Engineering Commons^™

A Nonlocal Lattice Particle Method For Modeling Hcp Polycrystalline Solids, Di Liu

University of Kentucky Doctoral Dissertations

Polycrystalline materials, composed of individual grains with varying grain size, shape, and crystallographic orientation are widely used in various engineering and industrial applications. Conventional applications of polycrystalline materials rely on the macroscopic performance, and the microstructural features are usually homogenized out. With the advancement of modern technologies and improvement of characterization methods, polycrystalline materials find their applications in meso- and micro-scale systems. At these length scales, the microscopic features including grain boundary characteristics significantly affect the material physical responses. As a result, the conventional continuum mechanics models become problematic, especially for material failure problems where the microstructural features play dominant …

Non-Invasive Digital Restoration Of Damaged Photographic Film Negatives, Ankan Bhattacharyya

University of Kentucky Doctoral Dissertations

Physical restoration of damaged photographic film causes more damage. Also, existing non-invasive digital restoration of film negatives does not produce print-quality optical images. Instead, they produce X-ray projections, which are not the same as optical projections. This thesis addresses these problems and establishes a framework that can digitally restore old, damaged films without the need to open them physically. Virtual Unwrapping is an existing pipeline that has proven itself over the last couple of decades to work on unopenable papyrus scrolls, like the Herculaneum Scrolls. This thesis utilizes the concept of virtual unwrapping to restore damaged photographic film negatives. Due …

Frequency And Phase Synchronization Of Antenna Arrays With Phase Incoherent Microcontrollers, Harley W. Byrd

University of Kentucky Master's Theses

The construction of phased array antennas has traditionally been an expensive and complex task. It has recently been claimed that it is possible to construct high-performance Wi Fi antenna arrays using inexpensive consumer components. Motivated by some limited data available from online presentations of such devices, this thesis covers an attempt to construct a phased-array Wi-Fi antenna using several ESP32 chips, which have native Wi-Fi modulation and demodulation capabilities. While there are many positive aspects associated with utilizing ESP32 chips for this purpose, a key challenge is the inherent phase incoherence of their internal Phase Locked Loops (PLLs). The approach …

Development Of An Atmospheric Particle Imaging System (Apis), James W. Hebert

University of Kentucky Master's Theses

The study of atmospheric particulates plays a crucial role in both climate change studies and the improvement of hypersonic travel. The current issue at hand is a lack of knowledge of stratospheric particulate content and the high cost that is associated with conducting research at these altitudes. This project focuses on the development of an Atmospheric Particle Imaging System (APIS) to be a low-weight, low-cost optical payload. The goal is to make a device that can be mounted onto an uncrewed aerial system that has the capability of imaging particulates moving at steady flow velocities, and thereby characterize the individual …

Impact Of In-Cabin Human Machine Interface Designs On Passenger Trust In Urban Air Mobility, Ricole A. Johnson, Erika E. Gallegos

Journal of Aviation/Aerospace Education & Research

Urban Air Mobility (UAM) presents a promising solution for alleviating urban traffic congestion and enhancing transportation efficiency. However, the widespread acceptance of UAM, particularly sustained ridership of autonomous passenger air vehicles (PAVs), is contingent upon addressing critical human factors for building passenger trust, especially in the absence of a human pilot. This paper evaluates how different in-cabin human-machine interface (HMI) designs affect passenger trust in the aircraft and in-cabin display, situation awareness, and pilot preferences. Forty participants, equally split between early and late technology adopters, completed two simulated flights: a baseline flight with no HMI and a second flight featuring …

Instructional Fidelity In Virtual Flight: Applying A Structured Learning Model For Vr-Based Pilot Training, Lindsay Gouedy, Bryce Jarrell, Mary Fendley, Brandon Wolf

Journal of Aviation/Aerospace Education & Research

As immersive training technologies reshape the future of aviation education, this study explores the impact of integrating Virtual Reality (VR) into a structured instructional model for B-52 pilot training. With the development and implementation of the I-BUFF (Integrated B-52 Unit Flight Familiarization) model, an innovative framework built upon the 4C/ID (Four Component Instructional Design) and SEEV (Salience, Effort, Expectancy, Value) models, this research evaluates whether structured VR environments improve training transfer and accelerate task proficiency for in-air refueling tasks. A sample of 233 pilot trainees was assessed across three groups: traditional training (non-VR unstructured), VR semi-structured, and VR fully structured …

