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Emerging Technologies And Advanced Analyses For Non-Invasive Near-Surface Site Characterization, Aser Abbas

All Graduate Theses and Dissertations, Fall 2023 to Present

This dissertation introduces novel techniques for estimating the soil small-strain shear modulus (G_max) and damping ratio (D), crucial for modeling soil behavior in various geotechnical engineering problems. For G_max estimation, a machine learning approach is proposed, capable of generating two-dimensional (2D) images of the subsurface shear wave velocity, which is directly related to G_max. The dissertation also presents a method for estimating frequency dependent attenuation coefficients from ambient vibrations collected using 2D arrays of seismic sensors deployed across the ground surface. These attenuation coefficients can then be used in an inversion process …

Positron Emission Tomography In Oncology And Environmental Science, Samantha Delaney

Dissertations, Theses, and Capstone Projects

The last half century has played witness to the onset of molecular imaging for the clinical assessment of physiological targets. While several medical imaging modalities allow for the visualization of the functional and anatomical properties of humans and living systems, few offer accurate quantitation and the ability to detect biochemical processes with low-administered drug mass doses. This limits how physicians and scientists may diagnose and treat medical issues, such as cancer, disease, and foreign agents.

A promising alternative to extant invasive procedures and suboptimal imaging modalities to assess the nature of a biological environment is the use of positron emission …

Dinitroxides In Rapid Scan Electron Paramagnetic Resonance Imaging, Lukas B. Woodcock

Electronic Theses and Dissertations

Local tissue physiology is an important parameter in understanding disease behavior. Rapid Scan (RS) electron paramagnetic resonance (EPR) offers a unique, non-invasive tool for investigation of these so-called microenvironments through EPR Imaging (EPRI). Research into advancement of EPRI falls into many categories. Not least among those are advances in instrumentation and methodology. Presented here are updates to a benchtop EPRI instrument operating at 1 GHz targeted at pre-clinical EPRI applications. Newly developed methods for reducing RS-EPR background through inversion of the magnetic field are also demonstrated. EPR applications are limited in native biological systems due to the miniscule concentration of …

Microfabrication Of Silicon Carbide And Metallized Polymers Using A Femtosecond Laser, Joseph Taylor Eddy

Theses and Dissertations

Femtosecond lasers deliver a high peak concentration of optical power while maintaining low average power. With an accompanying optical setup, this power can be focused and used for high-precision fabrication of metallized polymers via ablation, creating conductive structures on a thin film. These lasers can also be harnessed in tandem with hydrofluoric acid and the two-photon absorption principle to selectively etch silicon carbide, a very durable and machining-resistant semiconductor with desirable properties. This thesis presents improvements made to the Laser-Assisted Chemical Etching (LACE) technique and the ablation system. ��, the two- photon absorption coefficient of silicon carbide, is measured and …

Does Chronic Low Back Pain Influence Breathing Mechanics And Diaphragm Positioning? A Pilot Study, Lindsey Wensel

Theses and Dissertations

Background and objective: Chronic low back pain (CLBP) is a complex musculoskeletal condition and often the source of the pain is not clear. A correlation has been found to exist between incidences of low back pain (LBP) and those with respiratory diseases such as COPD. This could give reason to believe that the sequence of events could be reversed, and LBP could elicit changes in respiratory function. The purpose of this study is to investigate if CLBP has an influence on breathing mechanics and the positioning of the diaphragm in the trunk. Methods: Volunteers were recruited between the ages of …

Interferometric Imaging Of Lightning Initiation Through Lofar: Uncovering The Spontaneous And Not-So-Spontaneous Nature Of Lightning Initiation In 3d, Christopher Sterpka

Doctoral Dissertations

With recent advances in instrumentation and the continued development and refinement of analytical methods, the hindrances that previously existed in uncovering the physical processes governing the behavior of lightning are diminishing. The focus of this dissertation research, interferometric imaging of lightning initiation through beamforming via the Low Frequency Array (LOFAR), will describe in detail how both the instrumentation and methods cooperate to enable the detection of lightning processes in which are below the level of the galactic and thermal very high frequency (VHF) background on individual antennas within the array. These conditions have proven to be integral in uncovering of …

