Physical Sciences and Mathematics Commons^™

Estimating The Coefficients Of A Linear Differential Operator, Maria Ivette Barraza

Open Access Theses & Dissertations

Principal Differential Analysis (PDA; Ramsay, 1996) is used to obtain low dimensional representations of functional data, where each observation is represented as a curve. PDA seeks to identify a Linear Differential Operator (LDO) L = ω0I + ω 1D + ... + ωmDm, where I denotes the identity function and D j the jth derivative, that satisfies as closely as possible that Lx = 0 for each functional observation x. A theorem from analysis establishes that the coefficients of the LDO are in the Sobolev space, and thus can be approximated by B-splines. Current PDA software used to estimate the …

Synthesis Of New Fullerene Derivatives For Photovoltaic And Biological Applications, Edison Castro

Open Access Theses & Dissertations

Functionalized fullerenes exhibit improved solubility and different chemical and physical properties that allow applications in multiple fields such as photovoltaic and biological applications. Currently, perovskite solar cells (PSCs) are the most rapidly developing type of solar cells with certified efficiencies rising from 3.8% in 2009 to 22.1% in 2016. The good electron transporting and solution processable properties of most fullerene derivatives make them the most popular electron transporting materials (ETMs) in inverted perovskite solar cells (PSCs).

The work is reported in 11 chapters. We start with a fullerene overview followed by cleaver and elegant methodologies that allow the synThesis of …

Methods For Producing Graphene From Petroleum By-Products, Eva M. Deemer

Open Access Theses & Dissertations

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Quantifying The Characteristic Length Of A Combustor For An Ionic Liquid Monopropellant Thruster, Kimberly Marie Hogge

Open Access Theses & Dissertations

Ionic liquid monopropellants are currently being researched as a promising alternative to hydrazine in propulsion systems. This report presents a flame study that delineates the flame length of the expected decomposition products from an ionic liquid monopropellant. Through these studies, the characteristic length of a combustion chamber will be defined through calculations and empirical correlations. There is limited information on designing a propulsion system for an ionic liquid monopropellant. Therefore, defining the magnitude for an effective characteristic length serves as beneficial in designing a propulsion system for an ionic liquid monopropellant thruster.

The Former Asarco Demolition Fallout, A Post Study On Lead Soil Concentrations And Environmental Agents Of Redistribution In El Paso, Texas, Stephanie A. Robinson

Open Access Theses & Dissertations

The former El Paso ASARCO Smelting and Refining Co. operated between 1877 and 1999, the pyrometallurgic activity was estimated to have discharged excess of a 1,000 tons of lead (Pb) into the atmosphere from 1969-71. It was estimated 96 tons of (Pb) were emitted on an annual basis from the standing ore and fluid beds. The Environmental Protection Agency (EPA) determined that lead (Pb) is the heavy metal of the highest concentration within the vicinity of the smelter. After the smelter production ceased, flash flooding common to the southwest, such as the 2006 historic flood, increased transportation of superficial contaminants …

Raman Microscopic Analysis Of Internal Stress In Boron-Doped Diamond Thin Films, Emma M.A. Sundin

Open Access Theses & Dissertations

The correlations between induced stress on undoped and boron-doped diamond (BDD) thin films, sample chemical composition, and fabrication substrate are investigated in this study via confocal Raman microspectroscopic analysis. Stability of BDD films is relevant to fast-scan cyclic voltammetry, as film delamination and dislocation of BDD-coated electrodes that can occur during neurosurgical electrode implantation can negatively impact the biosensing reliability of this technique. Electrodes were fabricated by coating cylindrical tungsten rods using a custom-built chemical vapor deposition reactor. The results of the analysis reveal a direct correlation between regions of pure diamond and enhanced material stress, as well as preferential …

Evaluation Of A Roller Method For Geochemical Leach Testing, Troy Allen Svede

Open Access Theses & Dissertations

Currently, multiple tests are being used when evaluating an MSE wall backfill material for pH, conductivity, chloride concentration, and sulfate concentration. There is no one test to measure all four characteristics when testing a soil. Texas Department of Transportation (TxDOT) uses four different tests to measure these characteristics. The goal of this research was to refine a simplified test procedure that was created by David Borrok et al., the Tex-620-M. The method that was developed to replace the current TxDOT test procedures Tex-620-J, Tex-128-E, and Tex-145-E test procedures is the Tex-620-M2. Leaching kinetics were analyzed for gravel and fines by …

