Physical Sciences and Mathematics Commons^™

The Mechanism Of Hydrotrope Action Of A Dicarboxylic Acid, Stig Friberg, S. B. Rananavare, D. W. Osborne

Chemistry Faculty Research & Creative Works

The mechanism of the hydro trope action of a dicarboxylic acid Mono soap was investigated by determination of the change in order parameter of the amphiphile in a lamellar liquid crystal. The results showed addition of the hydro trope considerably to reduce the order while addition of a surfactant had no effect. © 1986.

Race, Sex And Occlusive Cerebrovascular Disease: A Review, L. R. Caplan, P. B. Gorelick, D. B. Hier

Chemistry Faculty Research & Creative Works

No abstract provided.

Interobserver Agreement In The Diagnosis Of Stroke Type, Cynthia R. Gross, David Shinar, Jay P. Mohr, Daniel B. Hier, Louis R. Caplan, Thomas R. Price, Philip A. Wolf, Carlos S. Kase, Irene G. Fishman, Sandra Calingo, Selma C. Kunitz

Chemistry Faculty Research & Creative Works

Interobserver Agreement is Essential to the Reliability of Clinical Data from Cooperative Studies and Provides the Foundation for Applying Research Results to Clinical Practice. in the Stroke Data Bank, a Large Cooperative Study of Stroke, We Sought to Establish the Reliability of a Key Aspect of Stroke Diagnosis: The Mechanism of Stroke. Seventeen Patients Were Evaluated by Six Neurologists. Interobserver Agreement Was Measured When Diagnosis Was based on Patient History and Neurologic Examination Only, as Well as When It Was based on Results of a Completed Workup, Including a Computed Tomographic Scan. Initial Clinical Impressions, based Solely on History and …

A Non-Aqueous Lamellar Liquid Crystal With An Ionic Surfactant-Long Chain Alcohol Combination, Stig Friberg, Paul Liang, Yuh Chirn Liang, Bettye Greene, Ron Van Gilder

Chemistry Faculty Research & Creative Works

A non-aqueous lamellar liquid crystal of sodium dodecyl sulfate, decanol and glycerol was prepared and compared with its aqueous counterpart. The results show that the stability of the liquid crystal with glycerol is critically dependent on the surfactant/alcohol ratio, whereas the liquid cry. The interlayer spacing was smaller for the glycerol system than for the water system at finite amount of solvent, but the value extrapolated to zero so. © 1986.

Foams From A Three-Phase Emulsion, Hironobu Kunieda, Stig Friberg

Chemistry Faculty Research & Creative Works

Foam stability was related to phase behavior in a foamed three-phase region consisting of an aqueous solution (L1), an alcohol solution (L2) and lamellar liquid-crystalline (LC) phases in the C8H17SO3Na/C8H17OH/H2O system. The state of the system before foaming was LC/L2 + LC/L1 or L1 + L2/LC type emulsions up to a high octanol/water ratio of 77/23. In L2 + LC/L1 emulsion, the LC droplets exist separately from the alcohol droplets in an aqueous continuous medium. The viscosity of the system was enhanced with an increase in the content of dispersed phases, i.e. alcohol and/or liquid crystal phases contributing to the …

Solvation Changes Induced In A Lyotropic Lamellar Liquid Crystal Containing Solubilized Benzene, Anthony J.I. Ward, Shankar B. Rananavare, Stig Friberg

Chemistry Faculty Research & Creative Works

Deuterium NMR quadrupole splitting's of deuterated benzene and water were studied as a function of their composition in the aqueous lamellar phase of Penta ethylene glycol n-dodecyl ether. An interpretation of the results is given in terms of hydration changes of the poly(oxyethylene) chains related to changes in the benzene solvation and location within the head-group region. © 1986, American Chemical Society. All rights reserved.

