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The Effect Of Wing Shape And Ground Proximity On Unsteady Fluid Dynamics During The Perching Maneuver., Dibya Raj Adhikari

Electronic Theses and Dissertations, 2020-2023

While landing, birds often perform a perching maneuver, which involves pitching their wings upwards while decelerating to a complete stop. By performing this perching maneuver, the birds can continue generating higher lift and drag force while slowing down, resulting in a smooth landing. The present study is motivated by the perching maneuver and aims to investigate two critical aspects of it. First, we want to explore how the proximity of the ground affects the unsteady forces and the flow field during the perching flight; and second, we want to analyze how a wing sweep influences a perching maneuver. To explore …

Comparing Hydrogen Peroxide And Sodium Perborate Ultraviolet Advanced Oxidation Processes For 1,4-Dioxane Removal From Wastewater Effluent, Tulsi Shukla

Electronic Theses and Dissertations, 2020-2023

Ultraviolet advanced oxidation processes were compared using sodium perborate (UV/NaBO3 AOP) or hydrogen peroxide (UV/H2O2 AOP) for 1,4-dioxane removal from tertiary wastewater effluent. Both UV/H2O2 and UV/NaBO3 AOPs were also tested with the addition of acetic acid. Results revealed that sodium perborate performed similarly to hydrogen peroxide – the UV/NaBO3 AOP with 6 milligrams per liter (mg/L) as H2O2 resulted in 43.9 percent 1,4-dioxane removal, while an equivalent UV/H2O2 AOP showed 42.8 percent removal. Although the oxidants performed similarly, NaBO3 is an average of 3.3 times more expensive than H2O2. However, the solid form of NaBO3 can provide a major …

Probing Endothelial Cell Mechanics Under Disturbed Fluid Flow, Jingwen Wu

Electronic Theses and Dissertations, 2020-2023

Endothelial cells, which form the inner layer of the vasculature, interact with the extracellular matrix (ECM) by exerting mechanical contractile cell-substrate stress called tractions and cell-cell stresses called intercellular stresses. This cellular mechanical behavior involves many fundamental biological processes, including cell migration, differentiation, angiogenesis, and wound healing. Also, the inner surface of the vasculature, where endothelial cells reside, is constantly exposed to various fluid flows. The most variable fluid flow regimes occur primarily within branching regions of the vasculature. Endothelial cells residing within these regions experience disturbed flow, which consists of irregular flow patterns and extreme wall shear stress gradients. …

Design And Simulation Analysis Of A Bipv (Building Integrated With Pv) Air-Duct System For Residential High-Performance Development, Arash Zarmehr

Electronic Theses and Dissertations, 2020-2023

A growing number of buildings are integrating building-integrated photovoltaics (BIPV) devices to increase energy efficiency and reduce energy costs. A building's heating and cooling loads are impacted by the thermal resistance of the air duct BIPV because of the change in thermal resistance. Therefore, augmenting the efficiency of (BIPV) devices will benefit many building architectures and mechanical engineering applications. This work introduces a low-cost and low- maintenance air duct system design augmenting BIPV systems. This novel approach increases airflow velocity and decreases air temperature for BIPV, resulting in improved performance for the PV system electricity output, increased PV lifespan due …

Coalition Formation And Beamsteering Optimization For Directional Software-Defined Radios, Sayanta Seth

Graduate Thesis and Dissertation 2023-2024

Dynamic Spectrum Access (DSA), also known as Dynamic Spectrum Management, is the method of utilizing a set of spectrum techniques in real time to provide the ability to share wireless channels between Primary (or licensed) users (PUs) and Secondary (or unlicensed) users (SUs). The system is so designed that under normal circumstances, the PUs always get priority, but DSA enables the SUs to use the licensed bands as long as they do not create any interference on the PUs. Hence, the goal of utilizing the spectrum more efficiently can be achieved. Though DSA has been researched extensively as a new …

Low Energy Photon Detection, Tianyi Guo

Graduate Thesis and Dissertation 2023-2024

Detecting long wave infrared (LWIR) light at room temperature has posed a persistent challenge due to the low energy of photons. The pursuit of an affordable, high-performance LWIR camera capable of room temperature detection has spanned several decades. In the realm of contemporary LWIR detectors, they can be broadly classified into two categories: cooled and uncooled detectors. Cooled detectors, such as MCT detectors, excel in terms of high detectivity and fast response times. However, their reliance on cryogenic cooling significantly escalates their cost and restricts their practical applications. In contrast, uncooled detectors, exemplified by microbolometers, are capable of functioning at …

