Engineering Commons^™

Pretreatment Of Corncob With Green Deep Eutectic Solvent To Enhance Cellulose Accessibility For Energy And Fuel Applications, Sanphawat Phromphithak, Nakorn Tippayawong, Thossaporn Onsree, Jochen A. Lauterbach

Faculty Publications

Fossil fuels are the primary source of energy for a long period in spite of excessive environmental hazards, such as greenhouse gas emissions. Production of energy and fuel from lignocellulosic biomass has been the goal of the study in pursuit of renewable alternatives to fossil materials. Corncob is common agricultural biomass waste found in many countries. It can be utilized to produce bioenergy, but the conversion efficiency is limited. Pretreatment may be applied to improve the efficiency of corncob conversion; for example, by the fractionation of lignocellulosic biomass. Choline chloride (ChCl) and glycerol are considered as synthetic deep eutectic solvents …

Event-Triggered Optimal Adaptive Control Of Partially Unknown Linear Continuous-Time Systems With State Delay, Rohollah Moghadam, Vignesh Narayanan, Sarangapani Jagannathan

Publications

This paper proposes an event-triggered optimal adaptive output feedback control design approach by utilizing integral reinforcement learning (IRL) for linear time-invariant systems with state delay and uncertain internal dynamics. In the proposed approach, the general optimal control problem is formulated into the game-theoretic framework by treating the event-triggering threshold and the optimal control policy as players. A cost function is defined and a value functional, which includes the delayed system output, is considered. First, by using the value functional and applying stationarity conditions using the Hamiltonian function, the output game delay algebraic Riccati equation (OGDARE) and optimal control policy are …

A Comparison Of Robotic Hand Thumb Designs, Ryon Miro

Journal of the South Carolina Academy of Science

No abstract provided.

Tutorial: Knowledge-Infused Learning For Autonomous Driving (Kl4ad), Ruwan Wickramarachchi, Cory Henson, Sebastian Monka, Daria Stepanova, Amit Sheth

Publications

Autonomous Driving (AD) is considered as a testbed for tackling many hard AI problems. Despite the recent advancements in the field, AD is still far from achieving full autonomy due to core technical problems inherent in AD. The emerging field of neuro-symbolic AI and the methods for knowledge-infused learning are showing exciting ways of leveraging external knowledge within machine/deep learning solutions, with the potential benefits for interpretability, explainability, robustness, and transferability. In this tutorial, we will examine the use of knowledge-infused learning for three core state-of-the-art technical achievements within the AD domain. With a collaborative team from both academia and …

Tutorial: Neuro-Symbolic Ai For Mental Healthcare, Kaushik Roy, Usha Lokala, Manas Gaur, Amit Sheth

Publications

Artificial Intelligence (AI) systems for mental healthcare (MHCare) have been ever-growing after realizing the importance of early interventions for patients with chronic mental health (MH) conditions. Social media (SocMedia) emerged as the go-to platform for supporting patients seeking MHCare. The creation of peer-support groups without social stigma has resulted in patients transitioning from clinical settings to SocMedia supported interactions for quick help. Researchers started exploring SocMedia content in search of cues that showcase correlation or causation between different MH conditions to design better interventional strategies. User-level Classification-based AI systems were designed to leverage diverse SocMedia data from various MH conditions, …

Direct Material Property Determination: One-Dimensional Formulation Utilising Full-Field Deformation Measurements, Sreehair Rajan-Kattil, Michael A. Sutton, Subramani Sockalingam, Frank Thomas, Tusit Weerasooriya, Stephen Alexander

Faculty Publications

A direct approach is described to determine the elastic modulus distribution in a nominally heterogeneous material subject to tensile/compression loading and primarily experiencing deformations in the axial direction. The formulation is developed for uniaxial applications using basic theoretical constructs, resulting in a computational framework that has a matrix form [A] {E} = {R}, where the [A] matrix components are known functions of measured axial strains and axial positions, {R} components are known functions of axial body forces, applied loads and reactions and {E} components are the unknown elastic moduli at discrete locations along the length of the specimen. For a …

Versatile And Robust Non-Iterative Coupling Algorithm For Vehicle-Structure Interaction, Arya Datta

