Chemistry Commons^™

A Study Of The Ability Of Surface Active Materials To Increase The Evaporation Rates Of Small, Freely Falling Water Drops, David Alan Sierawski

Masters Theses

"The evaporation rate at 30°C of water droplets partially covered by surface active materials (SAM) were determined. While two of the SAM were studied at a single dew point depression (ΔT_DP), seven others were examined over a range of ΔT_DP values. It was found, by comparison with pure water drops under identical conditions, that SAM increases the evaporation rate as compared to the rate of an uncontaminated drop. The lack of effect of the hydrophobic chain length and the possible effect of the hydrophilic group on this phenomenon are discussed. The explanation proposed is that at 30°C …

Desorption Of Phosphorus From Si (111) Surfaces, Cesar Michel Magnin

Masters Theses

"Auger electron spectroscopy and mass analysis are used as complementary methods in evaluating desorption kinetics. For phosphorus on silicon, the order of desorption and activation energies of desorption are determined from continuously monitored phosphorus Auger electron signals during heating. These measurements indicate that diatomic phosphorus dissociates when adsorbed onto clean silicon. Mass spectrometer flash desorption spectra show that at least four distinct surface bonds are associated with the desorption of phosphorus. The dominant desorbed species is diatomic phosphorus at high coverage (> 0. 1 monolayer) and atomic phosphorus at low coverage (< 0.07 monolayer)"--Abstract, page ii.

Studies Of Neutron Capture Produced Rare Gas Isotopes In Rocks And Minerals Containing Chlorine, Selenium And Tellurium, David E. Sinclair

Masters Theses

"Noble gas mass spectrometry was used to study rare nuclear processes in terrestrial rocks and minerals. An excess of ³⁶Ar was detected in a chlorine-rich rock. The excess ³⁶Ar has been produced in rocks near the earth's surface due to capture of cosmic-ray-produced neutrons on ³⁵Cl. Measurement of ³⁶Ar formed by the ³⁵Cl(n, γ)³⁶Cl(β^-)³⁶Ar process makes possible a new method for determining the surface residence time of chlorine-rich minerals

Excess ⁸²Kr and excess ⁸³Kr were detected in selenium-rich ores. The excess ⁸²Kr results from double beta …

A Study Of Some Complexometric Titrations In Nonaqueous Solvents, Ngo The Hung

Masters Theses

"Complexometric titrations of calcium, zinc and lead with polyaminocarboxylic acids: ethylenediaminetetraacetic acid (EDTA), 1,2-diaminocyclohexanetetraacetic acid (DCTA), ethyleneglycol-bis(2-aminoethylether)tetraacetic acid (EGTA) and tetraethylenepentamine (tetren) have been investigated and compared in the following organic solvents: methanol, dimethyl formamide, dimethyl sulfoxide and methyl ethyl ketone. Various end point detection methods have been used: direct visual titration with metallochromic indicators and instrumental detection by photometry, potentiometry (mercury electrode and lead ion selective electrode) and amperometry. Calcium, zinc and lead can be determined up to trace levels (ppm) under specific conditions. A concrete application of this thesis is the determination of zinc or calcium in a …

Adsorption Of Dichromate At The Air-Solution Interface, Josephine Juch Wang

Masters Theses

"The adsorption of dichromate ion with the surfactants, tetradecylpyridinium bromide and tetradecyltrimethylammonium bromide at the air-solution interface was studied by surface tension and turbidity measurements in order to better understand the process of ion flotation. Surface tension measurements were used to study the effect of dichromate ion concentration on precipitation in dilute surfactant solutions. At higher concentration, near and above the cmc, light scattering was used to detect precipitation. The concentration of dichromate required to cause precipitation decreases with increasing surfactant concentration until the erne is approached, after which increasing concentrations of dichromate are required with increasing concentration of surfactant. …

The Halogen And Uranium Content Of Sedimentary Rocks, Tektites, Impact Glasses, And Obsidians, Victor J. Becker Jr.

