Digital Commons Network^™

Emulsion Liquid Membrane (Elm) Enhanced By Nanoparticles And Ionic Liquid For Extracting Vanadium Ions From Wastewater, Qusay Al-Obaidi, Nora Yehia Selem, Muthanna H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

Emulsion liquid membrane (ELM) stands out as an extraction process that has drawn much attention due to its promising prospects in industrial wastewater treatment technology. Nevertheless, the pivotal challenge is to reach high membrane stability to overcome the obstacle of applying ELM at the industrial scale. In this study, ELM was boosted by using nanoparticles (superparamagnetic iron oxide (Fe₂O₃)) in the stripping phase (W1) and ionic liquid (1-methyl-3-octyl-imidazolium-hexafluorophosphate [OMIM][PF6) in the oil phase (O) for recovering/extracting vanadium from synthetic wastewater to near completion and at the same time enhancing emulsion stability to be appropriate for industrial …

A Study Of Directionality Effects In Three-Beam Coaxial Titanium Wire-Based Laser Metal Deposition, Remy Mathenia, Braden Mclain, Todd Sparks, Frank Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Coaxial wire-based laser metal deposition is a versatile and efficient additive process that can achieve a high deposition rate in the manufacturing of complex structures. In this paper, a three-beam coaxial wire system is studied, with particular attention given to the effects of the deposition direction and laser beam orientation on the resulting bead geometry symmetry. With the three-beam laser delivery, the laser spot pattern is not always symmetric with respect to the deposition direction. Single titanium beads are deposited in different directions and at varying deposition rates, and the bead profile is quantitatively scored for multiple symmetry measures. Through …

Analytical And Fem Models For Thermal Analysis And Residual Stresses Using Wire Arc-Based Welding And Additive Manufacturing Of Sus304, Muhammad Arif Mahmood, Usman Tariq, Mihai Oane, Frank Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Austenitic stainless steel, also known as SUS304, has a wide industrial application. The resultant residual stresses and deformation due to arc welding play a critical role in an in-service SUS04 part failure. Various experimental studies have been presented to predict residual stresses and part deformation. However, these techniques are expensive and time-consuming owing to the trial-and-error approach, limiting their application to industrial applications. Based on the emergent need, this study introduces two simulation models based on analytical and FEM techniques for thermal distribution and residual stress estimation. The experimentally calibrated models results have been implemented for SUS304 multi-pass arc welding. …

Surface Acoustic Waves-Based Point-Of-Care Biosensor, Debdyuti Mandal

Theses and Dissertations

A biosensor is an analytical tool consisting of biologically active material used in close conjunction with a device that converts a biochemical signal into a quantifiable electrical signal. The early detection of the disease biomarkers can enhance the increased curability of the disease, reduce healthcare costs, and finally, improve the quality of life for patients. Thus, for the following purpose, there is always a need for an effective biosensor as a diagnostic device. The biosensor typically consists of an actuator, a bio-recognition component, and a transducer that converts captured signals into a meaningful display. The bio-recognition component uses biomolecules to …

Quantifying Extreme Events: Applications Of Probabilistic Methods To Quantify Riverine And Coastal Flood Dynamics In South Carolina And Neighboring Coastal Communities, Ryne Phillips

Theses and Dissertations

Extreme flood events have been persistent throughout history and have challenged human populations around the globe. Over time, scientists and engineers have developed tools and technology to support flood risk management. Most, if not all, of these tools rely on some form of the field of stochastic hydrology. Stochastic hydrology is a broad discipline, but the overarching principle is to use statistical and data-driven techniques to develop an understanding of one or more hydrologic variables (e.g., flood flow or peak storm tide). However, the need for large sample sizes of data that offer insight into all possible combinations of outcomes …

Control Optimization And Adaptive Tuning Of Droop Controlled Systems For Dc Bus Stability Via Terminal Impedance Shaping, Andy Wong

