Engineering Commons^™

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, …

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 …

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 …

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 …

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 …

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 …

Barriers To Use Of Cross-Laminated Timber In Maine, Shane R. O'Neill

Forest Resources Faculty Scholarship

To increase understanding of both the adoption rate and in-state manufacturing of mass timber In Maine, the 131^st Legislature and Governor Mills passed LD 881, a resolve directing a study of the barriers facing cross-laminated timber In Maine and provide recommendations to promote their use in construction. This study was developed in response to the resolve. The study engaged 108 unique participants to define available training, education, and experiences across the stakeholders throughout the building lifecycle process in the state.

From this information, the following five recommendations are proposed:

1. Understand the policies and initiatives of other states to develop …

Surrogate Modeling With Multi-Fidelity Data Sets, Yasaman Asiaee

Electronic Theses and Dissertations

In the realm of science and engineering, there is a need for models that can accurately describe complex systems. High-fidelity models are often used for this purpose, but they tend to be costly to create and impractical to use for many applications including design optimization. On the other hand, low-fidelity models offer a more affordable alternative, but sacrifice accuracy. To strike a balance between accuracy and cost, multifidelity surrogate modeling (MFSM) has emerged as a viable solution by integrating data from sources with different levels of fidelity. This research aims to contribute to the understanding of MFSM by exploring the …

Homocysteine Reduction For Stroke Prevention: Regarding The Recent Aha/Asa 2021 Prevention Of Stroke In Patients With Stroke And Transient Ischemic Attack, Craig Brown, Jianhua Wang, Hong Jiang, Merrill F. Elias

Maine-Syracuse Longitudinal Papers

Reduction of secondary ischemic stroke risk following an initial stroke is an important goal. The 2021 Prevention of Stroke in Patients With Stroke and Transient Ischemic Attack assembles opportunities for up to 80% secondary stroke reduction. Homocysteine reduction was not included in the recommendations. The reduction of homocysteine with low doses of folic acid has been shown to reduce ischemic stroke and all stroke. This has been obscured by studies using high doses of folic acid and cyanocobalamin in patients with renal failure and Methylenetetrahydrofolate reductase (MTHFR) polymorphisms. The confounding impacts of high dose folic acid and cyanocobalamin toxicity in …

Development And Characterization Of Shear Thinning Cnf-Tempo Hydrogels For Use In Aquaculture Vaccines, Jacob A. Holbrook

Electronic Theses and Dissertations

Aquaculture has shown significant growth within the past few decades and is expected to continue expanding rapidly as the global demand for fish consumption continues to increase. A significant loss within the aquaculture industry is due to pathogen transmission within the farm systems. These pathogens are mitigated through various methods that are not cost effective or have limited protection. The most common method of pathogen mitigation is through oil-based injection vaccines as they provide even protection across vaccinated fish and provides the longest protection compared to other vaccination methods. These oil-based injection vaccines are not without their flaws as they …

The Performance Analysis And Optimization Of Wave Energy Converters From Modeling To Basin Testing, Lauren Dickson

Electronic Theses and Dissertations

The successful development and optimization of wave energy converters (WECs) are pivotal to the pursuit of sustainable and renewable energy sources. This thesis explores the elements in a workflow that develops and demonstrates the protocols for the optimization of WECs using a rapid design\build\test procedure. This thesis establishes the characterization of scaled ocean test sites, develops the performance metrics, generates the performance modeling techniques to predict the optimum design geometries which will be produced for final testing, and finally, establishes the basin test plan which will be used to conduct the testing on the optimum design. The findings of this …

Investigating The Effect Of Bead Geometry On Fiber Orientation And Thermomechanical Properties For Large-Format Extrusion-Based Additive Manufacturing, Joanna F. Keaton

Electronic Theses and Dissertations

In large-format extrusion-based additive manufacturing of polymer composites, the relationship between material properties and processing parameters requires further investigation. This thesis focuses on the relationship between fiber orientation and thermomechanical properties for short fiber-filled thermoplastic polymer systems manufactured by extrusion-based additive manufacturing. Fiber orientation is particularly important in determining the thermomechanical properties of the composite material as properties in the direction of deposition are expected to be higher for highly aligned fibers than randomly aligned fibers. Fiber orientation distribution, which is related to processing parameters and deposition conditions, can be efficiently represented by the orientation tensor. The orientation tensor can …