Masters Theses

"The iodine and uranium concentrations in sedimentary rocks were measured by irradiating the samples in a neutron flux, radiochemically separating iodine, and ß-counting the resulting activity. The values obtained for uranium are in good agreement with previous estimates of the uranium content in sedimentary rocks. The values obtained for iodine define a distribution pattern similar to that reported for chlorine and bromine, in contrast with the distribution pattern previously reported for iodine in sedimentary rocks. The concentrations of chlorine, bromine, iodine and uranium were determined in tektites, obsidians and impact glasses by neutron activation. The uranium content found in tektites …

Mass Fraction And The Isotopic Anomalies Of Xenon And Krypton In Ordinary Chondrites, Edward W. Hennecke

Masters Theses

"The abundance and isotopic composition of all noble gases are reported in the Wellman chondrite, and the abundance and isotopic composition of xenon and krypton are reported in the gases released by stepwise heating of the Tell and Scurry chondrites. Major changes in the isotopic composition of xenon result from the presence of radiogenic Xe¹²⁹ and from isotopic mass fractionation. The isotopic composition of trapped krypton in the different temperature fractions of the Tell and Scurry chondrites also shows the effect of isotopic fractionation, and there is a covariance in the isotopic composition of xenon with krypton in the manner …

A Measurement Of The Capture Coefficient And Of The Vapor Pressure Of Co₂ From 69ºk To 80ºk, Michel Louis Chouarain

Masters Theses

"The capture coefficient of CO₂ gas at 135ºK on a surface of CO₂ at temperatures between 69ºK and 80ºK is measured by means of quartz crystal microbalances. The vapor pressure of CO₂ is measured in the same range of temperature"--Abstract, page ii.

The Oxidative Decarboxylation Of Aminopolycarboxylic Acids With Cerium (Iv) In Sulfuric Acid, Rita Kathleen Hessley

Masters Theses

"The rates of oxidation of four chelating agents, NTA, EDTA CDTA, and DTPA with Ce(IV), in sulfuric acid media, were determined spectrophotometrically by a stopped-flow technique. The reductive ability is in the order CDTA>EDTA>DTPA>NTA. The influence of varying the acidity of the medium was studied, and in each case a maximum in the rate constant [H +] plot was observed. A possible interpretation of the reactivities and the influence of acidity is advanced"--Summary, page 1.

A Kinetic Study Of The Reductive Abilities Of Four Polyaminocarboxylic Acids (Edta, Cdta, Dtpa And Nta) Towards Cerium(Iv) In Perchloric Acid Media, Salem Ahmed Attiga

Masters Theses

"The reduction of Ce(IV) in HC10₄ solutions by four polyaminocarboxylic acids, which are commonly used as chelating agents, has been studied by the stopped-flow technique. The rates of reduction first increase with increasing acidity, reach maxima which are characteristic of the chelating agent and the medium, then progressively decrease with increasing the acid concentration in the media. At their maximum reactivities, trans-1,2-diaminocyclohexane tetraacetic acid (CDTA) shows the highest reductive ability; this is followed by ethylenedinitrilotetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), and finally nitrilotriacetic acid (NTA). The observed maxima can be qualitatively explained in terms of a mechanism which involves unhydrolyzed …

A Study Of The Oxygen Exchange Between Chromate Ion And Water, James Hsiao-Hsin Chiang

Masters Theses

"The kinetics of the isotopic exchange reaction between O¹⁸-enriched chromate ion and solvent water have been measured as a function of pH and chromate ion concentration. The exchange kinetics can be explained in terms of the dimerization equilibria HCrO_4̄ + Cr₂O[subscript 7 with double dash above] [double arrows] Cr₂O[subscript 7 with double dash above] + OH⁻ and 2HCrO_4̄ [double arrows] Cr₂O[subscript 7 with double dash above] + H₂O except at high pH, where it is independent of pH. Rate constants at 30ºC for the reactions of the dimerization equilibria and the first order reaction at the high pH …

Enhanced Evaporation Of Water Droplets Due To Surface Contamination, Robert Bernard Hughes

Masters Theses

"Experimental evidence for enhanced evaporation of small (3-9 µ radius) water droplets are presented. Both "pure" droplets and droplets contaminated with surface active materials fell into air of known relative humidity (96-99 per cent) at an ambient temperature of 29.9C and evaporated. The rates of evaporation were determined by photographing the evaporating drops, measuring the distance a drop fell during a fixed time interval, and applying Stokes law. The contaminated droplets exhibited a rate of evaporation 1.8µ² sec⁻¹ faster than "pure" drops. This can be compared with rates for pure drops of 1.9 and 5.7µ² sec⁻¹ at 0.1 and 0.3C …