The Role Of User Experience In Virtual Reality Flight Training: A Comparison With Pc-Based Simulation, Tianxin Zhang, Christina M. Frederick, Barbara Chaparro

Journal of Aviation/Aerospace Education & Research

The current project explores how user experience (UX) in virtual reality (VR) flight simulation influences both cognitive learning outcomes and procedural skill acquisition when compared to traditional desktop-based simulation.. Using a quasi-transfer of training design, 48 student pilots were randomly assigned to VR, Desktop, or Control groups and trained on the Chandelle maneuver. UX was measured with the User Experience Questionnaire (UEQ), while training effectiveness was evaluated through a post-training knowledge test and recorded maneuver performance on a high-fidelity flight training device. Results indicated that the VR group reported significantly higher UX scores in Attractiveness, Stimulation, and Novelty, and showed …

Utilising Video Recordings To Assess Student Pilot Performance: An Exploratory Study During A Simulated Training Flight, Bradley Moncion, Shi Cao, Allison Lynch, Suzanne K. Kearns, Elizabeth Irving, Ewa Niechwiej-Szwedo

Journal of Aviation/Aerospace Education & Research

In ab initio flight training, the quality of the feedback a flight instructor provides their student is essential to their success. While other high-performance and safety-critical industries have incorporated the use of video recordings into training and assessments, the aviation industry generally has not. There are some studies addressing the potential benefits of video recordings in training professional pilots, but there is a lack of research at the ab initio level. In this study, five flight instructors assessed the performance of student pilots conducting a simulated training flight using a 4-point marking scale. The flights instructors were then tasked with …

Evaluation Of Tactile Cueing Embedded In An Aviation Headset On Pilot Altitude Control, Nicholas D. Wilson, Jessica Van Bree, Matthew Cleveland, Sunny Charakuru, Thomas Petros, Richard Ferraro, Kouhyar Tavakolian

Journal of Aviation/Aerospace Education & Research

This study evaluated the effectiveness of tactile cueing integrated into a pilot’s headset on pilot altitude control during simulated instrument conditions. Pilots typically rely on visual and auditory inputs to maintain situational awareness, but in high-workload or instrument meteorological conditions (IMC), these channels can become overloaded. One underutilized alternative for alerting is a tactile cueing apparatus. Using an X-Plane simulation of a Piper Archer equipped with a G-1000 avionics suite, 39 FAA-certified pilots flew two precision approaches. The experimental group (n = 20) received haptic cues via ear seal-embedded tactors when deviating from assigned altitude or glideslope. The control group …

Navigating The Challenges: Preflight Planning With Notam In Australia’S General Aviation Sector, Joshua Chiang, Guido Carim Junior

Journal of Aviation/Aerospace Education & Research

Notices to Airmen (NOTAMs) are an integral part of a pilot’s preflight navigational briefing, providing pertinent information in textual format. However, significant shortcomings have been found in the NOTAM system and in its use, with many of the shortcomings revolving around the interface. This study aimed to identify and evaluate the challenges general aviation pilots face when interacting with NOTAMs during preflight navigational planning. A thematic analysis study was conducted and included episodic semi-structured interviews with 15 pilots and document analysis. The interview transcription and excerpts of NOTAMs were analyzed following a thematic analysis technique. The findings of this preliminary …

Manufacturing And Performance Evaluation Of Carbon/Epoxy Laminated Composites Cured Using Single- And Six-Magnetron Microwave Applications, Nayan Pundhir

Doctoral Dissertations

Microwave curing is fast, energy-efficient, and a viable alternative to conventional thermal curing processes. It has been widely adopted for processing carbon fiber-reinforced polymer (CFRP) composites because the high electrical conductivity of carbon fibers enables strong microwave coupling, leading to rapid volumetric heating and reduced energy consumption. The aim of this study is to investigate the use of microwave curing for manufacturing CFRP composites. IM7/Cycom 5320-1 unidirectional prepreg was utilized to fabricate laminated composites in two thickness ranges: 16-layer laminates (2.5 mm thickness) and 64-layer laminates (9.2 mm thickness). Two lay-up configurations were examined: symmetric cross-ply and quasi-isotropic. Different curing …

