Engineering Commons^™

Support The Next Generation By Sponsoring The 2024 Windstorm Challenge!, Advanced Structures And Composites Center

General University of Maine Publications

The Windstorm Challenge is a unique opportunity for middle and high school students to get hands-on engineering practice at the Advanced Structures and Composites Center (ASCC). Organized by the same team that brings you AFloat, the Windstorm Challenge seeks to educate the next generation of floating offshore wind innovators.

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 …

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 …

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 …

S8e10: How Can Nature-Inspired Engineering Improve Human Health?, Ron Lisnet, Caitlin Howell

The Maine Question

Antibiotic resistance has become a growing problem in the treatment of bacterial infections. In addition to minimizing or negating the effects of existing medicine, these antibiotic-resistant bacteria, or “superbugs,” are mutating faster than the development of new remedies.

Caitlin Howell, University of Maine associate professor of biomedical engineering, is working on new tools that take notes from nature to combat antibiotic-resistant bacteria. Similar to the way in which the human body keeps balance with its own bacterial populations, Howell’s devices use nontoxic, non-invasive surface-based technology to trap bacteria and prevent them from spreading.

In this episode of “The Maine Question” …

Simulation And Testing Of A High-Temperature Oscillator Circuit, Jude Zanoni

Honors College

A high-temperature Pierce oscillator circuit was designed, analyzed, simulated, built and tested. The oscillator was designed as part of a high-temperature sensor system for monitoring the condition of equipment operating in harsh environments. The oscillator was designed using a silicon carbide (SiC) metal-oxide-semiconductor field effect transistor (MOSFET) common source amplifier with an LC tank resonant circuit. It was manufactured using gold paste on alumina with 1 mil gold wire bonded between components. All components needed to be capable of operating at temperatures up to 400°C. To this end, high-temperature spiral planar inductors were designed and fabricated. These were found to …

Exploring The Relationship Between Designing And Composing With An Analog Synthesizer, Felix Morrissey

Honors College

For my electrical engineering capstone, I designed and built a handheld analog synthesizer. This analog synthesizer is a musical instrument which uses electrical analog components to generate sounds with properties based on the user’s input. My goal when creating this device was to maximize its utility while remaining within the scope of the capstone project. After the synthesizer was built, I wrote and recorded several pieces of music which each utilized the synthesizer prominently. The aim of this process was to be able to explore the relationship between an instrument’s design and the quality of the music produced utilizing it. …

A Study On Scaling Floating Offshore Wind Turbine Geometry And Hydrostatics With Increasing Turbine Size, Samuel Davis

Honors College

Floating offshore wind offers a clean and sustainable alternative to fossil fuels for the future of energy production. In Maine in particular, there is a great opportunity to take advantage of the wind resource off the coast and become a global leader in offshore wind. With the Maine coastal waters being too deep for fixed-bottom turbine structures, floating platforms that support the turbines have the opportunity to gain traction as the technology matures. As wind turbines increase in size and capacity, the floating hulls must also increase in size. The research presented in this thesis aimed to calculate and examine …

On The Fly Audio Processing For The Vocal Conditioning Unit, Tim Lester

Honors College

The Vocal Conditioning Unit was a device designed, constructed, and programmed as a senior design project in Electrical and Computer Engineering by Tim Lester and Grady White. The device’s intended goal was to perform a role similar to Auto-Tune, but as a standalone device similar to effects pedals used by guitarists and other musicians on stage. On-the-fly audio processing, however, was deprioritized in the design of the original device due to other design considerations. In this thesis project, the original design of the Vocal Conditioning Unit is analyzed, and critical functionalities of the device are identified. Then, the device is …

Thermal Stability Of Platinum-Silicon Alloy Films Grown On Langasite Substrates For Use In Microwave Acoustic Sensor Technology, Kell Fremouw

Honors College

Wireless sensors that can operate in temperatures up to 1000°C are widely needed for real time monitoring of large-scale industrial processes. Such sensors will improve efficiency and prevent component failure. Under previous work at UMaine, Surface Acoustic Wave Resonator (SAWR) sensors fabricated on piezoelectric langasite (La₃Ga₅SiO₁₄) wafers have shown promise for wireless strain measurements at high temperatures. However, there is a major technical challenge in attaching SAWR langasite based sensors to metal parts because the large differences in the coefficient of thermal expansion (CTE) between langasite and metals leads to large thermal stresses and …

Stackpole Bridge: Rebuilding A Connection To The Past, Abigail Morrison-Ouellette

Honors College

Many historical structures are still appreciated today for their beauty, the skill required to construct them, and how they preserve and complement the natural environment. Aqueducts, buildings, and bridges constructed by ancient civilizations are excellent examples of some of the stone structures that remain standing today that offer tangible ties to the past. Many of these structures foster local pride, create a strong sense of community, and provide economic benefits beyond their physical function.

