Engineering Commons^™

Thermodynamic Modeling Of Hydrogen–Water Systems With Gas Impurity At Various Conditions Using Cubic And Pc-Saft Equations Of State, Amer Alanazi, Saleh Bawazeer, Muhammad Ali, Alireza Keshavarz, Hussein Hoteit

Research outputs 2022 to 2026

Hydrogen (H2) has emerged as a viable solution for energy storage of renewable sources, supplying off-seasonal demand. Hydrogen contamination due to undesired mixing with other fluids during operations is a significant problem. Water contamination is a regular occurrence; therefore, an accurate prediction of H2-water thermodynamics is crucial for the design of efficient storage and water removal processes. In thermodynamic modeling, the Peng–Robinson (PR) and Soave Redlich–Kwong (SRK) equations of state (EoSs) are widely applied. However, both EoSs fail to predict the vapor-liquid equilibrium (VLE) accurately for H2-blend mixtures with or without fine-tuning binary interaction parameters due to the polarity of …

The Effects Of Host-Like Environmental Signals And Gene Expression On Capsule Growth In Cryptococcus Neoformans, Yu Min Jung

McKelvey School of Engineering Graduate Student Theses & Dissertations

Cryptococcus neoformans is a fungal pathogen that causes cryptococcosis, a disease that kills almost 200,000 people worldwide each year. A unique feature of this deadly yeast is its polysaccharide capsule, which is known to be associated with its virulence. Here, we systematically explore the effects of all possible combinations of 4 capsule-inducing signals on gene expression, cell size, and capsule size. These signals are medium (YPD, DMEM or RPMI), temperature (30°C or 37°C), CO₂ (room air or 5%), cAMP (0 mM or 20 mM), and pH buffer (HEPES/no HEPES). We explore the effects of exogenous cAMP at a range …

A 3d Tissue Engineering Model To Study Mitral Valve Annulus Calcification Under Diabetic Conditions, Erin James

All Theses

The most complex heart valve is the mitral valve (MV). Many pathologies can affect the MV, including stenosis, regurgitation, prolapse, and mitral annulus calcification (MAC). MAC is chronic degeneration of the annulus, which is the fibrous, saddle-shaped “ring” that can contract and relax with the myocardium. The prevalence of MAC is around 15% but increases in patients with other cardiovascular diseases and risk factors. It is also thought to increase in patients with type 2 diabetes, but MAC has not been properly characterized within this population because of confounding factors such as cardiac disease and kidney disease. The goal of …

Soft Robotic Arms For Fall Mitigation: Design, Control And Evaluation, Param Malhotra

All Theses

Most fall mitigation devices present a heavy system that avoid injuries to the user by preventing the impact of a fall. They are dependent on the user capability or on the probability that the user falls in the assumed manner the system was designed for. Often that is not the case, hence this project initiates a novel concept of using soft robotic arms to prevent falls from happening in the first place itself and save the user from any injuries. This thesis describes the prototype and development of a soft continuum robotic backpack system. The system can validate its use …

An Evaluation Of Energy Consumption Comparing Conventional Water Treatment Plants To Microfiltration And Ultrafiltration Water Treatment Plants, Danielle Larsen

All Theses

The use of low-pressure, hollow fiber microfiltration (MF) and ultrafiltration (UF) membranes has become increasingly prominent in drinking water treatment plant configurations over the past 30 years. At the same time, the topics of energy efficiency and sustainability in industry are becoming progressively more important. Although MF and UF are highly successful in filtration, they are generally thought of as significant energy consumers; however, the data have not yet been available to compare multiple plants in various contexts to determine the factors that most affect energy use. This research compares the energy use of MF and UF treatment plants to …

Rapidly Deployable Structures For Disaster Relief And Military Use, Jayson Leonard

All Theses

Rapidly deployable structures currently play a vital role in the recovery aspect of disaster-stricken areas and the safety of military personnel in hostile zones. More recently there has also been a need for the structures to deal with unforeseen disruptions caused by the COVID pandemic, such as COVID testing centers or backyard pop-up offices. These structures could be used in different environments and serve many other purposes. Along with the structural performance of these shelters, they need to integrate into systems set in place effortlessly. For that reason, four key factors were taken into consideration, namely (1) deployability (how difficult …

Development Of A New Affinity Membrane For Rapidly Purifying Non-Antibody Proteins, Friendship Edioma

All Theses

This thesis project describes the modification and evaluation of a new affinity membrane for rapid chromatographic purification of non-antibody proteins. The affinity membrane utilizes Im7/CL7 coupling technology developed by Dr. Vassylyev's lab at the University of Alabama Birmingham (UAB), licensed by TriAltus Bioscience. The behavior of the membrane was evaluated using purified CL7-tagged Cas9 as my model protein for static and dynamic binding capacity analysis.

