Development of a Novel Bi-Directional Isolated Multiple-Input DC-DC Converter (open access)

Development of a Novel Bi-Directional Isolated Multiple-Input DC-DC Converter

There is vital need for a compact, lightweight, and efficient energy-storage system that is both affordable and has an acceptable cycle life for the large-scale production of electric vehicles (EVs) and hybrid electric vehicles (HEVs). Most of the current research employs a battery-storage unit (BU) combined with a fuel cell (FC) stack in order to achieve the operating voltage-current point of maximum efficiency for the FC system. A system block diagram is shown in Fig.1.1. In such a conventional arrangement, the battery is sized to deliver the difference between the energy required by the traction drive and the energy supplied by the FC system. Energy requirements can increase depending on the drive cycle over which the vehicle is expected to operate. Peak-power transients result in an increase of losses and elevated temperatures which result in a decrease in the lifetime of the battery. This research will propose a novel two-input direct current (dc) dc to dc converter to interface an additional energy-storage element, an ultracapacitor (UC), which is shown in Fig.1.2. It will assist the battery during transients to reduce the peak-power requirements of the battery.
Date: October 24, 2005
Creator: Li, H.
Object Type: Report
System: The UNT Digital Library
Current Advances in the Computational Simulation of the Formation of Low-Mass Stars (open access)

Current Advances in the Computational Simulation of the Formation of Low-Mass Stars

Developing a theory of low-mass star formation ({approx} 0.1 to 3 M{sub {circle_dot}}) remains one of the most elusive and important goals of theoretical astrophysics. The star-formation process is the outcome of the complex dynamics of interstellar gas involving non-linear interactions of turbulence, gravity, magnetic field and radiation. The evolution of protostellar condensations, from the moment they are assembled by turbulent flows to the time they reach stellar densities, spans an enormous range of scales, resulting in a major computational challenge for simulations. Since the previous Protostars and Planets conference, dramatic advances in the development of new numerical algorithmic techniques have been successfully implemented on large scale parallel supercomputers. Among such techniques, Adaptive Mesh Refinement and Smooth Particle Hydrodynamics have provided frameworks to simulate the process of low-mass star formation with a very large dynamic range. It is now feasible to explore the turbulent fragmentation of molecular clouds and the gravitational collapse of cores into stars self-consistently within the same calculation. The increased sophistication of these powerful methods comes with substantial caveats associated with the use of the techniques and the interpretation of the numerical results. In this review, we examine what has been accomplished in the field and present …
Date: October 24, 2005
Creator: Klein, R. I.; Inutsuka, S.; Padoan, P. & Tomisaka, K.
Object Type: Article
System: The UNT Digital Library
Coupling Multi-Component Models with MPH on Distributed Memory Computer Architectures (open access)

Coupling Multi-Component Models with MPH on Distributed Memory Computer Architectures

A growing trend in developing large and complex applications on today's Teraflop scale computers is to integrate stand-alone and/or semi-independent program components into a comprehensive simulation package. One example is the Community Climate System Model which consists of atmosphere, ocean, land-surface and sea-ice components. Each component is semi-independent and has been developed at a different institution. We study how this multi-component, multi-executable application can run effectively on distributed memory architectures. For the first time, we clearly identify five effective execution modes and develop the MPH library to support application development utilizing these modes. MPH performs component-name registration, resource allocation and initial component handshaking in a flexible way.
Date: March 24, 2005
Creator: He, Yun & Ding, Chris
Object Type: Article
System: The UNT Digital Library
DNA Sliding Clamps: Just the Right Twist to Load onto DNA (open access)

DNA Sliding Clamps: Just the Right Twist to Load onto DNA

Two recent papers illuminate a long sought step in DNA sliding clamp loading. One paper reveals the structure of the PCNA clamp wrapped around DNA--still open from being loaded--while a second paper discovers that the clamp may assist this process by forming a right-handed helix upon opening.
Date: October 24, 2005
Creator: Barsky, D & Venclovas, C
Object Type: Article
System: The UNT Digital Library
Laser-Plasma Interactions in High-Energy Density Plasmas (open access)

