Serial/Series Title
OIT Tip Sheets
10
Establishment of an Industry-Driven Consortium Focused on Improving the Production Performance of Domestic Stripper Wells Quarterly Report
8
Fiscal Year 2004
8
Enhanced Wellbore Stabilization and Reservoir Productivity with Aphron Drilling Fluid Technology
6
Fiscal Year 2003
6
Small Wind Electric Systems Consumers' Guides
6
Cost-Effective Reciprocating Engine Emissions Control and Monitoring for E&P Field and Gathering Engines Progress Report
4
Differential Soil Impedance Obstacle Detection Quarterly Report
4
Field Demonstration of a Membrane Process to Separate Nitrogen From Natural Gas Progress Report
4
Fundamentals of Reservoir Surface Energy as Related to Surface Properties, Wettability, Capillary Action, and Oil Recovery From Fractured Reservoirs by Spontaneous Imbibition Quarterly Report
4
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RP-5 Renewable Energy Efficiency Project
This is the sixth quarterly technical report for the RP-5 Renewable Energy Efficiency Project. The report summarizes the work progress, effort and activities that took place during the period from October 1, 2003 through December 31, 2003. The report has been prepared in accordance with the Department of Energy (DOE) Guidelines. In coordination with the DOE, IEUA has revised the original Cooperative Agreement to reflect the actual and current project scope of work. The original Agreement statement of work (SOW) included conceptual and preliminary equipment and systems, which were further evaluated for feasibility and suitability for the project. As a result, some of the equipment was taken out of the project scope. In response to questions from the DOE, IEUA has submitted a summary report on the Organic Rankine Cycle (ORC) secondary power generation units for availability and suitability for this project and associated safety concerns pointed out by the DOE. IEUA has awarded the consulting engineering contract to Parsons Water and Infrastructure, Inc. to provide the project's design and construction services. The project's pre-design kickoff meeting was held at IEUA's headquarters on December 11, 2003. IEUA has submitted a proposal for a grant offered by California Energy Commission (CEC) …
Date:
January 29, 2004
Creator:
Clifton, Neil; Whitman, Eliza Jane & Zughbi, Jamal A.
Object Type:
Report
System:
The UNT Digital Library
A fourth order accurate adaptive mesh refinement method forpoisson's equation
We present a block-structured adaptive mesh refinement (AMR) method for computing solutions to Poisson's equation in two and three dimensions. It is based on a conservative, finite-volume formulation of the classical Mehrstellen methods. This is combined with finite volume AMR discretizations to obtain a method that is fourth-order accurate in solution error, and with easily verifiable solvability conditions for Neumann and periodic boundary conditions.
Date:
August 20, 2004
Creator:
Barad, Michael & Colella, Phillip
Object Type:
Article
System:
The UNT Digital Library
Bridging the Gap between Quantum Mechanics and Large-Scale Atomistic Simulation
The prospect of modeling across disparate length and time scales to achieve a predictive multiscale description of real materials properties has attracted widespread research interest in the last decade. To be sure, the challenges in such multiscale modeling are many, and in demanding cases, such as mechanical properties or dynamic phase transitions, multiple bridges extending from the atomic level all the way to the continuum level must be built. Although often overlooked in this process, one of the most fundamental and important problems in multiscale modeling is that of bridging the gap between first-principles quantum mechanics, from which true predictive power for real materials emanates, and the large-scale atomistic simulation of thousands or millions of atoms, which is usually essential to describe the complex atomic processes that link to higher length and time scales. For example, to model single-crystal plasticity at micron length scales via dislocation-dynamics simulations that evolve the detailed dislocation microstructure requires accurate large-scale atomistic information on the mobility and interaction of individual dislocations. Similarly, modeling the kinetics of structural phase transitions requires linking accurate large-scale atomistic information on nucleation processes with higher length and time scale growth processes.
Date:
August 16, 2004
Creator:
Moriarty, J. A.
