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Welcome To The Fruit Farm: How Queer Farmers Are Shaping The Agroecology Of The Future, Alessandra Del Brocco

Theses and Dissertations--Sociology

The question of sustainability has many different facets, but one of the most urgent issues is that of sustainable agriculture. Decades of agricultural policy demanded farmers go big or get out, more colloquially known as the government directive of the 20^th century to farm “fencerow to fencerow”. In the 21^st century, we now face a near-critical consolidation of farmland and decline in the overall number of farmers. If sustainability calls for a resilient, diversified agrisystem, how can we change direction at this point in the trajectory?

In this study, I demonstrate how queer farmers make valuable contributions to …

A Gis Tool For Optimal Forage Species Selection, David B. Hannaway, Christopher Daly, Michael D. Halbleib, Linda Brewer, Sophie Baur, Chelsea Clark, Emilie Krecklow, Scott Bassett

IGC Proceedings (1977-2023)

To determine appropriate forage species for US ecoregions, geographic information technologies (GIS) are being used to create climatic and soil factor maps. Excel spreadsheets and RStudio are used to create response functions of forage species to minimum and maximum temperature, annual precipitation, soil pH, soil salinity, and salinity. National forage data and expert opinion will evaluate quantitative tolerances, seasonal yield profiles, and pollinator suitability. These maps and agronomic and livestock use information will be shared with forage specialists and farmers to provide alternatives for improved perenniality, increased diversity, and system circularity. Future work will include development and evaluation of climate …

Extended Conformations Of Bifurcating Electron Transfer Flavoprotein Constitute Up To Half The Population, Possibly Mediating Conformational Change, Sharique A. Khan, Alan Hicks, Wellington C. Leite, James Byrnes, Biswajit Gorai, Maria-Andrea Mroginski, Hugh O'Neill, Anne-Francis Miller

Markey Cancer Center Faculty Publications

Electron transfer bifurcation enables biological systems to drive unfavourable (endergonic) electron transfer by coupling it to favourable (exergonic) transfer of a second electron. In electron transfer flavoproteins (ETFs), a domain-scale conformational change is believed to sever the favourable pathway after a single electron has used it, thereby preventing the energy dissipation that would accompany exergonic transfer of the second electron. To understand the conformation change that participates in turnover, we have deployed small-angle neutron scattering (SANS) and computational techniques to characterize the bifurcating ETF from Acidaminococcus fermentans (AfeETF). SANS data reveal an overall radius of gyration (Rg) of 30.1 ± …

Machine-Learning-Assisted Design Of Deep Eutectic Solvents Based On Uncovered Hydrogen Bond Patterns, Usman Lame Abbas, Yuxuan Zhang, Joseph Tapia, Md Selim, Jin Chen, Jian Shi, Qing Shao

Markey Cancer Center Faculty Publications

Non-ionic deep eutectic solvents (DESs) are non-ionic designer solvents with various applications in catalysis, extraction, carbon capture, and pharmaceuticals. However, discovering new DES candidates is challenging due to a lack of efficient tools that accurately predict DES formation. The search for DES relies heavily on intuition or trial-and-error processes, leading to low success rates or missed opportuni- ties. Recognizing that hydrogen bonds (HBs) play a central role in DES formation, we aim to identify HB features that distinguish DES from non-DES systems and use them to develop machine learning (ML) models to discover new DES systems. We first analyze the …

Perfluorooctanesulfonic Acid Exposure Leads To Downregulation Of 3-Hydroxy-3-Methylglutaryl-Coa Synthase 2 Expression And Upregulation Of Markers Associated With Intestinal Carcinogenesis In Mouse Intestinal Tissues, Josiane Weber Tessmann, Pan Deng, Jerika Durham, Chang Li, Moumita Banerjee, Qingding Wang, Ryan A. Goettl, Daheng He, Chi Wang, Eun Y. Lee, B. Mark Evers, Bernhard Hennig, Yekaterina Y. Zaytseva

