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Full-Text Articles in Physical Sciences and Mathematics

Review Of Current Reactive Force Field Potentials For Use In Simulating The Atomic Layer Deposition Of Alumina On Aluminum, Devon T. Romine Jan 2022

Review Of Current Reactive Force Field Potentials For Use In Simulating The Atomic Layer Deposition Of Alumina On Aluminum, Devon T. Romine

MSU Graduate Theses

Alumina has recently garnered quite a bit of attention for use as a tunnel barrier in Josephson tunnel junctions. The quality of the metal oxide layer in the Josephson tunnel junction is a key factor in its effectiveness. To optimize the deposition method of alumina, we need a deep understanding of the large-scale surface interactions that cannot be reached using ab initio molecular dynamics. In this study, I have compared two existing reactive force field (ReaxFF) parameters to determine their abilities to model the atomic layer deposition (ALD) of alumina on an aluminum surface. ReaxFF molecular dynamics was chosen because …


Bat Mortality At Ontario Wind Farms Quantified And Compared Using Four Candidate Estimator Equations, Bethany G. Thurber, Catherine B. Jardine, J. Ryan Zimmerling Jan 2022

Bat Mortality At Ontario Wind Farms Quantified And Compared Using Four Candidate Estimator Equations, Bethany G. Thurber, Catherine B. Jardine, J. Ryan Zimmerling

Human–Wildlife Interactions

Wind farm development is expanding globally. While wind energy is a low-cost option for new electricity supply, the impacts to wildlife populations, including bats (Chiroptera), are of ecological concern. To quantify these impacts, scientists have developed estimator equations to estimate bat mortality, which vary in assumptions related to correction factors. We compared the results of 4 estimators applied to post-construction monitoring data from Ontario, Canada, wind farms to evaluate the effects of field methods and correction factors on estimator consistency. To conduct our study, we obtained data from 21 wind farms between 2011 and 2017 for a total of 26 …


Stakeholder Knowledge And Perceptions Of Free-Roaming Equids And Their Management At A Western U.S. Land-Grant University, Hollee S. Wood, S. Nicole Frey, Terry A. Messmer Jan 2022

Stakeholder Knowledge And Perceptions Of Free-Roaming Equids And Their Management At A Western U.S. Land-Grant University, Hollee S. Wood, S. Nicole Frey, Terry A. Messmer

Human–Wildlife Interactions

The horse (Equus ferus caballus), originally native to North America, became extinct on the continent approximately 10,000 years ago. Horses that migrated from North America to Eurasia across the Bering Strait continued to evolve and were domesticated along with burros (E. asinus). Both species were then transported to the Americas where they were intentionally released or escaped into the wild, forming feral herds. The Wild Free-Roaming Horses and Burros Act of 1971 (WFRHBA) provided federal oversight and protection for feral horses and burros (hereafter, free-roaming equids) that inhabited designated areas on public lands in the western …


Downstream Dispersal Of Fine Tailings, Chat And Metals In Channel Sediment Of Big River, Old Lead Belt, Southeast Missouri, Jennifer Pace Witt Jan 2022

Downstream Dispersal Of Fine Tailings, Chat And Metals In Channel Sediment Of Big River, Old Lead Belt, Southeast Missouri, Jennifer Pace Witt

MSU Graduate Theses

In St. François County, Missouri, compromised above-ground tailings piles and containment ponds from historical mining activities in the Old Lead Belt released considerable amounts of dolomitic, Pb- and Zn-contaminated waste sediments to the Big River, contributing to significant downstream floodplain and channel sediment contamination. Previous studies have documented the effects of heavy metals on Big River biota and water quality, as well as benthic habitat disruption resulting from the influx of small sediments. Few have considered the effects and future contamination risk of the coarse waste sediments (2-16 mm in diameter), locally called “chat”, which retain high Pb and Zn …