Theses and Dissertations

Many traditional AC systems have been moving towards DC in recent decades due to advancements in power electronics and semiconductor devices. DC power distribution systems, such as DC microgrids, have become increasing popular due to energy efficiency, resiliency, and renewable energy integration. However, with such systems which commonly utilize droop control, comes an issue of system stability due to the interconnection of multiple feedback-controlled converters to a common bus. To combat this issue, this thesis proposes a control optimization and adaptive tuning approach for maintaining DC bus stability and dynamic performance of droop controlled systems. First, a terminal impedance model …

Exploring Shape Dependency Of Catalysts For Chemical Reactions, Kaveh Shariati

Theses and Dissertations

Recent advancements in the synthesis of nanoparticles, particularly one-dimensional (1D) nanoparticles, have significantly enhanced the catalytic activity of various processes by enabling precise control over their morphologies and exposing unique crystallographic facets. The shape of nanoparticles is closely linked to their chemical, physical, electrical, optical, magnetic, and catalytic properties. This dissertation investigates the impact of 1D nanoparticle catalysts on two distinct and well-known chemical reactions. In the first part of the study, we explore the catalytic activity and selectivity of silver catalysts in the ethylene epoxidation reaction, which are intrinsically linked to their faceting. Silver nanowire catalysts representing Ag(100) and …

Simulation Of A Passive Osmosis-Integrated Electrolyzer For Seawater Electrolysis, Masoomeh Ghasemi

Theses and Dissertations

Efforts to develop direct seawater electrolysis technology have been ongoing due to the need for pure water in electrolysis and the abundance of seawater. However, progress has been hampered by several issues, including competition with the chlorine evolution reaction, higher membrane resistance, corrosion of electrodes, and scaling from multivalent cations [1]. To avoid these issues, our project has proposed a new reactor that integrates passive osmosis (extracting fresh water from seawater) with electrolysis. In this thesis, we will discuss the operation of the osmosis-integrated electrolyzer and show theoretical predictions of the osmotic pressure differential and water flux/velocity profiles under different …

Multidimensional Simulation Of Cool Diffusion Flame, Ejaz Ahmed

Theses and Dissertations

Understanding the behavior of spherical cool diffusion flames in microgravity conditions is crucial for advancing combustion research. This knowledge has significant implications for both fundamental science and practical applications, such as spacecraft fire safety and the development of advanced, high-efficiency engines that benefit from low-temperature chemistry. Spherical cool diffusion flames are typically characterized by peak temperatures between 500 and 1000K and are often followed by the radiative extinction of a hot flame. Some low-temperature ignitions can sustain indefinitely at around 700K, leading to chain-branching pathways that produce intermediate species such as C2H4, H2O2, HO2, CH2O, CH3O, and HCO. In some …

Accelerating Numerical Modeling And Optimization Of Structural Mechanical Systems, Fatemeh Hashemian

Theses and Dissertations

This research proposal presents Bayesian optimization and reduced order modeling methods to accelerate numerical analysis and design of structure mechanical system. First, a holistic framework of Bayesian optimization (BO) based on parameterized numerical models and genetic algorithm-guided adaptive sampling is developed to automate and accelerate the design of a front-loading washing machine. The research aims to address challenges associated with the model parameterization and global optimization and design. A multibody dynamics model of the washing machine incorporating a set of 9 key design variables is developed. The design variables are implemented to enable automated modifications of the dynamics model for …

Investigating The Effects Of Calcitonin Gene Related Peptide On Heart Failure And The Gut Microbiome, Talia Charlotte Kepniss

Theses and Dissertations

Heart failure affects millions of people worldwide with current available treatments that are limited in their efficacy. The financial burden for care of those with heart failure is over 20 billion dollars in the US alone. Calcitonin gene related peptide has demonstrated cardioprotective and powerful vasodilator effects. In this study our objective is to prevent the onset of heart failure and treat early stages of heart failure with injections of calcitonin gene related peptide in C57BL/6 mice. In order to model heart failure, experimental mice underwent a transverse aortic constriction surgery. Echocardiograms and fecal collections were completed to observe changes …