Active Learning Effect On The Public's Perception Of Anthropogenic Global Climate Change, Ivy Gisselle Trevizo

Open Access Theses & Dissertations

Anthropogenic, or human-caused global climate change has been debated for many years among the public despite the growing evidence that there is scientific consensus on this topic. A gap has been discovered between scientific evidence of increasing temperatures and the public's perception on climate change. This gap has been hypothesized to come from the method in which the scientific community represents scientific evidence. The goal of this study was to determine if active learning techniques around local and regional climate change and climate change impacts changes the awareness, perception, and behavioral intentions of different segments of the public. The study …

Renewable Energy Systems Optimization Using Monte Carlo Simulation And Evolutionary Algorithms, Nicolas Lopez

Open Access Theses & Dissertations

This Dissertation explores the Renewable Energy Integration Problem, and proposes a Genetic Algorithm embedded with a Monte Carlo simulation to solve large instances of the problem that are impractical to solve via full enumeration. The Renewable Energy Integration Problem is defined as finding the optimum set of components to supply the electric demand to a hybrid

microgrid. The components considered are solar panels, wind turbines, diesel generators, electric batteries, connections to the power grid and converters, which can be inverters and/or rectifiers. The methodology developed is explained as well as the combinatorial formulation. In addition, 2 case studies of a …

Ac Susceptibility And Epr Investigations Of Superspin Dynamics In Manganese Oxide Nanoparticles, Mahesh Koirala

Open Access Theses & Dissertations

We have investigated the superspin dynamics of 5 nm and 10 nm mixed state Mn3O4 nanoparticles utilizing ac-susceptibility and electron paramagnetic resonance measurements. The out of phase component of the ac-susceptibility measurements show a magnetic anomaly below (T

A New Method For Ultra-Low Sulfate Extraction And A Pilot Study In Arid Soils, Marisela Montelongo

Open Access Theses & Dissertations

Sulfur in soils is a crucial nutrient for all organisms including plants. Sulfate (SO42-), a water soluable anion, is a good source of this important element. Because of the importance of sulfur for agriculture, the use of sulfate has been well studied in temperate climate zones, and it is generally accepted that microbes play a critical role in controlling the availability of sulfate. Organically bound sulfur, such as sulfate esters and carbon-bonded sulfur, compounds that are generated and decomposed by microbes, are essential sulfur sources for plants under these conditions. For arid environments, knowledge of sulfate turnover in soils by …

Exposure Of Commercial Titanium Dioxide And Copper Hydroxide Nanomaterials On Basil (Ocimum Basilicum): A Life Cycle And Transgenerational Study, Wenjuan Tan

Open Access Theses & Dissertations

Although thousands of reports have shown that engineered nanomaterials (ENMs) can alter several agronomical, physiological, and biochemical parameters in plant and mammal systems, the effects of long-term exposure and varietal responses are scarce. Titanium dioxide nanoparticles (nano-TiO2) and copper hydroxide nanoparticles [nano-Cu(OH)2], which are widely used in agriculture, medicine, food industry, textile, among other areas, are among the ENMs with high production and consumption globally. Though reports indicate that these ENMs affected plant development and metabolism, their interactions with basil (Ocimum basilicum) are unknown. Basil is a popular culinary herb worldwide, featured in Asian and European cuisine and has more …

Essays On Sofwtare Development Projects: Impact Of Social And Technological Factors On Project Performance And Co-Diffusion Of Software Sourcing Arrangements, Niharika Dayyala

Open Access Theses & Dissertations

Software development is a complicated process which is accomplished by the combined effort of the key elements such as people, processes, and technology. Software development firms are on a constant quest to identify the best practices for managing the key elements to improve their software development project outcomes and to deliver successful software projects. This Dissertation aims to study key elements that can influence the software development project performance through three distinctive studies. The first essay of this Dissertation investigates the impact of people factors on software project outcomes. Specifically, it examines the impact of team characteristics on the software …

Neutrino Oscillations And The Reno Experiment, Karla Rosita Tellez Giron Flores

Open Access Theses & Dissertations

Neutrinos are the second most common particles in the universe, after the photons. Neutrinos (and antineutrinos) exist in three different "flavors", namely, electron, tau and muon neutrinos. A physical neutrino, however, can oscillate among these three flavors and, thus, it is said to be a mix of the three flavor states. In quantum mechanics representation, it is said that the three flavor states are the mixture of the three mass states. This mixture of neutrinos can generally be parameterized by the three so-called mixing angles (&thetas;12, &thetas;23, &thetas;13), three squared mass differences Δmij 2, i, j = 1, 2, 3 …