Some of the most durable historical structures are stone arch bridges, which have been used worldwide for centuries for transportation over terrain that would otherwise be …

Medical Foods For Lowering Homocysteine In Hypertensive Patients, Merrill F. Elias, Craig J. Brown

Maine-Syracuse Longitudinal Papers

In a recent commentary, Elias and Brown review the history of skepticism about the value of homocysteine for preventing hypertension and stroke. They argue that this skepticism is not supported by recent literature. This paper was stimulated by a recent comprehensive review of the literature on this topic by Smith and Refsum. Prior to these papers, a commentary and review by Skeete and DiPette provided evidence for the value of homocysteine-lowering in the treatment of hypertension. Elias and Brown supported this conclusion. Both papers emphasized that more work is needed to clarify the beneficial effects of lowering homocysteine.

Elias and …

S7e9: What New Frontiers Await For Maine’S Space Economy?, Ron Lisnet, Ali Abedi, Joseph Patton

The Maine Question

University of Maine research and education have ascended beyond Earth’s atmosphere since the 1990s. For example, UMaine scientists have tested the latest hypervelocity decelerators for NASA space travel and created a wireless leak detection system for the International Space Station. Through its latest inventions and studies, and scholarship and fellowship programs, UMaine plays a critical role in advancing the state’s space economy and training future leaders in the aerospace industry. But the university is far from reaching its final frontier.

In recent years, UMaine researchers have been developing the state’s first small research satellite with the University of Southern Maine …

Integration Of Material Characterization, Thermoforming Simulation, And As-Formed Structural Analysis For Thermoplastic Composites, Philip M. Bean, Roberto A. Lopez-Anido, Senthil Vel

Civil Engineering Faculty Scholarship

An improved simulation-based thermoforming design process based on the integration of material characterization and as-formed structural analysis is proposed. The tendency of thermoplastic composites to wrinkle during forming has made simulation critical to optimized manufacturing, but the material models required are complex and time consuming to create. A suite of experimental methods has been developed for measurement of several required properties of the molten thermoplastic composite. These methods have the potential to enhance thermoplastic composites manufacturing by simplifying and expediting the process. These material properties have been verified by application to thermomechanical forming predictions using commercial simulation software. The forming …

The Performance Assessment Of A Small Lighter-Than-Air Vehicle For Earth Science Remote Sensing Missions, Maxwell F. Burtis

Honors College

This summer, a lighter-than-air (LTA) drone was tested in Alaska to measure glacier bedrock fracture density and orientation. Five flights were made in low wind conditions, and the directional stability of the airship made it too challenging to control in flight to realistically acquire useful image sets. The directional stability of the airship, when compared to an actively stabilized consumer-grade quadcopter was inferior. Flight logs and GPS data from the GPS on the LTA drone were analyzed and a quantitative assessment of the observed instability was made. The yaw axis and pitch were analyzed, and the yaw axis instability was …

Near-Field Thermal Radiation In Graphene-Based Systems, Hua Lin

Honors College

Radiative heat transfer between two media separated by a sub-wavelength distance (the dominant wavelength of thermal radiation at room temperature is around 10 m.) is referred to as near-field radiative heat transfer (NFRHT). Graphene was found to have one of the greatest levels of NFRHT [1]. Additionally, NFRHT of graphene can be modulated externally via application of a bias voltage to the material [1][2], thereby altering its Fermi energy level. As such, graphene is an ideal candidate for several applications such as NFRHT for thermal switching, nano-gap thermophotovoltaic waste heat recovery, and thermal rectification. Modulation ratios as large as 77.7274 …

Life Cycle Analysis And Implications Of 3d Printed Bio-Based Homes, A Preliminary Study, Claire Liedtka

Honors College

The purpose of this study is to evaluate the life cycle, embodied energy, and sustainability potential for large scale additive manufacturing of 3D printed homes. Additive manufacturing is the process of selectively depositing materials using a 3D printing process, which optimizes material usage and reduces waste. I performed a preliminary Cradle to Cradle Life Cycle Analysis for constructing 3D printed homes using a bio-based material, poly-lactic acid (PLA) filled with wood flour. For purposes of this study, I consider the Life Cycle Analysis to be the environmental assessment of each stage of a product’s life cycle, from material sourcing, processing, …

Investigating 3d-Printability Of A Maine-Based Bio-Ink, Jordyn Judkins

Honors College

Biofabrication is the process of creating complex biologic products, such as artificial tissues, from raw materials such as living cells, biomaterials, and molecules. This can be done using 3D printed bio-ink, which is a combination of biomaterials and cells. However, the bio-ink must be a shear thinning fluid to allow for high-resolution and continuous printing, but also demonstrate post-printing mechanical integrity to self- support the structure, which is challenging to achieve. The research conducted here investigates how to improve the mechanical functionality of bio-ink using additives available in Maine. Chitosan, sodium alginate, and TEMPO nano fibrillated cellulose were chosen as …

