Chemical Engineering Commons^™

Selective Extraction Of Colorful Proteins Using Reverse Micelles, Loren E. Connell

Theses and Dissertations

Biotechnology is an ever expanding field of science. As the field has expanded, research into bioseparation processes has also expanded. The need for more cost effective ways to deliver products that are in high demand is greater now than ever. Bioseparation processes are a very costly part of the overall process of product development. While traditional separation process are effective, there is promise in many new techniques being developed which have the potential to lower the costs of bioseparations.

The continuous separation method of liquid-liquid extraction using reverse micelles is one such technique. While this technique has been researched in …

Catalytic Partial Oxidation Reforming Of Jp8 And S8, Thomas G. Howell

Theses and Dissertations

Catalytic partial oxidation (CPOX) reforming experiments were performed using a 10 kW Aspen Products Group, Inc. fuel processing prototype utilizing military logistic fuels JP8 and S8. S8 is a sulfur-free Fisher-Tropsch fuel, while JP8 is a multi-fuel blend, which could impact reforming efficiency, product distribution and byproduct production. Sulfur contained within the JP8 will adversely affect the product distribution; therefore, desulfurization beds, capable of removing up to 1000 ppm sulfur, were incorporated into the system. The catalyst used in the prototype is noble metal dispersed on cordierite monolith. The goal of this experiment was to evaluate the efficiency and product …

Pharmacokinetics Of Ultrasonically-Released, Micelle-Encapsulated Doxorubicin In The Rat Model And Its Effect On Tumor Growth, Bryant J. Staples

Theses and Dissertations

Chemotherapy is one of the most successful cancer treatments used today. Unfortunately, the amount of chemotherapy a patient can receive is limited by the associated negative side effects, such as cardiotoxicity, immune system suppression, and nephrotoxicity. Encapsulation of these drugs, Doxorubicin (DOX) in particular, in stabilized Pluronic micelles (Plurogel TM) shows success in limiting these harmful side effects. In previous studies, low-frequency ultrasound (US) has been shown, in vitro, to locally release DOX from these micelles. In this study, a novel drug delivery system involving the encapsulation of DOX in Plurogel and the release of the drug at the tumor …

Biomass And Coal Fly Ash In Concrete: Strength, Durability, Microstructure, Quantitative Kinetics Of Pozzolanic Reaction And Alkali Silica Reaction Investigations., Shuangzhen Wang

Theses and Dissertations

Biomass represents an important sustainable energy resource, with biomass-coal cofiring representing among the most effective and cost efficient CO2 reduction strategies. Fly ash generated during coal combustion represents a technically advantageous, inexpensive, and environmentally beneficial admixture in concrete production, partially replacing cement. However, strict interpretation of American Society of Testing and Materials (ASTM) and American Concrete Institute (ACI) standards prohibits use of fly ashes from any source other than coal in concrete production; therefore, fly ash from biomass coal cofiring is excluded from use in concrete. This dissertation discusses biomass impacts on concrete properties through experiments conducted on several combinations …

Modeling Three Reacting Flow Systems With Modern Computational Fluid Dynamics, Ralph J. Price

Theses and Dissertations

Computational fluid dynamics (CFD) modeling and analysis were used in three projects: solar CO2 conversion modeling, improved coal combustion modeling using STAR-CD, and premixed combustion modeling. Each project is described below. The solar CO2 conversion modeling project involved CFD simulations of a prototype solar CO2 converter that uses sunlight to dissociate CO2 into CO and O2. Modeling was used to predict the performance of this prototype converter using three CFD software packages, and involved predicting the flow, heat transfer, and chemical kinetics. Accuracy was determined by comparison of model predictions and experimental data. Parametric modeling studies were performed in order …

Continuous Co-Separation By Liquid Absorption In Aqueous Cuprous Chloride (Cucl) And Magnesium Chloride (Mgcl2) Solution, Paul J. Foster

Theses and Dissertations

The purpose of the research was to design, build, test, and recommend a process to economically separate CO from a gas mixture of CO, CO2, and O2. The general method considered in this research to accomplish the separation was liquid absorption in a packed column. Several experiments were performed to identify the best process solution to use in a prototype. The experiments, based on the COSORB process, consisted of CuCl mixed with a complexing agent (metal tri-chloride) and a solvent (metal tetra-chloride, toluene, ethanol, etc.). The best method consisted of an aqueous solution of CuCl and MgCl2, which has previously …

Structure And Nitrogen Chemistry In Coal, Biomass, And Cofiring Low-Nox Flames, Bradley David Damstedt