Determining Bond Strengths And Dissociation Dynamics Of Diatomic Metal-Containing Ions By Photofragment Imaging, Schuyler P. Lockwood

Doctoral Dissertations

Studies of simple metal ion – ligand complexes have primarily focused on understanding their roles in activating C-H and C-C bonds. However, data are often lacking on the fundamental properties of these species, which can have unusual bond orders and cluttered electronic structures with many states of multi-reference character, complicating their treatment in theoretical studies. Experimental work determining high-precision bond energies, ground state identities and excited state dynamics of a wider variety of metal-containing ions is needed to establish a robust set of well-characterized benchmark molecules. This work describes studies of the energetics and dynamics of several MX⁺ species, …

Advances In Deep-Sea Imaging And Soft Robotics, Russell Joseph Shomberg

Open Access Dissertations

This study contains three parts under the central theme of deep sea robotics for size, weight, power, and cost (SWAP-C) limited platforms.

1) We developed and deployed a rapid action pressure compensated deep sea hydraulic engine for Flexible Elastomeric Actuators (FEAs) and other soft robotic actuators. The engine draws low electric power and has a compact form factor, making it suitable for use on remote deep sea platforms such as science class Remote Operated Vehicles (ROVs) and other Unmanned Underwater Vehicles (UUVs). The design can be scaled and optimized for different use cases. The design principles, performance models, prototypes, and …

The Role Of Circadian Entrainment In Rice Blast Disease, Ciaran Griffin

School of Biological and Marine Sciences Theses

A circadian clock is present in some capacity in almost all forms of life, and is useful for a wide array of traits, but crucially allows organisms to predict future conditions and adapt their behaviour to synchronise with, and thrive under, their dynamic environment. Accordingly, plant environmental stress responses are gated in a circadian manner, including that for pathogenic defence and immunity. Comparatively less work has been carried out on the plant pathogens, but there are increasing reports of pathogens capable of rhythmically altering their behaviour and virulence-related traits. Magnaporthe oryzae, the fungal pathogen responsible for the destruction of enough …

Single-Shot, Ultrafast, Multi-Frame X-Ray Imaging Of Defect-Bearing Ablator Materials In Extreme Conditions, Daniel S. Hodge

Theses and Dissertations

Characterization of the dynamic behavior of defect-bearing ablator materials subjected to extreme conditions is essential in advancing fusion energy as an reliable and abundant energy source. By understanding how materials evolve spatially and temporally we can minimize hydrodynamic instabilities, which are major contributing factors to energy yield degradation in inertial confinement fusion (ICF) experiments. In this thesis we demonstrate the capabilities of an ultrafast x-ray imaging (UXI) detector, the Icarus V2, where we capture multiple frames of single void-bearing sample compressed by a high-intensity laser shockwave. Using the Matter in Extreme Conditions (MEC) instrument at the Linac Coherent Light Source …

Investigating Applications Of Deep Learning For Diagnosis Of Post Traumatic Elbow Disease, Hugh James

McKelvey School of Engineering Theses & Dissertations

Traumatic events such as dislocation, breaks, and arthritis of musculoskeletal joints can cause the development of post-traumatic joint contracture (PTJC). Clinically, noninvasive techniques such as Magnetic Resonance Imaging (MRI) scans are used to analyze the disease. Such procedures require a patient to sit sedentary for long periods of time and can be expensive as well. Additionally, years of practice and experience are required for clinicians to accurately recognize the diseased anterior capsule region and make an accurate diagnosis. Manual tracing of the anterior capsule is done to help with diagnosis but is subjective and timely. As a result, there is …

Geometric Algorithms For Modeling Plant Roots From Images, Dan Zeng

McKelvey School of Engineering Theses & Dissertations

Roots, considered as the ”hidden half of the plant”, are essential to a plant’s health and pro- ductivity. Understanding root architecture has the potential to enhance efforts towards im- proving crop yield. In this dissertation we develop geometric approaches to non-destructively characterize the full architecture of the root system from 3D imaging while making com- putational advances in topological optimization. First, we develop a global optimization algorithm to remove topological noise, with applications in both root imaging and com- puter graphics. Second, we use our topology simplification algorithm, other methods from computer graphics, and customized algorithms to develop a high-throughput …

