Materials Science and Engineering Commons^™

Machine Learning Mosa Monitoring System, Aditya G. Manjunath, Sabahudin Vrtagic, Fatih Dogan, Milan Dordevic, Mileta Zarkovic, Jasmin Kevric, Goran Dobric

Materials Science and Engineering Faculty Research & Creative Works

This research paper deals with the problem of Metal-Oxide Surge Arrester (MOSA) condition monitoring and a new methodology in surge arrester monitoring and diagnostics is presented. A machine learning algorithm (back propagation regression) is used to estimate the non-linearity coefficient of the surge arrester, based on operating voltage and leakage current of the arrester. Using a simulated system, this research investigates the possibility of application and efficiency of machine learning. It is shown that the applied learning algorithm results are competitive with the model results parameters calculated as R2 = 0.999 and mean absolute real error computed as 0.005 which …

Modeling Hierarchical Porous Electrodes With Tailored Anisotropic Structure, Debanjan Sarker

All Theses

Modern electric vehicles and consumer electronics applications demand high specific energy from Li-ion batteries, which can be charged and discharged faster. In the search for high specific energy, researchers have tried to make thicker battery electrodes which contain a greater proportion of active material. While chemical and structural modification of electrodes can help to increase the electronic conductivity of active material, the microstructure of porous electrodes can be engineered to enhance ion transport for fast charge and discharge. Previous research has shown that macropores introduced by directional freeze tape casting can enhance the performance of thick porous electrodes. For instance, …

Synthesis And Consolidation Of The Aluminosilicate Mineral Anorthite, Lauren E. Eccles

Pursuit - The Journal of Undergraduate Research at The University of Tennessee

Solid-state ceramic synthesis is a fabrication process involving high temperature reactions of solid component powders and is used to prepare materials with novel and advanced properties. Regarding synthetic mineral ceramics, the solid-state process makes it possible to design synthetic minerals with specific compositions and properties not commonly found in their natural, comparatively impure, counterparts. This study focuses on the synthesis of the feldspar anorthite, CaAl₂Si₂O₈, via solid-state procedures and the densification of the synthesized powders using the technique of uniaxial hot-pressing. Constituent powders of aluminum sesquioxide (Al₂O₃), silicon dioxide (SiO …

The Effects Of Curing Temperature On The Hydration Kinetics Of Plain And Fly Ash Pastes And Compressive Strength Of Corresponding Mortars With And Without Nano-Tio2 Addition., Dan Huang, Mirian Velay-Lizancos, Jan Olek

International Conference on Durability of Concrete Structures

Incorporation of fly ash in cementitious systems containing ordinary portland cement (OPC) increases their long-term strength and durability. However, replacement of cement by fly ash also reduces the heat of hydration of such systems and reduces early-age strength development. The reduced rate of strength development can increase the risk of durability problems, e.g. scaling, in cases when young concrete is exposed to low temperatures and deicing chemicals. This study investigated the potential of nano-titanium dioxide (nano-TiO₂) particles to modify the hydration kinetics of fly ash pastes and compressive strength development of corresponding mortars cured under low (4°C) and …

Corrosion Performance Of Embedded Steel Bar In Cl--Contaminated Limestone Calcined Clay Cement (Lc3) At Initial Stage Of Hydration, Weiwen Li, Zuhua Xu, Yaocheng Wang, Xin Wang, Feng Xing

International Conference on Durability of Concrete Structures

Limestone Calcined Clay Cement (LC3) presents brilliant properties in binding Cl^- so that the embedded steel bars are probably protected in Cl^--contaminated condition, which meets the need of sea sand application. However, the corrosion performance of steel bars embedded in LC3 paste with Cl^‑ is unclear, especially in early age hydration. Thus, a series of experiments were carried out to evaluate the corrosion performance of steel bars on initial and hardened stages of hydration, including concentration of OH^- and Cl^- in real pore solution, open circuit potential (OCP) and chemical elements of steel bars. …

Fracture Response Of Wollastonite Fiber-Reinforced Cementitious Composites: Evaluation Using Micro-Indentation And Finite Element Simulation, Sami Doner, Gideon A. Lyngdoh, Sumeru Nayak, Sumanta Das

