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Articles 33361 - 33390 of 34521
Full-Text Articles in Physical Sciences and Mathematics
Synthesis Of N-Methyl-D-Gulosamine And Methyl Ethers Of N-Methyl-D-Gulosamine, Hazrat Mohammed Noorzad
Synthesis Of N-Methyl-D-Gulosamine And Methyl Ethers Of N-Methyl-D-Gulosamine, Hazrat Mohammed Noorzad
University of the Pacific Theses and Dissertations
A great variety of amino sugars has been found in antibiotics among these D-gulosamine in the striptomyces group. In the same group, .an N-methylated amino-sugar, N-methyl-L~ glucosamine has been isolated. Although N-methyl-0-gulosamine .has not been found in nature until now, its ultimate discovery would not be surprising in this context. In the present work this amino-sugar and some important derivatives are prepared for the first time, starting from D-glucosamine, a pure benzyl· 3-0-acetyl-2-benzyloxycarbonylamido-2-deoxy-~-D-glucopyranoside (X) was obtained by a series of kno~n processes. Benzyl 3-0-acetyl~-methylsulfonyl-2-deoxy-~-D-glucopyranoside (XIII) and some of its derivatives were obtaine.d from (X). An attempt was made to obtain …
A Polarographic Study Of Selected Metal Complex Ions Of Several P-Tosyl Amino Acids, Joseph Martin Reyes
A Polarographic Study Of Selected Metal Complex Ions Of Several P-Tosyl Amino Acids, Joseph Martin Reyes
University of the Pacific Theses and Dissertations
A polarographic study of the complexes of selected metal ions and the p-Tosyl derivatives of the amino acids; glycine, glutamic acid and lysine has been made to determine their coordination number, formula, dissociation constant and free energy of formation.
The Effect Of Charged Interfaces On The Ionic Distribution In Solution, Myron Elliot Feinstein
The Effect Of Charged Interfaces On The Ionic Distribution In Solution, Myron Elliot Feinstein
Dissertations, Theses, and Capstone Projects
No abstract provided.
Study Of Resonance Effects In Allenic And Related Systems, Robert Andrew Steinkamp
Study Of Resonance Effects In Allenic And Related Systems, Robert Andrew Steinkamp
Doctoral Dissertations
"In order to investigate the possibility of resonance effects through a non-coplanar substituted acetylene, synthesis of bis-(2,5,8-trimethyl-l-naphthyl)-acetylene was attempted. Condensation of acetylene with 2,5,8-trimethyl-l-tetralone to yield an acetylenic glycol followed by dehydration and dehydrogenation was expected to yield the desired non-coplanar acetylene. Comparison of its ultraviolet spectrum with that of di-l-naphthyl-acetylene would have suggested the true nature of the acetylene pi cloud. The acetylene condensation was unsuccessful, however.
Substituted allenes, which contain one sp hybridized carbon atom, were then successfully synthesized for a similar analysis of potential resonance effects. A series of para-substituted 4-phenyl-2-methylbutadienoic acids were synthesized and their pKa's …
Mechanisms Of Base-Catalyzed Reactions: Part Iii: The Acidities Of Some Hydroxylic Compounds In T-Butyl Alcohol., Charles Frederick Seger
Mechanisms Of Base-Catalyzed Reactions: Part Iii: The Acidities Of Some Hydroxylic Compounds In T-Butyl Alcohol., Charles Frederick Seger
Masters Theses
"The KHA of water and five alcohols were determined in t̲-butyl alcohol employing sodium and potassium t̲-butoxides. The order of acidity is methanol>water>ethanol> 2-propanol~cyclohexanol>methanol. It was also shown that potassium t̲-butoxide was twice as strong a base as sodium t̲-butoxide. A spectrophotometric method was employed with p-nitroaniline as the indicator. Calculations were made employing the methods of Stearns and Wheland and of Hine and Hine"--Abstract, page iii.
Noble Gases In The Earth And Its Atmosphere, Robert Anthony Canalas
Noble Gases In The Earth And Its Atmosphere, Robert Anthony Canalas
Masters Theses
"Abundance of noble gases extracted from Fig Tree Shale exhibit a marked deviation from the gas content of eclogitic rocks purported to be mantle material. The abundances of the heavy noble gases in shale were found to exceed the highest known meteoritic values. The abundances of the lighter noble gases were found to be comparable to the abundances of these gases in typical chondrites.
