Chemical Engineering Commons^™

Preparation Of Active, Stable Supported Iron Catalysts And Deactivation By Carbon Of Cobalt Catalysts For Fischer-Tropsch Synthesis, Kamyar Keyvanloo

Theses and Dissertations

The first half of this dissertation reports the development of supported Fe FT catalysts including the effects of various, carefully chosen preparation methods on the performance of alumina-supported iron/copper/potassium (FeCuK/Al2O3); it was determined that non-aqueous slurry impregnation and co-impregnation yielded catalysts with activities as high as any reported in the literature. Furthermore, the effects of support properties including pore size, hydroxyl group concentration, and support stabilizer were investigated for FeCuK/Al2O3 catalysts containing 20 or 40% Fe. For the first time, we report the performance of a supported Fe FT catalyst that is not only more active and stable than any …

Particle Dispersion In Homogeneous Turbulence Using The One-Dimensional Turbulence Model, Guangyuan Sun, David O. Lignell, John C. Hewson, Craig R. Gin

Faculty Publications

Lagrangian particle dispersion is studied using the one-dimensional turbulence (ODT) model in homogeneous decaying turbulence configurations. The ODT model has been widely and successfully applied to a number of reacting and nonreacting flow configurations, but only limited application has been made to multiphase flows. Here, we present a version of the particle implementation and interaction with the stochastic and instantaneous ODT eddy events. The model is characterized by comparison to experimental data of particle dispersion for a range of intrinsic particle time scales and body forces. Particle dispersion, velocity, and integral time scale results are presented. The particle implementation introduces …

Development Of Ultrasound Sensitive Eliposomes Containing Doxorubicin For Drug Delivery, Chung-Yin Lin, William G. Pitt, Kuo-Chen Wei

Faculty Publications

Aims: A novel nanocarrier was formulated by remote loading of doxorubicin (Dox) into a dipalmitoylphosphatidylcholine (DPPC) liposome that also contains various perfluorocarbon (PFC) droplets within its aqueous interior. It was shown that Dox can be loaded to a level of up to 67% into these large unilamellar vesicles composed of DPPC and cholesterol by employing a transmembrane pH gradient technique.

Methods: The different encapsulation efficiencies for these eLipoDox constructs of differing PFC composition are 45.5% (PFC5), 31.5% (PFC6) and 66.7% (PFC5/PFC6 mixture, PFCm). At 30 seconds of insonation, the eLipoDox formulation with PFCm droplets appeared to release more Dox than …

Investigating The Stability Of Eliposomes At Elevated Temperatures, Ghaleb A. Husseini, William G. Pitt, Marjan Javadi

Faculty Publications

eLiposomes encapsulate a perfluorocarbon nanoemulsion droplet inside a liposome. Ultrasound is then used as a trigger mechanism to vaporize the perfluorocarbon, break the liposome, and release the desired drug to the tumor tissue. The purpose of this research is to show that eLiposomes synthesized using perfluoropentane are stable above the normal boiling point of the perfluoropentane and at body temperature and thus has potential for use in vivo. Experiments involving the release of fluorescent calcein molecules were performed on eLiposomes to measure the release of calcein at various temperatures in the absence of ultrasound. Results showed that eLiposomes are stable …

Investigating The Stability Of Eliposomes At Elevated Temperatures, Ghaleb A. Husseini, William G. Pitt, Marjan Javadi

Faculty Publications

eLiposomes encapsulate a perfluorocarbon nanoemulsion droplet inside a liposome. Ultrasound is then used as a trigger mechanism to vaporize the perfluorocarbon, break the liposome, and release the desired drug to the tumor tissue. The purpose of this research is to show that eLiposomes synthesized using perfluoropentane are stable above the normal boiling point of the perfluoropentane and at body temperature and thus has potential for use in vivo. Experiments involving the release of fluorescent calcein molecules were performed on eLiposomes to measure the release of calcein at various temperatures in the absence of ultrasound. Results showed that eLiposomes are stable …

Communication: Using Multiple Tethers To Stabilize Proteins On Surfaces, Brandon K. Loong, Thomas A. Knotts Iv