Low-Head Dam Removal Increases Functional Diversity Of Stream Fish Assemblages, Adam Christopher Jones Jan 2022

Low-Head Dam Removal Increases Functional Diversity Of Stream Fish Assemblages, Adam Christopher Jones

Masters Theses

Despite the growing number of dam removals to date, very few have been studied to understand their impacts on stream fish communities. Despite being the most common type of dam in the U.S., an even smaller proportion of studies focus on the impacts of low-head dam removals, instead, focusing on the impacts of removal of larger dams. In this study, two previously impounded Illinois rivers were monitored to assess the impacts of low-head dam removal on the functional assemblage of stream fishes. This was accomplished by aggregating fishes into habitat and reproductive guilds, relating community changes to habitat, environmental metrics, …


Interfacial Electrochemistry In Metallic Film Fabrication, Eric S. Tuala Jan 2022

Interfacial Electrochemistry In Metallic Film Fabrication, Eric S. Tuala

Masters Theses

An experimental determination of RC constant at the edge and the center of a disk electrode was done using in situ reflectance spectroscopy on a Au electrode immersed in HClO4 as electrolyte. The RC constant at the edge of the disk electrode was found much smaller than that at the center. Such differences contribute to the selective removal of the deposited Cu on an Au disk electrode.

Furthermore, the electrochemical corrosion of Cu2+ towards Co electrode (called cementation reaction) was investigated using a Co/Pt rotating disk electrode. The Open Circuit Potential of Co electrode in CuSO4 electrolyte …


Pd-Based Photocatalysts For Heck C-C Cross-Coupling Reactions, Suha Ali Alshehri Jan 2022

Pd-Based Photocatalysts For Heck C-C Cross-Coupling Reactions, Suha Ali Alshehri

Masters Theses

Heck C-C cross-coupling reaction has been widely employed in synthetic organic chemistry because of its high efficiency and simplicity, however the conventional Heck C-C cross-coupling reaction conditions involve the use of an expensive toxicant phosphine-ligated palladium complexes, and high temperature. To address these drawbacks, a highly efficient, homogeneous photocatalyst based on BODIPY for the Heck C-C cross-coupling reactions of aryl iodide and methyl acrylate in DMF solvent under inert conditions has been developed. The 4-Py-BDP-Pd, 3-Py-BDP-Pd and, 2-Py-BOD-Pd catalysts were synthesized and purified using column chromatography. The optical properties of products and intermediates were studied by UV/vis absorption and fluorescence …


The Photo-Transformation Of Free Methionine In The Presence Of Surrogate And Standard Isolate Dissolved Organic Matter Under Sunlit Irradiation, Benjamin J. Mohrhardt Jan 2022

The Photo-Transformation Of Free Methionine In The Presence Of Surrogate And Standard Isolate Dissolved Organic Matter Under Sunlit Irradiation, Benjamin J. Mohrhardt

Dissertations, Master's Theses and Master's Reports

Sulfur (S)-containing amino acids are key sources of carbon, nitrogen, and sulfur involved in protein synthesis, protein function, and providing energy for microbial growth. Dissolved free and combined methionine is one of two S-containing amino acids incorporated into proteins and has been attributed to their stability and function. The oxidation of methionine has received considerable attention given its ubiquitous presence in most biological systems and has been associated with losses in protein function and pathological disorders. In natural waters, methionine is rapidly and selectively taken up by microorganisms to achieve cellular requirements of carbon, nitrogen, and sulfur. The abiotic transformation …


The Variability Of The Saturation Ratio In Clouds, Jesse C. Anderson Jan 2022

The Variability Of The Saturation Ratio In Clouds, Jesse C. Anderson

Dissertations, Master's Theses and Master's Reports

The saturation ratio determines the growth of cloud droplets by condensation and activation of aerosol particles. In a uniform environment, the interactions between the saturation ratio and cloud droplets are well understood. However, the presence of turbulent mixing causes spatial and temporal variability in the temperature, water vapor and the saturation ratio. When applied to a cloud, the variability in S has been shown to broaden the cloud droplet size distribution through each droplet having its own growth rate and history. When droplets grow by condensation or evaporation, water vapor and heat feedback with the environment, altering the distribution of …


