Summary: Brazos River Authority, Texas; Water/Sewer (open access)

Summary: Brazos River Authority, Texas; Water/Sewer

Summary report profiling the credit rating for the Brasoz River Authority finances and investments, providing rationale, outlook, and related research for the new credit rating.
Date: July 21, 2009
Creator: Chapman, Theodore & Bryce, Russel
Object Type: Report
System: The Portal to Texas History
Special Report on Farm Loan Restructuring (open access)

Special Report on Farm Loan Restructuring

July report of the U.S. Congressional Oversight Panel describing their activities and findings regarding farm loan restructuring, including sections on agriculture markets, and farm credit markets.
Date: July 21, 2009
Creator: United States. Congressional Oversight Panel.
Object Type: Report
System: The UNT Digital Library
A Rule-Based Framework for Gene Regulation Pathways Discovery (open access)

A Rule-Based Framework for Gene Regulation Pathways Discovery

We present novel approach to discover the rules that govern gene regulation mechanisms. The method is based on supervised machine learning and is designed to reveal relationships between transcription factors and gene promoters. As the representation of the gene regulatory circuit we have chosen a special form of IF-THEN rules associating certain features (a generalized idea of a Transcription Factor Binding Site) in gene promoters with specific gene expression profiles.
Date: July 21, 2003
Creator: Wilczynski, B; Hvidsten, T; Kryshtafovych, A; Stubbs, L; Komorowski, J & Fidelis, K
Object Type: Article
System: The UNT Digital Library
Calibration of Regional Seismic Stations in the Middle East with Shots in Turkey (open access)

Calibration of Regional Seismic Stations in the Middle East with Shots in Turkey

The objective of this project is to calibrate regional travel-times and propagation characteristics of seismic waves in Turkey and surrounding areas in the Middle East in order to enhance detection and location capabilities in the region. Important data for the project will be obtained by large calibration shots in central and eastern Turkey. The first, a two-ton shot, was fired in boreholes near Keskin in central Anatolia on 23 November 2002. The explosives were placed in 14 holes, each 80 m deep, arranged in concentric circular arrays. Ninety temporary seismic stations were deployed within a 300 km radius around the shot. The permanent stations of the Turkish National Seismic Network provided a good azimuthal coverage as well as three radial traverses. Most stations within a radius of 200 km recorded the shot. Travel-time data have been analyzed to obtain a detailed crustal model under the shot and along the profiles. The model gives a 35 km thick crust, characterized by two layers with velocities of 5.0 and 6.4 km/s. The P{sub n} velocity was found to be 7.8 km/s. The crustal thickness decreases to the north where the profile crosses the North Anatolian fault. There is a slight increase in …
Date: July 21, 2003
Creator: Toksoz, M N; Kuleli, S; Gurbuz, C; Kalafat, D; Nekler, T; Zor, K et al.
Object Type: Article
System: The UNT Digital Library
Rapid Degradation of Alkanethiol-Based Self-Assembled Monolayers on Gold in Ambient Laboratory Conditions (open access)

Rapid Degradation of Alkanethiol-Based Self-Assembled Monolayers on Gold in Ambient Laboratory Conditions

Self-assembled monolayers (SAMs) consisting of alkanethiols and similar sulfur-containing molecules on noble metal substrates are extensively used and explored for various chemical and biological surface-functionalization in the scientific community. SAMs consisting of thiol- or disulfide-containing molecules adsorbed on gold are commonly used due to their ease of preparation and stability. However, the gold-thiolate bond is easily and rapidly oxidized under ambient conditions, adversely affecting SAM quality and structure. Here, the oxidation of dodecanethiol on gold is explored for various 12-hour exposures to ambient laboratory air and light. SAM samples are freshly prepared, air-exposed, and stored in small, capped vials. X-ray photoelectron spectroscopy (XPS) reveals nearly complete oxidation of the thiolate in air-exposed samples, and a decrease in carbon signal on the surface. Near-edge X-ray absorption fine structure spectroscopy (NEXAFS) at the Carbon K-edge shows a loss of upright orientational order upon air-exposure. Alternatively, the oxidation of the thiolate is minor when SAMs are stored in limited-air-containing small 15 ml vials. Thus, care must be taken to avoid SAM degradation by ensuring alkanethiolates on gold have sufficient durability for each intended environment and application.
Date: July 21, 2004
Creator: Willey, T M; Vance, A L; van Buuren, T; Bostedt, C; Terminello, L J & Fadley, C S
Object Type: Article
System: The UNT Digital Library
Excess Weapons Plutonium Disposition: Plutonium Packaging, Storage and Transportation and Waste Treatment, Storage and Disposal Activities (open access)