Laser-Plasma Interactions in High-Energy Density Plasmas

Laser-plasma interactions (LPI) have been studied experimentally in high-temperature, high-energy density plasmas. The studies have been performed using the Omega laser at the Laboratory for Laser Energetics (LLE), Rochester, NY. Up to 10 TW of power was incident upon reduced-scale hohlraums, distributed in three laser beam cones. The hot hohlraums fill quickly with plasma. Late in the laser pulse, most of the laser energy is deposited at the laser entrance hole, where most of the LPI takes place. Due to the high electron temperature, the stimulated Raman scattering (SRS) spectrum extends well beyond {omega}{sub 0}/2, due to the Bohm-Gross shift. This high-temperature, high-energy density regime provides a unique opportunity to study LPI beyond inertial confinement fusion (ICF) conditions.
Date: August 24, 2005
Creator: Constantin, C. G.; Baldis, H. A.; Schneider, M. B.; Hinkel, D. E.; Langdon, A. B.; Seka, W. et al.
Object Type: Article
System: The UNT Digital Library
Bessel-Zernike Discrete Variable Representation Basis (open access)

Bessel-Zernike Discrete Variable Representation Basis

The connection between the Bessel discrete variable basis expansion and a specific form of an orthogonal set of Jacobi polynomials is demonstrated. These so-called Zernike polynomials provide alternative series expansions of suitable functions over the unit interval. Expressing a Bessel function in a Zernike expansion provides a straightforward method of generating series identities. Furthermore, the Zernike polynomials may also be used to efficiently evaluate the Hankel transform for rapidly decaying functions or functions with finite support.
Date: October 24, 2005
Creator: Cerjan, C J
Object Type: Article
System: The UNT Digital Library
Actinic inspection of multilayer defects on EUV masks (open access)

Actinic inspection of multilayer defects on EUV masks

The production of defect-free mask blanks, and the development of techniques for inspecting and qualifying EUV mask blanks, remains a key challenge for EUV lithography. In order to ensure a reliable supply of defect-free mask blanks, it is necessary to develop techniques to reliably and accurately detect defects on un-patterned mask blanks. These inspection tools must be able to accurately detect all critical defects whilst simultaneously having the minimum possible false-positive detection rate. There continues to be improvement in high-speed non-actinic mask blank inspection tools, and it is anticipated that these tools can and will be used by industry to qualify EUV mask blanks. However, the outstanding question remains one of validating that non-actinic inspection techniques are capable of detecting all printable EUV defects. To qualify the performance of non-actinic inspection tools, a unique dual-mode EUV mask inspection system has been installed at the Advanced Light Source (ALS) synchrotron at Lawrence Berkeley National Laboratory. In high-speed inspection mode, whole mask blanks are scanned for defects using 13.5-nm wavelength light to identify and map all locations on the mask that scatter a significant amount of EUV light. In imaging, or defect review mode, a zone plate is placed in the reflected …
Date: March 24, 2005
Creator: Barty, A.; Liu, Y.; Gullikson, E.; Taylor, J. S. & Wood, O.
Object Type: Article
System: The UNT Digital Library
Determining Cross Sections for Reactions on Unstable Nuclei: A Consideration of Indirect Approaches (open access)

Determining Cross Sections for Reactions on Unstable Nuclei: A Consideration of Indirect Approaches

An indirect method for determining cross sections for reactions proceeding through a compound nucleus is presented. The appropriate theoretical framework for applications of this method is reviewed and theoretical and experimental challenges that need to be addressed in applications of the method are outlined. Two approximations are considered and their advantages and limitations are discussed.
Date: May 24, 2005
Creator: Escher, J & Dietrich, F S
Object Type: Article
System: The UNT Digital Library
The Limits of Quintessence (open access)

The Limits of Quintessence

We present evidence that the simplest particle-physics scalar-field models of dynamical dark energy can be separated into distinct behaviors based on the acceleration or deceleration of the field as it evolves down its potential towards a zero minimum. We show that these models occupy narrow regions in the phase-plane of w and w', the dark energy equation-of-state and its time-derivative in units of the Hubble time. Restricting an energy scale of the dark energy microphysics limits how closely a scalar field can resemble a cosmological constant. These results, indicating a desired measurement resolution of order \sigma(w')\approx (1+w), define firm targets for observational tests of the physics of dark energy.
Date: May 24, 2005
Creator: Caldwell, R.R. & Linder, Eric V.
Object Type: Article
System: The UNT Digital Library
Potential for Natural Gas Storage in Deep Basalt Formations at Canoe Ridge, Washington State: A Hydrogeologic Assessment (open access)

Potential for Natural Gas Storage in Deep Basalt Formations at Canoe Ridge, Washington State: A Hydrogeologic Assessment

