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INTRINSIC RESIDUAL STRESSES IN METAL FILMS SYNTHESIZED BY ENERGETIC PARTICLE DEPOSITION
None
Date:
September 15, 2000
Creator:
A. MISRA, M. NASTASI
Object Type:
Article
System:
The UNT Digital Library
Use of inelastic analysis in cask design
In this paper, the advantages and disadvantages of inelastic analysis are discussed. Example calculations and designs showing the implications and significance of factors affecting inelastic analysis are given. From the results described in this paper it can be seen that inelastic analysis provides an improved method for the design of casks. It can also be seen that additional code and standards work is needed to give designers guidance in the use of inelastic analysis. Development of these codes and standards is an area where there is a definite need for additional work. The authors hope that this paper will help to define the areas where that need is most acute.
Date:
May 15, 2000
Creator:
AMMERMAN,DOUGLAS J. & BREIVIK,NICOLE L.
Object Type:
Article
System:
The UNT Digital Library
The Migration and Entrapment of DNAPLs in Physically and Chemically Heterogeneous Porous Media - Final Report - 09/15/1996 - 09/15/2000
Hazardous dense nonaqueous phase liquids (DNAPLs), such as chlorinated solvents, are slightly water soluble and pose a serious threat to soil and groundwater supplies in many portions of the United States. The migration and entrapment of DNAPLs in the subsurface environment is typically believed to be controlled by physical heterogeneities; i.e, layers and lenses of contrasting soil texture. The rationale for this assumption is that capillarity, as determined by the soil texture, is the dominant transport mechanism. Capillarity also depends on interfacial tension and medium wettability. Interfacial tension and medium wettability may be spatially and temporally dependent due to variations in aqueous phase chemistry, contaminant aging, and/or variations in mineralogy and organic matter distributions. Such chemical heterogeneities have largely been ignored to date, even though they are known to have dramatic effects on the hydraulic property relations. Numerical multiphase flow and transport models typically assume that solids are water-wet and that interfacial tension is constant. The primary objective of this research is to investigate the influence of coupled physical and chemical heterogeneities on the migration and entrapment of DNAPLs. This objective will be accomplished through a combination of laboratory and numerical experiments. Laboratory experiments will be conducted to examine: (i) …
Date:
September 15, 2000
Creator:
Abriola, L. M. & Demond, A. H.
Object Type:
Report
System:
The UNT Digital Library
The Adiabatic Matching Section Solution for the Source Injector
Typical designs for a Heavy Ion Fusion Power Plant require the source injector to deliver 100 beams, packed into an array with a spacing of 7 cm. When designing source injectors using a single large aperture source for each beam, the emitter surfaces are packed into an array with a spacing of 30 cm. Thus, the matching section of the source injector must not only prepare the beam for transport in a FODO lattice, but also funnel the beams together. This can be accomplished by an ESQ matching section in which each beam travels on average at a slight angle to the axis of the quadrupoles and uses the focusing effect of the FODO lattice to maintain the angle. At the end of the matching section, doublet steering is used to bring the beams parallel to each other for injection into the main accelerator. A specific solution of this type for an 84-beam source injector is presented. PACS: 41.75.Ak,41.85.Ar, 41.85.Ja
Date:
September 15, 2000
Creator:
Ahle, L.; Grote, D. P.; Halaxa, E.; Henestroza, E.; Kwan, J. W. & Mac Laren, S. A.
Object Type:
Article
System:
The UNT Digital Library
The dynamics of combustion fronts in porous media
In this report, a method for solving this problem by treating the reaction region as a place of discontinuities in the appropriate variables, which include, for example, fluxes of heat and mass was proposed. Using a rigorous perturbation approach, similar to that used in the propagation of flames and smoldering combustion, appropriate jump conditions that relate the change in these variables across the front was derived. These conditions account for the kinetics of the reaction between the oxidant and the fuel, the changes in the morphology of the pore space and the heat and mass transfer in the reaction zone. The modeling of the problem reduces to the modeling of the dynamics of a combustion front, on the regions of either side of which transport of momentum (fluids), heat and mass, but not chemical reactions, must be considered. Properties of the two regions are coupled using the derived jump conditions. This methodology allows one to explicitly incorporate permeability heterogeneity effects in the process description, without the undue complexity of the coupled chemical reactions.