Probing Electron Correlations With First-Principles Calculations Of The High Harmonic Spectrum In Solids, Didarul Alam

Graduate Thesis and Dissertation 2023-2024

High harmonic generation (HHG) is an extreme non-linear phenomenon where strong laser fields interact with a medium to produce coherent and high-frequency harmonics of the incident light. It has emerged as a rapidly growing research area in bulk materials since its first observation in ZnO crystals in 2011. Over the past decade, pioneering studies have already been made in understanding the details of the microscopic mechanism behind this phenomenon, like the role of intra- and inter-band transitions, the contribution of the modulus and the phase of the dipole moment to even and odd harmonic peaks, the role of the oscillating …

Optimizing Deep Neural Networks Performance: Efficient Techniques For Training And Inference, Ankit Sharma

Graduate Thesis and Dissertation 2023-2024

Recent advances in computer vision tasks are mainly due to the success of large deep neural networks. The current state-of-the-art models have high computational costs during inference and suffer from a high memory footprint. Therefore, deploying these large networks on edge devices remains a serious concern. Furthermore, training these over-parameterized networks is computationally expensive and requires a longer training time. Thus, there is a demand to develop techniques that can efficiently reduce training costs and also be able to deploy neural networks on mobile and embedded devices. This dissertation presents practices like designing a lightweight network architecture and increasing network …

Dna Capture And Translocation Through Nanopore, Swarnadeep Seth

Graduate Thesis and Dissertation 2023-2024

This thesis investigates DNA dynamics and translocation through nanopores using Brownian dynamics (BD) simulations, offering insights into sequencing technologies, DNA marker detection, and accurate barcoding utilizing solid-state nanopore platforms. First, we in silico study the intricate process of capture and translocation in a single nanopore. Our simulation reveals a high probability of hairpin loop formation during the capture process. However, attaching a charged tag to one end of DNA improves multi-scan rates and enhances unidirectional translocations. We use modulating voltage biases to multi-scan a lambda-phage dsDNA with oligonucleotide flap markers (tags) through a single and double nanopore system. Our study …

Xps Study Of Calcium Lanthanum Sulfide Ceramics, Brian E. Butkus

Graduate Thesis and Dissertation 2023-2024

Long wave infrared (LWIR) optics that transmit in the 8 to 14 m wavelength range and, additionally, can withstand severe physical and thermal stresses are needed for advanced remote sensing, guidance and communication-based applications. However, most non-oxide transparent LWIR optics do not have the wider transmission range, nor the hardness and resistance to thermal shock needed for extreme environments. Because of these limitations, research is circling back to a promising material, calcium lanthanum sulfide (CLS), that could meet LWIR needs for extreme environments.

In this thesis, we will demonstrate the abilities of x-ray photoelectron spectroscopy (XPS) as a technique for …

Exploring A Lab-Scale Cascade Upflow Bioreactor System For Nitrogen Removal Via Biosorption Activated Media, Alejandra Robles Lecompte

Graduate Thesis and Dissertation 2023-2024

Many Best Management Practices (BMPs) have been developed to reduce excessive nutrients in stormwater runoff and mitigate harmful algal blooms in downstream receiving water bodies. This study demonstrates a new BMP by comparing two green sorption media (i.e., specialty adsorbents) for nutrient removal in cascade upflow biofiltration systems operated in parallel. The proposed filtration technology can control hydraulic gradients, prevent clogging and settlements, and increase hydraulic loading while removing more nutrients in an integrated physicochemical and microbiological treatment process. The two green sorption media being tested in this study include zero-valent-iron and perlite-based green sorption media (ZIPGEM) and biochar, iron, …

A Systematic Review Of Cryptocurrencies Use In Cybercrimes, Kieran B D Human

Graduate Thesis and Dissertation 2023-2024

Cryptocurrencies are one of the most prominent applications of blockchain systems. While cryptocurrencies promise many features and advantages, such as decentralization, anonymity, and ease of access, those very features can be abused. For instance, as documented in various recent works, cryptocurrencies have been frequently abused in many different forms of cybercrime. Despite the plethora of works on measuring and understanding the abuse of cryptocurrencies in the digital space, there has been no work on systemizing this knowledge by comprehensively understanding those contributions, contrasting them based on their merit, and understanding the gap in this research space.