Faculty Publications - Biomedical, Mechanical, and Civil Engineering

The paper presents indentation studies on wollastonite fiber incorporated cementitious systems. The acicular nature of the fibers is poised to delay the coalescence of micro-cracks in such systems thus leading to tougher building materials. Towards that end, load-penetration depth results from the indentation studies are employed to ascertain elastic and fracture properties of wollastonite-incorporated cementitious composites. While up to 10% mass-based cement-replacement by wollastonite results in comparable elastic moduli as compared to conventional binders, the fracture toughness increases by as much as 33%. In order to gain insights into the toughening mechanisms brought about by the fine fibers, a microstructure-guided …

Evaluating The Effects Of Granulated Rubber And Glass Fibers In Polymer Concrete As A Structural Material For Wafer Grinding Machines, Kevin Gabriel Kuehn, Philip Randall Streeter

Materials Engineering

Polymer concrete is a composite material used to replace cast iron and steel in wafer grinding machines for vibration damping. During the grinding and lapping processes of manufacturing silicon wafers, excessive vibrations may cause subsurface damage which requires additional polishing and reduces yield. Nine compositions containing various levels of granulated rubber and glass fibers were manufactured. CRM WRF-10 granulated rubber was examined at 0%, 5%, and 10% and Corning Cem-Fil glass fibers were added at 0%, 0.5%, and 1% by weight. Smooth-On EpoxAcast 690 epoxy resin was held constant at 16% for each composition. Crushed granite aggregate from Martin Marietta, …

Model-Based Design Of An Optimal Lqg Regulator For A Piezoelectric Actuated Smart Structure Using A High-Precision Laser Interferometry Measurement System, Grant P. Gallagher

Master's Theses

Smart structure control systems commonly use piezoceramic sensors or accelerometers as vibration measurement devices. These measurement devices often produce noisy and/or low-precision signals, which makes it difficult to measure small-amplitude vibrations. Laser interferometry devices pose as an alternative high-precision position measurement method, capable of nanometer-scale resolution. The aim of this research is to utilize a model-based design approach to develop and implement a real-time Linear Quadratic Gaussian (LQG) regulator for a piezoelectric actuated smart structure using a high-precision laser interferometry measurement system to suppress the excitation of vibratory modes.

The analytical model of the smart structure is derived using the …

Near-Earth Ion Irradiation Effects On Functional Ceramic Materials: A Combined Experimental-Monte Carlo Approach, William J. Sands

All Theses

The near-Earth space radiation environment is a complex system that creates a harmful environment for materials to operate in. Motivated by the search for using optical defects as an indicator of radiation damage, five single-crystal functional ceramic materials were selected to undergo ion irradiation at conditions found in the near-Earth space environment. Due to the complex nature of ion irradiation effects in ceramic materials, a host of calculations and experimental characterization methods were used. Calculations using the 2013 SRIM code were used to evaluate the ion projected range and the type and number of defects (vacancies) created by ion irradiation. …

Synthesis Of Monodisperse Nanoscintillators At High Temperatures For Biomedical Relevant Applications, Eric Zhang

All Dissertations

Luminescent sub-100 nm particulates continuously generate immense research interest in the biomedical field for imaging, theranostics, and optogenetics. Conventionally, upconversion nanoparticles or UV activated semiconductors are studied, however these materials are limited by biological barriers such as the skin which reduces the penetration depth of these excitation sources, tissue's auto- fluorescence, and toxicity. One approach to overcome these challenges is to use nanoscintillators (sub-100 nm materials that can generate visible light using high energy excitation sources such as x-rays) which can generate light locally to the human body. Numerous scintillators have been reported since the discovery of x-rays from the …

Is There Any Role Of Reduction Mammoplasty In Decreasing Breast Cancer Risk In Gigantomastia?, Fatma Nilay Tutak, Fatih Dogan

Materials Science and Engineering Faculty Research & Creative Works

Aim: Large breasts create psychological and physical problems in women, all of whom must also keep in mind the common problem of breast cancer. In the present study we examine the effect of breast reduction surgery on breast cancer risk. Materials and Methods: Our retrospective study is based on the records (between June 1, 2014, and June 30, 2019) of patients who underwent breast reduction surgery in the Plastic, Reconstructive and Aesthetical Surgery clinic of a training and research hospital. Statistical analyses were conducted using IBM SPSS Statistics (Version 25.0. Armonk, NY:IBMCorp.). Normal distribution of the data was analyzed with …

Manufacturing Of A Ceramic Turbine Rotor For A Compact Jet Engine, Bryan T. Leicht

