Physical Sciences and Mathematics Commons^™

Photoelectrical And Photoelectrochemical Characterization Of The Materials Used In Dye-Sensitized And Perovskite Solar Cells., Pom Lal Kharel

Electronic Theses and Dissertations

Solar energy is one of the most important alternative renewable energy sources to fulfill the increasing demand of energy in the world. Third-generation solar cells like dye-sensitized solar cells, perovskite solar cells, quantum dot solar cells, and organic solar cells are extensively studied to increase their photoconversion efficiency, and ultimately for their large-scale implementation. A dye-sensitized solar cell consists of a photoanode of a mesoporous film of titania sensitized with dye sandwiched with a counter electrode, which is usually a platinum-coated transparent conducting oxide, and a redox couple injected between the photoanode and counter electrode. Doping titania with rare-earth metal …

Statistical Approaches Of Gene Set Analysis With Quantitative Trait Loci For High-Throughput Genomic Studies., Samarendra Das

Electronic Theses and Dissertations

Recently, gene set analysis has become the first choice for gaining insights into the underlying complex biology of diseases through high-throughput genomic studies, such as Microarrays, bulk RNA-Sequencing, single cell RNA-Sequencing, etc. It also reduces the complexity of statistical analysis and enhances the explanatory power of the obtained results. Further, the statistical structure and steps common to these approaches have not yet been comprehensively discussed, which limits their utility. Hence, a comprehensive overview of the available gene set analysis approaches used for different high-throughput genomic studies is provided. The analysis of gene sets is usually carried out based on …

Design, Synthesis And Application Of Janus Gold Nanoprisms For Directed Self-Assembly., Md. Emtias Chowdhury

Electronic Theses and Dissertations

Colloidal Janus particles that possess more than one type of surface chemistry or functionalities have drawn significant interest due to their enormous potential in bottom-up synthetic strategies for complex superstructures. Moreover, the property of molecular recognition, tunability, and predictability of the DNA-mediated interactions enable a high degree of control over particle assembly to generate highly ordered nanostructures with emergent applications. In this dissertation, we present our works on the synthesis of Janus particles from anisotropic gold nanoprisms, and DNA- mediated assembly of nanoprisms and polymer beads in four major areas: 1) Facet selective asymmetric functionalization of gold nanoprisms for Janus …

Modified-Half-Normal Distribution And Different Methods To Estimate Average Treatment Effect., Jingchao Sun

Electronic Theses and Dissertations

This dissertation consists of three projects related to Modified-Half-Normal distribution and causal inference. In my first project, a new distribution called Modified-Half-Normal distribution was introduced. I explored a few of its distributional properties, the procedures for generating random samples based on Bayesian approaches, and the parameter estimation based on the method of moments. The second project deals with the problem of selection bias of average treatment effect (ATE) if we use the observational data. I combined the propensity score based inverse probability of treatment weighting (IPTW) method and the directed acyclic graph (DAG) to solve this problem. The third project …

Development And Applications Of Condensed Phase Cavity Ring-Down Spectroscopy For Studies Of Electrochemical And Interfacial., Shadi Ahmad Alnaanah

Electronic Theses and Dissertations

This dissertation reports the development of ultra-sensitive platforms based on the laser cavity ring-down spectroscopic (CRDS) technique to enable optical and spectroelectrochemical investigations in the condensed phase of matter at challenging scenarios. Firstly, an electrically-active solid/liquid interface for the evanescent-wave cavity ring-down spectroscopy (EW-CRDS) was developed to specroelectrochemically investigate redox events. By coating the interface of total internal reflection of the EW-CRDS platform with a high quality optically transparent and electrically conductive indium tin oxide thin film (ITO), we demonstrated that sufficiently long ring-down times can be achieved to allow for spectroelectrochemical investigations of redox species at solid/liquid interfaces at …

Computational Behavioral Analytics: Estimating Psychological Traits In Foreign Languages., Kristopher Wayne Reese

