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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

The effect of chelating agents on the oleic acid flotation of iron oxide from Wisconsin Gogebic Range taconite

Friz, Thomas Otto, January 1966 (has links)
Thesis (M.S.)--University of Wisconsin--Madison, 1966. / eContent provider-neutral record in process. Description based on print version record. Bibliography: l. 56-57.
12

The solubility of oleic acid, abietic acid, and their mixtures in propane up to the critical temperature; a basis for the practical separation of these acids ...

Hixson, Arthur Norman, January 1941 (has links)
Thesis (Ph. D.)--Columbia University, 1941. / Vita. "Literature cited": p. 28.
13

Conjugated Linoleic Acid/Styrene/Butyl Acrylate Bulk and Emulsion Polymerization

Roberge, Stéphane January 2016 (has links)
The potential for conjugated linoleic acid (CLA) incorporation into pressure-sensitive adhesive (PSA) formulations was evaluated. A series of free radical bulk copolymerizations of CLA/styrene (Sty) and CLA/butyl acrylate (BA) were designed to allow the estimation of reactivity ratios. Bulk terpolymerizations of CLA/Sty/BA were also evaluated before moving to emulsion terpolymerizations of CLA/Sty/BA. The polymers were characterized for composition, conversion, molecular weight and glass transition temperature while latexes were characterized for viscosity, particle size, tack, peel strength, and shear strength. All experiments were performed at 80oC and monitored with attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy. While bulk experiments were monitored off-line, the emulsion experiments were monitored in-line. Absorbance peaks related to the monomers and polymer were tracked to provide conversion and polymer composition data using a multivariate calibration method. Off-line measurements using gravimetry and 1H-NMR spectroscopy were compared to the ATR-FTIR data and no significant differences were detected between the measurement methods. Pseudo-kinetic models, developed and validated with the copolymer experimental data, were used to estimate reactivity ratios. The copolymer pseudo-kinetic models were extended to a terpolymer pseudo-kinetic model and validated with experimental data. The pseudo-kinetic models incorporated the ability of oleic acid, a common impurity found in CLA, to trap electrons thus influencing the reaction kinetics significantly. The influence of terpolymer composition, chain transfer agent concentration, cross-linker concentration, molecular weight, viscosity and particle size on tack, peel strength and shear strength was investigated by using a constrained mixture design. The final forms of the resulting empirical models allowed the creation of 3D response surfaces for PSA performance optimization. The incorporation of 30 wt.% CLA into a practical PSA application suitable for the removable adhesives category was achieved.
14

Effect of ethyl oleate and oleic anhydride on metronidazole release from poly(ortho esters) films

Chaudhury, Kamalika 01 January 1998 (has links)
In the present study, the effects of selected concentrations (0, 0.375, 0.75, 1.5 and 2.25% w/w) of ethyl oleate or oleic anhydride, the latentiated forms of catalyst oleic acid, were compared with regard to the release characteristics of metronidazole (1 0% w/w) from poly( ortho esters) films in distilled water at 3 7 °C. The rate of release of metronidazole from poly(miho esters) films was dependent on the ethyl oleate or oleic anhydride concentrations. The poly(ortho esters) films with adjuvants demonstrated slower drug release for all concentrations of ethyl oleate studied and for 0.375% and 0.75% w/w of oleic anhydride. The effects of drug loading (5, 7.5 and 10% w/w) and film thickness (150 to 400 !J.m) were also studied in the presence of 0.75 %w/w of either adjuvant. Increasing drug loading enhanced the rate of drug release from films of same thickness. However, variation of film thickness (150 to 400 !J.m) did not significantly alter the release profile possibly due to high concentration of the drug in the film (10% w/w). Gel permeation chromatography, scanning electron microscopy and near zero-order release, in vitro, suggested that the steady-state release of metronidazole from the poly( ortho esters) films following the burst effect occurred initially by a combination of diffusion and surface erosion of the polymer. Later, the release was further complicated by onset of bulk erosion of the polymer due to catalysis by oleic acid produced by ester or anhydride hydrolysis.
15

Oxidation of lipids in a supercriticalluid medium

Sparks, Darrell Lynn 03 May 2008 (has links)
Efficient use of renewable feedstocks for production of chemicals and intermediates is necessary to reduce dependence upon petroleum. A large portion of these chemicals could be produced using lipids from renewable feedstocks such as vegetable oils, animal fats, and bacterial lipids. For example, many lipid sources contain unsaturated fatty acids, which can be oxidized to form a variety of products such as diacids and epoxides. These chemicals are used to formulate herbicides, detergents, plasticizers, lubricants, paints, and other useful products. One of the most common unsaturated fatty acids is oleic acid, and it can be oxidized with an ozone/oxygen mixture to produce azelaic acid and pelargonic acid. Since the ozone/oxygen mixture is a gas and oleic acid is a liquid under reaction conditions, mass transfer limitations exist. However, a reduction of the mass-transfer limitations can be achieved if the reactants coexist in a single phase. When supercritical carbon dioxide (SC-CO2) is used as the reaction medium, it is possible for both oleic acid and the ozone/oxygen mixture to both exist in the same phase at the same time. Use of supercritical carbon dioxide also provides the possibility of product fractionation, depending upon the solubility of the products in SC-CO2. The overall goal of this research was to determine if any advantages could be realized by conducting the oleic acid oxidation in a supercritical fluid medium. First, the solubility of azelaic acid and pelargonic acid in supercritical carbon dioxide was determined over a range of temperatures and pressures. Pelargonic acid was found to have a significantly higher solubility than azelaic acid, which indicated the potential for product separation with supercritical carbon dioxide. Second, the impact of the solvent medium on reaction kinetics and product formation was determined using two oxidizers: ozone and potassium permanganate. Due to experimental limitations, no reaction was observed in the case of ozone in supercritical carbon dioxide. However, oxidation of oleic acid with potassium permanganate in supercritical carbon dioxide resulted in higher oleic acid conversion and increased yields of azelaic acid and pelargonic acid compared to the oxidation without SC-CO2.
16

