Physical Sciences and Mathematics Commons^™

The Impacts Of Water Availability On Macroinvertebrate, Ector Matias Martell

Open Access Theses & Dissertations

In many regions around the world climate is changing and biotic communities are changing with it. In areas like the southwestern U.S., drought is one of the major sources of disturbance. Although droughts are an integral part of the natural hydrological cycles, they can have devastating effects on freshwater ecosystems when disrupted by extended periods of drought, resulting in changes to the structure and function of biotic communities. In this study, we surveyed four streams in the Sacramento Mountains of New Mexico from 2010 to 2014: Agua Chiquita, Rio Peñasco, Wills Creek, and the Sacramento River; These years encompassed an …

Crustal Structure Beneath The Eastern Nepal Himalayas And Southern Tibet From Receiver Function Analysis, Arjun Sharma Neupane

Open Access Theses & Dissertations

The Himalayas are the results of continental collision between the Indian plate and the Eurasian plate and serve as a natural site to study the physical causes and process of mountain building. The crustal structure beneath the Himalayas has been subject to numerous geophysical studies and the variation in the velocity structure across the Himalayan region suggests significant differences in the crustal structure between the southern and northern portion in that region. In this research, a P receiver function analysis has been conducted on data collected for 14 years (2000-2014) from 211 different stations in Eastern Nepal and Southern Tibet, …

Latina/O High School Students' Standpoint On Environmental Justice In A Border Community: A Phenomenological Study, Cynthia Christina Ontiveros

Open Access Theses & Dissertations

This qualitative research is a transcendental phenomenology seeking to understand Latin@ high school students’ perceptions and standpoints as they participated lessons that addressed border environmental justice issues in an underrepresented, marginalized community. Seven students from Borderland High School, enrolled in a senior level course, Environmental Science, participated in the study which focused on their experiences in an environmental justice air quality thematic unit built around the complex issues surrounding a local refinery, American Smelting and Refining Company (ASARCO). The study analyzed the meaning students made and their standpoints regarding the impact of the factory and its one-hundred year history polluting …

Novel Classification Of Slow Movement Objects In Urban Traffic Environments Using Wideband Pulse Doppler Radar, Berta Rodriguez Hervas

Open Access Theses & Dissertations

Every year thousands of people are involved in traffic accidents, some of which are fatal. An important percentage of these fatalities are caused by human error, which could be prevented by increasing the awareness of drivers and the autonomy of vehicles. Since driver assistance systems have the potential to positively impact tens of millions of people, the purpose of this research is to study the micro-Doppler characteristics of vulnerable urban traffic components, i.e. pedestrians and bicyclists, based on information obtained from radar backscatter, and to develop a classification technique that allows automatic target recognition with a vehicle integrated system. For …

Microscopic And Spectroscopic Analysis Of Cadmium Telluride, Jessica Goretty Salazar

Open Access Theses & Dissertations

Cadmium telluride (CdTe) remains one of the materials of interest in the fabrication of photovoltaic cells and infrared devices, mainly because of its suitable crystal structure as well as of its small, direct bandgap of 1.5 eV. Since development of such devices requires a high quality and low defect material, the goal of this study is to microscopically and spectroscopically examine not only crystallinity, but also the induced stress in the material due to the effect of substrate orientation. This information is valuable if optimization of sample growth conditions is envisioned. Prior to CdTe deposition by close-spaced sublimation (CSS), Si …

Pre-Tuned Ridge Regression And Its Extension To Generalized Linear Models, Yaa Tawiah Wonkye

Open Access Theses & Dissertations

Ridge regression is regularization or shrinkage method and a common approach in dealing with multicollinearity in conventional regression analysis. Ridge regression is widely used by statistical analyst since it is one of the best compared to other regularization methods. Also, the introduction of high dimension and ultra-high dimensional data has become an issue of concern and ridge regression is one way of dealing with such data. One of the key issues associated with ridge regression is the determination of the tuning or ridge parameter. The common practice is to fit ridge regression for a different number of values of tuning …

Sequence Stratigraphy And Depositional Environment Of The Cambro-Ordovician Bliss Sandstone, Franklin Mountains Of El Paso, Texas, Drew Adam Chenoweth

