Engineering Commons^™

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 …

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 …

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 …

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 …

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 …

Microplate-Like Metal Pyrophosphate Engineered On Ni-Foam Towards Multifunctional Electrode Material For Energy Conversion And Storage, Rishabh Srivastava

Electronic Theses & Dissertations

High clean energy demand, dire need for sustainable development, and low carbon footprints are the few intuitive challenges, leading researchers to aim for research and development for high-performance energy devices. The development of materials used in energy devices is currently focused on enhancing the performance, electronic properties, and durability of devices. Tunning the attributes of transition metals using pyrophosphate (P₂O₇) ligand moieties can be a promising approach to meet the requirements of energy devices such as water electrolyzers and supercapacitors, although such a material’s configuration is rarely exposed for this purpose of study.

Herein, we grow …

Analysis And Characterization Of Embroidered Textile Strain Sensors For Use In Wearable Mechatronic Devices, Jose Guillermo Colli Alfaro

Electronic Thesis and Dissertation Repository

Stroke and musculoskeletal disorders affect hundreds of millions of people around the world. To aid in the recovery process of people affected by these conditions, the use of wearable mechatronic devices has been proposed during traditional rehabilitation therapies. However, factor such as rigidity, increased weight, and overall bulkiness have hindered the adoption of these devices in a clinical setting. Therefore, alternative solutions in the form of soft wearable mechatronic devices have been proposed recently. This is due to these devices being lightweight and comfortable, and compliant, which makes them easier to conform to the human body. To achieve such compliance, …

Stochastic Point Process Modeling For Engineering Applications, Samarth Motagi

Doctoral Dissertations and Master's Theses

Hawkes model or self-exciting point process model is a branching point process model. The model classifies the dataset of discrete events to background and offspring events. It has been used to study interconnected events in many fields, but relatively little work exists in applying these concepts to engineering problems. In our research, we use a self-exciting point process model for two engineering applications: (a) To identify secondary crashes from a given traffic data and (b) To quantify the agglomeration state and size of nanoparticles from computationally generated carbon nanotube microstructure using stochastic percolation model and experimentally generated titanium nanoparticle microstructures. …

Artificial Intelligence-Assisted Inertial Geomagnetic Passive Navigation, Andrei Cuenca

Doctoral Dissertations and Master's Theses

In recent years, the integration of machine learning techniques into navigation systems has garnered significant interest due to their potential to improve estimation accuracy and system robustness. This doctoral dissertation investigates the use of Deep Learning combined with a Rao-Blackwellized Particle Filter for enhancing geomagnetic navigation in airborne simulated missions.

A simulation framework is developed to facilitate the evaluation of the proposed navigation system. This framework includes a detailed aircraft model, a mathematical representation of the Earth's magnetic field, and the incorporation of real-world magnetic field data obtained from online databases. The setup allows an accurate assessment of the performance …

A Personal Tribute To Professor Ashok Midha, Larry L. Howell

Faculty Publications

When I received the news that Professor Ashok Midha had passed away, I was grieved by the unexpected news. But I also felt another emotion: gratitude for having known him. I am grateful for him, for the opportunity I had to learn from him, and for the influence he has had on my life and career. I wanted to honor his memory in some way. This document is in response to that desire.

Some of my thoughts at his passing are summarized in the first chapter and the conclusion. The other writing is taken from a draft of my personal …

Deep-Learning Based Multiple-Model Bayesian Architecture For Spacecraft Fault Estimation, Rocio Jado Puente

Doctoral Dissertations and Master's Theses

This thesis presents recent findings regarding the performance of an intelligent architecture designed for spacecraft fault estimation. The approach incorporates a collection of systematically organized autoencoders within a Bayesian framework, enabling early detection and classification of various spacecraft faults such as reaction-wheel damage, sensor faults, and power system degradation.

