Physical Sciences and Mathematics Commons^™

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, …

Versatility Of N-Peptidyl And N-Glycopeptidyl Nitroindolines For The Formation Of Peptide/Glycopeptide Acids, Amides, And Thioesters, Luis Alfonso Barrera

Open Access Theses & Dissertations

N-acyl-7-nitroindolines are photoreactive compounds that are known to acylate a number of nucleophiles in inert aprotic solvents under neutral conditions when illuminated at 350 nm. We have assembled a MUC1-derived peptide and Tn or STn-containing MUC1 glycopeptides with a C-terminal photoreactive 7-nitroindoline linker attached to Sieber amide resin by solid phase peptide synThesis using the Fmoc strategy. This type of construction allows for the cleavage of fully protected photoreactive peptides/glycopeptides from the resin with dilute trifluoroacetic acid, or for the direct photorelease of protected peptide/glycopeptide derivatives. Here we demonstrate that N-peptidyl and N-glycopeptidyl 7-nitrindolines can be photochemically converted into their …

Virtual Rapport With Extraverted Agents, Jacqueline Brixey

Open Access Theses & Dissertations

Studies from psychology conclude that "birds of a feather flock together"- or, in other words, people tend to seek companionship with those who have a similar personality to their own. Researchers in the fields of Linguistics and Psychology have found numerous markers that differentiate the dialogue of extroverts from that of introverts. Recent work in Human Computer Interaction has sought to understand the nature of creating and maintaining rapport between humans and Embodied Conversational Agents (ECAs).

Seeking an interdisciplinary approach that combines knowledge from HCI, Linguistics, and Psychology, I sought to establish whether introverted users report the highest level of …

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 …

Triphenylamine-, Porphyrin- And Fullerene-Based Derivatives For Photovoltaic And Other Applications, Danisha Marie Rivera Nazario

Open Access Theses & Dissertations

Proper collection of charges at the electrodes is an important process in organic solar cells. Interfacial layers between the electrodes and the photoactive layer have been design to improve charge collection and ohmic contacts. The most studied interfacial layer between the anode and the photoactive layer is the negatively charged polymer poly(3,4-ethylendioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), that possesses good hole transporting ability. However, inhomogeneities at the surface of the electrode after deposition of the polymer lower the stability and performance of the OPV devices. Triphenylamine (TPA) derivatives have received increased attention in the organic solar cells (OSCs) field because of their favorable light …

The Role Of Collaborative Ontology Development In The Knowledge Negotiation Process, Norma Rivera

Open Access Theses & Dissertations

Interdisciplinary research (IDR) collaboration can be defined as the process of integrating experts' knowledge, perspectives, and resources to advance scientific discovery. The flourishing of more complex research problems, together with the growth of scientific and technical knowledge has resulted in the need for researchers from diverse fields to provide different expertise and points of view to tackle these problems. These collaborations, however, introduce a new set of "culture" barriers as participating experts are trained to communicate in discipline-specific languages, theories, and research practices. We propose that building a common knowledge base for research using ontology development techniques can provide a …

Lithospheric Structure And Stress Field Orientations In The Northern Libya And East-Central Mediterranean Region, Abdusalam Ali Agail

Open Access Theses & Dissertations

This thesis is a combination of three studies including tomography using surface wave group velocities, stress orientations from focal mechanisms, and receiver functions. The study area covers northern Libya and the east central Mediterranean region. I utilized new data from the Libyan National Seismic Network to better understand the crustal thickness and stress orientation of northern Libya as well as the east central Mediterranean region. In the first study, I conducted surface wave group velocity tomography implementing the Gaussian beam method for obtaining 2-D velocity variations assuming an isotropic model. I constructed surface wave group velocity maps over a range …

Molecular Dynamics Study On Defect Reduction Strategies Towards The Fabrication Of High Performance Cd1-Xznxte/Cds Solar Cells, Jose Juan Chavez

Open Access Theses & Dissertations

Cadmium Telluride is a material widely used in terrestrial thin film photovoltaic applications due to its nearly ideal band gap (~1.5 eV) and high absorption coefficient. Due to its low manufacturing cost, this technology has the potential to become a significant energy resource if higher energy conversion efficiencies are achieved. However, the module efficiencies (~14%) are still far from the theoretical maximum (~30%) for this material in a single junction configuration. The reason behind this low performance is attributed to the high number of defects that are present within the device materials. The physics behind the formation mechanisms of these …

Bayesian Adaptive Penalized Splines In Nonparametric Regression And In Spectral Time Series Analysis, Luis Angel Mora

Open Access Theses & Dissertations

A Bayesian approach to nonparametric regression using Penalized splines (P-splines) is presented. The approach uses the linear mixed model formulation of P-spines. The usual model assumes a single value for the smoothing parameter controlling the amount of smoothing of the fitted function. The main focus of the Thesis is on spatially adaptive smoothing where the smoothing parameter is a function of the covariate so that different amounts of smoothing are applied in different regions of the covariate. An application to spectral time series analysis will be demonstrated. Markov chain Monte Carlo methods are used to make inference based on the …