Structural Characterization Of Factor Viii-Inhibitor Complexes And Factor Viii Lipid Binding Mechanics, Corbin Mitchell Jan 2022

Structural Characterization Of Factor Viii-Inhibitor Complexes And Factor Viii Lipid Binding Mechanics, Corbin Mitchell

WWU Graduate School Collection

Blood coagulation factor VIII (FVIII) is a crucial protein cofactor within the blood coagulation cascade and facilitates the proteolytic activation of factor X by activated factor IX. During coagulation FVIII is activated and binds, via its C1 and C2 domains, to activated platelet membranes coordinated by interactions with exposed phosphatidylserine on the membrane surface. A deficiency of functional FVIII within a patient's bloodstream leads to the blood disorder hemophilia A, which results in prolonged bleeding episodes. Current treatment for hemophilia A relies on FVIII replacement therapy via the injection of exogenous FVIII. The main complication which arises from FVIII replacement …


Nickel Phosphide Photothermal Catalyst Development For Co2-Derived Solar Fuels, Hannah K. Hennig Jan 2022

Nickel Phosphide Photothermal Catalyst Development For Co2-Derived Solar Fuels, Hannah K. Hennig

WWU Graduate School Collection

Converting CO2 to CO via the photocatalyzed reverse water gas shift (RWGS) reaction satisfies a critical step in the production of C1 solar fuels (e.g., CH4, CH3OH) and longer hydrocarbons via the Fischer-Tropsch process. Oxide-supported nickel phosphides (NixPy) are an emerging class of photocatalysts with a number of accessible crystalline phases. Additionally, the broad-spectrum absorption of NixPy materials affords photo-induced local heating to drive catalytic processes at mild operating temperatures. In the current project, NixPy with different P/Ni molar ratios were investigated as RWGS catalysts on two types of support materials: 1) silica (SiO2) as a relatively inert support, and …


Evaluating Remote Economic Benefits Of Watershed-Scale Acid Mine Drainage Restoration, Rachel E. Pell Jan 2022

Evaluating Remote Economic Benefits Of Watershed-Scale Acid Mine Drainage Restoration, Rachel E. Pell

Graduate Theses, Dissertations, and Problem Reports

In 2011, the West Virginia Abandoned Mine Lands and Reclamation Program (WVAML) implemented a watershed-scale restoration project in Three Fork Creek, a 103 square-mile watershed in rural West Virginia impaired by acid mine drainage (AMD). This was accomplished through the installation of four in-stream lime dosers in 2011. Due to the great capital investment in the restoration of Three Fork Creek and an interest in applying this watershed-scale approach to other watersheds throughout West Virginia, it is of great interest to demonstrate the successes of this remediation. It has already been demonstrated that the watershed has visibly improved and is …


Capillary Electrophoresis: Method Development And Application In Biomolecule Analysis, Lindsay Marie Veltri Jan 2022

Capillary Electrophoresis: Method Development And Application In Biomolecule Analysis, Lindsay Marie Veltri

Graduate Theses, Dissertations, and Problem Reports

Abstract

Capillary Electrophoresis: Method Development and Application in Biomolecule Analysis

Lindsay Veltri

Biomolecule analysis is essential in disease diagnostics and the development of therapeutic agents. There is a vast array of methods available for biomolecule analysis, however, capillary electrophoresis is well-suited due to minimal sample consumption (~nanoliters of solution) and fast analysis times. In this report, capillary electrophoresis was used to analyze glycosylation of therapeutic proteins. Additionally, a capillary electrophoresis-mass spectrometry method is reported for the analysis of proteins.

