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3-D Measurement of Deformation Microstructure of Al(0.2%)Mg Using Submicron Resolution White X-Ray Microbeams (open access)

3-D Measurement of Deformation Microstructure of Al(0.2%)Mg Using Submicron Resolution White X-Ray Microbeams

We have used submicron-resolution white x-ray microbeams on the MHATT-CAT beamline 7-ID at the Advanced Photon Source to develop techniques for three-dimensional investigation of the deformation microstructure in a 20% plane strain compressed Al(0.2%)Mg tri-crystal. Kirkpatrick-Baez mirrors were used to focus white radiation from an undulator to a 0.7 x 0.7 {micro}m{sup 2} beam that was scanned over bi- and tri-crystal regions near the triple-junction of the tri-crystal. Depth resolution along the x-ray microbeam of less than 5 microns was achieved by triangulation to the diffractibn source point using images taken at a series of CCD distances from the microbeam. Computer indexing of the deformation cell structure in the bi-crystal region provided orientations of individual subgrains to {approximately}0.01 degrees, making possible detailed measurements of the rotation axes between individual cells.
Date: November 29, 1999
Creator: Larson, B. C.; tamura, N.; Chung, J.-S.; Ice, G. E.; Budai, J. D.; Tischler, J. Z. et al.
Object Type: Article
System: The UNT Digital Library
Acceleration amplifications in nif structures subjected to earthquake base motions (open access)

Acceleration amplifications in nif structures subjected to earthquake base motions

NIF technical staff have questioned the possibility of obtaining acceleration amplifications (i.e. amplification of the ground acceleration values) in a structure which are significantly higher than the acceleration amplification exhibited across the period range in the input response spectrum. This note utilizes a simple example to illustrate that the acceleration amplification resulting from the dynamic response of a structural system can indeed be significantly higher than the amplifications indicated in the response spectrum, and that the GEMINI program is computing the appropriate acceleration levels for a simple MDOF system.
Date: November 29, 1999
Creator: McCallen, D.
Object Type: Report
System: The UNT Digital Library
Altus Times (Altus, Okla.), Vol. 100, No. 217, Ed. 1 Monday, November 29, 1999 (open access)

Altus Times (Altus, Okla.), Vol. 100, No. 217, Ed. 1 Monday, November 29, 1999

Daily newspaper from Altus, Oklahoma that includes local, state, and national news along with advertising.
Date: November 29, 1999
Creator: Bush, Michael
Object Type: Newspaper
System: The Gateway to Oklahoma History
The Alvin Sun (Alvin, Tex.), Vol. 108, No. 134, Ed. 1 Monday, November 29, 1999 (open access)

The Alvin Sun (Alvin, Tex.), Vol. 108, No. 134, Ed. 1 Monday, November 29, 1999

Weekly newspaper from Alvin, Texas that includes local, state, and national news along with advertising.
Date: November 29, 1999
Creator: Schwind, Jim & Holton, Kathleen
Object Type: Newspaper
System: The Portal to Texas History
Antireflection Coating Design for Series Interconnected Multi-Junction Solar Cells (open access)

Antireflection Coating Design for Series Interconnected Multi-Junction Solar Cells

AR coating design for multi-junction solar cells can be more challenging than in the single junction case. Reasons for this are discussed. Analytical expressions used to optimize AR coatings for single junction solar cells are extended for use in monolithic, series interconnected multi-junction solar cell AR coating design. The result is an analytical expression which relates the solar cell performance (through J{sub SC}) directly to the AR coating design through the device reflectance. It is also illustrated how AR coating design can be used to provide an additional degree of freedom for current matching multi-junction devices.
Date: November 29, 1999
Creator: AIKEN,DANIEL J.
Object Type: Article
System: The UNT Digital Library
Applications of Electro-Osmotic Transport in the Processing of Textiles (open access)

Applications of Electro-Osmotic Transport in the Processing of Textiles

We report development of a pilot process for the industrial rinsing of fabrics. This process combines hydraulic (pressure-driven) transport with electro-osmotic transport. It reduces the total amount of water required in certain rinsing operations by a factor of about five. Cotton exhibits an electro-osmotic transport coefficient of about 6 x 10{sup -9} m{sup 2}/s-V resulting from a partial ionization of hydroxyl groups on the cellulose polymer substrate. This process applies a field transverse to the fabric to effect the movement of water in the spaces between the 10 {micro}m cotton fibers which constitute the yam. The field strength is adjusted so that the induced electro-osmotic flux is comparable to a pressure-driven flux, which moves preferentially in the more open channels between the yams. For a fixed current density, solution conductivity and electro-osmotic transport vary inversely. The process is most practical for removal of liquids of relatively low conductivity (<500 {micro}S/cm). For removal of solutions of conductivity greater than 1200 {micro}S/cm, the rate of electro-osmotic flow may be too low to benefit the rinsing process if current densities are restricted to practical levels of about 30 mA/cm{sup 2}. Electra-osmotic transport may have important applications in wet processing of extremely fine textiles, …
Date: November 29, 1999
Creator: Cooper, J.F.; Krueger, R.; Hopper, R. & Cherepy, N.
Object Type: Article
System: The UNT Digital Library
Atmospheric Test Models and Numerical Experiments for the Simulation of the Global Distribution of Weather Data Transponders II. Vertical Transponder Motion Considerations (open access)

