Engineering Commons^™

Numerical Study Of Laryngeal Control Of Phonation Using Realistic Finite Element Models Of A Canine Larynx, Biao Geng

Electronic Theses and Dissertations

While many may take it for granted, the human voice is an incredible feat. An average person can produce a great variety of voices and change voice characteristics agilely even without formal training. Last several decades of research has established that the production of voice is largely a mechanical process: i.e., the sustained vibration of the vocal folds driven by the glottal air flow. Since one only has a single pair of vocal folds, the versatility comes with the ability to change the mechanical status of the vocal folds, including vocal fold length and thickness, tension, and level of adduction, …

Thermal And Mechanical Numerical Modeling Of Extrusion-Based 3d Printed Reinforced Polymers For Selecting Manufacturing Process Parameters, Sunil Bhandari

Electronic Theses and Dissertations

Extrusion-based 3D printing of thermoplastic polymer composites manufactures parts that have nonhomogenous, orthotropic, and process-dependent macro-scale material properties. As a part of the dissertation, research works were carried out to: • improve the interlayer mechanical properties and reduce the orthotropy, • use experimentally homogenized orthotropic material properties to numerically model the mechanical behavior of the non-homogenous orthotropic 3D printed parts, • create an efficient numerical thermal model to predict the process-dependent thermal history of the 3D printed part, and • aid the manufacturing process by selecting a suitable set of processing parameters based on a simplified sequentially coupled thermomechanical model. …

Investigation Of Mass-Manufactured Nanostructured Material For Contamination Detection Via Structural Color Analysis, Oisin Biswas

Electronic Theses and Dissertations

The spread of the SARS-CoV-2 virus has underlined the importance of monitoring surface contamination of infectious elements on commonly used surfaces. Current monitoring methods of surfaces are both lengthy and expensive. The work in this project took advantage of the optical phenomenon of structural color to develop a rapid, low-cost, and contactless method of surface contamination detection. To accomplish this, a mass-produced material imprinted with a nanostructured pattern capable of exhibiting this structural color phenomenon was used. Structural color, or the bands of color that appear as different wavelengths of light reflect off a textured surface, can vary as a …

Comparison Between Cpu And Gpu For Parallel Implementation For A Neural Network Model Using Tensorflow And A Big Dataset, Intisar Alkaabwi

Electronic Theses and Dissertations

Machine learning is a rapidly growing field that has become more common of late. Because of the demanding computational usage of machine learning, this field has many dimensions needing research. TensorFlow has been developed to deal with and analyze neural networks computation. In particular, TensorFlow is often used in one of the machine learning branches and is called deep learning. This work discusses the performance of a deep learning model to train a very large dataset with TensorFlow. It compares performance when the run happens on CPUs and on GPUs regarding the run time and speed. The run time is …

Techno-Economics And Life Cycle Analysis Of Upgrading Woody Biomass To Diesel Blendstock, Aysan Najd Mazhar

Electronic Theses and Dissertations

Woody biomass conversion to transportation fuels have been developed as alternatives to fossil fuel production to reduce greenhouse gas emissions and to increase energy security. Fast pyrolysis, a thermochemical technology, has the potential to offer high efficiencies to produce liquid transportation fuels from woody biomass. Fast pyrolysis involves rapid heating of biomass particles in the absence of air at approximately 500°C and results in non-condensable gases, bio-oil (pyrolysis oil), and char as products. The pyrolysis oil can be upgraded via integrated mild hydrogenation and etherification processes to a high energy density fuel that can be blended with diesel for transportation …

Computer Modeling Using The Finite-Difference Time-Domain (Fdtd) Method For Electromagnetic Wave Propagation, Atheer A. Oufi

Electronic Theses and Dissertations

The Finite-Difference Time-Domain (FDTD) technique is a numerical analysis modeling method to find the solutions of the partial derivatives in Maxwell’s equations to electromagnetic problems. In FDTD the electrical and magnetic fields components staggered in time and space by a method developed by Yee. The approximation of the solutions can be found using a set of updated equations.

