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Computational Fluid Dynamics Analysis Of Blalock-Taussig Shunt, Thomas Hess, Ramesh K. Agarwal

Mechanical Engineering and Materials Science Independent Study

Blalock-Taussig or BT shunts are a surgical procedure performed on infants suffering from cyanosis or “Blue Baby Syndrome.” Cyanosis refers the purple or blue color of the skin resulting from low blood oxygen saturation. A BT shunt is an artificial vessel placed between the right ventricle and the pulmonary artery to increase lung blood flow and blood oxygen saturation levels.During this independent study, the flow of blood through several different BT shunt configurations was analyzed using ANSYS Fluent, a Computational Fluid Dynamics (CFD) software analysis tool.Data from each shunt analysis was when compared to help determine the shunt parameters and …

Potential Graft Materials For Acl Reconstruction Surgery, Matthew Jenkins, Spencer Lake

Mechanical Engineering and Materials Science Independent Study

No abstract provided.

Post Processing Of Confocal Microscopy Images To Quantify Collagen Remodeling By Fibroblasts, Zhang Liu

Mechanical Engineering and Materials Science Independent Study

The ways that fibroblast cells remodel their local microenvironment is critical to a number of pathologies. To quantify this in a 3D environment, I an existing MATLAB script was modified to process the qualitative, visual information from confocal microscopy images and generate quantitative graphs representing the density of collagen around a fibroblast as a function of distance from the cell. While the earlier script used each 2D image from a confocal image stack and dilated the shape of the recognized cell to extract to find the coordinates of the surrounding collagen. The work in this study builds on the analysis …

Breakfast Machine, William Hallman, Tim Keenoy, Darius Rucker

Mechanical Engineering Design Project Class

The purpose of this project is to design a machine that makes a simple breakfast, consisting of a bowl of cereal with milk and a glass of orange juice on a tray. The machine will be able to prepare several breakfasts consecutively.

Redesigning A Bilateral Grip Strength Device For Assessing Forelimb Function In Rodents, Griffin Kivitz, Spencer Lake Dr.

Mechanical Engineering and Materials Science Independent Study

My primary complete accomplishment of the Fall 2017 semester in the Musculoskeletal Soft Tissue Laboratory is the addition of 3 3D printed parts to the grip strength device to improve the precision of the device. To reach the end result of these 3 parts, I 3D-modelled the parts, 3D printed the prototypes, and integrated the parts into the device for testing. Near the end of the semester I had seen this process through, and the grip strength device is now fully functional and the most accurate and precise it has been. Aside from my primary project of the grip strength …

Reducing Computation Time Of Vortex Position For Helicopter Flight Simulations, Matthew Tibbetts, David Peters

Mechanical Engineering and Materials Science Independent Study

The purpose of this investigation was to reduce the computational cost of vortex mapping for helicopter flight simulators, with the particular case of landing a helicopter on a moving ship. We pursued this goal by modeling the velocity using a series of Fourier transforms, linear fits, and Legendre polynomial fits. The end result was a matrix of 9 coefficient values which could be used to recreate the vortex behavior of the original data set with some accuracy. This technique will allow flight simulators to generate vortex data quickly to improve their effectiveness in training pilots.

Exploring Mindfulness Training Effects On Cognition And Psychological Wellbeing In Young And Older Adults, Rongxiang Tang

Arts & Sciences Electronic Theses and Dissertations

Previous investigations have revealed a range of cognitive, physiological, and psychological benefits following mindfulness training in young, middle-aged, and older adults. The aim of this thesis was to provide new insights into three issues that have not been adequately addressed in the extant literature. First, the application and integration of mindfulness training within conventional educational contexts is limited. In study 1, I provide evidence of the utility and effectiveness of mindfulness training incorporated as a part of traditional college curriculum. Second, although mindfulness training has been shown to offset age-related cognitive declines, studies have yet to combine mindfulness training with …

