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Evidence For The Existence Of Two Stable Sites For Cobalt Impurity Atoms In Aluminum, Arun Venkatachar

Dissertations and Theses

Using Fe⁵⁷Mössbauer spectroscopy, two alternative sites occupied by cobalt (10^-4 at. % ) impurity atoms in aluminum have been isolated. The substitutional site A is the stable position after annealing the sample above 840 K, followed by a rapid quench. The impurity atoms in site A are characterized by a single line Mössbauer spectrum (indicative of a cubic environment), a room-temperature f = 0.502 (r. m. s. displ. 0.071 A) and an I. S. (reI. to Fe) = -0.421 mm/sec. For anneals below 770 K the cobalt atoms migrate to site B, which is characterized by a …

13th Annual Rocky Mountain Spectroscopy Conference

Rocky Mountain Conference on Magnetic Resonance

Program and abstracts from the 13th annual meeting of the Rocky Mountain Spectroscopy Conference, hosted by the Rocky Mountain Section of the Society for Applied Spectroscopy. Held in Denver, Colorado, August 9-10, 1971.

A Study Of A Divalent Cation-Selective Electrode, William Stanhope Ryan Jr.

Master's Theses

The ion-selective membrane electrode, recently introduced commercially, has shown excellent promise as a tool for determining ionic activities and concentrations in solution. It was the intent of the author to study the Orion divalent cation-selective electrode with two objectives.

The first objective of this research was to characterize the response of the divalent cation-selective electrode to calcium and magnesium ions in aqueous solutions. The effect of anions, monovalent cations; and pH upon this response was investigated. An examination was made of the response of this electrode to other divalent cations and of the effect of organic solvents on the membrane …

The Response Of The Micro-Adsorption Detector To Inorganic Cations, David P. Mckay

Masters Theses

No abstract provided.

The Thermal Decomposition Of 2,2'-Azoisobutane, Mervin Dewain Atwood

Theses and Dissertations

Nitrogen, isobutane, isobutylene and 2,2,3,3-tetramethylbutane are the only products found in the thermal decomposition of 2,2'-azoisobutane. They are the results of the direct free radical dimerization and disproportionation. Ratio of the rate constants of disproportionation to dimerization was found to be 1.9 at 268°C and 4.5% azobutane in helium. This compared with Blackham and Eatough's value of 1.4 at 243°C and 3.6 at 290°C with 4% azobutane in helium. The ratio of the disproportionation to dimerization increased with an increase in temperature. A change in contact time affected the ratio at lower reaction temperatures but had little effect on it …

An Investigation Of Some Free Radicals.|Ni.|Pdecomposition Of Nitrosyl Disulfonate Ion In Polar Non-Aqueous Solvents.|Nii.|Preaction Between 2,2-Diphenyl -1- Picryl Hydrazyl And Nitrosyl Disulfonate Ion Free Radicals, Janan Mary Hayes

Theses and Dissertations

Part I reports the stud y of the decomposition of nitrosyl disulfonate ion in DMSO, acetonitrile, and dichloromethane. A multi-step mechanism involving sulfite ion, sulfite ion radical, and nitrosyl monosulfonate radical as intermediates is proposed. The products of the decomposition are nitrosonium ion, hydroxylamine disulfonate ion, and hydroxylamine trisulfonate ion. A competitive chain reaction was observed when the decomposition occurred in DMSO. The chain reaction was insignificant in carefully dried acetonitrile and dichloromethane. Part II reports the study of the reaction between 2,2-diphenyl-1-picryl hydrazyl (DPPH) and nitrosyl disulfonate ion. Product analysis and kinetic data obtained from stopped-flow procedures suggest that …

A Kinetic Analysis Of The Iodination Of Pyruvic Acid And Pyruvate Esters, Mohamed M. Fahmi Hegazi