Surfactant Association Structures And The Stability Of Emulsions And Foams, Stig Friberg, Concepcion Solans

Chemistry Faculty Research & Creative Works

Traditional surfactants in combination with water and a more hydrophobic amphiphile, such as an alcohol or a carboxylic acid, present a rich variety of colloidal association structures, both micelles and lyotropic liquid crystals. The presence of such association structures has a pronounced influence on the stability of macro dispersed systems such as emulsions and foams. A few examples of such an influence are discussed. © 1986, American Chemical Society. All rights reserved.

Stability Of Hydrophobic Foams, Stig Friberg, Irena Blute, Hironobu Kunieda, Per Stenius

Chemistry Faculty Research & Creative Works

The stability of foams was determined in two-phase regions containing an isotropic hydrocarbon solution and a lamellar liquid crystal. The lamellar liquid crystal showed surface activity with regard to the hydrocarbon solution. This was interpreted as due to the higher frequency of methyl groups at the surface of the liquid-crystalline state compared to the liquid state. The weaker intermolecular forces from the methyl groups were assumed to result in a lower surface tension of the liquid crystal in comparison to the liquid. This hypothesis was tested by the use of a low surface tension hydrocarbon, isooctane. No foam stability was …

Influence Of Geometric Factors Of The Substrate On Hydrophilic Surface Modification Of Polyurethane Sponges By Plasma Treatment, D. L. Cho, H. Yasuda

Chemistry Faculty Research & Creative Works

The surface modification by plasma treatment occurs by consecutive processes of excitation of gas(es) and deexcitation of excited species. The deexcitation occurs primarily at the surface yielding chemical modification of the surface (nonpolymer-forming plasmas) or deposition of material (polymer-forming plasma) on the substrate surface. Because of this sequence, geometric factors of the substrate in relation to the surrounding plasma phase have crucial influence on the effectiveness of plasma treatments. Simple mathematical models were developed to illustrate the effect of geometric factors involved in plasma treatments, and experimental results obtained with porous polyurethane sponges in various sizes were examined by the …

Flow Injection And Photometric Determination Of S(Iv) In Rainwater With Pararosaniline, Frank A. Hedgecock

Retrospective Theses and Dissertations

The photometric pararosaniline (pRA) method for determination of S(IV) has been adapted to flow injection sample processing (FIA). Prominent features of the method include a limit of detection of 0.010 ppm of dissolved sulfur dioxide and a sampling rate of 20 per hour. The concentration range investigated was 0.010 to 0.200 ppm S0₂. Sequential samples were collected from two rainstorms and SO₂ concentrations were measured for 19 samples. The suppression of interference by Cr(III), Mn(II), and Fe(III) using 1,2-cyclohexylenedinitrilotetraacetic acid (CDTA) and ethylenediaminetetraacetic acid (EDTA) was investigated. A comparison of the adapted FIA method and its parent …

New Synthetic Applications Of Enaminoketones, Timothy J. Buck

Retrospective Theses and Dissertations

This report discusses research concerning synthetic applications of enaminoketones. The work may be divided into four parts as follows: a) replacement of the dimethylamino group of certain enaminones by other amine groups through a simple procedure; b) formation of 3-alkyl-pyrazoles; c) formation of 2-amino-4-alkyl-pyrimidines; d) synthesis and subsequent reduction of iminium salts. The starting materials (E-1-(N,N-dimethylamino)-1-alkene-3-ones) have been condensed with hydrazine and guanidine to form pyrazoles and pyrimidines, respectively. The same starting materials have been reacted with POCl₃ in CH₂Cl₂ to produce chlorovinyliminium salts. These have then been reacted in situ with reducing agents to produce …

The Synthesis And Characterization Of Some Thermally Stable Polypyrazoles And Acetylene Terminated Aspartimides, John W. Connell

