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Articles 32611 - 32640 of 34531

Full-Text Articles in Physical Sciences and Mathematics

Titanium Assisted Alkylations Of Selected Alkynols, Leslie C. Smedley Jan 1976

Titanium Assisted Alkylations Of Selected Alkynols, Leslie C. Smedley

Dissertations, Theses, and Masters Projects

No abstract provided.


Part I. Thermodynamic Acidities Of Substituted Phenylacetylenes. Part Ii. Mercury Accumulation In Trout Of Southern Missouri, Eric T. Lloyd Jan 1976

Part I. Thermodynamic Acidities Of Substituted Phenylacetylenes. Part Ii. Mercury Accumulation In Trout Of Southern Missouri, Eric T. Lloyd

Masters Theses

"PART I: THERMODYNAMIC ACIDITIES OF SUBSTITUTED PHENYLACETYLENES The thermodynamic acidities (pKa) of phenylacetylene and several para substituted phenylacetylenes in methanol were determined at 25ºC. These acidity constants were determined using a quenching technique which involves converting the phenylacetylenic anion, present at equilibrium as sodium phenylacetylide, to the tritium labelled carbon acid. By liquid scintillation counting techniques, the concentration of the anion was determined and the pKa of the phenylacetylene compound calculated. The resulting pKa's are: p-nitrophenylacetylene, 17.98, p-bromophenylacetylene, 18.10, p-fluorophenylacetylene, 18.14, phenylacetylene, 18.50, and p-methylphenylacetylene, 18.60. The effect of a substituent in the para position on the relative acidities is …


Ua66/7/2 Newsletter, Wku Chemistry Jan 1976

Ua66/7/2 Newsletter, Wku Chemistry

WKU Administration Documents

Newsletter created by and about the WKU Chemistry department.


Experimental Testing Program In Elementary Chemistry: A Preliminary Report, Billie G. Broach, Howard L. Hodges Jan 1976

Experimental Testing Program In Elementary Chemistry: A Preliminary Report, Billie G. Broach, Howard L. Hodges

Journal of the Arkansas Academy of Science

An experimental testing program is described which utilizes questions that are partly computer composed, in addition to a section composed by the instructor, and a retesting option to the student. Results from a trial of the program for one term indicate that (1) course grades were improved, (2) the student withdrawal failure rate was unaffected, and (3) the employed students took greater advantage of the retest than did the unemployed students.


Composition Of Arkansas Grapes During Maturation, Cameron Jones, Dominic T.C. Yang, Thomas O. Whitley Jan 1976

Composition Of Arkansas Grapes During Maturation, Cameron Jones, Dominic T.C. Yang, Thomas O. Whitley

Journal of the Arkansas Academy of Science

Changes in organic acid and glucose content during maturation and ripening of grapes grown in Arkansas in 1973 are shown for four French hybrid varieties, S5279, S10878, SV23- 657, and S13053, and for four rotundifolia varieties, Scuppernong, Tarheel, Fry, and Magoon. In all varieties the concentrations of malates and tartrates were highest in the early stages of berry growth after veraison. During ripening the titratable acidity decreased and Balling and pH measurements increased. Although varieties reached maturity on different dates, changes in parameters followed similar curves typical for grapes of the species but occurring over a short period (Johnson and …


Polymerization Of Amino Acids On Kaolinite, Z. Badri Adnani-Gleason Jan 1976

Polymerization Of Amino Acids On Kaolinite, Z. Badri Adnani-Gleason

Dissertations and Theses

In the origin of life on the primitive earth a major step must have involved the condensation of amino acids to form the first polypeptides. Several suggestions as to how this might have occurred have been made by other workers. One of the more appealing proposals is that the polymerization was catalyzed by clay minerals. It has been reported, for example, that L-apartic acid polymerizes significantly faster than D-aspartic in the presence of kaolinite in aqueous suspension at 90˚. In this work an attempt was made to repeat this report and extend the pH range to include values presumably present …


A Precipitation Model And Experimental Correlation With Various Properties Of Pentaerythritol Tetranitrate, Thomas Rivera Dec 1975

A Precipitation Model And Experimental Correlation With Various Properties Of Pentaerythritol Tetranitrate, Thomas Rivera

Chemistry and Chemical Biology ETDs

A continuous precipitation method for the preparation of crystalline pentaerythritol tetranitrate (PETN) has been developed. The process involves the precipitation of PETN from an acetone solution by the addition of water in a static mixer. The principal independent variable is the ratio, R, of the acetone-PETN solution flow rate to the flow rate of water.

