Physical Sciences and Mathematics Commons^™

Universal Two-Electron Correlation Operator On Excited States, Bryan Thomas Nichols

Theses and Dissertations

Excited states of chemical systems are extremely important in understanding spectra, chemical phenomena, as well as how a particular compound behaves in reactions. Computationally, excited states are normally very expensive to calculate. The difficulty in calculating these states with wavefunction based methods can be mainly attributed to the calculation of large multi-determinant wavefunctions. One reason to use a complicated multi-determinant wavefunction is to include some of the effects of correlation energy. The quantity of correlation energy can most simply be defined as the reduction in energy caused by any two or more electrons trying to avoid each other. The most …

Analysis Of Hurricane Preparedness Levels And Evacuation Intent For South Carolina Coastal Residents, Wesley Chad Seigler

Theses and Dissertations

Many communities across the nation, especially those in coastal areas, are experiencing extensive growth and expansion. This growth and the associated need for additional infrastructure, goods and services, and basic human needs often place people and the things they value in harm’s way due to the threat of a natural disaster. In order to properly prepare and mitigate disaster impacts, individuals and communities must view disasters as events that will likely occur at least once during their lifetime rather than simply outside possibilities. Residents of coastal communities must prepare for potential impacts from hurricanes and resulting storm surges and must …

Measurement Of Polarization Observables PZ, PSZ, And PCZ In Double-Pion Photoproduction Off The Proton, Yuqing Mao

Theses and Dissertations

Meson production from excited nucleons is important in the study of baryon resonances and pion photoproduction is attracting much attention. To date a rather large amount of unpolarized cross-section measurements have been reported for both single- and double-pion photoproduction. However, polarization observables provide complementary information as they probe different combinations of transition amplitudes. The database for polarization observables remains quite sparse. Double-pion photoproduction have been studied in Hall B at Jefferson Lab with linearly polarized tagged photon beams incident on longitudinally polarized protons. The experiment covered center-of-mass energies between 1.4 GeV and 2.3 GeV. The target was a FROzen Spin …

Semiparametric Regression Analysis Of Bivariate Interval-Censored Data, Naichen Wang

Theses and Dissertations

Survival analysis is a long-lasting and popular research area and has numerous applications in all fields such as social science, engineering, economics, industry, and public health. Interval-censored data are a special type of survival data, in which the survival time of interest is never exactly observed but is known to fall within some observed interval. Interval-censored data arise commonly in real-life studies, in which subjects are examined at periodical or irregular follow-up visits. In this dissertation, we develop efficient statistical approaches for regression analysis of bivariate intervalcensored data, in which the two survival times of interest are correlated and both …

Mono-N-Acyl-2,6-Diaminopimelic Acid Derivatives: Analysis By Electromigration And Spectroscopic Methods And Examination Of Enzyme Inhibitory Activity, Jan Hlaváček, Miloslava Vítovcová, Petra Sázelová, Jan Pícha, Václav Vaněk, Miloš Buděšínský, Jiří Jiráček, Danuta M. Gillner, Richard C. Holz, Ivan Mikšík, Václav Kašička

Chemistry Faculty Research and Publications

Thirteen mono-N-acyl derivatives of 2,6-diaminopimelic acid (DAP)—new potential inhibitors of the dapE-encoded N-succinyl-l,l-diaminopimelic acid desuccinylase (DapE; EC 3.5.1.18)—were analyzed and characterized by infrared (IR) and nuclear magnetic resonance (NMR) spectroscopies and two capillary electromigration methods: capillary zone electrophoresis (CZE) and micellar electrokinetic chromatography (MEKC). Structural features of DAP derivatives were characterized by IR and NMR spectroscopies, whereas CZE and MEKC were applied to evaluate their purity and to investigate their electromigration properties. Effective electrophoretic mobilities of these compounds were determined by CZE in acidic and alkaline background electrolytes (BGEs) and by MEKC in acidic and alkaline BGEs …

Polyol Synthesis Of Silver Nanowires By Heterogeneous Nucleation And Mechanistic Aspects Influencing Its Length And Diameter, Waynie M. Schuette

Arts & Sciences Electronic Theses and Dissertations

Various additives are employed in the polyol synthesis of silver nanowires (Ag NWs), which are typically halide salts such as NaCl. A variety of mechanistic roles have been suggested for these additives. My research showed that the early addition of NaCl in the polyol synthesis of Ag NWs from AgNO3 in ethylene glycol results in the rapid formation of AgCl nanocubes, which induce the heterogeneous nucleation of metallic Ag upon their surfaces. Ag NWs subsequently grow from these nucleation sites. The conclusions are supported by studies using ex-situ generated AgCl nanocubes.