Theses and Dissertations

The primary goal of this study was to develop a low-cost, timely, scalable manufacturing method that produced a ceramic turbine that can be tested as a drop-in replacement on a JetCat P400 small scale gas turbine engine. This research compared two processes for manufacturing a ceramic turbine utilizing a pour casting method and 3D printing using stereolithography ceramic manufacturing (SLCM). The pour casting method used Silicon Nitride to create a cast turbine using a sacrificial 3D printed mold. The SLCM method evaluated producing an alumina turbine using an ADMATEC Admaflex 300 SLCM printer to directly print a ceramic turbine. This …

Thermal Considerations For Film Cooling Materials With Anisotropic Thermal Conductivity, Carol E. Bryant

Theses and Dissertations

Higher performance requirements and reduced core sizes are driving increases in turbine inlet temperature in gas turbine engines, surpassing the melting point of advanced materials. Newer materials, such as composites, are being introduced into the hot sections of gas turbine engines. Components in the hot section use film cooling to prevent melting. One unique aspect of some high-temperature composites is they have a bulk anisotropic thermal conductivity, therefore heat flow differs relative to traditional metallic components. Film cooling designs can be revolutionized by leveraging anisotropy in high-temperature materials. The purpose of this research is to examine thermal considerations for using …

The Effect Of Sodium Polymethacrylate On The Rheology Of The Positive Paste And Performance Of The Lead-Acid Battery, Julian Kosacki, Dimitri Feys, Fatih Dogan

Materials Science and Engineering Faculty Research & Creative Works

No abstract provided.

Mechanical Properties Of Boride Based Ceramics, Alec Murchie

Doctoral Dissertations

“This research focuses on the elevated mechanical properties of diboride based materials at room and elevated temperatures. These materials include a ZrB₂ ceramic, a ZrB₂-WC-SiC ceramic, and a (Hf,Mo,Nb,Ta,W,Zr)B₂ high entropy boride (HEB). The room temperature flexural strength for the ZrB₂ ceramic was 447 MPa and the fracture toughness was 2.3 MPa·m^1/2. The strength decreased to 196 MPa at 1800°C, and then increased to 360 MPa at 2300°C. The fracture toughness increased to 3.1 MPa·m^1/2 at 2200°C. The strength up to 1800°C was likely controlled by a combination of effects: surface damage …

Joining Of Ultra-High Temperature Ceramics To The Same And Refractory Metals Via Fusion Welding, Jecee Jarman

Doctoral Dissertations

"This research focuses on the joining of ultra-high temperature ceramics to either themselves or refractory metals/alloys via fusion welding and the mechanical strength of produced joints. The ceramics studied consisted of compositions within a diboride-carbide-carbide ternary system while metals studied consisted of molybdenum and a molybdenum alloy. SiC-ZrB2-ZrC ceramics on a binary join between pure SiC and the ternary eutectic composition were found to be weldable when SiC content was below ~57.5 vol%. Compositions above 57.5 vol% SiC were unweldable based on pitting and off-gassing behavior. Welded strength of ceramics was ~180-300 MPa in the SiC-ZrB2-ZrC ternary eutectic composition, ~180-220 …

Assembly Of Alumina Particles In Aqueous Suspensions Induced By High‐Frequency Ac Electric Field, James E. John, Shizhi Qian, Dipankar Ghosh

Mechanical & Aerospace Engineering Faculty Publications

The role of high-frequency alternating current (AC) electric field in the assembly of alumina particles in aqueous media was investigated. Field–particle interactions were in situ investigated for coarse and fine powder particles in very dilute suspensions. For both coarse and fine particles, AC field-induced assembly led to the formation of chains of particles within a minute, which were aligned in the field direction. However, a much finer network of particle chains evolved in fine particle suspensions. Threshold field strength for chain formation was also lower for fine particles (28 V/mm) than for coarse particles (50 V/mm), suggesting stronger interactions for …

Thermochemical Water-Splitting Using Novel High-Entropy Perovskite Oxides, Hector Alexis De Santiago Hernandez

Graduate Theses, Dissertations, and Problem Reports (ETD)

In this project, we designed, synthesized, and tested the transformative (La_0.8Sr_0.2)(Mn_[1-x]/3Fe_[1-x]/3Co_xAl_[1-x]/3)O₃ (0 ≤ x ≤ 1.0) high-entropy perovskite oxides (HEPOs) as redox active oxygen carriers for thermochemical hydrogen production with improved stability, kinetics, and H₂ yield. The developed HEPOs form an R3c (hexagonal) phase and were successfully synthesized using both the Pechini and solid-state reactions with the latter synthesis being the primary source for testing. These innovative perovskites demonstrated an improved kinetics with oxygen surface exchange coefficient, k, greater than 7.5 x 10^-4 cm/s, …