Theses and Dissertations

Addressing global climate change will require increasing sustainable energy usage. Cofiring biomass fuels with coal for electrical power generation is an efficient, cost effective method of CO2 mitigation. This work is an experimental investigation of the flame structure and nitrogen chemistry differences occurring between coal, biomass and cofiring flames. A pilot-scale facility was fired with a dual-feed low-NOx burner capable of independently conveying 2 separate fuels unblended to the burner. Spatially detailed gas species measurements were made for 8 flames, including a coal, straw, finely ground straw, wood, and 4 straw/coal cofiring flames. Particle samples were also obtained from 5 …

An Improved Model For Calculating Heats Of Dilution And Equilibrium Constants For High Temperature Aqueous Electrolyte Solutions, Xiaoyun Lin

Theses and Dissertations

At high temperatures, the properties of aqueous electrolyte systems differ markedly from those at 25°C. For mixed-electrolyte dilute solutions at high temperatures, the degree of ion-association is sufficiently large that the association equilibrium must be incorporated in any model describing the solutions. These association reactions usually do not occur to a measurable extent at room temperature. Oscarson and co-workers have designed a correlation model based on the excess Gibbs energy which can correlate log K and ∆H values as well as the heats of dilution for aqueous electrolyte systems as a function of temperature (T) and ionic strength (I) from …

High-Frequency Ultrasound Drug Delivery And Cavitation, Mario Alfonso Diaz

Theses and Dissertations

The viability of a drug delivery system which encapsulates chemotherapeutic drugs (Doxorubicin) in the hydrophobic core of polymeric micelles and triggers release by ultrasound application was investigated at an applied frequency of 500 kHz. The investigation also included elucidating the mechanism of drug release at 70 kHz, a frequency which had previously been shown to induce drug release. A fluorescence detection chamber was used to measure in vitro drug release from both Pluronic and stabilized micelles and a hydrophone was used to monitor bubble activity during the experiments. A threshold for release between 0.35 and 0.40 in mechanical index was …

Statistical Methods For Kinetic Modeling Of Fischer Tropsch Synthesis On A Supported Iron Catalyst, Brian L. Critchfield

Theses and Dissertations

Fischer-Tropsch Synthesis (FTS) is a promising technology for the production of ultra-clean fuels and chemical feedstocks from biomass, coal, or natural gas. Iron catalysts are ideal for conversion of coal and biomass. However, precipitated iron catalysts used in slurry-bubble column reactors suffer from high attrition resulting in difficulty separating catalysts from product and increased slurry viscosity. Thus, development of an active and selective-supported iron catalyst to manage attrition is needed. This thesis focuses on the development of a supported iron catalyst and kinetic models of FTS on the catalyst using advanced statistical methods for experimental design and analysis. A high …

Modeling And Data Analysis Of Conductive Polymer Composite Sensors, Hua Lei

Theses and Dissertations

Conductive polymer composite sensors have shown great potential in identifying gaseous analytes. To more thoroughly understand the physical and chemical mechanism of this type of sensors, a model was developed by combining two sub-models: a conductivity model and a thermodynamic model, which gives a relationship between the vapor concentration of analyte(s) and the change of the sensor signals. In this work, 64 chemiresistors representing eight different carbon concentrations (8–60 vol.% carbon) were constructed by depositing thin films of a carbon black–polyisobutylene composite onto concentric spiral platinum electrodes on a silicon chip. The responses of the sensors were measured in dry …

Experimental And Modeling Investigations Of Biomass Particle Combustion, Hong Lu

Theses and Dissertations

This investigation provides a comprehensive analysis of entrained-flow biomass combustion processes. Experimental and theoretical investigations indicate how particle shape and size influence biomass combustion rates. Experimental samples include flake-like, cylinder-like, and equant (nearly spherical) shapes with similar particle masses and volumes but different surface areas. Samples of small (less than 500 µm) particles were passed through a laboratory entrained-flow reactor in a nitrogen/air atmosphere and a maximum reactor wall temperature of 1600 K, while large samples were reacted in suspension in a single particle furnace operated at similar conditions as the entrained-flow reactor. A separately developed computer and image analysis …

Black Liquor Droplet Combustion And Modeling, Warren Benjamin Roberts

Theses and Dissertations

Black liquor is an intermediate product of pulp production. Recovery boilers process black liquor to recover the inorganic material for recycling in the mill and to generate electricity and steam for the paper mill. Black liquor droplet combustion rates and mechanisms dictate many aspects of recovery boiler performance. This investigation documents new experimental data on single droplet pyrolysis and combustion in a laboratory furnace that mimics many of the essential features of commercial boilers (temperature, composition, droplet size, etc.). These experiments monitored single droplets placed on a thermocouple wire and suspended from a mass balance. Simultaneous video images and pyrometry …

