Digital Commons Network^™

Two-Level Multi-Objective Design Optimization Including Torque Ripple Minimization For Stator Excited Synchronous And Flux Switching Machines, Ali Mohammadi, Oluwaseun A. Badewa, Yaser Chulaee, Dan M. Ionel

Electrical and Computer Engineering Graduate Research

Electric machine performance can be enhanced through torque ripple mitigation, which reduces mechanical vibrations and improves system stability and operation. This paper proposes a novel two-level optimization method for synchronous flux-switching and hybrid excitation machines, featuring an innovative multi-point spline shaping approach for torque ripple minimization. The study employs experimentally validated models based on a prototype with a similar topology. The optimization process is implemented on two distinct designs: a 20-pole inner rotor PM-excited stator machine and a 28-pole outer rotor DC-excited stator machine. Analysis results demonstrate that the proposed innovative method significantly reduces torque ripple in both configurations. Force …

Electromagnetic Design Characterization Of Synchronous Machines With Flux Switching Effect Employing Reluctance Rotors And Stators With Pms And Ac Concentrated Coils, Oluwaseun A. Badewa, Ali Mohammadi, Donovin D. Lewis, Somasundaram Essakiappan, Madhav Manjrekar, Dan M. Ionel

Electrical and Computer Engineering Graduate Research

This paper introduces an innovative design for a synchronous electric motor that has phase coils and permanent magnets (PM) embedded in the stator. The electric machine contains both concentrated winded phase coils in dedicated slots and spoke-type permanent magnets solely in the stator. The spoke-type magnet arrangement achieves a high flux intensity even with low remanence non-rare earth permanent magnets. As the rotor has no active electromagnetic components, the risk for demagnetization is reduced and advanced cooling applied to the stator can enable high-speed operation. The principle of operation and polarity of the motor are investigated with a unique approach …

Ai In Newsrooms: Assessing Perception, Challenges And Possibilities In Bangladesh’S Media Landscape, Nadia Rahman

Theses and Dissertations--Communication

With the relentless progression of technological advancements, artificial intelligence (AI) has become a transformative force across various sectors, and newsrooms are no exception. Developed nations have already integrated AI into journalistic practices, showcasing its versatility in different news functions. However, the developing nations, including Bangladesh, a south Asian nation faces challenges in catching up, marked by technological and economic disparities. As an emerging economic force Bangladesh encounters different obstacles in the adoption of AI in its media landscape. Despite the expansiveness of its media industry, the country grapples with limited technological support and inadequate training opportunities. These challenges bring up …

Black Love, Media Portrayals, And Social Identity, Nigel M. Taylor

Theses and Dissertations--Communication

This dissertation explores how media stereotypes about Black relationships influence Black individuals' perceptions, shaping their understanding and expectations of love. Using social identity theory as a foundation, a mixed-methods approach integrates both qualitative and quantitative methods to examine the impact of media portrayals on self-concept and relationship expectations. The quantitative findings investigate connections between media exposure, self-esteem, and partner preferences, revealing how media shapes ideas about ideal relationships and internalized racial dynamics. The qualitative analysis identifies seven themes that define Black Love and seven themes that depict media stereotypes of Black relationships. The study shows that while media often reinforce …

Cybersecurity Training As Risk Communication: A Theory-Informed Model Of Employee Learning And Behavior Change, Daniel Chaney

Theses and Dissertations--Communication

Cybersecurity threats like phishing remain a persistent and costly challenge for organizations. Despite widespread corporate cybersecurity training (CCT) programs, many fail to produce lasting behavior change. This dissertation introduces the Training Knowledge Flow (TKF) Model to assess why such efforts often fall short. Grounded in communication theory, risk messaging, and adult learning principles, the TKF Model conceptualizes cybersecurity training as a staged process of learning, application, and behavioral adaptation. The model includes three phases: (1) Employee as Learner, focusing on message clarity and cognitive engagement; (2) Employee as Practitioner, assessing workplace transfer and training relevance; and (3) Employee …

