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Test Plan for New SY Farm Annulus Leak Detectors (open access)

Test Plan for New SY Farm Annulus Leak Detectors

This document provides a plan for testing a new annulus leak detection device in the annulus of the waste storage tank 241 SY-102.
Date: August 13, 1999
Creator: ABUNDO, R.
Object Type: Report
System: The UNT Digital Library
A Numerical Feasibility Study of Three-Component Induction Logging for Three Dimensional Imaging About a Single Borehole (open access)

A Numerical Feasibility Study of Three-Component Induction Logging for Three Dimensional Imaging About a Single Borehole

A theoretical analysis has been completed for a proposed induction logging tool designed to yield data which are used to generate three dimensional images of the region surrounding a well bore. The proposed tool consists of three mutually orthogonal magnetic dipole sources and multiple 3 component magnetic field receivers offset at different distances from the source. The initial study employs sensitivity functions which are derived by applying the Born Approximation to the integral equation that governs the magnetic fields generated by a magnetic dipole source located within an inhomogeneous medium. The analysis has shown that the standard coaxial configuration, where the magnetic moments of both the source and the receiver are aligned with the axis of the well bore, offers the greatest depth of sensitivity away from the borehole compared to any other source-receiver combination. In addition this configuration offers the best signal-to-noise characteristics. Due to the cylindrically symmetric nature of the tool sensitivity about the borehole, the data generated by this configuration can only be interpreted in terms of a two-dimensional cylindrical model. For a fill 3D interpretation the two radial components of the magnetic field that are orthogonal to each other must be measured. Coil configurations where both …
Date: August 1, 1999
Creator: ALUMBAUGH, DAVID L. & WILT, MICHAEL J.
Object Type: Report
System: The UNT Digital Library
Oak Ridge Isotope Products and Services - Current and Expected Supply and Demand (open access)

Oak Ridge Isotope Products and Services - Current and Expected Supply and Demand

Oak Ridge National Laboratory (ORNL) has been a major center of isotope production research, development, and distribution for over 50 years. Currently, the major isotope production activities include (1) the production of transuranium element radioisotopes, including 252 Cf; (2) the production of medical and industrial radioisotopes; (3) maintenance and expansion of the capabilities for production of enriched stable isotopes; and, (4) preparation of a wide range of custom-order chemical and physical forms of isotope products, particularly in accelerator physics research. The recent supply of and demand for isotope products and services in these areas, research and development (R&D), and the capabilities for future supply are described in more detail below. The keys to continuing the supply of these important products and services are the maintenance, improvement, and potential expansion of specialized facilities, including (1) the High Flux Isotope Reactor (HFIR), (2) the Radiochemical Engineering Development Center (REDC) and Radiochemical Development Laboratory (RDL) hot cell facilities, (3) the electromagnetic calutron mass separators and the plasma separation process equipment for isotope enrichment, and (4) the Isotope Research Materials Laboratory (IRML) equipment for preparation of specialized chemical and physical forms of isotope products. The status and plans for these ORNL isotope production facilities …
Date: August 29, 1999
Creator: Aaron, W. S.; Alexander, C. W.; Cline, R. L.; Collins, E. D.; Klein, J. A.; Knauer, J. B., Jr. et al.
Object Type: Article
System: The UNT Digital Library
Data Torturing and the Misuse of Statistical Tools (open access)

Data Torturing and the Misuse of Statistical Tools

Statistical concepts, methods, and tools are often used in the implementation of statistical thinking. Unfortunately, statistical tools are all too often misused by not applying them in the context of statistical thinking that focuses on processes, variation, and data. The consequences of this misuse may be ''data torturing'' or going beyond reasonable interpretation of the facts due to a misunderstanding of the processes creating the data or the misinterpretation of variability in the data. In the hope of averting future misuse and data torturing, examples are provided where the application of common statistical tools, in the absence of statistical thinking, provides deceptive results by not adequately representing the underlying process and variability. For each of the examples, a discussion is provided on how applying the concepts of statistical thinking may have prevented the data torturing. The lessons learned from these examples will provide an increased awareness of the potential for many statistical methods to mislead and a better understanding of how statistical thinking broadens and increases the effectiveness of statistical tools.
Date: August 16, 1999
Creator: Abate, Marcey L.
Object Type: Article
System: The UNT Digital Library
An Improved Direct Measurement of Leptonic Coupling Asymmetries with Polarized Z{sup 0}'s (open access)

