Engineering Commons^™

Material Interactions And Self-Assembly In Inkjet Printing, Karam Nashwan Al-Milaji

Theses and Dissertations

Inkjet printing has attracted much attention in recent years as a versatile manufacturing tool, suitable for printing functional materials. This facile, low-cost printing technique with high throughput and accuracy is considered promising for a wide range of applications including but not limited to optical and electronic devices, sensors, solar cells, biochips, and displays. The performance of such functional devices is significantly influenced by the deposit morphology and printing resolution. Therefore, fabrication functional devices with precise footprints by inkjet printing requires deep understanding of ink properties, material interactions, and material self-assembly.

In conventional inkjet printing process, where sessile droplets are directly …

Cold X-Ray Effects On Satellite Solar Panels In Orbit, Myles Fogleman

Theses and Dissertations

An exo-atmospheric nuclear detonation releases up to 80 percent of its’ energy as X-rays. Satellite’s solar cells and their protective coatings are vulnerable to low energy X-ray radiation. Cold X-rays (~1-1.5 keV) are absorbed close to the surface of materials causing the blow-off and rapid formation of Warm Dense Plasmas (WDPs), particularly in a gap between the unshielded active elements of solar cells. To understand how WDPs are created, it is necessary to investigate the power density distribution produced by cold X-rays for typical solar panel surface materials. The Monte Carlo stepping model implemented in the GEANT4 software toolkit is …

Development Of An Eye Movement Based Predictive Model For Discrimination Of Parkinson's Disease From Other Parkinsonisms And Controls, Mary Anisa Kannan

Theses and Dissertations

Purpose: Due to the neurological aspects of Parkinson’s Disease (PD) and the sensitivity of eye movements to neurological issues, eye tracking has the potential to be an objective biomarker with higher accuracy in diagnosis than current clinical standards. Currently when PD is diagnosed clinically, there is an accuracy of 74% when diagnosed by a general practitioner and 82% when diagnosed by a movement disorder specialist. This study was designed to: 1. Assess eye movements as a potential biomarker for Parkinson’s Disease. 2. Determine if eye movements can distinguish between Parkinson’s Disease and commonly confounded movement disorders with parkinsonian symptoms. 3. …

Adhesion At Solid/Liquid Interfaces, Neda Ojaghlou

Theses and Dissertations

The adhesion at solid/liquid interface plays a fundamental role in diverse fields and helps explain the structure and physical properties of interfaces, at the atomic scale, for example in catalysis, crystal growth, lubrication, electrochemistry, colloidal system, and in many biological reactions. Unraveling the atomic structure at the solid/liquid interface is, therefore, one of the major challenges facing the surface science today to understand the physical processes in the phenomena such as surface coating, self-cleaning, and oil recovery applications. In this thesis, a variety of theory/computational methods in statistical physics and statistical mechanics are used to improve understanding of water adhesion …

Optimizing Nasal Cannulas For Infants Using Computational Fluid Dynamics, Ahmad El-Achwah Mr.

Theses and Dissertations

Aerosolized medications can potentially be delivered to the lungs of infants through a nasal cannula interface. However, nose-to-lung delivery technologies currently allow for ~1% of the loaded dose to reach an infant’s lungs. Conventional dry powder inhalers (DPI) are superior to other types of inhalers in many ways. However, passive DPIs that operate based on user inhalation and require large volumes of airflow are not applicable to infants. To overcome this challenge, positive pressure DPIs have been developed that enable aerosol delivery to infants. Unless an adequate nasal interface is used with these devices, a significant amount of drug will …

Assessment Of Access Methods For Mobile Maps For Individuals Who Are Blind Or Visually Impaired, David Parker

Theses and Dissertations

When people go to a mall, museums, or other such locations they tend to rely on maps to find their way around. However, for people who are blind or visually impaired (BVI) maps are not easily accessible and they depend on other means, such as a guide, to get around. Research has only just begun to investigate providing maps for people who are BVI on touch screen devices. Many different types of feedback have been used: audio (sound), tactile (touch), audio-tactile, and multitouch. Some research has been conducted on the benefit of using multiple fingers (multitouch) and has found conflicting …

Fabrication And Simulation Of Nanomagnetic Devices For Information Processing, Justine L. Drobitch

Theses and Dissertations

Nanomagnetic devices are highly energy efficient and non-volatile. Because of these two attributes, they are potential replacements to many currently used information processing technologies, and they have already been implemented in many different applications. This dissertation covers a study of nanomagnetic devices and their applications in various technologies for information processing – from simulating and analyzing the mechanisms behind the operation of the devices, to experimental investigations encompassing magnetic film growth for device components to nanomagnetic device fabrication and measurement of their performance.

