup -7} per year or smaller, which correspond to much longer earthquake return periods than most previous PSHA studies. These long return periods for the Yucca Mountain PSHA result in estimates of ground motion that are extremely high ({approx} 10 g) and that are believed to be physically unrealizable. However, there is at present no generally accepted method to bound ground motions either by showing that the physical properties of materials cannot maintain such extreme motions, or the energy release by the source for such large motions is physically impossible. The purpose of this feasibility study is to examine recorded ground motion and rock property data from nuclear explosions to determine its usefulness for studying the ground motion from extreme earthquakes. The premise is that nuclear explosions are an extreme energy density source, and that the recorded ground motion will provide useful information about the limits of ground motion from extreme earthquakes. The data were categorized by the source and rock properties, and evaluated as to what extent non-linearity in the material has …
Date:
February 14, 2005
Creator:
Hutchings, L. J.; Foxall, W.; Rambo, J. & Wagoner, J. L.
Object Type:
Report
System:
The UNT Digital Library
Mechanical properties of D0 Run IIB silicon detector staves
A proposed stave design for the D0 Run IIb silicon tracker outer layers featuring central cooling channels and a composite shell mechanical structure is evaluated for self-deflection and deflection due to external loads. This paper contains an introduction to the stave structure, a section devoted to composite lamina and laminate properties and finally a section discussing the beam deflections expected for assembled staves using these laminates.
Date:
June 14, 2001
Creator:
Lanfranco, Giobatta & Fast, James
Object Type:
Report
System:
The UNT Digital Library
Fabrication of Efficient, Large Aperture Transmission Diffraction Gratings by Ion-Beam Etching
The utilization of high-power short pulse laser employing chirped-pulse amplification (CPA) for material processing and inertial confinement research is widely increasing. The performance of these high-power CPA laser system continues to be limited by the ability of the pulse compression gratings to hold up to the high-average-power or high-peak-power of the laser. Pulse compression gratings used in transmission and fabricated out of bulk fused silica have intrinsically the highest laser damage threshold when compared with metal or multilayer dielectric gratings that work in reflection. LLNL has developed processing capability to produce high efficiency fused silica transmission gratings at sizes useful to future Petawatt-class systems, and has demonstrated high efficiency at smaller aperture. This report shows that fused silica diffraction exhibiting >95% efficiency into the -1 diffraction order in transmission (90{sup o} deflection of the incident light, at an incidence angle of 45{sup o} to the grating face). The microstructure of this grating consisted of grooves ion-beam etched to a depth of 1.6 microns with a pitch of 0.75 microns, using a holographically produced photoresist mask that was subsequently stripped away in significance to the fabrication of the small scale high efficiency grating was the development of the processing technology and …
Date:
September 14, 2000
Creator:
Nguyen, H T; Bryan, S R; Britten, J A & Perry, M D
Object Type:
Report
System:
The UNT Digital Library
Waveguide Fabrication in Fused Silica Using Tightly Focused Femtosecond Laser Pulses
Refractive index changes have been induced inside bulk fused silica by using femtosecond (fs) laser pulses tightly focused inside the material. Waveguides have been fabricated inside the glass by scanning the glass with respect to the focal point of the laser beam. The refractive index change is estimated to be {approx} 10{sup -4}. Other more complex three-dimensional structures have also been fabricated (curved waveguides, splitters, and interferometers). We also report on fluorescence spectroscopy of the fs-modified fused silica using a confocal microscopy setup. Using a 488 nm excitation source, a fluorescence at 630 nm is observed from the modified glass, which is attributed to the presence of non-bridging oxygen hole center (NBOHC) defects created by the fs pulses. The fluorescence decays with prolonged exposure to the 488 nm light, indicating that the defects are being photobleached by the excitation light.