Object Type:
Book
System:
The UNT Digital Library
Asymmetric injection of cathodic arc plasma into a macroparticlefilter
The cathodic arc plasmas produced by cathode spots usuallyinclude macroparticles, which is undesirable for many applications. Acommon way of removing macroparticles is to use curved solenoid filterswhich guide the plasma from the source to the substrate. In this work, anarc source with relatively small cathode is used, limiting the possiblelocations of plasma production. The relative position of cathodic arcsource and macroparticle filtered was systematically varied and thefiltered plasma current was recorded. It was found that axis-symmetricplasma injection leads to maximum throughput only if an anode aperturewas used, which limited the plasma to near-axis flow by scraping offplasma at larger angles to the axis. When the anode aperture was removed,more plasma could enter the filter. In this case, maximum filtered ioncurrent was achieved when the plasma was injected off-axis, namely offsetin the direction where the filter is curved. Such behavior wasanticipated because the plasma column in the filter is known to beshifted by ExB and centrifugal drift as well as by non-axis-symmetriccomponents of the magnetic field in the filter entrance and exit plane.The data have implications for plasma transport variations caused bydifferent spot locations on cathodes that are not small compared to thefilter cross section.
Date:
February 11, 2004
Creator:
Anders, Andre & MacGill, Robert A.
Object Type:
Article
System:
The UNT Digital Library
Classification of non-coding RNA using graph representations ofsecondary structure
Some genes produce transcripts that function directly in regulatory, catalytic, or structural roles in the cell. These non-coding RNAs are prevalent in all living organisms, and methods that aid the understanding of their functional roles are essential. RNA secondary structure, the pattern of base-pairing, contains the critical information for determining the three dimensional structure and function of the molecule. In this work we examine whether the basic geometric and topological properties of secondary structure are sufficient to distinguish between RNA families in a learning framework. First, we develop a labeled dual graph representation of RNA secondary structure by adding biologically meaningful labels to the dual graphs proposed by Gan et al [1]. Next, we define a similarity measure directly on the labeled dual graphs using the recently developed marginalized kernels [2]. Using this similarity measure, we were able to train Support Vector Machine classifiers to distinguish RNAs of known families from random RNAs with similar statistics. For 22 of the 25 families tested, the classifier achieved better than 70% accuracy, with much higher accuracy rates for some families. Training a set of classifiers to automatically assign family labels to RNAs using a one vs. all multi-class scheme also yielded encouraging …
Date:
June 7, 2004
Creator:
Karklin, Yan; Meraz, Richard F. & Holbrook, Stephen R.
Object Type:
Article
System:
The UNT Digital Library
Database of prompt gamma rays from slow neutron capture forelemental analysis
The increasing importance of Prompt Gamma-ray ActivationAnalysis (PGAA) in a broad range of applications is evident, and has beenemphasized at many meetings related to this topic (e.g., TechnicalConsultants' Meeting, Use of neutron beams for low- andmedium-fluxresearch reactors: radiography and materialscharacterizations, IAEA Vienna, 4-7 May 1993, IAEA-TECDOC-837, 1993).Furthermore, an Advisory Group Meeting (AGM) for the Coordination of theNuclear Structure and Decay Data Evaluators Network has stated that thereis a need for a complete and consistent library of cold- and thermalneutron capture gammaray and cross-section data (AGM held at Budapest,14-18 October 1996, INDC(NDS)-363); this AGM also recommended theorganization of an IAEA CRP on the subject. The International NuclearData Committee (INDC) is the primary advisory body to the IAEA NuclearData Section on their nuclear data programmes. At a biennial meeting in1997, the INDC strongly recommended that the Nuclear Data Section supportnew measurements andupdate the database on Neutron-induced PromptGamma-ray Activation Analysis (21st INDC meeting, INDC/P(97)-20). As aconsequence of the various recommendations, a CRP on "Development of aDatabase for Prompt Gamma-ray Neutron Activation Analysis (PGAA)" wasinitiated in 1999. Prior to this project, several consultants had definedthe scope, objectives and tasks, as approved subsequently by the IAEA.Each CRP participant assumed responsibility for the execution of specifictasks. …
Date:
December 31, 2004
Creator:
Firestone, R. B.; Choi, H. D.; Lindstrom, R. M.; Molnar, G. L.; Mughabghab, S. F.; Paviotti-Corcuera, R. et al.