Controlling The Thermal And Electrical Properties Of Camno3-Δ Based Perovskite Ceramics, Sergio Andres Paredes Navia

Graduate Theses, Dissertations, and Problem Reports (ETD)

Most of the energy lost during the conversion process comes in the form of waste heat. The world's energy consumption loses over 60% of its energy after conversion. In order to increase the efficiency of the conversion process, it is essential to harness waste heat and reutilize this energy resource. Heat recovery technology as thermoelectric (TE) technology is one of the growing alternatives to harvest excessive amounts of energy lost as waste heat for a more efficient, safe, and sustainable future. Due to the Seebeck effect, TE materials have the potential to convert waste heat directly into electricity, improving efficiency …

Carbon Monoxide Sensing Of Nickel Oxide At 1000 ℃ To 1200 ℃ For In Situ Combustion Control: Behavior, Mechanism, And Application, Yi Wang

Graduate Theses, Dissertations, and Problem Reports (ETD)

An advanced smart sensor network is essential to a combustion system, which is in favor of in situ, locally placed, and low-cost gas sensors. However, most chemical/electrochemical sensors fail to work in a combustion boiler, due to the demanding working temperatures (> 1000 ℃). This work for the first time reports a well-functioning mixed-potential type CO sensor at 1000 ℃ - 1200 ℃ using nickel oxide (NiO) as the sensing material. The influence of feed gas flow rate, electrode thickness, and porosity on sensor behavior is investigated, delivering notable and fast responses to 1000 ppm in 3% O₂: …

Modeling, Fabrication, And Characterization Of Rf-Based Passive Wireless Sensors Composed Of Refractory Semiconducting Ceramics For High Temperature Applications, Kavin Sivaneri Varadharajan Idhaiam

Graduate Theses, Dissertations, and Problem Reports (ETD)

Real-time health monitoring of high temperature systems (>500^oC) in harsh environments is necessary to prevent catastrophic events caused by structural failures, varying pressure, and chemical reactions. Conventional solid-state temperature sensors such as resistance temperature detectors (RTDs) and thermocouples are restricted by their operating environments, sensor dimensions and often require external power sources for their operation. The current work presents the research and development of RF-based passive wireless sensing technology targeting high temperatures and harsh environmental conditions. Passive wireless devices are generally classified as near-field and far-field devices based on the interrogation distance. Near-field sensors are placed at …

An Electrochemical-Mechanical Investigation Of Next Generation Lithium Metal Electrode And Solid Electrolyte, Andrew Meyer

Theses and Dissertations--Chemical and Materials Engineering

Lithium-ion batteries (LIBs) are a staple in today’s society. From our cellphones, laptops, power tools, the ever-growing electric vehicle, and many more application, LIBs are more important to us than most realize. They provide the best combination of both high-energy and high-power density compared to other battery types such as Ni-Cd, Ni-MH, or the lead acid batteries used in our cars. Plus, LIBs are much safer. However, as new technologies grow and are developed, the demand for higher energy and power density, better safety, lower costs, and longer life increases. One way to achieve the ever-increasing demands is to replace …

The Effect Of Air-Entraining On Concrete Durability, Jane Magdy Aziz Abadir

Archived Theses and Dissertations

No abstract provided.

Deep Learning-Guided Prediction Of Material’S Microstructures And Applications To Advanced Manufacturing, Jianan Tang

All Dissertations

Material microstructure prediction based on processing conditions is very useful in advanced manufacturing. Trial-and-error experiments are very time-consuming to exhaust numerous combinations of processing parameters and characterize the resulting microstructures. To accelerate process development and optimization, researchers have explored microstructure prediction methods, including physical-based modeling and feature-based machine learning. Nevertheless, they both have limitations. Physical-based modeling consumes too much computational power. And in feature-based machine learning, low-dimensional microstructural features are manually extracted to represent high-dimensional microstructures, which leads to information loss.

