Other Materials Science and Engineering Commons^™

Synthesis And Characterization Of Carbon Quantum Dots And Gold Nanoparticles For Norovirus Biosensing Applications In Water Systems, Breanne Evans

Master's Theses

Rapid, reliable detection of viral pathogens remains a significant challenge across water-treatment and environmental monitoring systems, including drinking-water, wastewater, water reuse, and environmental surveillance applications. Waterborne viral contamination can pose substantial public-health risks, making early detection essential for protecting water quality and responding quickly to treatment failures or contamination events. Direct potable reuse (DPR) is one particularly demanding example because it requires continuous verification of treatment performance and the broader need for rapid virus monitoring extends across many water-treatment and environmental surveillance applications. Norovirus is a priority target because of its widespread occurrence in wastewater, environmental persistence, and exceptionally low …

Direct Ink Writing Of Functional Fiber/Granular Composites, Zhuoyuan Yang

Doctoral Dissertations and Master's Theses

Direct ink writing provides a versatile manufacturing route for fabricating functional fiber and granular composites with controlled architecture, tunable interfaces, and customized material distributions. Fiber reinforced composites offer high stiffness, strength, fatigue resistance, and functional anisotropy, while granular composites provide scalable access to particle based structures with high material efficiency and broad resource compatibility. However, the additive manufacturing of these composite systems remains challenging. For fiber based composites, precise control of fiber placement, matrix impregnation, interfacial bonding, and freestanding deposition is difficult to achieve during printing. For granular composites, stable particle flow, controllable packing, binder infiltration, and shape retention are …

Operation Bite Block, Jennifer Aline Robles, Laura Marie Strobbe, William Pearce Graham, Annabelle Katherine Thalken

Mechanical Engineering

Current dental bite blocks, or mouth props, are typically manufactured in fixed sizes, and often result in patient discomfort, reduced procedural efficiency, and the need for dental offices to maintain multiple product sizes. This project sought to design, prototype, and validate an adjustable dental bite block capable of accommodating a wide range of patient mouth openings while maintaining comfort, structural integrity, sterilizability, and operator usability. Working in collaboration with Dr. Alan Latta, a practicing dentist in San Luis Obispo, the design process incorporated stakeholder feedback, patent and market research, engineering analysis, and iterative prototyping to develop a solution that addresses …

Temperature And Environmental Implications On Ti3c2cl2 Mxene Degradation Process, Yang Yang

McKelvey School of Engineering Graduate Student Theses & Dissertations

MXenes, a rapidly emerging class of two-dimensional transition metal carbides and nitrides, have attracted considerable attention owing to their exceptional electrical, mechanical, and chemical properties. However, the inherent thinness of their atomic structure and the reactivity of their functional groups render MXenes susceptible to environmental degradation, whereby the lattice integrity is compromised and desirable material functionalities are dimin- ished. In this work, ex situ electron microscopy characterisation is performed on Ti₃C₂Cl₂ MXene specimens subjected to controlled gas environments — nitrogen gas (N₂) and air — at annealing temperatures of 200°C and 600°C, with …

Physical And Optical Properties Of The Germanium-Arsenic-Selenium Glass Forming Region For Precision Glass Molding And Infrared Optics, Peter F. Wachtel Ii

All Dissertations

The growth and advancement of infrared optical systems for thermal imaging, multi-band imaging, hyperspectral imaging, medical diagnostics, and chemical sensing are pushing the material science community to better understand existing materials while also developing new materials. Additionally, the thermal imaging market continues to grow, and system designers are continually being asked to reduce size, weight, and power while reducing costs (SWaP-c). Market growth has shifted optics manufacturing towards higher volume processes such as precision glass molding, but this does require most materials to be recharacterized due to property changes resulting from the process. Affecting the SWaP-c requirements, manufacturing tolerances are …

The Influence Of Composition On Porosity And Strength In Planetary Analog Saline Ices, Tara C. Tomlinson

Dartmouth College Ph.D Dissertations

This thesis investigates how composition influences the physical structure and mechanical behavior of saline ice, with implications for both terrestrial sea ice and the ice shells of ocean worlds such as Europa and Enceladus. This is done through a multi-pronged approach of both numerical modeling and laboratory experiments. Modeling results re- veal that small-scale parameter variations in porosity, permeability, and permeability fac- tor may produce large discrepancies when extrapolated to planetary scales, underscoring the need for improved experimental constraints on pore connectivity and thermochemical conditions. Laboratory analyses show that while total porosity is relatively uniform with depth, it varies strongly …