Temperature gradient analyses show that excess heavy gases are released at low temperatures. This is interpreted to indicate a preferential adsorption of the heavy noble gases on fine-grained sediments when these gases were being released from …
A Study Of The Complexes Of Diketocyclobutenediol, Stewart Michael Condren
A Study Of The Complexes Of Diketocyclobutenediol, Stewart Michael Condren
Masters Theses
"In this study of the complexes of diketocyclobutenediol, squaric acid, the following original compounds were prepared: zirconyl squarate, indium (III) squarate; titanium (III) squarate, ruthenium (III) squarate, tungsten (VI) squarate, vanadium (III) squarate, and niobium (V) squarate, where squarate refers to the dianion of diketocyclobutenediol. Metal analyses were made on all of these except the ruthenium. However, only three of these metal analyses, namely those for titanium (III) squarate, indium (III) squarate, and zirconyl squarate, warrented [sic] further investigation. Carbon and hydrogen analyses were then made for these three compounds. From the percentage compositions, possible structures were proposed.
The tungsten, …
The Separation Of Optical Isomers By Gas Chromatography, Donald Ellis Carpenter
The Separation Of Optical Isomers By Gas Chromatography, Donald Ellis Carpenter
Masters Theses
"The purpose of this investigation was to study the separation of optical isomers by gas chromatography. An optically inactive solid support was coated with an optically active substrate. Racemic compounds were used as samples. The optically active packing materials tried were d-tartaric acid, d-diethyl tartrate, sucrose, d-camphoric acid, d-camphor-10-sulfonic acid, α -methyl-D-glucoside and L-(α)-glutamic acid.
Racemic compounds that were tried included 2-butanol, 3-methyl- 2-butanol, 2-methyl-1-butanol, 2-octanol, 2-bromooctane, 2-methoxy-octane, methyl-2-bromobutyrate, and 3-methylhexane.
It was found that racemic compounds could be separated by using an optically active material for packing in the gas chromatographic columns. Racemic 2-butanol, 3-methyl-2-butanol, and 2-methyl-1- butanol were …
Preparation And Spectra Of Some New Alkyl Ammonium Salts Of The Tetrachlorocuprate (Ii) Ion., Paul Douglas Griffin
Preparation And Spectra Of Some New Alkyl Ammonium Salts Of The Tetrachlorocuprate (Ii) Ion., Paul Douglas Griffin
Masters Theses
"Several compounds containing the complex tetrachlorocuprate(II) anion, CuCl₄=, and various alkyl or aryl cations were prepared. These include bis(methylammonium)tetrachlorocuprate(II), bis(isopropylammoniumtetrachlorocuprate(II), 1,3-propanediammoniumtetrachlorocuprate(II), bis(furfuryl-ammonium)tetrachlorocuprate(II), and a series of ethylene ammonium salts. Some unsuccessful and difficult preparations are described. Spectra were taken in acetone, 4-butyrolactone, and methanoleaf An explanation of the effects of various solvents on the absorption spectrum and structure of the complex ion is given"--Abstract, page ii.
Vapor Pressure And Heat Of Sublimation Of Gallium Acetylacetonate, Arthur John Massey
Vapor Pressure And Heat Of Sublimation Of Gallium Acetylacetonate, Arthur John Massey
Dissertations, Theses, and Masters Projects
No abstract provided.
Studies In Coprecipitation Of Trace Amounts Of Elements, Gerald Delano Schucker
Studies In Coprecipitation Of Trace Amounts Of Elements, Gerald Delano Schucker
Masters Theses
"A new approach to preconcentration of trace amounts of elements has been demonstrated whereby traces of metals tied up as chelates are coprecipitated on a column of solid organic material. Complete coprecipitation was found to occur within very narrow pH ranges, thereby allowing separation as well as concentration of the elements by careful adjustment of acidity and concentration of chelating agent. The separation is based on the difference in stability constants of the metal chelates. Preliminary studies with different physical forms of the carrier precipitate, indicate adsorptive processes could play a significant role in the mechanism of the column-coprecipitation process. …
Basic Iron (Iii) Alkanoate Complexes, Young Hee Kim
Basic Iron (Iii) Alkanoate Complexes, Young Hee Kim
Masters Theses
"Much information appears in the literature concerning the preparation, properties and structure of the basic iron (III) acetates...This study was initiated to prepare a number of the basic trinuclear iron (III) alkanoate complexes and to investigate the possibility of a common structure for all of these as suggested by the work of Orgel. The structural investigation was done on the basis of stoichiometric relationships, infrared spectra and magnetic moments"--Abstract, pages ii-iii.
