Other Materials Science and Engineering Commons^™

Surface Treatments' Effects On The Capacitor's Dielectric Performance Under Electro-Thermal Stresses, Haider. M. Umran, Feipeng Wang

Karbala International Journal of Modern Science

Biaxial-oriented polypropylene (BOPP) films are characterized by unfavorable aging behavior because of their poor susceptibility to high temperatures, humidity, and high electric fields. This makes them unqualified to withstand harsh operating conditions, such as in capacitor applications. This study investigates the impact of annealing BOPP samples at 100 °C for five hours after fluorination at different times (15, 30, and 60 minutes) on their electrical and mechanical performance under electro-thermal stresses. Scanning electron microscope (SEM) images confirm that there is an increase in surface roughness and the formation of a dense layer of fluorine-containing groups monotonically with fluorination time. So, …

A Guide To Fifty Years Of Research At Montana Tech: Part 3-Decontamination Of Ratioactively Contaminated Steel By Melt Refining/Slagging Processing, Larry G. Twidwell, Samuel A. Worcester

Metallurgy

This presentation includes a discussion of the research conducted at Montana Tech in the Department of Metallurgical and Materials Engineering. The discussion is focused on Decontamination of Radioactively Contaminated Steel by Melt Refining/Slagging. This presentation is based on the research of Master of Science graduate students, industrial and academic colleagues, at the Montana College of Mineral Science and Technology (which morphed to Montana Tech [1977], then to Montana Tech of The University of Montana [2000], then to Montana Technological University [2019]). The referenced work of each of the graduate students in this presentation is gratefully acknowledged. The following summary presentation …

The Interplay Of Spin, Charge, And Heat: From Metal/Insulator Heterostructures To Perovskite Bilayers, Sam M. Bleser

Electronic Theses and Dissertations

In this dissertation begin with an investigation of non-local spin transport in an amorphous germanium (a-Ge) sample via the inverse spin Hall effect (ISHE). In that study we show that commonly used techniques such as differential conductance and delta mode of a paired Keithley 6221/2182a for non-local resistance measurements can lead to false indicators of spin transport. Next, we turn out attention to a thickness dependent study in thermally-evaporated chromium (Cr) thin films on a bulk polycrystalline yttrium-iron-garnet (YIG) substrate. This project analyzed the spin transport in the Cr films versus thickness via the longitudinal spin Seebeck effect (LSSE). This …

Finite Element Analysis Of Thermal-Mechanical Instabilities In Nonmetallic Friction Composite Material, Joseph-Shaahu Shaahu

Electronic Theses and Dissertations

Thermal-mechanical instability (TMI) has been a research topic of interest as it focuses a lot on transportation systems. Thermal-mechanical instability was first noticed in railway and experimentally studied with a pin-to-pin or pin-to-surface setup of sliding contact. The topic has been extended into brakes and clutches which are two of the most common sliding systems most susceptible to thermal buckling and thermoelastic instability (TEI), where thermal buckling and thermoelastic instability are two sub-categories of thermal-mechanical instability. Thermal-mechanical instability is an ongoing research to better understand the phenomenon and the limits at which such instability occurs. This work delved into the …

A Bayesian Approach For Lifetime Modeling And Prediction With Multi-Type Group-Shared Missing Covariates, Hao Zeng, Xuxue Sun, Kuo Wang, Yuxin Wen, Wujun Si, Mingyang Li

Engineering Faculty Articles and Research

In the field of reliability engineering, covariate information shared among product units within a specific group (e.g., a manufacturing batch, an operating region), such as operating conditions and design settings, exerts substantial influence on product lifetime prediction. The covariates shared within each group may be missing due to sensing limitations and data privacy issues. The missing covariates shared within the same group commonly encompass a variety of attribute types, such as discrete types, continuous types, or mixed types. Existing studies have mainly considered single-type missing covariates at the individual level, and they have failed to thoroughly investigate the influence of …

Applicability Of Using Bio-Receptive Concrete For Building Facades In Egypt, Gina Roupheil

Theses and Dissertations

The significant increase in carbon dioxide emissions caused by the construction industry is detrimental to our planet. This is rapidly increasing with the urbanization of cities that is gradually taking its toll on the available green spaces, which help in balancing such emissions. Recently, researchers have been trying to make use of bio-receptivity to create biomaterial systems that could be spread on building envelopes and support the growth of small plant species and microorganisms to establish on. Out of those materials, comes the concrete as a promising material for bio-colonization.

