Engineering Commons^™

Effect Of Ported Shroud Casing Treatment Modifications On Operational Range And Limits In A Centrifugal Compressor, Alexander A. Newell

Theses and Dissertations

The implementation of a ported shroud casing treatment is often used to extend the operating range of a centrifugal compressor. This work utilizes the STAR-CCM+ CFD package to analyze steady-state, single-passage simulations of a centrifugal compressor with and without a ported shroud to better understand how a ported shroud affects compressor flow physics. Verification and validation of simulations were conducted by comparison of results with a time-accurate full-annulus simulation and experimental data. Four different ported shroud revisions were considered and modeled along the full range of their stable operation, with emphasis placed on the flow limits of choke and stall. …

Micromechanisms Of Near-Yield Deformation In Bcc Tantalum, Joshua Jr-Syan Tsai

Theses and Dissertations

New materials, optimized for increased strength, ductility, and other desirable properties, have the potential to improve every aspect of modern living. To achieve these optimums, the necessary technological advancements are impeded mainly by the limits of available material models. Innovations in this field rely on research into the nature of material behavior. While a typical model of material behavior in the region near yield involves the initial linear elastic response, followed by yield and isotropic hardening, this fails to explain various important phenomena that manifest in a range of materials, such as pre-yield nonlinearity, anelasticity, yield point phenomena, hardening stagnation, …

Characterizing Bacterial Resistance And Microstructure-Related Properties Of Carbon-Infiltrated Carbon Nanotube Surface Coatings With Applications In Medical Devices, Stephanie Renee Morco

Theses and Dissertations

Carbon-infiltrated carbon nanotube (CICNT) forests are carbon nanotube (CNT) forests infiltrated with pyrolytic carbon to increase durability by becoming a solid material. This material can be tuned to maintain the nanotube geometry of a CNT forest and can also be fabricated on a variety of materials and geometries. Additionally, the present work has indicated that CICNT forests may resist bacterial proliferation and biofilm formation. This phenomenon is not due to the CICNT chemistry; it is presumably due to the CICNT nanostructure morphology. Thus, both silicon and stainless steel substrates were used to investigate CICNT's structural resistance to Methicillin-resistant Staphylococcus aureus …

Deploying And Analyzing Air Quality Sensors In Mongolian Gers, Lehi Sttenio Alcantara

Theses and Dissertations

The purpose of this research is to develop best practices for deploying air quality sensors in a remote location such as Mongolia. I discussed the architecture and design constraints when collecting remote air quality sensors data, the challenges that emerge while implementing a sensor-based network in a remote location such as Mongolia. The tradeoffs of using different architectures are described. I observed the usage of electrical heaters in modified gers in remote locations and conclude how effective they are in reducing PM2.5 levels by analyzing air quality data and go through the process of cleaning up the data and removing …

Introducing The Water Data Explorer Web Application And Python Library: Uniform Means For Data Discovery And Access From Cuahsi And The Wmo Whos Systems, Elkin Giovanni Romero Bustamante

Theses and Dissertations

There has been a growing recognition in recent years of the need for a standardized means for sharing water data on the web. One response to this need was the development of the Consortium of Universities for the Advancement of Hydrologic Science (CUAHSI) Hydrologic Information System (HIS) and its accompanying WaterOneFlow and WaterML protocols. To date, the primary means for accessing data shared using these protocols has been limited to the Microsoft Windows HydroDesktop software, the WaterML R package, and the web based CUAHSI HydroClient which serves as an access point to the CUAHSI HIS database. We recognized the need …

Geoglows Hydroviewer: Open Software-As-A-Service For Localizing Global Hydrologic Forecasts Of The Group On Earth Observations Global Water Sustainability Initiative, Kyler Ralph Ashby

Theses and Dissertations

Earth observation data is increasingly ubiquitous, easily accessible, freely available, and generally usable due to improvements in software, data standards, network infrastructure, and national policies. As a result, greater opportunities arise for using these data in a wider field of application including decision support for local and regional environmental and water resources management efforts. In parts of the world where in situ data are less readily available, global Earth observation data used in such decision support tools can be a boon to underfunded government and private water management agencies. The United Nations Group on Earth Observations Global Water Sustainability initiative …

Effects Of Carbon-Infiltrated Carbon Nanotube Growth On The Biocompatibility Of 316l Stainless Steel, Sterling Charles Voss

