States

Developing Next Generation Natural Fracture Detection and Prediction Technology (open access)

Developing Next Generation Natural Fracture Detection and Prediction Technology

The purpose of the ''Next Generation'' project was to develop technology that will provide a quantitative description of natural fracture properties and locations in low-permeability reservoirs. The development of this technology has consistently been ranked as one of the highest priority needs by industry. Numerous researchers and resource assessment groups have stated that the ability to identify area where intense clusters of natural fractures co-exist with gas-charged sands, the so called ''sweet spots'', will be the key to unlocking the vast quantities of gas in-place contained in these low-permeability gas basins. To meet this technology need, the ''Next Generation'' project was undertaken with three performance criteria in mind: (1) provide an integrated assessment of the burial and tectonic stresses in a basin responsible for natural fracture genesis (using seismic data, a significantly modified application of geomechanics, and a discrete natural fracture generation model); (2) link the assessment of natural fracture properties and locations to the reservoir's fluid, storage and flow properties; and, (3) provide a reservoir simulation-based calculation of the gas (and water) production capacity of a naturally fractured reservoir system. Phase III of the ''Next Generation'' project entailed the performance of a field demonstration of the software in an …
Date: May 1, 2005
Creator: Billingsley, R.L.
Object Type: Report
System: The UNT Digital Library
A texture-based frameowrk for improving CFD data visualization in a virtual environment (open access)

A texture-based frameowrk for improving CFD data visualization in a virtual environment

In the field of computational fluid dynamics (CFD) accurate representations of fluid phenomena can be simulated but require large amounts of data to represent the flow domain. Most datasets generated from a CFD simulation can be coarse, {approx} 10,000 nodes or cells, or very fine with node counts on the order of 1,000,000. A typical dataset solution can also contain multiple solutions for each node, pertaining to various properties of the flow at a particular node. Scalar properties such as density, temperature, pressure, and velocity magnitude are properties that are typically calculated and stored in a dataset solution. Solutions are not limited to just scalar properties. Vector quantities, such as velocity, are also often calculated and stored for a CFD simulation. Accessing all of this data efficiently during runtime is a key problem for visualization in an interactive application. Understanding simulation solutions requires a post-processing tool to convert the data into something more meaningful. Ideally, the application would present an interactive visual representation of the numerical data for any dataset that was simulated while maintaining the accuracy of the calculated solution. Most CFD applications currently sacrifice interactivity for accuracy, yielding highly detailed flow descriptions but limiting interaction for investigating the …
Date: May 1, 2005
Creator: Biveins, Gerrick O'Ron
Object Type: Thesis or Dissertation
System: The UNT Digital Library
A texture-based framework for improving CFD data visualization in a virtual environment (open access)

A texture-based framework for improving CFD data visualization in a virtual environment

In the field of computational fluid dynamics (CFD) accurate representations of fluid phenomena can be simulated hut require large amounts of data to represent the flow domain. Most datasets generated from a CFD simulation can be coarse, {approx}10,000 nodes or cells, or very fine with node counts on the order of 1,000,000. A typical dataset solution can also contain multiple solutions for each node, pertaining to various properties of the flow at a particular node. Scalar properties such as density, temperature, pressure, and velocity magnitude are properties that are typically calculated and stored in a dataset solution. Solutions are not limited to just scalar properties. Vector quantities, such as velocity, are also often calculated and stored for a CFD simulation. Accessing all of this data efficiently during runtime is a key problem for visualization in an interactive application. Understanding simulation solutions requires a post-processing tool to convert the data into something more meaningful. Ideally, the application would present an interactive visual representation of the numerical data for any dataset that was simulated while maintaining the accuracy of the calculated solution. Most CFD applications currently sacrifice interactivity for accuracy, yielding highly detailed flow descriptions hut limiting interaction for investigating the field.
Date: May 5, 2005
Creator: Bivins, Gerrick O'Ron
Object Type: Thesis or Dissertation
System: The UNT Digital Library
A Precision Measurement of the Top Quark Mass (open access)

