A Bayesian Approach For Lifetime Modeling And Prediction With Multi-Type Group-Shared Missing Covariates, 2024 Communication University of Zhejiang
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, 2024 American University in Cairo
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), 2024 Louisiana State University and Agricultural and Mechanical College
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, 2024 University of Kentucky
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 …
Application Of Quantum Algorithms In The Synthesis Of Dynamic Objects, 2023 Tashkent State Technical University, Address: 2 Universitetskaya st., 100095, Tashkent city, Republic of Uzbekistan. E-mail: yakubova.noila@gmail.com, Phone: +998946853505.
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, 2023 The University of Southern Mississippi
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, 2023 University of Tennessee, Knoxville
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, 2023 University of Tennessee, Knoxville
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, 2023 University of Tennessee, Knoxville
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 …
Advancing Additive Manufacturing For Biomedical Applications: Antimicrobial And X-Ray Absorptive Composite Filaments For Fused Filament Fabrication, 2023 University of New Orleans, New Orleans
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 …
Material World, 2023 Clemson University
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 …
Temperature Gradient Effect On Solid-Liqid Interface Properties Of Al-Cu Alloy: A Molecular Dynamics Study, 2023 Clemson University
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., 2023 Queen's University - Kingston, Ontario
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, 2023 University of Denver
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, 2023 University of Denver
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 …
Experimental And Simulation Study Of Reactive Silver Ink Droplet Evaporation, 2023 Western University
Experimental And Simulation Study Of Reactive Silver Ink Droplet Evaporation, Weipeng Zhang
Electronic Thesis and Dissertation Repository
The evaporation of particle-free silver ink droplets on heated substrates directly impacts the morphology of the resultant silver particles and films. In this thesis, COMSOL Multiphysics simulations of the solvent (water-ethylene glycol mixture) droplet evaporation process are used to explain the microflows, mass transfers, and heat distribution responsible for the experimental observations. The reactive ink incorporates fluoro-surfactant FS-31 and poly (acrylamide) (PAM) to suppress the coffee-ring effect that negatively impacts the electrical conductivity. Experiments show that the droplet evaporation process results in varied silver particle morphology, depending on the locations within the droplet, leading to uneven surfaces. Large particles (3 …
Corrosion Case Study On Pipeline, 2023 McMaster University
Corrosion Case Study On Pipeline, Kangze Ren
Corrosion Research
The Kashagan pipeline leaks were likely caused by sulfur stress corrosion cracking, a combined corrosion mechanism developed by the presence of high pressure, the high level of hydrogen sulfide(the main "ingredient" of sour gas), and poor metallurgical choice. Improper welding and poor metallurgical examination were blamed for causing the leaking issue. The purpose of the current review is to raise the alarm about the inappropriate corrosion management of Kashagan oil production and its societal and environmental consequences.
Machine Learning Prediction Of Hea Properties, 2023 California Polytechnic State University, San Luis Obispo
Machine Learning Prediction Of Hea Properties, Nicholas J. Beaver, Nathaniel Melisso, Travis Murphy
College of Engineering Summer Undergraduate Research Program
High-entropy alloys (HEA) are a very new development in the field of metallurgical materials. They are made up of multiple principle atoms unlike traditional alloys, which contributes to their high configurational entropy. The microstructure and properties of HEAs are are not well predicted with the models developed for more common engineering alloys, and there is not enough data available on HEAs to fully represent the complex behavior of these alloys. To that end, we explore how the use of machine learning models can be used to model the complex, high dimensional behavior in the HEA composition space. Based on our …
The Synthesis And Optimization Of Sulfide And Halide Solid Electrolytes For All Solid-State Batteries, 2023 University of Tennessee, Knoxville
The Synthesis And Optimization Of Sulfide And Halide Solid Electrolytes For All Solid-State Batteries, Teerth Brahmbhatt
Doctoral Dissertations
Countries and organizations around the world have established ambitious targets to transition away from fossil fuel-based energy sources and devices. The transition is focused on cleaning up power generation by converting coal, natural gas, and oil-based power generation to renewables and nuclear energy. Decarbonizing other sectors of energy use, transportation for example, will require broader electrification. To drive this move away from fossil fuel powered transportation will require portable energy storage devices. Conventional lithium-ion batteries are a popular candidate to lead this shift. However, these batteries often rely on flammable liquid electrolytes and carbon anodes that suffer from low energy …
Preparation Of High Entropy Titanite Pyrochlore And Radiation Stability Study, 2023 Clemson University
Preparation Of High Entropy Titanite Pyrochlore And Radiation Stability Study, Adam Gootgeld
All Theses
Pyrochlore has been studied as a host phase for safe storage of radionuclides and exists naturally with long-term stability with good long-range order [1]. High entropy oxides show promising tunable properties that could demonstrate favorable bulk deposit of radioactive materials such as spent nuclear fuel (Uranium and other actinides). It is proposed that using high entropy oxides (HEOs) as the cation in this framework will shift the gibbs free energy so that radioactive nuclear waste will be stabilized for safe, long-term, eco-friendly storage. We have established a consistent method to fabricate high entropy titanite pyrochlores. In this study, ion beam …