Date:
June 15, 2000
Creator:
Akkutlu, I. Yucel & Yortsos, Yannis C.
Object Type:
Report
System:
The UNT Digital Library
Energy distribution in a relativistic DC electron beam
None
Date:
November 15, 2000
Creator:
Alexey Burov, Sergei Nagaitsev and Alexander Shemyakin
Object Type:
Report
System:
The UNT Digital Library
Radiation-induced segregation and void swelling in 304 stainless steel.
None
Date:
June 15, 2000
Creator:
Allen, T. R.; Cole, J. I. & Kenik, E. A.
Object Type:
Article
System:
The UNT Digital Library
Container Refurbishment Cycle Time Reduction (CTR) Project
In mid-1999, a Cycle Time Reduction (CTR) project was initiated by senior management to improve the overall efficiency of the Container Refurbishment process. A cross-functional team was formed by the Industrial Engineering Services group within Product Certification Organization to evaluate the current process and to propose necessary changes for improvement. The CTR team efforts have resulted in increased productivity equaling approximately $450K per year. The effort also significantly reduced the wait time required necessary to start assembly work on the shop floor. Increasing daily production time and identifying delays were key team goals. Following is a brief summary of accomplishments: (A) Productivity Improvements: (1) Reduced Radcon survey time for empty containers: (i) 50% at 9720-3 (ii) 67% at 9204-2 and (iii) 100% at 9212; (2) Eliminated container inspections at 9720-3; (3) Reduced charged time (includes hands-on labor and support functions) per empty container by 25%; (4) Reduced cycle time to refurbish a container by 25%. (Dramatic wait time reduction -Assembly); (5) Reduced the time for 9212 to receive empty, refurbished containers by 67-80%; (6) Reduced the time for 9204-2E to receive empty, refurbished containers from 1 day to immediate; (7) Implemented software to track time charged per container for continuous …
Date:
May 15, 2000
Creator:
Aloi, Tim; Anthony, Perry; Blair, Tom; Forester, Celina; Hall, Ken; Hawk, Todd et al.
Object Type:
Report
System:
The UNT Digital Library
Processing of High Level Waste: Spectroscopic Characterization of Redox Reactions in Supercritical Water - Final Report
Current efforts are focused on the oxidative dissolution of chromium compounds found in Hanford tank waste sludge. Samples of chromium oxides and hydroxides with varying degrees of hydration are being characterized using Raman, FTIR, and XPS spectroscopic techniques. Kinetics of oxidation reactions at subcritical and supercritical temperatures are being followed by Raman spectroscopy using a high temperature stainless steel cell with diamond windows. In these reactions both hydrogen peroxide and nitrate anions are used as the oxidizing species with Cr(III) compounds and organic compounds as reducing agents.
Date:
November 15, 2000
Creator:
Arrington, C. A., Jr.
Object Type:
Report
System:
The UNT Digital Library
Fabrication of Yb-123 Tapes
While Bi-2223 tapes have been the workhorses of the superconductor industry, their poor performance in applied magnetic fields restrict their use to below 30 K. Melt-processing of Ag-clad Yb-123 PIT tapes offers a simple and scalable technique for fabricating long-length HTS conductors capable of being used at 77 K. Under reduced oxygen partial pressure, the peritectic temperature of Yb-123 is below the melting point of Ag, and this facilitates the adaptation of melt-texturing methods for fabricating these tapes. The effect of melt-processing temperature on current density was also explored; a temperature of 965 C yielded optimal critical current values. The critical current density achieved at 4.2 K was 20,000 A/cm{sup 2}, corresponding to a critical current of 52 A. Based on the above results, an optimal processing zone for melt-processing of Ag-clad Yb-123 tapes was determined. These results hold promise for melt-processing of Ag-clad Yb-123 tapes as an alternative to Bi-2223 PIT technology.
