Chemical Engineering Commons^™

An Efficient Implementation Of Gibbs-Duhem Integration For Solid-Liquid Phase Coexistence In Binary Lennard-Jones System With Relevance To Aav Capsid Separation, Muhi Muntaka

Graduate Theses and Dissertations

Gene therapy using adeno-associated viruses (AAVs) holds promise for treating genetic diseases, but high manufacturing costs limit its widespread use. A major challenge is separating functional (full) AAV capsids from non-functional (empty) ones, which are produced in similar amounts and have nearly identical structures. Conventional purification methods, such as density gradient ultracentrifugation and chromatography, face drawbacks like low yield, poor scalability, and high cost, often requiring multi-step processes. Recently, selective crystallization has emerged as a promising alternative, offering improved efficiency, scalability, and product quality. However, optimizing this method requires a deep understanding of thermodynamic phase behavior in multicomponent systems. In …

Advanced Membrane Methods For Treatment Of Toxic Contaminants And Education Of Early-Career Researchers, Thomas Mckean Iii

Graduate Theses and Dissertations

Membrane technologies are attractive as they are linearly scalable and often require lower operating costs compared to other technologies. One area where they are particularly effective is the treatment of water contaminated with toxic substances. The simplicity of this removal mechanism provides reliable performance capable of meeting stringent removal requirements. However, membrane fouling is a major challenge that often limits their commercial viability. This research sought to investigate novel approaches to pretreatment and membrane modification to overcome fouling and high operating pressures. In addition, membrane separation processes can often be developed into simple yet educational experiments that are ideal for …

Polymer-Enhanced Nanopore Sensing, Eugene Gyasi Agyemang

Graduate Theses and Dissertations

The resistive pulse technique characterizes single analytes by detecting fluctuations in the ion current as they pass through a narrow orifice connecting two electrolyte-filled chambers, each containing a single electrode. The amplitude, shape, frequency, and duration of these fluctuations primarily provide information about the analyte’s size, shape, concentration, and net surface charge, respectively. One configuration for resistive pulse measurements is of an electrolyte-filled nanopipette immersed in a bath, where the nanopipette tip acts as the nanoscale orifice. It was previously shown that incorporating the large quantities polymer polyethylene glycol (PEG 8K, 50% w/v) into the external electrolyte bath dramatically enhanced …

Integrating Sustainability And Food Safety Through Quantitative Microbial Risk Assessment And Life Cycle Assessment Of Low-Moisture Foods, Jessica Bain

Graduate Theses and Dissertations

Food safety and sustainability are critical concerns in the food industry. However, these areas are often evaluated separately, leading to an incomplete understanding of the overall impact of food production on human health. This dissertation aims to integrate food safety with sustainability to provide a comprehensive assessment of the impact of low-moisture foods on human health, using the almond processing supply chain as a case study.

In addition to conducting life cycle assessments (LCA) of almond processing, wheat flour production, and dried apple processing, this dissertation aims to create a framework to bridge the gap between sustainability and food safety. …

Wind Tunnel Investigation Of The Along-Wind Dispersion In Finite-Duration Neutrally Buoyant Gas Releases, Daniel Williams

Graduate Theses and Dissertations

This thesis investigates the along-wind dispersion of hazardous gas releases within a turbulent boundary layer using controlled experiments in an ultra-low-speed wind tunnel, recognizing the limitations of numerical modeling and field tests. This study utilizes a neutrally buoyant gas mixture and dual Flame Ionization Detectors (FIDs) to capture representative, repeatable data on gas cloud behavior over finite durations. Ensemble averaging of 65 trials across varying release durations and downwind distances provided detailed insights into gas dispersion and the distinct time phases within finite-duration releases. Analysis revealed that along-wind dispersion coefficients depend on turbulence and vertical wind shear, with normalized coefficients …

Investigating The Detection And Transport Of Low Molecular Weight Species To Better Understand Their Impact On Disease Pathology And Treatment, Haley Michelle Duncan

Graduate Theses and Dissertations

Due to the drastic differences in the projects involved, this dissertation will be split into two sections: Alzheimer’s disease and chronic kidney disease. Each chapter will contain an introduction, materials and methods section, results and discussion, conclusions, and works cited section. The Alzheimer’s disease chapter will also have a supplemental figures section containing the polyacrylamide gels that were silver stained and quantified via ImageJ. The presence of elevated levels of amyloid beta oligomeric species in the brain has been related to the pathology of Alzheimer’s disease. As these oligomeric species are transient in nature, their kinetics pose a challenge to …

