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Radic Voice Authentication: Replay Attack Detection Using Image Classification For Voice Authentication Systems, Hannah Taylor May 2023

Radic Voice Authentication: Replay Attack Detection Using Image Classification For Voice Authentication Systems, Hannah Taylor

Undergraduate Honors Theses

Systems like Google Home, Alexa, and Siri that use voice-based authentication to verify their users’ identities are vulnerable to voice replay attacks. These attacks gain unauthorized access to voice-controlled devices or systems by replaying recordings of passphrases and voice commands. This shows the necessity to develop more resilient voice-based authentication systems that can detect voice replay attacks.

This thesis implements a system that detects voice-based replay attacks by using deep learning and image classification of voice spectrograms to differentiate between live and recorded speech. Tests of this system indicate that the approach represents a promising direction for detecting voice-based replay …


Trees Recommendation In Agroforestry Ecosystem Using Nlp, Omkar Sawant May 2023

Trees Recommendation In Agroforestry Ecosystem Using Nlp, Omkar Sawant

Electronic Theses, Projects, and Dissertations

Agroforestry farming is one of the challenging sectors to grow the crops or farming or variety of trees from the ancient days due to erosion and desertification. This Culminating Experience Project explored how recommendation system can be developed and used in agroforestry. The research questions are Q1. What methods can be used to improve the accuracy and reliability of soil-based agroforestry tree species recommendation systems? Q2. How can agroforestry tree species recommendation systems be tailored to the needs of different stakeholders, such as smallholder farmers or agribusinesses? Q3. What will be the top three, tree recommendations using natural language processing …


Computational Modeling Of Patterned Membranes And Spacers For Improved Hydrodynamics And Fouling Reduction In Reverse Osmosis Water Treatment Processes, Zuo Zhou May 2023

Computational Modeling Of Patterned Membranes And Spacers For Improved Hydrodynamics And Fouling Reduction In Reverse Osmosis Water Treatment Processes, Zuo Zhou

All Dissertations

My research goal is to discover ways to improve the hydrodynamics of reverse osmosis (RO) membrane systems through creative membrane surface patterning and spacer designs. Since concentration polarization (CP) usually promotes membrane fouling, improving hydrodynamics would result in reduced fouling and better membrane performance. With computational fluid dynamics (CFD), we can explore dozens or even hundreds of models with different geometries and boundary conditions. Through plotting their velocity profile, streamlines, shear stress, pressure profile, concentration profile, and so on, we can determine which design would lead to the best performance.

At first, patterned membranes were evaluated and compared with flat …


Molecular Dynamics Simulation On Molybdenum Disulfide: Thermal-Mechanical Properties And Phase Transitions Under External Loading, Mahabubur Rahman May 2023

Molecular Dynamics Simulation On Molybdenum Disulfide: Thermal-Mechanical Properties And Phase Transitions Under External Loading, Mahabubur Rahman

All Dissertations

Due to their remarkable properties, transition metal dichalcogenides (TMDs) have received much scientific interest throughout the past decade. Two layers of chalcogen atoms (S, Se, Te) sandwich a layer of transition metal atoms (Mo, W, Ta) to form the three-atom thick unit cell in TMDs. The interaction between TMD "single layers" is mediated by neighboring chalcogen planes and bonded by Van der Waals forces. Due to this weak out-of-plane interaction, bulk samples can be thinned down to a single layer by exfoliation. Among the TMDs, Molybdenum Disulfide (MoS2) shows promise in the field of electronics, optics, and sensing …


3d Printing With Photopolymerizable Polyester Resins For Resorbable Medical Device Applications, Mathew Murphy Stanford May 2023

3d Printing With Photopolymerizable Polyester Resins For Resorbable Medical Device Applications, Mathew Murphy Stanford

All Dissertations

In the past decade, the healthcare industry has seen a significant increase in the use of additive manufacturing (AM or “3D printing”) with subsequent improvement in clinical outcomes.As an exceptional AM technology, vat-photopolymerization (VP), often called stereolithography, can create complex structures and has thus been adopted for a range of biomedical applications including surgical guides, temporary implants, and resorbable tissue scaffolds.However, limitations remain in the availability of photopolymerizable resin materials with appropriate mechanical performance, biodegradability, and biocompatibility for application to resorbable medical devices.

