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Application of Concentration, Adsorption and pH in the Precipitation of the Metal Ions of Groups II and III

Description: In this thesis, the process involved in the precipitations and separations of the metal of Group II and Group III studied. Suggestions have also been offered whereby students can make an analysis without loosing metals in the initial precepitation.
Date: June 1937
Creator: Cockerell, Leone Doris
Partner: UNT Libraries
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Application of Novel Microporous Polyolefin Silica-Based Substrate in Paper Spray Mass Spectrometry (PS-MS)

Description: This study addressed five key applications of paper spray mass spectrometry (PS-MS): (i) comparative analysis of the microporous substrate with the cellulose-based substrate in drug detection; (ii) detection of more than 190 fentanyl analogs with their fragmentation pattern can be implemented in the future reference for quicker, accurate and sensitive determination; (iii) exploring sweat in a fingerprint to be considered an alternate method to recognize non-invasive markers of metabolites, lip… more
Date: December 2020
Creator: Weligamage De Silva, Imesha
Partner: UNT Libraries
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An Application of the Reformatsky Reaction to the Thiophene Series of Compounds

Description: In view of the increasing importance of thiophene derivatives as chemotherapeutic agents, it was considered of interest to apply the Reformatsky reaction to the synthesis of compounds containing the thiophene nucleus with the thought that these might serve as intermediates for further syntheses.
Date: 1949
Creator: Hicks, Howard A.
Partner: UNT Libraries
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Application of UV-Vis Spectroscopy to the Monitoring, Characterization and Analysis of Chemical Equilibria of Copper Etching Baths

Description: The continuously increasing demand for innovation in the miniaturization of microelectronics has driven the need for ever more precise fabrication strategies for device packaging, especially for printed circuit boards (PCBs). Subtractive copper etching is a fundamental step in the fabrication process, requiring very precise control of etch rate and etch factor. Changes in the etching chemical equilibrium have significant effects on etching behavior, and CuCl2 / HCl etching baths are typically m… more
Date: August 2017
Creator: Lambert, Alexander S.
Partner: UNT Libraries
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Applications of Metallic Clusters and Nanoparticles via Soft Landing Ion Mobility, from Reduced to Ambient Pressures

Description: Nanoparticles, simple yet groundbreaking objects have led to the discovery of invaluable information due to their physiological, chemical, and physical properties, have become a hot topic in various fields of study including but not limited to chemistry, biology, and physics. In the work presented here, demonstrations of various applications of chemical free nanoparticles are explored, from the determination of a non-invasive method for the study of the exposome via using soft-landing ion mobil… more
Date: August 2018
Creator: Aguilar Ayala, Roberto
Partner: UNT Libraries
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Applications of Nanomanipulation Coupled to Nanospray Mass Spectrometry in Trace Fiber Analysis and Cellular Lipid Analysis.

Description: The novel instrumentation of nanomanipulation coupled to nanospray mass spectrometry and its applications are presented. The nanomanipulator has the resolution of 10nm step sizes allowing for specific fine movement used to probe and characterize objects of interest. Nanospray mass spectrometry only needs a minimum sample volume of 300nl and a minimum sample size of 300attograms to analyze an analyte making it the ideal instrument to couple to nanomanipulation. The nanomanipulator is mounted to … more
Date: December 2008
Creator: Ledbetter, Nicole
Partner: UNT Libraries
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Applications of Single Reference Methods to Multi-Reference Problems

Description: Density functional theory is an efficient and useful method of solving single-reference computational chemistry problems, however it struggles with multi-reference systems. Modifications have been developed in order to improve the capabilities of density functional theory. In this work, density functional theory has been successfully applied to solve multi-reference systems with large amounts of non-dynamical correlation by use of modifications. It has also been successfully applied for geometr… more
Date: May 2015
Creator: Jeffrey, Chris C.
Partner: UNT Libraries
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An Approach Towards the Total Synthesis of Clonostachydiol

Description: The syntheses of the unsymmetrical 14-membered bismacrolides have been reviewed. A total synthesis of clonostachydiol, the latest to join this family, has been attempted using trimethylsilyl acetylene as the builiding block and palladium catalyzed reactions for the formation of key bonds. The alkyne groups were introduced by Stille coupling of trimethylstannylethynyltrimethylsilane with an acid chloride for one fragment and by addition of lithiotrimethylsilyl acetylene to an aldehyde for the ot… more
Date: August 1995
Creator: Maiti, Tushar B. (Tushar Baran)
Partner: UNT Libraries
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Aqueous Solubilities and Transformation of Chlorinated Benzenes