Areosense, Josephine Turney

Williams Honors College, Honors Research Projects

The AeroSense growing system is designed to make indoor aeroponic gardening easy and accessible for everyone. By combining sensors, automation, and AI, the system can monitor and adjust humidity, lighting, and nutrient levels to help plants thrive without requiring expert knowledge. The goal is to create a self-regulating garden that takes the guesswork out of growing fresh herbs and vegetables at home. The project involves building a working aeroponic prototype equipped with misters, pumps, and environmental sensors, all managed by a Raspberry Pi. Using computer vision and machine learning, AeroSense will be able to assess plant health and respond automatically …

Field-Assisted Post-Processing Of Cold-Sprayed Pure Copper, Alan Hensley

Theses and Dissertations--Mechanical and Aerospace Engineering

The properties of materials processed through cold spray, and many other AM processes, are non-uniform and unpredictable. In most cases, post-processing is required to achieve desired properties and better uniformity. In cold spray, the typical method is an annealing heat treatment (AHT), which can improve bond strength, reduce porosity, and restore ductility, among other effects. AHT alone, however, is unable to completely remedy any of the unfavorable properties. In addition, long treatments at high temperatures are often needed for satisfactory results. This increases energy consumption and extends production times for products made by the process. For these reasons, numerous investigations …

Engineering Disorder, Defects, And Electrical Transport For High-Performance Thermoelectric Fe2val Heusler Alloys, James Russell Taylor Iv

Dartmouth College Ph.D Dissertations

Fe₂VAl is a promising low-temperature thermoelectric material for waste-heat energy conversion because it is easily processed and comprised of earth-abundant, non-toxic, and low-cost elements. However, viability for applications faces two major challenges: high thermal conductivity and low p-type Seebeck coefficients. This primarily experimental work aims to address these issues through extrinsic and self-doping, point-defect and disorder generation through thermal and electrical processing, disordered and metastable phase composition quantification, and comparison of transport measurements to modeled electronic features.

An accessible phase quantification method was developed for bulk Fe₂VAl using laboratory X-ray diffraction equipment to compare thermoelectric properties …

Made On Mars: Design And Manufacturing Of Structural Polymer-Regolith Composites, Pailey M. Vitale

Williams Honors College, Honors Research Projects

Human exploration of Mars is constrained by harsh environmental conditions and the prohibitive cost of transporting materials from Earth. Long-term sustainability requires the local production of mechanical and structural components using resources available on Mars, thereby minimizing payload mass. This project investigates polymer–regolith composites derived from atmospheric CO₂ and mineral-rich regolith as a pathway toward in-situ manufacturing. These composites, when compatible with additive manufacturing, could replace imported plastics, enable on-demand fabrication, and support closed-loop recycling systems. The objective is to design and evaluate polymer–regolith composites that maintain mechanical integrity and environmental resistance under Martian conditions, including extreme temperature swings, radiation …

Design New Stage For Vacuum Pin On Disk, Miranda Boyd

Williams Honors College, Honors Research Projects

For my senior design project, I am redesigning the moving stage for the vacuum pin-on-disk test used in the Akron Engineering Tribology Lab. This system is used to evaluate bearings and lubricants for aerospace applications under controlled vacuum conditions. The current stage design limits flexibility when adjusting for different testing parameters, so my goal is to develop a new movable stage that allows for varying weights and loads to be applied accurately and safely. The redesigned stage will improve test efficiency, adaptability, and precision, ensuring the system can accommodate a wider range of experimental conditions and materials while maintaining compatibility …

Strain-Induced Nonvolatile Domain Switching And Tunable Elastic Modulus In Ba1-Xsrxtio3 Membrane By Phase-Field Simulation., Laveeza Ahmad

Material Science and Engineering Dissertations

Ferroelectrics underpin a broad spectrum of technological applications due to its switchable ferroelectric polarization and the associated electro-mechanical responses under electrical, optical, thermal, and mechanical stimuli. Recent advancement in membrane technology offers new opportunities to tune ferroelectric polarizations via mechanical strains at relatively large magnitude and scale. However, its influence on the tunability of mechanical responses of the membrane remains underexplored. Herein, we developed a phase-field model for free-standing Ba_1-xSr_xTiO₃ ferroelectric membranes with stress-free boundary conditions on top/bottom surfaces and achieved strain-induced nonvolatile ferroelectric domain switching in the membrane. It is discovered that a …

