Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons™

Open Access. Powered by Scholars. Published by Universities.®

Mechanical Engineering

Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 5071 - 5100 of 30090

Full-Text Articles in Engineering

Synthetic Data Generation For Intelligent Inspection Of Structural Environments, Noshin Habib Dec 2022

Synthetic Data Generation For Intelligent Inspection Of Structural Environments, Noshin Habib

Open Access Theses & Dissertations

Automated detection of cracks and corrosion in pavements and industrial settings is essential to a cost-effective approach to maintenance. Deep learning has paved the path for vast levels of improvement in the area. Such models require a plethora of data with accurate ground truth and enough variation for the model to generalize to the data, which is notwidely available. There has been recent progress in computer graphics being used for the creation of synthetic data to address the issue of deficient data availability, but it is limited to specific objects, such as cars and human beings. Textures and deformities within …


High-Temperature Valve Design For A Solid Oxide Fuel Cell/Gas Turbine Hybrid System Utilizing Smart Materials, Alba Jazmin Leyva Dec 2022

High-Temperature Valve Design For A Solid Oxide Fuel Cell/Gas Turbine Hybrid System Utilizing Smart Materials, Alba Jazmin Leyva

Open Access Theses & Dissertations

The topic of this project includes extensive research on the Solid Oxide Fuel Cell Gas Turbine (SOFC/GT) hybrid system located at the National Energy Technology Laboratory. The goal is to reduce pollution and generate energy by using natural gas and a combination of fuel cells, heat exchangers, bypass valves, turbines, and combustors as components working together to produce clean energy. The SOFC/GT system works by having the fuel cell pressurized by the gas turbine. The turbine then produces exhaust gas for the fuel cell, because the turbine recovers the majority of the heat and the pressurization contributes to the enhancement …


Cad-Based Aerial Trajectory Generation And 3d Mapping For Close-Quarter Inspection, Angel Guillermo Ortega Castillo Dec 2022

Cad-Based Aerial Trajectory Generation And 3d Mapping For Close-Quarter Inspection, Angel Guillermo Ortega Castillo

Open Access Theses & Dissertations

Robotic technologies for inspection purposes of large-scale structures have grown in interest.Such technologies are encouraged to reduce the risk in which human operators are involved and to reduce costs due to downtime of the equipment. In the Energy sector, high interest is placed on power plant components where their correct operation is paramount. This work is inspired by the synthetic vision systems for aerial vehicles that use three-dimensional space (3D) to provide pilots with clear and intuitive means of understanding their flying environment. This work can be separated into three main sections: Trajectory Generation from Computer-Aided Design (CAD) Models, Crack …


Fabrication, Microstructure And Mechanical Characterization Of Crvnbtaw High Entropy Alloy Coatings Using Magnetron Sputtering, Jorge Quezada Dec 2022

Fabrication, Microstructure And Mechanical Characterization Of Crvnbtaw High Entropy Alloy Coatings Using Magnetron Sputtering, Jorge Quezada

Open Access Theses & Dissertations

In this project a CrVNbTaW high entropy alloy was evaluated. The samples were made using radio frequency magnetron sputtering and were made under similar conditions. The deposition parameters were explored to find the ideal deposition process. The process included a pressure from 0.1-2mTorr, 600C, 1 hour duration, at 100W power to guns, and constant argon flow. The samples were fabricated under similar parameters using silicon steel and sapphire substrates. The samples were analyzed and characterized using X-ray diffraction, scanning electron microscopy, atomic force microscopy, nanoindentation and corrosion testing. Based on these results we were able to get a better understanding …


Fabrication And Characterization Of Iron-Based Catalysts For The Dehydrogenation Of Fossil Fuels, Victoria Isabel Reyes Dec 2022

Fabrication And Characterization Of Iron-Based Catalysts For The Dehydrogenation Of Fossil Fuels, Victoria Isabel Reyes

