Modeling And Simulation Of A Process For Upcycling Of Low-Density Polyethylene Plastic Waste To Ethylene, Xiaoyan Wang

Graduate Theses, Dissertations, and Problem Reports (ETD)

Ethylene is one of the most widely produced petrochemicals, with an estimated global output of 180 million metric tons in 2022. Approximately 82 million metric tons of ethylene are used annually for plastic production, primarily for polyethylene (PE), as well as polypropylene (PP) and polyvinyl chloride (PVC). The CO₂ emissions associated with PE production were approximately 14 million metric tons in 2022. Globally, an estimated 70 million metric tons of PE are produced and consumed each year, with the majority (~79%) ending up in landfills or the environment.

This project proposes a novel process in which waste low-density polyethylene (LDPE) …

Deep Target Recognition: Semi-Supervised Annotation, Sensor Fusion And Super-Resolution, Shoaib Meraj Sami

Graduate Theses, Dissertations, and Problem Reports (ETD)

Despite the recent expansion of machine learning algorithms to cover a wide range of disciplines, several areas of automatic target recognition (ATR) remain underexplored. This dissertation presents tools developed to improve performance in three significant aspects of ATR: semi-supervised annotation, sensor fusion, and image super-resolution. The aim of the semi-supervised methods is to automatically annotate targets in scenarios where labeled data are scarce in the target domain but available in the source domain. Secondly, to address the limitations of individual image sensors and enhance robustness under different environmental conditions and man-made constraints, a sensor fusion algorithm was developed to improve …

Evaluation Of Rare Earth Element Hydraulic Preconcentrate Material Strength Characteristics And Operation Manual Development For Triaxial Machine Testing, Nicholas C. Stalnaker

Graduate Theses, Dissertations, and Problem Reports (ETD)

As part of ongoing efforts to establish a domestic Rare Earth Elements (REE) supply chain, Hydraulic Preconcentrate (HPC) generated at the Horseshoe Bend (HsB) treatment plant was produced and evaluated as a potential feedstock source. Following adjustment of the site’s clarifiers to the required pH set points, HPC was collected and pumped into 24 geobags. These geobags were passively dewatered to raise the total solids content. The evaluation included three geobag types: woven geotextile, composite (woven and non-woven), and geobags enhanced with Capillary Channel Fiber (CCF) (Bird, 2024). Hydraulic Preconcentrate (HPC) material is collected through efforts to contain and properly …

Evaluation Of Small Unmanned Tailsitter Hybrid Air Vehicles Via Full Flight Simulation, Andrew Spencer Winters

Graduate Theses, Dissertations, and Problem Reports (ETD)

Small Unmanned Aerial Vehicles have exploded in popularity in the past 15 years among researchers and for industrial uses such as agriculture, search and rescue, and infrastructure inspection. Fixed wing and multirotor designs present two major paths that can be taken with these technologies. Fixed wing platforms have superior aerodynamic efficiency but require large areas for takeoff/landing and cannot hold a constant position in space, limiting their use. Multirotor configurations offer a more versatile platform that can maneuver in 3 dimensions independently but lack the endurance of fixed wing vehicles. This thesis analyses a quadrotor biplane and a variable wingspan …

Novel Design And Fabrication Of A High-Speed Transient Heat Flux Sensor For Application To Rotating Detonation Engines, Zachary Todd Tallman

Graduate Theses, Dissertations, and Problem Reports (ETD)

Rotating detonation engine (RDE) combustion systems have been a topic of interest in the pressure gain combustion community for their benefits over traditional gas turbine engine combustors. However, cooling requirements for these engines are significantly higher and less predictable than those of non-detonating engines. To understand and quantify the high-speed heat transfer dynamics within an RDE, a novel high-frequency heat flux sensor is presented. This study aims to design a robust, single-sided sensor that can withstand the high temperature and harsh environment of an RDE for extended durations. Screen printing is used to deposit a layered, platinum-yttria-stabilized zirconia (YSZ) film …

In-Plane Shear Stiffness Of Stay-In-Place Forms And Bracing Effects On The Torsional Stability Of Press-Brake-Formed Tub Girders, Ethan L. Host

Graduate Theses, Dissertations, and Problem Reports (ETD)

