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No description available.

No description available.

No description available.

No description available.

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Particle Collision Electrochemistry (PCE) has gained considerable attention in heterogeneous catalysis, petroleum chemistry and pharmaceutical fields. The PCE refers to a phenomenon in which a particle strikes on an inert electrode surface as a consequence of its Brownian motion and produces a spike of current for the direct oxidation/reduction of the individual particle. This method allows us characterization of individual particles and in-situ study of electrochemical reactions coupled to the particle. Herein, emulsion droplets were studied by PCE where toluene droplets contained hydrophobic tetrachloro-1,4-benzoquinone (Q). This was investigated as a model system to study the molecular effects that arise due to hydrogen bonding reagents (oleic acid, acetic acid) inside and outside of the droplets. The emulsions were prepared by sonicating toluene-quinone solution with the water phase containing an ionic liquid to provide conductivity to the droplet. Each droplet produced a current spike while colliding with the electrode surface that was held at a potential to reduce tetrachoro-1,4-benzoquinone. In bulk acetonitrile and toluene, tetrachoro-1,4-benzoquinone undergoes a two electron reduction process to form the tetrachloro phenolate di-anion (Q2-). It was shown that the hydrogen bonding affinity of Q2- for acetic acid (pKa = 4.8) was higher than for oleic acid (pKa = 9.9) for both bulk systems (as acetic acid is stronger hydrogen bonding donor than oleic acid). However, the reversed trend was observed in emulsified toluene droplets when studied by PCE. This was attributed to the preferential partition of the carboxylic acids between the two phases in the emulsion. Oleic acid stays inside the droplets due its hydrophobic nature and hydrogen bonding with Q2- takes place inside the droplet. In contrast, solvation of acetic acid by the surrounding water, causes the hydrogen bonding with Q2- to occur significantly less inside the droplet. Another redox system studied by PCE was hydrophobic ferrocene (Fc) trapped in the toluene droplet to determine the effect of surfactant on the particle size. The diameter determined electrochemically was compared with Dynamic Light Scattering (DSL) measurements. The presence of nonionic surfactant (triton X-100) was observed to affect the droplet’s size easily monitored by PCE. The mediated oxidation of cysteine by the oxidized Fc inside the droplet was investigated at different concentrations of cysteine.

As consumer demand for all-natural marinades increases, the need to replace phosphate with a natural product that can produce equivalent or improved yield in products such as but not limited to rotisserie chickens (RWOG) and boneless/skinless breast (BSB) is a challenge for processors. The objective of this study was to determine if using an all-natural non-phosphate blend (savorphos-200, SP) in water-based (WB) and oil-based (OB) marinades would perform better in quality and yield parameters than a commercial phosphate blend (PB). The treatments included WB+PB (water, 0.4% phosphate, 0.7% salt), WB+SP (water, 0.5% savorphos-200, 0.7% salt), OB+PB (water, 3% canola oil, 0.4% phosphate, 0.7% salt), and OB+SP (water, 3% oil, 0.5% savorphos-200, 0.7% salt). RWOG and BSB were injected with a multi-needle injector to 20% (wt/wt) pick-up at a constant pressure (15-20 psi). The parameters measured were marinade pick-up %, 20 min and 24 hr marinade retention %, and cook loss %. Color, tenderness, total moisture, and sensory test were conducted on BSB. Data were analyzed within marination type (WB and OB). Results for the RWOG indicated SP obtained higher pick-up yield (p<0.05) and lower cook loss in the OB marinade compared to the PB. For the BSB, pick-up yield on OB marinades are higher for SavoPhos (p<0.05) when compared to the PB. On WB marinades cook loss was lower on SavorPhos compared to the PB. On RWOG and BSB variability is lower for SP on pick-up and 20 min retention yield values. Texture shear values were lower (p<0.05) on SP samples when compared to the PB. A consumer triangle sensory test was not able to distinguish between treatments (p>0.05). Therefore, savorphos-200 can be used as a natural non-phosphate blend in water based marinades with no detriment to yield. In addition, savorphos-200 can be used as a natural non-phosphate blend in oil-based marinades with yield improvements.

<p> A theoretical and experimental study is presented of the effect of oil/water system physical properties, surfactant concentration, and drop size on the drop rest-time and lamella behaviour. </p> <p> The work has three distinct parts. The first part is based on the assumption that the dynamic pressure distribution in the lamella can be described by a simple three term polynomial. Equations for the relative lamella thickness profile are derived and are shown to accurately describe experimental lamella thickness profiles measured both in this work and by other investigators. </p> <p> The second part presents and discusses the experimentally measured drop rest-times and simultaneously observed lamella behaviour for the range of variables studied. Five mechanisms are proposed to account for the observed lamella behaviour. </p> <p> The third part derives equations to describe the lamella drainage, the interfacial distribution of adsorbed surfactant for a lamella undergoing drainage, and the dynamic lamella pressure distribution. The solution of the lamella drainage equation is then compared with experimentally determined profiles of the relative lamella thickness for both the complex model and a simple model based on a parallel disc lamella. </p> / Thesis / Doctor of Philosophy (PhD)

A study on high-viscosity oil-water flow in horizontal pipes has been conducted applying experimental, mechanism analysis and empirical modelling, and CFD simulation approaches. A horizontal 1 inch flow loop was modified by adding a designed sampling section to achieve water holdup measurement. Experiments on high-viscosity oil-water flow were conducted. Apart from the data obtained in the present experiments, raw data from previous experiments conducted in the same research group was collated. From the experimental investigation, it is found that that the relationship between the water holdup of water-lubricated flow and input water volume fraction is closely related to the oil core concentricity and oil fouling on the pipe wall. The water holdup is higher than the input water volume fraction only when the oil core is about concentric. The pressure gradient of water-lubricated flow can be one to two orders of magnitude higher than that of single water flow. This increased frictional loss is closely related to oil fouling on the pipe wall. Mechanism analysis and empirical modelling of oil-water flow were conducted. The ratio of the gravitational force to viscous force was proposed to characterise liquid-liquid flows in horizontal pipes into gravitational force dominant, viscous force dominant and gravitational force and viscous force comparable flow featured with different basic flow regimes. For viscous force dominant flow, an empirical criterion on the formation of stable water-lubricated flow was proposed. Existing empirical and mechanistic models for the prediction of water holdup and/or pressure gradient were evaluated with the experimental data; the applicability of different models is demonstrated. Three-dimensional CFD modelling of oil-water flow was performed using the commercial CFD code Fluent. The phase configurations calculated from the CFD model show a fair agreement with those from experiments and mechanism analysis. The velocity distribution of core annular flow is characterised with nearly constant velocity across the oil core when the oil viscosity is significantly higher than the water viscosity, indicating that the high-viscosity oil core flows inside the water as a solid body. The velocity profile becomes similar to that of single phase flow as the oil viscosity becomes close to the water viscosity.