Going Inside A Church Staff Group: A Qualitative Case Analysis Of Team Characteristics, Decision-Making, And Identity, Hillary Rose Hamilton

Theses and Dissertations--Communication

Many organizations, including churches, rely on leadership groups to coordinate efforts and fulfill their mission. Guided by the characteristics of highly effective teams, the functional theory of group decision-making, and symbolic convergence theory, this study examines how one church staff group engages in decision-making and enacts identity through socioemotional and task-related communication. This group is unique in that its members each lead different areas necessary for the church’s functioning. Data for this qualitative case-study consists of semi-structured interviews with each group members and five meeting observations. Findings provide insight into the group’s dynamics, decision-making process, and identity. However, of most …

Addressing The "Hidden Crisis" In Doctoral Education: Identifying The (De)Motivating Effects Of Memorable Messages From A Self-Determination Theory Perspective, Alexis A. Murphy

Theses and Dissertations--Communication

Although PhD students are academically capable, they paradoxically produce alarmingly high attrition rates. For several years, retention rates in PhD programs have averaged between 40% and 70% (Ames et al., 2018; Bowen & Rudenstine, 1992; Cochran et al., 2014; Gardner & GoPaul, 2012; Lovitts, 2001; Rockinson-Szapkiw & Spaulding, 2012). Scholars have presented several potential reasons that PhD students discontinue their studies, none of which include academic ability (Lovitts, 2001; Tucker, 1964; Sverdlick et al., 2018). Framed by self-determination theory (SDT), this study explores the social and communicative components of the doctoral education system by the psychological impact of memorable messages …

Virtual Speeches, Real Fears: Public Speaking Anxiety In The Online Communication Classroom, Timothy J. Bill

Theses and Dissertations--Communication

While universities have explored online course offerings for decades, the COVID-19 pandemic accelerated this trend. The foundational communication course—a course that continues to traditionally emphasize public speaking—has felt the pandemic influence to increase opportunities for students to learn public speaking via online instruction. While scholars have learned much about the student experience of public speaking anxiety (PSA) in face-to-face settings, less is known about their experience of PSA in online courses. This dissertation explored the fears students experience when presenting online and how they view the online presentation environment.

Using Bandura’s Social Cognitive Theory as a guide, this dissertation employed …

"The Lgbtq Community, That's My New Church": An Examination Of Lgbtq+ Former Church Members' Experiences Of Religious Exit, Samantha N. Pfeiffer

Theses and Dissertations--Communication

This study examines the experiences of LGBTQ+ individuals who previously attended Independent Fundamentalist Baptist (IFB) churches, considering their experiences of being in the church, leaving the church, and rebuilding outside of the church. It also examines sermons from IFB churches that addressed topics related to the LGBTQ+ community to examine the teachings these individuals received while in the church. My examination of this topic was based in scholarly literature addressing the rhetoric of church sermons, the process and experience of religious disaffiliation, and Weick’s (1995) theory of organizational sensemaking. I used multiple qualitative methods in this study, including qualitative content …

The Information Practices Of Undergraduates Encountering Material Objects As Information Resources In Classroom Learning Tasks, Christopher A. Miller

Theses and Dissertations--Communication

Undergraduate students sometimes encounter material objects as information resources in small-group classroom learning activities. Examples include art, artifacts, specimens, and anatomical models. This dissertation sought to identify common features of the students’ information practices in such situations, regardless of the activity’s discipline or content, and to explore how making material information central shapes students’ information practices. The conceptual framework combined theorizations of materiality and information practices. Methods involved video recording students doing a variety of simulated classroom activities with objects, video elicitation, qualitative content analysis, and praxiographic interpretation. The praxiographic interpretive descriptions illustrated how all aspects of the site–material, bodily, …

Player 2 Has Entered The Culture War: Discourse, Ideology, And Narrative In Gamergate 2.0, Ashley C. Mccann