The objective of this work was to employ novel photopolymerizable polyester-based macromers in the development of resorbable …


Mesoscale Modeling Of Controlled Degradation In Polymer Networks And Melts, Vaibhav Palkar May 2023

Mesoscale Modeling Of Controlled Degradation In Polymer Networks And Melts, Vaibhav Palkar

All Dissertations

Controlled degradation of polymers finds various applications in fields ranging from the design of functional soft materials to recycling of polymers. In several of these applications, the characteristic length scale at which relevant processes occur ranges from nanometers to microns, typically referred to as the mesoscale. Although analytical models and continuum approaches inform our current understanding, analysis of degradation at the mesoscale is exceptionally limited. For modeling degradation at the mesoscale, we use the Dissipative Particle Dynamics (DPD) technique and the LAMMPS simulation software. Within the DPD framework, we model controlled degradation or the breaking of covalent bonds within a …


Reducing Infiltration And Inflow In Small Collection Systems: Environmental, Economic, And Other Impacts, Andrew Hansen May 2023

Reducing Infiltration And Inflow In Small Collection Systems: Environmental, Economic, And Other Impacts, Andrew Hansen

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Wastewater treatment facilities (WWTFs) and the collection systems (CSs) which feed them provide essential services to society by collecting sewage (aka wastewater), biologically treating it, and minimizing risks to human health as well as the impact of waste on the environment. However, as collection systems age, increasing infiltration and inflow (I/I) from groundwater and stormwater can negatively affect the system. I/I is often mitigated to reduce flow and eliminate other negative impacts to the system.

Ten total case studies, seven mechanical water resource recovery facilities (WRRFs) and three lagoon facilities, were examined for the environmental, economic, and other impacts/benefits from …


Blood Flow Regulates Atherosclerosis Progression And Regression, Morgan A. Schake May 2023

Blood Flow Regulates Atherosclerosis Progression And Regression, Morgan A. Schake

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Atherosclerosis is the most prevalent pathology of cardiovascular disease with no known cure. Despite the many systemic risk factors for atherosclerosis, plaques do not form randomly in the vasculature. Instead, they form around bifurcations and the inner curvature of highly curving arterial segments that contain so-called disturbed blood flow that is low in magnitude and multidirectional over the cardiac cycle. Conversely, straight, non-bifurcated arterial segments that contain moderate-to-high and unidirectional (i.e., normal) blood flow are protected from plaque development. Thus, blood flow is a key regulator of atherosclerosis that may be able to be leveraged to develop new therapeutics. Towards …


Characterization Of Lignin And Cellulose Biopolymers Structure – Function Relationships, Zachariah Pittman May 2023

Characterization Of Lignin And Cellulose Biopolymers Structure – Function Relationships, Zachariah Pittman

All Dissertations

Biomass is vital to ongoing efforts to secure a sustainable future. While many of our efforts focus on finding alternative forms of energy, biomass among them, only biomass has the potential to serve as a sustainable materials feedstock. However, biomass is heterogenous, complicating the upgrading processes needed to manufacture commodity and performance products. For example, plant biomass consists largely of cellulose, a crystalline polysaccharide, and lignin, a highly stable polyaromatic. The specific properties of cellulose and lignin depend greatly on the plant, harvesting conditions, and isolation procedures. Thus, accurate and reliable determination of the fundamental properties of biomass is crucial …


Machine Learning-Based Data And Model Driven Bayesian Uncertanity Quantification Of Inverse Problems For Suspended Non-Structural System, Zhiyuan Qin May 2023

