Adsorption of Pure Methane, Nitrogen, and Carbon Dioxide and Their Mixtures on San Juan Basin Coal (open access)

Adsorption of Pure Methane, Nitrogen, and Carbon Dioxide and Their Mixtures on San Juan Basin Coal

The major objectives of this project were to (a) measure the adsorption behavior of pure methane, nitrogen, CO{sub 2} and their binary and ternary mixtures on wet Tiffany coal at 130 F and pressures to 2000 psia; (b) correlate the equilibrium adsorption isotherm data using the extended Langmuir model, the Langmuir model, the loading ratio correlation and the Zhou-Gasem-Robinson equation of state; and (c) establish sorption-time estimates for the pure components. Specific accomplishments are summarized below regarding the complementary tasks involving experimental work and data correlation. Representative coal samples from BP Amoco Tiffany Injection Wells No.1 and No.10 were prepared, as requested. The equilibrium moisture content and particle size distribution of each coal sample were determined. Compositional coal analyses for both samples were performed by Huffman Laboratories, Inc. Pure gas adsorption for methane on wet Tiffany coal samples from Injection Wells No.1 and No.10 was measured separately at 130 F (327.6 K) and pressures to 2000 psia (13.7 MPa). The average expected uncertainty in these data is about 3% (9 SCF/ton). Our measurements indicate that the adsorption isotherms of the two coal samples exhibit similar Langmuir-type behavior. For the samples from the two wells, a maximum variation of about 5% …
Date: March 1, 2002
Creator: Gasem, K. A. M.; Robinson, R. L. & Reeves, S. R.
Object Type: Report
System: The UNT Digital Library
Kalispel Resident Fish Project: Annual Report, 2001. (open access)

Kalispel Resident Fish Project: Annual Report, 2001.

In 2001 the Kalispel Natural Resource Department (KNRD) continued assessing habitat and population enhancement projects for bull trout (Salvelinus confluentus), westslope cutthroat (Oncorhynchus clarki lewisi) and largemouth bass (Micropterus salmoides). Habitat enhancement measures, as outlined in recommendations from the 1996, 1997, and 1998 annual reports, were monitored during field season 1999, 2000, and 2001. Post assessments were used to evaluate habitat quality, stream morphology and fish populations where enhancement projects were implemented.
Date: January 1, 2002
Creator: Andersen, Todd
Object Type: Report
System: The UNT Digital Library
Rainwater Wildlife Area, Watershed Management Plan, A Columbia Basin Wildlife Mitigation Project, 2002. (open access)

Rainwater Wildlife Area, Watershed Management Plan, A Columbia Basin Wildlife Mitigation Project, 2002.

This Management Plan has been developed by the Confederated Tribes of the Umatilla Indian Reservation (CTUIR) to document how the Rainwater Wildlife Area (formerly known as the Rainwater Ranch) will be managed. The plan has been developed under a standardized planning process developed by the Bonneville Power Administration (BPA) for Columbia River Basin Wildlife Mitigation Projects (See Appendix A and Guiding Policies Section below). The plan outlines the framework for managing the project area, provides an assessment of existing conditions and key resource issues, and presents an array of habitat management and enhancement strategies. The plan culminates into a 5-Year Action Plan that will focus our management actions and prioritize funding during the Fiscal 2001-2005 planning period. This plan is a product of nearly two years of field studies and research, public scoping, and coordination with the Rainwater Advisory Committee. The committee consists of representatives from tribal government, state agencies, local government, public organizations, and members of the public. The plan is organized into several sections with Chapter 1 providing introductory information such as project location, purpose and need, project goals and objectives, common elements and assumptions, coordination efforts and public scoping, and historical information about the project area. Key …
Date: March 1, 2002
Creator: Childs, Allen B.
Object Type: Report
System: The UNT Digital Library
Natural analogue synthesis report, TDR-NBS-GS-000027 rev00 icn02 (open access)

