Materials Properties Database for Selection of High-Temperature Alloys and Concepts of Alloy Design for SOFC Applications (open access)

Materials Properties Database for Selection of High-Temperature Alloys and Concepts of Alloy Design for SOFC Applications

To serve as an interconnect / gas separator in an SOFC stack, an alloy should demonstrate the ability to provide (i) bulk and surface stability against oxidation and corrosion during prolonged exposure to the fuel cell environment, (ii) thermal expansion compatibility with the other stack components, (iii) chemical compatibility with adjacent stack components, (iv) high electrical conductivity of the surface reaction products, (v) mechanical reliability and durability at cell exposure conditions, (vii) good manufacturability, processability and fabricability, and (viii) cost effectiveness. As the first step of this approach, a composition and property database was compiled for high temperature alloys in order to assist in determining which alloys offer the most promise for SOFC interconnect applications in terms of oxidation and corrosion resistance. The high temperature alloys of interest included Ni-, Fe-, Co-base superal
Date: November 24, 2002
Creator: Yang, Z Gary; Paxton, Dean M.; Weil, K. Scott; Stevenson, Jeffry W. & Singh, Prabhakar
Object Type: Report
System: The UNT Digital Library
20% Partial Siberian Snake in the AGS. (open access)

20% Partial Siberian Snake in the AGS.

An 11.4% partial Siberian snake was used to successfully accelerate polarized proton through a strong intrinsic depolarizing spin resonance in the AGS. No noticeable depolarization was observed. This opens up the possibility of using a 20% to 30% partial Siberian snake in the AGS to overcome all weak and strong depolarizing spin resonances. Some design and operation issues of the new partial Siberian snake are discussed.
Date: November 6, 2002
Creator: Huang, H.; Bai, M.; Brown, K. A.; Glenn, W.; Luccio, A. U.; MacKay, W. W. et al.
Object Type: Article
System: The UNT Digital Library
Structured Extended Finite Element Methods of Solids Defined by Implicit Surfaces (open access)

Structured Extended Finite Element Methods of Solids Defined by Implicit Surfaces

A paradigm is developed for generating structured finite element models from solid models by means of implicit surface definitions. The implicit surfaces are defined by radial basis functions. Internal features, such as material interfaces, sliding interfaces and cracks are treated by enrichment techniques developed in the extended finite element method (X-FEM). Methods for integrating the weak form for such models are proposed. These methods simplify the generation of finite element models. Results presented for several examples show that the accuracy of this method is comparable to standard unstructured finite element methods.
Date: November 17, 2002
Creator: Belytschko, T; Mish, K; Moes, N & Parimi, C
Object Type: Report
System: The UNT Digital Library
Contribution of Neutron Beta Decay to Radiation Belt Pumping from High Altitude Nuclear Explosion (open access)

Contribution of Neutron Beta Decay to Radiation Belt Pumping from High Altitude Nuclear Explosion

In 1962, several satellites were lost following high altitude nuclear tests by the United States and the Soviet Union. These satellite failures were caused by energetic electrons injected into the earth's radiation belts from the beta decay of bomb produced fission fragments and neutrons. It has been 40 years since the last high altitude nuclear test; there are now many more satellites in orbit, and it is important to understand their vulnerability to radiation belt pumping from nuclear explosions at high altitude or in space. This report presents the results of a calculation of the contribution of neutron beta decay to artificial belt pumping. For most high altitude nuclear explosions, neutrons are expected to make a smaller contribution than fission products to the total trapped electron inventory, and their contribution is usually neglected. However, the neutron contribution may dominate in cases where the fission product contribution is suppressed due to the altitude or geomagnetic latitude of the nuclear explosion, and for regions of the radiation belts with field lines far from the detonation point. In any case, an accurate model of belt pumping from high altitude nuclear explosions, and a self-consistent explanation of the 1962 data, require inclusion of the …
Date: November 13, 2002
Creator: Marrs, R
Object Type: Report
System: The UNT Digital Library
Fiscal Year 2003 Integrated Monitoring Plan for the Hanford Groundwater Monitoring Project (open access)

