Chemical Engineering Commons^™

Nonequilibrium Plasma Synthesis And Processing Of Iii-Nitride Materials, Dillon Patrick Moher

McKelvey School of Engineering Graduate Student Theses & Dissertations

Nitrogen is abundant on Earth as its diatomic form, and human activity has generated a significant demand for nitrogen-containing compounds. However, its triple bond energy of 941 kJ/mol makes it a poor reactive species in the ground state. Nitrogen-containing nonequilibrium plasmas are made up of background gas, electrons, ions, and a multitude of excited states of nitrogen or even atomic nitrogen. Many of these species have rather high reactivity. As such, the plasma medium is of great potential for driving chemical reactions that involve nitrogen as a reactant, i.e., nitrogen fixation into compounds like ammonia, high-energy-density polynitrogen compounds, and metal-nitride …

Techno-Economic Analysis Of Waste Plastic Gasification, Henrik Don-Yor Ketting

Master's Theses

The increasing generation of plastic waste and its environmental impact has driven interest in alternative disposal methods such as gasification. This study presents a techno-economic analysis of the gasification of waste plastics, specifically polypropylene (PP) and polyethylene (PE), to produce syngas. A two-stage process—thermal decomposition followed by steam reforming—was simulated using Aspen Plus. The simulation results were validated against experimental data available in the literature. The economic analysis was conducted by estimating the capital and operating costs of the gasification plant, considering factors such as feedstock costs, energy requirements, and syngas purification systems. Net Present Value Calculations were used to …

Antimicrobial Activity And Photostability Of Cationic Conjugated Polyelectrolytes, Mohammed Ismael Khalil

Chemical and Biological Engineering ETDs

Antimicrobial resistance is a growing global health concern, driving the need for novel

therapeutic strategies. This study explores the antimicrobial efficacy of conjugated

polyelectrolytes (CPEs) and oligo-phenylene ethynylenes (OPEs) in bacterial and viral

inactivation. Quantitative analysis revealed that light-activated CPEs and OPEs

effectively reduced bacterial viability within minutes, with significant log reductions

observed under both light and dark conditions. Additionally, the antiviral potential of a

cationic conjugated oligomer was investigated, demonstrating rapid and near-complete

inactivation of SARS-CoV-2 under visible light, both in solution and on filter materials.

Further analysis of their photophysical properties revealed that, even after

photobleaching, the compounds …

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 …

Effect Of Specimen Size On The Tensile Properties Of Selective Laser Melted Ti-6ai-4v, Timothy L. Tan

Master's Theses

Metal additive manufacturing (MAM) is a burgeoning industry. It is capable of manufacturing metal components with fine, intricate features and enables localized microstructural control. Due to its fine resolution and compatibility with common engineering alloys, selective laser melting (SLM) is one particular MAM process popular in academia and industry. The biomedical and aerospace industries have shown exceptional interest in the capabilities of SLM with the alloy Ti-6Al-4V. Because SLM Ti-6Al-4V components are aimed for use in critical applications, it is necessary to understand how SLM processing characteristics affect final part performance. One characteristic of SLM Ti-6Al- 4V that requires further …

Collapse Of Pre-Covid-19 Differences In Performance In Online Vs. In-Person College Science Classes, And Continued Decline In Student Learning, Gregg R. Davidson, Hong Xiao, Kristin Davidson

Faculty and Student Publications

Abstract: Studies comparing student outcomes for online vs. in-person classes have reported mixed results, though with a majority finding that lower-performing students, on average, fare worse in online classes, attributed to the lack of built-in structure provided by in-person instruction. The online/in-person outcome disparity was normative for non-major geology classes at the University of Mississippi prior to COVID-19, but the difference disappeared in the years after 2020. Previously distinct trendlines of GPA-based predictions of earned-grade for online and in-person classes merged. Of particular concern, outcomes for in-person classes declined to match pre-COVID-19 online expectations, with lower-GPA students disproportionally impacted. Objective …

Study Of Different Treatment Strategies In Epidemic Models Using Nonlinear Model Predictive Control, Hector Puebla, Luis A. Ricardez-Sandoval, Priti Kumar Roy

Annual Symposium on Biomathematics and Ecology Education and Research

No abstract provided.