Poisoning And Sulfation On Vanadia Scr Catalyst, Xiaoyu Guo

Theses and Dissertations

Deactivation of titania-supported vanadia commercial SCR catalysts exposed to flue gases from both coal and coal-biomass co-firing boilers were investigated. BET surface area and average pore diameter measurements on both fresh and exposed commercial catalyst samples indicated pore plugging occurred to exposed catalyst samples. ESEM analyses showed fouling on catalyst surface, and poison deposition on both catalyst surface and inner pores. Activity assessments of commercial monolith catalysts with various exposures (time and fuel type) indicated that catalyst deactivation involves fouling, pore plugging, and poisoning. Different mechanisms may dominate depending on exposure time, catalyst properties, and combustion environment. Better controlled lab-scale …

Cycle Performance Of A Pulse Detonation Engine With Supercritical Fuel Injection, Timothy M. Helfrich

Theses and Dissertations

Pulse detonation engines (PDE) rely on rapid ignition and formation of detonation waves. Because hydrocarbon fuels are composed typically of long carbon chains that must be reduced in the combustion process, it would be beneficial to create such reduction prior to injection of fuel into the engine. This study focused on PDE operation enhancements using dual detonation tube, concentric-counter-flow heat exchangers to elevate the fuel temperature up to supercritical temperatures. Variation of several operating parameters included fuel type (JP-8, JP-7, JP-10, RP-1, JP-900, and S-8), ignition delay, frequency, internal spiral length, and purge fraction. To quantify the performance, four key …

Graphitized Carbon Foam With Phase Change Material, Angelinda D. Fedden

Theses and Dissertations

This thesis examines the transient heating and cooling responses of graphitized carbon foam infiltrated with phase change material (PCM). The carbon foam provides rapid heat transfer throughout the PCM volume, while the PCM stores the heat for later removal. The foam/PCM system was heated with a copper heating block, and then cooled with a liquid-cooled heat removal block. Infiltrating the foam with PCM significantly increased the length of time before the system reached maximum temperature. The temperature response of the foam/PCM system was consistent over multiple cycles of heating and cooling. A high density foam had a faster heating and …

A Plastic-Based Thick-Film Li-Ion Microbattery For Autonomous Microsensors, Qian Lin

Theses and Dissertations

This dissertation describes the development of a high-power, plastic-based, thick-film lithium-ion microbattery for use in a hybrid micropower system for autonomous microsensors. A composite porous electrode structure and a liquid state electrolyte were implemented in the microbatteries to achieve the high power capability and energy density. The use of single-walled carbon nanotubes (SWNTs) was found to significantly reduce the measured resistance of the cathodes that use LiAl0.14Mn1.86O4 as active materials, increase active material accessibility, and improve the cycling and power performance without the need of compression. Optimized uncompressed macro cathodes were capable of delivering power densities greater than 50 mW/cm2, …

Fuel-Nox Formation During Low-Grade Fuel Combustion In A Swirling-Flow Burner, Chunyang Wu

Theses and Dissertations

Insufficient knowledge of fireside behavior in the near-burner region during biomass combustion is one of major factors preventing widespread use of this renewable fuel in pulverized coal power plants. The current research is aimed to investigate the impact of biomass cofiring on NO formation in the near-burner region through interpretation of computational fluid dynamics (CFD) predictions and data collected from a series of biomass tests in a pilot-scale (0.2 MW), swirling flow burner. Two-dimensional gas species mole fraction data were collected with state-of-theart instruments from nine experiments, composing one herbaceous biomass (straw), one woody biomass (sawdust), a low sulfur sub-bituminous …

Accelerating Whole-Cell Biocatalysis By Enhancing Outer Membrane Permeability, Ye Ni

Theses and Dissertations

Whole-cell biocatalysts are preferred in many biocatalysis applications. However, cell envelope often represents a formidable permeability barrier. As a result, reactions catalyzed by whole-cells are reportedly orders of magnitude slower than those of by their free enzyme counterparts. The present research addresses this critical issue by using membrane engineering approaches. Two E. coli strains with genetically altered outer membrane structures were used in the study, a lipopolysaccarides (LPS) mutant SM101 and a Braun's lipoprotein mutant E609L. The effects of outer membrane mutation on the permeability of substrates differing substantially in size and hydrophobicity were investigated by combining the mutant cells …

