Chemical Engineering Commons^™

Applications Of Cellular Components In Engineered Environments, Xiao Hu

Graduate Theses, Dissertations, and Problem Reports (ETD)

Manipulation of cellular components in synthetic environment has attracted interest for applications ranging from sensors to nanelectronics and from catalysis to biomedical devices. In such applications, biological-based processes such as specific recognition and self-assembly direct the formation of hierarchical structures, all at minimum energetic costs, with high efficiency and reliability.

Among such cellular machines, microtubules and kinesins have attracted special interest. Inside the cells, microtubules are giving structural integrity while serving as regular and uniform tracks for transport of vesicles or organelles. Kinesin uses a microtubule track in vivo to progress to specific locations with processive and coordinated steps, all …

Evaluation Of Silane-Doped Epoxy Coatings For Resisting Aluminum Corrosion By Oxalic Acid, An A. Niger Metabolite, Alex Pica

Williams Honors College, Honors Research Projects

The goal of this study was to investigate whether silane-doped epoxy coatings are capable of preventing corrosion of aluminum alloy 2024-T3 by oxalic acid, one of the primary metabolites of the fungus Aspergillus Niger. Previous research suggested the success of these types of coatings at preventing AA 2024-T3 corrosion in saline solutions, and this study was meant to build on those findings by investigating the efficacy of the coating in an acidic environment.

Each coating was applied to an AA 2024-T3 coupon by dissolving the epoxy and varying amounts of 3-aminopropyltriethoxysilane in acetone and then dripping the solution onto …

Electrospinning Aqueous Solutions Of Poly(Ethylene Oxide) Using A Corona-Type Apparatus, Nicholas Neill

Williams Honors College, Honors Research Projects

The purpose of this project was to evaluate working parameters for the corona spinneret to create electrospun fibers/ fiber mat. This project was set-up using a Box-Behnken design of experiment. The working parameters were investigated by performing the electrospinning process, altering the working conditions, collecting the electrospun fibers. The scope of this project includes three primary operational conditions: distance between the spinneret and the collection plate, the viscosity (weight percent) of PEO in the spinning solution and the weight percent of NaCl in the spinning solution. The distance between the spinneret and the collection plate were varied to 18 cm, …

Effects Of Hofmeister Ions On Gelation Of Gelatin And Pluronic Hydrogels, Eric Britton

Williams Honors College, Honors Research Projects

The purpose of the project was to observe the effects of the Hofmeister series of ions on the gelation of gelatin and Pluronic-127 hydrogels. Hydrogels are semi-solid materials that contain a network of joined molecules through intermolecular interactions which are capable of holding water. Gelatin and Pluronic-127 (PF-127) are thermoreversible, physical crosslinked gels. Gelation occurs when temperature, or other driving forces, reduce the polymer chain solubility until a distinct 2-phase system forms. When aqueous ions are present in solution, they exhibit specific ion effects that have either a stabilizing or destabilizing effect on the solubility of proteins and other polymers. …

Interfacial Corrosion Of Copper And The Formation Of Copper Hydroxychloride, Mary Teague, Shengxi Li, Hongbo Cong

Williams Honors College, Honors Research Projects

Electrical circuitry is an industry, among many others, heavily using the element of copper. Ensuring the mechanical integrity of Cu is crucial, especially in salt environments, for the multifaceted composition of circuits. 4N NaCl solution (equilibrium concentration in ~84% RH) simulated this three-phase system. Rectangular Cu samples were partially immersed in both ambient and continuous lab air sparging atmospheres to understand waterline corrosion of the metal. Open circuit potentials (OCP) were continuously taken during the immersion testing for a maximum of 5 days. A scanning electron microscopy (SEM) equipped with an energy dispersive X-ray spectrometer (EDS), Raman spectroscopy, and 3-D …

Tandem Mass Spectrometry (Ms/Ms) For Determination Of Architecture Of Synthetic Polymers, Shoumik Saha

Williams Honors College, Honors Research Projects

Tandem Mass Spectrometry (MS/MS) was used to determine the architecture of synthetic polymers and they are difluorene-N₃, 3-difluorene-N₃ and VPOSS-3-difluorene. VPOSS materials usually exhibit electrochemical properties and the research was performed to determine their accurate structure and to provide evidence of their proper synthesis. The compounds were mixed with a matrix solution, DCTB, and a silver salt to enable proper protonation. The solvent mixture was on a MALDI plate and then put into the mass spectrometer. The mass spectrum generated was analyzed and each fragment was identified to structures with the synthetic polymers via ChemDraw. Thus, trial …

