Final Technical Report (open access)

Final Technical Report

The research project focuses on the following topics: a) removal of artifacts in the Doppler spectra from the ARM cloud radars, b) development of the second generation Active Remote Sensing of Cloud Layers (ARSCL) cloud data products, and c) evaluation of ARM cloud property retrievals within the framework of the EarthCARE simulator. We continue to pursue research on areas related to radiative transfer, atmospheric heating rates and related dynamics (topics of interest to the ARM science community at this time) and to contribute on an ad-hoc basis to the science of other ARM-supported principal investigators.
Date: February 22, 2010
Creator: Eugene Clothiaux, Johannes Verlinde, Jerry Harrington
Object Type: Report
System: The UNT Digital Library
Opportunities for Energy Efficiency and Demand Response in the California Cement Industry (open access)

Opportunities for Energy Efficiency and Demand Response in the California Cement Industry

This study examines the characteristics of cement plants and their ability to shed or shift load to participate in demand response (DR). Relevant factors investigated include the various equipment and processes used to make cement, the operational limitations cement plants are subject to, and the quantities and sources of energy used in the cement-making process. Opportunities for energy efficiency improvements are also reviewed. The results suggest that cement plants are good candidates for DR participation. The cement industry consumes over 400 trillion Btu of energy annually in the United States, and consumes over 150 MW of electricity in California alone. The chemical reactions required to make cement occur only in the cement kiln, and intermediate products are routinely stored between processing stages without negative effects. Cement plants also operate continuously for months at a time between shutdowns, allowing flexibility in operational scheduling. In addition, several examples of cement plants altering their electricity consumption based on utility incentives are discussed. Further study is needed to determine the practical potential for automated demand response (Auto-DR) and to investigate the magnitude and shape of achievable sheds and shifts.
Date: December 22, 2010
Creator: Olsen, Daniel; Goli, Sasank; Faulkner, David & McKane, Aimee
Object Type: Report
System: The UNT Digital Library
Corrective Action Decision Document/Corrective Action Plan for the 92-Acre Area and Corrective Action Unit 111: Area 5 WMD Retired Mixed Waste Pits, Nevada National Security Site, Nevada (open access)

Corrective Action Decision Document/Corrective Action Plan for the 92-Acre Area and Corrective Action Unit 111: Area 5 WMD Retired Mixed Waste Pits, Nevada National Security Site, Nevada

This Corrective Action Decision Document/Corrective Action Plan (CADD/CAP) has been prepared for the 92-Acre Area, the southeast quadrant of the Radioactive Waste Management Site, located in Area 5 of the Nevada National Security Site (NNSS). The 92-Acre Area includes Corrective Action Unit (CAU) 111, 'Area 5 WMD Retired Mixed Waste Pits.' Data Quality Objectives (DQOs) were developed for the 92-Acre Area, which includes CAU 111. The result of the DQO process was that the 92-Acre Area is sufficiently characterized to provide the input data necessary to evaluate corrective action alternatives (CAAs) without the collection of additional data. The DQOs are included as Appendix A of this document. This CADD/CAP identifies and provides the rationale for the recommended CAA for the 92-Acre Area, provides the plan for implementing the CAA, and details the post-closure plan. When approved, this CADD/CAP will supersede the existing Pit 3 (P03) Closure Plan, which was developed in accordance with Title 40 Code of Federal Regulations (CFR) Part 265, 'Interim Status Standards for Owners and Operators of Hazardous Waste Treatment, Storage, and Disposal Facilities.' This document will also serve as the Closure Plan and the Post-Closure Plan, which are required by 40 CFR 265, for the 92-Acre …
Date: November 22, 2010
Creator: National Security Technologies, LLC
Object Type: Report
System: The UNT Digital Library
Next-Generation Flywheel Energy Storage: Development of a 100 kWh/100 kW Flywheel Energy Storage Module (open access)

Next-Generation Flywheel Energy Storage: Development of a 100 kWh/100 kW Flywheel Energy Storage Module

GRIDS Project: Beacon Power is developing a flywheel energy storage system that costs substantially less than existing flywheel technologies. Flywheels store the energy created by turning an internal rotor at high speeds—slowing the rotor releases the energy back to the grid when needed. Beacon Power is redesigning the heart of the flywheel, eliminating the cumbersome hub and shaft typically found at its center. The improved design resembles a flying ring that relies on new magnetic bearings to levitate, freeing it to rotate faster and deliver 400% as much energy as today’s flywheels. Beacon Power’s flywheels can be linked together to provide storage capacity for balancing the approximately 10% of U.S. electricity that comes from renewable sources each year.
Date: September 22, 2010
Creator: unknown
Object Type: Text
System: The UNT Digital Library
Mixer-Ejector Wind Turbine: Breakthrough High Efficiency Shrouded Wind Turbine (open access)