Electronic Theses and Dissertations

The rise of technology proliferating into the workplace has increased the threat of loss of intellectual property, classified, and proprietary information for companies, governments, and academics. This can cause economic damage to the creators of new IP, companies, and whole economies. This technology proliferation has also assisted terror groups and lone wolf actors in pushing their message to a larger audience or finding similar tribal groups that share common, sometimes flawed, beliefs across various social media platforms. These types of challenges have created numerous studies in psycholinguistics, as well as commercial tools, that look to assist in identifying potential threats …

Aspects Of Causal Inference., John A. Craycroft

Electronic Theses and Dissertations

Observational studies differ from experimental studies in that assignment of subjects to treatments is not randomized but rather occurs due to natural mechanisms, which are usually hidden from researchers. Yet objectives of the two studies are frequently the same: identify the causal – rather than merely associational – relationship between some treatment or exposure and an outcome. The statistical issues that arise in properly analyzing observational data for this goal are numerous and fascinating, and these issues are encompassed in the domain of causal inference. The research presented in this dissertation explores several distinct aspects of causal inference. This dissertation …

The Utilization Of Metal-Ligand Cooperativity For Electrocatalytic Reduction And Catalytic Hydration., Steven Cronin

Electronic Theses and Dissertations

Small molecules are building blocks for developing larger materials. These small molecules could be extremely small, such as hydrogen, or larger such as a nitrile, but their impact on the global economy is massive. This dissertation describes a catalyst for three reactions involving small molecules; 1) the hydrogen evolution reaction, 2) the carbon dioxide reduction reaction, 3) nitrile hydration. The catalyst Zn(DMTH) (DMTH = diacetyl-2-(4-methyl-3-thiosemicarbazonate)-3-(2-pyridinehydrazonato)) use “metal-ligand cooperativity” between the Lewis acid Zn(II) metal ion and an uncoordinated Lewis base nitrogen in the ligand framework to activate substrates. The complex has been analyzed via NMR, UV/Vis, single crystal X-ray crystallography, …

Exploring Information For Quantum Machine Learning Models, Michael Telahun

Electronic Theses and Dissertations

Quantum computing performs calculations by using physical phenomena and quantum mechanics principles to solve problems. This form of computation theoretically has been shown to provide speed ups to some problems of modern-day processing. With much anticipation the utilization of quantum phenomena in the field of Machine Learning has become apparent. The work here develops models from two software frameworks: TensorFlow Quantum (TFQ) and PennyLane for machine learning purposes. Both developed models utilize an information encoding technique amplitude encoding for preparation of states in a quantum learning model. This thesis explores both the capacity for amplitude encoding to provide enriched state …

Galaxy And Mass Assembly (Gama): A Wise Study Of The Activity Of Emission-Line Systems In G23, H. F.M. Yao, T. H. Jarrett, M. E. Cluver, L. Marchetti, Edward N. Taylor, M. G. Santos, Matt S. Owers, Angel R. Lopez-Sanchez, Y. A. Gordon, M. J.I. Brown, S. Brough, S. Phillipps, Benne Holwerda, A. M. Hopkins, L. Wang

Faculty Scholarship

We present a detailed study of emission-line systems in the Galaxy And Mass Assembly (GAMA) G23 region, making use of Wide-field Infrared Survey Explorer (WISE) photometry that includes carefully measured resolved sources. After applying several cuts to the initial catalog of. 41,000 galaxies, we extract a sample of 9809 galaxies. We then compare the spectral diagnostic Baldwin, Philips & Terlevich (BPT) classification of 1154 emission-line galaxies (38% resolved in W1) to their location in the WISE color-color diagram, leading to the creation of a new zone for mid-infrared "warm"galaxies located 2μm above the star-forming sequence, below the standard WISE active …

Galaxy And Mass Assembly: Luminosity And Stellar Mass Functions In Gama Groups, J. A. Vazquez-Mata, J. Loveday, S. D. Riggs, I. K. Baldry, L. J.M. Davies, A. S.G. Robotham, Benne W. Holwerda, M. J.I. Brown, M. E. Cluver, L. Wang, M. Alpaslan, J. Bland-Hawthorn, S. Brough, S. P. Driver, A. M. Hopkins, E. N. Taylor, A. H. Wright

