Engineering Commons^™

Investigation Of Low-Pressure Mercury Lamp System Configurations And Xenon Excimer Lamp System Development As Vacuum Ultraviolet Sources For Optimal Photolytic Degradation Of Poly-/Perfluoroalkyl Substances, Eman Zuhair Alhamdan

All Dissertations

PFAS are persistent synthetic chemicals, with unique properties that enable them to easily enter and accumulate in water sources. Their public health impacts have raised concern and highlighted the need for effective treatment. Numerous techniques for PFAS removal from water have been studied, few have proven the ability of breaking down PFAS rather than separating and concentrating it. Many of these methods are chain-length dependent, showing slower degradation rate of short-chain PFAS and requiring substantial amounts of energy, and chemical agents that may produce byproducts.

Among available PFAS destruction methods, direct photolysis by high-energy UV with wavelength below 200 nm …

Safe Control Design For Quadruped Locomotion In Unstructured Environments Using Linear Transfer Operators, Sriram Sundar Krishnamoorthy Shankara Narayanan

All Dissertations

Deploying quadruped robots in unstructured, obstacle-rich environments requires control and planning methods that remain safe and reliable despite complex terrain geometry, limited sensing, and inevitable modeling errors. This thesis develops operator-theoretic tools for safe control design of robotic systems using linear transfer operators, with a focus on quadruped locomotion in unstructured environments. The central goal is to develop a unified operator-theoretic framework for safe control design based on the Perron–Frobenius (P–F) and Koopman operators. In particular, the thesis leverages \emph{density functions} to develop safe navigation frameworks in the dual space of densities. In the operator-theoretic perspective, the P–F operator governs …

Interplay Between Phase Instability And Deformation Mechanisms In Beta Titanium Alloys In Aggressive Environments, Benjamin Elbrecht

All Dissertations

Modern designs, such as commercial jet turbines, are reliant on the high temperature performance of their constituent materials. Improvements to the strength-at-temperature of materials are critical to the continued advancement of efficiency and payload capacity in these advanced applications. This dissertation presents studies that progress towards this goal through the construction of a new experimental setup for complex temperature and force profiles that also accurately captures deformation behavior through non-contact measurements. Using this setup, studies into two specialty titanium alloys were executed: discovering the microscopic mechanisms responsible for the macroscale behavior and testing in conditions closely replicating aircraft turbine operating …

Learning Global Context For Sparse Activity Recognition In Lengthy Recordings With Limited Dataset Size, Zeyu Tang

All Dissertations

This dissertation describes methods to analyze lengthy recordings of data in order to detect sparsely occurring activities. The narrative below describes the progression of research that led to the development of these methods and their generalization into a unified framework. My research started with designing models for dietary monitoring, including detecting meals from day-long recordings and detecting intake gestures from meal-length recordings. Both tasks share some common characteristics: (a) the target event takes only a small portion of data recordings, and (b) there is global context within full-length data recordings that can help a model make better decisions. After finishing …

Experimental And Computational Investigation Of The Effects Of Neck Musculature During Head Impacts In American Football, Anthony P. Marino

All Dissertations

Anthropometric test devices (ATDs) are human surrogate models used to represent the human body response in the context of compliance and safety testing. These devices are used in multiple industries, including automotive and aerospace, and have recently been incorporated into impact testing for the evaluation of helmet performance in American football. The Hybrid III 50^th percentile male ATD head and neck assembly is the most commonly used surrogate for these tests, although it was developed for automotive frontal crash scenarios that induce an inertial force on the body, leading to head and neck motion primarily in the sagittal plane. …

Decision Making For Large-Scale Problems Under Uncertainty And Conflict, Benjamin J. Hamlin

All Dissertations

Large-scale decision-making problems appear in many areas including long-range forecasting such as energy generation forecasting. Many such problems are subject to conflicting objectives and uncertain data, and can be modeled as linear optimization problems. We study novel theoretical results and algorithms for large-scale linear decision problems under conflict and uncertainty. First, we propose a parametric Benders decomposition algorithm for solving large-scale linear optimization problems with multiple objectives or deterministically uncertain objectives. Second, we extend the parametric Benders decomposition to a multi-stage setting, developing a parametric stochastic dual dynamic programming algorithm, which enables decision-making when conflicts and uncertainty have planning impacts …

