Mechanical Engineering Commons^™

Judo Wearable, Alison Waugh, Natalie Masters

Williams Honors College, Honors Research Projects

Design a wearable sensor array to determine if a judo throw fulfills the requirements to win a match

Agv Design, Vincent Orzel, Zachary Woodrum

Williams Honors College, Honors Research Projects

This report details the design and calculation work done towards creating an autonomous guided vehicle (AGV) for use in the steel and metal related industries. Steel Equipment Specialists (SES) is a major manufacturer of coil transportation vehicles for these industries. SES believes the future of coil transportation within the mills includes AGVs in some circumstances. The team was tasked with exploring the design and cost of a base model for use in future designs, since SES has not yet modeled or manufactured an AGV. This design was successful under the stress from the application in calculations, and the cost of …

Mechanical Behavior Of Bioceramic Materials: Case Study Of The Skeleton Of The Staghorn Coral, Acropora Cervicornis And The Tibia Of The Laboratory Mouse, Mus Musculus, Mahmoud Omer

Electronic Theses and Dissertations, 2020-2023

I studied two types of bioceramics: (A) the aragonite CaCO3 skeleton of the staghorn coral, Acropora cervicornis and (B) the hydroxyapatite Ca10(PO4)6(OH)2 bones of the laboratory mouse, Mus musculus. The research aimed to analyze coral deformation behavior and study dietary and estrogen depletions effects on bone strength. I compared the mechanical and structural properties of staghorn coral skeletons cleaned by chemical bleaching and biological processes. Optical microscopy and computed tomography (CT) revealed a sophisticated microstructure of non-homogenously distributed pores. Staghorn coral skeletons showed ''gracious" fracture, where the unique pore arrangements resisted catastrophic crack growth and prevented instantanous failure. Elastic moduli …

Corticomuscular Adaptation To Mechanical Perturbations In A Seated Locomotor Task, Seyed Yahya Shirazi

Electronic Theses and Dissertations, 2020-2023

Cortical control during walking is most pronounced when the person is perturbed. Although seated locomotor tasks such as cycling or recumbent stepping improve walking performance, the electrocortical correlates of perturbed seated tasks have not been studied in detail. The primary purpose of this research was to quantify cortical and muscular responses to mechanical perturbations during recumbent stepping. We also aimed to quantify possible differences between young and older adults' responses to perturbed stepping. A secondary aim of this research was to determine the accuracy of electroencephalography (EEG) source imaging to interpret the electrocortical findings adequately. We hypothesized that both young …

Exergoeconomic Analysis And Optimization Of Novel Cogeneration Systems For Freshwater Production, Power And Cooling, Sattam Alharbi

Electronic Theses and Dissertations, 2020-2023

Global consumption of energy and freshwater is increasing continuously due to population growth and improving living standards. The world energy consumption is anticipated to increase by around 50% by 2050 according to the U.S Energy Information Administration (EIA). There is also very limited access to freshwater and cooling in many developing countries. Therefore, developing an efficient energy system, recovering the waste heat (cogeneration system or multigeneration) to produce freshwater and cooling, and using a renewable energy source are promising solutions to meet the energy demand and to reduce environment pollution associated with fossil fuels. In this study, several novel cogeneration …

Model-Form Uncertainty Quantification In Prognosis And Fleet Management With Physics-Informed Neural Networks, Arinan De Piemonte Dourado

Electronic Theses and Dissertations, 2020-2023

Prognosis and health management play an important role in the control of costs associated with the operation of large industrial equipment. By properly comprehending hardware degradation and accurately predicting the remaining useful life of such equipment, we can significantly lower operational costs by reducing asset downtime and maintenance interventions. However, complex interactions between operational conditions and component capability make accurately modeling damage accumulation for large fleets a daunting task. Unforeseen factors such as aggressive missions introduced by operators, exposure to harsh environments, manufacturing issues, amongst many others, can lead to large discrepancies between predicted and observed useful life. Motivated by …

Hotspot Cooling Performance For Confined Jet Impingement Cooling, Tanvir Ahmed Chowdhury