Faculty Scholarship

How do galaxy properties (such as stellar mass, luminosity, star formation rate, and morphology) and their evolution depend on the mass of their host dark matter halo? Using the Galaxy and Mass Assembly group catalogue, we address this question by exploring the dependence on host halo mass of the luminosity function (LF) and stellar mass function (SMF) for grouped galaxies subdivided by colour, morphology, and central/satellite. We find that spheroidal galaxies in particular dominate the bright and massive ends of the LF and SMF, respectively. More massive haloes host more massive and more luminous central galaxies. The satellites LF and …

Galaxy And Mass Assembly: A Comparison Between Galaxy⇓Galaxy Lens Searches In Kids/Gama, Shawn Knabel, Rebecca L. Steele, Benne W. Holwerda, Joanna S. Bridge, Alice Jacques, Andrew M. Hopkins, Stephen P. Bamford, Michael J.I. Brown, Sarah Brough, Lee Kelvin, Maciej Bilicki, John Kielkopf

Faculty Scholarship

Strong gravitational lenses are a rare and instructive type of astronomical object. Identification has long relied on serendipity, but different strategies—such as mixed spectroscopy of multiple galaxies along the line of sight, machine-learning algorithms, and citizen science—have been employed to identify these objects as new imaging surveys become available. We report on the comparison between spectroscopic, machine-learning, and citizen-science identification of galaxy–galaxy lens candidates from independently constructed lens catalogs in the common survey area of the equatorial fields of the Galaxy and Mass Assembly survey. In these, we have the opportunity to compare high completeness spectroscopic identifications against high-fidelity imaging …

Clean & Fast Amide Couplings In Water, Nicklas Buckbinder, Sudripet Sharma, Sachin Handa

Undergraduate Research Events

EDC

(1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide) is a carbodiimide that is well known reagent for the amide coupling reactions between an amine and carboxylic acid in the presence of a base. It is the commonly used coupling agent in industries because it produces a water-soluble urea byproduct, which can be easily removed by an aqueous work-up. However, our methodology, the desired amide product precipitates out of the reaction mixture, and no additional work-up is required.3 Using aqueous micelles of PS-750-M as a solvent dramatically increases the rate of reaction.2 The filtrate recovered can be recycled to perform several coupling runs after post-reaction manipulation.

The Sizes Of Z ∼ 9-10 Galaxies Identified In The Brightest Of Reionizing Galaxies (Borg) Survey, Benne W. Holwerda, Joanna S. Bridge, Rebecca L. Steele, Samir Kusmic, Larry Bradley, Rachael Livermore, Stephanie Bernard, Alice Jacques

Faculty Scholarship

Redshift z = 9-10 object selection is the effective limit of Hubble Space Telescope (HST) imaging capability, even when confirmed with Spitzer. If only a few photometry data points are available, it becomes attractive to add criteria based on their morphology in these J- and H-band images. One could do so through visual inspection, a size criterion, or alternate morphometrics. We explore a vetted sample of Brightest of Reionizing Galaxies (BoRG) z ∼ 9 and z ∼ 10 candidate galaxies and the object rejected by Morishita+ to explore the utility of a size criterion in z = 9-10 candidate selection. …

Using Saoimage Ds9 & Hubble Space Telescope Data To Identify Globular Clusters In Ic 219, Emily Spicer, Alice Jacques, Benne Holwerda

Undergraduate Research Events

Globular clusters are tightly bound spherical clusters of stars located within the halo of elliptical and spiral galaxies. They are among the oldest stars found in a galaxy, and their presence and abundance in a galaxy’s halo offer insight on the age, composition, and formation of the galaxy.1 I used a Hubble Space Telescope (HST) image and SAOImage DS9, a powerful imaging tool used to analyze astronomical data, to identify the size and locate the position of globular cluster (GC) candidates in IC 219.