Modernizing Plastics And Composites Manufacturing Using Hybrid Modeling Techniques, Luke Shannon

All Dissertations

Plastics and composites manufacturing encompasses a broad family of processes, including injection molding, resin transfer molding, compression molding, and extrusion, that together account for the vast majority of polymer and composite component production worldwide. These processes are inherently challenging due to the multi-physics nature of polymer processing, the vast possible combinations of resins, reinforcements, and additives, and the strong dependence of final part properties on process history. Among these processes, injection molding is one of the most widely deployed, producing high-volume components across automotive, medical, consumer electronics, and packaging industries. However, accurately monitoring and predicting process behavior in injection molding …

Optimal Allocation Of Flexible Servers In Healthcare Systems, Tong Zhang

All Dissertations

This dissertation investigates the optimization of worker allocation in healthcare systems, focusing on flexible staffing models and the strategic prioritization of healthcare tasks. This research explores the dynamics among pre-operative, operative, and post-operative care units under various cost and service-rate constraints, using a series of models that represent realistic healthcare scenarios within a comprehensive framework for improving patient flow and reducing waiting costs.

In Chapter 2, we model and analyze cross-trained nurse allocation policies within an inpatient surgical system. We model the surgical system as a tandem clearing queueing system and formulate Markov decision processes under different business rules governing …

Baseline Cervical Intervertebral Disc Biomechanics And Implications For Allograft Preservation, Nathan F. Buchweitz

All Dissertations

Neck pain has become an increasingly common orthopaedic healthcare issue. Evidence shows that degeneration of cervical intervertebral discs (the cartilage between the spinal vertebrae in the neck) may be associated. While disc degeneration in the lumbar spine has been extensively studied in relation to low back pain, it has received less attention in the cervical spine. Biomechanically, the cervical (neck) and lumbar (lower back) regions of the spine differ in function. Lumbar discs resist a greater burden of body weight, whereas cervical discs are adapted for mobility to aid flexible head orientation. Despite these key differences, disc injury and degeneration …

Development Of A Mixing-Controlled Combustion Model For 0d Engine Modeling: Using High-Order Models To Guide The Formulation Of Reduced-Order Models, James Gohn

All Dissertations

Vehicles are becoming increasingly complex to comply with the increasingly stringent regulations placed on all market sectors while still maintaining performance requirements. This increased complexity leads to increases in the cost and time it takes to develop and produce these next generation vehicles. To meet demand therefore, it becomes necessary to evaluate numerous design iterations using computer models. There are multiple levels of models that may be necessary for different purposes or use cases. All levels of modeling for virtual prototyping, however, require a level of validation and predictive ability to be useful. To this end, the following thesis presents …

What Is Passive And Active Release Retrofitting Rainwater Harvesting Systems?, Sarah E. Waickowski, Amy E. Scaroni, Beatriss H. Calhoun

Forestry and Natural Resources

Rainwater harvesting is the collection and temporary storage of rainwater for non-potable applications and stormwater management. Rainwater harvesting systems can be retrofitted with passive or active release to improve how well the systems manage stormwater runoff. This publication contains information that may be useful to municipalities, stormwater professionals, rainwater harvesting system owners and/or managers, homeowner associations, and stormwater educators, among others, on what is passive and active release, including their benefits and where to find more information.

Nahb Production Home Competition As A Learning Tool Towards Incorporating Business Skills In Construction Management Programs, George Berghorn, Chandler Jones, M.G. Matt Syal

The Professional Constructor

There is a growing realization in the construction industry that the traditional focus of Construction Management (CM) education on technical competencies (such as scheduling, estimating, and construction methods) is insufficient in preparing graduates to meet the strategic and leadership demands of the modern construction profession. A successful construction company requires more than project execution; it demands expertise in business development, financial management, marketing, risk management, and organizational leadership. The disparity between the technical and business aspects of CM education has produced graduates who may succeed in project management yet find it challenging to engage with comprehensive business operations.