A Precision Measurement of the Top Quark Mass

This dissertation describes the measurement of the top quark mass using events recorded during a {approx} 230 pb{sup -1} exposure of the D0 detector to proton-anti-proton (p{bar p}) collisions at a center of mass energy of 1.96 TeV. The Standard Model of particle physics predicts that the top quark will decay into a bottom quark and a W boson close to 100% of the time. The bottom quark will hadronize (bind with another quark) and produce a jet of hadronic particles. The W bosons can decay either into a charged lepton and a neutrino or a pair of quarks. this dissertation focuses on the top quark (t{bar t}) events in which one W decays hadronically and the other decays leptonically. Two methods of identifying t{bar t} events from the large number of events produced are used. The first is based on the unique topology of the final state particles of a heavy particle. By using the topological information of the event, the t{bar t} events can be efficiently extracted from the background. The second method relies on the identification of the remnants of the long lived bottom quarks that are expected to be produced in the decay of almost every …
Date: May 1, 2005
Creator: Black, Kevin Matthew & U., /Boston
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Reduced Form of Detailed Modeling of Wind Transmission and Intermittency for Use in Other Models (open access)

Reduced Form of Detailed Modeling of Wind Transmission and Intermittency for Use in Other Models

This paper, to accompany the corresponding poster, presents reduced-form outputs from the Wind Deployment Systems Model (WinDS) that can be implemented in other models with less- detailed wind power modeling capabilities. Other models will be able to use the reduced-form results to improve the accuracy of the wind power portion of their models. WinDS is a multiregional, multitime-period, Geographic Information System (GIS) and linear programming model of capacity expansion in the electric sector of the United States. WinDS is designed to address the market issues related to the penetration of wind power into the electric sector. These principal market issues include the geographic dependency of the resource, access to and cost of transmission, and the intermittency of wind power.
Date: May 1, 2005
Creator: Blair, N.; Short, W. & Heimiller, D.
Object Type: Article
System: The UNT Digital Library
Stochastic Cooling for Bunched Beams. (open access)

Stochastic Cooling for Bunched Beams.

Problems associated with bunched beam stochastic cooling are reviewed. A longitudinal stochastic cooling system for RHIC is under construction and has been partially commissioned. The state of the system and future plans are discussed.
Date: May 16, 2005
Creator: Blaskiewicz, M.
Object Type: Article
System: The UNT Digital Library
A Model Study of Transverse Mode Coupling Instability at National Synchrotron Light Source-II (Nsls-II). (open access)

A Model Study of Transverse Mode Coupling Instability at National Synchrotron Light Source-II (Nsls-II).

The vertical impedances of the preliminary designs of National Synchrotron Light Source II (NSLS-II) Mini Gap Undulators (MGU) are calculated by means of GdfidL code. The Transverse Mode Coupling Instability (TMCI) thresholds corresponding to these impedances are estimated using an analytically solvable model.
Date: May 15, 2005
Creator: Blednykh, A. & Wang, J. M.
Object Type: Article
System: The UNT Digital Library
Harmonic Cavity Performance for NSLS-II (open access)

Harmonic Cavity Performance for NSLS-II

NSLS-II is a 3 GeV ultra-high brightness storage ring planned to succeed the present NSLS rings at BNL. Ultralow emittance combined with short bunch length means that it is critical to minimize the effects of Touschek scattering and coherent instabilities. Improved lifetime and stability can be achieved by including a third-harmonic RF cavity in the baseline design. This paper describes the required harmonic RF parameters and the expected system performance.
Date: May 15, 2005
Creator: Blednykh, A.; Krinsky, S.; Podobedov, B.; Rose, J.; Towne, N. & Wang, J. M.
Object Type: Article
System: The UNT Digital Library
Reshimming of Tevatron dipoles: A Process-quality and lessons-learned perspective (open access)

Reshimming of Tevatron dipoles: A Process-quality and lessons-learned perspective

