Physical Sciences and Mathematics Commons^™

Infrastructure Development For Personalized Risk Prediction To Reduce Cardiovascular Disease In Childhood Cancer Survivors, Suman Shrestha

Dissertations and Theses (Open Access)

Although childhood cancer survivors have lengthy life expectancies, they run the risk of experiencing long-term health issues as a result of their treatment. The most frequent non-cancerous cause of morbidity and mortality for these survivors is cardiac disease. Radiation therapy (RT) has been linked in numerous cohort studies to a higher chance of developing a late cardiac disease in these survivors, and this risk rises with higher mean heart doses and increased RT exposure to larger cardiac volumes. Since, the heart is a heterogeneous organ made up of several distinct substructures, RT dose received by the entire heart does not …

Irreducible Representations From Group Actions On Trees, Charlie Liou

Master's Theses

We study the representations of the symmetric group $S_n$ found by acting on

labeled graphs and trees with $n$ vertices. Our main results provide

combinatorial interpretations that give the number of times the irreducible

representations associated with the integer partitions $(n)$ and $(1^n)$ appear

in the representations. We describe a new sign

reversing involution with fixed points that provide a combinatorial

interpretation for the number of times the irreducible associated with the

integer partition $(n-1, 1)$ appears in the representations.

On Variants Of Sliding And Frank-Wolfe Type Methods And Their Applications In Video Co-Localization, Seyed Hamid Nazari

All Dissertations

In this dissertation, our main focus is to design and analyze first-order methods for computing approximate solutions to convex, smooth optimization problems over certain feasible sets. Specifically, our goal in this dissertation is to explore some variants of sliding and Frank-Wolfe (FW) type algorithms, analyze their convergence complexity, and examine their performance in numerical experiments. We achieve three accomplishments in our research results throughout this dissertation. First, we incorporate a linesearch technique to a well-known projection-free sliding algorithm, namely the conditional gradient sliding (CGS) method. Our proposed algorithm, called the conditional gradient sliding with linesearch (CGSls), does not require the …

Ligand-Promoted Dissolution Of Uranyl Phosphate Across Scales, Brennan Ferguson

All Dissertations

The formation of uranyl phosphate precipitate is a remediation strategy because the low solubility of uranyl phosphate minerals, like chernikovite, limits the mobility of uranium in contaminated soils. However, organic ligands can complex with aqueous metal cations to form more soluble species. For example, citrate is a commonly occurring organic ligand produced by plants and microbes that increases the solubility of uranium and therefore the dissolution of uranyl phosphate minerals in the uranyl phosphate-citrate system. This effect is an important control on the mobility of uranium in organic-rich, and near-surface vegetated environments. Nevertheless, key aspects of the citrate-uranyl phosphate system …

Statistical Methods For Modern Threats, Brandon Lumsden

All Dissertations

More than ever before, technology is evolving at a rapid pace across the broad spectrum of biological sciences. As data collection becomes more precise, efficient, and standardized, a demand for appropriate statistical modeling grows as well. Throughout this dissertation, we examine a variety of new age data arising from modern technology of the 21st century. We begin by employing a suite of existing statistical techniques to address research questions surrounding three medical conditions presenting in public health sciences. Here we describe the techniques used, including generalized linear models and longitudinal models, and we summarize the significant associations identified between research …

Estimation Of Disaggregated Import Demand Functions For Nigeria, Chekwube V. Madichie, Uche C. Nwogwugwu, Franklin N. Ngwu, Olisaemeka D. Mauka

CBN Journal of Applied Statistics (JAS)

This paper estimates disaggregated import demand function for Nigeria using annual data from 1970 to 2019. The study employs the Zivot-Andrews unit root and Gregory-Hansen cointegration tests to account for the role of structural breaks and the error correction mechanism for shortrun analysis, respectively. The results show that household consumption, industrial output and domestic investment are the major determinants of import demand for consumer, intermediate and investment goods, respectively. Furthermore, the import demand for investment goods is not sensitive to variations in relative prices. However, relative prices is negative and significant to import demand for consumer and intermediate goods. Exchange …

Size And Determinants Of The Shadow Economy In Nigeria: Evidence From A Monetary Approach, Tari M. Karimo, Mohammed M. Tumala, Ibrahim U, Wambai