Accessible Autonomy: Exploring Inclusive Autonomous Vehicle Design And Interaction For People Who Are Blind And Visually Impaired, Paul D. S. Fink

Electronic Theses and Dissertations

Autonomous vehicles are poised to revolutionize independent travel for millions of people experiencing transportation-limiting visual impairments worldwide. However, the current trajectory of automotive technology is rife with roadblocks to accessible interaction and inclusion for this demographic. Inaccessible (visually dependent) interfaces and lack of information access throughout the trip are surmountable, yet nevertheless critical barriers to this potentially lifechanging technology. To address these challenges, the programmatic dissertation research presented here includes ten studies, three published papers, and three submitted papers in high impact outlets that together address accessibility across the complete trip of transportation. The first paper began with a thorough …

Longitudinal Case-Control Study Of Mammographic Breast Tissue Subtypes, Kendra Batchelder

Electronic Theses and Dissertations

Breast density is a known risk factor for breast cancer. However, there has been limited research on potential subtypes of mammographic dense breast tissue to identify areas of active dense tissue that is structurally reorganizing and links to cancer dynamics, versus areas of passive dense tissue which remains organized. We hypothesize that the amounts of subtypes of mammographic dense tissue and the associated rate of change through time could provide insights into breast cancer risk. A retrospective study was conducted to investigate breast cancer using longitudinal screening mammograms and accompanying pathology reports collected in 2015. Patients were matched by age …

Use Of Photo Isomers To Enhance The Removal Of Lignin From Woody Biomass Hydrolysate, Dipesh J. Karki

Electronic Theses and Dissertations

In this investigation we propose a novel method to enable precipitation of desired solutes using photo-isomers in the extraction solvent. This photo-switchable solvent would enable dissolution or precipitation of desired components using alternating UV or visible light to modify the solubility of the compounds of interest. Three photo-isomers namely native azobenzene, diethoxy azobenzene and diethylamino azobenzene were studied in three different organic solvents: medium chain length alcohol, ethanol and acetone. It was found that among the different combinations of solvent and photo-isomer, acetone and the 4,4’-diethoxy azobenzene solution was most efficient at precipitating dissolved lignin in response to UV light …

Mechanical Characterization Of Automated Fiber Placement And Additive Manufacturing Hybrid Composites, Lucan Haviland

Electronic Theses and Dissertations

This thesis presents the optimization of processing parameters based on the mechanical properties of Continuous Fiber-Reinforced Thermoplastic (CFRTP) Unidirectional (UD) consolidated tapes. The UD tapes were consolidated using an AFP head and a thermoforming press for comparison. The adhesive strength of hybrid parts consisting of CFRTP UD tape bonded to a 3D-printed substrate with the same matrix system were investigated. Large Area Additive Manufacturing (LAAM) was utilized for the 3D-printed parts. Different types of thermoplastic composite materials were explored, including Glass Fiber reinforced Polyethylene Terephthalate Glycol (GF/PETG), Carbon Fiber reinforced Polyethylene Terephthalate Glycol (CF/PETG), Carbon Fiber reinforced Polycarbonate (CF/PC), and …

Designing And Modeling A Fail-Safe Mechanism To Be Used In Attachment Of A Transcutaneous Femoral Implant To A Prosthetic Device, Emma Sperry

Electronic Theses and Dissertations

Amputations are quite common and even modern prosthetic devices are plagued by problems. There are approximately 2 million people living with limb loss in the U.S. and on average 185,000 amputations occur yearly. Common attachment mechanisms for external prosthetic components to a residual limb, that is, sockets, pose numerous challenges. Issues include skin irritation, discomfort, socket fit issues, and immobility. Issues include skin irritation, discomfort, socket fit issues, and immobility. Transcutaneous implants have great potential as a connection method for external prosthetic components to a residual limb but because the implants are typically solid, they correlate to extremely high infection …

Characterization Of Mammographic Dense Tissue Sub-Types Using Classification Algorithms On Metric Space Technique Output Functions, Madison Raza

