Digital Commons Network^™

Small-Satellite Attitude Control Using Sinusoidal Actuator Motion: Experiments On The International Space Station, K. Ryan Lush

Theses and Dissertations--Mechanical and Aerospace Engineering

In this work, we design, build, and test two 1.25U CubeSats. These small satellites were deployed on the International Space Station to perform attitude control experiments in microgravity. These CubeSats use an oscillating-mass actuation system for attitude control as opposed to traditional flywheels. Each CubeSat uses 3 pairs of servomotors to oscillate masses about 3 orthogonal axes. The servomotors have strict rotational stroke limits. Thus, they cannot spin continually. To oscillate each pair of masses, the angle of each servomotor is commanded using signals that are continuous and piecewise sinusoidal with amplitudes that do not violate the servomotor stroke constraints. …

Kentucky Re-Entry Universal Payload System (Krups): Hypersonic Re-Entry Flight, John Daniel Schmidt

Theses and Dissertations--Mechanical and Aerospace Engineering

The Kentucky Re-entry Universal Payload System (KRUPS) is a small capsule designed as a technology testbed for re-entry experiments. For its first incarnation, KRUPS has been designed to test Thermal Protection Systems (TPS) and instruments in re-entry flights. Because of the unique environment a vehicle undergoes during re-entry, there is a high-demand for experimental data from re-entry experiments. KRUPS has been developed at the University of Kentucky (UK) over the past seven years to meet this demand. After completing sub-orbital campaigns, the first KRUPS hypersonic re-entry mission was attempted. The mission involved building three 11-inch diameter capsules each outfitted with …

Experimental Comparison Of Two Sampled-Data Adaptive Control Algorithms For Rejecting Sinusoidal Disturbances, William Grayson Woods

Theses and Dissertations--Mechanical and Aerospace Engineering

We review two adaptive control algorithms that address the problem of rejecting sinusoids with known frequencies that act on an unknown asymptotically stable linear time-invariant system. We present modifications to the algorithms that address the problems of sensor noise and actuator saturation. We demonstrate the effectiveness of the algorithms and compare the performance of the algorithms via numerical simulation and experimental testing.

Numerical And Scaling Study On Application Of Inkjet Technology To Automotive Coating, Masoud Arabghahestani Dr.

Theses and Dissertations--Mechanical and Aerospace Engineering

A thorough literature review identified lack of precision control over quality of droplets generated by the currently available industrial sprayers and a growing need for higher quality droplets in the coating industry. Particularly, lack of knowledge and understanding in continuous inkjets (CIJ) and drop-on-demand (DOD) technologies is identified as significant. Motivated by these needs, this dissertation is dedicated to computational fluid dynamics (CFD) and scaling studies to improve existing inkjet technologies and develop new designs of efficient coating with single and/or multiple piezoelectric sensors to produce on-demand droplets. This dissertation study aims at developing a new DOD type coating technology, …

In-Situ Characterization Of Burr Formation In Finish Machining Of Inconel 718, Hamzah M. Zannoun

Theses and Dissertations--Mechanical and Aerospace Engineering

One of the undesirable byproducts that occur during the machining process is the development of burrs, which are defined as rough excess material that forms around the geometric discontinuities of a part. Burrs are especially problematic because they have negative impacts across the triple bottom line: economic, environmental, societal. For one, they are expensive to remove because the deburring process is entirely manual and requires skill. Further, burr material is typically discarded which is adding to the already mounting waste generated from machining such as in coolant and chip disposal. Lastly, there are many societal implications, such as operator injury …

Peridynamic Material Correspondence Models: Bond-Associated And Higher-Order Formulations, Wailam Chan

Theses and Dissertations--Mechanical and Aerospace Engineering

Peridynamic material correspondence model is able to incorporate material constitutive models directly from classical continuum mechanics theory. However, conventional correspondence model faces two major technical issues for its application to practical problems. The first is the material instability, which results severe oscillations in the predicted displacement fields. The second issue is the length scale effects of materials mechanical behavior at low length scales. This research journey mainly consists of three stages. The first two stages of this research journey focus on the development of the bond-associated peridynamic material correspondence model to inherently remove the material instability. The last stage focuses …

Shape Memory Behavior Of Nitihf Alloys Fabricated By Laser Powder Bed Fusion, Guher Pelin Toker

