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Critical current measurements on large conductors of niobium-titanium/copper cable embedded in an aluminum stabilizer (open access)

Critical current measurements on large conductors of niobium-titanium/copper cable embedded in an aluminum stabilizer

Insertion of a flat, Rutherford type, cable of NbTi/Cu composite strands into a rectangular profile of high purity aluminum is an established method of superconductor fabrication for certain applications. Although this processing scheme has numerous advantages it produces a composite material whose properties are difficult to predict with precision. The BABAR detector magnet currently being tested at the Stanford Linear Accelerator Center, uses high-purity aluminum stabilized superconducting cable. The performance of the superconductor is dependent on the quality of the fabrication of the composite conductor. Here we present measurements of the critical transport current of BABAR production grade conductors up to 10 kA, and at fields up to 10 T. Data are related to production variables, compared to estimates from simple models, and evaluated with respect to design specifications.
Date: June 1, 1999
Creator: Walsh, R. P.; Miller, J. R. & O'Connor, T. G.
System: The UNT Digital Library
Spectral partitioning in diffraction tomography (open access)

Spectral partitioning in diffraction tomography

The scattering mechanism of diffraction tomography is described by the integral form of the Helmholtz equation. The goal of diffraction tomography is to invert this equation in order to reconstruct the object function from the measured scattered fields. During the forward propagation process, the spatial spectrum of the object under investigation is ''smeared,'' by a convolution in the spectral domain, across the propagating and evanescent regions of the received field. Hence, care must be taken in performing the reconstruction, as the object's spectral information has been moved into regions where it may be considered to be noise rather than useful information. This will reduce the quality and resolution of the reconstruction. We show haw the object's spectrum can be partitioned into resolvable and non-resolvable parts based upon the cutoff between the propagating and evanescent fields. Operating under the Born approximation, we develop a beam-forming on transmit approach to direct the energy into either the propagating or evanescent parts of the spectrum. In this manner, we may individually interrogate the propagating and evanescent regions of the object spectrum.
Date: June 14, 1999
Creator: Lehman, S K; Chambers, D H & Candy, J V
System: The UNT Digital Library
Division of labor among the alpha-6 beta-4 integrin, beta-1 integrins and an E3 laminin receptor to signal morphogenesis and beta-casein expression in mammary epithelial cells (open access)

Division of labor among the alpha-6 beta-4 integrin, beta-1 integrins and an E3 laminin receptor to signal morphogenesis and beta-casein expression in mammary epithelial cells

None
Date: June 30, 1999
Creator: Muschler, J.; Lochter, A.; Roskelley, C. D.; Yurchenco, P. & Bissell, M. J.
System: The UNT Digital Library
Approaches to rid cathodic arc plasmas of macro- andnanoparticles: A review (open access)

Approaches to rid cathodic arc plasmas of macro- andnanoparticles: A review

A major obstacle for the broad application of cathodic arc plasma deposition is the presence of micro- and nanoparticles in the plasma, also often referred to as 'macroparticles'. This paper reviews the formation of macroparticles at cathode spots, their interaction with the arc plasma and substrate, and macroparticle separation and removal from the plasma by various filtering methods. Nineteen variants of filters are discussed, including Aksenov's classic 90{sup o}-duct filter, filters of open architecture, and the concept of stroboscopic filtering.
Date: June 1, 1999
Creator: Anders, Andre
System: The UNT Digital Library
Implementing Systems Engineering on a CERCLA Project (open access)

Implementing Systems Engineering on a CERCLA Project

The Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), enacted in 1980, provides a regulatory and legal mechanism to reduce risks from prior disposal of hazardous and toxic chemicals. Regulations, Standards, and Guidelines have been published to further define the CERCLA Process. The OU 7-10 Staged Interim Action Project at the Idaho National Engineering and Environmental Laboratory (INEEL) is a CERCLA project working to remediate the pre-1970 disposal pit in which transuranic materials have been disposed. This paper analyzes the CERCLA process from a systems engineering perspective and describes how systems engineering is implemented on this project.
Date: June 1, 1999
Creator: Beitel, George Alois
System: The UNT Digital Library
Issue Management Risk Ranking Systems (open access)

