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University of Texas Rio Grande Valley

Theses and Dissertations - UTB/UTPA

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Full-Text Articles in Physical Sciences and Mathematics

On Various Solutions To A (2+1) Dimensional General Camassa-Holm Equation, Eric J. Tovar Aug 2015

On Various Solutions To A (2+1) Dimensional General Camassa-Holm Equation, Eric J. Tovar

Theses and Dissertations - UTB/UTPA

We study a (2+1)-dimensional generalized Camassa-Holm (2dgCH) equation with both quadratic and cubic nonlinearity. We derive a peaked soliton (peakon) solution and multi-peakon solutions. In particular, the two-peakon dynamical system is explicitly presented and their collisions are investigated in detail. We also find weak kink and kink-peakon interactional solutions. Furthermore, we study all possible smooth one-soliton solutions for the system.


Zeros Of Cubic Eisenstein Series, Sahak D. Sandragorsian Aug 2015

Zeros Of Cubic Eisenstein Series, Sahak D. Sandragorsian

Theses and Dissertations - UTB/UTPA

This thesis provides a detailed exposition and extension of the work of F. K. C. Rankin and Swinnerton-Dyer on the location of the zeros of Eisenstein series for SL(2,Z). Exact values of the zeros in special cases will be given in terms of modular functions. Analogous new results on zeros of cubic Eisenstein series will be presented.


Financial Market And Pricing Of Emerging Financial Derivatives: A Mathematical Approach, Haicheng Gu Aug 2015

Financial Market And Pricing Of Emerging Financial Derivatives: A Mathematical Approach, Haicheng Gu

Theses and Dissertations - UTB/UTPA

Pricing has been one of the key problems of financial market theory. With the development of the modern financial market, various new financial derivatives have been created and need to be priced properly. In the thesis, we are going to use several mathematical tools to investigate the essential structure of the financial market and models for financial derivatives.


Higgs Boson Equation In De Sitter Spacetime: Numerical Investigation Of Bubbles Using Gpus, Jacob N. Banda Aug 2015

Higgs Boson Equation In De Sitter Spacetime: Numerical Investigation Of Bubbles Using Gpus, Jacob N. Banda

Theses and Dissertations - UTB/UTPA

The Higgs field, along with its corresponding boson, represent a milestone for modern day particle physics. In this work we consider the Higgs boson equation in de Sitter spacetime. Previous work by K. Yagdjian [23] has formulated sufficient conditions for the existence of the zeros of global solutions in the interior of their supports. In searching for such solutions, we turn to heterogeneous parallel computing, which allows for faster computation through graphical processing units (GPUs). Armed with general-purpose computation on graphics hardware (GPGPU) techniques and explicit numerical schemes, we approximate solutions of the equation for the Higgs boson along with …


Alternative Restoration Treatments To Maximize Growth And Survival Of Tamaulipan Thornscrub Species During Seeding Establishment, Jennifer Lynn Vela Jul 2015

Alternative Restoration Treatments To Maximize Growth And Survival Of Tamaulipan Thornscrub Species During Seeding Establishment, Jennifer Lynn Vela

Theses and Dissertations - UTB/UTPA

Anthropogenic activities that destroy, degrade, or fragment terrestrial ecosystems have long-lasting detrimental impacts on ecosystem function, services, and biodiversity. The Tamaulipan thornscrub ecoregion of south Texas and northeastern Mexico has sustained considerable loss, degradation, and fragmentation due land conversion for agriculture, urbanization, and introduction of invasive flora and fauna. In an attempt to restore habitat for endangered and migratory animals, United States Fish and Wildlife Service has undertaken a large-scale thornscrub revegetation effort in south Texas. The goal of this study was to develop effective restoration techniques to promote growth and survival of Tamaulipan thornscrub species during seedling establishment. Beginning …


A Study On Hispanic College Students' Mathematics Anxiety, Study Habits, And Academic Performances On Mathematics, Luis M. Fernandez Jul 2015

