Digital Commons Network^™

Evaluation And Modeling Of Electrodialysis For High-Recovery Brackish Water Desalination, Shahrouz Jafarzade Ghadimi

Open Access Theses & Dissertations

This research investigates the feasibility of desalination of brackish water with electrodialysis (ED), using laboratory testing and mathematical modeling. Several experiments were performed to characterize ion-specific transport and to evaluate tradeoffs between salinity removal and specific energy consumption. A 200 cm2 Ameridia ED stack was used to perform desalination experiments with real brackish groundwater from the Kay Bailey Hutchison desalination plant in El Paso, Texas, and the results showed limiting current density of 160 A/m2 for 5 cm/s. A higher conductivity reduction was observed for flow velocity of 5 cm/s compared to 13 cm/s. Ion transport selectivity (based on relative …

A Comparison Of Data-Driven And Process-Based Modeling For Nutrient Estimation In A Eutrophic Reservoir, Yohtaro Kobayashi

Open Access Theses & Dissertations

As land use around bodies of water changes, the need to model the body of water increases. Models help to educate, understand, and predict the state of water. Process-based models are commonly used in modelling bodies of water, but there are challenges with these kinds of models. They require data which can be difficult for certain communities to obtain due to logistics or cost, are computationally intensive, technically complicated, and require calibration. In contrast, a data-driven model simply connect relationships from the data, are not as computationally intensive nor technically complicated, and do not require calibration. This research compared a …

Weather Prediction: Improving Accuracy Using Data Mining And Forecasting Techniques, Pedro Marquez

Open Access Theses & Dissertations

This study is focused to provide the insights of weather to understand the significance of weather changes in any parameter. Weather forecasting contributes to the social and economic welfare in many sections of the society. Weather is extremely difficult to predict because it is a complex and chaotic system. This means that small errors in the initial conditions of a forecast grow rapidly and affect predictability. Nowadays, massive real-time data is being generated by IoT devices, radars, weather stations, and satellites. The need to adopt big data analytics in IoT applications is compelling. These two technologies have already been recognized …

Development Of A Multi-Axis Wire Embedding Device For A Large Area Thermoplastic Pellet-Fed Additive Manufacturing System, Christopher Jasiel Minjares

Open Access Theses & Dissertations

This research focused on the development and implementations of a six degrees of freedom (6DOF) articulated arm onto a Big Area Additive Manufacturing (BAAM) system to interact with complex 3D geometries. BAAM is a large-scale machine which falls under material extrusion additive manufacturing (AM) - a process that selectively dispenses molten plastic layer-by-layer. The development of the 6DOF articulated arm required a mechanical design which went through several iterations before getting to the final design. Also, implementation of the tool was performed with the help from Cincinnati Incorporated (CI) which is the company that developed the BAAM.

First, the mechanical …

Relating Surface Resistivity To Corrosion Of Rebar Embedded In Portland Cement Concrete, Luisa Alejandra Morales

Open Access Theses & Dissertations

Reinforced concrete is widely used as a construction material known for its durability and proficiency of withstanding large forces in severe environments. Despite that the majority of these structures result in long-term performance, there is still a large number of failures of reinforced concrete structures as a result in corrosion of the reinforcement and concrete degradation. It is critical to assess the state of the corroded structure to decide on whether maintaining or replacing the structure is needed. The objective of this study is to characterize a relationship between the steel reinforcement corrosion and the concrete's resistivity. It is widely …

Quantifying Spatiotemporal Patterns Of Past And Future Urban Trends In El Paso, Tx And Their Impact On Electricity Consumption Using Nlcd Data And The Ca-Markov Model, Joanne Michelle Moyer

Open Access Theses & Dissertations

As cities continue to grow, their urban form continues to evolve over. Understanding this evolution allows for planners, engineers, and decision makers to plan for a sustainable community. Change analysis was conducted for El Paso, Texas county to determine the areas of growth within the past 15-years (2001-2016). The results indicate that growth has primarily occurred within the city of El Paso, in particular Districts 5 (east side), 1 (west side), and 4 (northeast), with District 5 experiencing substantial growth. Developed sub-categories medium and High intensity experienced the fastest growth, which represents single-family housing and compact/commercial areas. However, landscape metrics …

