70193-Influence of Clastic Dikes on Vertical Migration of Contaminants in the Vadose Zonde at Hanford (open access)

70193-Influence of Clastic Dikes on Vertical Migration of Contaminants in the Vadose Zonde 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 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 hydrogeological 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 measurements of a …
Date: April 7, 2004
Creator: Murray, Christopher J; Ward, Anderson L. & Wilson, John L.
Object Type: Report
System: The UNT Digital Library
Age of an Indonesian Fossil Tooth Determined by Electron Paramagnetic Resonance (open access)

Age of an Indonesian Fossil Tooth Determined by Electron Paramagnetic Resonance

The first fossil hominid tooth recovered during 1999 excavations from the Cisanca River region in West Java, Indonesia, was associated with a series of bovid teeth from a single individual that was recovered 190 cm beneath the hominid tooth. The age of the fossil bovid teeth was determined using electron paramagnetic resonance (EPR) analysis as part of an effort to bracket the age of the hominid tooth. The EPR-derived age of the bovid teeth is (5.16 {+-} 2.01) x 10{sup 5} years. However, the age estimate reported here is likely an underestimate of the actual age of deposition since evidence of heating was detected in the EPR spectra of the bovid teeth, and the heating may have caused a decrease in the intensity of EPR components on which the age calculation is based.
Date: April 7, 2004
Creator: Bogard, JS
Object Type: Report
System: The UNT Digital Library
Analysis of Long-range Clean Energy Investment Scenarios forEritrea, East Africa (open access)

Analysis of Long-range Clean Energy Investment Scenarios forEritrea, East Africa

We discuss energy efficiency and renewable energy investments in Eritrea from the strategic long-term economic perspective of meeting Eritrea's sustainable development goals and reducing greenhouse gas emissions. Energy efficiency and renewable energy are potentially important contributors to national productive capital accumulation, enhancement of the environment, expansion of energy services, increases in household standard of living, and improvements in health. In this study we develop a spreadsheet model for calculating some of the national benefits and costs of different levels of investment in energy efficiency and renewable energy. We then present the results of the model in terms of investment demand and investment scenario curves. These curves express the contribution that efficiency and renewable energy projects can make in terms of reduced energy sector operating expenses, and reduced carbon emissions. We provide demand and supply curves that show the rate of return, the cost of carbon emissions reductions vs. supply, and the evolution of the marginal carbon emissions per dollar of GDP for different investment levels and different fuel-type subsectors.
Date: May 7, 2004
Creator: Van Buskirk, Robert D.
Object Type: Article
System: The UNT Digital Library
Analysis of Recombination Processes in 0.5 - 0.6eV Epitaxial GaInAsSb Lattice-Matched to GaSb (open access)

Analysis of Recombination Processes in 0.5 - 0.6eV Epitaxial GaInAsSb Lattice-Matched to GaSb

After a brief introduction and work motivation, static and dynamic methods for minority carrier lifetime measurements will be compared. Data on recombination velocity at heterointerfaces for both p-type and n-type quaternaries will be summarized. Radiative recombination and effect of photon recycling will be considered in detail.
Date: June 7, 2004
Creator: Donetsky, D.; Anikeev, S.; Ning, G.; Belenky, G.; Luryi, S.; Wang, C. A. et al.
Object Type: Report
System: The UNT Digital Library
Annual Hanford Seismic Report for Fiscal Year 2004 (open access)

Annual Hanford Seismic Report for Fiscal Year 2004

This report describes seismic activity at and around the Hanford Site during Fiscal Year 2004. It is also the first description of seismic activity during the fourth quarter of FY04.
Date: December 7, 2004
Creator: Hartshorn, Donald C.; Reidel, Steve P. & Rohay, Alan C.
Object Type: Report
System: The UNT Digital Library
Archaeofaunal insights on pinniped-human interactions in the northeastern Pacific (open access)

Archaeofaunal insights on pinniped-human interactions in the northeastern Pacific