Between 1999 and 2002, Pacific Gas Transmission Company (PGT) (now TransCanada Pipeline Company) and AVISTA Corporation, together with technical support provided by the Pacific Northwest National Laboratory and the U.S. Department of Energy (DOE) examined the feasibility of developing a subsurface, natural gas-storage facility in deep, underlying Columbia River basalt in south-central Washington state. As part of this project, the 100 Circles #1 well was drilled and characterized in addition to surface studies. This report provides data and interpretations of the geology and hydrology collected specific to the Canoe Ridge site as part of the U.S. DOE funding to the Pacific Northwest National Laboratory in support of this project.
Date: September 24, 2005
Creator: Reidel, Steve P.; Spane, Frank A. & Johnson, Vernon G.
Object Type: Report
System: The UNT Digital Library
The development of a ductility-based aging model for low temperature aged U-6Nb alloy (open access)

The development of a ductility-based aging model for low temperature aged U-6Nb alloy

This study focuses on the ductility evaluation of low-temperature (100 and 200 C) aged U-6Nb alloy. The objective is to develop a ductility-based aging model to improve lifetime prediction for weapon components in the stockpile environment. Literature review shows that the work hardening n-value and the strain-rate hardening mvalue are the two most important metallurgical factors for the uniform and the post-uniform (necking) ductility control, respectively. Unfortunately, both n and m values of the U-6Nb alloy are lacking. The study shows that the total ductility of U-6Nb is dominated by the uniform ductility, which deteriorates in both 100 C and 200 C aging. Further analysis shows that the uniform ductility correlates well with the work hardening n-value of the later stage deformation in which dislocation-slip is the mechanism. The kinetics of the loss of uniform ductility and the associated reduction in work-hardening n-value in low temperature aging will be used for the development of a ductility-based aging model. The necking ductility appears to be a minor but significant factor in the total ductility of U-6Nb. It does not show a clear trend due to large data scatter. The uncertain nature of necking failure may always hinder a reliable measurement of …
Date: March 24, 2005
Creator: Bridges, B
Object Type: Article
System: The UNT Digital Library
Stress and Sealing Performance Analysis of Containment Vessel (open access)

Stress and Sealing Performance Analysis of Containment Vessel

This paper presents a numerical technique for analyzing the containment vessel subjected to the combined loading of closure-bolt torque and internal pressure. The detailed stress distributions in the O-rings generated by both the torque load and the internal pressure can be evaluated by using this method. Consequently, the sealing performance of the O-rings can be determined. The material of the O-rings can be represented by any available constitutive equation for hyperelastic material. In the numerical calculation of this paper, the form of the Mooney-Rivlin strain energy potential is used. The technique treats both the preloading process of bolt tightening and the application of internal pressure as slow dynamic loads. Consequently, the problem can be evaluated using explicit numerical integration scheme.
Date: May 24, 2005
Creator: WU, TSU-TE
Object Type: Article
System: The UNT Digital Library
Field Test Program for Long-Term Operation of a COHPAC System for Removing Mercury from Coal-Fired Flue Gas (open access)

Field Test Program for Long-Term Operation of a COHPAC System for Removing Mercury from Coal-Fired Flue Gas

With the Nation's coal-burning utilities facing the possibility of tighter controls on mercury pollutants, the U.S. Department of Energy is funding projects that could offer power plant operators better ways to reduce these emissions at much lower costs. Sorbent injection technology represents one of the simplest and most mature approaches to controlling mercury emissions from coal-fired boilers. It involves injecting a solid material such as powdered activated carbon into the flue gas. The gas-phase mercury in the flue gas contacts the sorbent and attaches to its surface. The sorbent with the mercury attached is then collected by the existing particle control device along with the other solid material, primarily fly ash. During 2001, ADA Environmental Solutions (ADA-ES) conducted a full-scale demonstration of sorbent-based mercury control technology at the Alabama Power E.C. Gaston Station (Wilsonville, Alabama). This unit burns a low-sulfur bituminous coal and uses a hot-side electrostatic precipitator (ESP) in combination with a Compact Hybrid Particulate Collector (COHPAC{reg_sign}) baghouse to collect fly ash. The majority of the fly ash is collected in the ESP with the residual being collected in the COHPAC{reg_sign} baghouse. Activated carbon was injected between the ESP and COHPAC{reg_sign} units to collect the mercury. Short-term mercury removal …
Date: January 24, 2005
Creator: Bustard, Jean; Lindsey, Charles; Brignac, Paul; Starns, Travis; Sjostrom, Sharon; Taylor, Trent et al.
Object Type: Report
System: The UNT Digital Library
The Development of 6061-Aluminum Windows for the MICE Liquid Absorber (open access)