Press-brake-formed tub girders have welded internal angle bracing that is believed to be necessary for torsional stability under eccentric loading. However, this bracing creates fatigue weld hotspots overtime, which are subject to cracking. This study was performed to assess the torsional behavior of the Valmont U12 press-brake-formed tub girder (PBFTG) under various configurations using finite element analysis (FEA) modeling and experimental laboratory testing. The primary objective was to (1) determine the necessity of various angle bracing throughout the beam, and the effects removing said braces has on the torsional stiffness of the girder and (2) investigate the use of stay-in-place …

Implementation Of A Neural Network Execution Framework For Generalized And Cross-Platform Deep Learning Deployment And Inference On Spacecraft Systems, Rafael Polanco Segovia

Graduate Theses, Dissertations, and Problem Reports (ETD)

Recent advances in hardware and software technology have made it possible to implement more resource-demanding deep learning algorithms in constrained hardware environments. This creates opportunities to use deep learning for aerospace applications on increasingly smaller aerospace vehicles. This work presents the implementation of a Neural Network Execution Framework (NNEF), which aims to provide a cross-platform and reusable framework to deploy and execute trained neural networks for deep learning aerospace applications. The NNEF executes any neural network inference process regardless of the original deep learning framework in which it was created, for supported flight software platforms, and space-like computer boards. Users …

Green Bank Chime/Frb Outriggers Commissioning And Analog System Development, Kholoud Sharif Tag Alkhatem Khairy

Graduate Theses, Dissertations, and Problem Reports (ETD)

The main objective of this thesis is to document the development and commissioning of the Canadian Hydrogen Intensity Mapping Experiment. (CHIME) outrigger at the Green Bank Observatory. (GBO) in Green Bank, WV. This novel cylindrical wide-field radio transient telescope is currently operating in conjunction with CHIME. The CHIME outrigger at GBO aims to contribute significantly to the field of radio astronomy, with implications for both Fast Radio Burst. (FRB) science and broader astronomical research. The construction and commissioning of the CHIME outrigger at the GBO mark a pivotal step forward in pursuing high-precision wide-field detection and localization of radio transients, …

Characterization And Optimization Of Sand And Tung Oil-Based Resins For Binder-Jet 3d Printing, Daniel I. Ajiola

College of Graduate Studies: Theses & Dissertations

Binder-jet 3D printing as a transformative technology in additive manufacturing, offers the ability to fabricate complex structures with diverse materials. This thesis investigates the use of a sustainable tung oil-based resin to create composites, exploring the potential for an eco-friendly alternative to synthetic binders.

The aim of this research is to develop and characterize a bio-based resin formulation, using tung oil as the primary binder, for application in binder-jet 3D printing with sand as the reinforcement. The resin formulation was prepared by combining tung oil, n-butyl methacrylate, divinylbenzene, and di-tert-butyl peroxide in precise proportions, ensuring a balanced mixture that supports …

An Infrared Thermography Assessment For Monitoring Aging Mse Walls, Charles Lawal

College of Graduate Studies: Theses & Dissertations

Mechanically Stabilized Earth (MSE) walls play a vital role in ensuring the stability of transportation infrastructure, yet traditional inspection techniques often struggle to detect subsurface defects and demand significant labor. This research explores the application of Infrared Thermography (IRT) as a non-destructive, cost-effective approach for inspecting MSE walls across Southeast Georgia. By capturing thermal images under diverse environmental and operational conditions, the study aims to identify potential issues, including cracks, voids, delamination, and honeycombing, which can undermine integrity over time. Utilizing advanced image processing tools, the research implements specialized software to enhance the accuracy of defect detection, facilitating the generation …

Digital Modeling Of Temperature-Dependent Processes In Industrial Wastewater: Advancing Ultimate Oxygen Demand Prediction For Treatment Optimization, Fatima Iqbal

College of Graduate Studies: Theses & Dissertations

The pulp and paper industry is the third-largest consumer of freshwater globally and faces mounting pressure to optimize water usage and minimize environmental impact. Aerated stabilization basins are extensively utilized in the pulp and paper industry and play a crucial role in treating wastewater from these operations. The existing management practices fail to effectively optimize treatment processes due to the prolonged time required for testing key quality parameters. The utilization of models developed for treatment facilities presents a viable solution; however, existing open-source models often fall short in accurately predicting treatment efficiency across varying conditions and lack comprehensive accounting of …