Next-Generation Computing Hardware: Advancements In Tantalum Oxide Reram For Ai And Neuromorphic Applications, Rajas Ravindra Mathkari

Electronic Theses & Dissertations (2024 - present)

The rapid development of artificial intelligence, machine learning, and data-intensive computing has exposed the fundamental limitations of conventional von Neumann architectures, in which energy and time are continuously lost transferring data between physically separate memory and processing units. In contrast, the human brain performs complex computations directly at the point of memory storage through billions of parallel synaptic connections, a paradigm known as in-memory computing. Realizing this in hardware requires memory devices that are fast, energy-efficient, non-volatile, and capable of storing multiple resistance levels in an analog manner. Resistive Random Access Memory (ReRAM) based on tantalum oxide (TaOx) is one …

Mechanical Behavior Of Additively Manufactured Ti-6al-4v Eli Parts: Effects Of Laser Parameter Selection, Samuel Lopez

UNF Graduate Theses and Dissertations

Additive manufacturing (AM) of TI-6AL‑4V Extra‑Low Interstitial (ELI) enables complex geometries for fatigue‑critical medical device applications, yet fatigue performance remains sensitive to process‑induced defects. This work investigates the effect of laser process parameter selection on the microstructure, mechanical properties, and fatigue behavior of TI- 6AL‑4V ELI fabricated via laser powder bed fusion (L‑PBF) using a Renishaw RenAM system. The influence of laser parameters was isolated by holding powder chemistry, build orientation, scan strategy, sub‑transus annealing, and post‑processing constant between a non‑optimized baseline and an optimized parameter set selected based on tensile performance.

Optical microscopy showed the optimized condition exhibited improved …

Production Of Rare Earth Elements By Molten-Salt Electrolysis, Mohammed Moro

Graduate Theses & Non-Theses

Rare earth elements (REEs) are indispensable, high-value resources that play a crucial role in renewable energy, defense systems and advanced technological systems. REEs are commonly extracted from natural ores or recycled materials such as permanent magnets using hydrometallurgical or pyrometallurgical techniques. In hydrometallurgy, the REE source is leached with acid, followed by solvent extraction and precipitation steps to obtain rare earth compounds like oxides and fluorides. Pyrometallurgy involves dissolving rare earth compounds in a molten halide bath, followed by high-temperature electrolysis to convert them into metals, which are then recovered at the cathode. This process typically includes melting, refining, and …

In-Situ Investigations Of Calcium-Magnesium-Aluminosilicates (Cmas) Infiltration Effects On Thermal Barrier Coatings Under Extreme Environments Replicating Jet Engines, Zachary Stein

Doctoral Dissertations and Master's Theses

Calcium-magnesium-aluminosilicate (CMAS) particulates, such as sand or volcanic ash, are ingested by gas turbine jet engines during operation. When operating within high abundance regions, these particulates negatively interact and degrade the high temperature thermal barrier coatings (TBC) protecting underlying superalloy turbine blades vital to engine operation. These CMAS particulates melt within the engine and infiltrate into the ceramic coatings. In electron-beam physical vapor deposited (EB-PVD) TBCs, the CMAS within the intercolumnar gaps stiffens the coatings and causes thermomechanical induced high stress concentrations, risking crack formation. While molten, the CMAS thermochemically alters and destabilizes the coating, also risking coating failure. Premature, …

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 …

Emerging Solid Electrolytes For Solid-State Sodium Batteries: Synthesis And Interface Study., Xiaolin Guo

Electronic Theses and Dissertations

Over the past decade, solid-state batteries have attracted significant attention as the next-generation energy storage technology due to their higher energy density and enhanced safety. Given the abundant sodium (Na) resources relative to lithium (Li), the development of sodium-based batteries has become increasingly compelling. Within a solid-state battery, the solid electrolytes (SEs) serve the dual function of (i) electronically insulating and physically separating the electrodes, and (ii) transporting ions between the anode and cathode. To meet these essential requirements, ideal SEs must process high ionic conductivity with negligible electronic conductivity, robust structural and chemical stability, a wide electrochemical window, and …

Fabrication Of Transparent Conducting Electrodes By Chemical Approaches & Their Application Towards Sensing And Energy Storage, Namuni Sneha

Theses and Dissertations

In the intelligent era, there is a growing demand for developing highly efficient and robust wearable electrodes through simple chemical approaches. We developed highperforming transparent electrodes using interconnected Au nanoparticle networks via a simple liquid-liquid interface approach that offers high conductivity, transparency (>85%), and mechanical durability. Additionally, the prepared electrodes exhibit tunable transmittance and sheet resistance, and the method was also adaptable to various substrates without harsh chemical or thermal treatments.