Object Type:
Report
System:
The UNT Digital Library
Forest production responses to irrigation and fertilization are not explained by shifts in allocation.
Production increases in intensively managed forests have been obtained by improving resource availability through water and nutrient amendments. Increased stem production has been attributed to shifts in growth from roots to shoot, and such shifts would have important implications for below ground carbon sequestration. We examined above and below ground growth and biomass accumulation and distribution in two eastern cottonwood clones and American sycamore receiving irrigation(I), fertilization(F), orirrigation+fertilization(IF) and compared with non-treated controls(C). Above ground growth and biomass accumulation responded positively to both I and F in all genotypes. After three growing seasons, the largest trees were sycamore receiving the IF treatment, with a total mean annual biomass production of 9.4 Mg ha -1 yr -1. Total cottonwood mean annual biomass production in both clones was >5.0 Mg ha -1 yr -1 in the IF treatment. Above ground biomass production was 6.3 and >3.1 Mg ha -1 yr -1 for sycamore and cottonwoods, respectively. Total root mass fraction was lower in high resource treatments and declined as stands aged. To compare allocation in trees of equal size, we used allometric relationships between above and below ground tissue. Allometric relationships between woody perennial tissues rarely differed among treatments. Improved resource availability …
Date:
October 1, 2004
Creator:
Coyle, David R. & Coleman, Mark D.
Object Type:
Article
System:
The UNT Digital Library
Sustaining the Landscape: A Method for Comparing Current and Desired Future Conditions of Forest Ecosystems in the North Cumberland Plateau and Mountains
This project initiates an integrated-landscape conservation approach within the Northern Cumberlands Project Area in Tennessee and Kentucky. The mixed mesophytic forests within the Cumberland Plateau and Mountains are among the most diverse in North America; however, these forests have been impacted by and remain threatened from changes in land use across this landscape. The integrated-landscape conservation approach presented in this report outlines a sequence of six conservation steps. This report considers the first three of these steps in two, successive stages. Stage 1 compares desired future conditions (DFCs) and current prevailing conditions (CPCs) at the landscape-scale utilizing remote sensing imagery, remnant forests, and descriptions of historical forest types within the Cumberland Plateau. Subsequently, Stage 2 compares DFCs and CPCs for at-risk forest types identified in Stage 1 utilizing structural, compositional, or functional attributes from USFS Forest Inventory and Analysis data. Ecological indicators will be developed from each stage that express the gaps between these two realizations of the landscape. The results from these first three steps will directly contribute to the final three steps of the integrated-landscape conservation approach by providing guidance for the generation of new conservation strategies in the Northern Cumberland Plateau and Mountains.
Date:
December 22, 2004
Creator:
Druckenbrod, D. L.
