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University of Texas at El Paso

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Articles 2311 - 2340 of 2636

Full-Text Articles in Physical Sciences and Mathematics

Ozone Studies In The Paso Del Norte Region, Fernando Becerra-Davila Jan 2012

Ozone Studies In The Paso Del Norte Region, Fernando Becerra-Davila

Open Access Theses & Dissertations

The Paso del Norte region forms the largest contiguous bi-national conglomerate on the US-Mexico border. With a combined population of around 2 million inhabitants, the Paso del Norte region is isolated, more than 500 km away from the nearest urban area of comparable size, thus making it an ideal location for air quality studies of an isolated urban environment.

The meteorological conditions leading to a high ozone episode in this region, such as the historical ozone episode of June 2006, are analyzed. It is well known that stagnation and minimal winds, high temperatures, and pressure ridges over the region are …


Characterization Of Thrust Faults On The Moon Using Fault Dynamics And 3d Visualizations, Jaclyn Danielle Clark Jan 2012

Characterization Of Thrust Faults On The Moon Using Fault Dynamics And 3d Visualizations, Jaclyn Danielle Clark

Open Access Theses & Dissertations

Many small, lobate scarps, interpreted to be the surface traces of thrust faults, have been found all over Earth's moon by previous researchers. Fault dynamical calculations, assuming an initially completely molten Moon, have shown that these scarps can form due to compressional stresses that accumulate over time as the result of large-scale contraction of the Moon as it cooled. With high-resolution images from the Lunar Reconnaissance Orbiter Camera (LROC), previously undetected lobate scarps can be found globally and viewed at high resolution. By investigating these fault scarps, we can determine better constraints on the amount of crustal shortening and improve …


Lifting And Wavelets: A Factorization Method, Adrian Delgado Jan 2012

Lifting And Wavelets: A Factorization Method, Adrian Delgado

Open Access Theses & Dissertations

We begin with the concept of a discrete wavelet transformation. We begin with a scaling function satisfying a certain number of properties to be able to implement the wavelet transformation. We will then require translates of the scaling function to obey the same set of properties and this set will form what is called a Multiresolution Analysis. We then switch the ideas to the Fourier transform domain were we get equivalent results. However, instead of choosing a scaling function with coefficients to satisfy a set of properties, we will work backwards and construct a scaling function based on having a …


An Assessment Of Land Cover Change At The Indio Mountains Research Station, Rebecca Anne Escamilla Jan 2012

An Assessment Of Land Cover Change At The Indio Mountains Research Station, Rebecca Anne Escamilla

Open Access Theses & Dissertations

Land cover change is a significant contributor to environmental change on a global scale. In the arid regions of the southwest US, shrub encroachment is one of the most important forms of land cover change. Many factors contribute to shrub encroachment, which can impact structure and function. In the Chihuahuan Desert, mountain ecosystems are known as biodiversity hotspots and are especially susceptible to environmental change making them useful indicators of global change. The overarching goal of this dissertation is to improve i) understanding of land cover change in a Chihuahuan Desert mountain landscape, and ii) how knowledge of land cover …


Constrained Optimal Control For A Multi-Group Discrete Time Influenza Model, Paula Andrea Gonzalez Parra Jan 2012

Constrained Optimal Control For A Multi-Group Discrete Time Influenza Model, Paula Andrea Gonzalez Parra

Open Access Theses & Dissertations

During the last decades, mathematical epidemiological models have been used to understand the dynamics of infectious diseases and guide public health policy. In particular, several continuous models have been considered to study single in uenza outbreaks and the impact of dierent control policies. In this dissertation, a discrete time model is introduced in order to study optimal control strategies for in uenza transmission; since epidemiological data is collected on discrete units of time, a discrete formulation is more ecient. From a mathematical point of view, continuous time model are easier to analyze, however, the numerical solution of discrete-time models is …


Dna-Carbon Nanotubes Composites As Gene Sensors, Hugo Alarcon Jan 2012

Dna-Carbon Nanotubes Composites As Gene Sensors, Hugo Alarcon

Open Access Theses & Dissertations

Carbon fullerenes are unusually structured molecules with robust mechanical and electronic properties. Their versatility is astounding; envisioned applications range from field emission displays to impregnated metal composites, battery storage media, and nanoelectronic devices. The combination of simple constituency, diverse behavior, and ease of fabrication makes these materials a cornerstone topic in current research.

