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Articles 1 - 30 of 33
Full-Text Articles in Physical Sciences and Mathematics
Cationic And Anionic Micellar Catalyzed Hydrolysis Of Hydroxamic Acids, Douglas Eugene Conran
Cationic And Anionic Micellar Catalyzed Hydrolysis Of Hydroxamic Acids, Douglas Eugene Conran
Masters Theses
The hydrolysis of octanohydroxamic and N-methyloctanohydroxamic acids in the presence of cationic and anionic micelles was investigated. Rate constants were determined for the hydrolyses in cetyltrimethylammonium bromide (ctab), the cationic surfactant, with 0.1111 N NaOH and in sodium 1-dodecanesulfonate, the anionic surfactant, with 0.09270 N HC1 at 50.01 + 0.11°C. The acid hydrolysis and the base hydrolysis of N-methyloctanobydroxamic acid followed the standard model for micellar catalysis.
The Synthesis Of Potential Insecticides: Haloalkoxy Phenyl Diacylydrazines And 1,3,4-Oxadiazoles, Kathleen S. Gibbs-Rein
The Synthesis Of Potential Insecticides: Haloalkoxy Phenyl Diacylydrazines And 1,3,4-Oxadiazoles, Kathleen S. Gibbs-Rein
Retrospective Theses and Dissertations
The syntheses of two classes pf compounds, diacylhydrazines and 2,5-disubstituted 1,3,4-oxadiazoles, intended for subsequent investigation of pesticidal activity are discussed. The experimental conditions and procedures necessary for the preparation of these potential insecticides are also revealed. Finally, spectral data are interpreted and explained, and recommendations for further research are given.
Part I: The Synthesis Of New Potential Insecticides. Part Ii: New Aromatic Nucleophililic Subsitution Reactions, Fluoroalkoxylation And N,N-Dimethylamination, Cesar Colon
Retrospective Theses and Dissertations
A series of routes are described for the synthesis of new potential insecticides which are symmetrical or asymmetrical similogs of 2,5-Bis (dichloropheny1)-1,3,4-oxadiazole and its precursor diacyl hydrazine. Also two new aromatic nucleophilic substitution reactions are discussed. Activated aryl halides are reacted with fluorinated alkoxide anions. In all cases, substitution of the halogen by a fluoroalkoxy group was observed, and activated aryl halides are reacted with HMPA as an N, N-dimethyl aminating agent. In all cases, substitution of the halogen by a dimethyl amino group was observed. The effect of the activating group and the leaving group is described and a …
Synthesis Of Potential Agrochemicals And Reactions Of Vinamidinium And Azavinamidinium Salts With Organometallic/Borane Reagents And Activated Nitrales, Charles N. Moorefield
Synthesis Of Potential Agrochemicals And Reactions Of Vinamidinium And Azavinamidinium Salts With Organometallic/Borane Reagents And Activated Nitrales, Charles N. Moorefield
Retrospective Theses and Dissertations
This report discusses research which was conducted in two areas: the synthesis of potential agrochemicals and the study of vinamidinium and azavinamidinium salt chemistry. Four classes of compounds were synthesized and characterized in the study of new potential agrochemicals. These compounds include diacylhydrazines, semicarbazides, 2,5-disubstituted-1,3,4-oxadiazoles and bis-2,5-disubstituted-1,3,4-oxadiazoles. The reaction of [3-(dimethylamino)-2-azaprop-2-en-1-ylidene] dimethylammonium chloride (Gold's reagent) with organometallic/borane reagents was examined in efforts to find convenient syntheses for N,N-dimethylamino substituted alkyl and aryl compounds. Additionally, the reaction of 1,5-diazapentadienium chloride (Nair's reagent) with nitrile activated alkanes was examined to find a convenient synthesis of 3-substituted pyridines. Subsequent intramolecular ring closure of …
Solvents For Use In The Extractive Distillation Of Piperylene Concentrate, Abdulhadi Sagga
Solvents For Use In The Extractive Distillation Of Piperylene Concentrate, Abdulhadi Sagga
Retrospective Theses and Dissertations
This report describes an evaluation of the effectiveness of different solvents and solvent-organometallic compound mixtures for use in the extractive distillation of a piperylene mixture, consisting of five carbon olefins and diolefins obtained as a byproduct from an ethylene feedstock production plant. The most effective solvent is judged to be the one which gives the best separation of the lowest boiling and highest boiling points of the key components in the mixture. In this study twenty solvents and solvent mixtures were tested. Acetonitrile was found to be the most effective solvent and nitromethane the next most effective.