Object Type:
Report
System:
The UNT Digital Library
Edge Localized Mode Dynamics and Transport in the Scrape-Off Layer of the DIII-D Tokamak
High temporal and spatial resolution measurements in the boundary of the DIII-D tokamak show that edge localized modes (ELMs) are produced in the low field side, are poloidally localized and are composed of fast bursts ({approx}20 to 40 {micro}s long) of hot, dense plasma on a background of less dense, colder plasma ({approx}5 x 10{sup 18} m{sup {+-}3}, 50 eV) possibly created by the bursts themselves. The ELMs travel radially in the scrapeoff layer (SOL), starting at the separatrix at {approx}450 m/s, and slow down to {approx}150 m/s near the wall, convecting particles and energy to the SOL and walls. The temperature and density in the ELM plasma initially correspond to those at the top of the density pedestal but quickly decay with radius in the SOL. The temperature decay length ({approx}1.2 to 1.5 cm) is much shorter than the density decay length ({approx}3 to 8 cm), and the latter decreases with increasing pedestal (and SOL) density. The local particle and energy flux at the midplane wall during the bursts are 10% to 50% ({approx}1 to 2 x 10{sup 21} m{sup {+-}2} s{sup {+-}1}) and 1% to 2 % ({approx}20 to 30 kW/m{sup 2}) respectively of the LCFS average fluxes, …
Date:
December 3, 2004
Creator:
Boedo, J. A.; Rudakov, D. L.; Hollmann, E.; Gray, D. S.; Burrell, K. H.; Moyer, R. A. et al.
Object Type:
Article
System:
The UNT Digital Library
China's sustainable energy future: Scenarios of energy and carbonemissions (Summary)
China has ambitious goals for economic development, and mustfind ways to power the achievement of those goals that are bothenvironmentally and socially sustainable. Integration into the globaleconomy presents opportunities for technological improvement and accessto energy resources. China also has options for innovative policies andmeasures that could significantly alter the way energy is acquired andused. These opportunities andoptions, along with long-term social,demographic, and economic trends, will shape China s future energysystem, and consequently its contribution to emissions of greenhousegases, particularly carbon dioxide (CO2). In this study, entitled China sSustainable Energy Future: Scenarios of Energy and Carbon Emissions, theEnergy Research Institute (ERI), an independent analytic organizationunder China's Na tional Development and Reform Commission (NDRC), soughtto explore in detail how China could achieve the goals of the TenthFive-Year Plan and its longer term aims through a sustainable developmentstrategy. China's ability to forge a sustainable energy path has globalconsequences. China's annual emissions of greenhouse gases comprisenearly half of those from developing countries, and 12 percent of globalemissions. Most of China's greenhouse gas emissions are in the form ofCO2, 87 percent of which came from energy use in 2000. In that year,China's carbon emissions from energy use and cement production were 760million metric tons (Mt-C), …
Date:
March 10, 2004
Creator:
Zhou, Dadi; Levine, Mark; Dai, Yande; Yu, Cong; Guo, Yuan; Sinton, Jonathan E. et al.
Object Type:
Report
System:
The UNT Digital Library
Small-Column Ion-Exchange Alternative to Remove 137Cs from Low-Curie Salt Waste: Summary of Phase 1
A Small-Column Ion-Exchange (SCIX) system is being evaluated for removing cesium from the Type 2 and/or Type 3 dissolved saltcake wastes at the Savannah River Site (SRS) to ensure that the dissolved saltcake meets the waste acceptance criteria at the Saltstone Facility. Both crystalline silicotitanate (CST) and IONSIV{trademark} IE-96 zeolite were evaluated as the ion-exchange media. The accelerated alternative, using CST in the SCIX, could save as much as $3 billion in operating and storage costs and {approx}20 years in processing time compared to the current baseline. With its proven high cesium-loading capacity for the expected dissolved saltcake compositions and temperatures, CST is the preferred sorbent for SCIX. The low-cost alternative sorbent, zeolite, greatly increases the volume of sorbent required because of its much lower cesium-loading capacity. Thus, zeolite greatly increases the cost for the alternative, mainly because of the increased number of Defense Waste Processing Facility canisters required to dispose of the loaded sorbent (potentially over 7000 for zeolite, compared with <500 for CST). The models previously developed for predicting cesium loading on CST compared favorably with laboratory measurements of equilibrium distribution ratios and column loading performance using dissolved saltcake simulants. These models predict that a column of 432 …
Date:
May 12, 2004
Creator:
Walker, J. F. Jr.