Machine Learning-Based Data And Model Driven Bayesian Uncertanity Quantification Of Inverse Problems For Suspended Non-Structural System, Zhiyuan Qin

All Dissertations

Inverse problems involve extracting the internal structure of a physical system from noisy measurement data. In many fields, the Bayesian inference is used to address the ill-conditioned nature of the inverse problem by incorporating prior information through an initial distribution. In the nonparametric Bayesian framework, surrogate models such as Gaussian Processes or Deep Neural Networks are used as flexible and effective probabilistic modeling tools to overcome the high-dimensional curse and reduce computational costs. In practical systems and computer models, uncertainties can be addressed through parameter calibration, sensitivity analysis, and uncertainty quantification, leading to improved reliability and robustness of decision and …


Fluorescence Multiplexing With Combination Probes For Biological And Diagnostic Applications, Madeline Mccarthy May 2023

Fluorescence Multiplexing With Combination Probes For Biological And Diagnostic Applications, Madeline Mccarthy

All Dissertations

Cancer refers to a group of diseases containing more than 200 different subtypes. Cancer is a heterogeneous disease by nature, meaning that there are differences among tumors of the same type in different patients, and there are differences among cancer cells within a single tumor of one patient. Since cancer is not a single disease, nor does it have a single cause, it proves to be incredibly hard to diagnose and treat. The ability to study cellular markers, cell and tissue spatial arrangement, and gene function are all integral parts of cancer diagnostic and treatment efforts.

Here, I first present …


Intelligent And Explainable Solution To Predict Infant Birthweight And Preterm Birth In The United Arab Emirates, Wasif Khan May 2023

Intelligent And Explainable Solution To Predict Infant Birthweight And Preterm Birth In The United Arab Emirates, Wasif Khan

Dissertations

Adverse pregnancy outcomes such as Low Birth Weight (LBW) and Preterm birth (PTB) are complex pregnancy challenges that can lead to high perinatal mortality and long-term morbidity for infants. Early prediction of such adverse outcomes can be useful for averting catastrophic outcomes for the mother and her baby. With advances in machine learning (ML)-based algorithms, several models have been proposed for both PTB and LBW predictions. However, the risk factors associated with these outcomes are still unknown, particularly in the United Arab Emirates (UAE). Furthermore, existing ML-based prediction models work in a black-box manner and lack proper interpretations for clinicians, …


Synthesis, Radiolabeling And Evaluation Of A Suite Of Tracers With 44Sc For Detecting Extracellular Dna, Zhiyao Li May 2023

Synthesis, Radiolabeling And Evaluation Of A Suite Of Tracers With 44Sc For Detecting Extracellular Dna, Zhiyao Li

McKelvey School of Engineering Graduate Student Theses & Dissertations

Neutrophil extracellular traps involve the rapid translocation of DNA to the outside of the cell under certain stimuli. This structure forms a fibrous network that is able to limit the spread of pathogens and to kill microorganisms. It has also been shown to be present in various pathological processes such as inflammation, autoimmune diseases, and cancer metastasis. Currently, the formation process of NETs in vivo is being extensively studied. However noninvasive detection and quantitation has yet to be achieved. A class of PET tracers are described here that consists of a DNA dye as the backbone that is labeled with …


A Magneto-Rheological Platform To Dynamically Control Afterload In Engineered Micro Heart Muscles, David Schuftan May 2023

A Magneto-Rheological Platform To Dynamically Control Afterload In Engineered Micro Heart Muscles, David Schuftan

McKelvey School of Engineering Graduate Student Theses & Dissertations

Cardiovascular disease is the leading cause of death is the United States, accounting for nearly 1 in 5 deaths. Many types of cardiovascular disease are linked to the mechanical forces placed on the heart. However, how these mechanical forces exactly affect the cellular biology of the heart is not well defined. In vitro models using cardiomyocytes derived from human induced pluripotent stem cells enable researchers to develop medium throughput systems to study cardiac mechanobiology at the cellular level. Previous models have been developed to enable the study of mechanical forces such as cardiac afterload. However, most of these models require …