Natural analogue synthesis report, TDR-NBS-GS-000027 rev00 icn02

The purpose of this report is to present analogue studies and literature reviews designed to provide qualitative and quantitative information to test and provide added confidence in process models abstracted for performance assessment (PA) and model predictions pertinent to PA. This report provides updates to studies presented in the Yucca Mountain Site Description (CRWMS M&O 2000 [151945], Section 13) and new examples gleaned from the literature, along with results of quantitative studies conducted specifically for the Yucca Mountain Site Characterization Project (YMP). The intent of the natural analogue studies was to collect corroborative evidence from analogues to demonstrate additional understanding of processes expected to occur during postclosure at a potential Yucca Mountain repository. The report focuses on key processes by providing observations and analyses of natural and anthropogenic (human-induced) systems to improve understanding and confidence in the operation of these processes under conditions similar to those that could occur in a nuclear waste repository. The process models include those that represent both engineered and natural barrier processes. A second purpose of this report is to document the various applications of natural analogues to geologic repository programs, focusing primarily on the way analogues have been used by the YMP. This report …
Date: April 1, 2002
Creator: Simmons, A.; Nieder-Westermann, G.; Stuckless, J.; Dobson, P.; Unger, A.J.A.; Kwicklis, E. et al.
Object Type: Report
System: The UNT Digital Library
Habilitation Thesis on Neutrino Oscillations at the Bugey Reactor, Top Discovery in CDF, and the D0 SMT (open access)

Habilitation Thesis on Neutrino Oscillations at the Bugey Reactor, Top Discovery in CDF, and the D0 SMT

None
Date: May 1, 2002
Creator: Kajfasz, Eric
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Environmentally Assisted Cracking in Light Water Reactors : Semiannual Report, July 2000 - December 2000. (open access)

Environmentally Assisted Cracking in Light Water Reactors : Semiannual Report, July 2000 - December 2000.

This report summarizes work performed by Argonne National Laboratory on fatigue and environmentally assisted cracking (EAC) in light water reactors (LWRs) from July 2000 to December 2000. Topics that have been investigated include (a) environmental effects on fatigue S-N behavior of primary pressure boundary materials, (b) irradiation-assisted stress corrosion cracking (IASCC) of austenitic stainless steels (SSs), and (c) EAC of Alloys 600 and 690. The fatigue strain-vs.-life data are summarized for the effects of various material, loading, and environmental parameters on the fatigue lives of carbon and low-alloy steels and austenitic SSs. Effects of the reactor coolant environment on the mechanism of fatigue crack initiation are discussed. Two methods for incorporating the effects of LWR coolant environments into the ASME Code fatigue evaluations are presented. Slow-strain-rate tensile tests and posttest fractographic analyses were conducted on several model SS alloys irradiated to {approx}0.9 x 10{sup 21} n {center_dot} cm{sup -2} (E > 1 MeV) in He at 289 C in the Halden reactor. The results were used to determine the influence of alloying and impurity elements on the susceptibility of these steels to IASCC. A fracture toughness J-R curve test was conducted on a commercial heat of Type 304 SS that …
Date: April 1, 2002
Creator: Chopra, O. K.; Chung, H. M.; Gruber, E. E.; Shack, W. J.; Soppet, W. K.; Strain, R. V. et al.
Object Type: Report
System: The UNT Digital Library
Synthesis and Comparison of Baseline Avian and Bat Use, Raptor Nesting and Mortality Information from Proposed and Existing Wind Developments: Final Report. (open access)

Synthesis and Comparison of Baseline Avian and Bat Use, Raptor Nesting and Mortality Information from Proposed and Existing Wind Developments: Final Report.

Primarily due to concerns generated from observed raptor mortality at the Altamont Pass (CA) wind plant, one of the first commercial electricity generating wind plants in the U.S., new proposed wind projects both within and outside of California have received a great deal of scrutiny and environmental review. A large amount of baseline and operational monitoring data have been collected at proposed and existing U.S. wind plants. The primary use of the avian baseline data collected at wind developments has been to estimate the overall project impacts (e.g., very low, low, moderate, and high relative mortality) on birds, especially raptors and sensitive species (e.g., state and federally listed species). In a few cases, these data have also been used for guiding placement of turbines within a project boundary. This new information has strengthened our ability to accurately predict and mitigate impacts from new projects. This report should assist various stakeholders in the interpretation and use of this large information source in evaluating new projects. This report also suggests that the level of baseline data (e.g., avian use data) required to adequately assess expected impacts of some projects may be reduced. This report provides an evaluation of the ability to predict …
Date: December 1, 2002
Creator: Erickson, Wallace P.
Object Type: Report
System: The UNT Digital Library
Analysis of potential for jet-impingement erosion from leaking steam generator tubes during severe accidents. (open access)

Analysis of potential for jet-impingement erosion from leaking steam generator tubes during severe accidents.