Object Type:
Report
System:
The UNT Digital Library
Feasibility of using biological degradation for the on-sitet reatment of mixed wastes
This research was conducted to investigate the feasibility of applying microbial biodegradation as a treatment technology for wastes containing radioactive elements and organic solvents (mixed wastes). In this study, we focused our efforts on the treatment of wastes generated by biomedical research as the result of purifying tritium labeled compounds by high-performance liquid chromatography (HPLC). These wastes are typically 80 percent water with 20 percent acetonitrile or methanol or a mixture of both. The objective was to determine the potential of using biodegradation to treat the solvent component of tritiated mixed waste to a concentration below the land disposal restriction standard (1mg/L for acetonitrile). Once the standard is reached, the remaining radioactive waste is no longer classified as a mixed waste and it can then be solidified and placed in a secure landfill. This investigation focused on treating a 10 percent acetonitrile solution, which was used as a non-radioactive surrogate for HPLC waste, in a bioreactor. The results indicated that the biodegradation process could treat this solution down to less than 1 mg/L to meet the land disposal restriction standard.
Date:
April 20, 2004
Creator:
Stringfellow, William T.; Komada, Tatsuyuki & Chang, Li-Yang
Object Type:
Article
System:
The UNT Digital Library
Direct Measurement of Mercury Reactions in Coal Power Plant Plumes Technical Progress Report: May-October 2003
This project was awarded under U.S. Department of Energy (DOE) National Energy Technology Laboratory (NETL) Program Solicitation DE-PS26-02NT41422 and specifically addresses Program Area of Interest: No.5--Environmental and Water Resources. The project team includes the Electric Power Research Institute (EPRI) as the contractor and the University of North Dakota Energy & Environmental Research Center (EERC) and Frontier Geosciences as subcontractors. Wisconsin Energies and its Pleasant Prairie Power Plant acted as host for the field-testing portion of the research. The project is aimed at clarifying the role, rates, and end results of chemical transformations that may occur to mercury that has been emitted from elevated stacks of coal-fired electric power plants. Mercury emitted from power plants emerges in either its elemental, divalent, or particulate-bound form. Deposition of the divalent form is more likely to occur closer to the source than that of the other two forms, due to its solubility in water. Thus, if chemical transformations occur in the stack emissions plume, measurements in the stack may mischaracterize the fate of the material. Initial field and pilot plant measurements have shown significant and rapid chemical reduction of divalent to elemental mercury may occur in these plumes. Mercury models currently assume that the …
Date:
January 1, 2004
Creator:
Levin, Leonard
Object Type:
Report
System:
The UNT Digital Library
System Study of Rich Catalytic/Lean burn (RCL) Catalytic Combustion for Natural Gas and Coal-Derived Syngas Combustion Turbines: Final Report
Rich Catalytic/Lean burn (RCL{reg_sign}) technology has been successfully developed to provide improvement in Dry Low Emission gas turbine technology for coal derived syngas and natural gas delivering near zero NOx emissions, improved efficiency, extending component lifetime and the ability to have fuel flexibility. The present report shows substantial net cost saving using RCL{reg_sign} technology as compared to other technologies both for new and retrofit applications, thus eliminating the need for Selective Catalytic Reduction (SCR) in combined or simple cycle for Integrated Gasification Combined Cycle (IGCC) and natural gas fired combustion turbines.
