Chemical Engineering Commons^™

Cross-Linked Cellulose Ester/Linseed Oil Composites For Controlled Release Fertilizers, Ian Stark

USF Tampa Graduate Theses and Dissertations

Food scarcity is an ever-present concern for a growing population but can be mitigated through innovations in agriculture. Fertilizers are required to produce a sufficient amount of food, and while they contain key nutrients for crop growth, these nutrients can leech into the surrounding environment. Controlled release fertilizers slow the release of nutrients, encasing the prills in a semi permeable coating. Current coatings are non-biodegradable, causing microplastic soil contamination, which is very difficult to remove. Cellulose esters offer a compelling alternative, with an ability to cross-link into thin films that can be applied as coatings. The cellulose esterification was completed …

Ai-Assisted Spectral Fingerprinting Of Mg-Doped Zno Tracer Phosphors: Tuning Photoluminescence Emission And Investigating Lifetime Via Sol-Gel Synthesis Parameters, Thomas M. Brandte

USF Tampa Graduate Theses and Dissertations

Plastic sorting remains a major driver of recycling costs, and existing infrared (IR) optical identification systems cannot determine material prominence or quality, nor reliably identify dark polymers [1]. This work explores a PVA-stabilized sol–gel and thermal synthesis route for magnesium-doped zinc oxide (Mg:ZnO) as a tunable photoluminescent tracer phosphor.

Lattice-defect control forms the foundation of phosphorescent emission tuning, enabling unique spectral fingerprints to be generated based on synthesis parameters—Mg molar ratio (Mg%), PVA mass (g), and calcination temperature (°C). Photoluminescence (PL) spectra (400–850 nm) were analyzed using Gaussian peak fitting and principal component analysis (PCA), reducing hundreds of spectral features …

Quantifying Wellbore Effects During Co2 Sequestration In A Saline Aquifer, Uzoma Johnpaul Ajugwe

USF Tampa Graduate Theses and Dissertations

Carbon capture and storage (CCS) is a strategy for mitigating climate change by reducing greenhouse gas emissions from large stationary sources like fossil-fuel-fired power stations. One method of CCS involves carbon dioxide (CO2) sequestration in deep saline aquifers, where supercritical CO2 is injected into an aquifer. The success of such projects depends on accurate predictions of CO2 behavior within the subsurface, which are obtained through numerical simulations.

TOUGHREACT, a renowned simulation tool, models subsurface fluid flow, geochemical interactions, and solute transport, providing insights into the feasibility of CO2 sequestration projects. A critical aspect of these simulations is the apportioning of …

Surface Acoustic Wave Energy Driven Degradation Of Aqueous-Based Methylene Blue, Xieqi Gu

USF Tampa Graduate Theses and Dissertations

This study investigates the degradation behavior of methylene blue (MB) under surface acoustic wave (SAW) excitation, focusing on the effects of power, frequency, hydrogen peroxide (H2O2) concentration, and the use of perovskite oxide catalysts (LFO and LSF). Initial experiments showed that MB concentrations remained stable under SAW at ~10 MHz and ~30 MHz with power levels of 1–3 W in the absence of H2O2, though solution temperatures increased. Upon introducing 1 M H2O2, MB degradation followed a second-order rate constant, with degradation rates increasing with power and significantly higher at ~30 MHz, suggesting that both frequency and power enhance free …

Simulation Of Multi-Receiver Solar Power Tower By Enhancement Of Solarpilot Software And A Review Of Absorber Coating Materials For The Receivers, Yasser Mirza Baig

USF Tampa Graduate Theses and Dissertations

Central receiver concentrating solar power (CSP) towers offer significant potential for cost-effective renewable electricity but face increasing optical losses with larger heliostat fields. This thesis introduces enhancements to NREL’s SolarPILOT software through a Python-based API named CoPylot, which enables comprehensive optimization of heliostat field layouts for multi-receiver systems. The enhanced methodology incorporates per-heliostat ray tracing, receiver orientation optimization (tilt angle β), and an incidence-angle-dependent absorptance (α(θ)) model to evaluate optical performance, thermal losses, and techno-economic metrics within an integrated simulation framework.