Determination Of N,N'-Diphenylguanidine In Biological Tissues And Fluids Using High Pressure Liquid Chromatography, Edward Sidney Hunter Iii
Determination Of N,N'-Diphenylguanidine In Biological Tissues And Fluids Using High Pressure Liquid Chromatography, Edward Sidney Hunter Iii
Chemistry & Biochemistry Theses & Dissertations
N,N'-Diphenylguanidine (DPG) is a potentially toxic compound used in the vulcanization of rubber products. Distribution of DPG in hybrid mice (C57BL/6J interbred with DAB2) was determined following intraperitoneal injection. Urine, fecal material, whole blood and tissues were collected at various times after administration of DPG and the extracts analyzed for DPG by high pressure liquid chromatography. Recovery of DPG from spiked urine and whole blood exceed 90%, however, the recovery of DPG from spiked tissue samples was approximately 70%.
DPG concentration in whole blood reached a maximum within ten minutes and rapidly decreased through 180 minutes after administration …
A Microprocessor Controlled Pulsed Hollow Cathode Lamp For An Atomic Absorption Spectrometer, James B. Schilling
A Microprocessor Controlled Pulsed Hollow Cathode Lamp For An Atomic Absorption Spectrometer, James B. Schilling
Masters Theses
A Jarrell-Ash Atomic Absorption/Flame Emission 82-360 Spectrometer was interfaced to a Heathkit ETA-3400 microprocessor. The microprocessor is used to pulse the hollow cathode lamp from a "steady" current to a "peak " current during the opening of the chopper. The current from the photomultiplier-tube is converted to a proportional voltage which is supplied to a sample-and-hold circuit. A successive approximation routine is used to convert the voltage to a representative digital value. Digital values are obtained for the "blank" and "sample" and are used to calculate percent absorption values. The system can also be used to obtain emission values.
The …
The Products Of The Gas Phase Ozonolysis Of Tetramethylethylene, Anthony R. Deangelo
The Products Of The Gas Phase Ozonolysis Of Tetramethylethylene, Anthony R. Deangelo
Honors Theses
The products of the ozonolysis of tetramethylethylene (TME) in the gas phase was studied. Reactions were run at concentrations between 10 and 400ppm TME and lower concentrations of ozone. The reactions were run at room temperature and atmospheric pressure. Gaseous products were studies by gas chromatography, mass spectrometry and HPLC analysis, the latter using 2, 4-dinitrophenylhydrazine derivatives of carbonyl products. Ozone concentrations and the determination of possible peroxidic products was accomplished by measuring the absorbance of a buffered KI solution (352 nm) after reaction with a known volume of gas. The possibility of acetone/ ozone and TME/ peroxides reactions were …
Fluorescence Quenching Of Peptidyl Tryptophan By External Quenchers, Richard Dennin
Fluorescence Quenching Of Peptidyl Tryptophan By External Quenchers, Richard Dennin
Honors Theses
Fluorescence quenching data have been collected on several small peptides (1-4) residues which contain tryptophan. These data have been analyzed by a variety of methods. The classical Stern-Volmer equation is utilized to obtain Stern-Volmer plots of fluorescence quenching data. Substantial upward curvature is observed in the Stern-Volmer plots of all the peptides studied. Data were also analyzed via the modified Stern-Volmer static quenching model. Although this model could explain the deviation from simple Stern-Volmer behavior found in SV plots, the parameters used by the model were often physically “unrealistic”: Therefore, another form of data analysis was used. The newly proposed …
Sterically Hindered Esters: Mechanisms Of Saponification, Frederick F. Fenter
Sterically Hindered Esters: Mechanisms Of Saponification, Frederick F. Fenter
Honors Theses
This paper discusses the mechanisms of base catalyzed hydrolysis of the secondary-butyl ester of 2, 2-dimethyl-propanoic acid (secondary-butyl pivaloate). Kinetic studies were carried out at 53° and near neutral hydroxide ion concentrations, but due to the slow velocity of reaction, no conclusions concerning the order of the kinetics of hydrolysis could be drawn. Also discussed is a scheme for an experiment involving the utilization of 018 enriched water in the saponification reaction of secondary-butyl pivolate under similar conditions of pH and temperature. The purpose of this experiment is to determine the site of oxygen cleavage during the hydrolysis. The analysis …
Determination Of Aldehydes And Ketones In The Gas Phase, Clyde A. Kelly
Determination Of Aldehydes And Ketones In The Gas Phase, Clyde A. Kelly
Honors Theses
A recently developed method for the quantitative detection of carbonyl compounds in ambient air was investigated, specifically in order to further standardize and improve the process. The method involves drawing a gas phase sample of carbonyl compounds through impingers containing a 2, 4-Dinitrophenylhydrazine solution is then injected directly into the hplc for separation on a reversed phase column and quantitative determination by UV absorption at 254 nm and 360 nm simultaneously. The critical feature of the method (based upon a standard analytical derivatization reaction) is the use of the acetonitrile solvent. This allows for direct injection of the sampling solution …
