Engineering Commons^™

A Model For Spacecraft Relative Motion Using Continuous Periodic Thrust, Philip Alan Hittepole

Dissertations

A model for modifying the relative orbit of a deputy satellite with respect to a chief satellite in a near-circular orbit using continuous periodic thrust is presented. This model is built on the Lovell-Spencer relative orbital elements (ROEs). The four linear ROEs (xr, yr, ar, and Az) can be linearly modified. The two angular ROEs (Er and ) can be set to advance at a desired, constant rate. Each ROE can be modified individually but may cause intra-orbit variations in other ROEs which return to their original values at the end of a thrust cycle. A method to easily calculate …

Creating Advanced Processes Through Utilizing Renewable Eutectics For Gas Capture And Separation, Ahmad Mohammad Rasheed Al-Bodour

Dissertations

Global efforts to reduce emissions of environmentally harmful gases have intensified, with carbon dioxide (CO2) being identified as the most significant greenhouse gas and a key target for reduction strategies. Carbon dioxide (CO2) has the highest potential of threatening the environment. It is recognized as one of the greenhouse gases which has the potential of negative effects on the human being, atmosphere, and the environment. Even though CO2 gas has negative effects but at the same time it has high potential to be exploited in beneficial ways. For instance, CO2 is used in the energy field to produce the so-called …

The Synthesis, Characterization, And Application Of Polysaccharide-Based Additive To Improve Wet And Dry Strength And High-Barrier Properties Of Paper Products, Cornellius Marcello

Dissertations

Paper products play an essential role in our daily lives owing to their low cost, environment-friendly character, renewability, and recyclability. Paper manufacturers have been using petroleum-based strength additives (cPAM, GPAM, PAE) to meet the perceived needs of customers. On the other hand, paper produced from cellulose is hydrophilic and porous, leading to shallow water and grease resistance, causing paper manufacturers to use many kinds of coating materials such as poly-fluoroalkyl substances (PFAS) and synthetic plastic to improve water resistance, especially for food packaging paper products like cups, plates, food boxes, and packaging. However, PFAS are identified as likely carcinogenic to …

3d Automated Surgeon’S Hand Motion Assessment Using A Cascade Fuzzy Supervisor During Intelligent Box-Trainer System Skills Training In A Multi-Thread Video Processing, Fatemeh Rashidi Fathabadi

Dissertations

For certain surgical procedures, Minimally Invasive Surgery (MIS) has become more advantageous than traditional open surgery. Therefore, mastery of laparoscopic skills is an essential component of surgical training and requires considerable time and effort. The Fundamentals of Laparoscopic Surgery (FLS) program has been developed as a tool to improve and assess fundamental surgical skills. In fact, using a low-cost Box-Trainer or a simulator, laparoscopic surgeons are required to train using a set of structured tasks that can be objectively used to assess their laparoscopic skills, which must be mastered before carrying out real-life laparoscopic procedures. These tasks include peg transfer, …

Printed Graphite Electrodes For Fast-Charging Lithium-Ion Batteries, Guanyi Wang

Dissertations

The rapid growth of the electric vehicle (EV) market has demanded lithium-ion batteries (LIBs) with high energy density and fast charging capability. However, charging energy-dense LIBs with thick graphite electrodes at high current densities is typically facing challenges and leading to adverse performance, such as low energy density, short cycle life, rapid temperature rises and safety issues. The root cause is the onset of Li plating. During fast charging application, the sluggish lithium ions accumulated at the surface of graphite due to kinetic limitation and formed Li plating, especially when lithiated to a high state of charge (SOC). It has …

Sustainable And Cost-Effective Work Zone Scheduling On Two-Lane Highways With Managed Lanes, Ahmed Z. Edrees

Dissertations

Roadway maintenance projects greatly influence the roadway capacity, resulting in potential traffic disturbances captured by delays. Additionally, costs associated with these projects tend to be exorbitantly extensive. Most agencies and planners try to find a solution that minimizes roadway maintenance costs, traffic delays, crash risks, and environmental impact.

