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1980-1989
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UNT Scholarly Works
Solubility of Phenylacetic Acid in Binary Solvent Mixtures
Date: January 1985
Creator: Acree, William E. (William Eugene)
Description: This article discusses the solubility of phenylacetic acid in binary solvent mixtures. Abstract: Solubilities are reported for phenylacetic acid at 25.0 °C in binary mixtures of carbon tetrachloride with cyclohexane, n-heptane, n-octane, or isooctane and mixtures of cyclohexane with n-heptane or isooctane. The results are compared to the predictions of equations developed previously for solubility in systems of purely nonspecific interactions, with phenylacetic acid considered as either monomeric or dimeric molecules in solution. The dimer model provided the more accurate predictions and described the 15-fold range of solubilities in the carbon tetrachloride + isooctane system to within a maximum deviation of 15%.
Contributing Partner: UNT College of Arts and Sciences
Permallink:digital.library.unt.edu/ark:/67531/metadc152445/
Thermochemical Investigations of Gas-Liquid Chromatography. Partition Coefficients of Inert Solutes on Self-Associating Binary Solvent Mixtures
Date: April 1982
Creator: Acree, William E. (William Eugene)
Description: This article discusses partition coefficients of inert solutes on self-associating binary solvent mixtures. Abstract: A conventional nonelectrolyte solution model which has led to successful predictive equations for the partial molar excess properties of a solute in simple binary solvent systems is extended to include self-associating solvent components. An expression is developed and tested for its ability to describe gas-liquid partition coefficients in mixed solvents from measurements in the pure solvents. For n-hexane, n-heptane, and cyclohexane on blended mixtures of n-hexadecane and n-octadecane with N,N-dibutyl-2-ethylhexylamide, the newly derived expression is found to describe the chromatographic data to within 2%.
Contributing Partner: UNT College of Arts and Sciences
Permallink:digital.library.unt.edu/ark:/67531/metadc152444/
Comment on the Prediction of Gas Chromatographic Retention Behavior with Mixed Liquid Phases
Date: September 1980
Creator: Acree, William E. (William Eugene) & Rytting, J. Howard
Description: This article comments on the prediction of gas chromatographic retention behavior with mixed liquid phases.
Contributing Partner: UNT College of Arts and Sciences
Permallink:digital.library.unt.edu/ark:/67531/metadc146582/
Excess Molar Volumes of Binary Mixtures of Cyclohexane and y-Butyrolactone with Aromatic Hydrocarbons
Date: April 1985
Creator: Acree, William E. (William Eugene); Gholami, Kheirollah; McHan, Danny R. & Rytting, J. Howard
Description: This article discusses excess molar volumes of binary mixtures of cyclohexane and y-butyrolactone with aromatic hydrocarbons. Abstract: Excess molar volumes of cyclohexane + benzene, cyclohexane + toluene, cyclohexane + p-xylene, y-butyrolactone + benzene, y-butyrolactone + toluene, and y-butyrolactone + m-xylene have been measured at 298.15 K. For the first three systems, Vᴱ is positive throughout the entire concentration range. Vᴱ is negative for binary mixtures containing y-butyrolactone, which indicates significant interaction between y-butyrolactone and the aromatic hydrocarbon.
Contributing Partner: UNT College of Arts and Sciences
Permallink:digital.library.unt.edu/ark:/67531/metadc152457/
L- and M-shell x-ray production cross sections of Nd, Gd, Ho, Yb, Au, and Pb by 25-MeV carbon and 32-MeV oxygen ions
Date: October 15, 1987
Creator: Andrews, M. C.; McDaniel, Floyd Del. (Floyd Delbert), 1942-; Duggan, Jerome L.; Miller, P. D.; Pepmiller, P. L.; Krause, H. F. et al
Description: This article discusses L- and M-shell x-ray production. Abstract: L- and M-shell x-ray production cross sections have been measured for thin solid targets of neodymium, gadolinium, holmium, ytterbium, gold and lead by 25-MeV ₆¹²C(q)+ (q=4,5,6) and by 32-MeV ₈¹⁶O(q)+ (q=5,7,8). The cross sections were determined from measurements made with thin targets (less than 2.25 μg/cm2). For projectiles with one or two K-shell vacancies, the target x-ray production cross sections were found to be enhanced over those for projectiles without a K-shell vacancy. The sum of direct ionization to the continuum (DI) plus electron capture (EC) to the L,M,N,... shells and EC to the K shell of the projectile have been extracted from the data. The results are compared to the predictions of first Born theories, i.e., plane-wave Born approximation for DI and Oppenheimer-Brinkman-Kramers formula of Nikolaev for EC, and to the ECPSSR that accounts for energy loss and Coulomb deflection of the projectile as well as for relativistic and perturbed stationary states of inner-shell electrons.