In every simulation that utilizes the FDTD method, the factors of time and memory size are the two significant considerations. This study focused on reducing the computation time, as the time required to time-march the components of the electrical and magnetic fields …

Gradient Generating Microfluidic Coculture System For Disease Modeling And Neural Development, Phaneendra Chennampally

Electronic Theses and Dissertations

Cellular microenvironment or cell niche plays an important role in developmental biology and disease pathophysiology. Physical or chemical signals in microenvironment drive the cellular activity. These signaling molecules are generated from the surrounding cells/tissues as part of intercellular communication; a fundamental property of a cell. Dynamic profile of these signaling molecules in the microenvironment plays a pivotal role in transfer of molecular information from cell to cell in disease proliferation or fate determination. Recapitulating these signaling cues in an in vitro study is difficult to achieve using standard cell culture techniques. However microfluidic systems are capable of addressing these issues, …

Design, Quantification, And Strengthening Of Interface Interaction Between Aramid Fibers And Polymer Matrix, Karrar Al-Quraishi

Electronic Theses and Dissertations

Composites reinforced by aramid fibers may suffer poor interface interactions during mechanical loading due to the smooth and chemically inert surface of the fibers. Three main strategies have been used to improve the interface shear strength (IFSS) including increasing surface roughness, enriching fiber surface with functional groups, and surface coating with ceramic particles. Plasma treatment is usually employed to functionalize and roughen surface of the fibers, leading to strengthening of the interface between the fibers and polymer matrix. A concern for fibers reinforced polymers is that the IFSS would significantly decrease once the composite is exposed to elevated temperatures. To …

Determination Of Bridge Behavior Through Live-Load Testing And Advanced Numerical Analysis, Andrew Schanck

Electronic Theses and Dissertations

Bridges represent critical nodes in the United States’ transportation network, and an accurate understanding of their strength and durability is paramount to their continued use to transport people and goods. Traditionally, bridge assessment has been conducted through conventional beam-line analysis of isolated bridge components as specified by the American Association of State Highway and Transportation Officials (AASHTO). Although this method is reasonable for relatively new structures whose behavior are well understood, it can lead to significant over-conservative estimates of live-load capacity for older structures and for new types of structure for which design bases are still being developed. For such …

Development Of A Novel Haptic Feedback System For Gait Training Applications, Mohsen Alizadeh Noghani

Electronic Theses and Dissertations

Until recently, study and correction of motor or gait functions required costly sensors and measurement setups (e.g., optical motion capture systems) which were only available in laboratories or clinical environments. However, due to (1) the growing availability and affordability of inertial measurement units (IMUs) with high accuracy, and (2) progress in wireless, high bandwidth, and energy-efficient networking technologies such as Bluetooth Low Energy (BLE), it is now possible to measure and provide feedback in real-time for biomechanical parameters outside of those specialized settings. To enable gait training without an expert who can provide verbal feedback, augmented feedback, which is divided …

Optimization Of Thermoelectric Materials For Marine And Power Plant Application, Travis Thornton Wallace

Electronic Theses and Dissertations

Thermoelectric materials are an enabling technology that has the potential to increase overall plant efficiency and reduce greenhouse gas emissions for shoreside power plants and for the marine industry. These materials do this by directly converting waste heat energy into usable electricity that could be harnessed for use on any existing electrical grid. This dissertation describes work done to understand, model, and investigate improvements to bismuth telluride and bismuth telluride antimony thermoelectric materials to better match the materials to available heat flux from industrial plants. Presented within this work are models to investigate homogenous materials, functionally graded materials, and segmented …

Segmentation And Statistical Analysis Of Imaged And Simulated 3d Chromosome Territories, Hannah Varney

Electronic Theses and Dissertations

With advances in microscopy in the 21st century, more accurate measurements of the morphology and position of chromosome territories (CTs) during interphase within the cell nucleus can be obtained. These measurements have determined that CTs are non-randomly positioned, and their position and shape can change during diseases like breast cancer, pancreatic cancer, and Huntington’s Disease. The 2.5D Wavelet Transform Modulus Maxima segmentation method uses multi-scale edge detection to accurately segment objects in 3D images to find variables such as surface area, volume, and diameter without assuming a spherical or ellipsoidal shape. Measurements of centroid distance, shell distance and radial distance …

Understanding The Adhesion Mechanism In Mycelium-Assisted Wood Bonding, Wenjing Sun

Electronic Theses and Dissertations

The increasing environmental awareness has led to an increased interest in developing more sustainable materials as alternatives to petroleum-derived products. Among different nature-based products, fungal-mycelium-based bio-composites have gained considerable attention in various applications. Multiple materials with different densities and structures and potential applications can be fabricated by inoculating filamentous white-rot fungi in lignocellulosic materials and other substrates. Different from lower-density as-grown foam-like mycelium composites, higher-density mycelium-lignocellulosic panels have the potential to replace commercial particleboard and fiberboard bonded by petroleum-based resins. This kind of composite can be produced by directly adding heat and pressure to the low-density foams or by assembling …

The Effect Of Non-Local Electrical Conductivity On Near-Field Radiative Heat Transfer Between Graphene Sheets, Behrad Zeinali Tajani