Atmospheric Test Models and Numerical Experiments for the Simulation of the Global Distribution of Weather Data Transponders II. Vertical Transponder Motion Considerations

The vertical motion of constant density atmospheric balloons has been considered via an equation of motion for the vertical displacement of a balloon, due to vertical air motion, which can be numerically solved for balloon positions. Initial calculations are made for a constant density atmosphere. Various vertical wind models with relatively large amplitudes are applied to the model to determine how tightly the balloons are coupled to the reference level and the time scale for the balloons to change to the wind driven reference altitude. A surface launch of a balloon to a 6 km reference altitude is modeled using a detailed atmospheric pressure-density-temperature profile in the equation of motion. The results show the balloons to be relatively tightly coupled ({approx} 50-100 m) to the reference altitude.
Date: November 29, 1999
Creator: Grossman, A. & Errico, R.M.
Object Type: Report
System: The UNT Digital Library
The Baytown Sun (Baytown, Tex.), Vol. 78, No. 25, Ed. 1 Monday, November 29, 1999 (open access)

The Baytown Sun (Baytown, Tex.), Vol. 78, No. 25, Ed. 1 Monday, November 29, 1999

Daily newspaper from Baytown, Texas that includes local, state, and national news along with advertising.
Date: November 29, 1999
Creator: Cash, Wanda Garner
Object Type: Newspaper
System: The Portal to Texas History
CHARACTERIZATION OF MIXED-METAL OXIDES USING SYNCHROTRON-BASED TIME-RESOLVED X-RAY DIFFRACTION AND X-RAY ABSORPTION SPECTROSCOPY. (open access)

CHARACTERIZATION OF MIXED-METAL OXIDES USING SYNCHROTRON-BASED TIME-RESOLVED X-RAY DIFFRACTION AND X-RAY ABSORPTION SPECTROSCOPY.

None
Date: November 29, 1999
Creator: RODRIGUEZ,J.A.
Object Type: Article
System: The UNT Digital Library
Class 3 Tracking and Monitoring System Report (open access)

Class 3 Tracking and Monitoring System Report

The objective of Class 3 tracking system are to assist DOE in tracking and performance and progress of these projects and to capture the technical and financial information collected during the projects' monitoring phase. The captured information was used by DOE project managers and BDM-Oklahoma staff for project monitoring and evaluation, and technology transfer activities. The proposed tracking system used the Class Evaluation Executive Report (CLEVER), a relation database for storing and disseminating class project data; GeoGraphix, a geological and technical analysis and mapping software system; the Tertiary Oil Recovery Information System (TORIS) database; and MS-Project, a project management software system.
Date: November 29, 1999
Creator: Safely, Eugene & Salamy, S. Phillip
Object Type: Report
System: The UNT Digital Library
Contract Management: A Comparison of DOD and Commercial Airline Purchasing Practices (open access)

Contract Management: A Comparison of DOD and Commercial Airline Purchasing Practices

A letter report issued by the General Accounting Office with an abstract that begins "Pursuant to a congressional request, GAO provided information on the Department of Defense's (DOD) purchasing and pricing of commercially available spare parts, focusing on: (1) a comparative analysis between the purchasing and pricing practices of selected commercial passenger and freight airline companies and the practices of DOD; and (2) how airlines and DOD ensure that they are obtaining reasonable prices when buying commercial items from sole-source suppliers."
Date: November 29, 1999
Creator: United States. General Accounting Office.
Object Type: Report
System: The UNT Digital Library
Corrosion of glass-bonded sodalite as a function of pH and temperature. (open access)

Corrosion of glass-bonded sodalite as a function of pH and temperature.

