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The Oklahoma Daily (Norman, Okla.), Vol. 83, No. 95, Ed. 1 Monday, February 1, 1999
Student newspaper of the University of Oklahoma in Norman, Oklahoma that includes national, local, and campus news along with advertising.
Date:
February 1, 1999
Creator:
Allam, Heather
Object Type:
Newspaper
System:
The Gateway to Oklahoma History
The Oklahoma Daily (Norman, Okla.), Vol. 83, No. 115, Ed. 1 Monday, March 1, 1999
Student newspaper of the University of Oklahoma in Norman, Oklahoma that includes national, local, and campus news along with advertising.
Date:
March 1, 1999
Creator:
Allam, Heather
Object Type:
Newspaper
System:
The Gateway to Oklahoma History
The Oklahoma Daily (Norman, Okla.), Vol. 83, No. 131, Ed. 1 Thursday, April 1, 1999
Student newspaper of the University of Oklahoma in Norman, Oklahoma that includes national, local, and campus news along with advertising.
Date:
April 1, 1999
Creator:
Allam, Heather
Object Type:
Newspaper
System:
The Gateway to Oklahoma History
EVALUATION OF COATINGS AND MORTARS FOR PROTECTION OF CONCRETE COOLING TOWER STRUCTURES FROM MICROBIOLOGICALLY INFLUENCED CORROSION IN GEOTHERMAL POWER PLANTS.
None
Date:
October 1, 1999
Creator:
Allan, M. L.
Object Type:
Report
System:
The UNT Digital Library
GROUND WATER PROTECTION ISSUES WITH GEOTHERMAL HEAT PUMPS
Closed loop vertical boreholes used with geothermal heat pumps are grouted to facilitate heat transfer and prevent ground water contamination. The grout must exhibit suitable thermal conductivity as well as adequate hydraulic sealing characteristics. Permeability and infiltration tests were performed to assess the ability of cementitious grout to control vertical seepage in boreholes. It was determined that a superplasticized cement-sand grout is a more effective borehole sealant than neat cement over a range of likely operational temperatures. The feasibility of using non-destructive methods to verify bonding in heat exchangers is reviewed.
Date:
October 1, 1999
Creator:
Allan, M. L. & Philippacopoulos, A. J.
Object Type:
Article
System:
The UNT Digital Library
Preparation of the First Shipment of Transuranic Waste by the Los Alamos National Laboratory: A Rest Stop on the Road to WIPP
The Los Alamos National Laboratory (LANL) achieved a national milestone on the road to shipping transuranic (TRU) waste to the Waste Isolation Pilot Plant (WIPP) when it received certification authority on September 12, 1997. Since that time, LANL has been characterizing a non-mixed TRU waste stream and preparing shipments of this TRU waste for disposal in the WIPP. The paper describes the TRU waste identified as waste stream TA-55-43 Lot No. 01 from LANL Technical Area-55 and the process used to determine that it does not contain hazardous waste regulated by the Resource Conservation Recovery Act (RCRA) or the New Mexico Hazardous Waste Act (HWA). The non-mixed determination is based on the acceptable knowledge (AK) characterization process, which clearly shows that the waste does not exhibit any RCRA characteristics nor meet any RCRA listing descriptions. LANL has certified TRU waste from waste stream TA-55-43 Lot No. 01 and is prepared to certify additional quantities of TRU waste horn other non-mixed TRU waste streams. Assembly and preparation of AK on the processes that generated TRU waste is recognized as a necessary part of the process for having waste ready for shipment to the WIPP.
Date:
February 1, 1999
Creator:
Allen, G.; Barr, Alice; Betts, S. E.; Farr, J.; Foxx, J.; Gavett, M. A. et al.
Object Type:
Article
System:
The UNT Digital Library
Midwave Infrared (2-6{micro}m) Emitter-Based Chemical Sensor Systems
Long wavelength (2-6 {micro}m) diode emitters are desirable for many applications including monitoring of chemical species in the environment and manufacturing, long wavelength fiber-optic communications, lidar, and JR detector counter-measures. No practical diode lasers are available for any of these applications because the band structure of bulk III-V, II-VI, and IV-VI semiconductor alloys results in large Auger recombination rates at these wavelengths. Experimental and theoretical work at Sandia has resulted in new understanding of the electronic properties of narrow bandgap III-V heterostructures, and we have found methods of reducing the Auger rates in certain InAsSb superlattices and quantum wells. These devices enable us to begin chemical sensing demonstrations of important species such as CO-CO{sub 2} and numerous other compounds. This project will involve developing chemical sensing systems and determining the sensitivity and limitations of these systems. Concurrently, we will improve upon infrared emitters used in these systems.
