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Calculation of Hamaker constants in non-aqueous fluid media (open access)

Calculation of Hamaker constants in non-aqueous fluid media

Calculations of the Hamaker constants representing the van der Waals interactions between conductor, resistor and dielectric materials are performed using Lifshitz theory. The calculation of the parameters for the Ninham-Parsegian relationship for several non-aqueous liquids has been derived based on literature dielectric data. Discussion of the role of van der Waals forces in the dispersion of particles is given for understanding paste formulation. Experimental measurements of viscosity are presented to show the role of dispersant truncation of attractive van der Waals forces.
Date: May 9, 2000
Creator: BELL,NELSON S. & DIMOS,DUANE B.
Object Type: Article
System: The UNT Digital Library
Canister Storage Building (CSB) Acceptance for Beneficial Use Index Roadmap of Supporting Documents (open access)

Canister Storage Building (CSB) Acceptance for Beneficial Use Index Roadmap of Supporting Documents

None
Date: May 9, 2000
Creator: BLACK, D.M.
Object Type: Report
System: The UNT Digital Library
Perry Daily Journal (Perry, Okla.), Vol. 107, No. 92, Ed. 1 Tuesday, May 9, 2000 (open access)

Perry Daily Journal (Perry, Okla.), Vol. 107, No. 92, Ed. 1 Tuesday, May 9, 2000

Daily newspaper from Perry, Oklahoma that includes local, state, and national news along with advertising.
Date: May 9, 2000
Creator: Brown, Gloria
Object Type: Newspaper
System: The Gateway to Oklahoma History
The Express-Star (Chickasha, Okla.), Ed. 1 Tuesday, May 9, 2000 (open access)

The Express-Star (Chickasha, Okla.), Ed. 1 Tuesday, May 9, 2000

Daily newspaper from Chickasha, Oklahoma that includes local, state, and national news along with advertising.
Date: May 9, 2000
Creator: Bush, Kent
Object Type: Newspaper
System: The Gateway to Oklahoma History
Altus Times (Altus, Okla.), Vol. 101, No. 48, Ed. 1 Tuesday, May 9, 2000 (open access)

Altus Times (Altus, Okla.), Vol. 101, No. 48, Ed. 1 Tuesday, May 9, 2000

Daily newspaper from Altus, Oklahoma that includes local, state, and national news along with advertising.
Date: May 9, 2000
Creator: Bush, Michael
Object Type: Newspaper
System: The Gateway to Oklahoma History
The Baytown Sun (Baytown, Tex.), Vol. 78, No. 165, Ed. 1 Tuesday, May 9, 2000 (open access)

The Baytown Sun (Baytown, Tex.), Vol. 78, No. 165, Ed. 1 Tuesday, May 9, 2000

Daily newspaper from Baytown, Texas that includes local, state, and national news along with advertising.
Date: May 9, 2000
Creator: Cash, Wanda Garner
Object Type: Newspaper
System: The Portal to Texas History
The effect of the number of wavebands used in spectral radiation heat transfer calculations (open access)

The effect of the number of wavebands used in spectral radiation heat transfer calculations

A spectral radiation heat transfer model that conserves emitted and absorbed energy has been developed and used to model the combustion space of an industrial glass furnace. This comprehensive radiation heat transfer model coupled with a computational fluid dynamics (CFD) code was used to investigate the effect of spectral dependencies on the computed results. The results of this work clearly indicate the need for a spectral approach as opposed to a gray body approach since the gray body approach (one waveband) severely underestimates the energy emitted via radiation.
Date: May 9, 2000
Creator: Chang, S. L.; Golchert, B. & Petrick, M.
Object Type: Article
System: The UNT Digital Library
A numerical investigation of gasoline production from multi-stage FCC systems (open access)