Mixer-Ejector Wind Turbine: Breakthrough High Efficiency Shrouded Wind Turbine

Broad Funding Opportunity Announcement Project: FloDesign Wind Turbine’s innovative wind turbine, inspired by the design of jet engines, could deliver 300% more power than existing wind turbines of the same rotor diameter by extracting more energy over a larger area. FloDesign Wind Turbine’s unique shrouded design expands the wind capture area, and the mixing vortex downstream allows more energy to flow through the rotor without stalling the turbine. The unique rotor and shrouded design also provide significant opportunity for mass production and simplified assembly, enabling mid-scale turbines (approximately 100 kW) to produce power at a cost that is comparable to larger-scale conventional turbines.
Date: February 22, 2010
Creator: unknown
Object Type: Text
System: The UNT Digital Library
Co-Simulation of Building Energy and Control Systems with the Building Controls Virtual Test Bed (open access)

Co-Simulation of Building Energy and Control Systems with the Building Controls Virtual Test Bed

This article describes the implementation of the Building Controls Virtual Test Bed (BCVTB). The BCVTB is a software environment that allows connecting different simulation programs to exchange data during the time integration, and that allows conducting hardware in the loop simulation. The software architecture is a modular design based on Ptolemy II, a software environment for design and analysis of heterogeneous systems. Ptolemy II provides a graphical model building environment, synchronizes the exchanged data and visualizes the system evolution during run-time. The BCVTB provides additions to Ptolemy II that allow the run-time coupling of different simulation programs for data exchange, including EnergyPlus, MATLAB, Simulink and the Modelica modelling and simulation environment Dymola. The additions also allow executing system commands, such as a script that executes a Radiance simulation. In this article, the software architecture is presented and the mathematical model used to implement the co-simulation is discussed. The simulation program interface that the BCVTB provides is explained. The article concludes by presenting applications in which different state of the art simulation programs are linked for run-time data exchange. This link allows the use of the simulation program that is best suited for the particular problem to model building heat transfer, …
Date: August 22, 2010
Creator: Wetter, Michael
Object Type: Article
System: The UNT Digital Library
Commercial and Cost Effective Production of Two-Dimensional Read-Out Boards for Sub-Atomic Particle Detectors (open access)

Commercial and Cost Effective Production of Two-Dimensional Read-Out Boards for Sub-Atomic Particle Detectors

We report results from research aimed at developing and demonstrating production of 2-D readout structures for GEM (Gas Electron Multiplier) charged particle tracking chambers at Tech-Etch. Readout boards of two types, bi-planar and single plane, were fabricated and evaluated. The results show that Tech-Etch can produce suitable boards of either type however the single plane board has a number of advantages both in production and use that will likely make it the preferred choice for GEM tracking chambers.
Date: October 22, 2010
Creator: Crary, David & Majka, Richard
Object Type: Report
System: The UNT Digital Library
Photodetectors for Scintillator Proportionality Measurement (open access)

Photodetectors for Scintillator Proportionality Measurement

None
Date: October 22, 2010
Creator: Moses, William W.; Choong, W. -S.; Hull, G.; Payne, S.; Cherepy, N. & Valentine, J. D.
Object Type: Article
System: The UNT Digital Library
Enhanced Magnetism of Fe3O4 Nanoparticles with Ga Doping (open access)

Enhanced Magnetism of Fe3O4 Nanoparticles with Ga Doping

Magnetic (Ga{sub x}Fe{sub 1-x}){sub 3}O{sub 4} nanoparticles with 5%-33% gallium doping (x = 0.05-0.33) were measured using x-ray absorption spectroscopy and x-ray magnetic circular dichroism to determine that the Ga dopant is substituting for Fe{sub 3+} as Ga{sub 3+} in the tetrahedral A-site of the spinel structure, resulting in an overall increase in the total moment of the material. Frequency-dependent alternating-current magnetic susceptibility measurements showed these particles to be weakly interacting with a reduction of the cubic anisotropy energy term with Ga concentration. The element-specific dichroism spectra show that the average Fe moment is observed to increase with Ga concentration, a result consistent with the replacement of A-site Fe by Ga.
Date: October 22, 2010
Creator: Pool, V. L.; Klem, M. T.; Chorney, C. L.; Arenholz, E. & Idzerda, Y.U.
Object Type: Article
System: The UNT Digital Library
From many body wee partons dynamics to perfect fluid: a standard model for heavy ion collisions (open access)

