Digital Commons Network^™

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 …

Solvent And Concentration Effects Governing The Hierarchical Organization Of Asphaltenes: A Small-Angle X-Ray Scattering Study, Hasan Rejoanur Rahman

Open Access Theses & Dissertations

Asphaltenes are a group of planar molecules found in crude oil and are prone to aggregation which often causes blockage of pipes along the oil production stream resulting a huge economic downside. In an effort to understand the hierarchical organization of asphaltene in different solvents and concentrations, the solution structure of various asphaltene solutions were studied using small-angle x-ray scattering (SAXS). Solvents were chosen based on miscibility maps. Such maps are generated on the critical value of the solubility parameter difference between asphaltenes or asphaltene components, and a range of solvents. The critical factors that affect asphaltene and asphaltene component …

Efl Teachers' Identities And Their Teaching And Assessment Practices In A Public University Of A Major City In Colombia, Diana Patricia Pineda Montoya

Open Access Theses & Dissertations

This one-year long ethnographic case study seeks to add to the body of literature on EFL teachers' identities in Colombia by drawing on ethnographic methods and sociocultural theories to examine the identity construction of four EFL teachers at the university level. Specifically, this study explores how EFL teachers' identities shaped and were shaped by their teaching and assessment practices. The study was conducted at a public university and involved ethnographic participant-observation with four cátedra teachers (adjunct faculty) situated across five language programs in the Foreign Language Teaching Section (FLTS) of the Department of Languages.

The analysis of multiple data sources …

Optimization For The Allocation Of Funds For Pavement Maintenance In Pavement Management Systems, Armando Ramirez

Open Access Theses & Dissertations

Pavement maintenance and rehabilitation are critical and costly elements for highway agencies. A challenge for transportation agencies is to preserve roadways in an appropriate condition and extend the pavement service life while maintaining the safety and satisfaction of its users, and maximize the benefits obtained by the repair investments. Pavement maintenance programming is increasing in complexity due to limited resources and increments in traffic and population. Management decisions are usually based on personal judgment by pavement managers and sometimes those decisions are not even supported by previous experience. Research shows that optimization methods can produce significant benefits when transportation agencies …

Multi-State Multi-Objective Reliability Analysis Of Renewable Energy Systems, Luis Ramirez

Open Access Theses & Dissertations

This work presents a new multi-objective evolutionary algorithm (MOEA), capable of obtaining a system's reliability while considering other objectives that concurrently need to be optimized. The algorithm is applied in two different case studies. One of the problems considers a multi-state, multi-objective renewable energy system which tries to find a configuration between solar panels and wind turbines that maximizes the system's reliability of achieving specific energy demand, while also minimizes the purchasing cost of the system. The second case study analyzes a flexible manufacturing system that contains different machines that can perform different functions. The primary objective is to obtain …

Proactive Stress Management For Firefighters, Amanda M. Mead

Antioch University Dissertations & Theses

Firefighters in the United States face significant risks as they serve their communities. Despite research that has thus far demonstrated the benefits of proactive coping strategies, and a previously suggested need for a proactive stress management program for firefighters, no such program has yet been implemented or evaluated specifically for firefighters. The purpose of this dissertation was to research stress and stress management using qualitative interviews with New Hampshire and Arizona firefighters to inform the development of a future primary prevention program (proactive stress management) to this at-risk population. Results yielded themes of sleep deprivation, stigma, protectiveness, mental health, lack …

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 …

A Comparative Assessment Of Food Deserts Using Geographic Information Systems (Gis) In El Paso County, Tx And Loudoun County, Va, Amit Ugamraj Raysoni

Open Access Theses & Dissertations

BACKGROUND & SIGNIFICANCE: Consumption of processed foods high in sodium and fat can have a plethora of health complications, including, but not limited to hypertension, high cholesterol levels, obesity, diabetes and cancer. Previous studies have documented that lack of access to viable healthy eating options' grocery stores selling affordable fresh fruits and vegetables - in any neighborhood or area can result in negative public health outcomes. These areas devoid of such grocery stores and healthy eating options can be classified as "Food Deserts", as per one of the criteria adopted by the United States Department of Agriculture (USDA). In addition, …