CBN Journal of Applied Statistics (JAS)

Thiis study investigates the size and determinants of the shadow economy in Nigeria. It adopts an aggregation approach within the monetary framework and utilises the ARDL estimation technique to analyse quarterly data from 2010 Q1 to 2019 Q4. On average, the results suggest that the quarterly size of the shadow economy is about 55 per cent of the country’s GDP. The findings show that government size reduces the size of the shadow economy in the short run but increases it in the long run. The study also finds that interest rate, which is the opportunity cost of holding cash, and …

Fiscal And Monetary Policy Interactions In A Developing Economy: A Dsge-Based Evidence From Nigeria, Queen E. Oye, Philip O. Alege

CBN Journal of Applied Statistics (JAS)

This study characterizes the nature of fiscal-monetary interaction in Nigeria and gauges its macroeconomic effects by estimating a New Keynesian Dynamic Stochastic General Equilibrium (NK DSGE) model. Two policy simulations were also conducted. The first experiment considers the desirable active-passive policy mix while the second experiment ranks alternative monetary policy rules among the differing objectives of price, output and exchange rate stabilization. The study finds that fiscal and monetary policies interact as complements in an active monetary and passive fiscal policy mix over the sample period. The result from the first policy simulation reveals that the active monetary and passive …

Market Risk Factors And Stock Returns In The Nigerian Bourse, Omorose A. Ogiemudia, Osagie Osifo, Igbinovia L. Eghosa

CBN Journal of Applied Statistics (JAS)

This study examines the link between market risk and equity return in Nigeria between 1980 to 2019. It employs the vector error correction model (VECM) to determine the short run dynamics and long run effect of market risk factors on stock return. The findings revealed that a dynamic relationship exists between market risk factors and stock returns in Nigeria. Also, exchange rate risk and oil price risks have significant influence on stock return, while inflation and interest rate risk, and political instability risks have a non-significant impact on stock return. Finally, a unidirectional relationship was detected between interest rate, oil …

Savings-Investment Gap In Sub-Saharan Africa: Does The Interaction Of Financial Sector Development And Migrant Remittances Matter?, Wasiu Adekunle, Oluwatosin Adeniyi, Joshua Afolabi, Musibau Babatunde, Edward Omiwale

CBN Journal of Applied Statistics (JAS)

This study analyses the interactive effects of migrant remittances and financial development on savings-investment gap for a panel of 18 Sub-Saharan Africa (SSA) countries from 1990-2017. Results from a panel ARDL model show that migrant remittances reduce savings-investment gap in the long run. The gap is further reduced when the individual effect of financial development, and the interactive effects of migrant remittances and financial development are taken into consideration. Further analysis reveals evidence of widening effects of rising real GDP growth and bank deposits over a long-term horizon, while higher private sector credit widened the savings-investment gap only in the …

Impact Of Exchange Rate On Trade Flow In Nigeria, Victor U. Ijirshar, Isa J. Okpe, Jerome T. Andohol

CBN Journal of Applied Statistics (JAS)

This study examines the impact of exchange rate on trade flow in Nigeria from 1986 to 2021. The study utilises linear and nonlinear autoregressive distributed lag (ARDL and NARDL) models to test the J-Curve hypothesis and the Marshall-Lerner condition in Nigeria. The study found symmetric effects of exchange rate on trade balance, exports, and imports. The findings also show that real exchange rate depreciation has a strong negative influence on trade balance and exports in the short run but positive in the long run, exhibiting the shape typology of the J-curve. Furthermore, the study reveals evidence of the Marshall-Lerner condition …

Understanding Ecological Relationships To Improve Biofouling Management Practices In The Marine Environment, Ann Catherine Wassick

Theses and Dissertations

Biofouling, the growth of benthic invertebrates on anthropogenic surfaces, impacts many industries and is a major vector of non-native species worldwide. Understanding the ecological relationships between biofouling organisms and their environment is necessary to assist management practices. This study investigates the biofouling communities at Port Canaveral, Florida, in order to potentially refine biofouling mitigation practices. Recruitment panels were used to document the temporal changes in community composition, biofouling pressure, recruitment, and growth rates. These factors were also used to assess relationships with temperature and salinity. A second component of this work provided documentation on the variation in non-native species abundance …