The Possible Correlation Of Carcinogenic Activity With Electronic Structure Of Benz(A)Anthracene, Patricia Joan Blair

Masters Theses

"The electronic structure of benz(a)anthracene based on the sigma and pi electrons was predicted by the modified intermediate neglect of differential overlap (MINDO) molecular orbital method and compared with the pi electronic structure determined by the Pople method. The crystalline molecular structure was used for both methods. The Pople calculation was also done on the aromatic molecular structure and a combination structure which assumed the bond lengths of the crystal structure and the bond angles of the aromatic structure. Chemical properties predicted by the MINDO and POPLE electronic structures were compared; the MINDO results provided the best agreement with experimental …

Mass Spectrometric Study Of "Anomalous" Water, Bernard Jean Bouy

Masters Theses

"Considerable interest has developed recently in a material called "polywater" or "anomalous water". This material has properties quite different from those normally associated with liquid water. The purpose of this study is to give some mass spectrometric observations of "polywater". The "polywater" samples were produced within silica capillaries. These capillaries were heated by means of a helical coil to vaporize the "polywater". The vapor was directed into the source of a mass spectrometer. The results of this study show that a significant portion of the "anomalous water" samples is composed of a polymer of dimethylsiloxane. To date, the observations are …

The Radial Distribution Curve Of "Anomalous" Water By X-Ray Diffraction, Jerome Dechelette

Masters Theses

"Amorphous and liquid samples, believed to be "anomalous" water were studied by X-ray diffraction. A diffusion ring, characteristic of liquids and glass was observed at Θ =10.5º. For purposes of comparison an X-ray diffraction pattern was obtained for pure water under nearly identical conditions. By means of a microdensitometer, X-ray intensity curves were prepared from the diffraction patterns and corrected for absorption and polarization. From the Fourier transform of the intensities, we obtained the radial distribution curves. The radial distribution curve for water, obtained in previous work, shows an initial peak at 2.9Å. This peak is due to the nearest …

The Anodic Oxidation Of Oxalic Acid On Au, Jean Louis Lucien Desmartin

Masters Theses

"The anodic oxidation of oxalic acid on Au has been studied at 25ºC in aqueous media. The reaction rate was measured as a function of potential, oxalic acid concentration, pH, and temperature in H₂SO₄-K₂SO₄ solutions. A change in the Tafel slope in going from the lower to the higher Tafel region is explained by an alteration of the reaction mechanism due to electrical interactions between adsorbed species and the anode. Further details of an oxidation sequence involving resonant forms of oxalic acid are proposed"--Abstract, page 1.

The Ultraviolet Absorption Spectra Of Solutions Of 2, 4, 6-Trimethoxybenzoic Acid In Sulfuric Acid, Kathy Show-Shing Ho

Masters Theses

"Studies of the ultraviolet and proton magnetic resonance spectra of solutions of 2,4,6-tribromo-, trichloro-, trimethyl- and trinitro-benzoic acids dissolved in concentrated sulfuric acid by Dr. D. W. Beistel and his coworkers lead to the synthesis of the corresponding benzoate esters. In the present work the nature of ionic species formed in mixtures of sulfuric acid and 2,4,6-trimethoxybenzoic acid was examined, The spectral data suggest the presence of species similar to those assigned for the previous trisubstituted analogs, together with a species capable of fluorescence in the 2400 Å region. The reason of this unprecedented fluorescence has not been established"--Abstract, Page …

Metabolism Of 3-Iodotyrosine And 3,5-Diiodotyrosine By Thyroid Extracts, Shih-Ying Sun

Masters Theses

"A porcine thyroid enzyme was extracted from thyroid tissue by homogenization and differential centrifugation. The enzyme was capable of metabolizing both 3-iodotyrosine and 3,5-diiodotyrosine. All of the thyroid subcellular particles produced a fluorescent compound when incubated with these substrates. When the 1,000 x g sediment was supplemented with the 48,000 x g supernatant a second compound was formed. The compound was UV absorbing and has been identified as either 3-iodo-4-hydroxybenzaldehyde or 3,5-diiodo-4-hydroxybenzaldehyde depending upon which substrate was used. The 1,000 x g sediment was solubilized with 1% Conoco 1012-6 detergent. The activating factor in the 48,000 x g supernatant was …