To assess the effectiveness of this architecture, a range of performance metrics is employed. Through extensive numerical simulations and in-lab experimental testing utilizing a dedicated spacecraft testbed, the capabilities and accuracy of the proposed intelligent architecture are analyzed. These evaluations provide valuable insights into the architecture's ability to detect and classify …

Verification And Validation Of Robot Manipulator Adaptive Control With Actuator Deficiency, Sebastian Comeaux

Doctoral Dissertations and Master's Theses

This work addresses the joint tracking problem of robotic manipulators with uncertain dynamical parameters and actuator deficiencies, in the form of an uncertain control effectiveness matrix, through adaptive control design, simulation, and experimentation. Specifically, two novel adaptive controller formulations are implemented and tested via simulation and experimentation. The proposed adaptive control formulations are designed to compensate for uncertainties in the dynamical system parameters as well as uncertainties in the control effectiveness matrix that pre-multiplies the control input. The uncertainty compensation of the dynamical parameters is achieved via the use of the desired model compensation–based adaptation, while the uncertainties related to …

Assuring Netlist-To-Bitstream Equivalence Using Physical Netlist Generation And Structural Comparison, Reilly Mckendrick, Jeffrey Goeders, Keenan Faulkner

Faculty Publications

Hardware netlists are generally converted into a bitstream and loaded onto an FPGA board through vendor-provided tools. Due to the proprietary nature of these tools, it is up to the designer to trust the validity of the design’s conversion to bitstream. However, motivated attackers may alter the CAD tools’ integrity or manipulate the stored bitstream with the intent to disrupt the functionality of the design. This paper proposes a new method to prove functional equivalence between a synthesized netlist, and the produced FPGA bitstream. The novel approach is comprised of two phases: first, we show how we can utilize implementation …

Floating Wind Farm Experiments Through Scaling For Wake Characterization, Power Extraction, And Turbine Dynamics, Juliaan Bossuyt, OndˇRej FercˇÁk, Zein Sadek, Charles Meneveau, Dennice Gayme, Raúl Bayoán Cal

Mechanical and Materials Engineering Faculty Publications and Presentations

In this study, wind and water tunnel experiments of turbulent wakes in a scaled floating wind farm are performed. Scaling of a floating wind farm with a scaling ratio of 1:400 is made possible by relaxing geometric scaling of the turbine platform system, such that the dynamic response can be correctly matched, and to allow for relaxing Froude scaling such that the Reynolds number can be kept large enough. Four dimensionless parameters, describing the relative importance of wind and wave loads compared to turbine inertia, are used to guide the scaled floater design. Free decay tests of the pitch and …

Temperature-Controlled Partial Nitrification For Mainstream Wastewater Deammonification Using Batch, Semi-Batch And Continuous Systems, Niema Afroze

Electronic Thesis and Dissertation Repository

Aeration is a critical component of the two-step nitrification, the biological conversion of ammonia (NH₃) to nitrite (NO₂-) and then to nitrate (NO₃-), in municipal wastewater treatment plants. Aeration provides the necessary dissolved oxygen for the growth and activity of nitrifying bacteria to Partial nitrification-Anammox (PN-Anammox) is a two-step biological wastewater treatment process, used to remove nitrogen compounds from wastewater efficiently without the need for external carbon. It combines partial nitrification, where ammonia is partially oxidized to nitrite, with anaerobic ammonium oxidation (Anammox) to remove both ammonia and nitrite. About a 60% to 80% …

Reducing Scour Hole Dimensions Around Bridge Circular Piers Using Hexagonal Collars, Heba Kassem, El-Masry A. A, Reda Diab

Mansoura Engineering Journal

Bridge failure, due to local scour at bridge circular pier foundations, has become a critical issue in river and bridge engineering, which might lead to transportation disruption, loss of lives and economic problems. Based on an experimental perspective, this study is focused on the influence of collar’s shape on decreasing scour depth at bridge piers that were explored. Hexagonal collars with three shapes were investigated (sloped, sloped with holes, and sloped with ribs). The collars were installed on the bed level with diameter equals to three times the diameter of pier. To achieve the results, experiments were performed in clear-water …

Characterizing Tkr Biomechanics Using A Novel Muscle-Driven Joint Motion Simulator, Alexandre Galley

Electronic Thesis and Dissertation Repository

Total knee replacement (TKR) is the end-stage treatment for severe cases of knee osteoarthritis (OA). Despite its success in alleviating pain and restoring mobility to the knee, patient satisfaction rates post-TKR are still lower than other common joint replacement surgeries. Knee kinematics and stability, key determinants of successful TKR, are assessed intraoperatively and tracked post-operatively in in vivo clinical studies. However, the persistently low satisfaction rates suggest that more sophisticated pre-clinical testing methods are needed to better understand the biomechanics of these implants early in their development. During pre-clinical testing of TKR implants, different joint motion simulators are used for …