Open Access Theses & Dissertations

For a prosperous and sustainable future, hydrogen is an encouraging solution due to its simple transition for industrial decarbonization and synergy for economic development. Paradoxically, current hydrogen production pathways release substantial amount of greenhouse gases into the atmosphere contributing to climate change. To keep up with increasing demand, hydrogen could be produced through microwave-assisted thermocatalytic dehydrogenation of fossil fuels without emitting carbon dioxide. This requires specified catalysts to meet the requirements of hydrogen yield and selectivity. The objective of the present research is to fabricate, characterize, and compare iron-based alumina (FeAl_x O_y) catalysts produced via solution combustion synthesis and iron-based …


Multi-Fidelity Predictions For Control Allocation On The Nasa Ikhana Research Aircraft To Minimize Drag, Justice T. Schoenfeld Dec 2022

Multi-Fidelity Predictions For Control Allocation On The Nasa Ikhana Research Aircraft To Minimize Drag, Justice T. Schoenfeld

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Optimal control settings (camber scheduling) can be used by aircraft to minimize drag at various operating conditions during flight. In this work, camber schedules for minimum drag on the NASA Ikhana are obtained over a range of lift coefficients. A modern numerical lifting-line algorithm is used to predict the lift and drag of the aircraft as a function of operating condition and wing section shape (airfoil camber). The SLSQP optimization algorithm is used to solve for the camber schedule that minimizes drag for a given operating condition. The process is repeated, varying the number of control sections to evaluate the …


Linearized Rigid-Body Static And Dynamic Stability Of An Aircraft With A Bio-Inspired Rotating Empennage, Austin J. Kohler Dec 2022

Linearized Rigid-Body Static And Dynamic Stability Of An Aircraft With A Bio-Inspired Rotating Empennage, Austin J. Kohler

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The United States Air Force (USAF) will likely seek to remove the vertical tail of next-generation fighter aircraft. This work seeks to characterize the static and dynamic stability and handling qualities of a vertical-tailless aircraft concept that would satisfy the USAF’s goal. This concept aircraft, one modified with a Bio-Inspired Rotating Empennage (BIRE), does not have a vertical tail, and is instead capable of rotating the horizontal tail about the fuselage axis for maneuvering. The dynamic characteristics of the BIRE-modified aircraft are compared to a baseline unmodified aircraft, similar to the F16, with a traditional vertical tail. Linearized aerodynamic models …


Developing A Methane Detector For Aerospace Applications, Michael A. Kirk Dec 2022

Developing A Methane Detector For Aerospace Applications, Michael A. Kirk

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Greenhouse gasses in the atmosphere are raising the global temperature and causing adverse side effects. Of these greenhouse gasses, methane is one of the most impactful, second only to carbon dioxide. One of the methods for determining the concentration of methane in the atmosphere is taking images of the earth from space. The purpose of this project is to further a new imaging technology for detecting methane leaks called FINIS (Filter Incidence Narrow-band Infrared Spectrometer), thus improving our capability to detect and locate methane leaks and reduce greenhouse gas emissions. FINIS has been developed in various stages since 2018 and …


Development And Characterization Of Forcespinning® Mesquite Gum Nanofibers, Cristobal Rodriguez, Victoria Padilla, Karen Lozano, Alexa Villarreal, Luis A. Materon, Robert Gilkerson Dec 2022

Development And Characterization Of Forcespinning® Mesquite Gum Nanofibers, Cristobal Rodriguez, Victoria Padilla, Karen Lozano, Alexa Villarreal, Luis A. Materon, Robert Gilkerson

Mechanical Engineering Faculty Publications

In this study, nanofibers incorporating Prosopis glandulosa mesquite gum (MG) exudate combined with biodegradable polymers, pullulan (PL) and chitosan (CH), were produced via the Forcespinning® technique. The nonwoven composite membranes were characterized via scanning electron microscopy followed by thermogravimetric and Fourier-transform infrared spectroscopy analysis. MG nanofiber composites comprised long, continuous fibers with an average fiber diameter of 523 ± 180 nm and 760 ± 225 nm for 18.1 and 28 wt% of MG, respectively. These composite membranes were water-stable after crosslinking via heat treatment with a ∼3 % water absorption capacity, and demonstrated a thermal capability with an increasing …


