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Articles 31 - 60 of 214

Full-Text Articles in Materials Science and Engineering

Designing Physical And Chemical Confinement In Lithium Sulfur Battery Cathode For Suppression Of Shuttle Effect, Saisaban Fahad Jan 2022

Designing Physical And Chemical Confinement In Lithium Sulfur Battery Cathode For Suppression Of Shuttle Effect, Saisaban Fahad

Electronic Theses and Dissertations, 2020-2023

Lithium sulfur batteries (LSBs) are attracting attention as a next generation energy storage device because of their high energy density (2670WhKg-1), high specific capacity (1675 mAhg-1), low cost and environmental friendliness. However, there are several challenges that need to be overcome before LSBs can be implemented in general applications. This is due to the low electric conductivities of sulfur and lithium sulfide and large volume changes during charge/discharge cycling. Also, most importantly, the dissolution of lithium polysulfides into the electrolyte during cycling leads to capacity decay and low coulombic efficiency. Additionally, these lithium polysulfides can diffuse to the lithium anode …


The Effect Of Heat Transfer On Microstructural Development For Inconel718 Nickel-Based Superalloy In Laser Powder Bed Fusion, Erica Drobner Jan 2022

The Effect Of Heat Transfer On Microstructural Development For Inconel718 Nickel-Based Superalloy In Laser Powder Bed Fusion, Erica Drobner

Electronic Theses and Dissertations, 2020-2023

Inconel 718 (IN718) is a superalloy with excellent corrosion resistance and high temperature stability, giving rise to its popular use in the aerospace industry as well as other high performing applications. This study utilizes the relatively low conductivity of IN718 to focus in on the heat transfer procedures in which occur during the laser powder bed fusion (LPBF) manufacturing process of metals. Cylindrical samples of constant geometry with varying dimensions of thermal supports were fabricated using a compatible IN718 build plate. As thermal support size increased, heat dissipation to the build plate consequently increased. Theoretically, this modification of heat transfer …


Designing The Electrochemical Interface To Enable Lithium Metal Batteries, Supriya Koul Jan 2022

Designing The Electrochemical Interface To Enable Lithium Metal Batteries, Supriya Koul

Electronic Theses and Dissertations, 2020-2023

Although Li-ion battery is one of the most widely used energy storage devices, there have been extensive efforts to push its limit to meet the ever-increasing demands to improve its energy density for applications such as electric vehicles, portable electronics, and grid storages. Here, Li metal anode plays a key role in the next generation energy storage devices, ultimately enabling the anode-free configuration. However, there are major challenges that need to be overcome for a successful deployment of anode-free batteries. These include designing a competitive SEI, low Coulombic efficiency, and the formation of dendrites. To realize an effective anode-free configuration …


In Situ Transmission Electron Microscopy And Ab Initio Study Of The Electrochemomechanical Effect Of Lithium Penetration In Electrolytes For All-Solid-State Batteries, Megan Diaz Jan 2022

In Situ Transmission Electron Microscopy And Ab Initio Study Of The Electrochemomechanical Effect Of Lithium Penetration In Electrolytes For All-Solid-State Batteries, Megan Diaz

Electronic Theses and Dissertations, 2020-2023

Although the past twenty years have seen dramatic advancement in lithium-ion batteries (LIBs), these batteries are nearing their theoretical limit. Next generation energy storage technologies must therefore be developed to meet the ever-increasing demands for batteries with higher capacity, longer cycle lifetime, and increased safety. All-solid-state lithium battery (ASSLIB) technology is one of the promising candidates. It is equipped with a solid-state electrolyte (SSE) replacing the flammable organic liquid electrolyte used in current LIBs. The SSE's high modulus is expected to prevent lithium dendrites and enables the use of a lithium metal anode to contribute to its high capacity without …


Using Peptide Design To Engineer Polyelectrolyte Complex Biomaterials, Sara Tabandeh Dec 2021

