Engineering Commons^™

Community College Engineering Degree Partnerships With 4-Year Universities, Jeffrey Mark Stear

Electronic Theses and Dissertations

Increasing the number of STEM professionals and reducing inequities in STEM are national priorities. Community colleges are important to address these concerns because they represent a higher percentage of underrepresented minority (URM) and women students. However, students starting 4-year STEM degrees in community college have had a lower completion rate. Partnerships between community colleges and 4-year universities have the potential to improve success for community college students, but more research is necessary. The purpose of this ex post facto, quantitative, correlational study was to determine the relationships among participation in different types of partnerships between community colleges and 4-year universities, …

Development Of A High-Level Discrete Event Simulation Model For The Harvesting Of White Button Mushrooms With Human-Robot Collaboration (Hrc), Ava Recchia

Electronic Theses and Dissertations

Canada is a leading global mushroom producer, with the white button mushroom (Agaricus bisporus) being the most popular type produced. Harvesting activities are labour-intensive, and farms are currently experiencing labour shortages, which are impacting productivity, growth, and overall revenue. Robotic technologies are valid mechanisms for mushroom harvesting and demonstrate a potential to reduce this gap. Examining the performance of a harvesting system with different robotics scenarios, such as manual, robotics automation, and human robot collaboration (HRC) is crucial to realizing this potential. Simulation models are useful tools for testing and assessing systems without making any physical change to the system. …

Dynamic Material Characterization Of Polymeric Foam By Means Of Experimental, Analytical, Phenomenological And Numerical Methods, Foad Rahimidehgolan

Electronic Theses and Dissertations

The main objective of this study was to advance the experimental, numerical, phenomenological and analytical methods of assessing the dynamic compressive response of polymeric foams, especially at an intermediate strain rate range of 50 s-1 to 600 s-1. Different experimental apparatuses and techniques, including the universal compression/tension testing machine (strain rates up to 0.5 s-1), custom-build droptower (a strain rate range of 50 s-1 to 200 s-1) and pneumatic testing apparatus (a strain rate range of 200 s-1 to 600 s-1) were utilized in the macro-mechanical characterization. The microstructure of the investigated polymeric foams was studied by means of Scanning …

Applying Functional Data Analysis To Estimate The Mental Workload Of The Human Driver, David Olorunfemi Eniyandunmo

Electronic Theses and Dissertations

Recent studies have focused on accurately estimating mental workload using machine learning algorithms and extracting features from psycho-physiological measures. However, feature extraction leads to the loss of valuable information and often results in binary classifications that lack specificity in the identification of optimum mental workload levels. This study investigates the feasibility of using raw psycho-physiological data (EEG, facial EMG, ECG, EDA, pupillometry) combined with Functional Data Analysis (FDA) to estimate mental workload of human drivers. A driving scenario with five tasks was employed, and subjective ratings were collected using the modified Bedford workload scale. Results demonstrate that the FDA applied …

Dc-Link Capacitor State-Of-Health (Soh) Monitoring And Lifetime Extension For Ev Applications, Cameron Pickersgill

Electronic Theses and Dissertations

Electric vehicles offer the benefit of eliminating tailpipe emissions, which emit greenhouse gases (GHG) into the atmosphere, lead to diminished air quality, and contribute to global warming. Therefore, plenty of research has gone into the development and improvement of EV technologies to create more effective and reliable vehicles in comparison to traditional internal combustion engine (ICE) vehicles. The electric traction drive, or powertrain, is the fundamental system responsible for controlling the output response of the electric motor within an EV. High efficiency and reliability are extremely desirable traits for the electric drive to extend the range of the EV to …

Novel Approaches To Fast Ocv Characterization And Improved Capacity Estimation In Lithium Ion Batteries, James Vu Nguyen

Electronic Theses and Dissertations

This thesis considers the problem of open circuit voltage (OCV) to state of charge (SOC) characterization in li-ion batteries for battery reuse applications. The traditional approach to OCV-SOC characterization is done by collecting voltage and current data through a slow discharge and charge process; this process usually takes about 60 hours. Such OCV-SOC characterization is performed on a few sample batteries because the OCV-SOC characterization is considered to be the same for new batteries coming out of the same manufacturing process. However, the characteristics of a battery may change as it is used for years in different environmental and usage …

Ultrasonic Phased Array Imaging And Data Post Processing With Applications To Resistance Spot Welding, Milos Draskovic