A numerical investigation of gasoline production from multi-stage FCC systems

Staged, fluid catalytic cracking (FCC) processes are deemed to have the potential to enhance FCC performance in the areas of product selectivity, operating flexibility, throughput, reliability, operating costs, and emissions. Computational fluid dynamic (CFD) codes are used to analyze various staged FCC concepts to help accelerate their development into commercial products. Three conceptual multi-stage FCC systems were evaluated using a validated CFD code. The results indicated potential increases of gasoline production from these conceptual designs.
Date: May 9, 2000
Creator: Chang, S. L.; Zhou, C. Q. & Petrick, M.
Object Type: Article
System: The UNT Digital Library
A validation process for multi-phase reacting flow CFD code (open access)

A validation process for multi-phase reacting flow CFD code

Computational fluid dynamic (CFD) code calculates flow properties for the analysis of a flow system. Flow properties are computed based on conservation principles and various phenomenological models. The accuracy of the computed flow properties highly depends on the validity of the models and the degree of numerical convergence. Validation of a CFD code is essential for application of an engineering system. Multiphase reacting flows are common in industrial applications and few CFD code are available. A CFD code was developed for the simulation of multiphase reacting flows. A validation process was also developed for such a CFD code. The validation was performed for several cases. Examples of industrial devices which are multiphase reacting flow systems include catalytic cracking reactors, glass melting furnaces, coal-fired combustors, and diesel engines.
Date: May 9, 2000
Creator: Chang, S. L.; Zhou, C. Q. & Petrick, M.
Object Type: Article
System: The UNT Digital Library
Computational fluid dynamics simulations of a glass melting furnace (open access)

Computational fluid dynamics simulations of a glass melting furnace

The glass production industry is one of the major users of natural gas in the US, and approximately 75% of the energy produced from natural gas is used in the melting process. Industrial scale glass melting furnaces are large devices, typically 5 or more meters wide, and twice as long. To achieve efficient heat transfer to the glass melt below, the natural gas flame must extend over a large portion of the glass melt. Therefore modern high efficiency burners are not used in these furnaces. The natural gas is injected as a jet, and a jet flame forms in the flow of air entering the furnace. In most current glass furnaces the energy required to melt the batch feed stock is about twice the theoretical requirement. An improved understanding of the heat transfer and two phase flow processes in the glass melt and solid batch mix offers a substantial opportunity for energy savings and consequent emission reductions. The batch coverage form and the heat flux distribution have a strong influence on the glass flow pattern. This flow pattern determines to a significant extent the melting rate and the quality of glass.
Date: May 9, 2000
Creator: Egelja, A. & Lottes, S. A.
Object Type: Article
System: The UNT Digital Library
Using desktop graphics workstations for interactive remote exploration of large data sets (open access)

Using desktop graphics workstations for interactive remote exploration of large data sets

The interactive visualization and exploration of large scientific data sets is a challenging and difficult task; their size often far exceeds the performance and memory capacity of even the most powerful graphics workstations. To address this problem, we have created a technique that combines multiresolution data reduction methods with parallel computing to allow interactive exploration of large data sets while retaining full-resolution capability. We describe the creation of reduced data sets using several different criteria including user-specified error bounds or a preset performance criterion. We discuss the software architecture of the system with particular emphasis on the algorithms used to efficiently create a reduced data set and the software used to communicate between the remote data reduction server and the local graphics client. We present performance results for the visualization of Rayleigh-Taylor instability and hairpin vortex data sets.
Date: May 9, 2000
Creator: Freitag, L. A. & Loy, R. M.
Object Type: Article
System: The UNT Digital Library
Phase structure within a fracture network beneath a surface pond: Field experiment (open access)

Phase structure within a fracture network beneath a surface pond: Field experiment

