Physical Sciences and Mathematics Commons^™

An Integrated Machine Learning Geological Field Tool In The Age Of Big Data And Drones, Guillermo Vargas

Open Access Theses & Dissertations

Unmanned aerial vehicles (UAVs) and machine learning are relatively new research tools in the geosciences that can be used to collect and analyze large data sets rapidly. We combine the power of rapid data collection using unmanned aerial vehicles with machine learning algorithms to develop a field-based system to identify targeted geological features. For data collection, we have used a commercial-grade UAV which carried visible-wavelength and multispectral (visible- infrared) cameras. We analyzed the data with machine learning and machine vision algorithms that can classify rock units exposed in a field area. We have identified algorithms that in previous literature have …

Electrocatalysts Based On Organic Macrocycles For Electrochemical Water Splitting, Yanyu Wu

Open Access Theses & Dissertations

Water splitting, which is the dissociation of water into hydrogen and oxygen gases, can be separated into two half reactions corresponding to the hydrogen evolution reaction and oxygen evolution reaction (HER and OER, respectively). Both reactions offer a promising way for storing energy into the form of chemical bonds, which is an important strategy for the development of clean-energy technologies. A main area of interest while studying HER and OER is to design effective and robust electrocatalysts made from earth-abundant materials. This dissertation describes several homogeneous and heterogeneous systems for the electrocatalytic generation of hydrogen and oxygen gases.

In Chapter …

Geostatistical And Geospatial Distribution Of Multiple Metallic Elements In Agricultural Regions Of The Mid-Continental Usa, Najwah Alssaeidi Ahmed Almesleh

Open Access Theses & Dissertations

Regional geochemical mapping constitute the chemistry of the surface of the earth in a large scale and relatively low sample density. It is widely accepted scientific activity and man uses some cases to identify contamination. In the present study, data present in national geochemical survey database was used to investigate the chemical loading loading of the agricultural soil. In the mid-continent region of the United States. Several traditional parameters were used mainly the enrichment factor (EF), and geoaccumulation index (I geo). Total chemical influence (TCI) maps were used to guide sampling. In addition, regional trace element chemistry of bedrock was …

Forecasting Space Weather Using Deep Learning Techniques, Sumi None Dey

Open Access Theses & Dissertations

Solar activity gives rise to various kinds of space weather among which solar flares have serious detrimental eects on both near-Earth space and our upper atmosphere that will have consequent influence in our lives. For example, solar flares can damage satellite infrastructure, hinder power grids, disrupt Global Positioning Systems (GPS) and disrupt long-distance communication. Airplane pilots, cabin crew and astronauts can be aected by the harmful radiation released from the Sun. As a result, there is a need of a methodology to forecast space weather accurately. In this work, we have developed a deep learning architecture to do the short-range …

Detection Of Pharmaceuticals And Personal Care Products In The Rio Grande And Their Effects On A Model Aquatic Invertebrate (Rotifera, Monogononta: Plationus Patulus), Enrique David Garcia

Open Access Theses & Dissertations

Rivers, including the Rio Grande, receive discharges from urban, agricultural, and industrial areas. These discharges have potentially harmful contaminants that may affect life span, fecundity, and/or behaviors of aquatic organisms. In this project, water quality was analyzed near a discharge point source and impacts of pharmaceuticals and personal care products (PPCPs) on a non-target organism (Plationus patulus) were investigated. Long-term and integrative organic samplers (POCIS) were left in situ for about 1 month near a wastewater treatment plant that discharges effluent into the Rio Grande. Over 40 PPCPs, including carbamazepine (ranging from 17.50 to 584.29 ng/L), erythromycin (ranging from 0.51 …

Environmental Injustice And Racial/Ethnic Heterogeneity In Houston, Texas, Michel G. Loustaunau Garcia

Open Access Theses & Dissertations

This Thesis seeks to contribute to distributive environmental justice (EJ) research by analyzing racial/ethnic and intra-ethnic disparities in potential health risks from exposure to hazardous air pollutants (HAPs) in Harris County, the most populous county in Texas. Previous EJ research in this urban area has not examined intra-ethnic heterogeneity in exposure to air pollutants or attempted to compare social disparities in exposure to air pollution caused by vehicular (mobile) and point (stationary) sources. The goal of this study is to determine how the EJ implications of cancer risks from inhalation exposure to HAPs from mobile and stationary sources differ across …

Magnetotelluric Analysis Of Central Kenya Kenyan Rift Volcanoes For Geothermal Development, Anna Wairimu Mwangi