South Texas Wildlife Activity Across A Fragmented Landscape And Road Mitigation Corridor, Caitlin K. Brett

Theses and Dissertations

Wildlife crossing structures (WCS) and roadside fencing are commonly installed to mitigate habitat fragmentation, wildlife road mortalities, and other negative effects that roads can have on the surrounding landscape. Eight such WCS were constructed below Farm-to-Market (FM)106 in Cameron County, Texas, across a 16 km corridor transecting the Laguna Atascosa National Wildlife Refuge. These WCS, paired with adjacent roadside fencing, were intended to prevent road mortalities of the endangered ocelot (Leopardus pardalis) and to mitigate the barrier effect of FM106 on this and other meso-mammal species. This study will analyze camera trap data from roadside and habitat reference …

Grapefruit Peel Biochar Applications For Immobilizing Copper And Lead In Soil, Michael Alfredo Navarro

Theses and Dissertations

This study investigated the efficacy of grapefruit peel (GP) derived biochar materials (two pyrolysis temperatures 450°C and 800°C) as a potential adsorbent to immobilize heavy metal (copper and lead) in a local sandy loam clay soil. A batch adsorption test with heavy metal concentrations at 50 mg L-1, and 100 mg L-1 revealed that soil itself had the highest immobilization percentage compared to the GP biochars. A soil column experiment was conducted to determine how much the GP biochar samples and the tested soil will exhibit adsorptive characteristics for heavy metals when 50 ml of 50 mg L-1 copper or …

Synthesis Of Bioactive Heterocycles, Shaila Akter Shetu

Theses and Dissertations

The Discovery of a variety of heterocyclic drugs for the treatment of cancer and other diseases (e.g, neglected tropical diseases) is a medical breakthrough and inspiring for the research community as a whole. A wide range of natural, semi-synthetic, and synthetic anticancer drugs are synthesized using various methods. Among them, β -lactams stand out as a novel class of antibiotics that has different types of biological as well as anti-cancer properties. β -lactam has become a premier and active research subject towards the development of revolutionary anti-cancer drugs. In recent years, a large amount of investigations have been done to …

The Role Of Inputs Of Marine Wrack And Carrion In Sandy-Beach Ecosystems: A Global Review, Glenn A. Hyndes, Emma L. Berdan, Cristian Duarte, Jenifer E. Dugan, Kyle A. Emery, Peter A. Hamback, Christopher J. Henderson, David M. Hubbard, Mariano Lastra, Miguel A. Mateo, Andrew Olds, Thomas A. Schlacher

Research outputs 2022 to 2026

Sandy beaches are iconic interfaces that functionally link the ocean with the land via the flow of organic matter from the sea. These cross-ecosystem fluxes often comprise uprooted seagrass and dislodged macroalgae that can form substantial accumulations of detritus, termed ‘wrack’, on sandy beaches. In addition, the tissue of the carcasses of marine animals that regularly wash up on beaches form a rich food source (‘carrion’) for a diversity of scavenging animals. Here, we provide a global review of how wrack and carrion provide spatial subsidies that shape the structure and functioning of sandy-beach ecosystems (sandy beaches and adjacent surf …

Expressiveness Of Real-Time Motion Captured Avatars Influences Perceived Animation Realism And Perceived Quality Of Social Interaction In Virtual Reality, Alan D. Fraser, Isabella Branson, Ross C. Hollett, Craig P. Speelman, Shane L. Rogers

Research outputs 2022 to 2026

Using motion capture to enhance the realism of social interaction in virtual reality (VR) is growing in popularity. However, the impact of different levels of avatar expressiveness on the user experience is not well understood. In the present study we manipulated levels of face and body expressiveness of avatars while investigating participant perceptions of animation realism and interaction quality when disclosing positive and negative experiences in VR. Moderate positive associations were observed between perceptions of animation realism and interaction quality. Post-experiment questions revealed that many of our participants (approximately 40 %) indicated the avatar with the highest face and body …

Optical Properties And Simulated X-Ray Near Edge Spectra For Y2o2s And Er Doped Y2o2s, Nicholas Dimakis, Eric Baldemar Rodriguez Jr., Kofi Nketia Ackaah-Gyasi, Madhab Pokhrel

