What Do We Know About Ethanol and Alkylates as Pollutants? (open access)

What Do We Know About Ethanol and Alkylates as Pollutants?

Gov. Davis issued Executive Order D-5-99 in March 1999 calling for removal of methyl tertiary butyl ether (MTBE) from gasoline no later than December 31, 2002. The Executive Order required the California Air Board, State Water Resources Control Board (SWRCB) and Office of Environmental Health Hazard Assessment (OEHHA) to prepare an analysis of potential impacts and health risks that may be associated with the use of ethanol as a fuel oxygenate. The SWRCB contracted with the Lawrence Livermore National Laboratory (LLNL) to lead a team of researchers, including scientists from Clarkson University, University of Iowa, and University of California, Davis, in evaluating the potential ground and surface water impacts that may occur if ethanol is used to replace MTBE. These findings are reported in the document entitled Health and Environmental Assessment of the Use of Ethanol as a Fuel Oxygenate. This document has been peer reviewed and presented to the California Environmental Policy Council and may be viewed at: http://www-erd.llnl.gov/ethanol/. Ethanol used for fuels is made primarily from grains, but any feed stock containing sugar, starch, or cellulose can be fermented to ethanol. Ethanol contains 34.7% oxygen by weight. It is less dense than water, but infinitely soluble in water. …
Date: May 11, 2001
Creator: Rich, D W; Marchetti, A A; Buscheck, T & Layton, D W
Object Type: Article
System: The UNT Digital Library
Model Predictions of Chemically Controlled Slow Crack Growth with Application to Mechanical Effects in Geothermal Environments (open access)

Model Predictions of Chemically Controlled Slow Crack Growth with Application to Mechanical Effects in Geothermal Environments

Representative, simplified geothermal rock-fluid systems are investigated with a modeling approach to estimate how rock water interactions affect coupled properties related to mechanical stability and permeability improvement through fracturing. First, geochemical modeling is used to determine the evolution of fluid chemistry at temperatures up to 300 C when fluids are in contact with representative rocks of continental origin. Then, a kinetic crack growth model for quartz is used to predict growth rate for subcritical cracks in acidic and basic environments. The predicted growth rate is highly sensitive to temperature and pH in the ranges tested. At present, the model is limited to situations in which quartz controls the mechanical process of interest, such as well bore stability in silica cemented rocks and the opening of quartz filled veins to enhance permeability.
Date: April 11, 2001
Creator: Viani, B. E.
Object Type: Article
System: The UNT Digital Library
Forward-Inverse Adaptive Techniques for Reservoir Characterization and Simulation: Theory and Applications (open access)

Forward-Inverse Adaptive Techniques for Reservoir Characterization and Simulation: Theory and Applications

A novel approach called Forward-Inverse Adaptive Techniques (FIAT) for reservoir characterization is developed and applied to three representative exploration cases. Inverse modeling refers to the determination of the entire reservoir permeability under steady state single-phase flow regime, given only field permeability, pressure and production well measurements. FIAT solves the forward and inverse partial differential equations (PDEs) simultaneously by adding a regularization term and filtering pressure gradients. An implicit adaptive-grid, Galerkin, numerical scheme is used to numerically solve the set of PDEs subject to pressure and permeability boundary conditions. Three examples are presented. Results from all three cases demonstrate attainable and reasonably accurate solutions and, more importantly, provide insights into the consequences of data undersampling.
Date: June 11, 2001
Creator: Doss, S D; Ezzedine, S; Gelinas, R & Chawathe, A
Object Type: Article
System: The UNT Digital Library
Overview and Status of the Power Conditioning System for the National Ignition Facility (open access)

Overview and Status of the Power Conditioning System for the National Ignition Facility