Potassium Level Prediction Of Peach Tree Leaves Using A Hyperspectral Camera And Multivariate Analysis, Megan Io Ariadne Salimbangon Abenina

All Theses

The use of hyperspectral imaging is a valuable piece of technology used in precision agriculture. Hyperspectral imaging system could help farmers and researchers alike in analyzing tissue samples quicker compared to the current way of running a plant tissue analysis on the different nutrient levels that often takes time in generating results. The objective of this research was to measure the potassium level of peach trees using its leaves with a hyperspectral camera. The Senop HSC-2 was used to capture images of peach tree leaves during the fall of 2020 and 2021. The collected data were used to create a …

Design Of An Offner-Chrisp Imaging Spectrometer For A Planetary Fluorescence Instrument, Tristan Wells Carlson

McKelvey School of Engineering Theses & Dissertations

Spectrometers have been an integral part of space exploration in the late 20th and 21st centuries and will continue to provide quantitative measurements to answer exciting questions like, “Is or was there life on other planets?” PERISCOPE, Probe for Exploring Regolith and Ice by Subsurface Classification of Organics, Polycyclic aromatic hydrocarbons, and Elements, is a next generation spectrometer designed to explore icy worlds like Europa. It uses time-resolved ultraviolet (UV) fluorescence spectroscopy, a technique that identifies organic molecules, polycyclic aromatic hydrocarbons (PAH), and rare earth elements (REE). Photon wavelength discrimination is very important for this technique and is accomplished by …

Investigations Of External Resources And The Impact Of Imaging On Patient Flow In The Emergency Department, Marisa Shehan

All Theses

The problems associated with Emergency Department (ED) crowding are numerous, varied, and complex. Though overcrowded Emergency Departments are frequently attributed to overcrowded hospitals, crowding is also impacted by bottlenecks in patient flow. While discrete-event simulation (DES) is commonly used to model ED flow, external resources are typically excluded from these models due to their complexity and the limited amount of known information for these processes. Instead, external resources such as consults, labs, and imaging are modeled using estimation and/or educated guesswork. In this study, the impact of imaging on patient flow was assessed through data analysis of specific imaging factors, …

An Empirical Investigation Of The Evidence Recovery Process In Digital Forensics, Kevin Parviz

CCE Theses and Dissertations

The widespread use of the digital media in committing crimes, and the steady increase of their storage capacity has created backlogs at digital forensic labs. The problem is exacerbated especially in high profile crimes. In many such cases the judicial proceedings mandate full analysis of the digital media, when doing so is rarely accomplished or practical. Prior studies have proposed different phases for forensic analysis, to lessen the backlog issues. However, these phases are not distinctly differentiated, and some proposed solutions may not be practical. This study utilized several past police forensic analyses. Each case was chosen for having five …

Evaluating The Microbiome To Boost Recovery From Stroke: The Embrs Study, Tyler Hammond

Theses and Dissertations--Neuroscience

Accumulating evidence suggests that gut microbes modulate brain plasticity via the bidirectional gut-brain axis and may play a role in stroke rehabilitation. A severely imbalanced microbial community has been shown to occur following stroke, causing a systemic flood of neuro- and immunomodulatory substances due to increased gut permeability and decreased gut motility. Here we measure post-stroke increased gut dysbiosis and how it correlates with gut permeability and subsequent cognitive impairment.

We recruited 12 participants with acute stroke, 12 healthy control participants, and 18 participants who had risk factors for stroke, but had not had a stroke. We measured the gut …

System Measurements For X-Ray Phase And Diffraction Imaging, Erik Wolfgang Tripi

Legacy Theses & Dissertations (2009 - 2024)

In medical imaging, X rays are used to look inside the body to find fractures in bones, abnormal masses, cavities in teeth, and so on. What makes X rays so good at looking at these types of structures is the X ray’s penetration power. When imaging soft tissue to search for tumors, X-ray images tend to have difficulty performing well. The reason for this is that the background structures, such as fat or fibro glandular tissue have similar absorption coefficients as the tumor. Mammography tends to have a high false positive rate and can miss tumors entirely as well. There …

