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Self-consistent study of the alpha particle driven TAE mode
The interaction of high energy particles with an Alfven eigenmode is investigated self-consistently by using a realistic kinetic dispersion relation. All important poloidal mode numbers and their radial mode profiles as calculated with the NOVA-K code are included. A Hamiltonian guiding center code is used to simulate the alpha particle motion. The numerical simulations include particle orbit width, nonlinear particle dynamics and the effects of the modes on the particles. Modification of the particle distribution leading to mode saturation is observed. Particle loss is limited to devices in which the alpha particle gyro radius is a significant fraction of the minor radius.
Date:
April 1, 1994
Creator:
Wu, Y. & White, R. B.
Object Type:
Report
System:
The UNT Digital Library
Semantic modeling for theory clarification: The realist vs liberal international relations perspective
This paper describes a natural language based, semantic information modeling methodology and explores its use and value in clarifying and comparing political science theories and frameworks. As an example, the paper uses this methodology to clarify and compare some of the basic concepts and relationships in the realist (e.g. Waltz) and the liberal (e.g. Rosenau) paradigms for international relations. The methodology can provide three types of benefits: (1) it can clarify and make explicit exactly what is meant by a concept; (2) it can often identify unanticipated implications and consequence of concepts and relationships; and (3) it can help in identifying and operationalizing testable hypotheses.
Date:
April 1, 1994
Creator:
Bray, O. H.
Object Type:
Article
System:
The UNT Digital Library
Semi-annual sampling of Fourmile Branch and its seeplines in the F and H Areas of SRS: July 1992
In July 1992, water samples were collected from Fourmile Branch (FMB) and its seeplines in the vicinity of the F and H-Area seepage basins. The samples were collected from five seepline locations in F Area, five seepline locations in H Area, and three stream locations on FMB. The sampling event was the first in a series of three semi-annual sampling event was the first in a series of three semi-annual sampling events aimed at characterizing the shallow groundwater outcropping into FMB and its wetlands. In the past, this groundwater has been shown to contain contaminants migrating from the F- and H-Area seepage basins. The samples were analyzed for Appendix 9 metals, various radionuclides, selected volatile compounds, and selected inorganic constituents and parameters. Results from the July 1992 sampling event suggest that the seeplines in both F and H Areas and FMB continue to be influenced by contaminants migrating from the F- and H-Area seepage basins. However, when compared to 1989 measurements, the concentrations of most of the constituents have declined. Contaminant concentration measured in July 1992 were compared to primary drinking water standards (PDWS), secondary drinking water standards (SDWS), and maximum contaminant levels (MCL) enforceable in 1993. Results were also …
Date:
April 1, 1994
Creator:
Dixon, K. L. & Rogers, V. A.
Object Type:
Report
System:
The UNT Digital Library
Semiannual report to Congress, October 1, 1993--March 31, 1994
The report summarizes significant audit, inspection and investigative accomplishments for the reporting period. a large portion of which evaluated management controls that the Department of Energy uses to ensure efficient and effective operation of its programs. During this period, the Office of Inspector General (OIG) issued 128 audit and eight inspection reports. OIG also issued 37 investigative referrals to management for corrective action. As a result of audits of contract costs, OIG questioned $665,802 in costs. Management committed to talking corrective actions which OIG estimates will result in a more efficient use of funds totaling $55.9 million. For reports issued during the period, OIG made audit recommendations that when implemented by management, could result in $1.15 billion being put to better use. In addition, the OIG investigations led to 10 criminal convictions and pretrial diversions, as well as criminal and civil prosecutions which resulted in fines and recoveries of $4,052,206.
Date:
April 1, 1994
Creator:
unknown
Object Type:
Report
System:
The UNT Digital Library
SERAPHIM: A magnetic propulsion scheme for fast trains
We are attempting to develop and demonstrate a new type of linear synchronous induction motor capable of propelling a vehicle at high speed. The technology, based on a passive guideway containing sequential aluminum plates, was developed in Sandia`s electromagnetic launch program. As such, it was called a ``re-connection gun`` and launched an aluminum plate from between pairs of pancake coils. In the proposed propulsion scheme, the plates are fixed and the coils move. Pairs of closely spaced pancake coils on the vehicle straddle vertically mounted aluminum plates in the roadbed. The current in the coils is turned on when the plate is fully covered, peaks at some optimal time, and decreases to zero before separation. This induces currents in the plate which interact with the coil current to produce repulsive forces. In essence, the pulsed coils push off the edge of the plate because at the high frequency of operation, the current has insufficient time to fully penetrate. Since no embedded flux is required, the efficiency actually increases with speed. This concept has been named SERAPHIM, for SEgmented RAil PHased Induction Motor.