Electronic Theses and Dissertations, 2020-2023

The current trend in microelectronics is to manufacture devices with increased computational powers and reduced size. These devices with increased power densities are consequently subject to extreme thermal loads. Thermal management of these power loads is extremely challenging. The presence of the hotspots can make this challenge even more difficult. Jet impingement cooling is one of the top candidates for removing such extreme heat fluxes in microelectronics. Jet impingement cooling can achieve heat transfer coefficients (HTCs) due to its normal incident flow-field and ability to thin the local thermal boundary layer in the stagnation region. This dissertation presents the hotspot …

Process-Structure Relationship In The Directed Energy Deposition Of Cobalt-Chromium Alloy (Stellite 21) Coatings, Ziyad M. Smoqi, Joshua Toddy, Harold (Scott) Halliday, Jeffrey E. Shield, Prahalada K. Rao

Department of Mechanical and Materials Engineering: Faculty Publications

In this work, we accomplished the crack-free directed energy deposition (DED) of a multi-layer Cobalt- Chromium alloy coating (Stellite 21) on Inconel 718 substrate. Stellite alloys are used as coating materials given their resistance to wear, corrosion, and high temperature. The main challenge in DED of Stellite coatings is the proclivity for crack formation during printing. The objective of this work is to characterize the effect of the input energy density and localized laser-based preheating on the characteristics of the deposited coating, namely, crack formation, microstructural evolution, dilution of the coating composition due to diffusion of iron and nickel from …

Design, Fabrication, And Testing Of A High-Speed, Low-Cost Atomic Force Microscope Housing And Distance Measurement System, Jonathan Menke

All Undergraduate Theses and Capstone Projects

Advances to the state-of-the-art in fields like biology and material science often stand on the foundation of improved imaging. Here a low-cost Atomic Force Microscope (AFM) housing and distance measurement system was designed, fabricated, and tested. The instrument was developed around an Optical Pickup Unit (OPU) and designed for use as part of a high-speed AFM system. A structure to align the OPU with the probe holder was designed to ensure the beam of the OPU is positioned above the probe in addition to accommodating space, manufacturability, and cost constraints by using cost effective components. The designs were fabricated and …

Gamification Of Icebreaking Activities For Mechanical Engineering Students Embarking On A Problem Based Learning Module, Kevin Delaney, Gerard Nagle, Mingzhu Chen

Conference papers

When they enter the workforce engineering graduates must be able to engage collaboratively with others to find solutions to complex engineering challenges. This involves a great deal more than simply solving technical problems traditionally taught in engineering school. The Mechanical Engineering Discipline in Technological University Dublin (TU Dublin) has helped students develop real-world engineering skills through a team based Problem Based Learning (PBL) module since 2005. This module, involving third year students, can be particularly challenging since participants can join the third year of the program from other programs or universities and many will not have known each other prior …

Harvesting Heat From Safer, Energy-Dense Slow Pyrolant Mixtures For Future Space Missions, Katerina Chagoya

Electronic Theses and Dissertations, 2020-2023

Energy sources powering space missions range from highly energetic nuclear reactions to short-lifetime and low-output batteries. The proper selection of a power system is dependent on the mission duration and destination and oftentimes energy sources that may be optimal for the former may be unsuitable for the latter. Various limitations of these power sources hinder the capacity for regular and frequent space exploration. However, the ability to harvest heat for electrical power generation would allow for long-distance and long-duration missions at a reduced cost. By employing a regulated, self-propagating, exothermic chemical reaction between solid fuel and oxidizer, we hope to …

Mechanics Of Low Dimensional Biomimetic Scale Metamaterials, Hossein Ebrahimi

Electronic Theses and Dissertations, 2020-2023

Combination of topology and material could play an important role in giving rise to nontraditional behavior in mechanical structures and is a typical strategy in nature. Topology is concerned with the geometrical and spatial properties of the objects, which are preserved under continues mechanical deformation of the object such as stretching, bending, twisting, etc. In this work, we focus on structures based on fish scale inspired surface topology. The utilized idea for surface topology is a bioinspired design on the substrate of biological scale-covered systems. Scales are a path breaking evolutionary adaptation that accompanied vertebrate evolution for the past 500 …

Heart Rate Variability In Adults During 24-Hours With A Focus On Sleep Period, Ankur Ravikanth