Development And Experimental Assessment Of Friction-Type Shear Connectors For Frp Bridge Girders With Composite Concrete Decks, William G. Davids, Dante Guzzi, Andrew Philip Schanck

Civil Engineering Faculty Scholarship

This paper details the development and experimental assessment of a friction-type connector, designed to transfer shear flow between the top flange of a fiber-reinforced polymer (FRP) tub girder and a composite concrete deck for bridge applications. In contrast with previously used bearing-type connectors, this system relies on a deformed FRP surface to transfer shear via direct interlock with the concrete deck. The connector is materially efficient, simple to fabricate, can be used with lower-grade structural or stainless-steel fasteners, and provides a high degree of interface stiffness. Six compression-shear specimens were tested to assess the connector fatigue resistance and ultimate connection …

Effects Of Fiber Orientation On The Coefficient Of Thermal Expansion Of Fiber-Filled Polymer Systems In Large Format Polymer Extrusion-Based Additive Manufacturing, José Luis Colón Quintana, Lucinda Slattery, Jon Pinkham, Joanna Keaton, Roberto A. Lopez-Anido, Keith Sharp

Civil Engineering Faculty Scholarship

Large format polymer extrusion-based additive manufacturing has been studied recently due to its capacity for high throughput, customizable bead size and geometry, and ability to manufacture large parts. Samples from three fiber-filled amorphous thermoplastic materials 3D printed using a Masterprint 3X machine from Ingersoll Machine Tools were studied, along with their neat counterparts. Characterization techniques included thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and thermo-mechanical analysis (TMA). TGA results showed that the fillers decreased the degradation temperature for most of the materials investigated, with a 30°C decrease for polycarbonate (PC) and a 12°C decrease for polyethylene terephthalate glycol (PETG). For …

Wavelet-Based Automatic Breast Segmentation For Mammograms, Basel White

Honors College

As part of a first of its kind analysis of longitudinal mammograms, there are thousands of mammograms that need to be analyzed computationally. As a pre- processing step, each mammogram needs to be converted into a binary (black or white) spatial representation in order to delineate breast tissue from the pectoral muscle and image background, which is called a mammographic mask. The current methodology for completing this task is for a lab member to manually trace the outline of the breast, which takes approximately three minutes per mammogram. Thus, reducing the time cost and human subjectivity when completing this task …

Impact Of Uav Hardware Options On Bridge Inspection Mission Capabilities, Zahra Ameli, Yugandhar Aremanda, Wilhelm A. Friess, Eric N. Landis

Civil Engineering Faculty Scholarship

Uncrewed Aerial Vehicles (UAV) constitute a rapidly evolving technology field that is becoming more accessible and capable of supplementing, expanding, and even replacing some traditionally manual bridge inspections. Given the classification of the bridge inspection types as initial, routine, in-depth, damage, special, and fracture critical members, specific UAV mission requirements can be developed, and their suitability for UAV application examined. Results of a review of 23 applications of UAVs in bridge inspections indicate that mission sensor and payload needs dictate the UAV configuration and size, resulting in quadcopter configurations being most suitable for visual camera inspections (43% of visual inspections …

Numerical Modeling And Experimental Investigation Of Effective Elastic Properties Of The 3d Printed Gyroid Infill, Philip Bean, Roberto A. Lopez-Anido, Senthil Vel

Civil Engineering Faculty Scholarship

A numerical homogenization approach is presented for the effective elastic moduli of 3D printed cellular infills. A representative volume element of the infill geometry is discretized using either shell or solid elements and analyzed using the finite element method. The elastic moduli of the bulk cellular material are obtained through longitudinal and shear deformations of a representative volume element under periodic boundary conditions. The method is used to analyze the elastic behavior of gyroid infills for varying infill densities. The approach is validated by comparing the Young’s modulus and Poisson’s ratio with those obtained from compression experiments. Results indicate that …

Comparing Map Learning Between Touchscreen-Based Visual And Haptic Displays: A Behavioral Evaluation With Blind And Sighted Users, Hari Prasath Palani, Paul D. S. Fink, Nicholas Giudice

Computer Science Faculty Scholarship

The ubiquity of multimodal smart devices affords new opportunities for eyes-free applications for conveying graphical information to both sighted and visually impaired users. Using previously established haptic design guidelines for generic rendering of graphical content on touchscreen interfaces, the current study evaluates the learning and mental representation of digital maps, representing a key real-world translational eyes-free application. Two experiments involving 12 blind participants and 16 sighted participants compared cognitive map development and test performance on a range of spatio-behavioral tasks across three information-matched learning-mode conditions: (1) our prototype vibro-audio map (VAM), (2) traditional hardcopy-tactile maps, and (3) visual maps. Results …

