Mechanical Engineering Commons^™

Adaptation Of A Commercially Available Galvanic Skin Response Sensor To Measure Respiration Across The Chest For Heart Rate Variability Monitoring, Breno C. Dobal

Honors Undergraduate Theses

Heart rate variability (HRV) is a naturally occurring cardiovascular phenomenon referring to the changing timing between consecutive heartbeats. The connection between HRV and overall cardiovascular health and autonomic nervous system function has been well established through prior research and well documented in existing literature. The existing studies, however, included shorter HRV subject recording session, using traditional HRV monitoring methods that do not typically combine electrocardiogram (ECG), seismocardiogram (SCG) and galvanic skin response (GSR) respiration monitoring. The inclusion of longer HRV subject recording may allow for further insight on the possible effects of given observable biological phenomenon on HRV.

The current …

Sensor Tasking Strategies For Space-Based Observers In The Cislunar Environment, Smriti Nandan Paul, Roshan Thomas Eapen, Puneet Singla

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The cislunar space environment has witnessed an increase in activities, and future projections indicate significant growth in object population. Consequently, it becomes crucial to monitor these objects for space domain awareness (SDA) purposes. As the number of objects surpasses the available observers, meticulous sensor tasking becomes essential. This paper focuses on designing and exploring strategies for observing and keeping custody of known objects in cislunar space. Optical space-based telescopes, combined with lunar ground-based telescope, are employed for sensor tasking of cislunar objects residing in valuable orbits. The proposed research aims to address the following key points: (1) examination of the …

Development And Characterization Of An Ion Source To Simulate Low Earth Orbit Plasma Environment In A Vacuum Chamber, Emmanuel Kofi Asuako Wie-Addo, Scott Lucas, Daoru Han

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A magnetic filter-type plasma source has been installed and characterized in a 10 ft long x 6ft diameter vacuum chamber. The plasma source was characterized with a fleet of diagnostic probes including an in-house cylindrical Langmuir probe. This resulted in the measurement of key plasma parameters such as electron number density, electron temperature, plasma potential, Debye length, ion current density, streaming ion energy, ion number density, and streaming ion velocity. By varying the flow rates, discharge current, and distance, single points measurements were taken at three locations downstream of the plasma source to establish an optimum operating condition to simulate …

Machine Learning Applications In Spine Biomechanics, Farshid Ghezelbash, Amir Hossein Eskandari, Xavier Robert-Lachaine, Shufan Cao, Mehran Pesteie, Zhuohua Qiao, Aboulfazl Shirazi-Adl, Christian Larivière

Études primaires

Spine biomechanics is at a transformation with the advent and integration of machine learning and computer vision technologies. These novel techniques facilitate the estimation of 3D body shapes, anthropometrics, and kinematics from as simple as a single-camera image, making them more accessible and practical for a diverse range of applications. This study introduces a framework that merges these methodologies with traditional musculoskeletal modeling, enabling comprehensive analysis of spinal biomechanics during complex activities from a single camera. The real-world applications explored in this study include assessment in workplace lifting, evaluation of whiplash injuries in car accidents, and biomechanical analysis in professional …

Development Of A High-Pressure Infiltration Process For Phenol–Formaldehyde Matrix Composites, Samuel Weiler, Patrick Schwartzkopf, Henry Haffner, K. Chandrashekhara

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Phenol–formaldehyde (phenolic) thermosets are known for excellent heat and chemical resistance, high flame retardance, and good mechanical performance. However, phenolics are also known for their high brittleness, and tendency to form voids, due to a condensation reaction forming water during curing. These voids can decrease the mechanical performance of the resultant phenolic composite and introduce undesirable performance characteristics. This work aims to develop a technique that uses high-pressure infiltration to obtain dense phenolic matrix composites, with commercially available resin and fiber reinforcement. The high-pressure system developed in this work is compared to a conventional low-pressure resin infusion technique, and the …

On The Area-Averaged Effective Sound Absorption Coefficient Of Porous Materials Excited By A Monopole, Franck Sgard, Noureddine Atalla, Olivier Robin, Alain Berry

Études primaires

The area-averaged effective sound absorption coefficient (SAC) of a rigid-backed homogeneous porous material subjected to a monopole excitation is calculated as the absorbed-to-incident sound power ratio. Using Allard's model to describe the sound propagation above the porous material, an analytical model for this power-based SAC is proposed and proves to give a good approximation of the sound absorption performance under monopole excitation of sufficiently large areas of material. The impact of factors on the power-based SAC, such as monopole height, material radial dimension used to calculate the sound powers, and material properties is discussed. The power-based SAC frequency-dependent behavior is …

