Formal analysis of name accessing in programming languages. [R] (open access)

Formal analysis of name accessing in programming languages. [R]

None
Date: October 1, 1975
Creator: Smith, C. L.
System: The UNT Digital Library
Low temperature heat capacity of lutetium and lutetium hydrogen alloys (open access)

Low temperature heat capacity of lutetium and lutetium hydrogen alloys

The heat capacity of high purity electrotransport refined lutetium was measured between 1 and 20/sup 0/K. Results for theta/sub D/ were in excellent agreement with theta values determined from elastic constant measurements. The heat capacity of a series of lutetium-hydrogen solid solution alloys was determined and results showed an increase in ..gamma.. from 8.2 to about 11.3 mJ/g-atom-K/sup 2/ for hydrogen content increasing from zero to about one atomic percent. Above one percent hydrogen ..gamma.. decreased with increasing hydrogen contents. The C/T data showed an increase with temperature decreasing below about 2.5/sup 0/K for samples with 0.1 to 1.5 atomic percent hydrogen. This accounts for a large amount of scatter in theta/sub D/ versus hydrogen content in this range. The heat capacity of a bulk sample of lutetium dihydride was measured between 1 and 20/sup 0/K and showed a large increase in theta/sub D/ and a large decrease in ..gamma.. compared to pure lutetium.
Date: October 1, 1977
Creator: Thome, D. K.
System: The UNT Digital Library
Polariton effects in naphthalene crystals (open access)

Polariton effects in naphthalene crystals

The experimental verification of the two-step nature of energy dissipation of photon energy by a crystal is the subject of this dissertation. The ..cap alpha..(O,O) Davydov component of the lowest energy singlet transition in pure strain-free napthalene single crystals is shown to exhibit an increase in absorption with increasing temperature, due to an increase in polariton damping via polariton-phonon scattering processes. (GHT)
Date: October 1, 1977
Creator: Robinette, S. L.
System: The UNT Digital Library
Synthesis and characterization of an N-(2-hydroxyethyl)-ethylenediaminetriacetic acid resin (open access)

Synthesis and characterization of an N-(2-hydroxyethyl)-ethylenediaminetriacetic acid resin

A chelating ion-exchange resin with N-(2-hydroxyethyl)ethylene-diaminetriacetic acid (HEDTA) used as the ligand chemically bonded to XAD-4 by an ester linkage, HEDTA-4, was synthesized. It is stable under normal experimental conditions with the liquid chromatograph. The structure of the resin was confirmed by an infrared spectrum, and by potentiometric titrations. The capacity of the resin was also obtained by potentiometric titration and by a nitrogen analysis. The resin was used to pack a column of 5 mm internal diameter and 5 cm long. The effect of pH on the retention of different metal ions on the resin was studied. It was found that the resin was most selective for chromium(III), copper(II), lead(II), mercury(II), uranium(VI), zirconium(IV) and zinc(II) at a pH of less than 3. Furthermore, the resin proves to be functioning with a chelating mechanism rather than ion-exchange, and it can concentrate trace metal ions in the presence of a large excess of calcium and magnesium. This makes the resin potentially useful for purifying and analyzing drinking water.
Date: October 1, 1977
Creator: Lai, Y. F.
System: The UNT Digital Library
Stress induced reorientation of vanadium hydride (open access)

Stress induced reorientation of vanadium hydride

The critical stress for the reorientation of vanadium hydride was determined for the temperature range 180/sup 0/ to 280/sup 0/K using flat tensile samples containing 50 to 500 ppM hydrogen by weight. The critical stress was observed to vary from a half to a third of the macroscopic yield stress of pure vanadium over the temperature range. The vanadium hydride could not be stress induced to precipitate above its stress-free precipitation temperature by uniaxial tensile stresses or triaxial tensile stresses induced by a notch.
Date: October 1, 1977
Creator: Beardsley, M. B.
System: The UNT Digital Library
Electromigration of hydrogen and deuterium in vanadium, niobium, and tantalum (open access)