Electronic Theses and Dissertations

Resistance spot welding is a widely used metal joining method in the automotive industry due to its low cost, ease of automation and high throughput. Resistance spot welding is a process that joins two or more metal sheets through the application of force and high current in a localized region, or spot. With the average car containing thousands of such spot welds, some of which compose structural and safety components, the evaluation of the quality metrics related to this process is of key interest to the automotive sector. With this in mind, the evaluation of spot weld parameters including, size, …

Triple Current Control Of Transformer-Less Distributed Generators For Optimal Protection Coordination And Power Oscillation Elimination, Johnny Msawbah

Electronic Theses and Dissertations

Inverter-interfaced distributed generators (IIDGs) face issues related to disruptive power oscillations and overcurrent during unbalanced faults. This thesis focuses on a specific type of IIDGs known as the four-wire IIDG, often referred to as a transformer-less (TL)-IIDG. The TL-IIDG stands out as it possesses the unique capability to completely eliminate power oscillations in both active and reactive power. This is made possible by the addition of a fourth wire, which enhances control capabilities. To address these challenges, a triple current control (TCC) strategy is devised. It leverages sequence currents within a synchronous frame of reference, allowing the creation of a …

A Mems Planar Fresnel Lens For Cmut Array, Shivani Nilesh Upadhyay

Electronic Theses and Dissertations

This thesis presents a Microelectromechanical Systems (MEMS) planar Fresnel lens for use with a Capacitive Micromachined Ultrasonic Transducer (CMUT) array for high-resolution cardiac diagnostic imaging applications. The research exploited the excellent sound propagation and thermal properties of cross-linked silica aerogel, a nano-porous, nano-networked ultra-light-weight material, to design a planar thinfilm lens that can be easily microfabricated or integrated with a CMUT array. The designed lens, comprised of 32 various width concentric rings, was optimized to operate with a 256 element 6 MHz CMUT array. The 4 µm thick lens was designed to generate a 1.9 mm focal spot at a …

Numerical Analysis Of A Multi-Stage Elastohydrodynamic Seal For Aircraft Engines, Md Wasif Hasan

Electronic Theses and Dissertations

At present, both governmental and private aviation enterprises are trying to develop aircraft that are swifter, more lightweight, and more cost-effective in order to maintain competitiveness on both the domestic and global stage. Continuous innovation and sustainability efforts are necessary to achieve advancements in aviation systems, such as fans, compressors, combustors, and turbines, as well as sub-systems, like engine seals. Advanced engine seals exhibit considerable potential in enhancing the engine's pressure ratio and cycle temperatures, leading to reduced engine weight, increased thrust, and improved fuel economy. In this study, a novel multistage seal idea has been proposed for the supercritical …

Applications Of Predictive And Generative Ai Algorithms: Regression Modeling, Customized Large Language Models, And Text-To-Image Generative Diffusion Models, Suhaima Jamal

Electronic Theses and Dissertations

The integration of Machine Learning (ML) and Artificial Intelligence (AI) algorithms has radically changed predictive modeling and classification tasks, enhancing a multitude of domains with unprecedented analytical capabilities. Predictive modeling leverages ML and AI to forecast future trends or behaviors based on historical data, while classification tasks categorize data into distinct classes, from email filtering to medical diagnosis. Concurrently, text-to-image generation has emerged as a transformative potential, allowing visual content creation directly from textual descriptions. These advancements are pivotal in design, art, entertainment, and visual communication, as well as enhancing creativity and productivity. This work explores three significant studies in …

Robust Visual Observer And Controller Design For System Modeled On Se(3) With Camera Measurements, Tong Zhang

Electronic Theses and Dissertations

This dissertation presents a controlling method that utilizes visual observation to address the challenge of driving an autonomous vehicle with a kinematic model on SE(3), by using the data obtained from the onboard cameras. This controlling framework is applicable when direct retrieval of the vehicle's attitude information is not possible or when precision control of the vehicle is necessary. However, addressing several challenges to attain closed-loop stability for the observer-based control for autonomous vehicles on SE(3) is essential. 1. The analysis is further complicated by the presence of multiple equilibria in the error dynamics associated with the suggested method. 2. …

Compact Vhf And Uhf Antennas For Integration With Saw Devices In Harsh Environment, Sri Lekha Srimat Kilambi

Electronic Theses and Dissertations

With increasing demand for harsh environment (HE) wireless sensor applications, the need for antennas capable of operating under temperatures up to 1000° C and under corrosive and erosive environments also increases. These environments place severe survivability, stability, and performance demands on antennas designed and fabricated to operate in such conditions.