Work zones on two-way two-lane roadway typically avoids high-demand periods. Lane-closure scenario is commonly used and converts the open lane into a phantom intersection, alternating two-direction movements on one lane with the help of a flagger or a temporary signal. Alternatively, using shoulders as temporarily managed lanes allows for simultaneous two-way movements …

Network Slicing And Noma Enabled Mobile Edge Computing For Next-Generation Networks, Mohammad Arif Hossain

Dissertations

The advent of next-generation wireless networks ushers in a new era of potential, harnessing cutting-edge technologies like mobile edge computing (MEC), non-orthogonal multiple access (NOMA), and network slicing as pivotal drivers of transformation. Within this landscape, an innovative approach is proposed by introducing a NOMA-enabled network slicing technique within MEC networks. This approach aims to achieve multiple objectives: meeting stringent quality of service requirements, minimizing service latency, and enhancing spectral efficiency. By seamlessly integrating NOMA with network slicing in edge computing environments, significant reductions in overall latency are achieved, alongside ensuring optimal resource allocation for NOMA users. To address these …

Integrating Laser Charging And Drones For Secure Edge Computing, Weiqi Liu

Dissertations

Drone-mounted base stations (DBSs) have emerged as a promising solution to enhance the flexibility and coverage of wireless networks, potentially revolutionizing communication systems. This dissertation explores the integration of DBSs into 5G and beyond networks, focusing on methodologies to optimize their deployment and performance. A laser charging-enabled DBS framework is proposed to extend flight time and enhance network coverage. By leveraging laser charging technology, the DBS can receive continuous energy transmission from a ground-based charging station while providing communication services to users. The framework is formulated as an optimization problem to jointly maximize flight time and communication data rate, while …

Computational Microscopy For Biomedical Imaging With Deep Learning Assisted Image Analysis, Yuwei Liu

Dissertations

Microscopy plays a crucial role across various scientific fields by enabling structural and functional imaging with microscopic resolution. In biomedicine, microscopy contributes to basic research and clinical diagnosis. Conventionally, optical microscopy derives its contrast from the amplitude of the optical wave and provides visualization of the physical structure of the sample qualitatively. To understand the function at the cellular or tissue level, there is a need to characterize the sample quantitatively and explore contrast mechanisms other than light intensity. Image enhancement or reconstruction from microscopic imaging systems is known as computational microscopy, and it involves the application of computational techniques …

Interaction Of Particles With Plasma And Shock Produced By Pulsed Spark Discharge, Shomik Mukhopadhyay

Dissertations

Interactions of powders with high-temperature plasma and shockwaves occur in diverse scenarios, such as nuclear blasts, accidental industrial dust explosions, solid propellant combustion in explosive charges and when removing contaminants from surfaces. Electrostatic Discharge (ESD), known for generating shock and plasma, is a promising lab-scale technique for simulating these interactions. Studies with ESD involved placing powders near a spark-producing gap between electrodes and observing mechanical and chemical processes like particle motion and ignition. A limited range of spark conditions and material properties have been tested, which facilitated the development and validation of preliminary computational models describing this system. Significant gaps …

Machine Learning-Based Design Of Doppler Tolerant Radar, Kyle Peter Wensell

Dissertations

In this work, machine learning theory is applied to the design of a radar detector in order to train a machine learning-based detector that is robust against Doppler shifts. The radar system is designed to work with data that would be otherwise intractable to conventional optimal detector design, such as transmitted noise waveforms and the effects of one-bit quantization at the receiver. The detection performance of the one-bit receiver is shown to match the performance of the derived square-law sign correlator detector. The resulting learning-based detector also introduces Doppler tolerance to the system, which allows for the successful detection of …

Decentralized Control Of Renewable Generation Systems, Milad Shojaee

Dissertations

As the global community struggles with the escalating challenges of climate change and environmental degradation, the transition to renewable energy sources has emerged as a paramount solution. Harnessing energy from renewable sources such as solar, wind, and hydro power not only alleviates the adverse effects of conventional fossil fuel energy sources, but also establishes a foundation for a sustainable and resilient future. Microgrids have been utilized as a feasible platform to integrate renewable energy sources into the electrical power generation networks. They include one or more generation units connected to nearby users, and are able to operate in both grid-connected …