Electromigration of hydrogen and deuterium in vanadium, niobium, and tantalum

The electric mobility and effective valence of hydrogen and deuterium in vanadium, niobium, tantalum and three niobium-tantalum alloys were measured. A resistance technique was used to directly determine the electric mobility of hydrogen and deuterium at 30/sup 0/C while a steady-state method was used to measure the effective valence. The use of mass spectrographic techniques on a single specimen which contained both hydrogen and deuterium greatly increased the precision with which the isotope effect in the effective valence could be measured.
Date: October 1, 1977
Creator: Jensen, C. L.
System: The UNT Digital Library
Temperature dependence of resistivity of thin film samples of chalcogenide glasses (open access)

Temperature dependence of resistivity of thin film samples of chalcogenide glasses

None
Date: October 1, 1975
Creator: Kulkarni, A. K.
System: The UNT Digital Library
Magnetic excitations above the critical temperature (open access)

Magnetic excitations above the critical temperature

None
Date: October 1, 1975
Creator: Swanson, P. A.
System: The UNT Digital Library
Heated uranium tetrafluoride target system to release non-rare gas fission products for the TRISTAN isotope separator. [As replacement for uranyl stearate] (open access)

Heated uranium tetrafluoride target system to release non-rare gas fission products for the TRISTAN isotope separator. [As replacement for uranyl stearate]

Off-line experiments indicated that fluorides of As, Se, Br, Kr, Zr, Nb, Mo, Tc, Ru, Sb, Te, I and Xe could be volatilized, but except for Br, Kr, I and Xe, none of these elements were observed after mass separation in the on-line experiments. The results of the on-line experiments indicated a very low level of hydride contamination at ambient temperature and consequently, uranium tetrafluoride replaced uranyl stearate as the primary gaseous fission product target. Possible reasons for the failure of the heated target system to yield non-rare gas activities are discussed and suggestions for designing a new heated target system are presented.
Date: October 1, 1977
Creator: Gill, R. L.
System: The UNT Digital Library
Thermodynamics of solid and liquid group III-V alloys (open access)

Thermodynamics of solid and liquid group III-V alloys

Solid-state electrochemical techniques are applied to the Ga-In-Sb-O system to measure some thermodynamic properties important for the analysis of solid-liquid phase equilibria in these important semiconductor materials. The standard Gibbs energies of formation of the most stable oxides of gallium and of indium are determined with a high-temperature solid-state electrochemical cell utilizing calcia-stabilized zirconia as the solid electrolyte and a (CO + CO/sub 2/) gaseous mixture as the reference electrode.
Date: October 1, 1978
Creator: Anderson, T. J.
System: The UNT Digital Library
Evaluation of self-interaction parameters from binary phase diagrams (open access)

Evaluation of self-interaction parameters from binary phase diagrams

The feasibility of calculating Wagner self-interaction parameters from binary phase diagrams was examined. The self-interaction parameters of 22 non-ferrous liquid solutions were calculated utilizing an equation based on the equality of the chemical potentials of a component in two equilibrium phases. Utilization of the equation requires the evaluation of the first and second derivatives of various liquidus and solidus data at infinite dilution of the solute component. Several numerical methods for evaluating the derivatives of tabular data were examined. A method involving power series curve fitting and subsequent differentiation of the power series was found to be the most suitable for the interaction parameter calculations. Comparison of the calculated self-interaction parameters with values obtained from thermodynamic measurements indicates that the Wagner self-interaction parameter can be successfully calculated from binary phase diagrams.
Date: October 1, 1977
Creator: Ellison, T. L.
System: The UNT Digital Library
IN VIVO STUDIES OF RADIATION POTENTIATON BY IODOACETAMIDE AND OBSERVATIONS ON TUMOR TRANSPLANTATION IMMUNITY (open access)