Assembly Of Ceramic Particles In Aqueous Suspensions Induced By High-Frequency Ac Electric Field, James E. John Iv Dec 2022

Assembly Of Ceramic Particles In Aqueous Suspensions Induced By High-Frequency Ac Electric Field, James E. John Iv

Mechanical & Aerospace Engineering Theses & Dissertations

Ceramic materials processed using colloidal methods have been the focus of a great deal of research aimed at tailoring the final structure and microstructure of the finished ceramic sample. To this end, various external field effects have been investigated to modify the suspension microstructure without manipulating the ceramic particles directly. In a previous work in the field of ice templating it has been shown that AC electric fields are able to produce microstructural changes in ice templated ceramics that have significantly improved the final mechanical properties. However, the mechanisms for this process are still not well understood in ceramics.

To …


Numerical Simulation Of Electroosmotic Flow Of Viscoelastic Fluid In Microchannel, Jianyu Ji Dec 2022

Numerical Simulation Of Electroosmotic Flow Of Viscoelastic Fluid In Microchannel, Jianyu Ji

Mechanical & Aerospace Engineering Theses & Dissertations

Electroosmotic flow (EOF) has been widely used in various biochemical microfluidic applications, many of which often involve the use of viscoelastic non-Newtonian fluids. Due to the existence of the elastic effect, the viscoelastic EOF develops into chaotic flow under extremely low Reynolds numbers, which is known as elastic turbulence. The mechanism of elastic turbulence in electroosmotic flow remains unclear. Numerical simulation plays an important role in understanding the mechanisms of elastic turbulence. This dissertation is aimed to study the EOF of viscoelastic fluids in constriction microchannels under various direct current (DC) and alternating current (AC) electric fields. First, the EOF …


Solar Chimney Power Plants: A Mini Review, Ahmed Reda, Waseem Salah, Ahmed Suwailem, Shehab Eldin Ahmed, Omar Lasheen, Amira Elkodama, Moustafa R. Shousha, Amr Ismaiel, Anas A. Rahman Nov 2022

Solar Chimney Power Plants: A Mini Review, Ahmed Reda, Waseem Salah, Ahmed Suwailem, Shehab Eldin Ahmed, Omar Lasheen, Amira Elkodama, Moustafa R. Shousha, Amr Ismaiel, Anas A. Rahman

Future Engineering Journal

The main investigations of a novel solar thermal application known as SCPP are summarized in this paper. It is a method of producing electricity from solar energy that relies on the fact that air rises when it is heated. An adequate position within a tall chimney can be utilized to position a turbine to turn it, creating an updraft that can be used to generate power. This system's specifications, design, construction, and use are all covered in the paper along with experimental and analytical research related to it. It also emphasizes the development and execution of SCPP programs.


Low-Cost, Low-Weight Test Rig Design For A Laboratory-Scale Twin Rotor Wind Turbine, Ahmed Ayoub, Ahmed Elzeedy, Mahmoud Elkordy, Eslam Ayad, Mohamed Waleed, Amira Elkodama, Amr Ismaiel Nov 2022

Low-Cost, Low-Weight Test Rig Design For A Laboratory-Scale Twin Rotor Wind Turbine, Ahmed Ayoub, Ahmed Elzeedy, Mahmoud Elkordy, Eslam Ayad, Mohamed Waleed, Amira Elkodama, Amr Ismaiel

Future Engineering Journal

Multi-Rotor Wind Turbine (MRWT) has been proven advantageous over Single-Rotor Wind Turbine (SRWT) in many aspects. In order to study the performance of MRWT over SRWT, this work presents a low-cost and low-weight design for a test rig for laboratory-scale wind turbine configurations. The configurations under study are a single-rotor, and a twin-rotor of the same size with a diameter of 30 cm. Aerodynamic loads have been calculated using the Blade Element Momentum (BEM) method, then the loads were used for stress analysis over the test rig proposed. The test rig is designed on Solidworks and the aerodynamic and inertial …


