Engineering Commons^™

Sulfonated Ionomer Composite Membranes For Use In Vanadium Redox Flow Batteries, Xueting Wang

All Dissertations

While vanadium redox flow batteries (VRFBs) have garnered significant attention as a promising scalable energy storage technology, the current membrane material used in this technology, Nafion™, suffers from high cross mixing of vanadium ions in the liquid electrolytes, directly impacting battery performance properties such as the voltage and coulombic efficiencies, as well as resulting in a reduction in the overall battery lifetime. The use of ionomer nancomposites has proven to be one promising route of directly addressing the issue of high ion crossover, though the mechanism by which the nanoparticles act to reduce crossover remains in open question. Herein, the …

Study Of Electrospun Nanocomposite Nanofiber Nonwoven Mats With Precursor Solutions Prepared By Ultrasonic Processing, Stephanie Tussey

All Dissertations

Understanding the complexity of changes in a polymer solution through the addition of nanoparticles and the process used to prepare the solutions is vitally important to obtain desirable characteristics of electrospun nanofibers such as degree of crystallinity, morphological, thermal and mechanical properties. Although there have been significant efforts in this research area, a more in-depth understanding on how nanoparticles can affect the formation of polymeric structures during electrospinning is still needed to ensure overall quality and performance of the nonwoven material. The present study aimed to specifically explore the relationship between solution processing method, nanoparticle volume fraction, and solution properties …

Investigating Bimanual Haptic Exploration With Arm-Support Exoskeletons, Balagopal Raveendranath

All Dissertations

The ability to judge properties like weight and length of hand-held objects is essential in industrial work. Sometimes workers use devices like exoskeletons, which can augment their ability to lift and move heavy objects. Previous studies have investigated the perceptual information available for one-handed weight and length judgments. The current study investigated how blindfolded participants bimanually heft and wield objects to explore haptic information, to perceive object heaviness or length. The study also investigated the effects of using an arm-support exoskeleton (ASE) on the perceived weight of hand-held objects. We empirically tested whether people wield and manipulate objects differently, depending …

Toxicokinetics And Toxicodynamics Of Radium-226 In An Estuarine Sentinel Species Geukensia Demissa, Sarah Donaher

All Dissertations

The historical use of radioluminescent objects, most notably those containing radium-226 (²²⁶Ra)-based paint, has contributed to contemporary environmental contamination of radioactive material, often near naval installations or other military-associated coastal sites. The risk to both human and environmental health from this small-scale, discrete radioactive material is challenging to predict due to large uncertainties in the source terms, bioavailability, and toxicity of these objects. The objective of this study was to provide information on the accumulation and toxicity of acute ²²⁶Ra exposure in a sentinel species to improve risk assessments for small-scale, coastal radiological contamination. The sentinel species …

Additive Manufacturing With Bioresorbable Polymers: Process-Structure-Property Relationships For Biomimetic Tissue Scaffolds, Clayton Joseph Culbreath

All Dissertations

Tissue engineering has a base requirement of scaffold structures to support cell growth, proliferation, and regeneration. However, attempts to use artificial scaffold structures have often fallen short of clinical needs to justify the change away from the established, biologic-based current standard of care. Based on the limited number of successful tissue scaffolds produced by material extrusion modes of additive manufacturing, fused filament 3d printing and electrospinning, critical design specifications for a tissue scaffold are six minimum requirements: 1) biocompatibility, 2) porosity, 3) mechanical properties, 4) bioresorbable medical grade materials, 5) bioactivity, and 6) appropriately scaled production methods compliant with medical …

Machine Learning Assisted Discovery Of High-Performance Perovskites For Hydrogen Production, Ximei Zhai

All Dissertations

Hydrogen has significantly contributed to the global energy transition as a clean energy carrier. However, traditional hydrogen production involves energy-intensive processes with heavy carbon emissions. High-temperature water splitting to generate hydrogen has become a promising route for clean hydrogen production. Directly utilizing concentrated solar heat to perform solar thermochemical hydrogen (STCH) production is considered one of the most eco-friendly hydrogen production options. At the same time, high-temperature electrolysis in protonic ceramic electrolysis cells (PCECs) can efficiently utilize intermittent and cost-effective renewable electricity to produce hydrogen. Perovskite oxides with good redox capability and tolerance for oxygen deficiency are considered the most …

Multi-Scale Modeling Of Selective Laser Sintering: From Manufacturing Process And Microstructure To Mechanical Performance In Semi-Crystalline Thermoplastics, Cameron Zadeh