Honors Undergraduate Theses

The objective of this study is to investigate heart rate variability (HRV) over a period of 24 hours with special focus on patterns during the sleep period. Comparisons were made between sleep and the full 24-hour data. The Polar M430 watch was used to record heart rate (HR) data for about 24 hours, and the subject kept a journal of the activities they performed throughout the day. The data was visualized as heart rate in beats per minute (BPM) as a function of time. To check the accuracy of the Polar watch, a 7-minute recording of HR from the watch …

Electromyographic And Mechanomyogrpahic Signal Changes With Fatigue In Adults, Rehana Koilpillai

Honors Undergraduate Theses

Surface electromyography (sEMG) and mechanomyography (MMG) are well-studied signals that can reveal information about the physiological behavior of muscles during contraction. The purpose of this study was to quantify, characterize, and analyze the electrical and mechanical muscle responses to submaximal, isometric contractions in the rectus femoris in adults. Previous studies have investigated the use of EMG to monitor muscle fatigue. However, more information appears to be needed about the use of MMG to measure muscle fatigue during submaximal isometric contraction in the rectus femoris. In this study, the utility of MMG as a measure of muscle fatigue or muscle state …

Flow Field Dynamics As A Result Of Perforated Plates, Hector Perez

Honors Undergraduate Theses

Detonation to Deflagration Transition (DDT) is the process of accelerating a laminar flame to supersonic speeds to cause a detonation. A method used to reach Chapman-Jouguet (CJ) detonation velocities is the induction of turbulence to increase the surface area of the flame front, increasing the consumption rate of unburned gases and the propagation speed of the flame. Perforated plates helped achieve flame acceleration in previous studies to induce turbulence when the flame front interacts with the turbulator; previous work also accomplished detonation speeds with perforated plates. This work aims to visualize the flame front and perforated plate interaction and analyze …

Biofilm And Cell Adhesion Strength On Dental Implant Surfaces Via The Laser Spallation Technique, James D. Boyd, Arnold J. Stromberg, Craig S. Miller, Martha E. Grady

Statistics Faculty Publications

OBJECTIVE: The aims of this study are to quantify the adhesion strength differential between an oral bacterial biofilm and an osteoblast-like cell monolayer to a dental implant-simulant surface and develop a metric that quantifies the biocompatible effect of implant surfaces on bacterial and cell adhesion.

METHODS: High-amplitude short-duration stress waves generated by laser pulse absorption are used to spall bacteria and cells from titanium substrates. By carefully controlling laser fluence and calibration of laser fluence with applied stress, the adhesion difference between Streptococcus mutans biofilms and MG 63 osteoblast-like cell monolayers on smooth and rough titanium substrates is obtained. The …

Influence Of Ecm Composition And Intracellular Calcium On Endothelial Biomechanics And Prediction Of Cellular Stresses Using Machine Learning, Vignesh Aravind Subramanian Balachandar

Electronic Theses and Dissertations, 2020-2023

Endothelial cells, which form the inner layer of the vasculature, constantly interact with their external microenvironment called the extracellular matrix (ECM) by exerting contractile cell-substrate stresses called tractions and cell-cell stresses called intercellular stresses. This cellular mechanosensing can become aberrant and act as a precursor for many vascular pathological and physiological processes such as cancer metastasis, atherosclerosis, cell differentiation, migration, and morphogenesis. Also, intracellular calcium signalling plays an important role in endothelial cell motility and in maintaining vascular tone. Alteration in ECM composition has been linked to several pathologies, in fact, a transition to a fibronectin-rich matrix from a type …

Diffusion Biomarkers To Characterize Tissue Microstructure In Chronic Myocardial Infarction, Mohammad Tanjib Rahman

Electronic Theses and Dissertations, 2020-2023

Non-invasive imaging techniques to detect and characterize infarcted myocardium are critical for myocardial infarction (MI) prognosis and post-MI risk assessment. Many existing imaging techniques (such as T1-mapping) for MI detection require the use of contrast agents, which are not recommended for patients with renal failure. Cardiac diffusion tensor magnetic resonance imaging (cDTI), a non-contrast imaging technique, allows estimating the aggregate cardiomyocyte microstructure in healthy subjects and its remodeling as a result of cardiac diseases. Two main questions are investigated in this thesis: 1) how cDTI based biomarkers can characterize microstructural changes occurring post-MI; and 2) if cDTI based biomarkers can …