Date:
November 15, 2000
Creator:
Athur, S.; Balachandran, U. & Salama, K.
Object Type:
Article
System:
The UNT Digital Library
Final technical report: analysis of molecular data using statistical and evolutionary approaches
This document describes the research and training accomplishments of Dr. Kevin Atteson during the DOE fellowship period of September 1997 to September 1999. Dr. Atteson received training in molecular evolution during this period and made progress on seven research topics including: computation of DNA pattern probability, asymptotic redundancy of Bayes rules, performance of neighbor-joining evolutionary tree estimation, convex evolutionary tree estimation, identifiability of trees under mixed rates, gene expression analysis, and population genetics of unequal crossover.
Date:
February 15, 2000
Creator:
Atteson, K. & Kim, Junhyong
Object Type:
Report
System:
The UNT Digital Library
Science and technology of ultrananocrystalline diamond (UNCD) thin films for multifunctional devices.
MEMS devices are currently fabricated primarily in silicon because of the available surface machining technology. However, Si has poor mechanical and tribological properties, and practical MEMS devices are currently limited primarily to applications involving only bending and flexural motion, such as cantilever accelerometers and vibration sensors, However, because of the poor flexural strength and fracture toughness of Si, and the tendency of Si to adhere to hydrophyllic surfaces, even these simple devices have limited dynamic range. Future MEMS applications that involve significant rolling or sliding contact will require the use of new materials with significantly improved mechanical and tribological properties, and the ability to perform well in harsh environments. Diamond is a superhard material of high mechanical strength, exceptional chemical inertness, and outstanding thermal stability. The brittle fracture strength is 23 times that of Si, and the projected wear life of diamond MEMS moving mechanical assemblies (MEMS-MMAS) is 10,000 times greater than that of Si MMAs. However, as the hardest known material, diamond is notoriously difficult to fabricate. Conventional CVD thin film deposition methods offer an approach to the fabrication of ultra-small diamond structures, but the films have large grain size, high internal stress, poor intergranular adhesion, and very rough …
Date:
November 15, 2000
Creator:
Auciello, O.; Gruen, D. M.; Krauss, A. R.; Jayatissa, A.; Sumant, A.; Tucek, J. et al.
Object Type:
Article
System:
The UNT Digital Library
Meso-scale machining capabilities and issues
Meso-scale manufacturing processes are bridging the gap between silicon-based MEMS processes and conventional miniature machining. These processes can fabricate two and three-dimensional parts having micron size features in traditional materials such as stainless steels, rare earth magnets, ceramics, and glass. Meso-scale processes that are currently available include, focused ion beam sputtering, micro-milling, micro-turning, excimer laser ablation, femto-second laser ablation, and micro electro discharge machining. These meso-scale processes employ subtractive machining technologies (i.e., material removal), unlike LIGA, which is an additive meso-scale process. Meso-scale processes have different material capabilities and machining performance specifications. Machining performance specifications of interest include minimum feature size, feature tolerance, feature location accuracy, surface finish, and material removal rate. Sandia National Laboratories is developing meso-scale electro-mechanical components, which require meso-scale parts that move relative to one another. The meso-scale parts fabricated by subtractive meso-scale manufacturing processes have unique tribology issues because of the variety of materials and the surface conditions produced by the different meso-scale manufacturing processes.
Date:
May 15, 2000
Creator:
BENAVIDES,GILBERT L.; ADAMS,DAVID P. & YANG,PIN
Object Type:
Article
System:
The UNT Digital Library
Accurate Time-Linked Data Acqusition System Field Deploymemt and Operational Experience
None
Date:
November 15, 2000
Creator:
BERG,DALE E. & ZAYAS,JOSE R.