The authors performed a simple experiment to elucidate phase structure within a pervasively fractured welded tuff. Dyed water was infiltrated from a surface pond over a 36 minute period while a geophysical array monitored the wetted region within vertical planes directly beneath. They then excavated the rock mass to a depth of {approximately}5 m and mapped the fracture network and extent of dye staining in a series of horizontal pavements. Near the pond the network was fully stained. Below, the phase structure immediately expanded and with depth, the structure became fragmented and complicated exhibiting evidence of preferential flow, fingers, irregular wetting patterns, and varied behavior at fracture intersections. Limited transient geophysical data suggested that strong vertical pathways form first followed by increased horizontal expansion and connection within the network. These rapid pathways are also the first to drain. Estimates also suggest that the excavation captured from {approximately}10% to 1% or less of the volume of rock interrogated by the infiltration slug and thus the penetration depth could have been quite large.
Date: May 9, 2000
Creator: Glass Jr., Robert J. & Nicholl, M. J.
Object Type: Article
System: The UNT Digital Library
Defect structure of indium tin oxide and its relationship to conductivity (open access)

Defect structure of indium tin oxide and its relationship to conductivity

Doping In{sub 2}O{sub 3} with tin results in an improved transparent conducting oxide (TCO). Although indium tin oxide (ITO) is the most frequently used commercial TCO, its defect structure is still uncertain. Previously, its defect chemistry has been inferred based on the conductivity of the material. To directly study the defect structure of ITO, the authors prepared powders under different processing environments and performed neutron powder diffraction. Structural information was obtained by performing Rietveld analysis. The results include positions of the atoms, their thermal displacements, the fractional occupancy of the defect oxygen site, and the fractional occupancies of Sn on each of the two nonequivalent cation sites, showing a strong preference for the b site. These structural results are correlated with the measured electrical properties of the same samples.
Date: May 9, 2000
Creator: Gonzalez, G. B.; Cohen, J. B.; Hwang, J.-H.; Mason, T. O.; Hodges, J. P. & Jorgensen, J. D.
Object Type: Article
System: The UNT Digital Library
Rains County Leader (Emory, Tex.), Vol. 112, No. 47, Ed. 1 Tuesday, May 9, 2000 (open access)

Rains County Leader (Emory, Tex.), Vol. 112, No. 47, Ed. 1 Tuesday, May 9, 2000

Weekly newspaper from Emory, Texas that includes local, state, and national news along with advertising.
Date: May 9, 2000
Creator: Hill, Earl Clyde, Jr.
Object Type: Newspaper
System: The Portal to Texas History
The Oklahoma Daily (Norman, Okla.), Vol. 84, No. 155, Ed. 1 Tuesday, May 9, 2000 (open access)

The Oklahoma Daily (Norman, Okla.), Vol. 84, No. 155, Ed. 1 Tuesday, May 9, 2000

Student newspaper of the University of Oklahoma in Norman, Oklahoma that includes national, local, and campus news along with advertising.
Date: May 9, 2000
Creator: Jennings, Sarah
Object Type: Newspaper
System: The Gateway to Oklahoma History
Measurement of temperature distributions in large pool fires with the use of directional flame thermometers (open access)

Measurement of temperature distributions in large pool fires with the use of directional flame thermometers

Temperatures inside the flame zone of large regulatory pool fires measured during tests of radioactive materials packages vary widely with both time and position. Measurements made with several Directional Flame Thermometers, in which a thermocouple is attached to a thin metal sheet that quickly approaches flame temperatures, have been used to construct fire temperature distributions and cumulative probability distributions. As an aid to computer simulations of these large fires, these distributions are presented. The distributions are constructed by sorting fire temperature data into bins 10 C wide. A typical fire temperature distribution curve has a gradual increase starting at about 600 C, with the number of observations increasing to a peak near 1000 C, followed by an abrupt decrease in frequency, with no temperatures observed above 1200 C.
Date: May 9, 2000
Creator: KOSKI,JORMAN A.
Object Type: Article
System: The UNT Digital Library
The Boerne Star (Boerne, Tex.), Vol. 95, No. 37, Ed. 1 Tuesday, May 9, 2000 (open access)

