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Effect of coal beneficiation process on rheology/atomization of coal water slurries. Quarterly progress report, November 1, 1993--January 31, 1994

Description: The atomization study began with simulated fluids-(Mixtures of glycerine-water mixtures or corn syrup-water mixtures). This was done to minimize the experimental variables, optimize the experimental conditions for subsequent CWS atomization studies and also, simplify the analysis. The atomization data obtained for the simulated fluids are as shown in Table 1 and 2. The Air/Fuel ratio was varied from 0.12--0.40 in this study. variation of SMD as a Function of Viscosity. The SMD of glycerine-water mixtures at high Air/Fuel and low Air/Fuel data are plotted in Figures 5 and 6. The data show that at high Air/Fuel ratio, there is no significant change of the SMD as the viscosity is varied. However, at low Air/Fuel ratio the SMD shows a strong dependence on the viscosity. This is due to the fact that entrainment losses become more severe as A/F increases, In the high A/F regime, there is very little variation between the SMD and the viscosity of the glycerine-water solutions. This is probably due to the fact that the relative velocity between the droplets and the air is very high and this produces high pressure forces on the droplets to the same extent. Considerable dispersion of the droplets was also observed at high A/F ratios. This effect is minimized in the low A/F regime. Figures 5--8 show plots os SMD as a Function of Air/Fuel ratio. The plot show a linear dependence of SMD on the air to Fuel ratio. A fit of the experimental data to equation 1 in order to determine the necessary coefficients will be reported during the next quarter.
Date: June 1, 1994
Creator: Ohene, F.
Partner: UNT Libraries Government Documents Department

[Gamma scattering in condensed matter with high intensity Moessbauer radiation]

Description: This report discusses: quasielastic scattering studies on glycerol; gamma-ray scattering from alkali halides; lattice dynamics in metals; Moessbauer neutron scattering, x-ray diffraction, and macroscopic studies of high {Tc} superconductors containing tungsten; NiAl scattering studies; and atomic interference factors and nuclear Casimir effect.
Date: June 1, 1992
Partner: UNT Libraries Government Documents Department

A Classical Model for Closed-Loop Diagrams of Binary Liquid Mixtures

Description: A classical lattice model for closed-loop temperature-composition phase diagrams has been developed. It considers the effect of specific interactions, such as hydrogen bonding, between dissimilar components. This van Laar-type model includes a Flory-Huggins term for the excess entropy of mixing. It is applied to several liquid-liquid equilibria of nonelectrolytes, where the molecules of the two components differ in size. The model is able to represent the observed data semi-quantitatively, but in most cases it is not flexible enough to predict all parts of the closed loop quantitatively. The ability of the model to represent different binary systems is discussed. Finally, attention is given to a correction term, concerning the effect of concentration fluctuations near the upper critical solution temperature.
Date: March 1, 1994
Creator: Schnitzler, J.v. & Prausnitz, J. M.
Partner: UNT Libraries Government Documents Department

Inelastic scattering in condensed matter with high intensity Moessbauer radiation. Final technical report, December 1, 1989--November 30, 1992

Description: The QUEGS facility at MURR has produced a number of new results and demonstrated the range of potential applications of high resolution, high intensity Moessbauer scattering. This work has been carried out by both MU and Purdue researchers and includes published results on Na, W, pentadecane, polydimethylsiloxane and other systems, manuscripts submitted on alkali halides (Phys. Rev. B) and accurate Moessbauer lineshape measurements (Phys. Rev. C), and manuscripts in preparation on glycerol, NiAl and Moessbauer spectra obtained by modulating a scattering crystal. Recently, new collaborations have been initiated which will substantially enhance our efforts. These are with W. Steiner (Vienna), G. Coddens (Saclay), and R. D. Taylor (Los Alamos). Steiner is experienced with Fe-57 Moessbauer scattering, while Coddens specializes in quasielastic neutron scattering; both of these areas naturally complement our work. R. D. Taylor has pioneered Moessbauer spectroscopy from the time of its discovery and has already made important contributions to our study of lattice dynamics and superconductivity for lead alloyed with small quantities of tin. At the same time, a significant instrument upgrade is underway, funded in part by the DOE-URIP program.
Date: February 1, 1993
Creator: Yelon, W. B. & Schupp, G.
Partner: UNT Libraries Government Documents Department