Over the last two years corrections have been made for the skew quadrupole moment in 530 of the 774 installed dipoles in the Tevatron. This process of modifying the magnets in situ has inherent risk of degrading the performance of the superconducting accelerator. In order to manage the risk, as well as to ensure the corrections were done consistently, formal quality tools were used to plan and verify the work. The quality tools used to define the process and for quality control are discussed, along with highlights of lessons learned.
Date: May 1, 2005
Creator: Blowers, J. N.; Carson, J. A.; Hanft, R. W.; Harding, D. J. & Robotham, R. W.
Object Type: Article
System: The UNT Digital Library
FIONDA (Filtering Images of Niobium Disks Application): Filter application for Eddy Current Scanner data analysis (open access)

FIONDA (Filtering Images of Niobium Disks Application): Filter application for Eddy Current Scanner data analysis

As part of the material QC process, each Niobium disk from which a superconducting RF cavity is built must undergo an eddy current scan [1]. This process allows to discover embedded defects in the material that are not visible to the naked eye because too small or under the surface. Moreover, during the production process of SC cavities the outer layer of Nb is removed via chemical or electro-chemical etching, thus it is important to evaluate the quality of the subsurface layer (in the order of 100nm) where superconductivity will happen. The reference eddy current scanning machine is operated at DESY; at Fermilab we are using the SNS eddy current scanner on loan, courtesy of SNS. In the past year, several upgrades were implemented aiming at raising the SNS machine performance to that of the DESY reference machine [2]. As part of this effort an algorithm that enables the filtering of the results of the scans and thus improves the resolution of the process was developed. The description of the algorithm and of the software used to filter the scan results is presented in this note.
Date: May 1, 2005
Creator: Boffo, C. & Bauer, P.
Object Type: Report
System: The UNT Digital Library
Neutron Source Strength Estimates from (a, n) Reactions in Binary Mixtures of Actinide Particles and Light Element Particles (open access)

Neutron Source Strength Estimates from (a, n) Reactions in Binary Mixtures of Actinide Particles and Light Element Particles

The cumulative distribution of package dose rates, based on the 18 batches of historical PuO{sub 2} particle size distributions, is shown in Fig. 6 for ''Hanford 10-13% Pu-240'' plutonium. The calculated dose rates for all batches range from about 50 mrem/h to about 2,200 mrem/h, with over 50% of the batches being less than the 200 mrem/h limit for public transportation. A more refined analysis would show that almost all of the batches would be less than 200 mrem/h, but some could exceed this limit as seen by the distribution shape. Without detailed characterization of the BeO particle size distribution, additional analysis would not remove the uncertainty in these calculations. Because the actual amount of beryllium contamination is likely to be much less than 500 g, the dose rates would be expected to be much lower than those shown here. Based on the particle size distribution analysis of the 18 batches analyzed, it is also likely that most of the 3013 cans to be loaded in the 9975 Package will have dose rates that are less than the 200 mrem/h limit for the package surface. However, extra care will be required in performing, and verifying, the dose rate measurements at …
Date: May 6, 2005
Creator: Boles, J. L.; Hafner, R. S. & Fischer, L. E.
Object Type: Article
System: The UNT Digital Library
Neutronics Assessments for a RIA Fragmentation Line Beam Dump Concept (open access)

Neutronics Assessments for a RIA Fragmentation Line Beam Dump Concept

Heavy ion and radiation transport calculations are in progress for conceptual beam dump designs for the fragmentation line of the proposed Rare Isotope Accelerator (RIA). Using the computer code PHITS, a preliminary design of a motor-driven rotating wheel beam dump and adjacent downstream multipole has been modeled. Selected results of these calculations are given, including neutron and proton flux in the wheel, absorbed dose and displacements per atom in the hub materials, and heating from prompt radiation and from decay heat in the multipole.
Date: May 13, 2005
Creator: Boles, J. L.; Reyes, S.; Ahle, L. E. & Stein, W.
Object Type: Article
System: The UNT Digital Library
A Comparative Analysis of Community Wind Power DevelopmentModels (open access)