Investigating Haloacetonitrile (Han) Formation Potential From Nitrogenous Antibiotics And Agrochemicals, Kazi Shafayet Haider May 2023

Investigating Haloacetonitrile (Han) Formation Potential From Nitrogenous Antibiotics And Agrochemicals, Kazi Shafayet Haider

UNLV Theses, Dissertations, Professional Papers, and Capstones

Disinfection can promote safe drinking water. Chlorine and chloramines are the two most used disinfectants. While these disinfectants are effective in inactivating disease-causing pathogens, they also produce hazardous byproducts when they react with organic compounds (precursors). Nitrogenous disinfection byproducts (N-DBPs) are more toxic than their counterparts. The increased use of nitrogen-based agrochemicals and antibitics has led to their detection in different water sources. The presence of secondary amine and aniline in these compounds can act as a source of reactive nitrogen to form N-DBPs. In addition, the increased concentration of bromide in water systems due to anthropogenic activities can enhance …


An Investigation Of Soft Electrohydraulic Actuators: Theory, Characterization, And Conceptual Applications, Alexandrea Washington May 2023

An Investigation Of Soft Electrohydraulic Actuators: Theory, Characterization, And Conceptual Applications, Alexandrea Washington

UNLV Theses, Dissertations, Professional Papers, and Capstones

Electroactive polymer (EAP) materials are a novel soft electromechanical device that exploits the inherent electrical and mechanical advantages of flexible polymer materials. Within this groundbreaking field there are various actuator and sensor devices that have been developed for a variety of applications, from medical devices to artificial biological systems. This research focuses on electrohydraulic actuators, which are comprised of a flexible conductive medium, a dielectric fluid, and a compliant film material to encapsulate the dielectric fluid. This specific study centers around the electrohydraulic EAP actuator known as the Hydraulically Amplified Self-Healing Electrostatic (HASEL) actuator, first introduced by the Keplinger group …


Structure-Property-Processing Analysis Of Graphene Bioscaffolds For Viability And Differentiation Of C2c12 Cells, Lynn Karriem May 2023

Structure-Property-Processing Analysis Of Graphene Bioscaffolds For Viability And Differentiation Of C2c12 Cells, Lynn Karriem

Boise State University Theses and Dissertations

We investigated the structure – property – processing correlation of graphene bioscaffolds produced using three different methods. Bioscaffolds were prepared by chemical vapor deposition (CVD), sublimation of Silicon Carbide (SiC), and printed solvent assisted exfoliated graphene ink. To gain insight into the roughness and topography of graphene, AFM was performed on each bioscaffold. Raman spectroscopy mapping demonstrated differences in the I2D/IG ratio for each scaffold. Young’s modulus was determined by nanoindentation and indicated that epitaxial graphene had the highest average stiffness, followed by CVD, with printed graphene demonstrating the lowest average stiffness. To investigate the biocompatibility of …


Correlation Of Intracellular Metabolites With Optical Metabolic Imaging In Polarized Macrophages As Indicators Of Metabolic Reprogramming, Abby Claire Denison, Shelby Bess May 2023

Correlation Of Intracellular Metabolites With Optical Metabolic Imaging In Polarized Macrophages As Indicators Of Metabolic Reprogramming, Abby Claire Denison, Shelby Bess

Biomedical Engineering Undergraduate Honors Theses

Macrophages are a type of immune cell that are characterized by their ability to differentiate into various active phenotypes based on environmental stimuli. They can generally be classified as one of two extremes: inflammatory/M1 or wound-healing/M2. Macrophage populations in vivo, however, are rarely homogenous, and since macrophages play vital roles in the immune response, particularly in the context of the tumor microenvironment (TME), it’s important to be able to investigate and understand heterogenous macrophage populations to develop more effective treatments. Recently, autofluorescence imaging such as multiphoton microscopy and fluorescence lifetime imaging microscopy (FLIM) of metabolic cofactors NADH and FAD have …