Using Peptide Design To Engineer Polyelectrolyte Complex Biomaterials, Sara Tabandeh

Electronic Theses and Dissertations, 2020-2023

The self-assembly of oppositely charged polymers provides a versatile platform to design materials for diverse applications in biology and medicine. Electrostatically-driven phase separation of oppositely charged polymers in aqueous solution gives rise to the formation of a polymer-rich phase called a polyelectrolyte complex (PEC). PECs can be in the form of liquid droplets (complex coacervates) or amorphous solid precipitates. Unlike synthetic polymers, peptides are good candidates for developing tailor-made formulations and structure-property relationships due to their biocompatibility, precise control over sequences, and ability to program hydrogen bonding interactions. However, little is known about the effect of combining additional molecular interactions …


Structural Dynamics And Encapsulation Properties Of Polyelectrolyte Complex Micelles, Sachit Shah Dec 2021

Structural Dynamics And Encapsulation Properties Of Polyelectrolyte Complex Micelles, Sachit Shah

Electronic Theses and Dissertations, 2020-2023

Charged therapeutics such as nucleic acids and proteins can treat a vast range of human diseases that are traditionally undruggable. Their broadness in treating disease is due to their ability to influence cellular function. However, their high charge density and physiological barriers such as enzymatic degradation, hinder the deliverability of these molecules to the sites of disease. Polyelectrolyte complex (PEC) micelles are core-corona nanostructures that can encapsulate charged molecules and offer a platform for delivery. PECs form the core, when two oppositely charged polyelectrolytes are mixed in an aqueous solution, and the micelle corona is a neutral hydrophilic polymer that …


Surface Engineering Of Cerium Oxide Nanocyrstal Dispersions: Colloidal Properties, Ageing Effects, & Electroanalysis, Craig Neal May 2021

Surface Engineering Of Cerium Oxide Nanocyrstal Dispersions: Colloidal Properties, Ageing Effects, & Electroanalysis, Craig Neal

Electronic Theses and Dissertations, 2020-2023

Colloidal materials are highly diverse and present complex physicochemical properties which define their utilities in applications spanning diverse industries. In particular, nano-scale colloids have received tremendous attention due to their unique, specific activities as compared to larger-sized preparations. Within the biomedical sciences, nano-colloids are routinely used as inert carriers of therapeutics and/or diagnostic agents. Beyond this, researchers have developed functional colloids which demonstrate bio-active or diagnostic properties themselves: often related to an optimized, or tuned, surface character. Among these, nanoscale cerium oxide (nanoceria) has shown great promise as a bi-functional, therapeutic material: producing pro- or anti- oxidative chemical response in …


Atomic-Scale Simulation Of Dissipation And Adhesion During Interactions Between Mineral Surfaces, Baochi Doan Jan 2021

Atomic-Scale Simulation Of Dissipation And Adhesion During Interactions Between Mineral Surfaces, Baochi Doan

Electronic Theses and Dissertations, 2020-2023

Adhesion and dissipation during surface interactions are important phenomena with wide applications in materials science, including cold-spray technology for additive manufacturing and stiction in MEMS (Mircro ElectroMechanical Systems). In planet formation theories, energy dissipation in collisions between mineral grains is important to the formation of dust-grain aggregates and planetesimals. Early contact mechanics theories such as Hertz and Johnson-Kendall-Roberts have laid theoretical foundations for understanding these phenomena. Recently, there are breakthroughs in using non-equilibrium thermodynamics methods to elucidate dissipation. For example, the Green-Kubo method can calculate transport coefficients based on the Fluctuation-Dissipation theorem, and Jarzynski equality can be used to determine …


Processing Of 3d Porous Biomaterial Scaffolds To Enhance The In Vitro Breast Cancer Tumor Microenvironment, Zi Wang Jan 2021

Processing Of 3d Porous Biomaterial Scaffolds To Enhance The In Vitro Breast Cancer Tumor Microenvironment, Zi Wang

