Chemical Engineering Commons^™

Correlating Molecular Architecture Of A Radical Polymer Based Copolymer With Its Electrical Transport Properties, Holly Chan

Open Access Theses

The design and synthesis of electrically-conductive macromolecules can lead to significant improvements in the performance of polymer-based energy conversion devices (e.g., thermoelectric devices). For these organic electronic devices, conjugated polymers have dominated the area of conductive polymers; however, these materials are usually synthesized using conditions that lead to poorly-defined polymers. Furthermore, in these increasingly-standard polymers, the charge transport ability of the polymer thin films is largely affected by the degree of crystallinity, which is a difficult property to control in a reproducible fashion. Therefore, we seek to explore a new class of amorphous, non-conjugated polymers containing a stable radical …

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 …

Pharmacokinetic Characterization Of Procoagulation Proteins, Nicholas C. Vanderslice

Department of Chemical and Biomolecular Engineering: Dissertations, Theses, and Student Research

The cessation of bleeding in mammals occurs due to a well-conserved sequence of protein activation known as the coagulation cascade. However, people who have a deficiency in one or more proteins in this cascade, whether due to genetics or blood loss, struggle to maintain hemostasis. In order to aid patients in the restoration of hemostasis, exogenous proteins are often administered in response to bleeding events. However, these proteins are limited and costly due to limited supply of donor blood available for the production of plasma-derived proteins and the high cost of mammalian cell bio-reactors required for the production of recombinant …

Optimal Aggregation Of Fcεri With A Structurally Defined Trivalent Ligand Overrides Negative Regulation Driven By Phosphatases, Avanika Mahajan, Dipak Barua, Patrick Cutler, Diane S. Lidke, Flor A. Espinoza, Carolyn Pehlke, Rachel Grattan, Yuko Kawakami, Chang-Shung Tung, Andrew R. M. Bradbury, William S. Hlavacek, Bridget S. Wilson

Chemical and Biochemical Engineering Faculty Research & Creative Works

To investigate why responses of mast cells to antigen-induced IgE receptor (FcεRI) aggregation depend nonlinearly on antigen dose, we characterized a new artificial ligand, DF3, through complementary modeling and experimentation. This ligand is a stable trimer of peptides derived from bacteriophage T4 fibritin, each conjugated to a hapten (DNP). We found low and high doses of DF3 at which degranulation of mast cells sensitized with DNP-specific IgE is minimal, but ligand-induced receptor aggregation is comparable to aggregation at an intermediate dose, optimal for degranulation. This finding makes DF3 an ideal reagent for studying the balance of negative and positive signaling …

Horseradish Peroxidase-Attapulgite Clay Nanocomposites: Fabrication And Application To Sensing The Extracellular H2O2 Released From Cells, Ping Wu, Chen-Xin Cai

Journal of Electrochemistry

The nanostructured attapulgite clay was employed as a support matrix for immobilizing horseradish peroxidase (HRP). FTIR and electrochemical methods demonstrated that HRP had been effectively assembled on attapulgite surface with the formation of HRP-attapulgite nanocomposites. The HRP-attapulgite hybrid was deposited on the glassy carbon (GC) electrode forming the HRP-attapulgite/GC electrode. Cyclic voltammetric results showed a pair of well-defined redox peaks, which were ascribed to direct electron transfer (DET) of HRP, with the formal potential E₀′ = -335 mV (vs. SCE) in the phosphate buffer solution (PBS, pH 7.0). The dependence of E₀′ on solution pH indicated …

The Ionic Diffusion Model For The Solid Oxide Cathode And Its Verification By The Electrolysis Of Ta2O5 In Molten Cacl2, Hua-Lin Chen, Zhi-Yong Wang, Xian-Bo Jin, George Z. Chen

Journal of Electrochemistry

The deoxidation speed of a solid oxide cathode in molten CaCl₂ can be estimated by the PRS steady diffusion model of O^2-, which correlates the deoxidation speed with the precursor porosity, P, the metal-to-oxide molar volume ratio, R, and the cathode volume shrinkage S. The PRS model indicates that the porosity of the oxide cathode has important influence on the deoxidation speed, and provides a very simple equation for the prediction of the optimal cathode porosity. For the electrolysis of Ta₂O₅, the porosity of the cathode is better to be within 50%. …

Effects Of Oxygen Coverage And Hydrated Proton Model On The Dft Calculation Of Oxygen Reduction Pathways On The Pt(111) Surface, Li-Hui Ou, Sheng-Li Chen