Date:
February 1, 1999
Creator:
Allerman, A. A.; Biefeld, R. M. & Kurtz, S. R.
Object Type:
Report
System:
The UNT Digital Library
Advanced Concepts for High-Power VCSELS and 2-Dimensional VCSEL Arrays
We have developed high power vertical cavity surface emitting lasers (VCSELS) for multimode or single mode operation. We have characterized new cavity designs for individual lasers and 2-dimensional VCSEL arrays to maximize output power. Using broad area high power VCSELS under pulsed excitation, we have demonstrated the triggering of a photoconductive semiconductor switch (PCSS) with a VCSEL. We also have developed designs for high output power in a single mode. The first approach is to engineer the oxide aperture profile to influence the optical confinement and thus modal properties. A second approach focuses on "leaky-mode" concepts using lateral modification of the cavity resonance to provide the lateral refractive index difference. To this end, we have developed a regrowth process to fabricate single-mode VCSELS. The overall objective of this work was to develop high-power single-mode or multimode sources appropriate for many applications leveraging the many inherent advantages of VCSELS.
Date:
April 1, 1999
Creator:
Allerman, A. A.; Choquette, Kent D.; Chow, W. W.; Geib, K. M.; Hadley, R.; Hou, H. Q. et al.
Object Type:
Report
System:
The UNT Digital Library
InGaAsN: A Novel Material for High-Efficiency Solar Cells and Advanced Photonic Devices
This report represents the completion of a 6 month Laboratory-Directed Research and Development (LDRD) program that focused on research and development of novel compound semiconductor, InGaAsN. This project seeks to rapidly assess the potential of InGaAsN for improved high-efficiency photovoltaic. Due to the short time scale, the project focused on quickly investigating the range of attainable compositions and bandgaps while identifying possible material limitations for photovoltaic devices. InGaAsN is a new semiconductor alloy system with the remarkable property that the inclusion of only 2% nitrogen reduces the bandgap by more than 30%. In order to help understand the physical origin of this extreme deviation from the typically observed nearly linear dependence of alloy properties on concentration, we have investigated the pressure dependence of the excited state energies using both experimental and theoretical methods. We report measurements of the low temperature photoluminescence energy of the material for pressures between ambient and 110 kbar. We describe a simple, density-functional-theory-based approach to calculating the pressure dependence of low lying excitation energies for low concentration alloys. The theoretically predicted pressure dependence of the bandgap is in excellent agreement with the experimental data. Based on the results of our calculations, we suggest an explanation for …
Date:
July 1, 1999
Creator:
Allerman, Andrew A.; Follstaedt, David M.; Gee, James M.; Jones, Eric D.; Kurtz, Steven R. & Modine, Norman A.
Object Type:
Report
System:
The UNT Digital Library
Developing a CD-CBM Anticipatory Approach for Cavitation - Defining a Model-Based Descriptor Consistent Across Processes, Phase 1 Final Report Context-Dependent Prognostics and Health Assessment: A New Paradigm for Condition-based Maintenance SBIR Topic No. N98-114
The objective of this research, and subsequent testing, was to identify specific features of cavitation that could be used as a model-based descriptor in a context-dependent condition-based maintenance (CD-CBM) anticipatory prognostic and health assessment model. This descriptor is based on the physics of the phenomena, capturing the salient features of the process dynamics. The test methodology and approach were developed to make the cavitation features the dominant effect in the process and collected signatures. This would allow the accurate characterization of the salient cavitation features at different operational states. By developing such an abstraction, these attributes can be used as a general diagnostic for a system or any of its components. In this study, the particular focus will be pumps. As many as 90% of pump failures are catastrophic. They seem to be operating normally and fail abruptly without warning. This is true whether the failure is sudden hardware damage requiring repair, such as a gasket failure, or a transition into an undesired operating mode, such as cavitation. This means that conventional diagnostic methods fail to predict 90% of incipient failures and that in addressing this problem, model-based methods can add value where it is actually needed.