Numerical And Experimental Study Of The Wetting Characteristics Of Water Droplets On Solid Substrates, Zichen Du, Damena Agonafer

Mechanical Engineering and Materials Science Independent Study

In this study, the author first reviewed the background and the mechanism of a highly efficient cooling method—i.e., the thin film evaporative cooling, in which the heat removal performance is highly dependent on the wetting characteristics of the working fluid. Then, the author studied the wetting behavior of water on different solid substrate both numerically and experimentally. By minimizing the free energy, Surface Evolver was used to explore the profile of the static liquid meniscus and the corresponding contact angle of water droplets on plain solid substrate and pillar substrate with sharp edge. Besides, goniometer experiments were performed to study …

Computational Fluid Dynamics Analysis Of High Lift, Single Element, Inverted Airfoils In Ground Effect For An Fsae Car Front Wing, Michael Grabis, Ramesh K. Agarwal

Mechanical Engineering and Materials Science Independent Study

No abstract provided.

Application Of Pca To Cardiac Optical Mapping, Louis Woodhams

McKelvey School of Engineering Theses & Dissertations

Structural remodeling of the heart due to pathologies such as hypertension and myocardial infarction leads to the appearance of myofibroblasts, a phenotype largely absent in physiologic myocardium. While myofibroblasts are responsible for wound healing and structural repair of damaged myocardium, they are thought to have deleterious effects on electrical and mechanical properties of the heart. Understanding these effects is critical to developing effective treatments, and has motivated the development of a series of in vitro engineered heart tissues and cardiomyocyte-myofibroblast co-cultures whose mechanical and electrophysiological function can be deduced from video analysis. Electrophysiological properties are evident from changes in intensity …

Metallic Glass Composites-Understanding Nucleation And Growth, Ryogo Suzuki, Juan Wang, Anupriya Agrawal Dr., Katharine M. Flores Dr.

Mechanical Engineering and Materials Science Independent Study

No abstract provided.

The Analysis Of Asymmetric Micro Droplets, Benjamin Gaffney, Damena Agonafer

Mechanical Engineering and Materials Science Independent Study

The primary object of the research activities in this semester is to investigate how to adapt the Popov’s evaporation model to droplets with asymmetric geometries. Besides, extensive work with Surface Evolver were performed to analyze the equilibrium geometries of droplets on different solid substrate. Progress has been significant in the development of skills in Surface Evolver, specifically in investigating droplets at the point of bursting. Progress has been less significant in the adaptation of Popov’s Model as there are many aspects of this that require in-depth analysis, but the progress made has been promising. Outcomes of this semester include a …

Locating Unmanned Aerial Vehicles (Uavs), Ali Ghubaish

McKelvey School of Engineering Theses & Dissertations

Despite the popularity and usefulness of Unmanned Aerial Vehicles (UAVs) or drones, they are not allowed to fly in some areas without prior permission from the Federal Aviation Administration (FAA). However, many incidents of UAVs breaching such restrictions have been reported. A UAV location system can help the law enforcement to be alerted and can prevent UAVs breaching any restricted area without permission. This master thesis proposes a UAV location system where each UAV has a unique identification tag. The method consists of two stages: distance and location estimation. We compared distance estimation using three different methods: Time of Arrival …

Ls301 Fluorescence-Guided Photodynamic Therapy Of Brain Cancer Using Ppix Photosensitizer, Haini Zhang

McKelvey School of Engineering Theses & Dissertations

Incomplete brain tumor removal always causes neurologic deficit, disease recurrence and high mortality. Protoporphyrin IX (PpIX) accumulated in glioma cells with exogenous 5-aminolevulinic acid (5-ALA) serves as contrast agent for fluorescence-guided surgery and as well as acts as a photosensitizer for photodynamic therapy (PDT). However, the accurate tumor delineation using PpIX is limited by autofluorescence and superficial penetration depth. LS301 is a tumor-targeted near-infrared (NIR) contrast agent developed in our lab which allows deeper tumor imaging and avoids autofluorescence. My project aims to investigate whether LS301 can improve PpIX mediated PDT and tumor removal surgery. We have demonstrated co-localization of …