Faculty Publications

Protein surface interactions are important in many applications in biotechnology including protein arrays, but these technologies have not lived up to their transformative potential because it is difficult to attach proteins to surfaces in a manner that preserves function and theoretical understanding of the relevant phenomena remains limited. Here is reported the effect of using multiple tethers to attach a protein (lysozyme) to a surface and the effects on the structure and stability of the molecule. The simulations show how using two tethers can drastically change the folding mechanism such that a protein that is initially unstable and inactive when …

Catalytic Performance Of An Iron-Based Catalyst In Fischer–Tropsch Synthesis, Majid Sarkari, Farhad Fazlollahi, Hossein Ajamein, Hossein Atashi, William C. Hecker, Larry L. Baxter

Faculty Publications

This paper documents the performance and kinetics of an iron/manganese oxide catalyst in a fixed-bed reactor by Fischer–Tropsch synthesis (FTS) under conditions favoring the formation of gaseous and liquid hydrocarbons (P: 1–12 bar; T: 513–543 K; H2/CO:1, 1.5, 2 mol/mol; gas hourly space velocity: 4200–7000 cm3 (STP)/h/gcat). Based on the hypothesis that water inhibits the intrinsic FTS reaction rate, eight kinetic models are considered: six variations of the Langmuir–Hinshelwood–Hougen–Watson representation and two empirical power-law models. The kinetic expression/mechanism that most precisely fits the data assumes the following: (1) CO dissociation is reversible and does not involve hydrogen; (2) all hydrogenation …

Measurement And Modeling Of Fire Behavior In Leaves And Sparse Shrubs, Dallan R. Prince

Theses and Dissertations

Wildland fuels and fire behavior have been the focus of numerous studies and models which provide operational support to firefighters. However, fuel and fire complexity in live shrubs has resulted in unexpected and sometimes aggressive fire behavior. The combustion of live fuels was studied and modeled, and the results were assimilated into a shrub-scale fire behavior model which assumes fire spread by flame-fuel overlap. Fire spread models have usually assumed that radiation heat transfer is responsible for driving fire spread, but that assumption is a topic of continuing debate, and appears to contradict some experimental observations. A convection-based shrub-scale fire …

Comparison Of One-Dimensional Turbulence And Direct Numerical Simulations Of Soot Formation And Transport In A Nonpremixed Ethylene Jet Flame, David O. Lignell, Garrison C. Fredline, Adam D. Lewis

Faculty Publications

Accurate models of soot formation in turbulent flames are important for correctly predicting and simulating flames and fires. Modeling soot formation and transport is challenging due to the complex chemical formation processes, and differential diffusion of soot relative to a flame. Direct numerical simulations (DNS) have highlighted the importance of such transport on soot concentrations, however DNS is computationally expensive. The one-dimensional turbulence (ODT) model is able resolve a full range of length and timescales and solves the evolution of diffusive and reactive scalars in the natural physical coordinate. We present results of soot formation in ODT and compare the …

New Advances In Post-Installed Subsea Monitoring Systems For Structural And Flow Assurance Evaluation, Reza Asgharzadeh Shishavan, David Brower, John Hedengren, Alexis Brower

Faculty Publications

An overview of fiber optic sensors for temperature, pressure, strain, and fatigue of subsea structures is provided. Current progress details efforts to ensure proper installation and bonding to existing risers, flow-lines, mooring lines, trees, and other structures in actual subsea environments. Developments include clamp prototypes, bonding techniques, long-term fatigue analysis, sensor calibration, and temperature compensation. Fiber optic technology in subsea monitoring began over 20 years ago by migrating expertise from decommissioning of rocket motors. The first installations were on new installations of subsea pipelines, production risers, and drilling risers to measure strain and vibration for fatigue life monitoring. Of particular …

The Odijk Regime In Slits, Douglas R. Tree, Wesley F. Reinhart, Kevin D. Dorfman

Faculty Publications

De Gennes’ blob theory has been remarkably successful at describing weakly confined polymers in both slits and channels, and comparable results surround Odijk’s theory of deflection segments for strongly confined wormlike polymers in nanochannels. However, given the success of Odijk’s theory in channels, it is remarkable that there is no comprehensive theory for the simple case of a wormlike polymer strongly confined between two parallel plates. We propose such a theory by drawing inspiration from the existing literature on ideal wormlike chains in slits and Daoud and de Gennes’ idea of mapping a slit-confined chain to a two-dimensional chain. We …