Date:
December 1, 2004
Creator:
Etemad, Shahrokh; Smith, Lance & Burns, Kevin
Object Type:
Report
System:
The UNT Digital Library
Metals Processing Laboratory Users (MPLUS) Facility Annual Report FY 2002 (October 1, 2001-September 30, 2002)
The Metals Processing Laboratory Users Facility (MPLUS) is a Department of Energy (DOE), Energy Efficiency and Renewable Energy, Industrial Technologies Program, user facility designated to assist researchers in key industries, universities, and federal laboratories in improving energy efficiency, improving environmental aspects, and increasing competitiveness. The goal of MPLUS is to provide access to the specialized technical expertise and equipment needed to solve metals processing issues that limit the development and implementation of emerging metals processing technologies. The scope of work can also extend to other types of materials. MPLUS has four primary user centers: (1) Processing--casting, powder metallurgy, deformation processing (including extrusion, forging, rolling), melting, thermomechanical processing, and high-density infrared processing; (2) Joining--welding, monitoring and control, solidification, brazing, and bonding; (3) Characterization--corrosion, mechanical properties, fracture mechanics, microstructure, nondestructive examination, computer-controlled dilatometry, and emissivity; and (4) Materials/Process Modeling--mathematical design and analyses, high-performance computing, process modeling, solidification/deformation, microstructure evolution, thermodynamic and kinetic, and materials databases A fully integrated approach provides researchers with unique opportunities to address technologically related issues to solve metals processing problems and probe new technologies. Access is also available to 16 additional Oak Ridge National Laboratory (ORNL) user facilities ranging from state-of-the-art materials characterization capabilities, and high-performance computing to …
Date:
April 27, 2004
Creator:
Angelini, P
Object Type:
Report
System:
The UNT Digital Library
Use of Conducting Polymers for Electronic Communication with Redox Active Nanoparticles
Nanoscale materials provide unique properties that will enable new technologies and enhance older ones. One area of intense activity in which nanoscale materials are being used is in the development of new functional materials for battery applications.1-4 This effort promises superior materials with properties that circumvent many of the problems associated with traditional battery materials. Previously we have worked on several approaches for using nanoscale materials for application as cathode materials in rechargeable Li batteries.5-11 Our recent work has focused on synthesizing MnO2 nanoparticles and using conducting polymers to electronically address these particles in nanoparticle assemblies. This presentation will focus on those efforts. MnO2 nanoparticles that are encapsulated with poly(3,4-ethylenedioxythiophene) (PEDOT) are prepared using 3,4-ethylenedioxythiophene (EDOT) as a chemical reductant for permanganate anion. This non-aqueous preparation is based on a recent report of a similar method for preparation of PEDOT-encapsulated Au nanoparticles.12 We also describe the synthesis of MnO2 colloidal nanoparticles prepared using an aqueous route involving reduction of permanganate anion with butanol using a previously described route.13 We report the synthesis and characterization of the PEDOT material, and the aqueous colloidal material. We show that the aqueous colloidal nanoparticles can be trapped in thin films using a layer-by-layer deposition …
Date:
August 8, 2004
Creator:
Bazito, Fernanda; O'Brien, Robert & Buttry, Daniel A.
Object Type:
Article
System:
The UNT Digital Library
Type IIP supernovae as cosmological probes: A SEAM distance to SN1999em
Because of their intrinsic brightness, supernovae make excellent cosmological probes. We describe the spectral-fitting expanding atmosphere method (SEAM) for obtaining distances to Type IIP supernovae (SNe IIP) and present a distance to SN 1999em for which a Cepheid distance exists. Our models give results consistent with the Cepheid distance, even though we have not attempted to tune the underlying hydrodynamical model but have simply chosen the best fits. This is in contradistinction to the expanding photosphere method (EPM), which yields a distance to SN 1999em that is 50 percent smaller than the Cepheid distance. We emphasize the differences between the SEAM and the EPM. We show that the dilution factors used in the EPM analysis were systematically too small at later epochs. We also show that the EPM blackbody assumption is suspect. Since SNe IIP are visible to redshifts as high as z {approx}< 6, with the James Webb Space Telescope, the SEAM may be a valuable probe of the early universe.
Date:
June 1, 2004
Creator:
Baron, E.; Nugent, Peter E.; Branch, David & Hauschildt, Peter H.
Object Type:
Article
System:
The UNT Digital Library
Shillapoo Wildlife Area, Annual Report 2004-2005.