Date:
December 14, 2001
Creator:
Chan, J W; Huser, T; Risbud, S H & Krol, D M
Object Type:
Article
System:
The UNT Digital Library
Investigating the Heating of a Potassium-Doped Aluminosilicate Ion Source Using a 1 Micron Laser
The heavy ion fusion (HIF) program is interested in developing a high brightness ion source for high energy density physics (HEDP) experiments. One possible approach to obtaining higher brightness may be to raise the surface temperature of the ion source just prior to extraction. The current ion source material being studied is a layer of potassium-doped aluminosilicate bonded to a tungsten substrate. It is speculated that if the surface temperature of the source is raised above 1200 C (from a steady-state temperature of 900 C) for time periods on the order of 100's of nanoseconds, current densities of greater than 100 mA/cm{sup 2} of ions may be achievable. Typical aluminosilicate sources produce ion current densities (either K+ or Na+ ions) of {approx}10 mA/cm{sup 2} (at 1100 C). A number of heating methods might be possible, including lasers, diode arrays, and flash lamps. Here we assume laser heating. In this preliminary study, we used the LLNL RadHeat code to model the time-temperature history of the surface when hit by laser pulses and illustrate how RadHeat can be used to optimize the surface temperature response. Also of interest is the temperature history of the interface temperature between the ceramic and the metal …
Date:
December 14, 2004
Creator:
Schmitt, R. C.; Meier, W. R.; Kwan, J. W.; Abbott, R. P. & Latkowski, J. F.
Object Type:
Report
System:
The UNT Digital Library
Surface Based Differential Forms
Higher-order basis functions have been constructed for surface-based differential forms that are used in engineering simulations. These surface-based forms have been designed to complement the volume-based forms present in EMSolve[1], a finite element code. The basis functions are constructed on a reference element and transformed, as necessary, for each element in space. Lagrange polynomials are used to create the basis functions. This approach is a necessary step in creating a hybrid finite-element/integral-equation time-domain code for electromagnetic analysis.
Date:
December 14, 2004
Creator:
Pingenot, J.; Yang, C.; Jandhyala, V.; Champagne, N.; White, D.; Stowell, M. et al.
Object Type:
Article
System:
The UNT Digital Library
TEM verification of the <111>-type 4-arm multi-junction in [001]-Mo single crystals
To investigate and verify the formation of <111>-type 4-arm multi-junction by the dislocation reaction of 1/2[111] [b1] + 1/2[{bar 1}1{bar 1}] [b2] + 1/2[{bar 1}{bar 1}1] [b3] = 1/2[{bar 1}11] [b4], which has recently been discovered through computer simulations conducted by Vasily Bulatov and his colleagues.
Date:
March 14, 2005
Creator:
Hsiung, L
Object Type:
Report
System:
The UNT Digital Library
Finding the Circular Magnet Aperture Which Encloses an Artitrary Number of Midplane-Centered Beam Ellipses.
In specifying the magnets for an accelerator, one must be able to determine the aperture required by the beam. In some machines, in particular FFAGs, there is a significant variation in the closed orbit and beta functions over the energy range of the machine. In addition, the closed orbit and beta functions may vary with the longitudinal position in the magnet. It is necessary to determine a magnet aperture which encloses the beam ellipses at all energies and all positions in the magnet. This paper describes a method of determining the smallest circular aperture enclosing an arbitrary number of midplane-centered ellipses.
Date:
September 14, 2004
Creator:
Berg, S. J.
Object Type:
Article
System:
The UNT Digital Library
Key interactions in antibody recognition of synthetic sweeteners: Crystal structures of NC6.8 Fab co-crystallized with high potency sweetener compound SC45647 and with TES.
None
Date:
March 14, 2005
Creator:
Gokulan, K.; Khare, S.; Ronning, D.; Linthicum, S. D.; Rupp, B. & Sacchettini, J. C.
Object Type:
Article
System:
The UNT Digital Library
Insights to Repository Performance Through Study of a Nuclear Test Site
United States high-level nuclear waste from nuclear weapons production, naval propulsion programs, and the processing of commercial spent nuclear fuels is scheduled for immobilization in glass waste forms prior to permanent disposal in a mined geologic repository. Considerable attention has been directed to assessments of the subsequent long-term release of radionuclides from a repository under saturated and partially saturated conditions. Credible predictions of dose from a repository rely on insights to radionuclide sequestration in the glass, mechanisms of glass degradation, and radionuclide solubility and transport in the near-field. Underground nuclear test sites offer an unprecedented opportunity to evaluate processes relevant to repository performance in the absence of engineered barriers. Radionuclide migration programs at the Nevada Test Site represent a twenty-five year investment in the systematic investigation of the diverse radiologic source term from weapons testing and the evolution of the hydrologic source term which includes radionuclides dissolved in or otherwise available for transport by groundwater. The geology, hydrology, and geochemistry of the Nevada Test Site which includes the proposed Yucca Mountain repository provides an ideal natural laboratory to assess long-term radionuclide transport in the near and far-field. The Yucca Mountain repository shares with adjacent testing areas the following features: correlative …
Date:
January 14, 2000
Creator:
Smith, D. K.; Kersting, A. B.; Thompson, J. L. & Finnegan, D. L.