Design And Development Of Oligonucleotide Microarrays And Their Application In Diagnostic And Prognostic Estimation Of Human Gliomas, G. Scott Taylor

Theses and Dissertations

DNA microarrays represent an ultra-high throughput gene expression assay employed to study the transcriptomic profiles of biological tissues. These devices are increasingly being used to study many aspects of gene regulation, and there is growing interest in the biotechnology and pharmaceutical industries for developing such devices in efforts toward rational product/drug design. The DNA microarray also provides a unique and objective means for diagnosis and prognosis of human diseases based on patterns of gene expression. This is especially important in cancer research and the thrust toward personalized medicine. This dissertation details the design and development of oligonucleotide microarrays and the …

Green Engineering And Gate-To Gate Life Cycle Assessments For Pharmaceutical Products, Daniel Fichana

Theses and Dissertations

The research of this thesis focused on the environmental and processing metrics during the development of two different drugs. Previous research in life cycle assessments and green engineering have focused on other products and processes, but only a limited amount of studies have been conducted for pharmaceutical applications. This analysis concerned a gate-to-gate analysis of two distinct pharmaceutical products along with the development of a solvent selection table. The goal of this research was to determine how various processing and environmental metrics were affected by process improvements.

The first drug was the pravastatin, which was made via a fermentation route. …

A New Method For The Rapid Calculation Of Finely-Gridded Reservoir Simulation Pressures, Benjamin Arik Hardy

Theses and Dissertations

A new method for the determination of finely-gridded reservoir simulation pressures has been developed. It is estimated to be as much as hundreds to thousands of times faster than other methods for very large reservoir simulation grids. The method extends the work of Weber et al. Weber demonstrated accuracies for the pressure solution normally requiring millions of cells using traditional finite-difference equations with only hundreds of cells. This was accomplished through the use of finite-difference equations that incorporate the physics of the flow. Although these coarse-grid solutions achieve accuracies normally requiring orders of magnitude more resolution, their coarse resolution does …

Mpsa Effects On Copper Electrodeposition: Understanding Molecular Behavior At The Electrochemical Interface, Clint Gordon Guymon

Theses and Dissertations

In this work the structure of the electrochemical metal-liquid interface is determined through use of quantum mechanics, molecular simulation, and experiment. Herein are profiled the molecular dynamics details and results of solid-liquid interfaces at flat non-specific solid surfaces and copper metal electrodes. Ab initio quantum-mechanical calculations are reported and define the interatomic potentials in the simulations. Some of the quantum-mechanical calculations involve small copper clusters interacting with 3-mercaptopropanesulfonic acid (MPSA), sodium, chloride, bisulfate and cuprous ions. In connection with these I develop the electrode charge dynamics (ECD) routine to treat the charge mobility in a metal. ECD bridges the gap …

Properties Model For Aqueous Sodium Chloride Solutions Near The Critical Point Of Water, Bing Liu

Theses and Dissertations

Traditional excess Gibbs energy models in terms of temperature, pressure, and concentration become progressively less effective in describing the thermodynamics of aqueous solutions at temperatures above 300 ¢ªC, and are totally inadequate in the critical region of water. This deficiency is due to the strong ion association and the large property fluctuations (such as density) with small variations in pressure, temperature, and solute concentration around the critical point of water. In this work, a speciation-based model has been developed to describe the thermodynamic properties of aqueous sodium chloride solutions in the critical region of water. The anomalous fluctuation problem is …

Generation Of Biomarkers From Anthrax Spores By Catalysis And Analytical Pyrolysis, Phillip R. Smith

Theses and Dissertations

Anthrax spores, in weaponized form, are dangerous biological warfare agents. Handheld technology for the rapid detection of anthrax is greatly needed to improve national security. Methods to detect anthrax spores are diverse, with most taking at least an hour for positive identification. A viable option for rapid detection is analytical pyrolysis (AP), which produces chemicals containing taxonomical information (biomarkers). AP methods are reviewed and critically analyzed to show that reproducible detection of anthrax spores in a rapid manner (< 5 min) with a handheld device is not currently possible. A promising alternative to AP is the use of a catalyst to produce biomarkers from anthrax spores with improved selectivity and reproducibility. Catalytic materials having promise for this include platinum, nickel, and superacids. Experiments evaluating several of these materials are described. A biomarker mass spectral library was created, based on information available in the scientific literature, to facilitate analysis and identification of the biomarkers produced experimentally. The RAMFAC algorithm was used to deconvolute chromatographic peaks to produce clean mass spectra and match them against entries in the biomarker library. While the library is not complete, its use with the RAMFAC algorithm enabled detection of many important biomarkers in experiments involving catalytic breakdown of anthrax spores. Experimental results from preliminary tests of several catalysts are presented and discussed. Addition of catalysts in the form of platinum nanoclusters and superacids to bacterial spores in a commercial pyrolyzer effected an increase in the amount of biomarkers produced at mild conditions over traditional pyrolysis methods. Electroformed nickel mesh, on the other hand, demonstrated low catalytic activity for the production of biomarkers, likely due to poor contact of the spores with the mesh. Biomarkers similar to those published in the literature were observed, including dipicolinic acid, picolinic acid, propionamide, acetamide, diketopiperazines, fatty acids, furfuryl alcohol, and DNA bases. A statistically designed factorial study was used to determine the importance of temperature, spore loading, and nanocluster loading on the production of three important biomarkers. The relative importance of these variables differs for each of the three important biomarkers, suggesting they are produced by different reaction mechanisms.