Strontium Titanate For Capacitor And Energy Storage Applications At Cryogenic Temperatures, Hung Trinh

Doctoral Dissertations

This study investigates the dielectric properties of single crystal and ceramic strontium titanate (SrTiO₃) for cryogenic capacitor applications from room temperature to 4 K. Permittivity (k) and loss tangent are dependent on temperature, frequency, mechanical stress, and applied DC electric field. Accordingly, the dielectric constant and loss tangent were measured at various frequencies and DC bias levels. Loss tangent data are also presented as equivalent series resistance (ESR). For single crystal SrTiO₃, an impurity level of ≈500 ppm barium resulted in an increase of the maximum permittivity to approximately 50,000 at 6 K. This relatively high …

Architecting A Complex Adaptive System Model For Selecting Policies To Reduce Kidney Discard, Lirim Ashiku

Doctoral Dissertations

"The kidney allocation system is a complex, evolving system involving multiple heterogeneous agents. Each agent exhibits emergent behavior that may not fully align with the complex system goals. Therefore, there is a need for a transdisciplinary systems approach to visualize the interdependency among agents and understand the dominant patterns that shape the kidney allocation system.

First, this research presented an incremental hierarchical system engineering approach in identifying the agents’ needs and behaviors toward the complex systems’ goal of maximizing deceased donor kidney utilization and reducing kidney discard. The hierarchical systems approach linked with model-based system engineering aided in eliciting agents’ …

Integrating Stakeholder Priorities Into Resilience Planning And Investment Decision-Making, Victoria Jeaneen Kraemer

Doctoral Dissertations

"Resilience is a system’s ability to bounce back from a disruption. However, resilience needs may vary across different stakeholders. To better integrate stakeholder input into resilience planning and investment decision-making, existing frameworks were combined to develop the Integrated Stakeholder-Centered Resilience Framework. This broad framework is tailorable across contexts and stakeholder types. Research results demonstrate the use of this framework to evaluate the effects of disruptions and represent stakeholder preferences for investments. In the first study, participants were randomly assigned to power outage scenarios, which did not affect their criteria priorities. An exploratory factor analysis revealed two main priorities, (1) Absorption …

Senescent Fibroblasts In Aging And Pulmonary Fibrosis, Sara B. Palega, Aiwei Y. Borengasser, Yan Y. Sanders

Department of Biomedical and Translational Sciences Faculty Publications

Aging is a major risk factor for many chronic lung diseases, including Idiopathic Pulmonary Fibrosis (IPF), a fatal and incurable disease characterized by progressive fibrotic remodeling. Age-associated structural alterations, impaired regenerative capacity, and dysregulated cellular signaling collectively create a pro-fibrotic microenvironment. A central driver of this pathological shift is the accumulation of senescent cells, which undergo irreversible growth arrest and develop a robust pro-inflammatory senescence-associated secretory phenotype (SASP). Emerging evidence identifies senescent lung fibroblasts as critical mediators of IPF pathogenesis. These cells promote excessive extracellular matrix deposition, myofibroblast differentiation, and tissue stiffening, while simultaneously impairing epithelial regeneration. Together, these effects …

H2 Matrix Compression For Fast Magnetic Field Post-Processing, Calvin M. Demps

University of Kentucky Master's Theses

Large-scale computational electromagnetic simulations frequently require the assembly of dense system matrices, whose computation time and memory cost grow rapidly with problem size and can render high-resolution simulations impractical. This thesis presents a benchmark of the H² hierarchical matrix method applied to the construction of a coupling matrix that maps magnetization current in a structure to the magnetic field at observation points external to the structure. The underlying field interaction is derived from Maxwell's equations and discretized using a Nyström approach, producing a dense matrix.