Performance Comparison Of Several Control Algorithms For Tracking Control Of Pantograph Mechanism, Laylaa Mahmoud Eng, Mohamed Shamseldin Dr, Mohamed Sallam Dr, Abdelghany Mohamed Prof Nov 2022

Performance Comparison Of Several Control Algorithms For Tracking Control Of Pantograph Mechanism, Laylaa Mahmoud Eng, Mohamed Shamseldin Dr, Mohamed Sallam Dr, Abdelghany Mohamed Prof

Future Engineering Journal

A sort of parallel manipulator known as a pantograph robot mechanism was created primarily for industrial requests that required high precision and satisfied speed. While tracking a chosen trajectory profile requires a powerful controller. Because it has four active robot links and one robot passive link in place of just two links like the open chain does, it can carry more loads than the open chain robot mechanism while maintaining accuracy and stability. The calculated model for a closed chain pantograph robot mechanism presented in this paper takes into account the boundary conditions. For the purpose of simulating the dynamics …


Relative Rate Observer Self-Tuning Of Fuzzy Pid Virtual Inertia Control For An Islanded Microgrid, Ahmed H. Mohamed, Helmy M. El Zoghby, Mohiy Bahgat, A. M. Abdel Ghany Nov 2022

Relative Rate Observer Self-Tuning Of Fuzzy Pid Virtual Inertia Control For An Islanded Microgrid, Ahmed H. Mohamed, Helmy M. El Zoghby, Mohiy Bahgat, A. M. Abdel Ghany

Future Engineering Journal

Expanding the usage of renewable energy in islanded microgrids leads to a reduction in its total inertia. Low inertia microgrids have difficulties in voltage and frequency control. That affected saving its stability and preventing a blackout. To improve low inertia islanded microgrids' dynamic response and save their stability, this paper presented relative rate observer self-tuning fuzzy PID (RROSTF-PID) based on virtual inertia control (VIC) for an islanded microgrid with a high renewable energy sources (RESs) contribution. RROSTF-PID based on VIC's success in showing remarkable improvement in the microgrid's dynamic response and enhancement of its stability. Moreover, it handles different contingency …


Characterization Of Materials Properties In Additively Manufactured Aisi-420 Martensitic Steel Deposited By Laser Engineered Net Shaping, Md Mehadi Hassan Nov 2022

Characterization Of Materials Properties In Additively Manufactured Aisi-420 Martensitic Steel Deposited By Laser Engineered Net Shaping, Md Mehadi Hassan

Nanoscience and Microsystems ETDs

Metal additive manufacturing (AM) is a disruptive technology enabling the fabrication of complex and near-net-shaped parts by adding material layer-wise. It offers reduced lead production time. AM processes are finding applications in many industrial sectors such as aerospace, automotive, biomedical, and mold tooling. Despite the tremendous advantages of AM, some challenges still prevent this technology's adoption in high-standard applications. Anisotropy and inhomogeneity in the mechanical properties of the as-built parts and the existence of pores and lack-of-fusion defects are considered the main issues in directed energy deposition (L-DED) parts. Laser-engineered net shaping LENS® offers excellent possibilities to fabricate metal tools …


True Stress-Strain Behavior Of Al-Based Cast Automotive Alloy Under Different Ageing Conditions And The Effect Of Trace Zr, Mashiur Rahman Shoummo, Akib Abdullah Khan, Mohammad Salim Kaiser Nov 2022

True Stress-Strain Behavior Of Al-Based Cast Automotive Alloy Under Different Ageing Conditions And The Effect Of Trace Zr, Mashiur Rahman Shoummo, Akib Abdullah Khan, Mohammad Salim Kaiser

Journal of Mechanical Engineering Science and Technology (JMEST)