Excess Weapons Plutonium Disposition: Plutonium Packaging, Storage and Transportation and Waste Treatment, Storage and Disposal Activities

A fifth annual Excess Weapons Plutonium Disposition meeting organized by Lawrence Livermore National Laboratory (LLNL) was held February 16-18, 2004, at the State Education Center (SEC), 4 Aerodromnya Drive, St. Petersburg, Russia. The meeting discussed Excess Weapons Plutonium Disposition topics for which LLNL has the US Technical Lead Organization responsibilities. The technical areas discussed included Radioactive Waste Treatment, Storage, and Disposal, Plutonium Oxide and Plutonium Metal Packaging, Storage and Transportation and Spent Fuel Packaging, Storage and Transportation. The meeting was conducted with a conference format using technical presentations of papers with simultaneous translation into English and Russian. There were 46 Russian attendees from 14 different Russian organizations and six non-Russian attendees, four from the US and two from France. Forty technical presentations were made. The meeting agenda is given in Appendix B and the attendance list is in Appendix C.
Date: July 21, 2004
Creator: Jardine, L J & Borisov, G B
Object Type: Article
System: The UNT Digital Library
Quarkonium at Finite Temperature. (open access)

Quarkonium at Finite Temperature.

The author discusses quarkonium spectral functions at finite temperature reconstructed using the Maximum Entropy Method. The author shows in particular that the J/{psi} survives in the deconfined phase up to 1.5T{sub c}.
Date: July 21, 2003
Creator: Petreczky, P.
Object Type: Article
System: The UNT Digital Library
Engineering Annual Summary 2003 (open access)

Engineering Annual Summary 2003

None
Date: July 21, 2004
Creator: Patterson, S R
Object Type: Report
System: The UNT Digital Library
Polymer pendant crown thioethers for removal of mercury from acidic wastes: synthesis, characterization and application (open access)

Polymer pendant crown thioethers for removal of mercury from acidic wastes: synthesis, characterization and application

Removal of mercury ions from industrial waste streams is a difficult and expensive problem requiring an efficient and selective extractant that is resistant to corrosive conditions. We have now developed an acid-resistant thiacrown polymer that has potential utility as a selective and cost-effective Hg{sup 2+} extractant. Copolymerization of a novel C-substituted thiacrown, N,N-(4-vinylbenzylmethyl)-2-aminomethyl-1,4,8,11,14-pentathiacycloheptadecane, with DVB (80% divinylbenzene) using a radical initiator generated a highly cross-linked polymer containing pendant thiacrowns. Mercury extraction capabilities of the polymer were tested in acidic media (pH range: 1.5 to 6.2) and the extraction of Hg{sup 2+} was determined to be 95% at a mixing time of 30 minutes. The thiacrown polymer was also determined to be selective for Hg{sup 2+}, even in the presence of high concentrations of competing ions such as Pb{sup 2+}, Cd{sup 2+}, Al{sup 3}, and Fe{sup 3+}. The bound Hg{sup 2+} ions can then be stripped from the polymer, allowing the polymer to be reused without significant loss of loading capacity. The binding of Hg{sup 2+} to the polymer has been examined by X-ray photoemission spectroscopy. The thiacrown appears unaffected by incorporation into the polymer and the Hg{sup 2+} appears to be bound to the polymer complex in a similar manner …
Date: July 21, 2000
Creator: Reynolds, J G; Baumann, T F; Nelson, A J & Fox, G A
Object Type: Article
System: The UNT Digital Library
Analysis of the November 1999 Dead Sea Calibration Shots (open access)