Date:
April 1, 1994
Creator:
Marder, B. M.; Frost, C. A.; Lipinski, R. J. & Cowan, M.
Object Type:
Article
System:
The UNT Digital Library
Shear wall ultimate drift limits
Drift limits for reinforced-concrete shear walls are investigated by reviewing the open literature for appropriate experimental data. Drift values at ultimate are determined for walls with aspect ratios ranging up to a maximum of 3.53 and undergoing different types of lateral loading (cyclic static, monotonic static, and dynamic). Based on the geometry of actual nuclear power plant structures exclusive of containments and concerns regarding their response during seismic (i.e.,cyclic) loading, data are obtained from pertinent references for which the wall aspect ratio is less than or equal to approximately 1, and for which testing is cyclic in nature (typically displacement controlled). In particular, lateral deflections at ultimate load, and at points in the softening region beyond ultimate for which the load has dropped to 90, 80, 70, 60, and 50 percent of its ultimate value, are obtained and converted to drift information. The statistical nature of the data is also investigated. These data are shown to be lognormally distributed, and an analysis of variance is performed. The use of statistics to estimate Probability of Failure for a shear wall structure is illustrated.
Date:
April 1, 1994
Creator:
Duffey, T. A.; Goldman, A. & Farrar, C. R.
Object Type:
Report
System:
The UNT Digital Library
Signal processing and classification of acoustic signatures from Bjoerk-Shiley Convexo-Concave heart valves
None
Date:
April 1, 1994
Creator:
Thomas, G. H.; Clark, G. A.; Crawford, S. L.; Buhl, M. R. & Borate, N.
Object Type:
Article
System:
The UNT Digital Library
Simple geometry dose rate benchmarks for spent fuel cask analysis
Two sets of simple geometry benchmarks were analyzed using two independent Monte Carlo radiation transport codes to estimate the expected accuracies of both the spent fuel source terms and the neutron and gamma-ray transport for typical spent fuel storage/transport cask applications. The first set of dose rate measurements were performed at General Electric-Morris Operation for single, unshielded spent fuel assemblies in both dry and wet configurations. The second set of benchmark experiments carried out in Japan consisted of a series of dose rate measurements for a {sup 252}Cf neutron source and a {sup 60}Co photon source impinging onto shields of cask material of varying thicknesses. The details of the analysis of these measurements is described herein along with comparison with experimentally obtained neutron and gamma dose rates.
Date:
April 1, 1994
Creator:
Taniuchi, H. & Broadhead, B. L.
Object Type:
Article
System:
The UNT Digital Library
Simulation and performance analysis of a quadruple-effect lithium bromide-water absorption
In order to investigate the possibility of improving utilization of high temperature heat sources, such as natural gas, for absorption chillers, performance simulation has been conducted for a quadruple-effect lithium bromide-water cycle, capable of substantial performance improvement over state-of-the-art double-effect cycles. The system investigated includes four condensers and four desorbers coupled together, forming an extension of the conventional double-effect cycle; based on prior experience, a parallel flow system was perferred over series flow, and double-condenser coupling (DCC) was employed, extending from triple-effect cycles, to further improve performance. A modular computer code for simulation of absorption systems (ABSIM) was used to investigate the performances of the cycle. The simulation was carried out over a range of operating conditions, including investigation of the influence of some major design parameters. A coefficient of performance in the neighborhood of 2.0 (cooling) was calculated at the design point, with a heat supply temperature of 600{degrees}F at the solution outlet from the high temperature desorber. With some optimization of the weak (pumped) solution flowrate and of the solution split among the four desorbers, this COP may be raised above 2.2, without any increase in the heat transfer surface of the system`s components.
Date:
April 1, 1994
Creator:
Grossman, G.; Zaltash, A. & DeVault, R. C.
Object Type:
Article
System:
The UNT Digital Library
Simulation of stellar speckle imaging
Standard FFT-based phase screen generation methods do not accurately model low frequency turbulence characteristics. This paper introduces a new phase screen generation technique which uses low frequency subharmonic methods. The structure functions for this new method match very closely the structure functions of Kolmogorov turbulence theory.