An Impedance Tube Technique For Estimating The Insertion Loss Of Earplugs, K. Carillo, O. Doutres, F. Sgard

Études primaires

This paper proposes a quick and straightforward technique for estimating the insertion loss (IL) of earplugs measured on an acoustical test fixture (ATF) using a commercial impedance tube. In this method, the earplug's acoustic properties (i.e., its transmission loss and the reflection coefficient of its medial surface) are determined from its transfer matrix measured using the three-microphones impedance tube method modified here for the current application. The IL is then estimated using a one-dimensional analytical model of open and occluded earcanals based on the wavefield decomposition theory. The method is evaluated numerically and experimentally from 50 Hz to 6.5 kHz. …

An Evaluation Of Methods For Assessing Robot Kinematic Model Accuracy In The Presence Of Noise, Mitchell R. Woodside, Patrick Bazzoli, Philip A. Olubodun, J. Adam Nisbett, Guixiu Qiao, Douglas A. Bristow

Mechanical and Aerospace Engineering Faculty Research & Creative Works

While there are many works developing methods for modeling and calibrating robot kinematics, assessing the accuracy of those models has received little attention. However, accuracy assessment is critically important for applications where the robot must operate with absolute accuracy over a large region of workspace, such as in robotic machining. When the model of such a system is well calibrated, the remaining deterministic error can be quite complex, owing to complicated gearing errors, deformations, and quasi-static thermal changes. Locating the largest deterministic error requires an exploration over the workspace, but assessing the largest error is complicated by repeatability error and …

Hyper-Thick Electrodes For Lithium-Ion Batteries Enabled By Micro-Electric-Field Process, Tazdik Patwary Plateau, Gracie Boyer, Jonghyun Park

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Increasing electrode thickness is a key strategy to boost energy density in lithium-ion batteries (LIBs), which is essential for electric vehicles and energy storage applications. However, thick electrodes face significant challenges, including poor ion transport, long diffusion paths, and mechanical instability, all of which degrade battery performance. to overcome these barriers, a novel micro-electric-field (μ-EF) process is introduced that enhances particle alignment during fabrication with reduced distance between anode and cathode. This process produces hyper-thick (≈700 µm) electrodes with low tortuosity and improved ion diffusion. the μ-EF electrodes achieve high areal capacities (≈8 mAh cm−2), while maintaining power density and …

Investigating Bistable Dynamics Of Coupled Oscillators With Similarities To Neural Activity In Epilepsy, Nilay Kant, Ranjan Mukherjee

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The dynamics of an oscillator, which exhibits a stable equilibrium and a stable limit cycle, is investigated. We refer to it as a bistable oscillator unit (BOU) and show that two coupled BOUs (CBOUs) exhibit dynamics analogous to neural activity patterns in epilepsy, including healthy, localized, and fully spread epileptic states. By treating each CBOU as an independent system influenced by the state of the other, we establish local input-to-state stability near the equilibrium and the limit cycle and estimate the ultimate bounds of the trajectories. Our analysis identifies the domain of the initial conditions and estimates the coupling parameter …

Modeling Human Strategy For Flattening Wrinkled Cloth Using Neural Networks, Nilay Kant, Ashrut Aryal, Rajiv Ranganathan, Ranjan Mukherjee, Charles Owen

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This paper explores a novel approach to model strategies for flattening wrinkled cloth learning from humans. A human participant study was conducted where the participants were presented with various wrinkle types and tasked with flattening the cloth using the fewest actions possible. A camera and Aruco marker were used to capture images of the cloth and finger movements, respectively. The human strategies for flattening the cloth were modeled using a supervised regression neural network, where the cloth images served as input and the human actions as output. Before training the neural network, a series of image processing techniques were applied, …

Inherently Porous Metal Structures With Sufficient Mechanical Properties Through Direct Writing Of Bio-Based Inks, Havva Eda Aysal

Graduate Theses, Dissertations, and Problem Reports (ETD)