Damping And Ejection Of Sloshing Liquid Drops From Elastic Substrates, Md Erfanul Alam

Electronic Theses and Dissertations, 2020-2023

Liquid slosh is a potential source of disturbance of the motion of a moving structure. In this thesis, we probe the damping technique of sessile drop by absorbing a portion of the kinetic energy. The sloshing dynamics are typically represented by a mechanical model of a spring mass damper. However, damping by drop sloshing is dependent on viscosity, surface tension, drop size and drop location. We explore highly-coupled fluid-solid mechanics using singular liquid drop with varying viscosity and surface tension resting on a millimetric cantilever. Cantilevers are displaced 0.6 mm and their free end is allowed to vibrate freely. Cantilever …

Photocatalytic Inactivation Efficacy Of Sars-Cov-2 In Hvac Systems, Andrew J. Freeman, Sudharshan Anandan, Ernest R. Blatchley Iii, W. Travis Horton, David M. Warsinger

Discovery Undergraduate Interdisciplinary Research Internship

The coronavirus pandemic has emphasized a need for robust and reliable air purification systems in buildings; with that comes a need for a standardized testing methodology for air purification technologies in HVAC air circulation systems. One such method of air purification is photocatalytic oxidation (PCO), a mechanism in which a catalyst irradiated by light produces reactive molecules that degrade a wide range of pollutants, including the aerosols that carry COVID. This technology has primarily been used in aqueous applications, but there have recently been developments in air purification that have made it a promising contender to existing technologies. One of …

Automated Control System For The Remote-Controlled Torch Positioner, Christopher Ferguson, Anna Abate, Kyle Cramer, Alex Sabitsch, Jacob Stefanko

Williams Honors College, Honors Research Projects

The goal of this project is to design and implement a controls system for Dr. Morscher’s burner rig. The rig serves to simulate jet turbine conditions and test how materials, specifically ceramic matrix composites, react under high temperatures and stresses. Currently, the location of the torch relies solely on manual adjustments and has no automated control system. The improved design will automatically adjust the torch position based on the desired temperature of the sample being tested, therefore maintaining a steady environment for the sample. The current method of manual adjustments for regulating temperature is a crude solution that does not …

Kinetics Of Photolysis And Photocatalytic Oxidation Of Ammonium Sulfite For Hydrogen Production, Moustafa A. Soliman, Maryam Zakaria

Chemical Engineering

The production of hydrogen via photocatalytic water splitting is one of the most promising technologies for obtaining chemical energy from direct solar energy while maintaining the least possible waste and pollutants. In this paper, we obtain the kinetic parameters necessary for the design of a photoreactor for photolysis and photocatalysis of ammonium sulfite solution. For the case of photolysis, we obtain the kinetics for the effect of changing the pH on the produced amount of hydrogen. For the case of photocatalysis, the intrinsic kinetic parameters of photocatalysis of water splitting reaction of ammonium sulfite and water in the presence of …

Analysis Of A Solar Hybrid Sulfur Ammonia Copper Oxide Thermochemical Cycle For Hydrogen Production, Moustafa A. Soliman, Abdel Moniem Abomosalam, Noran Shedid, Mohamed Othman, Toka Hatem, Marc Samer

Chemical Engineering

Solar energy conversion to hydrogen by water splitting is a promising technique because it is sustainable and environmentally friendly. One option for water splitting is through thermochemical cycles in which one of the steps is electrolytic or photocatalytic. In this paper, the economics of a thermochemical process that combines photocatalysis, photovoltaics, high temperature thermal energy and energy storage to harvest solar energy is assessed. This paper focuses on the standard hybrid sulfur ammonia thermochemical cycle (SA) in which the electrolytic step of the hydrogen production from ammonium sulfite solution is augmented by a photocatalytic step. Trying to make use of …

Variational Inference For Morphological Modification To 3d Geometry : An Application To The Support Generation For Metal Additive Manufacturing, Mugdha Swanand Joshi