The National Ignition Facility (NIF) Power Conditioning System (PCS) is a modular capacitive energy storage system that provides over 34 kilojoules of energy to each of the nearly 8000 flashlamps in the NIF laser. Up to 400 megajoules of energy can be stored in the NIF PCS system, discharged through spark gaps and delivered to the flashlamps through a coaxial transmission line system requiring nearly 100 miles of high-voltage cable. The NIF PCS has been under development for nearly 4 years. During this time, the system was developed and designed by Sandia National Laboratory in Albuquerque, NM (SNLA) in conjunction with Lawrence Livermore National Laboratory (LLNL). Extensive reliability testing was performed at SNLA on the First Article NIF Test Module (FANTM) test facility and design improvements were implemented based on FANTM test results, leading to the final design presently undergoing system reliability testing at LLNL. Low-cost energy-storage capacitors, charging power supplies, and reliable, fault-tolerant components were developed through partnerships with numerous contractors. Extensive reliability and fault testing of components has also been performed. This paper will provide an overview of the many efforts that have culminated in the final design of the NIF PCS. The PCS system design will be …
Date: September 11, 2001
Creator: Newton, M A; Fulkerson, E S; Hulsey, S D; Kamm, R E; Pendleton, D L; Petersen, D E et al.
Object Type: Article
System: The UNT Digital Library
Stochastic Engine Convergence Diagnostics (open access)

Stochastic Engine Convergence Diagnostics

The stochastic engine uses a Markov Chain Monte Carlo (MCMC) sampling device to allow an analyst to construct a reasonable estimate of the state of nature that is consistent with observed data and modeling assumptions. The key engine output is a sample from the posterior distribution, which is the conditional probability distribution of the state of nature, given the data. In applications the state of nature may refer to a complicated, multi-attributed feature like the lithology map of a volume of earth, or to a particular related parameter of interest, say the centroid of the largest contiguous sub-region of specified lithology type. The posterior distribution, which we will call f, can be thought of as the best stochastic description of the state of nature that incorporates all pertinent physical and theoretical models as well as observed data. Characterization of the posterior distribution is the primary goal in the Bayesian statistical paradigm. In applications of the stochastic engine, however, analytical calculation of the posterior distribution is precluded, and only a sample drawn from the distribution is feasible. The engine's MCMC technique, which employs the Metropolis-Hastings algorithm, provides a sample in the form of a sequence (chain) of possible states of nature, …
Date: December 11, 2001
Creator: Glaser, R
Object Type: Report
System: The UNT Digital Library
Yucca Mountain Site Charecteization Project Summary of Socioeconomic Data Analysis Conducted in Support of the Radiological Monitoring Program, During FY 2001 (open access)

Yucca Mountain Site Charecteization Project Summary of Socioeconomic Data Analysis Conducted in Support of the Radiological Monitoring Program, During FY 2001

This report is a summary of socioeconomic data analyses conducted in support of the Radiological Monitoring Program during fiscal year 2001. Socioeconomic data contained in this report include estimates for the years 2000 and 2001 of the resident population in the vicinity of Yucca Mountain. The estimates presented in this report are based on selected Census 2000 statistics, and housing and population data that were acquired and developed in accordance with LP-RS-00 1 Q-M&0, Scientific Investigation of Economic, Demographic, and Agricultural Characteristics in the Vicinity of Yucca Mountain. The study area from which data were collected is delineated by a radial grid, consisting of 160 grid cells, that is suitable for evaluating the pathways and potential impacts of a release of radioactive materials to the environment within a distance of 84 kilometers from Yucca Mountain. Data are presented in a tabular format by the county, state, area, and grid cell in which housing units, households, and resident population are located. Also included is a visual representation of the distribution of the 2000 residential populations within the study area, showing Census 2000 geography, county boundaries, and taxing district boundaries for selected communities.
Date: December 11, 2001
Creator: Roe, L.K.
Object Type: Report
System: The UNT Digital Library
12th International Workshop on Plant Membrane Biology (open access)

12th International Workshop on Plant Membrane Biology

This report is on 12th International Workshop on Plant Membrane Biology
Date: August 11, 2001
Creator: Spalding, Edgar P.
Object Type: Article
System: The UNT Digital Library
D0 Run IIB Silicon Detector Upgrade: Technical Design Report (open access)

D0 Run IIB Silicon Detector Upgrade: Technical Design Report

None
Date: October 11, 2001
Creator: Denisov, Dmitri S. & Soldner-Rembold, Stefan
Object Type: Report
System: The UNT Digital Library
Effect of catalyst structure on oxidative dehydrogenation of ethane and propane on alumina-supported vanadia (open access)