Enabling Novel Nanopore Sensing Approaches For Personalized Medicine Through Chemical Modifications To Analytes, Zehui Zhang

Theses and Dissertations

Nanopore sensors have garnered significant attention recently, not only for their groundbreaking advancements in single-molecule DNA sequencing but also for their diverse applications in stochastic sensing, single-molecule chemistry, and protein unfolding. The interaction of single molecules with the nanopore sensing interface leads to characteristic ionic current modulations, reflecting the composition, charge, distribution, structure, and sequence of the translocating molecule. With the electrical resistive pulse nanopore sensing, its single-molecule sensitivity and specificity have opened doors to numerous potential applications in personalized medicine. I will discuss recent advancements in the sensitivity and specificity of personalized medicine using nanopore sensors, focusing on proteomic …

Machine Learning Approaches To The Exploration Of Ammonia Synthesis Catalysts Utilizing Experimental Data, Rasika Jayarathna

Theses and Dissertations

Traditional heterogeneous catalyst discovery process relies upon human expert-guided experiments based on domain knowledge and human intuition supported by catalyst characterization. However, this process is time and resource-consuming and suffers from human bias. Machine learning (ML) models trained on experimental data have the potential to significantly accelerate this discovery process by guiding experiments to optimize the catalyst performance and increase the understanding of the catalysts. Ammonia synthesis catalysts are a class of catalysts widely investigated in the literature, which has generated decades of experimental data. Moreover, ammonia has been gaining attention since it can be used as a carbon-free next-generation …

Development Of A Large Format Additive Manufacturing System Based On An Off-The-Self Pellet Extruder, Aywan Das

Theses and Dissertations

Large Format Additive Manufacturing (LFAM), or Big Area Additive Manufacturing (BAAM), was introduced to resolve the limitations of the low deposition rate, low scalability, and therefore long print times, of traditional 3D printing methods when applied to the manufacturing of large structures and tooling. LFAM can be used to overcome the high conventional tooling costs of large structures. However, even with robotic setups, LFAM still mainly relies on quasi-planar, 2.5D printing strategies. This fails to reap the advantages of multi-axis printing, such as improved adhesion, reduced support material use, and the ability to create complex curved surfaces. In this research, …

Applications Of Catalytic Ammonia Chemistry: From Low-Pressure Ammonia Synthesis To The Decomposition Of Tritiated Ammonia As A By-Product Of Magnetically Confined Nuclear Fusion, Jennifer Kules Naglic

Theses and Dissertations

Ammonia is the 2nd most produced chemical in the world with vital importance for its use in fertilizer as the global population has grown in accordance with the industrialization of NH3. While 80% of NH3 produced goes to fertilizer, it has gained attention recently as a hydrogen storage and transportation vessel. Industrially, NH3 is produced at high temperatures and pressures which in turn require high electrical input. Turning to a green NH3 cycle with low temperature and pressure membrane reactors for both NH3 synthesis and decomposition would allow for much lower energy input as well as a renewable energy to …

Geometrically Exact Beam Theory For Gradient-Based Optimization, Taylor Mcdonnell, Andrew Ning

Faculty Publications

Decades of research have progressed geometrically exact beam theory to the point where it is now an invaluable resource for analyzing and modeling highly flexible slender structures. Large-scale optimization using geometrically exact beam theory remains nontrivial, however, due to the inability of gradient-free optimizers to handle large numbers of design variables in a computationally efficient manner and the difficulties associated with obtaining smooth, accurate, and efficiently calculated design sensitivities for gradient-based optimization. To overcome these challenges, this paper presents a finite-element implementation of geometrically exact beam theory which has been developed specifically for gradient-based optimization. A key feature of this …

Characteristics Of Pyrolysis Products Of California Chaparral And Their Potential Effect On Wildland Fires, Mahsa Alizadeh, David R. Weise, Thomas H. Fletcher