Three Dimensional Photonics Structures: Design And Applications, Mansoor Sultan

Theses and Dissertations--Electrical and Computer Engineering

Photonics is an emerging technology for light control, emission, and detection. Photonic devices control photons the same way electronic circuits control electrons in active or passive mode depending on the energy requirement of the device. This dissertation will discuss the design, fabrication, testing of photonic structures with applications including imaging and renewable energy. First, we developed a novel lithography method for fluoropolymer resist based on variable pressure electron beam lithography (VP-EBL). VP-EBL proves to be an efficient method for patterning a widely used, but challenging to process, fluoropolymer, Teflon AF. However, rather than solely mitigating charging, the ambient gas is …

Development Of A Muc16-Targeted Near-Infrared Antibody Probe For Fluorescence-Guided Surgery Of Pancreatic Cancer, Madeline T. Olson

Theses & Dissertations

Pancreatic cancer (PDAC) is an extremely lethal disease with an overall survival rate of 10%. Surgery remains the only potentially curative treatment option, but resections are complicated by infiltrative disease, proximity of critical vasculature, peritumoral inflammation, and dense stroma. Surgeons are limited to tactile and visual cues to differentiate cancerous tissue from normal tissue. Furthermore, translating preoperative images to the intraoperative setting poses additional challenges for tumor detection, and can result in undetected and unresected lesions. Thus, PDAC has high rates of incomplete resections, and subsequently, disease recurrence. Fluorescence-guided surgery (FGS) has emerged as a method to improve intraoperative detection …

Wave Optics In Scanning Electron Microscopy, Surya Kamal

Theses

Better quality imaging is often needed for all optical instruments including the scanning electron microscope (SEM). Inside the SEM, an electron beam is generated by applying a voltage to the electron gun. The electron beam propagates through the SEM column and illuminates the specimen with a small probe. Our research is oriented towards the end goal of obtaining better images by modeling the SEM column which contains the lens system needed for probe formation. This probe which scans the specimen to produce the final image is one of the pivotal factors which determines the fundamental resolution of a SEM. We …

Angular-Dependent Three-Dimensional Imaging Techniques In Multi-Pass Synthetic Aperture Radar, Jan Rainer Jamora

Theses and Dissertations

Humans perceive the world in three dimensions, but many sensing capabilities only display two-dimensional information to users by way of images. In this work we develop two novel reconstruction techniques utilizing synthetic aperture radar (SAR) data in three dimensions given sparse amounts of available data. We additionally leverage a hybrid joint-sparsity and sparsity approach to remove a-priori influences on the environment and instead explore general imaging properties in our reconstructions. We evaluate the required sampling rates for our techniques and a thorough analysis of the accuracy of our methods. The results presented in this thesis suggest a solution to sparse …

Taste Learning In Insular Cortex: Plasticity Is Influenced By Experience Type, Stephanie Marie Staszko

Theses and Dissertations (ETD)

The gustatory cortex (GC) has long been studied as the main cortical area encoding taste stimuli and likely integrates sensory, visceral, and emotional information to guide taste-related behaviors. However, our understanding of cortical taste coding on a single-cell level has only become clear in recent years. The anatomical location of GC on the lateral and ventral surface of the brain makes it difficult to target with traditional imaging methods. Thus, much of what we know about cortical taste coding and cortical taste plasticity has been derived either from multiunit electrode recordings or anesthetized imaging experiments, techniques which lack the ability …

Injectable Ct/Mri Contrast Agent For Gastrointestinal Tumor Tracking, Luna Zhang

McKelvey School of Engineering Theses & Dissertations

Gastrointestinal cancers remain to be of the most common and deadly cancers worldwide. Early detection and treatments are crucial for reducing mortality and improving patient outcome. Radiation therapy is a non-invasive localized tumor treatment method, and utilizes radiation to kill the cancerous cells and shrink tumors at specific sites. Precise localization at the target tumor site is therefore important before radiation therapy, especially for gastrointestinal tumor sites located in the moving bowel. Currently, invasive endoscopies along with ink tattoos are used for identifying tumor location, which often require sedation and bring much discomfort. Imaging tests, including CT and MRI, play …

Quantifying Blood Flow Patterns In The Pediatric Heart Using Blood Speckle Imaging, Harrison Dean