Characterization Of The Cylinderical Split Internal-Loop Photobioreactor With Scenedesmus Microalgae: Advanced Culturing, Modeling, And Hydrodynamics, Laith S. Sabri

Doctoral Dissertations

"Microalgae are fast growing photoynthetic microorganisms and it have very wide range of industrial applications such as biofuels and wastewater treatment. These cells can be grown in a wide variety of systems ranging from open culture systems (e.g., ponds) to closed culture systems of photobioreactor (e.g., airlift). The open culture systems exist in the external environment, and hence, are not intrinsically controllable. However, the microalgae production in enclosed photobioreactors faces prohibitively high production costs with special difficulty in reactor design and scale-up. The light availability and utilization efficiency in the photobioreactor in terms of design and scale-up consider as the …

The Impact Of Gallium Content On Degradation, Bioactivity, And Antibacterial Potency Of Zinc Borate Bioactive Glass, Alireza Rahimnejad Yazdi, Lawrence Torkan, Wendy Stone, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Zinc borate glasses with increasing gallium content (0, 2.5, 5, 10, and 15 Wt % Ga) were synthesized and their degradation, bioactivity in simulated body fluid (SBF), and antibacterial properties were investigated. ICP measurements showed that increased gallium content in the glass resulted in increased gallium ion release and decreased release of other ions. Degradability declined with the addition of gallium, indicating the formation of more symmetric BO₃ units with three bridging oxygens and asymmetric BO₃ units with two bridging oxygens in the glass network as the gallium content in the series increased. The formation of amorphous Ca-P …

A Constitutive Model For Entangled Polydisperse Linear Flexible Polymers With Entanglement Dynamics And A Configuration Dependent Friction Coefficient. Part Ii. Modeling "Shear Modification" Following Cessation Of Fast Shear Flows, David W. Mead, Saman Monjezi, Joontaek Park

Chemical and Biochemical Engineering Faculty Research & Creative Works

The polydisperse Mead-Park (MP) "toy" molecular constitutive model developed in Paper I [Mead et al., J. Rheol. 62, 121-134 (2017)] as well as our previously published work [e.g., J. Rheol. 59, 335-363 (2015)] is used in the "forward" direction to study model polydisperse melts of entangled linear flexible polymers in severe, fast shear flows. The properties of our new model are elucidated by way of numerical simulation of a representative model polydisperse polymer melt in step shear rate and interrupted shear flow. In particular, we demonstrate how the MP model simulates the individual molecular weight distribution (MWD) component dynamics as …

A Proactive Drilling System To Prevent Stuck Pipe And Differential Sticking, Ethar H. K. Alkamil

Doctoral Dissertations

"During drilling operations for the E oilfield in the Mishrif formation in southern Iraq, stuck pipe and differential sticking have been identified as significant geomechanical and drilling problems for several deviated wells. In this work, an integrated approach with three phases is presented to serve as a proactive geo-drilling system to prevent wellbore instability. In the first phase, a comprehensive geomechanical assessment of the Mishrif formation has been carried out to evaluate the in-situ stresses, maximum horizontal stress orientation, pore pressure, rock properties, and rock strength parameters. Moreover, the geomechanical evaluation has been incorporated into the mud design using three …

Geomechanical Characterizations And Correlations To Reduce Uncertainties Of Carbonate Reservoir Analysis, Farqad Hadi

Doctoral Dissertations

"Although carbonate reservoirs hold a wealth of hydrocarbon, they are among the most difficult types of reservoirs to be characterized. Carbonate reservoirs by nature have complex depositional environments and diagenetic processes in which brittle, ductile, fractured rocks, and vugular pores may all exist within small interval. This huge variance in the rock mechanical properties can cause challenges in the reservoir's development, especially in applications related to geomechanics.