This work describes experiments conducted on nanotubes using Dynamic light scattering (DLS). The aim is to detect cluster formation from individual carbon nanotube (CNT) solutions using a nanotube DNA binding sequence and a secondary recognizing complementary DNA sequence to bind neighboring CNTs. Dynamic Light Scattering is an …


Applied Evaluation For Life Cycle Impact Assessment Methodologies In The Medical Industry, Aaron Arturo Martinez Jan 2012

Applied Evaluation For Life Cycle Impact Assessment Methodologies In The Medical Industry, Aaron Arturo Martinez

Open Access Theses & Dissertations

In the present thesis, a comparative evaluation using different Life Cycle Impact Assessment (LCIA) Methodologies is presented; the study is performed considering the LCIA of ChloraPrep 26 mL Hi-Lite Applicator produced in a local manufacturing company. The focus of the research is to analyze the different aspects such as: characterization, classification and normalization; that each of the LCIA methodologies evaluate and are used for a policy regulations and sustainable development. The evaluation will determine which aspects could be used depending on the Life Cycle Inventory, since limited information is available if not using softwares, such as SimaPro or GaBi, to …


Upgrades To Nrlmol Code, Luis Basurto Jan 2012

Upgrades To Nrlmol Code, Luis Basurto

Open Access Theses & Dissertations

This project consists of performing upgrades to the NRLMOL code in order to enhance its performance by increasing its flexibility by utilizing dynamically allocated arrays and enable the simulating of larger systems than it's currently capable of executing, as well as exploring simultaneous concurrent executions of the program through the use of an already existing MPI environment.


Development Of New Mathematical Methods For Post-Pareto Optimality, Victor Manuel Carrillo Jan 2012

Development Of New Mathematical Methods For Post-Pareto Optimality, Victor Manuel Carrillo

Open Access Theses & Dissertations

Many real-world applications of multi-objective optimization involve a large number of objectives. A multi-objective optimization task involving multiple conflicting objectives ideally demands finding a multi-dimensional Pareto-optimal front. Although the classical methods have dealt with finding one preferred solution with the help of a decision-maker, evolutionary multi-objective optimization (EMO) methods have been attempted to find a representative set of solutions in the Pareto-optimal front. Multiple objective evolutionary algorithms (MOEAs), which are biologically-inspired optimization methods, have become popular approaches to solve problems with multiple objective functions. With the use of MOEAs, multiple objective optimization becomes a two-part problem. First, the multiple objective …


Market Reactions To Publicly Announced Privacy And Security Breaches Suffered By Companies Listed On The United States Stock Exchanges: A Comparative Empirical Investigation, Adolfo S. Coronado Jan 2012

Market Reactions To Publicly Announced Privacy And Security Breaches Suffered By Companies Listed On The United States Stock Exchanges: A Comparative Empirical Investigation, Adolfo S. Coronado

Open Access Theses & Dissertations

Using a sample of security and privacy breaches the present research examines the comparative announcement impact between the two types of events. The first part of the dissertation analyzes the impact of publicly announced security and privacy breaches on abnormal stock returns, the change in firm risk, and abnormal trading volume are measured. The second part of the dissertation analyzes differential impact between security and privacy breaches on abnormal stock returns, the change in firm risk, and abnormal trading volume are measured.