Cationic Copolymerization Of Styrene And Beta-Pinene: The Effect Of Solvent On Monomer Reactivity Ratios, George Yusun Paik
Cationic Copolymerization Of Styrene And Beta-Pinene: The Effect Of Solvent On Monomer Reactivity Ratios, George Yusun Paik
Honors Theses
Copolymers of styrene and B- pinene were synthesized at 30 degrees Celcius in methylene dichloride, carbon tetrachloride, and nitrobenzene. NMR analysis was used to determine the mole percent of styrene and B-pinene in the copolymer. These data were used to calculate monomer reactivity ratios in the three different solvents. It was also found that the styrene reactivity ratio increased when solvents with low dielectric constants were used. The B-pinene reactivity ratio also increased as the dielectric constant of the solvent increased. Pyrolysis and gas chromatography indicated that copolymerization may not have occurred in nitrobenzene and carbon tetrachloride if the mole …
Syntheses And Fluorescence Properties Of Sterically-Hindered Esters Of 9-Anthroic Acid, Richard Leslie Dubs
Syntheses And Fluorescence Properties Of Sterically-Hindered Esters Of 9-Anthroic Acid, Richard Leslie Dubs
Honors Theses
For over a decade, Professor Thomas C. Werner and his students have been studying the unusual florescence properties of methyl-9-anthroate. In the ground state of this ester, the carboxyl group lies perpendicular to the anthracene rings due to steric inhibition by the peri hydrogens. Werner has postulated that, upon excitation, the carboxyl group rotates to form a planar configuration with the anthracene rings, and that this rotation is the cause of the unusual spectral properties. In our work, we have attempted to prove or disprove this hypothesis. We have chosen to synthesize analogues of methyl-9-anthroate in which carboxyl group rotation …
The Apple Ii, Daniel M. Laby
The Apple Ii, Daniel M. Laby
Honors Theses
The apple II+ microcomputer was interfaced to an Aminco-Morrow stopped-flow Apparatus. This interface package can be broken into two parts; the hardware, or electrical connections necessary to link the two instruments, and secondly, the software, or programs written to control the interface package. A circuit was constructed as part of the interface hardware. This circuit consisted of several operational amplifiers connected in such a way as to transform the output voltage of the stopped-flow into one acceptable by the Apple computer. The software for this interface package is extensive. Programs were written that allowed the user to initialize the correct …
The Combined Effect Of Cu And Zn On Selenastrum Capricornutum, Helmer Colonia-Roque
The Combined Effect Of Cu And Zn On Selenastrum Capricornutum, Helmer Colonia-Roque
Dissertations and Theses
It has been demonstrated that the toxicity of heavy metals depends on their chemical speciation and can be related to their free ion activities, rather than the total metal concentrations. The objective of this study was to determine the effect of combined free ions of zinc and copper on the toxicity to the green alga Selenastrum capricornutum. This alga was grown in a defined medium, under controlled laboratory conditions, with a varying range of zinc and copper concentrations. The growth rate of the alga was inhibited at pZn = 5.93 or at pCu = 7.24. The results suggest that …
Cell-Mediated Immunity Of The Dog Lung And Effects Of Inhaled 239puo2 Or Pulmonary Tumors, Jennifer Baker Galvin
Cell-Mediated Immunity Of The Dog Lung And Effects Of Inhaled 239puo2 Or Pulmonary Tumors, Jennifer Baker Galvin
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Cell-mediated immunity (CMI) in the lung has not been well characterized due to the lack of applicable tests. A major objective was to define pulmonary CMI serially in immunized and control lung lobes using the leukocyte procoagulant (LPCA) assay in young adult dogs. This was compared to a standard, but less reproducible CMI assay, macrophage migration inhibition facet (MIF). The CMI response, as measured by the LPCA assay, peaked in the blood 7 days after lung immunization. The pulmonary CMI response measured with cells obtained by bronchial lavage from the immunized and control lung lobes peaked at 9 to 12 …
Studies In Peptide Synthesis Towards The Lanthionine Analog Of Des-N-Tetramethyl Triostin A, Ganesh Devdas Kini
Studies In Peptide Synthesis Towards The Lanthionine Analog Of Des-N-Tetramethyl Triostin A, Ganesh Devdas Kini
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Studies have been carried out towards the synthesis of bicyclic octadidepsipeptide lanthionine 4, an analog of des-N-tetramethyl triostin A. Starting with a symmetrical lanthionine unit 5 (R1, R3 = Me; R2, R4 = t-butyloxycarbonyl), synthesized from the corresponding cystine by contraction with hexaethylphosphorus triamide, linear octadidepsipeptides 29 and 32 were synthesized.