Information Theoretic Bounds For Capacity And Bayesian Risk, Ian Zieder

Dissertations

In this dissertation, the problem of finding lower error bounds on the minimum mean-squared error (MMSE) and the maximum capacity achieving distribution for a specific channel is addressed. Presented are two parts, a new lower bound on the MMSE and upper and lower bounds on the capacity achieving distribution for a Binomial noise channel. The new lower bound on the MMSE is achieved via use of the Poincare inequality. It is compared to the performance of the well known Ziv-Zakai error bound. The second part considers a binomial noise channel and is concerned with the properties of the capacity-achieving distribution. …

A Molecular Dynamics Study On The Destruction Mechanism Of Per And Polyfluoroalkyl Substances Due To Ultrasound Technology, Bruno Bezerra De Souza

Dissertations

Per- and polyfluoroalkyl substances (PFAS) are a group of stable synthetic chemicals that are highly persistent and harmful pollutants to the environment and human health. PFAS have caused a strong public and regulatory response due to their ubiquitous presence in the environment and toxicity to humans. The application of ultrasound is one of the most effective treatment technologies for the mineralization of PFAS in contaminated water. However, this technology is treated as a black box causing the inability to be optimized. Therefore, there is a pressing need to investigate the intricate dynamics of PFAS degradation under ultrasound to unlock its …

Molecular-To-Continuum Scale Modeling Of Aerosols: Atmospheric Application And Beyond, Ella Ivanova

Dissertations

Aerosol modeling is critical for various applications, such as climate forecasting, air quality, and human health impact assessment. During their lifetime, aerosols undergo a complex evolution, usually divided into several stages — formation, processing, transport, and removal — that occur on different scales. Thus, the choice of modeling methods depends on the stage considered. For example, certain stages of particle formation may require nano-scale modeling while aerosol-cloud interactions span from microscale to mesoscale. This study examines the modeling of aerosol behavior over a wide range of scales, from nano to microscale, with implications to mesoscale.

This dissertation focuses on two …

Microplastic Abundance And Removal In Stormwater Using Green Infrastructure, Meghana Parameswarappa Jayalakshmamma

Dissertations

Microplastics (MPs) are increasingly recognized as a pervasive environmental contaminant, conveying other contaminants, accumulating in aquatic organisms, and posing ecological risks. The existing research has primarily focused on MPs in wastewater treatment plant effluents in surface waters. However, the role of stormwater systems in MP transport has been less explored. Given the rise in MPs from urban sources, stormwater runoff from urban areas may serve as a critical conduit for transporting land-based MPs into aquatic environments. Green infrastructures (GIs) have been recognized for mitigating flooding and improving water quality from minor storms by trapping stormwater pollutants. Yet, the capability of …

Reproducible Fluid Structure Interaction For Complex Flows In Engineered Systems, Allen Prasad Varghese

Dissertations

This dissertation focuses on the application of numerical models to study Fluid Structure Interaction (FSI) in the industrial context. The emphasis is on a series of case studies belonging to practical applications in design and manufacturing and that are solved by a synergistic use of theoretical and computational models. The first study looks into the hydrodynamic actions experienced by vibrating slender structures immersed in viscous fluids near the free surface. This study case is relevant to applications such as, for example, marine propulsion, micro-electro-mechanical systems, and atomic force microscopy. The hydrodynamic problem is governed by three parameters, namely the frequency, …

Development Of Super Hydrophobic Membranes And Their Applications, Sumona Paul

Dissertations

Effective liquid phase separation is vital across industries, especially in aviation, chemicals, fuels, and textiles. Membrane technology offers advantages over traditional methods like distillation, with low energy consumption and protection for heat-sensitive molecules. Membrane performance is assessed based on factors such as materials, surface modification, and interactions. This research targets superhydrophobic membranes for liquid-liquid filtration and antiwetting omniphobic membranes for membrane distillation, focusing on properties like contact angle and thermal resistance.