Observing Characteristics Of Successful Interdisciplinary Design Courses Involving Engineering, Art, Marketing, Psychology And Occupational Therapy, Xiaohan Li, Mark J. Jakiela

Mechanical Engineering and Materials Science Independent Study

Collaboration among disciplines has been popular in education because of its flexibility in expanding scopes of knowledge and versatile approaches. In an interdisciplinary course during September - December 2017 at Washington University in St. Louis, students and professors across five different disciplines worked in collaboration to design a special sportswear for people in wheelchairs with spinal cord injuries. A qualitative research was conducted to investigate how participants’ educational background influences the design process in such an interdisciplinary course setting through methodologies involving observations, documents, interviews and audio-visual materials of the course participants. This report is a documentation of the research. …

Solar Heating In Commercial Buildings, Phillip Irace, Harold Brandon

Mechanical Engineering and Materials Science Independent Study

Heating, ventilation, and air conditioning (HVAC) equipment accounts for 40% to 50% of a commercial building’s energy usage. This energy is supplied using either electricity or natural gas. Combustion products from natural gas pollute the environment and the burning of fossil fuels to produce electricity also pollutes the environment. The world must turn to clean, renewable energy resources to stop pollution. Solar energy has the potential to play a huge role in the renewable energy movement. Solar energy can be harnessed through active or passive solar techniques. Active solar uses solar collectors to harness the sun’s energy and passive solar …

The Domain-Generality And Durability Of Efficient Learning, Christopher Zerr

Arts & Sciences Electronic Theses and Dissertations

People differ in how quickly they learn information and how long they remember it, and a common finding in the literature is that a quicker rate of learning coincides with better retention for the learned material. Zerr and colleagues (2017) termed the relation between learning rate and retention as learning efficiency, with more efficient learning representing both a faster acquisition rate and better memory performance after a delay. Zerr et al. also demonstrated in separate experiments that how efficiently someone learns is stable across a range of days and years. The current thesis includes two experiments addressing additional questions …

Exploring The Underlying Mechanisms Of Structure Building, Reshma Gouravajhala

Arts & Sciences Electronic Theses and Dissertations

Structure building, the ability to build a coherent mental model of any narrative, requires the identification and integration of important parts of that narrative, as well as the suppression of irrelevant details. Critically, while individual differences in structure building have been shown to have important consequences in the classroom, little has been concluded about underlying deficits and causal mechanisms of low structure building ability. In the present study, we tested the theory that an impaired ability to suppress unimportant details is low structure builders’ sole deficit (Gernsbacher, 1990). We presented participants with educationally authentic text materials that offered varying degrees …

Investigation Of Neonatal Pulmonary Structure And Function Via Proton And Hyperpolarized Gas Magnetic Resonance Imaging, Nara Savoye Higano

Arts & Sciences Electronic Theses and Dissertations

Magnetic resonance imaging (MRI) is a modality that utilizes the phenomenon of nuclear magnetic resonance (NMR) to yield tomographic images of the body. Proton (1H) MRI has historically been successful in soft tissues but has suffered in the lung due to a variety of technical challenges, such as the low proton-density, rapid T2* relaxation time of the lung parenchymal tissue, and inherent physiological motion in the chest. Recent developments in radial ultrashort echo time (UTE) MRI have in part overcome these issues. In addition, there has been much progress in techniques for hyperpolarization of noble gases (3He and 129Xe) out …

Roles Of Peroxisomes And Peroxisome-Derived Products In Controlling Plant Growth And Stress Responses, Elizabeth May Frick