Post-translation protein modifications like glycosylation, play an important in protein structure and function. Modifications of protein glycosylation can lead to improved …


Ion Velocity Distribution Functions In Cutting-Edge Plasmas, Mitchell Cameron Paul Jan 2022

Ion Velocity Distribution Functions In Cutting-Edge Plasmas, Mitchell Cameron Paul

Graduate Theses, Dissertations, and Problem Reports

Cutting-edge plasma experiments continue to push the frontiers of plasma science. Two such groups of experiments, helicon sources and laboratory magnetic reconnection, are the focus of this thesis. The relatively high plasma density achieved for modest input powers makes helicon source plasmas ideal testbeds for fusion-relevant phenomena without the complexities associated with fusion devices. Examples include plasma-material interaction (PMI) studies, divertor region studies, and boundary physics studies. As advancements in helicon source design and technology make operation at higher power for longer times possible, understanding of the plasma dynamics, particularly ion dynamics, is vital.

Laboratory experiments are essential to advancing …


Heterogeneous Oxidation Of Multi-Component Aqueous Organic Aerosols: The Effect Of Transport Phenomena And Reaction Compartment On Reaction Kinetics., Tadini Wenyika Masaya Jan 2022

Heterogeneous Oxidation Of Multi-Component Aqueous Organic Aerosols: The Effect Of Transport Phenomena And Reaction Compartment On Reaction Kinetics., Tadini Wenyika Masaya

Graduate Theses, Dissertations, and Problem Reports

The surface-bulk partitioning of small organic molecules in aqueous droplets was investigated using molecular dynamics. The air-particle interface was modeled using a 80-Å cubic water box containing series of organic molecules and surrounded by gaseous OH radicals. The properties of the organic solutes within the interface and the water-bulk were examined at a molecular-level using density profiles and radial pair distribution functions. Molecules containing only polar functional groups such as urea and glucose are found predominantly in the water bulk, forming an exclusion layer near the water surface. Substitution of a single polar group by an alkyl group in sugars …


Root Phenotyping Of Peptide-Treated Glycine Max, Salem Jackson, Fiona Goggin Jan 2022

Root Phenotyping Of Peptide-Treated Glycine Max, Salem Jackson, Fiona Goggin

Inquiry: The University of Arkansas Undergraduate Research Journal

Plant elicitor peptides (Peps) – endogenous chains of amino acids involved in natural plant defense – have been shown to decrease damage from herbivores and pathogens by inducing an immune response, increasing the emission of volatile organic compounds (VOCS), transcripts, and metabolites. Exogenous treatment of soybean seeds with plant elicitor peptide GmPep3 has been shown to induce these broad-spectrum defenses and offers a new method for increasing crop yield. However, the effects of GmPep3 on indicators of soybean health – root characteristics, growth stages, etc. – have not been fully realized. Using the root-phenotyping platform RhizoVision Explorer, several root traits …


Ferrihydrite Enrichment In The Rhizosphere Of Unsaturated Soil Improves Nutrient Retention While Limiting Arsenic And Uranium Plant Uptake, Arindam Malakar, Daniel D. Snow, Michael Kaiser, Jordan Shields, Bijesh Maharjan, Harkamal Walia, Daran Rudnick, Chittaranjan Ray Jan 2022

Ferrihydrite Enrichment In The Rhizosphere Of Unsaturated Soil Improves Nutrient Retention While Limiting Arsenic And Uranium Plant Uptake, Arindam Malakar, Daniel D. Snow, Michael Kaiser, Jordan Shields, Bijesh Maharjan, Harkamal Walia, Daran Rudnick, Chittaranjan Ray

Nebraska Water Center: Faculty Publications

Improvement of nutrient use efficiency and limiting trace elements such as arsenic and uranium bioavailability is critical for sustainable agriculture and food safety. Arsenic and uranium possess different properties and mobility in soils, which complicates the effort to reduce their uptake by plants. Here, we postulate that unsaturated soil amended with ferrihydrite nanominerals leads to improved nutrient retention and helps reduce uptake of these geogenic contaminants. Unsaturated soil is primarily oxic and can provide a stable environment for ferrihydrite nanominerals. To demonstrate the utility of ferrihydrite soil amendment, maize was grown in an unsaturated agricultural soil that is known to …


