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Mechanical Engineering

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2021

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In-Situ Process Monitoring For Metal Additive Manufacturing (Am) Through Acoustic Technique, Md Shahjahan Hossain Jan 2021

In-Situ Process Monitoring For Metal Additive Manufacturing (Am) Through Acoustic Technique, Md Shahjahan Hossain

Electronic Theses and Dissertations

Additive Manufacturing (AM) is currently a widely used technology in different industries such as aerospace, medical, and consumer products. Previously it was mainly used for prototyping of the products, but now it is equally valuable for commercial product manufacturing. More profound understanding is still needed to track and identify defects during the AM process to ensure higher quality products with less material waste. Nondestructive testing becomes an essential form of testing for AM parts, where AE is one of the most used methods for in situ process monitoring. The Acoustic Emission (AE) approach has gained a reputation in nondestructive testing …


Nebulizer-Based Systems To Improve Pharmaceutical Aerosol Delivery To The Lungs, Benjamin M. Spence Jan 2021

Nebulizer-Based Systems To Improve Pharmaceutical Aerosol Delivery To The Lungs, Benjamin M. Spence

Theses and Dissertations

Combining vibrating mesh nebulizers with additional new technologies leads to substantial improvements in pharmaceutical aerosol delivery to the lungs across therapeutic administration methods. In this dissertation, streamlined components, aerosol administration synchronization, and/or Excipient Enhanced Growth (EEG) technologies were utilized to develop and test several novel devices and aerosol delivery systems. The first focus of this work was to improve the poor delivery efficiency, e.g., 3.6% of nominal dose (Dugernier et al. 2017), of aerosolized medication administration to adult human subjects concurrent with high flow nasal cannula (HFNC) therapy, a form of continuous-flow non-invasive ventilation (NIV). The developed Low-Volume Mixer-Heater (LVMH) …


Toward Intelligent Welding By Building Its Digital Twin, Qiyue Wang Jan 2021

Toward Intelligent Welding By Building Its Digital Twin, Qiyue Wang

Theses and Dissertations--Electrical and Computer Engineering

To meet the increasing requirements for production on individualization, efficiency and quality, traditional manufacturing processes are evolving to smart manufacturing with the support from the information technology advancements including cyber-physical systems (CPS), Internet of Things (IoT), big industrial data, and artificial intelligence (AI). The pre-requirement for integrating with these advanced information technologies is to digitalize manufacturing processes such that they can be analyzed, controlled, and interacted with other digitalized components. Digital twin is developed as a general framework to do that by building the digital replicas for the physical entities. This work takes welding manufacturing as the case study to …


Quality Assurance Of Lightweight Structures Via Phase-Based Motion Estimation, Ikenna E. Ifekaonwu Jan 2021

Quality Assurance Of Lightweight Structures Via Phase-Based Motion Estimation, Ikenna E. Ifekaonwu

Electronic Theses and Dissertations

In recent years, lightweight structures have become mature and adopted in various applications. The importance of quality assurance cannot be overemphasized hence extensive research has been conducted to assess the quality of lightweight structures. This study investigates a novel process that exploits motion magnification to investigate the damage characteristics of lightweight mission-critical parts. The goal is to assure the structural integrity of 3D printed structures and composite structures by determining the inherent defects present in the part by exploiting their vibration characteristics. The minuscule vibration of the structure was recorded with the aid of a high-speed digital camera, and the …


The Development Of A Holistic Quality Score Using In-Situ Monitoring Of Laser Powder Bed Fusion, Ryan Daigneault Jan 2021

The Development Of A Holistic Quality Score Using In-Situ Monitoring Of Laser Powder Bed Fusion, Ryan Daigneault

Electronic Theses and Dissertations

Additive manufacturing processes allow for a great degree of flexibility in terms of part production. The process is autonomous once the part has started printing in that the operator generally does not need to intervene until the part is finished. One issue that this introduces, however, is an inability to determine part quality during the printing process. Once a part has started printing, the operator must either wait until the part is finished or regularly check on the part during the print to determine the part quality. Using data gathered from multiple sensors, a quality score can be used to …


Reclamation Of Fused Silica From Investment Shells Used For Casting Steel, Samuel L. Holt Jan 2021

Reclamation Of Fused Silica From Investment Shells Used For Casting Steel, Samuel L. Holt

Electronic Theses and Dissertations

Fused silica is widely used for investment casting shell molds. Fused silica shells are discarded after being used for casting one time. This is due to the transformation of fused silica to beta cristobalite above 1652℉ (900℃). To reduce cost and waste of investment casting foundries, this study is exploring a method to inhibit transformation of fused silica and reclaim it from high temperature investment casting shells. This research has employed firing to minimalize fused silica transformation to cristobalite. The phase transformation is minimalized due to sintering and coarsening of the particles during firing. Coarsening reduces surface area to volume …


Experimental And Numerical Investigation Of Naca Airfoil Wing With Winglets, Courtney Danielle Bachmann Jan 2021

Experimental And Numerical Investigation Of Naca Airfoil Wing With Winglets, Courtney Danielle Bachmann

Electronic Theses and Dissertations

This research was performed in order to study wingtip devices and, in particular, winglets. Winglets are attached to commercial aircraft for the purpose of reducing induced drag caused by wake vortices on the wingtip. A winglet device can save an aircraft anywhere from 3-7% in fuel consumption. Over the course of a year, this can add up to hundreds of thousands of dollars saved. This research consisted of two parts: one part experiment and one part equipment design. The latter phase of this research examined various methods of testing in a subsonic wind tunnel laboratory setting. Experimental results found with …


Design And Development Of Soft Earthworm Robot Driven By Fibrous Artificial Muscles, Beau Ragland Jan 2021

Design And Development Of Soft Earthworm Robot Driven By Fibrous Artificial Muscles, Beau Ragland

Electronic Theses and Dissertations

Earthworm robots have proven their viability in the fields of medicine, reconnaissance, search and rescue, and infrastructure inspection. These robots are traditionally typically hard-shelled and must be tethered to whatever drives their locomotion. For this reason, truly autonomous capabilities are not yet feasible. The goal of this thesis is to introduce a robot that not only sets the groundwork for autonomous locomotion, but also is safe for human-robot interaction. This was done by ensuring that the actuation principle utilized by the robot is safe around humans and can work in an untethered design. Artificial muscle actuation allowed for these prerequisites …


Design Of Compact Signal Distribution Device For Hoffman Reflex Methodologic Applications In Sports Medicine, Abayomi E. Folaranmi Jan 2021

Design Of Compact Signal Distribution Device For Hoffman Reflex Methodologic Applications In Sports Medicine, Abayomi E. Folaranmi

Electronic Theses and Dissertations

A study is presented on the design of compact sized signal distribution device for Hoffman reflex methodological applications in sports medicine. Established conventional method for measuring and recording human or animal nervous system response to external electrical stimulus was considered in this study. Challenges with measuring and recording techniques which introduces inaccuracies and unreliability of reflex response data obtained was analyzed, this work is aimed at improving the reliability of H-reflex d measuring and recording technique for the purpose of reducing inaccuracies introduced to data obtained because of conventional methodologic approach. Inaccuracies due to changes in subject muscle geometry and …