This report summarizes analytical evaluation of crack-opening areas and leak rates of superheated steam through flaws in steam generator tubes and erosion of neighboring tubes due to jet impingement of superheated steam with entrained particles from core debris created during severe accidents. An analytical model for calculating crack-opening area as a function of time and temperature was validated with tests on tubes with machined flaws. A three-dimensional computational fluid dynamics code was used to calculate the jet velocity impinging on neighboring tubes as a function of tube spacing and crack-opening area. Erosion tests were conducted in a high-temperature, high-velocity erosion rig at the University of Cincinnati, using micrometer-sized nickel particles mixed in with high-temperature gas from a burner. The erosion results, together with analytical models, were used to estimate the erosive effects of superheated steam with entrained aerosols from the core during severe accidents.
Date: May 1, 2002
Creator: Majumdar, S.; Diercks, D. R.; Shack, W. J. & Technology, Energy
Object Type: Report
System: The UNT Digital Library
Final Project Report G-Plus Windshield Coatings (open access)

Final Project Report G-Plus Windshield Coatings

Samples of Sungate windshield material provided by PPG were analyzed to ascertain failure mechanisms observed at the interface between a copper busbar and the electrically conductive coating in use. Samples of “failed” windshield material were characterized using optical and electron microscopy, as well as surface analysis methods. These were compared to corresponding samples of “good” coatings. The primary failure mechanism of the coated windshield appears to be related to electrical discharges that originate where air-filled gaps are present between the copper busbar and the conductive coating. Gaps are produced by irregularities or wrinkles in the copper busbar that may result from the installation process.
Date: August 1, 2002
Creator: Matson, Dean W. & Koram, Kwaku
Object Type: Report
System: The UNT Digital Library
Simulation of Transport Phenomena in Aluminum Nitride Single-Crystal Growth (open access)

Simulation of Transport Phenomena in Aluminum Nitride Single-Crystal Growth

None
Date: June 1, 2002
Creator: de Almeida, V.F. & Rojo, J.C. (Crystal IS, Inc.)
Object Type: Report
System: The UNT Digital Library
Pressurized Fluidized Bed Combustion Second-Generation System Research and Development (open access)

Pressurized Fluidized Bed Combustion Second-Generation System Research and Development

Research is being conducted under United States Department of Energy (DOE) Contract DE-AC21-86MC21023 to develop a new type of coal-fired plant for electric power generation. This new type of plant--called a Second-Generation or Advanced Pressurized Circulating Fluidized Bed Combustion (APCFB) plant--offers the promise of efficiencies greater than 45% (HHV), with both emissions and a cost of electricity that are significantly lower than conventional pulverized-coal-fired plants with scrubbers. The APCFB plant incorporates the partial gasification of coal in a carbonizer, the combustion of carbonizer char in a pressurized circulating fluidized bed boiler (PCFB), and the combustion of carbonizer syngas in a topping combustor to achieve gas turbine inlet temperatures of 2300 F and higher. A conceptual design was previously prepared for this new type of plant and an economic analysis presented, all based on the use of a Siemens Westinghouse W501F gas turbine with projected carbonizer, PCFB, and topping combustor performance data. Having tested these components at the pilot plant stage, the referenced conceptual design is being updated to reflect more accurate performance predictions together with the use of the more advanced Siemens Westinghouse W501G gas turbine and a conventional 2400 psig/1050 F/1050 F/2-1/2 in. steam turbine. This report describes the …
Date: November 1, 2002
Creator: Robertson, A.; Horazak, D.; Newby, R. & Goldstein, H.
Object Type: Report
System: The UNT Digital Library
Enzymatic Upgrading of Heavy Crudes via Partial Oxidation or Conversion of PAHs (open access)