An Improved Direct Measurement of Leptonic Coupling Asymmetries with Polarized Z{sup 0}'s

We report new direct measurements of the Z{sup 0}-lepton coupling asymmetry parameters A{sub e}, A{sub {mu}} and A{sub r}, with polarized Z{sup 0}'s collected by the SLD detector at the SLAC Linear Collider. The parameters are extracted from the measurement of the left-right-forward-backward asymmetries for each lepton species. The 1996, 1997 and 1998 SLD runs are included in this analysis and combined with published data from the 1993-95 runs. Preliminary results are A{sub e} = 0.1558 {+-} 0.0064, A{sub {mu}} = 0.137 {+-} 0.016 and A{sub {tau}} = 0.142 {+-} 0.016. If lepton universality is assumed, a combined asymmetry parameter A{sub l} = 0.1523 {+-} 0.0057 results. This translates into an effective weak mixing angle sin{sup 2} {theta}{sub W}{sup eff} = 0.23085 {+-} 0.00073 at the Z{sup 0} resonance.
Date: August 3, 1999
Creator: Abe, Toshinori
Object Type: Report
System: The UNT Digital Library
Analysis of Ignition Testing on K-West Basin Fuel (open access)

Analysis of Ignition Testing on K-West Basin Fuel

Approximately 2100 metric tons of spent nuclear fuel (SNF) discharged from the N-Reactor have been stored underwater at the K-Basins in the 100 Area of the Hanford Site. The spent fuel has been stored in the K-East Basin since 1975 and in the K-West Basin since 1981. Some of the SNF elements in these basins have corroded because of various breaches in the Zircaloy cladding that occurred during fuel discharge operations and/or subsequent handling and storage in the basins. Consequently, radioactive material in the fuel has been released into the basin water, and water has leaked from the K-East Basin into the soil below. To protect the Columbia River, which is only 380 m from the basins, the SNF is scheduled to be removed and transported for interim dry storage in the 200 East Area, in the central portion of the Site. However, before being shipped, the corroded fuel elements will be loaded into Multi-Canister OverPacks and conditioned. The conditioning process will be selected based on the Integrated Process Strategy (IPS) (WHC 1995), which was prepared on the basis of the dry storage concept developed by the Independent Technical Assessment (ITA) team (ITA 1994).
Date: August 10, 1999
Creator: Abrefah, J.; Huang, F.H.; Gerry, W.M.; Gray, W.J.; Marschman, S.C. & Thornton, T.A.
Object Type: Report
System: The UNT Digital Library
Analysis of Ignition Testing on K-West Basin Fuel (open access)

Analysis of Ignition Testing on K-West Basin Fuel

Ignition tests and analyses of damage/corroded N-Reactor spent nuclear fuel (SNF) were performed by Pacific Northwest National Laboratory as part of a series of studies on the deteriorating spent fuel in the Hanford K-Basins. The ignition temperature tests were conducted to assess tie pyrophoric properties of selected spent fuel elements from K-West Basin. The objective of these tests was to determine pyrophoric characteristics of samples cut from both damaged and undamaged regions of fhel elements. Furnace ignition tests were also petiormed on samples subjected to the conditioning process proposed by the Independent Technical Assessment and the Integrated Process Strategy to establish any significant effect on the SNF pyrophoric pefiormance parameters. Part of the analysis of the ignition data in this report was petiormed by FIuor Daniel Northwest. One of the safety issues being evaluated is the possibility of a fiel ignition during processing, handling, and transportation to the interim storage facility.
Date: August 10, 1999
Creator: Abrefah, John; Huang, Fan-Hsiung F.; Gerry, William M.; Gray, Walter J.; Marschman, Steven C. & Thornton, Thomas A.
Object Type: Report
System: The UNT Digital Library
Theory of high-T{sub c} cuprates based on experimental evidence. (open access)

Theory of high-T{sub c} cuprates based on experimental evidence.

