Physical Sciences and Mathematics Commons^™

Functionalized Materials From Atom Transfer Radical Processes, Sean Fischer

Electronic Theses and Dissertations

This work is focused on the synthesis, characterization, and application of functionalized materials prepared from atom transfer radical processes. Atom transfer radical processes encompass both atom transfer radical addition (ATRA) and polymerization (ATRP) reactions, both of which are catalyzed by ppm amounts of copper complexes. The synthetic efforts of ATRA include increasing adduct selectivity through optimization of reaction conditions to generate small molecules in high to moderate yields. ATRA provides retention of the halogen moiety, which is an attractive functional group that can be further modified with other transformations. Specifically, the copper-catalyzed azide-alkyne [3+2] cycloaddition (CuAAC) allows for the realization …

Accurate Quantitation Of Hexavalent Chromium For Reference Standard Certification And Quality Control Testing Using Speciated Isotope Dilution Mass Spectrometry, James E. Henderson

Electronic Theses and Dissertations

The ability to perform accurate, repeatable, and defensible elemental and molecular speciated analysis is immensely significant for measurements that support human health, environmental science, and industry. This is especially true since trivalent chromium [Cr(III)] is necessary for proper nutrition, while hexavalent chromium [Cr(VI)] is extremely toxic, genotoxic, and carcinogenic. The main challenges associated with speciated analysis are related to reactive species that are continuously transformed or converted to other species during sample processing. Accurate determination of Cr(III) and Cr(VI) species require a method that is capable of monitoring and correcting for interconversion, bias, and instrumental error. Traditional quantitative methods, such …

Control Of Corrosion On Ss316l Using Surface Initiated Polymers, Alexander Rupprecht

Electronic Theses and Dissertations

Pitting corrosion is arguably one of the most destructive and dangerous forms of corrosion, resulting in damage to structures, the environment, and public health. In addition, damage caused to structures such as bridges, pipelines, and boats, corrosion also has a profound effect on the biomedical community. Implanted metallic devices (i.e., vascular stents and artificial joints) are prone to pitting corrosion caused by aggressive ions present in extracellular fluid. To provide a corrosion-resistant surface on SS316L, films of poly(styrene), poly(methyl acrylate), and poly(methyl methacrylate) were formed using surface-initiated atom transfer radical polymerization (SI-ATRP). The resulting hydrophobic polymer films had a fractional …

Isolation, Structure Elucidation, And Synthesis Of Natural Products From Marine Cyanobacteria, Keren Solomon

Electronic Theses and Dissertations

This thesis describes the isolation, structure elucidation, and synthesis of natural products from marine cyanobacteria. A crude extract from a cyanobacterium collected in Curacao showed selective affinity for the dopamine D₅ receptor in a screen against a panel of CNS receptors. Due to the high similarity of the D₅ and D₁ receptor, to date there are no known ligands that differentiate them. Attempts to purify the compound responsible for this affinity led to the isolation of the known compound caylobolide A. A second extract from a cyanobacterium collected in Panama underwent bioassay-guided fractionation and yielded the novel …

Using Tandem Mass Spectrometry And Irmpd Spectroscopy To Determine The Intrinsic Reactions Of Uranyl-Containing Ions, Irena Tatosian

Electronic Theses and Dissertations

Developing a comprehensive understanding of the intrinsic reactivity of uranium-containing species remains an important goal, as it may influence future developments in areas ranging from new approaches to nuclear fuel processing to studies of the migration and fate of the element in the environment. At a more fundamental level, such studies contribute to the understanding of the role that 5-f electrons may play in chemical bonding, the so called “f-electron challenge”. Electrospray ionization (ESI) is an effective way to generate gas-phase complexes containing uranium and uranyl ions for subsequent studies of intrinsic structure and reactivity. Studies in the gas-phase are …

N-Terminal Imine Derivatization For Enhanced De Novo Peptide Sequencing: A Study Of The Fragmentation Pattern Generated From Cid Of Peptide-Imines, Khiry L. Patterson