Date:
June 1, 1999
Creator:
Allgood, G. O.; Dress, W. B. & Kercel, S. W.
Object Type:
Report
System:
The UNT Digital Library
The AMTEX (tm) Computer-Aided Fabric Evaluation (CAFE) Project
The American textile industry has lost an estimated 400,000 jobs to offshore competitors since 1980. If trends continue unchanged, it is predicted they will lose an additional 600,000 jobs by the year 2002. These losses and the resulting economic threat to the U.S. textile industry can be attributed to the low operating costs of their offshore competitors' extensive use of cheap labor. In order to stem these rising losses and gain back lost market shares, the American textile industry has entered into a cooperative research and development agreement (CRADA) with the U.S. Department of Energy (DOE) in a program called the American Textile Partnership (AMTEX). AMTEX is a working relationship aimed at leveraging technologies that currently exist at the DOE national laboratories for the benefit and development of a competitive market edge for the U.S. textile manufacturers. The application of these technologies to identified needs will result in new and emerging manufacturing innovations for the U.S. textile industry and its vendor.
Date:
May 1, 1999
Creator:
Allgood, Glenn O. & Kametches, Mark L.
Object Type:
Report
System:
The UNT Digital Library
Accomplishments of the Abacc-Doe Cooperation Program
None
Date:
November 1, 1999
Creator:
Almeida, G. L. De; Palhares, L. & Al, Et
Object Type:
Article
System:
The UNT Digital Library
Laterally graded multilayer double-monochromator.
The authors describe a tunable multilayer monochromator with an adjustable bandpass to be used for reflectivity and grazing incidence diffraction studies on surfaces at energies near 10 keV. Multilayers have a bandpass typically 100 times larger than the Si(111) reflection, and by using multilayers an experimenter can significantly increase data collection rates over those available with a Si monochromator. The transmission through 1 and 2 laterally graded multilayer (LGML) reflections was recorded versus photon energy. The identical LGMLs were comprised of 60 bilayers of W and C on 100 x 25 x 3 mm float glass with a bilayer spacing varying from 35 to 60 {angstrom}. The average gradient was 0.27 {angstrom}/mm along the long dimension. The rms deviation of the data for the bilayer spacing from a linear fit was 0.36 {angstrom}. Data were obtained for a nondispersive ({+-}) double-multilayer arrangement. The relative bandpass width (FWHM) when the two multilayers exposed the same bilayer spacing was measured to be 2.2% with a transmission of 78.7 {+-} 1.6%. This value is consistent with the transmission of 88.9% that they also measured for a single LGML at HASYLAB beamline D4. The bandpass was tunable in the range 1.1% to 2.2%.
Date:
September 1, 1999
Creator:
Als-Nielsen, J.; Erdmann, J.; Gaarde, P.; Krasnicki, S.; Liu, C.; Macrander, A. T. et al.
Object Type:
Article
System:
The UNT Digital Library
A Hybrid Hydrologic-Geophysical Inverse Technique for the Assessment and monitoring of Leachates in the Vadose Zone
The objective of this study is to develop and field test a new, integrated Hybrid Hydrologic-Geophysical Inverse Technique (HHGIT) for characterization of the vadose zone at contaminated sites. This new approach to site characterization and monitoring can provide detailed maps of hydrogeological heterogeneity and the extent of contamination by combining information from 3D electric resistivity tomography (ERT) and/or 2D cross borehole ground penetrating radar (XBGPR) surveys, statistical information about heterogeneity and hydrologic processes, and sparse hydrologic data. Because the electrical conductivity and dielectric constant of the vadose zone (from the ERT and XBGPR measurements, respectively) can be correlated to the fluid saturation and/or contaminant concentration, the hydrologic and geophysical measurements are related.
Date:
June 1, 1999
Creator:
Alumbaugh, David L.; Yeh, Jim; LaBrecque, Doug & Glass, Robert J.
Object Type:
Report
System:
The UNT Digital Library
Analytical methods for the determination of carbon tetrachloride in soils.