Theses and Dissertations--Communication

My thesis addresses the ever-evolving landscape of Gamergate 2.0. Once a reactionary misogynistic harassment movement dedicated to attacking women in video games, the new iteration of Gamergate has evolved into an entirely new community. In its new iteration, Gamergate is even less ostensibly concerned with video games and more with reactionary content, mixing together nerd media, general pop culture, and right-wing politics. To study this community, I approach the Gamergate 2.0 community as an anti-fandom and reactionary affinity space. I argue that GamerGate 2.0 exists as its own powerful reactionary community that creates a worldview consisting of the desired destruction …

Crystal Structures And Low-Affinity Complex Formation Of Halogenase Ctcp And Fad Reductase Ctcq From The Chlortetracycline Biosynthetic Pathway, Caixia Hou, Sylvie Garneau-Tsodikova, Oleg V. Tsodikov

Pharmaceutical Sciences Faculty Publications

Enzymatic halogenation in natural products has been intensely investigated due to its potential utility as a tool to improve pharmacological and pharmaceutical properties of drug leads. Chlortetracycline (CTC), the first tetracycline (TC) antibiotic discovered nearly eight decades ago, contains a chlorine group. This chlorine is installed enzymatically by the flavin adenine dinucleotide (FAD)-dependent halogenase CtcP. CtcP and the FAD reductase CtcQ, which is also encoded in the CTC biosynthetic gene cluster, function as a two-component system. Structural information on CtcP and CtcQ has been lacking. In this study, we determined crystal structures of CtcP from Kitasatospora aureofaciens in a complex …

Borreliosis And Doxycycline Treatment Disrupt Gut Microbiota And Immune Responses In Nonhuman Primates, Ethan G. Napier, Isaac R. Cinco, Sheridan B. Wagner, Ethan V. Stuart, Qi Qiao, Joshua Taylor, Brian Stevenson, Ilhem Messaoudi

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Borrelia burgdorferi (Bb) is the spirochete that causes Lyme disease (LD). Transmission to humans occurs via bites of infected Ixodes spp. ticks. Doxycycline is often used to treat LD patients, which is sometimes delayed due to current diagnostic challenges. Recently, several lines of evidence show dysbiosis of the gut microbiome in LD patients, which may be a host factor contributing to pathogenesis and symp tomology but is still an understudied area in the field. To address this knowledge gap, we longitudinally compared the immune response and gut microbial composi tion of Japanese macaques after intradermal infection with Bb strain 297 …

Aluminum In Beverages And Foods: A Comprehensive Compilation Of Regulations; Concentrations In Raw, Prepared, And Stored Beverages And Foods; And Intake, Robert Yokel

Pharmaceutical Sciences Faculty Publications

The history and controversy concerning aluminum use in beverage and food preparation and storage are reviewed. This review on aluminum in drinking water, foods, and beverages updates and exceeds prior reviews. Country and international organization regulations that permit incorporation of aluminum containing food additives, their use limit, and purposes are presented. The aluminum concentration in beverages and foods consumed worldwide was gleaned from approximately 2100 sources available to the author. The approximately 17700 values are compiled in 175 tables by beverage or food category that include the analytical method used, sample source, and reference. The tables are posted on the …

A Cocaine Hydrolase Engineered From Human Butyrylcholinesterase As A Medical Countermeasure For Aldicarb Poisoning, Johnathan E. Lesaint, Nellore Bhanu Chandar, Annet Kyomuhangi, Huimei Wei, Fang Zheng, Chang-Guo Zhan

Pharmaceutical Sciences Faculty Publications

Aldicarb is known to be the most toxic carbamate pesticide and could be used easily by terrorists to cause a mass casualty incident. It is highly desired to discover a medical countermeasure for aldicarb poisoning. Based on structural insights from molecular modeling and in vitro experimental validation, CocH3-Fc(M3), a potent cocaine hydrolase engineered from human butyrylcholinesterase (BChE), has a ~4-fold improved binding affinity with aldicarb compared to wild-type human acetylcholinesterase (AChE) and BChE and a 9-28-fold improved bimolecular rate constant for the carbamylation with aldicarb compared to AChE. CocH3-Fc(M3) also has significant catalytic activity for aldicarb hydrolysis and, hence, is …