This report summarizes accomplishments, challenges and successes on WDFW's Shillapoo Wildlife Area funded under Bonneville Power Administration's (BPA) Wildlife Mitigation Program (BPA project No.2003-012-00) during the Fiscal Year 05 contract period October 1, 2004-September 30, 2005. The information presented here is intended to supplement that contained in BPA's PISCES contract development and reporting system. The organization below is by broad categories of work but references are made to individual work elements in the PISCES Statement of Work as appropriate. The greatest success realized during this contract period was completion of the water system that will provide water to wetland basins within the Vancouver Lake Unit and three independent basins on adjoining Clark County owned lands. The water system paid for by Clark Public Utilities was designed and built under the direction of Ducks Unlimited. Having a reliable water supply for these areas has allowed us for the first time to begin making significant progress toward our wetland vegetation management goals on this unit. A reduction in the density of reed canary grass has already been noted and increased levels of native plant occurrence have been observed. Our most notable setback was an increase in the infestation of purple loosestrife within …
Date:
October 1, 2004
Creator:
Calkins, Brian
Object Type:
Report
System:
The UNT Digital Library
Interpretation of long-offset transient electromagnetic data fromMount Merapi, Indonesia, using a three-dimensional optimizationapproach
In the years 1998, 2000, and 2001, long-offset transientelectromagnetic (LOTEM) surveys were carried out at the active volcanoMerapi in Central Java. The measurements investigated the conductivitystructure of the volcanic edifice. Our area of interest, which is belowthe summit and the upper flanks, was investigated using horizontal andvertical magnetic field time derivative data from seventransmitter-receiver setups. Because of topography and athree-dimensional (3-D) underground structure, a 3-D interpretation isused. The method optimizes few parameters of a 3-D model by a stableleast squares joint inversion of the data, providing sufficientresolution capability. Reasonable data fits are achieved with anonhorizontally layered model featuring a very conductive basement belowdepths of 1.5 km. While hydrothermal alteration is also considered, wetentatively explain the high conductivities by aqueous solutions withrelatively high salt contents. A large magma body or a small superficialreservoir below Merapi's central volcanic complex, as discussed by otherauthors, cannot be resolved by the LOTEM data.
Date:
June 2, 2004
Creator:
Commer, Michael; Helwig, Stefan L.; Hordt, Andreas & Tezkan, Bulent
Object Type:
Article
System:
The UNT Digital Library
A low power ultra-fast current transient measuring device.
We have studied the feasibility of an innovative device to sample 1ns low-power single current transients with a time resolution better than 10 ps. The new concept explored here is to close photoconductive semiconductor switches (PCSS) with a Laser for a period of 10 ps. The PCSSs are in a series along a Transmission Line (TL). The transient propagates along the TL allowing one to carry out a spatially resolved sampling of charge at a fixed time instead of the usual timesampling of the current. The fabrication of such a digitizer was proven to be feasible but very difficult.
Date:
October 1, 2004
Creator:
Doyle, Barney Lee; Rossi, Paolo; Armendariz, Marcelino G.; Sullivan, John Patrick; Foltynowicz, Robert J. & Zutavern, Fred J.