Fiscal Year 2003 Integrated Monitoring Plan for the Hanford Groundwater Monitoring Project

This document is an integrated monitoring plan for the Groundwater Monitoring Project. It documents well and constituent lists for the monitoring required by the Atomic Energy Act of 1954 and its implementing orders.
Date: November 1, 2002
Creator: Hartman, Mary J.; Dresel, P. EVAN; Lindberg, Jon W.; McDonald, John P.; Newcomer, Darrell R. & Thornton, Edward C.
Object Type: Report
System: The UNT Digital Library
Time-Resolved Emittance Characterization of an Induction Linac Beam using Optical Transition Radiation (open access)

Time-Resolved Emittance Characterization of an Induction Linac Beam using Optical Transition Radiation

An induction linac is used by Lawrence Livermore National Laboratory to perform radiographic testing at the Flash X-ray Radiography facility. Emittance characterization is important since x-ray spot size impacts the resolution of shadow-graphs. Due to the long pulse length, high current, and beam energy, emittance measurement using Optical Transition Radiation is an attractive alternative for reasons that will be described in the text. The utility of OTR-based emittance measurement has been well demonstrated for both RF and induction linacs. We describe the time-resolved emittance characterization of an induction linac electron beam. We have refined the optical collection system for the induction linac application, and have demonstrated a new technique for probing the divergence of a subset of the beam profile. The experimental apparatus, data reduction, and conclusions will be presented. Additionally, a new scheme for characterizing the correlation between beam divergence and spatial coordinates within the beam profile will be described.
Date: November 5, 2002
Creator: Le Sage, G P
Object Type: Report
System: The UNT Digital Library
Alternative Fuels and Vehicles Information Resources (Brochure) (open access)

Alternative Fuels and Vehicles Information Resources (Brochure)

A brochure listing and describing Web sites and telephone numbers of resources for people interested in alternative fuels and related vehicles. Most are sponsored by DOE.
Date: November 1, 2002
Creator: unknown
Object Type: Text
System: The UNT Digital Library
Groundwater Monitoring Plan for the 216-B-63 Trench on the Hanford Site (open access)

Groundwater Monitoring Plan for the 216-B-63 Trench on the Hanford Site

This document presents a groundwater monitoring plan for the 216-B-63 trench in the 200 East Area of the Hanford Site. The monitoring will be conducted in accordance with regulatory requirements specified in the Resource Conservation and Recovery Act (RCRA) of 1976. The objective of the monitoring is to determine whether any hazardous constituents are detectable in the groundwater beneath the trench. This monitoring plan will serve as the basis for demonstrating monitoring compliance at the B-63 trench under the RCRA.
Date: November 14, 2002
Creator: Sweeney, Mark D.
Object Type: Report
System: The UNT Digital Library
OPPIS UPGRADE FOR 2003 POLARIZED RUN IN RHIC. (open access)

OPPIS UPGRADE FOR 2003 POLARIZED RUN IN RHIC.

The polarization dilution by molecular ions which are produced in the ECR primary proton source is discussed. The molecular component can be reduced to about 5% by ECR source-operation optimization. It is further suppressed by optimization of the extraction electrode optics and by the decelerating einzel lens in the 35 keV LEBT line. As a result, the proton polarization of the accelerated beam was increased to over 80%. as measured in the 200 MeV proton-deuterium polarimeter. The OPPIS upgrade for 6 2/3 Hz repetition rate operation is also discussed.
Date: November 6, 2002
Creator: ZELENSKI,A. ALESSI,J. BRISCOE,B. KPONOU,A. KOKHANOVSKI,S. KLENOV,V. LODESTRO,V. RITTER,J. ZUBETS,V.
Object Type: Article
System: The UNT Digital Library
Out-of-Core Construction and Visualization of Multiresolution Surfaces (open access)

