Engineering Commons^™

Development And Evaluation Of A Modeling Platform For Evaluating Immunotherapeutic Efficacy In The Tumor Microenvironment., Dylan Andrew Goodin

Electronic Theses and Dissertations

The tumor microenvironment (TME) represents the complex outcome of numerous tumor, stromal, and immune interactions, and whose composition can significantly affect treatment response. Particularly, immunotherapeutic efficacy is subject to multiple tumor-specific TME interactions that may be difficult to evaluate/predict clinically. Mathematical modelling has been formulated to evaluate specific aspects of the TME, including vasculature, ECM deposition, and immune-tumor interactions. However, the computational challenge of simulating multiple TME interactions has led to sacrificing varying degrees of model generalizability and clinical relevance. This work describes increased computational performance of a 3D continuum model that simulates tumor tissue, ECM, and vasculature using a …

Novel Designs Of Soft Tactile Sensor And Robot Finger Manipulator Based On Optical Fibers., Seokyoung Han

Electronic Theses and Dissertations

Robotic manipulation is one of the main types of automated labor that humans want to achieve in order to free ourselves from mundane and hazardous tasks. The range of realizations could be very broad, from massive industrial robots to highly advanced medical devices for human healthcare. Given the critical nature of these application spaces, they require robust, safe, and most of all versatile designs. In that direction, one of the most interesting topics is the anthropomorphic robotic manipulator. Since it is inspired by human hands’ function and structure, it is able to achieve the aforementioned system requirements. However, the perfect …

Smart Manufacturing Of Cement: From Lab-Scale Simulation And Testing To Industry-Scale Deployment., Juan David Tabares Tamayo

Electronic Theses and Dissertations

Cement kilns are controlled by experienced process operators who follow experience-based industry guidelines using data collected and fundamental knowledge. The manufacturing process, which is equipped with sensors and equipment, transfers data/information to the operators to aid standardized decision-making operations. In contrast, companies have used such data to develop and implement digital solutions for predictive control systems; in effect, FLSmidth and Rockwell Automation. However, despite the availability of automated control systems and investigation in automation for process monitoring and optimization, opportunities to radically optimize cement manufacturing are still abundant and in need of implementation. Therefore, this research developed simulation models and …

A Design Science And Implementation Framework For Studying Interruptions And Its Application In A Dental Clinic., Carsten Ziegler

Electronic Theses and Dissertations

Interruptions during dental treatment are frequent, and often have detrimental effects on quality of care, patient safety and processing times, and have an impact on provider satisfaction and performance. Interruptions can significantly increase the cognitive load on dental providers, making it hard for them to concentrate on complex procedures. Frequent interruptions also disrupt the workflow in general, leading to delays in treatment, which can reduce the overall throughput of a clinic. Unfortunately, there is no comprehensive approach to collectively (i) analyze interruptions in dental healthcare, (ii) design an intervention, and (iii) implement and sustain it. This research proposes a comprehensive …

Electrokinetic Particle Trapping Performance Of Conductive Nanofiber Mats In Microfluidic Wells., Jacob Hunter West

Electronic Theses and Dissertations

The frequency dependence of electrokinetic particle trapping using large-area (>mm²) conductive carbon nanofiber (CNF) mat electrodes is investigated. The fibers provide nanoscale geometric features for the generation of high electric field gradients, which is necessary for particle trapping via dielectrophoresis (DEP). A device was fabricated with an array of microfluidic wells for repeated experiments; each well included a CNF mat electrode opposing an aluminum electrode. Fluorescent microspheres (1 µm) were trapped at various electric field frequencies between 30 kHz – 1 MHz. Digital images of each well were analyzed to quantify particle trapping. DEP trapping by the …

Fly Ash Based Geopolymer: Water, Curing Temperature And, Cao Content Effects On Microstructure And Compressive Strength., Lujain Salem

Electronic Theses and Dissertations

Geopolymer, an emerging alternative to Portland cement-based concrete, relies on alumina and silica-rich precursors like fly ash for its formation. Geopolymerization is a chemical process that creates a three-dimensional polymer network by reacting with an alkaline activator. While fly ash's calcium oxide (CaO) content is crucial in its classification, it behaves differently in geopolymerization, where it competes with hydration. Therefore, a better understanding of the impact of CaO content in fly ash on geopolymerization is needed to effectively utilize fly ash. This study investigates the effects of CaO content, water, and curing temperature on geopolymerization. Using fly ash from a …