Analysis of glycerin waste in A-Area sanitary treatment facility material

Description: TNX has a large supply of 55 gallon drums containing pure glycerin and glycerin with additives. The glycerin drums were procured to simulate the glass stream in a pilot-scale melter process at TNX. Since the glycerin was not used for this process, TNX is looking at disposing the material in a sanitary waste treatment facility onsite. The effect of adding the contents of the drums to sewage bacteria was tested. A drum of pure glycerin and a drum of glycerin mixed with lithium chloride were tested. The test consisted of mixing sanitary sludge material with the glycerin material. The purpose of the test was to determine if the glycerin impacted the aerobic bacterial population. The bacterial densities were determined by taking samples from the sludge/glycerin mixtures and using aerobic plate count methods. The total organic carbon (TOC) levels were measured before and after testing. The results indicate that the cell density of the aerobic bacteria increased with the addition of glycerin and the glycerin mixture and the TOC removal rate was different for all tests. Disposal of glycerin in the wastewater treatment facilities should pose no problems. Additional testing and analysis of the mixed samples should be done before its disposal in a waste water treatment facility.
Date: January 1, 1995
Partner: UNT Libraries Government Documents Department

Aerated atomization of coal water slurry

Description: In order to better understand the process of slurry atomization, it is important to observe the influence of fluid non-Newtonian rheological behavior on the spray formation process. As a first step, glycerin-water solutions have been atomized. This report describes findings of photographs taken during atomization. 19 figs.
Date: January 5, 1989
Creator: Buckner, H.N.; Sojka, P.E. & Lefebvre, A.H.
Partner: UNT Libraries Government Documents Department

Aerated atomization of coal-water slurry fuels

Description: Despite the body of work describing the performance of effervescent atomizers, its potential for use with coal water slurries (CWS) had not been evaluated prior to this study. This programs was therefore undertaken: to demonstrate that effervescent atomization can produce CWS sprays with mean drop sizes below 50 {mu}m; to determine a lower size limit for effervescent atomizer produced CWS sprays; to determine the mechanism(s) responsible for the formation of effervescent atomizer produced sprays. This report describes results of a mathematical analysis in order to better understand physical phenomena involved. 12 figs.
Date: April 1, 1989
Creator: Buckner, H.N.; Sojka, P.E. & Lefebvre, A.H.
Partner: UNT Libraries Government Documents Department

Progress in the detection of single molecules in levitated droplets

Description: This report briefly describes a method for the detection of single molecules of rhodamine-6G in levitated droplets. 4 refs. CBS
Date: January 1, 1990
Creator: Whitten, W.B.; Ramsey, J.M. (Oak Ridge National Lab., TN (USA)); Arnold, S. (Polytechnic Inst. of Brooklyn, NY (USA)) & Bronk, B.V. (Chemical Research, Development and Engineering Center, Aberdeen Proving Ground, MD (USA))
Partner: UNT Libraries Government Documents Department

Aerated atomization of coal-water slurry fuels

Description: In order to observe the effects of rheology on the atomization of highly viscous non-Newtonian liquids, glycerin-water solutions and cellulose-glycerin-water solutions have been atomized. In this series of tests, nozzle pressure, air-liquid ratio and liquid viscosity were altered, and the effects were observed. 14 figs.
Date: September 30, 1988
Creator: Buckner, H.N.; Sojka, P.E. & Lefebvre, A.H.
Partner: UNT Libraries Government Documents Department

Inelastic scattering in condensed matter with high intensity Moessbauer radiation

Description: The QUEGS facility at MURR has produced a number of new results and demonstrated the range of potential applications of high resolution, high intensity Moessbauer scattering. This work has been carried out by both MU and Purdue researchers and includes published results on Na, W, pentadecane, polydimethylsiloxane and other systems, manuscripts submitted on alkali halides (Phys. Rev. B) and accurate Moessbauer lineshape measurements (Phys. Rev. C), and manuscripts in preparation on glycerol, NiAl and Moessbauer spectra obtained by modulating a scattering crystal. Recently, new collaborations have been initiated which will substantially enhance our efforts. These are with W. Steiner (Vienna), G. Coddens (Saclay), and R. D. Taylor (Los Alamos). Steiner is experienced with Fe-57 Moessbauer scattering, while Coddens specializes in quasielastic neutron scattering; both of these areas naturally complement our work. R. D. Taylor has pioneered Moessbauer spectroscopy from the time of its discovery and has already made important contributions to our study of lattice dynamics and superconductivity for lead alloyed with small quantities of tin. At the same time, a significant instrument upgrade is underway, funded in part by the DOE-URIP program.
Date: February 1, 1993
Creator: Yelon, W.B. & Schupp, G.
Partner: UNT Libraries Government Documents Department