Amino Acid Sequence Of An Iodotyrosyl-Containing Peptide Produced By Tryptic Digestion Of Thyroglobulin, Pai-Chun Chiang

Masters Theses

"Thyroglobulin was digested with trypsin. An iodotyrosyl-containing peptide was isolated from tryptic digests by a combination of electrophoresis and paper chromatography. The amino acid sequence of this peptide was determined by applying the Edman degradation and by using the proteolytic enzyme, carboxypeptidase A. The sequence of this peptide is: NH₂-Ala-Ile(Leu)-Ala-Ser-Phe-Gly-Asp-Tyr-Glu-Phe-COOH The importance of the position of the tyrosyl residue which is iodinated to form monoiodotyrosine (MIT) , diiodotyrosine (DIT) , and thyroxine (T₄) is considered in connection with the structure-activity relationship of the protein"--Abstract, page ii.

The Semibullvalene Question: A Semi-Empirical Molecular Orbital And Bond Energy Approach, Shiow Yeh Lee

Masters Theses

"Semi-empirical molecular orbital calculations of the Extended Ruckel and MIND0/1 type have been performed on semibullvalene and the supposed transition state for its degenerate [3,3] sigmatropic rearrangement. The results have been coupled with bond energy calculations to ascertain whether semibullvalene is homo-aromatic or is undergoing a rearrangement of exceedingly low activation energy. A preponderance of the resulting data suggests that semibullvalene is homo-aromatic"--Abstract, page ii.

Isotopic Anomalies Of Noble Gases In Natural Gas, Garry A. Bennett

Masters Theses

"This investigation of the abundance and isotopic composition of noble gases in helium-rich gas wells was undertaken in order to obtain new data which might be used to elucidate the origin of isotopic anomalies of noble gases in the atmosphere. Since noble gases are presently leaking to the atmosphere (Damon and Kulp, 1958a; Bieri et al., 1967-) the isotopic composition of the present atmosphere is not static. The direction of change, and ultimately the origin of anomalous noble gases, might therefore be discovered in studying the noble gases presently leaking from the earth. Since the two major noble gas isotopes …

The Incorporation Of Oxygen-18 Into Oxindole Acid By Cells Of Hygrophorous Conicus, William Green Allen

Masters Theses

"To understand the mechanism of a biological oxidation in which oxygen is incorporated into a substrate, it is necessary to determine the origin of the incorporated oxygen. The objective of this investigation was to determine the origin of the oxygen atom incorporated into indoleacetic acid (IAA) by the IAA oxidase of Hygrophorous conicus through the use of oxygen-18. To determine the source of the oxygen atom incorporated into IAA it is necessary to incubate H. conicus cells with tryptamine or IAA in the presence of ¹⁸O₂ and H₂¹⁶O in one case and ¹⁶O₂ and H₂¹⁸O in another. An examination of …

Thermochemical Investigations Of The Methanol-Isopropanol System, Elmer Lee Taylor

Masters Theses

"Heats of solution and partial molar excess volumes at infinite dilution were determined for n-butanol, acetone, chloroform, and water in pure methanol, pure isopropanol, and several mixtures of the two at 25.0⁰C. The partial molar excess enthalpies of methanol and isopropanol were also determined and were combined to obtain integral heats of mixing. All heat data were obtained using a calorimeter of the heat-leak design, containing approximately 300 ml of solvent. Sample sizes ranged for 0.1 to 8 ml. Individual heat measurements were reproducible to 0.05 calories and reported values are considered to be accurate to 1% + 0.5 calorie …

Michael Reactions Part Iv Syntheses With Carboalkoxycarbenes, Frederick Ralph Carman

Masters Theses

"A preliminary investigation has been made involving syntheses with dicarboalkoxycarbenes for the purpose of developing new heterocyclic and alicyclic synthese employing functionalized carbenes. The ultimate goals were the development of a stereospecific synthesis of trans fused and angularly substituted ring systems suitable for conversion to natural products and the development of useful synthetic paths to the azabullvalene system. Although these ultimate goals were not realized, new and improved syntheses of alkyl substituted anisoles and diazomalonic esters, including the first reported synthesis of di-tert-butyl-diazomalonate were accomplished. The addition of dicarboalkoxycarbenes to di-, tri- and tetra- substituted ethylenes, tropilidene and 7-aza-tropilidenes by …

