Engineering Commons^™

High Fidelity Computational Modeling And Analysis Of Voice Production, Weili Jiang

Electronic Theses and Dissertations

This research aims to improve the fundamental understanding of the multiphysics nature of voice production, particularly, the dynamic couplings among glottal flow, vocal fold vibration and airway acoustics through high-fidelity computational modeling and simulations. Built upon in-house numerical solvers, including an immersed-boundary-method based incompressible flow solver, a finite element method based solid mechanics solver and a hydrodynamic/aerodynamic splitting method based acoustics solver, a fully coupled, continuum mechanics based fluid-structure-acoustics interaction model was developed to simulate the flow-induced vocal fold vibrations and sound production in birds and mammals. Extensive validations of the model were conducted by comparing to excised syringeal and …

An Experimental Investigation Of Alternative Wave Attenuation Mechanisms For A Modular Breakwater, Richard Perry

Electronic Theses and Dissertations

Global warming and sea level rise threaten to render traditional coastal protection structures as less effective. Floating breakwaters offer the advantages of adapting to rising sea level, allowing important material transport to occur, and being able to deploy and adapt to varying environmental conditions (seabed, depth, etc.). Traditional floating breakwaters typically consist of reflective concrete structures that are limited semi-sheltered locations. This research aimed to construct floating breakwaters out of lightweight materials with a smaller footprint while utilizing alternative attenuation mechanisms. Three breakwaters consisting of a box, beach, and pipe designs were constructed at 1:40 scale and tested in a …

Modeling Of Non-Newtonian Fluid Flow In A Porous Medium, Hamza Azzam

Electronic Theses and Dissertations

Flows of Newtonian and non-Newtonian fluids in porous media are of considerable interest in several diverse areas, including petroleum engineering, chemical engineering, and composite materials manufacturing. In the first part of this thesis, one-dimensional linear and radial isothermal infiltration models for a non-Newtonian fluid flow in a porous solid preform are presented. The objective is to investigate the effects of the flow behavior index, preform porosity and the inlet boundary condition (which is either a known applied pressure or a fluid flux factor) on the infiltration front, pore pressure distribution, and fluid content variation. In the second part of the …

Evaluating Tlb (Translation Lookaside Buffer) Performance Overhead For Nvm (Non-Volatile Memory) Hybrid System, Xiang Guo

Electronic Theses and Dissertations

As the non-volatile memory (NVM) technology offers near-DRAM performance and near-disk capacity, NVM has emerged as a new storage class. Conventional file systems, designed for hard disk drives or solid-state drives, need to be re-examined or even re-designed for NVM storage. For example, new file systems such as NOVA, HMFS, HMVFS and Ext4-DAX, have been developed and implemented to fully leverage NVM’s characteristics, such as fast fine-grained access. This thesis research uses a variety of I/O workloads to evaluate the performance overhead of the TLB (translation lookaside buffer) in various file systems on emulated NVM storage systems, in which NVM …

Use Of Gis To Find Optimum Locations For Anaerobic Digestion Or Composting Facilities In Maine, Usha Humagain

Electronic Theses and Dissertations

As per US EPA, in 2017, 41 million tons of food waste was generated, but only 6.3% was diverted from landfills (US EPA, 2020). When landfilled or incinerated, organic waste (food waste, sludge, manure, agricultural waste) causes environmental pollution through greenhouse gas emissions, land, water, and air pollution. In contrast, if we compost or digest organic waste, we can generate soil additives and a mixture of methane and carbon dioxide gas to produce electricity or energy. Both digestion and composting reduce greenhouse gas emissions, improve the land through additives, and boost the economy. Many countries are adopting anaerobic digestion and …

Design And Fabrication Of A 3-Dimensional Capacitive-Based Force Sensor, Md Shafiqur Rahman

Electronic Theses and Dissertations

The detection of abnormal gait patterns is imperative for early diagnoses and treatment of serious health issues such as loss of mobility and balance, risk of falls, cardiovascular disease, etc. Human gait analysis is the tool used to detect abnormal gait patterns. Gait analysis also can help to understand the cause of gait abnormalities and to make a treatment plan for individual patients. Ground reaction forces (GRFs) at the foot during walking or running are essential for kinetic analysis of the human gait. However, there are no wearable systems that can directly measure three-directional (3D) forces during daily walking. Currently, …