Development Of A Ghrelin Deacylase To Attenuate Drug Reward And Associated Effects Of Methamphetamine, Madeline J. Stewart, Huimei Wei, Nellore Bhanu Chandar, Fang Zheng, Chang-Guo Zhan

Pharmaceutical Sciences Faculty Publications

All addictive substances directly or indirectly interact with the dopamine reward system to alter the brain’s dopamine receptor activities. It is essential for a truly effective addiction medication to attenuate substance reward and normalize the brain’s physiological functions. Conventional pharmacological intervention approaches to the treatment of substance addiction usually aim to develop and deliver a potential therapeutic agent to the brain to directly block or decrease actions of the substance or its therapeutic target in the brain. However, it is a grand challenge to attenuate the substance reward without affecting the normal physiological functions of brain receptors or transporters. Here, …

Effects Of Biased Analogues Of The Kappa Opioid Receptor Agonist, U50,488, In Preclinical Models Of Pain And Side Effects, Ross Van De Wetering, Loan Y. Vu, Lindsay D. Kornberger, Dan Luo, Brittany Scouller, Sheein Hong, Kelly F. Paton, Thomas E. Prisinzano, Bronwyn M. Kivell

Pharmaceutical Sciences Faculty Publications

Kappa opioid receptor (KOR) agonists have well-established antinociceptive effects. However, many KOR agonists have negative side effects, which limit their therapeutic potential. Some researchers have suggested that the development of biased agonists that preferentially stimulate KOR G-protein pathways over β-arrestin pathways may yield drugs with fewer adverse side effects. This was investigated in the current study. We describe the synthesis and characterization of three U50,488 analogues, 1, 2, and 3. We evaluated the acute and chronic antinociceptive effects of these compounds in mice using the warm-water tail flick assay and in a paclitaxel-induced neuropathic pain model. Side …

Effects Of Fentanyl-Adulterated Methamphetamine On Circulating Ghrelin In Rats, Huimei Wei, Elise C. Maul, Shawn Park, Kaniz Fatema, Daniel J. Peter, Chang-Guo Zhan, Fang Zheng

Pharmaceutical Sciences Faculty Publications

The appetite hormone ghrelin influences biological processes that are responsible for substance use disorder, which is related to alcohol and most abused drugs including cocaine, methamphetamine, nicotine, etc. In general, upregulation of the ghrelin system enhances drug cravings and substance use. Studies reported in the literature consistently demonstrated that the ghrelin system is associated with stimulants. However, research on opioids in combination with methamphetamine has not been reported. In this study, we examined the relationship of circulating ghrelin with the polydrug use of fentanyl and methamphetamine in male Sprague-Dawley rats, demonstrating for the first time that concurrent use of fentanyl …

Effects Of Fentanyl-Laced Cocaine On Circulating Ghrelin, Insulin, And Glucose Levels In Rats, Huimei Wei, Elise C. Maul, Annet Kyomuhangi, Shawn Park, Maddilynn L. Mutchler, Chang-Guo Zhan, Fang Zheng

Pharmaceutical Sciences Faculty Publications

Opioid mixed with cocaine has been increasingly implicated in overdose deaths, including both intentional co-use of opioid and cocaine and fentanyl-adulterated drug supply. As ghrelin plays an important role in drug reward and can also influence insulin, this study aimed to assess responses of the circulating ghrelin, insulin, and glucose levels to the combined use of fentanyl and cocaine (a polydrug) in rats by performing combined animal behavioral experiments and biochemical analysis. The experimental data consistently revealed that the fentanyl and cocaine co-use can significantly elevate both the acyl-ghrelin and desacyl-ghrelin levels and significantly decrease the insulin level without significant …

Fluorescence-Guided Resection Of Gl261 Red-Fluc And Trp-Mcherry-Fluc Mouse Glioblastoma Tumors, Louis T. Rodgers, Bryan J. Maloney, Anika M. S. Hartz, Björn Bauer

Pharmaceutical Sciences Faculty Publications

Background: Most preclinical studies on glioblastoma (GBM) fail to provide translational utility in the clinic. Fluorescence-guided surgery using 5-aminolevulinic acid (5-ALA) improves tumor resection, disease prognosis, and, thus, patient outcomes. Given the critical role of surgery in managing recurrent GBM, it is essential to incorporate surgical elements into preclinical models to accurately reflect clinical scenarios and enhance translational success. However, existing protocols for 5-ALA-guided resection in preclinical models are limited and often lack clinical relevance.