A Study Of Solvent Effects On The Reaction Between P-Nitrobenzyl Chloride And Hydroxide Ion In Aqueous Dioxane Homogeneous Media, Ken K. Ho

Masters Theses

"The kinetics and activation parameters of the reaction between p̲, p̲' - dinitrostilbene quantitatively, have been studied in five aqueous dioxane solvent systems at five different temperatures between 20⁰ and 40⁰C. At any one temperature the second-order rate constants are minimum in the 30% dioxane solvent mixture, reach a maximum in the 50% dioxane systems, and fall off slightly in the 60% and 70% dioxane systems. The Arrhenius activation energies are highest in the 30% dioxane and lowest in the 70% dioxane systems. The free energies of activation change in the same direction but the magnitude of change is much …

Surface Interactions Between Nickel Ions And Sodium Dodecyl Sulfate, Ralph Edward Coleman

Masters Theses

"In this research the interaction of nickel ions with the surfactant sodium dodecyl sulfate at the liquid-air interface was studied. Surface tension measurements were performed on pure sodium dodecyl sulfate solutions, with and without the addition of nickel ions. Results of these measurements showed that the addition of nickel ions lowered the equilibrium surface tension values of pure sodium dodecyl sulfate solutions and shifted the critical micelle concentration to lower concentrations. The foam fractionation technique was used to determine if the nickel ions could be removed from surfactant solutions. It was found that the removal of nickel ions was influenced …

The Effect Of Impurities On The Time Dependence Of The Surface Tension Of Aqueous Surfactant Systems, Elizabeth Ann Munson

Masters Theses

"In this study surface tension measurements were made on tetradecylpyridinium bromide (TPB) solutions both in water in solutions containing various concentrations of impurities. Three impurities were studied, dodecyl alcohol, decyl alcohol and dodecylpyridinium bromide. Surface tension vs. time plots were constructed and show a definite dependence on the concentration of the impurity added. As the concentration of the impurity increases the equilibrium surface tension decreases. The decrease in the equilibrium surface tension is also dependent upon the concentration of the tetradecylpyridinium bromide. As the concentration of the surfactant (TPB) increases the effect of the impurity is reduced"--Abstract, page i.

Endogenous Metabolism Of Polyporus Sulfureus. : Utilization Of Exogenous Carbohydrates And Fatty Acids, Shu-Mei Wang

Masters Theses

"A strain of Polyporus sulfureus from the collection at the University of Missouri at Rolla was used in this investigation. Organisms of this genus have been reported to produce eburicoic acid in good yield and this was confirmed for the organism used in this study by the isolation and identification of eburicoic acid from the mycelium. Growth studies of this organism showed that 4% malt extract is a better medium than synthetic media containing asparagine, nitrate or nitrate plus 0.5% yeast extract as nitrogen sources. An examination of the pH of the culture medium led to the conclusion that regardless …

Geochemical Abundance Of Iodine, Jane Hanisch Bennett

Masters Theses

"The research reported herein includes unpublished iodine and uranium data on a group of United States Geological Survey standards and on a group of ultrabasic rocks. Data are also included for the major rock types, deep sea sediments, and for graphite and troilite inclusions in iron meteorites. Tellurium data for the troilite are also reported. Appendix I is a literature article (Bennett and Manuel, 1967a) on Canyon Diablo Graphite. Appendix II is a literature article (Bennett and Manuel, 1967b) on deep sea sediments. The results of this study show that most of the earlier estimates of the crustal abundance of …

A Kinetic Investigation Of The Reaction Of Ethylenedinitrilotetraacetic Acid (Edta) And Cerium (Iv) In Acid Solution, Sahmia K. Al-Hashimi

Masters Theses

"The reaction between Ce(IV) salt solutions and EDTA solution was followed titrimetrically and spectrophotometrically and found to occur in stages. Four equivalents of Ce(IV) are reduced per mole of EDTA almost instantaneously at room temperature or even lower. With increasing temperature and reaction time an ultimate of about 14 equivalents of Ce(IV) is consumer per mole of EDTA. Formaldehyde, carbon dioxide, and other unidentified compounds are the products of oxidation of EDTA with Ce(IV). The kinetics of the reaction in aqueous sulfuric acid (0.09 - 2.95 M̲) was studied over the temperature range 11.7-40⁰ by a spectrophotometric technique. In the …