12.04.2023 Orsp Newsletter, Liz Williamson

ORSP Newsletter

Week of December 4, 2023

Metal Organic Framework Modifications Of Structural Fibers, Marwan Al-Haik

Publications

A reinforced carbon composite can include a carbon sub­strate and a metal organic framework bonded to the carbon substrate. For example, a reinforced carbon composite can include a first layer, a second layer, and a resin adhered to the first layer and the second layer. The first layer can include a carbon substrate and a metal organic framework bonded to the carbon substrate. The second layer can include a carbon substrate and a metal organic framework bonded to the carbon substrate.

Development Of Battery-Grade Silicon Through Magnesiothermic Reduction Of Halloysite-Derived Silica, Nathan Clarke

Theses and Dissertations

The production of halloysite-derived silicon (HDS) is investigated as a potential anode material in lithium-ion batteries (LIBs). Other researchers have found HDS to be electrochemically active in small test cells. To test larger electrochemical cells, the production process needs to be scaled up and optimized. HDS is produced through magnesiothermic reduction of acid-etched halloysite. The reduction process is very exothermic and requires special consideration while being scaled up. A reactor and pressure release system were designed and fabricated to perform the reduction process in a safe manner. Various steps of the process were tested to determine their influence on the …

Void Formation And Mortality During Liquid Composite Molding, Jared Michael Turner

Theses and Dissertations

Within the high-performance composite manufacturing industry, there exists a need to improve the reliability of LCM (Liquid Composite Molding) manufacturing processes in producing composite parts that better approach the quality and consistency of pre-impregnated composite tapes that are cured in autoclaves with cost being a driving factor of this need. One obstacle to that end is the phenomenon of void formation during the LCM infusion processes. The formation of these voids through different mechanisms leads to composite parts with lower mechanical properties and consistency than their pre-impregnated autoclave cure counterparts. The objective of this research is to investigate the different …

Dam Failure And Incident Investigations, Nathaniel Gee

Theses and Dissertations

There are multiple dam failures and dam safety incidents every year in the United States. There are currently no standard policy requirements for when or how to conduct failure or incident investigations. This paper first reviews one of the most significant failures in US history, the failure of Buffalo Creek Dam No. 3 in order to explore the impacts of one significant failure on dam safety policy in the US. The paper then explores the currents state of the industry by reviewing 58 different dam failure or incident investigation reports based on incidents that occurred in the United States from …

Commercial Adsorbents For Co2 Removal For Biogas Upgradation: An Experimental Study, Aakriti Bagla

McKelvey School of Engineering Theses & Dissertations

No abstract provided.

Impacto De La Pandemia Por Covid-19 En La Decisión De Los Pacientes Sometidos A Cirugía Refractiva En Una Institución Privada En Bogotá, Colombia, Juliana Palacio Varona, Brian Pérez Riaño, María Paula Castro Mora, María Andrea Estevez Florez, Luis Guillermo Isaza Gómez, Diana V. Rey-Rodríguez

Ciencia y Tecnología para la Salud Visual y Ocular

En el 2020, durante la pandemia por covid-19, disminuyeron los procedimientos en los centros de cirugía refractiva, pero resurgieron para octubre de ese mismo año, ya que aumentaron un 4 % en comparación con el 2019. Existe una información limitada sobre el impacto de la pandemia en la realización de cirugías y la razón que obedece a dicho aumento. Objetivo: identificar el efecto de la pandemia por covid-19 en la cirugía refractiva mediante la delimitación de las principales motivaciones para la realización del procedimiento. Métodos: estudio descriptivo observacional de corte transversal, por medio de la respuesta de un cuestionario sobre …

Glaucoma Neovascular, Una De Las Consecuencias De La Oclusión De La Vena Central De La Retina, Nicol Daniela Jiménez Rojas

Ciencia y Tecnología para la Salud Visual y Ocular

Objetivo. Estudiar y describir la relación entre la oclusión de la vena central de la retina y el glaucoma neovascular, su etiología, epidemiología, fisiopatología, factores de riesgo, presentación clínica y tratamientos. Metodología. Revisión de la literatura acerca del glaucoma neovascular secundario a oclusión de la vena central de la retina, tomando artículos comprendidos entre 2014 y 2022, con criterios de exclusión artículos de series de casos. Resultados. El glaucoma neovascular (GNV) es una afectación patológica ocular, secundaria a una afección ocular y/o sistémica hipóxica que conduce a isquemia retiniana, dentro de las etiologías más comunes (33 %) se encuentra la …