Characterization Of A Three-Way Catalyst For High Efficiency Spark Ignition Engines, Cavin Hesketh Jan 2022

Characterization Of A Three-Way Catalyst For High Efficiency Spark Ignition Engines, Cavin Hesketh

Electronic Theses and Dissertations

The push for environmental protection and sustainability has led to strict emission regulations for automotive manufacturers as evident in EURO VII and 2026 EPA requirements set to take effect in the coming years. The modern gasoline spark ignition (SI) engine typically employs various in-cylinder emission reduction techniques along with an exhaust after-treatment system to comply with emission standards. The three-way catalyst (TWC) is wholly responsible for removing the engine-out emissions including hydrocarbons (HC), carbon monoxide (CO) and nitrogen oxides (NOx). The main objective of this thesis is to investigate the impact of extensive exhaust gas recirculation (EGR) on …


Hardware Implementations Of Spiking Neural Networks And Artificially Intelligent Systems, Alexander J. Leigh Jan 2022

Hardware Implementations Of Spiking Neural Networks And Artificially Intelligent Systems, Alexander J. Leigh

Electronic Theses and Dissertations

Artificial spiking neural networks are gaining increasing prominence due to their potential advantages over traditional, time-static artificial neural networks. Custom hardware implementations of spiking neural networks present many advantages over other implementation mediums. Two main topics are the focus of this work. Firstly, digital hardware implementations of spiking neurons and neuromorphic hardware are explored and presented. These implementations include novel implementations for lowered digital hardware requirements and reduced power consumption.

The second section of this work proposes a novel method for selectively adding sparsity to a spiking neural network based on training set images for pattern recognition applications, thereby greatly …


Studies Of Layered Elastomeric Substrates And Shellac Films For Stretchable And Printed Electronics, Calum Noade Jan 2022

Studies Of Layered Elastomeric Substrates And Shellac Films For Stretchable And Printed Electronics, Calum Noade

Electronic Theses and Dissertations

Wearable electronics are becoming increasingly common in daily life for a variety of uses. Wearable electronic devices that wish not to be bulky and cumbersome to the user must be stretchable and conformable to the human body. This is a challenge, however, as stretchable polymers are often not as conductive as metal conductors, and metal films applied to elastic substrates are themselves inelastic and will rupture at very low elongations, rendering devices unusable. By using subsurface modification of a multilayered elastomer and brittle layer system, it is possible to offer strain delocalization to a gold film in order to induce …


The Equality Case Of The Kraft And The Kraft-Mcmillan Inequalities, Xavier Nunes Jan 2022

The Equality Case Of The Kraft And The Kraft-Mcmillan Inequalities, Xavier Nunes

Electronic Theses and Dissertations

In this thesis, we analyze the Kraft Inequality and the Kraft-McMillan Inequality in their equality cases. Kraft’s Inequality deals with prefix-free code and Kraft-McMillan’s Inequality deals with uniquely decodable codes. The focus of the Kraft Inequality analysis is to study the occurrence of prefix-free codes that satisfy the equality case and the structure of words in the code when the equality condition is met. The second part of the thesis touches on the Kraft-McMillan Inequality. Since the proof of this latter inequality uses limits, we cannot immediately analyse its equality cases. The paper will therefore study the equality cases of …


Enhancing Multi-View 3d-Reconstruction Using Multi-Frame Super Resolution, Michael Lee Jan 2022

Enhancing Multi-View 3d-Reconstruction Using Multi-Frame Super Resolution, Michael Lee

Electronic Theses and Dissertations

Multi-view stereo is a popular method for 3D-reconstruction. Super resolution is a technique used to produce high resolution output from low resolution input. Since the quality of 3D-reconstruction is directly dependent on the input, a simple path is to improve the resolution of the input.