IN VIVO STUDIES OF RADIATION POTENTIATON BY IODOACETAMIDE AND OBSERVATIONS ON TUMOR TRANSPLANTATION IMMUNITY

Iodoacetamide has been shown by others to be a radiation sensitizer for bacteria and for certain mammalian cells tested in vitro. This work describes an examination of the effectiveness of iodoacetamide used in vivo. Survival of ascites tumor cells maintained in the peritoneal cavity of mice was used as an indicator of sensitization. Survival was assessed using TD{sub 50} and total tumor cell population determination methods. A comparison of results obtained by these methods is made. The effects of oxygen tension and radiation dose rate upon results was examined. Iodoacetamide was found to be effective as a radiation sensitizer under all conditions although to a lesser degree than that reported by others for in vitro experiments with bacteria. Radioactive tracer studies indicate that iodoacetamide has rapid and total access to most if not all tissues of the body. This fact coupled with the observation of a sensitization in an in vivo system where the anoxia so prevalent in well developed tumors was present, suggests the possibility of clinical usefulness of iodoacetamide in cancer radiation therapy. Certain observations are reported on the effect of various cell and host treatment procedures upon cell population growth kinetics seen subsequent to inoculation of hosts …
Date: October 1, 1970
Creator: Richards, F. Robert & Kelly, Lola S.
System: The UNT Digital Library
Crystal and molecular structure of organophosphorus insecticides (open access)

Crystal and molecular structure of organophosphorus insecticides

The crystal and molecular structures of the following organophosphorus (OP) insecticides have been determined by three-dimensional X-ray analysis: ronnel (0,0-dimethyl 0-2,4,5 trichlorophenyl phosphorothioate), ronnel oxon (0,0-dimethyl 0-2,4,5 trichlorophenyl phosphate), bomophos (0-(4-bromo-2,5-dichlorophenyl) 0,0-dimethyl phosphorothioate), Ruelene (0-(4-tert-Butyl-2-chlorophenyl)-0-methyl-N-methyl phosphoroamidate), fospirate (0,0-dimethyl 0-3,5,6-trichloro-2-pyridyl phosphate) and chlorpyrifos (0,0-diethyl 0-3,5,6-trichloro-2-pyridyl phosphorothioate). Phosphorus to meta hydrogen distances for the respective compounds are: 5.51, 5.49, 5.42, (5.68, 5.13), 5.79 and 5.78 A. All of these distances fall well within the range of literature values cited for the intramolecular active site-separation distance for insect acetylcholinesterase (AChE), yet are well outside that for mammalian AChE. In addition the crystal structure of ronnel displays a hydrogen-sulfur intermolecular interaction in the b direction and a phosphorus which is readily accessible for phosphorylation of AChE. The structure of ronnel oxon is quite similar to that of ronnel. CNDO 11 molecular orbital calculations are presented to show the charge distribution in the compound. A likely intramolecular hydrogen bond in bromophos restricts rotation about the phenolic C-O bond. The configuration of Ruelene is substantiated by CNDO 11 molecular orbital calculations and van der Waals arguments and features a possible weak intramolecular hydrogen bond which somewhat restricts rotation about the phenolic C-O bond. Charge density information …
Date: October 1, 1977
Creator: Baughman, R. G.
System: The UNT Digital Library
Chemical shift anisotropies of /sup 1/H in H/sub 2/O(s), H/sub 2/S(s), and C/sub 6/H/sub 6/(s) (open access)

Chemical shift anisotropies of /sup 1/H in H/sub 2/O(s), H/sub 2/S(s), and C/sub 6/H/sub 6/(s)

The proton NMR in powdered samples of H/sub 2/O(s), H/sub 2/S(s), and C/sub 6/H/sub 6/(s) have been studied by multiple pulse line narrowing techniques. The resultant spectra provide nuclear magnetic shielding tensors that are (at least approximately) axially symmetric. The anisotropy is 34.2 +- 1.0 ppM for ice, 11.1 +- 1.0 ppM for the highest-temperature phase of solid hydrogen sulfide, and -5.3 +- 0.3 for benzene. Comparisons are made with previous experimental and theoretical work.
Date: October 1, 1977
Creator: Ryan, L. M.
System: The UNT Digital Library
Effects of electron irradiation on p-type germanium at liquid helium temperatures using ac hopping conductivity (open access)

Effects of electron irradiation on p-type germanium at liquid helium temperatures using ac hopping conductivity

