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The ASCI Network for SC '98: Dense Wave Division Multiplexing for Distributed and Distance Computing
This document highlights the DISCOM's Distance computing and communication team activities at the 1998 Supercomputing conference in Orlando, Florida. This conference is sponsored by the IEEE and ACM. Sandia National Laboratories, Lawrence Livermore National Laboratory, and Los Alamos National Laboratory have participated in this conference for ten years. For the last three years, the three laboratories have a joint booth at the conference under the DOE's ASCI, Accelerated Strategic Computing Initiatives. The DISCOM communication team uses the forum to demonstrate and focus communications and networking developments. At SC '98, DISCOM demonstrated the capabilities of Dense Wave Division Multiplexing. We exhibited an OC48 ATM encryptor. We also coordinated the other networking activities within the booth. This paper documents those accomplishments, discusses the details of their implementation, and describes how these demonstrations support overall strategies in ATM networking.
Date:
June 1, 1999
Creator:
Adams, Roger L.; Butman, Wayne; Martinez, Luis G.; Pratt, Thomas J. & Vahle, Michael O.
Object Type:
Report
System:
The UNT Digital Library
Assessing Sources of Stress to Aquatic Ecosystems: Using Biomarkers and Bioindicators to Characterize Exodure-Response Profiles of Anthropogenic Activities
Establishing causal relationships between sources of environmental stressors and aquatic ecosystem health if difficult because of the many biotic and abiotic factors which can influence or modify responses of biological systems to stress, the orders of magnitude involved in extrapolation over both spatial and temporal scales, and compensatory mechanisms such as density-dependent responses that operate in populations. To address the problem of establishing causality between stressors and effects on aquatic systems, a diagnostic approach, based on exposure-response profiles for various anthropogenic activities, was developed to help identify sources of stress responsible for effects on aquatic systems at ecological significant levels of biological organization (individual, population, community). To generate these exposure-effects profiles, biomarkers of exposure were plotted against bioindicators of corresponding effects for several major anthropogenic activities including petrochemical , pulp and paper, domestic sewage, mining operations, land-development activities, and agricultural activities. Biomarkers of exposure to environmental stressors varied depending on the type of anthropogenic activity involved. Bioindicator effects, however, including histopathological lesions, bioenergetic status, individual growth, reproductive impairment, and community-level responses were similar among many of the major anthropogenic activities. This approach is valuable to help identify and diagnose sources of stressors in environments impacted by multiple stressors. By identifying …
Date:
March 29, 1999
Creator:
Adams, S.M.
Object Type:
Article
System:
The UNT Digital Library
Volatilization of Fission Products from Metallic Melts in the Melt-Dilute Treatment Technology Development for Al-Based DOE Spent Nuclear Fuels
The melt-dilute treatment technology is being developed to facilitate the ultimate disposition of highly enriched Al-Base DOE spent nuclear fuels in a geologic repository such as that proposed for Yucca Mountain. Currently, approximately 28 MTHM is expected to be returned to the Savannah River Site from domestic and foreign research reactors. The melt-dilute treatment technology will melt the fuel assemblies to reduce their volume and alloys them with depleted uranium to isotopically dilute the 235U concentration. The resulting alloy is cast into a form for long term geologic repository storage. Benefits accrued from the melt-dilute process include the potential for significant volume reduction; reduced criticality potential, and proliferation concerns. A critical technology element in the development of the melt-dilute process is the development of offgas system requirements. The volatilization of radioactive species during the melting stage of the process primarily constitutes the offgas in this process. Several of the species present following irradiation of a fuel assembly have been shown to be volatile or semi-volatile under reactor core melt-down conditions. Some of the key species that have previously been studied are krypton, iodine, and cesium. All of these species have been shown to volatilize during melting experiments however, the degree …
Date:
November 18, 1999
Creator:
Adams, T.
Object Type:
Article
System:
The UNT Digital Library
Ion Beam Sputter Fabrication of Micro-Grooving and Micro-Threading Tools
This paper presents techniques for fabricating microscopic, nonplanar features in a variety of materials. Micro-grooving and micro-threading tools having cutting dimensions of 10-30{micro}m are made by focused ion beam sputtering and used in ultra-precision machining. Tool fabrication involves directing a 20 keV gallium beam at polished cylindrical punches made of cobalt M42 high-speed steel or C2 tungsten carbide. This creates cutting edges having radii of curvature less than 0.4 {micro}m, and rake features similar to conventional lathe tools. Clearance for minimizing frictional drag of a tool results from the sputter yield dependence on ion herd target incidence angle. Numerically controlled, ultra-precision machining with micro-grooving tools results in a close matching between tool width and feature size. Microtools controllably machine 13 {micro}m wide, 4 {micro}m deep, helical grooves in polymethyl methacrylate and 6061-T6 Al cylindrical substrates. Micro-grooving tools also fabricate sinusoidal waveform features in polished metal substrates.