A model of superconductivity in layered high-temperature superconducting cuprates is proposed, based on the extended saddle point singularities in the electron spectrum, weak screening of the Coulomb interaction and phonon-mediated interaction between electrons plus a small short-range repulsion of Hund's, or spin-fluctuation, origin. This permits to explain the large values of T{sub c}, features of the isotope effect on oxygen and copper, the existence of two types of the order parameter, the peak in the inelastic neutron scattering, the positive curvature of the upper critical field, as function of temperature etc.
Date: August 17, 1999
Creator: Abrikosov, A. A.
Object Type: Article
System: The UNT Digital Library
1998 Chemical Technology Division Annual Technical Report. (open access)

1998 Chemical Technology Division Annual Technical Report.

The Chemical Technology (CMT) Division is a diverse technical organization with principal emphases in environmental management and development of advanced energy sources. The Division conducts research and development in three general areas: (1) development of advanced power sources for stationary and transportation applications and for consumer electronics, (2) management of high-level and low-level nuclear wastes and hazardous wastes, and (3) electrometallurgical treatment of spent nuclear fuel. The Division also performs basic research in catalytic chemistry involving molecular energy resources, mechanisms of ion transport in lithium battery electrolytes, and the chemistry of technology-relevant materials. In addition, the Division operates the Analytical Chemistry Laboratory, which conducts research in analytical chemistry and provides analytical services for programs at Argonne National Laboratory (ANL) and other organizations. Technical highlights of the Division's activities during 1998 are presented.
Date: August 6, 1999
Creator: Ackerman, J. P.; Einziger, R. E.; Gay, E. C.; Green, D. W. & Miller, J. F.
Object Type: Report
System: The UNT Digital Library
Sepradyne/Raduce High Vacuum Thermal Process for Destruction of Dioxins in Ineel/Werf Fly Ash. (open access)

Sepradyne/Raduce High Vacuum Thermal Process for Destruction of Dioxins in Ineel/Werf Fly Ash.

This study investigated the use of an indirectly heated, high temperature (900 C), high vacuum (28 inch Hg) rotary kiln, developed and patented by Raduce, Inc. (subsidiary of Sepradyne Corp.), to treat a dioxin contaminated mixed waste incinerator ash from the Idaho National Engineering Lab (INEEL) Waste Experimental Reduction Facility (WERF). A 500 cm{sup 3} bench-scale rotary vacuum thermal desorption and destruction unit (DDU) was used at Brookhaven National Laboratory (BNL) to demonstrate this thermal treatment process. Dioxins and furans were successfully decomposed at both low (450 C) and high (700-800 C) temperature regimes. In addition, substantial volume and mass reduction of the ash was achieved. Stabilization of the nonvolatile residues by a post-treatment encapsulation process may be required to reduce the leachability of RCRA metals to levels below the EPA Toxicity Characteristic Leaching Procedure (TCLP) requirements.
Date: August 2, 1999
Creator: Adams, J. W.; Kalb, P. D. & Malkmus, D. B.
Object Type: Report
System: The UNT Digital Library
Sepradyne/Reduce High Vacuum Thermal Process for Destruction of Dioxins in Ineel/Werf Fly Ash. (open access)

Sepradyne/Reduce High Vacuum Thermal Process for Destruction of Dioxins in Ineel/Werf Fly Ash.

This study investigated the use of an indirectly heated, high temperature (900 C), high vacuum (28'' Hg) rotary kiln, developed and patented by Raduce, Inc. (subsidiary of Sepradyne Corp.), to treat a dioxin contaminated mixed waste incinerator ash from the Idaho National Engineering Lab (INEEL) Waste Experimental Reduction Facility (WERF). A 500 cm{sup 3} bench-scale rotary vacuum thermal desorption and destruction unit (DDU) was used at Brookhaven National Laboratory (BNL) to demonstrate this thermal treatment process. Dioxins and furans were successfully decomposed at both low (450 C) and high (700-800 C) temperature regimes. In addition, substantial volume and mass reduction of the ash was achieved. Stabilization of the nonvolatile residues by a post-treatment encapsulation process may be required to reduce the leachability of RCRA metals to levels below the EPA Toxicity Characteristic Leaching Procedure (TCLP) requirements.
Date: August 2, 1999
Creator: Adams, J. W.; Kalb, P. D. & Malkmus, D. B.
Object Type: Report
System: The UNT Digital Library
Standard Electronic Format Specification for Tank Characterization Data Loader Version 3.0 (open access)

Standard Electronic Format Specification for Tank Characterization Data Loader Version 3.0