P-type germanium single crystals (8 x 10/sup 14/Ga/cm/sup 3/ and 6 x l0/ sup 1 Ga/cm/sup 3) were irradiated with 1.1-Mev electrons at pumped liquid helium temperatures and defect production and annealing studied using ac hopping conductivity. Production rates obtained from measurements at 1.5 deg K and 10/ sup 4/ Hz were 0.6 cm/sup -10/ for samples doped 6 x 10/sup 15/ Ga/cm/sup 3/ and 0.11 cm/sup -10/ for samples doped 8 x 10/ sup 14/ Ga/cm/sup 3/. Above 10/sup 14/ e,/cm/sup 2/ fluence the production rates for the higher doped samples decreased to approximately 0.06 cm/sup -1/ at 10/sup 15/ e/cm/sup 2/ fluence except for one sample which was anomalous. No such long irradiation of the low doped samples was made. The apparent inconsistency between these results and production rates of less than 3 x 10/sup -4/ cm/sup -1/ observed by previous workers was resolved by introducing a donor level for the defect produced by irradiation near the chemical acceptor level, so that the defect would be neutral at temperatures near 30 deg K and charged + 1 at l.5 deg K. Surface effects were observed which did not affect production rate measurements at 1.5 deg K more than …
Date: October 1, 1973
Creator: Roop, Raymond Marvin
System: The UNT Digital Library
Piezoelectric response of bone and tendon subjected to inhomogeneous stress (Chapters I--IV) (open access)

Piezoelectric response of bone and tendon subjected to inhomogeneous stress (Chapters I--IV)

None
Date: October 1, 1974
Creator: Breger, L.H.
System: The UNT Digital Library
Two-nucleon transfer reactions induced by polarized protons (open access)

Two-nucleon transfer reactions induced by polarized protons

None
Date: October 1, 1973
Creator: Macdonald, J.A.
System: The UNT Digital Library
Translocation Dynamics of 239-Plutonium (open access)

Translocation Dynamics of 239-Plutonium

>Thesis. The translocation dynamics of /sup 239/Pu(NO/sub 3/)/sub 4/ and /sup 239/PuO/sub 2/ from ulated puncture wounds in the paws of beagle dogs were studied. The difference between the more soluble Pu(NO/sub 3/)/sub 4/ form the insoluble high fired PuO/sub 2 particles was assumed to bring about highly differing translocation dynamics from the wound site, through lymphatic channels into the system's circulation and to organs of deposition and of excretion. There was rapid movement of Pu from the paw to the first major lymph node with a resulting buildup and regression pattern for activity within the node. Differential translocation, concentration, retention, and excretion of Pu and Am were demonstrated with both chemical forms. The effectiveness of DTPA administration for Pu removal from the body was dependent on the chemical form of the Pu contaminant. ( CH)
Date: October 1, 1973
Creator: Bistline, R.W.
System: The UNT Digital Library
K-matrix fits to $pi$N $Yields$ N$pi$ and N$pi$$pi$ in the resonance region $Root$s = 1.3 to 2.0 GeV (open access)

K-matrix fits to $pi$N $Yields$ N$pi$ and N$pi$$pi$ in the resonance region $Root$s = 1.3 to 2.0 GeV

Thesis. Starting with partial wave amplitudes for pi N yields N pi and pi N yields several isobar model states of N pi pi , one can apply the constraint of unitarity (using the K-matrix). This permits the removal of the overall phase ambiguity of the isobar amplitudes at each energy. The K-matrix fits generated a smooth prescription for the T-matrix amplitudes, enabling one to search the complex energy plane for poles. The uniqueness of these poles was demonstrated by doing Breit-Wigner refits to the fitted T-matrix amplitudes. The success of the results and the obvious interpretation justified a simple determination of coupling signs for which there can be checks with theory. This thesis corresponds closely to a forthcoming paper submitted to Physical Review except that here the K-matrix is based on a 1972 solution A'' isobar-model fits to N pi pi data, and in the final paper solution B'' is used. (auth)
Date: October 1, 1973
Creator: Longacre, R. S.
System: The UNT Digital Library
Stimulated Brillouin and backward Raman light scattering (open access)

Stimulated Brillouin and backward Raman light scattering

Thesis. The definition, production, and properties of brillouin and Raman scattering using lasers are discussed. (JFP)
Date: October 1, 1973
Creator: Bonnett, D.
System: The UNT Digital Library