Out-of-Core Construction and Visualization of Multiresolution Surfaces

We present a method for end-to-end out-of-core simplification and view-dependent visualization of large surfaces. The method consists of three phases: (1) memory insensitive simplification; (2) memory insensitive construction of a multiresolution hierarchy; and (3) run-time, output-sensitive, view-dependent rendering and navigation of the mesh. The first two off-line phases are performed entirely on disk, and use only a small, constant amount of memory, whereas the run-time system pages in only the rendered parts of the mesh in a cache coherent manner. As a result, we are able to process and visualize arbitrarily large meshes given a sufficient amount of disk space; a constant multiple of the size of the input mesh. Similar to recent work on out-of-core simplification, our memory insensitive method uses vertex clustering on a uniform octree grid to coarsen a mesh and create a hierarchy, and a quadric error metric to choose vertex positions at all levels of resolution. We show how the quadric information can be used to concisely represent vertex position, surface normal, error, and curvature information for anisotropic view-dependent coarsening and silhouette preservation. The run-time component of our system uses asynchronous rendering and view-dependent refinement driven by screen-space error and visibility. The system exploits frame-to-frame …
Date: November 4, 2002
Creator: Lindstrom, P
Object Type: Article
System: The UNT Digital Library
Data Management Guide Version 1.5.3 (open access)

Data Management Guide Version 1.5.3

The FEMIS Data Management Guide provides the information needed to manage the data used to support the administrative, user-environment, database management, and operational capabilities of FEMIS.
Date: November 20, 2002
Creator: Burnett, Robert A.; Carter, Richard J.; Holter, Nancy A.; Johnson, Daniel M.; Johnson, Ranata L.; Johnson, Sharon M. et al.
Object Type: Text
System: The UNT Digital Library
Influence of BK7 Substrate Solarization on the Performance of Hafnia and Silica Multilayer Mirrors (open access)

Influence of BK7 Substrate Solarization on the Performance of Hafnia and Silica Multilayer Mirrors

Transport mirrors within the National Ignition Facility, a 192-beam 4-MJ fusion laser at 1053 nm, will be exposed to backscattered light from plasmas created from fusion targets and backlighters. This backscattered light covers the UV and visible spectrum from 351-600 nm. The transport mirror BK7 substrates will be intentionally solarized to absorb >95% of the backscattered light to prevent damage to the metallic mechanical support hardware. Solarization has minimal impact on the 351- and 1053-nm laser-induced damage threshold or the reflected wavefront of the multilayer hafnia silica coating. Radiation sources of various energies were examined for BK7 darkening efficiency within the UV and visible region with 1.1 MeV gamma rays from a Cobalt 60 source ultimately being selected. Finally, bleaching rates were measured at elevated temperatures to generate a model for predicting the lifetime at ambient conditions (20 C), before solarized BK7 substrates exceed 5% transmission in the UV and visible region. Over a 30-mm thickness, BK7 glass will bleach in 10 years to 5% transmission at 600 nm, the most transmissive wavelengths over the 351-600 nm regions.
Date: November 26, 2002
Creator: Stolz, C J; Menapace, J A; Genin, F; Ehrmann, P; Miller, P & Rogowski, G
Object Type: Article
System: The UNT Digital Library
Nanoscale Bio-Molecular Control Using EC-OWLS (open access)

Nanoscale Bio-Molecular Control Using EC-OWLS

A recently developed technique termed ''Electrochemical Optical Waveguide Lightmode Spectroscopy'' (EC-OWLS) [1] combines evanescent-field optical sensing with electrochemical control of surface adsorption processes. Initial EC-OWLS investigations efficiently monitored molecular surface adsorption and layer thickness changes of an adsorbed polymer layer examined in situ as a function of potential applied to a waveguide1. A layer of indium tin oxide (ITO) served as both a high refractive index waveguide for optical sensing, and a conductive electrode; an electrochemical flow-through fluid cell incorporated working, reference and counter electrodes. Poly(L-lysine)-grafted-poly(ethylene glycol) (PLL-g-PEG) served as a model, polycation adsorbate. Results indicate that adsorption and desorption of PLL-g-PEG from aqueous buffer are a function of applied potential, and that binding events subsequent to PLL-g-PEG functionalization are dependent on reorganization in the molecular adlayer.
Date: November 20, 2002
Creator: Bearinger, J P; Voros, J; Hubbell, J A & Textor, M
Object Type: Article
System: The UNT Digital Library
300 Area Uranium Leach and Adsorption Project (open access)