Enzymatic Upgrading of Heavy Crudes via Partial Oxidation or Conversion of PAHs

The objective of this program was to investigate new enzyme-based technologies for upgrading of heavy oils. Enzymes were selected for screening from those capable of conversion of polyaromatic hydrocarbons (PAHs) reported in the literature. Oxidative reactions of PAHs using hydrogen peroxide as an oxidant with conversion to partially oxidized products were used. The enzymes (lignin peroxidase, cytochrome c) were tested in various organic solvents and found to loose activity in pure organic solvents. A thermodynamic analysis revealed lack of effective interaction between the substrate and enzyme as the cause for low activity. The protein cytochrome c was modified to work in organic media by chemical hydrophobic group attachment. Two different modifications were made: attachment of polyethylene glycol (PEG) and alkyl groups. Alkyl groups, being small could be attached at interior locations within the core of the enzyme and possibly near the active site. Increase in the threshold solvent concentration where maximum enzyme activity occurred indicated potential of this strategy for effective enzyme-substrate interaction. Further improvements in enzyme activity called for other diverse methods due to the unavailability of sufficient chemical modification sites. Genetic techniques were therefore explored for further improvements. These experiments focused on cloning of a gene for the …
Date: July 1, 2002
Creator: Borole, A. P.; Davison, B. H. & Kuritz, T.
Object Type: Report
System: The UNT Digital Library
Carbon Dioxide Sequestering Using Microalgal Systems (open access)

Carbon Dioxide Sequestering Using Microalgal Systems

This project evaluated key design criteria, the technical feasibility, and the preliminary economic viability of a CO{sub 2}-sequestering system integrated with a coal-fired power plant based on microalgae biofixation. A review of relevant literature was conducted, and a bench-scale algal-based sequestration system was constructed and operated to verify algal growth capabilities using a simulated flue gas stream. The bench-scale system was a 20-gallon glass aquarium with a 16-gallon operating volume and was direct-sparged with a simulated flue gas. The flue gas composition was based on flue gas analyses for a 550-MW Coal Creek Power Station boiler in Underwood, North Dakota, which averaged 12.1% CO{sub 2}, 5.5% O{sub 2}, 423 ppm SO{sub 2}, 124 ppm NO{sub x}, and an estimated 50 mg/m{sup 3} fly ash loading. The algae were grown in Bold's basal growth medium. Lighting was provided using a two-tube fluorescent ''grow-light'' bulb fixture mounted directly above the tank. Algal growth appeared to be inhibited in the presence of SO{sub 2} using mixed cultures of green and blue-green cultures of algae. Samples of Monoraphidium strain MONOR02 and Nannochloropsis NANNO02 algal samples were obtained from the University of Hawaii Culture Collection. These samples did not exhibit inhibited growth in the presence …
Date: February 1, 2002
Creator: Stepan, Daniel J.; Shockey, Richard E.; Moe, Thomas A. & Dorn, Ryan
Object Type: Report
System: The UNT Digital Library
Long-Term Stewardship Program Science and Technology Requirements (open access)

Long-Term Stewardship Program Science and Technology Requirements

Many of the United States’ hazardous and radioactively contaminated waste sites will not be sufficiently remediated to allow unrestricted land use because funding and technology limitations preclude cleanup to pristine conditions. This means that after cleanup is completed, the Department of Energy will have long-term stewardship responsibilities to monitor and safeguard more than 100 sites that still contain residual contamination. Long-term stewardship encompasses all physical and institutional controls, institutions, information, and other mechanisms required to protect human health and the environment from the hazards remaining. The Department of Energy Long-Term Stewardship National Program is in the early stages of development, so considerable planning is still required to identify all the specific roles and responsibilities, policies, and activities needed over the next few years to support the program’s mission. The Idaho National Engineering and Environmental Laboratory was tasked with leading the development of Science and Technology within the Long-Term Stewardship National Program. As part of that role, a task was undertaken to identify the existing science and technology related requirements, identify gaps and conflicts that exist, and make recommendations to the Department of Energy for future requirements related to science and technology requirements for long-term stewardship. This work is summarized in …
Date: September 1, 2002
Creator: McDonald, Joan
Object Type: Report
System: The UNT Digital Library
Development of Kinetic Models for the Liquid Phase Methanol (LPMEOH tm) Process (open access)