This thesis initiates the …

A Holistic Work System Approach To Creating Flow During Transactional Work, Steven Clapp

Electronic Theses and Dissertations, 2020-2023

Psychological flow is a positive mental state where one is so fully concentrated in a challenging task that self-consciousness falls away, time seems to stand still, and the reward is the experience of meeting the challenge. Previous research on flow in the workplace has been performed on how to create conditions to promote its occurrence in workers, to describe its attendant individual and organizational benefits, and to measure it through self-reported means and physiologically. Such research has been focused on creative endeavors (such as the arts, sports, medicine, teaching), where individuals have high agency over the execution of activities needed …

Instrumental Approaches For High Resolution Photoluminescence Spectroscopy And Its Applications To Environmental Analysis, Anthony Santana

Electronic Theses and Dissertations, 2020-2023

Photoluminescence phenomena provide valuable information for the direct analysis of target chemicals in complex samples. To take full advantage of the information content of fluorescence and phosphorescence phenomena, the analyst should have access to instrumentation capable to record data formats in the wavelength and time domains. Previous efforts in our lab have developed laser-based instrumentation to combine spectral and lifetime information into data formats known as wavelength time matrices (WTMs) and time-resolved excitation emission matrices (TREEMs). Recording WTMs during the emission decay of the sample makes it possible to unambiguously identify chemicals on the bases of spectral and lifetime information. …

Identification And Influence Of Species-Informative 16s Ribosomal Rna Sequences And Evaluation Of Ocean Biofilms, Nikhil Bose

Electronic Theses and Dissertations, 2020-2023

16S ribosomal RNA (rRNA) gene sequences are commonly analyzed for taxonomic and phylogenetic purposes because they contain variable regions that help distinguish genera. However, intra-genus classification is difficult due to high sequence similarity among closely related species. The biological impact of nucleotide variants in 16S variable regions are often unknown and hence their sequence differences are weighted evenly during classification, which provides poor species identity confidence. In this dissertation, I determined that analysis of intra-genus 16S allelic variants can provide species information and that nucleotide changes in 16S rRNA variable regions can impact ribosome quality. In one study, I analyzed …

Navigating With Sharks: How The Marketing Practices Help To Create Successful Phishing Emails, Erica Castilho

Graduate Thesis and Dissertation 2023-2024

A phishing email is a crime where a scammer sends an email to get sensitive data. Everyday phishing email attacks impact billions of people worldwide. Preparing users to better identify phishing and avoid risky engagement with it is essential to combat this threat. We consider that as phishing emails and email marketing aim to target email clicks, scammers can use marketing practices in phishing emails to achieve their goals. However, the security research community doesn't explore deeply the similarities between phishing and email marketing. This study presents a distinctive framework known as the Phishing Engagement Marketing Optimization (PEMO). The primary …

Exploring The Feasibility Of Machine Learning Techniques In Recognizing Complex Human Activities, Shengnan Hu

Graduate Thesis and Dissertation 2023-2024

This dissertation introduces several technical innovations that improve the ability of machine learning models to recognize a wide range of complex human activities. As human sensor data becomes more abundant, the need to develop algorithms for understanding and interpreting complex human actions has become increasingly important. Our research focuses on three key areas: multi-agent activity recognition, multi-person pose estimation, and multimodal fusion.

To tackle the problem of monitoring coordinated team activities from spatio-temporal traces, we introduce a new framework that incorporates field of view data to predict team performance. Our framework uses Spatial Temporal Graph Convolutional Networks (ST-GCN) and recurrent …

Towards A Robust And Efficient Deep Neural Network For The Lidar Point Cloud Perception, Zixiang Zhou

Graduate Thesis and Dissertation 2023-2024

In recent years, LiDAR has emerged as a crucial perception tool for robotics and autonomous vehicles. However, most LiDAR perception methods are adapted from 2D image-based deep learning methods, which are not well-suited to the unique geometric structure of LiDAR point cloud data. This domain gap poses challenges for the fast-growing LiDAR perception tasks. This dissertation aims to investigate suitable deep network structures tailored for LiDAR point cloud data, and therefore design a more efficient and robust LiDAR perception framework. Our approach to address this challenge is twofold. First, we recognize that LiDAR point cloud data is characterized by an …