Chapter one provides an overview on biopharmaceutical drug production process development. I discuss how protein drugs are produced, isolated, and purified from the cell supernatant after upstream phases are completed. Despite increasing demands for biologics, …

Deep Learning Based Localization Of Zigbee Interference Sources Using Channel State Information, Dylan Kensler

All Theses

As the field of Internet of Things (IoT) continues to grow, a variety of wireless signals fill the ambient wireless environment. These signals are used for communication, however, recently wireless sensing has been studied, in which these signals can be used to gather information about the surrounding space. With the development of 802.11n, a newer standard of WiFi, more complex information is available about the environment a signal propagates through. This information called Channel State Information (CSI) can be used in wireless sensing. With the help of Deep Learning, this work attempts to generate a fingerprinting technique for localizing a …

The Evacuation Simulation Of Wheelchair Users In A Building Fire: An Initial Dynamic Characterization Of Structural Egress Components, Haley Hostetter

All Theses

People with disabilities are one of the most vulnerable groups involved in building fires. According to the U.S. Fire Administration, in the United States alone, an estimated 700 home fires involve people with physical disabilities each year while over 1700 involve those with mental health disorders. Despite this, the current body of literature shows few studies focused on the evacuation of disabled people. This is a direct result of past and present social injustice on people with disabilities and has resulted in high injury and death rates during fires. To combat this, enrich the literature, and improve their experiences in …

Creep Behavior Of A Ti-Based Multi-Principal Element Alloy, Benjamin Elbrecht

All Theses

Abstract

The understanding of microstructural damage mechanisms is the foundation of better understanding existing materials and future material development. There are significant challenges to measuring these damage mechanisms in-situ as continuous observation of the state of the microstructure is difficult or impossible for many experimental setups. This thesis presents a method for measuring grain boundary sliding (GBS) and local strain concentrations in-situ via a Heaviside function based algorithm. GBS is the shearing of two grains along their shared grain boundary and is a common damage mechanism in creep which presents as a discontinuity that can be measured with a Heaviside …

Characterization Of Thermal Gelation Properties In Bioresorbable Thermally Activated Hydrogel Polymers For Hernia Surgery Applications, Alexander Mayfield

All Theses

Hydrogel adhesives are a new class of materials with excellent biocompatibility, which makes them very attractive for biomaterial applications. It has been previously shown that Tetronic T1107, a four-arm poly (propylene oxide)-poly (ethylene oxide) (PPO-PEO) block copolymer, is useful as a chemical crosslinking thermo-responsive hydrogel for bioadhesive applications. The end groups of this polymer are modified with acrylate and N-hydroxysuccinimide (NHS) functional groups. The acrylate end group gives the polymer cohesive properties with long-range chemical crosslinking using dithiothreitol (DTT), while the NHS end group gives the polymer adhesive properties through bonding with amines found in organic tissue. It was found …

Park Equity Modeling: A Case Study Of Asheville, North Carolina, Anisa Young

All Theses

Parks and greenspaces are publicly available entities that serve the vital purpose of promoting multiple aspects of human welfare. Unfortunately, the existence of park disparities is commonplace within the park setting. Specifically, marginalized individuals encounter limited park access, insufficient amenity provision, and poor maintenance. To remedy these disparities, we propose a process in which we select candidate park facilities and utilize facility location models to determine the optimal primary parks from both existing and candidate sites.