Chess As A Testing Grounds For The Oracle Approach To Ai Safety, James D. Miller, Roman Yampolskiy, Olle Häggström, Stuart Armstrong

Faculty Scholarship

To reduce the danger of powerful super-intelligent AIs, we might make the first such AIs oracles that can only send and receive messages. This paper proposes a possibly practical means of using machine learning to create two classes of narrow AI oracles that would provide chess advice: those aligned with the player's interest, and those that want the player to lose and give deceptively bad advice. The player would be uncertain which type of oracle it was interacting with. As the oracles would be vastly more intelligent than the player in the domain of chess, experience with these oracles might …

Factor Structure And Measurement Invariance Of The Maslach Burnout Inventory In Emergency Medicine Residents, Tim P. Moran, Nicole Battaglioli, Simiao Li-Sauerwine

Journal of Wellness

Introduction: Emergency medicine residents suffer from high rates of occupational burnout. Recent research has focused on identifying risk and protective factors for burnout as well as targets for intervention. This research has primarily employed the Maslach Burnout Inventory to evaluate burnout in this population. Factor analytic work has identified three underlying factors measured by the Maslach Burnout Inventory: Emotional Exhaustion, Depersonalization, and Personal Accomplishment. However, this three-factor structure has not been evaluated in emergency medicine residents. Furthermore, its structural equivalence has not been demonstrated across commonly-studied risk factors, such as gender and year of post-graduate training. In the present study, …

(Pseudo)Phase Tuning In The Service Of Synthesis: Technologies For Sustainable Catalysis., Justin Douglas Smith

Electronic Theses and Dissertations

Strategies for manipulation of chemical phases were explored with emphasis on synthetic chemistry applications. Some strategies are fairly divergent from their origin, but all ultimately began from investigations of micellar media. Accordingly, Chapter 1 reviews the historical development of micellar catalytic processes. Chapters 2 and 3 detail development of synthetic methods in micellar solutions of designer surfactant PS-750-M. PS-750-M was designed to create benign micellar solutions which effectively mimic toxic organic solvents; it contains a proline-based linker between its hydrophobic and hydrophilic regions which imparts increased polarity to the micellar core. Chapter 2 details an interfacial nucleophilic substitution of perfluoroarenes …

A Gis-Based Method For Archival And Visualization Of Microstructural Data From Drill Core Samples., Elliott Holmes

Electronic Theses and Dissertations

Core samples obtained from scientific drilling could provide large volumes of direct microstructural and compositional data, but generating results via the traditional treatment of such data is often time-consuming and inefficient. Unifying microstructural data within a spatially referenced Geographic Information System (GIS) environment provides an opportunity to readily locate, visualize, correlate, and explore the available microstructural data. Using 26 core billet samples from the San Andreas Fault Observatory at Depth (SAFOD), this study developed procedures for: 1. A GIS-based approach for spatially referenced visualization and storage of microstructural data from drill core billet samples; and 2. Producing 3D models of …

Marginal Methods And Software For Clustered Data With Cluster- And Group-Size Informativeness., Mary Elizabeth Gregg

Electronic Theses and Dissertations

Clustered data result when observations have some natural organizational association. In such data, cluster size is defined as the number of observations belonging to a cluster. A phenomenon termed informative cluster size (ICS) occurs when observation outcomes vary in a systematic way related to the cluster size. An additional form of informativeness, termed informative within-cluster group size (IWCGS), arises when the distribution of group-defining categorical covariates within clusters similarly carries information related to outcomes. Standard methods for the marginal analysis of clustered data can produce biased estimates and inference when data have informativeness. A reweighting methodology has been developed that …

Water Cluster Motifs In Structurally Similar N-(2-Aminoethyl)-1-Methylimidazole-2-Carboxamide Metal Complexes: Synthesis, Characterization, Thermal And Electrical Properties., Nina Saraei

