University of Tennessee Institute of Agriculture
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Towards Quantum Utility on NISQ Hardware
No full textQuantum utility in the noisy intermediate-scale quantum (NISQ) era requires hardware-focused design to maximize resources and minimize the effects of noise and decoherence. In studying quantum simulation and optimization, this involves choosing the optimal bases, hardware type, and quantum algorithm. In this dissertation, I present past work in 5 projects. The first is a proposition to obtain non-Abelian anyons in the Z2 lattice gauge theory system on neutral atom hardware. We perform numerical simulations of the quantum processor and present a scheme for quantum computation using the anyons. Then we solve the weighted MaxCut and low autocorrelation binary sequences (LABS) problems using the quantum imaginary time evolution (QITE) algorithm, and compare with state of the art classical and quantum methods. In the third project, we solve power grid optimization problems on Rydberg neutral atom hardware using 2 hardware-centric algorithms and benchmark the processor noise. Then, the analog nature of the neutral atom platform is used to study the entanglement dynamics of the critical Ising model and experimentally compute an entanglement witness. Finally, a NISQ-suitable quantum chemistry algorithm is developed for ground state calculations on superconducting quantum hardware and compared to classical methods. To conclude, I give directions for future work
Dynamics Driven Cost Optimization for Hybrid Manufacturing
No full textWhile additive manufacturing (AM) offers many advantages, parts produced by AM may not provide sufficient surface finish and accuracy for all engineering applications. Therefore, machining operations are often required to qualify the final part geometry. The combination of AM and machining is known as hybrid manufacturing (HM). HM uses an AM process, such as laser powder bed fusion (LPBF), to create a preform that is then machined on a computer numerically controlled (CNC) machine tool. The combination of user-selected machining parameters, including radial immersion, axial depth, and spindle speed, determines the effectiveness of the machining operation. Improper combinations may result in chatter, an unstable machining condition caused by self-excited vibrations, or high amplitude vibrations that result in dimensional inaccuracies, known as surface location error (SLE). The effectiveness of the machining process is directly dependent on the flexibility, or compliance, of both the workpiece and the tool-holder-spindle-machine assembly. The dynamics of the workpiece are initially set by the AM preform geometry and continuously change as material is removed during machining.
This work describes a novel framework that simultaneously optimizes the preform geometry and machining parameters. The optimization objective is to minimize HM cost for industrially relevant geometries while avoiding chatter and mitigating SLE. A parametric representation of the preform geometry is coupled with a finite element analysis (FEA) solver to predict evolving preform dynamics as material is removed by machining. A structural shape optimization algorithm is introduced to minimize static compliance for a given amount of preform volume. A numerical, time-domain simulation is then used to select optimal machining parameters. Finally, Bayesian optimization is used to find the optimal preform volume that minimizes HM cos
Durable and Dynamic Building Envelopes: Insulation Performance Longevity and Active Thermal Control
No full textAdvancing building envelope technologies is essential for improving energy efficiency, reducing peak demand, and enhancing resilience under variable climate conditions. In addition to improving the long-term thermal performance of static foam insulation systems, this work explores innovative approaches to active envelope systems that dynamically manage heat flow. Thermally active envelopes can redistribute energy in response to changing weather and indoor conditions, reducing unwanted heat transfer and improving occupant comfort.
Active building envelopes, such as the Thermally Anisotropic Building Envelope (TABE), have demonstrated the ability to harness naturally available thermal energy through integration with thermal storage devices or geothermal loops. To fully realize these benefits, effective control strategies are required to minimize reliance on conventional HVAC systems and stabilize energy demand. This study implements novel reduced-order modeling and predictive control approaches to optimize the performance of active envelope systems. Field demonstrations and simulations across multiple climates show substantial reductions in heating and cooling energy use, peak electrical loads, and overall operating costs.