Analysis of the November 1999 Dead Sea Calibration Shots

In November 1999 three chemical explosions were conducted in the Dead Sea for the purposes of calibrating the International Monitoring System (IMS) for the Comprehensive Nuclear-Test-Ban Treaty (CTBT). These shots were organized and conducted by the Geophysical Institute of Israel (GII). Large chemical explosions are the most valuable form of ground truth as the location, depth and origin time are very well known. We focus on the two largest shots (M{sub w} {ge} 3.6) and performed several types of analysis of the regional recordings and travel times of these shots. These data provide valuable new information about the region and offer an opportunity to test monitoring strategies. A crustal and uppermost mantle velocity model was inferred from the travel times of the regional phases: Pn, Pg and Sg. This effort utilized a grid search method to find suitable models of the structure. Results indicate that the crust is relatively thin (32 km) with lower than average crustal velocities (mean V{sub P} = 6.1-6.2 km/s). We located each shot treating the other shot as a calibration explosion. Locations were computed using both station static corrections and kriged correction surfaces. Results show that the locations with static corrections can be better or …
Date: July 21, 2000
Creator: Rodgers, A J; Myers, S; Mayeda, K & Walter, W
Object Type: Article
System: The UNT Digital Library
Virtual Proving Ground for Assessing Reliability and Uncertainty (open access)

Virtual Proving Ground for Assessing Reliability and Uncertainty

The process for accurately estimating product reliability early in the development process can be a difficult and costly task. Traditional methods like Reliability Prediction Models and Life Testing Strategies yield beneficial results when relative information is known about the product that is to be analyzed. When there is minimal information (e.g., prior failure rates, etc.), such as in new concept design, these above reliability methods have limitations. For these cases computer simulation technology has proven to yield valuable results. This paper will demonstrate analysis procedures for assessing the margin and reliability of product design in the early product development stage. This analysis process is composed of requirements definition, a mathematical model, model validation, parameter diagram, design of experiment (DOE), response surface, and optimization. The analysis process shows its impacts, in the following areas: reducing the product development cycle, reducing cost, increasing confidence, and estimating product reliability. This is particularly important early in the concept development process.
Date: July 21, 2004
Creator: Hsieh, H & Sam, D
Object Type: Article
System: The UNT Digital Library
Uranium Geochemistry in Vadose Zone and Aquifer Sediments from the 300 Area Uranium Plume (open access)

Uranium Geochemistry in Vadose Zone and Aquifer Sediments from the 300 Area Uranium Plume

This report documents research conducted by the RCS Project to update the record of decision for the 300-FF-5 Operable Unit on the Hanford Site.
Date: July 21, 2005
Creator: Zachara, John M.; Davis, Jim A.; Liu, Chongxuan; McKinley, James P.; Qafoku, Nik; Wellman, Dawn M. et al.
Object Type: Report
System: The UNT Digital Library
Synchrotron x-ray study of multilayers in Laue geometry (open access)

Synchrotron x-ray study of multilayers in Laue geometry

Zone plates with depth to zone-width ratios as large as 100 are needed for focusing of hard x-rays. Such high aspect ratios are challenging to produce by lithography. We are investigating the fabrication of high-aspect-ratio linear zone plates by multilayer deposition followed by sectioning. As an initial step in this work, we present a synchrotron x-ray study of constant-period multilayers diffracting in Laue (transmission) geometry. Data are presented from two samples: a 200 period W/Si multilayer with d-spacing of 29 nm, and a 2020 period Mo/Si multilayer with d-spacing of 7 nm. By cutting and polishing we have successfully produced thin cross sections with section depths ranging from 2 to 12 {micro}m. Transverse scattering profiles (rocking curves) across the Bragg reflection exhibit well-defined interference fringes originating from the depth of the sample, in agreement with dynamical diffraction theory for a multilayer in Laue geometry.
Date: July 21, 2004
Creator: Kang, H. C.; Stephenson, G. B.; Liu, C.; Conley, R.; Macrander, A. T.; Maser, J. et al.
Object Type: Article
System: The UNT Digital Library
Interim-Status RCRA Groundwater Monitoring Plan for the 216-A-10, 216-A-36B, and 216-A-37-1 PUREX Cribs (open access)

Interim-Status RCRA Groundwater Monitoring Plan for the 216-A-10, 216-A-36B, and 216-A-37-1 PUREX Cribs