Electronic Theses and Dissertations

In recent years breast cancer has become the leading cause of global cancer incidence. One of the most common forms of screening is through the use of digital x-ray screening mammography. Risk assessment models which help predict a patient’s risk of developing breast cancer rely mainly on patient history and qualitative breast density assessment from screening. The 2D wavelet transform maxima modulus (2D WTMM) method uses a sliding window approach to quantify the spatial organization of underlying mammographic tissue according to Hurst- exponent ranges (H) as fatty (H ≤ 0.45), healthy dense (H ≥ 0.55) and …

Exploring The Use Of Audible Sound In Bone Density Diagnostic Devices, Evan J. Bess

Electronic Theses and Dissertations

Osteoporosis is a medical condition in which there is a progressive degradation of bone tissue that correlates with a characteristic decrease in bone density (BD). It is estimated that osteoporosis affects over 200 million people globally and is responsible for 8.9 million fractures annually. Populations at risk for developing osteoporosis include post-menopausal women, diabetic patients, and the elderly, representing a large population within the state of Maine. Current densitometric and sonometric devices used to monitor BD include quantitative computed tomography (QCT), dual-energy x-ray absorption (DXA), and ultrasound (QUS). All methods are expensive and, in the cases of QCT and DXA, …

Wave Attenuation Through Submerged Oyster Aquaculture Cages, Liam T. Hanley

Electronic Theses and Dissertations

Coastal erosion presents a growing issue to shorelines around the world and is especially harmful to Maine, a region where sea-level rise is higher than the global average. Green and hybrid coastal defense strategies are being implemented around the country to provide sustainable, habitat-friendly solutions to erosion control. Maine is a hotspot for commercial aquaculture, with an estimated $13.6 million economic impact. This study looks to bridge the gap between Maine aquaculture and the living shorelines initiative, by determining the wave attenuating properties of submerged oyster cages. The project will be able to inform local oyster farmers, resource planners, and …

Measuring Of Thermal Conductivity And Heat Capacity Of Different Papers And Heat-Sealing Process Of Papers With A Polymer Layer, Amenah Khalaf

Electronic Theses and Dissertations

Packaging is an important and safe way to protect our food and other things through transportation, but the use of plastic based packaging is causing issues with plastic pollution. To replace plastic packaging with a paper-based option that has a barrier coating, good heat sealing will be needed to be a drop-in replacement. While much as been studied on the heat sealing of polymer layers, little has been reported around the heat sealing of paper that has a polymeric barrier coating.

Experiments were conducted to characterize the thermal conductivity and heat capacity of paper as a function of press pressure …

Impact Of Solar Generation On Ieee 9-Bus System, Tasnim Ikra Rahman

Electronic Theses and Dissertations

There has been an increasing interest in renewable energies due to public awareness of the negative effects of fossil fuel-fired electricity generation on the environment, and policies have been enacted requiring progressive reduction of such generation. Due to some favorable characteristics of solar over other renewables, solar power has grown considerably. Integration of solar generation into the existing power grids poses significant challenges. Solar generators' limited reactive power capability can cause several problems, such as significant voltage drops or rises in the system. Therefore, voltage stability is a major concern. This thesis presents an investigation of the voltage characteristics of …

Nanocellulose Based Foams For Low-Cost Disposable Medical Applications, Dominic Kugell

Electronic Theses and Dissertations

Polyurethane foams have been a staple material for their use in medical positioners, such as post-surgery elevation pillows as well as specific tailored positioners for their use during surgery. Polyurethane foams are preferred because of their lower cost compared to other petroleum derived foams, their versatility, and suitable mechanical properties. However, the environmental impact, including both cost and perception, of these foams is immense. Therefore, alternatives are being explored with biopolymers emerging as a promising class of materials. Cellulose is one such polymer that has recently demonstrated desirable properties. In this study, cellulose nanofibrils (CNF), a household foaming agent, and …

Corrosion Condition Rating Database, Zahra Ameli, Eric Landis

Non-Thesis Student Work

This dataset contains 514 RGB images and corresponding pixel-level annotation files in two separate formats; .json and .txt. The images are collected from steel bridge elements using a drone and a Nikon camera. The images was randomly split into 412 training images and 90 validation and 12 testing images. Two dataset for training Mask RCNN and YOLOv8 models are included in the database. All the annotations are carefully performed for quality assurance. The three classes used in this study, represents different levels of corrosion severity (corrosion condition states) according to American Association of State Highway and Transportation Officials (AASHTO) and …

