Physical Sciences and Mathematics Commons^™

Charged-Particle Interactions To Generate Novel Coatings And Materials, Pradnya D. Rao

Electronic Theses and Dissertations

A typical paper coating formulation contains anionically charged pigments and latex to provide a high-quality surface for printing. However, during application and drying, the latex can migrate to the surface or deep into the paper, resulting in weak coating layers or the need to use a high latex content to obtain the same strength properties. In this thesis, we have explored the introduction of cationically charged particles into the suspension as a way to reduce the amount of binder in the coatings, improve coating strength and reduce binder migration. With these aims in mind, we have generated cationic precipitated calcium …

Robot Learning From Human Observation Using Deep Neural Networks, Michael Elachkar

Electronic Theses and Dissertations

Industrial robots have gained traction in the last twenty years and have become an integral component in any sector empowering automation. Specifically, the automotive industry implements a wide range of industrial robots in a multitude of assembly lines worldwide. These robots perform tasks with the utmost level of repeatability and incomparable speed. It is that speed and consistency that has always made the robotic task an upgrade over the same task completed by a human. The cost savings is a great return on investment causing corporations to automate and deploy robotic solutions wherever feasible.

The cost to commission and set …

Dynamic Interactions In Semiconducting Polymers; New Materials For Soft Electronics With Biomimetic Properties, Michael Udunyi Ocheje

Electronic Theses and Dissertations

The development of materials that can stretch while remaining conductive has generated significant research interest. The push for the development of these materials is due to their potential for cheaper, more durable electronics with the new functions (stretchability and healability) and form factors required for the next generation of wearable and skin-inspired electronics. Polymeric semiconductors have emerged as prime candidates for the development of these materials, due to their π-delocalized network which makes them conductive, their synthetic versatility, and their intrinsic mechanical properties. Furthermore, their ability to be solution processed provides an avenue for printing, roll-to-roll, and large area solution …

Diketopyrrolopyrrole Derivatives For Single Material Solar Cells, Adam M. Cassar

Electronic Theses and Dissertations

Although diketopyrrolopyrroles (DPPs) have been extensively studied as organic pigments and dyes and as building blocks for molecular and polymeric organic electronic materials, their propensity for self-organization has been given surprisingly little attention. Self-organization provides control over the morphology and supramolecular structure of materials and, consequently, the performance of a material. The dependence of performance on supramolecular structure is particularly delicate in bulk heterojunction organic solar cells and the emerging low-cost single material organic solar cells (SMOSC). Most donor-acceptor dyads and triads presently developed for SMOSCs consist of dyes as electron donors and fullerene derivatives as electron acceptors, but their …

Calculated Charge State Distributions And Anisotropies Following The Β-Decay Of 6he, Eva E. Sculhoff

Electronic Theses and Dissertations

According to the standard model the beta-decay of 6He is a pure Gamow-Teller transition. The aim of this thesis is to provide theoretical support in the search for new physics beyond the standard model by examining the angular distribution of beta particles following decay. The simple structure of 6He, along with its ability to under go beta-decay into 6Li+ makes it an ideal candidate for studying the weak force. Due to the sudden increase in nuclear charge from Z = 2 to Z = 3, and the recoil momentum of the daughter nucleus resulting from the emitted leptons, this decay …

Quantitative Magnetic Resonance Imaging Methodology Development, Layale Bazzi

Electronic Theses and Dissertations

Magnetic Resonance Imaging (MRI) is a non-invasive medical imaging modality that provides excellent soft tissue contrast and resolution. Objects with high magnetic susceptibility distort the magnetic field, leading to severe artifacts in conventional MRI. It is very challenging to image around metal implants. Novel strategies may exploit the field distortion for spatial encoding. The magnetic field map is required in the development of these methods. A robust field map can also be employed to quantify high susceptibility particles that play a major role in cell tracking studies and hyperthermic treatment of cancers.