Furthermore, using Au 1L (1-layer) nanonetwork, a highly transparent breath sensor is fabricated with short response and recovery times (1.1 s and 1.3 s). The Au-1L sensor is …

Crevice Corrosion Mechanisms Of Cocrmo Alloys In Orthopedic Implants: Retrieval Analysis, Nano-Tribocorrosion And Cellular Responses, Hwaran Lee

All Dissertations

Mechanically assisted corrosion and non-mechanically (chemically) driven corrosion in modular junctions of orthopedic implants using cobalt-chromium-molybdenum (CoCrMo) alloys remain clinical concerns and may contribute to implant failure. The underlying corrosion mechanisms are not yet fully understood, leaving a critical research gap. We hypothesized that corrosion in modular junctions may be driven by aggressive local environments, including fretting, metal ion release (cobalt ion, Co²⁺), low pH and reactive oxygen species (ROS). This dissertation aims to (1) analyze corrosion modes and potential causes in modular junctions; (2) identify chemically driven corrosion modes on CoCrMo alloys using simulated inflammatory modular taper …

Shape Memory Behavior In Medium To High Entropy Shape Memory Alloys: Design, Prediction, And Experimental Analysis, Hatim Raji

Theses and Dissertations

This dissertation provides a data-driven system integrating synthetic data generation and machine learning (ML) techniques to create multicomponent SMA compositions with specific transformation temperatures (TTs). Models were trained to represent the nonlinear dependencies influencing martensitic transformation behavior by using elemental, thermodynamic, and process-related aspects. The capacity of the ML models on medium entropy NiTiHfPd and high entropy NiTiHfZrCu systems accuracy was confirmed by experimental validation showing TTs closely matched with model outputs.

Advancing Multi-Physics Modeling For Microwave Heating: Application In Micro-Reactor Design And Optimization, Raghav Adhikari

All Theses

Microreactors are a type of small-scale chemical reactors for achieving reduced volume, improved product selectivity and higher reaction rate. It allows precise temperature control, which is crucial for sensitive chemical processes. Microreactors can be employed as key components of conducting small-scale reactions with improved reactor configuration and process efficiency. It is important to identify a localized and precise heating mechanism to trigger and control the corresponding chemical reactions.

In fact, microwave heating has gathered significant attention in recent years due to its ability to deliver efficient, rapid, and localized heating, which can accelerate reaction rates and enhances the reaction selectivity. …

Synthesis And Characterization Of Magnetic Nanoparticles To Study Effective Magnetic Anisotropy For Biomedical And Catalytic Applications, Alexander Malaj

All Dissertations

This dissertation focuses on understanding how to tune the magnetic properties of nanoparticles through controlling the effective magnetic anisotropy (Keff), which is a key variable in determining a nanoparticle’s Néel relaxation time, which will dictate its magnetic behavior in various applications. In this work, magnetocrystalline anisotropy is tuned by synthesizing tri-metallic substituted ferrite (Fe3-x-yMnxCoyO4) nanoparticles with specific metallic compositions that were informed by computer simulations using density functional theory (DFT) to target magnetocrystalline anisotropy values. A drip synthesis was used to control the size and composition of the tri-metallic ferrites, which were revealed to be monodisperse and compositionally mixed by …

Understanding The Metallic And Oxide Phases In Platinum-Based Bimetallic Heterogeneous Catalysts After High-Temperature Oxidation, Stephen John Porter Jr

Nanoscience and Microsystems ETDs

Platinum (Pt) and palladium (Pd) are critical components in diesel emission control systems, enabling the conversion of harmful pollutants under demanding conditions. However, Pt’s effectiveness is hindered by sintering under high-temperature oxidizing environments. This dissertation investigates how Pt and Pd evolve under oxidizing conditions at 800°C, highlighting their distinct thermodynamic behaviors and interactions. Using TEM, EDS, EELS, XRF, XRD, and EXAFS, we show that Pd suppresses Pt sintering by reducing the volatility of PtO₂, leading to the formation of stable particles. Both Pt and Pd are present in metallic and oxide states, forming biphasic 'Janus' particles with conjoined metal and …