Issue Management Risk Ranking Systems

Thousands of safety issues have been collected on-line at the Idaho National Engineering and Environmental Laboratory (INEEL) as part of the Issue Management Plan. However, there has been no established approach to prioritize collected and future issues. The authors developed a methodology, based on hazards assessment, to identify and risk rank over 5000 safety issues collected at INEEL. This approach required that it was easily applied and understandable for site adaptation and commensurate with the Integrated Safety Plan. High-risk issues were investigated and mitigative/preventive measures were suggested and ranked based on a cost-benefit scheme to provide risk-informed safety measures. This methodology was consistent with other integrated safety management goals and tasks providing a site-wide risk informed decision tool to reduce hazardous conditions and focus resources on high-risk safety issues. As part of the issue management plan, this methodology was incorporated at the issue collection level and training was provided to management to better familiarize decision-makers with concepts of safety and risk. This prioritization methodology and issue dissemination procedure will be discussed. Results of issue prioritization and training efforts will be summarized. Difficulties and advantages of the process will be reported. Development and incorporation of this process into INEELs lessons learned …
Date: June 1, 1999
Creator: Novack, Steven David; Marshall, Frances Mc Clellan; Stromberg, Howard Merion & Grant, Gary Michael
System: The UNT Digital Library
Microbial Ecology Assessment of Mixed Copper Oxide/Sulfide Dump Leach Operation (open access)

Microbial Ecology Assessment of Mixed Copper Oxide/Sulfide Dump Leach Operation

Microbial consortia composed of complex mixtures of autotrophic and heterotrophic bacteria are responsible for the dissolution of metals from sulfide minerals. Thus, an efficient copper bioleaching operation depends on the microbial ecology of the system. A microbial ecology study of a mixed oxide/sulfide copper leaching operation was conducted using an "overlay" plating technique to differentiate and identify various bacterial consortium members of the genera Thiobacillus, “Leptospirillum”, “Ferromicrobium”, and Acidiphilium. Two temperatures (30°C and 45°C) were used to select for mesophilic and moderately thermophilic bacteria. Cell numbers varied from 0-106 cells/g dry ore, depending on the sample location and depth. After acid curing for oxide leaching, no viable bacteria were recovered, although inoculation of cells from raffinate re-established a microbial population after three months. Due to low the pH of the operation, very few non-iron-oxidizing acidophilic heterotrophs were recovered. Moderate thermophiles were isolated from the ore samples. Pregnant liquor solutions (PLS) and raffinate both contained a diversity of bacteria. In addition, an intermittently applied waste stream that contained high levels of arsenic and fluoride was tested for toxicity. Twenty vol% waste stream in PLS killed 100% of the cells in 48 hours, indicating substantial toxicity and/or growth inhibition. The data indicate …
Date: June 1, 1999
Creator: Bruhn, Debby Fox; Thompson, David Neal & Noah, Karl Scott
System: The UNT Digital Library
Performance Characteristics of an Extended Throat Flow Nozzle for the Measurement of High Void Fraction Multi-phase Flows (open access)

Performance Characteristics of an Extended Throat Flow Nozzle for the Measurement of High Void Fraction Multi-phase Flows

An extended throat flow nozzle has been examined as a device for the measurement of very high void fraction (a ³ 0.95) multi-phase flows. Due to its greater density and partial contact with the wall, the equilibrium velocity of the liquid phase appreciably lags that of the lighter gas phase. The two phases are strongly coupled resulting in pressure drops across the contraction and in the extended throat that are significantly different than those experienced in single-phase flow. Information about the mass flow rates of the two phases can be extracted from the measured pressure drops. The performance of an extended throat flow nozzle has been evaluated under multi-phase conditions using natural gas and hydrocarbon liquids at 400 and 500 psi. Two hydrocarbon solvents were used as the test liquids, Isopar MÒ (sp = 0.79) and Aromatic 100â (sp = 0.87). These data are compared to prior air-water data at nominally 15 psi. The high and low pressure data were found to be consistent, confirming that the temperature, pressure, and size scaling of the extended throat venturi are correctly represented. This consistency allows different sized devices to be applied under different fluid conditions (temperature, pressure, gas and liquid phase composition, …
Date: June 1, 1999
Creator: Fincke, James Russell; Jeffery, Charles Lee; Ronnenkamp, C.; Kruse, D.; Krogue, J. & Householder, D.
System: The UNT Digital Library
Application of Systems Engineering to U.S. Department of Energy Privatization Project Selection at the Hanford Nuclear Reservation (open access)