The Development of 6061-Aluminum Windows for the MICE Liquid Absorber

The thin windows for the Muon Ionization Cooling Experiment (MICE) liquid Absorber will be fabricated from 6061-T6-aluminum. The absorber and vacuum vessel thin windows are 300-mm in diameter and are 180 mm thick at the center. The windows are designed for an internal burst pressure of 0.68 MPa (100 psig) when warm. The MICE experiment design calls for changeable windows on the absorber, so a bolted window design was adopted. Welded windows offer some potential advantages over bolted windows when they are on the absorber itself. This report describes the bolted window and its seal. This report also describes an alternate window that is welded directly to the absorber body. The welded window design presented permits the weld to be ground off and re-welded. This report presents a thermal FEA analysis of the window seal-weld, while the window is being welded. Finally, the results of a test of a welded-window are presented.
Date: August 24, 2005
Creator: Lau, W.; Yang, S. Q.; Green, M. A.; Ishimoto, S. & Swanson, J.
Object Type: Article
System: The UNT Digital Library
Recent Improvements to an Advanced Atmospheric Transport Modeling System (open access)

Recent Improvements to an Advanced Atmospheric Transport Modeling System

The Atmospheric Technologies Group (ATG) has developed an advanced atmospheric modeling capability using the Regional Atmospheric Modeling System (RAMS) and a stochastic Lagrangian particle dispersion model (LPDM) for operational use at the Savannah River Site (SRS). For local simulations concerning releases from the Central Savannah River Area (CSRA), RAMS is run in a nested grid configuration with horizontal grid spacing of 8 and 2 km for each grid, with 6-hr forecasts updated every 3 hours. An interface to allow for easy user access to LPDM had been generated, complete with post-processing results depicting surface concentration, deposition, and a variety of dose quantities. A prior weakness in this approach was that observations from the SRS tower network were only incorporated into the three-dimensional modeling effort during the initialization process. Thus, if the forecasted wind fields were in error, the resulting plume predictions would also be erroneous. To overcome this shortcoming, the procedure for generating RAMS wind fields and reading them into LPDM has been modified such that SRS wind measurements are blended with the predicted three-dimensional wind fields from RAMS using the Barnes technique. In particular, the horizontal components in RAMS are replaced with the observed values at a series of …
Date: October 24, 2005
Creator: Buckley, R. L. & Hunter, C. H.
Object Type: Article
System: The UNT Digital Library
Flow-Based Detection of Bar Coded Particles (open access)

Flow-Based Detection of Bar Coded Particles

We have developed methods for flow control, electric field alignment, and readout of colloidal Nanobarcodes{copyright}. Our flow-based detection scheme leverages microfluidics and alternate current (AC) electric fields to align and image particles in a well-defined image plane. Using analytical models of the particle rotation in electric fields we can optimize the field strength and frequency necessary to align the particles. This detection platform alleviates loss of information in solution-based assays due to particle clumping during detection.
Date: June 24, 2005
Creator: Rose, K A; Dougherty, G M & Santiago, J G
Object Type: Article
System: The UNT Digital Library
Savannah River National Laboratory Involvement in the European ENSEMBLE Program (open access)

Savannah River National Laboratory Involvement in the European ENSEMBLE Program

Many atmospheric transport and dispersion models now exist to provide consequence assessment during emergency response to near-field releases. One way of estimating the uncertainty for a given forecast is to statistically analyze an ensemble of results from several models. ENSEMBLE is a European Union program that utilizes an internet-based system to ingest transport results from numerous modeling agencies. This paper addresses the involvement of the Savannah River National Laboratory (SRNL) in ENSEMBLE, and the resulting improvements in SRNL modeling capabilities. SRNL, the only United States agency involved in the ENSEMBLE program, uses a prognostic atmospheric numerical model (the Regional Atmospheric Modeling System, RAMS) to provide three-dimensional and time-varying meteorology as input to a stochastic Lagrangian particle mode . The model design used by SRNL is discussed, including recent upgrades to the system using parallel processing which allows for finer grid resolution in the generation of the meteorology.
Date: October 24, 2005
Creator: Buckley, R. L. & Addies, Robert P.
Object Type: Article
System: The UNT Digital Library
Ligand Rearrangement Reactions of Cr(CO)6 in Alcohol Solutions:Experiment and Theory (open access)