Effect of catalyst structure on oxidative dehydrogenation of ethane and propane on alumina-supported vanadia

The catalytic properties of Al2O3-supported vanadia with a wide range of VOx surface density (1.4-34.2 V/nm2) and structure were examined for the oxidative dehydrogenation of ethane and propane. UV-visible and Raman spectra showed that vanadia is dispersed predominantly as isolated monovanadate species below {approx}2.3 V/nm2. As surface densities increase, two-dimensional polyvanadates appear (2.3-7.0 V/nm2) along with increasing amounts of V2O5 crystallites at surface densities above 7.0 V/nm2. The rate constant for oxidative dehydrogenation (k1) and its ratio with alkane and alkene combustion (k2/k1 and k3/k1, respectively) were compared for both alkane reactants as a function of vanadia surface density. Propene formation rates (per V-atom) are {approx}8 times higher than ethene formation rates at a given reaction temperature, but the apparent ODH activation energies (E1) are similar for the two reactants and relatively insensitive to vanadia surface density. Ethene and propene formation rates (per V-atom) are strongly influenced by vanadia surface density and reach a maximum value at intermediate surface densities ({approx}8 V/nm2). The ratio of k2/k1 depends weakly on reaction temperature, indicating that activation energies for alkane combustion and ODH reactions are similar. The ratio of k2/k1 is independent of surface density for ethane, but increase slightly with vanadia surface …
Date: September 11, 2001
Creator: Argyle, Morris D.; Chen, Kaidong; Bell, Alexis T. & Iglesia, Enrique
Object Type: Article
System: The UNT Digital Library
Database Transformations for Biological Applications (open access)

Database Transformations for Biological Applications

The goal of this project was to develop tools to facilitate data transformations between heterogeneous data sources found throughout biomedical applications. Such transformations are necessary when sharing data between different groups working on related problems as well as when querying data spread over different databases, files and software analysis packages.
Date: April 11, 2001
Creator: Overton, C.; Davidson, S. B.; Buneman, P. & Tannen, V.
Object Type: Report
System: The UNT Digital Library
Revisiting the 'Buy versus Build' Decision for Publicly Owned Utilities in California Considering Wind and Geothermal Resources (open access)

Revisiting the 'Buy versus Build' Decision for Publicly Owned Utilities in California Considering Wind and Geothermal Resources

The last two decades have seen a dramatic increase in the market share of independent, nonutility generators (NUGs) relative to traditional, utility-owned generation assets. Accordingly, the ''buy versus build'' decision facing utilities--i.e., whether a utility should sign a power purchase agreement (PPA) with a NUG, or develop and own the generation capacity itself--has gained prominence in the industry. Very little of this debate, however, has focused specifically on publicly owned electric utilities, and with few exceptions, renewable sources of supply have received similarly scant attention. Contrary to historical treatment, however, the buy versus build debate is quite relevant to publicly owned utilities and renewables because publicly owned utilities are able to take advantage of some renewable energy incentives only in a ''buy'' situation, while others accrue only in a ''build'' situation. In particular, possible economic advantages of public utility ownership include: (1) the tax-free status of publicly owned utilities and the availability of low-cost debt, and (2) the renewable energy production incentive (REPI) available only to publicly owned utilities. Possible economic advantages to entering into a PPA with a NUG include: (1) the availability of federal tax credits and accelerated depreciation schedules for certain forms of NUG-owned renewable energy, and …
Date: December 11, 2001
Creator: Bolinger, Mark; Wiser, Ryan & Golove, William
Object Type: Article
System: The UNT Digital Library
Design of the superconducting section of the SPL Linac at CERN (open access)