Pure phase encoding (PPE) techniques with short encoding …

Lipophilic Probes For Cellular Ethylene Detection, Morgan R. Brown

Electronic Theses and Dissertations

The structure of ethylene is simple, yet its biological effects are significant. When considering its role in biology it is almost exclusively regarded as a plant hormone. Research on ethylene from plants was progressed by several advancements in analytical instrumentation, from its discovery to elucidation of its signaling pathway. There is currently limited understanding of ethylene’s role in mammals, but evidence suggests that it may be a biomarker for oxidative stress! Additional tools and technology are crucial to study this surprising and important signaling role in mammals. Our group has developed molecular ethylene probes as a strategy to detect ethylene …

Synthesis And Characterization Of Multimetallic Clusters Featuring Iron, Cobalt, And 2,6-Bis(Trialkylsilylamino)Pyridines, Lynn Nguyen

Electronic Theses and Dissertations

Extended metal atom chain (EMAC) complexes are multimetallic complexes of three or more metals, often containing M-M bonds, with the metal ions arranged linearly. These complexes have significant potential as molecular wires. They can elicit unique physical properties and reactivities, sometimes a result of direct magnetic exchange between metal centers, especially when incorporating first row transition metals. The synthesis of the first linear, triiron (II) complex with 2,6-bis[(trimethylsilyl)amino]pyridine (H₂L^Me) featuring Fe-Fe bonding from our group, Fe₃L^Me₃, motivated the expansion of linear multimetallic EMAC complexes with Fe and Co, incorporating M-M bonds. …

Patterns And Behaviours Of Barrier Breaching In Lacustrine Environments: A Case Study From The Point Pelee Foreland, Jenny Gharib

Electronic Theses and Dissertations

The Great Lakes are non-tidal, but experience significant water level fluctuations at hourly, seasonal, and decadal scales. In response to elevated water levels, barrier beach-ridges, including those located on the eastern shore of the Point Pelee foreland, experience accelerated erosion, overwash, and breaching leading to the removal or burial of vegetation, and damage to infrastructure and vulnerable habitat. Historical aerial imagery between 1931–2022 and annual average lake levels between 1920–2022 were examined to characterize barrier retreat and breach initiation, expansion, and closure. The timing and rate of transgression and progradation, overwash, and breaching are dependent on decadal-scale variations in water …

Examining The Credibility Of Story-Based Causal Methodologies, Megan E. Kauffmann

Electronic Theses and Dissertations

The purpose of this study was to explore how evaluators justify using story-based methodologies when examining causality. The two primary research questions of the study included: 1) what arguments are made by evaluators to justify the credibility of story-based causal methodologies to evaluation stakeholders; and 2) from the perspective of evaluators, how do contextual factors influence whether story-based causal methodologies are perceived as credible by evaluation stakeholders? A case study was conducted to examine the cases of four evaluators who had experience implementing a story-based methodology in an evaluation. Data collection procedures included two interviews with each participant and a …

Reinforcement Learning: Low Discrepancy Action Selection For Continuous States And Actions, Jedidiah Lindborg

Electronic Theses and Dissertations

In reinforcement learning the process of selecting an action during the exploration or exploitation stage is difficult to optimize. The purpose of this thesis is to create an action selection process for an agent by employing a low discrepancy action selection (LDAS) method. This should allow the agent to quickly determine the utility of its actions by prioritizing actions that are dissimilar to ones that it has already picked. In this way the learning process should be faster for the agent and result in more optimal policies.

Characterization Of Functionalized Carbon Nanotubes And Polystyrene/Cnt Composites Prepared With Microwave-Induced Polymerization, Allen Hulette

Electronic Theses and Dissertations

The use of carbon nanotubes in polymer composites can increase the mechanical properties of the resulting product. Carbon nanotubes are known to have chemical interactions that make them attracted to one another and fall out of solution. To reduce this agglomeration and disperse the mechanical properties throughout the composite, functional groups are covalently added to the carbon nanotubes. Another known property of carbon nanotubes is their ability to absorb microwaves and convert it into other forms of energy. This research investigates the effects of carbon nanotube absorption of microwaves and initiation of styrene monomer polymerization. Grignard reactions are used to …

Cryptography Through The Lens Of Group Theory, Dawson M. Shores

Electronic Theses and Dissertations

Cryptography has been around for many years, and mathematics has been around even longer. When the two subjects were combined, however, both the improvements and attacks on cryptography were prevalent. This paper introduces and performs a comparative analysis of two versions of the ElGamal cryptosystem, both of which use the specific field of mathematics known as group theory.