Electronic Theses and Dissertations

In this work, the fragmentation pattern derived from model peptides derivatized to create N-terminal imines (Schiff bases) were evaluated. Collision-induced dissociation of the protonated peptide-imines ([M+H]⁺) generally produced complete series of the sequence informative a_n and b_n ions, now undoubtedly characteristic of the peptide ion species. A novel product ion was also observed, denoted the y^ǂ ion, determined by IRMPD spectroscopy and density functional theory to be generated from the elimination of the N-terminal amino acid residue despite the N-terminal modification. It was concluded the pathway involved a nucleophilic attack by an amide nitrogen and …

A Study Of Chloride Levels In Pine Creek, Allegheny County, Pa, Selina Prettner

Electronic Theses and Dissertations

Pine Creek is a 22.8-mile long tributary to the Allegheny River draining over 67 square miles of northern Allegheny County, PA. The main stem runs along Route 8 and receives extensive runoff from road salt from deicing. A site near Etna, PA sampled biweekly in 2013 consistently showed elevated conductivity that correlated with increased chloride levels. Winter road deicing runoff produced acute chloride concentrations up to 678 mg/L. Chloride fluctuated in the summer and autumn months but did not exceed the USEPA Secondary Drinking Water Standard (250 mg/L) or the aquatic life criterion for chronic concentrations (230 mg/L). Sampling throughout …

Greening Of Catalytic Processes Using First-Row Transition Metals For Atom Transfer Radical Addition And Transfer Hydrogenation, Gabrielle Pros

Electronic Theses and Dissertations

This work focused on “greening” catalytic processes, atom transfer radical addition (ATRA), which adds an alkyl halide across and alkene, and transfer hydrogenation/dehydrogenation, which reduces a carbonyl without needing direct H₂ gas. Part of “greening” of these processes is through using abundant first row metals, Cu and Ni for catalysis. One aim was to design new ligands which would be more active in these systems; the second was investigation of additives for catalyst regeneration to reduce the catalyst loading necessary for high yields.

The TPMA^* family was investigated in ATRA. Rate constants followed the expected trend, which increased …

C-Metalated Nitriles: Diastereoselective Alkylations And Arylations, Robert John Mycka

Electronic Theses and Dissertations

Development of an sp³ hybridized halogen-magnesium exchange route to Grignard reagents, chelation-controlled asymmetric induction of γ- and δ-hydroxynitriles as well as a diastereoselective arylation procedure for C-zincated nitriles have been explored. Sequential addition of i-PrMgCl and n-BuLi to 3- and 4-carbon iodoalcohols triggers a facile halogen-metal exchange to generate cyclic magnesium alkoxides capable of intercepting electrophiles to produce a diverse range of substituted alcohols. This work advances progress toward the synthesis of highly desirable chiral Grignard reagents.

Double deprotonation of γ- and δ-acyclic hydroxynitriles with i-PrMgCl effects highly diastereoselective alkylations via a singly-chelated magnesiated nitriles. …

Identifying Risk Factors Related To Premature Birth Through Binary Logistic And Proportional Odds Ordinal Logistic Regression, Clayton Elwood

Electronic Theses and Dissertations

Premature birth has been identified as the single greatest cause of death worldwide in children under the age of five. This thesis will implement binary logistic regression and proportional odds ordinal logistic regression to predict different levels of premature birth and identify associated risk factors. The models will be built from the Center for Disease Control and Prevention's 2014 Vital Statistics Natality Birth Data containing nearly 4 million live births within the United States. Odds ratios and confidence intervals on risk factors were produced utilizing binary logistic regression.

Triple Functionalization Of Titanium Aluminum Vanadium For Orthopedic Implant Applications, Ashley Blystone

Electronic Theses and Dissertations

Orthopedic implant surgeries are on the rise in the United States, with well over a million surgeries performed annually. Common materials used for these applications include titanium and its alloy, titanium aluminum vanadium (Ti-6Al-4V). Ti-6Al-4V is chosen for this application due to its mechanical strength and corrosion resistance. However, Ti-6Al-4V does not support osseointegration and is susceptible to bacterial colonization. Therefore, these implants suffer from aseptic loosening and infection, necessitating removal and replacement. Revision surgery and treatment is financially burdensome and taxing on the patient. Current approaches focus on modifying the surface of Ti-6Al-4V through a variety of means to …

Using An Extended Broken Symmetry Approximation To Characterize Structure And Spectroscopic Properties Of 2fe-2s Clusters, Ashlyn M. Koval