A thorough investigation has been carried out on the Al-12Si-1Mg-1Cu-1Ni automotive alloy considering different properties, specially mechanical properties associated with true stress and true strain with Zr addition of trace amount. A commercially available piston is melted to produce the alloy, and trace amount of Zr is added to make another. The base alloy along with the Zr added alloy had been applied to homogenization, solution treatment, quenching, and ageing in order to get the age-hardening response. The alloys have been heat-treated at 25 ºC, 200 ºC, and 300 ºC, respectively, for four hours for attaining the under, peak and …


The Effect Of Nozzle Temperature, Infill Geometry, Layer Height And Fan Speed On Roughness Surface In Petg Filament, Doohan Taqdissillah, Aris Zainul Mutaqqin, Mahros Darsin, Dedi Dwilaksana, Nasrul Ilminnafik Nov 2022

The Effect Of Nozzle Temperature, Infill Geometry, Layer Height And Fan Speed On Roughness Surface In Petg Filament, Doohan Taqdissillah, Aris Zainul Mutaqqin, Mahros Darsin, Dedi Dwilaksana, Nasrul Ilminnafik

Journal of Mechanical Engineering Science and Technology (JMEST)

3D printing is a process of making three-dimensional solid objects from a digital file process created by laying down successive layers of material until the object is created. Many filaments can be used in 3D printing, one of which is PETG (PolyEthylene Terephthalate Glycol). PETG is a modification of PET (PolyEthylene Terephthalate) with added glycol at a molecular level to offer different chemical properties that provide significant chemical resistance, durability, and excellent formability for manufacturing. This study aims to find the most optimal parameter of surface roughness of PETG with different parameters of nozzle temperature, infill geometry, layer height and …


Backpack Effects On Two-Dimensional Gait Spatiotemporal And Kinematic Parameters, Nardo Rizaldy, Alvin Alvin, Wirawan Lingga, Ethan B.W. Goeij, F. Ferryanto Nov 2022

Backpack Effects On Two-Dimensional Gait Spatiotemporal And Kinematic Parameters, Nardo Rizaldy, Alvin Alvin, Wirawan Lingga, Ethan B.W. Goeij, F. Ferryanto

Journal of Mechanical Engineering Science and Technology (JMEST)

Loads could affect the body gait in various ways. Backpacks, sling bags, suitcases, and even trolleys could hugely affect human gait without us realizing it. The effects of these loads have been scientifically researched in biomechanics and sports science for the past few years. For instance, the comparison of walking with and without a backpack could easily reveal significant differences in body segments, which could be utilized for therapy and medicine development. The aim of this research is to determine the differences of the spatiotemporal kinematic parameters between a conventional human gait and a backpackloaded gait. Some parameters to be …


Investigate The Potential Renewable Energy Of Microalgae Spirulina Sp Using Proximate Analyzer, Sem-Edx, And Thermogravimetry, Yahya Zakaria, Sukarni Sukarni, Poppy Puspitasari, Nandang Mufti, Samsudin Anis, Anwar Johari Nov 2022

Investigate The Potential Renewable Energy Of Microalgae Spirulina Sp Using Proximate Analyzer, Sem-Edx, And Thermogravimetry, Yahya Zakaria, Sukarni Sukarni, Poppy Puspitasari, Nandang Mufti, Samsudin Anis, Anwar Johari

Journal of Mechanical Engineering Science and Technology (JMEST)

Microalgae Spirulina sp which has been cultivated by the Brackishwater Aquaculture Development Center, Situbondo Indonesia were tested for their potential energy performance using proximate analyzer, SEMEDX, and thermogravimetry. The proximate analyzer showed volatile matter (VM), fixed carbon (FC), moisture, ash content (AC), total sulfur of microalgae Spirulina sp 68.15, 12.57, 11.22, 8.06, and 0.67 (wt%, ar), respectively, and the gross calorific value (GCV) is 4971 kcal/kg (dry basis). SEM-EDX test showed the morphology and chemical content of Spirulina sp. The content of microalgae Spirulina sp is dominated by carbon (C) and oxygen (O), then followed by chlorine (Cl), sodium (Na), …