Using a sample of 114 security (65) and privacy (49) breaches on average, security breaches resulted in more …


Metal Catalyzed Activation Of E-H Bonds, E = Si, Ge, Sn, Renzo Nelson Arias Ugarte Jan 2012

Metal Catalyzed Activation Of E-H Bonds, E = Si, Ge, Sn, Renzo Nelson Arias Ugarte

Open Access Theses & Dissertations

The present project covers the use of complexes of the type: (C5H5)M(CO)nLMe, (M = Fe, n = 1; L = CO, Ph3P; M = Mo, n = 2; L = CO, Ph3P); M(CO)6, (M = Cr, Mo, W) and M(CO)5NMe3 as catalysts for the activation of E-H bonds (E = Si, Ge and Sn). The work is divided in three sections; the first two involves dehydrogenation and the last one amide reduction.


Analytical And Numerical Solution To The Partial Differential Equation Arising In Financial Modeling, Pavel Bezdek Jan 2012

Analytical And Numerical Solution To The Partial Differential Equation Arising In Financial Modeling, Pavel Bezdek

Open Access Theses & Dissertations

In this work we will present a self-contained introduction to the option pricing problem. We will introduce some basic ideas from the probability theory and stochastic differential equations. Later we will move to the partial differential equations since the option pricing problem arising in financial mathematics when asset is driven by a stochastic volatility process and assumed presence of transaction cost leads to solving non-linear partial dif- ferential equation. We will also present the complete process from deriving the desired partial differential equation to the proof of existence of a solution and also the numerical simulations. Using techniques form stochastic …


Three-Dimensional Deformation And Stress Models Of The Death Valley And San Andreas Fault Zones, Cecilia Del Pardo Jan 2012

Three-Dimensional Deformation And Stress Models Of The Death Valley And San Andreas Fault Zones, Cecilia Del Pardo

Open Access Theses & Dissertations

Crustal deformation studies of tectonic motions have been the topic of many scientific investigations, as they can provide critical information about how tectonic structures shape and deform the Earth. While crustal deformation studies using observational data alone can provide a great deal of information about how the Earth is presently deforming, it is standard practice to implement mathematical and physics-based models to investigate the underlying causes of deformation in the crust. These models, constrained by geological, geodetic and seismic data, have successfully contributed key constraints of ongoing deformation processes and have provided predictions of past and future tectonic behavior of …


Comparative Investigation Of Cognitive And Pragmatic Thinking Modes Linear Algebra, Enayatollah Kalantarian Jan 2012

Comparative Investigation Of Cognitive And Pragmatic Thinking Modes Linear Algebra, Enayatollah Kalantarian

Open Access Theses & Dissertations

The analysis focused on the presence of different thinking modes found on the interview and responses to questions related to linear independence, span, and spanning sets of two students taking their first linear algebra course at the college level. The findings provide insight on how first year linear algebra students move from one thinking mode to another. The focal point of this research was to document and discern the similarities and differences between student thinking modes displayed on their interviews and class assignments.

Based on the analysis, it was concluded that the level of exposure of the two students to …


San Miguel Volcanic Seismicity And Structure In Central America: Insight Into The Physical Processes Of Volcanoes, Ezer Patlan Jan 2012

San Miguel Volcanic Seismicity And Structure In Central America: Insight Into The Physical Processes Of Volcanoes, Ezer Patlan

Open Access Theses & Dissertations

San Miguel volcano lies near the city of San Miguel, El Salvador (13.43°N, 88.26°W). An active stratovolcano, it presents a significant natural hazard for the city of San Miguel. In general, the internal state and activity of volcanoes like San Miguel remains an important component to understanding volcanic hazards. The main technology for addressing volcanic hazards and associated processes is through the analysis of data collected from the deployment of seismic sensors that record ground motion. Six seismic stations were deployed by UTEP around San Miguel volcano during the 2007-2008 the time period to define internal structure or magmatic plumbing …


