Engineering Commons^™

Convergence Properties Of Solutions Of A Length-Structured Density-Dependent Model For Fish, Geigh Zollicoffer

Rose-Hulman Undergraduate Mathematics Journal

We numerically study solutions to a length-structured matrix model for fish populations in which the probability that a fish grows into the next length class is a decreasing nonlinear function of the total biomass of the population. We make conjectures about the convergence properties of solutions to this equation, and give numerical simulations which support these conjectures. We also study the distribution of biomass in the different age classes as a function of the total biomass.

The Development Of A Novel Blood-Brain Barrier, Organ-On-A-Chip System And The Identification Of Erythrocytes As A Key Contributor To Age-Associated Neurological Decline, Payam Amiri

KGI Theses and Dissertations

Advancements in modern medicine have greatly extended human life expectancy. However, with the onset of age-associated conditions such as Alzheimer’s disease, autoimmune disorders, and certain cancers, healthy aging is becoming an increasingly pressing issue. Blood exchanges between young and old partners demonstrate old blood can cause detrimental effect to the young animal, notably on the brain tissue. However, the complexity of blood makes it difficult to identify what role the individual factors play in the aggregate observed effect. This dissertation seeks to explore the potential effects of erythrocytes on the brain as we age. Erythrocyte morphology and rigidity changes as …

Investigation Of An Optimized Occupancy-Driven Hvac Control Strategy And Development Of A Scalable House/Grid Simulation, Kaleb Pattawi

Mechanical Engineering Master's Theses

Energy consumption in buildings is projected to increase more than 50% by 2050. Renewable energy sources are expected to increase and will help alleviate some of the energy demand; however, the intermittent nature of renewables makes it tough to effectively use energy in buildings. Various pricing schemes, including time of use electricity pricing, are used to encourage users to shift loads. Buildings need to be able to proactively react to changing energy sources and electricity prices in order to reduce over-generation of electricity and save money. This work demonstrates an optimized Heating Ventilation and Air Conditioning (HVAC) control strategy that …

Comparing The Efficiency Of A Marsh-Sill And Oyster Reef Balls In Attenuating Waves, Navid Tahvildari, Alexa Leone

December 17, 2021: Natural and Nature-Based Solutions (Part 2)

No abstract provided.

Active Membrane Energy Exchanger For Air Cooling And Dehumidification, Songhao Wu, Andrew Fix, David M. Warsinger, James E. Braun

Discovery Undergraduate Interdisciplinary Research Internship

Heating, ventilation and air conditioning (HVAC) equipment consume 35% of total building energy use in the US, among which a large share is used for cooling and dehumidification. The majority of air dehumidification systems take the conventional approach of moisture condensation removal. It requires air to be cooled below its dew point temperature and is an energy-intensive process, especially for areas with hot and humid climates. Vapor selective membrane systems are promising alternatives for air dehumidification as they do not require cooling energy for latent (humidity) heat removal. It allows water vapor transport through the membrane while blocking air. Previous …

Detecting Viral Particles In Vitro Using Photoacoustic Flow Cytometry, Anie-Pier Samson

Electronic Theses and Dissertations

The Covid-19 pandemic is a powerful example of just how damaging the rapid spread of an unknown virus can be. Viruses have the ability to spread rapidly amongst individuals if not treated and controlled. The first key step towards treatment is the timely and specific diagnosis of the virus causing the infection. An innovative method for the rapid detection of viral particles in solution consists of tagging the viral particles paired with using photoacoustic flow cytometry to irradiate the particles and get a signal. The high affinity of Streptavidin for Biotin can be used to bind Streptavidin-coated microspheres to biotinylated …

Real-Time Monitoring Of Cell Death Progress Using Capacitance Spectroscopy, Suyang Wu

Electronic Theses and Dissertations

Biologics, including the monoclonal antibody (mAb), has experienced rapid development in the last decade. However, the price of biologics is often prohibitively high because of the low process efficiency. Delaying the inevitable cell death improves the productivity of upstream bioprocessing, whose success relies on monitoring the cell death onset that indicates the timing for preventive actions.