Collectively, these advancements illustrate a pathway toward next-generation buildings that combine resilience with intelligent thermal management. The results demonstrate how the adoption of advanced building envelope technologies can enhance both building and grid energy security
Nuevo Narratives: Testimonios of Belonging By Latina/o/x College Students in the Nuevo South
No full textThe present study examines the lived experiences of Latina/o/x college students attending large, public, predominantly white institutions (PWI) in the Nuevo South region of the United States. Through a critical lens rooted in LatCrit and Sense of Belonging theory (Strayhorn, 2008), the study observes,analyzes, and tells the complex interplay of identity, power structures, and institutional climates that shape the sense of belonging among Latina/o/x students. Utilizing narrative inquiry and testimonio as methodology, the study captures the individual and collective voices and experiences of 12 self identified Latina/o/x college students
The Humanistic Application of Non-Euclidean Geometry: A Transparent Social Network Analysis
No full textThis three-manuscript dissertation uses social network analysis to examine distributed leadership as a pedagogical tool to support student-to-student collaborations in undergraduate geometry. The first manuscript is a macro-level literature review of current research on distributed leadership through social network analysis. The second manuscript is a meso-level, empirical study of one undergraduate geometry course. The third manuscript is a micro-level autoethnography utilizing non-Euclidean geometry to critically examine my experiences as a transparent through a time of political unrest in the south. Together, the three manuscripts provide a scoping review of how distributed leadership is operationalized in the educational setting through social network analysis, empirical observation of how distributed leadership was implemented in pedagogical practice, and liberatory methodologies that offer new applications to express one’s identity in mathematics
Participation Factor-Based Model Reduction and Partitioning for Accelerating Power System Simulations
No full textThe increasing deployment of Inverter-Based Resources (IBRs) introduces fast dynamics such as sub-synchronous oscillations (SSOs), fault ride-through events, and stability challenges that are often inadequately captured by traditional phasor-domain simulators. Accurate representation of these dynamics necessitates computationally intensive electromagnetic transient (EMT) simulations. A practical solution is to focus EMT simulations on a localized critical zone—typically containing IBRs, generators, and associated network elements—while representing the rest of the system with simplified equivalents.
This research proposes a novel framework for EMT boundary determination and model reduction by leveraging both linear and nonlinear participation factors (PFs). Linear PFs are used to identify critical states for model simplification, while nonlinear PFs, computed using normal form theory, help capture higher-order dynamic interactions in near-resonant conditions. To enable scalable computation of high-order NPFs, a tensor contraction–based approach combined with a dynamic batching strategy is introduced, allowing memory-efficient computation up to arbitrary expansion orders.
For systems exhibiting time-periodic behavior—common in EMT simulations—a Floquet theory–based method is developed for PF calculation and EMT boundary determination. This method captures modal behavior across harmonics by analyzing the system over a single 60 Hz cycle, enabling efficient detection of SSOs and informing boundary placement. A data-driven version of this method is also proposed, requiring one cycle time-domain responses for PF computation, making it applicable to black-box models. Furthermore, a mathematical connection is established between participation factors in linear time-invariant (LTI) and linear time-periodic (LTP) systems, revealing that phasor-domain PFs are a special case corresponding to the zero-harmonic component in the broader Floquet-based framework.
Collectively, this dissertation aims to lay the foundation for more accelerated while accurate simulation of modern power systems with high IBR penetration, enabling new model reduction approaches, advanced boundary determination, and data-driven dynamic analysis
Development and characterization of a portable electrochemical aptasensor for Staphylococcus aureus detection in food matrices
No full textAlthough foodborne illnesses are often perceived as preventable, contamination by Staphylococcus aureus (S. aureus) remains a critical public health and food safety challenge. S. aureus produces heat-stable enterotoxins that resist conventional cooking and processing methods, making its detection and control difficult. Traditional laboratory techniques such as culture, enzyme-linked immunosorbent assay (ELISA), or polymerase chain reaction (PCR) are accurate but often slow, expensive, and impractical for on-site food monitoring. Outbreaks may go undetected until it is too late, posing serious health risks and economic losses.
Rapid, accurate, and portable detection methods are needed to bridge this gap. In this work, we developed a novel electrochemical aptasensor for real-time detection of S. aureus in food matrices. Aptamers are short, single-stranded oligonucleotides that bind specific targets with high affinity and are employed as biorecognition elements. Our aptasensor integrates gold nanoparticles (AuNPs) onto screen-printed carbon electrodes (SPCEs) that bind to aptamers specific to the IsdA protein (a key surface biomarker of S. aureus), serving as the biorecognition element and offering high selectivity and sensitivity. The sensor\u27s performance is validated by cyclic voltammetry (CV) and impedance spectroscopy (EIS), while scanning electron microscopy (SEM) and fluorescence imaging confirm its structural and functional properties.
To deepen the understanding of aptamer–target interactions, we performed kinetic and equilibrium studies directly in real food matrices, extracting binding constants, maximum binding capacity, and association/dissociation rates. These analyses revealed the sensor’s quantitative performance under realistic conditions, providing insight into binding behavior and supporting rational biosensor design. To further support field deployment, we introduce a smartphone-compatible system for data acquisition and real-time interpretation, using machine learning algorithms to analyze complex voltammetry signals. We also fabricated a novel electrode system using alternative nanomaterials, such as silver nanoparticles (AgNPs) and titanium dioxide nanoparticles (TiO2NPs), and compared them with AuNPs to improve the aptasensing performance.