There is currently a burgeoning interest in developing 3D printed metal structures with inherent porosity and sufficient mechanical properties for mass customization in the biomedical field. Current approaches for 3D printing of biocompatible metals rely on powder-bed fusion methods which are energy intensive and utilize large amounts of metal powder that is challenging to recycle. In addition, such methods aim on producing dense parts and porosity generation, within the printed part, is challenging due to the complex physics of the melting pool. Here, a relatively new and promising approach is undertaken to study the 3D printing of inherently porous structures …

On Uncertainty For Ill-Posed Robot Decision Problems, Jared Joseph Beard

Graduate Theses, Dissertations, and Problem Reports (ETD)

As robots adopt more real world responsibilities, they will be expected to solve more complicated problems. In some cases limited prior knowledge will result in unmodelled environmental conditions; in others, multiple users may have competing perspectives on how to frame a decision problem. Many existing frameworks, namely Markov decision processes (MDP) presuppose users have identified a specific problem with models sufficient to solve or learn a problem. If we wish to extend MDPs to novel problems or those heavily dependent on user feedback, autonomous decision makers must be able to identify limitations in how a given problem is framed and …

An Investigation Of The Performance Of A 140 Kw Solar Panel In West Virginia, Rumana Subnom

Graduate Theses, Dissertations, and Problem Reports (ETD)

Solar panels are recognized as a viable technology for producing electricity from sunlight. The performance of a solar panel is influenced by factors such as solar irradiance, tilt angle, orientation, shading, panel age, degradation, and various environmental conditions including ambient air temperature, humidity, dust, soil, and snow.

In this research, a mobile solar panel testing system consisting of a mobile cart, a solar panel, and a portable power station was designed and fabricated to evaluate the performance of a solar panel. The battery is equipped with a thermal management system controlling its temperature and charging and discharging system. The current …

Bridging Evolutionary And Bayesian Optimization For Enhanced Safety Verification In Control Systems, Joshua M. Yancosek

Graduate Theses, Dissertations, and Problem Reports (ETD)

The rigorous safety verification of control systems in critical applications is essential, given their in creasing complexity and integration into everyday life. Simulation-based falsification approaches play a pivotal role in the safety verification of control systems, particularly within critical applications. These methods systematically explore the operational space of systems to identify configurations that result in violations of safety specifications. However, the effectiveness of traditional simulation based falsification is frequently limited by the high dimensionality of the search space and the sub stantial computational resources required for exhaustive exploration. This thesis presents Bayesian Evolutionary Approach for COuNterexample, or BEACON, a novel …

Laser Deposition Additive Manufacturing Of Multi-Material And Metal-Ceramic Composite Structures, Manikanta Grandhi

Graduate Theses, Dissertations, and Problem Reports (ETD)

The increasing performance requirements of modern industrial systems, coupled with the imperative for decarbonization, necessitate a fundamental rethinking of metallic component design and manufacturing. Traditional materials, with their inherent limitations in property optimization, susceptibility to degradation, and weight constraints, are proving insufficient. Multi-material joining offers a potential solution, enabling designers to strategically integrate diverse materials with specific, tailored properties into single component. Functionally graded materials (FGMs) and oxide dispersion strengthened (ODS) materials are prime examples of this approach, delivering substantial improvements in wear resistance, thermal regulation, high-temperature resilience, and overall weight efficiency. However, conventional manufacturing approaches further exacerbate the limitations …

Machine Learning-Assisted Multiscale Simulation And Design Optimization Of Composite Jackets Under Low-Velocity Impacts, Masoud Mohammadi

Graduate Theses, Dissertations, and Problem Reports (ETD)

This research presents the development of a data-driven machine learning-assisted approach to simulate and optimize the design of composite materials subjected to low-velocity impacts. It focuses on a specific type of hybrid composite comprised of fiberglass and Kevlar fabrics stitched with Kevlar threads. The study begins by creating a multiscale finite element simulation for the composite under a low-velocity impact, which operates across three scales: microscale, mesoscale, and macroscale. This simulation accepts various inputs, such as different layer configurations and orientations, and provides impact outputs including maximum load and energy absorption capacity and displacement at failure.

Python and MATLAB scripts …

Economic Profitability Of Sustainable Buildings Industry, Mohanad Ibrahim Altuma, Hanadi Abdulridha Lateef, Ayad Abdulkhaleq Al-Yousuf

Al-Esraa University College Journal for Engineering Sciences

The increasing global awareness of the Earth's deteriorating condition and the unpredictable effects of climate change has given rise to worldwide phenomena that impact several elements like the economy, agricultural security, water availability, and energy supplies. Buildings contribute significantly to the generation of greenhouse gases, as well as the disposal of pollutants and energy consumption. Therefore, they play a crucial role in addressing environmental issues.

