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Investigation Of Fatigue Response With Analytical And Machine Learning Models And Hygroscopic Analysis Of Asymmetric Bistable Cfrp Composites, Shoab Ahmed Chowdhury

All Dissertations

Asymmetric bistable carbon fibre reinforced plastic (CFRP) composites enable a broad range of applications as they can sustain multiple stable configurations and have small snap-through load requirements. These unique features, coupled with their light strength-to-weight and stiffness-to-weight ratios, have made them preferred options for multifunctional systems. This study investigates the fatigue and hygroscopic response of 2-ply, [0/90] bistable CFRP laminates and proposes predictive modeling approaches for improved performance.

While previous studies widely researched and documented the fatigue of general composites in axial loading, fatigue analysis of asymmetric bistable composites in the out-of-plane snap-through direction is inadequate. This study performs fatigue …

Investigating The Potential Of A Cell-Based Gene Editing Therapy For Inherited Metabolic Liver Disease, Ilayda Ates

All Dissertations

Inherited metabolic diseases (IMDs) affecting the liver are relatively rare but collectively have a prevalence of 1 in 800 live births. These diseases result from autosomal recessive single-gene mutations, leading to organ dysfunction and potentially fatal consequences if left untreated. One potential therapeutic strategy for IMDs of the liver involves using CRISPR-Cas9-induced loss of function mutations. However, translating this approach into the clinic is limited by the need for safe and effective CRISPR delivery methods. Adeno-associated viral vectors (AAVs), commonly used for CRISPR delivery, are associated with significant safety and efficacy concerns, including risks for immunogenicity, off-target mutagenesis, and genotoxicity …

Extensional Flows Of Polymer Solutions In Planar Microchannels, Mahmud Kamal Raihan

All Dissertations

Non-Newtonian fluids such as polymer solutions often flow under microscale extensional conditions in many natural and engineering flow fields such as in microfluidic chips, porous rocks, biological membranes and filters, printheads in additive manufacturing, etc. The changing cross sectional areas of the internal flow passages therein exert additional extension on the flow along with the shearing. Numerous studies have been dedicated to understanding the extensional flows of polymer solutions over the years. However, most of these studies only focused on flexible polymers exhibiting elasticity in their macroscopic rheology, whereas rigid polymers that portray shear-thinning but often elude elasticity in the …

Accurate Orientation Control Of Tendon Driven Continuum Robots That Exhibit Elasticity, Manu Srivastava

All Dissertations

This dissertation makes new contributions to the modeling and implementation of Tendon Driven Continuum Robots (TDCRs). Specifically, motivated by 3D printing of concrete using a continuum hose robot in construction applications, we focus on TDCRs featuring compliance in the robot backbone and actuating tendons, e.g. surgical robots/endoscopes/catheters with tendon actuation. We expand previous mechanics-based models to show how and why such compliance significantly restricts performance when traditional kinematics-based planning and control techniques are applied.

The main contribution of this work is a new Elasticity Compensation(EC) model that explains why the ad hoc approach of preloading/pretensioning the tendons compensates for compliance …

Injectable Immunomodulatory Strategies To Enhance Muscle Recovery Following Injury, Tai Huu Huynh

Graduate Theses and Dissertations

Although skeletal muscle displays an astonishing regenerative capacity, injuries or diseases that resulted in bedridden or chronic muscle wasting can overwhelm this intrinsic feature of skeletal muscle and lead to functional deficit (range of motion and/or strength) and overall reduction in quality of life. Microenvironmental cues within injured skeletal muscle dictate regenerative and repair process which are tightly coordinated interplay among resident cells, cells recruitment and immune response following an assault in the muscle extracellular matrix (ECM). The successful regeneration of functional tissues requires both appropriate modulation of the inflammatory response, and activation of a variety of cell populations. Biomaterials …

Facial Expression Recognition Using Convolutional Neural Networks (Cnns) And Generative Adversarial Networks (Gans) For Data Augmentation And Image Generation, Shekhar Singh

UNLV Theses, Dissertations, Professional Papers, and Capstones

Facial expressions play a crucial role in human communication, serving as a powerful means to convey emotions. However, classifying facial expressions using artificial intelligence (AI) can be challenging, especially with small datasets and images. Facial Expression Recognition (FER) is an active area of research, with Convolutional Neural Networks (CNNs) being widely employed for classification. In this research, we propose a CNN-based approach for FER that utilizes both original and augmented datasets to enhance classification accuracy. Experimental results on the FER2013 dataset show test accuracies of 63.39% and 64.59% for the original and augmented datasets, respectively, in a seven-class classification task. …