New Evidence For Homocysteine Lowering For Management Of Treatment-Resistant Hypertension, Merrill F. Elias, Craig J. Brown

Maine-Syracuse Longitudinal Papers

Treatment-resistant hypertension is a topic of great importance and the subject of editorial comments in the American Journal of Hypertension. Homocysteine is an intermediate compound in the vitamin regulated One Carbon Methylation pathway which affects glutathione, methionine, and nitric oxide metabolism. Elevated homocysteine, triggered by genetic mutations or insufficient body stores of active vitamins B6, B12, folate, riboflavin, indicates oxidative stress and is associated with impaired nitric oxide synthesis causing small vessel vasoconstriction in the central nervous system. High homocysteine (defined later) is also a risk factor for hypertension.

Higher Yogurt Intake Is Associated With Lower Blood Pressure In Hypertensive Individuals: Cross-Sectional Findings From The Maine–Syracuse Longitudinal Study, Alexandra T. Wade, Benjamin A. Guenther, Fayeza S. Ahmed, Merrill F. Elias

Maine-Syracuse Longitudinal Papers

Associations between fermented dairy products and blood pressure are unclear. The current study therefore examined the association between yogurt and blood pressure in hypertensive and non-hypertensive individuals. Cross-sectional analyses were undertaken on 915 community-dwelling adults from the Maine-Syracuse Longitudinal Study. Habitual yogurt consumption was measured using a food frequency questionnaire. The primary outcomes were systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), and pulse pressure. Secondary outcomes included BMI (kg m^-2), total cholesterol (mg dL^-1), glucose (mg dL^-1), HDL (mg dL^-1), LDL (mg dL^-1), triglycerides (mg …

Growth Ring Orientation Effects In Transverse Softwood Fracture, Parinaz Belalpour Dastjerdi, Eric N. Landis

Civil Engineering Faculty Scholarship

In this study, the fracture mechanics of eastern spruce were characterized in relation to end-grain orientation. Compact tension-type specimens with small pre-formed cracks were prepared such that grain angle varied relative to the load axis. Specimens were loaded under crack mouth opening displacement (CMOD) control as to maintain stable crack growth. Specimen fracture was characterized using both R-curve and bulk fracture energy approaches. The results showed that under a RT grain orientation, as well as grain deviations up to about 40^∘, cracks will follow a path of least resistance in an earlywood region. As the grain angle exceeds …

Lateral Spreading And Stability Of Embankments Supported On Fractured Unreinforced High-Modulus Columns, Aaron P. Gallant, Danilo Botero Lopez

Non-Thesis Student Work

Construction of column-supported embankments (CSEs) with unreinforced high-modulus elements is now common practice to accelerate fill placement. These brittle columns are susceptible to column fracturing and CSE designs often limit the degree of lateral spreading such that tensile rupture will not occur, which stems from salient concerns that fracturing may trigger uncontrolled lateral spreading and/or the cessation of intended vertical load transfer. However, tensile rupture is unlikely to coincide with full mobilization of available passive resistance at the toe. Thus, it is disputed in industry whether some degree of column fracturing is tolerable. The objective of this study is to …

Repeatable Use Assessment Of Silicon Carbide As Permanent Susceptor Bed In Ex Situ Microwave Remediation Of Petroleum-Impacted Soils, Ritchie Lafaille, Yigit C. Bozkurt, Emmy Pruitt, Janelle Lewis, Rene Bernier, Deyuan Kong, Paul Westerhoff, Paul Dahlen, Onur G. Apul

Civil Engineering Faculty Scholarship

Efficiency of microwave-enabled ex situ soil remediation can be improved by dielectric susceptors. Cost, and environmental burden of these susceptors can be minimized if they are used repeatedly in a permanent bed set-up. In this study, carbon nanofibers, activated carbon, magnetite, and silicon carbide were tested at the lab scale for repeated use in permanent microwave-induced thermal soil remediation. Despite their superior ability to convert microwaves into heat, carbon nanofibers experienced electrokinesis and activated carbon partially combusted in the microwave cavity, which complicates their pragmatic use in remediation applications. Magnetite was also able to convert microwaves into heat effectively and …

Afloat 2021: American Floating Offshore Wind Technical Summit, Advanced Structures And Composites Center

General University of Maine Publications

Email invitation to the "AFloat 2021: American Floating Offshore Wind Technical Summit" scheduled for September 8 and 9, 2021. Due to the emergence of COVID variants and the health risks they pose, a decision was made to hold the event virtually to ensure everyone's safety.