An Analysis And Representation In An Atlas Reference Space Of Putative Appositions From Neurons Expressing Alpha-Melanocyte-Stimulating Hormone With Neurons Expressing Hypocretin/Orexin Or Melanin-Concentrating Hormone, Vanessa Inez Navarro

Open Access Theses & Dissertations

The hypothalamus is a brain structure at the center of a variety of regulatory functions that have been explored by scientists and clinicians for almost a century. Among these functions, metabolic regulation and the control of appetitive behaviors have been fields of intensive research. Some of the major neural substrates involved in the hypothalamic control of feeding and the regulation of metabolic state include neuronal populations that express the neuropeptides alpha-melanocyte stimulating hormone (αMSH), melanin-concentrating hormone (MCH) and hypocretin/orexin (H/O). αMSH has been characterized in part as an anorexigenic peptide, while MCH and H/O have been characterized as having orexigenic …

Oxidation Of Niobium Silicides Obtained By Self-Propagating High-Temperature Synthesis, Frank Anthony Perez

Open Access Theses & Dissertations

Niobium silicide-based composites are promising materials for high-temperature structural applications, such as gas turbines. One attractive method for their fabrication is mechanically activated self-propagating high-temperature synThesis (MASHS). However, oxidation resistance of niobium silicides produced by MASHS has not been studied yet. In this present work, the oxidation of Nb/Nb5Si3 composites obtained by MASHS was investigated by using non-isothermal thermogravimetric analysis (TGA) and differential scanning analysis (DSC). Both techniques have shown that the oxidation starts at about 500 °C and the materials become fully oxidized at 750 â?? 800 °C. Model-based analysis of the TGA data has shown that the Avrami-Erofeev …

Stochastic Modeling Of Earthquakes And Option Pricing Using Bns-Gamma-Ou Model, Mandela Bright Quashie

Open Access Theses & Dissertations

High frequency data are becoming increasingly popular these days. They are fundamental in basically every facet of people’s lives. They are the determining factors in hedging in the field of finance. In geology, they help in the accurate prediction of earthquakes’ magnitude which goes along way to help save lives and properties.

High frequency data are also used more and more frequently for speculations. For this reason, it is important not only for scientists to apply models allowing correct quantification of these data, but also to improve the eciency of these models.

The Black-Scholes model, which is widely used because …

Distributions Of Axons Immunoreactive For Alpha-Melanocyte Stimulating Hormone And Neurons Immunoreactive For Neuronal Nitric Oxide Synthase In The Hypothalamus Of The Adult Male Rat: An Analysis Of Interactions And Their Representation In An Atlas Reference Space, Eduardo Peru

Open Access Theses & Dissertations

In the present study, we have provided two sets of high spatial-resolution maps for neuronal populations containing the immunoreactive presence of the key feeding-related peptides hypocretin/orexin (H/O), alpha-melanocyte stimulating hormone (αMSH) and the nitric oxide-producing enzyme, neuronal nitric oxide synthase (nNOS). These were mapped across the mediolateral and dorsoventral extents of the hypothalamus in the Swanson rat brain atlas, from levels 23–30. The first set of these maps are of the chemoarchitectural distributions for each of the neuronal populations mentioned, which are novel in two ways. First, they were generated across multiple animals to serve as the basis for probability …

Development And Assesment Of Local Scaled Self-Interaction Corrected Density Functional Method With Simple Scaling Factor, Selim Romero

Open Access Theses & Dissertations

The Hohenberg-Kohn-Sham (HKS) density functional theory (DFT) is widely used to compute electronic structures of atoms, molecules, and solids. It is an exact theory in which ground state electron density plays the role of basic variable, same as the wavefunction does in quantum mechanics. The total ground state energy is a functional of electron density. The practical application of HKS DFT require approximation to the exchange-correlation energy functional. Many density functional approximations (DFAs) with various degree of sophistication and complexities have been developed. Depending on the complexity, these functionals include electron density, density gradients, density Laplacian, kinetic energy densities, Hartree-Fock …

Multi-Wavelength Pyrometry For Emissivity Mapping And Accurate Surface Temperature Measurement In Powder Bed Fusion Systems, Md Moinuddin Shuvo