From The Perspectives Of School Staff: The Helpful And Hindering Factors Of Recovery From A School Crisis, Andria Weiser

Antioch University Dissertations & Theses

The impact of a violent event at a high school has an effect that ripples throughout the entire community. The present study sought to review what led teachers and school staff to recover after an unexpected violent event killed two students. The study sought to understand the process of recovery, including the post crisis intervention, response, and factors of personal resiliency, from the perspective of the staff and teachers involved. Enhanced Critical Incident Technique (ECIT), a robust qualitative research methodology used to study phenomenological constructs in a systematic way, was employed to give voice to the participants and understand the …

Tribological Characterization Of Ti-Based Alloys For Biomedical Applications In Simulated Body Fluid, Edgar Reyes

Open Access Theses & Dissertations

Tribology is a terminology introduced in the 1960's and it is a study that relates to the investigation of the damage of materials. Titanium, as a material used for a wide range of application, it has been brought to the attention of researchers some characteristics such as its much lower density if compared to steel, its capability as an alloying agent with an amount of metals to enhance physical and mechanical properties, to name just a few characteristics. This paper will discuss the performance on tribology behavior in two different Titanium alloys. These Titanium alloys are Ti-6Al-4V (Ti64), and Ti-24Nb-4Zr-8Sn …

Geant4 Study Of A Gamma Ray Collimator For Proton Therapy, Selim Romero

Open Access Theses & Dissertations

This Thesis presents the results of an investigation of the use of collimators in proton therapy. The problem to solve is that in the proton therapy, we do not have the certainty if the target-tumor is receiving all the energy to destroy it or if we are really shooting at this one, so the remaining question is: where the beam is hitting? How to know it? to answer those questions our work has the propose of study proton therapy to determine where the proton interactions occur, these kinds of interactions usually produce gamma rays, and we simulated in GEANT4 the …

Facies Changes Associated With Formation Of An Extensive Salt Shoulder By The Coastal And Eolian Carmel And Entrada Formations, Gypsum Valley, Colorado, Ryan Burtron Ronson

Open Access Theses & Dissertations

A salt shoulder forms a zone at the margin of a salt diapir where that margin steps relatively abruptly inward. These shoulders form when the salt rise rate near the diapir margin substantially decreases or stops relative to the salt rise rate at the inboard central part of the diaper. Based on current models of interactions between these salt shoulders and overlying sediment, it was anticipated that the thickness changes of the Entrada and Carmel formations would be only gradual and that any notable thinning would take place proximal to the neck portion of the diapir that would still have …

Evaluation Of Orthophosphate Based Corrosion Inhibitors In Treated Water For El Paso Region, Francisco Solis Jr

Open Access Theses & Dissertations

Corrosion is an electrochemical phenomenon that involves the deterioration of a metal by the reaction of itself with its surrounding environment. One of the greatest issues for water utilities around the country is to keep the water quality safe. Corrosion can affect the quality of the water that we use on a daily basis by adding a bad taste, increasing the concentration of heavy metals, and allowing outside contaminants to enter the distribution system. The use of phosphate based corrosion inhibitors was tested in two different metals: iron and copper. The phosphate in the inhibitors react with the calcium in …

Tungsten Doping Induced Superior Mechanical Properties Of Hafnium Oxide For Energy Applications, Ann Marie Uribe

Open Access Theses & Dissertations

Hafnium oxide, or hafnia, is a high temperature refractory material with good electrical, chemical, optical, and thermodynamic properties. The effects of dopants have been widely studied, especially after the discovery of ferroelectricity induced in hafnia thin films. While attractive and used in the opto-electronic, memory devices, and semiconductor industries, there is a lack in the literature on enhancing the mechanical properties of hafnium oxide, specifically through doping it with tungsten, another material of interest particularly for future high temperature device applications. Thus, this work aimed to grow hafnia thin films doped with varying amounts of tungsten. The samples were grown …