Date:
April 1, 1994
Creator:
Johansson, E. M. & Gavel, D. T.
Object Type:
Article
System:
The UNT Digital Library
Simulation of the GEM central tracker performance using GEANT
The GEM (Gamma Electron Muon) central tracker (one of the proposed detectors for the Superconducting Supercollider (SSC)) has been simulated using the high energy physics Monte Carlo code GEANT. The performance of the GEM central tracker in terms of momentum, impact parameter, and z vertex resolution has been determined. The resolutions will be presented for both the full tracker which includes a silicon portion and an IPC portion and for the 10{sup 34} configuration which is comprised of only IPC chambers. The resolution of electrons vs. muons will also be presented.
Date:
April 1, 1994
Creator:
Brooks, M. L.
Object Type:
Report
System:
The UNT Digital Library
A simulation study of infiltration into surficial sediments at the Subsurface Disposal Area, Idaho National Engineering Laboratory
Soil moisture monitoring data in the surficial sediments at the Subsurface Disposal Area (SDA) at the Idaho National Engineering Laboratory were used to calibrate two numerical infiltration models. The calibration was performed with the ultimate goal of providing a reliable estimate of hydraulic properties and infiltration amounts to be used in other modeling efforts. Two neutron probe access tubes and a tensiometer nest were monitored from 1986 to 1990 and again during 1993. The field measurements of moisture content and matrix potential inside the SDA were used as calibration data for the two locations. The two locations showed vastly different behavior, which was well captured in the models. The average root mean square error between simulated and measured moisture contents over the simulation period was 0.03 and 0.06 for the two locations. The hydraulic parameters resulting from the calibration compared favorably with laboratory and field scale estimates. The simulation results also provided the opportunity to partially explain infiltration and redistribution processes occurring at the SDA. The underlying fractured basalt appears to behave similar to a capillary barrier. This behavior inhibits moisture movement into the underlying basalts until moisture contents in the overlying silts approach saturation. As a result, a large …
Date:
April 1994
Creator:
Martian, P. & Magnuson, S. O.
Object Type:
Report
System:
The UNT Digital Library
Single molecule detection using charge-coupled device array technology. Final report
An ultra sensitive technique for the detection of fluorescent species in a flowing stream has been developed. The extension of this technique to the detection of fluorescently tagged nucleotides will be a significant benefit to one of the novel approaches for DNA sequencing being developed at Los Alamos National Laboratories. The detection scheme is based on a novel mode of operating a Charge-Coupled Device (CCD) which greatly enhances the discrimination between fluorescence from the analyte and the background Raman scattering from the solvent. Register shifts between rows in the CCD are synchronized with the sample flow velocity so that fluorescence from a single species is collected in a single moving charge packet occupying an area approaching that of a single pixel while the background is spread evenly among a large number of pixels. This research has demonstrated that this technique is highly effective for the detection of fluorescently labelled latex microspheres. With additional development, the authors believe that this technique will achieve single molecule detection.
Date:
April 1, 1994
Creator:
Denton, M. B.
Object Type:
Report
System:
The UNT Digital Library
[Six men posing together photograph]
A photograph of (left to right) Chris Thompson, Tom Teves, Denny Maust, William Waybourn, an unknown individual, and George Harris. The men pose with their arms around each other, smiling at the camera.
Date:
April 1994
Creator:
unknown
Object Type:
Photograph
System:
The UNT Digital Library
Slipstream, Volume 32, Number 4, April 1994
Monthly magazine published by the Maverick Region of the Porsche Club of America containing stories related to the organization or of interest to the group's members including news, upcoming and past events, other feature articles, and classified advertisements.
Date:
April 1994
Creator:
Porsche Club of America. Maverick Region.
Object Type:
Journal/Magazine/Newsletter
System:
The Portal to Texas History
Sloan digital sky survey
The Sloan Digital Sky Survey will produce a detailed digital photometric map of half the northern sky to about 23 magnitude using a special purpose wide field 2.5 meter telescope. From this map we will select {approximately} 10{sup 6} galaxies and 10{sup 5} quasars, and obtain high resolution spectra using the same telescope. The imaging catalog will contain 10{sup 8} galaxies, a similar number of stars, and 10{sup 6} quasar candidates.