The method is benchmarked across various geometries of increasing complexity and for increasing mesh …

Enhanced Hydrophilicity And Self-Cleaning Properties Of Tio₂ Thin Films On Glass For Photovoltaic Applications: Influence Of Precursor Concentration And Light Irradiation, Fatma Refaat, Hany Hashem, Mohamed Mahmoud Gouda, Ibrahim Ahmed, Khaled Abdelwahed, Ahmed Bakr El Basaty

Trends in advanced sciences and technology

This study investigates the modification of glass substrates with TiO₂ thin films to enhance surface hydrophilicity and self-cleaning behavior. The films were deposited on glass by spin coating using different precursor concentrations, followed by thermal treatment. Structural and optical properties were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and UV–Vis spectroscopy, while surface wettability was evaluated through water contact angle measurements. XRD confirmed the formation of pure anatase TiO₂, while FTIR spectra verified the presence of Ti–O and Ti–O–Ti bonds. Wettability analysis showed that films prepared with the lowest precursor concentration exhibited the …

Construction-Phase Leed Compliance In Egypt: Development Of A Rule-Based Expert System For Contractor Decision Support, Mohamed R. Ahmed, Atef A. Ragab, Sameh Y. Mahfouz

Mansoura Engineering Journal

This study develops a rule-based expert system implemented in Python to support contractors in achieving LEED BD+C: New Construction v4 certification during the construction phase in Egypt. The research identifies and validates construction-phase obstacles affecting LEED compliance through a structured questionnaire targeting building contractors in Egypt. The questionnaire process was conducted in two stages: a pilot survey was used to screen and refine the initially identified obstacles, while the main survey was used to validate the practical relevance of the retained obstacles within the Egyptian construction context. In parallel, the study analyzes construction-phase prerequisites and credits relevant to contractors through …

Enhancing Traffic State Estimation At Bottlenecks Through Improved Demand Modeling: A Greenshields-Grounded Approach, Yuyan Annie Pan, Xianbiao Hu, Qing Tang, Yanyan Chen, Xuesong (Simon) Zhou

Civil & Environmental Engineering Faculty Publications

Accurate estimation of traffic state under oversaturated conditions is fundamental to a wide range of transportation applications. While intuitive, volume-to-capacity (q/qc) ratio-based link performance functions (LPF) are challenged by the U-shaped pattern of real-world speed-flow plots, which contradict the monotonic assumptions of link performance models such as the Bureau of Public Roads (BPR) function, particularly when q/q_c ≥ 1. This study addresses this critical gap by proposing an enhanced demand estimation method grounded in the Greenshields model, incorporating a real-time inflow correction factor to more accurately capture traffic demand at bottlenecks. In parallel, a modified LPF is introduced, replacing …

Optimizing Maintenance Routes For Highway Infrastructure Using Leader-Follower Autonomous Vehicles, Qing Tang, Chenxi Chen, Xianbiao Hu, Yuxin Ding, Tianjia Yang

Civil & Environmental Engineering Faculty Publications

The Autonomous Truck Mounted Attenuator (ATMA), a leader–follower style connected and automated vehicle system, enhances safety during transportation infrastructure maintenance in work zones. However, the significantly lower speed of ATMA, compared to regular vehicles, causes moving bottlenecks that reduce roadway capacity and prolong queuing, leading to further delays. Different ATMA routes lead to varying patterns of time-dependent capacity drop, affecting the user equilibrium traffic assignment and resulting in differing system costs. This study aims to optimize ATMA routing within a network to minimize the system cost associated with its slow-moving operation. To this end, a queuing-based traffic assignment approach is …

Element-Based Predictive Modeling Of Hydrothermal Liquefaction Bioproducts Derived From Corn Stover, Isamu Umeda, Meicen Liu, Yi Zheng, Jiefu Wang, Zhiwu Wang, Sandeep Kumar

Civil & Environmental Engineering Faculty Publications

The hydrothermal liquefaction (HTL) process offers an energetic advantage over pyrolysis because it does not require prior drying of the biomass feedstock. However, there are significant challenges in simultaneously estimating both the yields and characteristics of products from the HTL of biomass with theoretical support. This study developed a unique element-based kinetic model to predict the yields, higher heating values, and fuel characteristics of solid residue and heavy bio-oil, based on the temperature, residence time, solid loading, and elemental composition (C, H, N, and O) of corn stover. Furthermore, the model predicted the weights of dissolved carbon and nitrogen in …