Open Access Theses & Dissertations

The Bliss Formation formed along the Southwestern continental shelf of

Laurentia during the Late Cambrian and records the craton]wide Cambrian

transgression previously described by Sloss. This study divides the Bliss into five facies associations which were used to determine the depositional environments: 1) The Basal Transgressive Lag (BTL) was interpreted to be a high energy fluvial deposit the top of which has been reworked and winnowed during transgression. 2) The Lower Cyclic Sandstones and Silty Sandstones (LCSS) were interpreted to be be tidal delta or tidal estuary deposits composed of delta deposits, slackwater deposits, and tidal dunes within tidal channels. …

Nanoceria Exposure To Kidney Beans (Phaseolus Vulgaris): Implications On Plant Physiology, Nutrition And Their Transfer To Next Trophic Level, Sanghamitra Majumdar

Open Access Theses & Dissertations

Previous studies investigating the effects of cerium oxide nanoparticles (nanoceria, nCeO2) on plants have primarily focused on the physiological and biochemical changes at early growth stages. Comprehensive information on the effects of nCeO2 through the entire life cycle of plants and the nutritional quality of the edible tissues is limited. No studies have been reported on the interactions between nCeO2 and common beans (Phaseolus vulgaris). Common beans are leguminous crops, which are societally important due to their nutritional benefits. The beans are rich in proteins and essential nutrients like folate, iron, zinc, molybdenum and magnesium, and are consumed worldwide. This …

Why Lattice-Valued Fuzzy Values? A Mathematical Justification, Rujira Ouncharoen, Vladik Kreinovich, Hung T. Nguyen

Departmental Technical Reports (CS)

To take into account that expert's degrees of certainty are not always comparable, researchers have used partially ordered set of degrees instead of the more traditional linearly (totally) ordered interval [0,1]. In most cases, it is assumed that this partially ordered set is a lattice, i.e., every two elements have the greatest lower bound and the least upper bound. In this paper, we prove a theorem explaining why it is reasonable to require that the set of degrees is a lattice.

Numerical Study Of The Supercritical Solution Of The Stationary Forced Korteweg-De Vries (Sfkdv) Equation, Sumi Dey

Open Access Theses & Dissertations

The time independent surface waves on a two dimensional incompressible and inviscid fluid flow passing over a bump on a flat bottom are considered. The stationary forced Korteweg-de Vries (fKdV) equation is defined in an unbounded interval. In this project, this unbounded interval is considered as three parts - on the bump, left hand side of the bump and right hand side of the bump. Exact boundary conditions are applied to the end points of the bump. All the possible combination of boundary conditions are used. A numerical approach is proposed to find the solitary wave solutions of fKdV equation …

Combining Semiparametric Regression And Kriging For Prediction Of Pm2.5 Pollutant Levels At Unmonitored Locations With Meterological And Traffic Data, Justin Jonathan Strate

Open Access Theses & Dissertations

Particulate matter (PM) is defined by the Texas Commission on Environmental Quality (TCEQ) as "a mixture of solid particles and liquid droplets found in the air". These particles vary widely in size. Those particles that are less than 2.5 micrometers in aerodynamic diameter are known as Particulate Matter 2.5 or PM2.5. These particles are inhaled, and their health effects are still largely being studied. Past studies have assessed PM2.5 exposure of a population, yet individual exposure is more diffcult to assess and may vary widely in a population. Recent studies have combined semiparametric models with kriging (Li et. al [2012]) …

A Bayes Approach In Step-Stress Accelerated Life Testings, Hao Yang Teng

Open Access Theses & Dissertations

A Bayesian analysis for the Weibull proportional hazard (PH) model is presented. A comparison between the Weibull PH model and the Weibull cumulative exposure (CE) model is made graphically and mathematically. The PH model is as flexible as the CE model in fitting step-stress data and the mathematical form of the PH model enables researchers to do Bayesian inferencemuch easier than the CE model. In addition, the PH model has the desirable proportional hazard property. A convex tent prior is used for Bayesian analysis. Markov chain Monte Carlo methods are used for posterior inferences. In this study, we adopt two …