All Dissertations

Selective laser sintering is an additive manufacturing process that opens many design possibilities but is limited in its reliability and reproducibility. Numerical simulations validated by experimental data yield insights into the process and resulting part properties, allowing users to make more informed decisions. In this dissertation, a model for the process and microstructure is developed and validated, followed by a coupling to mechanical models to predict part performance. Further developments include a new addition of a reaction kinetics model to the process model to describe the interplay between thermal degradation and melt pool properties, and an exploration of the parameter …

Photovoltaics And Battery-Based End-To-End Direct Current Sustainable Power Networks- Concept, Design, And Control, Vishwas Powar

All Dissertations

The consequences of climate change have emphasized the need for a power network that is centered around green, low-cost, and renewable sources of energy. Currently, photovoltaics (PV) and wind turbines are the only two technologies that can convert renewable energy from the sun and wind, respectively, into large-scale power for the electricity network. This dissertation aims to provide a novel solution to implement direct current-based architecture for PV generation coupled with lithium-ion battery storage in an efficient and sustainable manner. Such a power network can enable efficiency, reliability, low cost, and sustainability with minimum impact on the environment. The first …

Volatile Crystalline Semiconductor Core Fibers, Thomasina Zaengle

All Dissertations

Optical fibers play critical roles across many facets of everyday life from communications to e-commerce to sensing and security. The ubiquity of optical fibers arises from their intrinsic clarity and, as glasses, their ability to be thermally drawn at high speeds over long distances when suitably heated about their glass transition temperature. Sixteen years ago, the first thermally drawn crystalline core fibers were fabricated using the molten core method, whereby a melt is confined within a glass capillary tube that is then drawn to fiber. This opened the door to crystalline semiconductor core fibers, which are now the backbone of …

Tin-Silver As A Novel Biodegradable Metallic Biomaterial, Charley Goodwin

All Dissertations

The Essure device is a non-hormonal, minimally-invasive, permanent female sterilization implant, removed from the market due to an increase in adverse events, hypothesized to be caused by corrosion of the Sn-Ag component of the implant. The goals of this dissertation were to first develop implant retrieval methods for Essure devices and surrounding tissue, documenting signs of degradation and metallic degradation products, then to characterize the electrochemical behavior of Sn-Ag in biologically representative environments and finally, to assess the biological interaction of Sn-Ag. Retrieval analyses developed successful methods, qualifying the degree of corrosion, primarily of the Sn-Ag component and finding Sn …

Evacuation Of Students With Intellectual Disability In Building Fires: A Three-Part Methodology, Haley Hostetter

All Dissertations

People with disabilities are one of the most vulnerable groups in building fires. Despite this, they have traditionally been overlooked by fire evacuation researchers. This is perhaps the most alarming for the group with Intellectual Disability when given their present statistics for fire involvement, injuries, and death. Annually, people with mental disabilities are involved in 1700 home fires, resulting in 39 fatalities and 122 injuries per 1000 fires. Additionally, 40% of these fires were started intentionally by people with mental disabilities. When combined with their high fire risk, the lack of evacuation research focused on people with Intellectual Disability shows …

Real-Time Degradation Abatement Framework For Energy Storage System In Automotive Application Using Data-Driven Approaches, Laxman Timilsina

All Dissertations

The increasing popularity of electric vehicles (EVs) is driven by their compatibility with sustainable energy goals. However, the decline in the performance of energy storage systems, such as batteries, due to their degradation puts EVs and hybrid electric vehicles (HEVs) at a disadvantage compared to traditional internal combustion engine (ICE) vehicles. The batteries used in these vehicles have limited life. The degradation of the battery is accelerated by the operating conditions of the vehicle, which further reduces its life and increases the reliability and economic concerns for the vehicle’s operation. The aging mechanism inside a battery cannot be eliminated but …

Remote Controlled Skid-Steer, Levi Schaider, Glory Burgin, Harrison Fentress

Mechatronics Final Projects

Our devices are a bluetooth remote controller and a remote-controlled omnidirectional loader. The vehicle functions are programmed through two PICs on the vehicle and another two PICs inside the controller. It features a double jointed shoveling arm designed to raise and lower to pick up and drop various loads (ex: sand or a flower). It uses “mecanum” wheels to achieve omni-directional driving. These wheels are controlled using a modified skid-steer system that allows for diagonal and left-right movement while the vehicle stays facing in the same direction. The pair of LED headlights can turn on either by a switch on …