Theses and Dissertations

The purpose of this research is to identify the effects of the carbon-infiltrated carbon nanotube (CICNT) growth process on the material properties of 316L stainless steel, particularly those properties which are essential for biocompatibility. Physically altering the micro-topography of a surface can dramatically affect its capacity to support or prevent biofilm growth. Growing CICNTs on biomedical materials is one approach which has demonstrated success at preventing biofilm growth. Unfortunately, the high temperature and carbon-rich gas exposure required for this procedure has proven to have deleterious effects. Rusting has been observed on samples that have been coated with CICNTs and then …

A Review Of Fitness Tracker Game Elements And A Novel Game Approach For The Design Space, Aatish Neupane

Theses and Dissertations

Physical activities like walking have proven health benefits. People are adopting fitness trackers to track physical activity, but they often stop using them after a relatively short time. Many apps and games exist in the app markets that use gamification to tackle this problem of motivation. In this thesis, we examined these existing gamified fitness tracker apps from app markets and looked at the usage of different game elements within these apps. We conducted a systematic review of existing fitness Tracker Apps from Google Play Store and Apple App Store and used a mixed-method approach to identify apps, categorize them …

Shtëpit E Mençura, Teknologjia, Implementimi Dhe Zgjerimi I Saj Sot, Blendi Robaj

Theses and Dissertations

Sistemet e shtëpive të mençura arritën popullaritet të madh në dekadat e fundit ashtu si edhe ato rrisin komoditetin dhe cilësinë e jetës. Shumica e sistemeve të shtëpive të mençura kontrollohen nga smartphone dhe mikrokontrollues. Një aplikacion smartphone përdoret për të kontrolluar dhe monitoroni funksionet e shtëpisë duke përdorur teknikat e komunikimit pa kabllo. Në këtë punim përmes metodës së analizës do ta trajtojmë në mënyrë me specifike rendësin e shtëpive të mençura (smart home).

Shtëpia e zgjuar është zgjerimi rezidencial i automatizimit të ndërtesës dhe përfshin kontrollin dhe automatizimin e të gjithë teknologjisë së saj të ngulitur. Ajo përcakton …

Dobesite Ne Infrastruktuen E Web-It, Alba Kelmendi

Theses and Dissertations

Siguria në aplikacionet e bazuara në UEB është shume komplekse dhe esenciale. Në këtë punim ne do të shtjellojmë aplikimin e sigurisë gjatë përdorimit të infrastrukturës të internetit. Meqë gjithmonë gjatë përdorimit të kompjuterëve jemi të lidhur me internet ky bëhet shkas që të bëhemi target kryesor i sulmeve të ndryshme. Në pjesën e parë të projektit i kemi shtjelluar sulmet që ndodhin në UEB-server (DoS, MITM, Injektimet SQL.). Në pjesën e dytë kemi dhëne instruksione praktike se si bëhet depërtimi jo-legjitim i UEB-aplikacioneve përmes sulmeve të ndryshme. Në pjesën e fundit kemi specifikuar hakimin e koncepteve të ndryshme të …

E-Ditari, Enis Halimi

Theses and Dissertations

Pasi bota u godit nga një pandemi e cila bëri që të mbyllen shkollat, mësimi nëpër shkolla u vendos të vijonte online. Kjo bëri që shumë gjëra tradicionale të shkollave si ditarët e shumë gjëra tjera të mos përdoren më. Synimi i këtij punimi është zhvillimi i një ditari elektronik ose E-Ditari. E-Ditari është një web aplikacion i cili bën zgjidhjen e këtyre problemeve duke zëvendësuar ditarët e shkollave të ndryshme. Programi ndahet në dy pjesë, atë të nxënësit/prindërit si dhe mësimdhënësit/stafit të shkollës. Qasjen në program mund të bëhet përmes internetit duke përdorur shfletuesit si dhe qasje do të …

Anisotropic Wave Behavior In Isotropic Material With Orthogonal Surface Perturbation, Khaleda Akter

Theses and Dissertations

Elastic wave propagation in anisotropic media is of great interest in various branches of engineering and applied sciences. In this study, an anisotropic wave propagation behavior in isotropic material with orthogonal surface perturbation is presented. The conventional method of estimating dispersion equations for isotropic material is to apply Helmholtz decomposition on the potential functions for Rayleigh-Lamb wave and Shear Horizontal (SH) waves. However, the presence of isotropic material with orthogonal surface perturbations in two coordinate directions significantly affect the wave propagation behavior due to its direction dependency, and hence, the Helmholtz decomposition of the potential functions cannot be applied to …

