Characterization Of Landslide Processes From Radar Remote Sensing And Hydromechanical Modeling, Yuankun Xu

Earth Sciences Theses and Dissertations

Landsides are a natural geomorphic process yet a dangerous hazard which annually causes thousands of casualties and billions of property loss in a global scale. Understanding landslide motion kinematics from early initiation to final deposition is critical for monitoring, assessing, and forecasting landslide movement in order to mitigate their hazards. Landslides occur under diverse environmental settings and appear in variable types; however, all types of landslides can be mechanically attributed to shearing failure at the basal surface due to stress regime shift contributed by internal and/or external forcing. Typical internal factors include soil/rock weathering, whereas typical external triggering forces encompass …

Bimetallic Catalyst For Lignin Depolymerization, Qishen Lyu

McKelvey School of Engineering Graduate Student Theses & Dissertations

This thesis is motivated by concerns regarding the need to develop more sustainable and economic technologies to meet rising global manufacturing and energy demands. These concerns have renewed governmental, industrial, and societal determination to reduce the world’s dependence on conventional natural resources and has led to considerable research on producing fuels and chemicals from feedstocks other than petroleum. Lignocellulosic biomass represents an abundant and renewable resource that could displace petroleum feedstock producing biofuels and multiple valuable chemical products with reduced greenhouse gas emissions. Lignin is the second abundant biopolymer source in nature and is found almost everywhere. Since the 1950’s, …

Laminin-Mimetic Peptide-Functionalized Hydrogel Systems For The Phenotypic Modulation Of Cells Of The Nucleus Pulposus, Marcos Nicolas Barcellona

McKelvey School of Engineering Graduate Student Theses & Dissertations

The intervertebral disc (IVD) has been widely observed to undergo significant structural and biochemical changes with age and maturation. As degeneration progresses, changes in extracellular matrix composition and deposition, tissue cellularity, and metabolic activity have been characterized. Although the epidemiology of disc degeneration remains unclear, it is believed that the nucleus pulposus (NP) region of the IVD may be implicated in early degeneration. Specifically, cells of the nucleus pulposus have been observed to undergo a shift from their notochordal-like juvenile phenotype to a more fibroblast-like state in a manner concomitant to degenerative events. Because the disc has inherently little capacity …

Cortical Organization In Humans And Nonhuman Primates: The Evolution Of Cognitive Areas And Circuits, Chad Joseph Donahue

McKelvey School of Engineering Graduate Student Theses & Dissertations

Similarities in organization of cerebral cortex in humans and nonhuman primates offer the promise of leveraging data from invasive animal studies to better understand the complexities of the human brain, particularly those related to higher cognitive function (e.g. attention, working memory, language). Such comparisons necessitate the identification of convincing cortical homologues (areas or regions presumed to have derived from a common ancestor), requiring an accurate interspecies mapping of cortical areas and features. To this end, I describe (i) a survey of connectivity and its measures across primate species, particularly retrograde tracing and diffusion tractography, (ii) a morphometric analysis of cognitive …

Understanding A Role For Synovium In Intra-Articular Drug Clearance: A Computational And Experimental Approach, Young Guang

McKelvey School of Engineering Graduate Student Theses & Dissertations

The synovium is a membranous tissue that governs molecular transport between the intra-articular (IA) joint space and the systemic circulatory system. Drug delivery to the IA space is an attractive option to treat localized joint diseases such as osteoarthritis. However, short residence times due to rapid clearance from the joint diminishes efficacy of IA injected drugs. While many studies exist on the clearance of drugs from the IA space, these studies lack the ability to isolate and characterize trans-synovial transport.The first aim of this dissertation establishes a computational finite element (FE) model of trans-synovial transport using multiphasic mixture theory. The …

Converting Inorganic Rust To Organic Nanostructured Conducting Polymers: Synthesis And Applications, Yifan Diao

McKelvey School of Engineering Graduate Student Theses & Dissertations

Iron rust is a type of corrosion product, coming from the chemical reaction between iron and oxygen in the presence of water that first documented ca. 800 BCE. It is a heterogeneous inorganic solid-state material composed of multiple phases and is ubiquitous throughout the universe. Rust species such as Hematite (α-Fe2O3), Akaganeite (β-FeOOH), and ferrous hydroxide (Fe(OH)2), make up the solid-state chemical family composed of iron oxides, oxyhydroxides, and hydroxides that are typically recognized as chemical waste. Conducting polymer is a type of organic plastic composed of long chains with repeating subunits that bonding with strong interactions between neighboring molecules. …