All Master's Theses

In the present work the relative rates of iodination of pyruvic acid and ethyl and methyl pyruvate have been compared at 25.0° C. These studies allow the determination of the respective free energies of activation for these processes. Measurements have also been carried out at various temperatures to determine the enthalpies and entropies of activation for the spontaneous and base catalysed iodinations of these pyruvate systems. The present thesis also includes a comparison of the solvent deuterium isotope effects associated with the spontaneous rate of iodination of pyruvic acid and the alkyl pyruvates. Also, the catalytic rate coefficients associated with …

Synthesis And Characterization Of Some Dioxane Complexes, James Donald Satterlee

All Master's Theses

The boron trifluoride, tin (IV) fluoride and titanium (IV) fluoride complexes with 1,4-dioxane have been prepared and studied using infrared techniques. The compositions of the complexes have been determined and correspond to the 1:1 adducts in the case of the tin and titanium compounds. The boron trifluoride adduct is a 2:1 (acid:base) adduct. Infrared spectra in the region 1300 cm.-1 to 550 cm.-1 are given and the effects of coordination upon the ligand vibrations are described.

Stereochemistry And Circular Dichroism Of Trans-Diacidobisdiamine Complexes Of Cobalt(Iii), Jack A. Tiethof

Dissertations

No abstract provided.

Studies Of Pig Brain Thiamin Pyrophosphokinase, James Weldon Peterson

Theses and Dissertations

Pig brain thiamin pyrophosphokinase (TPK) (ATP: thiamin pyrophosphotransferase, EC 2.7.6.2) was purified 260-fold over extracts of brain acetone powder. The purification was followed using a direct, radiometric assay. As determined in an analytical ultracentrifuge and by disc-gel electrophoresis, the most highly purified enzyme preparations were not homogeneous. The purified enzyme has a broad pH optimum extending from 8.3 to 9.3 in phosphate-glycylglycine buffer. It has an isoelectric point at about pH 4.2. For optimal enzymatic activity, the ratio of magnesium to ATP must be 0.6. Any deviation from this ratio causes a rapid drop in enzymatic activity. A study of …

Analytical Aspects Of Laser-Induced Degradation Of Organic And Inorganic Compounds, William T. Ristau

Chemistry and Chemical Biology ETDs

The rapid deposition of energy by means of a pulsed ruby laser to degrade organic and inorganic materials is investigated as an analytical tool. Advantages and disadvantages of using a laser are discussed and compared to current conventional pyrolysis methods. The interaction of laser radiation with matter is briefly discussed. A number of different organic compounds including saturated and aromatic hydrocarbons, heterocyclic compounds, and polymers have been studied. The degradation products were separated and identified by use of a gas chromatograph. Degradation studies have also been done on a series of inorganic salts including nitrates, sulfates, thiosulfates, and oxalates. The …

The Synthesis Of Some New Condensed Pyridazines, Pyridazine N-Oxides And Pyrimidines As Potential Chemotherapeutic Agents, Donald E. Pichler

Chemistry and Chemical Biology ETDs

The need for new antimicrobial and antifungal agents as well as medicinals possessing antiprotozoal activity against special strains of malaria resistant to most synthetic antimalarials prompted the synthesis of new compounds that may have the desired antimetabolite properties. The structural similarities of the 1,2,5-thiadiazolo[3,4-d] pyridazines and the v-triazolo[4,5-d]pyridazines with the biologically important purines prompted the synthesis of members of these ring systems. The 1,2,5-thiadiazoles synthesized as intermediates ware also screened as potential chemotherapeutic agents. Similarly, the pyridazine N-oxides and the 5-nitro substituted pyrimidines are structurally similar to the pyrazine N-oxides and the pyridine N-oxides, which are known to possess a …

Electron Densities For Homonuclear Diatomic Molecules From The Thomas-Fermi-Dirac Theory, Jerry Goodisman