Nonphotochemical Hole Burning and Dispersive Kinetics in Amorphous Solids

Description: Results covering burn intensities in the nW to {mu}W/cm{sup 2} range, of dispersive hole growth kinetics are reported for Oxazine 720 in glycerol glasses and polyvinyl alcohol polymer films and their deuterated analogues. A theoretical model which employs a distribution function for the hole burning rate constant based upon a Gaussian distribution for the tunnel parameter is shown to accurately describe the kinetic data. This model incorporates the linear electron-phonon coupling. A method for calculating the nonphotochemical quantum yield is presented which utilizes the Gaussian distribution of tunnel parameters. The quantum yield calculation can be extended to determine a quantum yield as a function of hole depth. The effect of spontaneous hole filling is shown to be insignificant over the burn intensity range studied. Average relaxation rates for hole burning are {approximately}8 orders of magnitude greater than for hole filling. The dispersive kinetics of hole burning are observed to be independent over the temperature range of these experiments, 1.6 to 7.0 K. 6 refs., 20 figs., 1 tab.
Date: September 21, 1990
Creator: Kenney, M. J.
Partner: UNT Libraries Government Documents Department

Roles of additives and surface control in slurry atomization

Description: Objectives: of this projects are to: promote further understanding of the mechanisms and the roles of additives in airblast atomization of coal water slurry (CWS); and investigate the impacts of coal particle surface properties and interparticle forces on CWS rheology and coal cleanability. This study covers rheology and airblast atomization of micronized coal water slurry. Airblast atomization is carried out in a bench scale unit equipped with a twin-fluid jet atomizer and a Malvern Particle Sizer 2600C for drop size measurement. The coal water slurries are composed of 0.40 to 0.47 volume fractions of micronized 4.4 {mu}m Upper Freeport coal and micronized 3.7 {mu}m Illinois {number sign}6 in aqueous solutions containing 20% to 80% glycerol, 42% ethylene glycol, or 50% isopropanol. 2 figs., 2 tabs.
Date: January 1, 1990
Creator: Tsai, S.C.
Partner: UNT Libraries Government Documents Department

Cavity-enhanced spontaneous emission rates for rhodamine 6-G in levitated microdroplets

Description: Fluorescence decay kinetics of Rhodamine 6-G molecules in levitated glycerol microdroplets (4--20 microns in diameter) have been investigated to determine the effects of spherical cavity resonances on spontaneous emission rates. For droplet diameters greater than 10 microns, the fluorescence lifetime is essentially the same as in bulk glycerol. As the droplet diameter is decreased below 10 microns, bi-exponential decay behavior is observed with a slow component whose rate is similar to bulk glycerol, and a fast component whose rate is as much as a factor of 10 larger than the bulk decay rate. This fast component is attributed to cavity enhancement of the spontaneous emission rate and, within the weak coupling approximation, a value for the homogeneous linewidth at room temperature can be estimated from the fluorescence lifetime data.
Date: January 1, 1992
Creator: Barnes, M.D.; Whitten, W.B.; Ramsey, J.M. (Oak Ridge National Lab., TN (United States)) & Arnold, S. (Polytechnic Inst., of New York, Brooklyn, NY Microparticle Photophysics Lab. (United States))
Partner: UNT Libraries Government Documents Department

Separation of compounds with multiple -OH groups from dilute aqueous solutions via complexation with organoboronate. [1,2-propanediol]

Description: The complexing extractant agent investigated in this work is 3-nitrophenylboronic acid (NPBA) in its anionic form (NPB). NPBA and Aliquat 336 (quaternary amine) is dissolved in 2-ethyl-l-hexanol, and the extractant is contacted with aq. NaOH. Solutes investigated were 1,2-propanediol, glycerol, fructose, sorbitol and lactic acid. Batch extraction experiments were performed at 25{degree}C. Partition coefficients, distribution ratios and loadings are reported for varying concentrations of solute and NPB. All solutes complexed with NPB{sup {minus}}, with all complexes containing only one NPB{sup {minus}} per complex. The 1:1 complexation constants for the solutes glycerol, fructose and sorbitol follow trends similar to complexation with B(OH){sub 4}{sup {minus}} (aq.), i.e. the complexation constants increase with increasing number of {minus}OH groups available for complexation. Assumption of 1:1 complex is not valid for 1, 2-propanediol, which showed overloading (more than one mole of solute complexed to one mole NPB{sup {minus}}) at higher concentrations. The {minus}OH group on the NPB{sup {minus}} which is left uncomplexed after one solute molecule had bound to the other two {minus}OH groups may be responsible for the overloading. Overloading is also observed in extraction of tactic acid, but through a different mechanism. It was found that TOMA{sup +} can extract lactic acid to an extent comparable to the uptake of lactic acid by NPB{sup {minus}}. The complexation is probably through formation of an acid-base ion pair. Losses of NPBA into the aqueous phase could lead to problems, poor economics in industrial separation processes. One way of overcoming this problem would be to incorporate the NPBA onto a solid support.
Date: May 1, 1992
Creator: Chow, Tina Kuo Fung.
Partner: UNT Libraries Government Documents Department