Prevalencia De Astenopia En Niños Escolares De 6 A 17 Años, Por El Uso De Pantallas Digitales Durante La Pandemia Por Covid-19 (2020-2022): Revisión Sistemática, Jenny Paola Acosta Castellanos, Nancy Piedad Molina-Montoya

Ciencia y Tecnología para la Salud Visual y Ocular

Introducción: El uso de dispositivos electrónicos es primordial en la vida cotidiana a nivel mundial y gracias a la emergencia sanitaria por COVID-19 se incrementó, obligando a los estudiantes a tomar clases virtuales, y esto aumento la prevalencia de astenopia. Objetivo General: Determinar la prevalencia de astenopia reportada por la literatura en niños escolares de 6 a 17 años, por el uso de pantallas digitales durante la pandemia por COVID-19. Método de Investigación: Se realizo una revisión sistemática cualitativa mediante la pregunta PECO; la búsqueda bibliográfica de realizo en bases las bases de datos, con ecuaciones construidas con palabras clave …

Robotic Arms For Microgravity Manufacturing, Connor Talley, Joshua Diamond, Mickael Bah

Senior Design Project For Engineers

There is a need to reduce manufacturing cost in space to avoid sending earth manufactured parts that could suffer damage during launch. The proposed idea consists of a dual robotic arm system attached on a precision gantry setup. The team developed an innovative design that is flexible and efficient for different assemblies, improving space manufacturing. With its two specialized robotic arms, our system maximizes versatility by catering to a wide variety of applications from manufacturing to assembly. The dual arms made of Al 7075 coupled with the gantry provides stability and performance in microgravity environments.

Impact Of Methylene Blue On Enhancing The Hydrocarbon Potential Of Early Cambrian Khewra Sandstone Formation From The Potwar Basin, Pakistan, Muhammad Ali, Abdul M. Shar, Nurudeen Yekeen, Hussein Abid, Muhammad S. Kamal, Hussein Hoteit

Research outputs 2022 to 2026

Significant amounts of hydrocarbon resources are left behind after primary and secondary recovery processes, necessitating the application of enhanced oil recovery (EOR) techniques for improving the recovery of trapped oil from subsurface formations. In this respect, the wettability of the rock is crucial in assessing the recovery and sweep efficiency of trapped oil. The subsurface reservoirs are inherently contaminated with organic acids, which renders them hydrophobic. Recent research has revealed the significant impacts of nanofluids, surfactants, and methyl orange on altering the wettability of organic-acid-contaminated subsurface formations into the water-wet state. This suggests that the toxic dye methylene blue (MB), …

Guidelines For Sustainable Use Of Mobile Instant Messaging Apps In Higher Education: A South African Case Study, Bronwyn C. Swartz, Sweta Patnaik

Higher Learning Research Communications

Objective: The purpose of the study was to propose guidelines to facilitate the sustainable and successful use of mobile instant messaging apps for learning and teaching based on a review of the literature and perceptions of educators. Fraser’s model of redistribution, recognition, and representation served as the theoretical framework. This study provides a mechanism for the development of a socially just and inclusive online classroom environment.

Method: We conducted two focus groups (n = 4 and n = 3) in November 2021 at a university of technology in South Africa to explore the perceptions of educators on using mobile …

Multi-Dimensional Qos And Collaborative Mac Layer Design For Dense, Diverse, And Dynamic Iot Network, Jiyang Bai

Electronic Thesis and Dissertation Repository

With the ubiquitous proliferation of Internet of Thing (IoT) devices, Access Points (APs) of future Wireless Fidelity (Wi-Fi) networks are expected to support dense Stations (STAs) with diverse Quality-of-Service (QoS) requirements under dynamic channel conditions. On account of high access collision and optimization problem complexity, the performance degradation brings new challenges to the existing Media Access Control (MAC) layer design in Wi-Fi. This thesis proposes novel technologies to enable low-latency high-performance MAC layer designs, which support dense access of STAs with real-time solutions of resource allocation and link adaptation problems. Both grouping and collaborative architectures are utilized based on game …