Sonodegradation Of Amitriptyline And Ibuprofen In The Presence Of Mxene, Minjung Jeon

Theses and Dissertations

Environmental pollution has intensified and accelerated due to a steady increase in the number of industries, and finding methods to remove hazardous contaminants, which can be typically divided into inorganic and organic compounds, have become inevitable. One of the widely used water treatment technologies is adsorption and various kinds of adsorbents for the removal of inorganic and organic contaminants from water have been discovered. Recently, MXene, as an emerging nanomaterial, has gained rapid attention owing to its unique characteristics and various applicability. Particularly, in the area of adsorptive application, MXene and MXene-based adsorbents have shown great potential in a large …

Preferential Vaporization Potential Of Crude Oils And Its Impact On Flame Flashback Behaviors, Ayuob Al Wahaibi

Theses and Dissertations

As combined cycle gas turbines for power generation operating on light distillate fuels provide a sufficient energy, there is a global trend in using heavy liquids (e.g. HFO, crude oils) for direct-firing in gas turbine. However, using these heavy fuels imposes many challenges due to their wide range of physical/chemical properties, which control near-limit combustion behaviors, such lean blow-out and flashback. In addition, the ignition propensity of these heavy fuels is not reported in crude assays, and utilizing a simple, with small sample, and quick methodology to characterize the ignition propensity is important in determining the fuel quality.

In this …

Polymer Microparticles For Encapsulation And Presentation Of Anti-Inflammatory Agents For Inflammatory Diseases, Christopher Isely

Theses and Dissertations

Inflammatory diseases have a huge economic impact on the healthcare system. Incidence of obesity and muscle atrophy, two high profile inflammatory diseases, continues to increase. Anti-inflammatory agents are potential therapeutics for these diseases. Resveratrol is a polyphenol that has anti-inflammatory effects; however, resveratrol suffers from low bioavailability and hasn’t had impressive clinical results when delivered orally. Mannose is a monosaccharide that also has anti-inflammatory effects, however, effects are highest when mannose is presented on the surface of a support the size of a bacteria. Incorporation of resveratrol and mannose into biodegradable polymer microparticles could be a feasible approach to overcome …

Defining The Pathophysiology Of Gut Humoral Immunodeficiency, Ahmed Dawood Mohammed

Theses and Dissertations

Mucosal antibodies maintain gut homeostasis by promoting spatial segregation between host tissues and luminal microbes. Antibody-deficiency is the most common form of primary immunodeficiency observed in humans. In antibody-deficient humans, abnormal composition of the gut microbiota ('dysbiosis') is associated with chronic inflammatory responses and gastrointestinal complications. However, the mechanisms by which dysbiosis promotes inflammatory disease are poorly defined. In the studies described in this dissertation, we utilize CD19-/- mice as a model of antibody deficiency to test the hypothesis that antibody deficiency negatively impacts gut physiology under steady-state conditions. Chapter #1 is an overview of B cell development and how …

Experimental Evaluation Of Drying Spent Nuclear Fuel For Dry Cask Storage Through Vacuum And Forced Helium Dehydration, Jonathan Ellis Perry

Theses and Dissertations

Currently approximately 80,000 tons of spent nuclear fuel (SNF) are in either dry or wet storage at nuclear power plants or designated spent fuel storage facilities. Over 2,000 tons are added to that sum each year. All SNF must be dried to an accepted Nuclear Regulatory Commission (NRC) drying criteria before being placed in dry storage. Inadequately drying SNF increases the risk of detrimental effects to the fuel while in dry storage. Two commonly used drying operations in the nuclear industry are vacuum drying and forced helium dehydration (FHD). Although these drying processes have been used for many years, there …

Age And Sex Dependency Of Thoracic Aortic Aneurysm Progression In A Mouse Model Of Marfan Syndrome, Nazli Gharraee

Theses and Dissertations

Aneurysm of the ascending aorta is the most common type of thoracic aortic aneurysm, and it is a life-threatening manifestation of Marfan syndrome (MFS), a connective tissue disorder caused by mutation of the FBN1 gene. Incidence of Marfan syndrome is similar for men and women; however, men suffer from more severe aortic events compared to women.