Electronic Theses and Dissertations

Every object above zero kelvin emits electromagnetic radiation with the dominant wavelength determined using the Wien’s law (10 microns at room temperature). These waves can transfer energy and hence are the foundation of radiative heat transfer (RHT). RHT consists of two regimes: far-field and near-field. If the distance between the heat exchanging media is more than the dominant wavelength, the regime is far-field and is limited to the ideal Planck’s blackbody, and only propagating waves contribute to heat transfer. On the other hand, when the distance is less than the dominant wavelength, the regime is called the near-field. In near-field …

Structural And Material Characterization Of Inflatable Drop-Stitch Panels Used In Bending Applications, Elisabeth M. Waugh

Electronic Theses and Dissertations

Inflatable beams, arches and panels have become increasingly popular for load-bearing applications and have a variety of military and civil applications. The popularity of these structures comes from being lightweight, easy to transport, and being able to regain shape after the structure has been overloaded and the load is removed. The majority of inflatable beams and arches – commonly termed “airbeams” – are cylindrical pressure vessels with a circular cross-section. In contrast, drop-stitch panels incorporate yarns that connect the top and bottom surfaces, giving a wide, shallow cross-section with parallel top and bottom surfaces. Unlike airbeams, drop-stich panels do not …

Comparison Of Land Use And Flowslide Incidence In Palu Valley Following The 2018 Mw 7.5 Palu-Donggala Earthquake, Peta C. Fifield

Electronic Theses and Dissertations

The September 28 Mw 7.5 Palu-Donggala earthquake in Indonesia was the deadliest natural disaster in 2018. Five flowslides on the eastern side of Palu Valley, which were attributed to the substantial majority of deaths and economic losses in the region, occurred due to liquefaction of naturally dry alluvial deposits in gently sloping ground (2 to 6%). The requisite conditions for soil liquefaction are the presence of loose granular sediments and full saturation. Instigation of these catastrophic ground failures were linked to artificial saturation by an unlined agricultural irrigation canal. From a civil engineering perspective, the Palu ground failures on the …

Hydrodynamic Impacts Of Expanding Aquaculture, Zhilong Liu

Electronic Theses and Dissertations

Climate change may potentially change aquatic systems and bring certain risks for aquaculture development. Understanding interactions between aquaculture and the environment helps to ensure aquaculture expansion is sustainable in the future. It is critical to determine how farms influence tidal flow patterns, turbulence, mixing and material transport in estuaries. This research aims to determine the flow response of an oyster farm, predict how expanding farms and farm placement will alter estuarine dynamics, and understand how the design of a farm influences material transport.

The hydrodynamic response of a floating oyster aquaculture farm in a low inflow estuary (the Damariscotta River …

Manipulation Of Particles And Fluid With Surface Acoustic Waves, Joel Scott Tewksbury

Electronic Theses and Dissertations

Small biomolecules can be challenging and expensive to isolate and manipulate, but they may be the key for developing more efficient diagnostic tools for the detection of biomarkers, such as those associated with pancreatic cancer. Pancreatic cancer has a survival rate of less than 10% five years after diagnosis. For this reason, the research and establishment of cheap, effective screening tools are highly desired. One promising method of screening is separating and identifying biomarkers in a patient’s blood that are indicative of pancreatic cancer. The purpose of this project is to develop a system using surface acoustic waves (SAWs), in …

Nanostructured Self-Assembled Thin Films Of Cationic Bottlebrush Block Copolymers, Hathaithep Senkum

Electronic Theses and Dissertations

Biofouling which is an accumulation of small species on submerged surfaces that causes detrimental impacts on economic and environmental factors for aquaculture activities and human health. To suppress the fouling, polymeric coatings from amphiphilic block copolymers provide nanostructured surfaces and carry multiple functional groups in a molecular chain. Polymers with quaternary ammonium functional groups enable material coatings to inhibit microbial adhesion by killing bacteria, consequently prolonging the material efficiency of, for example, medical implanted devices. Herein, well-defined architectures with full-arm density of quaternary ammonium bottlebrush polymers were generated from grafting-through ring opening metathesis polymerization (ROMP). Factors such as the halide …

Characterization Of Coated Particles To Use In High-Temperature Solid Particle Receivers, Seyed Adib Taba

Electronic Theses and Dissertations

High-temperature solid particle receivers have been widely studied for use in concentrated solar power systems to absorb concentrated solar radiation. Many efforts have been made to select a particle that can increase the performance of these systems. In this experimental study, available coating technology for particles is used to examine whether it could enhance heat transfer. A packed bed setup is designed and validated to assess the heat transfer of these particles. The validated packed bed opens the scope in which a packed bed can be used as a primary experiment for the prediction of suitable alternative particles and reduce …

Gait Rehabilitation Using Biomechanics And Exoskeletons, Jacob Bloom

Electronic Theses and Dissertations

A healthy gait is often taken for granted when walking. However, if a stroke, spinal cord injury (SCI), or traumatic event occurs the ability to walk may be lost. In order to relearn how to walk, gait rehabilitation is required. Including arm swing in gait rehabilitation has been shown to help in this process. This thesis presents two tasks to investigate the mechanics of arm swing and ways to provide assistance to induce arm swing in gait rehabilitation.

