Programmable applications in a heterogeneous and concurrent environment (open access)

Programmable applications in a heterogeneous and concurrent environment

Equipe Basis (EB) is a new system for programmable applications which is under development at Lawrence Livermore Laboratory. EB is designed to permit user control of teams of interconnecting processes in a heterogeneous environment. Current systems work with programs written in Fortran or C on a single processor. The programs of the future will be in many languages and distributed over many processors. The object-oriented kernel can communicate data and commands between processes that are unaware of each other`s inner structure. The programming language, Eiffel, is described. This document consists of extensive viewgraphs.
Date: July 21, 1995
Creator: Dubois, P.F.
Object Type: Article
System: The UNT Digital Library
APT/LEDA RFQ vacuum pumping system (open access)

APT/LEDA RFQ vacuum pumping system

This paper describes the design and fabrication of a vacuum pumping system for the ATP/LEDA (Low Energy Demonstration Accelerator) RFQ (Radio Frequency Quadrupole) linac. Resulted from the lost proton beam, gas streaming from the LEBT (Low Energy Beam Transport) and out-gassing from the surfaces of the RFQ cavity and vacuum plumbing, the total gas load will be on the order of 7.2 x 10{sup -4} Torr-liters/sec, consisting mainly of hydrogen. The system is designed to pump on a continual basis with redundancy to ensure that the minimal operating vacuum level of 1 x 10{sup -6} Torr is maintained even under abnormal conditions. Details of the design, performance analysis and the preliminary test results of the cryogenic pumps are presented.
Date: July 21, 1997
Creator: Shen, S., LLNL
Object Type: Article
System: The UNT Digital Library
Improved MCFC performance with Li/Na/Ba/Ca carbonate electrolyte. (open access)

Improved MCFC performance with Li/Na/Ba/Ca carbonate electrolyte.

Earlier electrolyte segregation tests of Li/Na carbonate used chemical analysis such as inductively coupled plasma/atomic emission spectroscopy (ICP/AES) of matrix strips wetted with carbonate and exposed to 5- to 20-V potential gradients. A segregation factor was correlated to the Li/Na carbonate composition. While fairly substantial segregation occurs at the eutectic composition of 52% Li, it is minimal at 60% to 75% Li. Such lithium-rich Li/Na carbonates may not be practical because the melting points are too high (i.e., liquidus point is 625 C). By adding calcium and barium to the lithium/sodium carbonates, we were able to lower the melting point and maintain nonsegregating behavior. This work is directed at examining the long-term stability of the quaternary Li/Na/Ba/Ca electrolytes. Electrolyte optimization work evaluates Li/Na ratio and Ba/Ca level to improve cell performance at 320 mA/cm{sup 2} and reduce temperature sensitivity. A number of cells with quaternary Li/Na/Ba/Ca electrolytes ranging from 3 to 5% Ba/Ca have operated well with stable, long-term performance. Congruent melting carbonate is important for commercial development. The best so far is 3.5% Ba/Ca/Na/Li (3.5 mol%/3.5 mol% Ba/Ca) carbonate (m.p. 440 C). Performance at 160 mA/cm{sup 2} is increased up to 150mV as compared with the baseline cell containing …
Date: July 21, 1999
Creator: Centeno, C.-J.; Kaun, T. D.; Krumpelt, M. & Schoeler, A.
Object Type: Article
System: The UNT Digital Library
X-ray reflectivity study of formation of multilayer porous anodic oxides of silicon. (open access)

X-ray reflectivity study of formation of multilayer porous anodic oxides of silicon.