Human exploitation of pinnipeds has considerable antiquity but shows increasing impacts on population numbers in the Holocene. Pinnipeds are a rich source of fat as well as protein. A few well-documented cases of regional extirpation of seals and sea lions by non-industrial peoples exist. The northeastern Pacific region, from southern California to Alaska, has yielded archaeological evidence for distributions and abundances of eared seals that differs markedly from historically documented biogeography. This is especially true of the northern fur seal (Callorhinus ursinus), among the most common pinnipeds in many archaeological sites from the Santa Barbara Channel area through to Kodiak Islands. This chapter reviews contemporary eared seal biogeography, evidence for the earlier timing and extent, of occurrence of northern fur seals along the northeastern Pacific coast, zooarchaeological and isotopic evidence for their foraging and probable maintenance of rookeries in lower latitudes, and for their disappearance from the southernmost part of their ancient distribution well before European contact. It also reviews ongoing debates over the behavioral ecology of ancient fur seals and over humans role in contributing to their disappearance.
Date: February 7, 2004
Creator: Gifford-Gonzales, D; Newsome, S; Koch, P; Guilderson, T; Snodgrass, J & Burton, R
Object Type: Book
System: The UNT Digital Library
Assessment of Renal Ischemia By Optical Spectroscopy (open access)

Assessment of Renal Ischemia By Optical Spectroscopy

Introduction: No reliable method currently exists for quantifying the degree of warm ischemia in kidney grafts prior to transplantation. We describe a method for evaluating pretransplant warm ischemia time using optical spectroscopic methods. Methods: Lewis rat kidney vascular pedicles were clamped unilaterally in vivo for 0, 5, 10, 20, 30, 60, 90 or 120 minutes; 8 animals were studied at each time point. Injured and contra-lateral control kidneys were then flushed with Euro-Collins solution, resected and placed on ice. 335 nm excitation autofluorescence as well as cross polarized light scattering images were taken of each injured and control kidney using filters of various wavelengths. The intensity ratio of the injured to normal kidneys was compared to ischemia time. Results: Autofluorescence intensity ratios through a 450 nm filter and light scattering intensity ratios through an 800 nm filter both decreased significantly with increasing ischemia time (p < 0.0001 for each method, one-way ANOVA). All adjacent and non-adjacent time points between 0 and 90 minutes were distinguishable using one of these two modalities by Fisher's PLSD. Conclusions: Optical spectroscopic methods can accurately quantify warm ischemia time in kidneys that have been subsequently hypothermically preserved. Further studies are needed to correlate results with …
Date: January 7, 2004
Creator: Fitzgerald, J T; Demos, S; Michalopoulou, A; Pierce, J L & Troppmann, C
Object Type: Article
System: The UNT Digital Library
Authorized Limits Request: Radiological Clearance of Select Hanford Reach National Monument Lands (open access)

Authorized Limits Request: Radiological Clearance of Select Hanford Reach National Monument Lands

This document describes development of radiological release criteria (Authorized Limits) for Hanford Reach National Monument lands that DOE plans to release to the U.S. Department of the Interior.
Date: May 7, 2004
Creator: Napier, Bruce A. & Glines, Wayne M.
Object Type: Report
System: The UNT Digital Library
Bioremediation of Petroleum and Radiological Contaminated Soils at the Savannah River Site: Laboratory to Field Scale Applications (open access)

Bioremediation of Petroleum and Radiological Contaminated Soils at the Savannah River Site: Laboratory to Field Scale Applications