This study proposes to develop a real-time monitoring model that quantifies the dying cell percentage in lab-scale bioreactors using capacitance spectroscopy. The capacitance spectroscopy contains cell death-related information due to various physical properties changes during the cell death process, e.g., cytoplasmic conductivity change. The …

Development Of Polymeric Cxcr4 Targeting Carriers For Sirna Delivery To Treat Acute Kidney Injury, Weimin Tang

Theses & Dissertations

Acute kidney injury (AKI) is a major kidney disease that is characterized by a sudden loss of renal function which manifests by a decrease in urine output and an increase in serum creatinine. AKI is a global healthcare burden associated with high morbidity, mortality, and increasing cost. Currently there are no effective pharmacological treatments available. Apoptosis induced by p53 has been demonstrated as an important pathological mechanism for the development of AKI. Meanwhile, CXCR4/SDF-1 axis has been associated with the inflammation during AKI, and CXCR4 is overexpressed on injured tubules. This dissertation hypothesized that polycations with CXCR4 targeting ability could …

Characterization Of Phase Behavior In Idp Solutions By Uv-Vis Spectrophotometry And Phase Volume Fraction Measurements In Capillaries, Qing Sun

Biomedical Engineering ETDs

Intrinsically disordered proteins (IDPs) play vital roles in cell signaling and regulation by changing conformation dynamically under various stimulus. Thus, it is crucial to understand their physical properties in vitro especially liquid-liquid phase separation (LLPS). Here, we first used UV-vis spectrophotometry to investigate two of IDPs' physical properties – transition temperature (Tt) and coacervate size. This deeper insight allows us to further understand the dynamics of phase growth. We then constructed a binodal curve in the phase diagram by measurement of volume ratios in phase separated IDP solution in glass capillaries.

A Literature Review Of Wetland Treatment Systems Used To Treat Runoff Mixtures Containing Antibiotics And Pesticides From Urban And Agricultural Landscapes, Emily R. Nottingham, Tiffany L. Messer

Biosystems and Agricultural Engineering Faculty Publications

Wetland treatment systems are used extensively across the world to mitigate surface runoff. While wetland treatment for nitrogen mitigation has been comprehensively reviewed, the implications of common-use pesticides and antibiotics on nitrogen reduction remain relatively unreviewed. Therefore, this review seeks to comprehensively assess the removal of commonly used pesticides and antibiotics and their implications for nitrogen removal in wetland treatment systems receiving non-point source runoff from urban and agricultural landscapes. A total of 181 primary studies were identified spanning 37 countries. Most of the reviewed publications studied pesticides (n = 153) entering wetlands systems, while antibiotics (n = 29) had …

Prediction Equations To Determine Induced Force On Reinforcing Elements Due To Laterally Loaded Piles Behind Mse Wall And Lateral Load Test On Dense Sand, Pedro David Garcia Montesinos

Theses and Dissertations

Researchers performed 35 full-scale lateral load tests on piles driven within the reinforcement zone of a mechanically stabilized earth wall (MSE wall). Data defining the induced tensile force on the reinforcements during lateral pile loading was used to develop multi-linear regression equations to predict the induced tensile force. Equations were developed by previous researchers that did not consider the diameter of the pile, the fixed head condition, relative compaction, or cyclic loading. The purpose of this research was to include this tensile force data and develop prediction equations that considered these variables. Additionally, a full-scale lateral load test was performed …

Systems And Methods For Scalable Retinal Screening Programs, Jeremy Richard Benson

Computer Science ETDs

This dissertation addresses gaps in artificial intelligence-based computer vision tasks in the medical image processing field. We demonstrate effective methods for standardizing and augmenting digital fundus photographs so that robust convolutional neural network-based systems can perform high-throughput disease classification and generalize to never-before-seen data from novel camera technologies, scaling with the changing hardware landscape, as well as keeping up with vast amount of incoming data from the ever-increasing population. We also tackle the problem of discovering relevant samples in an unlabeled cohort of image data, thus widening the bottleneck to all downstream supervised machine learning tasks.