Attempted cyclizations of 29 and 32 to the bicyclic octapeptide were unsuccessful.
The failure of the symmetrical approach to 4 prompted the synthesis of an unsymmetrical lanthionine unit with appropriate compatible protecting groups. Attempts to synthesize unsymmetrical lanthionines by nucleophilic displacement on …
Cow Brain Glutaminase: Purification And Influence Of Phosphate And Borate Ions On Its Activity And Molecular Weight, Mahnaz Badamchian
Cow Brain Glutaminase: Purification And Influence Of Phosphate And Borate Ions On Its Activity And Molecular Weight, Mahnaz Badamchian
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
An efficient and simple purification procedure for cow brain glutaminase (L- glutamine amidohydrolase, EC 3.5.1.2) is described. The main steps consisted of acetone extraction and French press treatment in the presence of phosphate ions, precipitation of nucleic acids and lipids by 0.08 % protamine·S04 and high speed centrifugation (300,000xg), ammonium sulfate fractionation, and gel filtration on Sepharose 4B first as the low molecular weight and then as the aggregated form. The yield was 22% and the final preparation had a specific activity of 142 μmoles/min/mg. The purification was more than 8000-fold over crude brain homogenate. The enzyme showed one strong …
Photochemical Energy Storage (Photosensitized Isomerization Of Norbornadiene To Quadricyclane By Copper(I) Complexes), Dennis J. Fife
Photochemical Energy Storage (Photosensitized Isomerization Of Norbornadiene To Quadricyclane By Copper(I) Complexes), Dennis J. Fife
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
This research has focused on the sensitized photoisomerization step of a solar energy storage system based on the interconversion of norbornadiene (NBD) and quadricyclane (Q). Sensitizers studied in the photoisomerization were arylphosphine complexes of copper(I) halides [(Ph3P)3CuX, (MePh2P)3CuX, (DIPHOS)CuCl; X = Cl, Br, I and DIPHOS = Ph2P(CH2)2PPh2]. The lowest electronic excited state of the complexes can be an effective triplet energy sensitizer as evidenced by a maximum quantum yield of 1.0 with (MePh2P)3CuX. The sensitization mechanism of the L …
Kinetics And Mechanism Of Acylation Of Amines With 2-Naphthoyl Azide, Abraham L. Faburada
Kinetics And Mechanism Of Acylation Of Amines With 2-Naphthoyl Azide, Abraham L. Faburada
Dissertations
The reaction of 2-naphthoyl azide with primary and secondary amines in protic and aprotic solvents follows second-order kinetics. The effect of increasing solvent polarity is shown to increase the rate of reaction. For amines of similar basicity, the rate of reaction decreases with increasing steric hindrance on the amine. The changes in free energy and entropy of activation for n-butylamine and cyclohexylamine are in accord with steric requirements of amines. For amines of similar steric hindrance, the rate of reaction increases with increasing amine basicity. The mechanism of addition-elimination involving the formation of a tetrahedral intermediate is consistent with the …
The Effects Of Various Chemical Treatments On The Surface Area Of Coals, Maria Margaret Ludvig
The Effects Of Various Chemical Treatments On The Surface Area Of Coals, Maria Margaret Ludvig
Dissertations and Theses
Surface areas of most American coals are small when measured by N2 adsorption at 77 K and large when measured by CO2 adsorption at 298 K, implying that the majority of the pores are less than 5 Å in diameter. This small pore size would restrict many gaseous and liquid reactants from entering the internal pore system of the coal, and hence, reduces the efficiency of coal conversion. Therefore, if the surface area, as measured by N2 (77 K), could be increased, that is, to increase the pore size, the conversion of coal into useful products should …
Preparation And Characterization Of Tertiary Phosphine Carbonyl Ruthenium (0) Complexes, Joann C. Bady
Preparation And Characterization Of Tertiary Phosphine Carbonyl Ruthenium (0) Complexes, Joann C. Bady
Masters Theses
Dichlorocarbonyltris(triphenylphosphine)ruthenium (II), Ru(CO)(Cl)2(Ph3P)3, was prepared by modification of a procedure reported to yield the dimer, (Ru(CO)(Cl)2(Ph3P)2)2. Dissolution of Ru(CO)(Cl)2(Ph3P)3 in acetonitrile resulted in loss of triphenylphosphine and dimer formation.