Date:
April 1, 1994
Creator:
Kent, S. M.; Stoughton, C.; Newberg, H.; Loveday, J.; Petravick, D.; Gurbani, V. et al.
Object Type:
Article
System:
The UNT Digital Library
A small, portable gas chromatograph-quadrupole mass spectrometer for on-site analysis
Gas chromatography-mass spectrometry (GC-MS) is the analytical tool of choice for the exact identification of unknown organic chemicals in environmental samples. Capillary gas chromatography, combined with the specific identification capabilities of mass spectrometry, allows the rapid and complete characterization of individual compounds in complex mixtures. As the technology has developed, many manufacturers have offered bench-top MS systems that provide a variety of analytical capabilities. Many instruments have been promoted as ``detectors for gas chromatography.`` More recently, manufacturers have offered integrated packages that can be transported to the field to provide analytical capabilities previously available only in the laboratory. The demonstrated field utility of these field-transportable units has triggered an interest in smaller, lighter weight, and more portable instruments. However, the current weight (>100 lb), large size, and laboratory-based power consumption requirements of these units is viewed as a liability by some potential field instrument users. Over the past several years, the interest in field-deployable instruments has resulted in research and development into smaller GC-MS systems designed with limited applications. While the development of these instruments is certainly worthwhile, a reliable and robust GC-MS instrument that clearly addresses the field-deployable needs for all environmental sampling and analysis would have considerable utility. …
Date:
April 1, 1994
Creator:
Andresen, B.; Coutts, G.; Alcaraz, A.; Bushman, J. & Cornish, J.
Object Type:
Report
System:
The UNT Digital Library
The Social Security Administration's Decentralized Computer Strategy: Issues and Options
The report highlights some of the opportunities and challenges faced by a major federal agency in: 1 ) implementing the Administration’s “National Performance Review and “National Information Infrastructure” programs, and 2) addressing issues raised in OTA’s 1993 report Making Government Work: Electronic Delivery of Federal Services.
Date:
April 1994
Creator:
United States. Congress. Office of Technology Assessment.
Object Type:
Report
System:
The UNT Digital Library
Solar Electric Generating System II finite element analysis
On June 2, 1992, Landers` earthquake struck the Solar Electric Generating System II, located in Daggett, California. The 30 megawatt power station, operated by the Daggett Leasing Corporation (DLC), suffered substantial damage due to structural failures in the solar farm. These failures consisted of the separation of sliding joints supporting a distribution of parabolic glass mirrors. At separation, the mirrors fell to the ground and broke. It was the desire of the DLC and the Solar Thermal Design Assistance Center (STDAC) of Sandia National Laboratories (SNL) and to redesign these joints so that, in the event of future quakes, costly breakage will be avoided. To accomplish this task, drawings of collector components were developed by the STDAC, from which a detailed finite element computer model of a solar collector was produced. This nonlinear dynamic model, which consisted of over 8,560 degrees of freedom, underwent model reduction to form a low order nonlinear dynamic model containing only 40 degrees of freedom. This model was then used as a design tool to estimate joint dynamics. Using this design tool, joint configurations were modified, and an acceptable joint redesign determined. The results of this analysis showed that the implementation of metal stops welded …
Date:
April 1, 1994
Creator:
Dohner, J. L. & Anderson, J. R.
Object Type:
Report
System:
The UNT Digital Library
Solubility, viscosity and density of refrigerant/lubricant mixtures. Final technical report, [1 October 1992--19 April 1994]
This report presents the results of experimental measurements on low refrigerant concentration mixtures (0, 10, 20 and 30 weight percent) and high refrigerant concentration mixtures (80, 90 and 100 weight percent) of chlorofluorocarbon (CFC) 12, hydrochlorofluorocarbons (HCFC`s) 22, 123, 124 and 142b, and hydrofluorocarbons (BFC`s) 134a, 32, 125, 152a and 143a with mineral oil, alkylbenzene, polyalkylene glycol and polyolester lubricants. Viscosity, solubility (vapor pressure) and density data are reported for thirty five working fluids which are selected combinations of these refrigerants and companion lubricants. These data, reduced to engineering form, are presented in the form of a Daniel Chart and a plot of density versus temperature and composition. Extensive numerical analysis has been performed in order to derive equations which allow two independent variables (temperature and composition) and to provide for corrections in composition due to vapor space volume in the test apparatus.