A Study On Hispanic College Students' Mathematics Anxiety, Study Habits, And Academic Performances On Mathematics, Luis M. Fernandez

Theses and Dissertations - UTB/UTPA

Mathematics anxiety has been described as a feeling of apprehension, fear, tension, and discomfort when confronted with mathematics. Mathematics anxiety has also been shown to interfere with mathematics performance; therefore, for our research we investigated what portions of individuals seem to suffer higher levels of mathematics anxiety and to what extent they are affected by it. We also investigated the study habits of the students and how these affect their mathematics anxiety levels and overall mathematics performance. Our data was obtained from Hispanic undergraduate students (n=405) who took Elementary Algebra (Math 1300), Intermediate Algebra (Math 1334), College Algebra (Math 1340) …


Evaluation Of Control Strategies For The Spread Of Citrus Greening, Vicente Valle Martinez Jul 2015

Evaluation Of Control Strategies For The Spread Of Citrus Greening, Vicente Valle Martinez

Theses and Dissertations - UTB/UTPA

Huanglongbing, also known as citrus greening, is a vector-based disease in citrus (with no cure known to date) that has drastically affected the citrus production in Florida in less than a decade and has been recently detected in Texas and California. In this paper, an epidemic model of the spatial spread of the disease is implemented among commercial and residential groves by taking into consideration the diffusion patterns of the psyllid vectors. A system of differential equations resembling one for malaria infection in humans is derived to evaluate different control methods such as quarantine, treatment, removal, foliar treatment, and pest …


Approximate Analysis Solution Of Burgers-Kdv Equation, Hani Aldirawi Jul 2015

Approximate Analysis Solution Of Burgers-Kdv Equation, Hani Aldirawi

Theses and Dissertations - UTB/UTPA

In this thesis, we study the Two-Dimensional Burgers-Kortewege-de Vries(2D-BKdV) equation by analyzing the equivalent Abel equation, which indicates that under some particular conditions, the 2D-BKdV equation has a unique bounded traveling wave solution. By using the theorem of contractive mapping, a traveling wave solution to the 2D-BKdV equation is expressed explicitly.


Oxidation Of Dibenzothiophene To Dibenzothiophene-Sulfone Using Molybdenum (Vi) Oxide, Tungsten (Vi) Oxide, And Ratios Of Molybdenum (Vi) Oxide And Tungsten (Vi) Oxide At Atomspheric Pressure, Sean M. Pelfrey May 2015

Oxidation Of Dibenzothiophene To Dibenzothiophene-Sulfone Using Molybdenum (Vi) Oxide, Tungsten (Vi) Oxide, And Ratios Of Molybdenum (Vi) Oxide And Tungsten (Vi) Oxide At Atomspheric Pressure, Sean M. Pelfrey

Theses and Dissertations - UTB/UTPA

This is a study of the catalytic oxidation of dibenzothiophene to dibenzothiophene sulfone using molybdenum (VI) oxide, tungsten (VI) oxide, and mixtures of molybdenum (VI) oxide and tungsten (VI) oxide at atmospheric pressure. The oxidative desulfurization reaction is studied with respect to the kinetics and thermodynamics of the process. Five catalysts were synthesized using a precipitation reaction. The five catalysts were 100% MoO3, 75/25% MoO3/WO3, 50/50% MoO3/WO3, 25/75% MoO3/WO3, and 100% WO3. Each catalyst was calcinated at three different temperatures 250oC, 500oC, 750oC and characterized using X-Ray Diffraction. Reactions of DBT-catalyst were held, under reflux, at temperatures from 140 oC …


Use Of A Simulated Directional Social Network To Compare Measures Of User Influence, Jose G. Villarreal Jr. May 2015

Use Of A Simulated Directional Social Network To Compare Measures Of User Influence, Jose G. Villarreal Jr.