Design And Regioselective Synthesis Of Fullerene Derivatives For Metal-Organic Hybrid Architectures, Catalina Suarez

Open Access Theses & Dissertations

In the last years different fullerene derivatives and endohedral fullerenes have been reported and their potential applications as electronic, magnetic, catalytic, biological and optical materials have been explored. In this work we describe the characterization of new endohedral fullerenes; the exohedral functionalization of fullerenes with organic addends or metal clusters and their application in metal-organic hybrid architectures.

We synthesized fullerene polymers with a variety of staircase linear architectures, zigzag polymers and a perfectly linear polymer using an hexakis-fullerene adduct with two 4,5-diazafluorene groups located at trans-1 positions, using Hg, Cd, Zn and33 Cu as the metal centers. Our results showed …

Self-Interaction Corrected Polarizabilities Of Small Molecules, Sharmin Akter

Open Access Theses & Dissertations

Density Functional Theory (DFT) is one of the most successful and popular computational Quantum Mechanical approaches to understand materials. DFT allows the prediction of material properties from the electron density. Although in principle density functional theory is exact, it, however, relies on approximate functional for exchange-correlation energy. Due to the approximate nature of the exchange-correlation functional, the self-Coulomb energy of the electrons is not exactly canceled out by the self-exchange leading the spurious self-interaction error (SIE). This error is responsible for the unphysical orbital energies of DFT and delocalization of the orbitals. The orbital energies of the valence electrons are …

Depositional Controls And Sequence Stratigraphy Of Lacustrine To Marine Transgressive Deposits In A Rift Basin, Lower Cretaceous Bluff Mesa, Indio Mountains, West Texas, Andrew Anderson

Open Access Theses & Dissertations

Successful hydrocarbon exploration in former rift basins of the South Atlantic pre-salt has generated interest in understanding depositional, diagenetic, and stratigraphic controls on pre-salt deposits. However, most studies to date have focused on attributes and controls on presalt lacustrine carbonate reservoir systems and little work has been done on the overlying marine sealing facies. Currently our standard sequence stratigraphic model of marine transgression of rift systems involves a single pulse of marine flooding over fluvially-incised valleys resulting in backstepping of fluvial and estuarine siliciclastic facies within the erosionally confined zone of an incised valley. However, the pre-salt systems of the …

Studies Of Air Pollutants And Their Impact On Respiratory And Cardiovascular Diseases In The El Paso Del Norte Region With Emphasis On Mobile Emissions, Juan Gustavo Arias Ugarte

Open Access Theses & Dissertations

Air pollution may cause different diseases, such as cardiovascular and lung diseases. Traffic is a major source of mobile emissions causing air pollution. Exhaust emissions from mobile sources (Emissions of Carbon Monoxide, Nitrogen Oxides and Hydrocarbons) and Non-exhaust (Brake and Tire) are complex mixtures of gases and dust, including a large number of ultrafine particles, especially in areas with high traffic density. Recent studies have shown high rates of morbidity and mortality in people exposed to these types of emissions because the fine and ultrafine particles can be transported from the respiratory airways to the organs, thus contributing to increase …

Structural Modifications In The Rbxcs1-Xpo 4 (0 ≤ X ≤ 1) Superprotonic Conductor Series: A Single-Crystal X-Ray Diffraction And Impedance Spectroscopy Study, Andres Jose Encerrado Manriquez

Open Access Theses & Dissertations

We have used single-crystal X-ray diffraction measurements to investigate the structural modifications induced by Rb-doping of the protonic conductor CsH2PO4. Data collected on the RbxCs 1-xH2PO4 (0 ≤ x ≤ 1) series shows that the monoclinic P21/m CsH2PO4 presentation persists upon Rb-doping up until x = 0.8. Rb0.8Cs0.2H2PO 4 exhibits a previously unreported P21/c monoclinic structure, where the mirror plane is lost and disorder is present in the PO4 tetrahedra even at room temperature. Higher levels of x display a tetragonal I-42d unit cell isomorphic with the known structure of RbH2PO 4. The temperature dependence of the proton conductivity determined …

Analysis Of Gesture Frequency And Amplitude As A Function Of Personality In Virtual Agents, Alex Michael Rayon

Open Access Theses & Dissertations

Embodied conversational agents are changing the way humans interact with technology. Agents are expected to behave like people, both verbally and non-verbally. Researchers within the Human-Computer Interaction community have found many attributes of an agentâ??s gesture contribute to an agentâ??s perceived personality and believability.