Chemistry - All Scholarship

Electron densities are calculated from approximate solutions to the Thomas-Fermi-Dirac equation for homonuclear diatomic molecules. The accuracy of expectation values calculated from these densities is assessed. In general, one obtains fair agreement with self-consistent-field and experimental results, but this is insufficient when a property is a difference between electronic and nuclear contributions. An important example is the Hellmann-Feynman force on a nucleus, the net force necessarily being repulsive, as for closed-shell atoms. Forc and energy results for such a situation are compared with experiment. Finally, it is shown that a modified theory, previously applied to atoms, gives improvement in expectation …

A Study Of The Acetic Anhydride Method For The Determination Of Citric Acid, Russell Kent Odland

Master's Theses

Citric acid is an important compound of many systems. Numerous methods, both qualitative and quantitative, have been used for the determination of the compound. Some of the biological systems investigated include fermentation studies, action on yeasts, antioxidant in fruits, additive in bakery goods and salad dressing preparations, amounts in vegetables, and others.The above examples are not complete; they only show the varied applications of citric acid. The purpose of this project was to investigate a quantitative spectrophotometric method using anhydrous conditions based on the citric acid-acetic anhydride-pyridine reaction. Conditions affecting the reaction were investigated and optimized for maximum sensitivity and …

Analytical And Other Applications Of Some Quaternary Ammonium Compounds, Robert Grant Dosch

Chemistry and Chemical Biology ETDs

Analytical and other applications of some quaternary ammonium compounds were studied. Conditions are described for the quantitative determination of perchlorate by precipitation as tetra-n-pentylammonium perchlorate. Results of qualitative studies of interferences from other anions and quantitative studies on the separation and determination of perchlorate in the presence of chlorate are presented. With careful work, relative errors of ± 0.2% can be expected in the range of 50-100 mg of perchlorate, ± 1.0% in the 10-50 mg range, and ± 5.0% in the range from 2-10 mg of perchlorate. A method is described for the separation and determination of Ta in …

Mercury Content Of Tobacco Products, Karen S. Mrozek

Senior Scholar Papers

Mercury contamination of food products results from contact with soil, water, and air polluted with mercury from industrial sources, as well as from the use of mercury-containing pesticides and fungicides on plants. A method was developed for extracting mercury from tobacco products. The mercury content of various tobacco products was determined, using an atomic absorption spectrophotometer.

Solid-Liquid Phase Equilibria Studies :|Bi. Several Charge Transfer Systems ; Ii. A Metallic System ; Iii. A Liquid Crystal, Dee Edward Oyler

Theses and Dissertations

Solid-liquid phase equilibria studies were used to investigate possible compound formation in solutions of (i) N,N-dimethylformamide (DMF) and (ii) N,N-dimethylacetamide (DMA) with a series of halogenated hydrocarbons that were selected to give a wide range of acceptor properties. Solid 1:1 intermolecular compounds were identified from solutions of (i) DMF and (ii) DMA with CCl_4, CBrCl_3, and C_6H_5CCl_3. The intermolecular compounds (DMF)_2•CCl_4 and (DMF)_2•CBrCl_3 were also found. The results suggest charge transfer from DMF or DMA to the chlorine atoms of the acceptor molecule as the process for compound formation. Thermal methods were used to determine with high precision the solid-liquid …

A Calorimetric Study Of Metal Ion Cyclic Polyether Interaction :|Bi. Cation Binding Properties Of Macrocyclic Polyethers In Aqueous Solution As A Function Of Temperature ; Ii. Effect Of Solvent Dielectric Constant On The Binding Properties Of Cyclic Polyethers For Na[Superscript +] And K[Superscript +], Dennis Pershing Nelson

Theses and Dissertations

The complexation properties of the two isomers of the cyclic polyether dicyclohexyl-18-crown-6 are examined in aqueous solution for a series of metal ions at various reaction temperatures. The results are discussed in terms of size relationships and salvation characteristics of both polyether and metal ions. ΔCp° values are determined from the temperature dependence of the ΔH° values. A discussion of the errors involved in the determination of ΔH° from the temperature dependence of log K values is also included. Comparisons are made between the results of this study and those of a similar study by H. K. Frensdorff, E. I. …

