Physical Sciences and Mathematics Commons^™

Mathematical Modeling Of Microemulsification Processes, Numerical Simulations And Applications To Drug Delivery, Ogochukwu Nneka Ifeacho

Open Access Theses & Dissertations

Microemulsion systems are a great pharmaceutical tool for the delivery of formulations containing multiple hydrophilic and hydrophobic ingredients of varying physicochemical properties. These systems are gaining popularity because of its long shelf life, improved drug solubilisation capacity, easy preparation and improvement of bioavailability. Despite the advantages associated with the use of microemulsion systems in pharmaceutical industries, the major challenge impeding their use has been and continues to be the lack of understanding of these systems.

Microemulsions can be mathematically modeled by an initial boundary value problem involving a sixth order nonlinear time dependent equation. In this Thesis, we present a …

Stochastic Modeling Of Earthquakes And Option Pricing Using Bns-Gamma-Ou Model, Mandela Bright Quashie

Open Access Theses & Dissertations

High frequency data are becoming increasingly popular these days. They are fundamental in basically every facet of people’s lives. They are the determining factors in hedging in the field of finance. In geology, they help in the accurate prediction of earthquakes’ magnitude which goes along way to help save lives and properties.

High frequency data are also used more and more frequently for speculations. For this reason, it is important not only for scientists to apply models allowing correct quantification of these data, but also to improve the eciency of these models.

The Black-Scholes model, which is widely used because …

Water Sourcing Strategies Of Highly Resilient Vegetation In Desert Soils: Stable Isotope Analysis Of A Northern Chihuahuan Desert Ecosystem, Hayden Eleanor Thompson

Open Access Theses & Dissertations

Plant water use strategies and water transport dynamics are important for understanding ecosystem productivity and soil-vegetation-atmosphere interactions within an environment (Li et al., 2007). Recent research using stable isotope analysis in wet and humid climates has found that vegetation uses tightly particle-bound water stored in the soil that does not participate in translatory flow (Brooks et al., 2010; Goldsmith et al., 2011; McDonnell 2014). In arid and semi-arid deserts of the United States, highly resilient vegetation, such as the Honey Mesquite (Prosopis glandulosa) and the Creosote shrub (Larrea tridentata), exhibit some degree of activity year-round despite limited water availability during …

Brian Valdez - Dynamics And Control Of A 3-Dof Manipulator With Deep Learning Feedback, Brian Orlando Valdez

Open Access Theses & Dissertations

With the ever-increasing demands in the space domain and accessibility to low-cost small satellite platforms for educational and scientific projects, efforts are being made in various technology capacities including robotics and artificial intelligence in microgravity. The MIRO Center for Space Exploration and Technology Research (cSETR) prepares the development of their second nanosatellite to launch to space and it is with that opportunity that a 3-DOF robotic arm is in development to be one of the payloads in the nanosatellite. Analyses, hardware implementation, and testing demonstrate a potential positive outcome from including the payload in the nanosatellite and a deep learning …

Lévy Processes: Characterizing Volcanic And Financial Time Series, Peter Kwadwo Asante

Open Access Theses & Dissertations

In this work, we use the Diffusion Entropy Analysis (DEA) to analyze and detect the scaling properties of time series from both emerging and well established markets as well as volcanic eruptions recorded by a seismic station, both financial and volcanic time series data are known to have high frequencies (i.e they are collected at an extremely fine scale). The objective is to determine the characterization i.e whether they follow a Gaussian or Lévy distribution. If they do follow a Lévy distribution we are then interested in finding if they are characterized by a Lévy walk which has a finite …

Fluvial Interactions Of The Jurassic Salt Wash Member Of The Morrison Formation With The Gypsum Valley Salt Diapir, Co, Clair Henry Bailey

Open Access Theses & Dissertations

Gypsum Valley diapir in Gypsum Valley Colorado is an ideal location to investigate the interaction between a fluvial system and a diapir going through late stage collapse and rise. The outcrop exposures in Gypsum Valley allow for the analysis in changes of the fluvial system of the Salt Wash Member of the Morrison Formation as it gets redirected by the salt wall and deposits sediment on top of, on the margins, and in the Disappointment and Dry Creek minibasins. Previous work has focused on understanding and predicting how fluvial systems react when they encounter a salt diapir, but all the …