Rock-Paper-Scissors Robot, Cora Lewis, Zachary Moyer, Aakriti Acharya, Reece Colson

Mechatronics Final Projects

The design incorporates a sophisticated Rock Paper Scissors (RPS) playing interface, amalgamating robotics, audio control, gesture recognition, and display functionalities. At its core, the system employs a robotic hand mechanism featuring pulleys and fishing wire to simulate finger movements. This mechanism is orchestrated by servo motors through a PIC system, which receives commands from the Arduino. The Arduino serves as the central processor and begins a round when the player hits the reset button. It triggers an audio prompt at the onset of each round using an Icstation Recordable Sound Module, prompting the player to make their move. The Arduino …

Temperature Controlled Box, Dennis Butts, Gabriel Alford, John Hawes, Holden Soderstrom

Mechatronics Final Projects

The temperature-controlled box is a project developed in the Spring of 2024. Its main goal is to maintain a setpoint temperature by switching both a heating element on for heating and a fan on for cooling.

Magdm Model Using Single-Valued Neutrosophic Credibility Matrix Energy And Its Decision-Making Application, Jun Ye, Rui Yong, Wanlu Du

Neutrosophic Systems with Applications

This paper aims to develop a MAGDM model using single-valued neutrosophic credibility matrix (SVNCM) energy in a SVNCM scenario. To do it, first, SVNCM energy and its score function are presented as a conceptual extension of existing single-valued neutrosophic matrix (SVNM) energy. Then, a MAGDM model is developed in terms of SVNCM energy and its score function in a SVNCM scenario and also its decision algorithm is provided to solve MAGDM problems with SVNCMs. Finally, the developed MAGDM model is applied in the school site selection problem as an actual example, then the comparative investigation of the decision results in …

Geomagnetic Substorms Prediction Model Using Combined Physics-Based And Deep Learning Modeling Techniques, Ruthba Yasmin

Graduate Theses and Dissertations (2019 - present)

This thesis aims to develop a hybrid physics-incorporated neural network model (PINN) for classifying geomangnetic substorms in Earth's Magnetosphere. The model is trained using a comprehensive list of substorm onsets, ground magentometer data from a global network, and solar wind parameters from the Advanced Composition Explorer (ACE) satellite. Two different neural network architectures are used, and the physics model used for training is called WINDMI. The magnetic field components on the ground, which are a function of the ionospheric currents, are captured by the SML index. The methodology involves using 60-minute data segments preceding an event to train the hybrid …

Modeling Sex-Specific Changes In Myocardial Fibrosis, Grace Martin

Chemical Engineering Undergraduate Honors Theses

Heart disease the leading cause of death for both men and women in the United States. Cardiac fibrosis, or accumulation of extracellular matrix proteins in the heart, can occur after a heart attack and increase the risk for further complications. Current treatments for heart disease do not include extracellular matrix regulators, partly due to the complicated signaling network responsible for the production of these proteins. By using a computational model of the signaling network in cardia fibroblasts, the relationship between particular molecules and downstream extracellular matrix production can be examined.

Biological sex is an important factor for cardiac health and …

Investigation Into The Effect Of Mixture Composition On Setting Time Of Magnesium Phosphate Cement, Autumn Broglen

Civil Engineering Undergraduate Honors Theses

Magnesium phosphate cement (MPC) is a cementitious material that is formed through an acid-base reaction between magnesia and phosphate. This reaction occurs rapidly, making MPC an appealing choice for rapid repair applications. The purpose of this project is to investigate the impact of different proportions of class F fly ash, set retarder consisting of a mixture of boric acid and dextrose, magnesium to phosphate ratio, and water/cement ratio on the initial setting time of MPC paste. Different mixtures of MPC paste were developed to vary the proportions of each constituent, and setting time of each mixture was determined using the …

Coal Cleat Network Stimulation Through A Combination Of Acidizing And Liquid Nitrogen Fracturing, Mohsen Farrokhrouz, Hamed Akhondzadeh, Yongfei Yang, Faisal U. R. Awan, Stefan Iglauer, Maxim Lebedev, Alireza Keshavarz