Markey Cancer Center Faculty Publications

Perfluorooctanesulfonic acid (PFOS) is a widely recognized environment pollutant known for its high bio- accumulation potential and a long elimination half-life. Several studies have shown that PFOS can alter multiple biological pathways and negatively affect human health. Considering the direct exposure to the gastrointestinal (GI) tract to environmental pollutants, PFOS can potentially disrupt intestinal homeostasis. However, there is limited knowledge about the effect of PFOS exposure on normal intestinal tissues, and its contribution to GI- associated diseases remains to be determined. In this study, we examined the effect of PFOS exposure on the gene expression profile of intestinal tissues of …

Sedimentation Of Large, Soluble Proteins Up To 140 Kda For 1h-Detected Mas Nmr And 13c Dnp Nmr – Practical Aspects, Dallas Bell, Florian Lindemann, Lisa Gerland, Hanna Aucharova, Alexander Klein, Daniel Friedrich, Matthias Hiller, Kristof Grohe, Tobias Meier, Barth Van Rossum, Anne Diehl, Jon Hughes, Leonard J. Mueller, Rasmus Linser, Anne-Frances Miller, Hartmut Oschkinat

Markey Cancer Center Faculty Publications

Solution NMR is typically applied to biological systems with molecular weights < 40 kDa whereas magic-angle-spinning (MAS) solid-state NMR traditionally targets very large, oligomeric proteins and complexes exceeding 500 kDa in mass, including fibrils and crystalline protein preparations. Here, we propose that the gap between these size regimes can be filled by the approach presented that enables investigation of large, soluble and fully protonated proteins in the range of 40–140 kDa. As a key step, ultracentrifugation produces a highly concentrated, gel-like state, resembling a dense phase in spontaneous liquid-liquid phase separation (LLPS). By means of three examples, a Sulfolobus acidocaldarius bifurcat- ing electron transfer flavoprotein (SaETF), tryptophan synthases from Salmonella typhimurium (StTS) and their dimeric β-subunits from Pyrococcus furiosus (PfTrpB), we show that such samples yield well-resolved proton-detected 2D and 3D NMR spectra at 100 kHz MAS without heterogeneous broadening, similar to diluted liquids. Herein, we provide practical guidance on centrifugation conditions and tools, sample behavior, and line widths expected. We demonstrate that the observed chemical shifts correspond to those obtained from μM/low mM solutions or crystalline samples, indicating structural integrity. Nitrogen line widths as low as 20–30 Hz are observed. The presented approach is advantageous for proteins or nucleic acids that cannot be deuterated due to the expression system used, or where relevant protons cannot be re-incorporated after expression in deuterated medium, and it circumvents crystallization. Importantly, it allows the use of low-glycerol buffers in dynamic nuclear polarization (DNP) NMR of proteins as demonstrated with the cyanobacterial phytochrome Cph1.

Investigation Of Delta-Focused Ictal Electrical Source Imaging In Refractory Focal Epilepsy, Jared A. Rybarczyk

Theses and Dissertations--Electrical and Computer Engineering

Refractory focal epilepsy is characterized by the presence of seizures that cannot be controlled via anti-seizure medications. For patients suffering from this form of epilepsy, accurate identification of the seizure onset zone is a crucial step for many modalities of treatment. Electrical source imaging (ESI) allows for estimation of the seizure onset zone from electroencephalography. EEG feature extraction is an important step that can impact the final accuracy of source estimates. This work provides a review of 23 ictal ESI studies and proposes a delta-focused ictal ESI methodology. Our proposed delta-focused ictal ESI is implemented across 33 refractory focal epilepsy …

Electronics Design For Krepe Atmospheric Entry Capsule Avionics, Matt Ruffner

Theses and Dissertations--Electrical and Computer Engineering

This research documents the design, testing, and implementation of sensing, control, and communications subsystems for small atmospheric entry capsules. Atmospheric entry capsules pose a unique electronics design challenge given mission requirements, environmental constraints, and inherent risk involved in space based missions. Previous work on small satellites developed the CubeSat platform as a means of ensuring reliability after university-led small satellite missions experienced failures. The publication of the CubeSat platform allowed researchers to focus on the payload science utilizing a standardized form-factor and reusable electronics. Environmental and operational constraints of CubeSats and atmospheric entry capsules overlap and best-practices associated with building …