Yeast Surface Display Of Multiple Heterologous Proteins Via Molecular And Biochemical Processing Techniques, Shadrach Ibinola

Graduate Theses and Dissertations

The arming of yeast cell wall, also known as yeast surface display, is an effective technology for expressing target proteins extracellularly. It has been shown to provide bioengineered yeast with qualities that are not known to native yeast such as the ability to survive harsh conditions including high pH and temperature, for example. Furthermore, this technique has been implemented for various applications which include, protein engineering, bioethanol production, bioremediation, vaccine construction, and antibody development. The major mechanisms of yeast surface display exploit agglutination, flocculation, or proteins with internal repeats as the means by which a target (protein) is covalently attached …

Developing Anisotropic Soft Matter As Functional Materials To Interface With Biological Systems, Homa Ghaiedi

Graduate Theses and Dissertations

Liquid crystals (LCs) constitute a subset of soft matter possessing hybrid characteristics from both liquid and crystalline phases. In this state, the center of masses remains uncorrelated similar to an isotropic phase, while the long axis of molecules aligns in parallel, resulting in molecules exhibiting orientational and positional order, either individually or concurrently. The directional alignment inherent in LCs arises from the asymmetrical shape and structure of the constituent molecules, causing a spontaneous self-assembly into ordered phases. This cooperative molecular behavior manifests distinctive optical features when subjected to cross polarizers. The remarkable sensitivity of LCs to external stimuli, including temperature, …

Development Of Lignin-Based Copolymers And Polymer Blends, David Chem

Graduate Theses and Dissertations

Increasing industrial interest in reducing fossil fuels in virgin polymer production and incorporating bio-based polymeric materials has led researchers to explore the potential of utilizing plant-based polymers such as lignin. Chapter 1 of this thesis presents a comprehensive overview of copolymerization and blending techniques for lignin and synthetic polymers, emphasizing different types of modifications and copolymerization techniques as well as key parameters such as temperature, reaction time, pH level, and solution compositions. These valorization methods are directed towards the development of high-value lignin-based materials with properties well-suited for various commercial applications. Chapter 2 offers a fundamental exploration into the amination …

Wind Tunnel Modeling Of The Jack Rabbit Ii Mock Urban Environment Chlorine Releases Based On Comparison With Field Scale Video Record, Samuel Gallimore

Graduate Theses and Dissertations

Unintentional releases of hazardous gases have led to significant injuries and fatalities in severe cases. Field tests can be used to release hazardous gases to document and evaluate the behavior of the gases. Chlorine is an especially hazardous gas due to its toxicity. The Jack Rabbit II Phase I field tests released chlorine within a mock urban environment (MUE) consisting of Conex containers arranged in rows to simulate buildings and streets. The number of field tests is limited by both expense and time. Simulation of a field test using a wind tunnel model can provide additional data and opportunity for …

Investigation Of The Flow Field In The Jack Rabbit Ii Mock Urban Environment Field Tests Using A 1:50 Scale Wind Tunnel Model, Paulo Victor De Freitas Lopes

Graduate Theses and Dissertations

Accidental release of toxic chemicals can put workers and nearby populations at significant risk. Consequence assessment of accidents in urban environments is of particular interest. Urban geometries create wind channels between buildings, along with particularly dangerous areas downwind of buildings, where near-stagnant flow is present. Furthermore, recirculation zones can be formed between buildings, trapping high concentrations of toxic gases at ground level, particularly for denser-than-air gases. In 2015, the Department of Homeland Security conducted the Jack Rabbit II Field Test (JR-II) at Dugway Proving Ground, UT. During JR-II, chlorine was released at the center of a Mock Urban Environment (MUE) …

Treating High Salinity Produced Water Using Hybrid Membrane Processes: Electrocoagulation-Microfiltration/Ultrafiltration-Membrane Distillation-Crystallization, Mahmood Gheni Jebur

Graduate Theses and Dissertations

Produced water (PW) is considered the largest industrial wastewater stream in the world. PW generated from oil and gas operations generally contains a range of contaminants including high total dissolved solids, high total suspended solids, polar and nonpolar organic compounds, and low surface tension dissolved species. Treating PW is very challenging and applying only membrane-based technologies is not sufficient due to membrane fouling, which affects their long-term performance. Hence, integrated membrane processes are required to treat PW effectively. Hybrid membrane processes, which may result from combining a conventional process with a membrane separation, could be used to address the issues …