Open Access Theses & Dissertations

Abstract

High temperature geothermal resources are vast along rift margins because of emplacement of magma in shallow crust. This is the case along the Kenyan Rift valley also known as the Gregory Rift. It is the Eastern arm of the East African rift and a chain of volcanoes along the rift graben characterizes it. We use (MT) magnetotelluric method to image beneath the peralkaline province of the Kenya Rift i.e. Olkaria, Eburru, Badlands, and Longonot volcanoes. The resistivity structure shows active geothermal activity happening at the upper 3km from the subsurface as evidenced by low resistivity cap rock comprised of …

Determing Fault Location Within An Active Rift Basin Using Gravity Analysis To Determine Fault Movemnet And Effect On Water Recharge, Mark Andrew Ornelas

Open Access Theses & Dissertations

The growth of the El Paso, TX and Ciudad Juárez, Chihuahua, metropolitan area has increased reliance of groundwater pumping from the Hueco Bolson. With growing demands for water and recharge of the bolson not occurring at a fast enough rate, water storage within the bolson is beginning to diminish. My study focuses on locating and understanding how faults interact with water flow into the basin and how they aid in storing water on the northwestern side of the bolson. Previous studies in the northernmost part of my study area have delineated a series of faults that predominantly trend northwest-southeast. In …

Extraction Of Fiber Morphology From Sem Images For Quality Control Of Fiber Reinforced Composites Manufacturing, Md Fashiar Rahman

Open Access Theses & Dissertations

The morphology of fibers (e.g. spatial uniformity, orientation, and length) plays a decisive role in determining the material properties or fabrication quality of fiber-reinforced nanocomposites. Hence, determining the morphology becomes a very critical issue in the field of nanocomposite quality control. The conventional way of quality inspection is to take the scanning electron microscopic (SEM) images of the cross-section of composite material and do the visual checking of these SEM images to evaluate the nanofiber alignment and length distribution. But this type of inspection is often subjective, inaccurate and time consuming. Moreover, the extremely small size of nanofibers makes the …

Characterization And Geochemistry Of Carbonate Caprock Associated With The Gypsum Valley Salt Wall, Paradox Basin, Colorado: Implications For Understanding Lateral Caprock Emplacement, Piper Lee Poe

Open Access Theses & Dissertations

On the northeastern side of Gypsum Valley salt wall in the Paradox Basin of Colorado, discontinuous exposures of layered gypsum and carbonate rocks were previously mapped as the contact between diapiric Paradox Formation and marine limestone of the Pennsylvanian Honaker Trail Formation. Utilizing new and existing mapping, petrographic and isotopic geochemical analyses, this study reinterprets this zone to represent lateral gypsum and carbonate caprock that formed in the Triassic during passive rise of the Gypsum Valley salt wall. Gypsum Valley lateral carbonate caprock can be distinguished from Pennsylvanian and Permian depositional carbonate strata exposed elsewhere on the salt wall by …

Geophysical Investigations Of Southcentral Alaska, Felix Dziedzorm Ziwu

Open Access Theses & Dissertations

The Castle Mountain Fault (CMF) is the closest (<50 km) active fault to Anchorage, Alaska and is known to be capable of producing earthquakes of magnitude 7.0 â?? 7.1. While several mapping and trenching studies have been conducted along the CMF, geophysical investigations along the fault zone have been limited. We use over 700 recently collected, closely spaced gravity observations, in addition to existing regional gravity, aeromagnetic, seismic reflection, well log data, and geologic information, to develop new 2D models of the deeper structure of the CMF system. We developed four 2D integrated forward models across the Castle Mountain Fault. These models indicate differences between the western and eastern segments of the Castle Mountain Fault. The models show a thick sequence of Tertiary to Mesozoic sediments overlying the Peninsular terrane basement at varying depths within the area. We identified two main intrusive granitic rocks based on the varying susceptibilities. These granitic rocks share a possible fault contact with the Mesozoic sedimentary rocks. The model also shows that the CMF cuts through the Mesozoic sediments at depth. These rocks can create strong coupling along the fault and with the decreasing eastward angle of subduction, it is highly for fluid migration to the eastern edge of the subducting Yakutat microplate. Seismic events plotted along the profiles supports the Holocene motion along the western CMF (WCMF) and indicates a deeper extent of the CMF into the crust. The eastern CMF shows high rate of deformation based on the structures associated with the Mesozoic rocks.