Additionally, the final mean silver nanowire diameter is found …

Tuning Electronic Correlation With Pressure, Gilberto Fernandes Lopes Fabbris

Arts & Sciences Electronic Theses and Dissertations

Strongly correlated electron systems display some of the most exotic ground states in condensed matter. In this thesis high pressure is used to tune the degree of electron correlations in systems of current interest. Their electronic and structural properties were investigated at high pressure using x-ray spectroscopy and scattering as well as transport techniques in a diamond anvil cell. The interplay between short- and long-range structural order, one-dimensional charge ordering, and superconductivity was studied in La_1.875Ba_0.125CuO₄. At ambient pressure, this material displays charge ordering at the onset of a low temperature structural phase transition, …

Isotope Harvesting At Heavy-Ion Fragmentation Facilities, Tara Elise Mastren

Arts & Sciences Electronic Theses and Dissertations

Isotope harvesting from heavy-ion fragmentation facilities is a potential source of isotopes of interest for applications research. With the upgrade of the National Superconducting Cyclotron Laboratory (NSCL) to the Facility for Rare Isotope Beams (FRIB) usable quantities of many isotopes of interest will be produced and available for harvest from an aqueous beam dump. If available, these isotopes would be of interest to a broad range of applications such as medicine, geology, and stockpile stewardship. Preliminary experiments were performed at the NSCL in order to determine the feasibility of isotope harvesting at (FRIB).

A water target station that consisted of …

The Late Ordovician Biogeochemical Carbon Cycle, John Garrecht Metzger

Arts & Sciences Electronic Theses and Dissertations

The isotopic composition of the carbonate carbon (δ13Ccarb) is one of the best tools for understanding the biogeochemical carbon cycle through Earth history. δ13Ccarb is also used to chemostratigraphically correlate coeval strata. This dissertation has three main foci that all utilize δ13Ccarb as the common data type. The geologic interval investigated was the Late Ordovician (458-444 Ma) with emphasis on the Guttenberg δ13C excursion, a globally correlated, positive ~3 / event that is ~400 kyr in duration. In the first topic we evaluate post-depositional alteration (i.e., diagenesis) of δ13Ccarb signals. In the second topic, we make reconstructions of sea level …

The Effects Of Gamifying Optional Lessons On Motivation, Aaron Zemach

McKelvey School of Engineering Theses & Dissertations

Adding video-game elements to non-video-game interfaces (“gamification”) has become a common engagement strategy over the past several years in the domain of education. While prior studies have found that adding game elements to mandatory educational materials can increase students’ motivation to complete the materials, there has yet to be a study to investigate if game elements can make users more likely to engage with optional educational materials. In this study, we investigate whether users of a gamified educational interface are more motivated than users of a non-gamified interface to voluntarily complete educational materials. We found users of a gamified interface …

Kinetic Analysis And Inhibition Studies Of Iron-Dependent Histone Demethylases, Barbara Gordon Cascella

Arts & Sciences Electronic Theses and Dissertations

The research presented herein focuses on the kinetics and inhibition of the KDM4 subfamily of Jumonji C (JmjC) domain-containing histone demethylases (HDMs). Belonging to the larger class of alpha-ketoglutarate (alpha-KG)-dependent, non-heme iron monooxygenases, the JmjC-HDMs remove methyl groups from mono-, di-, and tri-methylated histone lysine residues through an Fe(IV)-oxo-catalyzed hydroxylation reaction. JmjC-HDMs have been found to play integral roles in the maintenance of genomic integrity as well as in the regulation of transcription. Three KDM4 members were studied: the mixed H3K9/H3K36 demethylases KDM4A and KDM4C, and the pure H3K9 demethylase KDM4E. KDM4C is a hypoxia-inducible factor 1 (HIF-1) target gene …

Synthesis And Characterization Of Pbs Quantum Sheets Through Lamellar Assembly, And Updates To The Cdse Quantum Wire Synthesis, Paul James Morrison

Arts & Sciences Electronic Theses and Dissertations

This dissertation reports the novel synthesis of PbS quantum plates (QPs) via a reaction executed at low temperatures. The PbS QPs are grown in a template-assisted mechanism, with the first excitonic peak observed in the visible region of light at ~620 nm (2.0 eV), at an energy radically different than the band gap of bulk PbS (~3000 nm, 0.42eV). The large energy shift is due to the extremely thin dimension of these nanoplates, which is determined to be ~1 nm in thickness. Thickness measurements are made in a powder X-ray diffractometer (XRD) at low angles (between 2-15º 2θ). These measurements …