Development of Kinetic Models for the Liquid Phase Methanol (LPMEOH tm) Process

This report covers our recent work on the kinetics of the LPMEOH{trademark} process. The major part of the report concerns the development of more robust kinetic models for the LPMEOH{trademark} reaction system. The development was needed to meet the requirements for more accurate process simulations over a wide range of conditions. To this end, kinetic experiments were designed based on commercial needs and a D-Optimal design package. A database covering 53 different conditions was built. Two new reactions were identified and added to the LPMEOH{trademark} reaction network. New rate models were developed for all 15 reactions in the system. The new rate models are more robust than the original ones, showing better fit to the experimental results over a wide range of conditions. Related to this model development are some new understandings about the sensitivity of rate models and their effects on catalyst life study. The last section of this report covers a separate topic: water injection to the LPMEOH{trademark} reactor and its effects on the LPMEOH{trademark} process. An investigation was made of whether water injection can enhance the reactor productivity and how this enhancement depends on the composition of the major syngas feed. A water injection condition that resulted …
Date: June 1, 2002
Creator: Peng, Xiang-Dong
Object Type: Report
System: The UNT Digital Library
Residential hot water distribution systems: Roundtablesession (open access)

Residential hot water distribution systems: Roundtablesession

Residential building practice currently ignores the lossesof energy and water caused by the poor design of hot water systems. Theselosses include: combustion and standby losses from water heaters, thewaste of water (and energy) while waiting for hot water to get to thepoint of use; the wasted heat as water cools down in the distributionsystem after a draw; heat losses from recirculation systems and thediscarded warmth of waste water as it runs down the drain. Severaltechnologies are available that save energy (and water) by reducing theselosses or by passively recovering heat from wastewater streams and othersources. Energy savings from some individual technologies are reported tobe as much as 30 percent. Savings calculations of prototype systemsincluding bundles of technologies have been reported above 50 percent.This roundtable session will describe the current practices, summarizethe results of past and ongoing studies, discuss ways to think about hotwater system efficiency, and point to areas of future study. We will alsorecommend further steps to reduce unnecessary losses from hot waterdistribution systems.
Date: August 1, 2002
Creator: Lutz, James D.; Klein, Gary; Springer, David & Howard, Bion D.
Object Type: Article
System: The UNT Digital Library
Quality Assurance Program Plan for TRUPACT-II Gas Generation Test Program (open access)

Quality Assurance Program Plan for TRUPACT-II Gas Generation Test Program

The Gas Generation Test Program (GGTP), referred to as the Program, is designed to establish the concentration of flammable gases and/or gas generation rates in a test category waste container intended for shipment in the Transuranic Package Transporter-II (TRUPACT-II). The phrase "gas generationtesting" shall refer to any activity that establishes the flammable gas concentration or the flammable gas generation rate. This includes, but is not limited to, measurements performed directly on waste containers or during tests performed on waste containers. This Quality Assurance Program Plan (QAPP) documents the quality assurance (QA) and quality control (QC) requirements that apply to the Program. The TRUPACT-II requirements and technical bases for allowable flammable gas concentration and gas generation rates are described in the TRUPACT-II Authorized Methods for Payload Control (TRAMPAC).
Date: March 1, 2002
Creator: Office, Carlsbad Field
Object Type: Report
System: The UNT Digital Library
Mechanism and Estimation of Fatigue Crack Initiation in Austenitic Stainless Steels in LWR Environments. (open access)

Mechanism and Estimation of Fatigue Crack Initiation in Austenitic Stainless Steels in LWR Environments.