On Numerical Stochastic Optimal Control Via Bellman's Dynamic Programming Principle, Prince Osei Aboagye

Open Access Theses & Dissertations

In this work, we present an application of Stochastic Control Theory to the Merton's portfolio optimization problem. Then, the dynamic programming methodology is applied to reduce the whole problem to solving the well-known HJB (Hamilton-Jacobi-Bellman) equation that arises from the Merton's portfolio optimization problem subject to the power utility function. Finally, a numerical method is proposed to solve the HJB equation and the optimal strategy. The numerical solutions are compared with the explicit solutions for optimal consumption and investment control policies.

Effects Of Increasing Deciduous Shrub Litter On Ecosystem Functioning In Alpine Tundra, Alejandro Emmanuel Benhumea

Open Access Theses & Dissertations

Rising temperatures due to global warming have resulted in rapid environmental changes in northern environments, resulting in an increase in deciduous shrub growth which has the potential to alter soil ecosystem properties and processes. In order to address some potential mechanisms by which shrubs alter ecosystem properties and processes, we designed an experiment which separated the effects of physical shrub presence and the effects of litter quantity in a fully factorial experiment on a north facing alpine plateau in the southwest Yukon, Canada. Specifically, we asked the following questions: What are effects of shrub litter, independent of shrub presence, on …

Photo-Induced Charge Transport In Graphene And Semiconducting Wse2 Integrated With Zero-Dimensional Materials For Enhancing Optoelectronic Device Characteristics, Srishti Chugh

Open Access Theses & Dissertations

Two-dimensional (2D) materials encompass a diverse array of properties from the metallic-like character of graphene to the semiconducting nature of many of the transition metal dichalcogenides (TMDCs) such as tungsten diselenide (WSe2). These materials exhibit intriguing interactions with incoming radiation which makes them interesting for electronics and optoelectronics, especially given the high electron mobility and the ballistic nature of the electronic transport under certain conditions. In particular, the semiconducting TMDCs, such as WSe2, express an indirect-to-direct optical transition with scaling from the bulk to monolayers. Despite the enhanced optical absorption characteristics of monolayer WSe2 stemming from its direct band gap, …

Development Of A Dna Aptamer That Specifically Inhibits Human Carbonic Anhydrase Ii, Afroz Karim

Open Access Theses & Dissertations

Carbonic anhydrases (CA) are a family of enzymes that catalyze the rapid interconversion of carbon dioxide and water to bicarbonate. Carbonic anhydrase II is the most abundant protein in the cytosol. CA II inhibitors are emergent therapeutic targets for the development of antiglaucoma agents. Glaucoma is a disease affecting large number of people and characterized by an elevated intraocular pressure due to excessive secretion of aqueous humor. The enzyme CA II is responsible for the secretion of aqueous humor. Isoforms of CA II such as CA IV and CA I are present in many tissues and organs other than the …

Exploring The Effects Of Zinc Nanoparticle Concentration, Antioxidant, And Media On Cilantro (Coriandrum Sativum), And Radish (Raphanus Sativus) Plants Growth, Venkata Laxma Reddy Pullagurala

Open Access Theses & Dissertations

Engineered nanomaterials (ENMs) have proven to be one of the emerging chemicals of concern in the contemporary times. Soil acts as one of the major sinks of these ENMs. Reports have shown that ENMs have varied effects on soil biota. Particularly, their effects on plants are inconsistent. Amongst these ENMs, ZnO nanoparticles (nZnO) are the fourth largest raw materials in the nanotechnology industry. Globally, it is estimated that around 34,000 tons of n ZnO are utilized per year. The nZnO exposure on terrestrial plants yielded both beneficial as well as detrimental effects. Recently, there is an emerging evidence about the …

Mapping Complex Fold-Thrust Systems In An Inverted Rift Basin: Indio Mountains, West Texas, Samantha Ramirez

Open Access Theses & Dissertations

This study reports on new geologic mapping in the southern Indio Mountains of west Texas, where minimal research has been done since development of modern fold-thrust belt concepts. This study integrated an analysis of structure and the stratigraphy of the region. A stratigraphic column of the middle Cretaceous upper Yucca Formation was measured to 1) compare the lithology to that of the section previously measured in the hanging wall of the Squaw Peak thrust in the footwall of the Indio normal fault, 2) create informal members in the formation to aid mapping; and 3) identify previously unmapped structures in the …

A Comparative Study Characterizing Traffic Related Air Pollutant Concentrations At Near-Road Communities In El Paso, Texas, Adan Rangel