The Boerne Star (Boerne, Tex.), Vol. 95, No. 37, Ed. 1 Tuesday, May 9, 2000

Semiweekly newspaper from Boerne, Texas that includes local, state, and national news along with advertising.
Date: May 9, 2000
Creator: Keasling, Edna & Fierro, Jennifer
Object Type: Newspaper
System: The Portal to Texas History
Substituent effects on the sol-gel chemistry of organotrialkoxysilanes (open access)

Substituent effects on the sol-gel chemistry of organotrialkoxysilanes

Silsesquioxanes have been the subject of intensive study in the past and are becoming important again as a vehicle for introducing organic functionalities into hybrid organic-inorganic materials through sol-gel processing. Depending on the application, the target hybrid material may be required to be a highly cross-linked, insoluble gel or a soluble polymer that can be cast as a thin film or coating. The former has applications such as catalyst supports and separations media; the latter is an economically important method for surface modification or compatiblization for applying adhesives or introducing fillers. Polysilsesquioxanes are readily prepared through the hydrolysis and condensation of organotrialkoxysilanes, though organotriaminosilane and organotrihalosilane monomers can also be used. This paper explores the kinetics of the preparation route.
Date: May 9, 2000
Creator: LOY, DOUGLAS A.; BAUGHER, BRIGITTA M.; BAUGHER, COLLEEN R.; SCHNEIDER, DUANE A. & RAHIMIAN, KAMYAR
Object Type: Article
System: The UNT Digital Library
Molecular engineering with bridged polysilsesquioxanes (open access)

Molecular engineering with bridged polysilsesquioxanes

Bridged polysilsesquioxanes are a class of hybrid organic-inorganic materials that permit molecular engineering of bulk properties including porosity. Prepared by sol-gel polymerization of monomers with two or more trialkoxysilyl groups, the materials are highly cross-linked amorphous polymers that are readily obtained as gels. The bridging configuration of the hydrocarbon group insures that network polymers are readily formed and that the organic functionality is homogeneously distributed throughout the polymeric scaffolding at the molecular level. This permits the bulk properties, including surface area, pore size, and dielectric constant to be engineered through the selection of the bridging organic group. Numerous bridging groups have been incorporated. This presentation will focus on the effects that the length, flexibility, and substitution geometry of the hydrocarbon bridging groups have on the properties of the resulting bridged polysilsesquioxanes. Details of the preparation, characterization, and some structure property relationships of these bridged polysilsesquioxanes will be given.
Date: May 9, 2000
Creator: LOY,DOUGLAS A. & SHEA,KENNETH J.
Object Type: Article
System: The UNT Digital Library
Porosity in polysilsesquioxane xerogels (open access)

Porosity in polysilsesquioxane xerogels

Polysilsesquioxanes, [RSiO{sub 1.5}]{sub n} are a class of hybrid organic-inorganic materials in which silicon atoms are linked with up to three siloxane bonds to other monomer units in the polymer and the organic group is a pendent functionality. Polysilsesquioxanes are prepared by the hydrolysis and condensation of organotrialkoxysilanes (Scheme l). Organotrialkoxysilanes RSi(OR{prime}){sub 3}, have been extensively used as coupling agents for composites or surface treatments for materials. Polysilsesquioxanes have become increasingly popular for generating specialty coatings such as low k dielectric materials for microelectronic applications. While there is extensive information on the formation of polysilsesquioxanes, there has not been a survey of the ability of organotrialkoxysilanes to form gels until recently. The formation of polysilsesquioxanes gels has been shown to be very sensitive to the nature of the organic group. Many monomers will only form soluble oligomers or polymers upon hydrolysis and condensation, even when the reaction is conducted solvent-free with neat monomer and aqueous catalyst. Furthermore, there is little information concerning the influence of the organic group, R, on the porosity of the polysilsesquioxanes gels that are formed. In this paper the authors describe the preparation of polysilsesquioxane gels where R = H, methyl, ethyl, cyanoethyl, vinyl, dodecyl, hexadecyl, …
Date: May 9, 2000
Creator: Loy, Douglas A.; Schneider, Duane A.; Baugher, Brigitta M. & Rahimian, Kamyar
Object Type: Article
System: The UNT Digital Library
Comparison of mechanical properties of glass-bonded sodalite and borosilicate glass high-level waste forms (open access)