Postruminal flow, digestibility, and utilization of fatty acylamides or conjugated linoleic acid for milk fat synthesis by lactating Holstein cows

Loor, Juan Jose 11 December 1997 (has links)
Four Holstein cows with ruminal and duodenal cannulas were used to evaluate the effects of dietary fatty acylamides (canolamide) or abomasally infused conjugated linoleic acid on milk production and composition. In the first experiment, cows were fed diets with no supplemental fat(control), or the control diet supplemented at 3.3% of DM with canola oil, canolamide, or a mixture of equal amounts of canola oil and canolamide in a 4 x 4 Latin square. DMI and milk yield were decreased when cows were fed canolamide. Intake and duodenal flow of diet components and fatty acids were decreased by canolamide, but their apparent digestibilities were not affected by treatment. Fat supplementation decreased concentrations of fatty acids with 8 to 16 carbons and increased oleic acid in milk. In the second experiment, cows were infused abomasally with 100 g Linoleic acid (LA) or a mixture of 100 g LA plus 100 g conjugated linoleic acid (LA-CLA) for 24 h in a single crossover design. Infused CLA was a mixture of 70% cis-9, trans-11-18:2 and 30% trans-10, cis-12-18:2. Milk yield and DMI were not affected by treatment. Milk fat percentage and yield were decreased by LA-CLA. Concentration and yield of oleic and arachidonic acid and fatty acids with 6 to 16 carbons in milk were reduced by LA-CLA. Stearic acid and CLA concentrations in milk, however, were higher in response to LA-CLA. Infusion of LA-CLA led to increased (from 23 to 45%) concentration of unsaturated fatty acids with a concomitant decrease (from 70 to 42%) in saturated fatty acid concentration in milk fat. Feeding canolamide at 3.3% significantly decreased DMI and milk yield compared with canola oil or the mixture of canola oil and canolamide. However, results indicated that oleic acid and CLA concetration in milk fat can be increased proportionally to their flow into the small intestine. Utilization of these fatty acids for milk fat synthesis may cause a reduction in the amount of medium and short chain fatty acids synthesized de novo within the mammary gland. Furthermore, CLA appears to be a potent inhibitor of milk fat synthesis and desaturation of stearic and linoleic acid. / Master of Science
17

Aqueous-Organic Phase Transfer of Gold and Silver Nanoparticles Using Thiol-Modified Oleic Acid

López-Millán, Alejandra, Zavala-Rivera, Paul, Esquivel, Reynaldo, Carrillo, Roberto, Alvarez-Ramos, Enrique, Moreno-Corral, Ramón, Guzmán-Zamudio, Roberto, Lucero-Acuña, Armando 09 March 2017 (has links)
The handling of metallic nanoparticles often requires their dispersion into several polar and nonpolar solvents. Solid-phase stages or polymer-based ligands are commonly required to complete the transfer. The construction of a thiol ligand based in oleic acid, and its ability to efficiently assist in gold and silver nanoparticle aqueous-organic phase transfer is reported. After the transfer, the particles are completely dispersed in an organic solvent, preserving their diameter and morphology, as confirmed by ultraviolet-visible spectroscopy and scanning transmission electron micrographs.
18

OLEIC ACID VESICLES: FORMATION, MECHANISMS OF REACTIVITY, AND USES IN DETERMINATION OF TERPENE ACTIVITY

Walther, Laura A. 01 January 2019 (has links)
This dissertation will focus on the volatile compounds released upon the burning of incense which are numerous and varied. The first part of this dissertation is the gas chromatography-mass spectral (GC-MS) analysis of burning incense collected via solid phase microextraction (SPME) with the aim of developing a library of compounds found in incense as used in the Orthodox church. The second part of this dissertation has the aim of developing a method for forming oleic acid bilayer vesicle membranes and a fluorescence spectroscopy method by which the reactivities of these vesicles can be analyzed. These reactivities include permeability, fluidity, aggregation, and fusion of the membranes. One family of the volatile compounds found in incense are the terpenes and terpenoids. The reactivity of the terpenes and terpenoids found in incense will be analyzed using the oleic acid vesicles with the hypothesis that terpenes of the same structural groups will act similarly on oleic acid vesicle membranes and these reactivities can be related to mechanistic interactions.
19

Proteina isolada da soja (glycinae max) .Influencia no metabolismo do acido oleico verificada com o emprego do I-125

SOSA de PEREIRA, NILDA P. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:23:46Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:57:09Z (GMT). No. of bitstreams: 1 01005.pdf: 1669281 bytes, checksum: e0964528b687aaa8cc09a76baf3c0352 (MD5) / Dissertacao (Mestrado) / IEA/D / Instituto de Biociencias, Universidade de Sao Paulo - IB/USP
20

Proteina isolada da soja (glycinae max) .Influencia no metabolismo do acido oleico verificada com o emprego do I-125

SOSA de PEREIRA, NILDA P. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:23:46Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:57:09Z (GMT). No. of bitstreams: 1 01005.pdf: 1669281 bytes, checksum: e0964528b687aaa8cc09a76baf3c0352 (MD5) / Dissertacao (Mestrado) / IEA/D / Instituto de Biociencias, Universidade de Sao Paulo - IB/USP

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