In the process of Savannah River Site (SRS) operations limited amounts of waste are generated containing petroleum, and radiological contaminated soils. Currently, this combination of radiological and petroleum contaminated waste does not have an immediate disposal route and is being stored in low activity vaults. SRS developed and implemented a successful plan for clean up of the petroleum portion of the soils in situ using simple, inexpensive, bioreactor technology. Treatment in a bioreactor removes the petroleum contamination from the soil without spreading radiological contamination to the environment. This bioreactor uses the bioventing process and bioaugmentation or the addition of the select hydrocarbon degrading bacteria. Oxygen is usually the initial rate-limiting factor in the biodegradation of petroleum hydrocarbons. Using the bioventing process allowed control of the supply of nutrients and moisture based on petroleum contamination concentrations and soil type. The results of this work have proven to be a safe and cost-effective means of cleaning up low level radiological and petroleum-contaminated soil. Many of the other elements of the bioreactor design were developed or enhanced during the demonstration of a ''biopile'' to treat the soils beneath a Polish oil refinery's waste disposal lagoons. Aerobic microorganisms were isolated from the aged refinery's …
Date: June 7, 2004
Creator: BRIGMON, ROBINL.
Object Type: Article
System: The UNT Digital Library
Characterization of liquid phase epitaxial GaAs forblocked-impurity-band far-infrared detectors (open access)

Characterization of liquid phase epitaxial GaAs forblocked-impurity-band far-infrared detectors

GaAs Blocked-Impurity-Band (BIB) photoconductor detectors have the potential to become the most sensitive, low noise detectors in the far-infrared below 45.5 cm{sup -1} (220 {micro}m). We have studied the characteristics of liquid phase epitaxial GaAs films relevant to BIB production, including impurity band formation and the infrared absorption of the active section of the device. Knowledge of the far-infrared absorption spectrum as a function of donor concentration combined with variable temperature Hall effect and resistivity studies leads us to conclude that the optimal concentration for the absorbing layer of a GaAs BIB detector lies between 1 x 10{sup 15} and 6.7 x 10{sup 15} cm{sup -3}. At these concentrations there is significant wavefunction overlap which in turn leads to absorption beyond the 1s ground to 2p bound excited state transition of 35.5 cm{sup -1} (282 {micro}m). There still remains a gap between the upper edge of the donor band and the bottom of the conduction band, a necessity for proper BIB detector operation.
Date: April 7, 2004
Creator: Cardozo, B. L.; Reichertz, L. A.; Beeman, J. W. & Haller, E. E.
Object Type: Article
System: The UNT Digital Library
Characterization of the Series 1000 Camera System (open access)

Characterization of the Series 1000 Camera System

The National Ignition Facility requires a compact network addressable scientific grade CCD camera for use in diagnostics ranging from streak cameras to gated x-ray imaging cameras. Due to the limited space inside the diagnostic, an analog and digital input/output option in the camera controller permits control of both the camera and the diagnostic by a single Ethernet link. The system consists of a Spectral Instruments Series 1000 camera, a PC104+ controller, and power supply. The 4k by 4k CCD camera has a dynamic range of 70 dB with less than 14 electron read noise at a 1MHz readout rate. The PC104+ controller includes 16 analog inputs, 4 analog outputs and 16 digital input/output lines for interfacing to diagnostic instrumentation. A description of the system and performance characterization is reported.
Date: April 7, 2004
Creator: Kimbrough, J. R.; Moody, J. D.; Bell, P. M. & Landen, O. L.
Object Type: Article
System: The UNT Digital Library
Classification of non-coding RNA using graph representations ofsecondary structure (open access)

Classification of non-coding RNA using graph representations ofsecondary structure

Some genes produce transcripts that function directly in regulatory, catalytic, or structural roles in the cell. These non-coding RNAs are prevalent in all living organisms, and methods that aid the understanding of their functional roles are essential. RNA secondary structure, the pattern of base-pairing, contains the critical information for determining the three dimensional structure and function of the molecule. In this work we examine whether the basic geometric and topological properties of secondary structure are sufficient to distinguish between RNA families in a learning framework. First, we develop a labeled dual graph representation of RNA secondary structure by adding biologically meaningful labels to the dual graphs proposed by Gan et al [1]. Next, we define a similarity measure directly on the labeled dual graphs using the recently developed marginalized kernels [2]. Using this similarity measure, we were able to train Support Vector Machine classifiers to distinguish RNAs of known families from random RNAs with similar statistics. For 22 of the 25 families tested, the classifier achieved better than 70% accuracy, with much higher accuracy rates for some families. Training a set of classifiers to automatically assign family labels to RNAs using a one vs. all multi-class scheme also yielded encouraging …
Date: June 7, 2004
Creator: Karklin, Yan; Meraz, Richard F. & Holbrook, Stephen R.
Object Type: Article
System: The UNT Digital Library
Comparison of Electron Cloud Simulation and Experiments in the High-Current Experiment (open access)