Object Type:
Article
System:
The UNT Digital Library
Automatic Generation of Data Types for Classification of Deep Web Sources
A Service Class Description (SCD) is an effective meta-data based approach for discovering Deep Web sources whose data exhibit some regular patterns. However, it is tedious and error prone to create an SCD description manually. Moreover, a manually created SCD is not adaptive to the frequent changes of Web sources. It requires its creator to identify all the possible input and output types of a service a priori. In many domains, it is impossible to exhaustively list all the possible input and output data types of a source in advance. In this paper, we describe machine learning approaches for automatic generation of the data types of an SCD. We propose two different approaches for learning data types of a class of Web sources. The Brute-Force Learner is able to generate data types that can achieve high recall, but with low precision. The Clustering-based Learner generates data types that have a high precision rate, but with a lower recall rate. We demonstrate the feasibility of these two learning-based solutions for automatic generation of data types for citation Web sources and presented a quantitative evaluation of these two solutions.
Date:
February 14, 2005
Creator:
Ngu, A. H.; Buttler, D. J. & Critchlow, T. J.
Object Type:
Article
System:
The UNT Digital Library
The Importance of Geometric Nonlinearity in Finite Element Studies of Yielding in Trabecular Bone
None
Date:
February 14, 2005
Creator:
Kinney, J H & Stolken, J S
Object Type:
Article
System:
The UNT Digital Library
Investigation into the Role of Initial Conditions on Rayleigh-Taylor Instabilities by Low Atwood Experiments and Simulations
The primary goal of the research being conducted this summer is to investigate the role of initial conditions in the development of a two fluid mix driven by Rayleigh-Taylor instability. The effects of initial conditions will be studied through the use of experimental facilities located at the Buoyancy-Driven Mixing Lab at Texas A&M University and through high resolution direct numerical simulations of the experiment by the MIRANDA code developed at Lawrence Livermore National Lab. The Experimental Objectives are: (1) Analyze the early time development of a two fluid Rayleigh-Taylor driven mix between two miscible fluids at low Atwood numbers. (2) Quantify the initial conditions of the unstably stratified fluids by means of statistical mixing parameters and spectral analysis of the centerline density fluctuations. (3) Capture PLIF images of initial development of the flow for use in simulation setup. (Wayne Kraft) (4) Determine exactly what component of the experimental mixing data (position downstream from the splitter plate) most accurately represents the initial conditions of the experiment. The Simulation Objectives are: (1) Perform two dimensional and three dimensional simulations of the experimental setup. Analyze the results of these simulations for comparison to the experimental results. (2) Various methods of implementing the initial …
Date:
July 14, 2003
Creator:
Mueschke, N; Andrews, M & Schilling, O
Object Type:
Report
System:
The UNT Digital Library
Saturation of Stimulated Brillouin Backscattering in Two-dimensional Kinetic Ion Simulations
None
Date:
October 14, 2004
Creator:
Cohen, B. I.; Divol, L.; Langdon, A. B. & Williams, E. A.