Journal of Electrochemistry

DFT calculation is used to study various possible steps in the oxygen reduction reaction (ORR), including the adsorption and dissociation process of O₂ and the serial protonation process of dissociated products to form H₂O on the Pt(111) surface. By using slabs of different sizes, and different numbers of pre-adsorbed oxygen atoms, the coverage effects on the pathways are investigated. The calculated results using different hydrated proton models are also compared. It is shown that the initial step of the ORR is the formation of a protonated end-on chemisorbed state of OOH*, which can transform to an unprotonated …

Calculated Vs. Experimental Values For Volume And Surface Resistivity In Various Polymer Compounds, Megan Webster

Pursuit - The Journal of Undergraduate Research at The University of Tennessee

Versatile due to their resistance to high stress environments including but not limited to extreme temperature, pressure, and stress, polymers additionally have many uses in electrical applications wherein antistatic or conductive properties are preferential, i.e. conductive seals, oil pipeline spheres, and gaskets, to name a few. Being a complex material, many factors may affect the electrical resistivity of a given polymer compound including type and amount of carbon black, type of rubber, cure time and temperature, and dispersion, amongst other factors. External conditions such as relative humidity and temperature also play key roles. This paper will analyze five different rubber …

X-Ray Digital Industrial Radiography (Dir) For Local Liquid Velocity (Vll) Measurement In Trickle Bed Reactors (Tbrs): Validation Of The Technique, K. A. M. Salleh, M. F. A. Rahman, Hyoung-Koo Lee, Muthanna H. Al-Dahhan

Nuclear Engineering and Radiation Science Faculty Research & Creative Works

Local liquid velocity measurements in Trickle Bed Reactors (TBRs) are one of the essential components in its hydrodynamic studies. These measurements are used to effectively determine a reactor's operating condition. This study was conducted to validate a newly developed technique that combines Digital Industrial Radiography (DIR) with Particle Tracking Velocimetry (PTV) to measure the Local Liquid Velocity (V_LL) inside TBRs. Three millimeter-sized Expanded Polystyrene (EPS) beads were used as packing material. Three validation procedures were designed to test the newly developed technique. All procedures and statistical approaches provided strong evidence that the technique can be used to measure …

Insights Into The Epitaxial Relationships Between One-Dimensional Nanomaterials And Metal Catalyst Surfaces Using Density Functional Theory Calculations, Debosruti Dutta

USF Tampa Graduate Theses and Dissertations

This dissertation involves the study of epitaxial behavior of one-dimensional nanomaterials like single-walled carbon nanotubes and Indium Arsenide nanowires grown on metallic catalyst surfaces. It has been previously observed in our novel microplasma based CVD growth of SWCNTs on Ni-Fe bimetallic nanoparticles that changes in the metal catalyst composition was accompanied by variations in the average metal-metal bond lengths of the nanoparticle and that in turn, affected nanotube chirality distributions. In this dissertation, we have developed a very simplistic model of the metal catalyst in order to explain the nanotube growth of specific nanotube chiralities on various Ni-Fe catalyst surfaces. …

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 …

Simulation And Analysis Of Inhomogeneous Degradation In Large Format Limn2O4/ Carbon Cells, Yiling Dai, Long Cai, Ralph E. White

Faculty Publications

Degradation phenomena are not distributed uniformly in a large-format cell. To better understand the inhomogeneous degradation in large-format cells, a two-dimensional model was developed for a LiMn₂O₄ (LMO)/Carbon cell. The model includes both the non-uniform porous electrode properties and the electrode mismatch. The simulation results show that when the anode edge is extended over the cathode edge, the LMO particles near the edge suffer larger potential difference, larger charge/discharge depth, and higher insertion-induced stress. Therefore, the predicted loss of LMO is more pronounced near the edge as has been seen experimentally. The influence of different design adjustable …

Developent Of A Phospholipid Encapsulation Process For Quantum Dots To Be Used In Biologic Applications, Logan Grimes

Master's Theses

The American Cancer Society predicts that 1,665,540 people will be diagnosed with cancer, and 585,720 people will die from cancer in 2014. One of the most common types of cancer in the United States is skin cancer. Melanoma alone is predicted to account for 10,000 of the cancer related deaths in 2014. As a highly mobile and aggressive form of cancer, melanoma is difficult to fight once it has metastasized through the body. Early detection in such varieties of cancer is critical in improving survival rates in afflicted patients. Present methods of detection rely on visual examination of suspicious regions …