Understanding The Interactions Between Acoustic Fields And Motile Microorganisms In Microfluidic Systems, Minji Kim

McKelvey School of Engineering Graduate Student Theses & Dissertations

Acoustofluidics utilizes ultrasonic standing waves in microscale fluidic channels to manipulate cells, microorganisms, and other objects sized from tens of nanometers to tens of microns. When exposed to an ultrasonic standing wave field, particles suspended in a fluid become confined to potential minima (nodes) of the acoustic field. I will present a number of related studies that involve the interactions between acoustic fields and motile microorganisms. First, I will show how an acoustic trap-and-release method enables rapid quantification of cell motility. As a demonstration, the newly developed motility assay is applied to discriminate swimming of wild-type and mutant Chlamydomonas reinhardtii …

Multiprincipal Element Alloy Development Via High-Throughput Experiments, Mu Li

McKelvey School of Engineering Graduate Student Theses & Dissertations

Multiprincipal element alloys (MPEAs) are a novel class of engineering materials. As opposed to conventional alloys, where one or two elements are dominant with others in minor amount to provide improvements or supplements to the properties, there is a lack of clear solvent species in MPEAs. Since the discovery in 2004, MPEAs have stimulated the exploration of the vast compositional space offered by the increased number (≥ 3) of principal elements, and the studied alloy compositions cover an exceptionally broad range of microstructures and properties. Despite the unparalleled potential of MPEAs, the considerable number of choices in number, type and …

Post-Traumatic Elbow Contracture Characterization And Physical Therapy-Based Treatment Strategies In A Preclinical Model, Alex Reiter

McKelvey School of Engineering Graduate Student Theses & Dissertations

The elbow is the most commonly dislocated joint in the pediatric population and second most common in adults. As one of the most congruous joints in the body, slight changes in biomechanics due to injury can lead to drastic reductions in range of motion causing potential quality of life issues. Post-traumatic joint contracture occurs in 12% of patients following elbow dislocation or fracture, and it is characterized by a loss in ROM, joint stiffness, and pain. Preventing joint contracture and functional deficits from occurring is one of the primary goals when managing these injuries. A rat model of joint contracture …

Interaction Of Aqueous U(Vi) With Goethite, Montmorillonite, And Uo2(S), Anshuman Satpathy

McKelvey School of Engineering Graduate Student Theses & Dissertations

Uranium contamination in subsurface environments is a matter of great concern throughout the world. Fate and transport of uranium in the subsurface can be controlled by U(VI) adsorption and reduction onto common iron (oxy)hydroxides and clay minerals. Aqueous U(VI) can also exchange uranium atoms with solids comprised of uranium which can potentially lead to changes in the morphology of the uranium-containing solids and affect their stability. First, the performance of multiple surface complexation models (SCMs) on adsorption of U(VI) onto goethite was analyzed for a broad range of input conditions. Individual models could fit the data for which they were …

Subject-Specific Musculoskeletal Modeling Of Hip Dysplasia Biomechanics, Ke Song

McKelvey School of Engineering Graduate Student Theses & Dissertations

Developmental dysplasia of the hip (DDH) is characterized by abnormal bony anatomy, causes pain and functional limitations, and is a prominent risk factor for premature hip osteoarthritis. Although the pathology of DDH is believed to be mechanically-induced, little is known about how DDH anatomy alters hip biomechanics during activities of daily living, partly due to the difficulties with measuring hip muscle and joint forces. Musculoskeletal models (MSMs) are useful for dynamic simulations of joint mechanics, but the reliability of MSMs for DDH research is limited by an accurate model representation of the unique hip anatomy. To address such challenges, this …

Rational Design And Optimization Of Perovskite Semiconductors, Arashdeep Thind

McKelvey School of Engineering Graduate Student Theses & Dissertations

ABSTRACT OF THE DISSERTATIONRational design and optimization of perovskite semiconductors by Arashdeep Singh Thind Doctor of Philosophy in Materials Science and Engineering Washington University in St. Louis, 2021 Professor Rohan Mishra, Chair

Lead-halide perovskites have emerged as a promising class of semiconductors for next-generation solar cells and optoelectronic devices. Since the report of the photovoltaic effect in 2009 in CH3NH3PbBr3 and CH3NH3PbI3, the power conversion efficiency of these perovskites has rapidly approached 25.2% from 3.8%. These perovskite semiconductors can be synthesized using low-cost solution-based techniques, unlike traditional semiconductors that require slow and expensive growth techniques to reduce the formation of …