Clay As A Control Technique For Karenia Brevis: Water Chemistry Dynamics And Physiological Impacts On Benthic Invertebrates, Victoria Devillier

Graduate Thesis and Dissertation 2023-2024

Clay-based compounds are globally the most advanced and widely used method of direct suppression of marine harmful algal blooms, and are currently undergoing investigation as an option to control Karenia brevis blooms in Florida. Before clay may be accepted for widespread use, there are multiple concerns and challenges that must be addressed regarding the environmental safety of this method, such as effects on water quality, the fate of toxins, and potential impacts of clay treatment to non-target organisms. To contribute to ongoing assessments of clay as a potential control method for K. brevis blooms, we conducted experiments with a formulation …

Surface Engineering Of Nanoparticles For Efficient Polymerization Inhibition, Catalysis, And Plasmonic Sensing, Pooria Golvari

Graduate Thesis and Dissertation 2023-2024

Surface modification of colloidal nanoparticles is essential for broadening the scope of nanotechnology. In this dissertation, we discuss novel approaches to functionalize the surface of nanoparticles to tailor their properties for applications including radical polymerization inhibitors, supported heterogeneous catalysts, and building blocks for plasmonic devices. First, we investigate the interaction of hydrogen-terminated silicon nanoparticles (H-SiNPs) with Karstedt's catalyst and report a room‑temperature synthesis of Pt-coated SiNPs with highly tunable Pt loading. Analysis of the Pt on-Si ensemble reveals surface-bound Pt(II) on SiNPs which can undergo ligand exchange. Upon calcination, Pt-loaded SiNPs catalyze the hydrogenation of phenyl acetylene, and the SiNP …

Functionalization Of 1d And 2d Nanostructures And Their Applications, Yuen Yee Li Sip

Graduate Thesis and Dissertation 2023-2024

Material discovery and development has been playing a significant role in shaping human civilizations, by studying and improving materials for appealing observations to aid in our survival as well as to satisfy our curiosity. From the common earthly materials that give us strong building structures and hunting weapons to the Silicon Age that contributes to the creation of modern electronics and computers, the development of novel and enhanced materials continues to grow. Recently, a new field has emerged that is rapidly expanding the engineering circle; these are called nanomaterials. By shrinking bulk materials into structures with nanoscale dimensions, there is …

Chemical Approach To Tire Mark Analysis, John Lucchi

Graduate Thesis and Dissertation 2023-2024

Fatal accidents on the road are an unfortunate daily occurrence, with almost 30,000 deaths resulting from hit-and-runs in the USA between 2006 and 2021. The identification of the driver responsible for this road crime can become a challenge. Nonetheless, the accident scene provides a large amount of trace evidence that can prove critical to this matter, one of them being the tire marks. While traditional tire mark analysis is full of physical information helping the reconstruction of the event, additional information can be extracted from the rubber left during the braking event. Each tire model is manufactured with a specific …

Leadership And Military Power – Can A Leadership Approach Provide A Competitive Advantage?, Lawrence E. Skelly Iii

Graduate Thesis and Dissertation 2023-2024

Leadership and Military Power – Can a Leadership Approach Provide a Competitive Advantage? When does a military commander's leadership approach give his or her unit a performance advantage? U.S. Army senior leaders have asserted that forces led using the mission command approach will have an edge in future combat. Mission command decentralizes decision-making to empower subordinates to react more successfully and seize battlefield opportunities. American forces have struggled to employ mission command partly because of a lack of understanding of the approach. This study applied two concepts from organizational psychology, empowering leadership and directive leadership, to better define and examine …

Solid State Nuclear Magnetic Resonance Probing Of Structures Of The Rous Sarcoma Virus Capsid, Amyloid Beta, And Reflectin Proteins, Tyrone Thames

Graduate Thesis and Dissertation 2023-2024

Solid State Nuclear Magnetic Resonance (ssNMR) spectroscopy can be a powerful tool for investigating the atomic-level structures and dynamics of biological macromolecules, including proteins. In this dissertation, I present an ssNMR study of three diverse proteins, revealing insights into their respective secondary structures, conformational variations, and intermolecular interactions. Additionally, I introduce novel computational methods to facilitate the assignment of chemical shifts of ssNMR spectra. The first of the proteins is the capsid protein of the Rous Sarcoma Virus. In previous research, the structure of the hexameric lattice of the in-vitro tubular assembly of the capsid protein was determined. In this …

Multi-Kilowatt Fiber Laser Amplifiers And Hollow-Core Delivery Fibers, Matthew Cooper

Graduate Thesis and Dissertation 2023-2024

High-power fiber lasers have emerged as a cornerstone in the realm of laser technology. Characterized by their exceptional efficiency, ruggedness, and versatility, fiber lasers are experiencing widespread use in manufacturing, medical, defense, science, and in long range sensing. Unfortunately, high-power applications require strict spatial and spectral performance characteristics to be maintained, which has yet to be perfected.

