Physical Sciences and Mathematics Commons^™

Multiplicative And Additive Arithmetic Functions And Formal Power Series, John Byron Snell

Open Access Theses & Dissertations

The theory of arithmetic functions and the theory of formal power series are classical andactive parts of mathematics. Algebraic operations on sets of arithmetic functions, called convolutions, have an important place in the theory of arithmetic functions. The theory of formal power series also has its place firmly anchored in abstract algebra. A first goal of this Thesis will be to present a parallelism of known characterizations of the concepts of multiplicative and additive for arithmetic functions (Theorems 2.1.2 and 2.2.3) on the one hand and for formal power series on the other (Theorems 3.4.3 and 3.4.4). Therefore, in Chapter …

The Hybridizing Ions Treatment (Hit) Method Development And Computational Study On Sars-Cov-2 E Protein., Shengjie Sun

Open Access Theses & Dissertations

Fast and accurate calculations of the electrostatic features for highly charged biomolecules such as DNA, RNA, highly charged proteins, are crucial but challenging tasks. Traditional implicit solvent methods calculate the electrostatic features fast, but they are not able to balance the high net charges in the biomolecules effectively. Explicit solvent methods add unbalanced ions to neutralize the highly charged biomolecules in molecular dynamic simulations, which require more expensive computing resources. Here we developed a novel method, the Hybridizing Ions Treatment (HIT) method, which hybridizes the implicit solvent method with the explicit method to realistically calculate the electrostatic potential for highly …

Structural Characterization Of Two Large Icosahedral Dna Viruses And Their Capsid Assembly Mechanisms, Yuejiao Xian

Open Access Theses & Dissertations

In the last three decades, many large DNA viruses were discovered and grouped into a loosely defined clade of Nucleocytoplasmic Large DNA Viruses (NCLDVs). NCLDVs infect a wide range of hosts from single cellular protists to large animals. Recently, these viruses were classified as a new phylum of Nucleocytoviricota under the kingdom of Bamfordvirae. The genomes of these Nucleocytoviricota viruses (NCVs) are remarkedly large and complicated, containing many cellular genes from all three domains of life, which raised intensive debates on their evolutionary origins. Despite being classified in the same phylum, their physical structures vary and can be roughly classified …

Fundamental Studies Of Nanomaterial-Mediated Photothermal Effects And Novel Applications In Visual Quantitative Disease Diagnoses, Wan Zhou

Open Access Theses & Dissertations

Infectious diseases and cancers frequently cause public health concerns and high burdens on health care globally. Early diagnosis of these diseases can provide an important guide on prevention, treatment, and prognosis in clinical practice. However, current laboratory diagnostic methods, such as nucleic acid- and protein-based detection methods, require sophisticated infrastructure, expensive and bulky instrumentation, well-trained personnel, and time-consuming processes, which significantly leads to high cost of detection assays and limit their wide accessibility, especially in low-resource settings. To address these issues, we have developed multiple simple, low-cost, and visual quantitative diagnostic methods based on nanomaterial-mediated photothermal effects for the detection …

Design And Operability Of A Pressurized Oxy-Combustion System, Mehrin Chowdhury

Open Access Theses & Dissertations

Fossil fuel powers more than two-thirds of the world’s electricity, a significant share of which is derived from coal power plants. Despite coal being an abundant and energy-rich fuel, the major halt to its progress is greenhouse gas emissions. Greenhouse gases are detrimental to the environment. The search for clean fossil fuel leads to the oxy-combustion process. Oxy-fuel combustion produces sequestrable carbon dioxide as exhaust. Pressurization makes carbon capture more accessible and more energy-efficient. Pressurized oxy-combustion cycles can achieve theoretically high thermal efficiencies along with a 90% carbon capture rate. Additionally, the high energy density allows smaller turbomachinery and save …

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 …

Classification Of The Subalgebras Of The Algebra Of All 2 By 2 Matrices, Justin Luis Bernal

Open Access Theses & Dissertations

Classification of the subalgebras of the familiar algebra of all $n\times n$ real matrices over the real numbers can get quite unwieldy as all subalgebras are of dimension ranging from $1$ to $n^2$. Classification of the subalgebras of the algebra of all $2\times 2$ real matrices over the real numbers is an interesting first start.

Since $\2$ is of dimension $4$ then its possible subalgebras are of dimension $1, 2, 3,$ or $4$. The one-dimensional subalgebra and four-dimensional subalgebra need little to no attention. The two-dimensional and three-dimensional subalgebras however turn out to be of significance.