Object Type:
Report
System:
The UNT Digital Library
Multi-Attribute Seismic/Rock Physics Approach to Characterizing Fractured Reservoirs
Most current seismic methods to seismically characterize fractures in tight reservoirs depend on a few anisotropic wave propagation signatures that can arise from aligned fractures. While seismic anisotropy can be a powerful fracture diagnostic, a number of situations can lessen its usefulness or introduce interpretation ambiguities. Fortunately, laboratory and theoretical work in rock physics indicates that a much broader spectrum of fracture seismic signatures can occur, including a decrease in P- and S-wave velocities, a change in Poisson's ratio, an increase in velocity dispersion and wave attenuation, as well as well as indirect images of structural features that can control fracture occurrence. The goal of this project was to demonstrate a practical interpretation and integration strategy for detecting and characterizing natural fractures in rocks. The approach was to exploit as many sources of information as possible, and to use the principles of rock physics as the link among seismic, geologic, and log data. Since no single seismic attribute is a reliable fracture indicator in all situations, the focus was to develop a quantitative scheme for integrating the diverse sources of information. The integrated study incorporated three key elements: The first element was establishing prior constraints on fracture occurrence, based on …
Date:
November 30, 2004
Creator:
Mavko, Gary
Object Type:
Report
System:
The UNT Digital Library
Laser hazard analysis for LASIRIS Model MAG-501L-670M-1000-45[degree]-K diode laser associated with high resolution pulsed scanner.
A laser hazard analysis and safety assessment was performed for the LASIRISTM Model MAG-501L-670M-1000-45o-K diode laser associated with the High Resolution Pulse Scanner based on the ANSI Standard Z136.1-2000, American National Standard for the Safe Use of Lasers and the ANSI Standard Z136.6-2000, American National Standard for the Safe Use of Lasers Outdoors. The laser was evaluated for both indoor and outdoor use.
Date:
November 1, 2004
Creator:
Augustoni, Arnold L.
Object Type:
Report
System:
The UNT Digital Library
Development of the Resin Infusion between Double Flexible Tooling process : assessment of the viability of in-mold coating and implementation of UV curing.
As composites gain wider acceptance in all sectors of the economy, new methodologies must be developed to increase their cost effectiveness in manufacturing. The neoteric Resin Infusion between Double Flexible Tooling (RIDFT) process is undergoing modifications to improve its cost-effectiveness by developing methodologies for in-mold coating and the incorporation of UV curing. In-mold coating is desired by the composites industry since it eliminates the current paint process, which is not only laborious and time consuming, but expensive, and presents safety issues. Two methodologies (paint films and coinfusion) for implementing in-mold coating were investigated. It was demonstrated that thermoformable paint films could be used to produce coated RIDFTed components. Coinfusion was also successfully implemented. This work also investigated the feasibility of designing and incorporating a Cure on Demand system into the RIDFT process, using ultraviolet (UV) light for the curing of composite laminates. The objective was to develop a process for the RIDFT that would eliminate or reduce the inflexibility in the current production process, resulting in shortened production cycle times. UV-cured laminates were produced at a fraction of the time required to produce catalyst-cured laminates. Mechanical and material characterization tests were performed on each of the UV-cured laminates produced. The …
Date:
December 1, 2004
Creator:
Okoli, Okenwa I. (. FAMU-FSU College of Engineering, Tallahassee, FL)
Object Type:
Report
System:
The UNT Digital Library
A capillary valve for microfluidic systems.
Microfluidic systems are becoming increasingly complicated as the number of applications grows. The use of microfluidic systems for chemical and biological agent detection, for example, requires that a given sample be subjected to many process steps, which requires microvalves to control the position and transport of the sample. Each microfluidic application has its own specific valve requirements and this has precipitated the wide variety of valve designs reported in the literature. Each of these valve designs has its strengths and weaknesses. The strength of the valve design proposed here is its simplicity, which makes it easy to fabricate, easy to actuate, and easy to integrate with a microfluidic system. It can be applied to either gas phase or liquid phase systems. This novel design uses a secondary fluid to stop the flow of the primary fluid in the system. The secondary fluid must be chosen based on the type of flow that it must stop. A dielectric fluid must be used for a liquid phase flow driven by electroosmosis, and a liquid with a large surface tension should be used to stop a gas phase flow driven by a weak pressure differential. Experiments were carried out investigating certain critical functions …
Date:
October 1, 2004
Creator:
Cummings, Eric B.; Kanouff, Michael P. & Rush, Brian M.
Object Type:
Report
System:
The UNT Digital Library