Study On Predictive Maintenance Of V-Belt In Milling Machines Using Machine Learning, Reza Aulia Rahman, Mohammad Faishol Erikyatna, Achmad Fauzan Hery Soegiharto Nov 2022

Study On Predictive Maintenance Of V-Belt In Milling Machines Using Machine Learning, Reza Aulia Rahman, Mohammad Faishol Erikyatna, Achmad Fauzan Hery Soegiharto

Journal of Mechanical Engineering Science and Technology (JMEST)

Towards industry 4.0, monitoring the degradation of machine tools’ components becomes a key feature so that smooth productivity is achieved. To preserve the functionality and performance of the machine tools, proper maintenance activities must be planned and carried out. V-belt is important component in machine tools that transmits power from the electric motor spindle in order to machine to work and cut desired material properly. The purpose of this research is to develop a predictive maintenance system for v-belt milling machine Krisbow 31N2F using machine learning. The machine learning algorithm models using multiple and simple linear regression algorithm was developed …


Effect Of Graphene Addition On Bacterial Cellulose-Based Nanocomposite, Jibril Maulana, Heru Suryanto, Aminnudin Aminnudin Nov 2022

Effect Of Graphene Addition On Bacterial Cellulose-Based Nanocomposite, Jibril Maulana, Heru Suryanto, Aminnudin Aminnudin

Journal of Mechanical Engineering Science and Technology (JMEST)

Bacterial cellulose (BC) is a widespread, low-cost biopolymer that has generally been produced from plants and biomass waste. A method for improving the range of applications for bacterial cellulose is adding graphene material. It has an outstanding feature that can increase the performance of nanocomposite materials. The research aims to observe the effect of graphene on the surface morphology, crystallinity, chemical bonding, and tensile strength of BC/CuO nanocomposite. For this study's synthesis, BC was synthesized by fermenting pineapple peel extract for 10 to 14 days. The produced BC was crushed, homogenized with a nano homogenizer machine, and filtered. Filtered BC, …


Efects Of Non‑Newtonian Viscosity On Arterial And Venous Fow And Transport, Sabrina Lynch, Nitesh Nama, C Alberto Figueroa Nov 2022

Efects Of Non‑Newtonian Viscosity On Arterial And Venous Fow And Transport, Sabrina Lynch, Nitesh Nama, C Alberto Figueroa

Department of Mechanical and Materials Engineering: Faculty Publications

It is well known that blood exhibits non-Newtonian viscosity, but it is generally modeled as a Newtonian fluid. However, in situations of low shear rate, the validity of the Newtonian assumption is questionable. In this study, we investigated differences between Newtonian and non-Newtonian hemodynamic metrics such as velocity, vorticity, and wall shear stress. In addition, we investigated cardiovascular transport using two different approaches, Eulerian mass transport and Lagrangian particle tracking. Non-Newtonian solutions revealed important differences in both hemodynamic and transport metrics relative to the Newtonian model. Most notably for the hemodynamic metrics, in-plane velocity and vorticity were consistently larger in …


Machine Learning-Based Classification Of Combustion Events In An Rcci Engine Using Heat Release Rate Shapes, Radhika Sitaraman, Sadaf Batool, Hoseinali Borhan, Javad Mohammadpour Velni, Jeffrey Naber, Mahdi Shahbakhti Nov 2022

Machine Learning-Based Classification Of Combustion Events In An Rcci Engine Using Heat Release Rate Shapes, Radhika Sitaraman, Sadaf Batool, Hoseinali Borhan, Javad Mohammadpour Velni, Jeffrey Naber, Mahdi Shahbakhti