The paper reports data on the kinetics of anodic oxide films growth on silicon in aqueous solutions of phosphoric acids as well as a study of the morphology of the oxides grown in a special regime of the oscillating anodic potential. X-ray reflectivity measurements were performed on the samples of anodic oxides using an intense synchrotron radiation source. They have a multilayer structure as revealed by theoretical fitting of the reflectivity data. The oscillations of the anodic potential are explained in terms of synchronized oxidation/dissolution reactions at the silicon surface and accumulation of mechanic stress in the oxide film.
Date: July 21, 1999
Creator: Chu, Y.; Fenollosa, R.; Parkhutik, V. & You, H.
Object Type: Article
System: The UNT Digital Library
Diamond Anvils With Integrated Diamond-Encapsulated Microprobes for High-Pressure Electrical Transport Experiments (open access)

Diamond Anvils With Integrated Diamond-Encapsulated Microprobes for High-Pressure Electrical Transport Experiments

We have fabricated diamond anvils specially designed for use in ultra-high pressure electrical transport experiments. These anvils, which we refer to as ''designer anvils'', feature thin-film metal microprobes which are encased in a layer of high-quality, epitaxial, chemically vapor deposited (CVD) diamond. The synthetic diamond film ensures that the microprobes are survivable to Mbar pressures, and also serves to electrically insulate the microprobes from the high-pressure gasket. High-pressure resistivity experiments were performed on KI and FeO to pressures of approximately 1.8 and 1.7 Mbars, respectively. Future possible applications of designer anvils are also discussed. [electrical conductivity, synthetic diamond, band overlap, metallization, designer anvils]
Date: July 21, 1999
Creator: Akella, J.; Catledge, S. A.; Vohra, Y. K. & Weir, S. T.
Object Type: Article
System: The UNT Digital Library
Synchrotron x-ray reflectivity study of oxidation/passivation of copper and silicon. (open access)

Synchrotron x-ray reflectivity study of oxidation/passivation of copper and silicon.

Synchrotron x-ray-scattering technique studies of copper and silicon electrochemical interfaces are reported. These two examples illustrate the application of synchrotron x-ray techniques for oxidation, passivation, and dissolution of metals and semiconductors.
Date: July 21, 1999
Creator: Chu, Y.; Nagy, Z.; Parkhutik, V. & You, H.
Object Type: Article
System: The UNT Digital Library
A novel thin film solid oxide fuel cell for microscale energy conversion (open access)

A novel thin film solid oxide fuel cell for microscale energy conversion

A novel approach for the fabrication and assembly of a solid oxide fuel cell system is described which enables effective scaling of the fuel delivery, manifold, and fuel cell stack components for applications in miniature and microscale energy conversion. Electrode materials for solid oxide fuel cells are developed using sputter deposition techniques. A thin film anode is formed by co-deposition of nickel and yttria-stabilized zirconia (YSZ). This approach provides a mixed conducting inter-facial layer between the nickel electrode and electrolyte layer. Similarly, a thin film cathode is formed by co-deposition of silver and yttria-stabilized zirconia. Additionally, sputter deposition of yttria-stabilized zirconia thin film electrolyte enables high quality, continuous films to be formed having thicknesses on the order of 1-2 {micro}m. This will effectively lower the temperature of operation for the fuel cell stack significantly below the traditional ranges at which solid oxide electrolyte systems are operated (600-1000 C), thereby rendering this fuel cell system suitable for miniaturization, Scaling towards miniaturization is accomplished by utilizing novel micromachining approaches which allow manifold channels and fuel delivery system to be formed within the substrate which the thin film fuel cell stack is fabricated on, thereby circumventing the need for bulky manifold components which …
Date: July 21, 1999
Creator: Jankowski, Alan F. & Morse, Jeffrey D.
Object Type: Article
System: The UNT Digital Library
Development of NDE methods for hot gas filters. (open access)

Development of NDE methods for hot gas filters.

Ceramic hot gas candle filters are currently under development for hot gas particulate cleanup in advanced coal-based power systems. The ceramic materials for these filters include nonoxide monolithic, nonoxide-fiber-reinforced composites, and nonoxide reticulated foam. A concern is the lack of reliable data on which to base decisions for reusing or replacing hot gas filters during plant shutdowns. The work in this project is aimed at developing nondestructive evaluation (FIDE) technology to allow detection, and determination of extent, of life-limiting characteristics such as thermal fatigue, oxidation, damage from ash bridging such as localized cracking, damage from local burning, and elongation at elevated temperature. Although in-situ NDE methods are desirable in order to avoid disassembly of the candle filter vessels, the current vessel designs, the presence of filter cakes and possible ash bridging, and the state of NDE technology prevent this. Candle filter producers use a variety of NDE methods to ensure as-produced quality. While impact acoustic resonance offers initial promise for examining new as-produced filters and for detecting damage in some monolithic filters when removed from service, it presents difficulties in data interpretation, it lacks localization capability, and its applicability to composites has yet to be demonstrated. Additional NDE technologies being …
Date: July 21, 1999
Creator: Deemer, C.; Ellingson, W. A.; Koehl, E. R.; Lee, H.; Spohnholtz, T. & Sun, J. G.
Object Type: Article
System: The UNT Digital Library
Low frequency electromagnetic signals from underground explosions: On-site inspections research progress report (open access)