A Heterogeneous Multiscale Method For Poroelasticity, Paul M. Delgado

Open Access Theses & Dissertations

In this Thesis, we develop and analyze a heterogeneous multiscale model for coupled fluid flow and solid deformation in porous media based on operator splitting and finite volume method. The splitting method results in two elliptic multiscale PDE's in the form of a reaction diffusion equation and a linear elasticity equation. We extend our previous multiscale method from 1D to higher dimensions and develop new approaches for the inclusion of mixed boundary conditions and source terms. We derive an error estimate for our multiscale method and analyze the stability of our splitting method. We also test the effectiveness of our …

High Performance Computing In Air Quality Models An Their Applications, Roberto A. Perea

Open Access Theses & Dissertations

High Performance Computing has become an important tool for many applications and services in the areas of Air Quality research. One important aspect is the use of computational technology in simulation and modeling of complex Air Quality models which makes it affordable in terms of data analysis, processing and speed. For this Dissertation, three projects using Air quality models were developed using high performance computing.

For the first project, ozone concentrations for the Paso del Norte Region are simulated using air quality models and compared against experimental data. For the second project, the Development of models and optimization of codes …

Aerosol Physical And Chemical Properties Over Tropical Atlantic Ocean, Elsa Castillo

Open Access Theses & Dissertations

The atmospheric aerosol mass size distributions, modal characteristics, and a comparative analysis of the characteristic of PM2.5 versus trace gases: CO, O3, and SO2 over tropical Atlantic Ocean have been evaluated for Nov-Dec 2013. This study took place during the IX AEROSE expedition while the National Oceanic and Atmospheric Administration (NOAA) research vessel Ronald H. Brown traveled south along 23°W between 3°N and 5°S.

Aerosol mass size distributions were measured directly with a California Instruments Model PC-2H Quartz Crystal Microbalance (QCM). The corresponding values of average mass for accumulation, nuclei and coarse mode obtained were: 0.00124±0.00077, 0.00506±0.00254, and 0.00176±0.00114 μg/m …

Short-Term Forecasting Analysis Of Municipal Water Demand In El Paso, Texas, Alejandro Ceballos

Open Access Theses & Dissertations

Short-term water demand forecasts inform decisions regarding budgeting, rate design, water supply system operations, and effective implementation of conservation policies. This study develops a Linear Transfer Function (LTF) forecasting model for El Paso, Texas, a growing city located in the desert Southwest region of the United States. The model is used to generate monthly-frequency out-of-sample simulations of water demand for periods when actual demand is known. To measure the accuracy of the LTF projections against viable alternatives, a set of benchmark forecasts is also developed. Both descriptive accuracy metrics and formal statistical tests are used to analyze predictive performance. The …

Characterization Of Kendex® 0834 (Heavy Resins) & Kendex® 0897 (Light Resins), Victor Correa

Open Access Theses & Dissertations

Characterization of crude oil and some of its refined products has always been a challenge in the refining industry. This is mainly due to the high molecular complexity of crude oil. In this research, Heavy and Light Resins extracted from Penn Grade crude oil were analyzed with a wide variety of techniques, ranging from X-Ray Diffraction, Electron Microscopy, Fourier Transformed Infrared, C-13 Nuclear Magnetic Resonance, and chromatographic methods. An asphaltene extraction protocol was performed on both products. Only the Heavy Resin sample yielded a low amount of asphaltene. Results show that both Resins have a high degree of carbon branching, …

A Pilot Study Of Arsenic In Young Children From Two Rural West Texas Communities: Blood Levels, Household Water Levels, And Behavioral Outcomes, Michelle Del Rio

Open Access Theses & Dissertations

Background & Significance: Heavy metals have been identified as a child health hazard because children are highly vulnerable to the effects of exposure, which can be physical, cognitive, and behavioral. Levels of arsenic (As) greater than the EPA Maximum Contaminant Level (10μg/L) were identified in some household water samples in two rural west Texas communities located within 20 miles of the U.S.-Mexico border by a Health Impact Assessment conducted in 2013 (Hargrove, Juarez-Carillo, & Korc 2015). Whether home water samples predicted child blood As levels needed to be examined. Since lead (Pb) is another common heavy metal contaminant in the …

Wind Farm Optimization Using Evolutionary Algorithms, Carlos Marco Ituarte-Villarreal