This study aims to provide a better understanding of age and sex dependency of cell and extracellular matrix alterations of the aortic wall during the progression of the aneurysm caused by Marfan syndrome. To achieve this goal, the C1041G/+ mouse model of Marfan syndrome …

Removal Of Heavy Metals Using Novel Adsorbent Materials, Lesley Joseph

Theses and Dissertations

Heavy metal contamination is a growing concern throughout the world, particularly as industrial and urban activities have increased. Inadequate water and wastewater treatment, coupled with increased industrial activity, have led to increased heavy metal contamination in rivers, lakes, and other water sources in developing countries. To address these concerns, a significant amount of research has been conducted on various novel adsorbents to evaluate their ability to remove heavy metals. Thus, in this study, MIL-100(Fe) and MIL-101(Cr) are fabricated and investigated to determine their ability to remove copper (Cu2+), cadmium (Cd2+), and lead (Pb2+) from aqueous solution. The experimental data fit …

Fate Of Nitrogen And Effectiveness Of Evaporation On Managing Leachate In Collection And Storage Ponds: A Case Study At The Three Rivers Solid Waste Authority Regional Landfill, Kaitlen Rose Drafts

Theses and Dissertations

Treatment of leachate from municipal solid waste (MSW) landfills can be complex and difficult, due to the variety of contaminants present. The purpose of this work was to evaluate the fate of nitrogen and effectiveness of leachate evaporation in a leachate storage and collection pond at the Three Rivers Solid Waste Authority (TRSWA) MSW landfill in Jackson, South Carolina. This was accomplished by determining the fate of nitrogen species in the pond, exploring effect of the site’s Lilypad droplet sprayer system on ammonia-nitrogen, and exploring potential to reduce overall quantity of leachate to be treated through evaporation from the pond. …

Deep Learning Based Sound Event Detection And Classification, Alireza Nasiri

Theses and Dissertations

Hearing sense has an important role in our daily lives. During the recent years, there has been many studies to transfer this capability to the computers. In this dissertation, we design and implement deep learning based algorithms to improve the ability of the computers in recognizing the different sound events.

In the first topic, we investigate sound event detection, which identifies the time boundaries of the sound events in addition to the type of the events. For sound event detection, we propose a new method, AudioMask, to benefit from the object-detection techniques in computer vision. In this method, we convert …

Removal Of Selected Organic Contaminants By Various (Nano) Adsorbent-Ultrafiltration Hybrid Systems, Sewoon Kim

Theses and Dissertations

Organic contaminants, which result from overuse and discharge of dyes, pharmaceutically active compounds, personal care products, and endocrine-disrupting compounds, have been received attention as contemporary water issues. However, conventional water and/or wastewater treatment system cannot sufficiently control for these contaminants for their stability and complexity. In this study, combined novel adsorbent with ultrafiltration (UF) hybrid system (termed ‘adsorbent-UF’) was applied to removal selected organic contaminants. UF with upstream adsorption has positive effects on performance in terms of the removal of selected organic contaminants, separating used adsorbents and reducing foulants. Activated biochar, metal organic frameworks, and Ti3C2TX MXene were used as …

Experimental Investigation Of Single And Two-Phase Heat Transfer Performance In Microchannels With Surface Modifications And Multiple Inlet Restrictors, Saad Kadham Oudah

Theses and Dissertations

Due to shrinking component sizes and faster switching speeds, the volumetric heat generation rates and surface heat flux in many advanced power electronic devices have increased exponentially, creating an urgent need for efficient cooling technologies. It has become particularly challenging to maintain an optimal temperature at the device level. Among advanced cooling techniques, single-phase and two-phase microchannel heat sinks show considerable promise in removing a significant amount of heat from a small surface area. Considered one of the most efficient heat dissipaters, the two-phase microchannel heat sink can handle very high heat flux at a small footprint and requires relatively …

Multimodal Robotic Health In Future Factories Through Iiot, Data Analytics, And Virtual Commissioning, Clint Saidy

Theses and Dissertations

The manufacturing sector is continuously reinventing itself by embracing opportunities offered by the industrial internet of things and big data, among other advances. Modern manufacturing platforms are defined by the quest for ever increasing automation along all aspects of the production cycle. Furthermore, in the next decades, research and industry are expected to develop a large variety of autonomous robots for a large variety of tasks and environments enabling future factories. This continuing pressure towards automation dictates that emergent technologies are leveraged in a manner that suits this purpose. These challenges can be addressed through the advanced methods such as …