Object Type:
Article
System:
The UNT Digital Library
EFFECTS OF HUMIDITY AND OTHER VARIABLES ON THE STRENGTH OF PBX 9501
None
Date:
September 15, 2000
Creator:
BROWNING, R. Y. & MEYER, T.
Object Type:
Article
System:
The UNT Digital Library
Bottom production
In the context of the LHC experiments, the physics of bottom flavoured hadrons enters in different contexts. It can be used for QCD tests, it affects the possibilities of B decays studies, and it is an important source of background for several processes of interest. The physics of b production at hadron colliders has a rather long story, dating back to its first observation in the UA1 experiment. Subsequently, b production has been studied at the Tevatron. Besides the transverse momentum spectrum of a single b, it has also become possible, in recent time, to study correlations in the production characteristics of the b and the b. At the LHC new opportunities will be offered by the high statistics and the high energy reach. One expects to be able to study the transverse momentum spectrum at higher transverse momenta, and also to exploit the large statistics to perform more accurate studies of correlations.
Date:
March 15, 2000
Creator:
Baines, J.; Baranov, S. P.; Bartalini, P.; Bay, A.; Bouhova, E.; Cacciari, M. et al.
Object Type:
Article
System:
The UNT Digital Library
Practical superconductor development for electric power applications.
None
Date:
November 15, 2000
Creator:
Balachandran, U.
Object Type:
Report
System:
The UNT Digital Library
Oral History Interview with James S. Bargsley, December 15, 2000
The National Museum of the Pacific War presents an oral interview with James S. Bargsley. Bargsley grew up in Texas and joined the Navy in 1942. Once he finished training, he was assigned to duty on the USS Fallard (DE-222) and then the USS Bassett (APD-73). From San Diego, they departed for Pearl Harbor, knowing they were preparing for the invasion of Japan. In June 1945 they departed for Eniwetok Atoll, then to Guam, then to the Ulithi Atoll. On July 2, 1945, the ship reported to Commander Philippine Sea Frontier for duty. On August 3, 1945, the ship went to rescue the survivors of the USS Indianapolis (CA-35). The survivors were transferred to the fleet hospital the next day. Then they went to New Guinea, where they heard of the atomic bomb being dropped, and in September to Manila. From the Philippines the ship went to Okinawa and then to Wakayama, Japan with the LCT convoy. The Bassett detached from her duties in November and Bargsley was discharged in December 1945.
Date:
December 15, 2000
Creator:
Bargsley, James S.
Object Type:
Sound
System:
The Portal to Texas History
Oral History Interview with James S. Bargsley, December 15, 2000
The National Museum of the Pacific War presents an oral interview with James S. Bargsley. Bargsley grew up in Texas and joined the Navy in 1942. Once he finished training, he was assigned to duty on the USS Fallard (DE-222) and then the USS Bassett (APD-73). From San Diego, they departed for Pearl Harbor, knowing they were preparing for the invasion of Japan. In June 1945 they departed for Eniwetok Atoll, then to Guam, then to the Ulithi Atoll. On July 2, 1945, the ship reported to Commander Philippine Sea Frontier for duty. On August 3, 1945, the ship went to rescue the survivors of the USS Indianapolis (CA-35). The survivors were transferred to the fleet hospital the next day. Then they went to New Guinea, where they heard of the atomic bomb being dropped, and in September to Manila. From the Philippines the ship went to Okinawa and then to Wakayama, Japan with the LCT convoy. The Bassett detached from her duties in November and Bargsley was discharged in December 1945.
Date:
December 15, 2000
Creator:
Bargsley, James S.
Object Type:
Text
System:
The Portal to Texas History
Energy transfer properties and mechanisms [Ion-imaging measurements of the collision step-size distribution]. Final report
None
Date:
May 15, 2000
Creator:
Barker, John R.