Multiphysics Numerical Modeling For Pfas Transport Within Vadose And Saturated Zones, Pierrette Iradukunda

Boise State University Theses and Dissertations

The extent and severity of wildfires have increased around the world, necessitating a greater understanding of the consequences of wildfire and post-fire impacts on soil and groundwater. Wildfire suppression techniques like aqueous film-forming foams (AFFF) can also contaminate the soil with per- and polyfluoroalkyl substances (PFAS), which can contribute to human and environmental health concerns. PFAS are dangerous man-made chemical compounds that are persistent, mobile, poisonous, and a major cause of soil and groundwater contamination. In addition to contamination by aqueous film-forming foams, PFAS has accumulated in the environment as a result of being utilized in numerous other goods over …

Development Of Predictive Rockfall Runout Maps Based On Calibrated Rockfall Models, Olivia Tabor

Boise State University Theses and Dissertations

Cliffs formed in columnar jointed basalt have the proper geometry and discontinuities to initiate rockfall events. There are a number of locations in Boise, Idaho that may experience rockfall events from columnar jointed basalt cliffs. Publicly available LiDAR data coupled with site reconnaissance activities were used to develop calibrated two-dimensional rockfall models at a study site in southeast Boise. Photogrammetry was used to determine the volume of seven calibration boulders. The study site, located on Whitney Terrace, consists of a columnar jointed basalt cliff followed by a slope with a subdivision at the toe of the slope.

The two common …

Electromagnetic Simulations Of The Lansce Chopper Structure, Yusuf Sahin

Electrical and Computer Engineering ETDs

Particle accelerators are important for basic research as well as in applications such as ion implantation and cancer therapy. One important accelerator is the Los Alamos Neutron Science Center (LANSCE) located at Los Alamos National Laboratory (LANL) that primarily produces neutrons for research. The beam chopper simulation described here is a study to provide better modeling of this subsystem of LANSCE. A chopper is a device in which particles are intermittently sliced and directed to a target and/or experiment. The simulations in this thesis are used to analyze the correct operating parameters of the chopper. A good chopper model can …

Comparison Of Random Coupling Model To Stochastic Dyadic Green’S Function When Coupling To A Distributed Port, Evelyn Anne Dohme

Electrical and Computer Engineering ETDs

The Random Coupling Model (RCM) provides statistical representation of coupling between ports in a highly overmoded resonant cavity based on knowledge of radiation impedances of system ports and cavity properties. A recent variant of RCM, the Stochastic Dyadic Green’s Functions (S-DGF), provides the statistical distribution of fields in the cavity. By using Source Reconstruction Methods (SRM) to approximate equivalent surface currents, I hypothesized that the S-DGF can calculate the fields at their location, enabling a statistical estimate of the coupled power. Using nearfield radiation from simple patch antenna simulations and the SRM to estimate the equivalent fields and account for …

Ultrasensitive Tapered Optical Fiber Refractive Index Glucose Sensor, Erem Ujah

Biomedical Engineering Theses & Dissertations

Refractive index (RI) sensors are of great interest for label-free optical biosensing. A tapered optical fiber (TOF) RI sensor with micron-sized waist diameters can dramatically enhance sensor sensitivity by reducing the mode volume over a long distance. Here, a simple and fast method is used to fabricate extremely sensitive refractive index sensors based on localized surface plasmon resonance (LSPR). Two TOFs (l = 5 mm) with waist diameters of 5 µm and 12 µm demonstrated sensitivity enhancement at λ = 1559 nm for glucose sensing (5–45 wt%) at room temperature. The optical power transmission decreased with increasing glucose concentration due …

Evaluating Direct Filtration As An Alternative To Conventional Carbon-Based Advanced Treatment For Indirect Potable Reuse, Savannah M. Flemmer

Civil & Environmental Engineering Theses & Dissertations

Hampton Roads Sanitation District (HRSD) is recharging purified wastewater into the Potomac Aquifer via the Sustainable Water Initiative for Tomorrow (SWIFT) project. Conventional SWIFT treatment applies coagulation, flocculation, sedimentation, ozonation, biofiltration, granular activated carbon (GAC) adsorption, and ultraviolet disinfection to secondary effluent to produce water that meets drinking water standards for managed aquifer recharge. HRSD is considering implementing direct filtration as an alternative to conventional treatment for two additional SWIFT facilities. Direct filtration presents an opportunity for significant cost savings by eliminating sedimentation, shortening flocculation detention time, and reducing coagulant usage. Without upstream removal of solids and organics, however, biofilters …