A mathematical model based on dispersed plug-flow equations adequately represents the physical process. The relationships developed can be used to predict particle size distributions, two explosion properties of PETN, and estimate the effective kinetics involved in the precipitation process. The mass-weighted mean particle size, L, …


The P-Nitrobenzyl System. Iv. Base-Induced Transformations In P-Nitrobenzyl Chloride, Bromide, Iodide, Tosylate, And Sulfonium Salts, Samir B. Hanna, Paul H. Ruehle Dec 1975

The P-Nitrobenzyl System. Iv. Base-Induced Transformations In P-Nitrobenzyl Chloride, Bromide, Iodide, Tosylate, And Sulfonium Salts, Samir B. Hanna, Paul H. Ruehle

Chemistry Faculty Research & Creative Works

No abstract provided.


A Study Of Selected Variables For Prediction Of Success And Placement In General Chemistry At Western Michigan University, Stephen M. Yekeson Dec 1975

A Study Of Selected Variables For Prediction Of Success And Placement In General Chemistry At Western Michigan University, Stephen M. Yekeson

Dissertations

Chapter I

The Problem

Introduction

The traditional philosophy that a college-or a university is an exclusive institution in which only highly selected individuals receive a concentrated training in the traditional liberal arts no longer exists. In America, for instance, as early as 1870, Harvard, the colonial college with a narrow curriculum, was transformed rather rapidly into a modern university with many new subjects and the elective system (Garrett, 1949). Also, since 1642, when the first entrance requirements were instituted for American higher education, a continuing debate has developed over what constitutes a sound curriculum for education. There are those who …


Calorimetric Determination Of The Interaction Of Cu, Fe, And V Oxides With So₂ And Measurement Of Sulfur (Iv) And Sulfur (Vi) In Particulate Samples From Utah Valley, Douglas F. Cannon Dec 1975

Calorimetric Determination Of The Interaction Of Cu, Fe, And V Oxides With So₂ And Measurement Of Sulfur (Iv) And Sulfur (Vi) In Particulate Samples From Utah Valley, Douglas F. Cannon

Theses and Dissertations

The adsorption of SO2 by metal oxides suspended in decane were studied by calorimetric titration. The adsorption per surface area decreases in order CuO > Cu2O > Fe2O3 > V2O5. An Andersen High Volume sampler was used to obtain particulate samples from five sites in Utah County. Particulate sulfur (IV) and sulfur (VI) was analyzed by thermometric titration with K2Cr2O7 and by a direct injection enthalpimetric determination using BaCl2. Results show that little oxidation of the S(IV) occurs after it is released from the Kennecott smelter stack.


Anion Assisted Redox Rates Between Cobalt (Ii) - Cobalt (Iii) Polypyridyl Complexes In Acetophenone, Seyed Garmestani Dec 1975

Anion Assisted Redox Rates Between Cobalt (Ii) - Cobalt (Iii) Polypyridyl Complexes In Acetophenone, Seyed Garmestani

Masters Theses & Specialist Projects

The effects of ionic strength and various anions on the rate of electron transfer between tris(2,2'-dipyridine) cobalt(III) and bis(2,2',2"-tripyridine) cobalt(II) complexes have been examined in acetophenone. The redox rate was found to increase with increasing ionic strength in both the presence and absence of added salts. The reaction was first order with respect to each reactant and second order overall in all cases. The influence of the C104, BF4, and B(C6H5)4 anions on the reaction rate was studied with their order of effectiveness being: C104- > BF4 >> B(C6 …


Excited States And Photochemistry Of Saturated Molecules. I. General Approach And Application To Propane, Patrick M. Saatzer, Robert D. Koob, Mark S. Gordon Sep 1975

Excited States And Photochemistry Of Saturated Molecules. I. General Approach And Application To Propane, Patrick M. Saatzer, Robert D. Koob, Mark S. Gordon

Mark S. Gordon

Following Ruedenberg, we suggest that a useful measure of chemical binding is the two-center, one-electron interference contribution to the energy in the electronic state of interest. Using this conceptual framework, the vertical valence excited states of propane in the optimal ground state geometry are examined using INDO in its original parametrization. The results are compared with available experimental information. The calculations yield bond energies which are consistent with observed decomposition modes for ground states of small alkanes and excited states of propane. Configuration interaction calculations are discussed in the case of propane. Inclusion of all single excitations from the ground …


17th Annual Rocky Mountain Spectroscopy Conference Aug 1975

17th Annual Rocky Mountain Spectroscopy Conference

Rocky Mountain Conference on Magnetic Resonance

Final program and abstracts from the 17th 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 4-8, 1975.