Attention Guided Data Augmentation For Improving The Classification Performance Of Vision Transformers., Nada Baili

Electronic Theses and Dissertations

For over a decade, Deep Neural Networks (DNNs) have been rapidly progressing and achieving great success, forming a robust foundation of state of the art machine learning algorithms that impacted various domains. The advances in data acquisition and processing have undeniably played a major role in these breakthroughs. Data is a crucial component in building successful DNNs, as it enables machine learning models to optimize complex architectures, necessary to perform certain difficult tasks. However, acquiring large-scale data sets is not enough to learn robust models with generalizable features. Instead, an ideal training set should be diverse enough and contain enough …

Context Dependent Training Data Selection For Automatic Target Detection., Tylman Michael

Electronic Theses and Dissertations

An Automatic Target Detection (ATD) algorithm is capable of identifying the location of targets of interest captured by Infra-Red imagery in vastly different contexts. ATD is often a precursor in a 2-stage methodology in order to ascertain the location and nature of a target in both military and civilian applications. In order to train an ATD algorithm, a large amount of data from varied sources is required. One drawback of this requirement is that some sources of data may harm the performance of the method in different contexts. This thesis explores utilizing an unsupervised method to identify a subset of …

Multithreaded Applications On The Heterogeneous Research Computing Environment., Sungbo Jung

Electronic Theses and Dissertations

Bioinformatics is a domain that has experienced rapid research growth in recent years, as evidenced by the increasing number of articles in biomedical databases such as PubMed, which adds over a million publications every year. However, this also poses a challenge for researchers who need to find relevant citations for their work. Therefore, developing efficient indexing and searching methods for text data is crucial for Bioinformatics. One key technique for information retrieval is document inversion, which involves creating an inverted index to enable efficient searching through vast collections of text or documents. This Ph.D. research aims to design the research …

Development, 3d Printing, And Sintering Of Aluminum-Magnesium Alloy Pastes For In-Space Manufacturing Applications, Fatou Ndiaye

Electronic Theses and Dissertations

This study explores the additive manufacturing process of paste printing, sintering, and de-binding for fabricating aluminum-magnesium alloy components. The paste formulation involved combining aluminum powder with varying magnesium concentrations, utilizing acrylic polyol, solvent, and plasticizer to create a homogeneous mixture. Printing parameters were optimized to ensure continuous pressure for improved extrusion. Sintering conditions involved incremental temperature increases with nitrogen flow to remove solvents. Density measurements, tensile tests, and shrinkage calculations were conducted to assess part quality post-sintering. The study revealed significant improvements in part quality with 5 wt.% magnesium incorporation within aluminum, although density and tensile strength fell short of …

Mechanical Property Simulations Of Ploybenzimidazole Membranes., Blake Alexander Clark

Electronic Theses and Dissertations

This work explores mechanical properties of membranes made of polybenzimidazole utilizing molecular simulations. These simulations researchers to narrow down polybenzimidazole membrane compositions to viable candidates. These simulations are quicker than current purely experimental methods. The increase in throughput would be achieved by eliminating compositions that have unfavorable mechanical properties through preliminary simulation work before moving onto experimental methods. Determining polybenzimidazole membranes’ mechanical properties experimentally would, therefore, allow for researchers to speed up research in areas such as fuel cells and electrolyzers that make use of polybenzimidazole membranes. This study uses Materials Studio and the COMPASS III forcefield to perform these …

Mems Optical Cavities For Low Power Communication., Jacob Schopp

Electronic Theses and Dissertations

This thesis discusses the use of MEMS (microelectromechanical systems) optical cavities for use in low power communication. MEMS optical cavities are thin air gaps between an actuated MEMS mirror and a fixed glass encapsulation. By moving the MEMS mirror the reflectivity of the MEMS optical cavity can be changed. This change in reflectivity can be used to transmit information passively by modulating reflected light intensity instead of generating new light using a light source. These MEMS optical cavities are demonstrated using optical fibers for illumination delivery and reflected light collection. In addition to being reflected for communication, the illuminating light …