300 Area Uranium Leach and Adsorption Project

The objective of this study was to measure the leaching and adsorption characteristics of uranium in six near-surface sediment samples collected from the 300 Area of the Hanford Site. Scanning electron micrographs of the samples showed that the uranium contamination in the sediments is most likely present as co-precipitates and/or discrete uranium particles. Molecular probe techniques also confirm the presence of crystalline discrete uranium bearing phases. In all cases, the uranium is present as oxidized uranium (uranyl [U(VI)]). Results from the column leach tests showed that uranium leaching did not follow a constant solubility paradigm. Four of the five contaminated sediments showed a large near instantaneous release of a few percent of the total uranium followed by a slower continual release. Steady-state uranium leachate concentrations were never measured and leaching characteristics and trends were not consistent among the samples. Dissolution kinetics were slow, and the measured leach curves most likely represent a slow kinetically controlled desorption or dissolution paradigm. Batch adsorption experiments were performed to investigate the effect of pH and uranium and carbonate solution concentrations on uranium adsorption onto the uncontaminated sediment. Uranium adsorption Kd values ranged from 0 to > 100 ml/g depending on which solution parameter was …
Date: November 26, 2002
Creator: Serne, R. Jeffrey; Brown, Christopher F.; Schaef, Herbert T.; Pierce, Eric M.; Lindberg, Michael J.; Wang, Zheming et al.
Object Type: Report
System: The UNT Digital Library
The Center for Data Intensive Computing (open access)

The Center for Data Intensive Computing

CDIC will provide state-of-the-art computational and computer science for the Laboratory and for the broader DOE and scientific community. We achieve this goal by performing advanced scientific computing research in the Laboratory's mission areas of High Energy and Nuclear Physics, Biological and Environmental Research, and Basic Energy Sciences. We also assist other groups at the Laboratory to reach new levels of achievement in computing. We are ''data intensive'' because the production and manipulation of large quantities of data are hallmarks of scientific research in the 21st century and are intrinsic features of major programs at Brookhaven. An integral part of our activity to accomplish this mission will be a close collaboration with the University at Stony Brook.
Date: November 1, 2002
Creator: Glimm, J.
Object Type: Report
System: The UNT Digital Library
Workshop Highlights and Summary. (open access)

Workshop Highlights and Summary.

Based on this workshop, a plan for upgrading polarized proton acceleration in the AGS was developed. The construction of a strong partial Siberian snake was initiated. Although in principle this single device would avoid all sources of depolarization in the AGS its construction, installation and commissioning will take several years. Also mismatch of the polarization direction at injection into the AGS will cause some depolarization. Plan 1 outlined above will be pursued in the meantime. A warm helical partial Siberian snake will replace the present solenoid snake. It will avoid the coupling resonances and can also be used in the future to avoid injection mismatch with the strong partial snake. Existing quadrupoles will be moved to locations where they can be used to suppress the weak intrinsic resonances as discussed at this workshop by Andreas Lehrach. This approach should give maximum polarization from the AGS as soon as possible and also provide a long term solution that is operationally simple and offers additional polarization improvements if the rf dipole method shows residual depolarization.
Date: November 6, 2002
Creator: Roser, T.
Object Type: Article
System: The UNT Digital Library
Ribbon Fiber with Multiple Antiguided Phase-Locked Gain Cores (open access)