Gesture amplitude and frequency are two of the attributes that contribute to the naturalness of a gesture. Currently, no previous studies have defined an empirical baseline for generating natural gestures for these two attributes. I seek to discover whether gesture amplitude and frequency affect how users perceive an agentâ??s naturalness, and which gestures would be preferred …

Advancing High Spatial And Spectral Resolution Remote Sensing For Observing Plant Community Response To Environmental Variability And Change In The Alaskan Arctic, Sergio Armando Vargas

Open Access Theses & Dissertations

The Arctic is being impacted by climate change more than any other region on Earth. Impacts to terrestrial ecosystems have the potential to manifest through feedbacks with other components of the Earth System. Of particular concern is the potential for the massive store of soil organic carbon to be released from arctic permafrost to the atmosphere where it could exacerbate greenhouse warming and impact global climate and biogeochemical cycles. Even though substantial gains to our understanding of the changing Arctic have been made, especially over the past decade, linking research results from plot to regional scales remains a challenge due …

Spectroscopic Analysis Of Neurotransmitters: A Theoretical And Experimental Raman Study, Matthew Alonzo

Open Access Theses & Dissertations

Surface-enhanced Raman spectroscopy (SERS) was applied to investigate the feasibility in the detection and monitoring of the dopamine (DA) neurotransmitter adsorbed onto silver nanoparticles (Ag NPs) at 10-11 molar, a concentration far below physiological levels. In addition, density functional theory (DFT) calculations were obtained with the Gaussian-09 analytical suite software to generate the theoretical molecular configuration of DA in its neutral, cationic, anionic, and dopaminequinone states for the conversion of computer-simulated Raman spectra. Comparison of theoretical and experimental results show good agreement and imply the presence of dopamine in all of its molecular forms in the experimental setting. The dominant …

Gypsum, Calcite, And Dolomite Caprock Fabrics And Geochemistry From The Gypsum Valley Salt Diapir, Paradox Basin, Southwestern Colorado, Kevin Lerer

Open Access Theses & Dissertations

Caprocks are found on top of or in a lateral position relative to salt diapirs. The caprocks predominantly comprise sulfate minerals such as anhydrite or gypsum, which presumably accreted during the dissolution of salt from evaporite sediments. In some cases, the sulfate minerals are replaced by carbonate minerals, referred to as "carbonate caprock". Carbonate caprocks associated with salt diapirs are important because they can act as reservoirs or conduits for hydrocarbons, and because they can be easily misidentified as carbonate lithologies belonging to the stratigraphy of the sedimentary sequences adjacent to the diapir, which can jeopardize the accurate interpretation of …

Genesis Of Unique Carbonate Fans In A Pre-Salt Reservoir Analogue, Indio Mountains, West Texas, Andre Llanos

Open Access Theses & Dissertations

Hydrocarbon exploration in pre-salt sediments of rift basins on the South Atlantic Margin have proven to be successful major oil plays. Located on the western margin of the rift, the Brazilian pre-salt reservoirs of the Santos, Campos, and Espirito Santo Basins are hosted by lacustrine/marine-influenced carbonates that comprise laterally extensive, laminated microbialite facies. The Indio Mountains, located in West Texas, provide well-exposed outcrops of Lower Cretaceous marine and non-marine rift basin strata that can be considered a reservoir-analog to the South Atlantic Margin pre-salt facies. Of particular interest for hydrocarbon exploration are unique carbonate features that have been discovered in …

Integration Of Heterogeneous Traffic Data To Address Mobility Challenges In The City Of El Paso, Daniel Michael Mejia

Open Access Theses & Dissertations

Transportation performance measures are defined as quantitative and qualitative indicators that rely on data or information to explain mobility, traffic congestion, safety, environmental sustainability and other factors. Although performance measures have been used for freeways and other highways, not many have been specified and applied to the freight transportation system. Under the Fixing America's Surface Transportation Act (FAST Act), state transportation agencies and metropolitan planning organizations in the United States are implementing freight performance measurement systems for performance assessment. This research aims to expand the existing limited freight performance measures and organize them into a comprehensive framework that can be …