A Comparative Study Of The Impact Of Depth In Deep Learning Architectures, Kirsten Byers

Open Access Theses & Dissertations

Machine Learning continues to evolve as applications become more complex. Neural Networks, or Deep Networks, are integral to machine learning and the entire taxonomy of Artificial Intelligence [Sze17]. Intelligent structures and algorithms continue to advance, keeping pace with the complexi-ty of data. Changes in architecture, algorithms, and parameters are necessary to keep up with com-putational complexity and data available. This study focuses on how changes in depth of the archi-tecture affect performance on three distinct datasets, including one on Heart Disease. An adaptable network is created in original code, trained, and tested on these datasets. Its performance parameters are observed …

Shallow Seismic Modeling Of The Hydrothermal Plumbing System Beneath Old Faithful Geyser In The Upper Geyser Basin Of Yellowstone National Park, Jordan Rigdon Caylor

Open Access Theses & Dissertations

In November 2016, a 2-D and 3-D seismic survey was performed around Old Faithful Geyser in the southeastern portion of the Upper Geyser Basin in Yellowstone National Park. The survey consisted of 521 3-component seismic receiver locations including 39 receivers on a ~1km NE-SW trending line crossing Old Faithful Geyser. A 5.4kg sledgehammer striking a metal plate was our source with a dominant frequency of ~40Hz. Our 2-D line crosses Old Faithful in a NE-SW direction with station spacing at 25-30m with ~100m spacing on either side of Old Faithful and a total length of 1024m. Our 3-D seismic grid …

Understanding The Connections: An Analysis Of Climate Change And Human Security, Erica Martinez

Open Access Theses & Dissertations

Increasing evidence shows that the impacts of anthropogenic climate change have magnified and will have dramatic implications for both the natural and social systems (Adger et al., 2014). While research on the security implications of climate change has been found to have a major bearing on policy making, experts have not reached a consensus about how climate change and human security are related, leaving the climate-security nexus and corresponding policies underdeveloped.

The purpose of this study is to delineate and scrutinize the relationship between climate change and human security so that a more comprehensive understanding of the phenomenon is achieved. …

Compound Vision Approach For Autonomous Vehicles Navigation, Michael Mikhael

Open Access Theses & Dissertations

An analogy can be made between the sensing that occurs in simple robots and drones and that in insects and crustaceans, especially in basic navigation requirements. Thus, an approach in robots/drones based on compound eye vision could be useful. In this research, several image processing algorithms were used to detect and track moving objects starting with images upon which a grid (compound eye image) was superimposed, including contours detection, the second moments of those contours along with the grid applied to the original image, and Fourier Transforms and inverse Fourier Transforms. The latter also provide information about scene or camera …

Free Semigroups And Identites For A Class Of Monoids, Enrique Salcido

Open Access Theses & Dissertations

The study of words as a mathematical object is a deep and rich field of study. Algebra, Combinatorics, Theoretical Computer Science etc., are major disciplines, which are fully using this study. Combinatorial properties (via Codes, Free Hulls, Infinite Words), and algebraic properties of words are presented in this Thesis. The free semigroup on a set (alphabet) X and finite presentation of semigroups have a central place in the algebraic study of words. The last part of the Thesis is devoted to the study of identities in the alphabet X = {x,y} for a class of monoids. The characterization of such …

Investigation Of Iron Doped Gallium Oxide (Ga-Fe-O) System: Structure Property Relationship And Performance Evaluation For Optical And Catalytic Applications, Swadipta Roy

Open Access Theses & Dissertations

From September 2012 to May 2015, a phenocam monitored the seaward edge of a protected mangrove forest. Calculated GCC revealed seasonal greening patterns of a mangrove species, Rhizophoa apiculata, and an overall increase in the GCC, suggesting mangrove expansion. In comparing temperature and precipitation effects, it was found that this particular mangrove species had a greening optima at temperatures between 28°C and 28.5°C, and greening and canopy development response lag time of 10 weeks in response to precipitation. Tree saplings were monitored and showed to grow by 50%, mostly during a three month period during the rainy season. The establishment …

Density Functional Calculations On Single Molecular (1d) And Van Der Waals Bi -Layered (2d) Magnets., Md Shamsul Alam