Low frequency electromagnetic signals from underground explosions: On-site inspections research progress report

We are investigating the characteristics of extremely low frequency (ELF) electromagnetic pulse (EMW) phenomena from underground nuclear and chemical explosions and from surface chemical explosions as they may be applied in an On-Site Inspection (OSI) context under a Comprehensive Test-Ban Treaty (CTBT). The principal application of these phenomena is for discrimination among underground chemical explosions, underground nuclear explosions, and earthquakes. Underground chemical and nuclear explosions both generate low-frequency EMP signals (about 1 Hz) that are observable within several kilometers of ground zero. During this fiscal year we have been gathering data from explosions of opportunity to see if ELF EMP signals are observable from large ripple-fired blasts and from smaller dedicated explosions such as those occurring at the NTS. In addition, we are continuing to review data from the Henderson Mine deployment that took place during FY94 and data from previous underground nuclear tests including Hunter`s Trophy and past underground nuclear tests have been analyzed and we here make estimates of the properties of the EMP ftom underground nuclear ard chemical explosions, including detectability, dependence on yield, and dependence on distance from the source. Data from the Henderson Mine provide information about detection of EMP from typical moderate size underground …
Date: July 21, 1995
Creator: Sweeney, J. J.
Object Type: Report
System: The UNT Digital Library
Procedure for stacking Tile-Cal submodules using the Argonne designed stacking fixture (open access)

Procedure for stacking Tile-Cal submodules using the Argonne designed stacking fixture

The purpose of this fixture is to provide a general purpose tool that is simple to construct, simple to use, and flexible enough to adapt to different Tile-Cal Hadron Calorimeter submodule heights and configurations. It is also adaptable for modules that are shorter in radius, if two different lengths are necessary to accommodate the support of the liquid argon cryostat. With minor changes, this fixture can also be used to stack the proposed modules for the ``Crack Filler``. It is expected that minor modifications may be necessary to adapt this fixture to different facilities and working conditions. It is not presumed that this procedure will be satisfactory for every institution that will use it, and suggestions for changes to this procedure will be accepted as constructive and useful information.
Date: July 21, 1995
Creator: Hill, N.F.
Object Type: Report
System: The UNT Digital Library
Evaluation of the 1998 Predictions of the Run-Timing of Wild Migrant Yearling Chinook and Water Quality at Multiple Locations on the Snake and Columbia Rivers using CRiSP/RealTime, 1998 Technical Report. (open access)

Evaluation of the 1998 Predictions of the Run-Timing of Wild Migrant Yearling Chinook and Water Quality at Multiple Locations on the Snake and Columbia Rivers using CRiSP/RealTime, 1998 Technical Report.

Since 1988, wild salmon have been PIT-tagged through monitoring and research programs conducted by the Columbia River fisheries agencies and Tribes. Workers at the University of Washington have used detection data at Lower Granite Dam to generate predictions of arrival distributions for various stocks at the dam. The prediction tool is known as RealTime. In 1996, RealTime predictions were linked to a downstream migration model, CRiSP.1. The composite model, known as CRiSP/RealTime, predicts the arrival distribution and fraction transported at downriver locations.
Date: July 21, 1999
Creator: Beer, W. Nicholas; Hayes, Joshua A. & Shaw, Pamela
Object Type: Report
System: The UNT Digital Library
Hydrocarbon rate coefficients for proton and electron impact ionization, dissociation, and recombination in a hydrogen plasma. (open access)

Hydrocarbon rate coefficients for proton and electron impact ionization, dissociation, and recombination in a hydrogen plasma.