Cross-Layer Design Of Highly Scalable And Energy-Efficient Ai Accelerator Systems Using Photonic Integrated Circuits, Sairam Sri Vatsavai

Theses and Dissertations--Electrical and Computer Engineering

Artificial Intelligence (AI) has experienced remarkable success in recent years, solving complex computational problems across various domains, including computer vision, natural language processing, and pattern recognition. Much of this success can be attributed to the advancements in deep learning algorithms and models, particularly Artificial Neural Networks (ANNs). In recent times, deep ANNs have achieved unprecedented levels of accuracy, surpassing human capabilities in some cases. However, these deep ANN models come at a significant computational cost, with billions to trillions of parameters. Recent trends indicate that the number of parameters per ANN model will continue to grow exponentially in the foreseeable …

Nonuniform Sampling-Based Breast Cancer Classification, Santiago Posso

Theses and Dissertations--Electrical and Computer Engineering

The emergence of deep learning models and their success in visual object recognition have fueled the medical imaging community's interest in integrating these algorithms to improve medical diagnosis. However, natural images, which have been the main focus of deep learning models and mammograms, exhibit fundamental differences. First, breast tissue abnormalities are often smaller than salient objects in natural images. Second, breast images have significantly higher resolutions but are generally heavily downsampled to fit these images to deep learning models. Models that handle high-resolution mammograms require many exams and complex architectures. Additionally, spatially resizing mammograms leads to losing discriminative details essential …

Mitigation Of Reflected Overvoltage In Wind-Turbine Generator-Converter Systems With A Smart Coil Concept, Lulu Wei

Theses and Dissertations--Electrical and Computer Engineering

In the recent decade, ultra-fast wide bandgap switching devices such as Silicon Carbide (SiC) Metal-Oxide-Semiconductor Field-Effect Transistors (MOSFETs) have been increasingly utilized in power electronic converters for renewable energy power generation systems due to their advantages of enabling high energy efficiency and high power density. However, the much higher voltage slew rate (i.e., dv/dt) with SiC power converters may induce voltage reflection and reliability concerns in machine-converter systems, especially for medium-voltage systems with long cable connections. In wind-turbine power generation systems, generators are typically located in the nacelles, and medium-voltage power converters are mostly placed at the bottom of the …

Multi-Physics Modeling Of Immersion Cooled Electric Power Apparatuses, Reza Ilka

Theses and Dissertations--Electrical and Computer Engineering

Electric power conversion apparatuses such as electromagnetic transformers and power electronic converters play a backbone role in the global power and energy industries, such as power transmission and distribution, electrified transportation vehicle systems, industry automation, and the like. To investigate the performance (efficiency, reliability, etc.) of such critical power conversion apparatuses, high-fidelity multi-physics modeling becomes critical which involves dedicated coupling among multiple physical domains, including electrical, magnetic, thermal, mechanical, and material engineering. Nevertheless, the majority of the existing models for these power conversion apparatuses focus only on one or two physical domains, and the modeling fidelity needs to be further …

A Novel Processor Architecture Implementing The Stacked Error Diffusion Algorithm And Its Zynq-Based Realization, Qishi Hu

Theses and Dissertations--Electrical and Computer Engineering

Digital halftoning reproduces continuous-tone images using patterns of black and white dots, while multitoning extends this concept by incorporating inks with intermediate intensities. These techniques are extensively utilized in the printing industry to accommodate the limited range of inks available in printers. Stacked error diffusion is a high-quality multitoning algorithm that adheres to the blue-noise dithering standard. This thesis research studies the potential parallelism inherent in the algorithm and introduces the design of a novel processor architecture optimized for efficient execution. The architecture is realized on an FPGA development board featuring a Zynq SoC. Additionally, the hardware prototype can also …

Information-Theoretic Learning Framework Based On Covariance Operators On Reproducing Kernel Hilbert Spaces, Jhoan Keider Hoyos Osorio

Theses and Dissertations--Electrical and Computer Engineering

Information theory provides tools to quantify uncertainty, dependence, and similarity between probability distributions, which are crucial for addressing various machine-learning problems. However, estimating these quantities is challenging because data distributions are usually unknown, and only observations are available for analysis. In this dissertation, we advance the field of information-theoretic learning by developing a comprehensive framework using kernel methods for analyzing probability distributions using reproducing kernel Hilbert spaces (RKHS). By leveraging covariance operators in this representation space, we propose approaches to estimate a set of fundamental information-theoretic quantities, that, because of their resemblance with conventional quantities in information theory, we call …