Pulsed Arc Additive Manufacturing Of A Functionally Graded Er2209 Duplex Stainless Steel And Hsla-100 Structure: Morphology, Characterization, And Mechanical Performance, Stevens G. Hill Jr

College of Graduate Studies: Theses & Dissertations

Wire arc additive manufacturing is a process well suited to the efficient production of large structures. Duplex stainless steel exhibits high corrosion resistance and good strength which can be highly beneficial for industrial use. However, its use is limited due to its cost and complexity in controlling microstructure to achieve desired properties. In many cases, it can be highly beneficial to manufacture a component which uses specialty steel grades such as duplex stainless steel only where necessary, and utilizes more affordable, commonly available steels for reinforcement or bulk structural support. A functionally graded material satisfies these requirements by providing a …

Dynamic Modulus Of Sbs-Modified Asphalt Mixtures Added With Ground Tire Rubber Content, Azharul Islam

College of Graduate Studies: Theses & Dissertations

The study investigates the improvement of the dynamic shear modulus in the base and styrene butadiene styrene (SBS) modified asphalt mixture by accumulating varying amounts of ground tire rubber through an Asphalt mixture performance tester (AMPT). This thesis specifically explores how different percentages of ground tire rubber (GTR) influence the mechanical properties and durability of the asphalt mixture articulated with two grades, PG 64-22 and PG 76-22. The experimental framework consisted of preparing asphalt mixtures blended with 10% to 15% of the binder for PG 64-22 and 3% to 8% of GTR for PG 76-22. The laboratory testing involved using …

Computational Investigation Of Underbody Slant Angle Variation Effect On A Hatchback Vehicle, Nufile Uddin Ahmed

College of Graduate Studies: Theses & Dissertations

Electric Vehicles, despite many advantages over their gasoline-powered counterparts, have the following main challenges towards mass adoption – the charging infrastructure and the range of the vehicle. Among the myriads of factors affecting the range, the coefficient of drag and the required power to overcome it are noteworthy. This study aims to investigate the effect of rear underbody slant angle on a common, simplified hatchback-shaped Electric Vehicle. The rear underbody slant angles (upward) assessed were 0°, 5°, 10°, and 15° and they were subjected to three freestream velocities representative of urban (16 m/s), highway (25 m/s) and interstate (40 m/s) …

Evaluating The Effectiveness Of Lidar And Photogrammetry For Inspecting Mse Walls In Bridges, Shakil Ahmed

College of Graduate Studies: Theses & Dissertations

Mechanically Stabilized Earth (MSE) retaining walls are vital components of transportation infrastructure, providing structural support for embankments and bridge approaches. As many walls approach or exceed their design life, concerns regarding long-term stability, settlement, and displacement have increased. Traditional visual inspection remains the most common assessment method; however, it is subjective and often unable to detect subtle geometric changes that may precede structural distress or failure. This study evaluates Terrestrial LiDAR (Light Detection and Ranging) Scanning (TLS) and Close-Range Photogrammetry (CRP) as nondestructive, noncontact alternatives for detecting displacement in MSE retaining walls. Three representative sites were investigated: a Control Wall …

In Vitro Microfluidics System For Mechanobiologic Investigations, Michael A. Daanen

Honors Theses

Mechanobiology is an emerging field that aims to study the relationships between mechanical forces and cellular behavior. Such mechanobiological relationships are especially critical in the cardiovascular system, where endothelial cells lining the vasculature align in response to fluid shear stresses from blood flow (Sinha, 2016). Implanted flow devices, diabetes, chronic hypertension, and various other diseases and pathophysiologies alter vessel geometries and flow dynamics. Such alterations impact fluid shear stress and endothelial cell behavior, leading to microcirculatory dysfunction, vessel leakage, and organ failure (Poredos, 2021; Papadaki, 1999; Leitschuh, 1987). To simulate dysfunctional endothelial cell behavior in vitro and evaluate novel therapeutic …

On High-Speed Breakup Of Water Droplets Behind High Mach Number Shocks, Sydney M. Briggs