Comprehensive Long- And Short- Read Sequencing Approaches To Screen The Mutational Landscape After Therapeutic Crispr-Editing For Duchenne Muscular Dystrophy, Mary Jia, Made Harumi Padmaswari, Landon Burcham, Shilpi Agrawal, Alexis Ivy, Abbey Bryan, Christopher E. Nelson May 2023

Comprehensive Long- And Short- Read Sequencing Approaches To Screen The Mutational Landscape After Therapeutic Crispr-Editing For Duchenne Muscular Dystrophy, Mary Jia, Made Harumi Padmaswari, Landon Burcham, Shilpi Agrawal, Alexis Ivy, Abbey Bryan, Christopher E. Nelson

Biomedical Engineering Undergraduate Honors Theses

Duchenne muscular dystrophy (DMD) is an X-linked muscle wasting disease caused by mutations in the Dmd gene resulting in non-functional dystrophin. Adeno-associated virus (AAV)-mediated delivery of classical CRISPR systems resulting in double-stranded breaks (DSBs) has yielded promise as a curative DMD therapeutic. However, the consequences of AAV-CRISPR require more thorough characterization. PCR-enriched short-read amplicon sequencing at cut sites is the most common method of sequencing CRISPR editing, but PCR bias results in unreliable quantification of on-target edits. We analyze orthogonal long- and short-read sequencing approaches to screen the outcomes of CRISPR technologies at the DNA and RNA-level for DMD. We …


Characterizing Endothelial Damage During Ischemic Stroke Treatment With 3d Cerebrovascular Live Cellular And Finite Element Models, Ana Regina Martinez Dehesa May 2023

Characterizing Endothelial Damage During Ischemic Stroke Treatment With 3d Cerebrovascular Live Cellular And Finite Element Models, Ana Regina Martinez Dehesa

Theses and Dissertations

Stent retriever mechanical thrombectomy (SRMT) is part of the clinical standard-of-care for acute ischemic stroke (AIS) patients with large vessel occlusion (LVO). Endothelial injury (EI) is widely associated with SRMT. Studies report finding EI markers in over 50% of retrieved clots, suggesting the frequency of EI in MT patients is rather common. The mechanism of EI and its contribution to MT failure and clinical outcomes remain poorly understood because of a lack of techniques to observe EI and study it in vitro. This study aims to investigate the mechanisms of EI induced by SRMT, as well as the effect stent …


Experimental Investigation Of The Self-Healing Potential Of Bacteria For Sustainable Concrete Structures, Pitiporn Asvapathanagul, Simone Galano, Andrea Calabrese, Mehran Rahmani, Maggie Ly, Daniela Flores, Michael Hernandez, Nicholas Banuelos May 2023

Experimental Investigation Of The Self-Healing Potential Of Bacteria For Sustainable Concrete Structures, Pitiporn Asvapathanagul, Simone Galano, Andrea Calabrese, Mehran Rahmani, Maggie Ly, Daniela Flores, Michael Hernandez, Nicholas Banuelos

Mineta Transportation Institute

Although concrete is the most widely used building material in the world, its limited tensile strength makes cracking a common phenomenon in concrete elements. This study investigates the potential of autonomous self-healing as an eco-friendly and lowcost method to increase the durability of concrete. The crack-healing potential of different types of high-alkaline-tolerant bacteria or calcite-precipitation microorganisms is investigated. High-alkaline-tolerant bacteria and calcite-precipitation microorganisms were used to retrofit lab-fractured concrete samples. The samples healed with each of these bacteria groups were cast and tested under compressive load up to failure to measure the compressive strength of the concrete samples. The outcomes …


Automated Visualization Pipeline For Near Real-Time Risk Management System, Paris Joslin May 2023