Barocaloric Heat Pumps Based On Soft Materials., Naveen Weerasekera

Electronic Theses and Dissertations

Solid-state refrigeration offers a promising alternative to traditional vapor compression systems that are relatively inefficient, unreliable, and have a high global warming potential. Various solid-state cooling technologies, including those based on electrocaloric, magnetocaloric, and elastocaloric effects have been investigated in the recent past. However, concerns regarding their efficiency, scalability and cost remain. Refrigeration and heat pump technologies based on the barocaloric effect (temperature/entropy change due to hydrostatic pressure) hold great promise but have received comparatively less attention. Barocaloric heating/cooling based on low cost, compressible soft materials with large barocaloric response have the potential to pave the way for efficient, scalable, …

Mechanical Properties And Microstructure Of Multi-Materials Fabricated Through A Combination Of Lpbf And Ded Additive Manufacturing Techniques, Christopher J. Bettencourt

All Graduate Theses and Dissertations, Fall 2023 to Present

This research explores the use of different metals combined through 3D-printing to enhance the performance of materials, with a focus on making heat exchangers more cost-effective for renewable energy. The goal is to replace a costly high-temperature alloy with a more affordable low-temperature alloy, using metal additive manufacturing for its benefits such as less material waste, faster production, reduced weight, and the ability to print entire assemblies in one go. The study delves into a unique combination of two 3D-printing techniques, Directed Energy Deposition and Laser Powder-Bed Fusion, to create a multi-material composed of stainless steel 316L and a nickel-based …

Tracking Perfluoroalkyl Substances From Wastewater Influent To Its Accumulation In Vegetables And Forage Grass, Simon Kozik

All Graduate Theses and Dissertations, Fall 2023 to Present

Per and poly-fluorinated alkyl substances (PFAS) are a class of chemicals that are persistent in the environment. PFAS was found in wastewater, which can be used after wastewater treatment for irrigation water, and in the biosolids that can be mixed with soils to provide nutrients and generally improve soil quality. This study found when wastewater was used it increases the level of PFAS in vegetables and forage grass. PFAS concentrations were tracked from the influent of the wastewater treatment plant to the effluent, to the irrigation water, to the soil, and finally into the vegetable and forage grass grown on …

Field Flow Measurements For Pipe Installations With Non-Ideal Conditions, Jake Douglas

All Graduate Theses and Dissertations, Fall 2023 to Present

Accurate flow measurement data is necessary to effectively manage water resources. The purpose of this research is to investigate options to improve field flow measurement by investigating alternatives for calibrating flow meters installed in non-ideal piping. Typically, to accurately measure a flow rate using most types of flow meters, it is recommended that a straight section of pipe be installed immediately upstream and downstream of the flow meter to avoid flow fluctuations at the meter location. However, in many cases, flow disturbances upstream of the meter are unavoidable.

The performance of field flow measurements in non-ideal piping scenarios were studied …

Development And Testing Of An 8-Bit Digitally Throttled Hybrid Rocket Motor, Trevor W. Coombs

All Graduate Theses and Dissertations, Fall 2023 to Present

Hybrid rocket motors that use a solid fuel grain and liquid oxidizer are low-cost and safer alternatives to traditional rocket motors. Another benefit of hybrid rocket motors is that during a burn, the amount of oxidizer into the combustion chamber can be changed, this capability is called throttling. To take advantage of the throttling ability of hybrid rocket motors, a throttling valve made up of 8 individually controlled valves is designed, developed, and tested, which is documented in this thesis. The results of the testing campaign show that the 8-bit digital throttling valve technology is an effective throttling technology and …

Development Of A Model To Predict Maximum Crack Width And Spacing In Reinforced Concrete Beams Under Flexural Stress, Saeed Alghamdi

Theses and Dissertations

Cracking in reinforced concrete structures is unavoidable due to the low tensile strength of concrete. Even though minimizing cracks on exposed concrete surfaces is significantly important from the aesthetics point of view, it is also very important for the durability and overall performance of the structure.