Plasmonically-Enhanced Ultrasensitive Biodetection Technologies, Zheyu Wang

McKelvey School of Engineering Graduate Student Theses & Dissertations

Detection and quantification of biomolecules within biological fluids and tissues is of fundamental importance to biomedical research and clinical diagnostics. It is impossible to fully characterize complex, non-linear, biochemical systems without being able to accurately and quantitatively determine the component molecules. This problem is ubiquitous across all domains of biomedical research, and it is a major barrier to fully understanding health, ageing, and disease. Such bottlenecks are extremely challenging to be solved, especially for proteins and peptides, which do not have amplification schemes such as polymerase chain reaction for nucleic acids, because relevant concentrations of molecules related to diseases such …

Engineering Nucleus Pulposus Cell-Matrix Interactions With Laminin Ligands For Tissue Regeneration, Julie Elizabeth Speer

McKelvey School of Engineering Graduate Student Theses & Dissertations

Low back pain and degenerative conditions of the intervertebral disc (IVD) represent major global socioeconomic and medical burdens. The structures that comprise the IVD including the anulus fibrosis and the nucleus pulposus (NP) work together to stabilize the axial skeleton and distribute mechanical forces. However, the degenerative cascade, which is thought to begin with changes to the NP, results in alterations to the disc that can be seen across length scales including elongated cell shapes, tissue dehydration, and loss of disc height. Patients who present clinically with these changes may also experience altered biomechanics, pain upon motion, impairments to their …

Assessment And Diagnosis Of Human Colorectal And Ovarian Cancer Using Optical Imaging And Computer-Aided Diagnosis, Yifeng Zeng

McKelvey School of Engineering Graduate Student Theses & Dissertations

Tissue optical scattering has recently emerged as an important diagnosis parameter associated with early tumor development and progression. To characterize the differences between benign and malignant colorectal tissues, we have created an automated optical scattering coefficient mapping algorithm using an optical coherence tomography (OCT) system. A novel feature called the angular spectrum index quantifies the scattering coefficient distribution. In addition to scattering, subsurface morphological changes are also associated with the development of colorectal cancer. We have observed a specific mucosa structure indicating normal human colorectal tissue, and have developed a real-time pattern recognition neural network to localize this specific structure …

Magnetic Resonance-Guided High Intensity Focused Ultrasound (Mrghifu) Induced Hyperthermia (Ht) For Treatment Of Cervical Cancer, Lifei Zhu

McKelvey School of Engineering Graduate Student Theses & Dissertations

Hyperthermia (HT), which refers to increasing the temperature of the tumor tissue to 40–45°C for an extended period of time, has been reported to be one of the most effective sensitizers for radiation therapy (RT) and/or chemotherapy. High intensity focused ultrasound (HIFU) has been developed as a non-invasive and non-ionizing tool to induce localized HT. Magnetic resonance thermometry (MR thermometry) is one of the most reliable methods for non-invasively and precisely measuring the in vivo volumetric temperature in real time. The integration of MR thermometry with HIFU has been implemented in commercially available magnetic resonance guided high intensity focused ultrasound …

Efficient And Scalable Computing For Resource-Constrained Cyber-Physical Systems: A Layered Approach, An Zou

McKelvey School of Engineering Graduate Student Theses & Dissertations

With the evolution of computing and communication technology, cyber-physical systems such as self-driving cars, unmanned aerial vehicles, and mobile cognitive robots are achieving increasing levels of multifunctionality and miniaturization, enabling them to execute versatile tasks in a resource-constrained environment. Therefore, the computing systems that power these resource-constrained cyber-physical systems (RCCPSs) have to achieve high efficiency and scalability. First of all, given a fixed amount of onboard energy, these computing systems should not only be power-efficient but also exhibit sufficiently high performance to gracefully handle complex algorithms for learning-based perception and AI-driven decision-making. Meanwhile, scalability requires that the current computing system …

Data-Driven Modeling And Control Of A Two-Link Flexible Manipulator (Tlfm), Samuel Ayankoso

Theses and Dissertations

Two-link flexible manipulators (TLFMs) are used in different application domains, and their merits include lightweight, low energy consumption, high operational speed, transportability, maneuverability, and low cost. Despite the merits of TLFMs, the flexibility of the links introduces modeling and control problems. The existing mathematical modeling techniques of a TLFM, such as the assumed mode method (AMM), finite element method (FEM) and finite difference method (FDM are mathematically complex and do not accurately match the physical system dynamics. Lumped parameter method (LPM) model is a simplified model, but it is also inaccurate. Moreover, different forms of control problems are applicable to …