We estimate cross sections and rate coefficients for proton and electron impact ionization, dissociation, and recombination of neutral and ionized hydrocarbon molecules and fragments of the form C{sub x}H{sub y}{sup k}, x = 1-3, y = 1-6, k = 0,1 in a thermalized hydrogen-electron plasma.
Date: July 21, 1999
Creator: Alman, D. A.; Brooks, J. N.; Ruzic, D. N. & Wang, Z.
Object Type: Report
System: The UNT Digital Library
Interaction region vacuum system design at the PEP-II B factory (open access)

Interaction region vacuum system design at the PEP-II B factory

The Interaction Region Vacuum System in the PEP-II B-Factory at SLAC must produce average pressures in the 10{sup -10} Torr range. low beamline pressures will minimize the background radiation encountered by the BaBar Detector A combination of copper and stainless steel vacuum chambers with continuous antechambers are used to make up the beam tubes. Linear Non-Evaporable Getter (NEG) pumps are used to produce distributed pumping along the length of these beam tubes. High conductance microwave type screens provide RF shields between the beam aperture and the NEG pumps. In this paper the design features of the beam tubes, NEG pumps, and RF pump screens are described and the vacuum and impedance analyses conducted in support of the design are discussed.
Date: July 21, 1997
Creator: Bertolini, L., LLNL
Object Type: Article
System: The UNT Digital Library
Measurement Techniques in Dry-Powdered Processing of Spent Nuclear Fuels (open access)

Measurement Techniques in Dry-Powdered Processing of Spent Nuclear Fuels

High-performance liquid chromatography (HPLC) with inductively coupled plasma mass spectrometry (ICPMS) detection, {alpha}-spectrometry ({alpha}-S), and {gamma}-spectrometry ({gamma}-S) were used for the determination of nuclide content in five samples excised from a high-burnup fuel rod taken from a pressurized water reactor (PWR). The samples were prepared for analysis by dissolution of dry-powdered samples. The measurement techniques required no separation of the plutonium, uranium, and fission products. The sample preparation and analysis techniques showed promise for in-line analysis of highly-irradiated spent fuels in a dry-powdered process. The analytical results allowed the determination of fuel burnup based on {sup 148}Nd, Pu, and U content. A goal of this effort is to develop the HPLC-ICPMS method for direct fissile material accountancy in the dry-powdered processing of spent nuclear fuel.
Date: July 21, 1999
Creator: Bowers, Delbert L.; Hong, Jon-Sook; Kim, Ho-Dong; Persiani, Paul J. & Wolf, Stephen F.
Object Type: Article
System: The UNT Digital Library
EVOLVE - an advanced first wall/blanket system. (open access)

EVOLVE - an advanced first wall/blanket system.

A new concept for an advanced fusion first wall and blanket has been identified. The key feature of the concept is the use of the heat of vaporization of lithium (about 10 times higher than water) as the primary means for capturing and removing the fusion power. A reasonable range of boiling temperatures of this alkali metal is 1200 to 1400 C, corresponding with a saturation pressure of 0.035 to 0.2 MPa. Calculations indicate that a evaporative system with Li at {approximately}1200 C can remove a first wall surface heat flux of >2 MW/m2 with an accompanying neutron wall load of >10 MW/m2. Work to date shows that the system provides adequate tritium breeding and shielding, very high thermal conversion efficiency, and low system pressure. Tungsten is used as the structural material, and it is expected to operate at a surface wall load of 2 MW/m2 at temperatures above 1200 C.
Date: July 21, 1999
Creator: Khater, H.; Majumdar, S.; Malang, S.; Mattas, R. F.; Mogahed, E.; Nelson, B. et al.
Object Type: Article
System: The UNT Digital Library
Design of the linear non-evaporable getter pump for the PEP-II B factory (open access)