From many body wee partons dynamics to perfect fluid: a standard model for heavy ion collisions

We discuss a standard model of heavy ion collisions that has emerged both from experimental results of the RHIC program and associated theoretical developments. We comment briefly on the impact of early results of the LHC program on this picture. We consider how this standard model of heavy ion collisions could be solidified or falsified in future experiments at RHIC, the LHC and a future Electro-Ion Collider.
Date: July 22, 2010
Creator: Venugopalan, R.
Object Type: Article
System: The UNT Digital Library
Analysis of the National Ignition Facility Ignition Hohlraum Energetics Experiments (open access)

Analysis of the National Ignition Facility Ignition Hohlraum Energetics Experiments

A series of forty experiments on the National Ignition Facility (NIF) [E. I. Moses et al., Phys. Plasmas 16, 041006 (2009)] to study energy balance and implosion symmetry in reduced- and full-scale ignition hohlraums was shot at energies up to 1.3 MJ. This paper reports the findings of the analysis of the ensemble of experimental data obtained that has produced an improved model for simulating ignition hohlraums. Last year the first observation in a NIF hohlraum of energy transfer between cones of beams as a function of wavelength shift between those cones was reported [P. Michel, et al, Phys of Plasmas, 17, 056305, (2010)]. Detailed analysis of hohlraum wall emission as measured through the laser entrance hole (LEH) has allowed the amount of energy transferred versus wavelength shift to be quantified. The change in outer beam brightness is found to be quantitatively consistent with LASNEX [G. B. Zimmerman and W. L. Kruer, Comments Plasma Phys. Control. Fusion 2, 51 (1975)] simulations using the predicted energy transfer when possible saturation of the plasma wave mediating the transfer is included. The effect of the predicted energy transfer on implosion symmetry is also found to be in good agreement with gated x-ray framing …
Date: November 22, 2010
Creator: Town, R. J.; Rosen, M. D.; Michel, P. A.; Divol, L.; Moody, J. D.; Kyrala, G. A. et al.
Object Type: Article
System: The UNT Digital Library
A molecularly defined duplication set for the X chromosome of Drosophila melanogaster (open access)

A molecularly defined duplication set for the X chromosome of Drosophila melanogaster

We describe a molecularly defined duplication kit for the X chromosome of Drosophila melanogaster. A set of 408 overlapping P[acman] BAC clones was used to create small duplications (average length 88 kb) covering the 22-Mb sequenced portion of the chromosome. The BAC clones were inserted into an attP docking site on chromosome 3L using C31 integrase, allowing direct comparison of different transgenes. The insertions complement 92% of the essential and viable mutations and deletions tested, demonstrating that almost all Drosophila genes are compact and that the current annotations of the genome are reasonably accurate. Moreover, almost all genes are tolerated at twice the normal dosage. Finally, we more precisely mapped two regions at which duplications cause diplo-lethality in males. This collection comprises the first molecularly defined duplication set to cover a whole chromosome in a multicellular organism. The work presented removes a long-standing barrier to genetic analysis of the Drosophila X chromosome, will greatly facilitate functional assays of X-linked genes in vivo, and provides a model for functional analyses of entire chromosomes in other species.
Date: July 22, 2010
Creator: Venken, Koen J. T.; Popodi, Ellen; Holtzman, Stacy L.; Schulze, Karen L.; Park, Soo; Carlson, Joseph W. et al.
Object Type: Article
System: The UNT Digital Library
EVALUATION OF POTENTIAL ELUANTS FOR NON-ACID ELUTION OF CESIUM FROM RESORCINOL-FORMALDEHYDE RESIN (open access)

