Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network™

Open Access. Powered by Scholars. Published by Universities.®

2020

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 1801 - 1830 of 28874

Full-Text Articles in Entire DC Network

Combining Implicit Geological Modeling, Field Surveys, And Hydrogeological Modeling To Describe Groundwater Flow In A Karst Aquifer, Fernando M. D’Affonseca, Michael Finkel, Olaf A. Cirpka Dec 2020

Combining Implicit Geological Modeling, Field Surveys, And Hydrogeological Modeling To Describe Groundwater Flow In A Karst Aquifer, Fernando M. D’Affonseca, Michael Finkel, Olaf A. Cirpka

KIP Articles

In three-dimensional (3-D) implicit geological modeling, the bounding surfaces between geological units are automatically constructed from lithological contact data (position and orientation) and the location and orientation of potential faults. This approach was applied to conceptualize a karst aquifer in the Middle Triassic Muschelkalk Formation in southwest Germany, using digital elevation data, geological maps, borehole logs, and geological interpretation. Dip and strike measurements as well as soil-gas surveys of mantel-borne CO 2 were conducted to verify the existence of an unmapped fault. Implicit geological modeling allowed the straightforward assessment of the geological framework and rapid updates with incoming data. Simultaneous …


The Implementation And Comparison Of Fuzzy Logic Control Systems To Modern Control Methods On Low-Cost Hardware, Cristian A. Barron Dec 2020

The Implementation And Comparison Of Fuzzy Logic Control Systems To Modern Control Methods On Low-Cost Hardware, Cristian A. Barron

Theses and Dissertations

Modern control engineering provides many options to automate systems for which a mathematical model is required. Another control does not rely on the mathematical model of the system and is known as fuzzy logic control. In this study, a literature review is conducted on existing control systems strategies such as proportional integral and derivative (PID), linear quadratic regulator (LQR), and fuzzy logic controller (FLC), the complexity of the systems they control, and their strengths and weaknesses. In addition, a series of experiments are conducted, both through simulations in MATLAB Simulink and using their implementation using the actual physical hardware to …


Chemical Investigation Of Avocado (Persea Americana) Seed Husk (Testa): A Waste Of Waste, Orlando A. Castillo Scheren Dec 2020

Chemical Investigation Of Avocado (Persea Americana) Seed Husk (Testa): A Waste Of Waste, Orlando A. Castillo Scheren

Theses and Dissertations

Food chemistry is a new field in the world and is currently still expanding into the types of market in which it can be tapped into. There are about 1.3 billion tons of food waste produced in 2016 in the world, and food chemistry is going to help get rid of that waste by finding new and exciting applications to the things currently considered as waste. In these products, there might be new and undiscovered drugs that can be used in the market to help treat diseases for which might not have a cure at the current moment. The avocado …


Developing A Uhf/Vhf Phased-Array Satellite Ground Station, Brent K. Cole Dec 2020

Developing A Uhf/Vhf Phased-Array Satellite Ground Station, Brent K. Cole

Theses and Dissertations

Earth-satellite communications and tracking of spacecraft are accomplished using ground stations. Traditionally, this has been achieved by using a large parabolic antenna or pair of antennas that point at a source of interest and mechanically steer the antenna(s) as the source moves throughout the sky. Phased arrays, which have often been used in radio astronomy, can provide multiple benefits when used as a ground station including fast scanning speeds across the sky, tracking and communication of multiple sources simultaneously, and significant improvements to overall gain, signal-to-noise ratio (SNR), and data bandwidth. This thesis presents a preliminary analysis of a 20-element …


Synthesis, Characterization, And Application Of Meso-Tetraphenyl Metalloporphyrin Photocatalysts Under Visible Light, Alexis Echavarria Dec 2020

Synthesis, Characterization, And Application Of Meso-Tetraphenyl Metalloporphyrin Photocatalysts Under Visible Light, Alexis Echavarria

Theses and Dissertations

The photocatalytic activity of meso-Tetraphenyl Metalloporphyrins with different metal centers was investigated. The synthesized metalloporphyrin photocatalysts was performed and analyzed using FT-IR spectroscopy, UV-VIS spectroscopy, and powder X-Ray Diffraction analysis. The synthesized TPP crystals were determined to be tetragonal crystal structure and the structure was observed in all synthesized metalloporphyrin catalysts. The Soret (B) bands, Q bands, FT-IR functional groups were identified. Reaction progress was investigated by sampling at intervals of one hour and analysis of the samples was performed using Gas Chromatography-Mass Spectrometry. GC-MS analysis was used to identify the products of the photochemical catalytic redox reactions performed under …


The Relationship Between The 9th Grade State Assessment And Extra Curricular School Activities And Gender For Disadvantaged Hispanic Students In South Texas, Paz Elizondo Jr. Dec 2020

The Relationship Between The 9th Grade State Assessment And Extra Curricular School Activities And Gender For Disadvantaged Hispanic Students In South Texas, Paz Elizondo Jr.