Automated Visualization Pipeline For Near Real-Time Risk Management System, Paris Joslin

Industrial Engineering Undergraduate Honors Theses

In modern society, technological capabilities and the amount of data readily available to users continue to grow exponentially. Many have adopted these new capabilities but lack the infrastructure needed to efficiently utilize high-powered software and programs. Without a method to collect, store, and process large datasets in real-time, individuals and businesses can quickly become overwhelmed, inhibiting effective decision-making processes. There is potential to improve decision-making abilities by enhancing the computing infrastructure. To accomplish this task, we will explore the ideas surrounding High Performance Computing (HPC) and data visualization software. High Performance Computing is the ability to process data and perform …


A Proof Of Concept For Detection Of Palato-Lingual Contact Without Intraoral Electrodes In A Human Participant, Amitava Biswas May 2023

A Proof Of Concept For Detection Of Palato-Lingual Contact Without Intraoral Electrodes In A Human Participant, Amitava Biswas

Master's Theses

The author of this thesis conceived and investigated an unexpected electrical signal that may not be noticed during regular electroglottography (EGG) when electrodes are conventionally placed on the anterior surface of the throat. It appears that there is a measurable electrical signal from the EGG equipment when electrodes are placed over the frontal cheek (belly of zygomatic muscle), and the tongue is elevated to contact the hard palate, or the tongue is lowered to break the contact. Therefore, this phenomenon is designated as unconventional electroglottography (UEGG, Dr. Steven Cloud, private communication, July 17, 2022).

Two distinctive patterns of waveforms were …


Algae Against Deforestation: Algae Oil As A Potential Palm Oil Substitute, Abiela Meek May 2023

Algae Against Deforestation: Algae Oil As A Potential Palm Oil Substitute, Abiela Meek

Undergraduate Honors Capstone Projects

This capstone project is an effort to pursue sustainability through circular engineering design. With increasing interest in sustainable production of consumer products, creative and multifaceted solutions are the pathway forward to a more circular economy. Palm oil production is a key driver of deforestation worldwide and an unsustainable industry. As palm oil is a large player in the commodities market, evaluating a potential replacement provided a unique opportunity for sustainable circular engineering. High nitrogen and phosphorus concentrations in wastewater are also a cause for environmental concern as they can lead to harmful algal blooms. By utilizing the nitrogen and phosphorus …


An Integrated Experimental And Modeling Approach To Design Rotating Algae Biofilm Reactors (Rabrs) Via Optimizing Algae Biofilm Productivity, Nutrient Recovery, And Energy Efficiency, Gerald Benjamin Jones May 2023

An Integrated Experimental And Modeling Approach To Design Rotating Algae Biofilm Reactors (Rabrs) Via Optimizing Algae Biofilm Productivity, Nutrient Recovery, And Energy Efficiency, Gerald Benjamin Jones

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Microalgae biofilms have been demonstrated to recover nutrients from wastewater and serve as biomass feedstock for bioproducts. However, there is a need to develop a platform to quantitatively describe microalgae biofilm production, which can provide guidance and insights for improving biomass areal productivity and nutrient uptake efficiency. This paper proposes a unified experimental and theoretical framework to investigate algae biofilm growth on a rotating algae biofilm reactor (RABR). The experimental laboratory setups are used to conduct controlled experiments on testing environmental and operational factors for RABRs. We propose a differential-integral equation-based mathematical model for microalgae biofilm cultivation guided by laboratory …


Historic Downtown Streetscape Plan Price City, Utah, Patricia Beckert May 2023

Historic Downtown Streetscape Plan Price City, Utah, Patricia Beckert

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

The idea of a small-town Main Street has profound meaning within the American culture that has prevailed for the past two centuries. Historically, Main Street serves as the beating heart of a community, a place where economic, social, cultural, and civic activities are centered (Francaviglia, 1996; Main Street America, n.d.). Since the beginning of the 19th century, many factors have led to the decline of Main Streets, and despite a variety of efforts from different stakeholders, that decline has only intensified in recent decades (Isenberg, 2008; Orvell, 2014 Howard, 2015). In 1980, after a three-year project conducted by the National …