A Study Of The Electrolytic Oxidation Of Antioxidants At A Stationary Platinum Microelectrode, Mark Anthony Forte Aug 1975

A Study Of The Electrolytic Oxidation Of Antioxidants At A Stationary Platinum Microelectrode, Mark Anthony Forte

Master's Theses

Phenolic antioxidants have a Wide variety of uses. They are em- ployed to prevent oxidative and thermal degradation of everything from plastics to foodstuffs. They may even have potential as carcinostatic agents. In general, they act as chain terminators in free radical type reactions.


An Atomic Absorption Method For Determining Micromolar Quantities Of Primary Aliphatic Amines In The Presence Of Secondary And Tertiary Aliphatic Amines, Nathalie Harwood Perkins Aug 1975

An Atomic Absorption Method For Determining Micromolar Quantities Of Primary Aliphatic Amines In The Presence Of Secondary And Tertiary Aliphatic Amines, Nathalie Harwood Perkins

Master's Theses

A method for the determination of primary aliphatic amines in the presence of secondary and tertiary amines is described. The primary amine is reacted wit ha complexing reagent containing cupric chloride, salicylaldehyde and triethanolamine. The copper complex formed is extracted into 10% hexanol in toluene. The amount of copper in the toluene layer is determined by atomic absorption spectroscopy. This is a measure of the primary amine in the sample. The method can be successfulyl applied to both monoamines and diamines as well as an amino alcohol. Data for the analysis is + 0.05% at the 2% level and below. …


Spectroscopic Studies Of The Hydrogen-Chlorine Flame, Gonzalo Pizarro Aug 1975

Spectroscopic Studies Of The Hydrogen-Chlorine Flame, Gonzalo Pizarro

Masters Theses

No abstract provided.


The Effect Of Nitroalkanes On The Electrolytic Oxidation Of Tertiary Butyl Amine And Tertiary Amyl Amine, Karl Lloyd Bergen Aug 1975

The Effect Of Nitroalkanes On The Electrolytic Oxidation Of Tertiary Butyl Amine And Tertiary Amyl Amine, Karl Lloyd Bergen

Theses and Dissertations

The electrolyses of tert.-butyl and tert.-amyl amines were run with a voltage of approximately 3v., as measured across the cell, with and without the presence of 1-2% nitro-tert.-alkane. A graphite anode was used; the supporting electrolyte was NaClO4; the solvent was the reacting amine(s) with 10-20% water to solubilize the NaClO4. The products were azo compounds, azoxy compounds, 1,3-disubstituted ureas and traces of nitroso compounds. In the case of tert.-butyl amine di-tert.-butyl carbodiimide was also shown to be a product. The presence of nitro compounds increased the yields of azoxy and nitroso compounds and decreased the yields of azo compounds. …


Synthesis And Stereochemistry Of 2,6,10-Triazatricyclo [5.2.1.0⁴ ¹⁰] Decane Derivatives, Susan Elaine Foulger Aug 1975

Synthesis And Stereochemistry Of 2,6,10-Triazatricyclo [5.2.1.0⁴ ¹⁰] Decane Derivatives, Susan Elaine Foulger

Theses and Dissertations

The synthesis and stereochemical aspects of derivatives of the new ring system 2,6,10-triazatricyclo [5.2.1.04,10] decane are discussed. Sythesis of 2-nitro-2-methyl-1,3-disubstitutedaminopropanes, followed by reduction of these compounds to 2-amino-2-methyl-1,3-disubstituted aminopropanes afforded the necessary starting materials for a cyclization reaction similar to that resulting in already known 2,6-dioxa-10-azatricyclo [5.2.1.04,10] decanes. Reaction of the triamines with 2,5-hexanedione resulted in 2,6-disubstituted-1,4,7-trimethyl-2,6,10-triazatricyclo [5.2.1.04,10] decanes. The stereochemical aspects of this ring system are interesting from the standpoint of nitrogen inversion barriers on nitrogens 2 and 6. Existence of a high inversion barrier for these nitrogens in shown by isolation of different diastereomers of the tricycle. Methods …


Macrocyclic Polyether Sulfide Syntheses :|Bthe Preparation Of Thia-Crown-6, 7, And 8 Compounds, Robert Askew Reeder Aug 1975

Macrocyclic Polyether Sulfide Syntheses :|Bthe Preparation Of Thia-Crown-6, 7, And 8 Compounds, Robert Askew Reeder

Theses and Dissertations

Macrocyclic polyether sulfides have been prepared by reacting an oligoethylene glycol dichloride with a dithiol in refluxing basic ethanol. The following new compounds were prepared: 1,5-dithia-(19- crown-6), 3-hydroxy-1,5-dithia-(19-crown-6), 1,4-dithia-(21-crown-7), 3-hydroxy-1,5-dithia-(22-crown-7), and 1,4-dithia-(24-crown-8). One other previously reported macrocyclic polyether sulfide was also prepared. The thesis includes a review of macrocyclic sulfides and other related compounds, the thermodynamics of interaction of several macrocyclic polyether sulfides with Ag^+, Hg^2+, and Pb^2+ ions, and a discussion of the structure of these materials.