Open Access Theses & Dissertations

Low-dimensional magnetic materials show novel properties that is not seen in bulk magnets. The weak interactions such as spin-orbit interactions, electron correlation, van der Waals interaction in case magnetic bi-layers, play an important role in determining the properties of the system. Using density functional theory, we computationally investigated two categories of magnetic material- 1: Single Molecular Magnets (SMM) 2: Van der Waals layered Cr-Halide magnets. We used different classes of density functionals to examine the spin ordering and magnetic anisotropy barriers in several single molecule magnets - Mn12, Co4, Ni4, V15. We find that the magnetic anisotropy barrier significantly depends …

Associations Of Traffic Related Air Pollution With Physical Activity And Cardiorespiratory Health Outcomes In At-Risk Populations From El Paso, Texas, Juan Aguilera

Open Access Theses & Dissertations

Exposure to air pollution from traffic-related emissions is a considerable preventable cause of respiratory and cardiovascular diseases. However, the impacts on at-risk populations, such as children with asthma and low-income residents, are yet to be fully understood in the border city of El Paso, TX. This dissertation focused on the most common traffic-related pollutants which include particulate matter (PM2.5 and PM10), nitrogen dioxide (NO2), and ozone (O3). The research described in this work provides an overview of air pollution measurements and shares insights from three different studies in our region.

People with asthma are more likely adversely affected by traffic …

Robust Estimation And Inference For Multivariate Financial Data, Afua Kwakyewaa Amoako Dadey

Open Access Theses & Dissertations

Predicting and forecasting are routine day-to-day activities that guide us in making the best possible choices. They play an integral role in financial analysis. A lot of work has been done on one dimensional geometric Brownian motion (GBM) in stock price prediction. In this line of work, we focus mainly on how to use the one dimensional geometric Brownian motion and the multidimensional geometric Brownian motion in predicting future stock prices. There are several stock prices in the financial market and the multidimensional geometric Brownian motion gives a more realistic prediction compared to the one dimensional GBM. The reason being …

General Penalized Logistic Regression For Gene Selection In High-Dimensional Microarray Data Classification, Derrick Kwesi Bonney

Open Access Theses & Dissertations

High-dimensional data has become a major research area in the field of genetics, bioinformatics and bio-statistics due to advancement of technologies. Some common issues of modeling high-dimensional gene expression data are that many of the genes may not be relevant. Also, reducing the dimensions of the data using penalized logistic regression is one of the major challenges when there exists a high correlation among genes. High-dimension data correspond to the situation where the number of variables is greater or larger than the number of observations. Gene selection proved to be an effective way to improve the results of many classification …

Toward Automated Region Detection & Parcellation Of Rat Brain Tissue Images, Alexandro Arnal

Open Access Theses & Dissertations

People who analyze images of biological tissue often rely on segmentation of structures as a preliminary step. In particular, laboratories studying the rat brain manually delineate brain regions to position scientific findings on a brain atlas to propose hypotheses about the rat brain, and ultimately, the human brain. Our work intersects with the preliminary step of delineating regions in images of brain tissue via computational methods.

We investigate pixel-wise classification or segmentation of brain regions using ten histological images of brain tissue sections stained for Nissl substance, and two deep learning models: U-Net and Tile2Vec. Our goal is to assess …

Some Fermi-Lowdin Orbital Self-Interaction Correction Studies On Atomic Systems, Christopher Alexis Ibarra

Open Access Theses & Dissertations

Density Function Theory (DFT) is a popular quantum chemistry calculation method with many appeals but also deficiencies. Many modification and additions to the method have been made over the years, such as self-interaction corrections and new density functional approximations. We review here the theoretical background needed for a basic understanding of quantum chemistry calculations. In addition, we present the quantum chemistry calculation method used in this paper called Fermi-Lowdin Self-Interaction Correction (FLOSIC), including the base code it was implemented on, the Naval Research Laboratory Molecular Orbital Library (NRLMOL) Code, and the resulting modified code simply called FLOSIC. Furthermore, we explore …

Glacier Segmentation In Satellite Images For Hindu Kush Himalaya Region, Bibek Aryal