Arts & Sciences Electronic Theses and Dissertations

The peroxisome is a vital organelle conserved through the entire eukaryotic lineage. In all examined species, peroxisomes are responsible for such essential processes as fatty acid beta-oxidation and metabolism of reactive oxygen species (ROS). In plants, peroxisomes have taken on additional specialized roles, such as production of some plant hormones and vitamins. In this work, I have uncovered novel factors regulating peroxisome number in model species Arabidopsis thaliana, and novel mechanisms governing how peroxisomes respond to salt stress. I discovered a role for Arabidopsis MAP KINASE17 (MPK17) as a negative regulator of peroxisome division that acts in the salt-stress response …

Structured Illumination Diffuse Optical Tomography For Mouse Brain Imaging, Matthew Reisman

Arts & Sciences Electronic Theses and Dissertations

As advances in functional magnetic resonance imaging (fMRI) have transformed the study of human brain function, they have also widened the divide between standard research techniques used in humans and those used in mice, where high quality images are difficult to obtain using fMRI given the small volume of the mouse brain. Optical imaging techniques have been developed to study mouse brain networks, which are highly valuable given the ability to study brain disease treatments or development in a controlled environment. A planar imaging technique known as optical intrinsic signal (OIS) imaging has been a powerful tool for capturing functional …

New Ventures In Amidine-Based Catalyst Design, Nicholas Alan Ahlemeyer

Arts & Sciences Electronic Theses and Dissertations

Two new cascade transformations of α,β-unsaturated thioesters catalyzed by amidine-based catalysts have been developed. First, a reagent-free transformation of o-formylaryl cinnamoyl thioesters catalyzed by HBTM-2 to produce 2-substituted thiochromenes achieved high enantioselectivities and yields while forming carbon dioxide as the only byproduct. Second, a highly diastereo- and enantioselective tandem rearrangement of less reactive enone thioesters into tricyclic thiochromanes in the presence of electron-rich amidine-based catalysts was developed. These catalysts were designed with the help of DFT calculations. H-PIP, the first chiral amidine-based catalyst synthesized in our group, performed the best overall in the thiochromane synthesis.

The second chapter of this …

Fast Monte Carlo Simulations For Quality Assurance In Radiation Therapy, Yuhe Wang

Arts & Sciences Electronic Theses and Dissertations

Monte Carlo (MC) simulation is generally considered to be the most accurate method for dose calculation in radiation therapy. However, it suffers from the low simulation efficiency (hours to days) and complex configuration, which impede its applications in clinical studies. The recent rise of MRI-guided radiation platform (e.g. ViewRay’s MRIdian system) brings urgent need of fast MC algorithms because the introduced strong magnetic field may cause big errors to other algorithms. My dissertation focuses on resolving the conflict between accuracy and efficiency of MC simulations through 4 different approaches: (1) GPU parallel computation, (2) Transport mechanism simplification, (3) Variance reduction, …

Analysis Of Argonaute-Small Rna-Transcription Factor Circuits Controlling Leaf Development, John Steen Hoyer

Arts & Sciences Electronic Theses and Dissertations

Experimental studies of plant development have yielded many insights into gene regulation, revealing interactions between core transcriptional and post-transcriptional regulatory pathways present in all land plants. This work describes a direct connection between the three main small RNA-transcription factor circuits controlling leaf shape dynamics in the reference plant Arabidopsis thaliana. We used a high-throughput yeast 1-hybrid platform to identify factors directly binding the promoter of the highly specialized ARGONAUTE7 silencing factor. Two groups of developmentally significant microRNA-targeted transcription factors were the clearest hits from these screens, but transgenic complementation analysis indicated that their binding sites make only a small contribution …

Regulation Of Early Zebrafish Embryogenesis By Calcium Signaling And Dachsous1b Cadherin, Jiakun Chen

Arts & Sciences Electronic Theses and Dissertations

Early animal embryogenesis entails a dynamic combination of embryonic cleavages, axial patterning, and gastrulation movements to shape a basic body plan. The underlying molecular signaling responsible for regulating this process remains poorly understood. In this thesis work, I first review recent progress in understanding of gastrulation movements in various model organisms brought by advances in imaging techniques. The externally developing and optically translucent zebrafish embryo is an ideal model organism to study vertebrate embryonic development by in vivo imaging. The objective of my thesis research is to leverage experimental advantages in the zebrafish model to uncover novel regulators and elucidate …