Date:
November 5, 1999
Creator:
Adams,David P.; Vasile,M. J. & Krishnan,A. S. M.
Object Type:
Article
System:
The UNT Digital Library
Experimental Investigation of In Situ Cleanable HEPA Filters
For the past several years studies have been conducted to investigate the use of innovative, alternative approaches to conventional disposable high efficiency particulate air filters.
Date:
January 7, 1999
Creator:
Adamson, D.J.
Object Type:
Report
System:
The UNT Digital Library
FY'99 final report for the expedited technology demonstration project: demonstration test results for the MSO/off-gas and salt recycle system
Molten Salt Oxidation (MSO) is a promising alternative to incineration for the treatment of a variety of organic wastes. Lawrence Livermore National Laboratory (LLNL) has prepared a facility in which an integrated pilot-scale MSO treatment system is being tested and demonstrated. The system consists of a MSO vessel with a dedicated off-gas treatment system, a salt recycle system, feed preparation equipment, and a ceramic final waste forms immobilization system. This integrated system was designed and engineered based on operational experience with an engineering-scale reactor unit and extensive laboratory development on salt recycle and final forms preparation. The MSO/off-gas system has been operational since December 1997. The salt recycle system and the ceramic final forms immobilization became operational in May 1998. In FY98, we have tested the MSO facility with various organic feeds, including chlorinated solvents, tributyl phosphate/kerosene, PCB-contaminated waste oils and solvents, booties, plastic pellets, ion exchange resins, activated carbon, radioactive-spiked organics, and well-characterized low-level liquid mixed wastes. MSO is shown to be a versatile technology for hazardous waste treatment and may be a solution to many waste disposal problems in DOE sites. The results of the demonstration conducted in FY98 has been reported [1]. In FY99 (October 1998 to …
Date:
May 1, 1999
Creator:
Adamson, M G & Hsu, P C
Object Type:
Report
System:
The UNT Digital Library
Treatment of solid wastes with molten salt oxidation
None
Date:
March 1, 1999
Creator:
Adamson, M G; Ford, T D; Foster, K G; Hsu, P C; Pruneda, C O; Wallman, P H et al.
Object Type:
Article
System:
The UNT Digital Library
Thermodynamics of the Volatilization of Actinind metals in the High-Temperature Treatment of Radioactive Wastes
We are performing a detailed study of the volatilization behavior of U, Pu and possibly Am and Np under conditions relevant to the thermal treatment (destruction) of actinide containing organic-based mixed and radioactive wastes. The primary scientific goal of the work is to develop a basic thermochemical understanding of actinide volatilization and partitioning/speciation behavior in the thermal processes that are central to DOE/EM's mixed waste treatment program. This subject addresses at least two key technical needs/problem areas recently identified by DOE/EM's Office of Science & Technology: emission-free destruction of organic wastes, and interactions between actinides and organic residues in materials stabilization. A sound basis for designing safe and effective treatment systems, and the ability to allay public concerns about radioactive fugitive emissions, will be the principal benefits of the project. The proposed work is a combination of experimental studies and thermodynamic modeling. Vapor pressure measurements will be made to determine U, Pu and possibly Am volatile species and the extent of their volatilization when UO2/U3O8, PuO2 and AmO2 solids are heated to temperatures of 500 to1200 C under pyrolyzing (reducing) conditions or under oxidizing conditions in the presence of chlorine. Work on uranium volatilization under reducing conditions is being performed …
Date:
June 1, 1999
Creator:
Adamson, Martyn, G. & Olander, Donald R.