Comparison of Electron Cloud Simulation and Experiments in the High-Current Experiment

A set of experiments has been performed on the High-Current Experiment (HCX) facility at LBNL, in which the ion beam is allowed to collide with an end plate and thereby induce a copious supply of desorbed electrons. Through the use of combinations of biased and grounded electrodes positioned in between and downstream of the quadrupole magnets, the flow of electrons upstream into the magnets can be turned on or off. Properties of the resultant ion beam are measured under each condition. The experiment is modeled via a full three-dimensional, two species (electron and ion) particle simulation, as well as via reduced simulations (ions with appropriately chosen model electron cloud distributions, and a high-resolution simulation of the region adjacent to the end plate). The three-dimensional simulations are the first of their kind and the first to make use of a timestep-acceleration scheme that allows the electrons to be advanced with a timestep that is not small compared to the highest electron cyclotron period. The simulations reproduce qualitative aspects of the experiments, illustrate some unanticipated physical effects, and serve as an important demonstration of a developing simulation capability.
Date: October 7, 2004
Creator: Cohen, R; Friedman, A; Covo, M K; Lund, S; Molvik, A; Bieniosek, F et al.
Object Type: Report
System: The UNT Digital Library
Computational Chemical Dynamics: From Gas- Phase to Condensed - Phase Systems (Poster Book) (open access)

Computational Chemical Dynamics: From Gas- Phase to Condensed - Phase Systems (Poster Book)

None
Date: October 7, 2004
Creator: Cramer, Christopher J.
Object Type: Article
System: The UNT Digital Library
Conceptual Design of a Prototype LSST Database (open access)

Conceptual Design of a Prototype LSST Database

This document describes a preliminary design for Prototype LSST Database (LSST DB). They identify key components and data structures and provide an expandable conceptual schema for the database. The authors discuss the potential user applications and post-processing algorithm to interact with the database, and give a set of example queries.
Date: October 7, 2004
Creator: Nikolaev, S; Huber, M E; Cook, K H; Abdulla, G & Brase, J
Object Type: Report
System: The UNT Digital Library
Corrosion of Spent Nuclear Fuel: The Long-Term Assessment (open access)

Corrosion of Spent Nuclear Fuel: The Long-Term Assessment

Spent nuclear fuel, essentially U{sub 2}, accounts for over 95% of the total radioactivity of all of the radioactive wastes in the United States that require disposal, disposition or remediation. The UO{sub 2} in SNF is not stable under oxiding conditions and may also be altered under reducing conditions. The alteration of SNF results in the formation of new uranium phases that can cause the release or retardation of actinide and fission product radionuclides. Over the long term, and depending on the extent to which the secondary uranium phases incorporate fission products and actinides, these alteration phases become the near-field source term.
Date: October 7, 2004
Creator: Ewing, Rodney C.
Object Type: Report
System: The UNT Digital Library
Data acquisition and analysis for the Fermilab Collider RunII (open access)

Data acquisition and analysis for the Fermilab Collider RunII

Operating and improving the understanding of the Fermilab Accelerator Complex for the colliding beam experiments requires advanced software methods and tools. The Shot Data Acquisition and Analysis (SDA) has been developed to fulfill this need. The SDA takes a standard set of critical data at relevant stages during the complex series of beam manipulations leading to {radical}(s) {approx} 2 TeV collisions. Data is stored in a relational database, and is served to programs and users via Web based tools. Summary tables are systematically generated during and after a store. Written entirely in Java, SDA supports both interactive tools and application interfaces used for in-depth analysis. In this talk, we present the architecture and described some of our analysis tools. We also present some results on the recent Tevatron performance as illustrations of the capabilities of SDA.
Date: July 7, 2004
Creator: al., Paul L. G. Lebrun et
Object Type: Article
System: The UNT Digital Library
Development and Characterization of a High Performance Thin-Film Planar Solid-Oxide Fuel Cell Stack (open access)

