The gas transport and separation properties of polymers have been successfully exploited in commercial ventures. Industrial applications employing membrane processes range from production of pure gases to barrier coatings for protection against environmental elements. Membrane separations are simple, energy efficient processes, which can be economically competitive with traditional separation technologies. Membrane separation and permeation characteristics for a particular mixed gas system is typically calculated from single-component transport parameters, namely, diffusion coefficients and solubility constants. In certain gas systems involving gaseous or vapor mixtures, where mass transport is affected by coupling effects or competition between penetrants for unrelaxed free volume, such calculations can lead to erroneous estimates of the membrane separation efficiency. Attempts to study the true transport phenomena effective during mixed gas permeation through membranes have been restricted due to experimental limitations. Also, the absence of rigorous theoretical models hinders the complete understanding of the transport phenomena. The current research involved design and development of an experimental set-up for observing mixed gas permeation through non-porous membranes with real time resolution. The technique employs a gas chromatograph as the selective detector for monitoring the variation in gas concentration, as the gases permeate through the membrane. The same set-up can also be used for conducting single gas permeation experiments. The novelty in the experimental set-up is the In-line sampling interface, used for injection of permeate gases in the GC without introducing any leaks in the permeate volume. Also, a novel data cropping technique is used to elucidate the transport properties of gases through membranes under mixed gas permeation conditions. Mixed gas feed concentration studies performed on a rubbery polymer (PDMS: poly dimethyl siloxane) showed no coupling effects. However, with a glassy polymer (NEW TPI: thermoplastic polyimide), the synergistic effects of gases is observed to play a major role in altering the gas transport and separation properties of the membrane. / Ph. D.

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Field studies conducted in Missouri and Mississippi, in 2017 and 2018, respectively, indicated no droplet size effect on PRE herbicide efficacy, regardless of the herbicide, weed, soil, crop residue and weather conditions during spraying. Nozzle type enhanced herbicide efficacy for one location and herbicide. The TTI60 dual fan nozzle increased pendimethalin weed control, up to 91%, in a high organic matter (OM) soil with large clods and substantial weed pressure. Pendimethalin efficacy was reduced under high OM soils (> 2%) while metribuzin efficacy was reduced under low OM (< 0.7%), low cation exchange capacity (<13.1%) soils and 12.2 mm of rain three days after application. The greenhouse studies indicated that increasing crop residue levels reduced velvetleaf control by 7%. Simulated rainfall eight days after herbicide application decreased johnsongrass dry weight reductions by 29% in comparison to two day rainfall.

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The billion dollar pharmaceutical research and development pipeline suffers greatly from high attrition rates of novel therapeutic compounds within pre-clinical and clinical trials. Poor bioavailability in many new drugs, originating in the various methodologies of high throughput screening, may explain part of these growing failure rates. One interpretation of this phenomenon relies on bioavailability's correlation with aqueous solubility; much modern processing allows chemicals to fully develop without touching water, yielding upwards of 90% of new chemical entities practically insoluble in aqueous media. Thus, one approach to alleviating bioavailability and potentially clinical attrition rates necessitates augmented aqueous solubility. The amorphous nanoparticle presents the largest boost in aqueous solubility of a chemical through processing alone. In this contribution, we propose electrospray as a novel, competitive candidate to produce pharmaceutical amorphous nanoparticles with the intent of augmenting solubility. Electrospray represents an idyllic nominee for three reasons: repeatability, flexibility, and scalability. Electrospray offers low batch to batch variation with less than 30% relative standard deviation between various droplets. This triumphs over the several orders of magnitude in variation in pneumatic sprays. Electrospray's flexibility draws from its ability to attain diameters over several orders of magnitude, ranging from hundreds of microns to several nanometers; in this contribution droplets are produced between 500 nm and 1[micro]m. Finally, electrospray displays scalability to any industrial requirement; though a single nozzle operates at mere microliters per hour, a single multiplexed array of emitters may increase this throughput by several orders of magnitude. This exploration, utilizing Indomethacin as a model low solubility chemical, verifies electrospray as a compatible processing tool for the pharmaceutical industry. Scanning electron microscopy coupled with the image analysis software ImageJ gleans the size and shape of emitted (and dried) particles. Amorphicity verification of particles employs grazing angle x-ray diffraction. Finally, ultraviolet and visual spectrum spectroscopy evaluates the solubility advantage of particles.