Eutrophication Of Small Lakes, Lynn T. Kenison

Theses and Dissertations

An estimate was made to determine the amount of nitrate and phosphate entering Utah Lake in 1968. To make this estimate, the flow data for 1968 and the nitrate and phosphate concentrations for 1970 were used. This was done because of the lack of information. The results show that the total nitrate added to Utah Lake in 1968 was 7,638,000 pounds. The total phosphate added was 1,740,200 pounds. Of this amount, 12,4 per cent of the nitrate and 18.0 per cent of the phosphate was released from the lake through the Jordan River. The rest remained in the lake to …

The Roles Of Chlorine Azide In Chemical Lasers, Walter Wood Rice

Theses and Dissertations

ClN_3 was photolyzed in various gas mixtures to transform its chemical energy into laser radiation. Reaction mechanisms, energy distribution in reaction products, and relative reaction rates were deduced from the laser emission. Flash photolysis of ClN_3-H_2 mixtures produced HCl laser emission; however, due to a narrow range of operating conditions and many competing reactions, the laser output was less than that obtained from comparable Cl_2-H_2 mixtures. The rate constants for H + ClN_3 —> HCl* (v=n) + N_3 were determined to be 0.45 ± 0.05 of the corresponding rate constants for H + Cl_2 —> HCl* (v=n) + Cl. Chlorine …

Solid-Liquid Phase Equilibria Of The Potassium-Rubidium And Rubidium-Cesium Alloy Systems, Elisabeth M. Delawarde

Theses and Dissertations

Thermal methods of high precision were used to determine the solid-liquid phase equilibria diagrams for the potassium-rubidium and the rubidium-cesium systems. Both form minima in the liquidus curves occurring at 307.00° K with 0.667 mole fraction rubidium in the potassium-rubidium system and 282.85° K with 0.530 mole fraction cesium in the rubidium-cesium system. In the potassium-rubidium system, the liquidus and solidus points are very close together, giving a very narrow temperature range for the two phase region. The freezing point minimum in the potassium-rubidium system occurs at 0.667 mole fraction rubidium, suggesting the possible formation of a KRb2 intermetallic compound.

I. Studies Toward The Synthesis Of Echinodithianic Acid And Ii. The Temperature Dependent Nmr Spectrum Of Methyl N-Acetylsarcosinate, Alan Leroy Love

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Approaches to the preparation of echinodithianic acid (5) from 2,5-dicarbomethoxy-1,4-dithiane (1) were not successful, due to the inability to carboxylate or carboalkoxylate 1 at carbons 2 and 5. Studies toward the synthesis of 5 utilizing methyl 2-acetamidoacrylate (8) have been investigated. The electrophilic addition of sulfur dichloride to 8 yielded bis-(2-acetamido-2-carbo-methoxyvin-1-yl) sulfide, while the addition of thiocyanogen chloride to 8 produced methyl 2-acetamido-3-thiocyanato-acrylate.

As electrophilic additions of unsymmetrical dipolar reagents to methyl 2-acetamidoacrylate (8) are not reported in the literature, the addition of hydrogen bromide to 8 was studied to determine the orientation effect of the acetamido group.

Methyl 2-acetamido-2-bromopropionate …

Calcium Carbonate Dissolution And Precipitation In Water: Factors Affecting The Carbonate Saturometer Method, Lyle M. Dabb

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The carbonate saturometer method developed by Weyl (1961) was studied in respect to the effect of several variables on the solubility of carbonates. The solubility of three solid carbonate materials was measured in four different salt solutions, at four ionic strengths, and at two different temperatures. The solids studied included: calcite, dolomite, and a calcareous soil.

It was found that the three solid carbonate materials varied in solubility from a low in the soil carbonates to a high in dolomite.

Increasing the ionic strength of the solution increased the solubility of most of the solid carbonate materials.