Michigan Tech Publications, Part 1

Reactivity controlled compression ignition (RCCI) mode offers high thermal efficiency and low nitrogen oxides (NOx) and soot emissions. However, high cyclic variability at low engine load and high pressure rise rates at high loads limit RCCI operation. Therefore, it is important to control the combustion event in an RCCI engines to prevent abnormal engine combustion. To this end, combustion in RCCI mode was studied by analyzing the heat release rates calculated from the in-cylinder pressure data at 798 different operating conditions. Five distinct heat release shapes are identified. These different heat release traces were characterized based on start of combustion, …


A Focused Review On Structures And Ionic Conduction Mechanisms In Inorganic Solid-State Proton And Hydride Anion Conductors, Shichen Sun, Qiming Tang, Kangkang Zhang, Yeting Wen, Aidan Billings, Kevin Huang Nov 2022

A Focused Review On Structures And Ionic Conduction Mechanisms In Inorganic Solid-State Proton And Hydride Anion Conductors, Shichen Sun, Qiming Tang, Kangkang Zhang, Yeting Wen, Aidan Billings, Kevin Huang

Faculty Publications

Solid-state proton and hydride anion conductors are an important family of materials as electrolytes for solid state electrochemical cells such as fuel cells, batteries, sensors, and gas separation membranes. Searching for new proton and hydride-anion conductors has been an active research area for many decades. The focus of this article is on reviewing the types and mechanisms of each proton/hydride-anion conductor developed and their pros and cons. This review starts off with the most studied and most promising perovskite structured oxides as proton conductors, followed by other types of perovskite-related structures such as the Ruddlesden–Popper phase, pyrochlores and rare earth …


Prediction Of Curing Time/Shear Strength Of Non-Conductive Adhesives Using A Neural Network Model, Kyung-Eun Min, Jae-Won Jang, Jun-Ki Kim, Sung Yi, Cheolhee Kim Nov 2022

Prediction Of Curing Time/Shear Strength Of Non-Conductive Adhesives Using A Neural Network Model, Kyung-Eun Min, Jae-Won Jang, Jun-Ki Kim, Sung Yi, Cheolhee Kim

Mechanical and Materials Engineering Faculty Publications and Presentations

Electronic packaging has been developed with high resolution and fine interconnection pitches. Non-conductive adhesives (NCAs) have been growing with the increase of I/O pad count and density, along with fine pad bond pitch interconnections. Prediction and optimization of NCA characteristics are inherently complicated due to various and extensive materials composing NCAs. In this study, a framework predicting the curing time and shear strength of an NCA is established by a neural network model. NCA formulations with 4 resins, 3 hardeners, 8 catalysts, and a coupling agent were selected from in-house experiments, and an artificial neural network (ANN) with one dense …


Enhanced Electron Correlation And Significantly Suppressed Thermal Conductivity In Dirac Nodal-Line Metal Nanowires By Chemical Doping, Amanda L. Coughlin, Zhiliang Pan, Jeonghoon Hong, Tongxie Zhang, Xun Zhan, Wenqian Wu, Dongyue Xie, Tian Tong, Thomas Ruch, Jean J. Heremans, Jiming Bao, Herbert A. Fertig, Jian Wang, Jeongwoo Kim, Hanyu Zhu, Deyu Li, Shixiong Zhang Nov 2022

Enhanced Electron Correlation And Significantly Suppressed Thermal Conductivity In Dirac Nodal-Line Metal Nanowires By Chemical Doping, Amanda L. Coughlin, Zhiliang Pan, Jeonghoon Hong, Tongxie Zhang, Xun Zhan, Wenqian Wu, Dongyue Xie, Tian Tong, Thomas Ruch, Jean J. Heremans, Jiming Bao, Herbert A. Fertig, Jian Wang, Jeongwoo Kim, Hanyu Zhu, Deyu Li, Shixiong Zhang

Department of Mechanical and Materials Engineering: Faculty Publications

Enhancing electron correlation in a weakly interacting topological system has great potential to promote correlated topological states of matter with extraordinary quantum properties. Here, the enhancement of electron correlation in a prototypical topological metal, namely iridium dioxide (IrO2), via doping with 3d transition metal vanadium is demonstrated. Single-crystalline vanadium-doped IrO2 nanowires are synthesized through chemical vapor deposition where the nanowire yield and morphology are improved by creating rough surfaces on substrates. Vanadium doping leads to a dramatic decrease in Raman intensity without notable peak broadening, signifying the enhancement of electron correlation. The enhanced electron correlation is further …