Application of Systems Engineering to U.S. Department of Energy Privatization Project Selection at the Hanford Nuclear Reservation

The privatization efforts at the U.S. Department of Energy's Hanford Nuclear Reservation have been very successful primarily due to a disciplined process for project selection and execution. Early in the development of Privatization at Hanford, the Department of Energy determined that a disciplined alternatives generation and analysis (AGA) process would furnish the candidate projects with the best probability for success. Many factors had to be considered in the selection of projects. Westinghouse Hanford Company was assigned to develop this process and facilitate the selection of the first round of candidate privatization projects. Team members for the AGA process were assembled from all concerned organizations and skill groups. Among the selection criteria were legal, financial and technical considerations which had to be weighed.
Date: June 1, 1999
Creator: Layman, John Scott
System: The UNT Digital Library
Function Analysis and Decomposistion using Function Analysis Systems Technique (open access)

Function Analysis and Decomposistion using Function Analysis Systems Technique

The "Father of Value Analysis", Lawrence D. Miles, was a design engineer for General Electric in Schenectady, New York. Miles developed the concept of function analysis to address difficulties in satisfying the requirements to fill shortages of high demand manufactured parts and electrical components during World War II. His concept of function analysis was further developed in the 1960s by Charles W. Bytheway, a design engineer at Sperry Univac in Salt Lake City, Utah. Charles Bytheway extended Mile's function analysis concepts and introduced the methodology called Function Analysis Systems Technique (FAST) to the Society of American Value Engineers (SAVE) at their International Convention in 1965 (Bytheway 1965). FAST uses intuitive logic to decompose a high level, or objective function into secondary and lower level functions that are displayed in a logic diagram called a FAST model. Other techniques can then be applied to allocate functions to components, individuals, processes, or other entities that accomplish the functions. FAST is best applied in a team setting and proves to be an effective methodology for functional decomposition, allocation, and alternative development.
Date: June 1, 1999
Creator: Wixson, James Robert
System: The UNT Digital Library
Numerical Calculations of Wind Flow in a Full-Scale Wind Test Facility (open access)

Numerical Calculations of Wind Flow in a Full-Scale Wind Test Facility

Numerical studies on wind flow around the Texas Tech University (TTU) Wind Engineering Research Field Laboratory (WERFL) building were conducted. The main focus of this paper is wind loads on the TTU building in the INEEL proposed Windstorm Simulation Center. The results are presented in the form of distributions of static pressure, dynamic pressure, pressure coefficients, and velocity vectors on the surface and the vicinity of the TTU building.
Date: June 1, 1999
Creator: Oh, Chang H & Lacey, Jerry Mark
System: The UNT Digital Library
Technology Assessment Tool - An Application of Systems Engineering to USDOE Technology Proposals (open access)

Technology Assessment Tool - An Application of Systems Engineering to USDOE Technology Proposals

This paper discusses the system design for a Technology Assessment (TA) tool that can be used to quantitatively evaluate new and advanced technologies, products, or processes. Key features of the tool include organization of information in an indentured hierarchy; questions and categories derived from the decomposition of technology performance; segregation of life-cycle issues into six assessment categories; and scoring, relative impact, and sensitivity analysis capability. An advantage of the tool's use is its ability to provide decision analysis data, based on incomplete or complete data.
Date: June 1, 1999
Creator: Rynearson, Michael Ardel
System: The UNT Digital Library
Characteristics of a Mixed Thorium - Uranium Dioxide High-Burnup Fuel (open access)