Metathesis of Ru(CO)(Cl)2(Ph3P)3 in hexane with excess tertiary phosphine yielded complexes of the type Ru(CO)(Cl)2-(R2R′P)3 where R2R′P is Ph2MeP or PhMe2P. 1H and 31p nmr spectra of these materials showed that two phosphines are …
Preparation Of 2,5-Diaryl-1,3,4-Oxadiazoles, Joachim D. Dobe
Preparation Of 2,5-Diaryl-1,3,4-Oxadiazoles, Joachim D. Dobe
Retrospective Theses and Dissertations
This report regards the research conducted in the synthesis of 2,5-disubstituted-1,3,4-oxadiazoles as potential insecticides which are closely related to the known insecticide DOWCO 416R, 2,5-bis(2,4-dichlorophenyl)-1,3,4-oxadiazole. The following compounds were synthesized: 2-(2,4-dichloro-5-nitrophenyl)-5-(2,4-dichlorophenyl)-1,3,4-oxadiazole, (2-(2,4-dichloro-5-nitrophenyl)-5-phenyl-1,3,4-oxadiazole, 2-(2,4-dichloro-5-aminophenyl)-5-aminophenyl)-5-(2,4-dichlorophenyl)-1,3,4-oxadiazole and 2-(2,4-dichloro-5-aminophenyl)-5-phenyl-1,3,4-oxadiazole.
From the commercially available starting material, 2, 4-dichlorobenzoic acid, preparation of the above compounds involved nitration, reduction, esterification, preparation of monoacylhydrazines, preparation of substituted diacylhydrazines and preparation of 2, 5-disubstituted-1, 3, 4-oxadiazoles. All these compounds were characterized via NMR and infrared spectroscopy. In addition, this report includes discussion and recommendations concerning the experimental procedures and conditions for the preparation of these compounds.
Synthesis Gas Conversion With Zs M-5 Supported Ruthenium Catalysts, Robin Elizabeth Young Eaton
Synthesis Gas Conversion With Zs M-5 Supported Ruthenium Catalysts, Robin Elizabeth Young Eaton
Theses and Dissertations
Some bifunctional ZSM-5 supported ruthenium catalysts (Ru/ ZSM-5) were prepared by an extraction technique employing Ru 3(C0)12 • The weight percentage Ru ranged from approximately 1% to 8% Ru as determined by Atomic Absorption Spectroscopy. Characterization data employing Infrared (IR) Spectroscopy, X-ray Powder Diffractometry (XRPD), X-ray Photoelectron Spectroscopy (XPS/ESCA), Ion-Scattering Spectrometry (ISS) and Chemisorption were obtained for the catalysts. The data indicated the presence of highly dispersed Ruo2 particles of less than 60 A on the surface of the as-prepared (AP) catalysts. Calcination of the AP catalysts at 500°C for 24 h increased the particle size of …
Internal Rotation Effects And Nuclear Hyperfine Structure In The Microwave Spectrum Of Propyne-Hf, Roger E. Bumgarner
Internal Rotation Effects And Nuclear Hyperfine Structure In The Microwave Spectrum Of Propyne-Hf, Roger E. Bumgarner
Masters Theses
The microwave spectrum of the weakly bound propyne-HF/DF complex in the region between 6 and 16 GHz was analyzed. The spectrum was characteristic of a distorted T-shaped asymmetric top exhibiting torsional splitting caused by a low barrier to internal rotation of the methyl top relative to the propyne-HF frame. Deuterium substitution of HF confirms that the acid proton of HF is located between the F atom and the propyne triple bond. The spectroscopic constants given below are consistent with the fluorine atom being displaced toward the methyl group from a line perpendicular to and bisecting the propyne triple bond, suggesting …
Analysis Of Clay Minerals, Other Silicate And Nonsilicate Minerals, And The Grading Of Chrysotile Asbestos By Attenuated Total Reflection Infrared Spectrophotometry (With Atlas), Ashraf Muhammad Chaudhry
Analysis Of Clay Minerals, Other Silicate And Nonsilicate Minerals, And The Grading Of Chrysotile Asbestos By Attenuated Total Reflection Infrared Spectrophotometry (With Atlas), Ashraf Muhammad Chaudhry
University of the Pacific Theses and Dissertations
This study of ATR-IR involved taking spectra of various silicate minerals in powder samples, finding similarities and differences in nature, and locating various bands and intensities of absorption bands for identification and classification purposes. This study is limited to 4000-300 cm-1 with major emphasis on absorptions in the 2000-300 cm-1 region.
