Other Materials Science and Engineering Commons^™

Intensification Of Thermal Energy Storage Systems Based On Sodium Nitrate, Hari Suthan V Mr

Theses and Dissertations

Thermal energy storage (TES) systems employing phase change materials (PCM) bridge the gap between thermal energy demand and supply. The low thermal conductivity of sodium nitrate (NaNO3), an inorganic PCM for high-temperature TES systems restricts charging and discharging kinetics, reducing system-level performance. This thesis investigates the intensification of sodium nitrate-based thermal energy storage systems through the incorporation of different classes of additives. Metal oxides (zinc oxide and aluminium oxide) and carbon-based materials (graphene oxide (GO) and expanded graphite (EG)), were incorporated into NaNO3 to improve its thermophysical properties (thermal conductivity, latent heat, specific heat).

Composites were prepared using low-energy ball …

Investigating The Effects Of Draw Parameters On The Refractive Index Profiles Of Phosphosilicate Fibers, Brandi Baldus

All Theses

P₂O₅ is a common dopant core material in silica-based glass optical fibers, in part due to its ability to increase the refractive index of silica, required for the fiber to guide light. However, P₂O₅-doped fibers can show a significant decrease in the refractive index profile compared to that of the parent preform. The question arises as to whether the refractive index decreasing could be a direct result of the fiber draw process and, if so, what is it about the draw process that causing such changes in phosphosilicate fibers. More specifically, this Thesis explores the hypothesis that these draw-induced reductions …

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 …

Microstructural Shielding And Advanced Fatigue Crack Analysis In The Presence Of Deformation Twinning, Seyed Ali Asli

All Dissertations

Design methods to mitigate fatigue failures have remained relatively stagnant, as engineers have relied on existing continuum-level models and adhered to the damage tolerance design methodology. Although damage-tolerant design has led to increased safety, extended component in-service life, and better life predictions, it still relies on maintenance routines to identify dangerous cracks. This research aims to test the hypothesis that bundles of deformation twin boundaries will increase the resistance to fatigue crack growth (FCG). Slip and twinning are two dominant mechanisms of plastic deformation in metals. Slip is more common in materials with face-centered cubic (FCC) crystal structures at room …

Efficient And Scalable Visual Computing For Nanoscale Imaging, Hao Wang

All Dissertations

Nanoscale analysis often relies on instrument-mediated scientific imaging methods to capture visual signals that are difficult to observe, interpret, or quantify through ordinary perception alone. These domains are often characterized by low signal quality, limited annotations, complex morphology, non-natural visual statistics, and strong dependence on physical acquisition processes. This dissertation focuses on efficient visual computing for nanoscale imaging, with an emphasis on the representation, reconstruction, and analysis of high-resolution scientific visual data. In our early work, we relied on rule-based algorithms and conventional machine learning methods for feature extraction. However, these approaches struggle to scale with the increasing complexity and …

Multifunctional Engineering Of Manganese Malate For Supercapacitors, Krithika M Ms

Theses and Dissertations

Supercapacitors are promising energy storage devices owing to their rapid charge-discharge capability and long cycle-life. Based on the charge storage mechanism, supercapacitors are broadly categorised into electric double-layer capacitors (EDLCs), pseudocapacitors and hybrid capacitors. In this work, manganese malate (MnM) is systematically developed as a versatile electrode material for supercapacitor applications through rational synthesis, textural engineering, compositional modification, phase transformation and sustainable resource utilisation.