Vertical Deformation Along The San Andreas Fault, Garrett Thornton Jan 2012

Vertical Deformation Along The San Andreas Fault, Garrett Thornton

Open Access Theses & Dissertations

There have been numerous M 6+ earthquakes along the San Andreas Fault System (SAFS) (Schwartz et al., 1984) (Figure. 1.1) in the historical past. These rupture events have created millions of dollars worth of damage, and have been responsible for multiple lives lost. An improved understanding of the motions and crustal characteristics along the SAFS can lead to better hazard mitigation (Bakun et al., 2005). Horizontal crustal motions of the SAFS have been widely studied and applied to seismic hazard models (WGCEP, 2007), however vertical motions are not often utilized due to their complicated origin and sometimes large uncertainties. This …


Assessing Impulsive-Analytic Disposition: The Likelihood-To-Act Survey And Other Instruments, Kien H. Lim, Amy E. Wagler Jan 2012

Assessing Impulsive-Analytic Disposition: The Likelihood-To-Act Survey And Other Instruments, Kien H. Lim, Amy E. Wagler

Departmental Papers (Math)

The likelihood-to-act (LtA) survey is a 32-item instrument that measures impulsive and analytic dispositions in solving math problems. In this research report, we compare it to other instruments related to the impulsive-analytic construct such as Frederick’s Cognitive Reflection Test (CRT) and the Barratt Impulsive Scale in terms of mean scores, Cronbach alpha values, and correlation values. Both LtA-Impulsive and LtA-Analytic subscales have acceptable reliabilities of 0.79 and 0.83 respectively. The LtA-Analytic and LtA-Difference (analytic-impulsive difference) correlated well with other the Need for Cognition subscale and CRT scores. The correlations involving LtA-Impulsive subscale were unexpected and call for further investigation.


Impulsive-Analytic Disposition In Mathematical Problem Solving: A Survey And A Mathematics Test, Kien H. Lim, Amy E. Wagler Jan 2012

Impulsive-Analytic Disposition In Mathematical Problem Solving: A Survey And A Mathematics Test, Kien H. Lim, Amy E. Wagler

Departmental Papers (Math)

The Likelihood-to-Act (LtA) survey and a mathematics test were used in this study to assess students’ impulsive-analytic disposition in the context of mathematical problem solving. The results obtained from these two instruments were compared to those obtained using two widely-used scales: Need for Cognition (NFC) and Barratt Impulsivity Scale (BIS). The exhibited correlations of the LtA scores with the NFC, BIS, and a math test provide evidence of the criterion validity of the analytic LtA items, and suggests further revision of the impulsive LtA items to improve the overall measurement validity of the LtA scale. Students LtA scores were found …


Development Of The Control And Ignition Systems On A High Pressure Gas Turbine Combustor, Carlos Alejandro Valdez Jan 2012

Development Of The Control And Ignition Systems On A High Pressure Gas Turbine Combustor, Carlos Alejandro Valdez

Open Access Theses & Dissertations

The ignition and control systems of a laboratory scale high-pressure gas turbine combustor were developed in the present work. This work provides a detailed description of the design, development and testing of the remote control system developed for a High Pressure Gas Turbine Combustor (HPTC).

The combustor has the capability to operate at pressures up to 1.5 MPa and temperatures up to 2400 K. It is also designed for a maximum air and fuel flow rates of 81.93 g/s and 35.77 g/s respectively. The fuel used will be CH4 for the early experiments but it is designed to operate using …


New Multi-Objective Evolutionary Game Theory Algorithm For Border Security, Franciso Oswaldo Aguirre Jan 2012

New Multi-Objective Evolutionary Game Theory Algorithm For Border Security, Franciso Oswaldo Aguirre

Open Access Theses & Dissertations

The complexity of border security relays on the diversity and volume of illegal activity that must be controlled, and the variety of resources that can be deployed to secure the border. A key operational problem encountered by those charged with the task of border security is the scheduling and deployment of patrols. Patrolling can be defined as the act of walking or traveling around an area - network-, at regular intervals, in order to protect or supervise it. The problem of optimizing schedules for patrolling open areas is one that arises in many contexts, and has attracted significant attention from …


Microelement Localization In Leaves Of Populus Spp. And Tolerance Mechanisms To Boron-Salt Toxicity, Daniel Arriaga Jan 2012