Understanding Biomass Upgrading Through Hydrogenolysis Reactions: Kinetics And Mechanism, Jalal Tavana

Electronic Theses and Dissertations

This dissertation involves several hydrogenolysis reactions but is mainly focused on hydrodechlorination (HDC) of chlorobenzene (PhCl) and hydrodeoxygenation (HDO) of 2-furancarboxylic acid (FCA). Hydrodechlorination of PhCl has been the subject of research for some time. Here, we used a Pd/C catalyst to study this reaction though rigorous kinetics and mechanistic analyses in a CSTR reactor. The H₂/D₂ kinetic isotope effect (KIE) experiment revealed that H₂ is not involved in a rate controlling step. The kinetics data are in agreement with similar systems reported before and follow a first-order dependence on chlorobenzene, half order for hydrogen and …

Reaction Kinetics And Mechanism Investigations Of Renewable Chemicals Production From Biomass, Hussein Talib Abdulrazzaq

Electronic Theses and Dissertations

The development of the technologies and the improved processes for the production of high value bio-based chemicals is one of the most important challenges at the present time. This new movement is not only important from an environmental perspective, but also it is a profitable approach to provide affordable and efficient processes. Therefore, the chemical catalytic upgrading processes over various homogenous and heterogeneous catalysis could be an outstanding modification to upgrade biomass-derived platform molecule to high value applications. In this dissertation, we highlight our recent progress in developing new chemistries and processes for upgrading biomass-derived molecules and address the challenges …

The Design And Validation Of A Uav Propeller Intended For Extremely Low Reynolds Number Environments, Benjamin Hebert

Electronic Theses and Dissertations

Mars exploration and UAV development have both advanced significantly over the past century, and are now being considered in tandem. Currently needed are UAV propellers that can operate in the Martian atmosphere. Flow will be in the range of Re < 20,000, creating extreme conditions not typically examined. A Blade Element Momentum Theory (BEMT) algorithm is developed using a variety of corrections designed specifically for low Reynolds number and rotational flows. Due to both the simplicity of the basic BEMT formulation, corrections are easy to put in place and often necessary to achieve accurate estimates. Aerodynamic coefficients are determined from XFOIL code, and have questionable accuracy in this regime. To account for this, a correction model is developed by comparing XFOIL results to experimental results of airfoils at low Re. This is all tested against a previous low Re propeller experiment. The results of this comparison are used to adjust the values in the correction, to produce more accurate results for theoretical design.

From here, a design philosophy for the propeller is developed using established methods and previous experimental data. High thrust is prioritized, with efficiency being a secondary concern. A hard mach limit of 0.7 is set to avoid major drag penalties, limiting the usable ranges of RPM and radius. Airfoil designs are then examined, based on previous designs, theoretical intuition, and …

Inter-Annual To Inter-Decadal Spatiotemporal Effects Of Storm And Nourishment Events In North Myrtle Beach, South Carolina, Christina Mary Boyce

Electronic Theses and Dissertations

No abstract provided.

Durability Of Entrapped Gas In Quasi-Saturated Porous Media: Two Geotechnical Perspectives, Babak Mahmoodichanzab

Electronic Theses and Dissertations

Entrapped gas bubbles in quasi-saturated porous media are of practical importance in the field of science and engineering. Gas bubbles, which may occur naturally or be introduced artificially, significantly influence the mechanical behavior of soil. In this study, the durability of gas is examined from two geotechnical engineering perspectives. In the field of geotechnics, the artificial introduction of gas is being considered, as it has been widely recognized that entrapped gas, even in nearly-saturated sediments, has an appreciable influence on soil’s mechanical behavior. Entrapped gas bubbles in quasi-saturated sediments significantly increase the pore fluid compressibility and suppress the generation of …

Fly-In Visualization Of Tubular Objects: Theory And Application In Virtual Colonoscopy., Mostafa Mohamed