Optimal Control And Evaluation Of Shipboard Power Systems, Musharrat Sabah

Theses and Dissertations--Electrical and Computer Engineering

Electric warships are involved in complex missions consisting of multiple simultaneous operations. In order to ensure mission success, future ships must be designed in a way that optimizes their performance in the presence of complex mission loads. The focus of this research is an effort to optimally control the performance of shipboard systems during missions involving multiple scenarios or vignettes. The evaluation of the performance of mission-oriented power systems is based on the degree to which these systems deliver power to the loads required to perform the mission at hand. The performance of such systems involves a dynamic interplay between …

High Reliability Motor-Drive Systems For Electric Aircraft Propulsion, Majid Tahmasbi Fard

Theses and Dissertations--Electrical and Computer Engineering

The transition towards electric propulsion in aircraft applications requires significant advancements in enhancing the efficiency and power density of power transmission and distribution systems. Among the critical power components in electric aircraft propulsion systems, power electronic converters hold paramount importance as they provide a pivotal interface between batteries and propulsion motors while providing a high degree of controllability and flexibility to the system. Integrating medium voltage DC (MVDC) and the emerging wide bandgap switching devices into power converters not only amplifies converter performance but also unlocks multifarious system-level benefits, including reduced power losses, weight savings, and the utilization of high-speed …

The Effects Of Potassium Fertilization Regime On High Tunnel Tomato Production, Sapana Pandey

Theses and Dissertations--Plant and Soil Sciences

A two-year field experiment (2022-2023) was conducted at the University of Kentucky Horticulture Research Farm in Lexington, KY to study the effects of potassium (K2O) fertilization rates on tomato yield and ripening disorders in determinate and indeterminate varieties (‘BHN-589’ and ‘Big Beef’, respectively). In the first year, K2O rates representing the soil test result-based commercial recommendation (0 lbs/acre) and sequentially greater rates (150, 300, and 450 lbs K2O/acre) were applied. In the second year, K2O rates were increased based on lack of fruit quality response and were 0, 300, 600, and 900 lbs K2O/acre. Leaf tissue nutrients, tomato yield, and …

Identifying Physiological, Morphological, And Genetic Drivers Of Key Intermediary Phenotypic Traits Associated With Stalk Lodging Resistance Within Genetically Diverse Maize Germplasm And Sorghum, Norbert Bokros

Theses and Dissertations--Plant and Soil Sciences

Maize stalk lodging reduces grain yields due to the permanent breakage or deformation of stalk tissue before grain harvest. To reveal new insights into the complex problem of maize stalk lodging, this dissertation will examine three primary objectives. First, the direct, diurnal influence of turgor pressure will be shown to have only marginal effects on stalk bending strength, a key trait associated with stalk lodging resistance. Up to a dozen individual stalks, grown to physiological maturity within the same field, were tested using a DARLING testing device. In parallel, stalk turgor status as measured by leaf water potential and turgor …

Functionalized Microfiltration Membranes For Aerosol Capture To Chloro-Organic Degradation, Rollie George Mills

Theses and Dissertations--Chemical and Materials Engineering

The environmental remediation of water and air sources is a challenging field, due to widespread contamination, pollutant variety, and efficiency of existing treatment options. Remediation of certain pollutants, such as per- and polyfluorinated chemicals (PFAS), polychlorinated biphenyls (PCBs), volatile organic compounds (VOCs), and viral aerosols, has shown promise via adsorptive, degradative, or filtration-based processes, each with their respective advantages and limitations. Membrane technology is one option that has exhibited considerable pollutant removal from environmental sources via reverse osmosis (RO) filtration, but is limited by low permeabilities and lack of pollutant detoxification. With the support of NIEHS and NSF, the functionalization …

Molecular Understanding And Design Of Deep Eutectic Solvents And Proteins Using Computer Simulations And Machine Learning, Usman Lame Abbas