This study …

Construction Industry Preparedness For Generation Z And Millennials: Aligning Industry Characteristics With Workforce Job Preferences, Ameenullah Amiri, Dhaval R. Gajjar, Jason D. Lucas

The Professional Constructor

The construction industry in the United States suffers from workforce shortages, partly due to younger generations being hired more slowly than baby boomers retire. Generation Z’s (Gen Z) lack of interest in joining the construction industry, coupled with the retirement of older workers, has amplified the problem. This paper investigates existing literature to identify the work and career preferences of Gen Z and Millennials and determine where the industry may focus efforts to attract these two generations. Through a systematic literature review, this study identified overlaps and gaps between the current construction industry workforce’s perceptions of the industry and the …

Heat-Related Injuries And Fatalities In Roofing: Osha Investigations From 2003-2024, Kenneth S. Sands Ii, Benjamin Marshall

The Professional Constructor

This study examines 52 heat-related roofing incidents recorded by the Occupational Safety and Health Administration (OSHA) between 2003-2024 to describe patterns in outcomes and identify trade-specific prevention opportunities. Researchers built a structured dataset from OSHA investigation summaries and analysed frequencies of the incidents and their associations with month, time of day, project type, end use, and age to complement a thematic review of narrative abstracts. Fifty-eight percent of cases were fatalities, with the remainder split between hospitalized and non-hospitalized injuries; these statistics underscore the consequences of heat events that trigger OSHA reporting. There was a clear relationship between number of …

The Professional Constructor, Full Issue

The Professional Constructor

Full Issue, Winter 2026

Volume 50, Number 01

The Development Of A Convenient And Consistent Methodology For Flight Proficiency To Certify Multi-Rotor Uas Pilots For State Departments Of Transportation, Colin H. Dees, Joseph M. Burgett

The Professional Constructor

To fly an unmanned aircraft system (UAS), commonly referred to as a “drone,” the Federal Aviation Administration (FAA) requires pilots to pass a knowledge test. There is no requirement at the state or federal level for drone operators to demonstrate the ability to operate a UAS. The National Institute of Science and Technology (NIST) has created an exam for public and private entities to assess basic UAS flight proficiency. It is the only nationally recognized flight proficiency protocol. NIST does not provide a scoring recommendation and leaves it to the user to determine the minimum criteria to pass. There is …

Integrating Dft And Machine Learning To Predict Structural Properties In High Entropy Alloys, Nathan Linton

All Dissertations

In the past decade, a paradigm shift in the design of metal alloys has been observed. These new alloys are commonly referred to as high entropy alloys (HEAs), multi-principal element alloys (MPEAs), or complex, concentrated alloys (CCAs). In contrast to conventional alloys, which consist of one main element (for example 80%) with other elements in small amounts, HEAs are made of four or more main elements ranging from 5 to 35% each element. Due to the large presence of multiple elements, HEAs have shown substantial material property improvements over conventional alloys such as steel. For example, they have high ductility …

Measurement-Based Dynamic Load Model Parameterization Via A Stacked Long Short-Term Memory - Deep Neural Network, Zach H. Smith

All Theses

Increases in distributed generation and changes to predominate load types in modern power systems are driving the need for updated or newly developed dynamic load models. Accurate load modeling is necessary for transmission planning and operation, post-mortem analysis, and inter-regional transfer studies. The most widely used dynamic load model is the WECC Composite Load (CMLD). The CMLD model is an aggregation of substation impedance, under voltage and frequency controls, dynamic motor loads, and static loads. Parameterizing dynamic load models, especially composite models with high parameter counts like the CMLD, is can be difficult. This work proposes a measurement-based, machine learning …

Study On The Knock Resistance Offered By Thermally Stratifying Water Injections In A Single Cylinder Spark Ignition Engine, Aditya Datar

All Theses

Stochastic end-gas autoignition in SI engines, commonly called ‘knock’, limits attainable engine efficiencies. Multiple pathways to extend SI engine operation into knock-limited regions have been studied, including direct water injection (DWI). This study employs single-cylinder engine experiments and modeling to investigate the knock resistance offered by compression stroke water injections, which have shown to thermally stratify the cylinder in HCCI. In SI, thermally stratifying injections are expected to forcibly widen the cylinder temperature distribution by preferentially cooling the cylinder periphery. The end-gas is in the cylinder periphery; therefore, a cooler end-gas would result in longer ignition delays, thus providing knock …