Electronic Theses and Dissertations, 2020-2023

Tumors contain heterogeneous cell populations within the tumor microenvironment (TME). TME supports tumor progression and development via the function of multiple cell types and cell-extracellular matrix (ECM) interactions. 3D porous biomaterial scaffolds can be a type of in vitro tumor models to mimic TME ECM. Current tumor models lack structural complexity replicating tumor ECM, tunable mechanical properties, and have limited mass exchange between cells and their microenvironment. In this work, we firstly developed scaffolds with a hierarchical pore structure via the Freeze-FRESH(FF) fabrication technique that combines 3D printing and freeze-casting. Later, we studied the effect of varying processing parameters and …


Microstructural Development Of Inconel 625 Nickel-Based Superalloy As Function Of Laser Powder Bed Fusion Parameters, Sofia Nucci Jan 2021

Microstructural Development Of Inconel 625 Nickel-Based Superalloy As Function Of Laser Powder Bed Fusion Parameters, Sofia Nucci

Electronic Theses and Dissertations, 2020-2023

Additive manufacturing (AM) allows fabrication of complex components with features that are impractical or impossible to achieve through conventional methods. Selective laser melting (SLM) powder bed fusion AM technology was selected for this study on Inconel 625, a widely utilized high-temperature alloy that is hard to machine. The present work investigates impact of laser power and scanning speed variations on the resulting characteristics of fabricated IN625 samples. Gas atomized metallic alloy powders were acquired and analyzed through laser diffraction to verify acceptable size distribution. Cubic samples were built with a range of laser scan speeds in 200 mm/s intervals for …


Actin Cytoskeleton Dynamics And Organization Modulated By Macromolecular Crowding, Cation Interaction, And Nanomaterials, Jinho Park Jan 2021

Actin Cytoskeleton Dynamics And Organization Modulated By Macromolecular Crowding, Cation Interaction, And Nanomaterials, Jinho Park

Electronic Theses and Dissertations, 2020-2023

The assembly of actin, the essential cytoskeleton protein, into filaments and bundles/networks is important in various cellular processes including cell movement and morphogenesis. Actin bundle formation occurs in crowded intracellular environments with the aid of actin-crosslinking proteins. The role of actin-crosslinking proteins such as fascin and a-actinin in bundle formation has been investigated, however, how intracellular environments affect actin crosslinker-induced bundle formation is unknown. In the first two parts of this dissertation, we explore the effects of macromolecular crowding and cation interactions on the organization and mechanics of actin crosslinker-induced bundles. To determine how changing environmental conditions modulate actin bundling, …


Uv-Ozone Oxide Treatments For High-Efficiency Silicon Photovoltaic Devices, Munan Gao Jan 2021

Uv-Ozone Oxide Treatments For High-Efficiency Silicon Photovoltaic Devices, Munan Gao

Electronic Theses and Dissertations, 2020-2023

Fabrication of solar cells with higher efficiency, simpler processes and lower cost is largely perceived as the ultimate goal for photovoltaic research. To reach such a goal each step needs to be refined and optimized. In this dissertation, a UV-ozone treatment is proposed as a simple and versatile process that can be applied to multiple fabrication steps for improvement. The UV-ozone cleaning method provides comparable surface cleaning quality to more expensive and hazardous industrial standard RCA clean with less chemical used. A good passivation quality was achieved on both n-type and p-type silicon wafer by a silicon oxide/aluminum oxide passivation …


Solidification Cracking In Binary Al-Cu Alloys Additively Manufactured Through Laser Powder Bed Fusion, Keegan Muller Jan 2021

Solidification Cracking In Binary Al-Cu Alloys Additively Manufactured Through Laser Powder Bed Fusion, Keegan Muller