Flexural members must be designed to minimize cracking that may occur during the structure's service life. Even though there has been a lot of experimental work on crack width over the last several decades, a literature review reveals that researchers still can't agree on which variables are most important. Part of the reason for …

Test And Evaluation Model For Midwater Docking Of Autonomous Underwater Vehicles, Parker Baillon

Theses and Dissertations

This research created a Test and Evaluation (T&E) model for midwater Autonomous Underwater Vehicle (AUV) capture. The creation of this model will allow for a better assessment of the feasibility of midwater AUV capture. To achieve this, the T&E model was exposed to various flow conditions to assess stability. Capturing an AUV in midwater, the area below the wave-affected zone to the sea floor, has many benefits for an AUV and its mission. AUVs basing missions from a midwater dock will not be affected by wave motions. A midwater dock can be transported to any mission site and deployed with …

Improving Static Cold Storage Life Of The Human Heart Before Transplant, Juan Sebastian Rodriguez Paez

Theses and Dissertations

Organ storage and transportation are critical steps for the success of organ transplantation. Static cold storage (SCS) of hearts for heart transplantation (HTx) remains the standard approach. However, SCS may involve damage to the tissue resulting from extended hypothermic preservation, potentially affecting organ viability. More over, the temperature distribution on and within the heart is unknown during heart transplantation. Therefore, there is an interest to study different stages of the heart transplantation process towards determining the 3D temperature distribution on and within the heart. There could be a possibility of having a hypothermic injury in different parts of the heart …

Methodologies For Optimization And Surface Heat Flux Estimation For Hybrid Thermal Protection Systems, Syed Arafun Nabi

Theses and Dissertations

Thermal protection system (TPS) plays a pivotal role in safeguarding space vehicles from extreme aerothermal heating during atmospheric entry. To ensure effective thermal management, Hybrid Thermal Protection seamlessly integrating both active and passive TPS is an innovative solution. The passive TPS consists of an insulative layer on vehicle skin to counteract the aerothermal heat. Although a thicker layer enhances insulation, a trade-off arises between the thickness of the passive layer and the spacecraft’s weight. Beneath the passive TPS layer lies the active TPS functioning as a heat exchanger where the vehicle fuel liquid is considered as coolant. The effectiveness of …

Artificial Neural Networks As The Solution Of Inverse Heat Conduction Problems In Multidimensional Domains, Andrea Carolina Martinez Mundarain

Theses and Dissertations

Surface heat flux measurement is essential in various industrial applications including atmospheric entry of space vehicles, machining processes, non-destructive testing and more. While direct measurement of surface heat flux is known to be a very difficult, if not infeasible, task, acquiring temperature measurement from sub- surface locations are often viable. The problem of evaluating the surface heat flux using internal temperature measurements is known as an inverse heat conduction problem (IHCP). IHCPs are considered as mathematically ill-posed as they are highly sensitive to measurement error. This research presents a solution based on the implementation of artificial neural networks (ANNs) to …

Investigating Endothelial Damage During Ischemic Stroke Treatment Using In Vitro And Computational Models, Zackary Lorton

Theses and Dissertations

Large vessel occlusion during acute ischemic strokes requires mechanical thrombectomy (MT) procedures using stent retrievers (SR). However, complete clot removal typically takes several attempts, which can amplify endothelial cell injury (EI). This project aims to characterize the extent of EI during MT using an in vitro vascular platform and a finite-element model (FEM). Impact of SR diameter and characterization of SR mechanical forces are assessed and correlated with human umbilical vein endothelial cell (HUVEC) response. HUVECs were seeded on fibronectin (4 µg/cm²) coated true-scale PDMS arterial phantoms with 2.5 mm luminal diameter. Test groups (n=6) either …

Synthesis Of Durable Zeolite 13x Insertion Coatings And Scaled-Up Experimental Demonstration For Co2 Capture, Daniel Jamil Hocheimy

Theses and Dissertations

Minimizing the energy requirement for capturing carbon dioxide (CO₂) from post-combustion sources is critical to efficient industrial decarbonization and subsequent mitigation of the effects of climate change. The current portfolio of CO₂ capture technologies includes absorption, membrane separation and packed bed adsorption, which suffer from high energy and temperature requirements, scalability, and location dependency issues. Adsorption-based systems could cater to these concerns; however, their current embodiments primarily use packed adsorbent bed design and electricity-driven vacuum pumps to regenerate them. While simple and easy to fabricate, these designs are not scalable and cannot use heat to regenerate them …