Open Access Theses & Dissertations

Climate change poses a risk to individuals whose livelihoods depend on the health of glacier ecosystems. Monitoring glaciers in the Himalayan Hindu Kush (HKH) region is of high importance especially when we consider the impact of recent climate change on them. Our work aims to provide an automated method to outline glaciers using machine learning techniques and publicly available remote sensing imagery.In this work, we present ways to delineate glaciers from Landsat-7 imagery using various machine learning and computer vision techniques. The multi-step methodology that we present in this work is generalizable across different types of satellite and overhead imagery, …

Development Of Software Tools And Experimental In Situ Electron Spin Resonance For Characterizing The Magnetic And Electrocatalytic Properties Of Transition Metal Chalcogenide Crystals, Jose Armando Delgado

Open Access Theses & Dissertations

Studying the magnetic properties and crystal defects of transition metal chalcogenide crystals is of paramount importance for utilizing them for next generation spintronics devices and hydrogen evolution reaction catalysts. Hydrothermally grown transition metal chalcogenide nanocrystals (MoS2, Ru2S3, Rh2S3, Co2S8) were chosen as catalysts for the hydrogen evolution reaction due to their low dimensionality and previous utilization as catalysts for hydrodesulfurization. The relationship between crystal defect sites and catalytic activity must be discerned to maximize the efficiency of hydrogen production during the hydrogen evolution reaction. ESR spectroscopy was utilized as a spin sensitive technique to study the defects and local changes …

Towards The Development Of A Cohesive Design-Driven Code Quality Metrics, Omar Masmali

Open Access Theses & Dissertations

Software complexity is an indicator of expected future maintenance and sustainability. Excessive complexity suggests that software or a component of software has a design or implementation that is difficult to understand, modify, and maintain. Several complexity measures have been developed by researchers to identify and characterize degrees of complexity. Code smells are widely adopted as indicators for low code quality. Many studies have adopted fixed threshold values for code smells and other quality metrics. These fixed threshold values often ignore the uniqueness of each software system and the unique roles each component play. Moreover, these thresholds are largely fixed throughout …

Discovery Of Glycan-Based Biomarkers For Cutaneous Leishmaniasis And Chagas Disease By Reversed Immunoglycomics, Alba Lucia Montoya

Open Access Theses & Dissertations

Protozoa are the causative agents of a number of diseases that affect humans and mammalian animals. Several forms of leishmaniasis are caused by different Leishmania species (Leishmania spp.), while Chagas disease (CD) is caused by the parasite Trypanosoma cruzi (T. cruzi). These members of the Trypanosomatidae family have characteristic glycoconjugates broadly distributed on their cell surfaces, which can be useful for diagnosis and follow-up of chemotherapy for the diseases.

Leishmania spp. expresses an “exotic” surface glycocalyx mainly composed of a number of glycosyl-phosphatidylinositol (GPI)-anchored proteins, a complex lipophosphoglycan (LPG) and a family of low-molecular mass glycoinositol-phospholipids (GIPLs), some of them …

The Effect Of K2co3 Concentration In Kerosene Emulsions On Spray Droplet Sizes For A Magnetohydrodynamic Power Generator, Alejandra Castellano

Open Access Theses & Dissertations

Potassium carbonate (K2CO3) is an effective seeding material to introduce potassium vapor in oxy-fuel combustion to create a conductive plasma. Injecting potassium carbonate before combustion promotes particle volatilization and improves the generation of potassium vapor. This can be achieved by emulsifying a potassium carbonate solution with kerosene. Several studies have investigated creating stable emulsions with kerosene with water by using differing surfactants. However, the effects of using varying concentrations of K2CO3 dissolved in deionized water have not been fully explored. Based on methods of creating successful emulsions, the development of a successful mixture comprised of kerosene and K2CO3 solution is …

Independent And Simultaneous Control Of Electromagnetic Wave Properties In Self-Collimating Photonic Crystals Using Spatial Variance, Jesus Javier Gutierrez

Open Access Theses & Dissertations

Photonic crystals are engineered periodic structures that provide great control over electromagnetic waves. One of these mechanisms is self-collimation, in which the electromagnetic wave travels through the photonic crystal along an axis of the lattice without diffracting or spreading. This mechanism of self-collimation is a dispersion phenomenon, which is dependent on the unit cell's physical and geometrical characteristics. An algorithm for generating spatially variant lattices (SVL) was developed that can change geometrical properties in photonic crystals as a function of position, like unit cell orientation, fill fraction, symmetry, and others in a manner that is smooth, continuous, and virtually free …