Harnessing Activated Sludge For The Treatment Of Hydrothermal Liquefaction Wastewater: A Proof-Of-Concept Study, Cyrus Li, Jiefu Wang, Meicen Liu, Yi Zheng, Sandeep Kumar, Isamu Umeda, Chandan Mahata, John Norton

Civil & Environmental Engineering Faculty Publications

Although hydrothermal liquefaction (HTL) is the leading technology in converting wet biomass into bioenergy, the treatment of its toxic-laden aqueous phase wastewater presents a major challenge on its path toward commercial viability. This study presents the first-ever assessment of sewage sludge-fed HTL wastewater (SS-HTLWW) treatment and toxic compound removal using municipal activated sludge (AS) by optimizing its cultivation condition. It was found that AS with optimized pretreatment can remove up to 91.2% of the soluble chemical oxygen demand (sCOD) in SS-HTLWW, of which up to 82% can be attributed to biological mineralization and adsorption of sCOD by AS. Conventional bioprocess …

Nonstationary Spatial Correlation Of Earthquake Ground Motions In California, Pengfei Wang, Busra Bocekli, Junhui Yang, Scott J. Brandenberg, Jonathan P. Stewart

Civil & Environmental Engineering Faculty Publications

Assessing seismic risk to spatially distributed infrastructure systems requires realistic representations of spatially correlated ground motions. Existing models for the spatial correlations of ground motions rely on strong second-order stationarity assumptions, under which the correlation structure is assumed to be invariant across space, potentially masking regional variations. Because repeatable site and path effects can vary spatially, the resulting correlation structure is likely to be nonstationary. We propose a nonstationary spatial correlation method that captures geographically varying correlation decay behavior. We compute site-to-site Pearson correlations of within-event residuals using earthquakes recorded at both sites in each site pair and model the …

When Slides Replace Thinking: How Powerpoint Culture Undermines Conceptual Learning In Engineering Education, Shahin Nayyeri Amiri, Hamid Eisazadeh

Civil & Environmental Engineering Faculty Publications

Engineering education has gradually shifted from deep conceptual teaching to a culture dominated by presentation slides. In many universities today, core courses such as Statics, Dynamics, and Mechanics of Materials are taught through PowerPoint files rather than through reasoning, derivation, and problem solving. While slide-based instruction may appear efficient, it encourages passive learning and has severely weakened students’ ability to think independently and make sound engineering judgments. Traditionally, these fundamental courses were taught by seasoned instructors who had mastered the subjects and took genuine pride in explaining complex ideas with clarity and passion. They guided students through the logic behind …

Nature-Based Solutions For Urban Resilience And Environmental Justice In Underserved Coastal Communities: A Case Study On Oakleaf Forest In Norfolk, Va, Farzaneh Soflaei, Mujde Erten-Unal, Carol L. Considine, Faeghe Borhani

Civil & Environmental Engineering Faculty Publications

Climate change and sea-level change (SLC) are intensifying flooding in U.S. coastal communities, with disproportionate impacts on Black and minority neighborhoods that face displacement, economic hardship, and heightened health risks. In Norfolk, Virginia, sea levels are projected to rise by at least 0.91 m (3 ft) by 2100, placing underserved neighborhoods such as Oakleaf Forest at particular risk. This study investigates the compounded impacts of flooding at both the building and urban scales, situating the work within the framework of the UN Sustainable Development Goals (UN SDGs). A mixed-method, community-based approach was employed, integrating literature review, field observations, and community …

Co-Sputtered Cuni Heteroatomic Electrocatalyst For Enhanced 5-Hydroxymethylfurfural Selective Electrochemical Conversion, Moumita Dikshit, Baleeswaraiah Muchharla, Luz Vazquez Rivera, Kapil Kumar, Sunita Sanwaria, Kishor Kumar Sadasivuni, Abdennaceur Karoui, Sandeep Kumar, Adetayo Adedeji, Bijandra Kumar