Data-Driven Predictive Modeling To Enhance Search Efficiency Of Glowworm-Inspired Robotic Swarms In Multiple Emission Source Localization Tasks, Payal Nandi

Mechanical & Aerospace Engineering Theses & Dissertations

In time-sensitive search and rescue applications, a team of multiple mobile robots broadens the scope of operational capabilities. Scaling multi-robot systems (< 10 agents) to larger robot teams (10 – 100 agents) using centralized coordination schemes becomes computationally intractable during runtime. One solution to this problem is inspired by swarm intelligence principles found in nature, offering the benefits of decentralized control, fault tolerance to individual failures, and self-organizing adaptability. Glowworm swarm optimization (GSO) is unique among swarm-based algorithms as it simultaneously focuses on searching for multiple targets. This thesis presents GPR-GSO—a modification to the GSO algorithm that incorporates Gaussian Process Regression (GPR) based data-driven predictive modeling—to improve the search efficiency of robotic swarms in multiple emission source localization tasks. The problem formulation and methods are presented, followed by numerical simulations to illustrate the working of the algorithm. Results from a comparative analysis show that the GPR-GSO algorithm exceeds the performance of the benchmark GSO algorithm on evaluation metrics of swarm size, search completion time, and travel distance.

Assessing The Prevalence And Archival Rate Of Uris To Git Hosting Platforms In Scholarly Publications, Emily Escamilla

Computer Science Theses & Dissertations

The definition of scholarly content has expanded to include the data and source code that contribute to a publication. While major archiving efforts to preserve conventional scholarly content, typically in PDFs (e.g., LOCKSS, CLOCKSS, Portico), are underway, no analogous effort has yet emerged to preserve the data and code referenced in those PDFs, particularly the scholarly code hosted online on Git Hosting Platforms (GHPs). Similarly, Software Heritage is working to archive public source code, but there is value in archiving the surrounding ephemera that provide important context to the code while maintaining their original URIs. In current implementations, source code …

Adaptation Of Nirtrifiers And Heterotrophs To Low Dissolved Oxygen In An Activated Sludge Biological Nutrient Removal Pilot Plant, Shashank Khatiwada

Civil & Environmental Engineering Theses & Dissertations

Low dissolved oxygen (DO) operation is one of the innovative technologies in biological nutrient removal (BNR) processes that is being investigated due to the potential to reduce aeration requirements, reduce a treatment plant’s carbon footprint, and to lower costs associated with chemical addition to promote denitrification. These benefits are achieved through development of micro-zones, within aerated basins where simultaneous nitrification and denitrification (SND) can occur. In this study, an activated sludge BNR pilot was run in an anerobic/aerobic (A/O) configuration at a controlled temperature and constant flow to observe microorganism-driven transformations of nitrogen and phosphorus at varying low DO conditions. …

Synthesis And Characterization Of Cobalt(Iii) Complexes And A Vanadium(Iv) Complex With Flavonoids As Ligands, Ethan Schroeder

Chemistry & Biochemistry Theses & Dissertations

For many years now, transition metal complexes have been used as favorable additional chemotherapeutic approaches to medicine that were previously unexplored in the literature. One well-known chemotherapeutic drug, cisplatin, has been applied, but is limited in use due to its toxicity to the cells and its undesirable side effects to humans. Newly developed cobalt-based complexes with ligands known as flavonoids are being used to fight cancer. Flavonoids, compounds mainly found in fruits and vegetables, are shown to have antioxidative and anticancer properties. Use of flavonoids as ligands in transition metal complexes, e.g., those with a Ru(II) metal center, have been …

Liquid Crystalline Coacervates Composed Of Chromonic Mesogens And Polyelectrolytes, Elizabeth Adeogun

Graduate Theses and Dissertations

Complex coacervates are formed by liquid-liquid phase separation of an aqueous solution of oppositely charged ions. Although several mixtures of molecules of natural and synthetic macro-ion have been shown to form complex coacervates, the formation of liquid crystalline (LC) coacervates are sparsely reported. LC coacervates have a unique property in that they can change their shape and optical property in response to external stimuli such as changes in temperature, pH, or the presence of specific molecules. This property makes LC coacervates useful as a sensor, as they can be engineered to respond to specific stimuli and generate a measurable signal …

Non-Energy Circular Economy Potential Of Rice Husks: A Techno-Eco-Environmental Assessment, Winfred Oppong Yeboah