This work focuses on the design, fabrication, simulation and performance investigation of a compact (~1/25th to 1/10th of a wavelength) combined helical and microstrip antenna design operating as a normal mode helical antenna structure (NMHAS) around 300MHz. The ground plane of the microstrip line also serves as a ground plane …

Analysis Of Loading Rate, Fiber Orientation And Material Composition Through Image Processing And Digital Volume Correlation In High Performance Concrete, Aidan R. Carlson

Electronic Theses and Dissertations

Ultra High Performance Concrete (UHPC) and High Performance concrete (HPC) is characterized by high compressive strength and high toughness. This is achieved through maximizing the particle packing density in the matrix and the use of fibers to reinforce the matrix, increasing the materials toughness. The interactions of fibers and the matrix during loading is quite complex and involves several different energy dissipation mechanisms. The goal of this work and this thesis is to investigate these interactions and identify any changes in material response, and hope that these changes may be useful for the design of UHPC moving forward.

In this …

Numerical Investigation Of Subglottal Stenosis Effects On Human Voice Production, Dariush Bodaghi

Electronic Theses and Dissertations

This dissertation aimed to advance knowledge of how subglottal stenosis impacts voice production physiology. An in-house fluid-structure-acoustic interaction approach based on the hydrodynamic/acoustic splitting technique was employed. This technique was rigorously verified for simulating phonation by matching the acoustic behavior to a compressible flow solver for phonation-relevant geometries. Simulations of an idealized 2D vocal tract model demonstrated the effects of supraglottal acoustic resonance on vocal fold kinematics and glottal flow waveform. Results showed that the acoustic coupling between higher harmonics and formats generated pressure oscillations, modifying vocal fold dynamics and glottal flow rate.

A major novelty was the incorporation and …

The Development Of An Advanced Biorefinery To Produce Cellulosic Sugars And Bionanomaterials, Carlaile Fernanda De Oliveira Nogueira

Electronic Theses and Dissertations

Market trends show growing interest in cellulose nanomaterials due to their low environmental impact. However, current nanocellulose isolation technologies face technoeconomic and life cycle limitations. Previous research has shown that enzymatic treatments effectively reduce the energy input for mechanical nanocellulose isolation. Simultaneously, there is potential to improve the viability of cellulosic ethanol facilities by coproducing nanocelluloses as high-value product obtained from agricultural feedstock. Here, our goal was to study the mass balance of enzymatic-mechanical processes that coproduces cellulosic sugars and nanocelluloses, evaluating the technical feasibility of converting lignified and non-lignified materials.

First, we have determined a feasible 50:50 mass ratio …

Effects Of Back Reflectors And Thin Metal Covers On The Performance Of Near-Field Thermophotovoltaic Devices, Mehran Habibzadeh

Electronic Theses and Dissertations

Highly efficient energy harvesting devices that can recover a large amount of waste energy are of significant interest. Thermophotovoltaics (TPVs) are solid-state devices that can convert thermal energy radiated by a heated emitter into electrical power through the process of photovoltaic effect. In a TPV system, heat is converted to electricity by using a high-temperature emitter to radiate photons, which are then absorbed by a photovoltaic (PV) cell, generating electron-hole pairs and producing electrical power.

TPV devices have the advantages of producing High efficiency and being lightweight with low maintenance cost and zero pollution. However, these devices have not been …

Examining The Impact Of Centerline Rumble-Strip Installation In Prevention Of Head-On And Opposite Sideswipe Collisions In Maine, Jhan Kevin Gil Marin

Electronic Theses and Dissertations

Among all traffic collisions, lane departure crashes are the leading type of serious traffic crashes in Maine, comprising 72% of state-wide traffic fatalities. To reduce these crashes, Maine Department of Transportation (MaineDOT) installed shoulder and centerline rumble strips on roadways to prevent lane departure crashes in Maine. With a total installed length of 1503 miles of rumble strips, specifically 511 miles of centerline rumble strips in bidirectional and undivided rural two-lane roadways, there is a need to understand the impact of rumble strips in reducing lane departure crashes. In this thesis, observational before-after studies with two methods: comparison group, and …