Research outputs 2022 to 2026

Gas extraction from Coal Bed Methane has proved challenging mainly due to the low permeability of coals. This study investigated a combination of 2 stimulation techniques, Liquid Nitrogen (LN2) fracturing and acidizing, to increase pore structure and cleat network connectivity in coals. Microcomputed Tomography ( -CT) scanning results suggested that a combination of those 2 applications, in either sequence of implementation, has substantial potential in recovering mineralized fractures and inducing new fractures; thus, leading to wide-open cleat networks. X-ray images show that if LN2 fracturing of coal is preceded by acidizing, the stimulation efficiency increases from more than double the …

The Effect Of Methylene Blue On Stearic Acid-Aged Quartz/Co2/Brine Wettability: Implications For Co2 Geo-Storage, Fatemah Alhammad, Mujahid Ali, Nurudeen P. Yekeen, Muhammad Ali, Hussein Hoteit, Stefan Iglauer, Alireza Keshavarz

Research outputs 2022 to 2026

Carbon dioxide sequestration in geological formations has been proposed as a promising solution to reach net zero carbon emissions but the success of underground CO2 storage in sandstone formations depends on the brine/CO2 wettability of sandstone. Research evidence showed that natural geological formation is hydrophobic even in the presence of minute concentration of inherent organic acids. This study investigates the effect of methylene blue (MB) on CO2 wettability of organic-acid contaminated quartz through the tilted plate contact angle measurement method. Pure quartz substrates were aged in a stearic acid/n-decane solution for one week and subsequently modified with different concentrations of …

A Photocrosslinkable And Hemostatic Bilayer Wound Dressing Based On Gelatin Methacrylate Hydrogel And Polyvinyl Alcohol Foam For Skin Regeneration, Asghar Eskandarinia, Mohammad H. Morowvat, Seyyed V. Niknezhad, Moloud Amini Baghbadorani, Martin Michálek, Si Chen, Mohammad M. Nemati, Manica Negahdaripour, Reza Heidari, Amir Azadi, Younes Ghasemi

Research outputs 2022 to 2026

The enormous potential of multifunctional bilayer wound dressings in various medical interventions for wound healing has led to decades of exploration into this field of medicine. However, it is usually difficult to synthesize a single hydrogel with all the required capabilities simultaneously. This paper proposes a bilayer model with an outer layer intended for hydrogel wound treatment. By adding gelatin methacrylate (GelMA) and tannic acid (TA) to the hydrogel composition and using polyvinyl alcohol-carboxymethyl chitosan (PVA-CMCs) foam layer as supports, a photocrosslinkable hydrogel with an optimal formulation was created. The hydrogels were then examined using a range of analytical procedures, …

Accuracy Testing Of Different Methods For Estimating Weibull Parameters Of Wind Energy At Various Heights Above Sea Level, Sajid Ali, Hongbae Park, Adnan Aslam Noon, Aamer Sharif, Daeyong Lee

Research outputs 2022 to 2026

The Weibull algorithm is one of the most accurate tools for forecasting and estimating wind energy potential. Two main parameters of the Weibull algorithm are the ‘Weibull shape’ and ‘Weibull scale’ factors. There are six different numerical methods to estimate the two Weibull parameters. These six methods are the empirical method of Justus (method 1), the empirical method of Lysen (method 2), the maximum likelihood method (method 3), the modified maximum likelihood method (method 4), the energy pattern factor method (method 5) and the graphical method (method 6). Many commercial wind energy software programs use the Weibull algorithm, and these …

Enhanced Hoek-Brown (H-B) Criterion For Rocks Exposed To Chemical Corrosion, Hao Li, Leo Pel, Zhenjiang You, David Smeulders

Research outputs 2022 to 2026

Underground constructions often encounter water environments, where water–rock interaction can increase porosity, thereby weakening engineering rocks. Correspondingly, the failure criterion for chemically corroded rocks becomes essential in the stability analysis and design of such structures. This study enhances the applicability of the Hoek-Brown (H-B) criterion for engineering structures operating in chemically corrosive conditions by introducing a kinetic porosity-dependent instantaneous mi (KPIM). A multiscale experimental investigation, including nuclear magnetic resonance (NMR), X-ray diffraction (XRD), scanning electron microscopy (SEM), pH and ion chromatography analysis, and triaxial compression tests, is employed to quantify pore structural changes and their linkage with the strength responses …

Selective Transfection Of A Transferrin Receptor-Expressing Cell Line With Dna-Lipid Nanoparticles And Synthesis Of Parasite-Derived Glycans As Biomarkers For Leishmaniasis, Irodiel Vinales Lozano