Kinetics Of The Thermal Decomposition Of Pyridine, Tesfaye Biftu Aug 1975

Kinetics Of The Thermal Decomposition Of Pyridine, Tesfaye Biftu

Masters Theses

No abstract provided.


Synthesis And Analysis Of Dimers Of Alpha-Methylstyrene, Bhadreshkumar J. Mehta Aug 1975

Synthesis And Analysis Of Dimers Of Alpha-Methylstyrene, Bhadreshkumar J. Mehta

Masters Theses

Introduction

The heat of polymerization ∆Hp, of Alpha-methylstyrene (AMS) has been a source of study for many years. The structure of AMS is shown in Figure 1.

Roberts and Jessup carried out the first quantitative work to determine ∆Hp if AMS.1 Their data displayed a ∆Hp dependence on the degree of polymerization, DP. Several other reports were also published with new values for ∆Hp and new explanations for the apparent DP dependence.2, 3, 4, 5.

Samples of dimers of AMS have been prepared by various workers.6, 7, 8 The reactions were mostly carried out by using sulfuric …


A Stereochemical Study Of Some 2,2'-Bridged Biphenyls, Alan J. Quarfoot Aug 1975

A Stereochemical Study Of Some 2,2'-Bridged Biphenyls, Alan J. Quarfoot

Dissertations

No abstract provided.


A Spectrophotometric Equilibrium Study Of Nickel(Ii)-3, 4', 4", 4'"-Tetrasulfophthalocyanine, Stephen Lowery Aug 1975

A Spectrophotometric Equilibrium Study Of Nickel(Ii)-3, 4', 4", 4'"-Tetrasulfophthalocyanine, Stephen Lowery

Masters Theses & Specialist Projects

There have been several studies made on the effects of various central metal ions on the aggregation of tetrasulfonated Phthalocyanine dye complexes in aqueous solution, but there have been no studies made on the aggregation of the nickel(II)-4, 4', 4", 4'"-tetrasulfoohthalocyanine (NiII-TSPC) complex. Therefore, a study of the effects of nickel(II) on the aggregation of its aqueous tetrasulfonated Phthalocyanine dye complex was Proposed so that a comparison might be made with nrevious studies of central metal ion effects. It was found, however, that NiII-TSPC gives a much higher degree of aggregation in water than the metal …


Electronic Transitions Of Metal Complexes With Triphenylphosphine As A Ligand, Thomas Zimmer Aug 1975

Electronic Transitions Of Metal Complexes With Triphenylphosphine As A Ligand, Thomas Zimmer

Masters Theses & Specialist Projects

The spectra of transition metal complexes with triphenylphosphine have been measured near 260 nm and the results interpreted in terms of perturbation of the it electron system of the phenyl ring. All complexes studied show sou degree of delocalization of the d-orbital electrons of the metal into the phenyl ring. However, for first row transition metals, the primary affect was found to be polarization of the phenyl ring due to the presence of the metal ion. For second and third row transition metal ions, the primary effect was found to be metal-ligand back-bonding. However, the effect of polarization of the …


Composition And Structure Of A Stress Relieving Removable Epoxy Resin, Cecelia Victoria Krapcha Carter Jul 1975

Composition And Structure Of A Stress Relieving Removable Epoxy Resin, Cecelia Victoria Krapcha Carter

Chemistry and Chemical Biology ETDs

The aqueous modification of polyol modified anhydride cured diglycidyl ether of bisphenol A exhibits properties of a brittle solid when subjected to an impulse stress, and properties of a viscous fluid when subjected to a steady state stress. This behavior is markedly different from the nonaqueous system. Early attempts to understand the nature of the change in properties and the physical mechanism involved have not been completely successful. These attempts have typically taken a physical chemistry approach and have not fully investigated the organic nature of the polymer. In order to fully understand a polymer system an important step should …


The Synthesis Of New Maleimide Addition Polymer Precursors, Richard B. Brown Jul 1975

The Synthesis Of New Maleimide Addition Polymer Precursors, Richard B. Brown

Chemistry & Biochemistry Theses & Dissertations

1H-2,3-dimethylpyrrolo(1,2-a) benzimidazol-l-one (27) and 1H,9H- 2,3,7,8-tetramethyl-bispyrrolo(1,2-a:6,7-a')benzodiimidazo1-1,9-dione (32) have been synthesized from dimethylmaleic anhydride and o-phenylenediamine and 1,2,4,5-tetraaminobenzene, respectively. The presence of reactive olefinic double bonds in the synthesized compounds was of interest as a site for possible addition polymerization.