Magnetically Impelled Arc Butt Welding And Straight Tube Butt Welding Analysis Of Boiler Grade Tube Joints, Santhosh Kumar S

Theses and Dissertations

Boiler-graded tubes of T11, T12, T91, and T92 materials with a thickness of 4.5 mm thick and 44.5 mm outer diameter were selected for the Straight Tube Butt Welding process using Hot Wire (STBW-HW) and Cold Wire (STBW-CW) conditions. Moreover, the research investigates and compares the welding characteristics of dissimilar T11 and T91 boiler-graded tubes using STBW - HW & Magnetically Impelled Arc Butt (MIAB) welding techniques. Similar and dissimilar welding was performed in STBW – HW & CW conditions.

In dissimilar welding, the tensile strength was higher in the T11-T91 STBWHW joints of 663 MPa than in the T12-T92 …

Pd-Based Hydrogen Separation Membranes Synthesized Via A Liquid-Phase Route, Chase W. Thompson

Chemical and Biological Engineering ETDs

Palladium (Pd) membranes have gained significant attention for their ability to selectively separate hydrogen, a critical process for clean energy applications such as fuel cells and hydrogen storage. However, challenges such as grain growth, sintering, hydrogen embrittlement, and film uniformity limit their scalability and long-term stability. This thesis focuses on the controlled synthesis, deposition, and stability of Pd nanoparticles to optimize membrane performance for hydrogen separation. This work investigates solution-phase synthesis of Pd nanoparticles, focusing on temperature, precursor concentration, and solvent composition as key variables influencing particle growth and dispersion. Pd membranes were fabricated using nanoparticle deposition onto porous supports, …

In-Situ Defect Detection In Selective Laser Melting Using Convolutional Neural Networks, Ethan Gaigalas

Master's Theses

This thesis develops and trains a convolutional neural network (CNN) to classify defects in metal parts produced by selective laser melting (SLM) using acoustic emission (AE) data. The model successfully identified porosity and standard build layers with high accuracy but consistently struggled to classify lack of fusion (LOF) defects, regardless of input type, normalization, or class count. These results suggest that while AE signals contain distinguishable features for certain defect types, LOF signals may be too subtle or inconsistent for reliable detection. The study addresses the ongoing challenge of in-situ quality monitoring in metal additive manufacturing, where defects like cracks, …

Energy Conversion Materials: Computational Design Of Electrocatalysts Toward Sustainable Energy Applications, Courtney M. Brea

Dissertations, Theses, and Capstone Projects

As the global-scale need for sustainable energy technologies emerges due to anthropogenic climate change, electrocatalysis plays a crucial role in facilitating many sustainable processes. Several heterogenous cathode materials can perform different electrochemical activities using water, oxygen, hydrogen, carbon dioxide to deliver renewable electricity and value-added chemicals. By using the density functional theory method, it is possible to explore the structural and electronic properties that govern a catalysts’ activity and selectivity. In this thesis, we start by exploring 48 reconstructed transition metal dichalcogenides edges (MX₂, M = Mo, W; X = S, Se, Te) for carbon dioxide reduction reaction …

3d Printed Fixed Wing Aircraft Competition, Sidney E. Long, Mitchell Heise, Jack Bride, Daniel Salinas

Mechanical Engineering

Cal State LA and Arlington University, Texas are hosting the same 3D printed, fixed wing aircraft competition for 2025. Cal Poly requires a competitive plane that can adhere to each rule and be piloted remotely to achieve the longest time in the air. The plane must utilize solely 3D printing technology for the wings, body, and all other structures. The only off-the-shelf components can be the motor and electronics, as well as mechanical devices such as hinges.

Thermal Modeling Techniques For Additively Manufactured Porous Metals, Lucas D. Rambo

Master's Theses

Advances in additive manufacturing have enabled the creation of metallic components with tailored porosity, offering design flexibility for thermal, structural, and fluid transport applications. This thesis investigates the effective thermal conductivity (ETC) of porous Inconel 625 (IN625) and Inconel-ceramic composites (IN625-RAM2) fabricated by Laser Powder Bed Fusion (LPBF) using Elementum 3D’s PermiAM technology. Experimental measurements of thermal conductivity using the laser flash method are compared to numerical models built from micro-computed tomography data. Simulations were performed using both finite element (FE) and finite volume (FV) methods to evaluate thermal transport in real microstructures. The study investigates the effects of micro- …