Theses and Dissertations

The dynamic analysis of the vehicle-structure interactions can be extremely computationally expensive. A general non-iterative coupling algorithm based on the substructure approach has been presented. It retains the advantage of the substructure approach that smaller subsystems are solved instead of a large system, which is usually solved when monolithic systems are solved. However, the advantage of using this general coupling approach is that it is non-iterative in nature, instead of the substructure approach that usually uses iterative procedure. The general coupling algorithm developed has been implemented to analyze dynamic interactions between the vehicle and the structure, both in two and …

A Hybrid Experimental-Computational Study: Prediction Of Flow Fields And Full-Field Pressure Distributions On Three-Tab Asphalt Roofing Shingles Subjected To Hurricane Velocity Winds, Troy A. Myers

Theses and Dissertations

A novel hybrid experimental-computational study is performed to predict the flow fields and pressure distributions on the measured shapes of flexible, three-tab asphalt roofing shingles undergoing increasing uplift when exposed to hurricane velocity winds. StereoDIC analysis is performed to measure the transient full-field deformed shapes of full-size three-tab asphalt shingles when subjected to hurricane velocity winds for two hours. Steady state computational fluid dynamics (CFD) simulations of the shingled roof facsimile-plenum region representative of the experiments are successfully performed. The simulations are performed to predict wind loading of the uplifted shingle shapes by utilizing the measured full-field three-dimensional uplifted shapes …

Uav Rapidly-Deployable Stage Sensor With Electro-Permanent Magnet Docking Mechanism For Flood Monitoring In Undersampled Watersheds, Corinne A, Smith, Joud Satme, Jacob Martin, Austin Downey, Nikolaos Vitzilaios, Jasim Imran

Faculty Publications

The availability of historical flood data is vital in recognizing weather-related trends and outlining necessary precautions for at-risk communities. Flood frequency, magnitude, endurance, and volume are traditionally recorded using established streamgages; however, the material and installation costs allow only a few streamgages in a region, which yield a narrow data selection. In particular, stage, the vertical water height in a water body, is an important parameter in determining flood trends. This work investigates a low-cost, compact, rapidly-deployable alternative to traditional stage sensors that will allow for denser sampling within a watershed and a more detailed record of flood events. The …

Metaversekg: Knowledge Graph For Engineering And Design Application In Industrial Metaverse, Utkarshani Jaimini, Tongtao Zhang, Georgia Olympia Brikis

Publications

While the term Metaverse was first coined by the author Neal Stephenson in 1992 in his science fiction novel “Snow Crash”, today the vision of an integrated virtual world is becoming a reality across different sectors. Applications in gaming and consumer products are gaining traction, industrial metaverse applications are, still in their early stages of development with one of the challenges being interoperability across various metaverse development platforms and existing software tools. In this work we propose the use of a knowledge graph based semantic data exchange layer, the Metaverse Knowledge Graph, to enable seamless transfer of information across platforms. …

Achieving Sustainability In Urban Transit And High-Occupancy Vehicle Systems Through Emerging Technologies And Operations, Ruixiao Sun

Theses and Dissertations

It is critical to reduce road transportation emissions, as it is the major source contributing to greenhouse gas emissions (GHGs) and air pollution. However, the increasing travel demand due to the rise of population and economy makes the task challenging. Mathematically, road transportation emissions can be minimized in the manner of reducing total vehicle miles traveled (VMT) and lowering vehicle emission rate. Many strategies have been proven viable for achieving transportation sustainability. For example, the total VMT can be reduced by switching low-occupancy transportation modes (i.e., driving alone) to high-occupancy transportation modes (i.e., public transit, ridesharing). The development of alternative-fuel …

Applications Of Laser Liftoff Technique For Wide Bandgap Power And Flexible Electronics, Md Didarul Alam

Theses and Dissertations

Wide bandgap (WBG) AlGaN/GaN and ultrawide bandgap (UWBG) AlGaN/AlGaN III-nitride high electron mobility transistors (HEMTs) have come a long way since their initial demonstration and are desired for a multitude of applications in deep-scaled high-frequency, high-voltage, high-current, and high-temperature power electronics. Although AlGaN/GaN HEMTs have recently become state-of-the-art in consumer electronics chargers and amplifiers, the performance of the devices is limited by severe self-heating which significantly reduce their efficacy in demanding applications that require high-current density. One strategy to reduce this self-heating effect in GaN HEMTs is to use high thermal conductivity SiC or bulk AlN substrates. While this approach …

Supported Metal Bifunctional And Bimetallic Catalysts With Precisely Controlled Structures And Properties, Anhua Dong

Theses and Dissertations

In heterogenous catalysis, metallic nanomaterials play vital roles in numerous chemical processes. However, monofunctional catalysts are greatly impeded in their applications especially in the systems including tandem and/or sequential reaction steps. Besides, the catalytic performance can also be greatly influenced by the particle size, morphology, and geometry of the surface metal atoms.