Ligand Rearrangement Reactions of Cr(CO)6 in Alcohol Solutions:Experiment and Theory

The ligand rearrangement reaction of Cr(CO)6 is studied in a series of alcohol solutions using ultrafast, infrared spectroscopy and Brownian dynamics simulations.
Date: September 24, 2005
Creator: Shanoski, Jennifer E.; Glascoe, Elizabeth A. & Harris, Charles B.
Object Type: Article
System: The UNT Digital Library
Effect of cerium incorporation into zirconia on the activity ofCu/ZrO2 for methanol synthesis via CO hydrogenation (open access)

Effect of cerium incorporation into zirconia on the activity ofCu/ZrO2 for methanol synthesis via CO hydrogenation

The effects of Ce incorporation into ZrO2 on the catalyticperformance of Cu/ZrO2 for the hydrogenation of CO have beeninvestigated. A Ce0.3Zr0.7O2 solid solution was synthesized by forcedhydrolysis at low pH. After calcination at 873 K, XRD and Ramanspectroscopy characterization indicated that the Ce0.3Zr0.7O2 had a t''crystal structure. 1.2 wt percent Cu/Ce0.3Zr0.7O2 exhibited H2consumption peaks at low temperature (<473 K) during H2-TPRindicating a significant fraction (~; 70 percent) of Ce4+ is reduced toCe3+. 1.2 wt percent Cu/Ce0.3Zr0.7O2 is 2.7 times more active formethanol synthesis than 1.2 wt percent Cu/m-ZrO2 at 3.0 MPa attemperatures between 473 and 523 K and exhibits a higher selectivity tomethanol. In-situ infrared spectroscopy shows that, analogous toCu/m-ZrO2, the primary surface species on Cu/Ce0.3Zr0.7O2 during COhydrogenation are formate and methoxide species. A shift in the bandposition of the bridged methoxide species indicated that some of thesegroups were bonded to both Zr4+ and Ce3+ cations. For both catalysts, therate-limiting step for methanol synthesis is the reductive elimination ofmethoxide species. The higher rate of methanol synthesis onCu/Ce0.3Zr0.7O2 relative to Cu/m-ZrO2 was primarily due to a ~; 2.4 timeshigher apparent rate constant, kapp, for methoxide hydrogenation, whichis attributed to the higher surface concentration of H atoms on theformer catalyst. The increased …
Date: August 24, 2005
Creator: Pokrovski, Konstantin A.; Rhodes, Michael D. & Bell, Alexis T.
Object Type: Article
System: The UNT Digital Library
Research Program to Investigate the Fundamental Chemistry of Technetium (open access)

Research Program to Investigate the Fundamental Chemistry of Technetium

Technetium (99Tc, half-life = 2.13x105 years, ?-emitter) is one of the radionuclides of major concern for nuclear waste disposal. This concern is due to the long half-life of 99Tc, the ease with which pertechnetate, TcO4 -, migrates in the geosphere, difficulties in incorporating Tc into glass waste forms, and the corresponding regulatory considerations. The problem of mobility of pertechnetate in the environment is compounded by the fact that pertechnetate is the thermodynamically stable form of Tc in oxidizing environments. These factors present challenges for the separation and immobilization of Tc. The objective of this research project is to provide new knowledge about the chemical behavior of Tc so that the factors underlying its speciation in nuclear waste and in waste forms can be understood and the problems can be addressed. In particular, the behavior of Tc and Re in glass will be examined since Re is often used as a non-radioactive surrogate to predict the behavior of Tc.(1) In this project, glasses containing both Re and Tc will be prepared, so that the behavior of both metals can be compared under identical conditions
Date: September 24, 2005
Creator: Shuh, David K. & Pegg, Ian l.
Object Type: Report
System: The UNT Digital Library
Simulating Electron Cloud Effects in Heavy-Ion Beams (open access)

Simulating Electron Cloud Effects in Heavy-Ion Beams

None
Date: January 24, 2005
Creator: Cohen, R H; Friedman, A; Lund, S M; Molvik, A W; Azevedo, T; Vay, J et al.
Object Type: Article
System: The UNT Digital Library
Laser Machining For Fabrication Of Hohlraums And Capsules (open access)