Design of the linear non-evaporable getter pump for the PEP-II B factory

There are several regions in the PEP-II B Factory at SLAC that require distributed pumping to deal with large photo-desorbed gas loads or to produce very low pressures (< 10{sup -9} Torr). These regions include the Low Energy Ring Wiggler dump chambers, the transitions between the High Energy Ring arcs and straight sections, and most importantly the Interaction Region. They have designed a compact Non-Evaporable Getter pump using commercial getters that combines high pumping speed and high sorption capacity. They describe the design features of the NEG pumps, and the test results from prototype pumps. In addition, they discuss future variations of this style of NEG pump.
Date: July 21, 1997
Creator: Bertolini, L., LLNL
Object Type: Article
System: The UNT Digital Library
Implementation of U.S. transparency monitoring under the U.S./Russian HEU purchase agreement (open access)

Implementation of U.S. transparency monitoring under the U.S./Russian HEU purchase agreement

During the past three years US monitoring at Russian nuclear facilities, subject to the HEU Purchase Agreement, has evolved as MINATOM and DOE negotiators worked to improve transparency rights and as additional Russian facilities began processing HEU. The number of Russian nuclear facilities subject to US monitoring has increased from two in 1996 to the current four. In that time, physical monitoring, which only permitted visual inspections and access to process forms is being supplemented by instrumentation which detects U-235 enrichment of material in containers and instrumentation which is used to confirm that blending of HEU into LEU at the blending facilities is taking place. This paper summarizes the US HEU Transparency monitoring activities performed in Russian facilities. It then summarizes the process used to certify the Blend Down Monitoring System (BDMS) that is currently in use at one of these facilities.
Date: July 21, 1999
Creator: Benton, J B; Glaser, J W & Mastal, E F
Object Type: Article
System: The UNT Digital Library
Recent results from the National Transparent Optical Networks (NTON) (open access)

Recent results from the National Transparent Optical Networks (NTON)

We review the NTON program, its design and its recent progress on deployment. We then focus on one aspect of our design process, namely modeling the links of the network at the physical layer.
Date: July 21, 1999
Creator: Feng, H. X.; Heritage, J. P.; Lennon, W. J. & Thombley, R. L.
Object Type: Article
System: The UNT Digital Library
Tunneling spectra and superconducting gap in Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+delta} and Tl{sub 2}Ba{sub 2}CuO{sub 6+delta}. (open access)

Tunneling spectra and superconducting gap in Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+delta} and Tl{sub 2}Ba{sub 2}CuO{sub 6+delta}.

Tunneling spectra are reported for Bi{sub 2}Sr{sub 2}CaCu{sub 2} ({sub 8+{delta}}) (Bi-2212) over a wide doping range using superconductor-insulator-superconductor (SIS) break junctions. The energy gap inferred from the tunneling data displays a remarkable monotonic dependence on doping, increasing to very large values in the underdoped region even as T{sub c} decreases. This leads to unphysically large values of the strong coupling ratio ({approximately}20). The tunneling spectra are qualitatively similar over the entire doping range even though the gap parameter, {Delta}, changes from 12 meV to 80 meV. Each spectrum exhibits dip and hump features at high bias with characteristic energies that scale with the superconducting gap. Tunneling spectra of near optimally-doped Tl{sub 2}Ba{sub 2}CuO{sub 6+{delta}} (Tl-2201) also display a weak dip feature in superconductor-insulator-normal metal (SIN) junctions. Generated SIS spectra of Tl-2201 are compared with measured spectra on Bi-2212 and it is concluded that the dip and hump features are generic to high temperature superconductors.
Date: July 21, 1999
Creator: Miyakawa, N.; Qzyuzer, L. & Zasadzinski, J. F.
Object Type: Article
System: The UNT Digital Library
International Atomic Energy Agency/Hanford Site shared use of calorimeters (open access)