We note that platforms currently exist to identify the geographical areas where residents lack sufficient access to parks. However, these platforms do not yet …

The Physical Properties And Handling Characteristics Of Pelletized Biomass Materials, Ryan Dean

All Theses

Biomass and feed pellets can be handled and stored using similar equipment used for other bulk materials; however, their unique physical characteristics can lead to handling challenges. Understanding the flow characteristics of these materials is essential for handling and storage system design, but these characteristics are not well defined in less-than-ideal conditions. The overall objective of this study was to evaluate how moisture content and level of fines influence the angle of repose (AoR) of hardwood, pine bedding, and feed pellets along with determining the impacts of displacement on the shear stress of fuel pellets utilizing a modified linear wall …

Multi-Technique Characterization Of Superconducting Materials For Particle Accelerator Applications, Junki Makita

Physics Theses & Dissertations

We investigated the performance limitations of superconducting radio-frequency (SRF) cavities and materials using multiple experimental techniques. In particular, this study focuses on understanding the surface properties of nitrogen-doped Nb cavities and superconducting thin films with higher T_c such as Nb₃Sn. The main goal of this work is to use different techniques to better understand each aspect of the complex loss mechanism in superconductors to further improve the already highly efficient SRF cavities.

Nitrogen doping applied to a Nb SRF cavity significantly improves the quality factor Q₀ compared to a conventional Nb cavity, at an expense of …

Design, Synthesis And Characterization Of Triazole Based Glycoconjugates And 4,6-Acetal Protected D-Glucosamine Derivatives As Low Molecular Weight Gelators, Pooja Sharma

Chemistry & Biochemistry Theses & Dissertations

Low molecular weight gelators (LMWGs) are small molecules that can form gels in either organic solvents or water in their pure form or as mixtures. LMWGs self-assemble through noncovalent interactions such as hydrogen bonding, halogen bonding, van der Waals interactions and hydrophobic forces in solvents. They have shown great potential in biomedical industry, catalysis and environmental remediation to name a few. Moreover, the formation of metallogels can be used for detection of various ions as well as catalysis, which adds a new dimension to their applications. Among many classes of LMWGs based on the type of functional groups used, carbohydrate …

Quantification Of Wave Attentuation Of A Marsh Sill Living Shoreline And Application Of Numerical Modeling For Design Optimization And Adaptation, Maura K. Boswell

Civil & Environmental Engineering Theses & Dissertations

Living shorelines integrate structural and natural features to stabilize the shoreline, through reduction of erosion from the wave climate, while keeping the connectivity between land and aquatic ecosystems. With increasing sea levels, living shorelines have the potential to adapt to changing conditions when compared to armored shorelines due to maintaining a level of interconnectivity between land and water. However, to reduce the ecological tradeoffs associated with any type of shoreline erosion protection project that alters the natural state, the design should seek to minimize structural components to those necessary to provide the protection needed for upland habitat to survive erosive …

Applied Deep Learning: Case Studies In Computer Vision And Natural Language Processing, Md Reshad Ul Hoque

Electrical & Computer Engineering Theses & Dissertations

Deep learning has proved to be successful for many computer vision and natural language processing applications. In this dissertation, three studies have been conducted to show the efficacy of deep learning models for computer vision and natural language processing. In the first study, an efficient deep learning model was proposed for seagrass scar detection in multispectral images which produced robust, accurate scars mappings. In the second study, an arithmetic deep learning model was developed to fuse multi-spectral images collected at different times with different resolutions to generate high-resolution images for downstream tasks including change detection, object detection, and land cover …

Development Of High Quantum Efficiency Strained Superlattice Spin Polarized Photocathodes Via Metal Organic Chemical Vapor Deposition, Benjamin Belfore

Electrical & Computer Engineering Theses & Dissertations

Spin polarized photocathodes are necessary to examine parity violations and other fundamental phenomena in the field of high energy physics. To create these devices, expensive and complicated growth processes are necessary. While integral to accelerator physics, spin polarized electrons could have other exciting applications in materials science and other fields of physics. In order to explore these other applications feasibly, the relative supply of spin polarized photocathodes with a high rate of both polarization and photoemission needs to be increased. One such way to increase this supply is to develop the means to grow them faster and at a larger …

Adaptive Risk Network Dependency Analysis Of Complex Hierarchical Systems, Katherine L. Smith

Computational Modeling & Simulation Engineering Theses & Dissertations

Recently the number, variety, and complexity of interconnected systems have been increasing while the resources available to increase resilience of those systems have been decreasing. Therefore, it has become increasingly important to quantify the effects of risks and the resulting disruptions over time as they ripple through networks of systems. This dissertation presents a novel modeling and simulation methodology which quantifies resilience, as impact on performance over time, and risk, as the impact of probabilistic disruptions. This work includes four major contributions over the state-of-the-art which are: (1) cyclic dependencies are captured by separation of performance variables into layers which …