Microelement Localization In Leaves Of Populus Spp. And Tolerance Mechanisms To Boron-Salt Toxicity, Daniel Arriaga

Open Access Theses & Dissertations

Phytoremediation has been proposed as a low-cost, environmentally friendly alternative to clean highly contaminated sites. Phytoremediation using trees offer the advantage of metal immobilization (phytostabilization), high hydraulic pumping pressures, produce large plant biomass, absorption of total dissolved salts within their tissue, long life spans, less frequent irrigation and, a massive root system that helps soil attachment. Hybrid poplar varieties are long-lived, perennial, fast growing, and produce a large amount of foliage to harvest. Boron is an essential micronutrient for plants. Certain locations, such as California and Turkey, have suffered from high boron efflux from irrigation waters. It has been identified …


Granular Computing For Assessment Of Mild Traumatic Brain Injury, Melaku Ayenew Bogale Jan 2012

Granular Computing For Assessment Of Mild Traumatic Brain Injury, Melaku Ayenew Bogale

Open Access Theses & Dissertations

Mild traumatic brain injury (mTBI) is one of the most common neurological disorders. It is a serious public health problem in the United States. Although, penetrating (open) brain injuries that result in extended period of loss of consciousness (LOC) usually gets attention and well taken care of by the emergency departments, mild traumatic brain injury with no visible sign of damage, may be undetected or misdiagnosed. The clinical assessments and evaluations are mostly based on subjective cognitive and behavioral tests. Many people after suffering mTBI complain about decreased balance, coordination and stability even though the clinical evaluations show no sign …


Confirmation And Investigation Of Higher Science Curiosity In Juarez Middle School Students Compared To Their Peers In El Paso, Texas, Karla Carmona Miranda Jan 2012

Confirmation And Investigation Of Higher Science Curiosity In Juarez Middle School Students Compared To Their Peers In El Paso, Texas, Karla Carmona Miranda

Open Access Theses & Dissertations

In the last 20 years attitudes towards science and science classes in K-12 education have been an important topic of investigation due to the decreasing number of students choosing Science, Technology, Engineering and Math (STEM) related careers, and the increasing need for STEM prepared workers to cover the job demands of the future. The purpose of this study is to confirm a previously measured difference in scientific curiosity between middle school students in El Paso and in Ciudad Juarez, and to collect additional data that might tell us what the possible factors or reasons for this difference are. Our sample …


Dynamic Earthquake Triggering In The Continental U.S., Ibrahim Cerda Jan 2012

Dynamic Earthquake Triggering In The Continental U.S., Ibrahim Cerda

Open Access Theses & Dissertations

Seismological studies have classified the changes in field stress required to trigger remote earthquakes into two basic types: static and dynamic triggering. Static triggering mainly originates from geological faults already present in certain tectonic environments and they could be originated due to continental crust, subduction zones or even from a highly seismicity zone. Dynamic triggering occurs when an event (earthquake) has been induced by the passing of seismic waves from a large main shock located at least two or more fault lengths from the epicenter of the main shock. This study investigates details of dynamic triggering not seen in previous …


Sustainable Wastewater Management For Paso Del Norte Border Communities, Mariana Chew Jan 2012

Sustainable Wastewater Management For Paso Del Norte Border Communities, Mariana Chew

Open Access Theses & Dissertations

At the binational level, there is no enforceable formal or informal agreement for approval of a water or wastewater discharge from the United States or Mexico. The communities along the U.S.-Mexico border are included in the cooperative activities of: (1) U.S. Environmental Protection Agency (EPA) Region VI, (2) Mexico Secretarí­a de Medio Ambiente y Recursos Naturales (SEMARNAT), (3) the binational Border Environment Cooperation Commission (BECC) and Comisión de Cooperación Ecológica Fronteriza (COCEF), (4) the binational North American Development Bank (NADBANK) and Banco de Desarrollo de América del Norte (BDAN), and (5) the binational International Boundary and Water Commission (IBWC) and …


Stereo Matching - Improving Image Quality, Aritra Dattagupta Jan 2012

Stereo Matching - Improving Image Quality, Aritra Dattagupta

Open Access Theses & Dissertations

Stereo vision or stereopsis is a biological process in which the impression of the depth of a scene viewed by the two eyes is perceived. Stereo vision helps us to see where objects are in relation to our bodies. Computational stereo describes the process of synthesizing the mechanics of binocular vision; and stereo matching is an important process in the problem of computational stereo.