An X-Ray Study Of The Lead Titanate-Bismuth Chromate System, Tsen-Tsou Shih
An X-Ray Study Of The Lead Titanate-Bismuth Chromate System, Tsen-Tsou Shih
Masters Theses
"The lead titanate-bismuth chromate system was studied employing x-ray diffraction techniques at both room and high temperatures. Samples were prepared by sintering stoichiometric mixtures of the corresponding oxides followed by air quenching. Bismuth chromate was prepared by resintering and air quenching for four times. The results of the analyses show the structure of BiCrO₃ to be tetragonal with 8 molecules per unit cell. Solid solutions exist over the range 100 to 35 mole percent PbTiO₃ of the binary system, although small amounts of other phases are present in some regions. X-ray data at room temperature indicate the tetragonal perovskite structure …
The Acidic Transformaion Products Of Indoles Formed By Basidiomycetes, Chung-Ke Chang
The Acidic Transformaion Products Of Indoles Formed By Basidiomycetes, Chung-Ke Chang
Masters Theses
"A survey of the ability of basidiomycetes to convert tryptophan, tryptamine and indole acetic acid to other acidic indoles has been made.
The product formed from tryptamine by Tricholoma nudum was identified as indole acetic acid. The product formed by Cantharellus cibarius from D-tryptophan was identified as N-acetyl-D-tryptophan. The products were purified and identified by means of paper chromatography, thin layer chromatography, infrared spectroscopy and melting points.
The conversion of tryptamine and D-tryptophan was also studied in cultures of Leucopaxillus paradoxus, Hygrophorus conicus and Naucoria confragosa. H. conicus, L. paradoxus and N. confragosa transformed tryptamine and indole acetic acid into …
An Investigation Of The Reaction Of Benzhydryl Chloride With Potassium T-Butoxide In Dmso, Lawson Gibson Wideman
An Investigation Of The Reaction Of Benzhydryl Chloride With Potassium T-Butoxide In Dmso, Lawson Gibson Wideman
Masters Theses
"The ultimate aim of this study was to elucidate the mechanism of formation of tetraphenylethylene from benzhydryl chloride and potassium t-butoxide in dimethyl sulfoxide. The development of a suitable technique for following the reaction rate and of an analytical method to determine the extent of the reaction became an important object in this project"--Introduction, page 2.
The Study Of The Metal Complexes Of Alpha Aminohydroxamic Acids, Richard N. Nipe
The Study Of The Metal Complexes Of Alpha Aminohydroxamic Acids, Richard N. Nipe
Masters Theses
Introduction
The objectives of this investigation were to develop: 1) compounds similar to hydroxy urea, a compound known to have anti-tumor activity, 2) a method to prepare α-aminohydroxamic acids and to study the complexes of these compounds with several metal ions, 3) computer programs to determine the pK's1 of the hydroxamic acids and the stepwise stability constants2 for the ligands and several metal ions.
The values obtained for the stability constants were compared with values for the stability constants of acetohydroxamic acid and α-aminocarboxylic acids in an attempt to find which in the ligand formed bonds with the …
Host And Prophage Modifications Of Ultraviolet Induction In Salmonella Potsdam, Bela B. Toth
Host And Prophage Modifications Of Ultraviolet Induction In Salmonella Potsdam, Bela B. Toth
Loma Linda University Electronic Theses, Dissertations & Projects
In induction experiments with naturally occurring and artificially lysogenic strains of S. potsdam, cells were irradiated in buffer, transferred to complete medium, and then assayed for free phage. Irradiation was followed by half hourly samples for free phage from the growing populations of irradiated cells. For an estimation of burst sizes, the irradiated cells were diluted out to a final concentration of 1 cell per ml and distributed to tubes in 0.5 ml quantities. All assays were done by the top-layer method with streptomycin incorporated in the top-layer and SP2-strr as the bacterial indicator. The non-lysogenic strain S. …
8th Annual Meeting Rocky Mountain Spectroscopy Conference
8th Annual Meeting Rocky Mountain Spectroscopy Conference
Rocky Mountain Conference on Magnetic Resonance
Program and abstracts from the 8th annual meeting of the Rocky Mountain Spectroscopy Conference, sponsored by the Rocky Mountain Section of the Society for Applied Spectroscopy. Held in Denver, Colorado, August 8-9, 1966.