Development Of A Coating For Radiative Cooling Of Buildings, Sudhansh Pramod Harkut

USF Tampa Graduate Theses and Dissertations

This thesis investigates passive daytime radiative cooling (PDRC), aiming to enhance cooling efficiency for building applications. The study addresses the pressing need for effective and cost-efficient cooling solutions to mitigate global warming and reduce energy consumption. The research begins with a detailed literature review, tracing the evolution of radiative cooling materials and identifying existing research gaps. Experimental investigations involved testing various coatings, including combinations of aluminium phosphate, sodium silicate, polyvinylidene fluoride (PVDF), and wollastonite. Among the tested configurations, an acrylic-based coating incorporating barium sulphate (BaSO4) and calcium carbonate (CaCO3) was found to maintain temperatures around ambient levels under intense solar …

Boosting The Power Performance Of Microbial Fuel Cells By Using Dual Nanomaterial-Modified Carbon Felt Electrodes, Krishna Thapa, Wenyan Liu, Yuwei Zhang, David J. Westenberg, Yishu Zhou, Risheng Wang

Chemistry Faculty Research & Creative Works

Innovative design enhancements to microbial fuel cells (MFCs) are pivotal for improving their viability as renewable energy sources. This study introduces a dual approach to electrode modification, integrating polyaniline (PANI) and gold nanoparticles (AuNPs) on carbon felt (CF) anodes coupled with a unique cathode composed of DNA origami and chitosan. The synergistic effect of PANI and AuNPs significantly increases the hydrophilicity and conductivity of the anode, leading to a considerable surge in power density. Concurrently, the biocompatible DNA origami and chitosan-functionalized cathode facilitates efficient electron transfer without relying on conventional catalysts. Together, these modifications yield a 52.42% increase in the …

Ignis: A One-Dimensional Laminar Flame Code, Jansen P. Berryhill, Jacob K. Spinti, David O. Lignell

Faculty Publications

Laminar flame codes have an important role in combustion modeling. They can provide a fundamental understanding of flame dynamics and provide a basis for building subgrid scale models in turbulent flow simulations. This paper presents Ignis, an open-source laminar flame code with the capability to offload submodels, like soot formation and radiation, using external packages and libraries. Ignis is written in C++, is documented with Doxygen, and is available on GitHub. It contains three different flame formulations: diffusion flames, premixed flames, and laminar flamelets solved in the mixture fraction coordinate. An option to facilitate creation of a diffusion flame table …

The Effect Of Organic Semiconductor Electron Affinity On Preventing Parasitic Oxidation Reactions Limiting Performance Of N-Type Organic Electrochemical Transistors, Maryam Alsufyani, Benjamin Moss, Claudia E. Tait, William K. Myers, Maryam Shahi, Katherine Stewart, Xiaolei Zhao, Reem B. Rashid, Dilara Meli, Ruiheng Wu, Bryan D. Paulsen, Karl J. Thorley, Yuanbao Lin, Craig Combe, Charlie Kniebe-Evans, Sahika Inal, Sang Young Jeong, Han Young Woo, Grant Ritchie, Ji-Seon Kim, Jonathan Rivnay, Alexandra F. Paterson, James R. Durrant, Iain Mcculloch

Chemical and Materials Engineering Faculty Publications

A key challenge in the development of organic mixed ionic-electronic conducting materials (OMIEC) for high performance electrochemical transistors is their stable performance in ambient. When operating in aqueous electrolyte, potential reactions of the electrochemically injected electrons with air and water could hinder their persistence, leading to a reduction in charge transport. Here, the impact of deepening the LUMO energy level of a series of electron-transporting semiconducting polymers is evaluated, and subsequently rendering the most common oxidation processes of electron polarons thermodynamically unfavorable, on organic electrochemical transistors (OECTs) performance. Employing time resolved spectroelectrochemistry with three analogous polymers having varying electron affinities …