The goal of this work is to synthesize bifunctional or bimetallic nanoparticles with high metal dispersion and homogenous alloys by rational synthetic strategies to facilitate the catalyst function. Strong electrostatic adsorption (SEA) is an effective and facile methodology to produce well dispersed and uniform nanoparticles. Metal-acid bifunctional catalysts …

Impacts Of Preferential Vaporization Of Multi-Component Liquid Fuels On Near-Limit Combustion Behaviors, Seungjae Lim

Theses and Dissertations

Combustion technologies used in energy conversion devices involve multi-phase and multi-component combustion behaviors associated with chemical kinetic characteristics coupled with spray dynamics. For reliable engine operation, the engine operation envelope is necessarily required to be determined by near-limit combustion behaviors such as flame flashback, lean blowout, ignition, and extinction, which are influenced by both fuel chemical and physical properties. Liquid fuels are composed of a wide range of molecular structures and weights, therefore exhibiting relatively large distillation temperature range. When fuel chemical properties change during fuel vaporization, preferential vaporization effects could play a considerable role in near-limit combustion behaviors. In …

Mimo Antenna Systems For Wireless Handheld Devices, Ahmed H. Abdelgawwad

Theses and Dissertations

Mobile communications have seen tremendous growths in the last decades in the form of smartphones, watches, wireless enabled Personal Digital Assistants (PDAs) and so on. The current and future wireless communication systems require high data-rate capabilities to support high speed needs of users in modern applications. Multiple-input multiple-output (MIMO) antenna systems have become the most promising candidate to support the increased data demand. Therefore, they have emerged as an integral part of the new 5G wireless standard. One key challenge regarding MIMO systems for the handheld is to be able to successfully accommodate multiple miniature platform integrated antennas within a …

Towards Modeling Of Induction Welding Of Thermoplastic Laminates With A Mixed Finite Element Boundary Element Approach, Florentius Johannes Van Zanten

Theses and Dissertations

There is an increased interest in induction welding of carbon fiber reinforced thermoplastic composite laminates within the aerospace industry. Currently, optimal manufacturing process parameters (e.g., current, power, and frequency settings, coil movement speed, etc.) are determined through an experimental trial-and-error approach. To reduce the need for an experimental approach that can determine the manufacturing process parameters, which would be expensive in both time and money, accurate and computationally efficient numerical tools are desired. This research is focused on improving the existing numerical tool, WelDone, in regard to its speed and accuracy.

WelDone utilizes a hybrid element formulation that combines traditional …

Investigating The Impact Of Endothelial Dysfunction And Aging On Vascular Remodeling Using Mouse Models, Liya Du

Theses and Dissertations

Endothelial dysfunction, characterized by a reduction in the bioavailability of nitric oxide (NO), is a major factor in the initiation and progression of atherosclerosis, an age-related chronic inflammatory process in the arterial wall and the leading cause of mortality and morbidity globally. A better understanding of alterations in vascular structure and function associated with endothelial dysfunction can facilitate the early detection of atherosclerosis and the development of potential pharmaceutical interventions. This study aims to clarify the impact of endothelial dysfunction in conjunction with aging on the microstructure of aortic extracellular matrix (ECM) and to elucidate the relationship between microstructural adaptation …

Molten Salt Thermal Properties Database – Thermochemical Development And Thermodynamic Assessment Of Various Molten Salt Systems, Johnathon Chandler Ard

Theses and Dissertations

The Molten Salt Thermal Properties Database – Thermochemical (MSTDB-TC) is a validated open-source database for thermochemical modeling of molten salt reactor (MSR) relevant fluoride and chloride salt systems. The database has been created and populated by leveraging available models from literature as well as completing novel system assessments. The development and contents of the MSTDB-TC v1.2 initial release are detailed along with various system assessments performed in the course of the work. The database utilizes a major strength of the CALPHAD thermodynamic modeling method. This is the ability to estimate higher-order system behavior by combining modeled lower-order systems, …