Airborne Lead In El Paso, Texas, Usa, Lisa Marie Paz

Open Access Theses & Dissertations

Despite significant strides to minimize lead in our air, water, soil, food, homes, workplaces, and consumer products, sporadic and systemic lead poisoning persists in industrial societies, e.g., the contemporary Flint (Michigan, USA) municipal water tragedy. Because lead exposure is cumulative, the sum of exposure from all sources, it is important to document and update potential community or neighborhood exposure levels from such environmental compartments as air, water, and housing. Here we present ambient airborne lead levels in El Paso, Texas, USA, parsed by particulate matter (PM) size fraction, geography, and season. Dichotomous samplers at 8 stations collected particulate matter continuously …

Study Of Electron Gas On A Neutron-Rich Nuclear Pasta, Enrique Ramirez-Homs

Open Access Theses & Dissertations

This study used a classical molecular dynamics model to observe the role of electron gas on the formation of nuclear structures at subsaturation densities (Ï?<0.015 fm^-3) and low temperatures (T< 1MeV ). The simulations were performed by varying the Coulomb interaction strength on systems of isospin symmetric and asymmetric matter with periodic boundary conditions. The effect was quantified on the fragment size multiplicity, the inter-particle distance, the isospin content of the clusters, the nucleon mobility and cluster persistence, and on the nuclear structure shapes. The existence of the nuclear pasta structures was observed even with the absence of the Coulomb interaction but with a modication of the shapes formed. It was found that the presence of the electron gas tends to distribute matter more evenly, forms less compact objects, decreases the isospin content of clusters, modies the nucleon mobility, reduces the persistence and the fragment size multiplicity, but does not alter the inter-particle distance in clusters. The degree of these effects also varied on the nuclear structures and depended on their isospin content, temperature, and density.

Pyroelectric Ceramics As Temperature Sensors For Energy System Applications, Jorge Luis Silva

Open Access Theses & Dissertations

Temperature is continuously monitored in energy systems to ensure safe operation temperatures, increase efficiency and avoid high emissions. Most of energy systems operate at high temperature and harsh environments to achieve higher efficiencies, therefore temperature sensing devices that can operate under these conditions are highly desired. The interest has increased in temperature sensors capable to operate and in harsh environments and temperature sensors capable to transmit thermal information wirelessly. One of the solutions for developing harsh environment sensors is to use ceramic materials, especially functional ceramics such as pyroelectrics. Pyroelectric ceramics could be used to develop active sensors for both …

Synthesis And Post-Synthetic Transmetalations Of Metal-Organic Frameworks Containing Bimetallic Centers, Jose Miguel Veleta

Open Access Theses & Dissertations

The heterobimetallic metal-organic frameworks (MOFs) of the type HKUST-1 were obtained through post synthetic cation exchange processes, where Cu3(BTC)2 (BTC = 1,3,5-benzenetricarboxylate) was exposed to solutions of Mn2+, Fe2+, Co2+, or Ni2+ at time intervals of 6, 12, 24, 36, 48, and 72 hours. The elemental composition of the products was analyzed by inductively coupled plasma optical emission spectroscopy (ICP-OES), showing partial substitution of copper ions in the frameworks. Transmetalations done with Mn2+ and Ni2+ show a relatively low cation exchanged through the different time intervals, with maximum transmetalation percentages of 2.4 % for Mn2+ and 2 % for Ni2+ …

Near-Surface And High Resolution Seismic Imaging Of The Bennett Thrust Fault In The Indio Mountains Of West Texas, Alan Thomas Vennemann

Open Access Theses & Dissertations

My research investigates the structure of the Indio Mountains in southwest Texas, 34 kilometers southwest of Van Horn, at the UTEP (University of Texas at El Paso) Field Station using newly acquired active-source seismic data. The area is underlain by deformed Cretaceous sedimentary rocks that represent a transgressive sequence nearly 2 km in total stratigraphic thickness. The rocks were deposited in mid Cretaceous extensional basins and later contracted into fold-thrust structures during Laramide orogenesis. The stratigraphic sequence is an analog for similar areas that are ideal for pre-salt petroleum reservoirs, such as reservoirs off the coasts of Brazil and Angola …