The main objective of this research is to geomechanically characterize and correlate the carbonate mechanical properties with their petrophysical properties. A comprehensive review for the geomechanical-petrophysical properties of carbonates was conducted from previous …

Integrated Study On The Applicability Of Co₂-Eor In Unconventional Liquids Rich Reservoirs, Dheiaa Khafief Khashan Alfarge

Doctoral Dissertations

"Unconventional Liquids Rich Reservoirs (ULR) such as Bakken, Niobrara, and Eagle Ford have become the main target for oil and gas investors as conventional formations started to deplete and diminish in number. These unconventional plays have a huge oil reserve; however, the predicted primary oil recovery is still low as an average of 7.5 %. Unconventional Improved Oil Recovery (UIOR) techniques are still a new concept in the oil industry because there is no commercial project for any IOR technique so far. Injecting carbon dioxide (CO₂) might be the most potential strategy to improve oil recovery in such complex plays. …

The Active Phase Of Gold Catalyst For Propylene Epoxidation, Manchhiben Patel

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.

Residence Time Distribution Of Mixing Based On Mathematical Modeling, Michelle Ayers

Williams Honors College, Honors Research Projects

Two different mathematical models were investigated for their use in describing the residence time distribution (RTD) of an industrial mixer. The first model investigated was the tanks-in-series model, while the second model was a combination of two branches of tanks-in-series. The tanks-in-series model is capable of characterizing the mixing present in the flow, but cannot detect non-idealities in flow such as bypassing and dead space. The multi-branch model has mathematical complexity, but it uses the second branch of flow to detect the presence of this non-ideal flow, determine if it is dead space of bypassing, and characterize how well-mixed the …

Sweat Sensor Modelling, Katie Brumbaugh

Williams Honors College, Honors Research Projects

There are no in-situ electrolyte sodium sensors available in the marketplace, however there is a demand and use for them. An in-situ sodium sensor can be used to monitor bodily functioning in many applications like medical patient monitoring and athlete monitoring during workouts. Patients with cystic fibrosis attempt to monitor salt content in sweat to maintain homoeostatic body function, this sweat sensor would change the way those patients took care of themselves [1]. Sweat sensor samples were made using multiwalled carbon nanotubes (MWNT) and nylon 6. The MWNTs were functionalized on the nylon using cyclo-oligomeric calixarene [3]. In functionalizing the …

Investigation Of Scanning Kelvin Probe Techniques, Nicholas D'Angelo Jr., Hongbo Cong

Williams Honors College, Honors Research Projects

The original scope of this work was to advance the understanding of corrosion properties of additively manufactured (AM) materials by correlating microstructural defects in AM materials to the material conventional counterparts utilizing a scanning kelvin probe [Ametek VeraSCAN Electrochemical System]. However, upon the initiation of project research, it was observed that the system was not operational due to unknown hardware and software problems. The evolved scope of this work was to reconcile the operational issues and develop a repair and mitigation plan. After extensive troubleshooting, it was determined that the software was not properly configured, and the electrometer had permanently …

Reaction Kinetics Of The Hydrogenation Of Phenol In A Tubular Reactor, Michael Selzer

Williams Honors College, Honors Research Projects

The reaction kinetic parameters for the hydrogenation of phenol to cyclohexanone are determined for the liquid phase reaction with the palladium catalyst supported on an electrospun PVDF membrane. Runs of the reactor were completed at catalyst loadings of 40, 50, and 60 g/m², and tube diameters of 0.187 in and 0.25 in with a runtime of ten hours. One-dimensional and two-dimensional models of the experimental setup were developed. Fitting data to the one-dimensional model found that the pre-exponential factor was 2.50 x 10⁴, the activation energy was 7.69 kJ/mol, and the order with respect to phenol …

Polyhexamethylene Biguanide Release By Chitosan-Heparin Nanoparticles, Jacob Ress

Williams Honors College, Honors Research Projects

Chitosan and heparin were used to synthesize nanoparticles using polyelectrolyte complexation. The optimal mixing ratio was determined to be 1:4 by studying the particle characteristics of zeta potential and dynamic light scattering of the ratios 1:2, 1:3, 1:4, 1:5 and 1:6 (chitosan: heparin). The particles were loaded with the antibiotic polyhexamethylene biguanide (PHMB) and the release was measured over 335 hours using the dialysis membrane incubation method and detected via ultraviolet-visible (UV-Vis) spectroscopy. Around 80% of the encapsulated PHMB was released over the measured period. The goal of this part of the study was to determine the drug release behavior …