The ASME Boiler and Pressure Vessel Code provides rules for the construction of nuclear power plant components. Figures I-9.1 through I-9.6 of Appendix I to Section III of the Code specify fatigue design curves for structural materials. However, the effects of light water reactor (LWR) coolant environments are not explicitly addressed by the Code design curves. Existing fatigue strain-vs.-life ({var_epsilon}-N) data illustrate potentially significant effects of LWR coolant environments on the fatigue resistance of pressure vessel and piping steels. This report provides an overview of fatigue crack initiation in austenitic stainless steels in LWR coolant environments. The existing fatigue {var_epsilon}-N data have been evaluated to establish the effects of key material, loading, and environmental parameters (such as steel type, strain range, strain rate, temperature, dissolved-oxygen level in water, and flow rate) on the fatigue lives of these steels. Statistical models are presented for estimating the fatigue {var_epsilon}-N curves for austenitic stainless steels as a function of the material, loading, and environmental parameters. Two methods for incorporating environmental effects into the ASME Code fatigue evaluations are presented. The influence of reactor environments on the mechanism of fatigue crack initiation in these steels is also discussed.
Date: August 1, 2002
Creator: Chopra, O. K. & Technology, Energy
Object Type: Report
System: The UNT Digital Library
Production of Succinic Acid for Lignocellulosic Hydrolysates (open access)

Production of Succinic Acid for Lignocellulosic Hydrolysates

The purpose of this Cooperative Research and Development Agreement (CRADA) is to add and test new metabolic activities to existing microbial catalysts for the production of succinic acid from renewables. In particular, they seek to add to the existing organism the ability to utilize xylose efficiently and simultaneously with glucose in mixtures of sugars or to add succinic acid production to another strain and to test the value of this new capability for production of succinic acid from industrial lignocellulosic hydrolyasates. The Contractors and Participant are hereinafter jointly referred to as the 'Parties'. Research to date in succinic acid fermentation, separation and genetic engineering has resulted in a potentially economical process based on the use of an Escherichia coli strain AFP111 with suitable characteristics for the production of succinic acid from glucose. Economic analysis has shown that higher value commodity chemicals can be economically produced from succinic acid based on repliminary laboratory findings and predicted catalytic parameters. The initial target markets include succinic acid itself, succinate salts, esters and other derivatives for use as deicers, solvents and acidulants. The other commodity products from the succinic acid platform include 1,4-butanediol, {gamma}-butyrolactone, 2-pyrrolidinone and N-methyl pyrrolidinone. Current economic analyses indicate that this …
Date: June 1, 2002
Creator: Davison, B.H. & Nghiem, J.
Object Type: Report
System: The UNT Digital Library
Hanford Site National Environmental Policy Act (NEPA) Characterization (open access)

Hanford Site National Environmental Policy Act (NEPA) Characterization

This document describes the U.S. Department of Energy's (DOE) Hanford Site environment. It is updated each year and is intended to provide a consistent description of the Hanford Site environment for the many National Environmental Policy Act (NEPA) documents being prepared by DOE contractors. No statements of significance or environmental consequences are provided. This year's report is the thirteenth revision of the original document published in 1988 and is (until replaced by the fourteenth revision) the only version that is relevant for use in the preparation of Hanford NEPA, State Environmental Policy Act (SEPA), and Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) documents. The two chapters included in this document (Chapters 4 and 6) are numbered to correspond to the chapters where such information is typically presented in environmental impact statements (Weiss) and other Hanford Site NEPA or CERCLA documentation. Chapter 4.0 (Affected Environment) describes Hanford Site climate and meteorology, geology, hydrology, ecology, cultural, archaeological, and historical resources, socioeconomics, occupational safety, and noise. Chapter 6.0 (Statutory and Regulatory Requirements) describes federal and state laws and regulations, DOE directives and permits, and presidential executive orders that are applicable to the NEPA documents prepared for Hanford Site activities.
Date: September 1, 2002
Creator: Neitzel, Duane A.; Bunn, Amoret L.; Duncan, Joanne P.; Eschbach, Tara O.; Fowler, Richard A.; Fritz, Brad G. et al.
Object Type: Report
System: The UNT Digital Library
Habitat Evaluation Procedures (HEP) Report; Sandy River Delta, Technical Report 2000-2002. (open access)

Habitat Evaluation Procedures (HEP) Report; Sandy River Delta, Technical Report 2000-2002.