Theoretical sections of this dissertation include simulation-based modeling of perpendicular magnetic anisotropy magnetic tunnel junctions (p-MTJ) and …

Electrochemical Separation Of Multivalent Species On A Liquid Bismuth Cathode In Licl-Kcl Eutectic For Used Nuclear Fuel Reprocessing, Michael Woods

Theses and Dissertations

The presence of group I/II fission products (Cs-137, Sr-90, and Ba-137) within molten salt nuclear processes degrades operational efficiencies by contributing to increased radiation levels in the case of material handling processes or to loss of criticality in the case of a reactor. While methods such as zone freezing and ion exchange have been proven for the separation of these fission products in LiCl-KCl salts, they require extra equipment and processing steps. Addition of a liquid metal electrode to molten salt media, such as the electrorefiner of a pyroprocessing scheme or the salt cleaning stage of a molten salt fast …

Modeling Electrospun Fibrous Materials, Sina Hassanpouryousefi

Theses and Dissertations

Electrospinning has been the focus of countless studies for the past decades for applications, including but not limited to, filtration, tissue engineering, and catalysis. Electrospinning is a one-step process for producing nano- and/or micro-fibrous materials with diameters ranging typically from 50 to 5000 nm. The simulation algorithm presented here is based on a novel mass-spring-damper (MSD) approach devised to incorporate the mechanical properties of the fibers in predicting the formation and morphology of the electrospun fibers as they travel from the needle toward the collector, and as they deposit on the substrate. This work is the first to develop a …

Engineering Of Earth-Abundant Electrochemical Catalysts, Dylan D. Rodene

Theses and Dissertations

Alternative energy research into hydrogen production via water electrolysis addresses environmental and sustainability concerns associated with fossil fuel use. Renewable-powered electrolyzers are foreseen to produce hydrogen if energy and cost requirements are achieved. Electrocatalysts reduce the energy requirements of operating electrolyzers by lowering the reaction kinetics at the electrodes. Platinum group metals (PGMs) tend to be utilized as electrocatalysts but are not readily available and are expensive. Ni_1-xMo_x alloys, as low-cost and earth-abundant transition metal nanoparticles (NPs), are emerging as promising electrocatalyst candidates to replace expensive PGM catalysts in alkaline media. Pure-phase cubic and hexagonal Ni_{1-x …}

The Creation, Validation, And Implementation Of The Engineering Process Safety Research Instrument, Brittany Lynn Butler

Theses and Dissertations

The purpose of this study was to develop and validate an instrument that can measure how senior chemical engineering students make process safety decisions. The Engineering Process Safety Research Instrument (EPSRI) contains dilemmas that represent process safety scenarios, followed by three decision options, and 12-15 considerations that fall into pre-conventional, conventional, or post-conventional forms of reasoning. Three studies were completed as a part of this research. The content validation study ensured the dilemmas represented process safety scenarios, the considerations matched their perceived theoretical definitions, and that no content areas were omitted. This study resulted in validation of the content, following …

Design Synthesis Of Flexible Antennas Using Artificial Neural Network, Ali Isam Hammoodi

Theses and Dissertations

Nowadays, flexible devices have witnessed a great deal of interest in both industrial and academia. Consistently, flexible electronic systems require the integration of a conformal and flexible antenna operating in specific frequency bands to provide wireless connectivity which is highly demanded in today’s information-oriented society. Designing of microstrip antenna has become the focus of modern technologies due to their light weight, ease of fabrication, and ability to integrate electronics devices. Simple structure such has square patch, circular patch, or rectangular patch are easy to maintain using empirical equations which based on some experimental results. However, more complicated structures are hard …

Battery-Buffered Frequency-Controlled Smart Load With Time-Of-Use Energy Arbitrage, Ahmed Jabbar Abbas Zurfi