The Rotator Cuff Tendon-To-Bone Interface: Maturation, Aging, And 3d Bioprinting For Regeneration, Xiping Jiang

Theses & Dissertations

Rotator cuff tendon injuries often occur at the tendon-to-bone interface (i.e., enthesis) area with a high prevalence for the elderly population. In addition, regeneration of the gradient structure of the enthesis is still a significant clinical challenge. Our studies aim to identify the histological, molecular, and biomechanical alterations of the rotator cuff enthesis with maturation and aging, and develop a novel therapeutic method using three-dimensional (3D) bioprinting technique to regenerate a functional enthesis. Striking variations of the entheses were observed both histologically and biomechanically during the maturation process. The histological features did not show many differences at the insertion site …

Advancing Cell-Free Protein Synthesis Systems For On-Demand Next-Generation Protein Therapeutics And Clinical Diagnostics, Emily Ann Long Zhao

Theses and Dissertations

Recombinant proteins have many medical and industrial applications, but their use is complicated by commercial production and stability constraints. These issues are particularly challenging for recombinant proteins used in pharmaceutical therapeutics and clinical diagnostics. Expensive production and distribution limit the accessibility of therapeutics and diagnostics especially in the developing world. Additionally, clinical use of recombinant proteins face further challenges within biological systems including biological degradation and immunogenicity. To increase the accessibility of recombinant proteins, the cost and inefficiencies of protein manufacturing and distribution need to be significantly reduced. A powerful tool to aid in this endeavor is cell-free protein synthesis …

Synthetic Aperture Optical Imaging Interferometric Microscopy With Improved Image Quality, Preyom K. Dey

Electrical and Computer Engineering ETDs

The resolution limit of optical microscopy can be extended by using Imaging Interferometric Microscopy (IIM), which uses a low numerical aperture (NA) objective lens to achieve resolution equivalent to that of a high-NA objective lens with multiple sub-images. Along with the resolution enhancement challenge, IIM often suffers from poor image quality. In this dissertation, several image quality improvement methods are proposed and verified with simulation and experimental results. Next, techniques to extend the resolution limit of IIM to ≤ 100nm using a low-NA objective lens are demonstrated. An experimental technique of using a grating coupler on …

State-Of-The-Art Of Thermal Control Solutions To Establish A Modular, Multi-Orbit Capable Spacecraft Thermal Management System Design Methodology, Robert C. Consolo Jr

Doctoral Dissertations and Master's Theses

Today, the exploration and exploitation of space continues to become a more common occurrence. All types of spacecraft (S/C) utilize various types of thermal management solutions to mitigate the effects of thermal loading from the unforgiving vacuum of space. Without an appropriately designed thermal system, components on-board the S/C can experience failure or malfunction due to fluctuations in temperatures either beyond the designed operational parameters or unstable oscillating temperatures. The purpose of this study is to perform a comprehensive review of technologies available today that are being used for thermal management onboard S/C in addition to investigating the means to …

Numerical Simulation Of A Cryogenic Spray, Neel Kishorkumar Shah

Doctoral Dissertations and Master's Theses

Cryogenic sprays have many applications in modern engineering. Cooling of electronic equipment subject to high heat flows, surgical ablation of gastrointestinal mucosae or orbital maneuvering are a few examples of their versatility. However, the atomization of a cryogenic liquid is a complex process. During such an event, aerodynamic effects associated with secondary atomization are further affected by thermodynamic flashing. A better understanding of the characteristics of cryogenic sprays is then necessary to allow for improved design and optimization in applications. The overarching objective of this study is to document such characteristics. The numerical simulation was performed over cryogenic nitrogen spray …

In-Situ Monitoring Of Additive Manufacturing Using Digital Image Correlation, Martina Jani

Doctoral Dissertations and Master's Theses

Advances in additive manufacturing over the past decade have led to applications in multiple fields. In particular, additive manufacturing answers the need for high flexibility in designing complex structures, however, the rapid thermal fluctuations during processing lead to numerous defects and processing-induced residual stresses. In this research, an in-situ approach using Digital Image Correlation (DIC) is developed to monitor the deformation during the processing, and thereby analyze the formation of defects and residual stresses. DIC is a visual technique that compares the changes in speckle pattern in consecutive images of a specimen to determine the displacements and strains. This research …

Noise And Time Pressure Effects On Situation Awareness And Aviation Maintenance Tasks, Syaza R. M. Haris