EVALUATION OF POTENTIAL ELUANTS FOR NON-ACID ELUTION OF CESIUM FROM RESORCINOL-FORMALDEHYDE RESIN

Small-column ion exchange (SCIX) units installed in high-level waste tanks to remove Cs-137 from highly alkaline salt solutions are among the waste treatment plans in the DOE-complex. Spherical Resorcinol-Formaldehyde (sRF) is the ion exchange resin selected for use in the Hanford Waste Treatment and Immobilization Plant (WTP). It is also the primary ion exchange material under consideration for SCIX at the Hanford site. The elution step of the multi-step ion exchange process is typically done with 0.5 M nitric acid. An acid eluant is a potential hazard in the event of a spill, leak, etc. because the high-level waste tanks are made of carbon steel. Corrosion and associated structural damage may ensue. A study has been conducted to explore non-acid elution as an alternative. Batch contact sorption equilibrium screening tests have been conducted with 36 potential non-acid eluants. The sorption tests involve equilibrating each cesium-containing eluant solution with the sRF resin for 48 hours at 25 C in a shaker oven. In the sorption tests, an eluant is deemed to have a high cesium elution potential if it minimizes cesium sorption onto the sRF resin. The top candidates (based on lowest cesium sorption distribution coefficients) include ammonium carbonate, ammonium carbonate/ammonium …
Date: December 22, 2010
Creator: Adu-Wusu, K. & Pennebaker, F.
Object Type: Report
System: The UNT Digital Library
Characterization of the Wymark CO2 Reservoir: A Natural Analog to Long-Term CO2 Storage at Weyburn (open access)

Characterization of the Wymark CO2 Reservoir: A Natural Analog to Long-Term CO2 Storage at Weyburn

Natural accumulations of CO{sub 2} occur in the Duperow and other Devonian strata on the western flank of the Williston Basin in lithologies very similar to those into which anthropogenic CO{sub 2} is being injected as part of an EOR program in the Weyburn-Midale pool. Previous workers have established the stratgraphic and petrographic similarities between the Duperow and Midale beds (Lake and Whittaker, 2004 and 2006). As the CO{sub 2} accumulations in the Devonian strata may be as old as 50 Ma, this similarity provides confidence in the efficacy of long-term geologic sequestration of CO{sub 2} in the Midale-Weyburn pool. Here we attempt to extend this comparison with whole rock and mineral chemistry using the same sample suite used by Lake and Whittaker. We provide XRD, XRF, and electron microprobe analysis of major constituent minerals along with extensive backscattered electron and x-ray imaging to identify trace phases and silicate minerals. LPNORM analysis is used to quantify modal concentrations of minerals species. Samples from depth intervals where CO{sub 2} has been observed are compared to those where CO{sub 2} was absent, with no systematic differences in mineral composition observed. Gas accumulation can be correlated with sample porosity. In particular gas-bearing samples …
Date: November 22, 2010
Creator: Ryerson, F & Johnson, J
Object Type: Report
System: The UNT Digital Library
A Proposal for User-defined Reductions in OpenMP (open access)

A Proposal for User-defined Reductions in OpenMP

Reductions are commonly used in parallel programs to produce a global result from partial results computed in parallel. Currently, OpenMP only supports reductions for primitive data types and a limited set of base language operators. This is a significant limitation for those applications that employ user-defined data types (e. g., objects). Implementing manual reduction algorithms makes software development more complex and error-prone. Additionally, an OpenMP runtime system cannot optimize a manual reduction algorithm in ways typically applied to reductions on primitive types. In this paper, we propose new mechanisms to allow the use of most pre-existing binary functions on user-defined data types as User-Defined Reduction (UDR) operators. Our measurements show that our UDR prototype implementation provides consistently good performance across a range of thread counts without increasing general runtime overheads.
Date: March 22, 2010
Creator: Duran, A; Ferrer, R; Klemm, M; de Supinski, B R & Ayguade, E
Object Type: Article
System: The UNT Digital Library
Trace Assessment for BWR ATWS Analysis (open access)

Trace Assessment for BWR ATWS Analysis

A TRACE/PARCS input model has been developed in order to be able to analyze anticipated transients without scram (ATWS) in a boiling water reactor. The model is based on one developed previously for the Browns Ferry reactor for doing loss-of-coolant accident analysis. This model was updated by adding the control systems needed for ATWS and a core model using PARCS. The control systems were based on models previously developed for the TRAC-B code. The PARCS model is based on information (e.g., exposure and moderator density (void) history distributions) obtained from General Electric Hitachi and cross sections for GE14 fuel obtained from an independent source. The model is able to calculate an ATWS, initiated by the closure of main steam isolation valves, with recirculation pump trip, water level control, injection of borated water from the standby liquid control system and actuation of the automatic depres-surization system. The model is not considered complete and recommendations are made on how it should be improved.
Date: April 22, 2010
Creator: Cheng, L. Y.; Diamond, D. & Arantxa Cuadra, Gilad Raitses, Arnold Aronson
Object Type: Report
System: The UNT Digital Library
Lead-Cooled Fast Reactor (LFR) Design: Safety, Neutronics, Thermal Hydraulics, Structural Mechanics, Fuel, Core, and Plant Design (open access)