Effects Of Pressure On Coal Pyrolysis At High Heating Rates And Char Combustion, Dong Zeng

Theses and Dissertations

Clean coal technologies are now becoming popular because of their high efficiencies and minimal environmental impact. Higher operating pressures have been applied to clean coal technologies. The effect of pressure on coal pyrolysis and char combustion has been extensively studied but still remains to be further explored. The objective of this project was to characterize high pressure, high heating rate coal pyrolysis and char combustion, with emphasis on improving coal/char high pressure combustion models. A flat-flame burner was used in a high pressure laminar flow facility to conduct high temperature, high heating rate pyrolysis and combustion experiments for four coals. …

Biofilm Removal Using Bubbles And Sound, Michael R. Parini

Theses and Dissertations

Bacteria in biofilms adhere well to surfaces and are quite difficult to remove. Oral plaque is one example of a biofilm. Many researchers have studied ways to remove plaque and bacteria from surfaces. It has been found that the passage of a bubble across a surface to which bacteria has adhered can remove the bacteria from the surface. Biofilms of Streptococcus mutans were grown on glass coverslips as a simple model for oral plaque. The coverslips were mounted in a Plexiglas chamber filled with artificial saliva. A bubble stream was directed at the mounted biofilm. The velocity, gas fraction, median …

Autologous Fibrinogen Purification And Concentration For Use In Fibrin Sealant, Steven M. Alston

Theses and Dissertations

Fibrinogen concentrates are used widely as a sealant during and after surgery to reduce blood loss. Commercially available fibrin sealants are made from pooled human blood, which carries the risk of blood-borne diseases, and are expensive. These concerns have brought to focus the need for autologous fibrinogen concentrates. This need has been addressed by utilizing a unique approach in which fibrinogen is precipitated from plasma with protamine. The physical properties of fibrin sealant prepared from fibrinogen precipitated with protamine were evaluated. The optimal precipitation conditions included a plasma protamine concentration of 10 mg/mL at room temperature. Under these conditions 96% …

Stable Polymer Micelle Systems As Anti-Cancer Drug Delivery Carriers, Yi Zeng

Theses and Dissertations

Several temporarily stable polymer micelle systems that might be used as ultrasonic-activated drug delivery carriers were synthesized and investigated. These polymeric micelle systems were Plurogel®, Tetronic®, poly(ethylene oxide)-b-poly(N-isopropylacrylamide) and poly(ethylene oxide)-b-poly(N-isopropylacrylamide-co-2-hydroxyethyl methacrylate-lactaten). In previous work in our lab, Pruitt et al. developed a stabilized drug carrier named Plurogel® [5, 6]. Unfortunately, the rate of the successful Plurogel® synthesis was only about 30% by simply following Pruitt's process. In this work, this rate was improved to 60% by combining the process of adding 0.15 M NaCl and/or 10 µl/ml n-butanol and by preheating the solution before polymerization. Tetronics® were proved not …

Effects Of Moisture On Combustion Characteristics Of Live California Chaparral And Utah Foliage, Steven G. Smith

Theses and Dissertations

Current fire-spread models are based largely on empirical correlations based on fires burning through dead pine needles. There is a need to increase the accuracy of modeling wildfires in live vegetation. This project investigates the quantitative and qualitative ignition characteristics of eight live fuels, four from southern California (manzanita, scrub oak, ceanothus, and chamise) and four from Utah (canyon maple, gambel oak, big sagebrush, and Utah juniper). Individual leaves were observed as they were exposed to hot gases from a flat flame burner. The broadleaf species from both California and Utah had noticeable surface changes during the ignition process. All …