Theses and Dissertations--Chemical and Materials Engineering

Hydrophobic deep eutectic solvents (DESs) have emerged as excellent extractants. A major challenge is the lack of an efficient tool to discover DES candidates. Currently, the search relies heavily on the researchers’ intuition or a trial-and-error process, which leads to a low success rate or bypassing of promising candidates. DES performance depends on the heterogeneous hydrogen bond environment formed by multiple hydrogen bond donors and acceptors. Understanding this heterogeneous hydrogen bond environment can help develop principles for designing high performance DESs for extraction and other separation applications. This work investigates the structure and dynamics of hydrogen bonds in hydrophobic DESs …

Thermomechanical Process Simulation And Quantification Of Nanoscale Precipitation Influencing Ductility And Strength During Alloy Processing, Alyssa Stubbers

Theses and Dissertations--Chemical and Materials Engineering

Experimental process simulation and quantification of microstructure development during processing are challenging due to limitations with machinery temperature capability, inadequate resolution and sampling volume of currently available characterization techniques, and difficulty characterizing material microstructures as close to processing-relevant conditions as possible. This dissertation addresses how process simulation can be performed using Gleeble thermomechanical technologies and how microstructure development during these processing simulations can be quantified both in-situ and ex-situ.

The first portion of this dissertation demonstrates how Gleeble technologies can be applied to simulate complex material processing conditions in order to produce process-property profiles that can be used to inform …

Exploring The Effect Of Casting Solution Composition, Additives, And Casting Conditions On The Morphology And Separation Performance Of Pvdf Membranes, Rachel Kaplan

Theses and Dissertations--Chemical and Materials Engineering

Global water scarcity and quality concerns in the past decade have led to a looming global water crisis. Polymeric membranes have emerged as a potential solution due to their modularity, operational reliability, and wide range of contaminant removal. Polyvinylidene fluoride (PVDF) is often selected as a membrane material for its enhanced chemical resistance, thermal stability, and mechanical strength. However, these membranes often require more complex fabrication methods or support materials to achieve optimum performance. Flat-sheet unsupported PVDF membranes were fabricated via nonsolvent induced phase separation. The influence of solvent, polymer composition, pore forming additives, and casting conditions were explored with …

Development Of Glutathione-Responsive Disulfide-Containing Poly(Beta-Amino Esters) With Varied Hydrophilicity And Acrylate Functionality, Anastasiia Aronova

Theses and Dissertations--Chemical and Materials Engineering

Smart biomaterials are becoming promising for therapeutic deliveries due to their ability to respond to changes in the environment. Redox-responsive hydrogels are a promising type of smart polymer that can swell and degrade according to cellular oxidative stress levels. Glutathione, abundant in cells, is crucial in redox-responsive biomaterials, serving as a key reactive molecule. This study explored the degradation kinetics of glutathione-responsive poly(β-amino ester) (PBAE) polymers created through a single-step Michael addition. We examined how disulfide content influences the degradation kinetics of these PBAE networks. Additionally, we investigated how the hydrophilicity and functionality of acrylate affect the degradation of disulfide-containing …

Faceting Of Tungsten Via Environmental Control Of Temperature, Pressure And Chemistry, And Evolution Of Thermionic Cathode Materials, Huanhuan Bai

Theses and Dissertations--Chemical and Materials Engineering

Scandate cathode presents a great potential of being used as electron emitters in vacuum electron device due to its excellent emission performance. However, it is burdened by several issues, including poor emission uniformity, inadequate reproducibility, and limited lifetime, which have impeded its further industrial application. Therefore, extensive efforts and studies need to be conducted to obtain a more comprehensive understanding of scandate cathode.