Study Of Ii-Vi Colloidal Semiconductor Magic-Size Nanoclusters And Crystalline Quantum Platelets, Yuanyuan Wang

Arts & Sciences Electronic Theses and Dissertations

The main objective of this project is to prepare and isolate the smallest, discrete, magic-size nanoclusters of cadmium selenide (CdSe) and to grow crystalline, wurtzite CdSe quantum platelets (QPs) at room temperature. The achievement of these goals enables us to provide a general synthesis of II-VI semiconductor magic-size nanoclusters and low-temperature routes to well-passivated nanocrystals having a range of compositions and morphologies.

The magic-size nanocluster (CdSe)13 is grown in a lamellar-bilayer soft template at room temperature. The results described in this thesis strongly suggest that [(CdSe)13(n-octylamine)13] is the most thermodynamically stable nanocluster and serves as a key intermediate in the …

Zinc And Copper Isotopic Fractionation During Planetary Differentiation, Heng Chen

Arts & Sciences Electronic Theses and Dissertations

Zinc and copper are two important transition metal elements that are widely involved in every stage of planetary formation and differentiation. Their isotopic ratios are robust tracers used to understand the origin of the Solar System, planetary formation and differentiation processes. In this thesis, I focus on their isotopic behaviors during magmatic processes. I report the Zn isotopic compositions of representative igneous rocks to determine potential isotopic fractionations associated with magmatic processes, and to estimate the bulk silicate Earth value. I report isotopic compositions of various groups of iron meteorites (samples of which represent the core of asteroids) and discuss …

Applications Of Nonlinear Optimization, Yao Xie

Arts & Sciences Electronic Theses and Dissertations

We apply an interior point algorithm to two nonlinear optimization problems and achieve improved results. We also devise an approximate convex functional alternative for use in one of the problems and estimate its accuracy.

The first problem is maximum variance unfolding in machine learning. The traditional method to solve this problem is to convert it to a semi-definite optimization problem by defining a kernel matrix. We obtain better unfolding and higher speeds with the interior point algorithm on the original non-convex problem for data with less than 10,000 points.

The second problem is a multi-objective dose optimization for intensity modulated …

Comparison Of Conventional And Bayesian Analysis For The Ultrasonic Characterization Of Cancellous Bone, Amber Groopman

Arts & Sciences Electronic Theses and Dissertations

This dissertation investigates the physics underlying the propagation of ultrasonic waves in cancellous bone. Although quantitative ultrasound has the potential to evaluate bone quality even better than the current gold standard X-ray based modality, its clinical utility has been hampered by the incomplete understanding of the mechanisms governing the interaction between ultrasound and bone. Therefore, studies that extend the understanding of the fundamental physics of the relationship between ultrasound and trabecular bone tissue may result in improved clinical capabilities.

Ultrasonic measurements were carried out on excised human calcaneal specimens in order to study the effects of overlapping fast and slow …

Uncertainty Relation For Mutual Information, James Schneeloch, Curtis J. Broadbent, John C. Howell

Mathematics, Physics, and Computer Science Faculty Articles and Research

We postulate the existence of a universal uncertainty relation between the quantum and classical mutual informations between pairs of quantum systems. Specifically, we propose that the sum of the classical mutual information, determined by two mutually unbiased pairs of observables, never exceeds the quantum mutual information. We call this the complementary-quantum correlation (CQC) relation and prove its validity for pure states, for states with one maximally mixed subsystem, and for all states when one measurement is minimally disturbing. We provide results of a Monte Carlo simulation suggesting that the CQC relation is generally valid. Importantly, we also show that the …

Modeling The Progress And Retention Of International Students Using Markov Chains, Lucas Gagne

Lucas Gagne

Spectral Evolution Of Energetic Neutral Atom Emissions At The Heliospheric Poles As Measured By Ibex During Its First Three Yeras, M. Dayeh, F. Allegrini, R. Demajistre, M. I. Desai, R. W. Ebert, S. A. Fuselier, Paul H. Janzen, G. Livadiotis, D. J. Mccomas, Daniel B. Reisenfeld, N. A. Schwadron, M. Siewert