A Method For The Determination Of Trace Metals In Carbon By Atomic Absorption Spectroscopy, Leo Francis Meyer
A Method For The Determination Of Trace Metals In Carbon By Atomic Absorption Spectroscopy, Leo Francis Meyer
Master's Theses
The object of this research was to develop an accurate, rapid and economical method for determining trace amounts of metals in carbons, especially in activated carbons designed as gas adsorbents. More specifically, the investigation was directed primarily to the determination of K, Ca, and Fe in Carbons
Dimethyl Sulfoxide Oxidation Of Primary Alcohols, Carmen Vargas Zenarosa
Dimethyl Sulfoxide Oxidation Of Primary Alcohols, Carmen Vargas Zenarosa
Masters Theses
Historical
A method of selective oxidation of primary and secondary alcohols to the corresponding aldehydes and ketones has been developed recently, namely the use of dimethyl sulfoxide (DMSO) as the oxidizing agent, either alone or with dicyclohexylcarbodiimide (DCC)14, acid anhydrides1, or alkyl chloroformates10. The negatively polarized oxygen atom of the sulfoxide group in DMSO is ideally situated for a transfer to many electron-deficient substrates. The oxygen of the alcohol coordinates with the sulfur atom of DMSO through its oxygen atom; this is followed by β-elemination of dimethyl sulfide, thereby resulting in oxidation of the …
Synthesis Of A Substituted Tetrahydropyrimidopyrimidine, Jack Lee Parsons
Synthesis Of A Substituted Tetrahydropyrimidopyrimidine, Jack Lee Parsons
Masters Theses
Introduction
The purpose of this research was to develop a generalized synthesis of substituted tetrahydropyrimidopyrimidines. It was also of interest to prepare related compounds for the purpose of structure determination.
We were interested in tetrahydropyrimidopyrimidines as possible folic acid antagonists.
Studies On The Preparation Of Tetrasubstituted Hydrazones, William Kao
Studies On The Preparation Of Tetrasubstituted Hydrazones, William Kao
Masters Theses
Introduction
In a recent study of the ultraviolet spectra of substituted hydrazones, it was concluded that a sterio effect existed in tetrasubstituted hydrazones that significantly hindered complete rotation about the nitrogen-nitrogen bond. Weber16 noted that di- and tri-substituted hydrazones exhibited similar spectra with three strong absorption bands at approximately 235, 300, and 340 mu. In acid solutions, the spectra of these compounds showed a marked decrease in intensity of the long wavelength band. It has been postulated that this change was a consequence of the protonation of the non-bonding electron-pair on the amino nitrogen atom, and thus correlated the …
The Application Of The Verwey-Overbeek Theory To The Relative Sediment Volume Of Kaolin-Water Dispersions, James E. Kline
The Application Of The Verwey-Overbeek Theory To The Relative Sediment Volume Of Kaolin-Water Dispersions, James E. Kline
Masters Theses
Introduction
This paper describes an investigation intended to: 1. observe the effect of electrolyte concentration on the stability of kaolin-water systems, 2. evaluate the relative sediment volume measurement as a tool for determining the stability of such systems, 3. assess the applicability of the Verwey-Overbeek theory of stability of lyophobic colloids for predicting the observed effects, and 4. determine if any correlation exists between the effects predicted by the theory and observed through the relative sediment volume measurement.
The relative sediment volume measurement will be shown to be dependent upon the efficiency of packing of the pigment particles, which in …
Isolation Of A Toxic Substance From Centaurea Repens, Merton E. Sprengel
Isolation Of A Toxic Substance From Centaurea Repens, Merton E. Sprengel
Loma Linda University Electronic Theses, Dissertations & Projects
A poisonous steroid-type compound was isolated from Centaurea repens. After extraction with absolute ethanol, removal of the solvent, addition of 2% HCl to precipitate the pigments, and filtering, the pH was adjusted to 9 with aqueous anunonia. This solution was exhaustively extracted with chloroform, evaporated to dryness, and extracted with ethyl ether.