Multi-Objective Optimization Framework For Electrified Vehicle Penetration Based On Life Cycle Assessment And Life Cycle Cost., Eva Alondra Diaz Lozano May 2023

Multi-Objective Optimization Framework For Electrified Vehicle Penetration Based On Life Cycle Assessment And Life Cycle Cost., Eva Alondra Diaz Lozano

Open Access Theses & Dissertations

This research proposed a novel framework for creating optimal transportation scenarios that consider multiple objectives such as minimum greenhouse gas emissions, air pollutant levels, and cost of ownership. The thesis approach is a multi-objective evolutionary algorithm coupled with the AFEET tool, allowing us to efficiently explore the complex trade-offs between these objectives and identify a diverse set of optimal solutions. Through several case studies and a design of experiments, this demonstrates the effectiveness and practicality in different scenarios. This approach has significant implications for policymakers and industry professionals seeking to make sustainable and cost-effective decisions in the transportation sector.


Development Of A Cost-Constrained Intelligent Prosthetic Knee With Real-Time Machine Learning, Predictive Stumble Control, Lucas Jonathan Galey May 2023

Development Of A Cost-Constrained Intelligent Prosthetic Knee With Real-Time Machine Learning, Predictive Stumble Control, Lucas Jonathan Galey

Open Access Theses & Dissertations

The field of biomechatronics is evolving quickly with advances in computer science, biology, and electrical and mechanical engineering. Coupled with increased interests in machine learning (ML) across all industry sectors, there are opportunities to leverage advanced analytics in uniquely complex problems. This study aimed to deploy real-time ML predictions in a novel microprocessor-controlled prosthetic knee (MPK) device capable of identifying and responding to stumble-events to reduce amputee fall prevalence. Innately, stumbling is a chaotic event. Current MPKs operate by detecting gait characteristics and reacting to preprogrammed states. While these systems are beneficial in significant ways, such as energy expenditure and …


Additive Manufacturing Of Binary And Ternary Shape Memory Polyester Blends As A Pathway Towards High Entropy Polymer Systems., Luis Eduardo Lares Carrillo May 2023

Additive Manufacturing Of Binary And Ternary Shape Memory Polyester Blends As A Pathway Towards High Entropy Polymer Systems., Luis Eduardo Lares Carrillo

Open Access Theses & Dissertations

The purpose of this work is to incorporate additive manufacturing technology (AM) in the development of shape memory polymer blends. Two polyester blend systems were developed, one binary and the other ternary. The binary blend consisted of polycaprolactone (PCL) and thermoplastic polyurethane (TPU) and the ternary blend was composed of PCL, TPU and polylactic acid (PLA). Test specimens were fabricated with the AM technology of fused filament fabrication (FFF). Several tests were performed to characterize the mechanical and shape memory properties. A dynamic mechanical analyzer (DMA) was first used to establish the shape recovery temperature. Tensile testing was carried out …


Computational Analysis Of Water Braking Phenomena For High-Speed Sled And Its Machine Learning Framework, Jose A. Terrazas May 2023

Computational Analysis Of Water Braking Phenomena For High-Speed Sled And Its Machine Learning Framework, Jose A. Terrazas

Open Access Theses & Dissertations

Specializing in high-speed testing, Holloman High-Speed Test Track (HHSTT) uses a process called "water braking" as a method to bring vehicles at the test track to a stop. This method takes advantage of the higher density of water, compared to air, to increase braking capability through momentum exchange. By studying water braking using Computational Fluid Dynamics (CFD), forces acting on track vehicles can be approximated and prepared for prior to the actual test. In this study, focus will be made on the brake component of the track sled that is responsible for interacting with the water for braking. By discretizing …