Enhancement Of Mass Transfer And Electron Usage For Syngas Fermentation, James J. Orgill

Theses and Dissertations

Biofuel production via fermentation is produced primarily by fermentation of simple sugars. Besides the sugar fermentation route, there exists a promising alternative process that uses syngas (CO, H2, CO2) produced from biomass as building blocks for biofuels. Although syngas fermentation has many benefits, there are several challenges that still need to be addressed in order for syngas fermentation to become a viable process for producing biofuels on a large scale. One challenge is mass transfer limitations due to low solubilities of syngas species. The hollow fiber reactor (HFR) is one type of reactor that has the potential for achieving high …

A Sequential Grid, Relaxation Method For Use In Oil Reservoir Simulation, Brian Stimpson, Dr. Hugh Hales

Journal of Undergraduate Research

The demand for petroleum products has never been higher, despite the opposition and environmental skepticism that has been present against the petroleum industry in recent years. This requires the production of petroleum products to increase. However, as politics and nature will have it, the waning supply of petroleum is becoming ever more difficult to access and tap into. To make sure we are using our reserves in the best possible ways, this industry must adapt, create better technology, and have careful planning and predictions.

Advanced Measuring Techniques Of Ionic And Electronic Conductivities In Battery Electrodes, Joshua Flygare, Dr. Dean Wheeler

Journal of Undergraduate Research

Introduction: There are many significant barriers still to be overcome before chemical storage becomes satisfactory. One of the most significant issues is how much the electrodes vary in their electronic and ionic conductivities. Both of these issues are highly complex. My funding was used to help me learn the basic mathematics and physics that occur inside of batteries. I used this understanding to make two models, one using COMSOL multiphysics, and another cruder model using Excel. The most significant change made in my execution from my original proposal was I used all of my time in understanding and making models, …

Spin Cycle: Hand Powered Washing For Peru, Jared Bruton, Dr. Randy Lewis

Journal of Undergraduate Research

Washing clothes is time consuming and physically difficult for women on the islands of Lake Titicaca. Women fill buckets with water and soap, allow the clothes to soak, rub them together to get the dirt out, and then wring them out. Doing this is physically demanding, especially during the harsh cold of winter. This project develops a human-powered, affordable, and easy to build clothes-washing device that allows women to save time and energy washing clothes. It builds on a similar washing machine project from one year ago, but seeks to reduce the cost of the hand-powered machine from 300 Peruvian …

Model Predictive Control With A Rigorous Model Of A Solid Oxide Fuel Cell, Lee T. Jacobsen, Dr. John D. Hedengren

Journal of Undergraduate Research

Degradation of Solid Oxide Fuel Cells (SOFCs) can be minimized by maintaining reliability parameters during load changes. These reliability parameters are critical to maintain power generation efficiency over an extended life of the SOFC. For SOFCs to be commercially viable, the life must exceed 20,000 hours for load following applications. This is not yet achieved because transient stresses damage the fuel cell and degrade the performance over time. This study relates the development of a dynamic model for SOFC systems in order to predict optimal manipulated variable moves along a prediction horizon. The model consists of hundreds of states and …

Engineering Cell-Free Systems For Vaccine Development, Self-Assembling Nanoparticles And Codon Reassignment Applications, Mark T. Smith

Theses and Dissertations

This dissertation reports on the technology of cell-free protein synthesis (CFPS) including 1) stabilized lyophilized cell-free systems and 2) enhanced heterogeneous cell extracts. This work further considers applications of CFPS systems in 1) rapid vaccine development, 2) functional virus-based nanoparticles, 3) site-specific protein immobilization, and 4) expanding the language of biology using unnatural amino acids. CFPS technology is a versatile protein production platform that has many features unavailable in in vivo expression systems. The primary benefit cell-free systems provide is the direct access to the reaction environment, which is no longer hindered by the presence of a cell-wall. The “openness" …