Physics and Astronomy Faculty Publications

The Interstellar Boundary Explorer (IBEX) mission continues to measure energetic neutral atom (ENA) emissions produced by charge exchange between solar wind (SW) protons and interstellar neutrals at the edge of our heliosphere. Using the first 3 yr of IBEX-Hi ENA measurements (2009-2011), we examined the spectral evolution of ~0.5-6 keV ENAs at the polar regions (above 60°). We found the following: (1) pixels with a characteristic "ankle" spectra (lower spectral index at higher energies) increase by ~5% in 2010 and ~10% in 2011 compared to 2009. (2) The averaged spectral index in 2011 is smaller than that of 2009. (3) …

Privacy-Preserving And Outsourced Multi-User K-Means Clustering, Bharath Samanthula, Fang-Yu Rao, Elisa Bertino, Xun Yi, Dangxi Liu

Cyber Center Publications

Many techniques for privacy-preserving data mining (PPDM) have been investigated over the past decade. Often, the entities involved in the data mining process are end-users or organizations with limited computing and storage resources. As a result, such entities may want to refrain from participating in the PPDM process. To overcome this issue and to take many other benefits of cloud computing, outsourcing PPDM tasks to the cloud environment has recently gained special attention. We consider the scenario where n entities outsource their databases (in encrypted format) to the cloud and ask the cloud to perform the clustering task on their …

Comparative Population Genetics And Evolutionary History Of Two Commonly Misidentified Billfishes Of Management And Conservation Concern, Andrea M. Bernard, Mahmood S. Shivji, Eric Prince, Fabio H.V. Hazin, Freddy Arocha, Andres Domingo, Kevin A. Feldheim

Marine & Environmental Sciences Faculty Articles

Background: Misidentifications between exploited species may lead to inaccuracies in population assessments, with potentially irreversible conservation ramifications if overexploitation of either species is occurring. A notable showcase is provided by the realization that the roundscale spearfish (Tetrapturus georgii), a recently validated species, has been historically misidentified as the morphologically very similar and severely overfished white marlin (Kajikia albida) (IUCN listing: Vulnerable). In effect, no information exists on the population status and evolutionary history of the enigmatic roundscale spearfish, a large, highly vagile and broadly distributed pelagic species. We provide the first population genetic evaluation of the …

A Periodic Matrix Population Model For Monarch Butterflies, Emily Hunt

Senior Honors Projects, 2010-2019

The migration pattern of the monarch butterfly (Danaus plexippus) consists of a sequence of generations of butterflies that originate in Michoacan, Mexico each spring, travel as far north as Southern Canada, and ultimately return to the original location in Mexico the following fall. We use periodic population matrices to model the life cycle of the eastern monarch butterfly and find that, under this model, this migration is not currently at risk. We extend the model to address the three primary obstacles for the long-term survival of this migratory pattern: deforestation in Mexico, increased extreme weather patterns, and milkweed degradation.

An Analysis Of U.S./Canadian Fisheries Policy In Regards To Pacific Salmon And The Preservation Of Indigeneity In The Pacific Northwest, Michael James Lockwood

Masters Theses, 2010-2019

For more than 160 years, the Pacific salmon has been an important resource for the United States and Canada. However, it has been overexploited. Proper management of the species is essential not only for maintaining healthy populations but also maintaining the interests of diverse stakeholders. One set of stakeholders consists of the indigenous peoples of North America because the Pacific salmon are crucial to their food, social, and ceremonial traditions.

This thesis explores the impacts of Canadian and U.S. public policies on the cultural integrity of native peoples in the Pacific Northwest, specifically as those peoples rely on wild Pacific …

Policy Context Of The Endemic Flora Of The Maltese Islands In A Changing Taxonomic Landscape, Clara Agius

Masters Theses, 2010-2019

The degradation of the environment since the Industrial Revolution has been a turning point for legislation, leading to many countries, including EU states, to create legislations that conserve the environment. These legislations are based on scientific facts. This can create a divide between policy and science, as science and scientific methods are constantly changing, while policy has to keep up. Scientific facts of yesterday, may not necessarily be the same as today. This divide between science and policy may have implications on the designation of Protected Areas. One of the criteria of a Protected Area is the protection of an …

Performance Quantification Of Extensive Green Roof Substrate Blend: Expanded Shale And Biochar, James Sheats