Theses and Dissertations - UTB/UTPA

This paper proposes a new method for measuring user influence in directional social networks, derived from the works of Reilly et al. and Cha et al. The method being proposed in this paper considers an element from each of the two works. The first is the ratio of ‘messages forwarded’ over ‘messages posted’. The second element is the size of the audience. The second part of this study entails modeling and simulating an online social network. Using a data sample from the Twitter network to implement the simulation, it is going to allow us to compare the methods that are …


Removal Of Cobalt And Nickel From Water Using Mno2 And Mn3o4 Nanomaterials, Maria Dolores Pacheco May 2015

Removal Of Cobalt And Nickel From Water Using Mno2 And Mn3o4 Nanomaterials, Maria Dolores Pacheco

Theses and Dissertations - UTB/UTPA

Nanomaterials MnO2 and Mn3O4 were synthesized using a titration/precipitation technique and characterized with powder XRD. A pH assay determined the optimum binding for cobalt and nickel occurred at pH 5 for both nanomaterials. A time dependency study determined that cobalt and nickel required more time with MnO2 for maximum adsorption than Mn3O4. The binding capacity study showed cobalt and nickel have good binding capacity with both nanomaterials. Interfering ion assay in the presence of Na+ , Ca2+ and Mg2+ showed minimal difference in the adsorption of cobalt and nickel to MnO2 or Mn3O4. Cobalt and nickel showed a reduction in …


Effect Of Crimping, Multilayering, And Twisting On Polymer Fibers For Acl Replacement, Mariana Ocampo May 2015

Effect Of Crimping, Multilayering, And Twisting On Polymer Fibers For Acl Replacement, Mariana Ocampo

Theses and Dissertations - UTB/UTPA

The Anterior Cruciate Ligament (ACL) is the most common knee injury in the United States; roughly 150,000 ACL surgeries are performed annually. The ACL lacks self-healing properties due to its location inside the knee’s intra – articular environment (IA). Treatments for ACL ruptures involve the use of autogenous grafts or allografts. More suitable treatments can be found in new bio engineered tissue scaffolds, composed of natural and synthetic polymers. The polymers provide stronger mechanical properties and the ability to promote cell adhesion. It is believed that mimicking the crimping pattern of human ligaments will enhance polymer properties. Four polymers were …


Complex Short Pulse Equation And Its Integrable Discretizations, Raul M. Guajardo May 2015

Complex Short Pulse Equation And Its Integrable Discretizations, Raul M. Guajardo

Theses and Dissertations - UTB/UTPA

In this thesis, we are mainly concerned with the complex short pulse (CSP) equation which was proposed in Physica D [1]. We present the Lax pair of the CSP equation and show the compatibility condition gives the CSP equation. Therefore, the integrability is confirmed. Then, a set of bilinear equations is proposed which yields the CSP equation through the hodograph transformation. Based on the bilinear form, general N-soliton solution is given in determinant form. Regarding two-soliton solution, a bound state can be formed if the velocities of two solitons are equal. Furthermore, a semi- and fully discrete analogues are constructed …


Efficient Query Processing Over Uncertain Road Networks, Bamikole A. Ogundele May 2015

Efficient Query Processing Over Uncertain Road Networks, Bamikole A. Ogundele

Theses and Dissertations - UTB/UTPA

One of the fundamental problems on spatial road networks has been the shortest traveling time query, with applications such as location-based services (LBS) and trip planning. Algorithms have been made for the shortest time queries in deterministic road networks, in which vertices and edges are known with certainty. Emerging technologies are available and make it easier to acquire information about the traffic. In this paper, we consider uncertain road networks, in which speeds of vehicles are imprecise and probabilistic. We will focus on one important query type, continuous probabilistic shortest traveling time query (CPSTTQ), which retrieves sets of objects that …


Two Dimensional Mathematical Model Of Fluid Flow In A Growing Solid Tumor, Adriana Gracia Dec 2014

Two Dimensional Mathematical Model Of Fluid Flow In A Growing Solid Tumor, Adriana Gracia