Graduate Thesis and Dissertation post-2024

Water droplet breakup in high-speed flow is a relatively popular experimental study to analyze breakup mechanisms. There is a plethora of experiments performed at low Mach number and low Weber number, but studies with higher speed flows and higher Weber numbers are less common. In this study, water droplet breakup is assessed using high-speed shock waves (Mach 2.3-above Mach 5) in a shock tube. Multiple methods are used to introduce droplets, and multiple different water purity levels are considered. An assessment was made into whether cavitation played a role in the breakup process physically, as this has been a budding …

Evaluation Of Heavy Metal Bioaccumulation And Growth In Hemp From Chicken Manure, Vermicompost, And Wastewater Sludge With Biochar And Health Risk Assessment, Chutiphan Sangsoda

Chulalongkorn University Theses and Dissertations (Chula ETD)

Hemp (Cannabis sativa L.) has become an economically valuable crop with a wide range of benefits. To promote more sustainable agricultural systems, the use of recycled substrates has increasingly replaced traditional fertilizers. However, substrates such as dry chicken manure, vermicompost, and wastewater sludge (WWS) combined with biochar often contain heavy metal contaminants, which may pose health risks through exposure to hemp. This study investigated three cultivars Rosella, Superwoman S1, and Red Robin over a 120-day period. The objectives were: (1) to compare the effects of dry chicken manure, vermicompost, and wastewater sludge (with and without biochar) on soil nutrient quality …

Interaction Between Extreme Temperature Events And Air Pollution On Mortality In Thailand : A Nationwide Time Series Study, Phichet Khunthong

Chulalongkorn University Theses and Dissertations (Chula ETD)

Climate change has increased the frequency and intensity of extreme temperature events (ETEs; heat and cold waves), concomitantly affecting PM2.5 fluctuation. However, limited research has investigated the interaction of ETEs and PM2.5 on mortality, particularly in tropical regions where the interaction could influence differently from cold countries. A two-stage time-series using distributed lag non-linear models was employed to estimate region-specific relative risks and 95% confidence intervals (RRs and 95% CIs) of ETEs and PM2.5 on daily cardiovascular and respiratory mortality. The relative excess risk due to interaction (RERI) was examined to quantify additive effects. Cold waves had the greatest effect …

Exploration And Synthesis Of Tin Intermetallic Single Crystals, Jared L. Shortt

Graduate Theses/Dissertations

This thesis presents the synthesis and characterization of two tin-based intermetallic compounds: Mn₄.₁₂Sn and Ni₆Sn₈Ge₀.₄₇. Single crystals were grown using a high-temperature self-flux method, allowing for the formation of phase-pure samples suitable for structural and physical property analysis. The crystalline phases were identified and refined using powder and single-crystal X-ray diffraction (XRD), while scanning electron microscopy combined with energy-dispersive X-ray spectroscopy (SEM/EDS) was employed to verify stoichiometry and homogeneity. Magnetization measurements performed using a superconducting quantum interference device (SQUID) magnetometer revealed distinct magnetic behavior in the manganese-rich compound, while the nickel-based compound was explored for potential magnetic features arising from …

Evaluation Of Practical Methods To Determine If A Karst Creek Is Gaining Or Losing: Case Study Of Leith Creek, Elizabeth Jones

Graduate Theses/Dissertations

Karst landscapes are abundant in Missouri, with features such as caves, springs, and sinkholes that form through the dissolution of limestone. Leith Creek is a small stream in Polk County, Missouri fed by two springs and the shallow unconfined Springfield Plateau aquifer, a highly karstified aquifer which is made up of limestone and minor interbedded shale-mudstone units. To determine if Leith Creek is gaining or losing, stream flow, water chemistry and temperature sensors were monitored. Stream flow results required multiple visits to take measurements while temperature sensors required two visits, one to install the dataloggers and another to remove the …

พฤติกรรมการเปลี่ยนช่องจราจรบริเวณจุดรับส่งผู้โดยสาร, ศุภวิชญ์ มัธยมนันทน์

Chulalongkorn University Theses and Dissertations (Chula ETD)