Theses and Dissertations--Mechanical and Aerospace Engineering

NiTiHf-based alloys have emerged as potential materials for applications requiring high transformation temperatures (> 100 °C) with high strength and work output. Currently, it is challenging to produce complex shapes of these materials with tailored shape memory properties or reduce the material waste from machining operations given the cost of these materials. Additive manufacturing via Laser Powder Bed Fusion (L-PBF) represents an attractive way to fill this gap by producing unique geometries from powder-based feedstock. In this method, process parameters such as laser power, scanning speed, hatch spacing and energy density play significant roles in controlling the mechanical behavior and …

Experimental Investigation Of Roughness And Blowing Effects Over Ablator-Like Surfaces, Colby Borchetta

Theses and Dissertations--Mechanical and Aerospace Engineering

Two separate experiments using PIV were carried out to investigate the effects of
roughness and blowing over surfaces geometrically similar to ablation materials used for atmospheric re-entry. The first, water tunnel experiments, employed a dimpled surface similar to AVCOAT, while the second set was completed in a wind tunnel with a material similar to PICA. For the first set, the flow with blowing becomes destabilized, and more disorganized. The blowing disrupts the relatively simple vorticity shedding process and significantly modifies momentum transport via interaction of detached structures. Flow structure and their modifications were examined with a sPOD analysis. The focus …

Formation Control With Collision Avoidance For Fixed-Wing Unmanned Air Vehicles With Speed Constraints, Christopher Heintz

Theses and Dissertations--Mechanical and Aerospace Engineering

Advances in the miniaturization of powerful electronic components and motors, the democratization of global navigation satellite systems (GNSS), and improvements in the performance, safety, and cost in lithium batteries has led to the proliferation of small and relatively inexpensive unmanned aerial vehicles (UAVs). Many of these UAVs are of the multi-rotor design, however, fixed-wing designs are often more efficient than rotary-wing aircraft, leading to a reduction in the power required for a UAV of a given mass to stay airborne. Autonomous cooperation between multiple UAVs would enable them to complete objectives that would be difficult or impossible for a single …

Novel Mechanism Of Endogenous Pancreatic Cancer Cell Expression Of Immune Checkpoint Programmed Cell-Death 1 Protein (Pd-1) Inducing Epithelial-To-Mesenchymal Transition (Emt) Through The Met Pathway And Promoting Cancer Progression In An Immune-Independent Process, Megan M. Harper

Theses and Dissertations--Clinical and Translational Science

Pancreatic ductal adenocarcinoma (PDAC) remains one of the deadliest cancers with few treatment options, necessitating an urgent need for novel therapeutics. Immuno-oncologic (IO) therapies have revolutionized anti-cancer regimens in the past decade but typically involve reactivation of adaptive immune responses. In particular, immune checkpoint PD-1 is traditionally expressed only on immune cells while PD-L1 (PD-1 ligand) is overexpressed on cancer cells. When tumor-endogenous PD-L1 binds the PD-1 receptor on T-cells, the immune cells undergo anergy resulting in self-tolerance and cancer cell immune evasion. However, contrary to standard dogma, we previously demonstrated tumor-endogenous PD-1 expression in PDAC. Our data indicated that …

Progressive Endoscopic Approach To Balloon Dilation For Benign Esophageal Strictures, Chad J. Cooper

Theses and Dissertations--Clinical and Translational Science

Benign esophageal strictures are a frequently encountered problem in clinical practice. The management of benign esophageal strictures have slowly evolved over the decades based on “expert opinion.” Despite vast amounts of data about the efficacy and safety of dilation, unfortunately there is no consensus on a systematic and safe approach that is efficient, limits complications and provides long lasting improvement of dysphagia. Our group designed a progressive approach to endoscopic balloon dilation based on tailoring certain technical aspects of the dilation process.

Most studies in the literature concluded that endoscopic dilation is safe and effective in relieving dysphagia caused by …

Art Education In Medical Education: Benefits And Challenges, Sara K. Brown

Theses and Dissertations--Art and Visual Studies

Humanity is synergistic with art and medicine. Likewise, art education can be impactful throughout medical education. Art as a tool to develop the next generation of healthcare differs from the clinical goals of creative art therapies. Over the prior decade, many medical schools now provide curricular offerings in the arts and humanities. Less is known about the application in postgraduate medical settings. The focus of this thesis is to review the pairing of artist-educators with postgraduate medical training programs.