Theses and Dissertations - UTB/UTPA

We investigate the problem of steady and unsteady fluid flow in a growing solid tumor. We develop a mathematical model for the two dimensional fluid flow in a spherical tumor where the spatial variations of the interstitial velocity, interstitial pressure and the drug concentration within the tumor are, in general, with respect to the radial distance and the latitudinal angle in the spherical coordinates. The expressions for radial and latitudinal variations of the interstitial velocity, interstitial pressure, and the two investigated drug concentrations were determined analytically. We calculated these quantities in the tumor as well as in a corresponding normal …


Gps-Miv: The General Purpose System For Multi-Display Interactive Visualization, Irving A. Gonzalez Garza Dec 2014

Gps-Miv: The General Purpose System For Multi-Display Interactive Visualization, Irving A. Gonzalez Garza

Theses and Dissertations - UTB/UTPA

The new age of information has created opportunities for inventions like the internet. These inventions allow us access to tremendous quantities of data. But, with the increase in information there is need to make sense of such vast quantities of information by manipulating that information to reveal hidden patterns to aid in making sense of it. Data visualization systems provide the tools to reveal patterns and filter information, aiding the processes of insight and decision making. The purpose of this thesis is to develop and test a data visualization system, The General Purpose System for Multi-display Interactive Visualization (GPS-MIV). GPS-MIV …


Detection Of Gravitational Wave Signals From Ns-Ns Inspirals In Presence Of Non-Stationary Noise, Wenhui Wang Dec 2014

Detection Of Gravitational Wave Signals From Ns-Ns Inspirals In Presence Of Non-Stationary Noise, Wenhui Wang

Theses and Dissertations - UTB/UTPA

Gravitational Wave (GW) detection is an important and inspiring project. Once detected, it will open a new window to understand the universe. The laser interferometer GW detectors, specially LIGO, is the most sensitive detectors at the moment, which can detect GW signal as weak as 10−21. Chirp signal generated by neutron star binaries is a well modeled waveform. One goal of LIGO is to study chirp signal detection. In this field, matched filtering is a widely used method. But since LIGO noise is non-stationary, which will weaken the efficiency of general matched filtering. In this work, a modified matched filtering …


Sign Me Up! Determining Motivation For High School Chemistry Students Enrolling In A Second Year Chemistry Course, Nilda N. Camarena Dec 2014

Sign Me Up! Determining Motivation For High School Chemistry Students Enrolling In A Second Year Chemistry Course, Nilda N. Camarena

Theses and Dissertations - UTB/UTPA

A sample of 108 Pre-AP Chemistry students in Texas participated in a study to determine motivational factors for enrolling in AP Chemistry and University Chemistry. The factors measured were academic attitude, perceptions of chemistry, confidence level in chemistry, and expectations/experiences in the chemistry class. Students completed two questionnaires, one at the beginning of the year and one at the end. Four high school campuses from two school districts in Texas participated. Two campuses were traditional high schools and two were smaller magnet schools. The results from this study are able to confirm that there are definite correlations between academic attitudes, …


Pulsar J0453+1559, The 10th Double Neutron Star System In The Universe, Jose Guadalupe Martinez Nov 2014

Pulsar J0453+1559, The 10th Double Neutron Star System In The Universe, Jose Guadalupe Martinez

Theses and Dissertations - UTB/UTPA

Pulsars are neutron stars that spin rapidly, are highly magnetized, and they emit beams of electromagnetic radiation like a lighthouse out in space. These beams of radiation are only observed when the beams face towards Earth and can be measured by a radio telescope. Pulsar studies have an abundance of scientific implementations in solid state physics, general relativity, galactic astronomy, astronomy, planetary physics and have even opened windows in cosmology. This thesis reports the results of a study of pulsar (PSR) J0453+1559, a new binary pulsar discovered in the Arecibo All-Sky 327 MegaHertz Drift Pulsar Survey. The recorded observations of …


An Empirical Study Of Some Branching Processes With Upper Barrier, Alejandro Aguilar Aug 2014

An Empirical Study Of Some Branching Processes With Upper Barrier, Alejandro Aguilar

Theses and Dissertations - UTB/UTPA

We consider discrete time branching processes with a reflecting upper barrier. The processes differ in their offspring distributions being either binary splitting or binomial one. Two important factors for the behavior of the processes characteristics are studied as follows: time to extinction and total progeny up to the n th generation. More specifically, we investigate the distribution and expected value of the time to extinction as well as the probability mass functions of the total progeny. The tools used are basic results for a finite state Markov chain.