Predictors Of Email Response: Determinants Of The Intention Of Not Following Security Recommendations, Miguel Angel Toro-Jarrin

Engineering Management & Systems Engineering Theses & Dissertations

Organizations and government leaders are concerned about cyber incidents. For some time, researchers have studied what motivates people to act in ways that put the confidentiality, integrity, and availability of information in organizations at risk. Still, several areas remained unexplored, including the role of employees’ evaluation of the organizational systems and the role of value orientation at work as precursors of secure and insecure actions in relation to information technologies (information security [IS] action). The objective of this research project was to examine how the evaluations of formal and informal security norms are associated with the intention to follow them …

Collaborative Robotics Strategies For Handling Non-Repetitive Micro-Drilling Tasks Characterized By Low Structural Mechanical Impedance, Xiangyu Wang

Mechanical & Aerospace Engineering Theses & Dissertations

Mechanical micro-drilling finds widespread use in diverse applications ranging from advanced manufacturing to medical surgery. This dissertation aims to develop techniques that allow programming of robots to perform effective micro-drilling tasks. Accomplishing this goal is faced with several challenges. Micro-drills suffer from frequent breakage caused from variations in drill process parameters. Micro-drilling tasks afford extremely low feed rates and almost zero tolerance for any feed rate variations. The accompanying robot programming task is made difficult as mathematical models that capture the micro-drilling process complexities and sensitive variations in micro-drill parameters are highly difficult to obtain. Therefore, an experimental approach is …

Studies Of Multiphase Distribution And Flow In Bubble/ Slurry Bubble Columns With /Without Internals And Advanced Sustainable Construction Materials Using Sophisticated Measurement Techniques, Omar Farid

Doctoral Dissertations

"Bubble/slurry bubble columns have been widely studied and employed as multiphase flow reactors with and without vertical heat-exchanging tubes. In order to understand more deeply the effect of the dense internals on the hydrodynamics of bubble/slurry bubble column, systematic experiments were performed to visualize and quantify using the radioactive particle tracking (RPT) technique. A new methodology for implementing the radioactive particle tracking (RPT) technique has been developed to investigate the effect of the dense internals on the hydrodynamics of the bubble/slurry column reactor. Monte Carlo N-Particle (MCNP) simulation has been implemented to simulate the system to generate a large number …

The Effect Of Soft Tissue And Bone Morphology On The Stresses In The Foot And Ankle, Jinhyuk Kim

Mechanical & Aerospace Engineering Theses & Dissertations

The foot and ankle interface with the ground, thus they absorb reaction forces and initiate load distribution through the body. The plantar fascia (PF) is a flexible structure that absorbs reaction forces and distributes loading across the foot. It is frequently a source of foot pain especially when people have plantar fasciitis and/or diabetes mellitus. Finite element (FE) models of the foot and ankle were created to examine the function however, the plantar fascia is frequently modeled as a 1D tension only spring, which does not represent variations caused by injury and/or disease.

As models move toward being patient specific, …

Evaluation Of Generative Models For Predicting Microstructure Geometries In Laser Powder Bed Fusion Additive Manufacturing, Andy Ramlatchan

Computer Science Theses & Dissertations

In-situ process monitoring for metals additive manufacturing is paramount to the successful build of an object for application in extreme or high stress environments. In selective laser melting additive manufacturing, the process by which a laser melts metal powder during the build will dictate the internal microstructure of that object once the metal cools and solidifies. The difficulty lies in that obtaining enough variety of data to quantify the internal microstructures for the evaluation of its physical properties is problematic, as the laser passes at high speeds over powder grains at a micrometer scale. Imaging the process in-situ is complex …

Utilization Of Finite Element Analysis Techniques For Adolescent Idiopathic Scoliosis Surgical Planning, Michael A. Polanco

