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Physical Sciences and Mathematics Commons

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Duquesne University

2019

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Articles 1 - 14 of 14

Full-Text Articles in Physical Sciences and Mathematics

A Study Of Chloride Levels In Pine Creek, Allegheny County, Pa, Selina Prettner Dec 2019

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 Dec 2019

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 Dec 2019

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 Aug 2019

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 Aug 2019

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 Aug 2019

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 May 2019

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 May 2019

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 May 2019

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 May 2019

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 May 2019

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 May 2019

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 …


Fluoride Removal From Water Using A 3d Printed Calcium Carbonate Filter, Sophia Bakar, David Kahler, Benjamin S. Goldschmidt Apr 2019

Fluoride Removal From Water Using A 3d Printed Calcium Carbonate Filter, Sophia Bakar, David Kahler, Benjamin S. Goldschmidt

Undergraduate Research and Scholarship Symposium

Groundwater containing high concentrations of fluoride is the most common source of drinking water in rural areas in parts of east Africa, India, and China. The elevated levels of fluoride cause skeletal and dental fluorosis, which is the weakening and decay of bone structures due to the leeching of calcium from the body as calcium and fluoride bond by the process of adsorption. Over 150 million people are suffering from some form of fluorosis due to the consumption of groundwater. Calcium carbonate has been demonstrated to influence fluoride removal in several forms. To make fluoride removal a cost-effective and user-friendly …


Quantifying Iron Overload Using Mri, Active Contours, And Convolutional Neural Networks, Andrea Sajewski, Stacey Levine Apr 2019

Quantifying Iron Overload Using Mri, Active Contours, And Convolutional Neural Networks, Andrea Sajewski, Stacey Levine

Undergraduate Research and Scholarship Symposium

Iron overload, a complication of repeated blood transfusions, can cause tissue damage and organ failure. The body has no regulatory mechanism to excrete excess iron, so iron overload must be closely monitored to guide therapy and measure treatment response. The concentration of iron in the liver is a reliable marker for total body iron content and is now measured noninvasively with magnetic resonance imaging (MRI). MRI produces a diagnostic image by measuring the signals emitted from the body in the presence of a constant magnetic field and radiofrequency pulses. At each pixel, the signal decay constant, T2*, can be calculated, …