Electronic Theses and Dissertations

Iron-sulfur proteins perform a wide variety of biological functions that assist in mediating protein function via electron transfer reactions. The Rieske and mitoNEET iron-sulfur clusters have been shown to undergo proton coupled electron transfer facilitated by a histidine ligand. The protonation state of the histidine residue is key to understanding the mechanism of proton coupled electron transfer. This work reports a study of the 2Fe-2S ferredoxin, Rieske, and mitoNEET clusters using the extended broken symmetry approximation. Calculations were performed on the ferredoxin cluster to establish appropriate methodologies. Calculations were then performed for Rieske and mitoNEET clusters to suggest experiments capable …

Nontraditional Hydrogen Bonding In Asymmetric Lewis Acid Catalysis, Brandon Vernier

Electronic Theses and Dissertations

In the field of asymmetric induction, there is a shift from the synthesis of reaction

specific chiral auxiliaries towards a broader mechanistic approach. Our approach is to

develop a theory of asymmetric catalyst design from first principles. The Diels-Alder

reaction of 2-methacrolein and 1,3-cyclopentadiene in the presence of 15 mole % lmenthoxy

aluminum dichloride, reported by Koga, achieved the (S)-exo-Diels-Alder

cycloadduct with 72% ee (0% ee Endo for acrolein). The dramatic change from 72% to 0%

ee is a significant fact that has been overlooked in practical organic synthesis.

In the first phase of this work, the conformational landscape of …

The Effects Of Constructed Wetlands On Metal Solubilization And Bioavailability In Passive Mine Remediation, Elizabeth Cochran

Electronic Theses and Dissertations

The legacy of coal mining in Appalachia has left many watersheds impacted by abandoned mine drainage. The drainage degrades streams, groundwater and habitats with acidity and toxic heavy metals. The Lowber Passive Remediation System has been in operation since 2004 to remediate high amounts of dissolved Fe, SO₄, Al, and Mn. The site consists of six settling ponds and an extensive wetlands at the finish. This study investigated the resolubilization of Fe and Mn in the wetlands and the role of bacteria in resolubilization. During three seasons, field measurements of water quality and lab analysis of Fe, Mn, …

Water Quality Assessment Of Deer Lakes County Park Before, During And After Unconventional Shale Gas Drilling, Daniel Robinson

Electronic Theses and Dissertations

Allegheny County, Pennsylvania, signed a lease to allow unconventional natural gas extraction from Marcellus Shale beneath Deer Lakes County Park in 2014. The park has three man-made lakes and four waterways that eventually flow into the Allegheny River. Drilling commenced in early 2016, and there are now five producing wells. The park has an extensive abandoned coal mine network and several abandoned oil and gas wells. Thus, an independent water quality study was undertaken beginning in July 2015. Samples from seven different sites in the park were used to establish a water quality baseline prior to the drilling. Monthly sampling …

Unconventional Gas Extraction In Southwestern Pennsylvania: Complaints, Production, And Water Quality, Dannielle Pratt

Electronic Theses and Dissertations

The dramatic rise in unconventional oil and gas extraction in Pennsylvania has presented a challenge to the Pennsylvania Department of Environmental Protection in managing regulatory required data, and the uniformity of public access via their online databases. This study analyzed over a decade of all the oil and gas complaints and unconventional gas production in Washington County. Of the 1,811 wells drilled between 2004 and 2018, 1,683 are producing, 74 are plugged, 52 regulatory inactive, and 2 abandoned. The PADEP received 10,389 complaints from 2004 to 2018. Only 2,420 of 4,489 water quality complaints were resolved within the legally required …

Unconventional Oil And Gas Extraction In Ohio: Regulations, Production And Water Quality, Brittany Garman

Electronic Theses and Dissertations

The Utica shale play is the main target for unconventional oil and gas extraction in Ohio. Over 2,000 wells have been drilled since the first in 2011. This rapid expansion has led to concerns over the availability of information and potential environmental impacts. An assessment of readily available data was done through an examination of the ODNR website for oil and gas regulations, permits, spud and completion reports, water usage and waste data, and complaints, as well as brine and de-icer application. Water quality testing of an exceptional warm water tributary in the Captina Creek watershed in Belmont County, Ohio …

Synthesis, Characterization And Crystal Growth Of I2-Ii-Iv-Vi4 And I4-Ii-Iv2-Vi7 Diamond-Like Semiconductors With Potential In Ir-Nlo Applications, Jennifer Glenn