Effect Of Polymer Contaminants Sourced From Coated Paper On The Performance Of The Resulting Recycled Paper, Ezekiel J. Guevarra

All Theses

The growing demand for sustainable packaging has accelerated the use of paper-based materials as alternatives to plastics. To provide barrier and functional properties, these materials are often modified with polymer coatings. While beneficial during use, such coatings can persist as contaminants during recycling, potentially disrupting fiber bonding and reducing the quality of recycled paper. This study examined the impact of extrusion-coated low-density polyethylene (LDPE) films and two aqueous dispersions (Vapor/Water-Barrier, Acrylic Film (VWAF) and Oil & Grease Barrier (OGBF)) on contaminant distribution and mechanical performance of recycled handsheets. Kraft paper coated at varying levels was repulped and formed into handsheets, …

Ai-Optimized Resource Management In Next-Gen Wireless Networks, Fatemeh Lotfi

All Dissertations

Next-generation wireless networks must deliver highly adaptive, scalable, and intelligent connectivity to satisfy the heterogeneous demands of emerging services, including enhanced mobile broadband, massive machine-type communications, and ultra reliable low latency applications. The Open Radio Access Network (O-RAN) paradigm has emerged as a key enabler of this vision, introducing openness, virtualization, and artificial intelligence (AI)-driven control into the RAN ecosystem. O-RAN’s disaggregated architecture facilitates multi-vendor interoperability and empowers intelligent management through the RAN Intelligent Controller (RIC). However, achieving real-time, autonomous, and generalized optimization in such a dynamic environment remains a significant challenge due to its distributed nature, non-stationary traffic, and …

Machine Learning-Enabled Safety-Critical Model Predictive Control For Uncertain Dynamical Systems, Hossein Nejatbakhsh Esfahani

All Dissertations

This dissertation explores the interactions between Model Predictive Control (MPC), Safety-critical Control, and Artificial Intelligence (AI)/Machine Learning (ML) methods, with a particular focus on Reinforcement Learning (RL) and Bayesian Optimization (BO). We then leverage AI/ML to address several challenges in the control design and safe operation of uncertain dynamical systems. In many applications, ranging from autonomous vehicles and robotics to energy systems and industrial processes, ensuring safety is as essential as satisfying control objectives. The use of Control Barrier Functions (CBFs) within the MPC framework recently has emerged as a powerful tool to guarantee safety by enforcing constraints in optimal …

Adaptive Deep Learning In Physical Layer Applications, Ali Owfi

All Dissertations

Traditionally, signal processing models in communication systems have been designed based on solid foundations in statistics and information theory, often assuming linearity and optimizing for simplified models. However, real-world communication systems exhibit numerous imperfections and non-linearities that traditional linear models struggle to capture accurately. Deep Learning (DL)-based approaches, unconstrained by rigid mathematical models, have shown promise in optimizing system performance by accommodating specific hardware configurations and dynamic channel conditions as an alternative to the traditional methods. Despite all the recent research efforts on DL-based methods for physical layer applications, DL models have still not been widely applied to physical layer …

Digital Solutions For Bridging Language Barriers: Designing And Testing An App For Construction Spanish Safety Communication On Construction Jobsites, Adrian Cappella

All Theses

Language barriers between English-speaking supervisors and Spanish-speaking workers create safety risks on U.S. construction jobsites. Hispanic workers face higher injury and fatality rates, with miscommunication being a major contributing factor. Existing translation tools lack the accuracy, cultural context, and jobsite relevance needed for effective safety communication.