Electronic Theses and Dissertations

Water is a remarkable molecule and in all of its forms exhibits an amazing collection of properties and functions. Besides its crucial role in life and many technological processes, water displays some unusual and anomalous properties at various interfaces and under different conditions. Although the role of hydrogen-bonding interactions and their fluctuations are well known to determine the properties of water, the main obstacle exists in the complexity of correctly describing the interactions between water molecules. The key to understanding the behavior of water is to collect precise structural data of various H-bonded water networks in diverse environments. In this …

Convolution Inequalities And Applications To Partial Differential Equations., Matthew Reynolds

Electronic Theses and Dissertations

In this dissertation we develop methods for obtaining the existence of mild solutions to certain partial differential equations with initial data in weighted L p spaces and apply them to some examples as well as improve the solutions to some known PDEs studied extensively in the literature. We begin by obtaining a version of a Stein-Weiss integral inequality which we will use to obtain general convolution inequalities in weighted L p spaces using the techniques of interpolation. We will then use these convolution inequalities to make estimates on PDEs that will help us obtain mild solutions as fixed points of …

A Structural Study Of Correlated Materials: Incipient Mott Insulators And Low-Dimensional Systesm., Alaa Alfailakawi

Electronic Theses and Dissertations

Current theories of high-temperature superconductivity suggest that electrons must organize into Cooper pairs in order for a material to exhibit a superconducting phase. Electrons in insulators experience significant repulsive interactions that tend to keep electrons localized at atomic positions. In contrast, electrons in metals are delocalized, interact weakly, and are free to conduct electricity. Therefore, the formation of Cooper pairs should have different mechanisms for metals compared to insulators. This contrast raises the debate about the origin of high-temperature superconductivity in iron-based material, whether it depends on the strong or weak coupling. Many iron-based materials are metallic in the normal …

Linear Methods For Regression With Small Sample Sizes Relative To The Number Of Variables., Rajesh Sikder

Electronic Theses and Dissertations

In data sets where there are a small number of observations but a large number of variables observed for each observation, ordinary least squares estimation cannot be used for regression models. There are many alternative including stepwise regression, penalized methods such as ridge regression and the LASSO, and methods based on derived inputs such as principal components regression and partial least squares regression. In this thesis, these five methods are described. K-fold cross validation is also discussed as a way for determining regularization parameters for each method. The performance of these methods in estimation and prediction is also examined through …

Search For New Physics Using Lepton Flavor Violating Signatures In Modern Particle Colliders., Atanu Pathak

Electronic Theses and Dissertations

Charged lepton flavor violation is a clear signal of new physics. Such decays are not allowed in the Standard Model but highly anticipated in a large class of new physics models. A direct search for lepton flavor violation in decays of the Higgs boson with the ATLAS detector at the LHC is presented here. The analysis is performed in the H → l tau channel, where the leading lepton (l) can be either an electron or a muon, and the tau lepton decays into an opposite flavored lighter lepton or via the hadronic decay channel. Published results of this search …

A Comprehensive Study Of The Short-Term Variability Of The Migrating Diurnal Tide In The Mesosphere And Lower Thermosphere., Lokupatabendige Ashan Shivantha Vitharana

Electronic Theses and Dissertations

Our ability to understand and predict space weather has become vital due to its significant societal impacts on communication, transportation, and national defense. One of the most exciting discoveries in the last decade has been the realization that tropospheric weather can strongly influence space weather. It is now recognized that the atmospheric waves (gravity waves, atmospheric tides, and planetary waves) play a key role in coupling the lower and upper atmosphere. The focus of this dissertation is to study atmospheric tides. While the climatology of tides has been extensively studied, little is known about the tidal weather (tidal variability

Electrochemically-Modulated Surface Plasmon Waves At A Nano-Scale For Investigations And Applications Of Redox Assemblies., Aymen Hasan Qatamin