Regulation Of Gene Expression By Rna Binding Proteins And Micrornas, Kyle Cottrell

Arts & Sciences Electronic Theses and Dissertations

Regulation of gene expression is essential to life. Post-transcriptional regulation of gene expression is a complex process with many inputs that lead to changes in localization, translation and stability of mRNAs. The translation and stability of many mRNAs is regulated by cis-elements, such as mRNA-structure or codon optimality; and by trans-acting factors such as RBPs and miRNAs. Here I report on the complex interactions between RBPs, miRNAs and characteristics of their target mRNAs in respect to effects on translation and RNA stability.

Using a reporter based approach we studied modulation of microRNA-mediated repression by various mRNA characteristics. We observed the …

Accurate Determination And Application Of Local Strain For Studying Tissues With Gradients In Mechanical Properties, John Boyle

McKelvey School of Engineering Theses & Dissertations

Determination of the mechanical behavior of materials requires an understanding of deformation during loading. While this is traditionally accomplished in engineering by examining a force displacement curve for a whole sample, these techniques implicitly ignore local geometric complexities and local material inhomogeneities commonly found in biologic tissues. Techniques such as normalized cross correlation have been classically applied to address this issue and resolve deformation at the local level; however, these techniques have proven unreliable when deformations become large, if the sample undergoes a rotation, and/or if strain fields become incompatible (e.g. at or near failure).

Presented here is a toolbox …

Development Of In Vitro Drug Screening Platforms Using Human Induced Pluripotent Stem Cell-Derived Cardiovascular Cells, Yosuke Kurokawa

McKelvey School of Engineering Theses & Dissertations

Drug-induced cardiotoxicity is a critical challenge in the development of new drugs. Since the advent of human pluripotent stem cell-derived cardiomyocytes (CMs), researchers have explored ways to utilize these cells for in vitro preclinical drug screening applications. One area of interest is microphysiological systems (i.e. organ-on-a-chip), which aims to create more complex in vitro models of human organ systems, thus improving drug response predictions. In this dissertation, we investigated novel analysis methods and model platforms for detecting drug-induced cardiotoxicity using human induced pluripotent stem cell (iPSC)-derived cardiovascular cells.

First, we utilized human iPSC-derived CMs (iPS-CMs) to establish optical methods of …

Reconstruction Algorithms For Novel Joint Imaging Techniques In Pet, Homayoon Ranjbar

McKelvey School of Engineering Theses & Dissertations

Positron emission tomography (PET) is an important functional in vivo imaging modality with many clinical applications. Its enormously wide range of applications has made both research and industry combine it with other imaging modalities such as X-ray computed tomography (CT) or magnetic resonance imaging (MRI). The general purpose of this work is to study two cases in PET where the goal is to perform image reconstruction jointly on two data types.

The first case is the Beta-Gamma image reconstruction. Positron emitting isotopes, such as ¹¹C, ¹³N, and ¹⁸F, can be used to label molecules, and tracers, such …

Characterizing Anisotropy In Fibrous Soft Materials By Mr Elastography Of Slow And Fast Shear Waves, John Larson Schmidt

McKelvey School of Engineering Theses & Dissertations

The general objective of this work was to develop experimental methods based on magnetic resonance elastography (MRE) to characterize fibrous soft materials. Mathematical models of tissue biomechanics capable of predicting injury, such as traumatic brain injury (TBI), are of great interest and potential. However, the accuracy of predictions from such models depends on accuracy of the underlying material parameters. This dissertation describes work toward three aims. First, experimental methods were designed to characterize fibrous materials based on a transversely isotropic material model. Second, these methods are applied to characterize the anisotropic properties of white matter brain tissue ex vivo. Third, …