Ribbon Fiber with Multiple Antiguided Phase-Locked Gain Cores

We report on the first experimental demonstration of a scalable fiber laser approach based on phase-locking multiple gain cores in an antiguided structure. A novel fabrication technology is used with soft glass components to construct the multiple core fiber used in our experiments. The waveguide region is rectangular in shape and comprised of a periodic sequence of gain and no-gain segments having nearly uniform refractive index. The rectangular waveguide is itself embedded in a lower refractive index cladding region. Experimental results confirm that our five-core Nd doped glass prototype structure runs predominantly in two spatial antiguided modes as predicted by our modeling.
Date: November 20, 2002
Creator: Beach, R J; Feit, M D; Mitchell, S C; Cutter, K P; Dawson, J W & Payne, S A
Object Type: Article
System: The UNT Digital Library
OVERCOMING INTRINSIC AND COUPLING SPIN RESONANCES IN THE AGS. (open access)

OVERCOMING INTRINSIC AND COUPLING SPIN RESONANCES IN THE AGS.

In the Brookhaven AGS, polarized protons are accelerated from G{sub {gamma}} = 4.5 to G{sub {gamma}} = 46.5. During the acceleration, a total of 42 imperfection spin depolarization resonances and 7 intrinsic spin resonances are crossed. Currently, the depolarization at each imperfection spin resonance is overcome by a solenoid 5% snake and full spin flips are induced at 4 out of the 7 intrinsic resonances by the AGS rf dipole to avoid the polarization loss. No correction schemes are applied at the remaining 3 weak spin resonances. In addition, coupling spin resonances are also observed due to the solenoidal field of the snake and no correction is applied for these spin resonances other than keeping the horizontal and vertical betatron tunes separated. In order to achieve {ge} 50% beam polarization out of AGS, all of those spin resonances need to be corrected. This paper proposes three correction methods to overcome the. strong intrinsic spin resonances as well as the weak intrinsic spin resonances and the coupling spin resonances.
Date: November 6, 2002
Creator: BAI,M. AHRENS,L. ROSER,T.
Object Type: Article
System: The UNT Digital Library
Computational Design and Analysis of a Micro-Tab Based Aerodynamic Loads Control System for Lifting Surfaces (open access)

Computational Design and Analysis of a Micro-Tab Based Aerodynamic Loads Control System for Lifting Surfaces

A computational design and analysis of a microtab based aerodynamic loads control system is presented. The microtab consists of a small tab that emerges from a wing approximately perpendicular to its surface in the vicinity of its trailing edge. Tab deployment on the upper side of the wing causes a decrease in the lift generation whereas deployment on the pressure side causes an increase. The computational methods applied in the development of this concept solve the governing Reynolds-averaged Navier-Stokes equations on structured, overset grids. The application of these methods to simulate the flows over lifting surface including the tabs has been paramount in the development of these devices. The numerical results demonstrate the effectiveness of the microtab and that it is possible to carry out a sensitivity analysis on the positioning and sizing of the tabs before they are implemented in successfully controlling the aerodynamic loads.
Date: November 1, 2002
Creator: Van Dam, C.P.; Nakafuji, D.Y.; Bauer, C.; Chao, D. & Standish, K.
Object Type: Article
System: The UNT Digital Library
Reactive Transport Modeling Approach and its Initial Saltcake Dilution Chemical Modeling (open access)

Reactive Transport Modeling Approach and its Initial Saltcake Dilution Chemical Modeling

During waste retrieval, chemical reactions, waste property changes, and waste movements/mixing interact. Thus,to be accurate, a waste process assessment methodology must account for these physical and chemical waste characteristics and mechanisms. This study provides suggestions for column tests and simulation modeling efforts to investigate saltwell pumping of Hanford Tank S-112. In addition, GMIN chemical modeling was initiated for S-112 saltcake dilution with 50% and 100% water as the first step of evaluating the feasibility of the reactive transport code ARIEL as a waste retrieval assessment methodology. The chemical modeling predicted the S-112 saltcake chemistry reasonably well. Although it is too early to conclude the usefulness of this reactive transport modeling approach, it is worth further evaluating its applicability to the waste retrieval process.
Date: November 29, 2002
Creator: Onishi, Yasuo
Object Type: Report
System: The UNT Digital Library
Review of Corrosion Modes for Alloy 22 Regarding Lifetime Expectancy of Nuclear Waste Containers (open access)