In this dissertation, we explore the idea of using super resolution to improve 3D-reconstruction at the input stage of the multi-view stereo framework. In particular, we show that multi-view stereo when combined with multi-frame super resolution produces a more accurate 3D-reconstruction.

The proposed method utilizes images with sub-pixel camera movements to produce high resolution output. …


Largemouth Bass In The Upper Mississippi River: An Evaluation Of Management Strategies And Understanding Potential Factors Influencing Dynamic Rate Functions, Kylie Beth Sterling Jan 2022

Largemouth Bass In The Upper Mississippi River: An Evaluation Of Management Strategies And Understanding Potential Factors Influencing Dynamic Rate Functions, Kylie Beth Sterling

MSU Graduate Theses

The Upper Mississippi River (UMR) supports ecologically and economically important commercial and recreational fisheries. One recreational fishery in the UMR is the Largemouth Bass fishery. Recreational fisheries can be effectively managed using information on population dynamics, though little is known about Largemouth Bass population dynamics in large river ecosystems. Therefore, the objectives of this study were to 1) evaluate recruitment, growth, and mortality of three Largemouth Bass populations in the UMR, specifically within Pools 4, 8, and 13, and 2) to use those estimates of recruitment, growth and mortality to inform exploitation models to evaluate best management practices for each …


Structural, Electrical And Optical Properties Of Copper Oxide Phase Mixture: An Active Layer Of Solar Cell, Rifat Ara Shams Jan 2022

Structural, Electrical And Optical Properties Of Copper Oxide Phase Mixture: An Active Layer Of Solar Cell, Rifat Ara Shams

MSU Graduate Theses

Both CuO and Cu2O have been well studied and implemented individually as an active layer of a solar cell from early age of manufacturing. A mixture of these two-phase contents at different ratios can bring variance in absorbance which can present new and diverse aspect in solar cell fabrication with added efficiency. Previous works were successful to vary the phase mixture, and the nanostructures provided very high absorption co-efficient but poor optical response on electrical conductivity. The goal of this research is to find out the optimum parameter for the phase mixture of copper oxide with high absorption coefficient as …


Vision-Based Human Fall Detection In Smart Homes, Snigdha Chaudhari Jan 2022

Vision-Based Human Fall Detection In Smart Homes, Snigdha Chaudhari

MSU Graduate Theses

Falling is one of the leading causes of death from unintentional injuries in older adults. They are more common in people over the age of 65. Wearable sensor-based solutions are commercially available, but they possess limitations like recharging the sensors, and wearing them can be intrusive to the user. Consequently, vision-based fall detection approaches offer a feasible alternative due to the ever-increasing presence of cameras in smart homes. This thesis presents a novel two-stage human fall detection system for smart homes. The proposed approach uses humans as a sensor. It is a vision-based two-stage process where Stage-1 is dedicated to …


Photocatalytic Degradation Of Lignin By Supported Silver Nanoparticles, Ning Wei Jan 2022

Photocatalytic Degradation Of Lignin By Supported Silver Nanoparticles, Ning Wei

Theses and Dissertations--Chemical and Materials Engineering

Lignin is the second most abundant form of biomass on earth. The phenolic structure and high carbon to oxygen ratio make lignin an attractive renewable source of fuel and chemicals. However, its recalcitrance and heterogeneous nature prove difficult for decomposing lignin’s polymer structure and separation of the products. This work has focused on the use of low-energy catalytic approaches to overcome these barriers. A mimic of the lignin degrading enzyme laccase, consisting of a copper cluster Cu4Py4I4 modified with AgNO3, was developed to function similarly to the laccase active site. The prepared copper complex solution was found to be active …