Investigating Early Age Behavior Of Portland Cement Concrete In Arid Regions, Evan Wolf

Open Access Theses & Dissertations

The early-age behavior and properties of portland cement concrete change rapidly over time as a result of the hydration process. Comprised of a series of chemical reactions, this process accelerates nonlinearly with the curing temperature. Gaining knowledge and understanding of the phases of the hydration process (i.e., dormant, setting, and hardening) plays an important role in the timely opening of roads, resuming of construction, and achieving long-term performance. Standard tests such as ASTM C403 arbitrarily define the time of initial and final setting of concrete. Despite decades of studies concerning setting times, actual predictions still span hours, while the quality …

Upper Mantle Earth Structure In Africa From Full-Wave Ambient Noise Tomography, E. L. Emry, Yang Shen, A. A. Nyblade, A. Flinders, X. Bao

Graduate School of Oceanography Faculty Publications

Our understanding of the tectonic development of the African continent and the interplay between its geological provinces is hindered by unevenly distributed seismic instrumentation. In order to better understand the continent, we used long-period ambient noise full-waveform tomography on data collected from 186 broadband seismic stations throughout Africa and surrounding regions to better image the upper mantle structure. We extracted empirical Green's functions from ambient seismic noise using a frequency-time normalization method and retrieved coherent signal at periods of 7–340 s. We simulated wave propagation through a heterogeneous Earth using a spherical finite-difference approach to obtain synthetic waveforms, measured the …

Response Of Benthic Fauna To Experimental Bottom Fishing: A Global Meta-Analysis, Marija Sciberras, Jan Geert Hiddink, Simon Jennings, Claire L. Szostek, Kathryn M. Hughes, Brian Kneafsey, Leo J. Clarke, Nick Ellis, Adriaan D. Rijnsdorp, Robert A. Mcconnaughey, Ray Hilborn, Jeremy Collie, C. Roland Pitcher, Ricardo O. Amoroso, Ana M. Parma, Petri Suuronen, Michel J. Kaiser

Graduate School of Oceanography Faculty Publications

Bottom-contact fishing gears are globally the most widespread anthropogenic sources of direct disturbance to the seabed and associated biota. Managing these fishing disturbances requires quantification of gear impacts on biota and the rate of recovery following disturbance. We undertook a systematic review and meta-analysis of 122 experiments on the effects-of-bottom fishing to quantify the removal of benthos in the path of the fishing gear and to estimate rates of recovery following disturbance. A gear pass reduced benthic invertebrate abundance by 26% and species richness by 19%. The effect was strongly gear-specific, with gears that penetrate deeper into the sediment having …

Towards Process Standardization For Requirements Analysis Of Agent-Based Systems, Khaled Slhoub, Marco Carvalho

Electrical Engineering and Computer Science Faculty Publications

The development of agent-based systems is negatively impacted by the lack of process standardization across the major development phases, such as the requirements analysis phase. This issue creates a key barrier for agent technology stockholders regarding comprehending and analyzing complexity associated with these systems specifications. Instead, such fundamental low-level infrastructure is loosely attended to in an ad-hoc fashion, and important aspects of requirements analysis are often neglected altogether. The IEEE Std 830 model is a recommended practice aimed at describing how to write better quality requirement specifications of conventional software. Knowing that agent-based computing is a natural and logical evolution …

Spatio-Temporal Variations In The Urban Rhythm: The Travelling Waves Of Crime, Marcos Oliveira, Eraldo Ribeiro, Carmelo Bastos-Filho, Ronaldo Menezes

Electrical Engineering and Computer Science Faculty Publications

In the last decades, the notion that cities are in a state of equilibrium with a centralised organisation has given place to the viewpoint of cities in disequilibrium and organised from bottom to up. In this perspective, cities are evolving systems that exhibit emergent phenomena built from local decisions. While urban evolution promotes the emergence of positive social phenomena such as the formation of innovation hubs and the increase in cultural diversity, it also yields negative phenomena such as increases in criminal activity. Yet, we are still far from understanding the driving mechanisms of these phenomena. In particular, approaches to …