A Novel Voc Breath Tracer Method To Evaluate Indoor Respiratory Exposures In The Near- And Far-Fields; Implications For The Spread Of Respiratory Viruses, Hooman Parhizkar, Mark Fretz, Aurelie Laguerre, Jason Stenson, Richard Corsi, Kevin Van Den Wymelenberg, Elliott T. Gall Nov 2022

A Novel Voc Breath Tracer Method To Evaluate Indoor Respiratory Exposures In The Near- And Far-Fields; Implications For The Spread Of Respiratory Viruses, Hooman Parhizkar, Mark Fretz, Aurelie Laguerre, Jason Stenson, Richard Corsi, Kevin Van Den Wymelenberg, Elliott T. Gall

Mechanical and Materials Engineering Faculty Publications and Presentations

Background

Several studies suggest that far-field transmission (>6 ft) explains a significant number of COVID-19 superspreading outbreaks.

Objective

Therefore, quantifying the ratio of near- and far-field exposure to emissions from a source is key to better understanding human-to-human airborne infectious disease transmission and associated risks.

Methods

In this study, we used an environmentally-controlled chamber to measure volatile organic compounds (VOCs) released from a healthy participant who consumed breath mints, which contained unique tracer compounds. Tracer measurements were made at 0.76 m (2.5 ft), 1.52 m (5 ft), 2.28 m (7.5 ft) from the participant, as well as in the …


Exosomes Derived From Differentiated Human Admsc With The Schwann Cell Phenotype Modulate Peripheral Nerve-Related Cellular Functions, Bo Liu, Yunfan Kong, Wen Shi, Mitchell Kuss, Ke Liao, Guoku Hu, Peng Xiao, Jagadesan Sankarasubramanian, Chittibabu Guda, Xinglong Wang, Yuguo Lei, Bin Duan Nov 2022

Exosomes Derived From Differentiated Human Admsc With The Schwann Cell Phenotype Modulate Peripheral Nerve-Related Cellular Functions, Bo Liu, Yunfan Kong, Wen Shi, Mitchell Kuss, Ke Liao, Guoku Hu, Peng Xiao, Jagadesan Sankarasubramanian, Chittibabu Guda, Xinglong Wang, Yuguo Lei, Bin Duan

Department of Mechanical and Materials Engineering: Faculty Publications

Peripheral nerve regeneration remains a significant clinical challenge due to the unsatisfactory functional recovery and public health burden. Exosomes, especially those derived from mesenchymal stem cells (MSCs), are promising as potential cell-free therapeutics and gene therapy vehicles for promoting neural regeneration. In this study, we reported the differentiation of human adipose derived MSCs (hADMSCs) towards the Schwann cell (SC) phenotype (hADMSC-SCs) and then isolated exosomes from hADMSCs with and without differentiation (i.e., dExo vs uExo). We assessed and compared the effects of uExo and dExo on antioxidative, angiogenic, antiinflammatory, and axon growth promoting properties by using various peripheral nerve-related cells. …


Bulk Glass As Compressive Reinforcement In Structural Elements, John Cotter Nov 2022

Bulk Glass As Compressive Reinforcement In Structural Elements, John Cotter

USF Tampa Graduate Theses and Dissertations

All composites are formulations of materials that allow for the improvement of material properties by compositing materials with differing properties. For example, straw, which has a low compression strength and stiffness but relatively high tensile stiffness, composites well with clay, which has a high compression stiffness and low tensile strength, to create a material that utilizes a clay base with straw to greatly improve the strength of clay. In general, the most economical composites are those that combine a low-cost binder, or matrix, with higher strength reinforcing materials.

Contrary to popular knowledge, bulk glass is an exceedingly strong material when …