Eeg Signals Classification Using Lstm-Based Models And Majority Logic, James A. Orgeron

Electronic Theses and Dissertations

The study of elecroencephalograms (EEGs) has gained enormous interest in the last decade with the increase of computational power and availability of EEG signals collected from various human activities or produced during medical tests. The applicability of analyzing EEG signals ranges from helping impaired people communicate or move (using appropriate medical equipment) to understanding people's feelings and detecting diseases.

We proposed new methodology and models for analyzing and classifying EEG signals collected from individuals observing visual stimuli. Our models rely on powerful Long-Short Term Memory (LSTM) Neural Network models, which are currently the state of the art models for performing …

Toward Novel Optical Functionalities Through Intelligent Photonic Structure Design, Robert J. Williamson

Electronic Theses and Dissertations

Photonic Metamaterials is a branch of electromagnetism that has been of great interest in recent years. This is further enhanced by the introduction of micro- and nanofabrication methods capable of producing metamaterial structures with which it is possible to create specific optical phenomena. The study of iso-frequency k-surfaces is of importance when discussing optical interactions with media. Previous research found evidence of materials exhibiting k-surfaces of bi-hyperbolic nature, though they failed to find any further hyperboloid dispersions. In this thesis we describe the k-surface topologies and including tri- and tetra-hyperbolic as well as analyze the polariton-interactions that cause these hyperbolic …

License Plate Image Quality Enhancement Utilizing Super Resolution Generative Adversarial Networks, Mark Moelter

Electronic Theses and Dissertations

This thesis focuses primarily on enhancing the image quality of blurred license plates through the use of Super-Resolution Generative Adversarial Networks (SRGANs) [1]. We propose a synthetic dataset with SRGAN model to promote blurred image quality enhancement, and allow for model evaluation on a multitude of image input and output size combinations. SRGAN is mainly used for low-resolution image enhancement, but by heavily blurring the input images, the model is tested on its ability to blindly deblur and upsample images to the desired super-resolution (SR) size. The model enhances the image quality to nearly that of the reference images. The …

Human-Machine Collaboration In Healthcare Innovation, Breeze Fenton

Electronic Theses and Dissertations

Almost every individual has visited a healthcare institute, whether for an annual checkup, surgery, or a nursing home. Ensuring healthcare institutes are using human-machine collaboration systems correctly can improve daily operations. A maturity assessment and an implementation plan have been developed to help healthcare institutes monitor the human-machine collaboration systems. A maturity model, the Smart Maturity Model for Health Care (SMMHC), is a tool designed for maturity assessment. A four-step implementation plan was also created in this research. The implementation plan views the maturity of the institute and develops a strategy on how to improve it. The research utilized Integrated …

Elucidating Mechanisms For S-Nitrosoglutathione Reductase Activity And Control In Plants Using O-Aminobenzoyl-S-Nitrosoglutathione And A Novel Photo-Sensitive Probe, Leslie Ventimiglia

Electronic Theses and Dissertations

S-nitrosoglutathione reductase, (GSNOR) is widely accepted as the master regulator of stress through NO signaling and protein S-nitrosylation. GSNOR mediates stress response through the catalysis of its principal substrate S-nitrosoglutathione (GSNO). The instigation of various stressors in plants cause observable changes in plant phenotype, which are associated with changes in GSNOR activity. There are no current methods for measuring GSNOR activity directly in living plants. In this paper, a previously developed fluorogenic pseudo-substrate for human GSNOR, OAbz-GSNO, was applied to the Solanum lycopersicum plant model. OAbz-GSNO was identified as a promising novel pseudo- substrate to study changes …

Mosquito Species Distribution Models: Limitations And Best Practices, Justin Barker