Exploration Of Lignin-Based Superabsorbent Polymers (Hydrogels) For Soil Water Management And As A Carrier For Delivering Rhizobium Spp., Toby Adjuik Jan 2022

Exploration Of Lignin-Based Superabsorbent Polymers (Hydrogels) For Soil Water Management And As A Carrier For Delivering Rhizobium Spp., Toby Adjuik

Theses and Dissertations--Biosystems and Agricultural Engineering

Superabsorbent polymers (hydrogels) as soil amendments may improve soil hydraulic properties and act as carrier materials beneficial to soil microorganisms. Researchers have mostly explored synthetic hydrogels which may not be environmentally sustainable. This dissertation focused on the development and application of lignin-based hydrogels as sustainable soil amendments. This dissertation also explores the development of pedotransfer transfer functions (PTFs) for predicting saturated hydraulic conductivity using statistical and machine learning methods with a publicly available large data set. A lignin-based hydrogel was synthesized, and its impact on soil water retention was determined in silt loam and loamy fine sand soils. Hydrogel treatment …


Synthesis Of 6,6- And 7,7-Difluoro-1-Acetamidopyrrolizidines And Their Oxidation Catalyzed By The Nonheme Fe Oxygenase Lolo, Nabin Panth Jan 2022

Synthesis Of 6,6- And 7,7-Difluoro-1-Acetamidopyrrolizidines And Their Oxidation Catalyzed By The Nonheme Fe Oxygenase Lolo, Nabin Panth

Theses and Dissertations--Chemistry

One of the remarkable steps in loline alkaloid biosynthesis is the installation of an ether bridge between two unactivated C atoms in 1-exo-acetamidopyrrolizidine (AcAP). LolO, a 2-oxoglutarate-dependent nonheme Fe oxygenase, catalyzes both the hydroxylation of AcAP and the resulting alcohol's cycloetherification to give N-acetylnornoline (NANL). The mechanism of hydroxylation is well understood, but the mechanism of the oxacyclization is not. I synthesized difluorinated analogs of AcAP in an attempt to further understand the mechanism of the unusual cycloetherification step.

I prepared 6,6-F2-AcAP in eight steps from N,O-protected 4-oxoproline. The key step was a Dieckmann …


Crystal Engineering Of Asymmetric And Pyrene Fused Annulenes For Use In Organic Electronic Materials, Garrett Fregoso Jan 2022

Crystal Engineering Of Asymmetric And Pyrene Fused Annulenes For Use In Organic Electronic Materials, Garrett Fregoso

Theses and Dissertations--Chemistry

Since the development of TiPS Pentacene, the use of trialkylsilylethynyl groups has become a commonly utilized moiety for stabilizing, solubilizing, and directing crystal packing of acenes and acene-like compounds, leading to the development of a well-defined series of trends that aid in the prediction of crystal packing for the development of organic semiconducting materials. While these trends have been extensively studied in mainly symmetric linear systems, it is important to determine how, if at all, asymmetry of the aromatic core affects these well-defined trends. This constitutes the basis of Chapter 2, which explores the crystal engineering and physical properties of …


The Role Of Charge On Dna Packaging And Integrity Within Reconstituted Peptide-Dna Assemblies, Ehigbai Oikeh Jan 2022

The Role Of Charge On Dna Packaging And Integrity Within Reconstituted Peptide-Dna Assemblies, Ehigbai Oikeh

Theses and Dissertations--Chemistry

In nature, DNA exists primarily in a highly compacted form. The compaction of DNA in vivo is mediated by cationic proteins; histone in somatic nuclei and arginine-rich peptides called protamines in sperm chromatin. The packaging in the sperm nucleus is significantly higher than somatic nuclei resulting in a final volume roughly 1/20th that of a somatic nucleus. This tight packaging results in a near crystalline packaging of the DNA helices. While the dense packaging of DNA in sperm nuclei is considered essential for both efficient genetic delivery as well as DNA protection against damage by mutagens and oxidative species, …