One such program is ArtsCAFE (Arts Connect Around Food and Enrichment), an intercollegiate project fusing experienced arts educators with medical educators …

A Study Of The Analysis Of Hemp-Derived Oil Products: Development Of A Method For The Analysis Of Phytocannabinoids In Medicinal Products, Erin Johnson

Theses and Dissertations--Pharmacology and Nutritional Sciences

Human interactions with cannabis have a history spanning millennia as a source of fiber, food, and medicine. The plant came across Asia, Europe, and Africa with the movements of people and travelers eventually coming to the Americas with European explorers. In colonizing North America, cannabis fiber was key to the production of canvas and ropes for ships. Although fiber was the driver for cannabis production in the United States, medicinal uses were prevalent and propelled the eventual regulations. The Pure Food and Drug Act of 1906 mandated accurate labeling on drugs such as cannabis followed by the Marihuana Tax Act …

Modeling The Effects Of Adverse Childhood Experiences Using A Mouse Model Of Neglect: Mechanisms Of Adiposity Expansion In Females, Jacqueline Leachman

Theses and Dissertations--Pharmacology and Nutritional Sciences

Adverse childhood experiences (ACEs) are an independent risk factor for chronic disease, including obesity and metabolic syndrome. We have previously shown that a mouse model of early life stress, maternal separation and early weaning (MSEW), exacerbates high-fat diet (HF)-induced obesity only in adult female mice. In agreement, the analysis of several cohorts of participants exposed to ACEs have shown that women are more susceptible to develop obesity than men. Therefore, the aim of this study was to investigate the link between early life stress and obesity in pre-clinical and clinical settings. Male and female MSEW mice fed 1 week a …

Apoe Genotype And Cerebral Glucose Metabolism: A Multi-Omics Approach, Holden C. Williams

Theses and Dissertations--Physiology

Apolipoprotein E (APOE) is encoded by the APOE gene, present in humans as three main isoforms (E2, E3, and E4). E4 carriers face up to a 15-fold increased risk for developing late-onset Alzheimer’s disease (AD), while E2 carriers are protected. Understanding the risk conferred by E4 has been an extensive research focus for nearly three decades, but the exact mechanism has yet to be proven. Many studies have demonstrated attenuated roles of E4 in classical hallmarks of AD, notably amyloid processing and neurofibrillary formation, which normally present later in disease progression. How APOE influences hallmarks that present much earlier are …

Uncovering The Role Of Apoe4 On Alzheimer’S Disease-Related Neuroinflammation, Courtney Marie Kloske

Theses and Dissertations--Physiology

Alzheimer’s disease (AD) is the most common neurodegenerative disease and is characterized by two hallmark pathologies: amyloid-beta plaques (Ab plaques) and hyperphosphorylated, aggregated tau tangles. These pathologies are typically accompanied by the presence of neuroinflammation which is primarily mediated by microglia. Interestingly, several genetic risk factors that increase the risk of AD also have direct impacts on neuroinflammation. Of interest, Apolipoprotein E (ApoE) is the largest genetic risk factor for AD. ApoE has three isoforms- E4 confers an increased risk for AD, E3 is considered the “control” phenotype, and E2 is protective against AD. E4 plays a role in virtually …

Regulation Of Skeletal Muscle Plasticity By The Gut Microbiome, Taylor R. Valentino

Theses and Dissertations--Physiology

Recent evidence suggests that the gut microbiome could play a role in skeletal muscle plasticity, providing novel treatments for muscle wasting diseases and/or performance enhancements. I first sought to determine if the gut microbiome is necessary for skeletal muscle adaptation to exercise. Forty-two, four-month old, female C57Bl/6J underwent nine weeks of weighted wheel running or remained in cage with a locked wheel, without or without the administration of antibiotics (treated). In response to wheel running, I found that antibiotic depletion of the microbiome led to a blunted hypertrophic response in the soleus muscle as measured by normalized muscle wet weight …

Immunoregulatory Receptor Genetics, Expression, And Splicing Studies In Alzheimer’S Disease, Benjamin C. Shaw