Liquid Crystalline Coacervates Composed Of Chromonic Mesogens And Polyelectrolytes, Elizabeth Adeogun

Graduate Theses and Dissertations

Complex coacervates are formed by liquid-liquid phase separation of an aqueous solution of oppositely charged ions. Although several mixtures of molecules of natural and synthetic macro-ion have been shown to form complex coacervates, the formation of liquid crystalline (LC) coacervates are sparsely reported. LC coacervates have a unique property in that they can change their shape and optical property in response to external stimuli such as changes in temperature, pH, or the presence of specific molecules. This property makes LC coacervates useful as a sensor, as they can be engineered to respond to specific stimuli and generate a measurable signal …

Tangential Flow Treatment Of Poultry Processing Wastewater Using Stainless Steel Ultrafiltration Membrane, Saubana Olorunsola Dada

Graduate Theses and Dissertations

The current treatment of poultry processing wastewater (PPW) requires a large expanse of land, takes time, and requires chemical usage. The wastewater is typically treated prior to discharge. Apart from aiming to reuse the treated water for non-potable activities, this project aimed to reduce the footprint and time required for PPW treatment. To intensify the PPW treatment units, we studied the possibility of replacing dissolved air floatation (DAF) with a stainless steel ultrafiltration membrane (SSUF). Combined PPW from all processing units taken before the first DAF and the second DAF were used for this study with no pretreatment. The SSUF …

Dpd Guided Insight On The Formation Process Of Polyethersulfone Membranes By Nonsolvent Induced Phase Separation And The Effects Of Additives, Eric Ledieu

Graduate Theses and Dissertations

Dissipative particle dynamics (DPD), a coarse grain simulation method, was applied to the membrane formation process of non-solvent induced phase separation (NIPS) to gain further insight on the mechanism of certain variables and how they affect the final morphology. NIPS involves two solutions, an organic polymer dissolved in an organic solvent colloquially called the dope and an aqueous coagulation bath, brought into contact with one another. The solvents then mix, causing the polymer to fall out of solution as an asymmetric membrane with a dense surface layer and a more open subsurface layer in response to the decreasing solubility. Polyethersulfone …

Polymeric Biomaterials Approaches For Engineering The In Vitro Cellular Microenvironment For Mscs, Mahsa Letter-Mahsa Haseli

Graduate Theses and Dissertations

Cell therapy is a technology that relies on replacing diseased or dysfunctional cells with healthy functioning ones. One of the cells used for such advanced therapies are stem cells, owing to their ability to differentiate into specific cells required for repairing damaged or defective tissues or cells. The majority of cell-based products are intended to transiently persist in the patient, secreting factors which then allow the patient’s body to heal; in these products, the cells are subsequently eliminated from the body. Furthermore, unique manufacturing platforms, in addition to novel commercialization strategies, will be required to create a successful, sustainable cell …

Enhancing Human Schwann Cells Reparative Behavior Using Heparin/Collagen Layer-By-Layer Coatings, Luis Carlos Pinzon-Herrera

Graduate Theses and Dissertations

When a peripheral nerve injury (PNI) occurs, the gold standard for tissue regeneration is the use of autografts. However, due to the secondary effects produced by multiple surgeries involved in the removal and implantation of autografts for very small lesions, it is possible to replace them with the use of Nerve Guide Conduits (NGCs). However, NGCs are limited to short lesions (less than 1 cm). This limitation is caused by the absence of compounds in the extracellular matrix (ECM) that autografts can provide. Since much of the regenerative process takes place on the NGC surface, our work aims to modify …

Life Cycle Assessment Of Novel Electrochemical Struvite Recovery In Municipal Wastewater Treatment At The Plant And U.S. Watershed Scales, Karla Morrissey

Graduate Theses and Dissertations

As the supply of phosphorus decreases, nutrient recovery in municipal wastewater treatment has become an important area of research. Recovery methods for phosphorus-containing fertilizers, such as struvite, and other products are currently being developed and assessed for their efficiency and economic feasibility. Potential environmental impacts from nutrient recovery are also being assessed as design for the environment is important, especially with regards to the eutrophying potential of phosphorus in phosphorus-limited freshwater aquatic systems. Life cycle assessment (LCA) is a tool that can be used to estimate potential environmental impacts of a product or service focusing on its entire life cycle. …