Electronic Theses and Dissertations

In this dissertation, several new and existing diamond-like semiconductors (DLSs) were synthesized and investigated for their potential in infrared nonlinear optical (IR-NLO) applications. In Chapter 2 growth of large single crystals of Li₂MnGeS₄ was carried out using iodine vapor transport and a newly created graphite-tube containment system. This crystallization method produced sizable single crystals on the scale of 2x1x1 mm³, that were used to determine the material’s magnetic properties. Magnetization data indicate that the compound is antiferromagnetic with a Néel temperature of 10 K and an effective magnetic moment of 5.6 /f.u.. The specific heat …

Structure And Thermodynamics Of Polyglutamine Peptides And Amyloid Fibrils Via Metadynamics And Molecular Dynamics Simulations, Riley Workman

Electronic Theses and Dissertations

Aggregation of polyglutamine (polyQ)-rich polypeptides in neurons is a marker for nine neurodegenerative diseases. The molecular process responsible for the formation of polyQ fibrils is not well understood and represents a growing area of study. To enable development of treatments that could interfere with aggregation of polyQ peptides, it is crucial to understand the molecular mechanisms by which polyQ peptides aggregate into fibrils. Many experimental techniques have been employed to probe polyQ aggregation, however, observations from these studies have not lead to a unified understanding of the properties of these systems, instead yielding competing, fragmented theories of polyQ aggregation. This …

Environmental Assessment Of Road Brining And Injection Wells For Disposal Of Oil And Gas Liquid Waste, Marissa Madia

Electronic Theses and Dissertations

The dramatic increase in oil and gas drilling operations in Pennsylvania over the last decade has presented a challenge for their wastewater disposal (e.g., flowback, produced water). Currently, these fluids are treated in permitted brine treatment plants or exported out of state to deep injection well facilities. In Pennsylvania, road brining for dust control is permitted for conventional well brines, and permits for three injection wells for unconventional brines are pending. This study focused on water quality impacts due to road brining in Farmington Township (45 samples) and ground and surface water in Grant Township (41 samples) prior to the …

Effects Of A Green Chemistry Laboratory Design On First- Semester General Chemistry Students' Transformative Experiences In Chemistry, Lurea Joan Doody

Electronic Theses and Dissertations

The purpose of this study was to understand if a green chemistry laboratory design facilitated students’ transformative experiences in a first-semester general chemistry course for science majors. The study population consisted of 18 college students enrolled in the course at a small, rural, mid-Atlantic university. Traditional chemistry laboratories were replaced with three signature green chemistry laboratories over a period of 6-weeks at the end of the spring semester. Impact data were collected pre- and post, of the three labs using the Transformative Experience Questionnaire (TEQ) surveys. Open ended guided reflection questions were coded for elements of transformative experience (TE): expansion …

A Computational Model Of Team-Based Dynamics In The Workplace: Assessing The Impact Of Incentive-Based Motivation On Productivity, Josef Di Pietrantonio

Electronic Theses and Dissertations

Large organizations often divide workers into small teams for the completion of essential tasks. In an effort to maximize the number of tasks completed over time, it is common practice for organizations to hire workers with the highest level of education and experience. However, despite capable workers being hired, the ability of teams to complete tasks may suffer if the workers' individual motivational needs are not satisfied.

To explore the impact of incentive-based motivation on the success of team-based organizations, we developed an agent-based model that stochastically simulates the proficiency of 100 workers with varying abilities and motive profiles to …

Re-Evaluating Performance Measurement: New Mathematical Methods To Address Common Performance Measurement Challenges, Jordan David Benis

Electronic Theses and Dissertations

Performance Measurement is an essential discipline for any business. Robust and reliable performance metrics for people, processes, and technologies enable a business to identify and address deficiencies to improve performance and profitability. The complexity of modern operating environments presents real challenges to developing equitable and accurate performance metrics. This thesis explores and develops two new methods to address common challenges encountered in businesses across the world. The first method addresses the challenge of estimating the relative complexity of various tasks by utilizing the Pearson Correlation Coefficient to identify potentially over weighted and under weighted tasks. The second method addresses the …

Designing A Calibration Set In Spectral Space For Efficient Development Of An Nir Method For Tablet Analysis, Md Anik Alam

Electronic Theses and Dissertations

Designing a calibration set is the first step in developing a spectroscopic calibration method for quantitative analysis of pharmaceutical tablets. This step is critical because successful model development depends on the suitability of the calibration data. For spectroscopic-based methods, traditional concentration based techniques for designing calibration sets are prone to have redundant information while simultaneously lacking necessary information for a successful calibration model. The traditional method also follows the same design approach for different spectroscopic techniques and different formulations, thereby lacks the optimizing capability to be technique and formulation specific.