Natural convection heat transfer between arrays of horizontal cylinders and their enclosure

Description: The natural convection heat transfer between arrays of horizontal, heated cylinders and their isothermal, cooled enclosure was experimentally investigated. Four different cylinder arrays were used: two in-line and two staggered. Four fluids (air, water, 20 cs silicone, and 96% glycerine) were used with Prandtl numbers ranging from 0.705 to 13090.0. There was no significant change in the Nusselt number between isothermal and constant heat flux conditions of the cylinder arrays. The average heat transfer coefficient was most affected by the spacing between cylinders and the total surface area of the cylinder arrays. The enclosure reduced the expected increase in both the average and the local heat transfer coefficients caused by changing the inner body from an in-line arrangement to a staggered arrangement of comparable spacing. An increase in fluid viscosity reduced the influence of the geometric effects.
Date: January 1, 1984
Creator: Weaver, R.A. & Warrington, R.O.
Partner: UNT Libraries Government Documents Department

Metallography of maraging 350 steel

Description: A technique for etching maraging 350 steel with Glyceregia is described. Surface activation procedures are integral to this technique. Microstructural features revealed by this technique are compared with those obtained with Kalling's reagent, Fry's reagent, and 5% Nital, three etchants commonly used to reveal microstructures of maraging steels. Features which may be simultaneously revealed using Glyceregia include prior austenite grain boundaries, martensitic structure, precipitates, titanium carbo-nitrides, and reverted austenite. The other etchants examined in this investigation typically reveal only a few of the microstructural features detailed above at any one time. 11 refs., 10 figs., 2 tabs.
Date: January 1, 1987
Creator: Hutson, S.M. & Merten, C.W.
Partner: UNT Libraries Government Documents Department

Low-rank coal thermal properties and diffusivity: Final report

Description: This project developed techniques for measuring thermal properties and mass diffusivities of low-rank coals and coal powders. Using the concept of volume averaging, predictive models have been developed for these porous media properties. The Hot Wire Method was used for simultaneously measuring the thermal conductivity and thermal diffusivity of both consolidated and unconsolidated low-rank coals. A new computer-interfaced experiment is presented and sample container designs developed for both coal powders and consolidated coals. A new mathematical model, based upon volume averaging, is presented for the prediction of these porous media properties. Velocity and temperature effects on liquid-phase dispersion through unconsolidated coal were determined. Radioactive tracer data were used to determine mass diffusivities. A new predictive mathematical model is presented based upon volume averaging. Vapor-phase diffusivity measurements of organic solvents in consolidated lignite coal are reported. An unsteady-state pressure response experiment with microcomputed-based data acquisition was developed to estimate dispersion coefficients through consolidated lignite coals. The mathematical analysis of the pressure response data provides the dispersion coefficient and the adsorption coefficient. 48 refs., 59 figs., 17 tabs.
Date: June 1, 1987
Creator: Ramirez, W.F.
Partner: UNT Libraries Government Documents Department

Approaches to the preservation of human granulocytes by freezing

Description: Because of its simplicity, the FDA assay can be used effectively as a screening test to eliminate procedures and treatments that are damaging to cells. In this context, a number of conclusions can be drawn from the data presented: (1) Exposure to 1 and 2 M glycerol at room temperature damages human granulocytes in a few minutes. Reducing the exposure temperature to 0/sup 0/C reduces the amount of injury substantially. (2) Human granulocytes respond to freezing and thawing in a manner typical of many mammalian cells in that they exhibit a maximum in survival at an optimum cooling rate slightly above 1/sup 0/C/min when combined with rapid warming. The use of rapid warming and a high (2 M) concentration of glycerol reduces the dependence of survival on cooling rate by broadening the range of rates over which survival is relatively high. (3) Human granulocytes show some sensitivity to dilution stresses since survival depends somewhat on the concentration of glycerol used and the severity of the dilution procedure. The reasons for the sharp decrease in cell viability following incubation of frozen-thawed granulocytes at 37/sup 0/C are not known. One possibility is that the phosphate buffered saline suspending medium used is not suitable for incubation at 37/sup 0/C. A second possibility is that some cell injury is not expressed at 0/sup 0/C and remains undetected by the FDA assay until the cells are incubated at 37/sup 0/C. There is also the possibility that lysosomal enzymes released by a few damaged cells in a sample will cause additional damage in other cells at 37/sup 0/C.
Date: January 1, 1979
Creator: Frim, J & Mazur, P
Partner: UNT Libraries Government Documents Department