Civil & Environmental Engineering Faculty Publications

The electrochemical conversion of biomass-derived 5-hydroxymethylfurfural (HMF) represents a promising, economically viable, and environmentally sustainable approach for producing value-added chemicals using renewable energy and in situ hydrogen generated through water electrolysis. However, the electrochemical hydrogenation (ECH) of HMF remains challenging due to the inherently low catalytic activity and selectivity of the electrodes, compounded by competition with the kinetically favored hydrogen evolution reaction (HER) in aqueous electrolytes. In this work, we demonstrate that Cu_xNi_100-x heteroatomic thin films, fabricated via direct current (DC) magnetron co-sputtering, achieve a more than one order of magnitude increase in the HMF to 2,5-Bis-hydroxymethylfuran …

Iuse: A Gamified Virtual Learning Platform For Connected Vehicle Applications To Enhance Undergraduate Transportation Education, Tianyu Shen, Di Yang, Kai Sun, Hong Yang, Kun Xie, Mansoureh Jeihani

Civil & Environmental Engineering Faculty Publications

Emerging transportation technologies are rapidly reshaping transportation systems and industry practice. However, most transportation undergraduate curricula still emphasize foundational topics such as geometric design, travel demand forecasting, pavements, and soil properties, typically delivered through lecture-centric instruction. While these subjects remain essential to the discipline, they do not fully reflect the pace of technological change or provide sufficient opportunities for experiential learning with modern tools and data. This gap limits students’ exposure to CV concepts and their ability to translate theory into practice.

Focusing on a key emerging technology, connected vehicles (CVs), this paper bridges the above gap by introducing a …

Multi-Isotope Tracing Reveals Nitrate And Sulfate Sources And Fate Across Contrasting Activity Zones In A Semi-Arid Basin Of Northern China, Chang Yue, Ruizhong Gao, Limin Duan, Tianke Su, Xixi Wang, Tingxi Liu, Guoqiang Wang

Civil & Environmental Engineering Faculty Publications

In semi-arid surface water-groundwater systems, nitrate (NO₃^–) and sulfate (SO₄²^–) are jointly influenced by natural processes and anthropogenic activities, yet how their sources, transformations, and export vary across contrasting activity zones remains insufficiently understood. Integrating hydrochemistry, multiple stable isotopes, a Bayesian isotope mixing model, and representative-section flux analysis, this study investigated the source compositions, transformation processes, and export differences of NO₃^– and SO₄²^– in the Dahei River Basin.   New hydrological insights for the region: Results showed greater SO₄²^– enrichment in high-activity zones, whereas NO₃^– exceedance was more prominent in low-activity zones. In …

Short-Term Response Mechanisms Of Water Quantity And Quality Of Daihai Lake Under Temperature-Driven Changes, Hao Zhang, Xiaohong Shi, Xianhua Li, Junping Lu, Ruizhong Gao, Xixi Wang, Shuhao Zhang, Longmei Xie, Yu Liu

Civil & Environmental Engineering Faculty Publications

Temperature-driven mechanisms involving complex feedback and lag that affect the evolution of hydrological processes and ecological functions in cold- and arid-region lakes represent a core scientific issue in current hydrology and lake ecology research. In this study, based on month-scale temperature and environmental factor data from Daihai Lake in Inner Mongolia from January to December 2023, statistical methods (redundancy analysis, Tukey's test analysis, correlation analysis, structural equation modeling), time series analysis methods (dynamic time warping), and machine learning methods (random forest) were combined. A hierarchical and phased response framework was constructed that encompassed driver identification, path tracing, lag characterization, and …

Modeling Hepa Filter Media Performance And Evaluation Of Filtration Leak Test Success, Daniel M. Abraham, Steven J. Eckels, Shahin N. Amiri

Civil & Environmental Engineering Faculty Publications

This research presents a cost-effective microscale modeling analysis of high-efficiency particulate air (HEPA) filter media. We analyzed leak-free and leaking media with known leak sizes. A three-dimensional fibrous model with non-homogeneous fiber diameters (0.2–2 µm) and a packing density of 7.5% was developed to replicate a HEPA filter sheet (H14) microstructure. The objective was to simulate and analyze the pressure drop and collection efficiency of nanofibrous media for aerosol particles with a diameter of d_p ≤ 0.5 µm. The results were compared to prior experimental and theoretical models, exhibiting a high level of agreement with pressure drop and efficiency …