Object Type:
Report
System:
The UNT Digital Library
The Hybrid Emulsion Detector for MINOS R&D Proposal
The MINOS (Main Injector Neutrino Oscillation Search) experiment is designed to search for neutrino oscillations with a sensitivity significantly greater than has been achieved to date. The phenomenon of neutrino oscillations, whose existence has not been proven convincingly so far, allows neutrinos of one "flavor" (type) to slowly transform themselves into another flavor, and then back again to the original flavor, as they propagate through space or matter. The MINOS experiment is optimized to explore the region of neutrino oscillation "parameter space" suggested by previous investigations of atmospheric neutrinos: the Kamiokande, IMB, Super-Kamiokande and Soudan 2 experiments. The study of oscillations in this region with a neutrino beam from the Main Injector requires measurements of the beam after a very long flight path. This in turn requires an intense neutrino beam and a massive detector in order to have an adequate event rate at a great distance from the source. We propose to enhance significantly the physics capabilities of the MINOS experiment by the addition of a Hybrid Emulsion Detector at Soudan, capable of unambigous identification of the neutrino flavor. Recent developments in emulsion experiments make such a detector possible, although significant technological challenges must be overcome. We propose to …
Date:
April 1, 1999
Creator:
Adamson, P.; Alexandrov, K. V.; Allison, W. W.M.; Alner, G. J.; Ambats, I.; Anderson, B. et al.
Object Type:
Report
System:
The UNT Digital Library
Development and Testing of the NIF Prototype Module
The NIF Power Conditioning System (PCS) is required to deliver -68 kJ to each of the 3840 flashlamp pairs in the NIF laser in a current pulse with a peak of -500 kA and rise time of- 150 µs. The PCS will consist of 192 modules each of which drive 20 lamp-pairs. Each module will basically be a 6 rnF capacitor bank with a nominal charge voltage of 23.5 kV which is switched by a single pressurized air gas switch to 20 RG-220 cables that are connected to individual lamp loads. In addition each module will have a number of subsystems including; a lamp pre-ionization system, power supplies, isolation circuits, trigger systems, safety dump systems, gas system, and an embedded control system. A module will also include components whose primary function is to limit fault currents and thus minimize collateral damage in faults. In the Prototype Development and Testing effort at Sandia National Laboratories all of these were integrated into a single system and proper fimctionality was demonstrated. Extensive testing was done at nominal operating levels into resistive dummy loads and some testing in fault modes was also done. A description of the system and a summary of testing is …
Date:
June 25, 1999
Creator:
Adcock, J.; Harjes, C.; Mowrer, G. & Wilson, M.
Object Type:
Article
System:
The UNT Digital Library
The Effect of Presence of Support Systems and Level of Agreement on the Performance of Work Groups
In the study of team-based organizations most of the research has focus on the internal make-up and structure of teams. Recently there has been more interest in the effects that environment has on teams. With this new focus Support Systems in organizations have become an area of interest. Examining the perceptions of workers with respect to support systems of organizations could give insight into performance. This study specifically examines the interaction between a team's shared perception of the support in their environment and the level of support in their environment. The interaction between the two does seem to have a strong relationship with perceived performance. How do the two concepts interact, and what does this mean for organizational designers? Both questions are discussed.
Date:
May 1999
Creator:
Adcock, John R. (John Roger)
Object Type:
Thesis or Dissertation
System:
The UNT Digital Library
Physics-Based Damage Predictions for Simulating Testing and Evaluation (T and E) Experiments
This is the final report of a two-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). This report addresses the need to develop computational techniques and physics-based material models for simulating damage to weapons systems resulting from ballistic threats. Modern weapons systems, such as fighter aircraft, are becoming more dependent upon composite materials to reduce weight, to increase strength and stiffness, and to resist adverse conditions resulting from high temperatures and corrosion. Unfortunately, damaged components can have severe and detrimental effects, as evidenced by statistics from Desert Storm indicating that 75% of aircraft losses were attributable to fuel system vulnerability with hydrodynamic ram being the primary kill mechanism. Therefore, this project addresses damage predictions for composite systems that are subjected to ballistic threats involving hydrodynamic ram. A computational technique for simulating fluid-solid interaction phenomena and physics-based material models have been developed for this purpose.
Date:
March 1, 1999
Creator:
Addessio, Francis L.; Schraad, Mark W. & Lewis, Matthew W.