Lead-Cooled Fast Reactor (LFR) Design: Safety, Neutronics, Thermal Hydraulics, Structural Mechanics, Fuel, Core, and Plant Design

Fifth chapter from "A Compendium of Reactor Technology" discussing the history and design of lead-cooled fast reactors in nine sections: Lead-cooled Fast Reactor (LFR) Development, Design Criteria and General Specifications, Neutronics, Lead Properties, Compatibility of Structural Materials with Lead, Core, Reactor System, Decay Heat Removal System, and Nuclear Island.
Date: February 22, 2010
Creator: Smith, Craig; Cinotti, L.; Artoli, C. & Grasso, G.
Object Type: Book Chapter
System: The UNT Digital Library
Summary Report for the Development of Materials for Volatile Radionuclides (open access)

Summary Report for the Development of Materials for Volatile Radionuclides

The materials development summarized here is in support of the Waste Forms campaign, Volatile Radionuclide task. Specifically, materials are being developed for the removal and immobilization of iodine and krypton, specifically 129I and 85Kr. During FY 2010, aerogel materials were investigated for removal and immobilization of 129I. Two aerogel formulations were investigated, one based on silica aerogels and the second on chalcogenides. For 85Kr, metal organic framework (MOF) structures were investigated.
Date: November 22, 2010
Creator: Strachan, Denis M.; Chun, Jaehun; Henager, Charles H.; Matyas, Josef; Riley, Brian J.; Ryan, Joseph V. et al.
Object Type: Report
System: The UNT Digital Library
In-Situ Real Time Monitoring and Control of Mold Making and Filling Processes: Final Report (open access)

In-Situ Real Time Monitoring and Control of Mold Making and Filling Processes: Final Report

This project presents a model for addressing several objectives envisioned by the metal casting industries through the integration of research and educational components. It provides an innovative approach to introduce technologies for real time characterization of sand molds, lost foam patterns and monitoring of the mold filling process. The technology developed will enable better control over the casting process. It is expected to reduce scrap and variance in the casting quality. A strong educational component is integrated into the research plan to utilize increased awareness of the industry professional, the potential benefits of the developed technology, and the potential benefits of cross cutting technologies.
Date: December 22, 2010
Creator: Abdelrahman, Mohamed & Currie, Kenneth
Object Type: Report
System: The UNT Digital Library
Development of Extruded Scintillator and Single-Bit Tracking Calorimetry - Final Report (open access)

Development of Extruded Scintillator and Single-Bit Tracking Calorimetry - Final Report

Final Closeout report for DE-FG02-02ER41223
Date: June 22, 2010
Creator: Chakraborty, Dhiman
Object Type: Report
System: The UNT Digital Library
Comparison of the Wymark CO2 Reservoir with the Midale Beds at the Weyburn CO2 Injection Project (open access)

Comparison of the Wymark CO2 Reservoir with the Midale Beds at the Weyburn CO2 Injection Project

The Devonian carbonates of the Duperow Formation on the western flank of the Williston Basin in southwest Saskatchewan contain natural accumulations of CO{sub 2}, and may have done so for as long as 50 m.y. in the views of some investigations. These carbonate sediments are characterized by a succession of carbonate cycles capped by anhydrite-rich evaporites that are thought to act as seals to fluid migration. The Weyburn CO{sub 2} injection site lies 400 km to the east in a series of Mississippian carbonates that were deposited in a similar depositional environment. That natural CO{sub 2} can be stored long-term within carbonate strata has motivated the investigation of the Duperow rocks as a potential natural analogue to storage of anthropogenic CO{sub 2} that may ultimately provide additional confidence for CO{sub 2} sequestration in carbonate lithologies. For the Duperow strata to represent a legitimate analog for Midale injection and storage, the similarity in lithofacies, whole rock compositions, mineral compositions and porosity with the Midale Beds must be established. Previous workers have demonstrated the similarity of the lithofacies at both sites. Here we compare the whole rock compositions, mineralogy and mineral compositions. The major mineral phases at both locales are calcite, dolomite …
Date: November 22, 2010
Creator: Ryerson, F & Johnson, J
Object Type: Report
System: The UNT Digital Library
Microchannel Reactor System for Catalytic Hydrogenation (open access)