In this study a mobile application with construction-specific safety phrases in English and Spanish was designed and field tested. The research included a literature review, phrase collection and validation with industry experts, application development and design with a computer science collaborator, and usability testing with supervisors and workers. Surveys and field trials measured navigation, …

Capillary Imbibition Of Shear-Thinning Xanthan Gum Solutions, Aimee Sayster

All Theses

Capillary rise in confined geometries plays a critical role in numerous natural and industrial processes. While classical models such as the Lucas–Washburn equation accurately describe the dynamics of Newtonian fluids, they fail to capture the complex behavior of shear-thinning, non- Newtonian fluids whose viscosity varies with shear rate. This research investigates the capillary rise dynamics of shear-thinning xanthan gum polymer solutions in capillary tubes. The rheological behavior of each fluid is characterized using the Ellis model, which accounts for shear-thinning effects through three key parameters: zero-shear viscosity μ0, characteristic shear stress τ1/2 and viscosity index α. Experimental data was collected …

Optimal Control Of Human Exercise Using An Individualized Physiological Three-Tank Model And Dynamic Programming, Asal Lotfi

All Theses

This thesis develops a physiologically inspired three-tank model of human bioenergetics to describe and optimize fatigue and recovery during exercise. The aerobic, phosphagen, and glycogen systems are modeled as coupled reservoirs whose states constrain instantaneous power output. Building on this representation, dynamic programming is used to compute pacing strategies that respect physiological limits while maximizing task-specific goals such as peak power or total work over a fixed duration, enabling individualized, goal-driven exercise prescriptions. The three-tank dynamics are formulated in continuous time and then discretized under a zero-order-hold assumption for simulation and optimal control. Model parameters are linked to standard field …

Comparison Of The Recent Icrp Occupational Intakes Of Rradionuclides Series To Annual Limits On Intake (Ali) In The United States For Select Radionuclides, Aidan B. Barker

All Theses

Dose coefficients (DCs) and secondary limit values (such as the annual limit on intake [ALI] and derived air concentration [DAC]) are useful and convenient quantities in radiation protection (RP) for estimation of radiological dose and the practical application of dose limits. DCs link radioactivity intake to dose while secondary limit values express a dose limit in terms of the type and extent of exposure. The International Commission on Radiological Protection (ICRP), an international organization which provides guidance and recommendations for RP, calculates, tabulates, and updates DCs following new findings and updated knowledge relevant to dose determination (e.g. improved human biokinetics, …

Multi-Criteria Decision-Making For Sustainable Design: Stakeholder Prioritization And Methodological Comparison In Solar And E-Bike Applications, Swagath Madhu Gowda

All Theses

This thesis focuses on using Multi-Criteria Decision-Making (MCDM) methods to support sustainable product design by addressing the trade-offs between environmental, economic, and social goals. The research is presented through two studies that demonstrate how both subjective and objective decision-making approaches can guide sustainability evaluations.

The first study applies the Analytic Hierarchy Process (AHP) to assess residential solar panels by incorporating stakeholder perspectives from sustainability experts, end users, and industry professionals. Using Life Cycle Sustainability Assessment (LCSA) data, this study identifies how different stakeholder groups prioritize sustainability criteria and applies Aggregation of Individual Priorities (AIP) to combine their judgments. A one-at-a-time …

Locomotion And Balance Control In A Biped Robot With Continuum Legs And A Kangaroo-Inspired Tail, Gavin A. Platt

All Theses

This thesis work presents the design, testing, and validation of a continuum-legged biped robot equipped with a kangaroo inspired tail for enhanced stability and adaptability. Unlike traditional rigid link robots, this one expands on soft-legged robots and utilizes tendon-driven continuum robots to mimic octopus and kangaroo behavior for locomotion. The robot uses a hierarchical hybrid control framework to implement walking, obstacle avoidance, vaulting, and push recovery behaviors. To test the performance of the robot four sets of experiments were conducted to validate these systems and evaluate how they performed. The results demonstrate stable walking with rhythmic tail load transfer, effective …

Polypropylene/Polyethylene Blends With Asymmetric Viscosity: Fabrication, Characterization, And Recycling Potential, Bernadine Daichendt

All Dissertations

Polyolefin materials, polypropylene (PP) and polyethylene (PE), are widely used in day-to-day life both commercially and industrially, offering versatile applications due to their mechanical and chemical properties. The high consumption rate of these materials makes them important targets for recycling efforts. However, there are multiple contributing factors leading to low recycling of PP and PE, chiefly sorting factors: chemical similarity, changed properties after multiple rounds of processing, and the use of processing aids. It is necessary to point out that, because of multiple melt processing cycles, recycled PP has decreased molecular weight due to chain scission. Conversely, recycled PE molecular …