Open Access Theses & Dissertations

Accurate surface temperature measurement within powder bed fusion (PBF) systems during fabrication remains elusive for many reasons, despite the importance of knowing temperature for improving part quality, process control, repeatability and reproducibility, simulation capabilities, and more. Multi-wavelength (MW) pyrometry has been used previously to measure off-axis temperatures of a small region (~2.6mm in diameter) within an electron beam PBF (EBPBF) system. While this small region measurement makes it difficult to get a full field temperature map of the powder bed, it also allows for inline (on-axis) with laser temperature measurements for laser PBF (LPBF) systems. The MW pyrometry technique determines …

Evaluation Of Cyclo Olefin Polymer As Sabot Material For High-Density Projectiles, Estebanne Tarango

Open Access Theses & Dissertations

Assuring the integrity of spacecraft and its occupants are a priority in the field of space exploration. Micrometeoroids and orbital debris are one of the primary threats that affect spacecraft materials due to the high kinetic energies involved with hypervelocity impacts. Improvement of projectile launching capabilities prompts the investigation of adequate materials for the manufacturing of sabots able to carry high-density projectiles without catastrophic failure. Polycarbonate (PC) has been the chosen material by the Hypervelocity Team at White Sands Test Facility for sabots on the 0.50 caliber launcher; however, there is a material constraint when the projectile becomes significantly dense …

Mechanically Activated Combustion Synthesis Of Niobium Silicide Based Composites, Reina Trevino

Open Access Theses & Dissertations

Niobium silicide-based composites are promising materials for high-temperature structural applications, such as gas turbines, but their implementation is hindered by the lack of effective processing methods. Self-propagating high-temperature synThesis (SHS) is an attractive method for fabrication of advanced materials. However, it is difficult to perform SHS of niobium silicides because the melting point of Nb is higher than the combustion temperature, which greatly inhibits Nb-Si reaction. To ignite an Nb/Si mixture and obtain Nb5Si3, the desired phase in niobium silicides, either preheating or mechanical activation of the mixture is necessary. This problem becomes even more critical in the SHS of …

Life Cycle Studies To Evaluate The Physiological And Biochemical Effects Of Copper Oxide And Surface-Coated Titanium Dioxide Nanoparticles On Green Onion (Allium Fistulosum) And Carrot (Daucus Carota L.) Plants: Insights Utilizing Two-Photon Microscopy And Spectroscopy, Yi Wang

Open Access Theses & Dissertations

With the recent increase of nanomaterial production, nano copper oxide (nCuO) and surface-modified titanium dioxide nanoparticles (nTiO2) are among the most widely applied nanoparticles in industry and daily lives. Their use has resulted in accumulation in soils as a consequence of their direct or indirect release. Hence, these NPs may raise a potential risk to crops cultivated in soils. Moreover, the physiological effects of nCuO on green onion (Allium fistulosum) and surface-coated nTiO2 on full-grown carrot (Daucus carota L.) are still unknown. Green onion is characterized by its high content of the antioxidant allicin, and carrot is a worldwide economic …

Effect Of Flow Velocity And Geometry On The Signal From A Piezoelectric Flow Rate Sensor, Jad Gerges Aboud

Open Access Theses & Dissertations

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Multiple Change-Point Modeling Of Degradation Signal For Prognostics Improvement, Yuxin Wen

Open Access Theses & Dissertations

To fulfill the increasing demand on functionality and quality, modern engineering systems are usually built with overwhelming complexities. The more complex functions the system has been built, the higher reliability required of the system. This is mainly due to the fact that a single failure can result in catastrophic consequences. Therefore, methods that can predict and prevent such catastrophes have long been explored. Prognostics refer to the process of evaluating the current health of a system or a component and then predicting the remaining useful life (RUL) based on the information collected through condition monitoring. The fast development of information …

Who Is Willing To Speak Up And Why? Examining Individual And Organizational Predictors Of Employee Voice Behavior In Higher Education Institutions, Jessie Socorro Arellano

Open Access Theses & Dissertations

Employee voice behavior is central to the effectiveness, the development, and the adaptability of organizations to their environments. However, there is currently limited organizational research and knowledge on the factors that influence employee voice behaviors, especially in the context of higher education institutions. As such, the purpose of this study is to examine the predictors of employee voice behaviors in institutions of higher education. Specifically, this study examines the impact of key individual and organizational factors such as alumni status, organizational commitment, work motivation, communication climate, and organizational politics on employees' expression of promotive and prohibitive voice in higher education …

Using Machine Learning On An Imbalanced Cancer Dataset, James Ekow Arthur

Open Access Theses & Dissertations

With an estimated 1.4 million cancer diagnosis worldwide and the increasing death of cancer patients. It is prudent to investigate methods, approaches and smarter ways of predicting and diagnosing of cancer so that a holistic techniques can be used to curb or reduce false predictions , increase exact predictions and also meticulos prognosis information .