A Tectonic Analysis On The Central Region Of The Himalaya Collision Zone Using Double Difference Tomography, Chanel Perez

Open Access Theses & Dissertations

The Himalaya mountain range remains the only place on Earth undergoing continuous effects from the continental-continental collision between India and Asia. Because of this, the Himalayas have been subjected to extensive deformation and transpression, and contain five major shear zones. Extensive seismic analysis of the region, however, is lacking due to sparse seismograph coverage and complexity of the crustal structure. I examined seismic event data from two temporary seismic networks deployed in the central Himalaya, the HIMNT deployment from 2001-2003, and the Bhutan deployment from 2002-2003. Using this data I develop a 3-D earth model for the region using double-difference …

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 …

Contributions To The Solution Of Large Nonlinear Systems Via Model-Order Reduction And Interval Constraint Solving Techniques, Leobardo Valera

Open Access Theses & Dissertations

Many engineering problems boil down to solving partial differential equations (PDEs) that describe real-life phenomena. Nevertheless, efficiently and reliably solving such problems constitutes a major challenge in computational sciences and in engineering in general.

PDE-based systems can reach sizes so large after they are discretized. The large size in these problems generate several issues, among them we can mention: large space of storing, computing time, and the most important, lost of accuracy. A popular approach to solving such problems is assume that the PDE's solution is in a subspace, and the solution is sought there. This assumption and later searching …

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 …

Development Of 3-D Shear Wave Models Using A Multi-Objective Optimization Scheme, Lennox Emmanuel Thompson

Open Access Theses & Dissertations

Evidence of geologic activity still occurring in Rio Grande Rift (RGR) includes quaternary faulting, seismicity, and widening at a small rate. We map the crustal thickness and seismic velocity ratio to create crustal model cross sections that highlights the regional extension of the Southern Rio Grande Rift (SRGR). Specifically, we compute receiver functions and receiver function stacks for 147 USArray and previously collected data, and interpolate the crustal and velocity results using a kriging interpolation scheme. By incorporating gravity, magnetics, receiver functions, velocity models, and the interpretation of seismic reflection/refraction data, we produce a constrained crustal model that characterizes the …

Challenges In Assessing College Students' Conception Of Duality: The Case Of Infinity, Grace Olutayo Babarinsa-Ochiedike

Open Access Theses & Dissertations

Interpreting students' views of infinity posits a challenge for researchers due to the dynamic nature of the conception. There is diversity and variation among students' process-object perceptions. The fluctuations between studentsâ?? views however reveal an undeveloped duality conception. This study examined college students' conception of duality in understanding and representing infinity with the intent to design strategies that could guide researchers in categorizing students' views of infinity into different levels.

Data for the study were collected from N=238 college students enrolled in Calculus sequence courses (Pre-Calculus, Calculus I through Calculus III) at one of the southwestern universities in the U.S. …

Reinterpretation Of The Mesozoic Thrust Complex Of The Southern Spring Mountains, Nevada, Warren Harding Allen

Open Access Theses & Dissertations

The east verging Keystone thrust fault in the southern Spring Mountains west of Goodsprings, Nevada, is mapped with a sharp bend in its trace near Keystone Wash. This bend was previously explained in the context of out-of-sequence thrusting and a salient-recess relationship along the thrust system; a simple redirection of the Keystone thrust to a north verging thrust. Recent geochronological studies indicate that the east verging Keystone thrust to the north of Keystone Wash formed between 83-103Ma. Approximately 5 kilometers to the east a north verging branch of the fault system overlies rocks as young as 99Ma. At the location …

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 …

The Impacts Of Health Status And Exposure To Environmental Toxins On Children's Grade Point Average In El Paso, Texas, Stephanie Elizabeth Clark

Open Access Theses & Dissertations

Studies in the US have found that both exposure to environmental toxins and children's general health status negatively impact children's academic achievement. This Thesis will be made of up two papers. The first examines the impact of exposure to residential air toxins from a variety of sources on student's academic achievement and the second paper incorporates a measure of children's general health status into the statistical model from the first paper. This Thesis employs National Air Toxics Assessment (NATA) risk estimates from a variety of sources and individual-level data collected through a mail survey of fourth and fifth grade school …

Depositional Facies And Interpretation Of Salt-Sediment Interaction In The Lower Triassic Moenkopi Formation Adjacent To The Castle Valley Salt Wall, Paradox Basin, Utah, Ann Marie Foster

Open Access Theses & Dissertations

Stratigraphic, sedimentologic and compositional data collected from the Triassic Moenkopi Formation adjacent to the Castle Valley salt anticline, Paradox Basin, Utah indicate passive diapirism of the salt wall with well-developed topography and exposed salt during the Early Triassic. Moenkopi strata thin to 150m on to the Castle Valley salt anticline and thicken to an estimated 275m away from it, indicating control of sedimentation by salt-generated topography. The distribution of nine terrestrial facies assemblages within Moenkopi Formation strata on the margins of Castle Valley Salt Wall, in combination with identification of three halokinetic sequences interpreted from stratal architecture adjacent to the …