Object Type:
Report
System:
The UNT Digital Library
Origins of Total-Dose Response Variability in Linear Bipolar Microcircuits
LM1ll voltage comparators exhibit a wide range of total-dose-induced degradation. Simulations show this variability may be a natural consequence of the low base doping of the substrate PNP (SPNP) input transistors. Low base doping increases the SPNP's collector to base breakdown voltage, current gain, and sensitivity to small fluctuations in the radiation-induced oxide defect densities. The build-up of oxide trapped charge (N{sub ot}) and interface traps (N{sub it}) is shown to be a function of pre-irradiation bakes. Experimental data indicate that, despite its structural similarities to the LM111, irradiated input transistors of the LM124 operational amplifier do not exhibit the same sensitivity to variations in pre-irradiation thermal cycles. Further disparities in LM111 and LM124 responses may result from a difference in the oxide defect build-up in the two part types. Variations in processing, packaging, and circuit effects are suggested as potential explanations.
Date:
November 15, 2000
Creator:
Barnaby, H. J.; Cirba, C. R.; Schrimpf, R. D.; Fleetwood, D. M.; Pease, R. L.; Shaneyfelt, M. R. et al.
Object Type:
Article
System:
The UNT Digital Library
Planning for an Integrated Research Experiment
The authors describe the goals and research program leading to the Heavy Ion Integrated Research Experiment (IRE). They review the basic constraints which lead to a design and give examples of parameters and capabilities of an IRE. We also show design tradeoffs generated by the systems code IBEAM. A multi-pronged Phase 1 research effort is laying the groundwork for the Integrated Research Experiment. Experiment, technology development, theory, simulation, and systems studies are all playing major roles in this Phase I research. The key research areas are: (1) Source and injector (for investigation of a high brightness, multiple beam, low cost injector); (2) High current transport (to examine effects at full driver-scale line charge density, including the maximization of the beam filling-factor and control of electrons); (3) Enabling technology development (low cost and high performance magnetic core material, superconducting magnetic quadrupole arrays, insulators, and pulsers); and (4) Beam simulations and theory (for investigations of beam matching, specification of accelerator errors, studies of emittance growth, halo, and bunch compression, in the accelerator, and neutralization methods, stripping effects, spot size minimization in the chamber); and (5) Systems optimization (minimization of cost and maximization of pulse energy and beam intensity). They have begun the …
Date:
September 15, 2000
Creator:
Barnard, J. J.; Ahle, L. E.; Bangerter, R. O.; Bieniosek, F. M.; Celata, C. M.; Faltens, A. et al.
Object Type:
Article
System:
The UNT Digital Library
Zeolite thermodynamics and kinetics. Final report for June 15, 1996 to June 15, 2000 to the U.S. Department of Energy, Geosciences Research Program, Office of Basic Energy Sciences on Grant No. DE-FG02-96ER14634
This report summarizes results obtained on the thermodynamic and kinetic properties of zeolites. DOE funding supported the development of techniques of material preparation as well as experimental strategies and methods for measuring solubilities, hydration states, and rates of zeolite dissolution, precipitation, and nucleation. The hydrothermal experiments provided temperature-dependent solubility products, hydration states, and a set of standard free energies of formation for end-member Na-, K-, and Ca-clinoptilolite, mordenite, and analcime. Flow-through experimental methods were used to measure the rates of Na-clinoptilolite and analcime dissolution and precipitation as a function of reaction affinity to 250C. Finally, the experimental system was modified so that the clinoptilolite-to-analcime transformation was monitored, and its rates and mechanisms were evaluated.
Date:
June 15, 2000
Creator:
Barnes, H. L.; Wilkin, R. T. & Benning, L. G.
Object Type:
Report
System:
The UNT Digital Library
News Bulletin (Castroville, Tex.), Vol. 42, No. 24, Ed. 1 Thursday, June 15, 2000
Weekly newspaper from Castroville, Texas that includes local, state, and national news along with extensive advertising.
Date:
June 15, 2000
Creator:
Barnes, Thomas
Object Type:
Newspaper
System:
The Portal to Texas History