Electronic Theses and Dissertations

Understanding species distribution is fundamental to ecology and biogeography, with important implications for species management. This is especially true for species of public health concern—such as mosquitoes—which can impart both economic and health impacts. Species distribution models (SDMs) are powerful tools to accomplish this goal. However, obtaining reliable conclusions, those which are accurate and applicable for policy development, from SDMs is not straightforward owing to the many required considerations such as objective with respect to limitations of the available data. The goal of this thesis was to determine recommended methods to address known and unknown mosquito SDM limitations. First, I …

Analysis Of Count Data In One-Way Layout With Missing Response, Poonam Shrestha Malakar

Electronic Theses and Dissertations

Discrete data in the form of counts arise in many health science disciplines such as biology and epidemiology. Poisson models are widely used in the regression analysis of count data. The Poisson distribution has a property that the mean and the variance are equal. However in practice many count data sets often display extra-variation or over-dispersion relative to a Poisson model. Thus the Poisson distribution is not an ideal choice for analysing count data in many applications. One very convenient and common model to accommodate this extra dispersion is the two parameter negative binomial distribution. Count data in the form …

Optimization Of An Ultrasonic Non-Destructive Evaluation Technique For Laser Brazing, Dimitri Shinas

Electronic Theses and Dissertations

Brazing joins two sheets along a seam using a filler metal. In the brazing process, the filler metal is heated, along with the parts to be joined, to a temperature above the melting temperature of the filler material. This allows the filler metal to wet the surfaces of the parts to be joined through capillary action, resulting in the formation of metallic bonds, ultimately forming the joint.

Brazing, like all joining methods, is also susceptible to process variations. These process variations can include wear of the laser, plate misalignment, and external temperature changes. If left unchecked, such variations can eventually …

Detection Of Endangered Fish In Dianchi Lake, Kunming, China, Using Edna And Traditional Fishing, Kai Zhang

Electronic Theses and Dissertations

Dianchi Lake, Yunnan, China is a eutrophic plateau lake. Many native fish species in the lake are currently endangered or extinct due to a variety of stressors. Community surveys are important for ecological management and protection, though efforts are hampered by low abundance of some species. The goal of this thesis was to understand the community structure and distribution of fish in Dianchi Lake and to detect Sinocyclocheilus grahami, a critically endangered species endemic to the lake, using both traditional netting methods and environmental DNA. Using traditional netting and trapping, I found that the fish community of …

Banach Spaces On Topological Ramsey Structures, Cheng-Chih Ko

Electronic Theses and Dissertations

A Banach space T₁(d, θ) with a Tsirelson-type norm is constructed on the top of the topological Ramsey space T₁ defined by Dobrinen and Todorcevic [6]. Finite approximations of the isomorphic subtrees are utilised in constructing the norm. The subspace on each “branch” of the tree is shown to resemble the structure of an ℓ_∞ⁿ⁺¹ -space where the dimension corresponds to the number of terminal nodes on that branch. The Banach space T₁(d, θ) is isomorphic to (∑_n∊ℕ⊕ℓ_∞ⁿ⁺¹)_p , where d ∈ ℕ with d ≥ 2, …

Development Of A Chromatographic Method To Authenticate Aspirin Brands, Megan Guetzloff

Electronic Theses and Dissertations

Counterfeit pharmaceuticals pose a threat to society that can include inaccurate amounts of the active pharmaceutical ingredient (API), no API, or containing off-target compounds. For example, there are many recent examples of counterfeit pharmaceuticals containing potentially lethal doses (> 2 mg) of fentanyl (i.e., a synthetic opioid). Current measures to combat illicit pharmaceuticals (e.g., unique packaging and product serialization) have merit, however with evolved technologies, counterfeiters can relatively easily simulate these measures and continue to distribute illicit pharmaceuticals. The only accurate way to definitively determine that a suspected counterfeit is, in fact, counterfeit is advanced chemical analysis. However, current methods …

Regenerative Agriculture Effects On Invertebrate And Bird Communities And Insect-Provided Ecosystem Services, Alex Michels

Electronic Theses and Dissertations

Conventional agricultural practices can have unintended consequences on the environment and wildlife. Insects and birds are declining at rapid rates around the world, and the current conventional agricultural paradigm is a major driver through habitat loss and the intensification of production. Invertebrates in agroecosystems provide services to both farmers and the rest of society. Regenerative systems may promote the functioning of an agroecosystem by influencing invertebrate abundance, diversity, and ecosystem services and mitigate bird and insect declines through conservation practices that increase soil health, reduce disturbances, and increase biological diversity. Here I address knowledge gaps of the effects of regenerative …