A Bibliometric Perspective Survey Of Iot Controlled Ai Based Swarm Robots, Rhea Sawant, Ariz Shaikh, Chetna Singh, Aman Aggarwal, Shivali Amit Wagle, Harikrishnan R, Priti Shahane

Library Philosophy and Practice (e-journal)

Robotics is the ­new-age domain of technology that deals with bringing a collaboration of all disciplines of sciences and engineering to create a mechanical machine that may or may not work entirely independently but definitely focuses on making human lives much easier. It has repeatedly shown its ability to change lives at home and in the industry. As the field of robotics research grows and reaches new worlds, the military is one area where advances can have a significant impact, and the government is aware of this. Military technology has come a long way from the days where soldiers had …

Shift Register Puf Implementation On An Fpga, Sriram Thotakura

Electrical and Computer Engineering ETDs

In this thesis, a novel shift register-based physical unclonable function (PUF), called SRP, is proposed. The PUF is implemented on an FPGA and leverages the internal delay variations introduced by within-die process variations that occur within the Look-up tables (LUTs), routing and switches of the FPGA. PUFs are designed to generate bitstrings and keys on-the-fly that are device-specific (unique), random and reproducible. PUFs eliminate the need for a specialized (secure) non-volatile memory(NVM) to store the secret keys. This reduces the total cost of chips and systems, particularly those used in the Internet of Things, where it is common for systems …

Using Machine Learning Methods To Predict The Movement Trajectories Of The Louisiana Black Bear, Daniel Clark, David Shaw, Armando Vela, Shane Weinstock, John Santerre, Joseph D. Clark

SMU Data Science Review

In 1992, the Louisiana black bear (Ursus americanus luteolus) was placed on the U.S. Endangered Species List. This was due to bear populations in Louisiana being small and isolated enough where their populations couldn’t intersect with other populations to grow. Interchange of individuals between subpopulations of bears in Louisiana is critical to maintain genetic diversity and avoid inbreeding effects. Utilizing GPS (Global Positioning System) data gathered from 31 radio-collared bears from 2010 through 2012, this research will investigate how bears traverse the landscape, which has implications for gene exchange. This paper will leverage machine learning tools to improve upon existing …

Effects Of Genipin Crosslinking On The Properties Of Tendon Derived Extracellular Matrix Hydrogels, Alicia Cheyenne Coombs

Theses and Dissertations

Extracellular matrix (ECM) hydrogels are a useful biomaterial in the tissue engineering field used for injectables in drug delivery systems, wound dressing, tissue regeneration and many other applications. ECM hydrogels are highly biocompatible, contain proper ratios of biomolecules required for complex bioactivity of tissues and they promote tissue repair. However, ECM hydrogels typically have poor mechanical strength, which leads to hydrogel instability, and a limitation in their ability to be modified for translational applications. In this research, genipin, a natural crosslinker derived from plants, was utilized in an attempt to improve upon the mechanical limitations of ECM hydrogels. Genipin has …

A Temporal Investigation Of Crash Severity Factors In Worker-Involved Work Zone Crashes: Random Parameters And Machine Learning Approaches, Seyedmirsajad Mokhtarimousavi, Jason C. Anderson, Mohammed Hadi, Atorod Azizinamini

Civil and Environmental Engineering Faculty Publications and Presentations

In the context of work zone safety, worker presence and its impact on crash severity has been less explored. Moreover, there is a lack of research on contributing factors by time-of-day. To accomplish this, first a mixed logit model was used to determine statistically significant crash severity contributing factors and their effects. Significant factors in both models included work-zone-specific characteristics and crash-specific characteristics, where environmental characteristics were only significant in the daytime model. In addition, results from parameter transferability test provided evidence that daytime and nighttime crashes need to be modeled separately. Further, to explore the nonlinear relationship between crash …

Spectrum Modeling Of Rf Amplifiers Based On Intercept Points With Measurement Improvements, Siyuan Yan

Dissertations and Theses

Orthogonal frequency-division multiplexing has been developed into a popular modulation scheme for wireless communication systems, used in applications such as LTE and 5G. In wireless communication system, spectrum regrowth caused by RF amplifiers will generate distortions to both passband in use and adjacent channels such that the transmission quality will be degraded. The study of this dissertation aims to predict the spectrum regrowth for OFDM based signals at the output of a RF amplifier due to the nonlinearity. Based on Taylor polynomial coefficients, a power spectrum expression for amplified OFDM signals in terms of intercept points up to nth-order is …