Surface-Driven Instabilities At Oil-Water Interfaces, Anelisse Claros Mendieta

Graduate Theses and Dissertations

Fluid-fluid interactions are such a wide area and can be observed in different scenarios such as geothermal systems, waterflooding of reservoirs, oil recovery, and water treatment processes. This thesis aims to deepen the understanding of fluid-fluid interactions which include Marangoni flows, charge related instabilities, and surface activity. This thesis studied the interactions of micrometer-sized droplets of an oil (toluene) with surfactant Di-(2-ethylhexyl) phosphoric acid (DEHPA) in the aqueous phase. One of the main goals is to understand several surface-driven instabilities and how those can be manipulated for future applications.Furthermore, this thesis aims to use these oil-surfactant droplets as a medium …

Using Copper Oxide And Zwitterions To Prevent Membrane Fouling And Optimizing Ultrafiltration Membrane Fabrication With Green Solvents, Cannon Hackett

Graduate Theses and Dissertations

Membrane fouling and sustainable production of membranes are two of the most important challenges in membrane science. Chapter 1 of this dissertation introduces these challenges and covers previous research that has been done in those areas. Additionally, the objectives of this dissertation are stated. In chapter 2, a study was done in which polyethersulfone ultrafiltration membranes were functionalized with copper oxide nanoparticles and zwitterions for the purpose of reducing fouling on the membrane surface. Characterization confirmed the attachment of each component to the membranes. Dead-end filtration was performed with water and bovine serum albumin solution and showed that the functionalization …

Performance And Fouling During Bioreactor Harvesting, Da Zhang

Graduate Theses and Dissertations

Tangential flow filtration has many advantages for bioreactor harvesting as the permeate could be introduced directly to the subsequent capture step, the process is easy to scale up, and fouling of the filter is limited by the cross flow. However, membrane fouling has limited its widespread use. This is particularly problematic given the high cell densities encountered today. Here a reverse asymmetric commercial membrane, BioOptimal™ MF-SL (Asahi Kasei), where the more open surface faces the feed stream, and the tighter barrier layer faces the permeate stream, has been investigated for bioreactor harvesting. The open surface contains pores up to 40 …

Study Of Thermoelectric And Lattice Dynamics Properties Of 2d Layered Mx (M = Sn, Pb; X = S, Se, Te) And Zrs2 Compounds Using First-Principles Approach, Abhiyan Pandit

Graduate Theses and Dissertations

The aim of this dissertation is the investigation of thermoelectric and lattice dynamics properties of two-dimensional (2D) MX (M = Sn, Pb; X = S, Se, Te) and ZrS2 compounds based on the first-principles density functional theory. The dimensionality reduction (e.g., using 2D structure) of bulk materials is found to have enhanced thermoelectric efficiency. This enhancement is attributed to the increase of the Seebeck coefficient as a result of higher electronic density of states near the Fermi level in low-dimensional materials. In addition, lowering the dimensionality increases phonon scattering near interfaces and surfaces in 2D materials, which leads to a …

Wind Tunnel Modeling Of Jack Rabbit Ii Mock Urban Environment Gas Concentration Measurements, Sami S. Fares

Graduate Theses and Dissertations

The 2015 Jack Rabbit (JR) II field trials were conducted to improve understanding of the denser-than-air dispersion of chlorine in an urban environment. The field study involved five large-scale, outdoor release trials of chlorine in a mock urban environment (MUE) at Dugway Proving Ground (DPG). Various instrumentation was deployed, including JazTM Ultraviolet-Visible (UV-Vis) point sensors capable of measuring gas-phase chlorine concentration throughout the mock urban array.

The Chemical Hazards Research Center (CHRC) was tasked by the Chemical Security Analysis Center (CSAC) with the Mock Urban Wind Tunnel (MUWT) program to study the 2015 JR II Trials at wind tunnel scale. …

Optimizing Virus Prefiltration For Biopharmaceutical Manufacturing, Solomon Isu

Graduate Theses and Dissertations

Virus filters are single-use devices that use a size-based separation process. In virus filters, contaminating virus particles are retained while the therapeutic molecules pass through the membrane pores. Virus filters are an essential component of the overall virus clearance strategy. Sections 1 and 2 of this dissertation provide an introduction and extensive review of monoclonal antibody (mAb) process development, where virus filtration is pivotal. In section 3, prefiltration studies were performed with an industrially relevant IgG1 type mAb using adsorptive and size-exclusion-based prefilters with different mechanisms of action. This mAb has an isoelectric point range of 7.1 to 8.0 and …