Microchannel Reactor System for Catalytic Hydrogenation

We successfully demonstrated a novel process intensification concept enabled by the development of microchannel reactors, for energy efficient catalytic hydrogenation reactions at moderate temperature, and pressure, and low solvent levels. We designed, fabricated, evaluated, and optimized a laboratory-scale microchannel reactor system for hydrogenation of onitroanisole and a proprietary BMS molecule. In the second phase of the program, as a prelude to full-scale commercialization, we designed and developed a fully-automated skid-mounted multichannel microreactor pilot plant system for multiphase reactions. The system is capable of processing 1 – 10 kg/h of liquid substrate, and an industrially relevant immiscible liquid-liquid was successfully demonstrated on the system. Our microreactor-based pilot plant is one-of-akind. We anticipate that this process intensification concept, if successfully demonstrated, will provide a paradigm-changing basis for replacing existing energy inefficient, cost ineffective, environmentally detrimental slurry semi-batch reactor-based manufacturing practiced in the pharmaceutical and fine chemicals industries.
Date: December 22, 2010
Creator: Lawal, Adeniyi; Lee, Woo; Besser, Ron; Kientzler, Donald & Achenie, Luke
Object Type: Report
System: The UNT Digital Library
MEASUREMENTS OF PAST 14C LEVELS AND 13C/12C RATIOS IN THE SURFACE WATERS OF THE WORLD'S SUBPOLAR OCEANS. (open access)

MEASUREMENTS OF PAST 14C LEVELS AND 13C/12C RATIOS IN THE SURFACE WATERS OF THE WORLD'S SUBPOLAR OCEANS.

Under this project we have developed methods that allow the reconstruction of past {sup 14}C levels of the surface waters of the subpolar North Pacific Ocean by measuring the {sup 14}C contents of archived salmon scales. The overall goal of this research was to reduce of the uncertainty in the uptake of fossil CO{sub 2} by the oceans and thereby improve the quantification of the global carbon cycle and to elucidate the fate of anthropogenic CO{sub 2}. Ocean General Circulation Models (OGCMs), with their three dimensional global spatial coverage and temporal modeling capabilities, provide the best route to accurately calculating the total uptake of CO{sub 2} by the oceans and, hence, to achieving the desired reduction in uncertainty. {sup 14}C has played, and continues to play, a central role in the validation of the OGCMs calculations, particularly with respect to those model components which govern the uptake of CO{sub 2} from the atmosphere and the transport of this carbon within the oceans. Under this project, we have developed time-series records of the {sup 14}C levels of the surface waters of three areas of the subpolar North Pacific Ocean. As the previously available data on the time-history of oceanic surface water …
Date: April 22, 2010
Creator: Brown, T A
Object Type: Report
System: The UNT Digital Library
PRELIMINARY STUDY OF CERAMICS FOR IMMOBILIZATION OF ADVANCED FUEL CYCLE REPROCESSING WASTES (open access)

PRELIMINARY STUDY OF CERAMICS FOR IMMOBILIZATION OF ADVANCED FUEL CYCLE REPROCESSING WASTES

The Savannah River National Laboratory (SRNL) developed a series of ceramic waste forms for the immobilization of Cesium/Lanthanide (CS/LN) and Cesium/Lanthanide/Transition Metal (CS/LN/TM) waste streams anticipated to result from nuclear fuel reprocessing. Simple raw materials, including Al{sub 2}O{sub 3}, CaO, and TiO{sub 2} were combined with simulated waste components to produce multiphase ceramics containing hollandite-type phases, perovskites (particularly BaTiO{sub 3}), pyrochlores, zirconolite, and other minor metal titanate phases. Identification of excess Al{sub 2}O{sub 3} via X-ray Diffraction (XRD) and Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM/EDS) in the first series of compositions led to a Phase II study, with significantly reduced Al{sub 2}O{sub 3} concentrations and increased waste loadings. Three fabrication methodologies were used, including melting and crystallizing, pressing and sintering, and Spark Plasma Sintering (SPS), with the intent of studying phase evolution under various sintering conditions. XRD and SEM/EDS results showed that the partitioning of the waste elements in the sintered materials was very similar, despite varying stoichiometry of the phases formed. The Phase II compositions generally contained a reduced amount of unreacted Al{sub 2}O{sub 3} as identified by XRD, and had phase assemblages that were closer to the initial targets. Chemical composition measurements showed no significant issues …
Date: September 22, 2010
Creator: Fox, K.; Billings, A.; Brinkman, K. & Marra, J.
Object Type: Report
System: The UNT Digital Library