The purpose of this document is to describe the standard electronic format for data files that will be sent for entry into the Tank Characterization Database (TCD). There are 2 different file types needed for each data load: Analytical Results; and Sample Descriptions. The first record of each file must be a header record. The content of the first 5 fields is ignored. They were used previously to satisfy historic requirements that are no longer applicable. The sixth field of the header record must contain the Standard Electronic Format (SEF) version ID (SEF3.0). The remaining records will be formatted as specified below. Fields within a record will be separated using the ''|'' symbol. The ''|''symbol must not appear anywhere in the file except when used as a delimiter.
Date: August 12, 1999
Creator: Adams, M. R.
Object Type: Report
System: The UNT Digital Library
Texture Development During Equal Channel Angular Forging of BCC Metals (open access)

Texture Development During Equal Channel Angular Forging of BCC Metals

Equal channel angular forging (ECAF) has been proposed as a severe plastic deformation technique for processing metals, alloys, and composites [e.g. Segal, 1995] (Fig. 1). The technique offers two capabilities of practical interest: a high degree of strain can be introduced with no change in the cross-sectional dimensions of the work-piece, hence, even greater strains can be introduced by re-inserting the work-piece for further deformation during subsequent passes through the ECAF die. Additionally, the deformation is accomplished by simple shear (like torsion of a short tube) on a plane whose orientation, with respect to prior deformations, can be controlled by varying the processing route. There is a nomenclature that has developed in the literature for the typical processing routes: A: no rotations; B{sub A}: 90 degrees CW (clockwise), 90 degrees CCW (counterclockwise), 9O degrees CW, 90 degrees CCW...; Bc: 90 degrees CW, 90 degrees CW, 90 degrees CW...; and C: 180 degrees, 18 0 degrees.... The impact of processing route on the subsequent microstructure [Ferasse, Segal, Hartwig and Goforth, 1997; Iwahashi, Horita, Nemoto and Langdon, 1996] and texture [Gibbs, Hartwig, Cornwell, Goforth and Payzant, 1998] has been the subject of numerous experimental studies.
Date: August 8, 1999
Creator: Agnew, S. R.
Object Type: Article
System: The UNT Digital Library
Measurement of the {sup 44}Ti half-life and its significance for supernova. (open access)

Measurement of the {sup 44}Ti half-life and its significance for supernova.

In 1998, we reported the three-laboratory measurement of the {sup 44}Ti half-life which was determined relative to the well known value (5.2714 {+-} 0.0005 yr) of the {sup 60}Co half-life. We have continued the measurement at Argonne and Jerusalem and inclusion of data points for additional two years does not change our published value of 59.0 {+-} 0.6 yr.
Date: August 28, 1999
Creator: Ahmad, I.; Greene, J. P.; Kutschera, W. & Paul, M.
Object Type: Article
System: The UNT Digital Library
TELEMASP Bulletin, Volume 6, Number 5, August/September 1999 (open access)

TELEMASP Bulletin, Volume 6, Number 5, August/September 1999

Monthly bulletin issued to address topics related to law enforcement. This issue discusses "Family Violence Units" addressing the documented history of family violence and how to address it.
Date: August 1999
Creator: Ahmad, Janice & Mullings, Janet L.
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History
Experimental and Theoretical Investigation of Multiphase Flow in Fractured Porous media, SUPRI TR-116, Topical Report (open access)

Experimental and Theoretical Investigation of Multiphase Flow in Fractured Porous media, SUPRI TR-116, Topical Report

The fluid transfer parameters between rock matrix and fracture are not well known. Consequently, simulation of fractured reservoirs uses, in general, very crude and unproven hypotheses such as zero capillary pressure in the fracture and/or relative permeability linear with saturation. In order to improve the understanding of flow in fractured media, an experimental study was conducted and numerical simulations of the experiments were made. A laboratory flow apparatus was built to obtain data on water- air imbibition and oil-water drainage displacements in horizontal single-fractured block systems. For this purpose, two configurations have been used: a two-block system with a 1 mm spacer between the blocks, and a two-block system with no spacer. During the experiments, porosity and saturation measurements along the cores have been made utilizing an X-ray Computerized Tomography (CT) scanner. Saturation images were reconstructed in 3-D to observe matrix-fracture interactions. Differences in fluid saturations and relative permeabilities caused by changes in fracture width have also been analyzed.
Date: August 9, 1999
Creator: Akin, Serhat; Castanier, Louis M. & German, Edgar Rene Rangel
Object Type: Report
System: The UNT Digital Library
Progress Report for Annex II--Assessment of Solar Radiation Resources in Saudi Arabia 1993-1997 (open access)

Progress Report for Annex II--Assessment of Solar Radiation Resources in Saudi Arabia 1993-1997