Characteristics of a Mixed Thorium - Uranium Dioxide High-Burnup Fuel

Future nuclear fuel must satisfy three sets of requirements: longer times between refueling; concerns for weapons proliferation; and development of a spent fuel form more suitable for direct geologic disposal. This project has investigated a fuel consisting of mixed thorium and uranium dioxide to satisfy these requirements. Results using the SCALE 4.3 code system indicated that the mixed Th-U fuel could be burned to 72 MWD/kg or 100 MWD/kg using 25% and 35% UO2 respectively. The uranium remained below 20 % total fissile fraction throughout the cycle, making it unusable for weapons. Total plutonium production per MWD was a factor of 4.5 less in the Th-U fuel than in the conventional fuel; Pu-239 production per MWD was a factor of 6.5 less; and the plutonium produced was high in Pu-238, leading to a decay heat 5 times greater than that from plutonium derived from conventional fuel and 40 times greater than weapons grade plutonium. High decay heat would require active cooling of any crude weapon, lest the components surrounding the plutonium be melted. Spontaneous neutron production for plutonium from Th-U fuel was 2.3 times greater than that from conventional fuel and 15 times greater than that from weapons grade plutonium. …
Date: June 1, 1999
Creator: Herring, James Stephen & Mac Donald, Philip Elsworth
System: The UNT Digital Library
Characterizing Indoor Airflow and Pollutant Transport using Simulation Modeling for Prototypical Buildings. I. Office Buildings (open access)

Characterizing Indoor Airflow and Pollutant Transport using Simulation Modeling for Prototypical Buildings. I. Office Buildings

This paper describes the first efforts at developing a set of prototypical buildings defined to capture the key features affecting airflow and pollutant transport in buildings. These buildings will be used to model airflow and pollutant transport for emergency response scenarios when limited site-specific information is available and immediate decisions must be made, and to better understand key features of buildings controlling occupant exposures to indoor pollutant sources. This paper presents an example of this approach for a prototypical intermediate-sized, open style, commercial building. Interzonal transport due to a short-term source release, e.g., accidental chemical spill, in the bottom and the upper floors is predicted and corresponding HVAC system operation effects and potential responses are considered. Three-hour average exposure estimates are used to compare effects of source location and HVAC operation.
Date: June 1, 1999
Creator: Sohn, M. D.; Daisey, J. M. & Feustel, H. E.
System: The UNT Digital Library
Reversible (unitized) PEM fuel cell devices (open access)

Reversible (unitized) PEM fuel cell devices

Regenerative fuel cells (RFCs) are enabling for many weight-critical portable applications, since the packaged specific energy (>400 Wh/kg) of properly designed lightweight RFC systems is several-fold higher than that of the lightest weight rechargeable batteries. RFC systems can be rapidly refueled (like primary fuel cells), or can be electrically recharged (like secondary batteries) if a refueling infrastructure is not conveniently available. Higher energy capacity systems with higher performance, reduced weight, and freedom from fueling infrastructure are the features that RFCs promise for portable applications. Reversible proton exchange membrane (PEM) fuel cells, also known as unitized regenerative fuel cells (URFCs), or reversible regenerative fuel cells, are RFC systems which use reversible PEM cells, where each cell is capable of operating both as a fuel cell and as an electrolyzer. URFCs further economize portable device weight, volume, and complexity by combining the functions of fuel cells and electrolyzers in the same hardware, generally without any system performance or efficiency reduction. URFCs are being made in many forms, some of which are already small enough to be portable. Lawrence Livermore National Laboratory (LLNL) has worked with industrial partners to design, develop, and demonstrate high performance and high cycle life URFC systems. LLNL is …
Date: June 1, 1999
Creator: Mitlitsky, F.; Myers, B.; Smith, W. F. & Weisberg, Molter, T. M.
System: The UNT Digital Library
FXR fast beam imaging diagnostics (open access)