Faculty Publications

The aim of this study was to investigate the pyrolysis of selected California foliage and estimate the energy content of the released volatiles to show the significance of the pyrolysis of foliage and its role during wildland fires. While the majority of the volatiles released during the pyrolysis of foliage later combust and promote fire propagation, studies on the energy released from combustion of these compounds are scarce. Samples of chamise (Adenostoma fasciculatum), Eastwood’s manzanita (Arctostaphylos glandulosa), scrub oak (Quercus berberidifolia), hoaryleaf ceanothus (Ceanothus crassifolius), all native to southern California, and sparkleberry …

Solving Unsteady Potential Flow Problems In O(N) Time, Ryan Anderson, Andrew Ning

Faculty Publications

Design of vertical takeoff and landing aircraft is challenging in part due to significant aerodynamic interactions between rotors and wings. Computational models can aid in their design, but are computationally expensive. 3-D panel methods coupled with vortex particle wakes offer an attractive solution, but solving for the panel strengths scales poorly for large problems. Multigrid methods, such as Krylov subspace methods in conjunction with the fast multipole method (FMM), have been demonstrated to reduce the scaling to O(𝑁). We explore the performance and limitations of the Krylov-FMM method, traditional matrix-powered GMRES, LU decomposition, and a novel O(𝑁) multigrid approach to …

Theoretical Semi-Quantitative Risk Assessment Methodology For Tunnel Design And Construction Processes, Ozgur Satici, Esra Satici

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

All engineering projects involve risk management applications. Sometimes, risks cannot be effectively managed, leading to catastrophic consequences. Engineers must consciously or unconsciously manage these risks. Regardless of how risks are handled, project risks need to be systematically evaluated. Therefore, risk management procedures must be implemented in every project, particularly in geo-engineering projects, to mitigate undesirable consequences and achieve project objectives. However, the use of risk management procedures in underground excavation projects is not common. Numerous commonly employed underground excavation techniques lack assessment of risks, notably geotechnical risks. Most of them only evaluate rock structures and excavation stability in accordance with …

Microstructural Evolution In A Precipitate-Hardened (Fe0.3ni0.3mn0.3cr0.1)94ti2al4 Multi-Principal Element Alloy During High-Pressure Torsion, Matthew Luebbe, Jiaqi Duan, Peipei Cao, Zhaoping Lu, Rinat K. Islamgaliev, Ruslan Z. Valiev, Yuzi Liu, Haiming Wen

Materials Science and Engineering Faculty Research & Creative Works

Multi-principal element alloys demonstrate high strength, thermal stability, and irradiation resistance, making them excellent candidate materials for applications in nuclear reactors and other harsh environments. Some studies have examined the use of high-pressure torsion to strengthen MPEAs through grain size reduction and strain hardening. However, no studies have investigated the effect of HPT on secondary phases (precipitates) within an MPEA. Two alloys, (Fe_0.3Ni_0.3Mn_0.3Cr_0.1)₉₄Ti₂Al₄ containing Ni(Ti, Al) B2 phase, and CrFe σ phase, and single-phase Fe_0.3Ni_0.3Mn_0.3Cr_0.1, were fabricated by casting …

Experimental Study On The Detection Of The Existence And Location Of Mimicked And Unexpected Interface Debonding Defects In An Existing Rectangular Cfst Column With Pzt Materials, Qian Liu, Bin Xu, Genda Chen, Weilong Ni, Zhixun Liu, Chun Lin, Zhiyou Zhuang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Interface bonding conditions between concrete and steel materials play key roles in ensuring the composite effect and load-carrying capacity of concrete–steel composite structures such as concrete-filled steel tube (CFST) members in practice. A method using both surface wave and electromechanical impedance (EMI) measurement for detecting the existence and the location of inaccessible interface debonding defects between the concrete core and steel tube in CFST members using piezoelectric lead zirconate titanate (PZT) patches as actuators and sensors is proposed. A rectangular CFST specimen with two artificially mimicked interface debonding defects was experimentally verified using PZT patches as the actuator and sensor. …