Liquid Crystalline Collagen Assemblies As Substrates For Directed Alignment Of Human Schwann Cells, Homa Ghaiedi, Luis Carlos Pinzon-Herrera, Saja Alshafeay, Leonard Harris, Jorge Almodovar, Karthik Nayani

Chemical Engineering Faculty Publications and Presentations

Collagen is a key component of the extracellular matrix (ECM) and well-oriented domains of collagen are important for mimicking the local cell environment in vitro. While there has been significant attention directed towards the alignment of collagen, formation of large-scale oriented domains remains a key challenge. Type I collagen self-assembles to form liquid crystalline (LC) mesophases in acidic conditions at concentrations above 100 mg mL−1. The LC mesophase provides an efficient platform for large-scale alignment and patterning of collagen coated substrates. However, there still exist challenges related to solubilizing and processing of collagen at such high concentrations in order …

Zeta Potential Of Supercritical Co2-Water-Sandstone Systems And Its Correlation With Wettability And Residual Subsurface Trapping Of Co2, Jan Vinogradov, Miftah Hidayat, Mohammad Sarmadivaleh, David Vega-Maza, Stefan Iglauer, Lijuan Zhang, Dajiang Mei, Jos Derksen

Research outputs 2022 to 2026

Although CO2 geological storage (CGS) is thought to be one of the most promising technologies to sequester the anthropogenic CO2 to mitigate the climate change, implementation of the method is still challenging due to lack of fundamental understanding of controls of wettability, which is responsible for residual trapping of the gas and its flow dynamics. One of the key parameters that controls the wetting state is the zeta potential, ζ, at rock-water and CO2-water interfaces. ζ in systems comprising rocks, carbonated aqueous solutions and immiscible supercritical CO2 have not been measured prior to this study, where we detail the experimental …

Size And Shape Dependence Of Hydrogen-Induced Phase Transformation And Sorption Hysteresis In Palladium Nanoparticles, Xingsheng Sun, Rong Jin

Chemical and Materials Engineering Faculty Publications

Phase transitions of metals in hydrogen (H) environments are critically import- ant for applications in energy storage, catalysis, and sensing. Nanostructured metallic particles can lead to faster charging and discharging kinetics, increased lifespan, and enhanced catalytic activities. However, establishing a direct causal link between nanoparticle structure and function remains challenging. In this work, we establish a computational framework to explore the atomic config- uration of a metal-hydrogen system when in equilibrium with a H environ- ment. This approach combines Diffusive Molecular Dynamics with an itera- tion strategy, aiming to minimize the system’s free energy and ensure uniform chemical potential across …

Review On Spontaneous Imbibition Mechanisms In Gas-Water Systems: Impacts On Unconventional Gas Production And Co2 Geo-Sequestration, Yihang Xiao, Zhenjiang You, Zhengtong Du, Yongming He, Jun Zheng, Yujie Yuan, Lei Wang

Research outputs 2022 to 2026

Spontaneous imbibition, a fundamental process in porous media, involves the displacement of a non-wetting phase by a wetting phase driven by capillary pressure. It plays a key role in various applications, particularly in unconventional gas production and greenhouse gas geo-sequestration. Despite extensive research in this area, conflicting results and explanations persist regarding imbibition phenomena, particularly in gas-water systems. This paper aims to address this gap by providing a comprehensive review of basic concepts, mechanical analyses, pore-filling patterns, front evolutions, and influencing factors associated with spontaneous imbibition. Mechanical factors including capillary force, viscous force, gravitational force, hydrostatic force, inertial force, capillary …

Valorization Of Food Waste Into Hydrogen Energy Through Supercritical Water Gasification: Generation Potential And Techno-Econo-Environmental Feasibility Assessment, Md Sanowar Hossain, Fairuz Wasima, Md Sharul Islam Khan Shawon, Monjur Mourshed, Barun K. Das