Can a feasible technique be developed for the general problem of prognosis and diagnosis of cancer be developed ?

We will show here that this problem of cancer prognosis and diagnosis can be efficiently tackled with the aid of machine learning techniques and the best, …

Glacier Segmentation In Satellite Images For Hindu Kush Himalaya Region, Bibek Aryal

Open Access Theses & Dissertations

Climate change poses a risk to individuals whose livelihoods depend on the health of glacier ecosystems. Monitoring glaciers in the Himalayan Hindu Kush (HKH) region is of high importance especially when we consider the impact of recent climate change on them. Our work aims to provide an automated method to outline glaciers using machine learning techniques and publicly available remote sensing imagery.In this work, we present ways to delineate glaciers from Landsat-7 imagery using various machine learning and computer vision techniques. The multi-step methodology that we present in this work is generalizable across different types of satellite and overhead imagery, …

A Role For Mek3 In The Oncogenesis Of Acute Lymphocytic Leukemia: Inactivation Of Mapk P38 Promotes Cell Proliferation Through Enhanced Degradation Of Mutant Mek3, Yoshira Marie Ayala-Marin

Open Access Theses & Dissertations

In the United States, pediatric leukemia has the second-highest cancer mortality rate in Hispanic children, especially Acute Lymphocytic Leukemia (ALL). While treatment of ALL has improved overall the five-year survival rate of ~90 %, not everyone has benefited. Twenty percent of them will experience relapse, and from these, 30 - 50 % will die. Unfortunately, the cause behind these dreadful statistics is poorly understood due to the complex etiology of this disease. Thereby, it is essential to identify potential oncogenic proteins that promote ALL so that new strategies can be developed to diagnose and treat this cancer. Whole Exome Sequencing …

Identification Of Interkingdom Interactions Of Cryptococcus Neoformans In Pigeon Excreta Using Next Generation Sequencing, Marlynn Cadena

Open Access Theses & Dissertations

Cryptococcus neoformans is an encapsulated fungus with worldwide distribution and associated with pigeon excreta. C. neoformans causes pulmonary cryptococcosis in immunocompromised populations, which results in high mortality. C. neoformans main virulence factor is its polysaccharide capsule that confers the fungus with the ability to form biofilms. Interkingdom interactions can have a positive, neutral or negative effect on C. neoformans in relation to its virulence and/or pathogenicity. C. neoformans survival within polymicrobial and other challenging communities has been shown to affect the evolution of its virulence factors. For example, the size of C. neoformans polysaccharide capsule is modulated during interactions with …

The Dynamic Transition Of A Vertical Take-Off And Landing Drone, Luis Carlos Calvo Jr.

Open Access Theses & Dissertations

Unmanned aerial vehicles, or UAVs, are small pilotless aircrafts that are remotely controlled through a ground control station. They have increased in popularity because of their applications and the advantages that each UAV can provide based on their need. There are many types of UAVs, but this study focuses on a type of Vertical Take-Off and Landing (VTOL) UAV that is known as the Albatross UAV. This UAV was manufactured by a company known as Applied Aeronautics, and configurations were made to change the fixed-wing (FW) UAV to a VTOL UAV. This study was done to find methodologies to simulate …

Association And Predictive Abilities Of Jump And Throw Tests To Track Performance In Division I Athletes, Nicholas R. Cubillos

Open Access Theses & Dissertations

Sprinting jumping, and throwing are of the most vital abilities in track & field. Although various studies investigated relationships among these three aspects, there is limited empirical evidence as to how they may be correlated and predictive towards track performance. Purpose: To determine associations and predictive abilities of four field performance tests among a static (Accel30) and flying (Fly30) 30-meter sprint. This study also aimed to ascertain associations of kinematic and kinetic components of all field assessments to Accel30 and Fly30 sprint times. Methods: 23 subjects (18-25 years, 1.77 ± 0.10 meters, 78.67 ± 24.15 kg) performed two trials of …

The More You Know: How Adolescent Defendants' Age, Gender, And Psychosocial Maturity Influence Mock Jurors' Perceptions, Isabelle M. Clough