Electronic Theses and Dissertations

In this dissertation, visualization for tubular objects, i.e., projecting 2D images from 3D inner surfaces of tubular objects, is investigated. Given surface points on 3D objects, an approach that most accurately and effectively projects 2D images from the 3D surface with minimal loss of information is desired. A new visualization method for tubular surfaces is proposed, denoted by "Fly-In". The approach uses a virtual camera ring that moves along the inner surface's centerline, obtaining projections of the surrounding views, forming small 3D topological rings within the tube rendered as a 2D rectangular image. A new visualization loss measure is also …

Imparting 3d Representations To Artificial Intelligence For A Full Assessment Of Pressure Injuries., Sofia Zahia

Electronic Theses and Dissertations

During recent decades, researches have shown great interest to machine learning techniques in order to extract meaningful information from the large amount of data being collected each day. Especially in the medical field, images play a significant role in the detection of several health issues. Hence, medical image analysis remarkably participates in the diagnosis process and it is considered a suitable environment to interact with the technology of intelligent systems. Deep Learning (DL) has recently captured the interest of researchers as it has proven to be efficient in detecting underlying features in the data and outperformed the classical machine learning …

Development Of A Pediatric Cardiac Assist Maglev Pump For Use With A Universal Driver System., Landon Heath Tompkins

Electronic Theses and Dissertations

Heart failure (HF) remains the leading cause of death, affecting 26 million adults worldwide and 6.5 million adults in the United States. Pediatric HF patients have been a historically underserved population with few options for mechanical circulatory support (MCS) therapy, a leading treatment as an alternative to heart transplantation. To address this clinical need, the Inspired Universal MagLev System is being developed; a low cost, universal magnetically levitated extracorporeal MCS system with interchangeable single-use pumps that will ultimately provide adult and pediatric patients ventricular and respiratory assist therapies. The Inspired Pediatric VAD is the first single-use pump application for this …

The Use Of Nanoparticles And Electrospun Fibers For Intravaginal Delivery To Treat Viral And Bacterial Infections And Electrophysiological Measurements Of Synthetic Chloride Channels., Farnaz Minooei

Electronic Theses and Dissertations

Female reproductive viral and bacterial infections affect millions of women worldwide. Given the diversity and magnitude of these unmet reproductive health challenges, topical administration of antiretrovirals (ARVs) and antibiotics have emerged as promising approaches to maintain and restore reproductive health. However, currently available intravaginal dosage forms often suffer from low user adherence and the need for frequent, daily administration to achieve therapeutic effect. To address these challenges, the broad goal of this research was to focus on the development of new localized nanoparticle (NP) and electrospun fiber dosage forms to prolong the delivery and enhance the efficacy of active agents …

Impacts Of Environmental And Hydrologic Factors On Urban Stream Water Quality., Jason Patrik Ingram

Electronic Theses and Dissertations

Urban streams can be impacted by a multitude of hydrologic and environmental factors, making maintaining these water sources difficult. Urbanization can exacerbate these impacts creating new challenges in preserving suitable urban stream water quality. Urbanization is the development of city landscape and suburban living within an otherwise natural region. For this environmental impact study, the effects of city development on urban stream water quality was monitored for Mill Creek in Louisville, Kentucky. To study the effects of urbanization on Mill Creek, this project was completed utilizing the BACI method for comparing impacts. The results of the water quality monitoring were …

Hydrogenation Of 2-Methylnaphthalene In A Trickle Bed Reactor Over Bifunctional Nickel Catalysts, Matthew J. Kline

Electronic Theses and Dissertations

Biomass thermal conversion processes, such as pyrolysis, tend to produce mixtures of mono- and poly-aromatic species. While the high aromatic content is desirable in gasoline fractions, middle-distillate cuts, particularly jet fuel and diesel, require upgrading via hydrogenation and ring opening to achieve better combustion characteristics. There have been many proposed methods for producing drop-in fuels from woody biomass, one of them being Thermal DeOxygenation (TDO). The TDO process converts organic acids from cellulose hydrolysis into a low-oxygen bio-oil containing large amounts of substituted naphthalene compounds.