A Comparative Analysis of Community Wind Power DevelopmentModels

For years, farmers in the United States have looked with envy on their European counterparts ability to profitably farm the wind through ownership of distributed, utility-scale wind projects. Only within the past few years, however, has farmer- or community-owned windpower development become a reality in the United States. The primary hurdle to this type of development in the United States has been devising and implementing suitable business and legal structures that enable such projects to take advantage of tax-based federal incentives for windpower. This article discusses the limitations of such incentives in supporting farmer- or community-owned wind projects, describes four ownership structures that potentially overcome such limitations, and finally conducts comparative financial analysis on those four structures, using as an example a hypothetical 1.5 MW farmer-owned project located in the state of Oregon. We find that material differences in the competitiveness of each structure do exist, but that choosing the best structure for a given project will largely depend on the conditions at hand; e.g., the ability of the farmer(s) to utilize tax credits, preference for individual versus cooperative ownership, and the state and utility service territory in which the project will be located.
Date: May 20, 2005
Creator: Bolinger, Mark; Wiser, Ryan; Wind, Tom; Juhl, Dan; Grace, Robert & West, Peter
Object Type: Article
System: The UNT Digital Library
SDA-based diagnostic and analysis tools for Collider Run II (open access)

SDA-based diagnostic and analysis tools for Collider Run II

Operating and improving the understanding of the Fermilab Accelerator Complex for the colliding beam experiments requires advanced software methods and tools. The Shot Data Analysis (SDA) has been developed to fulfill this need. Data from the Fermilab Accelerator Complex 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. These tables (the Supertable, the Recomputed Emittances, the Recomputed Intensities and other tables) are discussed here.
Date: May 1, 2005
Creator: Bolshakov, T. B.; Lebrun, P.; Panacek, S.; Papadimitriou, V.; Slaughter, J. & Xiao, A.
Object Type: Article
System: The UNT Digital Library

Why Evolutionary Biology and Genome Sciences Need Each Other

None
Date: May 5, 2005
Creator: Boore, Jeffrey
Object Type: Presentation
System: The UNT Digital Library
Breaking Barriers to Low-Cost Modular Inverter Production & Use (open access)

Breaking Barriers to Low-Cost Modular Inverter Production & Use

The goal of this cost share contract is to advance key technologies to reduce size, weight and cost while enhancing performance and reliability of Modular Inverter Product for Distributed Energy Resources (DER). Efforts address technology development to meet technical needs of DER market protection, isolation, reliability, and quality. Program activities build on SatCon Technology Corporation inverter experience (e.g., AIPM, Starsine, PowerGate) for Photovoltaic, Fuel Cell, Energy Storage applications. Efforts focused four technical areas, Capacitors, Cooling, Voltage Sensing and Control of Parallel Inverters. Capacitor efforts developed a hybrid capacitor approach for conditioning SatCon's AIPM unit supply voltages by incorporating several types and sizes to store energy and filter at high, medium and low frequencies while minimizing parasitics (ESR and ESL). Cooling efforts converted the liquid cooled AIPM module to an air-cooled unit using augmented fin, impingement flow cooling. Voltage sensing efforts successfully modified the existing AIPM sensor board to allow several, application dependent configurations and enabling voltage sensor galvanic isolation. Parallel inverter control efforts realized a reliable technique to control individual inverters, connected in a parallel configuration, without a communication link. Individual inverter currents, AC and DC, were balanced in the paralleled modules by introducing a delay to the individual PWM …
Date: May 31, 2005
Creator: Borowy, Bogdan; Casey, Leo; Foshage, Jerry; Nichols, Steve & Perkinson, Jim
Object Type: Report
System: The UNT Digital Library
Improved Wind and Turbulence Measurements Using a Low-Cost 3-D Sonic Anemometer at a Low-Wind Site (open access)

Improved Wind and Turbulence Measurements Using a Low-Cost 3-D Sonic Anemometer at a Low-Wind Site

None
Date: May 10, 2005
Creator: Bowen, B M
Object Type: Article
System: The UNT Digital Library
Measurement of differential cross sections and Cx and Cz for gamma photon-proton going to kaon-lambda baryon and gamma photon-proton going to kaon-sigma baryon using CLAS at Jefferson Lab (open access)

Measurement of differential cross sections and Cx and Cz for gamma photon-proton going to kaon-lambda baryon and gamma photon-proton going to kaon-sigma baryon using CLAS at Jefferson Lab