Masters Theses, 2010-2019

Urban stormwater management practices often involve the redirection of runoff to local waterbodies. As such, the quality of runoff directly affects the condition of these receiving waters. Green roofs offer many benefits to the urban environment including attractive aesthetics, thermal insulation for buildings and stormwater runoff reduction. Unfortunately, in order to promote the spread of vegetation, fertilization is often practiced that can lead to elevated nutrient concentrations in runoff and, ultimately, nearby streams, rivers and bays. Different amounts of biochar, pyrolyzed biomass, were added to model green roof trays to test for the ability of this charcoal-like substance to prevent …

Examining The Effectiveness Of Ecotourism As A Funding Source For Protected Area Management In Guyana, Jordan S. Flagel

Masters Theses, 2010-2019

Protected areas in tropical rainforests serve many important ecosystem services, including carbon sequestration. These areas are often in need of donor or grant funding to operate as governments in tropical forested countries are not always able to provide adequate funds for protection. This paper focuses on the Iwokrama International Center for Rainforest Conservation and Development in the South American country of Guyana, which has had funding issues since the global economic crisis of 2008 and an accompanying shift in donor country financial priorities. Increasing the amount of sustainable ecotourism in the Iwokrama reserve was identified as a potential source for …

Colloidal And Biological Properties Of Triscationic Amphiphiles With One Or Two Tails, John N. Marafino

Masters Theses, 2010-2019

The decline in the development of novel antimicrobials, combined with the misusage and over prescription of antibiotics, has contributed to the increasing prevalence of antimicrobial-resistant infections. Thus development of effective novel disinfectants could reduce the transmission of pathogens and decrease the risk of infection by antibiotic resistant organisms. The antimicrobial activity of amphiphiles, compounds with hydrophobic and hydrophilic regions, was first reported in 1935, and has influenced the synthesis of amphiphiles with variations in structure. In this study, three series of amphiphiles were synthesized by two subsequent Menshutkin reactions. Each amphiphile contains one or two hydrocarbon tails ranging from 8 …

Offshore Wind Energy In The U.S. Mid-Atlantic Region And The Epa Clean Power Plan Proposed Rule, Kamil E. Armaiz Nolla

Masters Theses, 2010-2019

ABSTRACT

Offshore Wind Energy in the U.S. Mid-Atlantic Region and the EPA Clean Power Plan Proposed Rule

Kamil E. Armaiz Nolla

Carbon dioxide (CO₂) levels in the atmosphere have been experiencing a rapid rise since the start of the Industrial Era. Human activities have been recognized by the scientific community as the main contributors to CO₂ emissions by way of the combustion of fossil fuels such as coal, oil, and natural gas. Scientific consensus about human-induced climate change has been recognized since 1992 by the work of the United Nations Framework Convention on Climate. Since then, …

Polyculture Bioremediation: An Analysis Of Potential Nitrogen Assimilation And Removal By Mya Arenaria, Gracilaria Tikvahiae And Ulva Lactuca Harvests In The Corsica River, Md, Kathleen Hemeon

Masters Theses, 2010-2019

An analysis of nitrogen bioremediation in a tidal tributary of the Chesapeake Bay by the use of a hypothetical bivalve and macroalgae polyculture covering 1%, 3% and 5% of the Corsica River bottom area. This study was performed to illustrate the role ecosystem services play in managing diffuse watershed pollution, particularly nitrogen, resulting in water quality and living resource degradation. Excess concentrations of nitrogen in the Corsica River estuary lead to seasonal eutrophication and subsequent hypoxic events. Mya arenaria L. and Gracilaria tikvahiae (McLachlan, 1979) were chosen for this theoretical study due to their high assimilative capacities for nitrogen and …

Synthesis And Characterization Of Polymer (Sulfonated Poly-Ether-Ether-Ketone) Based Nanocomposite (H-Boron Nitride) Membrane For Hydrogen Storage, Naresh Muthu, S. Rajashabala, R. Kannan

Chemistry and Biochemistry Faculty Publications

The development of light weight and compact hydrogen storage materials is still prerequisite to fuel-cell technology to be fully competitive. The present experimental study reports the hydrogen storage capability of sulfonated poly-ether-ether-ketone (SPEEK)-hexagonal boron nitride (h-BN) (SPEEK-h-BN) nanocomposite membranes. The nanocomposite membranes are prepared by considering various amount of h-BN (0, 1, 3 and 5 wt. %) by phase inversion technique. The degree of sulfonation of the PEEK (SPEEK) is found to be 65% by Proton Nuclear Magnetic Resonance (¹H NMR) spectroscopy. Hydrogen adsorption studies have been carried out using a Seiverts-like hydrogenation setup. The membranes are characterized …