A case study for Daggett, California demonstrates that transitioning from a baseline single-receiver system (180 m tower, 5×5 m …

Cactus Infused Beads For Off-Flavor Mitigation In Aquaculture Systems, Rama Mahita Kambhampati

USF Tampa Graduate Theses and Dissertations

Aquaculture has become a vital component of global food production, now providing 50% of the world's fish supply. However, the industry encounters major challenges due to off-flavor compounds like Geosmin and 2-Methylisoborneol (MIB), which give fish an unpleasant earthy or musty smell. These compounds are detectable by humans at extremely low levels 0.7 parts per billion (ppb) for MIB and ten parts per trillion (ppt) for Geosmin—making them a persistent problem. Their presence not only reduces the sensory quality of aquaculture products but also results in significant economic losses, with U.S. catfish production incurring an additional $15–$23 million annually due …

Emergent Magnetism And Hyperthermia In Phase- And Size-Tunable Iron Oxide Nanostructures, K Mudiyanselage Tharindu Supun Bandara Attanayake

USF Tampa Graduate Theses and Dissertations

Iron oxide nanoparticles (IONPs) hold immense potential across diverse fields, from spintronics, magnetic hyperthermia to drug delivery, biodetection, and magnetic resonance imaging. Unlocking these applications hinges on our ability to tailor the magnetic properties of IONPs, and this dissertation presents novel and powerful approaches for enhancing magnetic and hyperthermic responses of multiphase iron oxide nanostructures. This is achieved by manipulating their phase volume fraction, size, and shape with a focus on the magnetic tunability of nanostructures via strategic control over structural and environmental parameters. The aforementioned has been achieved by the following three key approaches: (i) phase-tunability of iron oxide …

Integrated Process Modeling, Techno-Economic Analysis And Life Cycle Assessment For Enhanced Biogas-To-Energy Sustainability And Efficiency, Rarosue Jennifer Amaraibi

USF Tampa Graduate Theses and Dissertations

This dissertation aims to enhance the cost competitiveness and minimize the environmental footprint of technologies that convert biogas to energy, contributing to global climate change mitigation efforts. Biogas, a by-product of the anaerobic decomposition of organic waste from various sources, is a renewable energy source with the potential to reduce carbon emissions and meet local energy needs. However, widespread adoption requires the development of economically viable and environmentally friendly technologies.The central hypothesis of this dissertation suggests that by adopting a holistic strategy that combines cutting-edge techniques to purify biogas and improve its conversion into valuable liquid fuels, we can substantially …

Modeling Studies Of An Intensified Reforming/Fischer-Tropsch Synthesis Process For Gas To Liquid Conversion, Brian Gray

USF Tampa Graduate Theses and Dissertations

Despite rigorous study and advancement in fields of green energy, the world's transportation industry remains poised to continue reliance on liquid hydrocarbon fuels. To date, the primary source of diesel and jet fuels is the petroleum industry; however, continuing trends in rising greenhouse gas emissions present a need for study into processes for the production of synthetic hydrocarbon fuels. The most promising technologies to meet this goal are gas-to-liquid (GtL), biomass-to-liquid (BtL) and coal-to-liquid (CtL). The commonality of these technologies is that they utilize a feedstock to produce carbon monoxide and hydrogen gas (syngas) which becomes the building blocks of …

Integration Of Algae And Biomass Processes To Synthesize Renewable Bioproducts For The Circular Economy, Jessica Martin

USF Tampa Graduate Theses and Dissertations

Rapid population growth and global industrialization have substantially heightened the demand for fossil-based fuels and products in various sectors of the global economy, including energy production, transportation fuels, and as raw materials for petrochemicals. The intense consumption of fossil fuels has caused immense environmental impacts, especially pertaining to carbon dioxide emissions. Shifting to renewable feedstocks (raw materials) is expected to reduce these emissions by lowering the carbon footprint of fuels and products compared to traditional fossil-derived alternatives. This transition aligns with the goal of creating a sustainable and circular economy, emphasizing efficient resource use, and reducing waste generation through recycling …

Swelling Induced Buckling Of Photopatterned Hydrogel Beams, Chinar Yogesh Kokaje

USF Tampa Graduate Theses and Dissertations

The main goal of this study was to learn more about swelling induced buckling of surface-attached gel lines photo-patterned from thermally responsive polymers. A library of 10 different polymer compositions was synthesized using methacryloyloxybenzophenone (MABP) as the photo-cross-linking monomer. For each of the polymers, a series of beam-like patterns were prepared on polystyrene tissue culture dishes by first depositing a known amount of polymer into the tissue culture dish followed by pattern generation using a photo-lithography mask with line widths of 10, 20, 30, 50, and 80 μm. The target height of each polymer line was 100 μm. After development …

Cellulose Ester As Membranes For Controlled Release Fertilizer’S, Muhammed Salman Fajis