Pyrolysis Kinetics Of Wildland Vegetation Using Model-Fitting Methods, Ellie Amini, Mohammad-Saeed Safdari, Nathan Johnson Brigham, David R. Weise, Thomas H. Fletcher

Faculty Publications

Slow-heating pyrolysis experiments of 14 plant species native to forests in the southern United States were conducted in a TGA to find the kinetic parameters for slow pyrolysis of all live and air-dried plant samples. Kinetic coefficients were determined from the data using model-fitting methods, resulting in single kinetic parameters for the entire pyrolysis process which can be used by wildland fire modelers. The model forms explored here are a simple one-step model and single and multiple reaction distributed activation energy (DAE) models. The mass loss and derivative mass loss data were fitted simultaneously at heating rates of 10, 20, …

A Practical Methodology To Detect, Quantify And Characterize Experimental Uncertainties In The Dynamic Testing Of Structures, James L. Woodall

Civil Engineering ETDs

This thesis investigates the uncertainty in the experimental context of structural dynamics. This thesis proposes a method to estimate both the effect of boundary conditions, as well as two different methods to detect the location of sensors on a specimen. Firstly, this thesis proposes a technique to predict the dynamic behavior of any point along a cantilever beam with an uncertain transverse elastic restraint. Secondly, this thesis investigates the estimation of the location of a sensor given the output data of a physical experiment with two different methods. Small errors in the sensor location may go unnoticed in the frequency …

Resolving Anodic Current And Temperature Distributions In A Polymer Electrolyte Membrane Water Electrolysis Cell Using A Pseudo-Two-Phase Computational Fluid Dynamics Model, J. Lopata, Z. Kang, J. Young, G. Bender, J. W. Weidner, H-S. Cho, Sirivatch Shimpalee

Faculty Publications

Expanding upon our prior experimental work, we constructed a three-dimensional model of a polymer electrolyte membrane water electrolyzer using computational fluid dynamics. We applied the assumption of pseudo-two-phase flow, the flow of two phases with equal velocity. Experimental data were used to obtain parameters and to determine the conditions under which this model was valid. Anodic distributions of current density, temperature, liquid saturation, and relative humidity were obtained at various flow rates. The overall current density and temperature difference from inlet to outlet at the anode agreed strongly with experimental measurements under most circumstances. This verification allowed us to further …

Pepblock Builder Vr – An Open-Source Tool For Gaming-Based Bio-Edutainment In Interactive Protein Design, Venkata V. B. Yallapragada, Tianshu Xu, Sidney P. Walker, Sabin Tabirca, Mark Tangney

Cappa Publications

Proteins mediate and perform various fundamental functions of life. This versatility of protein function is an attribute of its 3D structure. In recent years, our understanding of protein 3D structure has been complemented with advances in computational and mathematical tools for protein modelling and protein design. 3D molecular visualisation is an essential part in every protein design and protein modelling workflow. Over the years, stand-alone and web-based molecular visualisation tools have been used to emulate three-dimensional view on computers. The advent of virtual reality provided the scope for immersive control of molecular visualisation. While these technologies have significantly improved our …

A Bibliometric Analysis Of Variable Displacement Pump For Optimal Control Of Operating Parameters, Anurag Ashokkumar Nema, Nagraj R. Gandhe

Library Philosophy and Practice (e-journal)

A centralized lubrication system or automatic lubrication system (ALS) is a system that delivers controlled amounts of lubricant to multiple locations on a machine while the machine is operating as per machine requirement. Lubrication occurs while the machinery is in operation, causing the lubricant to be equally distributed within the bearing and increasing the machine’s availability. Proper lubrication of critical components ensures the safe operation of the machinery. Less wear on the elements results in extension of component life, lower breakdowns, reduced downtime, reduced replacement costs, and reduced maintenance costs. If we can measure lubrication amounts, we can control the …

Impact Of Angiogenic And Osteogenic Factors In The Presence Of Biodegradable Piezoelectric Films, Jayla Millender

University Scholar Projects

One of the most common causes of bone graft rejection is lack of a vascular network connecting the graft to the existing native tissue – allowing for nutrient flow. Under current grafting techniques, the existing blood vessel network in the patient slowly invades the implant in order to supply the injured site with its necessary nutrients. The purpose of this research is to determine if a synthetic bone graft with a stable microvascular network can be developed in vitro. I hypothesize that the use of indirect angiogenic factors such as sonic hedgehog homolog and hypoxia-inducible factor-1 in combination with the …