Hybrid Long-Range Hyperbolic Phonon Polariton Waveguide Using Hexagonal Boron Nitride For Mid-Infrared Subwavelength Confinement, Yuchen Yang, Michael F. Finch, Di Xiong, Brian A. Lail

Electrical Engineering and Computer Science Faculty Publications

Long propagation waveguides are critical for any photonic-on-chip applications. There has been an extensive investigation in using plasmon polaritons for near-infrared and optical networks, however, for mid- to long-wave IR applications phonon polaritons are required given that plasmonic polaritonic effects are negligible. In recent years, extensive research has been conducted on hexagonal boron nitride (h-BN), which has shown h-BN to have naturally occurring subwavelength, volumetrically confined hyperbolic phonon polaritons (HPhPs). This work presents numerical results for both long- and short-range phononic volumetric polariton modes in a slab of h-BN. A hybrid long-range phononic waveguide consisting of two identical dielectric cylinder …

The Challenges And Outcomes Of Critical Diversity Scholarship, Inge Bleijenbergh, Lize A. E. Booysen, Albert J. Mills

Faculty Articles

No abstract provided.

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 …

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 …

Utilization Of Digital Image Correlation Technique In Asphalt Testing, Alejandra Escajeda

Open Access Theses & Dissertations

Over 90% of the roads in the United States are paved with hot mix asphalt (HMA). These asphalt pavements include many mix types, such as permeable friction course (PFC), stone mastic asphalt (SMA) and conventional dense graded mixes. The performance of the HMA is an important factor in pavement design programs used by many departments of transportation. The type of HMA selected not only influences the performance of the pavement structure, but also the pavement's life cycle cost. The performance life of an HMA mix is to be studied further with experimental data in order to contribute and expand on …

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 …

Investigating The 2016 Jackson, Wyoming Earthquake Sequence Using Waveform Cross-Correlation And Seismic Array Methods, Emily Jo Graves

Open Access Theses & Dissertations

During a visual inspection of PDAR data extracted for the catalog events, I observed additional, unreported events, which is to be expected during an energetic swarm or seismic sequence. The casual observation of missed events strongly implied that more such missed events could be found in the data, which could improve the completeness of the earthquake catalog for the Jackson, Wyoming area. Catalog completeness improves our assessment of a region's tectonic behavior and earthquake exposure. To search for recurring swarm or earthquake sequence behavior, I applied waveform correlation methods to scan nearly two decades of continuous PDAR waveforms, comparing to …

An Econometric Analysis Of The 2016-2017 Nba Regular Season, Michael Lynn Jaeger

Open Access Theses & Dissertations

This study examines the on-court performance of the thirty National Basketball Association (NBA) teams during the 2016-17 NBA basketball season. Cross sectional data are employed to analyze the wins for the 2016-17 NBA basketball season. Although the results are inconclusive, there is one notable outcome in the negative variable for human capital payroll. Field goal percentage is favored over other in game statistics. Replication of this study for the 437 teams in National Collegiate Athletics Association provides and intriguing opportunity for further research.

Age At First Offense As A Predictor Of Recidivism Among High-Risk Juvenile Delinquents Versus All Juvenile Delinquents, Claudia Iliana Lopez

Open Access Theses & Dissertations

Researchers have generally found a moderate negative correlation between juvenile delinquents' age at first offense and their risk of recidivism (Cottle, Lee, & Heilbrun, 2001). However, two studies at the El Paso Juvenile Probation Department (El Paso JPD) by Valenzuela (2011) and Ranadive (2014) found the correlation of age at first referral with recidivism to be non-significant and close to zero. A possible explanation for these findings at El Paso JPD is that age at first referral is predictive of recidivism among high-risk juvenile offenders but not in the general population of all juveniles referred to the justice system. The …