USF Tampa Graduate Theses and Dissertations

Growing environmental pollution and non-sustainable materials has escalated the need for research in sustainable practices for many areas including crop production and fertilization. The conventional coating for the controlled-release fertilizers (CRFs) is non-biodegradable. Hence, the development of novel biodegradable coatings for fertilizer prills has emerged as an important area of study. In this thesis, conducting synthesis and application of cellulose esters (biomass membrane) as an encapsulation for the controlled release fertilizers. Therefore, the coating would be effective for a controlled release of nutrients to the crops by sustaining nature. Here, synthesized biodegradable cellulose esters by 8 and 16-carbon fatty acids …

Wastewater Treatment Using Encapsulated Chabazite In Polyvinyl Alcohol-Sodium Alginate Hydrogel Biofilm Carriers, Susieanna Nevada Persaud

USF Tampa Graduate Theses and Dissertations

Nitrogen discharge from wastewater is a global issue and with increased urbanization as well as industrialization, it has become even more essential to develop more efficient wastewater treatment systems. The dominant form of nitrogen in wastewater is ammonium. Biological oxidation of ammonium to nitrite and nitrate is the first step in biological nitrogen removal processes. If left untreated, nitrogen can cause toxicity to aquatic life, unsafe changes in water quality, and eutrophication.

Biofilm carriers can help to improve the efficiency of traditional activated sludge wastewater treatment systems by reducing operating costs and reducing hydraulic retention time. Biofilm carriers also promote …

Exploration Of Corona Charge As A Novel In Vitro Human T Cell Dna Transfection Method, Molly A. Skinner

USF Tampa Graduate Theses and Dissertations

With gene-based immunotherapies on the rise to treat a multitude of diseases, the ability to genetically modify cells in a rapid and efficient fashion is necessary to keep up with demand. Gene electrotransfer (gene transfer by electroporation) is an appealing transfection method due to its low cost, high efficiency compared to other physical forms of gene delivery, and low toxicity compared to liposomal or viral vectors.

Traditional gene delivery via electroporation is done within a cuvette where the cell suspension is placed between two plate electrodes. This method requires cells to be moved from the treatment cuvette to a growth …

Scale-Up Of Perovskite Oxides For Conversion Of Co2 To Co Through Reverse Water-Gas Shift Chemical Looping, Hanzhong Shi

USF Tampa Graduate Theses and Dissertations

CO2 conversion to CO has the benefit of further conversion to hydrocarbon-based fuels and chemicals. Due to CO2 being an important greenhouse gas, its conversion to CO and an increase of the carbon cycling will help reduce the greenhouse effect. Reverse water-gas shift chemical looping (RWSG-CL) is a two-step process that can be employed for the conversion of CO2 to CO. The first step involves partial reduction of oxygen by hydrogen to form oxygen vacant oxide, and the second step is the conversion of CO2 to CO over these partially reduced materials to regain their original structures. The RWSG-CL process …

Synergistic Effect Of Temperature And Acid Catalyst To Enhance L-Ald, Prabhsimran Singh

USF Tampa Graduate Theses and Dissertations

Liquid Atomic layer deposition (LALD) is an emergent technology used for depositing thin films. Extensive research has been done on this method, designing different techniques and modifications for the deposition of films. Wastage of alkoxide precursors, extra purging cycle, and extensive time for the reaction when added stoichiometrically are some of the drawbacks which shift the focus from metal alkoxide as precursors. In this thesis, modifications for the L-ALD method for the complete reaction of alkoxide precursors when added stoichiometrically were achieved. Temperature and catalyst’s synergistic effects were utilized for the modification. This modified method was applied for the doping …

An Integrated Approach For Dynamic Process Modeling And Optimization Of Wastewater Treatment Facilities, Komal Rathore

USF Tampa Graduate Theses and Dissertations

The subareas of process systems engineering including process modeling, simulation, and optimization are becoming progressively substantial for understanding processes, making decisions, improving efficiency, and complying with stricter environmental and safety legislation. Additionally, the availability of user-friendly flowsheet simulators and computational resources with the current trend of data collection and analysis has allowed for a more accurate representation of complex processes such as wastewater treatment systems. Despite all the progress in the areas of process modeling and simulation, the first-principle mechanistic models for wastewater treatment processes are at best employed during the design stage, and therefore, not used optimally for day-to-day …

Development And Analysis Of Green Pathways For Biphasic Extraction At High Pressure, Kyle L. Cogswell