Open Access Theses & Dissertations

In recent years, the wind power industry has focused its efforts on solving the Wind Farm Layout Optimization (WFLO) problem. Wind resource assessment is a pivotal step in optimizing the wind-farm design and siting and, in determining whether a project is economically feasible or not. In the present work, three (3) different optimization methods are proposed for the solution of the WFLO: (i) A modified Viral System Algorithm applied to the optimization of the proper location of the components in a wind-farm to maximize the energy output given a stated wind environment of the site. The optimization problem is formulated …

Computation Offloading Decisions For Reducing Completion Time, Salvador Melendez

Open Access Theses & Dissertations

Mobile devices are being widely used in many applications such as image processing, computer vision (e.g. face detection and recognition), wearable computing, language translation, and battlefield operations. However, mobile devices are constrained in terms of their battery life, processor performance, storage capacity, and network bandwidth. To overcome these issues, there is an approach called Computation Offloading, also known as cyber-foraging and surrogate computing. Computation offloading consists of migrating computational jobs from a mobile device to more powerful remote computing resources. Upon completion of the job, the results are sent back to the mobile device. However, a decision must be made; …

When Can The Primitive Element Be Written As A Sum Of Two Algebraic Elements Adjoined To The Field Of The Rational Numbers, Mohamad Moussa

Open Access Theses & Dissertations

Given a field F and elements \alpha and \beta not in F, then F(\alpha, \beta) is the smallest field containing \alpha,\beta, and F. A simple extension is a field extension which is generated by the adjunction of a single element. The Primitive Element Theorem says that if F is a field of characteristic 0, and \alpha and \beta are algebraic over F, then there is an element \gamma in F(\alpha ,\beta ) such that

F(\alpha ; \beta ) = F(\gamma). When can we say that \gamma=\alpha+\beta? We will introduce some situations where \gamma=\alpha+\beta is true and some when this is …

A Geophysical Study Of The Castle Mountain Fault System And Matanuska-Susitna Valley Near Anchorage, Alaska, Shane Michael Schinagel

Open Access Theses & Dissertations

The Castle Mountain Fault (CMF) is the closest (~50 km) active fault to Anchorage, Alaska. Located within the Matanuska and Susitna (Matsu) Valleys, the CMF shows repeated, unmistakable evidence for Holocene motion. Recent geologic studies estimate that this fault is capable of producing earthquakes of magnitude 7.0 - 7.1. The Anchorage metropolitan area (which includes the Matsu Valley) contains most of Alaska's population as well as vital shipping and transportation facilities that serve much of inland Alaska. Expected magnitude >7 earthquakes pose seismic hazards to the expanding Anchorage area.

While several mapping and trenching studies have been conducted along the …

Reaction Of Liquid Aluminium- Samarium Alloys With B4c At Ultra High Temperatures, Sanjay Shantha-Kumar

Open Access Theses & Dissertations

Reactive studies between a packed bed of B4C and Al-Sm-Me (Me = Ti, Zr, Hf) alloy melts were carried out under a pseudo-isopiestic thermodynamic system. A graphite enclosure isolated the system under a temperature gradient with one end reaching temperatures greater than 1800 K and the opposite end of the graphite enclosure contains liquid Al with temperatures approximating 950 K. The liquid Al establishes an oxygen potential to control oxidation of very reactive elements (i.e., Al, Sm and Ti). The Al-Sm-Me alloy infuses into a packed bed of B4C reacting exothermically to form borides and carbides depending on the thermodynamic …

Elucidating The Electronic Structure Of Multiple Bonded Systems: Synthesis And Characterization Of Bimetallic Tungsten And Ruthenium Complexes, Karen Ventura

Open Access Theses & Dissertations

The following study is presented in two sections. In the first section variable-temperature magnetic and structural data of two pairs of diruthenium isomers (having an idealized D4h symmetry), one pair having axial ligands and the formula Ru2(DArF)4Cl (where DArF is the anion of a diarylformamidine isomer, and Ar = p-anisyl or m-anisyl) and the other one being essentially identical but devoid of axial ligands and having the formula [Ru2(DArF)4]BF4, show that the axial ligands have a significant effect on the electronic structure of the diruthenium core. Variable-temperature crystallographic and magnetic data as well as density functional theory (DFT) calculations unequivocally …