Time-Domain Measurement Of Magnetization Dynamics In Ferrofluids, Brian Egenriether

Theses and Dissertations

Time-domain measurements are made on a magnetite-based (Fe3O4) ferrofluid using an inductive technique. The constituent particles are 5.8% by volume, polydisperse, and have a nominal diameter of 10nm with a ~1nm-thick anionic hydrophobic coating. The ferrofluid is placed in a sealed channel on a coplanar waveguide (CPW) situated in an adjustable external magnetic bias field. A fast-rising step current in the CPW quickly reorients the local magnetic field above the signal trace causing the particles’ moments to align in the new field configuration. This changing magnetization induces a voltage in the CPW that is detected by a sampling oscilloscope. Precessional …

Enhanced Flow Boiling And Bubble Dynamics With Hfe7100 & Di Water In Interconnected Microchannels, Jiaxuan Ma

Theses and Dissertations

Flow boiling in microchannels using dielectric fluids is one of the most desirable cooling solutions for high power electronics. Primary two-flow patterns, including bubbly flow, slug flow, and annular flow, have been well established in microchannels. However, it is challenging to promote flow boiling performance, particularly critical heat flux (CHF), due to their unfavorable thermophysical properties. Considering these situations, flow boiling in parallel and isolated microchannels have been extensively studied. In this dissertation, a novel concept that has five parallel microchannels (W=200 µm, H=250 µm, L=10 mm) are interconnected by micro-slots (20 µm wide and 250 µm deep) starting from …

Modeling Human-Structure Interaction Using Control System When Bouncing On Flexible Structure, Ahmed Tamween Baeewi Al-Zubaidi

Theses and Dissertations

High performance materials have enabled engineers to design civil structures with lower dead loads. However, lower dead loads result in a higher live-to-dead load ratio and the possibility of excessive vibrations due to human loading. Classical methods that have been used to study this human-structure interaction (HSI) model the person as a mass-spring-damper (MSD) system. While these models are often able to represent the dynamics of the system, the human body is a more complex, dynamic system. For example, MSD systems cannot add energy to the overall human-structure system; therefore, they do not allow for the incorporation of excitation that …

Vascular Endothelial Dysfunction And Effects On Arterial Wall Microstructure, Jeffrey Thomas Rodgers

Theses and Dissertations

Vascular endothelial cell dysfunction (ECD) is a disease characterized by the inability of the vascular endothelial cells to transmit signaling molecules, namely nitric oxide (NO), in response to changes in blood flow rate. This disease is shown to be incident in the onset of more severe vascular disease such as hypertension, atherosclerosis, and heart failure. Long-term ECD is shown to cause long-term remodeling such as decreased flow-mediated dilation, increased pulse-wave velocity, intimal-medial thickening, and increased wall stiffness due to collagen deposition. We used second harmonic generation (SHG) microscopy to analyze this change in the collagen microstructure of the arterial extracellular …

Real-Time Probabilistic Solvers For Digital Twins Of Power Electronic Systems, Matthew Aaron Milton

Theses and Dissertations

In recent years, switching power electronic systems for use in power conversion, generation, and distribution have become increasingly larger and complex in their design. With the increase in complexity comes the increase in difficulty in performing analysis, experiments, and health management on such systems in physical space. Part of this difficulty comes from challenge of access to and understanding of the internal interplay of the numerous components, safety and cost of system operation, and the inherent uncertainty of physical characteristics of systems and their environment.

A recent approach for testing and diagnostics/prognostics of power electronic systems is the application of …

Prediction Of Residual Stress And Distortion In Laser Powder Bed Fusion Additive Manufacturing, Bhanuprakash Sairam Kosaraju

Theses and Dissertations

Additive Manufacturing (AM) has its proven advantages to unlock the design space and manufacturing capabilities for complex geometries with lightweights. Distortion is one of the most common defects that occur in Laser Powder Bed Fusion Additive Manufacturing (LPBFAM), which is caused by the significant residual stress during the printing process. This can lead to numerous process iterations to achieve the requisite form and fit tolerances.

In this study, Finite Element (FE) model that utilizes the element birth approach was developed to predict the residual stress and distortion in the LPBFAM process. The methodology leverages a simplified approach where the detailed …