This research lays the foundation for a portable, low-cost, high-performance biosensor capable of early detection of S. aureus. This platform can help reduce food recalls, enhance consumer safety, and guide the future development of biosensors targeting a broad range of pathogens across clinical, environmental, and industrial domains
Experimental Investigation of Cylinder Back-Pressuring Effects on Isolator Shock Train Dynamics
No full textThe operational viability of dual-mode scramjet (DMSJ) engines across a wide Mach range depends on the isolator\u27s ability to condition the flow for combustion while maintaining sufficient margin against inlet unstart. Experimental simulations of isolator back-pressure rise due to combustion often rely on methods that decouple the shock train response from the back-pressuring device itself. While useful for simulating gross pressure rise due to combustion heat release, these approaches fail to fully capture the coupled nature of three-dimensional, shock interaction effects that would be generated by a fuel injection flow blockage. The work presented here aims to address this knowledge gap by quantitatively assessing the formation process, propagation characteristics, and inherent unsteadiness of a shock train using a three-dimensional back-pressuring device.
Experimental testing of a shock train was conducted in the Mach 2.2 UTSI direct-connect isolator facility. Back-pressure was generated using a floor-mounted cylindrical rod inserted perpendicular to the flow at the exit plane of the isolator. The choice of a cylindrical rod was motivated by its known shock-feature similarity to a flush-wall fuel injector. Floor surface pressure measurements and optical diagnostic techniques including high-speed background-oriented schlieren and fast-response pressure sensitive paint were performed, and quantitative time-histories of shock features were extracted from the optical imagery using a custom tracking algorithm. Shock train unsteadiness and identification of the underlying propagation mechanism was analyzed using results from zero-crossing frequency estimates and cross-correlation of the tracked shock signals.
This work reveals the strong coupling between shock train behavior and three-dimensional back-pressuring, evidenced by distinct shock train propagation phases within the isolator that originate from cylinder-induced boundary layer separation events. The intentionally simple method of using a floor-mounted cylinder as a back-pressuring device was designed to integrate multiple, and previously isolated, research areas. Specifically, the cylindrical-rod representation of flow blockage caused by flush-wall fuel injection, the unsteady physics of cylinder-induced shock boundary layer interactions, and the complex sensitivity of shock train propagation to back-pressure effects all converge in this work, providing crucial insights into shock train stability and control strategies for the future development of robust DMSJ propulsion systems
A Game of Telephone: Mid-Managers\u27 Experiences Transitioning from Dissent Audience to Dissenter
No full textMid-managers are a commonly sought dissent audiences for subordinates expressing dissent about an organizational policy, practice, or procedure (Garner, 2016; Kassing, 2011). Resolving the subordinate’s dissent, however, might be out of the mid-manager’s power causing them to pass along the subordinate’s dissent to upper management or another organizational member. This research study sought to understand mid-manager’s dissent experiences of being dissented to by a subordinate, lacked the ability to act upon the dissent, and transitioned to a dissenter passing the subordinate’s dissent to another organizational member. Drawing on 20 interviews of mid-managers, this study found that mid-managers experienced a tension between emotions and rational thought when dissented to by the subordinate, went through a stage of preparation including information seeking and advice seeking to manage the uncertainty of what to do with the subordinate’s dissent, went outside of the traditional hierarchical chain of command to another organizational member (e.g., human resources) to express dissent, and conveyed the outcome of dissent with the subordinate through sensegiving. Theoretical implications for the field of organizational dissent and practical implications for mid-managers will be discussed
MENTAL HEALTH PROFESSIONALS’ NON-CLINICAL ROLES AS INFORMED BY ATTACHMENT: A SYSTEMATIC REVIEW OF RESEARCH
No full textWhile attachment informs the quality of the therapeutic relationship, which is the basis of all therapeutic work for professional counselors and related mental health professionals (MHPs), less attention has been given to the role of attachment in MHPs’ non-therapeutic roles such as engagement in professional development, teaching, and supervision. This systematic review analyzed 33 research studies that investigated MHPs’ attachment in the context of non-therapeutic roles, including professional development, supervision, and teaching. Findings are discussed in the context of four emergent themes: Professional Functioning and Well-being, Supervisory Relationships, Self-awareness, and Empathy. There is considerable evidence that MHP attachment style is relevant across professional roles. Findings are discussed, implications for counselor education and supervision practice are identified, and recommendations for additional research are provided