Monitoring And Understanding Decadal Scale Changes In Hydrology, Productivity And Carbon Balance In Arctic Tundra Ponds, Christian Gerardo Andresen

Open Access Theses & Dissertations

The Arctic is known for containing large stocks of soil organic carbon, which exists frozen in permafrost in a greenhouse inert state. With predicted future warming in these high northern latitudes, the mobilization of stored soil organic carbon and release to the atmosphere may increase and induce further positive climatic feedbacks. Previous studies have shown that Arctic wetlands and ponds cover a large percentage of the Arctic Coastal Plain and contribute large amounts of carbon to the atmosphere; however, it remains largely unknown how these systems are responding to a warming climate and how this change will impact regional carbon …

Associativity Forcing Commutativity In Left Nil Rings, Md Al Masum Bhuiyan

Open Access Theses & Dissertations

Our study in this thesis is concentrated on the AFC groups (Associativity Forces Commutativity) and observing the ring structure there. We are looking for abelian groups yielding ring structures (K) where associativity forces commutativity. We call them K-AFC groups.

We consider that the only conditions put on a ring multiplication are the distributive laws over the additive group addition. After [1], We say that an abelian group (G, +) is an AFC-group if (i) there exists a nonassociative and noncommutative ring (G, +, ˙) and (ii) all associative rings (G, +, ˙) are commutative.

We call a ring left-nil if …

Quantifying Weathering Rates On Tropical Volcanic Basse-Terre Island, French Guadeloupe: Insights From U-Series Isotopes In Weathering Rinds, Jacqueline Engel

Open Access Theses & Dissertations

Weathering of volcanic rocks plays many important roles at Earth’s surface such as modifying landscapes, providing nutrients to soil, and regulating atmospheric CO2. U-series isotopes (e.g. 238U-234U-230Th and 232Th) have been established as a chronometer used to constrain the formation rates of weathering rinds in tropical island environments. Here, U-series isotopes and major element concentrations were analyzed in two basaltic-andesite weathering rinds collected from the Deshaies watershed located in the northern, relatively dry (mean annual precipitation (MAP) = 1800 mm) region of tropical Basse-Terre Island, Guadeloupe. The two clasts are referred to as clasts AN-14-7.5 and AN-14-7.6. Elemental mobility trends …

Receiver Function Analysis To Study Crustal Structure Of The Northern Nepal And Tibetan Plateau, Mohan Pant

Open Access Theses & Dissertations

The teleseismic P-waveform receiver function analysis is a commonly used technique in earthquake seismology to study the crustal structure beneath a broadband seismic station. To understand the structure of the Northern Nepal and Tibetan plateau different studies have used the receiver function method to estimate the Moho depth and Vp/Vs ratio. The value suggested was ~ 30 km in the south and the ~ 75 km in the north. Other studies have used teleseismic body wave data to perform the travel time residuals to model the lithosphere structure. In our study, we analyzed data from 261 seismic stations to establish …

Predicting Irrigation Efficiency In The Rio Grande Project, Gerardo Melendez

Open Access Theses & Dissertations

Surface water losses in the Bureau of Reclamation’s (USBR) Rio Grande Project have become more prevalent within the past few years of the drought of the 2000’s. Simple regressions were performed in order to find correlations and determine factors that may affect the flows within the Rio Grande Project. Correlations were found in the difference between Rio Grande below Caballo flows and Rio Grande at El Paso flows, and between the diversion ratio and groundwater levels. Caballo Reservoir release amounts were found to be fairly well correlated with the difference between the Rio Grande below Caballo and the Rio Grande …

Single And Multiple Objective Biomass-To-Biofuel Supply Chain Optimization Considering Environmental Impacts, Claudia Evangelina Valles Sosa

Open Access Theses & Dissertations

Bioenergy has become an important alternative source of energy to alleviate the reliance on petroleum energy. Bioenergy offers diminishing climate change by reducing Green House Gas Emissions, as well as providing energy security and enhancing rural development. The Energy Independence and Security Act mandate the use of 21 billion gallons of advanced biofuels including 16 billion gallons of cellulosic biofuels by the year 2022. It is clear that Biomass can make a substantial contribution to supply future energy demand in a sustainable way. However, the supply of sustainable energy is one of the main challenges that mankind will face over …