By decreasing the …

Ion‐Pair Theory Of Concentrated Electrolytes. Iii. Variational Principle, Frank Stillinger, Ronald White

Center for Advanced Mineral and Metallurgical Processing (CAMP)

Two major contributions are devised for that theory of concentrated electrolytes which by convention regards the ions as completely paired into uncharged dipolar “molecules.” First, a more satisfactory expression is obtained for the wavelength‐dependent static dielectric “constant” ε(k). Second, a variational principle for Helmholtz free energy F is displayed whose minimization with respect to the ion‐pair size distribution p(1) serves to determine both F and p(1). In anticipation of future numerical applications, a binary collision approximation is specified for the short‐range interaction aspect of the functional F[p(1)].

Ion‐Pair Theory Of Concentrated Electrolytes. Iv. Ion Atmosphere Charge Distribution, Frank Stillinger, Ronald White

Center for Advanced Mineral and Metallurgical Processing (CAMP)

Arguments are presented indicating that the large‐size limiting behavior of the ion‐pair size distribution is qualitatively the same both with, and without, Coulomb interactions between ions. This in turn implies that the static dielectric response function ε0 / ε(k) derived in the preceding paper is nonanalytic at k = 0. The specific singular behavior of this response requires a branch cut along the imaginary k axis. It furthermore induces an r−8 tail in the ion atmosphere charge distribution at finite electrolyte concentration.

A Study Of The Mechanism Of The Ligand Exchange Between Triethilenetetraminenickel(Ii) And 1,10-Phenanthroline, James Allan Boersma

Dissertations

No abstract provided.

Synthesis Of Chromium Tricarbonyl Complexes Of 1,3-Diaryl-2-Propyl Methanesulfonates, Ashby French Johnson

Master's Theses

Various unsymmetrically substituted 1 , 3-dipheny l -2- propylmethanesulfonates were prepared and complexed with chromium hexacarbonyl. The major products obtained from this complexation contained one rr -complexed ring and the other ring substituted with more common groups.

A Theoretical Analysis Of The Electronic States Of 2nd And 3rd Row Transition-Metal Complexes;-A Spectroscopic Investigation Of D5 And D6 Systems, Howard James Clifford

Chemistry and Chemical Biology ETDs

A theoretical and experimental investigation of a number of transition-metal complexes was conducted. The compounds of primary interest were six-coordinated complexes containing group VIII metal ions belonging to the second and third transition series. The investigation involved the synthesis and purification of the compounds, the measurement of absorption and emission spectra and luminescent lifetimes, and the analysis of the observed spectral properties using a crystal-field model based on solutions of large secular determinants. The effects of variations of the Racah parameters on the energy­level diagrams of dⁿ ions (n = 2, 3, ... , 8) in an octahedral crystal …

Simplified Sheep Skin Tanning, Department Of Agriculture, Western Australia

Journal of the Department of Agriculture, Western Australia, Series 4

Most people would agree that a white sheepskin rug adds a touch of luxury to any home.

The following method will produce dressed, woolly sheep skins with chemicals and equipment available to any householder.

The Crystal Structure Of Ethyl P-Azoxybenzoate, W. R. Krigbaum, Patrick G. Barber

Chemistry & Physics Faculty Publications

The low-temperature form (solid I) of the smectogenic compound ethyl p-azoxybenzoate (C18H18N2Os) is stable below 90 °C. The triclinic unit cell of space group P] and dimensions a = 7.56 + 0.02, b-- 18"35 + 0.07, c= 6.28 + 0.01 A, ¢¢= 94.38 ° + 0.30 °, ,8= 97.21 _+ 0.31 °, and y = 83.97 ° + 0.25 ° contains two molecules and has a calculated density of 1.325 g.cm-3. The observed density is 1.315 + 0.013 g.cm-3. Integrated intensities were measured at room temperature by a 20--~ scan on a four-circle diffractometer equipped with a post-diffraction monochromator and …