Viologen Oxidation Properties, Adam Read, Dr. William Pitt

Journal of Undergraduate Research

The world always stands in need of a more efficient and low cost energy sources. Fuel cells present an environmentally friendly source of energy that could potentially replace the current fossil fuels that are now used. In addition fuel cells are normally light weight and have the ability to work in isolated regions where power is not easily accessible. Fuel cells have shown great potential but as of yet are not an economically favorable energy source due to high cost. One of the main reasons for this is the high cost of platinum which is commonly used as a catalyst. …

Encapsulating Liposomes For Stabilized Drug Delivery, Corbin Jacobs, Dr. William Pitt

Journal of Undergraduate Research

Liposomes are tiny vesicles composed of materials similar to a cell membrane’s bilayer and “are useful for delivering anticancer agents to tumors and reducing the severe side effects of the agents.”1 Following synthesis, liposomes containing drug are administered intravenously. Fortunately, tumors have hyperpermeable vasculature which facilitates liposomal accumulation by their leaking out of the capillaries surrounding the tumor.2 Once near the tumor, individual cells will endocytose or engulf the vesicles as long as they are between 10 nm and 1000 nm.3

Field Application Of Accelerated Mineral Carbonation, Brandon Reynolds, K. J. Reddy, Morris D. Argyle

Faculty Publications

Globally, coal-fired power plants are the largest industrial source of carbon dioxide (CO₂). CO₂ emissions from flue gas have potential for direct mineralization with electrostatic precipitator fly ash particles in the field. Demonstration scale accelerated mineral carbonation (AMC) studies were conducted at the Jim Bridger Power Plant, a large coal fired power plant located in Wyoming, USA. AMC produces kinetically rapid conditions for increased rates of mineralization of CO₂, sulfur dioxide (SO₂) and mercury (Hg) on fly ash particles. Control and AMC reacted fly ash particles were investigated for: change in carbon (expressed …

A2 Protein Incorporation Into The Qβ Virus-Like Particle, Derek Bush, Dr. Band Bundy

Journal of Undergraduate Research

Virus-like Particles (VLPs) are noninfectious synthetic copies of the outer protein shell of viruses. They are highly symmetrical nanostructures that self-assemble from approximately 200 copies of a single “coat” protein. This symmetry makes attachment of singular foreign entities to the VLPs difficult, which limits their current uses in medical and engineering applications. In this research project we have worked to demonstrate the insertion of a single copy of the “A2” protein into the VLP from the Qβ bacteriophage to serve as a possible location for future site-specific VLP modification. Ultimately we believe that this work will lead to the development …

Cfd Black Liquor Bed Simulation, Benjamin Ohran, Dr. Larry Baxter

Journal of Undergraduate Research

The objective of this project was to further the understanding of the bed region of a black liquor recovery boiler. The net output of carbon dioxide from burning black liquor (a paper pulping by-product) is zero, making it a desirable alternative fuel source; however, there are other problems associated with burning black liquor such as boiler fouling, and emissions of pollutants. With the understanding gained from this project it will be possible to further improve the efficiency and emissions of black liquor boilers, making it a more viable fuel alternative.

Theoretical Framework For Multiple-Polymorph Particle Precipitation In Highly Supersaturated Systems, B. B. Schroeder, D. D. Harris, S. T. Smith, D. O. Lignell

Faculty Publications

An overarching mathematical framework is proposed to describe entire mineral particle precipitation processes, including multiple polymorphic forms and ranges of temperatures. While existing models portray individual physical phenomena, the presented approach incorporates a diverse set of the physical phenomena simultaneously within a single mathematical description. The liquid and solid phase dynamics interact through coupling an aqueous ionic equilibrium-chemistry model with a set of population balance equations and a mixing model. Including the particle physical phenomena, nucleation, growth, dissolution, and aggregation together within a single framework allows for the exploration of nonintuitive and nontrivial coupling effects. To validate the proposed framework, …

Phase Transitions Of Perfluorocarbon Nanoemulsion Induced With Ultrasound: A Mathematical Model, William G. Pitt, Ram N. Singh, Krystian X. Perez, Ghaleb A. Husseini, Daniel R. Jack

Faculty Publications

While ultrasound has been used in many medical and industrial applications, only recently has research been done on phase transformations induced by ultrasound. This paper presents a numerical model and the predicted results of the phase transformation of a spherical nanosized droplet of perfluorocarbon in water. Such a model has applications in acoustic droplet vaporization, the generation of gas bubbles for medical imaging, therapeutic delivery and other biomedical applications. The formation of a gas phase and the subsequent bubble dynamics were studied as a function of acoustic parameters, such as frequency and amplitude, and of the physical aspects of the …