Theses and Dissertations

In existing long-established power systems, the grid control and balancing are implemented on the generation side in centralized schemes. As the use of renewable, non-dispatchable, inverter-based (inertia-less) energy sources is becoming increasingly pervasive in modern power systems, this paradigm will change and the need for decentralized demand-side control will be imperative to ameliorate the grid’s dynamic performance and stability. Battery energy storage (BES) is one of the essential constituents that will empower this transition. Battery energy storage systems (BESS) are eminent for their features of scalability, mobility, high energy density, and rapid response in tracking abrupt power fluctuations. These features …

Integrating Global And Local Forecasting Resources And Methods For Flood Warning Systems In Central America And Caribbean Region, José Fidel Pérez

Theses and Dissertations

Hurricanes and tropical storms occur very frequently in the Central American and Caribbean Region (CA&CR). These extreme weather events produce a lot of rain and consequently a lot of flooding. Damages and loses have been estimated to amount to 13.4 billion dollars in the last ten years. Flood Warning Systems (FEWS) are a key preventive strategy to reduce risk. Technological progress is improving the resources made available for FEWS to be more viable. In spite of the international support for FEWS and the fast development of ICT, there are very few countries in the CA&CR that have succeeded in developing …

Wall Shear Stress In Simplified And Scanned Avian Respiratory Airways, Michael Sterling Farnsworth

Theses and Dissertations

Birds uniquely produce sound through a vocal organ known as a syrinx. The presence of wall shear stress acting on the airway cells of any organism will affect how airway cells develop and multiply. Unique features of avian airway geometry and breathing pattern might have contributed to the development of the syrinx. This thesis examines wall shear stress in the trachea and first bronchi of avian geometries using computational fluid dynamics. The computational fluid dynamic simulations underwent grid- and time-independence studies and were validated using particle image velocimetry. Parameters such as bird size, bronchial branching angle, and breathing waveform were …

Organizimi I Ndërtimit Të Objektit Shumebanesor, Sokol Mehmeti

Theses and Dissertations

Ky punim do të trajtojë çështjen e organizimit të ndërtimit të një objekti shumëbanesor. Do të trajtohen tema dhe fusha si përshkrimi teknik, organizimi i punishtës me disa faza dhe pjesë përbërëse si punët përgaditore, rrugët e përkohshme, rrethoja, instalimet e përkohshme, zyret e përkohshme, mënyra e vendosjes, ushqimi dhe sigurimi shëndetësor i punëtoreve si dhe depot. E gjithë kjo do të paraqitet edhe me skemë lidhur me rregullimin e punishtës. Pas këtij përshkrimi, në punim do të përshkruhën edhe mënyrat e kryerjes së punëve kryesore ndërtimore, duke përfshirë punët tokësore, punën beton-armesë, si dhe proceset e tjera përcjellëse. Zgjedhja …

Roli Dhe Rëndȅsia E Mbrojtsjes Në Punë Në Sektorin E Ndȅrtimtarisë, Rinor Hajrizi

Theses and Dissertations

Sektori i ndërtimit paraqet një nga sektorët më të rëndësishem të zhvillimit gjatë të gjitha periudhave të zhvillimit njerëzor. Sot, në këtë sektor janë bërë shumë transformime falë avancimit tekniko-teknologjik dhe kërkimeve shkencore me qëllim të përsosjes së veglave, pajisjeve dhe makinerisë për kryerjen e punëve ndërtimore në mënyrë sa më të sigurtë dhe me shkallë të lartë të efikasitetit dhe produktivitetit. Avancimi tekniko-tekonologjik në sektorin e ndërtimit po lehtëson realizimin e veprave inxhinierike me shkallë më të lartë të sigurisë dhe mbrojtjes në punë. Por, pavarsisht të arriturave inxhinierike në lëmin e ndërtimit, prap se prap ky sektor, si …

Projekti Ideor "Rrugë Në Fshatin Damjan- Gjakovë", Andi Qarkaxhija

Theses and Dissertations

Ky punim synon të japë një pamje të përgjithshme të projektit ideor për ndërtimin e një rruge, duke treguar karakteristikat e ndryshme dhe hapat për të filluar ndërtimin e një rruge. Projektimi i rrugëve është një proces i ndërlikuar professional si dhe kërkimor i cili ka për qëllim zgjidhjet optimale, ku në kë këtë projekt ideor janë paraqitur të dhënat thelbësore për ndërtimin e një rruge siç janë: matjet gjeodezike në terren, pjesën tekstuale, pjesën grafike, paramasen dhe parallogarinë, raportin teknik etj.