Physics & Astronomy Faculty Publications

The electronic and optical properties of Y2O2S and its Er+3 doped counterparts at various concentrations are analyzed using density functional theory (DFT) and simulated x-ray near edge (XANES) spectra. Our simulations are complemented by absorption experiments, which show Y2O2S:Er+3 light emissions in the visible and near infrared. These emissions correspond to Er f–f intraband transitions. We use DFT and DFT+U to calculate the band structure of the Y2O2S and its Er+3 doped counterparts, whereas optical properties are calculated using the independent particle approximation (IPA). The host Y2O2S optical properties are also calculated using the random phase approximation (RPA) and …

Fossil Mammals From Hickory Tree Cave, Sullivan County, Tennessee, Alexis Rivera

Electronic Theses and Dissertations

Hickory Tree Cave, also known as Big Spring Cave, is located in the southern Appalachians and is known for fossils that are considered to be Quaternary in age. Fossil mammals were identified and assigned to the lowest taxonomical level possible. Most remains are fragmented or digested and it seems likely that various taphonomic processes are responsible for the resulting assemblage. The site lacks the extreme boreal component of Pleistocene cave faunas in the region (e.g. Baker Bluff Cave), with most reported taxa inhabiting Appalachian deciduous forest environments in North America today. While the presence of tapir (Tapirus sp.) …

Nitrogen-Doped And Phosphorus-Doped Epoxy-Sealed Carbon Fiber Ultramicroelectrodes As Electrochemical Sensors For Detection Of Hydrogen Peroxide, Emmanuel Peprah-Yamoah

Electronic Theses and Dissertations

Ultramicroelectrodes (UMEs) are useful as probes for evaluating electroactive species in confined spaces (e.g., inside living cells) and for measuring fast electrochemical reactions. However, UME applications often require modification of the electrode surface to improve selectivity and sensitivity towards target analytes. Previous research in our group demonstrated that a simple soft nitriding method introduces surface nitrogen (N)-containing groups on carbon fiber (CF), leading to improved electroreduction of hydrogen peroxide (H₂O₂) on CF-UMEs. However, sensitivity for H₂O₂ detection using N-CF-UMEs was low compared to that for other modified UMEs. As an alternative to N-CF-UMEs, …

Time Series Classification With Multistage Modeling Using Deep Learning, James Arthur

Open Access Theses & Dissertations

Time series classification (TSC) can be efficiently implemented with several techniques. Many techniques are based on analyzing 1-D signals in the time series data. In this work, we make an intrinsic analytical implementation of a new time series classification that involves a two-stage process. Firstly, by using Recurrence Plots (RP), we transform the time series into 2D images. The second stage consists in taking advantage of deep learn- ing models to perform our classification. The image illustration of time series introduces different feature types that are not available for all 1D signals, and therefore our classifi- cation problem is treated …

Transportation Asset Management For The Electric Road System, Kamalen Maria Santos Diaz

Open Access Theses & Dissertations

Electric road systems (ERS) have been presented as a new solution towards a sustainable transportation future, fueling the widespread adoption of electric vehicles by eliminating range anxiety, reducing battery size, and being regional friendly. These systems consist of four components: electric power supply, roads, vehicles, and operations. Much of the early research conducted on ERS has been on how to initially construct these systems by focusing on the first three components, however, there is limited knowledge on how ERS will impact traditional road operations after the systems are in place. Transportation Asset Management (TAM), a major focus within the transportation …

Online/Incremental Learning To Mitigate Concept Drift In Network Traffic Classification, Alberto R. De La Rosa

Open Access Theses & Dissertations

Communication networks play a large role in our everyday lives. COVID19 pandemic in 2020 highlighted their importance as most jobs had to be moved to remote work environments. It is possible that the spread of the virus, the death toll, and the economic consequences would have been much worse without communication networks. To remove sole dependence on one equipment vendor, networks are heterogeneous by design. Due to this, as well as their increasing size, network management has become overwhelming for network managers. For this reason, automating network management will have a significant positive impact. Machine learning and software defined networking …

Application Of Flo-Sic To F-Electron Systems: Sixth Row Elements And Ligated Molecules, Alexander Irun Johnson