Description: Aqueous solubilities of twelve chlorinated benzenes were determined by two methods. In one method, the solutions in water were prepared by a vigorous stirring method followed by n-hexane extraction and GC-ECD analysis. In the second method, HPLC was used to prepare the saturated solutions. Experimental results were compared with the predictive values, the relative standard deviations are around 10%. Most of the chlorinated benzenes exhibit water induced transformations. The transformation produ… more
Date: August 1990
Creator: Wang, Hui-Wen
Partner: UNT Libraries
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Aqueous Solubilities and Water Induced Transformations of Halogenated Benzenes

Description: Methods of determining the aqueous solubilities of twelve chlorinated benzenes were evaluated in pure and in different water matrices. In pure water, results were comparable with the calculated values. Higher chlorinated tetrachlorobenzenes (TeCBs), pentachlorobenzenes (PCBz), and hexachlorobenzenes (HCBs) gave better precision and accuracy than lower chlorinated monochlorobenzenes (MCBs), dichlorobenzenes (DCBs), or trichlorobenzenes (TCBs).
Date: August 1989
Creator: Kim, In-Young
Partner: UNT Libraries

Aromaticity, Supramolecular Stacks, and Luminescence Properties of Cyclic Trinuclear Complexes

Description: The dissertation covers three major topics: metal-assisted aromaticity, synthetic approaches to tailor donor-acceptor supramolecular stacks, and photoluminescence properties of cyclic trinuclear complexes (CTCs) of d10 metals. First, multiple theoretical approaches are adapted to discuss in detail the origin of aromaticity of CTCs, putting forward a metal-assisted aromaticity model. Next are the discoveries of donor-acceptor stacked CTC–CTC' complexes from both experimental and computational pe… more
Date: December 2022
Creator: Lu, Zhou
Partner: UNT Libraries
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Atomic Layer Deposition of Boron Oxide and Boron Nitride for Ultrashallow Doping and Capping Applications

Description: The deposition of boron oxide (B₂O₃) films on silicon substrates is of significant interest in microelectronics for ultrashallow doping applications. However, thickness control and conformality of such films has been an issue in high aspect ratio 3D structures which have long replaced traditional planar transistor architectures. B₂O₃ films are also unstable in atmosphere, requiring a suitable capping barrier for passivation. The growth of continuous, stoichiometric B₂O₃ and boron nitride (BN) f… more
Date: December 2020
Creator: Pilli, Aparna
Partner: UNT Libraries
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Atomic Layer Deposition of H-BN(0001) on Transition Metal Substrates, and In Situ XPS Study of Carbonate Removal from Lithium Garnet Surfaces

Description: The direct epitaxial growth of multilayer BN by atomic layer deposition is of critical significance forfo two-dimensional device applications. X-ray photoelectron spectroscopy (XPS) and low energy electron diffraction (LEED) demonstrate layer-by-layer BN epitaxy on two different substrates. One substrate was a monolayer of RuO2(110) formed on a Ru(0001) substrate, the other was an atomically clean Ni(111) single crystal. Growth was accomplished atomic layer deposition (ALD) cycles of BCl3/NH… more
Date: May 2020
Creator: Jones, Jessica C.
Partner: UNT Libraries
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Barbituric Acids. VII. 5-alkyl-derivatives of 5-ethoxy-barbituric Acid

Description: A great deal of research has been devoted in recent years to the search for new drugs for the treatment of epilepsy and related convulsive disorders. This emphasis is occasioned by the fact that no one drug is effective for all patients, and also by the fact that the toxicity of a drug varies considerably from one patient to another. Among the most effective drugs are certain members of the hydantoin and barbituric acid series. For some time there has been in progress in this laboratory an inve… more
Date: January 1955
Creator: Hyde, Harold Wayne
Partner: UNT Libraries
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Barbituric Acids. VIII. 5-substituted-5-(1-pyrrolidyl)barbituric Acids

Description: The purpose of this investigation then was the preparation of a series of 5-substituted-5-(1-pyrrolidyl)barbituric acids in which R would consist of alkyl groups ranging in size from methyl to amyl, and other groups such as phenyl and benzyl. These compounds are to be tested elsewhere for hypnotic and anticonvulsant activity.
Date: 1957
Creator: Compton, Ross Davis
Partner: UNT Libraries
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Barbituric Acids. V. 5-substituted-mercapto Derivatives of 5-isoamylbarbituric Acid

Description: Since no mention has been found in the literature of any 5-substituted mercapto-5-alkyl derivatives of barbituric acid, it was thought to be of interest to prepare a series of compounds containing sulfur attached directly to the barbituric acid nucleus. 5-substituted mercapto-5-isoamylbarbituric acids were chosen as representative of barbituric acids in which the alkyl group has a fairly high molecular weight.
Date: August 1952
Creator: Peterson, Paul Eugene
Partner: UNT Libraries
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