Theses and Dissertations--Physiology

Microglia are the resident immune cells of the brain, undertaking many critical tissue maintenance functions such as immune surveillance and phagocytosis. Microglial dysfunction has recently been identified as a multi-stage signature of many neurodegenerative diseases, including late-onset Alzheimer’s Disease (LOAD). Genome-wide association studies (GWAS) have identified single nucleotide polymorphisms (SNPs) in over thirty genes that modulate risk of developing LOAD. In the central nervous system, roughly half of these LOAD-associated genes are primarily expressed in microglia. The proteins encoded by these genes include cell surface receptors that contain either immunomodulatory tyrosine-phosphorylated activating motifs (ITAMs) or inhibitory motifs (ITIMs), including TREM2 …

Evaluating The Relationship Between Plasma Biomarkers And Dementia Using Hierarchical Clustering Analysis And Linear Modeling, Zachary Winder

Theses and Dissertations--Physiology

Dementia is a disorder characterized by a significant decline from baseline in one or more cognitive domains that interferes with independence. Prevalence of dementia worldwide is estimated at 50 million people, with that number expected to triple by 2030, coming with a cost of roughly $2 trillion. Clinically, dementia is diagnosed using cognitive evaluations, with varying domains affected and to different degrees depending on the underlying pathology and stage of disease. Alzheimer’s disease (AD) and vascular contributions to cognitive impairment and dementia (VCID) are the two leading causes of dementia, and both have pathologies which can be visualized using MRI. …

Investigating The Uncertainties In Ct Non-Small Cell Lung Cancer Radiomics, Gary Ge

Theses and Dissertations--Radiation Medicine

Radiomics is a technique that extracts quantitative features, termed radiomic features, from medical images using data-characterization algorithms. These radiomic features can be used to identify tissue characteristics and radiologic phenotyping that are not observable by clinicians in a non-invasive, low-cost manner, potentially generating image biomarkers for clinical decision. To date, there are still many uncertainties involved in radiomics which limit its clinical implementation. Herein, we propose to explore the impact of each component in the radiomics pipeline on predicting clinical outcomes. In Chapter II, we conduct a thorough review of CT lung cancer radiomics studies to examine the typical feature …

Non-Normative Critical Life Events: Where Dyadic Coping And Attachment Meet, Talley Mortara

Theses and Dissertations--Family Sciences

The aim of the current study was to examine both dyadic coping and anxious attachment following the experience of a critical non-normative life event. Pairfam, a nationally representative German sample, was used as a secondary data set for this quantitative study. Paired samples t-tests were used to analyze the data from 559 German couples to track statistically significant increases or decreases in the perception of dyadic coping responses and anxious attachment levels when a non-normative critical life event happened at some point in the previous two years. Results found that the partner of the anchor showed a statistically significant increase …

Nutritional Status In Critical Care Of Covid-19 Patients, Dolph Lewis Davis Iii

Theses and Dissertations--Nutrition and Food Systems

Critical care nutrition is a poorly researched, and such a sudden pandemic event requiring manipulation of nutritional status via propofol-induced sedation for mechanical ventilation is potentially impactful on patient outcomes. This paper seeks to provide context to the impact of critical care protocols on the nutritional status of obese patients suffering from COVID-19.

“It’S Just Part Of Our Hospitality:” Examination Of Cultural Factors That May Inform Future Initiatives To Improve Health Outcomes In A Rural Appalachian Community, Lauren Cassidy Batey

Theses and Dissertations--Nutrition and Food Systems

Diet and physical activity are influenced by a person’s culture and may contribute to the presence of health disparities within a geographic region. Health disparities are evident in Appalachia where a unique cultural identity exists. Culture-based initiatives focused on improving diet quality and increasing physical activity have improved health outcomes in diverse groups, yet interventions considering geographically tied cultures, like Appalachia, are limited. This study aims to identify specific aspects of Appalachian culture that influence health outcomes to inform and increase success of health focused interventions. Five focus groups were conducted in one rural Appalachian community in summer 2021. Grounded …

Farmers’ Market Incentive Program As An Intervention For Improving Behavior Regarding Fruit And Vegetable Consumption In Children And Adolescents, Madison Blades

Theses and Dissertations--Nutrition and Food Systems

Background: Previous research shows that there is low consumption of fruits and vegetables in children and adolescents, specifically those residing in the state of Kentucky which is ranked the lowest of all states in fruit and vegetable (F/V) consumption. The lack of F/V in a diet of someone during their developmental ages can result in negative health outcomes in the future.

Objective: To determine if the use of a farmers’ market incentive program as a nutritional intervention affects the consumption of F/V in children and adolescents.