Research outputs 2022 to 2026

Food waste (FW) is a significant portion of the solid waste produced by cities, and it has become a global problem due to the poor management of food distribution and consumption. The improper disposal of FW in landfills precipitates pervasive global environmental predicamentsHowever, effective management strategies have the potential to convert this large amount of garbage into a very effective renewable energy source, particularly through the generation of environmentally friendly hydrogen. This study examines the capacity for energy generation and the practicality of hydrogen production in Bangladesh using supercritical water gasification technology. The findings indicate that approximately 489 MW of …

Engineering The Coherent Phonon Transport In Polar Ferromagnetic Oxide Superlattices, In Hyeok Choi, Seung Gyo Jeong, Do-Gyeom Jeong, Ambrose Seo, Woo Seok Choi, Jong Seok Lee

Chemical and Materials Engineering Faculty Publications

Artificial superlattices composed of perovskite oxides serves as an essential platform for engineering coherent phonon transport by redefining the lattice periodicity, which strongly influences the lattice-coupled phase transitions in charge and spin degrees of freedom. However, previous methods of manipulating phonons have been limited to controlling the periodicity of superlattice, rather than utilizing complex mutual interactions that are prominent in transition metal oxides. In this study on oxide superlattices composed of ferromagnetic metallic SrRuO3 and quantum paraelectric SrTiO3 , phonon modulation by controlling the geometry of superlattice in atomic-scale precision is realized, demonstrating the coherent phonon engineering using structural and …

Characterization Of Aromatic Stationary Phases For Uses In High Performance Liquid Chromatography, Anastasia Davis

Honors Theses

High Performance Liquid Chromatography (HPLC) is an analytical chemist technique used to separate a sample into its components to characterize and study a specific molecule or compound. Traditionally, High-Performance Liquid Chromatography in different industries, such as the environmental and pharmaceutical fields, uses stationary phases that are already well characterized, such as the C18 stationary phase for separation. However, aromatic stationary phases have recently been produced, which have phenyl groups bonded to the interior surface of the column. Still, they have not been well characterized because of how modern they are. This project characterized several aromatic stationary phases (Biphenyl, pentafluorophenyl, and …

Investigating The Effect Of Microwave Pretreatment On Bastnasite Grinding For Comminution Energy Reduction And Rare Earth Recovery, Kaveh Asgari, Qingqing Huang, Rick Q. Honaker, Edward Sabolsky

Chemical and Materials Engineering Faculty Publications

This study explored the impact of microwave pretreatment on the grinding efficiency of bastnaesite ore using a stirred mill. Bastnaesite ore was prepared using a staged crushing and sieving process, followed by microwave pretreatment in a specially designed microwave furnace system. Representative samples of the crushed ore underwent stirred mill grinding, with power draw measurements recorded and adjusted to reflect only the specific energy input required for grinding. Particle size distribution was analyzed periodically using laser particle size analysis. In addition, a Box–Behnken design was used to statistically assess the effects of various parameters on the results, ensuring a robust …

Process Development And Techno-Economic Analysis For Combined And Separated Co2 Capture-Electrochemical Utilization, Abdullah Al Moinee, Ali A. Rownaghi, Fateme Rezaei

Chemical and Biochemical Engineering Faculty Research & Creative Works

Combining CO₂ capture and utilization into a single unit operation offers a feasible solution for converting a sustainable feedstock into marketable commodity chemicals, while reducing energy requirements from separated processes. In this research, we developed a process model and performed a techno-economic analysis (TEA) for point-source CO₂ capture and electrochemical-based utilization in light olefins production under both separated and integrated scenarios. CO₂ containing flue gas from a 500 MW power plant was utilized as a feed while CO₂ utilization involved electrochemical reduction reactions to produce light olefins directly from CO₂. A meticulous analysis was …