Land managers are often challenged with the mandate to control exotic and invasive plant species. Reed canarygrass (Phalaris arundinacea) and Himalayan blackberry (Rubus discolor) are 2 such species that are currently threatening natural areas in western United States. Reed canarygrass may be native to the inland northwest (Antieau 2000), but it has invaded many wetland areas as dense, monoculture stands. Spread of this plant species is largely attributed to human disturbances, e.g., draining, farming (Antieau 2000). Reed canarygrass often dominates other emergent vegetation such as cattail (Typha spp.) and bulrush (Scirpus spp.) (Whitson et al. 1996, Apfelbaum and Sams 1987), and the resulting habitat is largely unsuitable for wetland birds. Himalayan blackberry was introduced to the United States as a garden shrub and was planted at wildlife-management areas for food and cover. It easily colonizes disturbed places, such as roadsides, ditches, and flood plains (Hoshovsky 2000). Once established, it forms a thick, impenetrable stand, which excludes native shrub species. Although Himalayan blackberry does provide food and cover for wildlife, particularly during fall and winter, it decreases habitat diversity, and therefore, may decrease wildlife diversity. Furthermore, patterns of avian nest predation may be altered in some exotic-shrub communities (Schmidt and Whelan …
Date: February 1, 2002
Creator: Rocklage, Ann & Ratti, John
Object Type: Report
System: The UNT Digital Library
A Study of Future Measurements of W Boson Helicity in t -> Wb at CDF (open access)

A Study of Future Measurements of W Boson Helicity in t -> Wb at CDF

The interactions of the top quark will soon be coming under greater scrutiny at CDF with Run II of the Fermilab Tevatron collider. This investigation gauges CDF's improved ability to measure the helicity of W bosons produced in top quark decays. Such measurements will provide a direct indication of the spin structure of the weak interaction responsible for the top decay process. Simulated CDF Run II data is used to study the W helicity sensitivity of the muon momentum in {mu} + jets events, as limited by both statistical and systematic uncertainties. Optimization of helicity measurements via appropriate choices of event variables and data criteria is also addressed.
Date: February 1, 2002
Creator: Tweedie, Brock
Object Type: Report
System: The UNT Digital Library
Visualizing and Tracking Evolving Features in 3D Unstructured and Adaptive Datasets (open access)

Visualizing and Tracking Evolving Features in 3D Unstructured and Adaptive Datasets

The massive amounts of time-varying datasets being generated demand new visualization and quantification techniques. Visualization alone is not sufficient. Without proper measurement information/computations real science cannot be done. Our focus is this work was to combine visualization with quantification of the data to allow for advanced querying and searching. As part of this proposal, we have developed a feature extraction adn tracking methodology which allows researcher to identify features of interest and follow their evolution over time. The implementation is distributed and operates over data In-situ: where it is stored and when it was computed.
Date: August 1, 2002
Creator: Silver, D. & Zabusky, N.
Object Type: Report
System: The UNT Digital Library
Studies in High Current Density Ion Sources for Heavy Ion FusionApplications (open access)

Studies in High Current Density Ion Sources for Heavy Ion FusionApplications

This dissertation develops diverse research on small (diameter {approx} few mm), high current density (J {approx} several tens of mA/cm{sup 2}) heavy ion sources. The research has been developed in the context of a programmatic interest within the Heavy Ion Fusion (HIF) Program to explore alternative architectures in the beam injection systems that use the merging of small, bright beams. An ion gun was designed and built for these experiments. Results of average current density yield (<J>) at different operating conditions are presented for K{sup +} and Cs{sup +} contact ionization sources and potassium aluminum silicate sources. Maximum <J> values for a K{sup +} beam of {approx}90 mA/cm{sup 2} were observed in 2.3 {micro}s pulses. Measurements of beam intensity profiles and emittances are included. Measurements of neutral particle desorption are presented at different operating conditions which lead to a better understanding of the underlying atomic diffusion processes that determine the lifetime of the emitter. Estimates of diffusion times consistent with measurements are presented, as well as estimates of maximum repetition rates achievable. Diverse studies performed on the composition and preparation of alkali aluminosilicate ion sources are also presented. In addition, this work includes preliminary work carried out exploring the viability …
Date: June 1, 2002
Creator: Chacon-Golcher, E.
Object Type: Thesis or Dissertation
System: The UNT Digital Library