The Disposal Mode Of Maine’S Waste Governance, Travis Blackmer, Brieanne Berry, Michael Haedicke, Cindy Isenhour, Susanne Lee, Jean Macrae, Deborah Saber, Erin Victor

Maine Policy Review

Maine’s materials management system is stuck in a disposal mode of waste governance. Despite significant investments in programs and policies designed to reduce the amount of waste the state buries each year, recent shocks and uncertainties have resulted in increased waste generation and disposal. This paper analyzes specific ways through which materials management in Maine has become locked in to a disposal mode of waste governance. We build a framework to help understand various forms of lock-in and how they might be unlocked. This framework is applied to the extended producer responsibility packaging law that is presently under the rule-making …

Efficient Sintering Of Lunar Soil Using Concentrated Sunlight, Diprajit Biswas

Electronic Theses and Dissertations

Construction material is one crucial need for long-term habitation on the moon. When concentrated for high heat flux, solar radiation can heat lunar soil or regolith until it sinters at temperatures above 900°C. The solid, sintered soil simulant can be used as construction material. This work explores the conditions leading to effective lunar soil sintering for both direct and indirect irradiated sintering. Lunar soil simulants were sintered using concentrated light from a xenon-arc lamp with varying heat flux intensity. During direct sintering of LHS-1, a sintering range of 860°C-1140°C corresponding to a peak heat flux of 105-120 kW/m2 was identified …

Investigation Of Pulsed Electrolysis For Hypochlorous Acid Production, Khoa V. Kieu

Electronic Theses and Dissertations

Because of the Covid-19 pandemic along with the delay in the worldwide supply chain, there were disinfectant shortages that lasted for weeks around the world. Therefore, on-site production is a promising solution to satisfy the increasing demand. As more and more people are shifting toward safer and more environmentally friendly products, we are interested in investigating the electrolysis of sodium chloride (NaCl) solution to produce hypochlorous acid (HOCl). Electrolysis is inexpensive as it requires only sodium chloride and electricity, and it does not have any negative impact on the environment. Moreover, electrolysis can be coupled with renewable energy to utilize …

Laboratory Study Of Accelerated Carbonation With Hydrated Lime For Soil Stabilization, Sk Belal Hossen

Electronic Theses and Dissertations

Challenging subsurface conditions often dictate the need to augment subgrade soils’ in-situ properties via chemical stabilization, a simple method of construction that is widespread globally. Chemical stabilization typically involves the field mixing of calcium-based additives like cement, lime, or fly ash. However, there is increasing awareness of the large carbon footprint associated with typical stabilizing agents. The cement and lime industries currently contribute approximately 10% of all anthropogenic carbon dioxide emissions worldwide each year and are expected to increase. Thus, the development of approaches to chemically stabilize subgrade soils that reduce net carbon emissions would be desirable and align with …

Disinfection Applications Of On-Site Hypochlorous Acid Production, Deborah Ngabanyi Sebagisha

Electronic Theses and Dissertations

Hypochlorous acid (HOCl) is a weak acid, but strong oxidizing agent produced naturally in the human body to fight viruses and bacteria. Hypochlorous acid can be produced by electrolysis of sodium chloride and water enabling local production of disinfectant, where it is needed. Hypochlorous acid has many applications including in wound care, skin care, and disinfection of health and dental clinics. In this work, two hypochlorous acid applications were explored that could utilize local production by electrolysis. These applications were wastewater treatment and sanitization of dental operating rooms.

An electrochemical reactor and process were designed, constructed, and tested for hypochlorous …

Synthesis Of A Pharmaceutical Precursor From Bioderived Glucose, Justin O. P. Waters

Electronic Theses and Dissertations

Medication costs in the U.S. are high, and manufacturing and production comprise the largest share of those costs. As the world continues to shift to more sustainable methods of production, there are opportunities to reduce these costs through green synthesis. A large number of pharmaceuticals are derived from a precursor (S-3-hydroxy-gamma-butyrolactone ‘HBL’). Drugs that treat cancer, antivirals, antibacterial drugs, and some cholesterol medications all can be derived from HBL. Currently, HBL is almost exclusively derived from petroleum through an expensive and resource intensive process. Until recently, ‘green’ efforts to derive HBL from biomass have been plagued with many of the …