Electronic Theses and Dissertations, 2020-2023

Laser Powder Bed Fusion (LPBF) is an additive manufacturing technique with growing relevance in industry. However, alloys with a high susceptibility to micro-cracking during solidification cannot be feasibly manufactured through LPBF, such as in selected high-strength Al-alloys. The cracking susceptibility (CS) of Al-alloys varies with composition, so modeling CS with respect to composition is crucial in designing compatible alloys for LPBF. In a theoretical modeling of solidification cracking based on the Scheil equation, the relative CS is taken as the maximum value of |dT/d(fs^1/2)| when solidification is near completion. However, experimental observations of the crack density in Al-alloys suggest that …


Parametric Investigation And Optimization For Inconel 718 Nickel-Based Superalloy In Laser Powder Bed Fusion, Thinh Huynh Jan 2020

Parametric Investigation And Optimization For Inconel 718 Nickel-Based Superalloy In Laser Powder Bed Fusion, Thinh Huynh

Electronic Theses and Dissertations, 2020-2023

Excellent weldability and high temperature stability make Inconel 718 (IN718) one of the most desired alloys to be produced by additive manufacturing (AM). Within the flourishing field of AM technology, laser powder bed fusion (LPBF) is a popular prospective candidate capable of fabricating complex and near net-shape engineering components that traditional manufacturing methods cannot accomplish. In this study, the effects of processing parameters on the relative density and microstructure was investigated. Gas atomized IN718 powders were used to fabricate cuboidal specimens via LPBF for metallographic characterization. The specimens were printed with independently varied laser power (125 - 350 W), laser …


Optimization Studies For The Gas Atomization And Selective Laser Melting Processes Of Al10simg Alloy, Sharon Park Jan 2020

Optimization Studies For The Gas Atomization And Selective Laser Melting Processes Of Al10simg Alloy, Sharon Park

Electronic Theses and Dissertations, 2020-2023

Selective laser melting (SLM) is an additive manufacturing technology that can fabricate complex engineering components using a scanning laser beam to melt consecutive layers of powders with characteristics that significantly influence material properties. Present work investigates both the gas atomization and SLM processes for the Al10SiMg alloy with a focus on establishing the relationships among atomization parameters, powder characteristics, SLM parameters and materials properties. Al10SiMg alloy powders (Al-10wt.%Si-0.5wt.%Mg) were batch-produced through gas atomization by systematically varying the melt flow rate (0.012 - 0.037 kg/s), gas pressure (1.4 - 3.1 MPa), and melt temperature (850C -1000C). The highest yield of 80 …


Designing Metal Nanocatalysts And Tuning Their Microenvironment For Gas-Involving Electrocatalysis, Lin Hu Jan 2020

Designing Metal Nanocatalysts And Tuning Their Microenvironment For Gas-Involving Electrocatalysis, Lin Hu

Electronic Theses and Dissertations, 2020-2023

In the development of renewable energy technologies, electrocatalysis plays a central role in energy conversion processes, such as fuel cells and electrochemical fuel synthesis. Development of such technologies relies on the rational design of electrocatalysts as well as understanding their interaction with the working environment. Here we focus on gas-involving electrocatalytic reactions, particularly nitrogen electroreduction to ammonia and formic acid electrooxidation to carbon dioxide. First, to understand the structure-activity relationships for nitrogen electroreduction on Ru, we prepared a series of size-controlled Ru nanoparticles using atomic layer deposition. Both catalytic activity and selectivity for ammonia production on Ru catalysts strongly depend …


The Reliability Of Through Glass Vias And Solder Joints For Three Dimensional Multi Functional Integrated Systems, Omar Ahmed Jan 2020

The Reliability Of Through Glass Vias And Solder Joints For Three Dimensional Multi Functional Integrated Systems, Omar Ahmed