Doctoral Dissertations and Master's Theses

Aircraft maintenance technicians (AMTs) working in a line maintenance work setting are very susceptible to the deafening occupational noise from the airport vicinity or the maintenance machinery itself. Compared to a base maintenance working period, a line maintenance job requires AMTs to complete a task within a short time frame. The current study's objective is to determine if different noise levels and time pressure influence AMTs' performance and situation awareness (SA). Sixteen Embry-Riddle Aeronautical University students majoring in Aviation Maintenance Science participated in a within-subject experimental design. Each participant's performance, SA level, and perceived workload were measured during maintenance tasks …

Identifying And Evaluating Common Subgenres In Asymmetric Virtual Reality Games, Miah Dawes

Theses and Dissertations

Recent years have seen a significant growth in what designers and players call asymmetric virtual reality (AVR) games. This dissertation creates a framework that defines the relevant characteristics of AVR as a genre and describes five common genres of AVR games, including David(s) and Goliath, Hide and Seek, Perspective Puzzle, Order Simulation, and Lifeline. The core features of each subgenre are expounded. These subgenres are then evaluated using design workshops to observe novice game designs use these subgenres in their game design process. An analysis of the workshops found that the AVR subgenre framework may benefit novice game designers in …

Intracavity Phase Interferometry Based Fiber Sensors, Luke Jameson Horstman

Optical Science and Engineering ETDs

Intracavity Phase Interferometry (IPI) is a detection technique that exploits the inherent sensitivity of a laser's frequency to the parameters of its cavity. Intracavity interferometry is orders of magnitude more sensitive than its extracavity alternatives. This dissertation improves on previous free-space proof-of-concept designs. By implementing the technique in fiber optics, using optical parametric oscillation, and investigating non-Hermitian quantum mechanics and dispersion tailoring enhancement techniques, IPI has become more applicable and sensitive. Ring and linear IPI configurations were realized in this work, both operating as bidirectional fiber optical parametric oscillators. The benefit of using externally pumped synchronous optical parametric oscillation is …

Robotic Olfactory-Based Navigation With Mobile Robots, Lingxiao Wang

Doctoral Dissertations and Master's Theses

Robotic odor source localization (OSL) is a technology that enables mobile robots or autonomous vehicles to find an odor source in unknown environments. It has been viewed as challenging due to the turbulent nature of airflows and the resulting odor plume characteristics. The key to correctly finding an odor source is designing an effective olfactory-based navigation algorithm, which guides the robot to detect emitted odor plumes as cues in finding the source. This dissertation proposes three kinds of olfactory-based navigation methods to improve search efficiency while maintaining a low computational cost, incorporating different machine learning and artificial intelligence methods.

A. …

Identifying Structures For Ion Channel Kinetic Models, Kathryn Mangold

McKelvey School of Engineering Graduate Student Theses & Dissertations

Voltage-gated ion channels carry transmembrane current and underlie the voltages changes seen during the action potential. The ion channels open and close precisely, or gate, in response to voltage to create the specific cellular action potential waveform. The first models of voltage-gated ion channels gating dynamics were described by Hodgkin and Huxley when studying the neuronal action potential in the squid giant axon. While the probabilistic gating variables cleverly imagined by Hodgkin and Huxley to describe channel gating are still used today to describe cardiac ionic currents, Markov (or state-dependent) models provide a more accurate representation of channel dynamics. As …

Laser Stimulated Dynamic Thermal Imaging System For Tumor Detection, Hongyu Meng

McKelvey School of Engineering Graduate Student Theses & Dissertations

Laser stimulated dynamic thermal imaging system for tumor detectionby Hongyu Meng Doctor of Philosophy in Biomedical Engineering Washington University in St. Louis, 2021 Professor Samuel Achilefu, Chair Recent advances in infrared sensor technology have enabled the rapid application of thermal imaging in materials science, security and medicine. Relying on the infrared characteristics of living systems, thermal imaging has been used to generate individual heat maps, detect inflammation and tumor. As an imaging system, thermal imaging has the advantages of portability, real-time, non-invasive, and non-contact. But the low specificity of thermal imaging hinders its wide clinical application.