Open Access Theses & Dissertations

Numerous scientific studies have demonstrated the influence of traffic related air pollution at near-road communities and the associated health risks for these populations. This study uses on-site air quality monitors to characterize air pollutants at near-road schools in El Paso, TX to understand children's exposure to traffic-related air pollutants. Ambient air monitoring stations were installed at Coldwell Elementary, Bliss Elementary, and a residential house located in close proximity to major inter-state roadways. In this study, air quality data for PM2.5, PM10, NO2, and O3 was collected over a period of nine weeks in Fall 2018. The spatial and temporal variability …

Geophysical Studies Of Southwestern Part Of The North American Craton, Luis Martin Sandoval Magallanes

Open Access Theses & Dissertations

The present study, based on combined geophysical, geochronological and isotopic data identifies a cratonic block which we call the Western Chihuahua-Mesa Central megablock (WCMB) in northern Mexico. New Bouguer and isostatic gravity anomaly maps revealed a conspicuously distinct, spatially-extensive gravity minima over a region extending from north western Chihuahua to as far south as the Mesa Central (MC). This region can be differentiated from the surrounding mobile belts with significantly higher gravity anomaly values. Gravity modeling combined with sparse seismically determined crustal thickness estimates indicate that the proposed WCMB region has crustal thicknesses ranging from 38 to 42 km. The …

Back Calculation Of Intelligent Compaction Data For Mechanical Properties Of Soil System, Afshin Gholamy

Open Access Theses & Dissertations

For national economy, it is very important to have a reliable infrastructure. Because of this, all over the world, new roads are constantly being built and old roads are being maintained and, if necessary, expanded and/or repaired. Building a good quality road is very expensive, it costs several million dollars per kilometer. It is therefore crucial to make sure that the newly built and newly repaired roads are sufficiently stiff - so that they can withstand the predicted volume of traffic for a sufficient number of years. Current methods of estimating the stiffness are time-consuming and labor-consuming. The most accurate …

Experimental Laser Powder Bed Fusion System For Difficult To Process Metallic Materials, Syed Zia Uddin

Open Access Theses & Dissertations

The focus of this research was twofold, such as development of defect free fabrication parameters for laser powder bed fusion (LPBF) processing of crack prone or difficult to process metallic materials, and study of the temperature dependence of emissivity for some commonly used metal alloy powders in LPBF process. The later objective extends to the implementation of multiwavelength (MW) pyrometer technology for in situ true surface temperature measurement in LPBF process. LPBF is an additive manufacturing (AM) process capable of layer-by-layer manufacturing by successive laser melting of each layer according to CAD data. AM manufacturing has the inherent advantages of …

Walls And Wilderness: Analyzing The Impacts Of Border Barriers On U.S. Government Lands Of The United States - Mexico Border, Bryce Garrett Fugate

Open Access Theses & Dissertations

This paper seeks to describe the impacts of physical structures (fences, walls, barricades, etc.) on five selected areas of federally-protected U.S. lands along the U.S.-Mexico border that fall under the jurisdiction of the U.S. Department of the Interior. The five selected areas are: Santa Ana National Wildlife Refuge, Big Bend National Park, Organ Mountains - Desert Peaks National Monument, the Tohono O'odham Nation Reservation, and Organ Pipe Cactus National Monument. The research looks into the historical development of structures put in place on the U.S. - Mexico border, how they have become ever more ubiquitous in the region, and what …

Integrated Statistical And Machine Learning Algorithms For Predicting And Classifying G Protein-Coupled Receptors, Fredrick Ayivor

Open Access Theses & Dissertations

G protein-coupled receptors (GPCRs) are transmembrane proteins with important functions in signal transduction and often serve as drug targets. With increasing availability of protein sequence information, there is much interest in computationally predicting GPCRs and classifying them according to their biological roles. Such predictions are cost-efficient and can be valuable guides for designing wet lab experiments to help elucidate signaling pathways and expedite drug discovery. There are existing computational tools of GPCR prediction that involve principal component analysis (PCA), intimate sorting (IS), support vector machine, and random forest (RF) techniques using various sequence derived features. While accuracies of over 90\% …

Insights Into The Interaction Of Copper Oxide Nanopar-Ticles With Sweetpotato (Ipomoea Batatas (L.) Lam.): The Role Of Lignin On Copper Uptake And Translocation, Nestor Javier Bonilla Bird

Open Access Theses & Dissertations

Sweetpotato [Ipomoea batatas (L.) Lam.] is widely cultivated in many countries worldwide. The world production of sweetpotato is around 127 billion tons and it is ranked seventh in the world as a staple food. After harvesting, sweetpotato storage roots are treated with fungicides to prolong shelf life. Lignin plays an important role in the conservation of the storage roots. One of the practices to activate the lignification pathway is called “curing process.” The roots are placed under 80% relative humidity at a temperature of 29 ºC for a period of 7 to 15 days, followed by a cooling period at …