Methods: 261 children and adolescents, ages 3-14, from 160 families participated in a 10-week …

Family And Consumer Sciences Extension Agents Perception Of A Sustainable Eating Curriculum For Kentuckians, Lindley Barker

Theses and Dissertations--Nutrition and Food Systems

The population is rapidly increasing all over the world. As foods are produced for us to consume, the food system generates negative environmental impacts at each step. The extent of damage generated by food production depends on the amount of land, water, and energy depleted. These environmental impacts can result in reduced quantities of food produced, damages to the land and water used to grow/produce food, pollution of food, and food waste. All of which impact the amount of product produced. Thereby, shifting food-related behaviors of consumers toward sustainable eating may be a way to promote the health of people …

The Effect On Incorporating Fresh Fruits And Vegetables Into An Emergency Food Box Program In Rural Appalachia Kentucky, Zixuan Li

Theses and Dissertations--Nutrition and Food Systems

About 1 in 8 Kentuckians experiencing food insecurity. Low-income Appalachian Kentuckians often utilize food assistance programs and community resources to obtain food and they have lack regular access to fresh food, especially fruits and vegetables. Of concern is nutrition quality and the ability to use food items. The study aimed to explore if and how low-income Appalachian Kentuckians living in a food desert utilized their standard food pantry box as well as a supplemental box of free fresh produce. The study was done through distribution of supplemental fruit and vegetable boxes along with their emergency food box seven different times …

The Role Of Nitric Oxide In Inter- And Intra- Cellular Signaling In Plant Defense, Fan Xia

Theses and Dissertations--Plant Pathology

Plants have evolved a sophisticated immune system to defend themselves against pathogens. This immune response can be triggered in response to pathogen-associated molecular patterns (PAMP) or specialized effectors that are recognized by the plant resistance (R) proteins. The latter, commonly referred to as effector-triggered immunity (ETI), is well known to induce broad-spectrum resistance throughout the plants. This phenomenon known as systemic acquired resistance (SAR) is regulated by several chemical signals including salicylic acid (SA), and free radical nitric oxide (NO) and reactive oxygen species (ROS). These signals operate in two parallel branches with NO/ROS functioning downstream of pipecolic acid (Pip) …

An Examination Of Organic Options In Tomato Systems And Their Use As Alternatives To Copper-Based Products, Erica Ann Fealko

Theses and Dissertations--Plant Pathology

Organic farming is an ever-increasing segment of tomato production. Currently, limited information is available which directly compares conventional to organic treatment programs for disease control in tomato production. Furthermore, many methods available rely on the use of copper products which may be contribute to high Cu levels in agricultural soils. In this study, the efficacies of current conventional and organic methods were compared. In addition, newer disease-control programs, with and without copper were examined, which potentially could reduce over-reliance on copper products.

Standard organic and conventional spray programs were conducted over a four year period targeting two pathogens, Alternaria tomatophila …

Identifying Bisphosphonate Protein Biomarkers In Equine Sera Using Mass Spectrometry Methods, Malinda Jayne Alison Porter

Theses and Dissertations--Veterinary Science

Bone resorptive diseases affect humans and horses, alike. Examples of these diseases include osteoporosis, Paget’s disease, and osteogenesis imperfecta in humans, and navicular disease in the horse (Mitchell et al., 2019; Suva et al., 2021). Bisphosphonates are used to treat these diseases, and may remain in the bone for several years after administration, demonstrating the need for newer drug testing methods.

The purpose of the discovery phase of this study was to use blood samples of in-training horses which had been given an initial administration of the bisphosphonate tiludronate and identify protein biomarkers that changed in response to this class …

The Effect Of Intra-Articular Corticosteroids On The Systemic Messenger Rna Response In An Equine Experimental Inflammation Model, Emma Elaine Partridge

Theses and Dissertations--Veterinary Science

Intra-articular (IA) corticosteroids are regularly used in equine athletes for the control of joint inflammation. The goal of this study was to utilize an acute synovitis inflammation model to determine the residual effects of IA betamethasone and triamcinolone acetonide on various inflammatory parameters and lameness.

Five mixed-breed, 2-year-old horses were randomly allocated to an IA treatment of the radiocarpal joint with 9 mg of either betamethasone or triamcinolone acetonide. Two weeks following treatment, horses were injected with 1μg of lipopolysaccharide (LPS) diluted in 1 mL of 0.9% sterile saline. Following LPS injection, horses were crossed-over and both sets of injections …