Dynamics For The Compound Burgers-Kdv Equation, Xiangqian Zheng Aug 2014

Dynamics For The Compound Burgers-Kdv Equation, Xiangqian Zheng

Theses and Dissertations - UTB/UTPA

In this thesis, we study the Two-Dimensional Burgers-Korteweg-de Vries (2D-BKdV) equation and Two-Dimensional Compound Burgers-Korteweg-de Vries (2D-Compound BKdV) by analyzing the first integral equation, which indicates that under some particular conditions, the 2D-BKdV equation and 2D-Compound BKdV have exact traveling wave solutions. By using the elliptic integral and some transformations, traveling wave solution to the 2D-BKdV equation and 2DCompound BKdV are expressed explicitly.


Prediction Of Time-To-Graduation For Stem Hispanic Undergraduate Students, Gejun Zhu Aug 2014

Prediction Of Time-To-Graduation For Stem Hispanic Undergraduate Students, Gejun Zhu

Theses and Dissertations - UTB/UTPA

In this thesis, we study the time-to-graduation problem for STEM Hispanic undergraduate students. The response, time-to-graduation, was treated in two different ways: as a binary variable with graduated (by the 6th year) and not-graduated values, and as an ordinal variable with values year-4, year-5, year-6, and not-graduate. Mathematics education plays critical role in students’ timely graduation, especially for STEM students. We used students records data obtained from The University of Texas-Pan American to illustrate how mathematics background factors (including SAT math score, ACT math score, TASP math score) and mathematics performance variables (including mathematics GPA, number of dropped mathematics courses, …


Efficient Evaluation Of Sparql Property Path Queries Over Prov-Dm Provenance Graphs In An Rdbms, Rodolfo E. Roman Velasco Aug 2014

Efficient Evaluation Of Sparql Property Path Queries Over Prov-Dm Provenance Graphs In An Rdbms, Rodolfo E. Roman Velasco

Theses and Dissertations - UTB/UTPA

Millions of useful resources on the Web are enhanced with machine-processable annotations using W3C Resource Description Framework (RDF). It is crucial to design efficient data management techniques to support querying of existing RDF datasets using standard SPARQL queries. To address this challenge, we use a Relational Database Management System (RDBMS) for efficient and scalable storage and querying backend for RDF data. Our solution requires designing novel algorithms for translating SPARQL queries into equivalent SQL queries, such that the latter can be efficiently executed in an RDBMS. The focus of this work is on the translation of SPARQL property paths queries. …


Balanced Modular Parameterizations, Esteban J. Melendez Aug 2014

Balanced Modular Parameterizations, Esteban J. Melendez

Theses and Dissertations - UTB/UTPA

In this thesis, we show that Classical representations for certain modular forms have symmetric form. These symmetric formulations are interpreted in terms of more general balanced homogeneous polynomial representations resulting from a permutative action of Hecke congruence subgroups on quotients of theta functions. For prime levels between 5 and 19, sets of permuted theta quotients are constructed that generate the corresponding vector spaces of modular forms of weight one.


Radar Image Processing And Its Applications Based On Convolution Back Projection, Qitong Li Jul 2014

Radar Image Processing And Its Applications Based On Convolution Back Projection, Qitong Li

Theses and Dissertations - UTB/UTPA

A general synthetic aperture radar (SAR) signal model is derived from the Maxwell’s equations, and a SAR image processing algorithm called Convolution Back Projection (CBP) will be introduced in this thesis, which can be applied to data gathered by a Synthetic Aperture Radar (SAR) system to produce high resolution images. The purpose of this thesis is starting from Maxwell’s equations to study the CBP algorithm as it is applied to SAR image processing. Two different image simulation results will be provided by this method.