Interplay Between Chain Stiffness And Excluded Volume Of Semiflexible Polymers Confined In Nanochannels, Abhiram Muralidhar, Douglas R. Tree, Yanwei Wang, Kevin D. Dorfman

Faculty Publications

The properties of channel-confined semiflexible polymers are determined by a complicated interplay of chain stiffness and excluded volume effects. Using Pruned-Enriched Rosenbluth Method (PERM) simulations, we study the equilibrium properties of channel-confined polymers by systematically controlling chain stiffness and excluded volume. Our calculations of chain extension and confinement free energy for freely jointed chains with and without excluded volume show excellent agreement with theoretical predictions. For ideal wormlike chains, the extension is seen to crossover from Odijk behavior in strong confinement to zero-stretching, bulk-like behavior in weak confinement. In contrast, for self-avoiding wormlike chains, we always observe that the linear …

Student Mentoring In Research: Laser-Activated Drug Delivery To Cancer Cells, William G. Pitt

Journal of Undergraduate Research

Summary of Scope of Proposal This proposal was submitted in October of 2011 to organize and fund a mentoring group in the Pitt lab in Chemical Engineering. Marjan Javadi, then a PhD candidate in Chemical Engineering, and 5 uldergraduate students participated in this research group. The purpose was 2-­‐fold, both scientific and pedagogical. On the scientific side, Marjan was working on her PhD research to develop a novel drug delivery system called an eLiposome that encapsulated a drug along with a nanoemulsion that turns from liquid to gas upon exposure to ultrasound. The ultrasound can be non-­‐invasively (no surgery or …

Predicting Gas-Phase Reaction Rates For Elementary Diatomic Substitutions Using Molecular Dynamics Simulations, Karl Fails, Dr. Richard Rowley

Journal of Undergraduate Research

The purpose of this study was to examine a new method for predicting elementary gas-phase reaction rates using molecular dynamics simulations. The diatomic substitution reaction:was to be used as a test model for its simplicity. Molecular dynamics simulations were to be used to calculate the motion of the interacting atoms. Any associations, dissociations and substitutions were to be counted and recorded.

The Effects Of Combining Ultrasonic Frequency And Antibiotics To Escherichia Coli Biofilms In An In Vivo System, Rachel L. Robison, Dr. William G. Pitt

Journal of Undergraduate Research

Prosthetic devices are commonly used in modern medicine. There are two types of prosthetic devices, implanted and transdermal. Implanted devices such as vascular grafts, heart valves, and prosthetic joints frequently become colonized by bacteria due to improper surgical techniques or post-operative infections.2 Transdermal devices such as catheters or electrical leads often become infected when bacteria from the patient’s skin migrates along the transdermal device and gains entrance into the body.1 If this occurs, microorganisms can cause serious infection at the site of the prosthetic device.

Multiple Scattering Events In Human Blood Solutions, Xunhai Xu

Journal of Undergraduate Research

Recently, modem medical technology has enabled surgeons and other medical scientists to perform certain organ transplantation within human beings successfully. However, thromboembolization, the formation of thromboemboli (usually of irregular shapes with sizes approximately 10,000 times bigger than that of red blood cell), is likely to occur with such operations. The cause of the thromboemboli is believed to be the interaction between human blood and the foreign materials. Since thromboemboli is a much larger particles than normal blood cells (such as red blood cell, white blood cell and single platelet), their existence in the blood solution might be detrimental to the …

Evaluation Of The Tendency Of Biomaterials To Produce Microemboli, Jesse Hamilton

Journal of Undergraduate Research

Many people in today’s society depend on devices that contact their blood. Devices such as dialyzers and blood oxygenators are used every day in hemodialysis or coronary bypass. More permanent fixtures are also used such as artificial kidneys and hearts. These devices are wonderful and have contributed to longer and fuller lives for many people. However, man’s attempt to simulate the functions of the human body are simple at best, and there are serious problems that arise. These problems are tolerated by the medical profession at present because (1) they are not completely understood, and (2) the risks posed by …