Object Type:
Report
System:
The UNT Digital Library
The Virtual Library in Action
The SLAC Library has for many years provided SPIRES-HEP, a 300,000 record bibliographic database, to the world particle physics community via the Internet as well as through clone sites in Europe and Japan. The 1991 introduction of the e-print archives at LANL coupled with the World-Wide-Web (WWW) from CERN suddenly made it possible to provide easy linkage between bibliographic database records and the actual full-text of papers. The SLAC Library has turned this possibility into reality by converting hundreds of TeX source documents each month into viewable postscript complete with figures. These (now more than 20,000) postscript files are linked to the HEP database, and the full-text is rendered universally visible via WWW. We discuss the project, the collaboration of physicists and librarians, what is easy, what is hard, and our vision for the future.
Date:
July 2, 1999
Creator:
Addis, Louise
Object Type:
Report
System:
The UNT Digital Library
Risk management considerations for seismic upgrading of an older facility for short-term residue stabilization
Building 707 and its addition, Building 707A, were selected, after the production mission of Rocky Flats was terminated a few years ago, to stabilize many of the plutonium residues remaining at the site by 2002. The facility had undergone substantial safety improvements to its safety systems and conduct of operations for resumption of plutonium operations in the early 1990s and appeared ideally suited for this new mission to support accelerated Site closure. During development of a new authorization basis, a seismic evaluation was performed. This evaluation addressed an unanalyzed expansion joint and suspect connection details for the precast concrete tilt-up construction and concluded that the seismic capacity of the facility is less than half of that determined by previous analysis. Further, potential seismic interaction was identified between a collapsing Building 707 and the seismically upgraded Building 707A, possibly causing the partial collapse of the latter. Both the operating contractor and the Department of Energy sought a sound technical basis for deciding how to proceed. This paper addresses the risks of the as-is facility and possible benefits of upgrades to support a decision on whether to upgrade the seismic capacity of Building 707, accept the risk of the as-is facility for …
Date:
June 1, 1999
Creator:
Additon, S. L.; Peregoy, W. L. & Foppe, T. L.
Object Type:
Article
System:
The UNT Digital Library
An advanced control system for fine coal flotation
None
Date:
December 20, 1999
Creator:
Adel, G. T. & Luttrell, G. H.
Object Type:
Report
System:
The UNT Digital Library
Detecting data and schema changes in scientific documents
Data stored in a data warehouse must be kept consistent and up-to-date with the underlying information sources. By providing the capability to identify, categorize and detect changes in these sources, only the modified data needs to be transferred and entered into the warehouse. Another alternative, periodically reloading from scratch, is obviously inefficient. When the schema of an information source changes, all components that interact with, or make use of, data originating from that source must be updated to conform to the new schema. In this paper, the authors present an approach to detecting data and schema changes in scientific documents. Scientific data is of particular interest because it is normally stored as semi-structured documents, and it incurs frequent schema updates. They address the change detection problem by detecting data and schema changes between two versions of the same semi-structured document. This paper presents a graph representation of semi-structured documents and their schema before describing their approach to detecting changes while parsing the document. It also discusses how analysis of a collection of schema changes obtained from comparing several individual can be used to detect complex schema changes.
Date:
June 8, 1999
Creator:
Adiwijaya, I; Critchlow, T & Musick, R
Object Type:
Article
System:
The UNT Digital Library
Ensemble: 1999-11-08 - Les Petits Violons
Concert presented at the UNT College of Music Recital Hall.
Date:
November 8, 1999
Creator:
Adkins, Cecil
Object Type:
Sound
System:
The UNT Digital Library
Heat Pipe Solar Receiver Development Activities at Sandia National Laboratories
Over the past decade, Sandia National Laboratories has been involved in the development of receivers to transfer energy from the focus of a parabolic dish concentrator to the heater tubes of a Stirling engine. Through the isothermal evaporation and condensation of sodium. a heat-pipe receiver can efficiently transfer energy to an engine's working fluid and compensate for irregularities in the flux distribution that is delivered by the concentrator. The operation of the heat pipe is completely passive because the liquid sodium is distributed over the solar-heated surface by capillary pumping provided by a wick structure. Tests have shown that using a heat pipe can boost the system performance by twenty percent when compared to directly illuminating the engine heater tubes. Designing heat pipe solar receivers has presented several challenges. The relatively large area ({approximately}0.2 m{sup 2}) of the receiver surface makes it difficult to design a wick that can continuously provide liquid sodium to all regions of the heated surface. Selecting a wick structure with smaller pores will improve capillary pumping capabilities of the wick, but the small pores will restrict the flow of liquid and generate high pressure drops. Selecting a wick that is comprised of very tine filaments …
Date:
January 8, 1999
Creator:
Adkins, D. R.; Andraka, C. E.; Moreno, J. B.; Moss, T. A.; Rawlinson, K. S. & Showalter, S. K.