This document presents a groundwater monitoring program for three Resource Conservation and Recovery Act of 1976 (RCRA) waste management units at the Hanford Site combined under one groundwater quality assessment program. The units are the 216 A 10, 216 A 36B, and 216 A-37-1 cribs (the RCRA PUREX cribs). The three cribs have been grouped together based on their proximity to one another, similar construction and waste history, and similar hydrogeologic regime. The RCRA PUREX cribs are located in the 200 East Area of the Hanford Site. This document replaces the previous RCRA monitoring plan (Lindberg 1997-PNNL-11523, Rev.0) for these cribs.
Date: July 21, 2005
Creator: Lindberg, Jon W. & Elmore, Rebecca P.
Object Type: Report
System: The UNT Digital Library
LLNL Operation/Building Screening Report for Initial Hazard Classification Building 518/518A (open access)

LLNL Operation/Building Screening Report for Initial Hazard Classification Building 518/518A

None
Date: July 21, 2000
Creator: Mathews, C. E.
Object Type: Report
System: The UNT Digital Library
Transport Methods Conquering the Seven-Dimensional Mountain (open access)

Transport Methods Conquering the Seven-Dimensional Mountain

In a wide variety of applications, a significant fraction of the momentum and energy present in a physical problem is carried by the transport of particles. Depending on the circumstances, the types of particles might involve some or all of photons, neutrinos, charged particles, or neutrons. In application areas that use transport, the computational time is usually dominated by the transport calculation. Therefore, there is a potential for great synergy; progress in transport algorithms could help quicken the time to solution for many applications. The complexity, and hence expense, involved in solving the transport problem can be understood by realizing that the general solution to the Boltzmann transport equation is seven dimensional: 3 spatial coordinates, 2 angles, 1 time, and 1 for speed or energy. Low-order approximations to the transport equation are frequently used due in part to physical justification but many times simply because a solution to the full transport problem is too computationally expensive. An example is the diffusion equation, which effectively drops the two angles in phase space by assuming that a linear representation in angle is adequate. Another approximation is the grey approximation, which drops the energy variable by averaging over it. If the grey approximation …
Date: July 21, 2003
Creator: Graziani, Frank R. & Olson, Gordon L.
Object Type: Article
System: The UNT Digital Library
Estimate of external background radiation interference on a tomography scanner (open access)

Estimate of external background radiation interference on a tomography scanner

We have estimated interference from external background radiation for a computed tomography (CT) scanner. Our intention is to estimate the interference that would be expected for the high-resolution SkyScan 1072 desk-top x-ray microtomography system. The SkyScan system uses a Microfocus x-ray source capable of a 10-{micro}m focal spot at a maximum current of 0.1 mA and a maximum energy of 130 kVp. All predictions made in this report assume using the x-ray source at the smallest spot size, maximum energy, and operating at the maximum current. Some of the systems basic geometry that is used for these estimates are: (1) Source-to-detector distance: 250 mm, (2) Minimum object-to-detector distance: 40 mm, and (3) Maximum object-to-detector distance: 230 mm. This is a first-order, rough estimate of the quantity of interference expected at the system detector caused by background radiation. The amount of interference is expressed by using the ratio of exposure expected at the detector of the CT system. The exposure values for the SkyScan system are determined by scaling the measured values of an x-ray source and the background radiation adjusting for the difference in source-to-detector distance and current. The x-ray source that was used for these measurements was not the …
Date: July 21, 2000
Creator: Roberson, G P & Logan, C M
Object Type: Report
System: The UNT Digital Library
Lessons Learned in Risk Management on NCSX (open access)

Lessons Learned in Risk Management on NCSX

The National Compact Stellarator Experiment (NCSX) was designed to test physics principles of an innovative stellarator design developed by the Princeton Plasma Physics Laboratory and Oak Ridge National Laboratory. Construction of some of the major components and sub-assemblies was completed, but the estimated cost and schedule for completing the project grew as the technical requirements and risks became better understood, leading to its cancellation in 2008. The project's risks stemmed from its technical challenges, primarily the complex component geometries and tight tolerances that were required. The initial baseline, established in 2004, was supported by a risk management plan and risk-based contingencies, both of which proved to be inadequate. Technical successes were achieved in the construction of challenging components and subassemblies, but cost and schedule growth was experienced. As part of an effort to improve project performance, a new risk management program was devised and implemented in 2007-08. It led to a better understanding of project risks, a sounder basis for contingency estimates, and improved management tools. Although the risks ultimately were unacceptable to the sponsor, valuable lessons in risk management were learned through the experiences with the NCSX project.
Date: July 21, 2009
Creator: G.H. Neilson, C.O. Gruber, J.H. Harris, D.J. Rej, R.T. Simmons, and R.L. Strykowsky
Object Type: Article
System: The UNT Digital Library
7th International Workshop on Microbeam Probes of Cellular Radiation Response (open access)