System Identification For Motion Control Of Unmanned Aerial Vehicles Platform, Raj Ramesh Agarwal

Theses and Dissertations

Comprehensive research on Unmanned Aerial Vehicles (UAV) system identification for motion control parameters is presented in this thesis, with a focus on the necessity of precise control and improved performance. Using Pseudorandom Binary Sequence (PRBS) and Normally Distributed Random Numbers, it presents a unique technique for excitation of UAV dynamic systems. It also shows how effective random signals are in time-domain identification for precise control in a range of flying circumstances. The piece of research includes a thorough analysis and implementation of various approaches and its further improvements, highlighting the benefits and drawbacks of each. These approaches include the free …

Controlled Delivery Of Peptide And Gasotransmitter For Promoting Vascular Endothelialization, Shirin Changizi

Theses and Dissertations

Endothelial cells (ECs) are vital for maintaining proper vascular function and regulating processes such as hemostasis and inflammation. Disruption of endothelial cells integrity can lead to several pathological conditions, including coronary artery disease, vascular cognitive impairment, and dementia (VCID). Alterations in ECs distribution may lead to compromised blood-brain barrier (BBB) function, facilitating the passage of blood components and contributing to conditions such as Alzheimer's disease. Additionally, disruptions in ECs function can lead to early-stage thrombosis and intimal hyperplasia, resulting in graft failure in small-diameter (

This study aimed to develop innovative approaches for drug delivery to the BBB and TEVGs …

Deep Learning System Identification, Linearization And Control Of Dynamical Systems Utilizing Koopman Theory With Applications In Orbital Systems, George Mario Nehma

Theses and Dissertations

The computational and complexity burden of current linearization techniques is one that is a hinderance in the application of real world guidance, navigation and control systems. With the advancements in Deep Neural Networks, large data handling and Koopman Theory, the possibility of global linearizations of nonlinear systems is more prominent. This work demonstrates the capability of a Deep Neural Network learned Koopman operator to transform a nonlinear system into a Linear Time-Invariant system. The method presented is applied to both two purely dynamical systems and one controlled system to emphasize the ability for the technique to be applied in all …

Data Recovery Beyond The Obvious Using Digital Forensic Techniques, Smit Chandrakant Nayak

Theses, Dissertations and Culminating Projects

Advancement in drone technology, particularly for smaller drones, are creating new research fields and potential applications, particularly with regard to smaller drones. On the other hand, these enhancements bring forth additional hurdles in terms of adaptability, homogeneity, and safety. The purpose of this study is to investigate the science and technology behind drones, as well as their applications, the many ways in which citizens implement them, and the risks, precautions, and privacy problems that are associated with their utilization. This article discusses the existing literature, as well as the available solutions for drone cybersecurity, the security challenges related with drones …

High Performance Silicon Carbide Based Converters For Powertrain Electrification, Nan Lin

Graduate Theses and Dissertations

With the increasing concern towards environment protection, electric vehicles (EVs) and hybrid electric vehicles (HEVs) have become popular in recent years. They not only help reduce carbon emissions, but also come with other benefits such higher efficiency and better user experience. Many countries and vehicle manufactures have made their plans to keep up with this trend in vehicle electrification. Powertrain is an assembly of components in a vehicle that pushes it forward. As for EVs and HEVs, their powertrains are composed of one or more power electronics converters, which are significant to the system. Silicon carbide MOSFETs have shown superior …

Synthesis Of Bimetallic Nickel And Cobalt Phosphide Nanostructures For Electrocatalysis, Sarah Meixin York

Graduate Theses and Dissertations

Transition metal phosphides have become a new class of materials to be considered as promising catalysts for a number of applications including electrochemical hydrogen evolution (HER). Electrocatalysis in hydrogen evolution is a heavily studied field due to the increasing desire to develop more efficient and more cost-effective catalysts for clean hydrogen production. This project develops a chemical approach to synthesizing bimetallic cobalt-nickel phosphide nanostructures for their use in HER. The synthesis is accomplished by thermal decomposition of the metal precursors in the presence of carbon monoxide (CO) and trioctyl phosphine (TOP). The resulting nanostructures were characterized using transition electron microscopy …