Laser Machining For Fabrication Of Hohlraums And Capsules

Laser machining technology has been used to demonstrate the ability to rapidly perform jobs on all aspects of ICF targets. Lasers are able to rapidly perform modifications and repairs to the gold metal parts on hohlraums, make cuts in the delicate polymer parts of the hohlraum, and drill holes in the capsules to enable them to be filled with fuel. Lasers investigated in this work include 193 nm ArF and 248 nm KrF excimers and 810 nm chirped-pulse amplification Ti:Sapphire lasers. The excimer lasers showed a definite advantage in drilling and machining of polymeric materials and the ultrashort infrared pulses of the Ti:Sapphire laser were far better for the gold structures.
Date: June 24, 2005
Creator: Shirk, M. D.; Kelly, B. T.; Haynes, S. M.; Stuart, B. C.; Sanchez, J. J.; Moody, J. D. et al.
Object Type: Article
System: The UNT Digital Library
Analyzing Nuclear Fuel Cycles from Isotopic Ratios of Waste Products Applicable to Measurement by Accelerator Mass Spectrometry (open access)

Analyzing Nuclear Fuel Cycles from Isotopic Ratios of Waste Products Applicable to Measurement by Accelerator Mass Spectrometry

An extensive study was conducted to determine isotopic ratios of nuclides in spent fuel that may be utilized to reveal historical characteristics of a nuclear reactor cycle. This forensic information is important to determine the origin of unknown nuclear waste. The distribution of isotopes in waste products provides information about a nuclear fuel cycle, even when the isotopes of uranium and plutonium are removed through chemical processing. Several different reactor cycles of the PWR, BWR, CANDU, and LMFBR were simulated for this work with the ORIGEN-ARP and ORIGEN 2.2 codes. The spent fuel nuclide concentrations of these reactors were analyzed to find the most informative isotopic ratios indicative of irradiation cycle length and reactor design. Special focus was given to long-lived and stable fission products that would be present many years after their creation. For such nuclides, mass spectrometry analysis methods often have better detection limits than classic gamma-ray spectroscopy. The isotopic ratios {sup 151}Sm/{sup 146}Sm, {sup 149}Sm/{sup 146}Sm, and {sup 244}Cm/{sup 246}Cm were found to be good indicators of fuel cycle length and are well suited for analysis by accelerator mass spectroscopy.
Date: August 24, 2005
Creator: Biegalski, S R; Whitney, S M & Buchholz, B
Object Type: Article
System: The UNT Digital Library
Materials System for Intermediate Temperature Solid Oxide Fuel Cell (open access)

Materials System for Intermediate Temperature Solid Oxide Fuel Cell

AC complex impedance spectroscopy studies were conducted between 600-800 C on symmetrical cells that employed strontium-and-magnesium-doped lanthanum gallate electrolyte, La{sub 0.9}Sr{sub 0.1}Ga{sub 0.8}Mg{sub 0.2}O{sub 3} (LSGM). The objective of the study was to identify the materials system for fabrication and evaluation of intermediate temperature (600-800 C) solid oxide fuel cells (SOFCs). The slurry-coated electrode materials had fine porosity to enhance catalytic activity. Cathode materials investigated include La{sub 1-x}Sr{sub x}MnO{sub 3} (LSM), LSCF (La{sub 1-x}Sr{sub x}Co{sub y}Fe{sub 1-y}O{sub 3}), a two-phase particulate composite consisting of LSM-doped-lanthanum gallate (LSGM), and LSCF-LSGM. The anode materials were Ni-Ce{sub 0.85}Gd{sub 0.15}O{sub 2} (Ni-GDC) and Ni-Ce{sub 0.6}La{sub 0.4}O{sub 2} (Ni-LDC) composites. Experiments conducted with the anode materials investigated the effect of having a barrier layer of GDC or LDC in between the LSGM electrolyte and the Ni-composite anode to prevent adverse reaction of the Ni with lanthanum in LSGM. For proper interpretation of the beneficial effects of the barrier layer, similar measurements were performed without the barrier layer. The ohmic and the polarization resistances of the system were obtained over time as a function of temperature (600-800 C), firing temperature, thickness, and the composition of the electrodes. The study revealed important details pertaining to the ohmic …
Date: January 24, 2005
Creator: Pal, Uday B. & Gopalan, Srikanth
Object Type: Report
System: The UNT Digital Library