Within this context, this study aims at investigating the applicability …

A Study On High-Frequency Bending Fatigue, Microhardness, Tensile Strength, And Microstructure Of Parts Made Using Atomic Diffusion Additive Manufacturing (Adam) And Additive Friction Stir Deposition (Afsd), Hamed Ghadimi

LSU Doctoral Dissertations

This dissertation reports the findings of several studies on the mechanical and microstructural properties of parts made using atomic diffusion additive manufacturing (ADAM) and additive friction stir deposition (AFSD). The design of a small-sized bending-fatigue test specimen for an ultrasonic fatigue testing system is reported in Chapter 1. The design was optimized based on the finite element analysis and analytical solution. The stress–life (S–N) curve is obtained for Inconel alloy 718. Chapter 2 presents the findings of ultrasonic bending-fatigue and tensile tests carried out on the ADAM test specimens. The S-N curves were created in the very high-cycle fatigue regime. …

Thermomechanical Process Simulation And Quantification Of Nanoscale Precipitation Influencing Ductility And Strength During Alloy Processing, Alyssa Stubbers

Theses and Dissertations--Chemical and Materials Engineering

Experimental process simulation and quantification of microstructure development during processing are challenging due to limitations with machinery temperature capability, inadequate resolution and sampling volume of currently available characterization techniques, and difficulty characterizing material microstructures as close to processing-relevant conditions as possible. This dissertation addresses how process simulation can be performed using Gleeble thermomechanical technologies and how microstructure development during these processing simulations can be quantified both in-situ and ex-situ.

The first portion of this dissertation demonstrates how Gleeble technologies can be applied to simulate complex material processing conditions in order to produce process-property profiles that can be used to inform …

A Precision-Controlled Investigation Into The Fundamentals Which Drive The Incredible Superhydrophobic Properties Of Soot, Ashton Bressler

Theses and Dissertations

A PRECISION-CONTROLLED INVESTIGATION INTO THE FUNDAMENTALS WHICH DRIVE THE INCREDIBLE SUPERHYDROPHOBIC PROPERTIES OF SOOT

By Ashton Bressler

A thesis submitted as a partial fulfilment of the Virginia Commonwealth University requirements for a Masters of Science at Virginia Commonwealth University.

Virginia Commonwealth University, 2024.

This thesis investigates a precision controlled superhydrophobic soot surface, composed of semi-rigid linked chains of spheres, with a radii of roughly 14um. These spheres have exceptionally useful hydrophobic properties due to; their large surface area, their large triple phase line length, their low area fraction of solid-liquid interface, their ability to deform, and their strength from both …

Application Of Quantum Algorithms In The Synthesis Of Dynamic Objects, Noilakhon Yakubova

Chemical Technology, Control and Management

Around the world, the food industry is focusing on achieving energy and resource efficiency. One of the main challenges in the field of process automation is the creation of effective control systems using intelligent technologies to improve the quality of processes and achieve the production of high-quality products with less energy and resources. Therefore, it is necessary to work with a large amount of data. Particular attention is paid to the development of computational algorithms for automated high-speed computational analysis systems for processing this data at high speed. Therefore, the article discusses the use of quantum computing methods in controlling …

Thermally Rearranging Polyimide Networks For High-Temperature Applications, William Guzman

Dissertations

High-performance polymers can retain functional properties when exposed to long-term or short-term durations of harsh conditions, such as mechanical action, at elevated temperatures (>177 °C). A mixture of intramolecular and intermolecular forces of and between polymer chains provide excellent property retention at elevated temperatures. Specifically, the highly aromatic nature of high-performance polymer backbones provides outstanding thermal stability, which is typically attributed to π-π stacking. However, the interrelationship between thermal stability and high aromaticity creates a challenging structure-processing relationship paradigm, which causes poor polymer processability in most high-performance polymers. Herein, it was demonstrated that rationally designing a crosslinking phenylethynyl imide …

Atomic-Level Mechanisms Of Fast Relaxation In Metallic Glasses, Leo W. Zella

Doctoral Dissertations

Glasses are ubiquitous in daily life and have unique properties which are a consequence of the underlying disordered structure. By understanding the fundamental processes that govern these properties, we can modify glasses for desired applications. Key to understanding the structure-dynamics relationship in glasses is the variety of relaxation processes that exist below the glass transition temperature. Though these relaxations are well characterized with macroscopic experimental techniques, the microscopic nature of these relaxations is difficult to elucidate with experimental tools due to the requirements of timescale and spatial resolution. There remain many questions regarding the microscopic nature of relaxation in glass …

3d Experimental Studies Of Temperature And Crystallographic Effects On Creep And Strength In Rock Salt, Amirsalar Moslehy

Doctoral Dissertations

Salt domes utilization as storage reservoirs in the energy sector has led to extensive studies on rock salt’s mechanical and geothermal behavior. These important facilities’ safety and serviceability rely on understanding rock salt’s compressive strength and creep behavior under various loading directions, water contents, in-situ stresses, and temperatures. Despite numerous studies on rock salt’s mechanical behavior in the literature, there are still many unanswered questions about rock salt’s behavior. This dissertation was aimed at utilizing state-of-the-art experimental techniques such as 3D synchrotron micro-computed tomography (SMT) and 3D x-ray diffraction (3DXRD) along with hundreds of compression and creep experiments to enhance …