FXR fast beam imaging diagnostics

The Lawrence Livermore National Laboratory Flash X-ray (FXR) machine is being upgraded to produce two pulses. A very fast imaging system has been developed to characterize the electron beam diameter and shape. The system consists of a kapton target insertion mechanism and a framing camera. It has a fast gated imaging tube (500 ps) and CCD subsystem to capture and send the image to the control room. The beam diameter data provides insight on mechanisms that effect the x-ray spot size. These colorful beam measurements will be compared with our other diagnostics to form a more complete picture of beam behavior. A demonstration will be described where the image data was used to design a collimator to improve x-ray beam performance.
Date: June 1, 1999
Creator: Ferriera, T.; Gilliam, R.; Ong, M.; Wargo, P. & Zentler, J.
System: The UNT Digital Library
Acceleration schedules for a recirculating heavy-ion accelerator (open access)

Acceleration schedules for a recirculating heavy-ion accelerator

The recent development of miniature inductive adders has made it feasible to design programmable, high-repetition-rate pulsers with a substantially higher voltage than is possible using a conventional field-effect transistor architecture. Prototype pulsers using the new technology are being developed as part of a series of experiments at LLNL to test the concept of a recirculating induction accelerator. Preliminary numerical work is reported here to determine what effects the higher-voltage pulsers would have on the beam quality of the LLNL small recirculator.
Date: June 1, 1999
Creator: Grote, D. P. & Sharp, W.
System: The UNT Digital Library
Developments on the Toroid Ion Trap Analyzer (open access)

Developments on the Toroid Ion Trap Analyzer

Investigations into several areas of research have been undertaken to address the performance limitations of the toroid analyzer. The Simion 3D6 (2) ion optics simulation program was used to determine whether the potential well minimum of the toroid trapping field is in the physical center of the trap electrode structure. The results (Figures 1) indicate that the minimum of the potential well is shifted towards the inner ring electrode by an amount approximately equal to 10% of the r0 dimension. A simulation of the standard 3D ion trap under similar conditions was performed as a control. In this case, the ions settle to the minimum of the potential well at a point that is coincident with the physical center (both radial and axial) of the trapping electrodes. It is proposed that by using simulation programs, a set of new analyzer electrodes can be fashioned that will correct for the non- linear fields introduced by curving the substantially quadrupolar field about the toroid axis in order to provide a trapping field similar to the 3D ion trap cross- section. A new toroid electrode geometry has been devised to allow the use of channel- tron style detectors in place of the more …
Date: June 13, 1999
Creator: Lammert, S.A.; Thompson, C.V. & Wise, M.B.
System: The UNT Digital Library
Near field imaging of a saturated table top x-ray laser (open access)

Near field imaging of a saturated table top x-ray laser

High resolution 2D imaging experiment on the saturated 18.9 nm Ni-like soft X-ray laser is presented. The imaging experiment allows measurement of the absolute output energy and intensity of the X-ray laser, while it gives detailed information on the spatial characteristics of the X-ray laser for understanding the physics and further improving the performance of the X-ray laser.
Date: June 25, 1999
Creator: Dunn, J.; Li, Y.; Nilsen, J.; Osterheld, A. & Shlyaptsev, V. N.
System: The UNT Digital Library
Status of the U.S. Department of Energy/National Renewable Energy Laboratory Avian Research Program (open access)

Status of the U.S. Department of Energy/National Renewable Energy Laboratory Avian Research Program

As wind energy development expands, concern over possible negative impacts of wind farms on birds remains an issue to be addressed. The concerns are twofold: (1) possible litigation over the killing of even one bird if it is protected by the Migratory Bird Treaty Act and/or the Endangered Species Act, and (2) the effect of avian mortality on bird populations. To properly address these concerns, the National Renewable Energy Laboratory (NREL), working collaboratively with stakeholders including utilities, environmental groups, consumer advocates, regulators, government officials, and the wind industry, supports an avian-wind interaction research program. The objectives of the program are to conduct and sponsor scientifically based research that will ultimately lead to the reduction of avian fatality due to wind energy development throughout the United States. The approach for this program involves cooperating with the various stakeholders to study the impacts of current wind plants on avian populations, developing approaches to siting wind plants that avoid avian problems in the future, and investigating methods for reducing or eliminating impacts on birds due to the development of wind energy. This paper summarizes the research projects currently supported by NREL.
Date: June 21, 1999
Creator: Sinclair, K. C.
System: The UNT Digital Library
Combustion of TNT products in a confined explosion (open access)