ในสภาพการจราจรจริง การไหลของกระแสจราจรมักถูกรบกวนจากยานพาหนะที่จอดเพื่อรับ–ส่งผู้โดยสาร ส่งผลให้ยานพาหนะที่ขับขี่ตามมามีสองทางเลือก ได้แก่ การรอให้ยานพาหนะด้านหน้าเคลื่อนตัวต่อไป หรือการเปลี่ยนช่องจราจรไปยังช่องที่สามารถเคลื่อนที่ได้ ซึ่งทั้งสองทางเลือกล้วนทำให้ประสิทธิภาพการไหลของจราจรลดลงเมื่อเทียบกับกรณีที่ไม่มีการรบกวนดังกล่าว ในปัจจุบัน การใช้แบบจำลองจราจรช่วยให้สามารถทำความเข้าใจและคาดการณ์สภาพการจราจรได้โดยไม่ต้องทดลองในพื้นที่จริง แต่แบบจำลองทั่วไปยังขาดความเฉพาะเจาะจงเมื่อต้องเผชิญสถานการณ์เฉพาะทาง โดยมักใช้พฤติกรรมพื้นฐานเพียงชุดเดียวในการแทนพฤติกรรมผู้ขับขี่ทุกกรณี งานวิจัยนี้มีวัตถุประสงค์เพื่อศึกษาพฤติกรรมการเปลี่ยนช่องจราจรของผู้ขับขี่เมื่อแล่นตามหลังรถที่จอดรับ–ส่งผู้โดยสาร จากนั้นนำพฤติกรรมที่ได้จากภาคสนามไปใช้ในการพัฒนาแบบจำลองสภาพจราจรใน PTV VISSIM และทำการเปรียบเทียบกับพฤติกรรมจริง ข้อมูลภาคสนามถูกเก็บรวบรวมด้วยการบันทึกวิดีโอและประมวลผลด้วย Video Analytics ก่อนนำไปสร้างแบบจำลอง ผลการศึกษาพบว่า แบบจำลองสามารถจำลองพฤติกรรมการเริ่มต้นเข้าสู่การเปลี่ยนช่องจราจรได้ใกล้เคียงกับข้อมูลจริง โดยช่องว่างเชิงเวลา (Lag Gap) ของยานพาหนะที่ขับขี่ตามมามีค่าเฉลี่ย 0.425 วินาทีในภาคสนาม และ 0.375 วินาทีในแบบจำลอง อย่างไรก็ตาม แบบจำลองยังไม่สามารถสะท้อนพฤติกรรมการเปลี่ยนช่องจราจรได้ครบถ้วนทุกด้าน ซึ่งเป็นประเด็นที่ควรได้รับการพัฒนาเพิ่มเติมในงานวิจัยอนาคต

Extraction And Separation Of Metal Cations From Synthetic Acidic Solutions Using Emulsion Liquid Membrane, Nouhaila Filali

Masters Theses

The work is organized into two main papers supported by experimental and comparative studies using Emulsion Liquid Membrane (ELM) systems. The first paper explores the individual extraction of heavy metals (Cd, Cr, As, Ni) from synthetic phosphoric acid using Alamine 336 and D2EHPA as carriers. Alamine 336 achieved the highest extraction efficiency (>90%) and stability, offering a promising route to reduce toxic impurities in fertilizer-grade acid. The second paper examines the selective separation of Ni2+ and Co2+ from various acidic solutions using the ELM configuration. Systematic variation of carriers, stripping agent and feed acidity, clarified transport mechanisms and stability, …

Application Of Edge-Enhanced Phase Analysis To Active Microwave Thermographic Measurements, Douglas Blaine Fleetwood

Masters Theses

Nondestructive testing and evaluation (NDT&E) encompasses a range of inspection techniques that assess materials, components, and structures while maintaining their integrity and performance. Among these techniques, thermography is particularly attractive due to its non-contact imaging approach with easy-to-interpret results. Active Microwave Thermography (AMT) has emerged as a promising NDT&E inspection technique that utilizes electromagnetic energy to heat materials through dielectric and magnetic absorption, with subsequent infrared imaging used to detect subsurface defects. While AMT offers significant advantages including material-specific heating optimization and lower power requirements compared to conventional thermographic methods, the technique faces a persistent challenge related to the thermal …

Development Of A Mixed Reality Robotics Testing Environment, Haneen Hanoon

Graduate Theses, Dissertations, and Problem Reports (ETD)

Development of a Mixed Reality Robotics Testing Environment

Haneen Hanoon

This research presents the development of a Mixed Reality (MR) robotic framework that integrates real and virtual environments for experimental robotics, education, and visualization. The proposed system combines a motion-capture system, a simulator, and a projector to create a spatially aligned, interactive workspace where physical robots coexist with projected virtual objects. The framework enables real-robot motion to be tracked in real time and mirrored in the simulated environment, allowing projected obstacles, goals, and paths to be precisely aligned with the physical world.