Electronic Theses and Dissertations

In this thesis, an electrochemically-modulated surface plasmon resonance (EC-SPR) technique was developed for challenging investigations and applications in different redox assemblies. The principle of the technique is based on the nano-scale confined and sensitive interplay between a surface plasmon wave and a redox-active probe featuring an optical transition when undergoing a faradaic redox process. Such faradaic process is electrochemically controlled by modulating the surface electric potential of the SPR platform to create an optical output signal that is substantially immune to the negative impacts of background environment and enabling the identification and quantification minute properties linked to a molecular event …

Is Ngc 300 A Pure Exponential Disk Galaxy?, In Sung Jang, Roelof S. De Jong, Ivan Minchev, Eric F. Bell, Antonela Monachesi, Benne W. Holwerda, Jeremy Bailin, Adam Smercina, Richard D'Souza

Faculty Scholarship

NGC 300 is a low-mass disk galaxy in the Sculptor group. In the literature, it has been identified as a pure exponential disk galaxy, as its luminosity profile can be well fit with a single exponential law over many disk scale lengths (Type I). We investigate the stellar luminosity distribution of NGC 300 using Hubble Space Telescope archive data, reaching farther and deeper than any other previous studies. Color-magnitude diagrams show a significant population of old red giant branch (RGB) stars in all fields out to R ∼ 19 kpc (32′), as well as younger populations in the inner regions. …

Galaxy And Mass Assembly (Gama): Demonstrating The Power Of Wise In The Study Of Galaxy Groups To Z < 0.1, M. E. Cluver, T. H. Jarrett, E. N. Taylor, A. M. Hopkins, S. Brough, S. Casura, B. W. Holwerda, J. Liske, K. A. Pimbblet, A. H. Wright

Faculty Scholarship

Combining high-fidelity group characterization from the Galaxy and Mass Assembly survey and source-tailored z < 0.1 photometry from the Wide-Field Infrared Survey Explorer (WISE) survey, we present a comprehensive study of the properties of ungrouped galaxies, compared to 497 galaxy groups (4 ≤ N FoF ≤ 20) as a function of stellar and halo mass. Ungrouped galaxies are largely unimodal in WISE color, the result of being dominated by star-forming, late-type galaxies. Grouped galaxies, however, show a clear bimodality in WISE color, which correlates strongly with stellar mass and morphology. We find evidence for an increasing early-type fraction, in stellar mass bins between 1010 M o˙ ≲ M stellar ≲ 1011 M o˙, with increasing halo mass. Using ungrouped, late-type galaxies with star-forming colors (W2-W3 > 3), we define a star-forming main sequence (SFMS), which we use to delineate systems that have moved below the sequence ("quenched"for the purposes of this work). We find that with increasing halo mass, the relative number of late-type systems on the SFMS decreases, with a corresponding increase in early-type, quenched systems at high stellar mass (M stellar > 1010.5 M o˙), consistent with mass quenching. Group galaxies with masses M stellar < 1010.5 M o˙ show evidence of quenching consistent with environmentally driven processes. The stellar mass distribution of late-type, quenched galaxies suggests that it may be an intermediate population as systems transition from being star-forming and late-type to the "red sequence."Finally, we use the projected area of groups on the sky to extract groups that are (relatively) compact for their halo mass. Although these show a marginal increase in their proportion of high-mass and early-type galaxies compared to nominal groups, a clear increase in quenched fraction is not evident.

Projecting The Covid-19 Weekly Deaths And Hospitalizations For Jefferson County, Kentucky, Seyed Karimi, Natalie Dupre, W. Paul Mckinney, Bert B. Little, Naiya Patel, Sarah Moyer

The University of Louisville Journal of Respiratory Infections

Introduction: The trends in the numbers of active hospitalizations and fatalities caused by the COVID-19 in Jefferson County, Kentucky, were projected over the period May 7 to August 20, 2020.

Methods: The projections provided in this report are from a susceptible-exposed-infectious-recovered (SEIR) model. The model was calibrated using the COVID-19 transmission dynamics parameters from relevant literature and clinical dynamics parameters from the county’s data. The model was used to measure the impact of public health policy interventions designed to contain the infection. The policy was modeled by its intervention day and impact on the transmission of the virus such that …