The synthetic route involved, in both cases, a simple nucleophilic substitution reaction between the diamine(or tetraamine) and the anhydride to form an intermediate amide-acid-amine which rapidly cyclized to the imide amine. The final ring closure required more rigorous conditions and occurred at melt reaction temperatures.


Synthesis Of 2,4-Dichloro-6-Methylborazine And 2-Chloro-4,6-Dimethylborazine, Deborah Ann Scribner Jun 1975

Synthesis Of 2,4-Dichloro-6-Methylborazine And 2-Chloro-4,6-Dimethylborazine, Deborah Ann Scribner

Honors Theses

In the attempted preparation of 2, 4, 6-trimethylborazine, two unknown products were isolated. It was suspected that these could be 2-chloro-4, 6-dimethylborazine and 2, 4-dichloro-6-methylborazine. Due to the difficulty of separation of the two products, they were not positively identified. These two compounds were then chosen for synthesis and characterization since they would be useful starting materials for the preparation of unsymmetrically substituted borazines and since there is little data on unsymmetrical borazine derivatives. It was later decided that the 2, 4-dichloro-6-methyl-borazine would be synthesized first since it would be earlier to control the mole ratio of reactants to favor …


Calculation Of Pseudocontact Shifts For Co( Ch30h)5x2+ Complexes, Jerry Goodisman Jun 1975

Calculation Of Pseudocontact Shifts For Co( Ch30h)5x2+ Complexes, Jerry Goodisman

Chemistry - All Scholarship

In this article, we calculate pseudocontact shifts for tetragonal high-spin Co(I1) complexes using a crystal field model. Calculated results for the dipolar field strength and its variation with temperature are compared with values derived from experimental measurements on complexes of the form Co(CH30H)5X2+. The calculation involves evaluation of the anisotropy of the magnetic susceptibility, and proceeds by the following steps: (a) from the crystal field parameters Dq, Ds, Dt, and B the three orbital wave functions of lowest energy are found. (b) The effect of spin-orbit coupling over the 12 states (three orbital wave functions coupled with four spin states) …


Dielectric Constants And Pair Interactions In Polar Molecules, Guy Nicholas Pultz Jun 1975

Dielectric Constants And Pair Interactions In Polar Molecules, Guy Nicholas Pultz

Honors Theses

Intermolecular interactions effect the physical properties of polar substances to varying degrees. One property for which there exists the possibility of separating out the various components of this interaction (pairs, triplets, etc.) is the total molar polarization of a substance. These effects are quite dependent upon temperature and pressure, so if one is going to make measurements over a large range of these variables, one must develop a system that is capable of handling the conditions. Along with this there must be the necessary instrumentation and other apparatus for measuring dielectric constants which define total molar polarization. In this thesis, …


The Synthesis Of Primary O-Substituted Hydroxylamines For The Study Of Nucleophilic Substitution At The Electrophilic Nitrogen Center, Richard Martin Sommer Jun 1975

The Synthesis Of Primary O-Substituted Hydroxylamines For The Study Of Nucleophilic Substitution At The Electrophilic Nitrogen Center, Richard Martin Sommer

Honors Theses

Within the past fifteen years bimolecular nucleophilic substitution reactions at the sp3 hybridized nitrogen center have been the topic of some investigation. The synthesis of 0-substituted hydroxylamines was undertaken in order to obtain substrates for the study of these substitution reactions. Mesitylenesulfonyl chloride and t-butyl N-hydroxycarbamate were reacted to form the N-blocked t-butyl N-mesitylenesulfonyloxycarbamate. Subsequent acid cleavage of the nitrogen blocking group with trifluoroacetic acid yielded 0-mesitylenesulfonylhydroxylamine. Unsuccessful kinetic studies of the reaction of iodide with 0-mesitylenesulfonylhydroxylamine are reported. Attempts to synthesize 0-(2, 4-dinitrophenyl) hydroxylamine utilizing t-butyl N-hydroxycarbamate and ethyl acetohydroxamate as a sources of N-blocked hydroxylamine failed. In both …