Electronic Theses and Dissertations, 2020-2023

Three-dimensional (3D) integration technologies, including interposer-based integration, are among the most promising solutions to meet the increased demand for high performance computing, high chip density, and small form factor. Key technologies that enable 3D integration include through-substrate vias and solder joints. Glass is considered as a promising substrate material for interposer-based 3D integration technology especially in radio frequency applications because of glass's high resistivity, low dielectric constant, low electrical loss, and the adjustable coefficient of thermal expansion (CTE). However, during fabrication or service, through-glass vias can suffer from interface delamination and substrate cracking. The problem of copper protrusion is also …


Investigation Of Via Extrusion And The Effect Of Cap Layer For 3d Integrated Circuits, Golareh Jalilvand Jan 2020

Investigation Of Via Extrusion And The Effect Of Cap Layer For 3d Integrated Circuits, Golareh Jalilvand

Electronic Theses and Dissertations, 2020-2023

Copper (Cu) through-silicon via (TSV) is an essential structural and functional element in three-dimensional integration circuits (3D ICs), which offers substantial improvements in integration density, form factor, device performance, and power efficiency. However, Cu-filled TSVs are exposed to multiple thermal cycles during fabrication, test and operation, which lead to the development of considerable thermal stresses, in and around the vias, due to the large mismatch of the coefficient of thermal expansion (CTE) between Cu and silicon (Si). The stress subsequently raises reliability concerns, among which, via extrusion is an important one. Via extrusion can damage the adjacent components, in particular …


Additive Manufacturing Of Copper-Based Alloy By Laser Powder Bed Fusion, Binghao Lu Jan 2020

Additive Manufacturing Of Copper-Based Alloy By Laser Powder Bed Fusion, Binghao Lu

Electronic Theses and Dissertations, 2020-2023

Copper (Cu) and Cu-alloy are good candidates for the engineered components that require good thermal and electrical conductivity. Since industry often needs sophisticated components that cannot be made easily by traditional methods, such as casting, forging and machining, research for additive manufacturing of copper-based alloy is on demand. Therefore, this thesis focuses on the optimization of laser powder bed fusion (LPBF) of Cu-10 wt.% Sn alloy and pure Cu based on their characteristics such as relative density/porosity, surface roughness, phase constitutes, melt pool dimension, and dendrite arm spacings dimension, determined by optical microscopy, X-ray diffraction and Scanning electron microscope. LPBF, …


Mechanical Behavior Assessment Of Ti-6al-4v Alloy Produced By Laser Powder Bed Fusion, Asif Mahmud Jan 2020

Mechanical Behavior Assessment Of Ti-6al-4v Alloy Produced By Laser Powder Bed Fusion, Asif Mahmud

Electronic Theses and Dissertations, 2020-2023

The present work correlates quasi-static, tensile mechanical properties of additively manufactured Ti-6Al-4V (Grade 23) alloy to the phase constituents, microstructure and fracture surface characteristics that changed with post-heat treatment of stress relief (670 °C for 5h) and hot isostatic pressing (HIP with 100MPa at 920 °C for 2h). Ti-6Al-4V alloy tensile specimens in both the horizontal (i.e., X and Y) and vertical (Z) directions were produced by laser powder bed fusion (LPBF) technique. Mechanical properties were determined using quasi-static, tensile testing for both the as-stress-relieved (ASR) and HIP specimens. For the ASR and HIP samples built in X, Y and …


Enhancement Of Absorptance By Ultrafast Laser Pulse Shaping For Efficient Laser Processing Of Thin Polymers, Arifur Rahaman Jan 2020

Enhancement Of Absorptance By Ultrafast Laser Pulse Shaping For Efficient Laser Processing Of Thin Polymers, Arifur Rahaman

Electronic Theses and Dissertations, 2020-2023

Ultrashort-pulsed lasers have been used for high precision processing of a wide range of materials including dielectrics, semiconductors, metals, and polymers/polymer composites, enabling numerous applications ranging from micromachining, photonics to life sciences. However, there are challenges when applying this technology in the industry, which requires scale and throughput different from lab use. The goal of this research is to understand how ultrafast laser pulses interact with thin polymers/polymer composite materials and develop a method that is efficient for ultrafast laser processing of these materials. It is a common practice in industrial applications to run the laser at a high repetition …