Theses and Dissertations

Reactions involving the nucleophilic addition cyclization to activated acetylenes have been employed as a novel route to moderate to high molecular weight polymers. Polypyrazoles (PI to P12) have been prepared from the Michael-type addition cyclization of various aromatic dihydrazines to aromatic dipropynones in m-cresol. The aromatic dihydrazines employed were 4, 4'-dihydrazinodiphenyl ether (4,4' -DHDPE), 4,4 '-dihydrazinodiphenylmethane (4, 4'-DHDPM), and 4, 4' -dihydrazinodiphenyl sulfone (4,4'-DHDPS). The dipropynone sutilized were 1,1’- (1,4-phenylene) bis (3-phenyl- 2-propyn-l-one), (l,4 -PPPO), 1,1’ - (1, 3-phenylene) bis (3 -phenyl- 2 -propyn-l-one), (1,3-PPPO), 1,1 '-(1,4 -phenylene) bis (2 -propyn- l-one), (1,4 -PPO), and 1,1’- (1,3 -phenylene) bis (2 …

A Theoretical Investigation Of The One– And Two–Photon Properties Of Porphyrins, Mark Masthay, Leonore A. Findsen, Brian M. Pierce, David F. Bocian, James S. Lindsey, Robert R. Birge

Chemistry Faculty Publications

The one‐ and two‐photon properties of free base porphin, free base porphin dianion, and the 2,4‐substituted diformyl and divinyl analogs of these molecules are studied using a semiempirical SCF‐MO formalism (CNDO‐π‐SCF‐MO‐PSDCI) including extensive single and double configuration interaction. Strongly two‐photon allowed states are predicted to lie in the Soret region as well as in the region between the Soret and visible bands. A number of the two‐photon allowed states in the Soret region are predicted to have two‐photon absorptivities exceeding 100×10−50 cm4 s molecule−1 photon−1. The calculations indicate that the visible (Q) states are well characterized by the …

Structure Of L,L-Diphenylphosphorinanium Bromide Monohydrate, J. A. Campbell, R. Larsen, R. Ekeland, Sheldon E. Cremer

Chemistry Faculty Research and Publications

No abstract provided.

Correction Of The Basis Set Superposition Error In Scf And Mp2 Interaction Energies. The Water Dimer, M. M. Szczesniak, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

There has been some discussion concerning whether basis set superposition error is more correctly evaluated using the full set of ghost orbitals of the partner molecule or some subset thereof. A formal treatment is presented, arguing that the full set is required at the Møller–Plesset level. Numerical support for this position is provided by calculation of the interaction energy between a pair of water molecules, using a series of moderate sized basis sets ranging from 6‐31G∗∗ to the [432/21] contraction suggested by Clementi and Habitz. These energies, at both the SCF and MP2 levels, behave erratically with respect to changes …

The Synthesis Of Hindered Aliphatic Ketones For The Future Production Of Spiro [4.5] Decane Sesquiterpenes, Stephen Lee Hodges

Dissertations, Theses, and Masters Projects

No abstract provided.

Peroxo Complexes Of Vanadium(V) And Molybdenum(Vi) With Nicotine And Aspartic Acids, Sandra Jean Sheffield

Dissertations, Theses, and Masters Projects

No abstract provided.

The Stereospecific Synthesis Of Tetrahydropyrans And Tetrahydrofurans, Rhonda Carol Winstead

Dissertations, Theses, and Masters Projects

No abstract provided.

The Cure Reaction Of An Aromatic Thermosetting Polyimide, Michael Edward Whitham

Dissertations, Theses, and Masters Projects

No abstract provided.

Some Useful Synthetic Applications Of Gold's Reagent, John T. Gupton

Chemistry Faculty Publications

While looking for some appropriate research projects, I had been impressed by and interested in the work of Danishefsky¹ and others² regarding the use of "Eschenmoser's salt" (1). During the course of a literature search on an industrial project, we came across an article by Gold,³ which described the preparation of a rather interesting vinylogous iminium salt (2). The name assigned to this compound was [3-(dimethylamino)-2-azaprop-2-en-1-ylidene]dimethylammonium chloride. This terminology seemed a little cumbersome for routine discussions so we adopted the name "Gold's Reagent" for compound 2. Although the reagent had been prepared³ in 1960, very little …

Microemulsions With High Water Solubilizing Capacity At High Hydrocarbon Levels And Very Low Surfactant Concentrations, Raymond L. Venable, Kay Lynn Elders, Jiafu Fang

Chemistry Faculty Research & Creative Works

Phase diagrams have been determined showing the extent of the inverse micellar or microemulsion region for systems consisting of water-surfactant-cosurfactant or water-surfactant-hydrocarbon cosurfactant mixture with three surfactants and four cosurfactants. The surfactants are sodium dodecyl sulfate, sodium laurate, and tetradecyltrimethylammonium bromide while the cosurfactants are pentanol, hexanol, pentylamine, and hexylamine. Hexylamine is found to be a very effective cosurfactant giving rise to very good water solubilizing capacity at extremely low surfactant concentrations and very low cosurfactant levels at rather high initial hydrocarbon levels. © 1986.