W particles, as the base material, play a fundamental role in scandate cathode. Most recent experimental research has reported that the highly faceted crystallography of W grains contributes to the properties of scandate cathode. In order to …

Sustained Release Systems For Endometrial Cancer, Claire E. Rowlands

Theses and Dissertations--Chemical and Materials Engineering

Endometrial cancer (EC) is the sixth most common cancer in women worldwide and is the most common cancer of female reproductive organs. From 2007-2016 there has been a global rise in incidence of EC of 1.3 %. Typically, EC is treated with surgery, but at later stages surgery is less effective requiring chemotherapy and/or radiation therapy. These treatment options are less effective than surgery and there are very few FDA approved chemotherapies for EC. The minuscule number of effective treatment options as well as an increase in incidence shows the need for creating improved treatments for EC. There has been …

Experimental Characterization And Quantification Of Deformation Behavior In A Porous Carbon Fiber Network, Robert N Quammen

Theses and Dissertations--Chemical and Materials Engineering

Due to their wide range of attractive functional properties (such as low thermal conductivity and low density) porous materials are utilized in a variety of applications. In order to characterize these properties and others, the intrinsically heterogeneous microstructures of these materials need to be taken into account. These microstructures result in interactions across multiple length scales spanning several orders of magnitude. This makes the creation of robust computational models and straight-forward predictions of mechanical properties difficult for porous materials. With this in mind, this dissertation aims to provide experimental mechanical and deformation information spanning the length scales of interest for …

Novel Precursors For Carbon Fiber Prepared By Direct Carbonization, Leah Noble

Theses and Dissertations--Chemical and Materials Engineering

For decades carbon fiber-based composites have been most heavily employed in lightweight, structural applications where low density and high strength are necessary, most notably within the aerospace industry. However, the advancement of carbon fiber into a wider array of industries has largely been limited by the high financial and energetic costs associated with its manufacture. Moreover, with an increasing societal emphasis on sustainability, there is an ever-growing desire for low-energy carbon fiber production pathways. One such pathway is the conversion of precursor fiber to carbon fiber by direct carbonization, wherein the energy-intensive, pre-carbonization stabilization step is omitted from the carbonization …

Single-Atom Catalysts For Electrochemical Energy Conversion: Copper Single-Atom Catalyst For Oxygen Reduction Reaction And Quantification Of Site Density By Co Stripping Voltammetry, Dawatage Perera

Theses and Dissertations--Chemistry

Fuel cells are considered a promising technology for achieving cleaner and more sustainable energy production and utilization. However, one of the current major challenges is the economic viability associated with the extensive use of Pt group metal (PGM) catalysts, particularly on the cathode side. Therefore, non-PGM single-atom catalysts (SACs) have received considerable attention as alternatives for PGM catalysts in the oxygen reduction reaction (ORR), which occurs at the cathode of the fuel cell. Among various SAC structures, the non-PGM/nitrogen-doped carbon-based structure (M-N-C) stands out for its excellent ORR performance.

Chapter 2 illustrates the use of copper metal in place of …

Effect Of Π-Conjugated Ligands And A* Site Organic Cations On The Energetic Properties And Photovoltaic Performance Of Metal Halide Perovskites, Harindi R. Atapattu

Theses and Dissertations--Chemistry

Metal halide perovskites have gained interest in optoelectronic applications such as photovoltaics, lasers, LEDs, transistors, and photodetectors due to their excellent semiconducting properties considering their low cost. Metal halide perovskite (HP) photovoltaics have rapidly increased in power conversion efficiency (PCE), which now exceeds 25%. HPs have gained attention in these applications due to their high tolerance towards defects, long charge carrier diffusion lengths, high charge carrier mobility, high optical absorption, and bandgaps that are tunable over a large range. Even though HP photovoltaic PCEs are improved these are still not commercially available due to them showing lower stability and energy …

Understanding Of Processing Additives Influence In Tin Halide Perovskites: Chemistry, Defect, And Photovoltaic Performance, Syed Rahmath Ullah Joy

Theses and Dissertations--Chemistry

Metal halide perovskite semiconductors have attracted much interest for various applications, such as solar cells, light emitting diodes, photodetectors, and lasers, due to their excellent optoelectronic properties. Photovoltaic cell development is centered on Pb-based perovskites, which have equal photovoltaic performance compared to the traditional silicon photovoltaic. But concerns arising from the usage of toxic lead metal have motivated the research community to seek an alternative derivative. Among those, tin halide perovskites show much promise as an alternative to Pb-counterparts due to their ideal bandgap for single junction photovoltaics and similar optoelectronic properties to Pb perovskites. Nevertheless, tin perovskites suffer from …