Review of Corrosion Modes for Alloy 22 Regarding Lifetime Expectancy of Nuclear Waste Containers

Alloy 22 (UNS N06022) was selected to fabricate the corrosion resistant outer barrier of a two-layer waste package container for nuclear waste at the designated repository site in Yucca Mountain in Nevada (USA). A testing program is underway to characterize and quantify three main modes of corrosion that may occur at the site. Current results show that the containers would perform well under general corrosion, localized corrosion and environmentally assisted cracking (EAC). For example, the general corrosion rate is expected to be below 100 nm/year and the container is predicted to be outside the range of potential for localized corrosion and environmentally assisted cracking.
Date: November 15, 2002
Creator: Rebak, R. B. & Estill, J. C.
Object Type: Article
System: The UNT Digital Library
Interfacial Control of Creep Deformation in Ultrafine Lamellar TiAl (open access)

Interfacial Control of Creep Deformation in Ultrafine Lamellar TiAl

Solute effect on the creep resistance of two-phase lamellar TiAl with an ultrafine microstructure creep-deformed in a low-stress (LS) creep regime [where a linear creep behavior was observed] has been investigated. The resulted deformation substructure and in-situ TEM experiment revealed that interface sliding by the motion of pre-existing interfacial dislocations is the predominant deformation mechanism in LS creep regime. Solute segregation at lamellar interfaces and interfacial precipitation caused by the solute segregation result in a beneficial effect on the creep resistance of ultrafine lamellar TiAl in LS creep regime.
Date: November 26, 2002
Creator: Hsiung, L M
Object Type: Article
System: The UNT Digital Library
Thermogravimetric Thin Aqueous Film Corrosion Studies of Alloy 22; Calcium Chloride Solutions at 150C and Atmospheric Pressure (open access)

Thermogravimetric Thin Aqueous Film Corrosion Studies of Alloy 22; Calcium Chloride Solutions at 150C and Atmospheric Pressure

The extent of reaction of alloy-22 with limited amounts of aqueous calcium chloride (CaCl{sub 2}) was investigated. Alloy-22 is a highly corrosion-resistant nickel-chromium-molybdenum-tungsten alloy. Specimens were polished to a mirror finish prior to aerosol salt deposition. An aqueous film was formed by deliquescence of deposited CaCl{sub 2} at 150 C and 22.5% relative humidity (RH). The reactant gas was a continuous flow of purified humidified laboratory air. The reaction progress as a function of time was continuously measured in-situ by a micro-balance. An initial weight gain due to deliquescence of the CaCl{sub 2} was observed. A steady weight loss was observed over the next 72 hours, after which no further weight change was observed. During this weight loss, white precipitates formed and the specimen's surface became visibly dry. The precipitate crystals were identified as Ca(OH){sub 2} by post-test Raman spectroscopy; however, energy dispersive X-ray spectroscopy indicated that there was a significant amount of chlorine contained in them.
Date: November 12, 2002
Creator: Hailey, P & Gdoowski, G
Object Type: Article
System: The UNT Digital Library
Groundwater Conditions at Single-Shell Tank Waste Management Area TX-TY (January 1998 through December 2001) (open access)

Groundwater Conditions at Single-Shell Tank Waste Management Area TX-TY (January 1998 through December 2001)

This report presents the findings of continued groundwater monitoring at Waste Management Area TX-TY on the Hanford Site. This report covers the period from January 1998 through December 2001.
Date: November 1, 2002
Creator: Horton, Duane G.
Object Type: Report
System: The UNT Digital Library