Poly-aromatic molecules, such as those found in TDO oil, have low cetane numbers (CN), particularly …

Modeling And Analysis For Unit Cell Size, Material Anisotropy And Material Imperfection Effects Of Cellular Structures Fabricated By Powder Bed Fusion Additive Manufacturing., Yan Wu

Electronic Theses and Dissertations

Cellular structures are networks of interconnected struts or walls with porosities and are widely found in many natural load-bearing structures such as plants and bones. Cellular structures offer unique functional characteristics such as high stiffness to weight ratio, tailorable heat transfer coefficient, and enhanced mechanical energy absorption, which makes them highly attractive in various engineering disciplines such as biomedical implants, electrodes, heat exchangers, and lightweight structures. There exists an abundance of literatures that have investigated various mechanical properties of various cellular structures such as Poisson’s ratio, elastic modulus, ultimate strength, yield strength, and failure characteristics. Based on the classic cellular …

Hydration, Shrinkage, Cracking, And Mechanical Properties Of Cementitious Materials With Lignocellulosic Biomass Wastes., Aofei Guo

Electronic Theses and Dissertations

The disposal of lignocellulosic biomass wastes imposes a huge economic and environmental burden on this society. Recycling lignocellulosic biomass wastes and applying them to cementitious materials provides a sustainable and value-added way for both agriculture and concrete industries. To comprehensively identify the effect of lignocellulosic biomass wastes at different scales on cementitious materials, the hydration, shrinkage, cracking, and mechanical properties of cementitious materials with lignocellulosic biomass wastes were studied. Given the three different forms (powders, chips, and fibers) of lignocellulosic biomass wastes in this study, the research was implemented in three stages. In the first stage, hemp powders were collected …

Automatic Target Recognition With Convolutional Neural Networks., Nada Baili

Electronic Theses and Dissertations

Automatic Target Recognition (ATR) characterizes the ability for an algorithm or device to identify targets or other objects based on data obtained from sensors, being commonly thermal. ATR is an important technology for both civilian and military computer vision applications. However, the current level of performance that is available is largely deficient compared to the requirements. This is mainly due to the difficulty of acquiring targets in realistic environments, and also to limitations of the distribution of classified data to the academic community for research purposes. This thesis proposes to solve the ATR task using Convolutional Neural Networks (CNN). We …

Identifying The Need For Trained Machinists In The Greater Tri-Cities Area, Bradley Stufflestreet

Electronic Theses and Dissertations

Machinists are skilled tradespeople responsible for running a variety of machine tools to produce precision components for end-users or use in other manufacturing. This project identifies the current and future change in the number of machinists in the Tri-Cities area, especially the five-county service area of Northeast State Community College. Using an industry survey, the need for machinists is identified and evaluated to understand local employers’ needs. The results indicate industry needs more machinist to keep up with demand, as 6 out of 14 companies have open positions and, 8 reported difficulty filling openings. Furthermore, most companies are growing or …

An Exercise Device Used To Achieve Bone Formation Metrics For The Strengthening Of The Proximal Femur., Sean P. Coyle

Electronic Theses and Dissertations

Lateral falls often lead to hip fracture particularly in the elderly who have low bone mineral density. These fractures frequently lead to indirect mortality soon after injury. Normal use over the course over a lifetime leads to optimized adaptation of the bone in the proximal femur according to normal loading. A lateral fall generates non-normal, lateral loading at the proximal hip where the bone has not adapted to withstand such loading. The resulting fracture is generated by reversed strains on the bone tissue in the femoral neck in the hip in contrast to vertical, quotidian loading. Modern practices for preventing …

Understanding The Influence Of Nonlinear Seas On Wind Generated Waves, Taylor L. Bailey

Electronic Theses and Dissertations

An understanding of the influence of wind of the surface on irregular waves is important for improving ocean forecasting models. While many studies have investigated the phenomenon of wind wave suppression on the surface of mechanically generated waves in the laboratory, few studies have investigated the occurrence of this phenomenon for irregular waves. Chen and Belcher (2000) developed the first model to predict the suppression of wind waves as a function of the steepness of the long wave on which they travel. The Chen and Belcher (2000) model however, was only validated using monochromatic waves, not irregular waves, which are …

Wave Attenuation Capacity Of Suspended Aquaculture Structures With Sugar Kelp And Mussels, Longhuan Zhu