Development and Characterization of a High Performance Thin-Film Planar Solid-Oxide Fuel Cell Stack

A planar solid oxide fuel cell (SOFC) was fabricated using a tape-cast Ni/yttria-stabilized zirconia (YSZ) anode support, a YSZ thin film electrolyte, and a composite cathode of YSZ and (La{sub 0.85}Sr{sup 0.14}){sub 0.98}MnO{sub 3} (LSM). Using pure hydrogen as the fuel gas, a three cell stack with a cross-flow design and external manifolds produced peak power densities of 0.85 W/cm{sup 2} and 0.41 W/cm{sup 2} at 800 C and 700 C, respectively. Using wet methane as the fuel gas, the stack produced a peak power density of 0.22 W/cm{sup 2} at 700 C. Individual cells in the stack showed identical current-voltage (I -V) characteristics. Stack lifetime was limited because of degradation of the cells from oxidation products coming from the metallic interconnect used.
Date: April 7, 2004
Creator: Chung, Brandon W.; Chervin, Christopher N; Haslam, Jeffrey J.; Pham, Ai-Quoc & Glass, Robert S.
Object Type: Article
System: The UNT Digital Library
Drift Scale THM Model (open access)

Drift Scale THM Model

This model report documents the drift scale coupled thermal-hydrological-mechanical (THM) processes model development and presents simulations of the THM behavior in fractured rock close to emplacement drifts. The modeling and analyses are used to evaluate the impact of THM processes on permeability and flow in the near-field of the emplacement drifts. The results from this report are used to assess the importance of THM processes on seepage and support in the model reports ''Seepage Model for PA Including Drift Collapse'' and ''Abstraction of Drift Seepage'', and to support arguments for exclusion of features, events, and processes (FEPs) in the analysis reports ''Features, Events, and Processes in Unsaturated Zone Flow and Transport and Features, Events, and Processes: Disruptive Events''. The total system performance assessment (TSPA) calculations do not use any output from this report. Specifically, the coupled THM process model is applied to simulate the impact of THM processes on hydrologic properties (permeability and capillary strength) and flow in the near-field rock around a heat-releasing emplacement drift. The heat generated by the decay of radioactive waste results in elevated rock temperatures for thousands of years after waste emplacement. Depending on the thermal load, these temperatures are high enough to cause boiling …
Date: October 7, 2004
Creator: Rutqvist, J.
Object Type: Report
System: The UNT Digital Library
DRY TRANSFER FACILITY SEISMIC ANALYSIS (open access)

DRY TRANSFER FACILITY SEISMIC ANALYSIS

None
Date: April 7, 2004
Creator: N/A, EARNEST S - N /A KO H - N/A DOCKERY W - N/A PERNISI R -
Object Type: Report
System: The UNT Digital Library
An Eclectic Journey Through Experimental Nuclear Physics, or How I Learned to Stop Worrying and Love Nuclear Data (open access)

An Eclectic Journey Through Experimental Nuclear Physics, or How I Learned to Stop Worrying and Love Nuclear Data

In this paper, I illustrate how the ability to rapidly access the broad range of nuclear data has facilitated my research in fields from searches for double beta decay, to measurements of astrophysical reaction rates, to issues in homeland security. In doing this, I hope to persuade even the skeptics that for the benefit of the broad scientific community, it is imperative that the outstanding work of the nuclear data community continue.
Date: December 7, 2004
Creator: Norman, E B
Object Type: Article
System: The UNT Digital Library
The Effect of Annealing at 1500 C on Migration and Release of Ion Implanted Silver in CVD Silicon Carbide (open access)