A method for designing a calibration set in the Near …

Target Based Design And Synthesis Of Heterocycles In The Potential Treatment Of Cancer And Opportunistic Infection, Shruti Choudhary

Electronic Theses and Dissertations

Dose limiting toxicity and development of multidrug resistance by the tumors are the major limitations of current cancer chemotherapy. Microtubule targeting agents (MTAs) are a structurally diverse set of compounds that disrupt microtubule dynamics and exert their anticancer effect. Among the various classes of such agents, the colchicine site binding agents are particularly important as they circumvent the Pgp and β-III tubulin mediated clinical resistance. These resistance mechanisms, when manifested, are a major reason for the failure of clinically used agents such as taxanes and vinca alkaloids. A series of monocyclic pyrimidine analogs were designed and synthesized as colchicine site …

The Decline And Recovery Of Thermal Oxidative Stability Of Ultra-Low Sulfur Diesel Blends, Abigail Schoor Cohen

Electronic Theses and Dissertations

Dissertation supervised by Professor Bruce D. Beaver

The oxidative stability of ultra-low sulfur diesel (ULSD) has generally been expected to continuously decline over time. However, recent studies have suggested that it may fluctuate.^1-2 In this study, the oxidative stability of stored commercially purchased ULSD was monitored with a methanol extraction method.³ In this methodology, proposed by Hardy and Wechter, fuel blends are extracted with methanol before and after thermal stressing.⁴ The methanol-soluble layer contains the oxygenated and oxidizable components of the fuel (SMORS) and the change in this mass upon stressing thus represents the oxidative stability of …

Nitric Oxide Release From Poly(Lactic-Co-Glycolic Acid) Nanoparticles And Titanium Alloy, Nina A. Reger

Electronic Theses and Dissertations

Current methods for the treatment of bacterial infection involve the use of systemic antibiotics, which are high concentrations of antibiotics delivered over a long period time. Unfortunately, the use of systemic antibiotics can cause harmful side effects to the patient and increases the possibility for antibiotic resistance. The delivery of antibiotics or alternative antimicrobial compounds, such as nitric oxide, directly to the site of infection would decrease the amount of antibiotic necessary to treat a bacterial infection.

Poly (lactic-co-glycolic acid)/polyvinyl alcohol nanoparticles and a titanium- aluminum-vanadium metal oxide alloy implant were surface functionalized to deliver nitric oxide. Polymer nanoparticles can …

Rationalizing The Band Gap Tunability Of Semiconductors Via Electronic Structure Calculations, Matthew N. Srnec

Electronic Theses and Dissertations

The polymorphs of titanium dioxide and various diamond-like semiconductor materials are promising candidates in photovoltaic solar cell applications. Several of these polymorphs have been studied with experimental and computational methods, which often aim at tuning the electronic structure, particularly the band gap value of the crystalline solid. Prior studies report that the addition of a substituent into the structure of titanium dioxide decreases its band gap value, but the reasons for this are unknown. Possible explanations for the change in band gap involve the substituent atom's crystal radius, electronegativity, and ionization energy. Understanding the cause of these changes will provide …

Towards Structural Determination Of Human Α1-Glycine Receptor Allostery, Rathna Jyothi Veeramachaneni

Electronic Theses and Dissertations

Recent advances in technology have led to the determination of numerous notable structures of membrane proteins. While they provide valuable information about the structure of membrane proteins these studies often provide static images with potentially limited dynamics, and structural determination often requires truncation of flexible regions, and often utilizes bacterial homologs given the need for stable, heterologous overexpression. In order to better understand allostery at a molecular level, state-dependent crosslinking studies coupled with multidimensional mass spectrometry (MS) were conducted on glycine receptor (GlyR) stabilized in different allosteric states. Predominant allosteric states were stabilized using wild type or mutated receptor in …