Contributing Partner: UNT College of Arts and Sciences
Permallink:digital.library.unt.edu/ark:/67531/metadc139494/
O demonstratie directă a faptului că L1 (X, B, μ) verifică principiul tare al maximului modulului
Date: 1989
Creator: Anghel, Nicolae
Description: This paper proposes a new direct proof of the fact that L^1 verifies the strong maximum principle, i.e., any analytic map from the complex unit disk into L^1, constant in norm, must be constant.
Contributing Partner: UNT College of Arts and Sciences
Permallink:digital.library.unt.edu/ark:/67531/metadc152439/
Generalizarea problemei 0:59
Date: 1980
Creator: Anghel, Nicolae
Description: This note extends a certain combinatorics problem of I. Tomescu.
Contributing Partner: UNT College of Arts and Sciences
Permallink:digital.library.unt.edu/ark:/67531/metadc152440/
Varietăţi Grassmanniene Mixte
Date: 1982
Creator: Anghel, Nicolae
Description: This article discusses mixed Grassmann manifolds. Abstract: Se construieşte varietea grassmanniană modelată intr-un spaţiu Banach mixt, situaţie ce generalizează simultan conceptele grassmanniene real şi complex.
Contributing Partner: UNT College of Arts and Sciences
Permallink:digital.library.unt.edu/ark:/67531/metadc161697/
Carbon K-shell x-ray and Auger-electron production in hydrocarbons and carbon oxides by 0.6-2.0-MeV protons
Date: May 1, 1987
Creator: Bhalla, R. P.; McDaniel, Floyd Del. (Floyd Delbert), 1942- & Lapicki, G.
Description: This article discusses carbon K-shell x-ray and Auger-electron production in hydrocarbons and carbon oxides by 0.6-2.0-MeV protons. Abstract: Carbon K-shell x-ray and Auger-electron-production cross sections are reported for 0.6-2.0-MeV protons incident on CH4 (methane), C2H2 (acetylene), n-C4H10 (normal butane), i-C4H10 (isobutane), C6H6 (benzene), CO, and CO2. A variable-geometry end-window proportional counter with an alternative procedure for the determination of its transmission was used in collection of the x-ray data. A constant-energy-mode π/4 parallel-plate electrostatic analyzer served in the detection of Auger electrons. K-shell Auger-electron-production cross sections are compared with the predictions of the first Born theory and the perturbed-stationary-state theory which accounts for energy-loss, Coulomb deflection, and relativistic effects (ECPSSR). These data show fair agreement with the ECPSSR theory when the chemical shifts, of the carbon K-shell binding energy in molecules, are included in the calculations. This agreement is even better after effects of intramolecular scattering are considered. Validity of the geometrical model by Matthews and Hopkins [Phys. Rev. Lett. 40, 1326(1978)] is established after a scrutiny of the inelastic cross sections for scattering of Auger-electrons within the molecule and their effective dislocation out of the detector's window. The x-ray cross sections show particularly strong variations with the target molecular ...
Contributing Partner: UNT College of Arts and Sciences
Permallink:digital.library.unt.edu/ark:/67531/metadc139493/
L-shell x-ray production cross sections of Ni, Cu, Ge, As, Rb, Sr, Y, Zr, and Pd by (0.25-2.5)-MeV protons
Date: October 1985
Creator: Duggan, Jerome L.; Kocur, P. M.; Price, J. L.; McDaniel, Floyd Del. (Floyd Delbert), 1942-; Mehta, R. & Lapicki, Gregory
Description: In this article, L-shell x-ray production cross sections by ₁¹H+ ions are reported. The data are compared to the first Born approximation (plane-wave Born approximation for direct ionization and Oppenheimer-Brinkman-Kramers approximation for electron capture) and to the ECPSSR (energy-loss and Coulomb-deflection effects, perturbed stationary-state approximation with relativistic correction) theory. The energy of the protons ranged from 0.25 to 2.5 MeV in steps of 0.25 MeV. The targets used in these measurements were ₂₈Ni, ₂₉Cu, ₃₂Ge, ₃₃As, ₃₇Rb, ₃₈Sr, ₃₉Y, ₄₀Zr, and ₄₆Pd. The first Born theory generally agrees with the data found in the literature at high energies and overpredicts them below 1.5 MeV. The ECPSSR predictions are in better agreement with experimental cross sections. At 0.25 MeV the authors' data, however, are underestimated by this theory and tend to agree with the first Born approximation.
Contributing Partner: UNT College of Arts and Sciences
Permallink:digital.library.unt.edu/ark:/67531/metadc139485/