Electronic Theses and Dissertations

Large aquaculture systems may have the potential to damp wave energy for coastal protection. The performance of these systems are influenced by the dynamics of components such as flexible kelp blades and mussel droppers. In this thesis, the dynamics of kelp blades and mussel droppers were investigated with a consistent-mass cable model with focus on understanding the asymmetric motion of kelp blades. The results showed the asymmetric blade motion in symmetric waves is caused by the spatial asymmetry of the encountered wave orbital velocities due to blade displacements and the asymmetric action on the blade by vertical wave orbital velocities. …

Multiphysics Computational Model Of Fluid Flow And Mass Transport In Aneurysm, Tanja Cupac

Electronic Theses and Dissertations

The abdominal aortic aneurysm is progressive, asymptomatic, and can eventually lead to rupture which is a catastrophic event leading to massive internal bleeding and possibly death. AAA cases have been characterized by the development of an intraluminal thrombus (ILT). The ILT correlates with the progression of hypoxia in the arterial wall. The extent that ILT presence reduces oxygen flux to the wall has not been quantified and there is rather a poor understanding of key parameters that can affect thrombus-mediated oxygen transport in AAA. The purpose of this study is to address this gap and to assess the effects of …

Bacteria Analysis By Using A Supervised Machine Learning Algorithm Based On Droplet Microfluidics, Yulder Daniel Angarita

Electronic Theses and Dissertations

Sepsis is a major medical problem and massive resources have been invested in developing and evaluating alternative treatments. Statistics indicate that sepsis causes between one third and one half of all hospital deaths in the United States. Sepsis has a high impact on health care in the US, with direct sepsis costs in 2009 exceeding $15.4 billion. A research study found that a 1-hour delay in appropriate antimicrobial care resulted in a 7% - 10% rise in mortality. Several professional societies seek to reduce sepsis mortality by targeting the timely use of diagnostic tests and antimicrobial therapy. The diagnostic instruments …

Fabrication Of Silicon Microneedles For Dermal Interstitial Fluid Extraction In Human Subjects, Caleb A. Berry

Electronic Theses and Dissertations

The goal of this project is to design and develop a fabrication process for silicon microneedle arrays to extract dermal interstitial fluid (ISF) from human skin. ISF is a cell- free, living tissue medium that is known to contain many of the same, clinical biomarkers of general health, stress response and immune status as in blood. However, a significant barrier to adoption of ISF as a diagnostic matrix is the lack of a rapid, minimally invasive method of access and collection for analysis. Microfabricated chips containing arrays of microneedles that can rapidly and painlessly access and collect dermal ISF for …

Nonlinear Control And Observation Of Full-Variable Speed Wind Turbine Systems., Nicholas Hawkins

Electronic Theses and Dissertations

With increasing concern for the environmental effects of power generation from fossil fuels, wind energy is a competitive source for electrical power with higher efficiency than other clean sources. However, the nature of this power source makes controlling wind turbines difficult. The variability of wind as a source either requires highly accurate measurement equipment or sophisticated mathematical alternatives. In addition to the unknown quantities of the weather itself, the efficiency of power capture at the turbine blades is highly nonlinear in nature and difficult to ascertain. The ability of either determine these troublesome quantities, or control the system despite ignorance …

Inventory Management Of The Refrigerator's Produce Bins Using Classification Algorithms And Hand Analysis., Sarah Virginia Morris

Electronic Theses and Dissertations

Tracking the inventory of one’s refrigerator has been a mission for consumers since the advent of the refrigerator. With the improvement of computer vision capabilities, automatic inventory systems are within reach. One inventory area with many potential benefits is the fresh food produce bins. The bins are a unique storage area due to their deep size. A user cannot easily see what is in the bins without opening the drawer. Produce items are also some of the quickest foods in the refrigerator to spoil, despite being temperature and humidity controlled to have the fruits and vegetables last longer. Allowing the …

Mathematical Models And Analysis For Demand Side Management In Residential Electricity Distribution Networks., Arnab Roy

Electronic Theses and Dissertations

Development of smart grids along with communication technologies have led to the increased attention and adoption of demand side management (DSM) in the residential sector. Among various DSM schemes, demand response (DR) is a market- based mechanism to shave peak electricity consumption at the system level. In the past decade, the academia has seen a growing literature studying load management methodologies for residential consumers. A typical demand response program has three important facets: the energy cost, comfort of the consumers and overall system efficiency. In this dissertation, we investigate and develop models for effective load control to minimize energy cost …