7th International Workshop on Microbeam Probes of Cellular Radiation Response

The extended abstracts that follow present a summary of the Proceedings of the 7th International Workshop: Microbeam Probes of Cellular Radiation Response, held at Columbia University’s Kellogg Center in New York City on March 15–17, 2006. These International Workshops on Microbeam Probes of Cellular Radiation Response have been held regularly since 1993 (1–5). Since the first workshop, there has been a rapid growth (see Fig. 1) in the number of centers developing microbeams for radiobiological research, and worldwide there are currently about 30 microbeams in operation or under development. Single-cell/single-particle microbeam systems can deliver beams of different ionizing radiations with a spatial resolution of a few micrometers down to a few tenths of a micrometer. Microbeams can be used to addressquestions relating to the effects of low doses of radiation (a single radiation track traversing a cell or group of cells), to probe subcellular targets (e.g. nucleus or cytoplasm), and to address questions regarding the propagation of information about DNA damage (for example, the radiation-induced bystander effect). Much of the recent research using microbeams has been to study low-dose effects and ‘‘non-targeted’’ responses such as bystander effects, genomic instability and adaptive responses. This Workshop provided a forum to assess the …
Date: July 21, 2009
Creator: Brenner, David J.
Object Type: Report
System: The UNT Digital Library
Recent Fast Wave Coupling and Heating Studies on NSTX, with Possible Implications for ITER (open access)

Recent Fast Wave Coupling and Heating Studies on NSTX, with Possible Implications for ITER

The goal of the high harmonic fast wave (HHFW) research on NSTX is to maximize the coupling of RF power to the core of the plasma by minimizing the coupling of RF power to edge loss processes. HHFW core plasma heating efficiency in helium and deuterium L-mode discharges is found to improve markedly on NSTX when the density 2 cm in front of the antenna is reduced below that for the onset of perpendicular wave propagation (nonset ∝ B*k|| 2/ω). In NSTX, the observed RF power losses in the plasma edge are driven in the vicinity of the antenna as opposed to resulting from multi-pass edge damping. PDI surface losses through ion-electron collisions are estimated to be significant. Recent spectroscopic measurements suggest that additional PDI losses could be caused by the loss of energetic edge ions on direct loss orbits and perhaps result in the observed clamping of the edge rotation. Initial deuterium H-mode heating studies reveal that core heating is degraded at lower kφ (- 8 m-1 relative to 13 m-1) as for the Lmode case at elevated edge density. Fast visible camera images clearly indicate that a major edge loss process is occurring from the plasma scrape off …
Date: July 21, 2009
Creator: J.C. Hosea, R.E. Bell, E. Feibush, R.W. Harvey, E.F. Jaeger, B.P LeBlanc, R. Maingi, C.K. Phillips, L. Roquemore, P.M. Ryan, G. Taylor, K. Tritz, E.J. Valeo, J. Wilgen, J.R. Wilson, and the NSTX Team
Object Type: Article
System: The UNT Digital Library
Beam Energy and System Size Dependence of Dynamical Net Charge Fluctuations (open access)

Beam Energy and System Size Dependence of Dynamical Net Charge Fluctuations

We present measurements of net charge fluctuations in Au + Au collisions at {radical}s{sub NN} = 19.6, 62.4, 130, and 200 GeV, Cu + Cu collisions at {radical}s{sub NN} = 62.4, 200 GeV, and p + p collisions at {radical}s = 200 GeV using the dynamical net charge fluctuations measure {nu}{sub {+-},dyn}. We observe that the dynamical fluctuations are non-zero at all energies and exhibit a modest dependence on beam energy. A weak system size dependence is also observed. We examine the collision centrality dependence of the net charge fluctuations and find that dynamical net charge fluctuations violate 1/N{sub ch} scaling, but display approximate 1/N{sub part} scaling. We also study the azimuthal and rapidity dependence of the net charge correlation strength and observe strong dependence on the azimuthal angular range and pseudorapidity widths integrated to measure the correlation.
Date: July 21, 2008
Creator: STAR Collaboration
Object Type: Article
System: The UNT Digital Library
Lessons Learned in Risk Management on NCSX (open access)