Unfortunately, label-free DTI is …

Interfacial Engineering And Photoelectrochemistry Of Patterned Metal/Semiconductor Heterostructures, Che Tan

McKelvey School of Engineering Graduate Student Theses & Dissertations

Photoelectrochemical (PEC) cells enable the conversion of solar energy into storable fuels, which is critical in overcoming the intermittent nature of this largest renewable source. However, the majority of semiconductors used as photoelectrodes in these cells have low conversion efficiencies and/or stabilities. Silicon (Si) is an attractive semiconductor material for photoelectrodes, but the development of efficient Si-based photoanodes is challenging due to their instability in alkaline solutions. Thus, one focus of this dissertation is the design and fabrication of highly stable nickel (Ni)-patterned Si photoanodes through interfacial engineering of the barrier heights. Recently, hot carriers in plasmonic metal nanostructures have …

Advancements In Pressurized Oxy-Combustion Process: Pollutant Control And Process Development, Piyush Kumar Verma

McKelvey School of Engineering Graduate Student Theses & Dissertations

The emission of carbon dioxide from the power industry is one of the major causes of climate change. However, it is well established that the development of human societies across the globe depends on reliable and dispatchable power, which are generally the source of these emissions. There has been a recent growth in the integration of intermittent sources such as wind and solar which are carbon free. But these intermittent sources have significant temporal changes in power production and thus lack reliability and dispatchablity. This is a complicated problem to solve. However, flexible power plants with carbon capture and storage, …

Deep Learning Approach To Improved Image Quality For Medical Diagnostics, Olivia Loesch, Katie Leyba, Halyley Chan, Craig Goergen

Discovery Undergraduate Interdisciplinary Research Internship

The United Nation’s health-related Sustainable Development Goals are difficult to achieve in low- and middle-income countries due to workforce shortages and inadequate health surveillance systems. However, with the growth of artificial intelligence (AI) and computer algorithms, it is possible to apply AI to healthcare technologies to improve progress towards these UN standards. This project aims at using and improving computer algorithms and deep learning to aid in the extraction of important structural and functional information from murine carotid artery ultrasound and photoacoustic images. First, we created a large database of simulated photoacoustic images to optimize the algorithms. These images were …

Traffic Crash Prediction Using Machine Learning Models, Yifeng Chen

Dissertations and Theses

Traffic crashes account for most of casualties and injuries worldwide, and there has been growing concerns and studies regarding the contributing factors of traffic crashes. There are many factors causing or related to an occurrence of traffic crash, e.g., land use, traffic flow conditions, driver behavior and weather condition. This paper studied the spatial and temporal distribution of crashes on highway and developed real-time prediction models for crash occurrence. Traffic flow data, weather data, and crash data from multiple data sources were collected and processed to develop the model. Multiple machine learning models, such as SVM model and Decision Tree …

Plasmonically-Enhanced Dna-Rna Hybrid-Based Bioassay For Amplification-Free Quantification Of Sars-Cov-2, Yuxiong Liu

McKelvey School of Engineering Graduate Student Theses & Dissertations

Corona Virus Disease 2019 (COIVD-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is a highly infectious respiratory illness. Within just a few months, it spread around the whole world and became a global pandemic. Real-time reverse-transcription polymerase chain reaction (RT-PCR) works as a gold standard method diagnosing COVID-19 with high sensitivity and specificity. But due to the programs of RT-PCR, it usually takes more than 24 hours to get the results while specialized devices are also required. False-negative results can happen as well using RT-PCR which increase the risk of spreading coronavirus. To promote quicker detection of COVID-19, …

Numerical Investigations Of Logic Gates And Transistors In Quantum And Classical Information Processing, Anthony Corbin

McKelvey School of Engineering Graduate Student Theses & Dissertations

The development of numerical analysis techniques for electromagnetics and quantum mechanics problems has dramatically increased the rate of new discoveries. Propelled by the exponential growth of computers over the past decades, numerical software has brought the ability to reliably experiment with new ideas and predict new phenomena, even before the physical realizations of these ideas in the labs. This work will demonstrate the application of this capability by applying numerical analysis techniques to design and analyze new devices. First, a system of optical logic gates using a nonlinear metallodielectric grating is completely designed and simulated using numerical analysis. Second, the …