A Mixed Finite Element Method For The Coupling Of Linear Elasticity And Stokes Flow, Maranda Bean

Open Access Theses & Dissertations

The complex interaction between fluids and structures require the coupling the laws concerning structure mechanics and fluid dynamics and are of vital importance to many scientific and engineering fields. We propose a method for modeling the coupling of a linearly elastic solid and slow fluid flow modeled by Stokes equations. The model equations are expressed in terms of displacement, velocity and stress. With these primary variables, we use a single mixed finite element space based on the Hellinger-Reissner variational principle for linear elasticity to discretize the resulting system spatially. This results in more accurate approximations for stress than those obtained …

A Machine Learning Approach To Rendering 3d Stratigraphic Models Of The Hueco Bolson, Western Texas And Northern Mexico, Joel Gerardo Castro

Open Access Theses & Dissertations

Data visualization is an effective way to analyze large amounts of spatial information to identify correlations, trends, outliers, and patterns. In this Thesis I test the application of supervised machine learning algorithms to render a series of 3D visualizations designed to highlight general traits of the Hueco Bolson, a geologic basin located east of the Franklin Mountains in far west Texas and northern Mexico. A geologic basin is one of the most common inland places where sediments are collected. The geology of basins is of much interest to geophysicists, hydrologists, paleontologists, and oil prospectors. Here the task of 3D geologic …

Cerium Levels In Fine And Coarse Airborne Particulate Matter In El Paso, Texas - A Geospatial And Temporal Investigation, Esenam Adzo Fumador

Open Access Theses & Dissertations

The Paso Del Norte airshed is shared by two cities, El Paso, Texas, U.S.A. and Ciudad Juarez, Chihuahua, Mexico. Population growth in both cities and their desert climate has created persistent challenges in meeting air quality standards for particulate matter, which is generated from both natural and anthropogenic sources.

In Europe, ceria or cerium dioxide (CeO2), introduced into diesel road fuel as nanoparticles, has significantly reduced emissions as well as increased vehicle mileage. Concerns have been raised there about the fate and potential health risks associated with the nanoceria (n-Ce) emitted in diesel exhaust. In the U.S.A on-road use of …

A Framework To Audit Scheduling Events In The Linux Operating System, Edward G. Hudgins

Open Access Theses & Dissertations

Soft real-time systems have responsiveness requirements that are desirable but not critical for operational effectiveness. This Thesis describes a new scheduler logging framework named "Integrated Process Scheduler Archiver" (IPSA) intended to assist with this analysis. Due to human sensitivity to interface delays on gesture-driven devices, mobile devices are a common case of soft-real time systems. Mobile systems generally do not incorporate real-time schedulers, but instead utilize over-provisioning and a variety of scheduling heuristics to generally provide acceptable responsiveness. These devices are highly multi-programmed Energy limitations on mobile limit the extent of overprovisioning, thereby increasing the sensitivity of system behavior to …

Onshore-Offshore Velocity Models North Of The Mendocino Triple Junction In Northern California, Alan Jacquez

Open Access Theses & Dissertations

The Mendocino Triple Junction (MTJ) marks the boundary where the Gorda plate, North American Plate, and Pacific Plate meet, separating the Cascadia subduction zone to the North from transform tectonics of the San Andreas plate boundary. This actively deforming region experiences high seismic activity and young geological features. Here we examine offshore and onshore seismic wide-angle reflection and refraction data north of the MTJ crossing the Cascadia subduction zone from offshore northern California to the Western edge of the Sierra Nevada. We image subsurface structures in this region by creating P-wave velocity models using datasets collected in 1993 to 1994 …

A Combined Field, Experimental And Modeling Approach To Understand The Impacts Of Flood Irrigation On Pedogenic Caco3 And Co2 Dynamics In Drylands, Anna Cristina Ortiz

Open Access Theses & Dissertations

Soil salinization is a global problem affecting 10% of agricultural soils, particularly in irrigated arid-lands. This study investigated salt loading through flood-irrigation, particularly of calcite (CaCO3) salt in the southwest of the United States. To evaluate the impact that flood-irrigation has on CaCO3 buildup and its effect on C-cycling, a natural soil and two agricultural soils were sampled: a pecan orchard and an alfalfa field in the El Paso, TX region. Agricultural soils in this study are flood irrigated by the Rio Grande river and by ground waters in its absence, both of which are oversaturated with calcite.

To trace …