Masters Theses

"A key issue in metal additive manufacturing (AM) processes is the optimization of support geometry. Correct selection of support strategy can reduce build time, improve surface finish, reduce support removal time, and maximize build success. Strategies used to design support structure are time consuming and need skilled personnel. In this research we have deployed a deep generative model capable of making morphological modifications to the part. However, it is not similar to topology optimization where the aim is to reduce or eliminate support structure. The proposed model can make necessary changes to the part in order to transform it into …

Design And Development Of A Variable Resistance Hand Exerciser Using A Compliant Mechanism, Jyothi Komatireddy

Masters Theses

"Rehabilitation exercise plays a vital role in recovering from an injury or illness condition by improving flexibility and restoring muscle strength. If not done correctly, exercising can cause more damage to the health condition than in healing. Understanding the muscle’s resistance level while performing an exercise helps design the exercising equipment not to overstrain the muscle during operation. This research presents a methodology to develop a variable-resistance hand exerciser by using a compliant cam-follower mechanism. The proposed design comprised a compliant follower and a rigid cam. The rigid cam is synthesized using the human hand force-deflection profile as an input …

Layer-To-Layer Feedback Control For Direct Energy Deposition Additive Manufacturing, Michelle Gegel

Doctoral Dissertations

"Additive manufacturing (AM) has garnered much attention in recent years, some calling it the fourth industrial revolution. It was first used to create rapid prototypes, although recent efforts have been made to advance the technology towards production of functional parts. This requires advancement in the materials used in AM, as well as the ability to produce quality parts repeatably. More specifically, direct energy deposition (DED) of metal powders is a process capable of producing and repairing parts with complex geometries; however, it is not widely used in industry due to challenges with quality control. In this process, metal powder is …

Energy Consumption And Lifecycle Assessment Comparison Of Cutting Fluids For Drilling Titanium Alloy, Navneet Khanna, Prassan Shah, Jwalant Wadhwa, Anjali Pitroda, Julius M. Schoop, Franci Pusavec

Institute for Sustainable Manufacturing Faculty Publications

This study analyzes four cutting conditions (dry, flood, Liquid CO 2 (LCO2), and Liquid N2 (LN 2)) based on energy consumption and ecological impacts for drilling VT-20, a Titanium alloy. The lower cutting and total energy have been consumed for LCO2 as compared to others. The Life Cycle Assessment (LCA) analysis has been performed using ReCiPe 2016 midpoint (H) to identify the impact of cutting conditions on ecosystem, human health, and natural resources. Cryogenic environment with LN 2 has been found as the most ecological cutting condition next to dry machining, while flood coolant has 94-99% of total impact considering …

Mechanical Properties And Spectral Vibrational Response Of Si-O-C With And Without Graphene Toughening, Anthony Vozza

Electronic Theses and Dissertations, 2020-2023

The mechanical behavior of silicon oxycarbide polymer derived ceramics (SiOC-PDC) without and with a graphene toughening phase was studied under uniaxial compressive load with zero dwell time and with 200 second dwell time step loading in combination with in-situ Raman spectroscopy to determine spectral vibrational response of SiOC under compressive stress. SiOC without and with graphene ceramic samples were produced through the replica templating technique. The compressive strengths of SiOC without and with a graphene toughening phase measured with zero dwell time was determined to be equal to 165.65 (SD 54.21) and 163 (SD 24.2) MPa, respectively, while compressive strengths …

A Semi-Active Vibration Isolator For 3d Printing On Shipboard, Mohammad Z. Shahabuddin

College of Graduate Studies: Theses & Dissertations

In the recent years, additive manufacturing (AM) (aka 3D printing)-has become a viable alternative to traditional manufacturing due to its unique advantages, such as enabling the fabrication of complex geometries at reduced weight and costs as well as allowing on-site fabrication for maintenance and repair. One specific application area of the AM is the navy vessels. During extended voyages, the navy vessels likely require the convenience of on-site fabrication of the malfunctioned parts. However, the shipboard equipment suffers from a broad range of external excitations arising not only from the waves but also from the vessel’s engines, which …

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

College of Graduate Studies: Theses & 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 …