Geophysical Investigations Of The San Andreas Fault System And Evaluations In Geoscience Education, Sandra Hardy

Open Access Theses & Dissertations

Chapter 1: Investigating Earthquake Cycle Vertical Deformation Recorded by GPS And Regional Tide Gauge Stations in California

Geodetic and tide gauge measurements of vertical deformation record localized zones of uplift and subsidence that may document critical components of both long and short-period earthquake cycle deformation. In this study, we compare vertical tide gauge data from the Permanent Service for Mean Sea Level (PSMSL) and vertical GPS data from the EarthScope Plate Boundary Observatory (PBO) for 10 approximately co-located station pairs along coastal California from Point Reyes, CA to Ensenada, Mexico. To compare these two data sets, we first truncate both …

Deep Learning For Overhead Imagery: Algorithms And Applications, Anthony Manuel Ortiz Cepeda

Open Access Theses & Dissertations

Remote sensing using overhead imagery has critical impact to the way we understand our environment and offers crucial information for scene understanding, climate change research, disaster response, urban planning, forest management, and many other applications. At present, deep learning is increasingly used in remote sensing, but mostly borrowing algorithms developed for natural images in the computer vision community. Specific challenges arise while applying deep learning to remote sensing. These challenges include issues related to the high dimensionality and limited labeled data, security and robustness to adversarial attacks, and model generalization. In this Thesis we focus on tackling these key challenges. …

Mother Nature, Lady Justice: Ecofeminism And Judicial Decision-Making, Jonathan Alexis Picado

Open Access Theses & Dissertations

Ecofeminism offers a feminist perspective that links gender to how humans relate to the natural world. As such, this framework explores the connections between the oppression of nature and the oppression of women, such as widespread views that both women and nature are property, are to be dominated, and are most valuable when cultivated and curated by men. I apply this philosophical and sociological framework to judicial decision-making, where women judges should view environmental issues as women's issues and thus be more likely to vote in favor of the environmental protections relative to her male peers. I evaluate this theory …

Synthesis Of Nanotemplated, Glucose-Derived Adsorbents For The Removal Of Organic And Inorganic Pollutants From Water, Luis Alfonso Barrera

Open Access Theses & Dissertations

With an ever-present rise in population, along with an increase in industrial and manufacturing plants, contamination of potable water has become a global concern. While water treatment facilities exist which can help with the purification of water from bacterial and organic contaminants, these facilities are expensive to set in place and maintain. Therefore, in impoverished areas, point of use (POU) purification systems are often preferred, such as filters made from activated carbon. These filters are inexpensive and relatively easy to install and use. However, while activated carbons generally display excellent adsorption capabilities towards organic contaminants, their adsorption towards inorganic pollutants …

Reconciling Carbon Flux Discrepancies In A Desert Environment: Characterizing Influences Of Soil Processes Using Automated Co2 Flux Chambers, Alejandro Lara

Open Access Theses & Dissertations

Dryland ecosystems play a fundamental role in controlling the balance of carbon on a global scale. These ecosystems dominate the inter-annual variability of carbon uptake by terrestrial ecosystems, and this is driven by temperature and precipitation patterns. Despite this global importance, there are some important discrepancies that have been reported between CO2 fluxes measured with differing techniques, particularly between eddy covariance tower measurements of net ecosystem exchange (NEE) of carbon (C) versus on-the-ground methods such as chambers and biomass surveys. The discrepancy is a consequence of instrumentation and measurement technique differences; yet, its biological origins remain unknown. The goal of …

Benchmarking Machine Learning Methods For Molecular Property Prediction, Govinda Bahadur Kc

Open Access Theses & Dissertations

Machine learning (ML) techniques have been widely applied in a variety of areas ranging from pattern recognition, natural language processing, and computer games to self-driving cars, clinical diagnostics, and molecular structure prediction easing day to day life of human beings. Drug discovery is an expensive, complex, and time taking process. Currently, the pharma industry is hoping to leverage machine learning methods in expediting the drug discovery process. Molecular property prediction is one of the most important tasks in drug discovery. While developing a new drug relies on a proper understanding of molecular properties, there has been great interest in the …