Development Of Facile Microfabrication Technologies For The Fabrication And Characterization Of Multimodal Impedimetric, Plasmonic, And Electrophysiological Biosensors, Cacie Hart Jan 2020

Development Of Facile Microfabrication Technologies For The Fabrication And Characterization Of Multimodal Impedimetric, Plasmonic, And Electrophysiological Biosensors, Cacie Hart

Electronic Theses and Dissertations, 2020-2023

The objective of this dissertation was to develop novel methods of patterning inorganic and organic materials, develop biocompatibility evaluations, and subsequently apply these methods toward developing biosensors and lab-on-a-chip devices, such as Interdigitated Electrodes (IDEs) and Microelectrode Arrays (MEAs) on non-traditional (such as nanostructured and plasmonic) polymer substrates or deploy these methods to enhance precision cellular placement on traditional (glass) MEA substrates. It was hypothesized that a combination of such facile microfabrication techniques and patterning technologies on traditional and non-traditional substrates would increase the sensitivity and selectivity of such sensor platforms by several orders of magnitude, and potentially introduce new …


Integrating Graphene Into Polymer Derived Ceramics Towards The Development Of New Thermoelectric Materials, Elizabeth Barrios Jan 2020

Integrating Graphene Into Polymer Derived Ceramics Towards The Development Of New Thermoelectric Materials, Elizabeth Barrios

Electronic Theses and Dissertations, 2020-2023

Radioisotope thermoelectric generators (RTGs) have been an enabling technology for the exploration of deep space since the dawn of the Space Age. Since its first deployment in a meteorological satellite in the late 1960's, RTGs have been used to provide solid-state, maintenance-free power to 27 American spacecraft and scientific instruments. While showing great success in the past, the future usage of thermoelectric devices is limited by the low operating efficiencies and the use of hazardous or expensive materials, limiting the use of thermoelectric technologies to niche applications such as space exploration. Current research efforts that address these disadvantages have focused …


Development Of 3d Porous Chitosan-Based Platform For In Vitro Culture, Kailei Xu Jan 2020

Development Of 3d Porous Chitosan-Based Platform For In Vitro Culture, Kailei Xu

Electronic Theses and Dissertations, 2020-2023

Three-dimensional (3D) cell cultures have been widely used in biological research since two-dimensional (2D) cultures have many limitations including alteration of cell morphology, metabolic pathways and gene expression. Therefore, the application of 2D cell cultures in pharmaceutical companies for drug screening causes reproducibility issues in animal studies, which strongly influences the efficiency of drug development. The aim of my studies is to develop 3D cell culture models to better mimic the extracellular matrix (ECM) in tumor microenvironment, not only for deeper understanding of interaction between cells and ECM, but also for the application in drug screening. Three different compositions of …


Characterization Of Contact Resistance Properties Of Different Tlm Structure Designs, Nicole A. Karam Pannaci Jan 2020

Characterization Of Contact Resistance Properties Of Different Tlm Structure Designs, Nicole A. Karam Pannaci

Digital Repository: Showcase of Undergraduate Research Excellence

No abstract provided.


Understanding Solidification Behavior Of Selected Aluminum And Magnesium Alloys Additively Manufactured By Laser Powder Bed Fusion, Holden Hyer Jan 2020

Understanding Solidification Behavior Of Selected Aluminum And Magnesium Alloys Additively Manufactured By Laser Powder Bed Fusion, Holden Hyer

Electronic Theses and Dissertations, 2020-2023

Additive manufacturing (AM), also known as 3D printing, has demonstrated the ability to produce customized, complex engineering components from metallic alloys, not previously possible with traditional techniques such as subtractive machining of cast alloys. However, many desired lightweight metallic alloys such as high strength aluminum (Al) and magnesium (Mg) alloys, cannot be processed dense with AM due to the consequence of solidification cracking. Thus, a large knowledge gap remains in assessing already existing, and genesis of new alloys that can be processed dense by AM, without solidification cracking. The present work investigates the AM processing and solidification behavior of selected …