Formulation, Structure, And Applications Of Therapeutic, Amino Acid, And Water-Based Deep Eutectic Solvents, Md Sajjadur Rahman

Electronic Theses and Dissertations

In the design of greener chemicals, deep eutectic solvents (DESs) are considered as one of the most versatile alternative solvents with widespread applications. DESs have the advantages of being nonflammable with negligible vapor pressure compared to traditional solvents. They share many characteristics of ionic liquids, but DESs are cheaper to formulate, typically nontoxic, recyclable, biodegradable, and are suitable for use with biological systems. In my Ph.D. research, three types of emerging and unconventional types of DESs, namely therapeutic DES (THEDES), amino acid-based DES (AADES), and water-based DES (WDES), have been investigated. To formulate these DES easily available and cheaper chemicals, …

Using Long Short-Term Memory Networks To Make And Train Neural Network Based Pseudo Random Number Generator, Aditya Harshvardhan

Electronic Theses and Dissertations

Neural Networks have been used in many decision-making models and been employed in computer vision, and natural language processing. Several works have also used Neural Networks for developing Pseudo-Random Number Generators [2, 4, 5, 7, 8]. However, despite great performance in the National Institute of Standards and Technology (NIST) statistical test suite for randomness, they fail to discuss how the complexity of a neural network affects such statistical results. This work introduces: 1) a series of new Long Short- Term Memory Network (LSTM) based and Fully Connected Neural Network (FCNN – baseline [2] + variations) Pseudo Random Number Generators (PRNG) …

Response Of Soil Biochemical And Physical Properties To Long Term Prairie Cordgrass And Kura Clover Intercropping System, Vaishnavi Varikuti

Electronic Theses and Dissertations

Prairie cordgrass (Spartina pectinata) (PCG) is a warm-season perennial grass that can be used as a biofuel feedstock and can be grown on marginal lands. Previous studies on intercropping of a perennial legume i.e., kura clover (Trifolium ambiguum) (KC) with PCG can improve soil biochemical properties, increase biomass production, mitigate greenhouse gas (GHG) emissions while reducing the chemical fertilizer requirement. However, there is a lack of evidence about the effects of PCG production on soil biochemical and physical properties during the cropping season and at deeper soil depths in reference to support plant growth, environmental implications and enhance the soil …

Soil Hydro-Physical Properties, Computed Tomography Measured Pore Parameters, And Soil Health Indicators As Influenced By Tillage And Crop Rotation Systems, Goutham Thotakuri

Electronic Theses and Dissertations

Long-term tillage and crop rotation systems are important agricultural management practices as these can have direct impact on the soil’s key properties. The objectives of this study were to (ⅰ) quantify the soil pore characteristics under long-term tillage and crop rotation using X-ray computed tomography (XCT) and to assess the relationships between XCT-measured pore parameters and soil hydro-physical properties; and (ⅱ) evaluate the impacts of long-term tillage and crop rotation on select soil health indicators. The objective (ⅰ) was carried out at Haskell Agricultural Laboratory (HAL), Concord, NE; and objective (ⅰi) was carried out at South Central Agricultural Laboratory (SCAL), …

It's Not Just No-Till: Crop Rotations Are Key To Improving Soil Quality And Grain Yields At Dakota Lakes Research Farm, Natalie Sturm

Electronic Theses and Dissertations

No-till is increasingly promoted as a vital agricultural practice to address the challenge of improving soil quality while maintaining the ability to produce food, feed, fuel, and fiber. However, questions remain regarding 1) how different crop rotations impact soil quality under no-till management specifically and 2) whether significant improvements in soil quality can be made without negatively impacted crop yields. In this study, we demonstrate that even under the same long-term no-till management, differences in grain yields and soil biological, chemical, and physical properties exist between crop rotations at Dakota Lakes Research Farm in central South Dakota. We propose that …