It turns out there …

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 …

Machine Learning Analysis To Characterize Phase Variations In Laser Propagation Through Deep Turbulence, Luis Fernando Rodriguez Sanchez

Open Access Theses & Dissertations

The present Dissertation is focused on the analysis of the atmospheric conditions of a turbulent environmental system and its effects on the diffraction of a laser beam that moves through it. The study is based on the optical communication of two labs placed at the summit of two mountains located in Maui, Hawaii. The emitter system is located at the Mauna Loa mountain and the receiver at the Haleakala. The distance between both mountains is 150 km. The emitter system is at a height of 3.1 km and the receiver at 3.4 km. The maritime environment at the location experiences …

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 …

Positivity-Preserving Segregate-Flux Method For Infiltration Dynamics In Tumor Growth Models, Gilbert Danso Acheampong

Open Access Theses & Dissertations

We study the positivity preserving property and an incompressibility condition in a recently proposed tumor growth model as well as its numerical simulations. In this model, the biological process is described by a free-boundary problem of hyperbolic equations that govern the in-tumor motion of cancer cells and the infiltration of immune cells. Particularly, due to an assumption that cells take constant volume (the incompressibility condition), the tumor growth/shrinkage is closely correlated to the magnitude of infiltration of immune cells into the tumor.

Despite the fact that previous simulation results largely reproduced experimental data, there remain unanswered questions that are crucial …

Finalcache: Eviction Based On Implicit Entry Reachability, Adrian Veliz

Open Access Theses & Dissertations

Software caches for garbage collected systems are unaware which cache entries are referenced by a client program. Lacking this key information, software caches cannot determine the cache’s contribution to the program’s memory footprint. Furthermore, their eviction heuristics must rely on access history as a proxy for usage. Divergence between usage and access history can undermine the intention of eviction thereby resulting in problematic cache behavior.

This dissertation proposes designs for a novel family of “usage-based” software cache informed of entry reachability by the automatic memory management system. Unlike extant software caches, usage-based caches can accurately determine their memory footprint because …

Application Of Non-Seismic Methods To Analyze And Model The Geometry Of The Northern Margin Of The Onion Creek Salt Diapir, Paradox Basin, Utah, Julia Michelle Astromovich

Open Access Theses & Dissertations

The Onion Creek salt diapir lies within the Paradox Basin of Utah where it forms part of a series of salt walls that separate the Paradox Basin into smaller sub-basins. These sub-basins and associated salt diapirs remain key to several oil and gas traps in the region. A series of anomalous tight folds occur on the northern side of the Onion Creek diapir within the Permian Cutler Group Undifferentiated. These folds are thought to be associated with a shallow detachment horizon with three possible origins:1) a weak shale layer within the Cutler Group, 2) a salt shoulder, or 3) a …

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 …

Predicting Stochastic Volatility For Extreme Fluctuations In High Frequency Time Series, Md Al Masum Bhuiyan

Open Access Theses & Dissertations

This work is devoted to the study of modeling high frequency time series including extreme fluctuations. As the high frequency data are collected at extremely fine scales, the fluctuations can capture the dynamics of data that evolve over time. A class of volatility models with time-varying parameters is used to forecast the volatility in a stationary condition at different lags. The modeling of stationary time series with consistent properties facilitates prediction with much certainty.

A large set of high frequency financial returns, closing prices of stock markets, high magnitudes of seismograms generated by the natural earthquakes, and the mining explosions …

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 …

Using Prosody To Spot Location Mentions, Gerardo Cervantes

Open Access Theses & Dissertations

Identifying location mentions in speech is important for many information retrieval and information extraction tasks; here I explore the use of prosody for location spotting. While previous work has explored the use of prosody for spotting named entities, including locations, the specific value of prosody for finding locations in spontaneous speech has not been measured. Using the Switchboard corpus and LSTM modeling I obtain results indicating that prosody is useful in spotting location mentions. Further, I identify specific prosodic

features that tend to mark locations in American English.