Open Access Theses & Dissertations

Despite notable progress in lipid nanoparticle (LNP)-mediated gene delivery, achieving selective transfection of specific cell types, such as cancer cells, remains a significant hurdle, hindering the advancement of innovative gene therapies. In this study, we engineered an LNP formulation encapsulating plasmid DNA (pDNA) encoding the monomeric Green Lantern (mGL) fluorescent reporter protein. The DT7 peptide ligand targeting human transferrin receptor 1 (hTfR1) was also conjugated to the LNP surface for targeted delivery to hTfR1-expressing cells. Optimization of LNP composition yielded favorable particle diameter, ζ-potential, yield, and pDNA encapsulation efficiency. Evaluation of transfection selectivity using a panel of two engineered cell …

Comparative Analysis Of The Effects Of Post Processing On The Flexural Fatigue Endurance Of Additively Manufactured Ti-6al-4v, Cristian Banuelos

Open Access Theses & Dissertations

This study delves into analyzing the effects of various machining techniques on the flexural fatigue life of Ti-6Al-4V L-PBF specimens. The fatigue life and fracture behavior of specimens subjected to milling, grinding, polishing, and abrasive media blasting were compared. The findings reveal significant differences in the fatigue resistance between machined and non-machined parts. This study contributes to the understanding of the effects of post-processing on the durability of L-PBF manufactured components, offering insights for enhancing their application in critical aerospace and biomedical applications.

Sulfonated Polyethersulfone Membranes For Electrodialysis Desalination And The Influence Of Solvent Evaporation On Current Efficiency, Salinity Reduction, And Permselectivity, Li Chen

Open Access Theses & Dissertations

The high cost of ion exchange membranes significantly limits the public application of electrodialysis. The research of novel, inexpensive ion exchange membranes is essential to developing and applying electrodialysis desalination technology. This research focuses on fabricating cation exchange membranes with polyethersulfone (PES) and sulfonated PES (sPES) for water treatment. N-Methyl-2-Pyrrolidone (NMP) was used as an organic solvent to dissolve PES. After different solvent evaporation times were optimized from 0 hr to 24 hr, those membranes were formed through the phase inversion technique. The performance results show that the PES membranes performed the best when the solvent evaporated at 3 hr, …

Biofabrication Of Human Tissue-On-A-Chip Models Using Engineered Biocompatible Electrospun Scaffolds, Zayra Naomi Dorado

Open Access Theses & Dissertations

This study explored the adoption of furfuryl gelatin (F-gelatin) based electrospun scaffolds compared with poly-caprolactone (PCL) as promising biomaterials for tissue engineering applications. Tissue-on-a-chip models, incorporating F-gelatin and PCL electrospun scaffolds, offer promising avenues for healthy and disease-in-vitro tissue models that can be explored to investigate underlying physiological mechanisms involved in disease development. Previous research has demonstrated the cytocompatibility of F-gelatin when used for modifying implant surfaces and tissue repair applications [1]. Our earlier published works have also successfully utilized F-gelatin for in-vitro cardiac tissue engineering [2][3]. We designed F-gelatin and PCL electrospun scaffolds to replicate the native tissue extracellular …

Relations Between Printability And Rheology In A Ceramic Paste Extrusion Process, Nicholas Durand

Open Access Theses & Dissertations

Ceramic additive manufacturing (AM) uses the same fundamentals as material extrusion (MEX) that utilizes polymers or resins for printing applications. Ceramic AM uses the same process of slicing an STL file to determine a toolpath for the printer that will facilitate material deposition to manufacture full parts; ceramic AM also provides a low-cost advantage when compared to processes that require high powered lasers for melting metal powders or heated nozzles used for dispensing thermoplastics. Despite having the similar design freedom and ability for rapid prototyping that other printing methods benefit from with the addition of low cost, ceramic AM has …

Analysis Of Additively Manufactured Inconel 718 Combustion Behavior In Promoted Oxygen Environments, Dominic George Dieguez

Open Access Theses & Dissertations

Promoted combustion testing is a vital tool for engineers to establish the combustion and flammability characteristics of materials (metallic or otherwise) in oxygen enriched environments. Historically, much of the established data for metallic promoted combustion has been with regards to materials in their cast and wrought forms. However, with the emergence of additive manufacturing as a preferred method of fabrication, the need exists to evaluate how metals in that form behave. Recent testing has demonstrated that even if a metal or alloy is nominally the same with regards to chemistry, flammability between samples in the wrought form can differ significantly …