Promise And Limitations Of Supervised Optimal Transport-Based Graph Summarization Via Information Theoretic Measures, Sepideh Neshatfar

Electronic Theses and Dissertations

Graph summarization is a fundamental problem in the field of data analysis, aiming to distill extensive graph datasets into more manageable, yet informative representations. The challenge lies in creating compressed graphs that faithfully retain crucial structural information for downstream tasks. A recent advancement in this domain introduces an optimal transport-based framework that enables the incorporation of a priori knowledge regarding the importance of nodes, edges, and attributes during the graph summarization process. However, the statistical properties of this innovative framework remain largely unexplored. This master's thesis embarks on a comprehensive exploration of the field of graph summarization, with a particular …

Advances In Cellulose Nanomaterial-Based Foams For Environmental Applications, Md Musfiqur Rahman

Electronic Theses and Dissertations

The use of metal-oxide nanoparticles adsorbents is limited to fixed-bed columns in industrial-scale water treatment applications. This limitation is commonly attributed to the tendency of nanoparticles to aggregate, the use of non-sustainable and inefficient polymeric resins as supporting materials, or a lack of adsorption capacity. Foams and aerogels derived from cellulose nanomaterials have unique characteristics, such as high porosity and low density, which enables their use in a variety of environmental applications, including water treatment. However, the overall use of cellulose nanomaterial-based foams in various environmental sectors is limited due to the high cost of production associated with time- and …

Estimation Of Wood Pulp Fiber Species Composition From Microscopy Images Using Computer Vision, Tyler Seekins

Electronic Theses and Dissertations

Pulp mills and papermakers require careful control of input raw materials. The paper pulp composition, consisting of blends of different wood fiber types, affects multiple final product properties in interacting ways and impacts process operating conditions. Manual estimation of composition by classification and counting using microscopy is time consuming, repetitive, error-prone, and fibers are not always identifiable. Using a dataset of 359,840 fibers from 12,690 images of either hardwood or softwood fibers from 423 microscopy slides with data partitioned into 60% training, 20% validation, and 20% testing splits by slide, and a sequence of principal components analysis, Gaussian mixture, image …

Using Probe Data To Understand The Impact Of The Covid-19 Pandemic On Roadway Safety, Ennis W. Marshall

Electronic Theses and Dissertations

Following the onset of the COVID-19 pandemic there was an observed decrease in traffic safety in the United Sates. New England was no exception to this, with traffic fatality rates increasing in Maine and Connecticut. This increase was attributed to the possibility that drivers had more opportunities to speed following the implementation of COVID-19 stay-at-home orders on roads with drastically reduced volume and decreased speed enforcement. To determine the state of research into the pandemic's effect on traffic safety around the world, an extensive critical review was conducted. The reviewed studies showed that roadways did indeed become less safe with …

Experimental Measurement Of Near-Field Radiative Heat Transfer Between Two Macroscale Planar Media, Md Shofiqul Islam

Electronic Theses and Dissertations

Radiative heat transfer between two media separated by a gap smaller than the wavelength of thermal radiation (10 μm at room temperature) is referred to as near-field RHT. Near-field RHT exceeds the RHT between two blackbodies which is the maximum limit for RHT in the far-field regime (i.e., when the separation gap is much larger than the thermal wavelength). Due to this enhanced heat transfer, near-field RHT has found promising applications, for power enhancement of thermophotovoltaic devices, thermal rectification, localized cooling, and photonic cooling to name only a few. Graphene is an ideal material for near-field RHT applications as it …

A Map-Algebra-Inspired Approach For Interacting With Wireless Sensor Networks, Cyber-Physical Systems Or Internet Of Things, David Almeida

Electronic Theses and Dissertations

The typical approach for consuming data from wireless sensor networks (WSN) and Internet of Things (IoT) has been to send data back to central servers for processing and analysis. This thesis develops an alternative strategy for processing and acting on data directly in the environment referred to as Active embedded Map Algebra (AeMA). Active refers to the near real time production of data, and embedded refers to the architecture of distributed embedded sensor nodes. Network macroprogramming, a style of programming adopted for wireless sensor networks and IoT, addresses the challenges of coordinating the behavior of multiple connected devices through a …

Floating Offshore-Wind And Controls Advanced Laboratory Program: 1:70-Scale Testing Of A 15 Mw Floating Wind Turbine, Matthew J. Fowler