The firsts task completed was a study on the effects of forearm movement during gait. Twelve healthy subjects walked under three conditions …

Growth Of Perkinus Marinus By Bioreactor Fermentation, Caitlin Murphy

Electronic Theses and Dissertations

Perkinsus marinus is a marine protozoan responsible for “Dermo” disease in the eastern oyster species, Crassostrea virginica. P. marinus has been detected along the Atlantic Coast of the United States and Mexico. In laboratory studies, many parasites need to be maintained in vivo, which complicates the study of the organism. However, In vitro cell culture for P. marinus at a scale of 1 mL was established in 1993 by several groups with the 1995 optimization (Gauthier & Vasta, 1993, 1995) considered the gold standard for small scale growth of this species. In addition to its importance as a …

Active Blade Pitch And Hull-Based Structural Control Of Floating Offshore Wind Turbines, Eben Lenfest

Electronic Theses and Dissertations

Floating offshore wind turbines (FOWTs) have the potential to bring renewable energy to waters too deep for traditional offshore wind turbines while still being able to harness strong coastal winds in areas near population centers. However, these floating wind turbines come at a higher capital cost relative to fixed foundations and are more susceptible to vibrations induced by waves. Advances in control technologies offer the potential to reduce fatigue loads due to these vibrations, extending the life of the platform and thereby spreading the capital costs of the turbine over a longer period of time. One such advance is in …

Understanding Hydrologic Risk Within The Context Of Climate Variability And Atmospheric Moisture Pathways, Ali Aljoda

Electronic Theses and Dissertations

Nonstationarity in the means and extremes of water resources (e.g., streamflow) due to climate change presents challenges to water resources management and planning. Changes in hydrologic variables such as streamflow critically impact infrastructure, water use planning and adaptation strategies, and can lead to increased societal vulnerability. As such, existing water resources infrastructure designed based on limited records of historical flow may deteriorate under future hydro-climatic changes. Thus, important scientific tasks are: a) examining and redefining the risk, reliability, and return periods under nonstationary conditions, b) understanding the changes in extreme events statistics (i.e. frequency, and magnitude), and c) linking these …

Nanocellulose Conduits For Enhanced Regeneration Of Peripheral Nerve Injuries, Nicklaus R. Carter

Electronic Theses and Dissertations

Peripheral neuropathy is estimated to afflict 20 million people in the United States. Most cases of neuropathy result from physical injuries and trauma arising from automobile accidents and war. Peripheral nerves have the intrinsic ability to regenerate over time, bridging the injury gap. However native regeneration is limited to a distance of only a few millimeters. Current methods utilized to assist in the regeneration of peripheral nerves over distances exceeding those amenable to native repair include nerve autografts and allografts, and implantation of conduits. Nerve autografts are regarded as the most effective method but require a second surgical site to …

Development Of Hybrid Ultra-High Performance Concrete Thermoplastic Composite Panels For Blast And Ballistic Protection, Alyssa M. Libby

Electronic Theses and Dissertations

In recent years, ultra-high performance concrete (UHPC) has become a material of interest for structures needing resistance to impact and blast loadings. These types of loadings have induced brittle flexural failure in UHPC due to punching shear from the impactor. One way to improve the impact resistance, energy absorption, and ductility of UHPC is by adding fiber-reinforced polymer (FRP) skins to the front and rear faces of the concrete, resulting in a sandwich configuration. In this study, E-glass fiber-reinforced thermoplastic laminates were bonded to UHPC panels using a heated consolidation process known as stamp thermoforming. The bond between the UHPC …

Handling And Manipulation Of Water- And Air- Borne Biological Samples Using Liquid-Infused Surfaces, Daniel P. Regan

Electronic Theses and Dissertations

Research on novel materials to handling water- and airborne samples for biological threats analysis is in great demand due to the COVID-19 pandemic. Work conducted on a new field of material science, called liquid-infused surfaces, demonstrate strong potential for the handling and manipulation of biological samples. As a result of the field’s infancy, only a limited number of studies have explored how liquid-infused surfaces can apply droplet manipulation strategies to address real-world problems. Presented in this dissertation are two platforms that leverage liquid-infused surfaces to address the challenges associated with handling water- and airborne biological samples. When dealing with waterborne …