Improved methods for the determination of carbon tetrachloride are described. These methods incorporate purge-and-trap concentration of heated dry samples, an improved methanol extraction procedure, and headspace sampling. The methods minimize sample pretreatment, accomplish solvent substitution, and save time. The methanol extraction and headspace sampling procedures improved the method detection limits and yielded better sensitivity, good recoveries, and good performance. Optimization parameters are shown. Results obtained with these techniques are compared for soil samples from contaminated sites.
Date:
June 1, 1999
Creator:
Alvarado, J. S.; Spokas, K. & Taylor, J.
Object Type:
Article
System:
The UNT Digital Library
Modeling of the performance of weapons MOX fuel in light water reactors
Both the Russian Federation and the US are pursing mixed uranium-plutonium oxide (MOX) fuel in light water reactors (LWRs) for the disposition of excess plutonium from disassembled nuclear warheads. Fuel performance models are used which describe the behavior of MOX fuel during irradiation under typical power reactor conditions. The objective of this project is to perform the analysis of the thermal, mechanical, and chemical behavior of weapons MOX fuel pins under LWR conditions. If fuel performance analysis indicates potential questions, it then becomes imperative to assess the fuel pin design and the proposed operating strategies to reduce the probability of clad failure and the associated release of radioactive fission products into the primary coolant system. Applying the updated code to anticipated fuel and reactor designs, which would be used for weapons MOX fuel in the US, and analyzing the performance of the WWER-100 fuel for Russian weapons plutonium disposition are addressed in this report. The COMETHE code was found to do an excellent job in predicting fuel central temperatures. Also, despite minor predicted differences in thermo-mechanical behavior of MOX and UO{sub 2} fuels, the preliminary estimate indicated that, during normal reactor operations, these deviations remained within limits foreseen by fuel …
Date:
May 1, 1999
Creator:
Alvis, J.; Bellanger, P.; Medvedev, P.G.; Peddicord, K.L. & Gellene, G.I.
Object Type:
Report
System:
The UNT Digital Library
Effect of Operating Parameters and Chemical Additives on Crystal Habit and Specific Cake Resistance of Zinc Hydroxide Precipitates
The effect of process parameters and chemical additives on the specific cake resistance of zinc hydroxide precipitates was investigated. The ability of a slurry to be filtered is dependent upon the particle habit of the solid and the particle habit is influenced by certain process variables. The process variables studied include neutralization temperature, agitation type, and alkalinity source used for neutralization. Several commercially available chemical additives advertised to aid in solid/liquid separation were also examined in conjunction with hydroxide precipitation. A statistical analysis revealed that the neutralization temperature and the source of alkalinity were statistically significant in influencing the specific cake resistance of zinc hydroxide precipitates in this study. The type of agitation did not significantly effect the specific cake resistance of zinc hydroxide precipitates. The use of chemical additives in conjunction with hydroxide precipitation had a favorable effect on the filterability. The morphology of the hydroxide precipitates was analyzed using scanning electron microscopy.
Date:
August 1, 1999
Creator:
Alwin, Jennifer Louise
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Medium Energy Measurements of N-N Parameters. Final technical report
None
Date:
October 1, 1999
Creator:
Ambrose, David; Coffey, Patrick; Glass, George; McNaughton, Kok Hoeng; Riley, Peter & Tang, Jaw-Luen
Object Type:
Report
System:
The UNT Digital Library
Safety Analyses at the Idaho National Engineering and Environmental Laboratory Test Reactor Area - Past to Present
Test reactors are unique in that the core configuration may change with each operating interval. The process of safety analyses for test reactors at the Idaho National Engineering and Environmental Test Reactor Area has evolved as the computing capabilities, software, and regulatory requirements have changed. The evaluations for experiments and the reactor have moved from measurements in a set configuration and then application to other configurations with a relatively large error to modeling in three-dimensions and explicit analyses for each experiment and operating interval. This evolution is briefly discussed for the Test Reactor Area.
