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Full-Text Articles in Physical Sciences and Mathematics

The Possible Correlation Of Carcinogenic Activity With Electronic Structure Of Benz(A)Anthracene, Patricia Joan Blair Jan 1970

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 …


Amino Acid Sequence Of An Iodotyrosyl-Containing Peptide Produced By Tryptic Digestion Of Thyroglobulin, Pai-Chun Chiang Jan 1970

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.


Enhanced Evaporation Of Water Droplets Due To Surface Contamination, Robert Bernard Hughes Jan 1970

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 …


A Study Of The Oxygen Exchange Between Chromate Ion And Water, James Hsiao-Hsin Chiang Jan 1970

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 + Cr₂O[subscript 7 with double dash above] [double arrows] Cr₂O[subscript 7 with double dash above] + OH⁻ and 2HCrO [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 …


Metabolism Of 3-Iodotyrosine And 3,5-Diiodotyrosine By Thyroid Extracts, Shih-Ying Sun Jan 1970

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 …


The Semibullvalene Question: A Semi-Empirical Molecular Orbital And Bond Energy Approach, Shiow Yeh Lee Jan 1970

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.


The Radial Distribution Curve Of "Anomalous" Water By X-Ray Diffraction, Jerome Dechelette Jan 1970

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 Ultraviolet Absorption Spectra Of Solutions Of 2, 4, 6-Trimethoxybenzoic Acid In Sulfuric Acid, Kathy Show-Shing Ho Jan 1970

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 …


Mass Spectrometric Study Of "Anomalous" Water, Bernard Jean Bouy Jan 1970

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 Anodic Oxidation Of Oxalic Acid On Au, Jean Louis Lucien Desmartin Jan 1970

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.