In 1987, the United States Department of Energy (DOE) and the King Abdulaziz City for Science and Technology (KACST) signed a five-year Agreement for Cooperation in the Field of Renewable Energy Research and Development (R and D), which has been extended to 2000. Tasks include: (1) upgrade solar radiation measurements in Saudi Arabia; (2) assemble a database of concurrent solar radiation, satellite (METEOSAT), and meteorological data; (3) adapt NREL models and other software for Saudi Arabia; (4) develop procedures, algorithms, and software to estimate solar irradiance; and (5) prepare a grid of solar radiation data for preparing maps and atlases and estimating solar radiation resources and solar energy system performances at locations in Saudi Arabia.
Date: August 20, 1999
Creator: Al-Amoudi, Anmed; Alawaji, Saleh H.; Cornwall, Chris; Mahfoodh, Mohammed bin; Marion, Bill; Maxwell, Eugene L. et al.
Object Type: Report
System: The UNT Digital Library
Current and Future Trends in Computer Use in Elementary School Settings (open access)

Current and Future Trends in Computer Use in Elementary School Settings

The study examined current and future trends in computer use in elementary school settings. A survey instrument was developed and validated for distribution to a random sample of 200 technology coordinators in the public school districts in the state of Texas from whom 95 responses were received. The survey instrument was used to obtain information about five areas of computer use in elementary schools. These areas are: physical configurations, instructional uses, implementation issues, training and staff development, and Internet use. The study found that all public school districts that participated in the study have acquired computer hardware in their elementary schools. In addition, some other advanced computer technology components are starting to be found in elementary schools, such as teacher workstations, CD-ROM, interactive video, computer multimedia, LCD panels, and laser printers. Respondents reported that elementary school teachers in their districts have incorporated computers into their classrooms as an instructional tool and many changes have occurred in teachers’ teaching styles due to computers. However, there are some problems that hinder the effective use of computers. The major problem is lack of training. A high percentage of respondents, 81.3%, indicated that the majority of their elementary school teachers had completed less than …
Date: August 1999
Creator: Al-Awidi, Hamed M.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Empirical Calculations of {sup 29}Si NMR Chemical Shielding Tensors: A Partial Charge Model Investigation of Hydrolysis in Organically Modified Alkoxy Silanes (open access)

Empirical Calculations of {sup 29}Si NMR Chemical Shielding Tensors: A Partial Charge Model Investigation of Hydrolysis in Organically Modified Alkoxy Silanes

Organically modified alkoxy silanes play an important role in tailoring different properties of silica produced by the sol-gel method. Changes in the size and functionality of the organic group allows control of both physical and chemical properties of the resulting gel, with the kinetics of the polymerization process playing an important role in the design of new siloxane materials. High resolution {sup 29}Si NMR has proven to be valuable tool for monitoring the polymerization reaction, and has been used to investigate a variety of organically modified alkoxy silane systems.
Date: August 5, 1999
Creator: Alam, Todd M. & Henry, Marc
Object Type: Article
System: The UNT Digital Library
Bruker AMX Y Channel Heteronuclear Decoupling Using a Linear Amplifier (open access)

Bruker AMX Y Channel Heteronuclear Decoupling Using a Linear Amplifier

Under both static and common MAS conditions (< 15 kHz) the question of residual X-Y heteronuclear decoupling can become a complicating factor in the analysis of various NMR results. In our lab the impact of {sup 31}P-{sup 23}Na dipolar coupling on the observed {sup 23}Na M{sub 2} relaxation for a series of sodium phosphate glasses was recently investigated by employing continuous wave {sup 31}P decoupling during the entire pulse sequence. Initially these efforts were complicate by the inability to provide a gating pulse during the data acquisition using the standard Bruker nomenclature, go=2, for the acquisition loop. A pulse sequence to overcome these restrictions is given below. Our AMX400 instrument is configured with a 3 channel MCI, but utilizes a linear AMT amplifier on the 3rd channel (requiring gating pulse via the C4 program call during the entire time it is on). The standard acquisition loop has been replaced by direct adc and aq commands for data acquisition. Unlike the go=2 statement which does not allow a C4 gating command to be included, these individual acquisition commands can all include distinct C4 gating.
Date: August 2, 1999
Creator: Alam, Todd M. & Lang, David P.
Object Type: Article
System: The UNT Digital Library
Understanding the role of defect production in radiation embrittlement of reactor pressure vessels. (open access)

Understanding the role of defect production in radiation embrittlement of reactor pressure vessels.