A coordinate transformation and scaling process was implemented …

Evolving Secure Authentication From 5g To 6g: Advancing Privacy And Resilience In Next-Generation Networks, Isabella Deanne Lutz

Graduate Theses, Dissertations, and Problem Reports (ETD)

The fifth generation (5G) of mobile networks introduced groundbreaking improvements in connectivity, latency, and reliability. As 5G continues to expand across commercial and de- fense sectors, ensuring the privacy and integrity of its authentication mechanisms remains paramount. The foundation of 5G security lies in the Authentication and Key Agreement (AKA) protocol, which enhances user identity protection and establishes mutual authenti- cation between the user equipment (UE) and the network. Despite these advances, several weaknesses persist, including replay-based desynchronization, linkability, and correlation at- tacks under realistic adversary models. This thesis provides a unified analysis of these vulnerabilities and introduces a lightweight …

Deep Learning-Driven Biometric Security: Advancing Liveness Detection And Anti-Spoofing Techniques, Banafsheh Adami

Graduate Theses, Dissertations, and Problem Reports (ETD)

Biometric authentication has become a key part of our everyday lives—from unlocking smartphones with a fingerprint or face to verifying identities in banks and airports. These systems rely on our unique physical or behavioral traits, making them both convenient and secure. Unlike passwords, biometrics cannot be forgotten or stolen in the traditional sense. However, they are not without risk. One of the biggest concerns is spoofing: attempts by attackers to fool systems using fake biometric traits, such as silicone fingerprints or AI-generated videos.

As generative AI tools become more powerful and accessible, the ability to create convincing fake biometric data …

Stability And Resonance Of Cylindrical Wave Energy Converters, Gregory M. Ballen

Dissertations, Master's Theses and Master's Reports

With increased focus on wave energy converters that produce power in multiple degrees of motion, more tools are necessary to understand the behavior of these devices and cause them to reach critical resonance points. This thesis uses Floquet theory and a numerical solver to understand how a WEC of given parameters operating in surge, heave and pitch may approach points of instability using feedback control schemes. It finds that a WEC reaches these resonance points when the surge and pitch motions are driven to resonate at either the same frequency as the heave motion, or at half this frequency. This …

Heuristic Approaches For Coordination Of Heterogeneous Robotic Systems In Harvesting Automation With Size Constraints, Hyeseon Lee

Dissertations, Master's Theses and Master's Reports

This thesis presents the development of path planning algorithms for the coordination of heterogeneous robotic systems while considering size constraints. The objective is to generate practical and efficient solutions for real-world applications. The use of heterogeneous collaborative robots is beneficial in many applications, such as transportation operations in warehouses or manufacturing environments, surveillance, and monitoring, and task allocation and path planning are critical techniques that need to be addressed to deploy in real-world applications. This research focuses on automating lavender harvesting, where robots with varying capabilities must collaboratively navigate complex field layouts to efficiently complete harvesting tasks.

The problem considers …

Phase-Field Method Of Fracture In Fiber-Reinforced Polymer Composites: Theory, Modeling, And Validation, Akash Kumar

Dissertations, Master's Theses and Master's Reports

Fiber-reinforced polymer composites (FRPCs) are widely used in aerospace, automotive, and civil engineering due to their high specific strength, stiffness, and durability. However, their anisotropic and heterogeneous nature makes fracture prediction challenging, with damage modes classified as intralaminar failure (matrix cracking, fiber breakage, fiber-matrix debonding) and interlaminar delamination. Delamination, driven by weak through-thickness strength and high interlaminar stresses, is a predominant failure mechanism in FRPCs. While cohesive zone models (CZMs) are commonly used for delamination, they are computationally expensive and inefficient for capturing intralaminar fractures where crack paths are unknown. To address this, we developed a unified phase field-based cohesive …