Digital Twins In Advanced Manufacturing To Enhance Manufacturing Efficiency, Max Kirkpatrick

Theses and Dissertations

Digital Twins of manufacturing systems are an emerging tool for improvement, optimization, and monitoring of physical manufacturing systems. The idea of representing physical systems with digital depictions has been prevalent since the early days of Computer Aided Design (CAD), but recently the concept of a Digital Twin has been expanded to encapsulate more than just a digital model of a design. Instead, the Digital Twin offers a unique, comprehensive, and real-time toolset for analysis and improvement of physical systems. These tools can be used to improve system efficiency, perform “what-if” analyses, virtually commission manufacturing equipment, analyze system performance in real …

Self-Sensing Smart Products In Smart Manufacturing Systems, Juergen Lenz, Eric Macdonald, Ramy Harik, Thorsten Wuest

Faculty Publications

We are surrounded by a growing number of products with embedded intelligence relying on sensors and internet access. These smart products, that already transform our lives, are also physical entities that need to be manufactured. Manufacturing today similarly relies on data and data-driven insights to improve quality, efficiency, and safety on the shopfloor. This paper discusses the vision to utilize the ability of smart products to sense and communicate already during their own manufacturing to enrich the smart manufacturing system’s data for better insights development and optimization. We furthermore, discuss the barriers and opportunities embedded in such a paradigm shift.

Histomechanical Compatibility Of Coronary Artery Bypass Grafts, Colton J. Kostelnik

Theses and Dissertations

Coronary artery disease is a localized form of atherosclerosis that can severely restrict blood flow to the heart often requiring a surgical intervention known as coronary artery bypass grafting (CABG) to reestablish perfusion to this essential circulation. To some extent, the selection of the autograft tissue is at the surgeon’s discretion with factors such as stenosis location and the existing tissue’s pathological state contributing to a choice that could be deterministic in surgical outcomes. Many post-operative complications and premature graft failures originate from graft-target tissue incompatibilities and altered blood flow patterns. We hypothesize that mechanical mismatching between the graft material …

Experimental Investigations Of Yarn Pull-Out Behavior In Kevlar®: Influence Of Applied Metallic Coatings And Effect Of Dynamic Loading, Julie Ann Roark

Theses and Dissertations

Flexible woven Kevlar® textile fabrics are widely used in protective armor applications. Yarn pull-out, comprised of yarn uncrimping (i.e., straightening) and yarn translation, is a major energy absorption mechanism during ballistic impact onto these fabrics, especially for impact velocities below the ballistic limit. Yarn pull-out is influenced by various parameters including inter-yarn friction, pull-out distance, pull-out velocity, transverse pre-tension, fiber diameter, fabric architecture, fabric waviness, fabric count and yarn modulus.

The first part of this thesis investigates yarn pull-out behavior of commercially available Kevlar® KM2+ individual yarns coated with metallic layers (copper, aluminum, aluminum nitride, silver) via a directed vapor …

High-Throughput Computation Of Interfacial Thermal Management Of Wide-Bandgap Semiconductors, Hao-Wen Chen

Theses and Dissertations

As semiconductor electronics, in particular high electron mobility transistors, get hot in operation, people are trying to incorporate different semiconductor materials to solve the problem of heat dissipation to maintain the device efficiency and performance. In this master thesis, two different packages, LAMMPS and almaBTE, that are focusing on micro-scale and atomic scale respectively, are used to simulate the heat transfer process across interfaces in two different scales. In the LAMMPS simulation, the research is exploring how the location of atoms and the thickness of interfacial layers will influence the interfacial thermal conductance. On the other hand, using the almaBTE …

Uncrewed Aircraft Systems For Autonomous Infrastructure Inspection, Michail Kalaitzakis

Theses and Dissertations

Uncrewed Aircraft Systems (UAS) are becoming increasingly popular for infrastructure inspections since they offer increased safety, decreased costs and consistent results, compared to traditional methods. However, there are still many open challenges before fully autonomous, reliable, and repeatable UAS inspections. While a UAS platform has increased mobility and can easily approach hard to reach areas, it has limited range and payload capacity and is susceptible to environmental disturbances. Therefore, current operations are limited to Visual Line of Sight (VLOS) manual inspections that usually result in just a qualitative (visual) assessment of the structure.