Open Access Theses & Dissertations

Density functional theory - the most widely used theoretical method to study atoms,molecules, and solids - suffers from the well-known self-interaction error. A solution to the problem was suggested by Perdew and Zunger [1], who showed the self-interaction error can be removed with self-interaction correction. In 2014, Pederson showed a unitary transformation can be performed on the Kohn-Sham orbitals to generate Fermi-Löwdin orbitals which improve atomization energies, and avoid the computational costs of solving the localization equations.[2] This method is known as the Fermi-Löwdin Orbital Self-Interaction Correction (FLO-SIC). Until now, the FLO-SIC methodology has been used for atoms not containing …

A Case Study In Design, Construction, And Operation Of A Meromictic Solar Pond In Texas, Usa, Bianca Paola Meneses Brassea

Open Access Theses & Dissertations

Over the last four decades, meromictic solar ponds have been the subject of limnological studies and engineering research. A case of practical interest is the salinity gradient solar pond (SGSP). SGSP science and technologies have been systemically advanced in El Paso, Texas. This dissertation aims to share lessons learned in designing, constructing, and operating the El Paso Solar Pond, a NaCl-based solar pond that achieved high-temperature performance over two decades, commencing in 1984. Many of the practical lessons learned have not been published and are thus not readily available in archival journals, and this contribution provides a remedy. The value …

Hydrothermal Alteration Targeting And Geophysical Mineral Exploration Of Eureka And Sylvanite Mining Districts, Southwest New Mexico, Kenneth Singh

Open Access Theses & Dissertations

As part of the southwestern North American porphyry copper province, mining of natural resources in New Mexico has historically played a crucial role in economic development for over 150 years including this project area in the Little Hatchet Mountains. The northern half of the Little Hatchet Mountains lies in Grant County and includes the Eureka Mining District (EMD) whereas the southern half is in Hidalgo County and includes the Sylvanite Mining District (SMD), 38 miles southeast of Lordsburg. The EMD, a copper and silver-lead mining district from 1880-1961, had a total estimated production from the Laramide veins of 2.9 million …

Insights On The Behavior Of Nano-Copper In The Agroecosystem: Mycorrhizal Associations With Spearmint (Mentha Spicata), Suzanne Annette Apodaca

Open Access Theses & Dissertations

Nanotechnology offers significant potential benefits to our society, including the agriculture sector. With the advancement of nano-enabled agrochemicals towards sustainable and efficient agricultural practices, it is essential to address environmental issues associated with the use of nanoscale materials. The same properties that give promise to applications of nanotechnology in modern agriculture could have unintended consequences on ecosystem dynamics. A point of concern for risk management is the impact of engineered nanomaterials (ENMs) to beneficial microbial communities, which support a variety of ecosystem services.

Use of copper (Cu) products in agriculture are based on their abundance, role as a micronutrient, and …

Spectroscopic Study Of Bi5ti3feo15 Aurivillius Compound For Multifunctional Applications, Mariana Castellanos

Open Access Theses & Dissertations

No abstract provided.

Oil Particle Analysis Using Machine Learning And Holography Imaging, Daniel Cruz

Open Access Theses & Dissertations

Holographic cameras show potential as a sensor to monitor oil spills. Holographic cameras record the light interference from particles in a volume of space, producing an image called a hologram. Processing these holograms is known as hologram reconstruction. It produces a representation of particles located in three-dimensional space. These cameras can record precise shapes and sizes of particles in a volume of water. However, it is very time-consuming and resource-intensive to process the images. Most algorithms that perform particle analysis require the hologram reconstruction step. The well-documented hybrid method is one such algorithm. Machine learning is one possible technique that …

Direct Ink Write And Thermomechanical Characterization Of Thermoset Composites, Sergio Dante Favela

Open Access Theses & Dissertations

This research will be divided into two sections. The first section discusses direct ink writing and thermomechanical characterization for thermoset composites. The thermoset ink is prepared with fillers aiding the printing process by modifying the rheology of the ink and geometry retention by allowing for the part to have an initial UV cure step. Three specimen formulations with different weight percentages were printed by material extrusion in the shape of tensile specimens following ASTM standard D638 to characterize the mechanical properties at room temperature, 100â?? and 200â??. Furthermore, the ink resin was characterized through DSC, TGA, and rheology testing. The …