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CARBON AND DEUTERIUM NUCLEAR MAGNETIC RESONANCE IN SOLIDS

Description: In Chapter I we present the results on a study of cross polarization dynamics, between protons and carbon-13 in adamantane, by the direct observation of the dilute, carbon-13, spins. These dynamics are an important consideration in the efficiency of proton enhancement double-resonance techniques and they also provide good experimental models for statistical theories of cross relaxation. In order to test these theories we present a comparison of the experimental and theoretical proton dipolar fl… more
Date: July 1, 1976
Creator: Shattuck, Thomas Wayne
Partner: UNT Libraries Government Documents Department
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Desulfurization of coal-derived pyrite using solutions containing dissolved oxygen.

Description: The effect of alkaline solutions containing dissolved oxygen on coal-derived pyrite was investigated in a tubular reactor. The rate of total sulfur conversion seems to be affected by oxygen partial pressure, oxygen flow rate, particle size, pyrite charge size and system temperature. A shrinking core model was chosen to represent this chemical leaching process. From the results obtained, it seems that ash or product-layer difusion is the rate-limiting step for leaching with the alkaline solution… more
Date: July 1, 1979
Creator: Chen, M. C.
Partner: UNT Libraries Government Documents Department
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Methanation reaction on ruthenium thin films: a mechanistic investigation.

Description: The kinetics of the methanation reaction were measured on thin ruthenium films in the temperature range 548 to 623K. The pressures of the reactant gases were varied over the ranges 1.5 to 1500 ..mu..m for CO and 300 to 75000 ..mu..m for H/sub 2/ to yield kinetic orders for each gas. The CO kinetic order varied from +1 at low pressures to -2 at high pressures. As the H/sub 2/ pressure was increased its kinetic order varied from +2 to -1. Both of these order plots had unusually sharp maxima. The … more
Date: July 1, 1979
Creator: Slaughter, M. D.
Partner: UNT Libraries Government Documents Department
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Impact of surface coal mining and reclamation on the hydrogeology at Iowa Coal Project Demonstration Mine No. 1, Mahaska County, Iowa

Description: The groundwater effects of surface mining at ICP No. 1 can be classified primarily as water quality and water quantity effects. The water quantity effects are: the loss of groundwater saturation in spoil materials that were initially removed from over the coal and later replaced; the dewatering of high permeability geologic strata up gradient of mining area; the increase in porosity and possibly permeability in refilled spoil materials; and the change in groundwater gradients in mined areas and… more
Date: July 1, 1979
Creator: Stangl, D. W.
Partner: UNT Libraries Government Documents Department
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Floatability of coal and pyrite. [54 references]

Description: An experimental investigation was carried out to improve the froth flotation method of separating coal pyrite. The effect of several surface active agents on the floatability of an Iowa coal and its associated pyrite was studied in both the presence and absence of methyl isobutyl carbinol (MIBC), a commonly used frother. The effectiveness of a special method of chemical pretreatment for depressing pyrite was also investigated. The zeta potential of the same coal and pyrite was measured under th… more
Date: July 1, 1977
Creator: Le, H. V.
Partner: UNT Libraries Government Documents Department
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ELECTROCHEMICAL MACHINING OF CARBIDES AND BORIDES

Description: The use of high rate anodic dissolution (electrochemical machining) for shaping titanium carbide, zirconium carbide, titanium boride and zirconium boride has been investigated in 2N potassium nitrate and 3N sodium chloride under current densities ranging from 20 to 120 A/cm{sup 2} (corresponding to cutting rates of 0.3 to 1.8 mm/min). The dissolution stoichiometry for all these materials is independent of the current density in the range 20 to 120 A/cm{sup 2}. Both titanium and zirconium appear… more
Date: July 1, 1978
Creator: Dissaux, Bernard Antoine; Muller, Rolf H. & Tobias, Charles W.
Partner: UNT Libraries Government Documents Department
open access

OPTICAL DIFFERENCE FREQUENCY GENERATION OF FAR INFRARED RADIATION

Description: Three investigations of difference frequency generation (DFG) of far-infrared radiation by optical mixing are described: a theory of DFG by monochromatic, focused Gaussian pump laser beams, a theory of DFG by a picosecond pump laser pulse, and an experiment using ruby-pumped dye lasers. First, the theory of far-infrared generation by optical mixing of monochromatic, focused Gaussian beams in a uniaxial crystal is developed, taking into account the effects of diffraction, absorption, double refr… more
Date: July 1, 1977
Creator: Morris, J. R.
Partner: UNT Libraries Government Documents Department
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Calculations of the ground state energy and exchange integrals of crystalline $sup 3$He

Description: Thesis. The variational equation is derived and discussed using Jastrowtype wave functions, which are a product of pair wave functions, as the trail wave function. The various approximations used in simplifying the variational equations so as to obtain a form that is possible to solve numerically are discussed also. A Monte Carlo calculation is described using the wave function obtained. Exchange in /sup 3/He is discussed. (MHR)
Date: July 1, 1973
Creator: Lim, W L
Partner: UNT Libraries Government Documents Department
open access

Geometry of some metal halides

Description: Thesis. Two polarizable ion models are developed to describe the gas phase of metal dihalide molecules. Both models use electrostatic and repulsive interactions to predict molecular geometries and molecular constants. The first model is applied to the dihalides of the alkaline earths, group II-b metals, transition metals, group IV-a metals, and europium. In addition to the molecular geometry, bending frequencies are derived for most of these molecules. The second or linear'' model is applied to… more
Date: July 1, 1973
Creator: Yarnell, P.A.
Partner: UNT Libraries Government Documents Department
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The Chlorination of Amino Acid in Municipal Waste Effluents

Description: In model reaction systems to test amino acids in chlorinated waste effluents, several amino acids were chlorinated at high chlorine doses. (2000-4000 mg/1). Amino acids present in municipal waste effluents before and after chlorination were concentrated and purified using cation exchange and Chelex resins. After concentration and cleanup of the samples, the amino acids were derivatized by esterification of the acid functional groups and acylation of the amine groups. Identification and quantifi… more
Date: July 1977
Creator: Burleson, Jimmie L.
Partner: UNT Libraries
open access

META-T compiler--compiler

Description: No Description Available.
Date: July 1, 1974
Creator: Lucido, A.P.
Partner: UNT Libraries Government Documents Department
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