Graduate Theses and Dissertations

The non-energy circular bioeconomy potential of rice husks was examined via sustainability assessments, namely life cycle assessment (LCA), life cycle impact cost assessment (LCICA), and techno-economic assessment (TEA). The study was conducted with three objectives. The first objective was to review previous studies on the non-energy utilization potential of rice husks by the method of meta-analysis. This review followed a systematic approach where research papers were collected following a defined set of criteria. The study revealed 16 key utilization pathways, all of which showed promising results. However, a comprehensive sustainability assessment was lacking in all of the pathways. The second …

Treating High Salinity Produced Water Using Hybrid Membrane Processes: Electrocoagulation-Microfiltration/Ultrafiltration-Membrane Distillation-Crystallization, Mahmood Gheni Jebur

Graduate Theses and Dissertations

Produced water (PW) is considered the largest industrial wastewater stream in the world. PW generated from oil and gas operations generally contains a range of contaminants including high total dissolved solids, high total suspended solids, polar and nonpolar organic compounds, and low surface tension dissolved species. Treating PW is very challenging and applying only membrane-based technologies is not sufficient due to membrane fouling, which affects their long-term performance. Hence, integrated membrane processes are required to treat PW effectively. Hybrid membrane processes, which may result from combining a conventional process with a membrane separation, could be used to address the issues …

The Genetic And Non-Genetic Factors For Impulsivity, Erick Benjamin Saldes

Open Access Theses & Dissertations

Inhibitory control is an executive function suppressing inappropriate actions or thoughts and inhibitory control dysfunction leads to impulsivity. Impulsivity is associated with wide-ranging brain disorders including attention deficit hyperactivity disorder, autism spectrum disorder, substance use disorder, and dementia. The genetic and non-genetic factors contributing to impulsivity are poorly understood. This dissertation aims to begin closing this knowledge gap by identifying the genetic and non-genetic factors for impulsivity and the underlying mechanism in the model organism Drosophila melanogaster. For this task, we developed a new Go/No-Go test, which measures the fly's ability to suppress movements in situations that can endanger its …

Performance Evaluation Of E-Ticketing Technologies On Asphalt Paving Projects In New Mexico, Gena C. Robertson

Civil Engineering ETDs

The collection and processing of paper tickets for construction material delivery is an inefficient and antiquated practice that exposes inspectors on highway paving projects to substantial safety risks. An alternative to the collection of paper tickets is e-Ticketing, which uses web-based systems to deliver similar information. This research documented a current paper ticketing process and compared it to an e-Ticketing process that was implemented on several pilot projects. Data were obtained using stakeholder meetings, personnel interviews, and surveys. When compared to a paper ticketing system, e-Ticketing was shown to have fewer opportunities for error, require fewer decision points, and provide …

Hydrothermal Liquefaction Of Wastewater Sludges For Energy Resource Recovery, Carl L. Abadam

Civil Engineering ETDs

This study aims to identify how variabilities in wastewater process configurations impact the biocrude yields from sludges processed and stabilized by hydrothermal liquefaction. Clean and renewable energy sources are vital to ensure a sustainable future. However, the current consumption of fossil fuels limits the ability to achieve this goal. Hydrothermal liquefaction (HTL) is a thermochemical process that converts wet biomass to valuable biocrude oil and biochar while reducing solid masses. Wastewater sludges were sampled across three facilities with varying influent design capacities and biological treatment configurations. Lipids extracted via solvent extraction and biocrudes produced from HTL were determined gravimetrically. Relative …

Hydraulic Habitat Suitability For The Rio Grande Silvery Minnow At The Los Chavez Irrigation Outfall, New Mexico, Haley A. Ormsbee

Civil Engineering ETDs

It is essential to manage the Middle Rio Grande for aquatic species to preserve the native biodiversity of the river. During periods of low flow, endangered species such as the Rio Grande Silvery Minnow (RGSM) may get trapped in a drying reach without the ability to escape from isolated pools. Very little is known about how areas of refuge, such as irrigational outfall channels, buffer RGSM from stream flow intermittency. Hence, there is a crucial need to quantify available habitat for RGSM in areas of refuge. This study aims to make connections between flow regimes and physical-habitat conditions to help …

Role Of Endophytic Fungi On Arsenic Uptake In Solution: Insights For Bioremediation, Taylor Lillian Busch

Civil Engineering ETDs

Hazardous metals mobilized from natural deposits and mining legacy are environmental and human health concerns. The waters of our partner Native American communities affected by uranium and gold mining legacy exceed the EPA MCL of 10 µg/L arsenic (As). Bioremediation is a novel technology that uses native resources to remediate metals in the soil and groundwater. Plant-fungi symbiosis for bioremediation is widely studied, but the role of endophytic fungi in metal uptake is not well understood. The objectives of this study are to 1) determine As uptake by symbiotic endophyte Cadophora sp. and little bluestem grass (Schizachyrium scoparium) …