Atomic Layer Deposition Of Oxide Materials For Passivated Carrier Selective Contact Solar Cells, Geoffrey Gregory Jan 2020

Atomic Layer Deposition Of Oxide Materials For Passivated Carrier Selective Contact Solar Cells, Geoffrey Gregory

Electronic Theses and Dissertations, 2020-2023

Silicon-based devices have dominated the industrial solar cell marketplace for several decades, thanks to the low bulk defect concentration and technological relevance of silicon substrates. This has led to an oversupply of dopant-diffused homojunction technologies, which suffer from significant performance losses at the metal-silicon contact interface. In response, the research community has developed carrier-selective heterojunction contacts, which separate the metal from the silicon absorber with heavily-doped silicon layers. These novel contacts provide the same asymmetrical conductivity as the diffused junction in the previous generations of silicon solar cells, but with less processing complexity and greater device performance. Still, the silicon …


Non-Linear Inverse Liquid-Solid Chromatography As A Methodology To Characterize Drug Concentration Losses To Polymeric Materials Used In Body-On-A-Chip Devices For Drug Discovery, Mark Schnepper Jan 2020

Non-Linear Inverse Liquid-Solid Chromatography As A Methodology To Characterize Drug Concentration Losses To Polymeric Materials Used In Body-On-A-Chip Devices For Drug Discovery, Mark Schnepper

Electronic Theses and Dissertations, 2020-2023

Body-on-a-chip and human-on-a-chip systems are currently being used to augment and could eventually replace animal models in drug discovery and basic biological research. However, hydrophobic molecules, especially therapeutic compounds, tend to adsorb to the polymer materials used to create these microfluidic platforms, which may distort the dose-response curves that feed into Pharmacokinetic/Pharmacodynamic (PK/PD) models which translate preclinical data into predictions of clinical outcomes. Adsorption of hydrophobic molecules to these polymer materials needs better characterization. Inverse Liquid-Solid Chromatography paired with a numerical optimization based on the Langmuir model of adsorption was used to characterize the adsorption isotherm parameters of selected drugs …


Diffusion Of Fission Products In Nuclear Graphite, Kevin Graydon Jan 2020

Diffusion Of Fission Products In Nuclear Graphite, Kevin Graydon

Electronic Theses and Dissertations, 2020-2023

The next generation of nuclear reactors (Generation IV) are specified to use graphite as the choice material for neutron moderation and structural components. For this reason, study of diffusion behavior of the fission product, ruthenium (Ru), in the candidate graphite grades, POCO AXF-5Q & ZXF-5Q, IG-110, NBG-18 and PCEA, is necessary. Diffusion data for Ru in these grades is absent due to the lack of prior studies and this work aims to fill this void and begin the study of this metallic fission product's diffusion behavior. By utilizing physical vapor deposition (PVD), dynamic secondary ion mass spectroscopy (SIMS), and the …


Cerium Oxide Based Nanocomposites For Supercapacitors, Aadithya Jeyaranjan Jan 2020

Cerium Oxide Based Nanocomposites For Supercapacitors, Aadithya Jeyaranjan

Electronic Theses and Dissertations, 2020-2023

Access to clean, and sustainable energy is one of the biggest challenges of our generation. With the rapid growth of renewable energy harvesters, developing electrochemical energy storage devices (EEDs) that respond well to them is of significant interest. Supercapacitors are a class of EEDs with exceptional power densities and ultra-long cycle life. These properties make them an attractive candidate as a replacement, or to be used in combination with batteries and other EEDs. In this dissertation, nano cerium oxide (nano CeO2) based materials are examined as an active material for supercapacitor applications. The first part of this work details how …