Design of the superconducting section of the SPL Linac at CERN

In order to set up a powerful proton source for a future Neutrino Factory, increasing at the same time the flux of protons available for new and existing facilities, CERN is studying a 2.2 GeV superconducting H- linac for 4 MW beam power, called SPL. The superconducting part of this linac covers the energy range from 120 MeV to 2.2 GeV. Three sections made of 352 MHz cavities with nominal beta of 0.52, 0.7 and 0.8 bring the beam energy up to 1 GeV. From this energy, superconducting cavities from LEP or beta 0.8 cavities can be used up to the final energy of 2.2 GeV. This paper covers the optimization for the superconducting part, the beam dynamics design principles, the matching between sections, and the results of multiparticle simulations with up to 50 million particles. To demonstrate the stability of the design, matched and mismatched input beams are used.
Date: June 11, 2001
Creator: Gerigk, F.; Vretenar, M. & Ryne, Robert D.
Object Type: Article
System: The UNT Digital Library
Genetic Engineering of a Radiation-Resistant Bacterium for Biodegradation of Mixed Wastes (open access)

Genetic Engineering of a Radiation-Resistant Bacterium for Biodegradation of Mixed Wastes

The mixture of toxic chemicals, heavy metals, halogenated solvents and radionuclides in many DOE waste materials presents a challenging problem for separating the different species and disposing of individual contaminants. One approach for dealing with mixed wastes is to genetically engineer the radiation-resistant bacterium, Deinococcus radiodurans to survive in and detoxify DOE's mixed waste streams, and to develop process parameters for treating mixed wastes with such constructed strains. The goal for this project is to develop a suite of genetic tools for Deinococcus radiodurans and to use these tools to construct and test stable strains for detoxification of haloorganics in mixed wastes.
Date: June 11, 2001
Creator: Lidstrom, Mary E.
Object Type: Report
System: The UNT Digital Library
Zero-Valent Iron Permeable Reactive Barriers: A Review of Performance (open access)

Zero-Valent Iron Permeable Reactive Barriers: A Review of Performance

This report briefly reviews issues regarding the implementation of the zero-valent iron permeable reactive barrier (PRB) technology at sites managed by the U.S. Department of Energy (DOE). Initially, the PRB technology, using zero-valent iron for the reactive media, was received with great enthusiasm, and DOE invested millions of dollars testing and implementing PRBs. Recently, a negative perception of the technology has been building. This perception is based on the failure of some deployments to satisfy goals for treatment and operating expenses. The purpose of this report, therefore, is to suggest reasons for the problems that have been encountered and to recommend whether DOE should invest in additional research and deployments. The principal conclusion of this review is that the most significant problems have been the result of insufficient characterization, which resulted in poor engineering implementation. Although there are legitimate concerns regarding the longevity of the reactive media, the ability of zero-valent iron to reduce certain chlorinated hydrocarbons and to immobilize certain metals and radionuclides is well documented. The primary problem encountered at some DOE full-scale deployments has been an inadequate assessment of site hydrology, which resulted in misapplication of the technology. The result is PRBs with higher than expected flow …
Date: June 11, 2001
Creator: Korte, NE
Object Type: Report
System: The UNT Digital Library
Summary of Dissolved Concentration Limits (open access)

Summary of Dissolved Concentration Limits

According to the Technical Work Plan titled Technical Work Plan for Waste Form Degradation Process Model Report for SR (CRWMS M&O 2000a), the purpose of this study is to perform abstractions on solubility limits of radioactive elements based on the process-level information and thermodynamic databases provided by Natural Environment Program Operations (NEPO) and Waste Package Operations (WPO). The scope of this analysis is to produce solubility limits as functions, distributions, or constants for all transported radioactive elements identified by the Performance Assessment Operations (PAO) radioisotope screening. Results from an expert elicitation for solubility limits of most radioactive elements were used in the previous Total System Performance Assessments (TSPAs). However, the elicitation conducted in 1993 does not meet the criteria set forth by the U.S. Nuclear Regulatory Commission (NRC) due to lack of documentation and traceability (Kotra et al. 1996, Section 3). Therefore, at the Waste Form Abstraction Workshop held on February 2-4, 1999, at Albuquerque, New Mexico, the Yucca Mountain Site Characterization Project (YMP) decided to develop geochemical models to study solubility for the proposed Monitored Geologic Repository. WPO/NEPO is to develop process-level solubility models, including review and compilation of relevant thermodynamic data. PAO's responsibility is to perform abstractions based …
Date: June 11, 2001
Creator: Chen, Yueting
Object Type: Report
System: The UNT Digital Library
MAPPING INDUCED POLARIZATION WITH NATURAL ELECTROMAGNETIC FIELDS FOR EXPLORATION AND RESOURCES CHARACTERIZATION BY THE MINING INDUSTRY (open access)