USF Tampa Graduate Theses and Dissertations

Technological advancements over the last century have allowed for advancements not only in science and engineering but medicine as well. The use of supercritical fluids for processing continues today after its initial boom in the latter part of the last century; often being paired with co-solvents to extend the range of use for this technique. Supercritical fluid extraction may be paired with pressurized warm water extraction to yield a new intensified process for biphasic extractions that improves efficiency and reduces waste. This combination may be used to replace sequential extraction processes or supercritical extraction processes that make use of organic …

Evaluation Of Aluminum Dissolution, Current Density, And Pitting Patterns During Electrocoagulation, Monica Castro Carias

USF Tampa Graduate Theses and Dissertations

Electrocoagulation (EC) is a sustainable water treatment process involving the generation of coagulants on-site through the application of a voltage on metal (usually aluminum or iron alloys). The factors that impact EC system performance have been well researched, however further research is needed on the factors that impact anodic dissolution of aluminum electrodes, especially when the technology is transferred to full-scale applications. Electrode fouling is one of the factors that can impact dissolution of the anode during EC due to the formation of a protective oxide/hydroxide layer on the electrode surface. Previous studies have addressed electrode fouling by reversing polarity, …

Thermochemical Conversion Of Lipid-Extracted Algal Biomass To Value-Added Sustainable Products, Magdalini Tsarpali

USF Tampa Graduate Theses and Dissertations

The extensive use of fossil fuels has increased the CO2 emissions, a phenomenon that has increased the demand for renewable energy and resources. Algae, photosynthetic aquatic organisms, have recently caught attention due to their high growth rate and the high CO2 capture ability. Biofuels and bioproducts from algae are considered promising alternatives because of their lower carbon footprint. Lipids are by far the most popular algal product, as they find applications in both fuels, such as biodiesel, and products, such as nutraceuticals and cosmetics. However, after lipid extraction, conversion of the residual algal biomass to value-added products is viewed as …

Development Of Enhanced Algae Strains And Sustainable Cultivation Processes For Production Of Algal Lipids For Biofuels And Bioproducts, Enlin Lo

USF Tampa Graduate Theses and Dissertations

The establishment of an algae industry is crucial for addressing global biofuel and bioproduct demand that meets the Sustainable Development Goals (SDG) worldwide. Photosynthetic microalgae are excellent sources for food, fiber, fuel, feed, and fertilizer, which are the 5Fs of the SDG. However, at present, algae-based materials are not cost-competitive or sufficiently sustainable. Improved productivity, lower cultivation cost, and reduced use of resources are required to transition from lab to industry, necessitating the development of superior strains that have high productivity and can tolerate environmental stress, such as temperature and salinity, so they can be cultivated at large scale outdoors …

Techno-Economic And Sustainability Analysis Of Renewable Natural Gas (Rng) Production, Eesha Bhattacharjee

USF Tampa Graduate Theses and Dissertations

Natural Gas (NG) is one of the major sources of energy currently used in the United States. Its major applications include generating electricity, domestic, and industrial heating purposes and as a transportation fuel. The largest component of NG is methane, and it contains trace amounts of hydrocarbons, some CO2 and water vapor.

Biogas (produced by anaerobic digestion (AD) of biomass) upgraded to have high purity methane (often termed as biomethane or renewable natural gas) can be used as an alternative to NG. The upgrading techniques may include CO2 separation from the biogas stream or via to a methanation facility where …

Computationally Driven Design Of Shape-Controlled Polymeric Nanostructures, Davindra Tulsi

USF Tampa Graduate Theses and Dissertations

In the realm of shape control involving synthetic soft materials, block copolymers are ubiquitously exploited due to their ability to spontaneously self-assemble into a plethora of morphologies. The growing need in areas such as drug delivery, lithography, and microelectronics to generate new nanostructures demands ever finer control of copolymer self-assembly. It is desirable to better control the shape and size of soft nanostructures, with minimal post processing techniques to assert stability.

While there is an abundance of literature on diblock copolymer assembly, few relationships exist for sequence-controlled copolymers. It is well known that biological macromolecules are highly sequence specific and …

Multi-Material Hybrid Additive And Subtractive Manufacturing Of Photonic Devices, Roger Brandon Tipton

USF Tampa Graduate Theses and Dissertations

Optoelectronics focuses on the application of electronic devices that utilize forms of electromagnetic radiation including visible light and other wavelengths including ultraviolet and infrared. Optoelectronics typically include devices that emit light and detect light. Devices created using this technology include light-emitting diodes, laser diodes, photoresistors, photodiodes, solar cells, phototransistors, and fiber optics. Fiber optic interconnects are interesting devices in that they are used in conjunction with optoelectronic devices to transmit information between individual optoelectronic components.