In Chapter 2, MnM was electrodeposited onto stainless-steel foil via chronoamperometry at 2, 3 and 4 V. MnM electrodeposited at 2 V (MnM2) exhibits a specific capacitance of 186 F g-1 at 1 A g-1 with …

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 …

Synthesis, Characterisation, And Electrochemical Performance Of Efb-Derived Biochar-Metal Oxide Composite Electrodes For Hybrid Supercapacitors, Yogini Gunasekaran

Student Works (2020-2029)

Supercapacitors are essential for energy storage due to their high-power density and longevity, particularly in increasing demand for sustainable energy. However, their low energy density and specific capacitance hinder widespread use. Advancements in next-generation electrode materials that are high-performing, cost-effective, and scalable are necessary to address these issues. Herein, this work reports the development of novel electrode materials and explores the fundamental relationship between their structural properties and electrochemical performance in supercapacitors. In this study, biochar was derived from oil palm Empty Fruit Bunch (EFB) via a gasification process. Different samples of metal oxide/biochar composites were subsequently synthesized using a …

Machine Learning Assisted Development Of Al0.2cufemnni High Entropy Alloy Through Selective Laser Melting, Hareharen K Mr

Theses and Dissertations

High Entropy Alloys (HEAs) are an emerging class of advanced materials that have gained significant attention due to their exceptional mechanical strength, thermal stability, and structural performance. Unlike conventional alloys based on a single principal element, HEAs are composed of multiple elements in a near-equiatomic ratio. Despite these advantages, designing HEAs with tailored properties is difficult because of the enormous number of possible combinations and the limitations of traditional trial-and-error methods. To overcome these challenges, this study presents a machine learning (ML) based approach to accelerate the design and development of an HEA.

In this work, a newly designed composition, …

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 …

Synthesis And Performance Evaluation Of Zeolite-Based Ni–Cao For Integrated Co2 Capture And Conversion, Zhang Xinggang

Student Works (2020-2029)

Carbon capture and utilization (CCU) is increasingly being adopted as a strategy to minimize carbon dioxide (CO₂) emissions. Integrated CO₂ capture and utilization (ICCU) is more attractive as it reduces overall cost and energy consumption by eliminating the need for gas compression and transportation. Advances in ICCU and the development of dual functional materials (DFMs) capable of adsorbing and in situ converting CO₂ have attracted increasing attention in both academia and industry, driven by the need for efficient CO₂ utilization pathways. After a detailed analysis of the literature, zeolites have emerged as prominent materials for use as adsorbents and catalyst …

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 …

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 …

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 …

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 …

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 …

Towards All-Epitaxial Josephson Junctions With High-Temperature Superconductors, Daniela Amalfi Ojeda

UNF Graduate Theses and Dissertations

Josephson junctions are fundamental components of superconducting electronics. Although junctions based on conventional superconductors are well established, reproducible devices based on high-temperature superconductors remain challenging. This work investigates the growth, fabrication, and electrical characterization of all-epitaxial DyBa₂Cu₃O₇₋ₓ (DBCO) /SrTiO₃ (STO) /DBCO trilayer heterostructures for potential Josephson junction applications. An initial optimization of YBa₂Cu₃O₇₋ₓ (YBCO) growth produced reproducible films with a zero-resistance critical temperature ( ) of K and a maximum  of 89 K. These growth conditions were adapted to DBCO, resulting in reproducible superconducting films with values of approximately 80 K. DBCO/STO/DBCO trilayers were grown by molecular beam epitaxy and …

Investigating The Effects Of Pressure On Fe And Co Intercalated 2h-Tas2 Through First-Principle Calculations, Ronald E. Putnam Jr.

UNF Graduate Theses and Dissertations

Using first-principles methods, we investigate the effects of applied isotropic pressure on the electronic and magnetic properties of intercalated Fe1/3TaS2 and Co1/3TaS2. Fe1/3TaS2 has been shown to be a ferromagnet that undergoes structural and magnetic phase transitions under applied pressure. The magnetic phase transitions are observed to be linked to the structural shift, and a mixture of magnetic phase states is present between 3 GPa and 6 GPa. Co1/3TaS2 was found to be antiferromagnetic, as confirmed by experimental work. One- and two-unit-cell systems of Co1/3TaS2 are analyzed, both showing band splitting that disappears under pressure. The application of pressure forces …

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 …

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. …