Date:
November 1, 1999
Creator:
Ambrosek, Richard Garry & Ingram, Frederick William
Object Type:
Article
System:
The UNT Digital Library
High convergence implosion symmetry in cylindrical hohlraums
High convergence, hohlraum-driven implosions will require control of time-integrated drive asymmetries to 1% levels for ignition to succeed on the NIF. We review how core imaging provides such asymmetry measurement accuracy for the lowest order asymmetry modes, and describe recent improvements in imaging techniques that should allow detection of higher order asymmetry modes. We also present a simple analytic model explaining how the sensitivity of symmetry control to beam pointing scales as we progress from single ring per side Nova cylindrical hohlraum illumination geometries to NIF-like multiple rings per side Omega hohlraum illumination geometries and ultimately to NIF-scale hohlraums.
Date:
September 1, 1999
Creator:
Amendt, P. A.; Bradley, D. K.; Hammel, B. A.; Landen, O. L.; Suter, L. J.; Turner, R. E. et al.
Object Type:
Article
System:
The UNT Digital Library
Immersive CAD
This paper documents development of a capability for performing shape-changing editing operations on solid model representations in an immersive environment. The capability includes part- and assembly-level operations, with part modeling supporting topology-invariant and topology-changing modifications. A discussion of various design considerations in developing an immersive capability is included, along with discussion of a prototype implementation we have developed and explored. The project investigated approaches to providing both topology-invariant and topology-changing editing. A prototype environment was developed to test the approaches and determine the usefulness of immersive editing. The prototype showed exciting potential in redefining the CAD interface. It is fun to use. Editing is much faster and friendlier than traditional feature-based CAD software. The prototype algorithms did not reliably provide a sufficient frame rate for complex geometries, but has provided the necessary roadmap for development of a production capability.
Date:
February 1, 1999
Creator:
Ames, A. L.
Object Type:
Report
System:
The UNT Digital Library
CdZnTe Material Uniformity and Coplanar-Grid Gamma-Ray Detector Performance
None
Date:
October 1, 1999
Creator:
Amman, M.; Luke, P. N. & Lee, J. S.
Object Type:
Article
System:
The UNT Digital Library
Three-Dimensional Position-Sensitive Geranium Detectors
A critical component of the DOE decontamination and decommissioning effort is the characterization of radioactively contaminated equipment and structures. Gamma-ray spectroscopy and imaging with germanium (Ge) based detectors are powerful techniques that allow for the quick and accurate in-situ identification, spatial mapping, and quantification of radioactive contaminants. However, the image resolution obtained with a Ge detector can be limited by the accuracy to which the gamma-ray interaction events are spatially detected within the detector itself. Our primary objective is to develop the technologies necessary to produce Ge gamma-ray detectors with enhanced accuracy in locating gamma-ray interaction events thereby resulting in improved image resolution. Our approach is to locate the gamma ray interaction events within the detector in all three dimensions rather than just two. Additionally, we will base the detectors on known and tested LBNL fabrication technologies and utilize the simplest possible detector geometries and signal-readout electrode structures in order to reduce the system complexity and difficulties in fabrication. The technologies developed as a result of this research will form the basis for the design and construction of future high-performance gamma-ray imaging systems. These instruments will greatly facilitate DOE's radioactive materials characterization process.
Date:
June 1, 1999
Creator:
Amman,Mark & Luke, Paul N.
Object Type:
Report
System:
The UNT Digital Library
Isotope Production at the Hanford Site in Richland, Washington
This report was prepared in response to a request from the Nuclear Energy Research Advisory Committee (NERAC) subcommittee on ''Long-Term Isotope Research and Production Plans.'' The NERAC subcommittee has asked for a reply to a number of questions regarding (1) ''How well does the Department of Energy (DOE) infrastructure sme the need for commercial and medical isotopes?'' and (2) ''What should be the long-term role of the federal government in providing commercial and medical isotopes?' Our report addresses the questions raised by the NERAC subcommittee, and especially the 10 issues that were raised under the first of the above questions (see Appendix). These issues are related to the isotope products offered by the DOE Isotope Production Sites, the capabilities and condition of the facilities used to produce these products, the management of the isotope production programs at DOE laboratories, and the customer service record of the DOE Isotope Production sites. An important component of our report is a description of the Fast Flux Test Facility (FFTF) reactor at the Hbford Site and the future plans for its utilization as a source of radioisotopes needed by nuclear medicine physicians, by researchers, and by customers in the commercial sector. In response to …
Date:
June 1, 1999
Creator:
Ammoniums
Object Type:
Report
System:
The UNT Digital Library