Mechanical & Aerospace Engineering Theses & Dissertations

Adolescent Idiopathic Scoliosis, a three-dimensional deformity of the thoracolumbar spine, affects approximately 1-3% of patients ages 10-18. Surgical correction and treatment of the spinal column is a costly and high-risk task that is consistently complicated by factors such as patient-specific spinal deformities, curve flexibility, and surgeon experience. The following dissertation utilizes finite element analysis to develop a cost-effective, building-block approach by which surgical procedures and kinematic evaluations may be investigated. All studies conducted are based off a volumetric, thoracolumbar finite element (FE) model developed from computer-aided design (CAD) anatomy whose components are kinematically validated with in-vitro data. Spinal ligament stiffness …

Recrystallization Of Cu(In,Ga)Se2 Semiconductor Thin Films Via Metal Halides Treatment, Deewakar Poudel

Electrical & Computer Engineering Theses & Dissertations

The advancement of low-cost, highly efficient solar cell devices is a major technological challenge demanding suitable materials and fabrication processes. Polycrystalline Cu(In,Ga)Se_{2 (}CIGS) appear to be one of the most promising semiconductor in thin film photovoltaic technology due to its bandgap tunability, high absorption coefficient, and tendency to produce high efficiency solar cells. High-quality CIGS materials fabricated via a three-stage co-evaporation process can convert primary materials into devices with power conversion efficiency above 23%. Increasing the deposition rate and decreasing the deposition temperature, while maintaining high efficiency, is the major concern for the CIGS solar cells to compete …

A Quality Systems Economic-Risk Design Theoretical Framework, Abdallah S. Thefeid

Engineering Management & Systems Engineering Theses & Dissertations

Quality systems, including control charts theory and sampling plans, have become essential tools to develop business processes. Since 1928, research has been conducted in developing the economic-risk designs for specific types of control charts or sampling plans. However, there has been no theoretical or applied research attempts to combine these related theories into a synthesized theoretical framework of quality systems economic-risk design. This research proposes to develop a theoretical framework of quality systems economic-risk design from qualitative research synthesis of the economic-risk design of sampling plan models and control charts models. This theoretical framework will be useful in guiding future …

Fabrication Of Nb3Sn By Magnetron Sputtering For Superconducting Radiofrequency Application, Md Nizam Sayeed

Electrical & Computer Engineering Theses & Dissertations

Particle accelerators are considered as an important device that has wide applications in cancer treatment, sterilizing waste, preserving foods, ion implantation in semiconductor industry, and in production of isotopes for medical applications. Superconducting radiofrequency (SRF) cavities are the building blocks of a linear particle accelerator. Current particle accelerators use niobium (Nb) superconductors as the sheet material to fabricate a single SRF cavity for particle acceleration. With better superconducting properties (critical temperature T_c ~ 18.3 K, superheating field H_sh~ 400 mT), Nb₃Sn is considered a potential candidate in SRF technology. Magnetron sputtering is a promising deposition …

A Comparison Of Uniaxial Compressive Response And Inelastic Deformation Mechanisms In Freeze Cast Alumina-Epoxy Composites Without And With Rigid Confinement, Tareq Aljuhari

Mechanical & Aerospace Engineering Theses & Dissertations

Cellular ceramics have an array of improved mechanical properties that make them incredibly desired for different applications such as armor systems, aircraft structures, automobiles bumpers, and biomedical implants. It is also desirable that porous architecture could be shaped into bulk complicated shapes and easy to scale-up with low manufacturing cost. Despite several efficient techniques to fabricate cellular ceramics, some limitations are preventing us from meeting the high demand of the after mentioned applications. For that, freeze casting, also called ice-templating, is technique of solidifying an aqueous ceramic suspension under the effect of unidirectional temperature gradient. In this study, Ice-templated porous …

Engineering Of Ideal Systems For The Study And Direction Of Stem Cell Asymmetrical Division And Fate Determination, Martina Zamponi

Biomedical Engineering Theses & Dissertations

The cellular microenvironment varies significantly across tissues, and it is constituted by both resident cells and the macromolecules they are exposed to. Cues that the cells receive from the microenvironment, as well as the signaling transmitted to it, affect their physiology and behavior. This notion is valid in the context of stem cells, which are susceptible to biochemical and biomechanical signaling exchanged with the microenvironment, and which plays a fundamental role in establishing fate determination and cell differentiation events. The definition of the molecular mechanisms that drive stem cell asymmetrical division, and how these are modulated by microenvironmental signaling, is …