Synergetic Effect Of Viscosity Modifying Admixtures And Polycarboxylate Ether Superplasticizer On Key Characteristics Of Thixotropic Uhpc For Bonded Bridge Deck Overlay Rehabilitation, Le Teng, Ming Jin, Jiadi Du, Kamal H. Khayat

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Thin bonded ultra-high-performance concrete (UHPC) overlay is an advanced technology for bridge deck rehabilitation. UHPC should be tailored to secure adequate flowability and high thixotropy to facilitate mixing and placement with a low risk of sagging of the material on sloped bridge deck surfaces. The synergetic effect between nano clay (NC) and polycarboxylate ether (PCE) superplasticizer or cellulose-based viscosity modifying admixture (VMA) and PCE on the rheological properties (yield stress, plastic viscosity, and thixotropy), cement hydration, autogenous shrinkage, compressive strength, and porosity was systematically investigated. The bond strength between conventional concrete (CC) representing existing bridge deck concrete and thixotropic UHPC …

In Situ Synthesis, Characterization And Photocatalytic Efficacy Of Silver-Enhanced Mxene And Graphene Nanocomposites, Kishore Chand, M. Mustafa Azeem, Muhammad Nazim Lakhan, Mukhtiar Ahmed, Muhammad Jehanzaib Aslam, Ahmer Hussain Shah

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The emergence of 2D materials has significantly expanded the wide range of nanomaterials with diverse applications. Notably, their high conductivity, catalytic efficiency, and hydrophobicity have fueled heightened research interests for water treatment applications. This research aimed to investigate the synthesis and characterization of MXene and reduced graphene oxide (rGO) nanocomposites with silver nanoparticles (Ag) for enhanced catalytic activity in the decomposition of Direct Blue-24 dye. In this study, we employed well-established methods, previously documented in the literature, to prepare two distinct nanocomposites. Novel nanocomposites, namely reduced graphene oxide–silver nanoparticles (rGO–Ag) and MXene–silver nanoparticles (MXene–Ag), were synthesized using the hydrothermal and …

Predicting Iot Distributed Ledger Fraud Transactions With A Lightweight Gan Network, Charles Rawlins, Jagannathan Sarangapani

Electrical and Computer Engineering Faculty Research & Creative Works

Decision-making and consensus in traditional blockchain protocols is formulated as a repeated Bernoulli trial that solves a computationally intense lottery puzzle, called Proof-of-Work (PoW) in Bitcoin. This approach has shown robustness through practice but does not scale with increasing network size and generation of new transactions. Resource constrained Internet of Things (IoT) networks are incompatible with full computation of schemes like Bitcoin's PoW. Our effort proposes a first step towards an alternative consensus using machine learning-based decision-making with prediction of fraud transactions to alleviate need for intense computation. To improve base approval probabilities for fraud detection in an ideal security …

Exploring A New Conceptual Framework In Aviation Maintenance Incident Reporting Using Natural Language Processing, Christopher P. Braun

Doctoral Dissertations and Master's Theses

In the analysis of human error incidents, human factors specialists predominantly follow two schools of thought in categorization strategies. One is to categorize the operator’s actions by the physical properties of the activity (phenotypes); the other focuses on the cognitive behaviors preceding the incident (genotypes). These categorization strategies are intended to foster an understanding of the events, identify risks, and assist in the implementation of risk reduction interventions. Commercial aviation maintenance presents unique challenges to human factor practitioners in terms of task requirements, working environments, communication modalities, and safety standards. Complex tasks are handed from one shift of personnel to …

Situation Awareness Assessment Of Enhanced Stable Approach Flight Instrument Displays, David J. Hunter

Doctoral Dissertations and Master's Theses

Through the year 2022, runway-related events, including excursions, abnormal runway contact, and runway undershoot and overshoot, were the third leading causes of fatal aircraft accidents. Principal to these runway-related accidents was the presence of an unstable approach. Pilots currently must depend on the timely recall of stable approach criteria stored in long-term memory, application of those criteria against current flight conditions, perception and cognition of deviation from those criteria, and determination of potential courses of action. Such recall is fallible, and challenges to perception and cognition are ever-present.