Using The Differential Fay Identities For Ribbon Graph Enumeration, Indalecio Soto Jr. Jul 2014

Using The Differential Fay Identities For Ribbon Graph Enumeration, Indalecio Soto Jr.

Theses and Dissertations - UTB/UTPA

In this paper we are exploiting connections between the Differential Fay Identities and the partition function of Gaussian Unitary Random Matrices. The partition function has a asymptotic expression whose terms give the generating function for the enumeration of ribbon graphs partitioned by genus. These ribbon graphs (k; j), of k vertices of degree j have an orientation in genus g where the edges are represented as ribbons. Furthermore, we will develop connections between the Differential Fay Identities and introduce several theorems between the hierarchies of the identities. Lastly, we will briefly explore the first Differential Fay Identity that contains the …


Studies Of A Mathematical Model For Generating Rhythmic Behavior With A Simple Brain, Juan C. Morales Jul 2014

Studies Of A Mathematical Model For Generating Rhythmic Behavior With A Simple Brain, Juan C. Morales

Theses and Dissertations - UTB/UTPA

The rhythmic behavior of feeding in the pond snail, Lymnaea stagnalis can be described computationally by a model describing its central pattern generator network (CPG). The model includes coupled Hodgkin-Huxley type nonlinear ordinary differential equations describing four neurons connected by both inhibitory and excitatory synapses. We studied the system’s dependence on current parameters to generate periodic behavior. We also considered the effect of eliminating specific connections from the network. In addition, experiments on the biological system were used to motivate application of the model in Parkinson’s disease.


The Born Approximation, Multiple Scattering, And The Butterfly Algorithm, Alejandro F. Martinez Jul 2014

The Born Approximation, Multiple Scattering, And The Butterfly Algorithm, Alejandro F. Martinez

Theses and Dissertations - UTB/UTPA

Radar works by focusing a beam of light and seeing how long it takes to reflect. To see a large region the beam is pointed in different directions. The focus of the beam depends on the size of the antenna (called an aperture). Synthetic aperture radar (SAR) works by moving the antenna through some region of space. A fundamental assumption in SAR is that waves only bounce once. Several imaging algorithms have been designed using that assumption. The scattering process can be described by iterations of a badly behaving integral. Recently a method for efficiently evaluating these types of integrals …


The Generation Model Of Internal Waves In A Forced Rotation-Modified Ocean, Daqi Xin Jul 2014

The Generation Model Of Internal Waves In A Forced Rotation-Modified Ocean, Daqi Xin

Theses and Dissertations - UTB/UTPA

A two-layer model which contains the forcing term due to the barotropic tides which flow over a comparatively large bottom topography in the ocean was derived previously. The model can be used to describe the generation of nonlinear dispersive internal tides and the following disintegration into internal waves. We studied the influence of Coriolis effect. A numerical simulation shows that the Earth’s rotation affects the generation of the internal waves since it hampers the disintegration of internal tides into internal waves.


Isolation And Characterization Of Polychlorinated Biphenyl (Pcb) Degrading Bacteria Isolated From A Pcb Contaminated Reservoir In Donna, Tx, Sergio Cepeda Jul 2014

Isolation And Characterization Of Polychlorinated Biphenyl (Pcb) Degrading Bacteria Isolated From A Pcb Contaminated Reservoir In Donna, Tx, Sergio Cepeda

Theses and Dissertations - UTB/UTPA

The Donna Irrigation System (DIS) located in Donna, Hidalgo County, TX, was confirmed to be contaminated with polychlorinated biphenyls (PCBs) in 1993 and remediation of the site will be attempted in the future. The need to isolate novel PCB degrading bacteria for bioremediation has been an active area of research in recent decades; thus, it was hypothesized that a variety of microorganisms able to degrade PCBs could be isolated from sediments taken from the DIS. Two genes of the PCB degradation pathway, bphA1 and bphC, were detected in 43 bacterial isolates grown from DIS sediments using molecular and culture-based methodology, …