Study of droplet formation for preparation of spheres by internal gelation

Description: The internal-gelation process can be used to permanently immobilize highly radioactive nuclear wastes. A study was conducted to determine the factors affecting the formation of stable, uniform droplets from a vibrating nozzle, which is a critical step in this process. Experimental data were collected using four nozzle diameters (325 to 586 ..mu..m) with jet velocities ranging from 1 to 10 m/s, and three test liquids, whose physical properties cover the possible range of the waste fluid. A dimensional analysis identified the pertinent dimensionless groups as Reynolds, Weber, Froude, and Power numbers, and a dimensionless droplet spacing. Power-function correlations of the data in these dimensionless groups are presented, which define the region of good droplet formation. A unique catcher-stream design is also presented, which improves performance of the process at higher flow rates and frequencies.
Date: January 1, 1982
Creator: Chu, C.R. & Card, J.C.
Partner: UNT Libraries Government Documents Department

Pyrolysis mechanisms. Quarterly report, April-June 1981

Description: The data acquisition system for fast pyrolysis studies is summarized and discussed, based on preliminary applications to fast scans and peak switching of the quadrupole mass spectrometer. The free-jet expansion phenomena of internal-state cooling and clustering are discussed in terms of their relevance to pyrolysis product sampling interpretation. Primary pyrolysis spectra are shown for cotton, wood, and steam-exploded extracted lignin. Both pulsed and steady-state pyrolysis were used to observe the secondary cracking of cotton, wood, levoglucosan, glycerol, and methanol in steam-argon at a nominal 900/sup 0/C. The general plan of future studies is presented.
Date: December 1, 1981
Creator: Milne, T.A. & Soltys, M.N.
Partner: UNT Libraries Government Documents Department

(Gamma scattering in condensed matter with high intensity Moessbauer radiation)

Description: This report discusses: quasielastic scattering studies on glycerol; gamma-ray scattering from alkali halides; lattice dynamics in metals; Moessbauer neutron scattering, x-ray diffraction, and macroscopic studies of high {Tc} superconductors containing tungsten; NiAl scattering studies; and atomic interference factors and nuclear Casimir effect.
Date: January 1, 1992
Partner: UNT Libraries Government Documents Department

Long-distance communication and signal amplication in systemic acquired resistance

Description: This review article summarizes the involvement and interaction between long-distance systemic acquired resistance (SAR) signals and details the recently discovered role of lysine catabolite pipecolic acid (Pip) in defense amplification and priming that allows plants to acquire immunity at the systemic level.
Date: February 22, 2013
Creator: Shah, Jyoti & Zeier, J├╝rgen
Partner: UNT College of Arts and Sciences

Genomic Prospecting for Microbial Biodiesel Production

Description: Biodiesel is defined as fatty acid mono-alkylesters and is produced from triacylglycerols. In the current article we provide an overview of the structure, diversity and regulation of the metabolic pathways leading to intracellular fatty acid and triacylglycerol accumulation in three types of organisms (bacteria, algae and fungi) of potential biotechnological interest and discuss possible intervention points to increase the cellular lipid content. The key steps that regulate carbon allocation and distribution in lipids include the formation of malonyl-CoA, the synthesis of fatty acids and their attachment onto the glycerol backbone, and the formation of triacylglycerols. The lipid biosynthetic genes and pathways are largely known for select model organisms. Comparative genomics allows the examination of these pathways in organisms of biotechnological interest and reveals the evolution of divergent and yet uncharacterized regulatory mechanisms. Utilization of microbial systems for triacylglycerol and fatty acid production is in its infancy; however, genomic information and technologies combined with synthetic biology concepts provide the opportunity to further exploit microbes for the competitive production of biodiesel.
Date: March 20, 2008
Creator: Lykidis, Athanasios; Lykidis, Athanasios & Ivanova, Natalia
Partner: UNT Libraries Government Documents Department