Comparative experiments using high energy (10 MeV) electrons and test reactor neutrons have been undertaken to understand the role that primary damage state has on hardening (embrittlement) induced by irradiation at 300 C. Electrons produce displacement damage primarily by low energy atomic recoils, while fast neutrons produce displacements from considerably higher energy recoils. Comparison of changes resulting from neutron irradiation, in which nascent point defect clusters can form in dense cascades, with electron irradiation, where cascade formation is minimized, can provide insight into the role that the in-cascade point defect clusters have on the mechanisms of embrittlement. Tensile property changes induced by 10 MeV electrons or test reactor neutron irradiations of unalloyed iron and an Fe-0.9 wt.% Cu-1.0 wt.% Mn alloy were examined in the damage range of 9.0 x 10{sup {minus}5} dpa to 1.5 x 10{sup {minus}2} dpa. The results to date showed the ternary alloy experienced substantially greater embrittlement in both the electron and neutron irradiated samples relative to unalloyed iron. Surprisingly, despite their disparate nature of defect production, similar embrittlement trends with increasing radiation damage were observed for electrons and neutrons in both the ternary and unalloyed iron.
Date: August 4, 1999
Creator: Alexander, D. E.
Object Type: Article
System: The UNT Digital Library
A Low-Waste Electrospray Method for Applying Chemicals and Finishing Agents to Textiles Zh (open access)

A Low-Waste Electrospray Method for Applying Chemicals and Finishing Agents to Textiles Zh

This electrospray technology works by applying the desired chemicals onto a substrate as electrically generated, charged sprays. By imposing a potential difference between the application nozzle and the target, it is possible to precisely direct and control the spray. This electrospray method of application gives a small droplet size and a relatively uniform size distribution, with the added advantage of an easily controllable spray angle. It potentially offers substantial improvement over traditional methods in the area of application uniformity, resulting in improved product quality. Additionally, since the chemicals are electrically directed straight onto the fiber with a minimum of overspray, the electrospray method holds promise in the area of waste reduction, resulting in lowered production cost.
Date: August 1, 1999
Creator: Alexander, D.A. & Zhang, X.
Object Type: Report
System: The UNT Digital Library
The Power Politics of Hells Canyon (open access)

The Power Politics of Hells Canyon

This study examines the controversy regarding Hells Canyon on the Snake River, North America's deepest gorge. Throughout the 1950s, federal and private electric power proponents wrangled over who would harness the canyon's potential for generating hydroelectricity. After a decade of debate, the privately-owned Idaho Power Company won the right to build three small dams in the canyon versus one large public power structure. The thesis concludes that private development of Hells Canyon led to incomplete resource development. Further, support of private development led to extensive Republican electoral losses in the Pacific Northwest during the 1950s.
Date: August 1999
Creator: Alford, John Matthew
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Microstructural Characterization of Water-Rich Boehmite (AlO(OH)): TEM Correlation of Apparently Divergent XRD and TGA Results (open access)

Microstructural Characterization of Water-Rich Boehmite (AlO(OH)): TEM Correlation of Apparently Divergent XRD and TGA Results

An understanding of the solid-phase thermodynamics and aqueous speciation of aluminum is critical to our ability to understand and predict processes in a wide variety of geologic and industrial settings. Boehmite (AIO(OH)) is an important phase in the system Al<sub>2</sub>O<sub>3</sub>-H<sub>2</sub>O that has been the subject of a number of structural and thermodynamic studies since its initial synthesis [l] and discovery in nature [2]. Unfortunately, it has long been recognized that thermogravimetric analysis (TGA) of both synthetic and natural boehmite samples (that appear well crystallized by powder XRD methods) yields significant excess water - typically losing 16-16.5 wt. % on heating as compared with a nominal expected weight loss of 15.0 wt. % [3,4]. The boehmite used in our experiments was synthesized hydrothermally from acid-washed gibbsite (Al(OH)<suv>3</sub>) at 200°C. Powder XRD and SEM examination showed no evidence of the presence a contaminant phase. The TGA patterns do not suggest that this is due to adsorbed water, so a structural source is likely. We therefore undertook to examine this material by TEM to clarify this phenomenon.
Date: August 1999
Creator: Allard, L. F.; Anovitz, L. M.; Benezeth, P.; Coffey, D. W.; Palmer, D. A.; Porter, W. D. et al.
Object Type: Article
System: The UNT Digital Library