An Integrated Approach To Developing Technical Communication Skills In Engineering Students, Ronald S. Harichandran, David J. Adams, Michael Collura, Nadiye O. Erdil, David Harding, Jean Nocito-Gobel, Amy Thompson

Engineering and Applied Science Education Faculty Publications

The Project to Integrate Technical Communication Habits (PITCH) is being implemented across seven engineering and computer science undergraduate programs. The overarching goal of PITCH is to develop written, oral and visual communication skills and professional habits in engineering students. PITCH activities begin in the very first semester and are reinforced and extended through all four years of each program. Senior design becomes the culminating experience in which students demonstrate the skills and habits acquired through PITCH courses. Student outcomes for the project were established based on an extensive survey of employers, alumni and faculty. Communication instruments include technical memoranda, poster …

A Novel Silica-Based Nano Pigment As A Titanium Dioxide Replacement, Ryan Stoneburner

Masters Theses

This research focused on the evaluation of a new Silica-based pigment for the replacement of titanium dioxide (TiO₂) in paperboard coatings. The silica-based pigment has shown the ability to be a replacement in terms of functionality and runnability. TiO₂ is currently the highest opacifying pigment used in paper coatings, but it is also the most costly. Finding a less expensive pigment that doesn't reduce effectiveness is critical to reducing the cost of TiO₂ formulations. To evaluate the new pigment, coatings will be applied using a Cylindrical Laboratory Coater (CLC) with varying amounts of TiO₂ and …

Influence Of Nanofiller Morphology On The Viscoelastic Properties Of Cnf/Epoxy Resins, Liberata Guadagno, Marialuigia Raimondo, Khalid Lafdi, Annalisa Fierro, Salvatore Rosolia, Maria Rossella Nobile

Chemical and Materials Engineering Faculty Publications

In this paper we discuss the viscoelastic properties of CNF/Epoxy-Amine Resins for structural applications. The use of reactive diluent inside the unfilled and nanofilled epoxy mixture as proven to be of benefit to strongly decrease the viscosity.

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 …

Kinetic Analysis Of Thiol Oxidation To Study The Effects Of Fluorinated Groups On Metal Phthalocyanine Catalysts, Nellone Eze Reid

Dissertations

The oxidation of thiol (RSH) to disulfide (RSSR) is important biologically and industrially. Corrosive and malodorous thiols exist as contaminants in wastewater discharge from mining facilities, pulp and paper mills, tanneries, and oil refineries. The elimination of thiols from petroleum products is necessary for even cleaner fuels. Thiols in gas products can also inhibit catalyst activity for some downstream processes.

Experiments and mechanistic kinetic studies were conducted for the aerobic oxidation of 2-mercaptoethanol (2-ME) and 4-fluorobenzenethiol (4-FBT) catalyzed by cobalt phthalocyanines: H₁₆PcCo, F₁₆PcCo, and F₆₄PcCo, each exhibiting a metal center subject to increasing Lewis …

Hydrodynamic Cfd Modeling Of A Pharmaceutical Reactor Vessel Provided With A Retreat-Blade Impeller Under Different Baffling Conditions, Christopher G. Foehner

Theses

In the pharmaceutical industry, glass-lined reactors and vessels are often utilized to carry out a variety of different unit operations. Within these systems, both the vessel and impellers are typically glass-lined in order to provide superior corrosion resistance, prevent product contamination, and enhance cleanability. This approach, in turn, often requires the use of different, and sometimes sub-optimal, baffling conditions, which affect the hydrodynamics of the vessels and the reactor performance.

Computational Fluid Dynamics (CFD) is a computational tool that employs numerical methods and algorithms to discretize and numerically solve partial differential equations (PDEs) representing mass, energy, and momentum conservation equations …

Combustion Of Fine Magnesium Particles, Song Wang

Theses

Recent interest in developing Al-Mg alloys as reactive materials prompted studies of combustion mechanisms for particles of such alloys with different Al/Mg ratios. Reference experiments with pure Al and Mg powders are also desired to better understand and model combustion of the respective alloys. While combustion of pure Al powders has been addressed in many recent studies, combustion of magnesium explored mostly coarse, 50 μm, and larger particles. This effort is focused to characterize and understand combustion dynamics for fine Mg powders. Spherical, micron-sized magnesium particles were introduced in an air-acetylene flame using a custom-made screw feeder. Particles were observed …