Identifying The Required Ecological Flow For Sediment Movement In The Río Chama: Field Data Informed Visual Spatial Model, Cristian Kremer

Civil Engineering ETDs

The continuous alteration of flow regimes in rivers has led to negative impacts on habitats and biotic communities, causing irreversible effects on river biodiversity. Implementing e-flows in management strategies can repair historical mismanagement, prevent further degradation, and restore ecosystem services. In the case of the Rio Chama, damming has altered its hydrological regime, affecting sediment transport. Experts recommend specific e-flow conditions for the Rio Chama to improve ecological conditions, in particular a bankfull discharge of 70 m³s^-1 every 2 years for sediment flushing and channel maintenance. The Río Gallina, a tributary of the Rio Chama, plays a …

Development Of The Navigator: A Lagrangian Smart Sensing System To Characterize Aquatic Ecosystems., Aashish Sanjay Khandelwal

Civil Engineering ETDs

Most freshwater aquatic studies rely on Eulerian monitoring, i.e., water quality and quantity are monitored using grab samples or semi-continuous sensors deployed at fixed cross-sections. While Eulerian monitoring is practical, it provides a limited understanding of spatial and temporal heterogeneity and their effects on environmental processes. This dissertation summarizes the design and application of The Navigator, an alternative Lagrangian monitoring system that offers cost-effective solutions for in-situ, real-time data collection in lotic and lentic freshwater ecosystems such as streams, rivers, ponds, and reservoirs. The Navigator features a suite of methods – an autonomous surface vehicle (ASV) with GPS and LTE …

Combining Semi-Continuous And Discrete Water Quality Data To Characterize Solute Transport, Biogeochemical Processes, And Wildfire Disturbances In Fluvial Systems, Justin Rae Nichols

Civil Engineering ETDs

In the past decade, high-frequency water quality sondes have become more abundant in watersheds across North America and Europe and are gaining a foothold in Asia and South America. In this dissertation, three relevant topics associated with high-frequency data are investigated, i.e., the impact of winter’s precipitation on surface water quality and stream metabolism, the longitudinal propagation of wildfire disturbances through a fluvial network, and the use of machine learning with high-frequency data to estimate fluvial nutrient processing. First, we found that significant snow precipitation can cause surface water anoxia and declines in stream metabolism. Second, our data illustrate that …

Towards Sustainable Water Management: Soil Analysis, Modeling, And Sensor Implementation On A Micro-Basin Chile's Los Lagos Region, Tammy N. Huynh

Civil Engineering ETDs

The Los Lagos region of Chile is experiencing ecological and socioeconomic challenges because of climate change. Despite efforts by the agricultural sector to understand and manage water resources, the lack of basic water quantification data affects their ability to effectively plan and implement water management strategies. This research aims to address this critical issue through three key objectives. First, characterize soil properties related to texture and structure in a micro-basin of the Los Lagos region. Secondly, it aims to investigate the hydrologic budget of the micro-basin with an emphasis on soil moisture using the Soil Moisture Routing model (SMR). Lastly, …

Surface-Functionalized Silica Nanocarriers For Mitigating Water Stress In Wheat And Benefiting The Root Microbiome, Anthony Cartwright

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Changes in climate and shifting patterns of drought threaten the growth of important cash crops like wheat. The element silicon serves as a plant nutrient and shows promise for strengthening wheat against drought while remaining safe to both the crop and the positive bacteria that grow on its roots. Silicon can be added to wheat in the form of silicon-dioxide nanoparticles featuring protective coatings made from plant-beneficial nutrients. These nanoparticles can be engineered with high surface area or porous structures allowing them to be loaded with additional nutrients that can be delivered to crops. In a laboratory setting, such nanoparticles …

Exploring Versatile Glycosyltransferases From Microorganisms For Natural Product Biosynthesis, Jie Ren

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This dissertation is mainly focused on exploring versatile glycosyltransferases from different microorganisms with the purpose of biosynthesizing bioactive natural product glycosides through microbial fermentation. This engineered biosynthesis approach is environmentally friendly, safe, and efficient compared with plant extraction, chemical synthesis, and enzymatic synthesis. Additionally, we applied these characterized glycosyltransferases as efficient biocatalytic tools to produce novel glycosides to expand the chemical repertoire of nature. These novel compounds showed improved water solubility and some of them exhibited enhanced stability and biological activity, which laid the foundation for the development of new therapeutic agents.

In my dissertation research, I have discovered two …