Methods: To address this gap, we developed a novel protocol for the 5-ALA-guided resection in two mouse GBM models: TRP-mCherry-FLuc and GL261 Red-FLuc.

Results: The …

Development Of Zafirlukast Analogues For Improved Antithrombotic Activity Through Thiol Isomerase Inhibition, Justine A. Keovilay, Kaitlind C. Howard, Kirk A. Taylor, Sabeeya Khan, Sienna E. Wurl, Melanie K. Szahaj, Tanya Sage, Nishad Thamban Chandrika, Caixia Hou, Oleg V. Tsodikov, Jonathan M. Gibbins, Sylvie Garneau-Tsodikova, Daniel R. Kennedy

Pharmaceutical Sciences Faculty Publications

Background:   Thiol isomerases play essential and nonredundant roles in platelet activation, aggregation, and thrombus formation. Thiol isomerase inhibitors have the potential to overcome the 2 major drawbacks of current antithrombotic therapies, as they target both arterial and venous thrombosis without enhancing bleeding risks. Recently, a Food and Drug Administration–approved drug, zafirlukast (ZAF), was shown to be a promising pan-thiol isomerase inhibitor. The objective of this study is to develop analogues of ZAF with optimized thiol isomerase inhibition and antithrombotic activity.   Methods:   Thirty-five ZAF analogues were tested in an insulin turbidometric assay for thiol isomerase inhibition. Analogues were tested for platelet …

Functional And Structural Studies On The Esperamicin Thioesterase And Progress Toward Understanding Enediyne Core Biosynthesis, Erome D. Hankore, Mitchell D. Miller, Abigael J. Kosgei, Weijun Xu, Kemin Tan, Michael Endres, Minakshi Bhardwaj, Grazyna Joachimiak, Andrzej Joachimiak, George N. Phillips Jr., Jon S. Thorson, Steven G. Van Lanen

Pharmaceutical Sciences Faculty Publications

Enediynes are among the most potent antitumor and antibacterial natural products. Studies on their biosynthetic pathways have identified a shared, linear polyene precursor generated from an iterative type I polyketide synthase (PKSE) as the source of the enediyne warhead. A key step is the release of this polyene from the PKSE by a discrete thioesterase (TE). Here, we used X-ray crystallography, site-directed mutagenesis, and heterologous coexpression of PKSEs and TEs to elucidate how enediyne TEs mediate the production of the polyene. We solved the structure of wild-type EspE7 from esperamicin producer Actinomodura verrucosospora. The substrate binding pocket was also …

Association Between Lifetime Interpersonal Violence And Post– Covid-19 Condition Among Women In Kentucky, 2020-2022, Ayşe Güler, Heather M. Bush, Katie Schill, Nurlan Kussainov, Ann L. Coker

Biostatistics Faculty Publications

Objective: The COVID-19 pandemic increased the risk of interpersonal violence. We investigated the association between lifetime interpersonal violence experience and risk of post–COVID-19 condition (the persistence of symptoms of COVID-19 and severity of health problems associated with COVID-19 that last a few weeks, months, or years) among women with lifetime interpersonal violence experience.   Methods: Women participants aged ≥18 years in Kentucky’s Wellness, Health & You—COVID-19 study completed online quantitative surveys about the impacts of the pandemic, developing COVID-19, and symptoms of post–COVID-19 condition. We conducted cross-sectional analyses estimating rate ratios of developing COVID-19 and symptoms of post–COVID-19 condition during the …

Equatorial Flow Triangulations Of Gorenstein Flow Polytopes, Benjamin Braun, Alvaro Cornejo