Open Access Theses & Dissertations

Adolescents are considered less responsible than adults for criminal behavior due to their developmental immaturity (Cauffman & Steinberg, 2000). When adolescents are transferred from juvenile court to adult court, however, they may be judged by jury members who do not recognize adolescents' diminished maturity nor understand how maturity influences culpability. The present study therefore sought to examine how information about adolescent defendants' age, gender, and psychosocial maturity influences mock jurors' perceptions of responsibility, guilt, and appropriate sentencing severity. A pilot study (N = 113 undergraduates) first determined the most appropriate vignette for the final study: an adolescent charged with hit-and-run …

Integration Of 3d Structural And Sequence Features To Predict Gpcr Ligand Binding, Kwabena Owusu Dankwah

Open Access Theses & Dissertations

G protein-coupled receptors (GPCRs) are the largest class of cell-surface receptor proteins with important functions in signal transduction and often serve as therapeutic drug targets. With the rapidly growing public data on three dimensional (3D) structures of GPCRs and GPCR-ligand interactions, computational prediction of GPCR ligand binding becomes a convincing option to high throughput screening and other experimental approaches during the beginning phases of ligand discovery. Such predictions are cost-efficient and can be important aides for planning wet lab experiments to help elucidate signaling pathways and expedite drug discovery. There are existing computational tools for GPCR ligand binding prediction using …

Development Of Software Tools And Experimental In Situ Electron Spin Resonance For Characterizing The Magnetic And Electrocatalytic Properties Of Transition Metal Chalcogenide Crystals, Jose Armando Delgado

Open Access Theses & Dissertations

Studying the magnetic properties and crystal defects of transition metal chalcogenide crystals is of paramount importance for utilizing them for next generation spintronics devices and hydrogen evolution reaction catalysts. Hydrothermally grown transition metal chalcogenide nanocrystals (MoS2, Ru2S3, Rh2S3, Co2S8) were chosen as catalysts for the hydrogen evolution reaction due to their low dimensionality and previous utilization as catalysts for hydrodesulfurization. The relationship between crystal defect sites and catalytic activity must be discerned to maximize the efficiency of hydrogen production during the hydrogen evolution reaction. ESR spectroscopy was utilized as a spin sensitive technique to study the defects and local changes …

Women In The Legislature's Impact On Economic Growth And Women's Labor Force Participation, Ashley Elizabeth Docherty

Open Access Theses & Dissertations

This Thesis analyzes whether women in the legislature improve economic growth and womenâ??s participation in the labor force. The number of women in national legislatures and parliaments has increased dramatically in the past thirty years as over half of all countries have implemented gender quota laws. When women join the legislature, government spending on education and healthcare tends to increase. This leads to an increase in economic growth. Economic growth, along with the visibility of women in government, helps more women participate in the labor force. Women in government have a descriptive and substantive effect on womenâ??s economic empowerment. This …

Discourses Of Coloniality In The Understanding And Practices Of Translanguaging Pedagogy, Gabriela Dolsa

Open Access Theses & Dissertations

Dual language (DL) education has been regarded as a means toward equity and social justice for linguistic minorities. Several studies, however, question if DL programs can, in fact, overcome inequities in the education of emergent bilinguals. This ethnographic study followed these inquiries and explored how translanguaging theory and pedagogy could transform DL education to better serve social justice purposes in this US-Mexico border context. For translanguaging to achieve this, it is fundamental to know how DL educators understand and practice translanguaging in their classrooms. This study revealed that teachersâ?? understandings and practices of translanguaging were embedded in ideologies of coloniality …

Uav Parameter Estimation Through Machine Learning, Andres Enriquez Fernandez

Open Access Theses & Dissertations

Parameter identification of Unmanned Aerial Vehicles (UAV) is very helpful for understanding cause-effect relationships of physical phenomenon, investigating system performance and characteristics, fault diagnostics, control development/tuning, and more. Traditional ways of performing parameter identification involve establishing a mathematical model that describes the system's behavior. The equations in the model contain parameters that are estimated indirectly from measured flight data. This parameter identification process requires knowledge of the physics involved. Also, it necessitates a careful consideration of the aircraft instrumentation for accurate measurements. It also requires careful design of the flight maneuvers to ensure thorough excitation of the flight dynamics involved. …