Lessons Learned in Risk Management on NCSX

The National Compact Stellarator Experiment (NCSX) was designed to test physics principles of an innovative stellarator design developed by the Princeton Plasma Physics Laboratory and Oak Ridge National Laboratory. Construction of some of the major components and sub-assemblies was completed, but the estimated cost and schedule for completing the project grew as the technical requirements and risks became better understood, leading to its cancellation in 2008. The project's risks stemmed from its technical challenges, primarily the complex component geometries and tight tolerances that were required. The initial baseline, established in 2004, was supported by a risk management plan and risk-based contingencies, both of which proved to be inadequate. Technical successes were achieved in the construction of challenging components and subassemblies, but cost and schedule growth was experienced. As part of an effort to improve project performance, a new risk management program was devised and implemented in 2007-08. It led to a better understanding of project risks, a sounder basis for contingency estimates, and improved management tools. Although the risks ultimately were unacceptable to the sponsor, valuable lessons in risk management were learned through the experiences with the NCSX project.
Date: July 21, 2009
Creator: G.H. Neilson, C.O. Gruber, J.H. Harris, D.J. Rej, R.T. Simmons, and R.L. Strykowsky
Object Type: Report
System: The UNT Digital Library
Pawnee Nation Energy Option Analyses (open access)

Pawnee Nation Energy Option Analyses

Pawnee Nation of Oklahoma Energy Option Analyses In 2003, the Pawnee Nation leadership identified the need for the tribe to comprehensively address its energy issues. During a strategic energy planning workshop a general framework was laid out and the Pawnee Nation Energy Task Force was created to work toward further development of the tribe’s energy vision. The overarching goals of the “first steps” project were to identify the most appropriate focus for its strategic energy initiatives going forward, and to provide information necessary to take the next steps in pursuit of the “best fit” energy options. Description of Activities Performed The research team reviewed existing data pertaining to the availability of biomass (focusing on woody biomass, agricultural biomass/bio-energy crops, and methane capture), solar, wind and hydropower resources on the Pawnee-owned lands. Using these data, combined with assumptions about costs and revenue streams, the research team performed preliminary feasibility assessments for each resource category. The research team also reviewed available funding resources and made recommendations to Pawnee Nation highlighting those resources with the greatest potential for financially-viable development, both in the near-term and over a longer time horizon. Findings and Recommendations Due to a lack of financial incentives for renewable energy, …
Date: July 21, 2009
Creator: Matlock, M.; Kersey, K. & Riding In, C.
Object Type: Report
System: The UNT Digital Library
Travel for the 2004 American Statistical Association Biannual Radiation Meeting: "Radiation in Realistic Environments: Interactions Between Radiation and Other Factors (open access)

Travel for the 2004 American Statistical Association Biannual Radiation Meeting: "Radiation in Realistic Environments: Interactions Between Radiation and Other Factors

The 16th ASA Conference on Radiation and Health, held June 27-30, 2004 in Beaver Creek, CO, offered a unique forum for discussing research related to the effects of radiation exposures on human health in a multidisciplinary setting. The Conference furnishes investigators in health related disciplines the opportunity to learn about new quantitative approaches to their problems and furnishes statisticians the opportunity to learn about new applications for their discipline. The Conference was attended by about 60 scientists including statisticians, epidemiologists, biologists and physicists interested in radiation research. For the first time, ten recipients of Young Investigator Awards participated in the conference. The Conference began with a debate on the question: “Do radiation doses below 1 cGy increase cancer risks?” The keynote speaker was Dr. Martin Lavin, who gave a banquet presentation on the timely topic “How important is ATM?” The focus of the 2004 Conference on Radiation and Health was Radiation in Realistic Environments: Interactions Between Radiation and Other Risk Modifiers. The sessions of the conference included: Radiation, Smoking, and Lung Cancer Interactions of Radiation with Genetic Factors: ATM Radiation, Genetics, and Epigenetics Radiotherapeutic Interactions The Conference on Radiation and Health is held bi-annually, and participants are looking forward to …
Date: July 21, 2009
Creator: Brenner, David J.
Object Type: Report
System: The UNT Digital Library