This work presents several observables for the reactions γ<italic> p</italic> → <italic>K</italic><super>+</super>Λ and γ<italic> p</italic> → <italic>K</italic><super>+</super>Σ°. In addition to measuring differential cross sections, we have made first measurements of the double polarization observables <italic>C<sub>x</sub></italic> and <italic> C<sub>z</sub></italic>. <italic>C<sub>x</sub></italic> and <italic>C<sub> z</sub></italic> characterize the transfer of polarization from the incident photon to the produced hyperons. Data were obtained at Jefferson Lab using a circularly polarized photon beam at endpoint energies of 2.4, 2.9, and 3.1 GeV. Events were detected with the CLAS spectrometer. In the Λ channel, the cross sections support the recent observation of new resonant structure at <italic>W</italic> = 1900 MeV. Studies of the invariant cross section, <math> <f> <fr><nu>d<g>s</g></nu><de>dd</de></fr></f> </math> show scaling behavior suggesting that the production mechanism becomes <italic> t</italic>-channel dominated near threshold at forward kaon angles. The double polarization observables show that the recoiling Λ is almost maximally polarized along the direction of the incident photon from mid to forward kaon angles. While Σ<super>o</super> differential cross sections are of the same magnitude as the Λ differential cross sections, there is evidence of different physics dominating the production mechanism. The Σ° invariant cross sections do not show the same <italic>t</italic>-scaling behavior present in the Λ results. …
Date: May 11, 2005
Creator: Bradford, Robert
Object Type: Thesis or Dissertation
System: The UNT Digital Library
NGNP Graphite Testing and Qualification Specimen Selection Strategy (open access)

NGNP Graphite Testing and Qualification Specimen Selection Strategy

The available grades of graphite for the NGNP are reviewed. A selection matrix is presented outlining the available grades for the NGNP graphite irradiation program based upon input from potential NGNP vendors, graphite manufactures, and graphite experts.
Date: May 1, 2005
Creator: Bratton, Robert
Object Type: Report
System: The UNT Digital Library
I. Excluded Volume Effects in Ising Cluster Distributions and Nuclear Multifragmentation II. Multiple-Chance Effects in Alpha-Particle Evaporation (open access)

I. Excluded Volume Effects in Ising Cluster Distributions and Nuclear Multifragmentation II. Multiple-Chance Effects in Alpha-Particle Evaporation

In Part 1, geometric clusters of the Ising model are studied as possible model clusters for nuclear multifragmentation. These clusters may not be considered as non-interacting (ideal gas) due to excluded volume effect which predominantly is the artifact of the cluster's finite size. Interaction significantly complicates the use of clusters in the analysis of thermodynamic systems. Stillinger's theory is used as a basis for the analysis, which within the RFL (Reiss, Frisch, Lebowitz) fluid-of-spheres approximation produces a prediction for cluster concentrations well obeyed by geometric clusters of the Ising model. If thermodynamic condition of phase coexistence is met, these concentrations can be incorporated into a differential equation procedure of moderate complexity to elucidate the liquid-vapor phase diagram of the system with cluster interaction included. The drawback of increased complexity is outweighted by the reward of greater accuracy of the phase diagram, as it is demonstrated by the Ising model. A novel nuclear-cluster analysis procedure is developed by modifying Fisher's model to contain cluster interaction and employing the differential equation procedure to obtain thermodynamic variables. With this procedure applied to geometric clusters, the guidelines are developed to look for excluded volume effect in nuclear multifragmentation. In part 2, an explanation is …
Date: May 16, 2005
Creator: Breus, Dimitry E.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Helical Pulse Line Structures for Ion Acceleration (open access)

Helical Pulse Line Structures for Ion Acceleration

The basic concept of the ''Pulse Line Ion Accelerator'' is presented, where pulse power sources create a ramped traveling wave voltage pulse on a helical pulse line. Ions can surf on this traveling wave and achieve energy gains much larger than the peak applied voltage. Tapered and untapered lines are compared, and a transformer coupling technique for launching the wave is described.
Date: May 1, 2005
Creator: Briggs, R. J.; Reginato, L. L. & Waldron, W. L.
Object Type: Article
System: The UNT Digital Library
Technical Support Document for Version 2.4, Release 1 of the COMcheck-EZ Software (open access)