This fraction was chromatographed on silica-gel plates, using 10:1 1,2-dichloroethane-methanol as the developer. The band at Rf 4.2 was removed and found toxic to mice. Labored, slow, gasping respiration and frequent involuntary muscular contractions became apparent within a few minutes following the intraperitoneal injection into each animal. Death …
Development, Verification, And Use Of Methods To Model Chemical And Thermal Processes Lakes Mead And Powell, Bureau Of Reclamation
Development, Verification, And Use Of Methods To Model Chemical And Thermal Processes Lakes Mead And Powell, Bureau Of Reclamation
Publications (WR)
PURPOSE
The purpose of the proposed research is to quantify the effects that Lakes Mead and Powell have on the salinity in the Colorado River system, and to evaluate changes that cap be made to the operating system of the reservoirs (within legal/institutional constraints) to enhance salt precipitation and/or minimize evaporation within the reservoirs. The effect of any changes (i.e., selective withdrawal uses, pumped storage, etc.) on reservoir evaporation could also be evaluated with a goal of minimizing evaporation. This will be accomplished through the development of a mathematical model of the reservoirs as described below.
BACKGROUND
Two major problems …
Potential Neoplasm Inhibitors Ii, Ronald Lee Floyd
Potential Neoplasm Inhibitors Ii, Ronald Lee Floyd
Master's Theses
No abstract provided.
A Study Of The Base Catalyzed Decompositions Of Azoacetates, David V. Herman
A Study Of The Base Catalyzed Decompositions Of Azoacetates, David V. Herman
Masters Theses
Introduction
The formation of a benzyne intermediate has been shown by several investigators (2,5,6) to be developed in at least four different reactions; the reaction of o-dihalobenzenes with magnesium or lithium, aryl halides with strong nucleophiles, o-halobenzophenones with potassium amide in liquid ammonia, and the decomposition of benzenediazonium-2-carboxylate.(13) The mechanism propsed for one of the above most relevant to the following study, the reaction of o-halobenzophenones with potassium amide in liquid ammonia, is outlined in the following sequence:
Liquid Scintillators. The Stability Of Organic Scintillator Solutes Toward Ultra-Violet Radiation. The Photooxidation Of 2, 5-Diphenyloxazole., Harold A. Mackay
Liquid Scintillators. The Stability Of Organic Scintillator Solutes Toward Ultra-Violet Radiation. The Photooxidation Of 2, 5-Diphenyloxazole., Harold A. Mackay
Chemistry and Chemical Biology ETDs
An insight has been gained concerning the stability of organic scintillator solutes in toluene on exposure to ultraviolet light while in the presence of oxygen and water. Oxygen and water, from either solute or solvent, not only function as quenchers but may continue to react with the solute molecule via a photooxidation process. Removal of these materials from the 2, 5-diphenyloxazole toluene system resulted in a marked improvement in stability of the system on exposure to ultraviolet light. The choice of scintillator solute, in addition to water and oxygen, and the time of ultraviolet irradiation, has a pronounced effect on …
The Toluene-Aluminum Chloride-Hydrogen Chloride Complex, William Spencer Cassedy
The Toluene-Aluminum Chloride-Hydrogen Chloride Complex, William Spencer Cassedy
Honors Theses
It was the aim of the project to: 1- Develop analytical techniques to determine the relative amounts of the aluminum chloride, hydrogen chloride, and toluene in the dark liquid catalyst. 2 - Determine the change in the relative amounts of aluminum chloride, hydrogen chloride, and toluene with time as the addition of hydrogen chloride was discontinued and the reaction mixture was left standing, prot cted fro moisture by a drying tube.
Synthesis Of 2--Aryl--Tetrahydro--3--Methyl--4--H--1,3--Thiazine--4--One--1,1--Dioxides And Chloromrthylation Of P--Dichloro-Benzene, Robert Nye Downer
Synthesis Of 2--Aryl--Tetrahydro--3--Methyl--4--H--1,3--Thiazine--4--One--1,1--Dioxides And Chloromrthylation Of P--Dichloro-Benzene, Robert Nye Downer
Honors Theses
Extensive background material and experimentation on the synthesis of 2--aryl--tetrahydro--3--methyl--4--H--1,3--thiazine--4--one--1,1--dioxides and chloromrthylation of p--dichloro-benzene.