MAPPING INDUCED POLARIZATION WITH NATURAL ELECTROMAGNETIC FIELDS FOR EXPLORATION AND RESOURCES CHARACTERIZATION BY THE MINING INDUSTRY

In this quarter we completed the manufacture and bench testing of the first prototype of the MT-24/LF system to be used in the natural IP survey. The MT-24/LF will dramatically reduce field costs by simplifying field operations through the use of high accuracy GPS synchronization between wide band high accuracy (24 bit) autonomous recording systems. The simplification of field operations comes about from the elimination of the need for long lengths of telemetry cable and also from the elimination of trained operators for field data acquisition. Instead, all data is now synchronized by GPS and recorded to compact Flash media which is quickly and efficiently recovered and brought back to base for processing.
Date: July 11, 2001
Creator: Nichols, Edward
Object Type: Report
System: The UNT Digital Library
Friction and wear performance of low-friction carbon coatings under oil lubrication. (open access)

Friction and wear performance of low-friction carbon coatings under oil lubrication.

Amorphous carbon coatings with very low friction properties were recently developed at Argonne National Laboratory. These coatings have shown good promise in mitigating excessive wear and scuffing problems associated with low-lubricity diesel fuels. To reduce the negative effect of sulfur and other lubricant additives in poisoning the after-treatment catalyst, a lubricant formulation with a low level of sulfur may be needed. Exclusion of proven sulfur-containing extreme pressure (EP) and antiwear additives from oils will require other measures to ensure durability of critical lubricated components. The low-friction carbon coating has the potential for such applications. In the present study, we evaluated the friction and wear attributes of three variations of the coating under a boundary lubrication regime. Tests were conducted with both synthetic and mineral oil lubricants using a ball-on-flat contact configuration in reciprocating sliding. Although the three variations of the coating provided modest reductions in friction coefficient, they all reduced wear substantially compared to an uncoated surface. The degradation mode of oxidative wear on the uncoated surface was replaced by a polishing wear mode on the coated surfaces.
Date: December 11, 2001
Creator: Kovalchenko, A.; Ajayi, O. O.; Erdemir, A. & Fenske, G. R.
Object Type: Article
System: The UNT Digital Library
Application of Reservoir Characterization and Advanced Technology to Improve Recovery and Economics in a Lower Quality Shallow Shelf San Andres Reservoir. Quarterly Progress Report: July 1--September 30, 2001 (open access)

Application of Reservoir Characterization and Advanced Technology to Improve Recovery and Economics in a Lower Quality Shallow Shelf San Andres Reservoir. Quarterly Progress Report: July 1--September 30, 2001

The Class 2 Project at West Welch was designed to demonstrate the use of advanced technologies to enhance the economics of improved oil recovery (IOR) projects in lower quality Shallow Shelf Carbonate (SSC) reservoirs, resulting in recovery of additional oil that would otherwise be left in the reservoir at project abandonment. Accurate reservoir description is critical to the effective evaluation and efficient design of IOR projects in the heterogeneous SSC reservoirs. Therefore, the majority of Budget Period 1 was devoted to reservoir characterization. Technologies being demonstrated include: (1) Advanced petrophysics; (2) Three-dimensional (3-D) seismic; (3) Crosswell bore tomography; (4) Advanced reservoir simulation; (5) Carbon dioxide (CO{sub 2}) stimulation treatments; (6) Hydraulic fracturing design and monitoring; and (7) Mobility control agents.
Date: December 11, 2001
Creator: Hickman, T. Scott & Justice, James J.
Object Type: Report
System: The UNT Digital Library
Optical Imaging in Microstructures (open access)