Comparison of mechanical properties of glass-bonded sodalite and borosilicate glass high-level waste forms

Argonne National Laboratory has developed a glass-bonded sodalite waste form to immobilize the salt waste stream from electrometallurgical treatment of spent nuclear fuel. The waste form consists of 75 vol.% crystalline sodalite and 25 vol.% glass. Microindentation fracture toughness measurements were performed on this material and borosilicate glass from the Defense Waste Processing Facility using a Vickers indenter. Palmqvist cracking was confined for the glass-bonded sodalite waste form, while median-radial cracking occurred in the borosilicate glass. The elastic modulus was measured by an acoustic technique. Fracture toughness, microhardness, and elastic modulus values are reported for both waste forms.
Date: May 9, 2000
Creator: O'Holleran, T. P.; DiSanto, T.; Johnson, S. G. & Goff, K. M.
Object Type: Article
System: The UNT Digital Library
Sapulpa Daily Herald (Sapulpa, Okla.), Vol. 84, No. 204, Ed. 1 Tuesday, May 9, 2000 (open access)

Sapulpa Daily Herald (Sapulpa, Okla.), Vol. 84, No. 204, Ed. 1 Tuesday, May 9, 2000

Daily newspaper from Sapulpa, Oklahoma that includes local, state, and national news along with advertising.
Date: May 9, 2000
Creator: Quinnelly, Lorrie J.
Object Type: Newspaper
System: The Gateway to Oklahoma History
Further tests on liquid-nitrogen-cooled, thin silicon-crystal monochromators using a focused wiggler synchrotron beam (open access)

Further tests on liquid-nitrogen-cooled, thin silicon-crystal monochromators using a focused wiggler synchrotron beam

A newly designed cryogenically cooled, thin Si crystal monochromator was tested at the European Synchrotrons Radiation Facility (ESRF) beamline BL3. It exhibited less than 1 arcsec of thermal strain up to a maximum incident power of 186 W and average power density of 521 W/mm{sup 2}. Data were collected for the thin (0.7 mm) portion of the crystal and for the thick (>25 mm) part. Rocking curves were measured as a function of incident power. With a low power beam, the Si(333) rocking curve at 30 keV for the thin and thick sections was < 1 arcsec FWHM at room temperature. The rocking curve of the thin section increased to 2.0 arcsec when cooled to 78 K, while the thick part was unaffected by the reduction in temperature. The rocking curve of the this section broadened to 2.5 arcsec FWHM and that of the thick section broadened to 1.7 arcsec at the highest incident power. The proven range of performance for this monochromator has been extended to the power density, but not the absorbed power, expected for the Advanced Photon Source (APS) undulator A in closed-gap operation (first harmonic at 3.27 kev) at a storage-ring current of 300 mA.
Date: May 9, 2000
Creator: Rogers, C. S.; Mills, D. M.; Fernandez, P. B.; Knapp, G. S.; Wulff, M.; Hanfland, M. et al.
Object Type: Article
System: The UNT Digital Library
Spent Nuclear Fuel (SNF) Process Validation Technical Support Plan (open access)

Spent Nuclear Fuel (SNF) Process Validation Technical Support Plan

The purpose of Process Validation is to confirm that nominal process operations are consistent with the expected process envelope. The Process Validation activities described in this document are not part of the safety basis, but are expected to demonstrate that the process operates well within the safety basis. Some adjustments to the process may be made as a result of information gathered in Process Validation.
Date: May 9, 2000
Creator: SEXTON, R.A.
Object Type: Report
System: The UNT Digital Library