Additive Manufacturing Of Magnetic Materials For Electric Motor And Generator Applications, Haobo Wang

Doctoral Dissertations

This work details the research into the 3D Printing, also known as Additive Manufacturing (AM), of both impermanent and permanent magnets. This work also details the research in enabling such AM magnets in electrical machine applications, primarily motors and generators. The AM processes of many types of magnets are described in detail. The material properties of such AM magnets are also described. The two main types of AM magnets that are discussed in detail are AM NdFeB, and AM Silicon Steel. The implementation of AM NdFeB as rotor magnets, and the implementation of AM Silicon Steel as rotor and stator …

Material World, Nicole Weldy

All Theses

My thesis, Material World, delves into the use of the crochet unit as a construction technique for building forms. Through this, I aim to organize different materials in a way that responds to the challenges posed by the physical world. My artistic process is centered around honoring the inherent qualities of thread and uses these qualities to create form, lightness, and linearity. At the same time, I remain receptive to transformative processes such as combining three-dimensional (3D) printed lines and lace stiffener to push the boundaries of what thread can do. By combining manual craftsmanship with technology materialized as …

Advancing Additive Manufacturing For Biomedical Applications: Antimicrobial And X-Ray Absorptive Composite Filaments For Fused Filament Fabrication, John M. Arnold Jr

University of New Orleans Theses and Dissertations

The objective of this research was to investigate the use of nano- and microparticle amendments for the creation of Poly-lactic Acid composite materials for use in biomedical applications using the Fused Filament Fabrication process of Additive Manufacturing. Composites were created with the goal of imparting the useful properties of antimicrobial activity and x-ray absorption to the material. In addition to testing the efficacy of the particle amendments in achieving the desired properties, the thermal and mechanical properties of the composite materials were tested to ensure that the composites would be compatible with the Fused Filament Fabrication process and would produce …

Temperature Gradient Effect On Solid-Liqid Interface Properties Of Al-Cu Alloy: A Molecular Dynamics Study, Prashant Kumar Jha

All Theses

Aluminum-copper (Al-Cu) alloys are widely used in the aerospace industry due to their favorable strength-to-weight ratio, good fatigue resistance, and corrosion resistance. These properties make Al-Cu alloys an excellent choice for aircraft structural components that require high strength and low weight. Additive manufacturing (AM), also known as 3D printing, has emerged as a promising processing method for Al-Cu alloys in aerospace manufacturing. AM enables the production of lightweight optimized geometries difficult to manufacture through conventional subtractive methods. AM also reduces material waste by only depositing material where needed in the part geometry. The rapid solidification conditions in AM processes motivate …

Corrosion Of Oil Pipeline: A Case Study On The Niger Delta Region Of Nigeria., Victor U. Okoro

Corrosion Research

Corrosion of oil pipelines in Nigeria, particularly in the Niger Delta region, has extensive and detrimental environmental and societal impacts. This issue results in substantial financial losses and reputational damage for oil companies operating in the area. Local communities suffer economically, affecting agriculture and food security. Furthermore, corrosion-related oil spills lead to air quality degradation by releasing volatile organic compounds and greenhouse gases, contributing to respiratory issues and worsening climate change.

These oil spill cleanups are costly and time-consuming, with estimated expenses reaching billions of dollars. Using the Nembe Creek Trunk Line (NCTL) case study, it is evident that addressing …

Thermo-Mechanical Instabilities In Next-Generation Friction Materials In High-Speed Sliding Systems, Kingsford Koranteng

Electronic Theses and Dissertations

For centuries, the manufacturing industry has incorporated metals like copper into friction materials to enhance thermal properties and minimize thermo-mechanical instabilities (TMI) in high-speed sliding systems. Unfortunately, these metals have adverse environmental effects due to the emission of hazardous particulate matter. As a result, there is a growing movement towards adopting next-generation friction materials as an alternative solution.

The study begins by conducting experimental and numerical investigations to examine the instabilities found in metal-based friction materials. The primary objective is to utilize the insights gained from the investigations to computationally explore effective strategies for mitigating various instabilities that may arise …

Molecular Dynamics Study Of Characterization In Metal-Free Friction Materials, Yizhan Zhang

Electronic Theses and Dissertations

Metallic friction materials currently used in industry may adversely impact the environment. Substitutions for metals in friction materials, on the other hand, can introduce operational safety issues and other unforeseeable issues such as thermal-mechanical instabilities and insufficient strength. In view of it, this dissertation focuses on developing different kinds of materials from simple structure to complex structure and evaluating the material properties with the assistance of molecular dynamics (MD) tools at the nano scale.

First, the concept of the contacted surfaces in friction at the atomic scale was introduced in order to get accurate understanding of the friction process compared …