Mathematics Faculty Publications

Generalizing work of Athanasiadis for the Birkhoff polytope and Reiner and Welker for order polytopes, in 2007 Bruns and Römer proved that any Gorenstein lattice polytope with a regular unimodular triangulation admits a regular unimodular triangulation that is the join of a special simplex with a triangulated sphere. These are sometimes referred to as equatorial triangulations. We apply these techniques to give purely combinatorial descriptions of previously-unstudied triangulations of Gorensten flow polytopes. Further, we prove that the resulting equatorial flow polytope triangulations are usually distinct from the family of triangulations obtained by Danilov, Karzanov, and Koshevoy via framings. We find …

The Matrixschubert Package For Macaulay2, Ayah Almousa, Sean Grate, Daoji Huang, Patricia Klein, Adam Laclair, Yuyuan Luo, Joseph Mcdonough

Mathematics Faculty Publications

We introduce the MatrixSchubert package for the computer algebra system Macaulay2. This package has tools to construct and study matrix Schubert varieties and alternating sign matrix (ASM) varieties. The package also introduces tools for quickly computing homological invariants of such varieties, finding the components of an ASM variety, and checking if a union of matrix Schubert varieties is an ASM variety.

Root Polytopes, Tropical Types, And Toric Edge Ideals, Ayah Almousa, Anton Dochtermann, Ben Smith

Mathematics Faculty Publications

We consider arrangements of tropical hyperplanes where the apices of the hyperplanes are taken to infinity in certain directions. Such an arrangement defines a decomposition of Euclidean space where a cell is determined by its ‘type’ data, analogous to the covectors of an oriented matroid. By work of Develin–Sturmfels and Fink–Rincón, these ‘tropical complexes’ are dual to regular subdivisions of root polytopes, which in turn are in bijection with mixed subdivisions of certain generalized permutohedra. Extending previous work with Joswig–Sanyal, we show how a natural monomial labeling of these complexes describes polynomial relations (syzygies) among ‘type ideals’ which arise naturally …

Ribbon Schur Functors, Keller Vandebogert

Mathematics Faculty Publications

We investigate a generalization of the classical notion of a Schur functor associated to a ribbon diagram. These functors are defined with respect to an arbitrary algebra, and in the case that the underlying algebra is the symmetric/exterior algebra, we recover the classical definition of Schur/Weyl functors, respectively. In general, we construct a family of 3-term complexes categorifying the classical concatenation/nearconcatenation identity for symmetric functions, and one of our main results is that the exactness of these 3-term complexes is equivalent to the Koszul property of the underlying algebra A. We further generalize these ribbon Schur functors to the notion …

Quantitative Bounds In A Popular Polynomial Szemerédi Theorem, Xuancheng Shao, Mengdi Wang

Mathematics Faculty Publications

We obtain polylogarithmic bounds in the polynomial Szemerédi theorem when the polynomials have distinct degrees and zero constant terms. Specifically, let $A$ .

Koszulity, Supersolvability And Stirling Representations, Ayah Almousa, Victor Reiner, Sheila Sundaram

Mathematics Faculty Publications

Supersolvable hyperplane arrangements and matroids are known to give rise to certain Koszul algebras, namely their Orlik–Solomon algebras and graded Varchenko–Gel’fand algebras. We explore how this interacts with group actions, particularly for the braid arrangement and the action of the symmetric group, where the Hilbert functions of the algebras and their Koszul duals are given by Stirling numbers of the first and second kinds, respectively. The corresponding symmetric group representations exhibit branching rules that interpret Stirling number recurrences, which are shown to apply to all supersolvable arrangements. They also enjoy representation stability properties that follow from Koszul duality.

Sharing Pizza Among A Two Power Number Of Friends, Christian Ehrenborg, Didrik Ehrenborg, Michaël Ehrenborg, Richard Ehrenborg

Mathematics Faculty Publications

We extend the work of Hirschhorn, Hirschhorn, Hirschhorn, Hirschhorn and Hirschhorn on the problem of sharing pizza among several people. More specifically, we present a class of Coxeter arrangements in an even dimension n such that if one cuts a ball containing the origin with one of these arrangements, the slices can be partitioned into 2^n/2 blocks such that each block has the same volume.