Although sustainable buildings are widely acknowledged as a potential advancement, professionals in the property market still believe that the upfront costs of creating sustainable buildings are significantly higher than those of conventional buildings. This view …

Designing A Visual Control Framework Based On Feature Point Analysis To Guide Robots In Uncharted Areas, Isam Sadiq Rasham Al-Ghadhbawi

Al-Esraa University College Journal for Engineering Sciences

Image processing may be made more accurate and efficient with the use of optical processing technologies. In order to make better design judgments early in the package design process, visual packaging art simulation aims to swiftly develop realistic packaging effects. Conventional simulation techniques frequently yield findings that are neither realistic or detailed, and they also take a lot of time and human resources. Optical processing-based machine vision technology can fully utilize computer vision and image processing techniques to simulate package designs accurately and efficiently. This research proposes a foundation for machine vision technologies based on image optical processing. Real package …

Integration Of Infrared Thermography And Deep Learning For Real-Time In-Situ Defect Detection And Rapid Elimination Of Defect Propagation In Material Extrusion, Asef Ishraq Sadaf

College of Graduate Studies: Theses & Dissertations

This study presents a novel approach to overcoming process reliability challenges in Material Extrusion (ME), a prominent additive manufacturing (AM) technique. Despite ME's advantages in cost, versatility, and rapid prototyping, it faces significant barriers to commercial-scale production, primarily due to quality issues such as overextrusion and underextrusion, which compromise final part performance. Traditional manual monitoring methods severely lack the capability to efficiently detect these defects and highlight the necessity for an efficient and real-time monitoring solution. Considering these challenges, an innovative and field-deployable infrared thermography-based in-situ real-time defect detection and feedback control system is proposed in this thesis. A novel …

Numerical Analysis Of A Novel Elastohydrodynamic Seal For Supercritical Co2 Power Cycles With Experimental Verification, Ali Akbor Topu

College of Graduate Studies: Theses & Dissertations

Supercritical carbon dioxide (sCO₂) power cycles outperform conventional thermodynamic cycles regarding the efficiency and equipment footprint because of its unique property of maintaining the density of liquid in the gaseous phase at supercritical state (304.13 K and 7.37 MPa). It has robust use in concentrated solar power, fossil fuel power plants, geothermal electricity, nuclear power, and ship propulsion. To fully utilize sCO2 power cycles, technology readiness must be demonstrated at 10-60 MWe scale, with a working temperature and pressure of 350-700°C, and 10-35 MPa respectively. A crucial obstacle to the full realization of this technology is the absence …

Mathematical Modeling Of Coupled Heat And Mass Transfer In Metal-Hydride Hydrogen Storage Systems, Muhammad Hasnain

College of Graduate Studies: Theses & Dissertations

As a promising clean energy carrier hydrogen has recently gained significant interest, but its efficient and safe storage is a major challenge. Compared to the gaseous state and liquid state, metal hydrides (MH) offer a potentially more effective storage approach for hydrogen. However, the main challenge in this approach is the low thermal conductivity of the MH bed that leads to low heat transfer and ultimately to higher charging and discharging times. The purpose of this work is to develop an in-house comprehensive heat and mass transfer model for hydrogen sorption in MH reactors to simulate the dynamic behavior of …

Investigation Of Mechanically Fatigue Low-Frequency Energy Harvesting Effects On Isotropic Materials, Daniel J. Meade

College of Graduate Studies: Theses & Dissertations

This research project reports an exploratory investigation of energy harvesting effect on isotropic material that goes through low frequency mechanical fatigue. Energy harvesting is a growing field of study that can recycle ambient energy back into a system that would otherwise be lost. This is a significantly useful method for the ongoing energy crisis and provides an alternate route to design and upgrade systems to be more efficient and last longer than current system designs. However, it is time to investigate if there is any effect vibration-based energy harvesting has on the structure from which energy is being harvested. To …

Resonant Ultrasound Spectroscopy(Rus) For Material Characterization Of Metal Am Parts, Malik Marks