International Atomic Energy Agency/Hanford Site shared use of calorimeters

Hanford Site operators combine gamma ray isotopic and calorimetry measurements for nondestructive plutonium assay. Such measurements offer lower variability (particularly for heterogeneous materials) and decreased radiation exposure, cost, waste, intrusiveness, and material handling compared to destructive analysis. Until now, the International Atomic Energy Agency (IAEA) has relied on destructive analysis to perform the most accurate verification requirements for plutonium stored under safeguards at the Hanford Site. It was recognized that using calorimetry could significantly reduce the need for the IAEA to perform destructive analysis. To authorize the operator`s calorimeters for routine IAEA use, however, it was necessary to develop authentication features and perform independent 1558 testing. Authentication features include IAEA control of the hardware and calorimeter operating system software, measurement of certified IAEA standards, sealing of calorimeter chambers, and limited destructive analysis of IAEA selected items. A field test of these authentication features was performed at the Hanford Site in June 1997. The field test also was meant to enhance the credibility the IAEA imputes to calorimetry prior to its implementation. Progress in shared use of the Hanford Site calorimeters is reported.
Date: July 21, 1997
Creator: Welsh, T. L.
Object Type: Article
System: The UNT Digital Library
Testing of explosives mixed with clay to determine maximum explosive content of non-reactive mixtures (open access)

Testing of explosives mixed with clay to determine maximum explosive content of non-reactive mixtures

This report contains a detailed description of the experiments conducted to demonstrate that debris from explosives testing in a shot tank that contains 4 weight percent or less of explosive is non-reactive under the specified testing protocol in the Code of Federal Regulations. As such it is a companion report to UCRL-ID-128999, "Program for Certification of Waste from Contained Firing Facility - Establishment of Waste as Non-Reactive and Discussion of Potential Waste Generation Problems."
Date: July 21, 1998
Creator: Garza, R.; Green, L.; Maienschein, J. & Pruneda, C.
Object Type: Report
System: The UNT Digital Library
Development of a xenon detector for treaty verification. Final report (open access)

Development of a xenon detector for treaty verification. Final report

The project objective was to determine the feasibility of the gas proportional scintillator detector (GPSD) technology to sensitively and selectively detect the decay products of the metastable xenon isotopes as a means of treaty verification for the CTBT. During the course of the project, the investigation involved both computer simulations and laboratory measurements with a GPSD. During the fourth quarter the authors have further investigated the dedicated GPSD response to x-rays and conversion electrons from {sup 109}Cd and {sup 57}Co radioactive sources, comparing simulated and experimental results. The response of a customized high pressure GPSC was also simulated to the higher energy conversion electrons from xenon radioisotopes. An alternative hybrid detector system is proposed showing excellent prospects for xenon radioisotope detection.
Date: July 21, 1998
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Parallel programming of industrial applications (open access)

Parallel programming of industrial applications

In the introductory material, we overview the typical MPP environment for real application computing and the special tools available such as parallel debuggers and performance analyzers. Next, we draw from a series of real applications codes and discuss the specific challenges and problems that are encountered in parallelizing these individual applications. The application areas drawn from include biomedical sciences, materials processing and design, plasma and fluid dynamics, and others. We show how it was possible to get a particular application to run efficiently and what steps were necessary. Finally we end with a summary of the lessons learned from these applications and predictions for the future of industrial parallel computing. This tutorial is based on material from a forthcoming book entitled: �Industrial Strength Parallel Computing� to be published by Morgan Kaufmann Publishers (ISBN l-55860-54).
Date: July 21, 1998
Creator: Heroux, M.; Koniges, A. & Simon, H.
Object Type: Article
System: The UNT Digital Library
AX Tank Farm waste retrieval alternatives cost estimates (open access)

AX Tank Farm waste retrieval alternatives cost estimates

This report presents the estimated costs associated with retrieval of the wastes from the four tanks in AX Tank Farm. The engineering cost estimates developed for this report are based on previous cost data prepared for Project W-320 and the HTI 241-C-106 Heel Retrieval System. The costs presented in this report address only the retrieval of the wastes from the four AX Farm tanks. This includes costs for equipment procurement, fabrication, installation, and operation to retrieve the wastes. The costs to modify the existing plant equipment and systems to support the retrieval equipment are also included. The estimates do not include operational costs associated with pumping the waste out of the waste receiver tank (241-AY-102) between AX Farm retrieval campaigns or transportation, processing, and disposal of the retrieved waste.
Date: July 21, 1998
Creator: Krieg, S. A.
Object Type: Report
System: The UNT Digital Library