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Effect of Capture on the Slowing-Down Length of Neutrons in Hydrogenous Mixtures Containing Uranium

Description: Memorandum presenting a rigorous expression for the slowing-down length of neutrons in hydrogenous media under the assumption that the nonhydrogen nuclei have infinite mass and that capture is absent. Two expressions have been applied to the same sample mixture, a uranium-235 and water mixture with the ratio of hydrogen to uranium nuclei chosen as 25.
Date: April 1953
Creator: Volkin, H. C. & Soffer, L.
Partner: UNT Libraries Government Documents Department

De-coupling of exchange and persistence times in atomistic modelsof glass formers

Description: With molecular dynamics simulations of a fluid mixture of classical particles interacting with pair-wise additive Weeks-Chandler-Andersen potentials, we consider the time series of particle displacements and thereby determine distributions for local persistence times and local exchange times. These basic characterizations of glassy dynamics are studied over a range of super-cooled conditions and shown to have behaviors, most notably de-coupling, similar to those found in kinetically constrained lattice models of structural glasses. Implications are noted.
Date: August 15, 2007
Creator: Hedges, Lester O.; Maibaum, Lutz; Chandler, David & Garrahan, Juan P.
Partner: UNT Libraries Government Documents Department

Phase Equilibria: an Informal Symposium

Description: From introduction: The accurate prediction of phase equilibria plays an important. role in the chemical process industries. A grief overview of final phase equilibria predictive techniques is presented with special emphasis on methods in current use in industry. Areas were better fundamental understanding will lead to improved models are discussed whenever possible.
Date: January 1983
Creator: Eaton, B. E.; Ely, James F.; Hanley, H. J. M.; McCarty, Robert D. & Rainwater, James C.
Partner: UNT Libraries Government Documents Department

Vapor pressures of concentrated nitric acid solutions in the composition range 83 to 97 percent nitric acid 0 to 6 percent nitrogen dioxide, 0 to 15 percent water, and in the temperature range 20 to 80 C

Description: Report presenting total vapor pressures for 28 acid mixtures of the ternary system nitric acid, nitrogen dioxide, and water within a range of temperatures and compositions.
Date: September 17, 1953
Creator: McKeown, A. B. & Belles, Frank E.
Partner: UNT Libraries Government Documents Department

Solubility of Anthracene in Ternary 2,2,4-Trimethylpentane + Propanol + 1-Pentanol and 2,2,4-Trimethylpentane + Butanol + 1-Pentanol Mixtures

Description: Article on the solubility of anthracene in ternary 2,2,4-trimethylpentane + propanol + 1-pentanol and 2,2,4-trimethylpentane + butanol + 1-pentanol mixtures.
Date: February 29, 2008
Creator: Blake-Taylor, Brooke H.; Martine, Beth A. & Acree, William E. (William Eugene)
Partner: UNT College of Arts and Sciences

Solubility of Anthracene in Ternary Propanol + 2,2,4-Trimethylpentane + Cyclohexane and Butanol + 2,2,4-Trimethylpentane + Cyclohexane Solvent Mixtures

Description: Article on the solubility of anthracene in ternary propanol + 2,2,4-trimethylpentane + cyclohexane and butanol + 2,2,4-trimethylpentane + cyclohexane solvent mixtures.
Date: October 2, 1998
Creator: Deng, Taihe & Acree, William E. (William Eugene)
Partner: UNT College of Arts and Sciences

Low-Temperature, Vapor-Phase Oxidation of Fuel-Rich Hydrocarbon Mixtures

Description: Note presenting a study of the vapor-phase oxidation of methylcyclohexane in a flow system in the temperature range of 300 to 400 degrees Celsius under the conditions of 0.1 the stoichiometric amount of oxygen, a contact time of 8 seconds, and a spiral Pyrex reactor 10.5 inches long with an inside diameter of 3/32 inch. The yields of acids, aldehydes, ketones, hydrogen peroxide, organic peroxides, olefin, water, and unreacted hydrocarbon were determined in the products.
Date: January 1958
Creator: House, William T. & Orchin, Milton
Partner: UNT Libraries Government Documents Department

Experimental Investigations Concerning the Limits of Detonation in Gaseous Mixtures: Part 2

Description: Memorandum presenting an investigation concerning the limits of detonation in gaseous mixtures. In regards to the results, by progressive dilution of the explosive, the course of the chemical reaction becomes slower and slower until finally the transformation within the reaction zone becomes so slow that it is not there completed.
Date: February 1930
Creator: Wendlandt, Rudolf
Partner: UNT Libraries Government Documents Department

Combustion of Gaseous Mixtures

Description: This report not only presents matters of practical importance in the classification of engine fuels, for which other means have proved inadequate, but also makes a few suggestions. It confirms the results of Withrow and Boyd which localize the explosive wave in the last portions of the mixture burned. This being the case, it may be assumed that the greater the normal combustion, the less the energy developed in the explosive form. In order to combat the detonation, it is therefore necessary to try to render the normal combustion swift and complete, as produced in carbureted mixtures containing benzene (benzol), in which the flame propagation, beginning at the spark, yields a progressive and pronounced darkening on the photographic film.
Date: November 1932
Creator: Duchene, R.
Partner: UNT Libraries Government Documents Department

Intermolecular potential parameters and combining rules determined from viscosity data

Description: The Law of Corresponding States has been demonstrated for a number of pure substances and binary mixtures, and provides evidence that the transport properties viscosity and diffusion can be determined from a molecular shape function, often taken to be a Lennard-Jones 12-6 potential, that requires two scaling parameters: a well depth {var_epsilon}{sub ij} and a collision diameter {sigma}{sub ij}, both of which depend on the interacting species i and j. We obtain estimates for {var_epsilon}{sub ij} and {sigma}{sub ij} of interacting species by finding the values that provide the best fit to viscosity data for binary mixtures, and compare these to calculated parameters using several 'combining rules' that have been suggested for determining parameter values for binary collisions from parameter values that describe collisions of like molecules. Different combining rules give different values for {sigma}{sub ij} and {var_epsilon}{sub ij} and for some mixtures the differences between these values and the best-fit parameter values are rather large. There is a curve in ({var_epsilon}{sub ij}, {sigma}{sub ij}) space such that parameter values on the curve generate a calculated viscosity in good agreement with measurements for a pure gas or a binary mixture. The various combining rules produce couples of parameters {var_epsilon}{sub ij}, {sigma}{sub ij} that lie close to the curve and therefore generate predicted mixture viscosities in satisfactory agreement with experiment. Although the combining rules were found to underpredict the viscosity in most of the cases, Kong's rule was found to work better than the others, but none of the combining rules consistently yields parameter values near the best-fit values, suggesting that improved rules could be developed.
Date: May 7, 2010
Creator: Bastien, Lucas A.J.; Price, Phillip N. & Brown, Nancy J.
Partner: UNT Libraries Government Documents Department