Rruga e projektuar ndodhet në Komunën e Gjakovës, fshati Damjan dhe ka 727,14m gjatësi. Projekti është bërë duke …

Improving Detection Of Dim Targets: Optimization Of A Moment-Based Detection Algorithm, Shannon R. Young

Theses and Dissertations

Wide area motion imagery (WAMI) sensor technology is advancing rapidly. Increases in frame rates and detector array sizes have led to a dramatic increase in the volume of data that can be acquired. Without a corresponding increase in analytical manpower, much of these data remain underutilized. This creates a need for fast, automated, and robust methods for detecting dim, moving signals of interest. Current approaches fall into two categories: detect-before-track (DBT) and track-before-detect (TBD) methods. The DBT methods use thresholding to reduce the quantity of data to be processed, making real time implementation practical but at the cost of the …

Carbon Nanotube Fibers: Mechanical Behavior And The Effects Of The Space Environment, Ryan A. Kemnitz

Theses and Dissertations

Carbon nanotube materials are promising multifunctional materials for incorporation into aerospace structures because of their high tensile strength, high electrical conductivity, and low density. This research aimed to characterize the mechanical failure mechanisms of carbon nanotube fibers and examine the effects of the space environment on their material properties. Tensile tests were conducted at varying strain rates and on fibers of varying gage lengths to examine the underlying molecular failure mechanisms and impact of defects on fiber strength. Tensile strength and elastic modulus were observed to increase with increasing strain rate and decrease with increasing gage lengths. The observed effects …

Real-Time Heuristics And Metaheuristics For Static And Dynamic Weapon Target Assignments, Alexander G. Kline

Theses and Dissertations

The problem of targeting and engaging individual missiles (targets) with an arsenal of interceptors (weapons) is known as the weapon target assignment problem. This problem has been well-researched since the seminal work in 1958. There are two distinct categories of the weapon target assignment problem: static and dynamic. The static weapon target assignment problem considers a single instance in which a known number of incoming missiles is to be engaged with a finite number of interceptors. By contrast, the dynamic weapon target assignment problem considers either follow on engagement(s) should the first engagement(s) fail, a subsequent salvo of incoming missiles, …

Thermal Management Of Satellite Electronics Via Gallium Phase Change Heat Sink Devices, Brian O. Palmer

Theses and Dissertations

The purpose of this research was to determine the effectiveness and feasibility of additively manufactured heat sinks using gallium as a phase change material in the thermal management of satellite electronics. A design was created based on the footprint of an Astronautical Development, LLC Lithium 1 UHF radio and six heat sinks were additively manufactured; two each of stainless steel 316, Inconel 718, and ULTEM 9085. Each heat sink was filled with gallium for testing purposes. Models were created to simulate the behavior of the heat transfer and phase change processes occurring within the heat sink. Additionally, laboratory data was …

A Systematic Approach To High Blood Pressure Risk Analysis And Healthcare Cost Reduction In Young Adults [Metodología Sistemática Para El Análisis De Riesgo Y Reducción De Costos De Servicios Médicos De Hipertensión En Adultos Jóvenes], Francisco Rafael Torres Diaz

Theses and Dissertations

The purpose of this research is to utilize publicly available data to estimate the current rate of occurrence of undiagnosed High Blood Pressure (HBP) in young adults (18 to 24 years old) and the out-of-pocket healthcare expenses associated with complications of HBP, to provide feasible alternatives to mitigate the effects on a region's economy. This has been done by building a Risk Factor Simulation Model that utilizes known HBP risk factors’ correlation to HBP, insurance coverage data, and rate of diagnosis to formulate the average Risk Factor Value for a region, which through an Annual Expected Cost Function estimates the …

An Analytical Model Of Material Deformation In Rotary Friction Welding Of Thin-Walled Tubes, Caleb James Brown

Theses and Dissertations

A new model of the material flow in rotary friction welding of tubes is proposed. The material flow proposed is based on 3D scans of welds performed with tungsten tracers. The tracers indicate a bifurcation of flow into two deformation paths. A different analysis is performed on each path.The material in Path 1 interacts with the weld interface and exhibits large amounts of azimuthal flow. Previous analytical investigations that have analytically modelled the weld interface as a non-Newtonian fluid are used to calculate the strain rate in this zone.The material in Path 2 transitions from axial to primarily radial flow. …