In this dissertation, a deep learning-guided microstructure prediction framework is established. It uses a conditional generative adversarial network (CGAN) …

Creep Behavior And Deformation Mechanisms Of Spark Plasma Sintered Oxide Ceramics For Aerospace Systems At 1300˚C - 1400˚C, David D. Swanson

Theses and Dissertations

The mechanical behavior of YAG and LuAG was investigated at elevated temperatures. The specific materials investigated in this work include high-purity, polycrystalline YAG, high-purity, polycrystalline LuAG, and two doped variants of YAG: 2at% Yb-doped, polycrystalline YAG and 2at% Er-doped, polycrystalline YAG. Several billets of each material were prepared and processed by means of spark plasma sintering (SPS). Many different sintering parameters were utilized in order to obtain materials with various physical properties and to identify the effects of sintering parameters on the average grain size of the resulting materials. The compressive creep behavior of these materials was investigated at 1300°C …

Automated Mini-Tubular Ceramic Production, Hunter Brooks, Daniel Freeman, Leo Taranta-Slack

Mechanical Engineering

Researchers at Lawrence Livermore National Laboratory need a way to increase the rate of manufacturing of mini-tubular ceramics to be used in testing particulate air filters. This document outlines our process from researching and writing an initial scope of work all the way to fabricating and testing a final prototype. This journey takes us through the background research, ideation process and selection of a final design. We also detail the desired engineering specifications and our concept selection process. We dedicate a significant portion of this report to discussion of our final design. We delve into how it was manufactured as …

Investigation And Characterization Of New Optically Stimulated Luminescence (Osl) Dosimetric Materials, Linyu Pan

All Dissertations

Optically stimulated luminescence (OSL) dosimeters have attracted increasing attention due to advantages over TL dosimeters, including no thermal quenching and higher sensitivity. Nevertheless, currently, there are only two commercially available OSL dosimeters, BeO and Al₂O₃:C. An OSL dosimeter requires low effective atomic number (Z_eff < 16), at least one type of recombination center and one type of trap, and UV~blue emission. In this dissertation, motivated by the search of new OSL dosimetric materials, a systematic investigation of alumina (Z_eff = 11.3) and magnesium aluminate spinel (Z_eff = 11.2) based materials was performed in terms of the engineering of the recombination centers and electronic traps. Microstructural characterization was executed by means of X-ray diffraction (XRD) and Raman spectroscopy. Luminescence was characterized under X-ray excitation (radioluminescence; RL) at ambient and …

Microstructural And Optical Properties Of Mgal2o4 Spinel: Effects Of Mechanical Activation, Y2o3 And Graphene Additions, Nina Obradovic, William Fahrenholtz, Cole Corlett, Suzana Filipovic, Marko Nikolic, Bojan A. Marinkovic, Simone Failla, Diletta Sciti, Daniele Di Rosa, Elisa Sani

Materials Science and Engineering Faculty Research & Creative Works

Magnesium Aluminate and Other Alumina-Based Spinels Attract Attention Due to their High Hardness, High Mechanical Strength, and Low Dielectric Constant. MgAl₂O₄ Was Produced by a Solid-State Reaction between MgO and Α-Al₂O₃ Powders. Mechanical Activation for 30 Min in a Planetary Ball Mill Was Used to Increase the Reactivity of Powders. Yttrium Oxide and Graphene Were Added to Prevent Abnormal Grain Growth during Sintering. Samples Were Sintered by Hot Pressing under Vacuum at 1450◦C. Phase Composition and Microstructure of Sintered Specimens Were Characterized by X-Ray Powder Diffraction and Scanning Electron Microscopy. Rietveld Analysis Revealed 100% …

Development Of Eam And Rf-Meam Interatomic Potential For Zirconium Diboride, Bikash Timalsina

Graduate Theses/Dissertations

Embedded Atom Method (EAM) and Modified-EAM (MEAM) interatomic potentials were developed for zirconium diboride (ZrB₂). The EAM and “Reference Free” (RF) version of the Modified Embedded Atom Method (RFMEAM) potentials have been fitted by utilizing Density Functional Theory (DFT)-based datasets including lattice deformations and high-temperature ab-initio molecular dynamics (AIMD) simulation results. The occupancies of phonons for acoustic phonon modes from the density functional theory calculation shows that these modes of vibration, mostly due to heavier mass element (Zr), which occur below 8.711 THz, while a slight underestimation to that of DFT calculation predicted by EAM below 8.439 THz …

Review: Factors Affecting Composite Laminates Against Lightning Strikes, Aaryan Manoj Nair

Publications and Research

Lightning strike protection (LSP) have recently been a newly developing field particularly with the emergence of graphene thin film integration into carbon fiber composite structures. This technology has a widespread application in airplanes, wind turbines, and other instruments which are susceptible to frequent lightning strikes. Electrical discharge of the instrument in a safe manner is vital for the safety of the passengers (in the case of flights) as well as the integrity of the aircraft structures because of their specific mechanical and structural properties, which are essential for their functioning. The purpose of the study is to fabricate graphene thin …