This paper reports the results of corrosion tests with monoliths of sodalite, binder glass, and glass-bonded sodalite, a ceramic waste form (CWF) that is being developed to immobilize radioactive electrorefiner salt used to condition spent sodium-bonded nuclear fuel. These tests were performed with dilute pH-buffered solutions in the pH range of 5-10 at temperatures of 70 and 90 C. The pH dependence of the forward dissolution rates of the CWF and its components have been determined. The pH dependence of the dissolution rates of sodalite, binder glass, and glass-bonded sodalite are similar to the pH dependence of dissolution rate of borosilicate nuclear waste glasses, with a negative pH dependence in the acidic region and a positive pH dependence in the basic region. Our results on the forward dissolution rates and their temperature and pH dependence will be used as components of a waste form degradation model to predict the long-term behavior of the CWF in a nuclear waste repository.
Date: November 29, 1999
Creator: Morss, L. R.; Stanley, M.; Tatko, C. & Ebert, W. L.
Object Type: Article
System: The UNT Digital Library
Defense Inventory: Inadequate Compliance With Controls for Excess Firearms and Other Sensitive Items (open access)

Defense Inventory: Inadequate Compliance With Controls for Excess Firearms and Other Sensitive Items

A letter report issued by the General Accounting Office with an abstract that begins "Pursuant to a congressional request, GAO reviewed the Department of Defense's (DOD) procedures for the disposal and destruction of excess firearms, items with national security implications, and pharmaceuticals."
Date: November 29, 1999
Creator: United States. General Accounting Office.
Object Type: Report
System: The UNT Digital Library
Denoising of human speech using combined acoustic and em sensor signal processing (open access)

Denoising of human speech using combined acoustic and em sensor signal processing

Low Power EM radar-like sensors have made it possible to measure properties of the human speech production system in real-time, without acoustic interference. This greatly enhances the quality and quantify of information for many speech related applications. See Holzrichter, Burnett, Ng, and Lea, J. Acoustic. Soc. Am. 103 (1) 622 (1998). By using combined Glottal-EM- Sensor- and Acoustic-signals, segments of voiced, unvoiced, and no-speech can be reliably defined. Real-time Denoising filters can be constructed to remove noise from the user's corresponding speech signal.
Date: November 29, 1999
Creator: Ng, L C; Burnett, G C; Holzrichter, J F & Gable, T J
Object Type: Article
System: The UNT Digital Library
Depinning of flux lines and AC losses in magnet-superconductor levitation system (open access)

Depinning of flux lines and AC losses in magnet-superconductor levitation system

The AC loss characteristics of a magnet-superconductor system were studied with the magnet fixed to the free end of an oscillating cantilever located near a stationary melt-textured YBCO pellet. Below a threshold AC field amplitude {approx}2Oe, the dissipation of the oscillator is amplitude-independent, characteristic of a linear, non-hysteretic regime. Above threshold,dissipation increases with amplitude, reflecting the depinning and hysteretic motion of flux lines. The threshold AC field is an order of magnitude higher than that measured for the same YBCO material via AC susceptometry in a uniform DC magnetic field, A partial lock-in of flux lines between YBCO ab planes is proposed as the mechanism for the substantial increase of the depinning threshold.
Date: November 29, 1999
Creator: Terentiev, A. N.; Hull, J. R. & De Long, L. E.
Object Type: Article
System: The UNT Digital Library
Design Review Closure Report for the SY-101 Rapid Transfer System (open access)

Design Review Closure Report for the SY-101 Rapid Transfer System

The purpose of this report, is to document closure of design review open items, resulting from design reviews conducted for the SY-101 Respond And Pump In Days (RAPID) Transfer System. Results of the various design reviews were documented in the Design Review Report for The SY-101 Rapid Mitigation System, HNF-4519. In that report, twenty-three open items were identified. In this report the 23 items are reviewed and statused.
Date: November 29, 1999
Creator: Powell, William J.
Object Type: Report
System: The UNT Digital Library
Electronic structure studies of nanocrystalline diamond grain boundaries (open access)

Electronic structure studies of nanocrystalline diamond grain boundaries

Diamond growth from hydrogen-poor plasmas results in diamond structures that are profoundly different from conventionally CVD-grown diamond. High concentration of carbon dimers in the microwave plasma results in a high rate of heterogeneous renucleation leading to formation of nanocrystalline diamond with a typical grain size of 3--10 nm. Therefore, up to 10% of carbon atoms are located in the grain boundaries. In this paper the authors report on density-functional based tight-binding molecular dynamics calculations of the structure of a {Sigma}13 twist (100) grain boundary in diamond. Beginning with a coincidence site lattice model, simulated annealing of the initial structure was performed at 1,500 K followed by relaxation toward lower temperatures. About one-half of the carbons in the grain boundary are found to be three-coordinated. Coordination numbers, bond length and bond angle distributions are analyzed and compared to those obtained in previous studies.
Date: November 29, 1999
Creator: Zapol, P.; Sternberg, M.; Frauenheim, T.; Gruen, D. M. & Curtiss, L. A.
Object Type: Article
System: The UNT Digital Library