Object Type:
Article
System:
The UNT Digital Library
Evaluation of Fish Losses through Screen Gaps at Modified and Unmodified Intakes of Bonneville Dam Second Powerhouse in 2003
This report was prepared by the Pacific Northwest National Lab., Richland, Washington, BAE Systems, Inc., a subcontractor to the U.S. Army Engineer Research and Development Center (ERDC), Vicksburg, Mississippi. This study examined the effect of gatewell modifications on the proportion of fish lost through the gap between the top of submerged traveling screens (STSs) and the ceilings of intakes in one un-modified and two modified turbine units at Bonneville Dam Second Powerhouse (B2). Combined modifications reduced the proportion of flow through the gap from 44% to 16% and increased the proportion moving up the gatewell from 56% to 84%. We used a Dual-Frequency Identification Sonar (DIDSON) acoustic camera to record proportions of juvenile salmonids moving up into the gatewell and through the gap. The acoustic camera was used to record images of fish passing up into the gatewell and through the gap for 8-h on three successive nights in every intake of units 13, 15, and 17 (i.e., 9 intakes x 3 nights = 27 nights each season). Only 28.6% of the objects detected in spring and 12.9% in summer were determined to be fish. Other objects included sticks and debris. Although the true magnitude of STS gap-loss is unknown, …
Date:
June 14, 2004
Creator:
Ploskey, Gene R.; Weiland, Mark A. & Schilt, Carl R.
Object Type:
Report
System:
The UNT Digital Library
Shielding a Streak Camera from Hard X-rays
The targets used in the Hot Halfraum Campaign at OMEGA create many hot electrons, which result in a large flux of hard x-rays. The hard x-rays produce a high background in the streak camera. The background was significantly reduced by wrapping the streak camera with a high-Z material; in this case, 1/8' of Pb. The large hard x-ray flux also adds noise to images from framing cameras which use CCDs.
Date:
April 14, 2004
Creator:
Schneider, M.; Sorce, C.; Loughman, K.; Emig, J.; Bruns, H.; Back, C. et al.
Object Type:
Article
System:
The UNT Digital Library
ViSUS: Visualization Streams for Ultimate Scalability
In this project we developed a suite of progressive visualization algorithms and a data-streaming infrastructure that enable interactive exploration of scientific datasets of unprecedented size. The methodology aims to globally optimize the data flow in a pipeline of processing modules. Each module reads a multi-resolution representation of the input while producing a multi-resolution representation of the output. The use of multi-resolution representations provides the necessary flexibility to trade speed for accuracy in the visualization process. Maximum coherency and minimum delay in the data-flow is achieved by extensive use of progressive algorithms that continuously map local geometric updates of the input stream into immediate updates of the output stream. We implemented a prototype software infrastructure that demonstrated the flexibility and scalability of this approach by allowing large data visualization on single desktop computers, on PC clusters, and on heterogeneous computing resources distributed over a wide area network. When processing terabytes of scientific data, we have achieved an effective increase in visualization performance of several orders of magnitude in two major settings: (i) interactive visualization on desktop workstations of large datasets that cannot be stored locally; (ii) real-time monitoring of a large scientific simulation with negligible impact on the computing resources available. …
Date:
February 14, 2005
Creator:
Pascucci, V
Object Type:
Report
System:
The UNT Digital Library
Uncertainty: a discriminator for above and below boiling repository design decisions
The US nuclear waste disposal program is evaluating the Yucca Mountain (YM) site for possible disposal of nuclear waste. Radioactive decay of the waste, particularly spent fuel, generates sufficient heat to significantly raise repository temperatures. Environmental conditions in the repository system evolve in response to this heat. The amount of temperature increase, and thus environmental changes, depends on repository design and operations. Because the evolving environment cannot be directly measured until after waste is emplaced, licensing decisions must be based upon model and analytical projections of the environmental conditions. These analyses have inherent uncertainties. There is concern that elevated temperatures increase uncertainty, because most chemical reaction rates increase with temperature and boiling introduces additional complexity of vapor phase reactions and transport. This concern was expressed by the NWTRB, particularly for above boiling temperatures. They state that ''the cooler the repository, the lower the uncertainty about heat-driven water migration and the better the performance of waste package materials. Above this temperature, technical uncertainties tend to be significantly higher than those associated with below-boiling conditions.'' (Cohon 1999). However, not all uncertainties are reduced by lower temperatures, indeed some may even be increased. This paper addresses impacts of temperatures on uncertainties.
Date:
November 14, 2000
Creator:
Wilder, D G; Lin, W; Buscheck, T A; Wolery, T J & Francis, N D
Object Type:
Article
System:
The UNT Digital Library