The Effect of Annealing at 1500 C on Migration and Release of Ion Implanted Silver in CVD Silicon Carbide

The transport of silver in CVD {beta}-SiC has been studied using ion implantation. Silver ions were implanted in {beta}-SiC using the ATLAS accelerator facility at the Argonne National Laboratory. Ion beams with energies of 93 and 161 MeV were used to achieve deposition with peak concentrations at depths of approximately 9 and 13 {micro}m, respectively. As-implanted samples were then annealed at 1500 C for 210 or 480 hours. XPS, SEM, TEM, STEM, and optical methods were used to analyze the material before and after annealing. Silver concentration profiles were determined using XPS before and after annealing. STEM and SEM equipped with quantitative chemical analysis capability were used to more fully characterize the location and morphology of the silver before and after annealing. The results show that, within the uncertainty of measurement techniques, there is no silver migration, via either inter- or intragrannular paths, for the times and temperature studied. Additionally, the silver was observed to phase separate within the SiC after annealing. The irradiation damage from the implantation process resulted in a three-layer morphology in the as-implanted condition: (1) a layer of unaltered SiC, followed by (2) a layer of crystallized SiC, followed by (3) an amorphized layer which contained …
Date: October 7, 2004
Creator: MacLean, H. J.; Ballinger, R. G.; Kolaya, L. E.; Simonson, S. A.; Lewis, N. & Hanson, M. E.
Object Type: Report
System: The UNT Digital Library
Effect of Initial Conditions on Compressible Rayleigh-Taylor Instability and Transition to Turbulence (open access)

Effect of Initial Conditions on Compressible Rayleigh-Taylor Instability and Transition to Turbulence

Perturbations on an interface driven by a strong blast wave grow in time due to a combination of Rayleigh-Taylor, Richtmyer-Meshkov, and decompression effects. In this paper, we present the first results from a computational study of such a system under drive conditions to be attainable on the National Ignition Facility. Using the multiphysics, AMR, higher order Godunov Eulerian hydrocode, Raptor, we consider the late nonlinear instability evolution for multiple amplitude and phase realizations of a variety of multimode spectral types. We show that compressibility effects preclude the emergence of a regime of self-similar instability growth independent of the initial conditions by allowing for memory of the initial conditions to be retained in the mix-width at all times. The loss of transverse spectral information is demonstrated, however, along with the existence of a quasi-self-similar regime over short time intervals. The initial conditions are shown to have a strong affect on the time to transition to the quasi-self-similar regime.
Date: January 7, 2004
Creator: Miles, A R; Edwards, M & Greenough, J A
Object Type: Article
System: The UNT Digital Library
Effects of Large Area Liquid Lithium Limiters on Spherical Torus Plasmas (open access)

Effects of Large Area Liquid Lithium Limiters on Spherical Torus Plasmas

Use of a large-area liquid lithium surface as a first wall has significantly improved the plasma performance in the Current Drive Experiment-Upgrade (CDX-U) at the Princeton Plasma Physics Laboratory. Previous CDX-U experiments with a partially-covered toroidal lithium limiter tray have shown a decrease in impurities and the recycling of hydrogenic species. Improvements in loading techniques have permitted nearly full coverage of the tray surface with liquid lithium. Under these conditions, there was a large drop in the loop voltage needed to sustain the plasma current. The data are consistent with simulations that indicate more stable plasmas having broader current profiles, higher temperatures, and lowered impurities with liquid lithium walls. As further evidence for reduced recycling with a liquid lithium limiter, the gas puffing had to be increased by up to a factor of eight for the same plasma density achieved with an empty toroidal tray limiter.
Date: June 7, 2004
Creator: Kaita, R.; Majeski, R.; Boaz, M.; Efthimion, P.; Gettelfinger, G.; Gray, T. et al.
Object Type: Report
System: The UNT Digital Library