College of Graduate Studies: Theses & Dissertations

Additive manufacturing (AM) has revolutionized the manufacturing industry by offering flexibility, customization, and rapid prototyping capabilities. However, ensuring the quality and reliability of AM parts remains a significant challenge due to variations in material properties and process parameters. The NDE method used in this study is Resonant Ultrasound Spectroscopy (RUS). This method was used to evaluate and understand its ability to detect internal voids and defects. Dog-bone samples were made using the 316L stainless steel alloy which were fabricated by powder bed fusion (PBF) AM technique at different processing conditions and post processing conditions. These samples were tested to find …

Understanding The Impact Of Process Interruption On Mechanical Properties In Metal Additive Manufacturing: A Comprehensive Investigation, Poojith C. Chigurupati

College of Graduate Studies: Theses & Dissertations

Metal additive manufacturing techniques enable rapid prototyping and on-demand manufacturing while improving supply chain resiliency. Changes in microstructure and micro-mechanical characteristics of 3D printed metal parts occur due to the influence of process interruptions on melting-solidification cycles during the layer evolution in additive manufacturing processes. The process interruption can deteriorate the structural integrity of the 3D printed parts and generate micro-flaws in the interruption region. Manufacturing post-processing techniques such as Heat-Treatment methods can enhance the mechanical properties of the parts. Since variations commonly happen at the layer level, the investigation of mechanical properties must be done such that these variations …

Development And Characterization Of Vegetable Oil Based, Acrylated Resins For Stereolithography 3d Printing, Julius A. Adeyera

College of Graduate Studies: Theses & Dissertations

The increase in the demand for additively manufactured parts and the drive towards a sustainable economy with less environmental pollution has necessitated the need for renewable materials for use in 3D printing. This study shows the development and characterization of vegetable oil based, acrylated resins for 3D printing. Bio-based 3D resins were formulated using bio-based oils with a minimum of 70% bio-based content and were ready to be polymerized using the stereolithography (SLA) 3D printing process. Two distinct vegetable oils were used to develop biobased photopolymers. Biobased acrylated epoxidized photopolymers were successfully developed that have good mechanical and chemical properties. …

Natural Convection Heat Transfer Characteristics Of Sierpinski Carpet Fractal Fins In Horizontal And Vertical Orientations, Ayomide Ayoola

College of Graduate Studies: Theses & Dissertations

This study investigates the thermal performance of fins with perforations inspired by the Sierpinski carpet fractal pattern under natural convection conditions in both vertical and horizontal orientations. The objective is to analyze the effects of fractal iteration levels on three primary performance metrics: efficiency, effectiveness, and effectiveness per unit mass. Experimental evaluations were conducted for fractal fins from iterations 0 through 4, utilizing aluminum material, with each fin heated to controlled conditions. The results reveal that efficiency generally decreases with higher fractal iterations, reflecting increased thermal resistance associated with greater porosity and complex geometry. However, effectiveness per unit mass improves …

Extrusion-Based Additive Manufacturing Of Magnetic Heat Exchange Structures For Caloric Applications, Vaibhav Sharma

Theses and Dissertations

Currently, the commercial building sector accounts for 18% of total U.S. end-use energy consumption, of which almost a third was from on-site combustion of fossil fuels for space and water heating. Magnetic heat pumping (MHP) technology is an energy-efficient, sustainable, environmentally-friendly alternative to conventional vapor-compression cooling technology. Several MHP designs today are predicted to be highly energy efficient, on condition that suitable working materials can be developed. This materials challenge has proven to be daunting due to issues associated with intricate synthesis/post-processing protocols and complications related to shaping the mostly brittle magnetocaloric alloys into thin-walled channeled regenerator structures to facilitate …

Applying X-Ray Fluorescence With Monte Carlo Methods For Analysis Of Surface Defects On Coated Zr4, James Tyler Cahill

Theses and Dissertations

Chromium-coated Zircaloy-4 cladding represents a novel solution for creating nuclear cladding that has passive safety features. This and related developments aimed at improving nuclear safety are broadly categorized as accident-tolerant fuel and cladding. However, implementing this material presents practical challenges such as the vulnerability that cladding has to surface damage such as fretting wear. This research aims to determine if the pre-existing technique of X-ray fluorescence analysis is applicable for detecting these defects on the surface of the cladding. This was done by developing Monte Carlo N-Particle Transport models of a handheld device, the XL-5, alongside experimental measurements using this …

Hydrogen Production From Microbial Electrolysis Cells Powered With Microbial Fuel Cells, Dina Aboelela

Biochemical Engineering

No abstract provided.