The objective of this work is to …

Decellularization Strategies Of Naturally Derived Biomaterials For Tissue Engineering Applications, Julia Elizabeth Hohn

Theses and Dissertations

In 2017, over 3.5 million peripheral vascular surgeries were performed worldwide with over 400,000 vascular repair or replacement surgeries being performed in the United States each year alone. As the number of vascular repair surgeries, including both coronary and peripheral bypass grafting procedures, continues to increase each year, these statistics indicate an urgent need for more effective and readily available replacement materials. Regenerative medicine and tissue engineering (TE) approaches, including the design, fabrication, and validation of suitable biomaterials in vitro that direct the repair and regeneration of damaged tissues, have been proposed to alleviate this problem. While advanced biomaterials have …

Durability Enhancement Of Anion Exchange Membrane Based Fuel Cells (Aemfcs) And Water Electrolyzers (Aemels) By Understanding Degradation Mechanisms, Noor Ui Hassan

Theses and Dissertations

The past several years have seen remarkable progress in renewable energy sources such as solar and wind, showing excellent efficiency and significant cost reduction. The intermittent nature of renewable resources requires them to be integrated with energy storage systems that can hold or convert this excess energy into other forms. Though batteries have been the most popular, it is also possible to store the energy as chemicals and fuels, such as hydrogen (H₂). Hydrogen generation from water electrolysis has been receiving significant attention in recent years. Among the existing water electrolysis technologies, anion exchange membrane electrolyzers (AEMELs) are …

Fabrication Of Asymmetrical Hollow Fiber-Supported Thin Film Membranes, Stack Assembly, And Accelerated Long-Term Stability Test For Oxygen Production From Air, Myongjin Lee

Theses and Dissertations

Air separation is a widely used process for oxygen production. Several separation technologies have been developed for air separation, including cryogenic distillation, swing adsorption, redox process of metal oxides, and electrochemical process. Among these technologies, electrochemical permeation process stands out as a cost-effective and simple process for pure oxygen production from air. The electrochemical permeation process employs a gas-tight membrane to permeate and separate oxygen from air directly, where the membrane conducts both ions and electrons simultaneously. Different membrane designs have been studied to obtain the improved performance for oxygen permeation, typically planar and tubular designs. Among these membrane configurations, …

Shear Localization In The Metallic Nanolayered Composites, Shujing Dong

Theses and Dissertations

In this dissertation, the influences of layer thickness (h), interface orientation relationship (OR) and dislocation slip activities on shear band (SB) formation mechanisms was investigated by means of molecular dynamics (MD) simulations.

The effect of h and dislocation slip systems on the shear localization in Cu-FCC/Nb-BCC MNCs was studied. The strain softening observed in those samples was triggered by the SB formation. The microstructure evolutions and dislocation slips revealed that the unsymmetrical dislocation transmission across the interface induces the shear localization and promotes the SB formation. The quantitative analysis of the change in the separation distance of initially …

Cnn-Based Dendrite Core Detection From Microscopic Images Of Directionally Solidified Ni-Base Alloys, Xiaoguang Li

Theses and Dissertations

Dendrite core is the center point of the dendrite. The information of dendrite core is very helpful for material scientists to analyze the properties of materials. Therefore, detecting the dendrite core is a very important task in the material science field. Meanwhile, because of some special properties of the dendrites, this task is also very challenging. Different from the typical detection problems in the computer vision field, detecting the dendrite core aims to detect a single point location instead of the bounding-box. As a result, the existing regressing bounding-box based detection methods can not work well on this task because …

Physico-Mechanical Characterization Of Prototype Earth Block Material For Constitutive Modeling, Erika Lorena Rengifo-López

Theses and Dissertations

The comprehensive understanding and experimental characterization of the overall compressive behavior of earth masonry block materials, such as compressed and stabilized earth blocks (CSEBs), are essential for developing analytical and numerical tools to predict the mechanical response and designing earth masonry structures. Furthermore, advancing the understanding of the extent of the influence of testing parameters on the material's response, such as specimen geometry, is a critical step towards standardization.

CSEBs are produced by compressing a mixture of soil, water, and a stabilizer (e.g., Portland cement). The heterogeneity of the material accrues from the variety of soil particle morphology and potential …