Synthesis And Reactions Of Aromatic Ethers As Model Compounds For Coal, James Nicolas Ong Sy
Synthesis And Reactions Of Aromatic Ethers As Model Compounds For Coal, James Nicolas Ong Sy
Masters Theses
o-Anisic acid and o-ethoxybenzoic acid were reacted with pyridine hydriodide in pyridine at 115° for 3 days to yield 81% and 18% salicylic acid respectively. o-Anisic acid with KI in pyridine at 115° for 3 days gave 58% salicylic acid while o-anisic acid with LiI·3H2O in pyridine at 85° for 3 days gave 54% salicylic acid. p-Anisic acid and o-phenoxybenzoic acid did not undergo cleavage reactions with pyridine hydriodide under similar conditions.
Beta-methylnaphthyl beta-naphthyl ether(I) or alpha-methylnaphthyl alpha-naphthyl ether(II) with pyridine hydriodide in pyridine at 100-115° for 3 days showed no cleavage. Ether I …
Analysis Of The Surface Polysaccharides Of R. Trifolii Su843 And Its Sym Plasmid Alterated Mutants, Jauh-Lin Duh
Analysis Of The Surface Polysaccharides Of R. Trifolii Su843 And Its Sym Plasmid Alterated Mutants, Jauh-Lin Duh
Masters Theses
The Rhizobium trifolii polysaccharides from SU843 and mutants--HC843(pBR1AN), HC843, 8002--in which the sym plasmid is replaced, absent, or mutated by transposon Tn5 were isolated. The surface polysaccharides of genetically altered mutants were compared quantitatively and qualitatively with one another and with the parent strain. The interpretation of these results is discussed in relation to the function of Rhizobium surface polysaccharides in the symbiotic process. The symbiotic ability of SU843 and mutant strains is as follows: (a) SU843, nod+, fix+; (b) mutant 8002, roa+ (still attaches to root hair), hac-, nod-; (c) …
The Theory And Synthesis Of [2.2.2] Propellane, Theodore Mark Prociv
The Theory And Synthesis Of [2.2.2] Propellane, Theodore Mark Prociv
Dissertations, Theses, and Capstone Projects
INDO calculations indicated that the triplet state of dimethylene cyclohexane could rearrange to gometrically relaxed triplets which should collapse preferentially to the ground state [2.2.2] Propellane. A mercury sensitized photolysis of the dimethylene cyclohexane did in fact result in detectable quantities of the propellane, trapped as 1,4 dibromobicyclo octane. Synthesis of 1,4 dibromobicyclo octane and 1,1,6,6 tetradeuterodimethylene-cyclohexane are presented in the dissertation. Included in the dissertation are the results of INDO calculations of various propellane isomers having nitrogens and borons in the bridgehead positions.
A Study Of The Electroless Plating Of Sn Onto A Die-Cast Aluminum Alloy, Ann-Tinn Shen
A Study Of The Electroless Plating Of Sn Onto A Die-Cast Aluminum Alloy, Ann-Tinn Shen
Masters Theses
"A tin layer was immersion plated onto a zinc-silicon containing aluminum alloy by using a potassium stannate solution. Conventional aluminum pretreatment was used before immersion plating.
Effects of immersion time with immersion tin thickness and Al-Sn adhesion were studied. Conditions of subsequent Sn-Pb electroplating on Sn plated aluminum samples were investigated.
SEM (scanning electron microscope) and x-ray energy dispersion studies were extensively used on samples of each stage"--Abstract, page ii.