UNT Theses and Dissertations - 762 Matching Results

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Photochemical and Photophysical Properties of Mononuclear and Multinuclear Closed Shell D10 Coinage Metal Complexes and Their Metallo-organometallic Adducts

Description: This dissertation covers the studies of two major topics: the photochemistry of mononuclear and multinuclear gold(I) complexes and synthetic approaches to tailor photophysical properties of cyclic trinuclear d10 complexes. First a detailed photochemical examination into the photoreactivity of neutral mononuclear and multinuclear gold(I) complexes is discussed, with the aim of gold nanoparticle size and shape control for biomedical and catalysis applications. Next is a comprehensive systematic s… more
Date: December 2013
Creator: McDougald, Roy N., Jr.
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An Analysis of the Effectiveness of Computer Assisted Instruction in General Chemistry at an Urban University.

Description: The science-major General Chemistry sequence offered at the University of Houston has been investigated with respect to the effectiveness of recent incorporation of various levels of computer technology. As part of this investigation, questionnaire responses, student evaluations and grade averages and distributions from up to the last ten years have been analyzed and compared. Increased use of web-based material is both popular and effective, particularly with respect to providing extra informa… more
Date: May 2002
Creator: McGuffey, Angela
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Chemical Equilibria in Binary Solvents

Description: Dissertation research involves development of Mobile Order Theory thermodynamic models to mathematically describe and predict the solubility, spectral properties, protonation equilibrium constants and two-phase partitioning behavior of solutes dissolved in binary solvent mixtures of analytical importance. Information gained provide a better understanding of solute-solvent and solvent-solvent interactions at the molecular level, which will facilitate the development of better chemical separation… more
Date: August 1997
Creator: McHale, Mary E. R.
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An NMR Study of Trimethylsilylmethyllithium Aggregates and Mixed Trimethylsilylmethyllithium/Lithium trimethylsilylmethoxide Aggregates

Description: An NMR spectroscopy study of trimethylsilylmethyllilthium, TMSM-Li, indicates that TMSM-Li exists as two different aggregates in cyclopentane solution. Using previously reported colligative properties of TMSM-Li in different solutions in connection with new 13C and 6Li NMR data collected in this study, aggregation states were assigned as octamer and hexamer. Low temperature 13C and 6Li NMR peak intensities indicated an equilibrium exists between the two aggregates that shifts toward the octam… more
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Date: December 2004
Creator: Medley, Marilyn S.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Computational Studies of the Photophysical, Structural, and Catalytic Properties of Complex Chemical Systems

Description: Computational chemistry employs mathematical algorithms, statistics, and large databases to integrate chemical theory with experimental observations. Computational modeling allows us to make predictions concerning molecular properties and reactivity that ultimately lead to accurate assessment of the most important fundamental properties of chemical systems. Advances in theoretical techniques and computer power have dramatically increased the usefulness and importance of computational chemistry … more
Date: May 2021
Creator: Melancon, Kortney
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Interaction of learning approach with concept integration and achievement in a large guided inquiry organic class.

Description: A study was conducted to investigate the relationship of students' concept integration and achievement with time spent within a topic and across related topics in a large first semester guided inquiry organic chemistry class. Achievement was based on evidence of algorithmic problem solving; and concept integration was based on demonstrated performance explaining, applying, and relating concepts to each other. Twelve individual assessments were made of both variables over three related topics - … more
Date: August 2009
Creator: Mewhinney, Christina
Item Type: Refine your search to only Thesis or Dissertation
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Long-Range Carbon-13--Carbon-13 Spin-Spin Coupling Constants

Description: The study consists of three major areas of research. First, the dihedral angle dependence of vicinal carbon-carbon coupling constants is determined for aliphatic and alicyclic carboxylic acids wherein the formal hybridization and substituents are held constant. Second, the magnitudes and relative signs of long-range carbon-carbon coupling constants in a. triple- 13 C-labeled system are determined and compared with carbon-proton and/or proton-proton coupling constants in geometrically similar co… more
Date: December 1974
Creator: Miller, Denis E.
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The Preparation of Pyridinium Derivatives by the Knoevenagel Condensation

Description: An attempt is made in the work described in this paper to extend the series started by Hall and Platas by means of a Knoevenagel condensation between 3-hydroxy-1,4-naphtho-quinone-2-(4-methylpyridinium) anhydride and various aromatic aldehydes giving rise to a series of unsaturated substituents on the four position of the pyridine ring.
Date: May 1955
Creator: Miller, Eugene James
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Copper (II) Complexes with Deprotonated N-(2-hydroxyethyl)ethylenediamine

Description: This thesis reports the synthesis and characterization of two new copper(II) halide complexes with deprotonated N-(2-hydroxyethyl)ethylenediamine behaving as a bidentate. The magnetic properties of the new copper(II) complexes were studied from room temperature to liquid nitrogen temperatures. The magnetic data show that both complexes exhibit antiferromagnetic interactions with a singlet ground state and a thermally accessible triplet excited state. Magnetic data and infrared spectra indicate … more
Date: December 1975
Creator: Miller, Toney G.
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Reducing the Computational Cost of Ab Initio Methods