This study presents a highly hydrophobic membrane achieved by immobilizing carbon nanotubes (CNTs) onto a PTFE microfiltration membrane. It's designed for dewatering organic-water mixtures with trace water content via …

Enhancing Cybersecurity In Wireless Sensor Networks: Machine Learning, Blockchain And Future Perspectives, Ilemona Solomon Atawodi

Dissertations

Security in the Industrial Internet of Things encounters various security issues but the main issues can be broken down into three core issues: Availability, Integrity, and Confidentiality. Security challenges generally tend to be caused by a failure of the system in one of these areas or cause a failure in one of these areas. Therefore researching scalable solutions to these security issues is prudent to explore methods that could be applied to large-scale industrial IIoT with tens to hundreds of devices as well as small-scale systems on a tiny factory floor comprising of just a few devices. In our research, …

Enabling High-Rate Thermoplastic Composite Manufacturing Through Structure-Processing-Property Relationships Of Polyphenylene Sulfide, Lina Ghanbari

Dissertations

In this dissertation, relationships between polyphenylene sulfide (PPS) chain structure and melt processing parameters are linked to thermoplastic composite (TPC) properties and mechanical performance. Deviations from linear PPS structure and the formation of branching/crosslinked moieties upon exposure to TPC manufacturing steps presents an opportunity to systematically uncover the interdependencies of melt-state thermal history on polymer rheology, crystallization, crystal structure, and translate these properties to the continuum level. This work first explores unreinforced PPS and how the formation of non-linear chain architectures yield altered rheological states when held at melt processing temperatures. These hindered chains exhibit unconventional crystallization behavior and non-uniform …

Retrofit Prioritization Of Substandard Buildings For Earthquake Risk Management, Roshen John Joseph

Dissertations

Despite the pressing need for risk mitigation techniques for reinforced concrete (RC) structures designed without considering seismic design provisions, limited research has focused on selecting experimentally verified retrofit measures from various alternatives, particularly considering minimizing disruption to operating real-life buildings. Against this backdrop, this study is directed toward selecting reliable and costeffective retrofit techniques for improving the seismic performance of substandard RC buildings with different structural systems and heights common in medium seismicity regions. Contemporary retrofit approaches are investigated, including polyparaphenylene benzobisoxazole fiber-reinforced cementitious matrix (P-FRCM) composites, carbon FRCM (C-FRCM) composites, thin high-performance reinforced concrete (HPRC) jackets, and self-centering energy …

Valorization Of Date Palm Waste For The Isolation, Characterization, And Surface Chemistry Modification Of Nanocellulose, Mohsin Raza

Dissertations

This dissertation focuses on the utilization of date palm waste, a lignocellulosic material, as a source for the extraction of nanocellulose (NC), a versatile biopolymer with applications in biodegradable composites, bioplastics, and food packaging. Conventional methods of NC production using mineral acids such as sulphuric and hydrochloric acid are reaching their limits of toxicity, so more environmentally friendly alternatives such as ionic liquids (ILs) are being explored. The research focuses on the characterization of different date palm wastes to evaluate their α−cellulose content, lignocellulosic character, and thermal stability. By comparing extraction methods with mineral acids and ILs, the study evaluates …

Mathematical Modeling For Dental Decay Prevention In Children And Adolescents, Mahdiyeh Soltaninejad

Dissertations

The high prevalence of dental caries among children and adolescents, especially those from lower socio-economic backgrounds, is a significant nationwide health concern. Early prevention, such as dental sealants and fluoride varnish (FV), is essential, but access to this care remains limited and disparate. In this research, a national dataset is utilized to assess sealants' reach and effectiveness in preventing tooth decay, particularly focusing on 2nd molars that emerge during early adolescence, a current gap in the knowledge base. FV is recommended to be delivered during medical well-child visits to children who are not seeing a dentist. Challenges and facilitators in …

Development Of A Discrete Element Model For Artificial Turf, Justin Rittenhouse

Dissertations

NFL data exhibits a distinct correlation between an elevated lower extremity injury rate and synthetic surfaces. These ubiquitous injuries frequently relate to excessive foot traction (i.e., failure to release causing fracture or soft tissue damage). Consequently, a discrete element model was developed using open-source software to analyze stud traction. First, laboratory data was collected via bench level experiments covering seventeen different testing scenarios. A minimum of twenty-five samples were collected per scenario. Total work, average torque, and maximum torque were used as indicators of stud grip. And the latter two were statistically analyzed for outliers and significant differences. Next, an …

Enhancing Rotating Machinery Fault Diagnosis: A Dual-Head Attention Mechanism In Deep Learning Neural Networks, Qing Snyder