Technical Support Document for Version 2.4, Release 1 of the COMcheck-EZ Software

COMcheck EZ provides an optional way to demonstrate compliance with commercial and high-rise residential building energy codes. Commercial buildings include all use groups except single family and multifamily not over three stories in height. COMcheck EZ was originally based on ANSI/ASHRAE/IES Standard 90.1-1989 (Standard 90.1-1989) requirements and is intended for use with various codes based on Standard 90.1, including the Codification of ASHRAE/IES Standard 90.1-1989 (90.1-1989 Code) (ASHRAE 1989a, 1993b) and ASHRAE/IESNA Standard 90.1-1999 (Standard 90.1-1999).
Date: May 1, 2005
Creator: Briggs, Robert S.; Conover, David R.; Connell, Linda M.; Gowri, Krishnan; Halverson, Mark A.; Johnson, Jeffrey A. et al.
Object Type: Report
System: The UNT Digital Library
RHIZOSPHERE MICROBIOLOGY OF CHLORINATED ETHENE CONTAMINATED SOILS: EFFECTS ON PHOSPHOLIPID FATTY ACID CONTENT (open access)

RHIZOSPHERE MICROBIOLOGY OF CHLORINATED ETHENE CONTAMINATED SOILS: EFFECTS ON PHOSPHOLIPID FATTY ACID CONTENT

Microbial degradation of chlorinated ethenes (CE) in rhizosphere soils was investigated at seepline areas impacted by CE plumes. Successful bioremediation of CE in rhizosphere soils is dependent on microbial activity, soil types, plant species, and groundwater CE concentrations. Seepline soils were exposed to trichloroethylene (TCE) and perchloroethylene (PCE) in the 10-50 ppb range. Greenhouse soils were exposed to 2-10 ppm TCE. Plants at the seepline were poplar and pine while the greenhouse contained sweet gum, willow, pine, and poplar. Phospholipid fatty acid (PLFA) analyses were performed to assess the microbial activity in rhizosphere soils. Biomass content was lowest in the nonvegetated control soil and highest in the Sweet Gum soil. Bacterial rhizhosphere densities, as measured by PLFA, were similar in different vegetated soils while fungi biomass was highly variable. The PLFA soil profiles showed diverse microbial communities primarily composed of Gram-negative bacteria. Adaptation of the microbial community to CE was determined by the ratio of {omega}7t/{omega}7c fatty acids. Ratios (16:1{omega}7v16:1{omega}7c and 18:l{omega}7t/18:1{omega}7c) greater than 0.1 were demonstrated in soils exposed to higher CE concentrations (10-50 ppm), indicating an adaptation to CE resulting in decreased membrane permeability. Ratios of cyclopropyl fatty acids showed that the vegetated control soil sample contained the …
Date: May 26, 2005
Creator: Brigmon, R. L.; Stanhopc, A.; Franck, M. M.; McKinsey, P. C. & Berry, C. J.
Object Type: Article
System: The UNT Digital Library
Bunched beam stochastic cooling in the Fermilab Recycler Ring (open access)

Bunched beam stochastic cooling in the Fermilab Recycler Ring

Stochastic cooling with bunched beam in a linear bucket has been obtained and implemented operationally in the Fermilab Recycler Ring (RR). This is the first time that linear-rf bunched-beam stochastic cooling has been successfully used operationally in a high-energy facility. In this implementation the particle bunch length is much greater than the cooling system wavelengths, and that property is critical to the cooling success. The simultaneous longitudinal bunching enables cooling to much smaller longitudinal emittances than the coasting beam or barrier bucket system. Characteristics and limitations of bunched beam stochastic cooling are discussed.
Date: May 1, 2005
Creator: Broemmelsiek, D.; Burov, A.; Nagaitsev, S.; Neuffer, D. & /Fermilab
Object Type: Article
System: The UNT Digital Library