Physical Sciences and Mathematics Commons^™

Empirical Equations For Activity And Osmotic Coefficients, N. Ragunathan

Masters Theses

A system of equations for fitting the experimental activity and osmotic coefficients of single and mixed electrolytes in aqueous solutions has been empirically developed in the present research. The results obtained through the equations developed here are comparable to the Pitzer equations in terms of accuracy and range of fitting. The equation for activity coefficient developed in the present research compared to the Pitzer activity coefficient equation has a form which is conveinient for computational purposes. The equation for activity coefficients is ln g = -╎Z_mZ_x╎A_D[I^1/2/(1 + bI^1/2)] + E …

Characterization Of The Capsular Polysaccharides On Cell Membranes Of Rhizobium Trifolii And Three Of Its Nod- Mutants, Jesse Ardosa

Masters Theses

The ever-present specter of the inavailability of food production to increase in direct proportion to population growth haunts practically every nation of the world. As more and more tracts of land are incorporated to accommodate expanding cities, they become less available for food production. Emphasis, therefore, is placed on obtaining a higher yield per acreage planted. Since fertilization is not reliable in the long term due to an eventual depletion of raw materials for fertilizers, the ability of plants like legumes to assimilate free soil nitrogen on their own has become increasingly important [1,11,14,17]. However, the mechanisms involved are still …

Electrochemical Studies Of Transition Metal Carbonyls, Dwayne Edward Cooper

Masters Theses

The electrochemical oxidation of (OC)₅MP-PM'(CO)₅ (M=Cr, Mo, W; M'=Cr, Mo, W; M=M' or M≠M'; P-P=Ph₂PCH₂CH₂PPh₂) and the reduction of the oxidized products in a 0.1 M tetrabutyl-ammonium perchlorate methylene chloride solution at a platinum disc working electrode with a Ag/AgCl reference electrode have been studied. The number of electrons in the oxidation step was determined by comparison with the one electron oxidation of ferrocene which had a peak potential at +0.15 V.

The cyclic voltammograms of the homobimetallic and heterobimetallic complexes display two general chacteristics: quasi-reversible or irreversible one …

Synthesis Of Phosphine Trans-Substituted Derivatives Of Iron Pentacarbonyl, Karl Heinz Hecker

Masters Theses

The synthesis of trans-Fe (CO)₃(PR₃)₂ (PR₃ = PPh₃, PPh₂Me, PPh₂CHCH₂, P(c-C₆H₁₁)₃, P(n-C₄H₉)₃, PPh₂H) can be achieved by refluxing iron pentacarbonyl under reducing conditions in the presence of ligand in 1-butanol. Addition of iron pentacarbonyl to a 1-butanol solution of sodium borohydride at room temperature results in a quantitative conversion of the iron carbonyl complex to the corresponding mononuclear formyl complex. Upon heating the initially formed formyl species decomposes to form the …

Studies Of Sodium Dodecylbenzenesulfonate-Water-Electrolyte Interactions, Xiaoxiang Zhu

Masters Theses

A surfactant selective electrode using a PVC membrane was constructed. A surfactant (sodium dodecylbenzene-sulfonate)-H₂O system was studied at 15°, 19°, 25°, and 40°C with the PVC electrodes, a Na⁺ selective electrode, and a conductivity bridge. Pre-micelle regions at the above temparatures were observed. The critical micelle concentrations (CMC^b) obtained by the PVC electrodes in salt-free systems are: 1.63x10^-3 M at 15°C, 1.48x10^-3 M at 19.1°C, 1.52x10^-3 M at 25°C, and 1.73x10^-3 M at 41.6°C. The CMC'c obtained by the Na⁺ electrode are: 1.62x10^-3 M at 15°C, 1.37x10^-3 M …

Analysis Of The Charleston, Illinois Water Supply For The Presence Of Organic Mutagens Utilizing The Ames Salmonella/Microsome Assay, Steven Lee Washburn

Masters Theses

Water samples from the Charleston, Illinois water supply and selected agricultural run-off areas were tested for the presence of organic mutagenic chemicals. The Ames Salmonella/microsome mutagenicity assay utilizing strains TA98 and TA100 was used to analyze concentrated water samples. A special set of samples was exposed to the S9 activation system coupled with the TA98 strain to simulate the mammalian metabolic system.

No mutagens were detected in any of the samples tested. Several positive and negative control systems were included in the testing system. Negative control systems were used to determine the average spontaneous reversion rates for each strain for …

Syntheses And Electrochemistry Of Monosubstituted Carbonyl Complexes Of Low Valent Ruthenium, Nor Azowa Ibrahim

Masters Theses

The reactions of Ph₂MeP and PhMe₂P with (PPh₃)₄RuCl₂ yield (PPh₂Me)₄RuCl₂ and (PPhMe₂)₄RuCl₂, respectively. These complexes have been shown by conductivity studies to be dissociated in acetonitrile and exist as [(PPh₂Me)₄RuCl(CH₃CN)]Cl and [(PPhMe₂)₄RuCl(CH₃CN)]Cl. When carbon monoxide was bubbled into these solutions, monocarbonyl complexes were obtained. Elemental analyses, ¹H NMR, ³¹P NMR, infrared spectroscopy, conductivity measurements, and polarography were used to analyse the products, (PPh₂Me)_{2 …}

Enhancement Of Ether Cleaving Reactions By Intramolecular Hydrogen Bonding, Nobumi Takemura

Masters Theses

Rate constants of cleavages of fourteen alkyl-aryl ethers with HI, KI, or LiI in pyridine at 50-150°C were determined under pseudo first order conditions. The following ethers which have a six-membered ring intramolecular hydrogen bond underwent a bimolecular nucleophilic displacement by iodide ion in pyridine: 8-methoxy-1-naphthalenol, 8-ethoxy-1-naphthalenol, 2-methoxybenzoic acid, and 2-hydroxybenzyl methyl ether. The following ethers which lack a six-membered ring hydrogen bond were not cleaved or underwent cleavage slowly compared with the hydrogen bonded compounds: 1,8-dimethoxynaphthalene, 1,8-diethoxynaphthalene, 1-methoxynaphthalene, 4-methoxybenzoic acid, methyl 2-methoxybenzoate, 2-methoxybenzyl methyl ether, and 4-methoxybenzyl methyl ether. The pattern of ether reactivity indicated that a six-membered ring …

Isolation And Partial Analysis Of Proteins And Polysaccharides Of Rhizobium Trifolii, Manuelito M. Ordonez

Masters Theses

The outer membrane and periplasmic proteins of Rhizobium trifolii ANU 843 and its mutants ANU 851 and ANU 845(pRt150) were isolated and analyzed by polyacrylamide gel electrophoresis (PAGE). ANU 843 is the wild type strain which possesses all the characteristics necessary for nitrogen fixation. ANU 851 has a transposon (Tn5) inserted into the nodD gene of the root hair curling region of the symbiotic plasmid. It has lost its ability to cause root hair curling and therefore can not form nodules and can not fix nitrogen. ANU 845(pRt150) harbors only the 5.5 kb root hair curling region of the …