Description: In recent years, advances in computer technology combined with new ab initio computational methods have allowed for dramatic improvement in the prediction of energetic properties. Unfortunately, even with these advances, the extensive computational cost, in terms of computer time, memory, and disk space of the sophisticated methods required to achieve chemical accuracy - defined as 1 kcal/mol from reliable experimental data effectively - limits the size of molecules [i.e. less than 10-15 non-h… more
Date: August 2008
Creator: Mintz, Benjamin
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Predicting Chemical and Biochemical Properties Using the Abraham General Solvation Model

Description: Several studies were done to illustrate the versatillity of the Abraham model in mathematically describing the various solute-solvent interactions found in a wide range of different chemical and biological systems. The first study focused on using the solvation model to construct mathematical correlations describing the minimum inhibitory concentration of organic compounds for growth inhibition towards the three bacterial strains Porphyromonas gingivalis, Selenomonas artemidis, and Streptococc… more
Date: May 2009
Creator: Mintz, Christina
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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Determination of Solute Descriptors for Illicit Drugs Using Gas Chromatographic Retention Data and Abraham Solvation Model

Description: In this experiment, more than one hundred volatile organic compounds were analyzed with the gas chromatograph. Six capillary columns ZB wax plus, ZB 35, TR1MS, TR5, TG5MS and TG1301MS with different polarities have been used for separation of compounds and illicit drugs. The Abraham solvation model has five solute descriptors. The solute descriptors are E, S, A, B, L (or V). Based on the six stationary phases, six equations were constructed as a training set for each of the six columns. The si… more
Date: August 2015
Creator: Mitheo, Yannick K.
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Incorporating Electrochemistry and X-ray Diffraction Experiments Into an Undergraduate Instrumental Analysis Course

Description: Experiments were designed for an undergraduate instrumental analysis laboratory course, two in X-ray diffraction and two in electrochemistry. Those techniques were chosen due their underrepresentation in the Journal of Chemical Education. Paint samples (experiment 1) and pennies (experiment 2) were characterized using x-ray diffraction to teach students how to identify different metals and compounds in a sample. in the third experiment, copper from a penny was used to perform stripping analyses… more
Date: May 2012
Creator: Molina, Cathy
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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First-Semester General Chemistry Curriculum Comparison of Student Success on ACS Examination Questions Grouped by Topic Following an Atoms First or Traditional Instructional Approach

Description: This study uses the ACS first-term general chemistry exam to determine if one curriculum approach is more effective in increasing student success than the other based on their performance on the ACS exam. Two chemistry curriculum approaches were evaluated in this study; the traditional curriculum (TC) and the Atoms First (AF) approach. The sample population was first-semester general chemistry students at Collin College in Frisco, TX. An independent sample t-test was used to determine if there… more
Date: August 2014
Creator: Molina, Cathy D.
Item Type: Refine your search to only Thesis or Dissertation
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A Quantitative Study of the Common Metals Found in the Oak and the Pine

Description: The purpose of this study is to determine the amounts of the element sulfur, phosphorus, sodium, potassium, silicon, iron, aluminium, calcium, magnessium, and manganess found in the roots, hearts, sap, leaves, and bark of two plants, the short leaf pine and the blackjack oak.
Date: August 1938
Creator: Moore, Carver Yates
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Spectroscopic Investigation of Some Allyl Alkali Metal Compounds

Description: To gain better understanding of the nature of the carbonmetal bonding in 3-neopentylallyl alkali metal (5,5-dimethyl- 2-hexenyl alkali metal) systems, an investigation is extended to 3-neopentylallylpotassium. In addition, pertinent data on the 3-neopentylallyl systems are re-examined in an attempt to understand the trends in the bonding habits, as affected by the solvent, the cation and the temperature.
Date: May 1976
Creator: Moore, Michael L.
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The Analysis of PCDD and PCDF Emissions from the Cofiring of Densified Refuse Derived Fuel and Coal

Description: The United States leads the world in per capita production of Municipal Solid Waste (MSW), generating approximately 200 million tons per year. By 2000 A.D. the US EPA predicts a 20% rise in these numbers. Currently the major strategies of MSW disposal are (i) landfill and (ii) incineration. The amount of landfill space in the US is on a rapid decline. There are -10,000 landfill sites in the country, of which only 65-70% are still in use. The Office of Technology Assessment (OTA) predicts an 80%… more
Date: August 1990
Creator: Moore, Paul, 1962-
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Kinetics and Mechanism of Reactions of Disubstituted Octahedral Metal Carbonyls with Phosphorus Donor Ligands and Germanium Tetraiodide

Description: The kinetics and mechanism of the reactions of (tmpa)W-(CO)^ and (tmen)W(CO)^ (tmpa = N,N,N',N'-tetramethy1-1,3-diaminopropane and tmen = N,N,N1,N1-tetramethylethylenediamine) with four phosphorus donor ligands (triisopropyl phosphite, triphenyl phosphite, triphenylphosphine and "constrained phosphite", 4-methyl-2,6,7-trioxa-l-phosphabicylo[2.2.2]octane) in xylene have been investigated in detail. These reactions were found to take place by the ring-opening of the bidentate ligand in a reversib… more
Date: August 1976
Creator: Moradi-Araghi, Ahmad
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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