Dissertations

Rotating machinery is crucial to production efficiency and safety in manufacturing industries for an extended time. Ensuring machinery reliability necessitates effective diagnostic systems, particularly for rotating bearings, the key components of such equipment. Fault diagnosis in rotating machinery is essential to prevent failures and minimize downtime, thereby playing an important role in industrial operations. The application of advanced neural network techniques in industry has risen recently. Among these, attention-based neural networks, especially the Transformer models, are originally noteworthy for their sequential data handling capability. This research delves into attention-based algorithms for rotating machinery fault diagnosis, signifying a substantial advancement in …

Experimental Investigation Of Various Hydrogen Knock Limit Extension Strategies On A Hydrogen-Gasoline Dual Fuel Spark Ignition Engine, Sanad Thurakkal Puthan

Dissertations

Hydrogen is a clean and carbon free substitute with the ability to significantly cut down the harmful emissions while enhancing the energy efficiency of internal combustion engines (ICE) typically powered by conventional fossil fuels. Hydrogen is the most abundant elements which can be easily obtained from sources like water and biomass. The wide flammability range and high laminar flame velocity outstands hydrogen from other fuels. However, hydrogen fueled engines are more prone to abnormal combustion like knock and backfire due to its low ignition energy and high adiabatic flame temperature. To avoid backfire, several well developed approaches have been reported. …

Graphene 2d Heterostructures For Thz Applications, Omnia Samy Shaaban

Dissertations

THz technology is a promising field that has various applications in communication, medical imaging and diseases’ detection, scanning, and the food industry. Since THz technology is still in its early stages, there is a lot of work to be done to obtain devices that work efficiently in the THz range. One of these devices is THz absorbers that are the basic building blocks for the next generation THz systems whether in communication systems, imaging or shielding. THz absorbers are structures that can absorb electromagnetic waves in the THz range (0.1-10 THz). THz absorbers can be wideband (absorb a wide range …

Enzymatic Production Of Cyclodextrin Using Cyclodextrin Glycosyltransferase Immobilized In Metal Organic Frameworks (Mofs), Babatunde Azeez Ogunbadejo

Dissertations

Cyclodextrins (CDs) and their derivatives have attracted significant attention in the pharmaceutical, food, and textile industries, which has led to an increased demand for their production. CDs are typically produced by the action of cyclodextrin glycosyltransferase (CGTase) on starch. Owing to the relatively high cost of enzymes, the economic feasibility of the entire process strongly depends on the effective retention and recycling of CGTase in the reaction system, while maintaining the enzyme’s activity and stability. Previous supports used for this purpose such as silica and hydrogels, have numerous drawbacks, including enzyme leaching, activity loss and significant mass transfer limitations. The …

Valorization Of The Polymeric Constituents In Plastic Wastes Through Thermo-Chemical Processes By Using Viable Metal Oxides Additives, Labeeb Hamad Ali

Dissertations

The rapid accumulation of different types of plastic waste necessitates the development of effective and economically viable waste management operations. Such a process should ideally not only mitigate associated environmental burdens but also recycle and recover value-added products. Through incineration or pyrolysis, thermal processing has emerged as a mainstream approach to waste management of the ever-increasing loads of different categorized plastic wastes. Throughout the work of the thesis, we have utilized a multitude of complementary techniques spanning material characterizations, catalysis, kinetic modelling, and density functional theory (DFT) to comprehend the complex chemistry that underpins catalytic chemical recycling of plastic wastes. …

Synthesis And Structure-Property Relationships Of Sustainable Nanostructured Materials Towards Energy And Environment Applications, Nizamudeen Cherupurakal

Dissertations

This doctoral research aims to advance clean energy technologies by developing specialized nanostructured materials. The study covers significant research themes, each forming separate sections in the thesis, explaining the important role of nanostructures in enhancing the efficiency and sustainability of energy devices and photocatalytic technologies.

The enduring effort toward stabilizing and improving the efficiency of Dye-Sensitized Solar Cells (DSSCs) has stirred the solar research community to follow innovative approaches. The primary objective of the research is centered on electrode materials design, which improves photoanodes' Light-Harvesting Efficiency (LHE). To improve the Photoanode of DSSCs, a Metal-Organic Framework (MOF) derived porous photoanodes …