Protein structure affects the bioactivity and functionality of whey protein ingredients in food systems. Bioactivity of whey proteins and their derivatives are highly dependent upon primary, secondary and tertiary structure. The degree of denaturation of whey proteins is an important factor for determining how whey protein ingredients will perform in a food system. Several analytical methods have been developed to quantify protein denaturation of whey proteins. The goal of this project was to use a variety of analytical methods to quantify whey protein denaturation and to evaluate the correlation of denaturation to the functionality of whey protein powders. The objective of the first series of experiments was to compare three different analytical methods to measure denaturation of whey proteins in liquid whey obtained by various methods of separation and with varying degrees of heat treatment. A split plot experimental design was used. Raw bovine milk was skimmed and liquid whey was separated from the skim milk at natural pH. Three separation methods: 1) centrifugation, 2) membrane filtration and 3) enzyme coagulation, made up the first split plot. Each sub-plot of liquid whey was then divided into three split plots to receive heat treatment. Heat treatments were no heat, 76°C for fifteen seconds and 85°C for three minutes. Each of the resulting nine treatment combinations was analyzed by 1) polyacrylamide gel electrophoresis, 2) bicinchoninic acid-soluble protein assay and 3) fluorescence spectroscopy to determine the amount of denatured protein in the liquid whey. Fluorescence spectroscopy was found to be the most sensitive and reliable method for detecting differences in structure due to denaturation, while native polyacrylamide gel electrophoresis was found to be the least sensitive method. The sample which received the centrifugal treatment of isolation with no heat was found to be the most undenatured in structure while the sample which received the enzyme treatment of isolation with high heat was found to be the most denatured in structure. The objective of the second series of experiments was to evaluate the effect of denaturation on whey protein solubility in dried whey protein powders. Solubility is one of the most important functional properties to consider when selecting a whey protein ingredient, especially for beverage systems. Processing parameters are often manipulated in efforts to improve solubility. The protein structures of whey are considered to have an effect on solubility. Specifically, the degree of denaturation of whey proteins is thought to play a role in solubility. In this experimental design, raw bovine milk was skimmed and pasteurized then enzyme-coagulated at natural pH to separate the whey. Liquid whey was then split into three aliquots and each received one of the following treatments: 1) mild heat/ freeze dry, 2) mild heat/spray dry and 3) high heat/spray dry. Heat treatment was applied to liquid whey prior to concentration. Heat treated whey was then concentrated and dried. Powders were reconstituted and analyzed for denaturation using 1) bicinchoninic acid assay for soluble protein and 2) fluorescence spectroscopy and for solubility using an insolubility index. pH 4.6 solubility and fluorescence spectroscopy for quantifying denaturation correlated well to one another. Both found that the low heat treated samples were less denatured in structure than the sample which received the high heat treatment, regardless of drying method. However, the drying method of the protein powders was correlated to solubility rather than heat treatment. A correlation of denaturation measured in whey protein powders and solubility was apparent for the low heat, freeze dried sample and the high heat, spray dried sample. Several conclusions were made in this research. 1) Centrifugal force causes less denaturation than membrane filtration and enzyme coagulation, thus unheated liquid whey obtained by centrifugal force can be used as a control in research on denaturation. 1) Fluorescence spectroscopy is a better method for quantifying denaturation in liquid and powdered whey compared to native PAGE and pH 4.6 solubility measured by BCA. 3) Functional solubility is dependent on denaturation and can be correlated to analytical methods of measuring denaturation.

The thesis investigates the solubility of various sodium salts present in the waste tanks at the Hanford nuclear site. The experiments were conducted in different concentrations of caustic and in water at 25°C and 50°C. The results obtained from these studies will be used to improve existing databases for the Environmental Simulation Program (ESP, available from OLI Systems, Inc.), thereby increasing its accuracy in predicting waste behavior under high ionic strength conditions. Experiments were performed on the following systems: 1) NaF - NaNO3 - NaOH, 2) Na3PO4 - NaNO3 - NaOH, 3) NaF - Na3PO4 - 1m NaNO3 - NaOH, and 4) NaF - Na3PO4 - 3m NaNO3 - NaOH. The results obtained from these experiments were then compared to the ESP predictions and the available literature data. Comparision of the experimental work with the available literature data revealed that the data obtained from this study is in agreement with previous studies for the NaF - NaOH, NaNO3 - NaOH, and Na3PO4 - NaOH systems. This is the first report on solubilities for the Na - F - PO4 - OH system with added nitrate. The presence of sodium hydroxide was found to lower the solubility of natrophosphate, Na7F(PO4)2.19H2O. The solubility of this double salt was also significantly lowered in the presence of sodium nitrate. Error analysis of the experimental data was performed and indicated that the experimental molalities were accurate to within an average of + 0.02.

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