This study examined whether the presentation of stable approach criteria boundaries and …

In Situ Synthesis, Characterization And Photocatalytic Efficacy Of Silver-Enhanced Mxene And Graphene Nanocomposites, Kishore Chand, M. Mustafa Azeem, Muhammad Nazim Lakhan, Mukhtiar Ahmed, Muhammad Jehanzaib Aslam, Ahmer Hussain Shah

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The emergence of 2D materials has significantly expanded the wide range of nanomaterials with diverse applications. Notably, their high conductivity, catalytic efficiency, and hydrophobicity have fueled heightened research interests for water treatment applications. This research aimed to investigate the synthesis and characterization of MXene and reduced graphene oxide (rGO) nanocomposites with silver nanoparticles (Ag) for enhanced catalytic activity in the decomposition of Direct Blue-24 dye. In this study, we employed well-established methods, previously documented in the literature, to prepare two distinct nanocomposites. Novel nanocomposites, namely reduced graphene oxide–silver nanoparticles (rGO–Ag) and MXene–silver nanoparticles (MXene–Ag), were synthesized using the hydrothermal and …

Freezing-Thawing Hysteretic Behavior Of Soils, Jidong Teng, Antai Dong, Sheng Zhang, Xiong Zhang, Daichao Sheng

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The soil freezing characteristic curve (SFCC) plays a crucial role in investigating the soil freezing-thawing process. Due to the challenges associated with measuring the SFCC, there is a shortage of high-quality or rigorous test results with sufficient metadata to be effectively used for applications. Current researchers typically conduct freezing tests to measure the SFCC and assume a singular SFCC when studying the freezing-thawing process of soils, although limited studies indicated that there is a hysteresis during the freezing and thawing process. In this paper, a series of freezing-thawing tests were performed to assess the SFCC, utilizing a precise nuclear magnetic …

Optical Frequency Domain Reflectometry-Based High-Performance Distributed Sensing Empowered By A Data And Physics-Driven Neural Network, Zhaopeng Zhang, Wei Peng, Osamah Alsalman, Lingmei Ma, Jie Huang, Chen Zhu

Electrical and Computer Engineering Faculty Research & Creative Works

Optical frequency domain reflectometry (OFDR) based distributed strain sensors are the preferred choice for achieving accurate strain measurements over extensive sensing ranges while maintaining exceptional spatial resolution. However, the simultaneous realization of high spatial resolution, high strain resolution, large strain range, and an extended sensing range presents an exceedingly challenging endeavor. In this study, we introduce and experimentally demonstrate a data and physics-driven neural network-empowered OFDR system designed to attain high-performance distributed sensing. In our experiments, we successfully maintained an impressive sensing resolution of sub-microstrain (0.91 µε) alongside a sharp spatial resolution of sub-millimeter (0.857 mm) across a 140-m sensing …

Privacy-Preserved Data Trading Via Verifiable Data Disturbance, Man Zhang, Xinghua Li, Yanbing Ren, Bin Luo, Yinbin Miao, Ximeng Liu, Robert H. Deng

Research Collection School Of Computing and Information Systems

To motivate data owner (DO) to trade data, the existing data trading allows DO to sell the disturbed data to the data consumer (DC), where the disturbance parameter and the data price are negotiated by them, and DO independently adds the disturbance noise to data (usually continuous type) following the negotiation result. However, DOs may violate the negotiated parameter and add more noise to data while obtaining the negotiated price, which damages DC's disturbed data availability. This deficiency is rooted in the absence of supervision and verifiability on DOs’ independent disturbances. Aiming at the above problem, we devise a privacy-preserved …