Nonmetallic Jet Impingement Thermal Management For Power Electronics Via Additive Manufacturing, Reece Whitt

Graduate Theses and Dissertations

The increase in energy demanded by transportation and energy sectors has necessitated highly efficient thermal management for reliable power electronics operations. Conventional cooling techniques are limited by their inability to target switching location hot spot temperatures, leading to non-uniform thermal gradients. These devices, such as cold plates and heat sinks, also utilize heavy metallic structures that can accentuate electromagnetic interferences generated by high voltage switching processes. This work proposes a non-metallic jet impingement cooler for more customized thermal management, while simultaneously reducing the harmful effects of electromagnetic interferences. Additive manufacturing is utilized to enable jet impingement zones to target individual …

Greenhouse Tomatoes: Process Simulation, Juan Gabriel Marin Jr.

Graduate Theses and Dissertations

Growing population demand and challenges brought on by climate change have spurred the need for more resilient fruit and vegetable supply chains. One agricultural technology of significant interest is the use of greenhouses for food production. Greenhouses create a stable and adaptable environment for crops such as tomatoes to grow year-round. Fresh tomatoes are the second most consumed vegetable per capita in U.S. diets, currently averaging 20.7 pounds. The growing consumption of fresh tomatoes has been the result of increasing cultural diversity in the United States.

To meet the growing demand, Venlo-type greenhouses have been frequently used by growers. It …

Preliminary Development Of The Dialysis-Membrane-Based Passive Biocide Delivery System For Spacecraft Water Recovery Units, Rogelio Elias Garcia Fernandez

Graduate Theses and Dissertations

The purpose of this investigation is to explore the capabilities of a dialysis-membrane-based system for the in-line dosing of silver ions to treated water in spacecraft water recovery units. The spacecraft environmental control and life support system community (ECLSS) are interested in adopting silver ions as a biocide in future spacecraft water recovery processes since silver ions are effective biocide at concentrations that humans can safely consume. The system has been designed following the configuration of the Water Processor Assembly (WPA) aboard the International Space Station. In this configuration, silver ions have to be added at the last step in …

Recombinant Production And Purification Of Green Fluorescent Protein (Gfp)-Fused Metal Binding Protein For Palladium Nanoparticle Synthesis, Shadrach Ibinola

Graduate Theses and Dissertations

In lieu of chemical and physical methods, biologically guided synthesis is increasingly used as a cost-effective medium for the fabrication of nanoparticles (NP). Recently, a palladium metal binding sequence Pd4 (TSNAVHPTLRHL) has been demonstrated to be instrumental in the production of palladium (Pd) nanoparticles. Although, by eliminating the additional cost of purification of the protein, the crude lysate of E. coli containing Pd specific protein has been proven to be a viable cost-effective means for the synthesis of Pd NP, studies have not be done to ascertain the comparative catalytic activity of nanoparticles synthesized from both clarified lysate and pure …

Investigation Of Iron-Nickel Films Based Catalysts: Controlling Hydrogen Evolution Reaction (Her) Through An Electrode-Electrolyte Engineering Approach, Sergio Ivan Perez Bakovic

Graduate Theses and Dissertations

Electrochemical energy conversion technologies need to be economically viable in order to be adopted. Earth-abundant transition metals (i.e., Fe, Co, and Ni) have attracted attention due to their high availability, low cost, and catalytic characteristics that are in many cases found in and exploited by nature. Herein, we synthesize FexNi100-xOy electrocatalyst films and study how the electrocatalyst-electrolyte interactions alter the hydrogen evolution reaction (HER).In this work, FexNi100-xOy films were synthesized to study the composition, chemical state, and morphology. Characterization results provided a well-established electrocatalyst film platform to then proceed with electrochemical evaluations. The effects of the electrode composition and electrochemically …

Phase-Field Modeling Of The Polymer Membrane Formation Process For Micro- And Ultra-Filtration, Michael Rosario Cervellere

Graduate Theses and Dissertations

Porous polymer membrane filters are widely used in separation and filtration process. Micro- and ultra-filtration membranes are commonly used in biopharmaceutical applications such as filtering viruses and separating proteins from a carrier solution. The formation of these membrane filters via phase inversion is a complex and interconnected process where varying casting conditions can have a wide variety of effects on the final membrane morphol- ogy. Tailoring membrane filters for specific performance characteristics is a tedious and time consuming process. The time and length scales of membrane formation make it extremely difficult to experimentally observe membrane formation. Modeling the membrane formation …