This dissertation discusses the power scaling of ytterbium-doped fiber laser amplifiers, presenting three significant advancements. First, a novel photonic lantern-based method is introduced for real-time monitoring of laser beam modal content and beam quality. Initial tests highlight the photonic lantern's efficiency in predicting …

System Wide Analysis And Determination Of Accuracy, Precision, And Repeatability Of A Custom Prism Coupling Refractometry Instrument, Andrew W. Howe

Graduate Thesis and Dissertation 2023-2024

New optical designs have necessitated using refractive index data that is accurate to the third and fourth decimal points. Prism coupling refractometry could be attractive for this task because of a combination of factors. It allows for a direct assessment of the refractive index like interferometry or the minimum deviation method while being quick and convenient, like Kramers-Krönig analysis and spectroscopic ellipsometry. However, the accuracy, precision, and repeatability of this technique have not been revisited recently in the literature. This thesis seeks to identify the critical features of this technique that define its uncertainties and then provides some initial improvements …

Towards A Holistic And Comparative Analysis Of The Free Content Web: Security, Privacy, And Performance, Abdulrahman Alabduljabbar

Electronic Theses and Dissertations, 2020-2023

Free content websites that provide free books, music, games, movies, etc., have existed on the Internet for many years. While it is a common belief that such websites might be different from premium websites providing the same content types in terms of their security, a rigorous analysis that supports this belief is lacking from the literature. In particular, it is unclear if those websites are as safe as their premium counterparts. In this dissertation, we set out to investigate the similarities and differences between free content and premium websites, including their risk profiles. Moreover, we analyze and quantify through measurements …

The Successful Characteristics That Contribute To Black Male Students Matriculating Into Medical School, Cedric Brown

Electronic Theses and Dissertations, 2020-2023

In 2019, individuals that identified as Black represented 13.4% of the U.S. population, 12.5% of the undergraduate student enrollment population and 7.1% of the medical school population. Subsequently, this has yielded a 5% Black physician population and workforce consisting of just 2.3% Black male physicians (AAMC, 2018). The disproportionately low Black physician representation contributes to greater healthcare disparity outcomes within the U.S. Black population. This study is centered on the post-positive characteristics of Black male medical students that have successfully overcome barriers to entry and matriculated into medical school. The phenomenological post-positive study was conducted through the lens of Self-Efficacy …

Determination Of Damage Initiation Mechanisms In Aerospace Alloys Due To Stress Corrosion Cracking Via In-Situ Microscale Characterization Techniques, Remelisa Esteves

Electronic Theses and Dissertations, 2020-2023

Aluminum alloys are used on aerospace vehicles due to their high strength-to-weight ratio, formability and machinability. However, they become vulnerable to stress corrosion cracking (SCC) during their service life. SCC is primarily caused by the material's stress condition, a suitable corrosive environment and material susceptibility. It is also influenced by a mixture of electrochemical, mechanical, and chemical factors. Due to the complexity of SCC, tools with better resolution and sensitivity are needed to better understand the impact and interaction of the contributing factors. A vast amount of research has been done to study SCC behavior, but the scale of characterization …

Developing A Physics-Informed Deep Learning Paradigm For Traffic State Estimation, Jiheng Huang

Electronic Theses and Dissertations, 2020-2023

The traffic delay due to congestion cost the U.S. economy $ 81 billion in 2022, and on average, each worker lost 97 hours each year during commute due to longer wait time. Traffic management and control strategies that serve as a potent solution to the congestion problem require accurate information on prevailing traffic conditions. However, due to the cost of sensor installation and maintenance, associated sensor noise, and outages, the key traffic metrics are often observed partially, making the task of estimating traffic states (TSE) critical. The challenge of TSE lies in the sparsity of observed traffic data and the …