Combustion of TNT products in a confined explosion

The effects of turbulent combustion of detonation products gases in a confined explosion are explored via laboratory experiments and high-resolution numerical simulations. The expanded products from the detonation of a TNT charge are rich in C and CO, which act as a fuel. When these hot gases mix with air, they are oxidized to CO2--thereby releasing 2482 Cal/g in addition to the 1093 Cal/g deposited by the detonation wave. In this case, the exothermic power is controlled by the turbulent mixing rate, rather than by chemistry. A kinetic law of turbulent combustion is suggested for this process. Pressure histories from the numerical simulations were in good agreement with the experimental measurements--demonstrating that the numerical model contains the fundamental mechanism that controls the exothermic process.
Date: June 18, 1999
Creator: Ferguson, R E; Kuhl, A L & Oppenheim, A K
System: The UNT Digital Library
Simulations of an underground explosion in granite (open access)

Simulations of an underground explosion in granite

This paper describes the results of a computational study performed to investigate the behavior of granite under shock wave loading conditions. A thermomechanically consistent constitutive model that includes the effects of bulking, yielding, material damage, and porous compaction on the material response was used in the simulations. The model parameters were determined based on experimental data, and the model was then used in a series of one-dimensional simulations of PILE DRIVER, a deeply-buried explosion in a granite formation at the Nevada Test Site. Particle velocity histories, peak velocity and peak displacement as a function of slant range, and the cavity radius obtained from the code simulations compared favorably with PILE DRIVER data.
Date: June 14, 1999
Creator: Antoun, T; Glenn, L A; Lomov, I N & Vorobiev, O Y
System: The UNT Digital Library
Application of Systems Engineering to U.S. Department of Energy Privatization Project Selection at the Hanford Nuclear Reservation (open access)

Application of Systems Engineering to U.S. Department of Energy Privatization Project Selection at the Hanford Nuclear Reservation

The privatization efforts at the U.S. Department of Energy's Hanford Nuclear Reservation have been very successful primarily due to a disciplined process for project selection and execution. Early in the development of Privatization at Hanford, the Department of Energy determined that a disciplined alternatives generation and analysis (AGA) process would furnish the candidate projects with the best probability for success. Many factors had to be considered in the selection of projects. Westinghouse Hanford Company was assigned to develop this process and facilitate the selection of the first round of candidate privatization projects. Team members for the AGA process were assembled from all concerned organizations and skill groups. Among the selection criteria were legal, financial and technical considerations which had to be weighed.
Date: June 1, 1999
Creator: Layman, J. A.
System: The UNT Digital Library
Voltage breakdown limits at a high material temperature for rapid pulse heating in a vacuum (open access)

Voltage breakdown limits at a high material temperature for rapid pulse heating in a vacuum

The proposed Advanced Hydro Facility (AHF) is required to produce multi-pulse radiographs. Electron beam pulse machines with sub-microsecond repetition are not yet available to test the problem of electron beam propagation through the hydro-dynamically expanding plasma from the nearby previously heated target material. A proposed test scenario includes an ohmically heated small volume of target material simulating the electron beam heating, along with an actual electron beam pulse impinging on nearby target material. A pulse power heating circuit was tested to evaluate the limits of pulse heating a small volume of material to tens of kilo-joules per gram. The main pulse heating time (50 to 100 ns) was to simulate the electron beam heating of a converter target material. To avoid skin heating non-uniformity a longer time scale pulse of a few microseconds first heats the target material to a few thousand degrees near the liquid to vapor transition. Under this state the maximum electric field that the current carrying conductor can support is the important parameter for insuring that the 100 ns heating pulse can deposit sufficient power. A small pulse power system was built for tests of this limit. Under cold conditions the vacuum electric field hold-off limit …
Date: June 7, 1999
Creator: Pincosy, P. A. & Speer, R.
System: The UNT Digital Library