Ensemble: 1999-11-29 – Nova

Access: Use of this item is restricted to the UNT Community
Concert presented at the UNT College of Music Recital Hall.
Date: November 29, 1999
Creator: University of North Texas. Nova.
Object Type: Sound
System: The UNT Digital Library
Evaluation of an alkaline-side solvent extraction process for cesium removal from SRS tank waste using laboratory-scale centrifugal contactors (open access)

Evaluation of an alkaline-side solvent extraction process for cesium removal from SRS tank waste using laboratory-scale centrifugal contactors

An alkaline-side solvent extraction process for cesium removal from Savannah River Site (SRS) tank waste was evaluated experimentally using a laboratory-scale centrifugal contactor. Single-stage and multistage tests were conducted with this contactor to determine hydraulic performance, stage efficiency, and general operability of the process flowsheet. The results and conclusions of these tests are reported along with those from various supporting tests. Also discussed is the ability to scale-up from laboratory- to plant-scale operation when centrifugal contractors are used to carry out the solvent extraction process. While some problems were encountered, a promising solution for each problem has been identified. Overall, this alkaline-side cesium extraction process appears to be an excellent candidate for removing cesium from SRS tank waste.
Date: November 29, 1999
Creator: Leonard, R. A.; Conner, C.; Liberatore, M. W.; Sedlet, J.; Aase, S. B. & Vandegrift, G. F.
Object Type: Report
System: The UNT Digital Library
EXPERIMENTAL INVESTIGATIONS OF THE INTERACTION OF SO(2) WITH MGO. (open access)

EXPERIMENTAL INVESTIGATIONS OF THE INTERACTION OF SO(2) WITH MGO.

High resolution adsorption isotherms, temperature programmed desorption (TPD), x-ray diffraction (XRD) and x-ray absorption near edge spectroscopy (XANES) methods were used to investigate the interaction of SO{sub 2} with high quality MgO powders. The results of these investigations indicate that when SO{sub 2} is deposited on MgO in monolayer quantities at temperatures near 100K both SO{sub 2} and SO{sub 4} species form that are not removed by simply pumping on the pre-dosed samples at room temperature. TPD and XANES studies indicate that heating of pre-dosed MgO samples to temperatures above 350 C is required for full removal of the SO{sub 3}/SO{sub 4} species. XANES measurements made as a function of film thickness indicate for coverages near monolayer completion that the SO{sub 4} species form first.
Date: November 29, 1999
Creator: FREITAG,A.
Object Type: Article
System: The UNT Digital Library
The Express-Star (Chickasha, Okla.), Ed. 1 Monday, November 29, 1999 (open access)

The Express-Star (Chickasha, Okla.), Ed. 1 Monday, November 29, 1999

Daily newspaper from Chickasha, Oklahoma that includes local, state, and national news along with advertising.
Date: November 29, 1999
Creator: Bush, Kent
Object Type: Newspaper
System: The Gateway to Oklahoma History
Field Emission and Nanostructure of Carbon Films (open access)

Field Emission and Nanostructure of Carbon Films

The results of field emission measurements of various forms of carbon films are reported. It is shown that the films nanostructure is a crucial factor determining the field emission properties. In particular, smooth, pulsed-laser deposited amorphous carbon films with both high and low sp3 contents are poor field emitters. This is similar to the results obtained for smooth nanocrystalline, sp2-bonded carbon films. In contrast, carbon films prepared by hot-filament chemical vapor deposition (HE-CVD) exhibit very good field emission properties, including low emission turn-on fields, high emission site density, and excellent durability. HF-CVD carbon films were found to be predominantly sp2-bonded. However, surface morphology studies show that these films are thoroughly nanostructured, which is believed to be responsible for their promising field emission properties.
Date: November 29, 1999
Creator: Merkulov, V. I.; Lowndes, D. H. & Baylor, L. R.
Object Type: Article
System: The UNT Digital Library
Field Emission from Carbon Films Deposited by Controlled-Low-Energy Beams and CVD Sources (open access)

Field Emission from Carbon Films Deposited by Controlled-Low-Energy Beams and CVD Sources

The principal interests in this work are energetic-beam control of carbon-film properties and the roles of doping and surface morphology in field emission.
Date: November 29, 1999
Creator: Lowndes, D. H.; Merkulov, V.I.; Baylor, L.R.; Jellison, G. E., Jr.; Poker, D. B.; Kim, S. et al.
Object Type: Article
System: The UNT Digital Library
Final Report (open access)

Final Report

The primary goal was the characterization of tryptophan (Trp)-independent biosynthesis of the auxin indole-3-acetic acid (IAA). Our work and that of others indicates that indole is a precursor to IAA in a Trp-independent pathway and the objectives of this grant have been the isolation of indole-metabolizing genes from Arabidopsis.
Date: November 29, 1999
Creator: Normanly, J.
Object Type: Report
System: The UNT Digital Library