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 …

Uranium Series Dating And Geochemistry Of Fault Zone Precipitated Secondary Carbonates: Insights Into Paleo Fluid Sources, Tectonics And Climate In The Rio Grande Rift, Victor Higareda Garcia

Open Access Theses & Dissertations

Fault zones in the shallow crust impact a variety of geological processes including mineral deposition, fluid flow patterns in shallow and deep groundwater aquifers, and most importantly seismic activity. The specific interplays of fault zones, seismicity, and groundwater flows are complex and not well understood despite the importance they have to society. The Rio Grande rift is a region impacted by seismic and volcanic activity that place the first order control on mineral formation and fluid flow patterns. It is also a region that is often disregarded as a seismic hazard due to its inferred low tectonic rates and long …

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 …

Self-Similar Models: How Close The Diffusion Entropy Analysis And The Detrended Fluctuation Analysis Are From Other Models, William Kubin

Open Access Theses & Dissertations

Financial and seismic data, like many other high frequency data are known to exhibit memory effects. In this research, we apply the concepts of L ́evy processes, Diffusion Entropy Analysis (DEA) and the Detrended Fluctuation Analysis (DFA) to examine long-range persistence (long memory) behavior in time series data. L ́evy processes describe long memory effects. In other words, L ́evy process (where the increments are independent and follow the L ́evy distribution) is self-similar. We examine the relationship between the L ́evy parameter (α) characterizing the data and the scaling exponent of DEA (δ) and that of DFA (H) characterizing …

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 …

Spectroscopic Techniques To Characterize And Develop Sensing Methods For Titanium Dioxide Nanoparticles In Water, Reagan Scott Turley

Open Access Theses & Dissertations

Titanium dioxide nanoparticles are being used in ever increasing amounts and applications in many consumer products and industrial processes including water treatment. These nanoparticles have not been shown to be toxic to humans via ingestion, but it is worthwhile to develop a portable and rapid detection method to quantify the concentration of nanoparticles in treated drinking water. Current detection methods include single particle inductively coupled plasma mass spectrometry, inductively coupled plasma optical emission spectrometry, tunneling electron microscopy and scanning electron microscopy. While extremely sensitive, these techniques are expensive and sometimes require extensive sample preparation before analysis. A preliminary study on …

Autonomous Trading Strategies For Dynamic Energy Markets, Moinul Morshed Porag Chowdhury

Open Access Theses & Dissertations

With increasing energy demand and an intermittent supply of renewable energy sources, our current energy grid needs a transformation towards a more robust, reliable energy trading architecture. The smart grid promises this architecture as the future of the present energy market, where traders will use digital technologies to automate the management of power delivery. It will improve many issues of the current energy grid such as sustainable, clean, renewable, reliable and secure energy supply, customer participation in markets, distributed generation, and transparency in energy trading. Using autonomous trading agents, we can bridge several dynamic energy markets and ensure an efficient …

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 …

Applications Of Ornstein-Uhlenbeck Type Stochastic Differential Equations, Osei Kofi Tweneboah

Open Access Theses & Dissertations

In this Dissertation, we show with plausible arguments that the Stochastic Differential Equations (SDEs) arising on the superposition and coupling system of independent Ornstein-Uhlenbeck process is a new method available in modern literature that takes the properties and behavior of the data into consideration when performing the statistical analysis of the time series.

The time series to be analyzed is thought of as a source of fluctuations, and thus we need a model that takes this behavior into consideration when performing such analysis. Most of the standard methods fail to take into account the physical behavior of the time series, …

Photovoltage Enhancement For Stable Perovskite Solar Cells With A Temperature-Controlled Grain Growth Technique, Luis Eduardo Valerio

Open Access Theses & Dissertations

By performing strong characterizations methods, one can begin to fully understand the chemistry and composition behind a great performing perovskite solar cell. Understanding how the interaction between layers inside a solar cell is driven by the temperature and overall environment is a key element to improve the fabrication process and overall efficiency of such cells. This Thesis will present a study of the hybrid organic-inorganic, mixed-cation, mixed-halide, temperature and thickness-controlled perovskite solar cell. A constant power conversion efficiency (PCE) ranging between 15-17% and an open circuit voltage V¬oc above 1.05 V for a wide-band gap perovskite cell is presented.

Laplacian Spectra Of Kneser-Like Bipartite Graphs, Cesar Iram Vazquez

Open Access Theses & Dissertations

Given a,b ∈N such that a > b we define a Kneser-like bipartite graph G(a,b), whose two bipartite sets of vertices represent the a-subsets and b-subsets of S = {1,...,a + b + 1}, and whose edges are pairs of vertices X and Y such that X ∩Y = ∅. We prove that the eigenvalues of the Laplacian matrix of graphs G(a,1) are all nonnegative integers. In fact, we describe these eigenvalues, and their respective multiplicities.

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 …

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 …