Molded Features In Pdms For Fabricating Bacterial Cellulose For Various Geometries, Mitchell Habegger

Williams Honors College, Honors Research Projects

The purpose of producing features on bacterial cellulose (BC) is to facilitate the elongation and alignment for cells, in this case Normal Human Dermal Fibroblast (NHDF) cells. The elongated cells have applications in wound healing, tissue engineering, disease diagnostics, and many other fields. Experiments were run to test the effectiveness of transferring features to BC sheets from features induced by fracturing on polydimethylsiloxane (PDMS) and those duplicated from molds with existing features. The features were duplicated to BC sheets by either air drying or Guided Assembly-Based Biolithography (GAB). The research results showed that fracture inducing on PDMS produced very small …

Modeling The Effect Thickener Structure Has On The Oil Release Of Grease, Dana Cressman

Williams Honors College, Honors Research Projects

Our hypothesis was that the thickener type and micelle concentration of grease affected its viscoelastic properties. Measurements were made using a TA AR G2 rheometer and calculations were made using TA rheometer analysis software to characterize the viscoelastic response of grease under oscillatory shear and frequency tests. The oscillatory frequency tests determined the critical micelle concentration. The oscillatory stress tests were taken at temperatures from 5 to 65 degrees Celsius to create a master curve based on time temperature superposition of the measurements. The crossover points of G’ and G” on the oscillatory stress tests demonstrated where the grease transitions …

Galvanic And Pitting Corrosion Of A Fastener Assembly, Julie Shallman

Williams Honors College, Honors Research Projects

This research focuses on coupled galvanic/pitting corrosion of AA7075 when combined with stainless steel in a fastener assembly. A one-dimensional mathematical model of a well-mixed thin film electrolyte is developed to predict the damage profile of the AA7075 surface when its protective coating is damaged. The damage exposes the galvanic couple. A time dependent system of partial differential equations for potential, chloride concentration, aluminum ion concentration, and damage is developed and solved numerically. Two approaches to calculate the current density within aluminum pits are discussed. The first is a current balance between the cathodic, anodic and passive portions of the …

Investigation Of Combustion Characteristics Of A Heavy-Duty Diesel Engine Retrofitted To Natural Gas Spark Ignition Operation, Jinlong Liu

Graduate Theses, Dissertations, and Problem Reports (ETD)

The conversion of existing diesel engines to natural-gas spark ignition operation by adding a gas injector in the intake manifold for fuel delivery and replacing the diesel fuel injector with a spark plug to initiate and control the combustion process can reduce U.S. dependence on petroleum imports and curtail engine-out emissions. As the conventional diesel combustion chamber (i.e., flat head and bowl-in-piston) creates high turbulence, the engine can operate leaner, which would increase its efficiency and reduce emissions. However, natural gas combustion in such retrofitted engines presents differences compared to that in conventional spark ignited engines. Subsequently, the main goal …

Role Of Bed Design Characteristics On The Effective Thermal Conductivity Of A Structured Adsorbent, Pravin Bosco Charles Antony Amalraj

Theses and Dissertations

This work evaluates the role of different design variables on the effective thermal conduction of a structured adsorbent bed for its possible application in a temperature swing adsorption (TSA) process. The structured adsorbent bed is represented by eight parallel layers of intercalated smooth and corrugated foils of a metal support coated with 13X zeolite resulting in the formation of parallel triangular channels. The variables investigated include the thickness of the adsorbent coating, thickness of the metal, nature of contacts between smooth and corrugated foils, type of metal, presence and magnitude of an air gap between the foils, difference in alignment …

Combinatorial Study Of Oxidation Catalysts: Uncovering Synthesis-Structure-Activity Relationships, Kathleen B. Mingle

Theses and Dissertations

High throughput experimentation (HTE) in catalysis has proven useful in expediting materials discovery via parallelized synthesis, characterization, and testing of candidate materials. However, even in a high-throughput manner, the combinatorial explosion of relevant parameters far exceeds our ability to study. To further complicate the problem, a large time investment and great deal of characterization is often required to build an in-depth understanding of catalytic materials. It follows that the field of heterogeneous catalysis is rich with examples of catalytic systems that have been developed using trial and error efforts for which a lot is known but context is lacking. Techniques …