Stereo matching is used for Digital Elevation Modeling (DEM), which is the method of extracting 3D information from digital images obtained by cameras and, therefore, is a crucial process for representing a 3D view of surfaces …


Generalized Linear Latent Mixed Modeling Of Functional Independent Measures And Patient Outcomes, Maduranga Kasun Dassanayake Jan 2012

Generalized Linear Latent Mixed Modeling Of Functional Independent Measures And Patient Outcomes, Maduranga Kasun Dassanayake

Open Access Theses & Dissertations

The Functional Independent Measure (FIM) is one of the most widely accepted functional assessment measures used in the rehabilitation community. Past research studies have investigated the relationship between place of discharge, admission FIM scores or FIM difference scores, and patients' characteristics and found relationships between those variables. However, most of these studies fail to account for the multi-layered multidimensionality of the FIM and the measurement error associated with the FIM items. This study utilizes Generalized Linear Latent Mixed Models (GLLAMM) and Structural Equation Models (SEM) to assess which patient characteristics are associated with FIM difference scores and the structural relationship …


Raman And Infrared Study Of Electrospun Plla/Pcl Nanofiber Blends For Use In Tissue Engineering, Jose Luis Enriquez Carrejo Jan 2012

Raman And Infrared Study Of Electrospun Plla/Pcl Nanofiber Blends For Use In Tissue Engineering, Jose Luis Enriquez Carrejo

Open Access Theses & Dissertations

Recently, the biomedical engineering field has developed at a very fast pace as improved techniques and materials become available to promote its growth. Consequently, the research in polymeric biomaterials has been highly stimulated by this trend. The goal of the current research is to demonstrate the usefulness of the Raman scattering, Raman mapping, and infrared absorption spectroscopies to tissue engineering, by spectroscopically characterizing blends of PLLA and PCL polymers, which were prepared by electrospinning with and without cell addition. The proposed use of these blends is as primary biomaterials in biodegradable scaffolds used in tissue engineering. Both Raman and infrared …


Structural Analysis Of The Central Ibex Hills, Death Valley, California, Oscar Esparza Jan 2012

Structural Analysis Of The Central Ibex Hills, Death Valley, California, Oscar Esparza

Open Access Theses & Dissertations

The Ibex Hills, in southern Death Valley, California, are composed mainly of Late Proterozoic sedimentary rocks overlying middle Proterozoic basement that are complexly deformed by Mesozoic contractional structures overprinted by Neogene extensional/transtensional structures. Detail mapping of the Ibex Hills reveals evidence of several deformational events. Brittle deformation of both extensional and strike-slip origin are recognized throughout the mapped area, but the main structure identified is a low angle fault at the base of the Noonday Dolomite, Sentinel Peak member, herein called the Noonday Fault. This low angle fault is dipping toward the east-northeast and has a curved geometry that resembles …


Dihedral Cayley Directed Strongly Regular Graphs, Jose Jonathan Gamez Jan 2012

Dihedral Cayley Directed Strongly Regular Graphs, Jose Jonathan Gamez

Open Access Theses & Dissertations

A graph is a directed strongly regular graph (DSRG) if and only if the number of paths of length 2 from x to y is: λ, if there is an edge from x to y; μ, if there is not an edge from x to y (with x not equal to y); and t, if x = y. For every vertex in G, the in-degree and out-degree is k. The number of vertices in G is denoted by v. If G is a group and S a subset of G, then the …