Engineering Commons^™

Novel Breath Collection Techniques For Detection Of Covid-19., James Morris

Electronic Theses and Dissertations

Volatile Organic Compounds (VOC) generated endogenously in the human body can be used to detect diseases that induce oxidative stress and inflammation. Breath analysis has been used for the detection of diseases such as COPD, Depression, Lung Cancer and most recently COVID-19. Methods such as Exhaled Breath Condensate (EBC), Sorbent Tubes, Solid Phase Microextraction (SPME), and silicon microreactors have shown considerable capability in extracting and concentrating trace VOC’s present in human breath. Silicon microreactors functionalized with capture agents to derivatize carbonyl compounds are effective but the overall maximum flow rate of breath sample possible during analysis is low, making direct …

Addition Of Process Control Experiment To Unit Operations Ii Laboratory., Bradley Esselman

Electronic Theses and Dissertations

Process control is an essential aspect of manufacturing, contributing to improved process safety, efficiency, product consistency, and energy optimization. Chemical engineers are often responsible for ensuring the safe, efficient, and cost-effective operation of industrial processes, and process control plays a pivotal role in accomplishing this.

Chemical engineering students at the University of Louisville complete the course, Elements of Process Control, during the second semester of their fourth year. This lecture-based course offers limited hands-on, practical experience. To supplement the lack of hands-on experience in the classroom, a new process control experiment was designed and implemented into the Unit Operations …

The Study Of Corrosion On Additive-Manufactured Metals., Braydan Daniels

Electronic Theses and Dissertations

The purpose of this study was to investigate and compare the corrosion mechanisms between wrought and additive-manufactured (3D-printed) copper and stainless steel. The experimental procedure consisted of measuring the open circuit potential, electrochemical impedance spectroscopy, linear sweep voltammetry, Tafel analysis, surface topology, and scanning electron microscopy for each metal within salt water, tap water, sulfuric acid, and synthetic body fluid (excluding copper in synthetic body fluid).

Overall, printed stainless steel was more corrosion-resistant than wrought stainless steel in tap water and synthetic body fluid based on OCP, LSV, and surface topology results. Additionally, printed copper was more corrosion-resistant than wrought …

Novel Microdevices To Analyze Toxic Volatile Organic Compounds., Sujoy Halder

Electronic Theses and Dissertations

There has been a growing interest to measure volatile organic compounds (VOCs) in a range of environmental applications. The presence of toxic VOCs in the air has been associated with serious health problems including asthma, central nervous system dysfunction, cardiovascular disease and cancer, etc. Different analytical instruments such as gas chromatography-mass spectrometry (GC-MS) and sensor systems, such as metal oxide sensors are used to analyze VOCs. However, challenges still exist in the detection of airborne VOCs because of their trace concentration and interference with complex gas mixtures. In this dissertation, two microfabricated devices, a sensor array and a micropreconcentrator were …

Investigation Of Light Management Strategies And Photochemistry Of Si/Tio2 Tandem Microwire Slurries For Solar Hydrogen Generation., Saumya Gulati

Electronic Theses and Dissertations

The intermittent nature of the Sun makes it difficult to use it as a primary source of electricity and often needs to be supplemented by electricity from the grid which comes from fossil fuels. This motivates the need for solar energy storage. Photoelectrochemical (PEC) water-splitting has been explored as a means to convert solar energy into hydrogen (and oxygen), which can be stored as fuel. The current method of coupling PV and electrolyzer units has been widely commercialized, however, the cost of H₂ generated is far from the target of $1/kg set by the DOE under the Energy EarthShot …

Synthesis, Property Tuning And Degradation Studies Of Phosphorene-Based Materials., Usman Onuminya Abu

Electronic Theses and Dissertations

Two-dimensional (2D) layered materials have sparked the interest of researchers because of their interesting properties drawn from quantum confinement effects, elevated density of states (DOS), increased surface area, increased active sites, etc. Phosphorene, an interesting addition to the 2D material family in 2014, has interesting properties such as in-plane anisotropy, elevated carrier mobility and thickness-dependent bandgaps that have made it a material of intense interest. Furthermore, there have been theoretical studies predicting that phosphorene could be made even more versatile by intercalating alkali atoms into its layers. Intercalation has proven to be a veritable tool for synthesis, modification, transformation, and …

Chloramine Devulcanization Of Waste Rubber., Patrick Kroeger

Electronic Theses and Dissertations

The disposal of waste rubber, particularly tire rubber, continues to pose a challenge in the 21st century. As a result, most end-of-life tires (ELTs) are either dumped in landfills or burned as tire-derived fuel. Chloramine devulcanization may offer a viable solution to this problem. Chloramine devulcanization is a low-temperature, low-pressure, process that selectively breaks sulfur crosslinks while preserving the polymer backbone. Chloramine devulcanization enables the recovery of chloramine recovered carbon black (CrCB) and devulcanized rubber (CdR) as separate products. Initial analysis of CdR revealed that it was formable and malleable, suggesting that crosslinking was absent. Spectroscopy showed that CdR contained …

Compositional Engineering Of Precursor Inks For Intense Pulsed Light Compatible Deposition Of Perovskite Solar Cells., Blake Martin

Electronic Theses and Dissertations

Perovskite solar cell (PSC) technology offers a promising alternative to silicon-based photovoltaics (PVs), but challenges of stability, module efficiency, and scalability hinder commercialization. This study aims to explore potential solutions to overcome scalability and cost limitations of PSCs, addressing technical barriers to commercialization. We adapt the conventional three-stage perovskite deposition process (deposition, translational phase formation, and annealing) for scalable platforms using wide-area depositions, meniscus coating methods, forced laminar airflow drying, and radiative annealing methods, making it more suitable for roll-to-roll fabrication. A technoeconomic analysis shows that large-scale operations can produce solar films at a cost of $0.04-$0.10 per watt, making …

Detection Of Toxic Aldehydes In Aerosols Of Electronic Cigarettes., Ellie Bess Reed

Electronic Theses and Dissertations

Over the past decade, use of electronic cigarettes (e-cigarettes) has increased in the younger generations of the United States. With the broad range of flavors and devices distributed on the market, American youth are prime marketing targets for the e-cigarette industry. To create a more regulated market, research of this thesis has been conducted on newer generations of e-cigarette “MOD” devices to examine how e-cigarette battery power output and coil temperature, concentrations of propylene glycol and vegetable glycerin, added flavorings (strawberry, mango, and menthol), and the presence of nicotine affect generation of aerosol particles and aldehydes in aerosols emitted by …