Optical Imaging in Microstructures

This research was focused on developing morphology-dependent stimulated raman scattering (MDSRS) spectroscopy as an analytic optical imaging technique. MDSRS uses the cavity modes (called morphology dependent resonances, MDRs) associated with axisymmetric dielectric microstructures to generate nonlinear optical signals. Since different cavity modes span different regions inside the microstructure, it becomes possible to generate location-specific spectra. The information gotten from MDSRS imaging experiments is analogous with that generated from magnetic resonance imaging (MRI) studies in that spatial variations in chemical composition and molecular configuration within a structure can be mapped out. The authors demonstrated that MDSRS imaging is feasible and is free from nonlinear artifact. They did this by measuring the molecular structure variations that are present in the interfaces of 180 {micro}m dia. charged water droplets. The 4 publications that resulted from these studies are attached. From a chemical perspective a water droplet is, however, a simple thing. Will it be possible to use MDSRS imaging to study more complex systems such as combusting fuel droplets, layered polymer or glass fibers, or biological cells? The long-term goal of the research was to answer this question. The answer they have come up with is yes and no. The results on nitrate …
Date: April 11, 2001
Creator: Aker, P. M.
Object Type: Report
System: The UNT Digital Library
Distribution of Chromium Contamination and Microbial Activity in Soil Aggregates (open access)

Distribution of Chromium Contamination and Microbial Activity in Soil Aggregates

None
Date: July 11, 2001
Creator: Tokunaga, Tetsu K.; Wan, Jiamin; Hazen, Terry C.; Schwartz, Egbert; Firestone, Mary K.; Sutton, Stephen R. et al.
Object Type: Article
System: The UNT Digital Library
Foundation for a Syntactic Pattern Recognition System for Genomic DNA Sequences (open access)

Foundation for a Syntactic Pattern Recognition System for Genomic DNA Sequences

The goals of this project were to establish database access to several databases of interest, customizing bioJava for database applications, improving performance of bioJava applets, development of additional applets, and maintenance of GenLang for web applications.
Date: April 11, 2001
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Fracture and fatigue behavior at ambient and elevated temperatures of alumina bonded with copper/niobium/copper interlayers (open access)

Fracture and fatigue behavior at ambient and elevated temperatures of alumina bonded with copper/niobium/copper interlayers

None
Date: February 11, 2001
Creator: Kruzic, J. J.; Marks, R. A.; Yoshiya, M.; Glaeser, A. M.; Cannon, R. M. & Ritchie, R. O.
Object Type: Article
System: The UNT Digital Library
Pd/Cu site interchange in UCu{sub 5-x}Pd{sub x} (open access)

Pd/Cu site interchange in UCu{sub 5-x}Pd{sub x}

Although Pd/Cu site interchange in the non-Fermi liquid (NFL) material UCu{sub 4}Pd has been observed, the relationship between this disorder and the NFL behavior remains unclear. In order to better compare to the UCu{sub 5-x}Pd{sub x} phase diagram, they report results from Pd K edge x-ray absorption fine structure (XAFS) experiments on this series (x = 0.3-1.5) that determine the fraction of Pd atoms on the nominally Cu (16e) sites, s. They find that for these unannealed samples, s is at least 17% for all the samples measured, even for x < 1.0, although it does climb monotonically beyond its minimum at x = 0.7. These data are compared to changes in the lattice parameter as a function of x.
Date: July 11, 2001
Creator: Booth, C. H.; Bauer, E. D.; Maple, M. B.; Chau, R. & Kwei, G. H.
Object Type: Article
System: The UNT Digital Library
Ultra-High Resolution ARP Spectrometer System for NSLS Undulator Beamline U13. Final Report, August 15, 1996 - August 31, 2000j (open access)

Ultra-High Resolution ARP Spectrometer System for NSLS Undulator Beamline U13. Final Report, August 15, 1996 - August 31, 2000j

DOE award DEFG02-96ER45590 was for the construction of an ARP Spectrometer for installation at the National Synchrotron Light Source (NSLS) on undulator beamline U13. The spectrometer is completely assembled and under vacuum on the floor of the NSLS. It consists of vacuum chamber; pumps, sample cryostat and manipulator, and electronic energy analyzer. The analyzer has achieved energy resolution of 5 meV in multi-channel mode, angular resolution of 2 mR is expected though as yet unproven, and sample temperatures below 10K should be achieved. These specifications are either equal to or better than those described in the original proposal. The spectrometer has not yet been attached to beamline U13.
Date: April 11, 2001
Creator: Jensen, Eric
Object Type: Report
System: The UNT Digital Library