Electronic Theses and Dissertations

This thesis presents results from the Floating Offshore-wind and Controls Advanced Laboratory (FOCAL) Experiment which performed 1:70-scale model testing of a 15 mega-watt floating offshore wind turbine (FOWT) at the University of Maine’s Alfond Wind/Wave Ocean Engineering Laboratory (W2). The experimental campaigns supported the application of controls co-design to FOWTs by incorporating real-time wind turbine control and hull mounted tuned-mass damper (TMD) elements. A performance-matched scaling strategy was proposed and analysis in OpenFAST performed to design the scale models, including integration of the Reference OpenSource Controller (ROSCO) and modeling of the TMDs in the hull. Four test campaigns were conducted, …

Convolution And Autoencoders Applied To Nonlinear Differential Equations, Noah Borquaye

Electronic Theses and Dissertations

Autoencoders, a type of artificial neural network, have gained recognition by researchers in various fields, especially machine learning due to their vast applications in data representations from inputs. Recently researchers have explored the possibility to extend the application of autoencoders to solve nonlinear differential equations. Algorithms and methods employed in an autoencoder framework include sparse identification of nonlinear dynamics (SINDy), dynamic mode decomposition (DMD), Koopman operator theory and singular value decomposition (SVD). These approaches use matrix multiplication to represent linear transformation. However, machine learning algorithms often use convolution to represent linear transformations. In our work, we modify these approaches to …

Adaptive Personalized Drug Delivery Method For Warfarin And Anemia Management: Modeling And Control., Affan Affan

Electronic Theses and Dissertations

Personalized precision medicine aims to develop the appropriate treatments for suitable patients at the right time to obtain optimal results. Personalized medicine is challenging due to inter- and intra-patient variability, narrow therapeutic window, the effect of other medications, comorbidity (more than one disease at a time), nonlinear patient dynamics, and time-varying patient dose response characteristics which include bleeding (internal and external). This research aims to develop a framework for an adaptive personalized modeling and control method with minimum clinical patient specific dose response data for optimal drug dosing. The proposed methodology is applied to anemia and warfarin management. It is …

Design, Fabrication, And Integration Of Robotic Skin Sensors For Human Robot Interaction., Olalekan Olakitan Olowo

Electronic Theses and Dissertations

Enhancing physical human-robot interaction in modern robotics relies on refining the tactile perception of robot skin sensors. This research focuses on crucial aspects of the development process, including fabrication techniques, miniaturization, and integration for a more efficient collaborative human-robot interface. The fabrication process of robot skin sensors, designed to mimic human skin, is explored both within and outside cleanroom environments. An enhanced technique is presented to increase fabrication yield and create more miniaturized sensor designs with feature sizes in the tens of microns. These sensors function as piezoresistive arrays using organic polymers like PEDOT: PSS as the pressure-sensing medium. Various …

Investigating Mems Devices In Flow Conditions Relevant To Flow-Through Systems., Mohammad Shafquatul Islam

Electronic Theses and Dissertations

Advancements in microscale actuating technologies has substantially expanded the possibilities of interacting with the surrounding environment. Microstructures that deflect in response to mechanical forces are one of the largest application areas of microelectromechanical systems (MEMS). MEMS devices, functioning as sensors, actuators, and support structures, find applications in inertial sensors, pressure sensors, chemical sensors, and robotics, among others. Driven by the critical role of catalytic membrane reactors, this dissertation aims to evaluate enzyme activity on polymeric membranes and explore how fabrication methods from the field of Electrical and Computer Engineering (ECE) can incorporate sensing and actuation into these porous surfaces. Toward …

Quantifying Impacts Of Climate Change On Headwater Streamflow Regime In Robinson Forest: Insights From 35-Years Of Data Collection., Lauren Brown

Electronic Theses and Dissertations

Climate change may shift patterns of streamflow permanence in headwater systems by altering the frequency, magnitude, duration, timing, and rate of change of surface streamflow, impacting both local ecosystems as well as regional water budgets and availability. While much uncertainty surrounds modeling-based methods to quantify the impacts of climate change on water budgets, long-term hydrologic data collected from headwaters in experimental research forests serve as critical evidence to reduce such uncertainty. The objective of this study is to quantify shifts in frequency, magnitude, duration, timing, and rate of change of streamflow in two headwater catchments with relatively little recent disturbance …