Computational Search For Novel Magnetic Clusters With Large Magnetic Anisotropy Energy, Nabil Md Rakinul Hoque

Open Access Theses & Dissertations

The clusters of transition metal atoms often show high spin moments but generally are reactive with the environment. Passivation of the surface atoms can lead to more stable clusters. We have explored one such avenue for passivation in this work. We picked the As@Ni12@As20 cluster which in the neutral state has a magnetic moment of 3 μB. We doped this cluster with various numbers of Mn atoms by substituting Ni atoms. The substitutional doping leads to spin moments located on the Mn atoms. The doping leads to symmetry breaking and as a consequence the number of structural isomers and spin …

Iso-Power-Efficiency: An Approach To Scaling Application Codes With A Power Budget, Rogelio Long

Open Access Theses & Dissertations

For many applications, speedup saturates and parallel efficiency decreases if the problem size is held fixed while increasing the number of processors. For some problems, it is possible to maintain a fixed parallel efficiency by increasing both the problem size and the number of processing elements. The rate at which the problem size must increase to maintain constant efficiency for a given rate of increase of the number of processors is given by the iso-efficiency function. We have developed a new scalability function called iso-power-efficiency that determines the rate at which the problem size must increase to maintain constant efficiency …

Bounded Rationality In Decision Making Under Uncertainty: Towards Optimal Granularity, Joseph Anthony Lorkowski

Open Access Theses & Dissertations

Starting from well-known studies by Kahmenan and Tversky, researchers have found many examples when our decision making seems to be irrational. We show that this seemingly irrational decision making can be explained if we take into account that human abilities to process information are limited. As a result, instead of the exact values of different quantities, we operate with granules that contain these values. On several examples, we show that optimization under such granularity restriction indeed leads to observed human decision making. Thus, granularity helps explain seemingly irrational human decision making.

Similar arguments can be used to explain the success …

Exploratory Study Of Seasonal Indoor Bioaerosols And The Associated Health Outcomes In Low-Income Communities In El Paso, Texas, 2014, Eric Martinez

Open Access Theses & Dissertations

Introduction: Structural degradation, moisture levels, and building failures can influence poor indoor air quality and create a good environment for bioaerosols. People spend much of their time indoors and can potentially be exposed to these bioaerosols. Several studies have correlated exposures to high concentrations of bioaerosols to various health problems, severe allergies, asthma, or other respiratory illness. Objectives: The objectives of this study are to describe bioaerosol concentrations, meteorological factors, and health outcomes during the summer and fall seasons; characterize bioaerosols (bacteria and fungi) collected in low-income communities; compare bioaerosol concentrations by season; compare meteorological factors to bioaerosol concentrations by …

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 …

Constructing Negotiated Meaning And Knowledge For The Sol Y Agua Project's Role-Playing Adventure Game Focused On Sustainability Problems In The El Paso-Rio Grande Area, Claudia Chihiro Santiago

Open Access Theses & Dissertations

Video games that address environmental sustainability issues could engage students. However, video games make simplifications and establish idealistic expectations that do not resemble real life sustainability challenges and settings. Game developers and scholars believe that depicting the complexity of the real world could help video games become effective educational tools. They call for additional procedures that incorporate information from actual settings and real life situations. Furthermore, scholars have argued that video games addressing sustainability issues can be improved or made more meaningful with the participation of youth from underrepresented populations, e.g., Latinos. The Sol y Agua project at The University …

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; …

Ac-Susceptibility Investigations Of Superspin Blocking And Freezing In Interacting Magnetic Nanoparticle Ensembles, Joshua Logan Morris

Open Access Theses & Dissertations

We have investigated the effect of dipolar interactions on the superspin blocking and freezing of 10 nm average size Fe3O4 magnetic nanoparticle ensembles. Our dynamic susceptibility data reveals a two-regime behavior of the blocking temperature, TB, upon diluting a Fe3O4/hexane magnetic nanoparticle fluid. As the nanoparticle volume ratio, Phi, is reduced from an as-prepared reference Phi = 1 to Phi = 1/96, the blocking temperature decreases from 46.1 K to 34.2 K, but higher values reenter upon further diluting the magnetic fluid to Phi = 1/384 (where TB = 42.5 K). We show that cooling below TB within the higher …

Enterprise Systems, Information Security Management Systems And Their Impact On Enterprise Risk: A 3-Essay Dissertation, Fernando Parra Reyes

Open Access Theses & Dissertations

This 3-essay study offers a comprehensive examination of hypothetical concepts related to the behaviors, attitudes, outcomes, processes, experiences, manifestations and indicators connected with an organizationâ??s design, implementation and management of a coherent set of policies, processes and systems to manage risks to its information assets. Network analysis tools are used to examine the relationships found in Information Security Management Systems (ISMS) literature published within the last decade. This study examines the effect of upgrades and implementations of enterprise systems on enterprise risk, as perceived by external investors. Finally, this study also assesses the impact of external IT governance certifications on …

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 …

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]) …