Engineering Cell-Free Biosystems For On-Site Production And Rapid Design Of Next-Generation Therapeutics, Kristen Michelle Wilding

Theses and Dissertations

While protein therapeutics are indispensable in the treatment of a variety of diseases, including cancer, rheumatoid arthritis, and diabetes, key limitations including short half-lives, high immunogenicity, protein instability, and centralized production complicate long-term use and on-demand production. Site-specific polymer conjugation provides a method for mitigating these challenges while minimizing negative impacts on protein activity. However, the location-dependent effects of polymer conjugation are not well understood. Cell-free protein synthesis provides direct access to the synthesis environment and rapid synthesis times, enabling rapid evaluation of multiple conjugation sites on a target protein. Here, work is presented towards developing cell-free protein synthesis as …

Conceptual Design Of A Pilot-Scale Pressurized Coal-Feed System, Taylor L. Schroedter

Theses and Dissertations

This thesis discusses the results and insights gained from developing a CFD model of a pilot-scale pressurized dry coal-feed system using the Barracuda CFD software and modeling various design concepts and operating conditions. The feed system was required to transport approximately 0.00378 kg/s (30 lb/hr) of pulverized coal from a vertical hopper to a 2.07 MPa (20.4 atm or 300 psi) reactor with a CO2-to-coal mass flow ratio of 1-2. Two feed system concepts were developed and tested for coal mass flow, CO2-to-coal mass ratio, steadiness, and uniformity. Piping system components also were evaluated for pressure drop and coal roping.With …

Large-Scale Testing Of Low-Strength Cellular Concrete For Skewed Bridge Abutments, Rebecca Eileen Black

Theses and Dissertations

Low-strength cellular concrete is a type of controlled low-strength material (CLSM) which is increasingly being used for various modern construction applications. Benefits of the material include its ease of placement due to the ability of cellular concrete to self-level and self-compact. It is also extremely lightweight compared to traditional concrete, enabling the concrete to be used in fill applications as a compacted soil would customarily be used. Testing of this material is not extensive, especially in the form of large-scale tests. Additionally, effects of skew on passive force resistance help to understand performance of a material when it is used …

Repopulation And Stimulation Of Porcine Cardiac Extracellular Matrix To Create Engineered Heart Patches, Silvia Juliana Moncada Diaz

Theses and Dissertations

Heart failure is the main cause of death for both men and women in the United States. The only proven treatment for patients with heart failure is heart transplantation. The goal of this research is to create patches of tissue that could mimic the function of the native heart to repair the damaged portions of the heart. In this study, whole porcine hearts were decellularized to create a 3D construct that was recellularized with cardiomyocytes (CM) differentiated from human induced pluripotent stem (IPS) cells. At day 4 of differentiation, IPS-derived CMs were implanted onto cardiac extracellular matrix (cECM) and ten …

Characterization Of Pyrolysis Products From Fast Pyrolysis Of Live And Dead Vegetation, Mohammad Saeed Safdari

Theses and Dissertations

Wildland fire, which includes both planned (prescribed fire) and unplanned (wildfire) fires, is an important component of many ecosystems. Prescribed burning (controlled burning) is used as an effective tool in managing a variety of ecosystems in the United States to reduce accumulation of hazardous fuels, manage wildlife habitats, mimic natural fire occurrence, manage traditional native foods, and provide other ecological and societal benefits. During wildland fires, both live and dead (biomass) plants undergo a two-step thermal degradation process (pyrolysis and combustion) when exposed to high temperatures. Pyrolysis is the thermal decomposition of organic material, which does not require the presence …

Relationship Between Compressive Strength Of Different Shape And Thickness Specimens Of Type S Mortar, Theodore James Moffett

Theses and Dissertations

Mortar is the cementitious binding material placed between masonry blocks to create a composite system. The American Society of Testing and Materials (ASTM), along with other organizations, have established the testing of prismatic mortar specimens for evaluating mechanical properties, like compressive strength. Mortar joints, however, possess vastly different characteristics compared to prismatic specimens, especially in terms of geometry and water content. These differences prevent a direct comparison of compressive strength between prismatic specimens and actual mortar joints in the assembly. The objective of this study was to analyze Type S mortar joints, with particular emphasis on specimen shape and water …