Object Type:
Article
System:
The UNT Digital Library
Modeling and Imaging Flexural Plate Wave Devices
Sandia National Laboratories is developing a new form of flexural plate wave device (FPW) for sensor applications. In this device, Lorentz forces cause out of plane vibrations in a silicon nitride membrane. Current induced in transducer lines on the membrane provides information about the amplitude and phase of these surface vibrations. By tracking the large amplitude vibrations that occur at resonant frequencies, it is possible to infer information about loading on the membrane. In fabricating FPWs, it is important to understand the impact that minor defects can have on operation. Through modeling and testing, they are developing resilient designs that provide large amplitude signals with a high tolerance to defects. A finite element model has been developed to perform design trade-off studies, and results from the model are being verified with a unique measurement system that can image Angstrom scale displacements at vibrational frequencies up to 800 kHz. Results from FPW modeling and imaging efforts are presented in this paper.
Date:
July 9, 1999
Creator:
Adkins, D. R.; Butler, M. A.; Chu, A. S. & Schubert, W. K.
Object Type:
Article
System:
The UNT Digital Library
Modeling Transport in Gas Chromatography Columns for the Micro-ChemLab
The gas chromatography (GC) column is a critical component in the microsystem for chemical detection ({mu}ChemLab{trademark}) being developed at Sandia. The goal is to etch a meter-long GC column onto a 1-cm{sup 2} silicon chip while maintaining good chromatographic performance. Our design strategy is to use a modeling and simulation approach. We have developed an analytical tool that models the transport and surface interaction process to achieve an optimized design of the GC column. This analytical tool has a flow module and a separation module. The flow module considers both the compressibility and slip flow effects that may significantly influence the gas transport in a long and narrow column. The separation module models analyte transport and physico-chemical interaction with the coated surface in the GC column. It predicts the column efficiency and performance. Results of our analysis will be presented in this paper. In addition to the analytical tool, we have also developed a time-dependent adsorption/desorption model and incorporated this model into a computational fluid dynamics (CFD) code to simulate analyte transport and separation process in GC columns. CFD simulations can capture the complex three-dimensional flow and transport dynamics, whereas the analytical tool cannot. Different column geometries have been studied, …
Date:
September 1, 1999
Creator:
Adkins, Douglas R.; Frye-Mason, Gregory Charles; Hudson, Mary L.; Kottenstette, Richard; Matzke, Carolyn M.; Salinger, Andrew G. et al.
Object Type:
Article
System:
The UNT Digital Library
Noumena
Access:
Use of this item is restricted to the UNT Community
Recording of Mathew Adkin's Noumena. "Noumena" was a term used by Kant referring to the things that underline our experience both of the physical world and of our own mental state. This work is a number of short discrete sections that play continuously, with the sections alternating between "inner" and "outer" senses.
Date:
1999/2000
Creator:
Adkins, Mathew, 1972-
Object Type:
Sound
System:
The UNT Digital Library
Breaking
Access:
Use of this item is restricted to the UNT Community
Recording of Mathew Adkins' Breaking. This work mixes electronic sounds with those of classic R&B music.
Date:
1999
Creator:
Adkins, Monty
Object Type:
Sound
System:
The UNT Digital Library
Investigation of Ultrasonic Wave Interaction with Fluid-Saturated Porous Rocks
None
Date:
July 1999
Creator:
Adler, L.
Object Type:
Report
System:
The UNT Digital Library
Final report: Efficient thyratron modulator project
The purpose of this program was to examine methods of increasing the efficiency of producing pulses to drive Klystrons in the 150 MW range. This may include 2 Klystrons in the 75 MW range. Specific methods of interest to improve the pulse efficiency were the use of a circuit to add energy to the tail of the pulse, the use of a bipyrimidal transformer, and the use of gas insulation as a means of improving the pulse shape. These methods were investigated using both thyratron and IGBT switching. The low cost designs developed in this work consisted of low voltage designs which don't require the oil immersion. These designs can be ''hot tuned'' based on the use of simple, tunable inductors.
Date:
November 26, 1999
Creator:
Adler, R. J.; Richter-Sand, R. J. & Gregg, C. W.
Object Type:
Report
System:
The UNT Digital Library