Date:
April 1, 1994
Creator:
Henderson, D. R.
Object Type:
Report
System:
The UNT Digital Library
Solvent effects on the energetics and dynamics of ultrafast electron transfer in chlorophyll-porphyrin-acceptor triads
An understanding of the role of the medium that lies between electron donors and acceptors is particularly important for the study of photosynthetic reaction centers where the medium is thought to have a large influence on the observed rates of electron transfer. In the bacterial photosynthetic reaction center a bacteriochlorophyll (BChl) molecule lies between the dimeric bacteriochlorophyll (BChl{sub 2}) and the bacteriopheophytin (BPh) acceptor. Femtosecond transient absorption spectroscopy of native reaction centers has yielded evidence for both superexchange and two-step electron transfer mechanisms mediated by the bridging BChl. We have prepared molecules that mimic this structural arrangement to better understand the influence of solvation dynamics and the low-lying electron states of a bridging porphyrin molecule (ZP) on electron transfer rates within molecules that possess a chlorophyll donor (ZC) and either a napthoquinone (NQ) or a 3,4,9,10-perylenetetracarboxydiimide (PER) acceptor.
Date:
April 1, 1994
Creator:
Wiederrecht, G. P.; Watanabe, S. & Wasielewski, M. R.
Object Type:
Article
System:
The UNT Digital Library
The Sort on Radioactive Waste Type model: A method to sort single-shell tanks into characteristic groups
The Sort on Radioactive Waste Type (SORWT) model presents a method to categorize Hanford Site single-shell tanks (SSTs) into groups of tank expected to exhibit similar chemical and physical characteristics based on their major waste types and processing histories. This model has identified 29 different waste-type groups encompassing 135 of the 149 SSTs and 93% of the total waste volume in SSTs. The remaining 14 SSTs and associated wastes could not be grouped according to the established criteria and were placed in an ungrouped category. This letter report will detail the assumptions and methodologies used to develop the SORWT model and present the grouping results. In the near future, the validity of the predicted groups will be statistically tested using analysis of variance of characterization data obtained from recent (post-1989) core sampling and analysis activities. In addition, the SORWT model will be used to project the nominal waste characteristics of entire waste type groups that have some recent characterization data available. These subsequent activities will be documented along with these initial results in a comprehensive, formal PNL report cleared for public release by September 1994.
Date:
April 1, 1994
Creator:
Hill, J. G. & Simpson, B. C.
Object Type:
Report
System:
The UNT Digital Library
Source term development for the 300 Area Treated Effluent Disposal Facility
A novel method for developing a source term for radiation and hazardous material content of sludge processing equipment and barrels in a new waste water treatment facility is presented in this paper. The 300 Area Treated Effluent Disposal Facility (TEDF), located at the Hanford Site near Richland, Washington, will treat process sewer waste water from the 300 Area and discharge a permittable effluent flow into the Columbia River. A process information and hazards analysis document needed a process flowsheet detailing the concentrations of radionuclides, inorganics, and organics throughout the process, including the sludge effluent flow. A hazards analysis for a processing facility usually includes a flowsheet showing the process, materials, heat balances, and instrumentation for that facility. The flow sheet estimates stream flow quantities, activities, compositions, and properties. For the 300 Area TEDF, it was necessary to prepare the flow sheet with all of the information so that radiation doses to workers could be estimated. The noble method used to develop the 300 Area TEDF flowsheet included generating recycle factors. To prepare each component in the flowsheet, precipitation, destruction, and two recycle factors were developed. The factors were entered into a spreadsheet and provided a method of estimating the steady-state …
Date:
April 1, 1994
Creator:
Bendixsen, R. B.
Object Type:
Article
System:
The UNT Digital Library
South Korea: U.S. Defense Obligations
U.S. defense obligations to South Korea are contained in the U.S.-South Korean Mutual Defense Treaty, signed in 1953 and ratified in 1954. Under Article m of the treaty, the United States would "act to meet" an attack on South Korea "in accordance with its [U.S.] constitutional processes." At the time of ratification, the Senate Foreign Relations Committee did not define specifically the respective roles of the President and Congress in any decision to act militarily in accord with constitutional processes. The Committee stressed that Article did not set a requirement for an automatic American military response but that it did give the United States a wide range of possible actions
Date:
April 1, 1994
Creator:
Niksch, Larry A.
Object Type:
Report
System:
The UNT Digital Library