Biomedical Engineering Undergraduate Honors Theses

Congenital Heart Disease (CHD) is the most common type of congenital disease worldwide. Echocardiography using Doppler ultrasound is typically used to diagnose and monitor CHD; however, it is angle-dependent in nature and as a result is limited in its ability to accurately evaluate ventricular function. Blood Speckle Imaging (BSI) is a novel, angle-independent imaging modality that provides detailed blood flow information and visualization within a given area using speckle-tracking. In this study, velocity-field information obtained from BSI was used to calculate flow parameters such as kinetic energy (KE) and circulation using a custom created MATLAB program. BSI was performed on …

Design Of Multi-Layered Lenses For Resolusion Enhancement, S. M. Zia Uddin

Theses and Dissertations

Lenses are important optical device having numerous applications in our day-to-day life. As the conventional lenses, we use concave or convex lenses. These lenses are made with natural materials and the image quality imperfect. Furthermore, they are bulky, and design is complex. Consequently, mass production is difficult.

The shapes of entrance and exit faces of lenses has impact on its imaging capability. The Lens material also play a vital role for reconstructing the image. Flat lenses can be considered as a good alternative of the conventional lenses. One of the advantages of this Flat lenses is that it can restore …

Exploring Imaging Technology In The Diagnosis And Treatment Of Pediatric Medically Refractory Epilepsy With Intracranial Electroencephalography And Post-Surgical Evaluations, Nasheha Baset

Bioengineering Theses

Abstract Exploring Imaging Technology in the Diagnosis and Treatment of Pediatric Medically Refractory Epilepsy with Intracranial Electroencephalography and Post-Surgical Evaluations Nasheha Baset, MS The University of Texas at Arlington, May 2021 Supervising Professor: Dr. Christos Papadelis Epilepsy is a disorder that commonly causes seizures due to abnormal neurological activity, which can disrupt daily life. Of all patients with epilepsy, 60% suffer from focal epilepsy. Approximately 15% of these cases are considered to be drug resistant, or refractory, as the patient is not responsive to a combination of two or more anti-epileptic drugs (AED). Traditionally, approaches to treatment of medically refractory …

Indolizine Donor-Based Dyes For Applications In Fluorescence Biological Imaging, William Meador

Honors Theses

NIR emissive fluorophores are intensely researched due to their potential to replace modern imaging procedures. Many molecular strategies have been employed in the literature to optimize fluorophores for deeper NIR absorption and emission, biocompatibility, and higher fluorescence quantum yields. Amongst the fluorophores studied to date, proaromatic indolizine donors are attractive alternatives to traditional alkyl amine and indoline based donors due to their 1) lower energy absorption and emission facilitated by proaromaticity, 2) large Stokes shifts due to increased dihedral angles about the π-system, 3) ease of functionalization and capacity for bioconjugation at the phenyl ring, and 4) potential for further …

Developing A Method To Track Marine Snow Aggregation Through Individual Collisions Using Stereoscopic Imaging, Riley Henning

Theses

The aggregation of individual phytoplankton into marine snow allows particles to sink more quickly, thus resulting in the transport of particulate organic carbon from surface waters to the deep ocean. Aggregate formation has previously been measured in experiments indirectly by quantifying how particle size or particle concentration changes over time. Here, I present my thesis in which I applied high-resolution imaging to quantify aggregate formation using two different methodologies.

We conducted experiments to investigate aggregate formation using stereoscopic imaging, tracking individual particles directly in a 3D volume. Phytoplankton cultures were rolled in cylindrical tanks and imaged by two cameras illuminated …

Development Of Vibrating Sharp-Edge Spray Ionization (Vssi) Methods For Mass Spectrometry Analysis And Imaging, Nandhini Ranganathan

Graduate Theses, Dissertations, and Problem Reports

Mass Spectrometry (MS) is one of the widely used tools for chemical detection down to attomole concentrations for certain proteins. Ionization sources are a critical component for MS analysis. One of the major ionization methods is electrospray ionization (ESI), which remains a gold standard for proteins and peptides. ESI uses voltages up to ~4 kV to produce ions from solubilized molecules. Recently, a novel ionization method termed vibrating sharp-edge spray ionization (VSSI) that nebulizes liquids efficiently at the edge of a vibrating glass slide has been reported. The work in this thesis leverages the capabilities of VSSI for continuous flow-based …