Understanding Early Amyloid-Ss Aggregation To Engineer Polyacid-Functionalized Nanoparticles As An Inhibitor Design Platform, Nicholas Vander Munnik

Theses and Dissertations

Alzheimer’s disease (AD) is characterized by the presence of amyloid-ß (Aß) protein aggregates in the brains of those afflicted. This protein aggregates via a complex pathway to progress from monomers to soluble oligomers and ultimately insoluble fibrils. Due to the dynamic nature of aggregation, it has proven exceedingly difficult to determine the precise interactions that lead to the formation of transient oligomers. A statistical thermodynamic model has been developed to elucidate these interactions. Aß was simulated using fully-atomistic replica exchange molecular dynamics. We use an ensemble of 5 × 105 configurations taken from these simulations as input for a self-consistent …

Development Of Bimetallic Catalysts For Dry Reforming Of Methane And Hydrogenation Of Succinic Acid, Jayson Michael Keels

Theses and Dissertations

Advances in natural gas recovery have greatly impacted the global economy; the abundant supply of gas has revealed new opportunities and challenges in a wide range of markets within the fuels and chemicals industries. One such opportunity exists with the overabundance of gas from remote wells that is flared or emitted because of the high costs associated with transportation of a chemical with such a high molar volume. A possible solution is an on-site process to convert gas to higher value chemicals that are liquid at standard conditions, and can more easily be transported. As a first step, CO2 from …

Selective Deposition Of Platinum By Strong Electrostatic Adsorption Onto Cobalt- And Iron-Based Catalysts For Fischer-Tropsch Synthesis, Fahad A. Almalki

Theses and Dissertations

Cobalt and iron based catalysts are commercially predominant for Fischer-Tropsch synthesis, Co-based catalysts for their stability, activity, and inactivity for the water gas shift reaction and Fe-based catalysts for their cheap cost, high light-olefins and alcohols selectivity, and tolerance to H2/CO ratio. These catalysts are structure sensitive with lower activity at nanoparticle sizes smaller than 6-8 nm. Co-based catalysts exhibit high activity, low CH4 selectivity, and high C5+ selectivity, while Fe-based catalysts are more selective to low-molecular-weight hydrocarbons such as olefins and alcohols. The reducibility of cobalt and iron is another important factor which may be key for improving their …

Dynamic Simulation Of A Solar Powered Hybrid Sulfur Process For Hydrogen Production, Satwick Boddu

Theses and Dissertations

The Hybrid Sulfur process is a thermo-electrochemical cycle used to produce hydrogen from water. The process requires a high temperature energy source for H2SO4 decomposition with temperature reaching 800°C. This step is followed by SO2 - depolarized water electrolysis. Using solar energy as the high temperature energy source allows for efficient environmentally friendly production of hydrogen. This method is an alternative to traditional photovoltaic electrolysis for hydrogen production. Making the process economically competitive is a major challenge. Operating the process with changes in the availability of solar energy also increases process complexity. The dependence of the process on solar energy …

Three-Way Catalysts In Passive Selective Catalytic Reduction Systems, Calvin Thomas

Theses and Dissertations

Conventional gasoline-powered engines operate with a stoichiometric air-fuel ratio (AFR), but greater fuel economy is achieved in lean burn engines by increasing the AFR. The primary drawback to these engines is the nitrogen oxide (NOX) emissions, which cannot be reduced over a conventional three-way catalyst (TWC). Passive selective catalytic reduction (SCR) is a promising approach for the control of NOX emissions in lean burn systems. By periodically decreasing the AFR to fuel-rich levels, ammonia (NH3) can be produced over a TWC and stored on a downstream SCR catalyst for the reduction of NOX during normal lean operation. While passive SCR …

Nox Formation In Syngas/Air Combustion, Nazli Asgari

Theses and Dissertations

Syngas is a reliable energy source derived from the gasification of coal and other solid fuels. The feedstock type and the production process of syngas can affect the composition of syngas. Gas turbines utilizing high hydrogen content (HHC) fuels like syngas for power generation applications need to meet stringent pollutant emission standards, particularly with respect to nitrogen oxides (NOx). For gas turbine conditions, reliable experimental data, especially at high-pressure, is necessary for both generating accurate NOx prediction models and improving reaction pathways regarding the NOx chemistry. In this study, NOx formation in post-flame gases of syngas combustion at different conditions …