Anomalous Concentrations Of Co-58 And Cs-137 In Dardanelle Reservoir, David M. Chittenden Ii

Journal of the Arkansas Academy of Science

The unforseen occurrence of significant concentrations of Co-58 and Cs-1 37 in a quiescent backwater of Dardanelle Reservoir provided an opportunity to observe the equilibrium distribution of Cs-1 37 between solution and suspended solids. This equilibrium has not been observed in other areas of the reservoir because small amounts of this nuclide are regularly injected into the lake by the AP&L Nuclear I facility. The systematics of the Co-58 concentration lead to the conclusion that significant amounts of these two nuclides had been injected into the sampling area from a source unknown.

Nonadiabatic Theory Of Fine-Structure Branching Cross Sections For Na-He, Na-Ne, And Na-Ar Optical Collisions, Linda L. Vahala, P. S. Julienne, Mark D. Havey

Electrical & Computer Engineering Faculty Publications

The nonadiabatic close-coupled theory of atomic collisions in a radiation field is generalized to include electron spin and is used to consider the weak-field Na–rare-gas (RG) optical collision Na(²S_1/2)+RG+nhν μNa(²P_j)+RG+(n-1)hν. The effects of detuning and incident energy on the branching into the atomic Na 3p²P_3/2 and 3p²P_1/2 states are examined. The cross sections σ(j) are found to have a strong asymmetry between red and blue detuning as well as a complex threshold and resonance structure dependence on energy. A partial cross-section analysis …

Use Of Isomerizable N-Alkylmerocyanine Dyes To Robe Molecular Interactions Within Micellar Solubilization Sites, Kim Jason Dennis

University of the Pacific Theses and Dissertations

Effects of aqueous surfactant solutions upon cis/trans isomerization reactions of various N-alkyl-merocyanine dyes (II) were studied. Dramatic rate enhancements were found for all dyes in CTAB and SDS solutions above the CMC. CTAB solutions showed the greatest effect with some dye isomerizations catalyzed in excess of 1000-fold. Increases in either CTAB concentration or dye isomerization rates. N-methyl through N-pentyl dye isomerization rates were measured as a function of CTAB concentration and the data treated according to the pseudophase model for micellar catalysis. K_S values ranged from 198 to 2000 M^-1 for N-methyl to N-pentyl dyes, respectively. Micellar rate …

The Potential Energy Surface Of (Nh3)2, Z. Latajka, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

Ab initio calculations at the SCF and correlated levels are carried out to characterize the potential energy surface of the NH₃ dimer. The two basis sets used are 4‐31G∗ and a larger one containing two sets of d‐functions on N centers, 6‐31G∗∗ (1p, 2d). The only minimum occurring on the surface is a cyclic C_2h structure in which the two H‐bonding protons are displaced 42° from the N‐‐N axis. The surface contains a very shallow valley along the direction leading from this geometry to a single linear H bond although …

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 …

Secondary Isotope Effects Of Nucleophilic Vinylic Substitution, Paul Frederick Drees

Dissertations, Theses, and Masters Projects

No abstract provided.

Peroxo Complexes Of Molybdenum (Vi) And Vanadium (V) With Imidazole And Histidine, Jennifer Lisa Gundersen

Dissertations, Theses, and Masters Projects

No abstract provided.

Carbon Alkylation Of 2-Phenylthio-1,3-Cyclopentanediones, Karol Renee Parham

Dissertations, Theses, and Masters Projects

No abstract provided.

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 …