Optoelectronics are typically produced by traditional lithography methods including etching, writing, and printing on rigid silicon substrates for fabricating devices. Other techniques like glass or …

Material And Topographically Optimized Thermal Dissipation For High-Performance Electronic Devices Utilizing Vapor Chambers, Derek Joseph Daniels

USF Tampa Graduate Theses and Dissertations

Advances in materials science and engineering in the field of thermal transport and dissipation enable the use of higher-performance electronic devices that are smaller and generate more heat. Phase change thermal transport systems such as heat pipes and vapor chambers enable passive dissipation from devices that generate excessive heat without the need for actively pumped cooling systems. Properly designed vapor chamber enabled systems easily exceed the thermal conductivity of manufactured diamond at a small fraction of the cost.[1][2][3] While heat pipe phase change systems are generally one-dimensional with a limited cross section, vapor chambers are generally two-dimensional with a small …

Water Regulation For Enhancing Soil Quality Using Cactus Mucilage: A Theoretical And Experimental Analysis, Khuloud Alrashdi

USF Tampa Graduate Theses and Dissertations

As water is one of the primary sources of life, it is essential in an endless number of systems and processes to be utilized efficiently in nature and in practical applications. One of these applications includes farming, which depletes a lot of water as the water irrigation systems cover large soil areas. While water is a critical factor in growing crops, a question here stands, can the irrigation process be transformed? This is the overarching goal of my work since it is centered on studying if cactus mucilage, a natural substance, is capable of improving water absorption processes on crops …

Mutational Analysis Of Latency Associated Peptide For Therapeutic Application, Johnny Will Stephens

USF Tampa Graduate Theses and Dissertations

TGF-β is an important protein for regulation of the immune system, and has been linked to promotion of tumor progression and cancer growth. Inhibiting TGF-β has been shown to be an effective therapeutic technique for fighting multiple cancer types. Engineering TGF-β’s natural inhibitor, Latency Associated Peptide (LAP), to improve its biophysical properties has potential to increase therapeutic efficacy.

Rosetta and FoldX can be used in concert to engineer stabilizing mutations of proteins. In accordance with this, PyRosetta and FoldX were used to predict stabilizing mutations of LAP. The most stabilizing mutations from each program were combined with mutually predicted mutations. …

Preparation And Characterization Of Single Layer Conducting Polymer Electrochromic And Touchchromic Devices, Sharan Kumar Indrakar

USF Tampa Graduate Theses and Dissertations

Electrochromic devices (ECDs) have triggered great interest because of their potential applicability in energy-efficient buildings and low power display systems, including reflective type smart windows/mirrors and wearable-flexible devices. In the past decades, electrochromic technologies with different device structures and materials have been proposed. The idea of employing a simple device structure with a durable, cost effective electrolyte is crucial to designing and manufacturing high-performance ECDs. With this idea in mind, this thesis describes the various efforts to develop a simple ECD comprising of a composite single active layer gel electrolyte, sandwiched between two transparent conducting electrodes, lasting over 10,000 cycles …

Investigation Of Polymer-Plasticizer Blends For Btex Detection Using Quartz Crystal Microbalance, Abhijeet Iyer

USF Tampa Graduate Theses and Dissertations

Volatile organic compounds (VOCs) are chemicals that evaporate easily and become gases at ambient temperature and pressure. The EPA has made the monitoring of VOCs mandatory due to their health impacts, which range from headaches and nausea to cancer. The current techniques used for VOC monitoring such as photoionization, gas chromatography, mass spectroscopy, and e-noses sensors are expensive, time-intensive, demand rigorous sample preparation, and cannot quantify the VOCs in the air. Chemical sensors based on piezoelectric transduction like the quartz crystal microbalance (QCM) show promising results in terms of providing cost-effective real-time data, robustness, and low power requirements. In this …

A Barker Type Approach For Measuring And Interpreting Vle Of Polymer Mixed Solvent Systems, Vaishali Jain

USF Tampa Graduate Theses and Dissertations

The environment around us has a great impact on human health. A polluted environment can adversely impact human health and cause diseases like cancer, skin diseases, breathing problems and many more and hence altering the quality of life. Hence it is very important to develop sensors that can efficiently detect these harmful substances from environment. Volatile organic compounds (VOCs) are carbon-based chemical substances that are volatile even at ambient temperature and pressure conditions which enter the atmosphere through industrial processes, building materials, etc.

Acoustic wave devices can detect very low concentrations (ppm, ppb) of organic compounds in the environment. A …