Theses and Dissertations

The purpose of this study is to analyze the relationship between the 9th grade state assessment test scores for Disadvantaged Hispanic students who are taking the English I State of Texas Assessment of Academic Readiness End-of-Course exam. The group analyzed was comprised of the 2016-2017 cohort students from a South Texas High School.


Mexartivist As Resistance Against Media Representation Of Latinxs In The U.S., Jose Garcia Gilling Dec 2020

Mexartivist As Resistance Against Media Representation Of Latinxs In The U.S., Jose Garcia Gilling

Theses and Dissertations

MexArtivist comes as a response of wanting to reflect our experiences as Mexicanxs, Latinxs, Chicanxs and Mexican Americans. I've merged my recent academic years, research and knowledge along with my over then years of experience in the film and audiovisual production industry to create the audiovisual group called MexArtivist. Based on research regarding the image, representation, misrepresentation and lack of representation of Latinxs in U.S. films, I present a tangible proposal to try and better this issue.


The Influence Of College Preparation In The Relationship Between High School Socioeconomic Context And College Enrollment, Jeffery J. Huerta Dec 2020

The Influence Of College Preparation In The Relationship Between High School Socioeconomic Context And College Enrollment, Jeffery J. Huerta

Theses and Dissertations

Recent research has documented that the socioeconomic context of high schools plays a significant role in students’ postsecondary enrollment outcomes (Engberg & Wolniak, 2014; Roderick et al., 2011; Engberg & Wolniak, 2010; Nuñez & Kim, 2012; Hill, 2008; Perna & Titus, 2005; Perna, 2000), with lower college outcomes occurring due to students at lower SES high schools having lower amounts of capital, less access to rigorous curriculum, and more negative peer influences than students at higher SES high schools. However, absent in these studies is whether efforts of comprehensive college preparation were taking place and if such efforts are also …


The Design, Fabrication, And Testing Of A Cooling Garment, Richard James Garza Dec 2020

The Design, Fabrication, And Testing Of A Cooling Garment, Richard James Garza

Theses and Dissertations

The aim of this research is to design a device or technology capable of cooling the user – such as a college student walking to class, for example – in a manner as convenient as putting on a jacket. The idea is to use the peltier effect – a phenomenon in which two dissimilar semi-conductors heat up and cool down with the application of an electric current – as the source of heat absorption used to cool the user. In this research it will be determined whether or not it is feasible to use such a phenomenon to keep the …


Reinforcement Learning Environment For Orbital Station-Keeping, Armando Herrera Iii Dec 2020

Reinforcement Learning Environment For Orbital Station-Keeping, Armando Herrera Iii

Theses and Dissertations

In this thesis, a Reinforcement Learning Environment for orbital station-keeping is created and tested against one of the most used Reinforcement Learning algorithm called Proximal Policy Optimization (PPO). This thesis also explores the foundations of Reinforcement Learning, from the taxonomy to a description of PPO, and shows a thorough explanation of the physics required to make the RL environment. Optuna optimizes PPO's hyper-parameters for the created environment via distributed computing. This thesis then shows and analysis the results from training a PPO agent six times.


Assessing The Performance Of Reconditioned Railroad Tapered-Roller Bearings Used In Freight Rail Service, Veronica Valeria Hernandez Dec 2020

Assessing The Performance Of Reconditioned Railroad Tapered-Roller Bearings Used In Freight Rail Service, Veronica Valeria Hernandez

Theses and Dissertations

The rail industry currently utilizes two wayside detection systems to monitor the health of freight railcar bearings in service: The Trackside Acoustic Detection System (TADS™) and the wayside Hot-Box Detector (HBD). Bearings that are removed from service are sent to specialized facilities where they undergo a reconditioning process before the bearings can be returned to rail service. The reconditioning process has been used for decades although there has been no previous study on the effectiveness of the reconditioning process on defective bearings that were removed from service. This persuaded the researchers from the University Transportation Center for Railway Safety (UTRCS) …


On Coupled Reaction Diffusion Equations And Their Applications, Juan J. Huerta Dec 2020

On Coupled Reaction Diffusion Equations And Their Applications, Juan J. Huerta

Theses and Dissertations

Reaction-diffusion equations are nonlinear partial differential equations that have been used extensively in mathematical modeling. An interesting case in this type of equation is the Fisher-Kolmogorov system, which has been used to study a low-grade glioma, a group of primary brain tumors. In the first part of this thesis, a stochastic version of the Fisher-Kolmogorov system will be studied, and exact and numerical solutions will be presented.

The second part of this thesis will show how the speed of information propagation affects disease spread and vaccination uptake through networks in epidemics. In this model, the information reaches different people at …


Traffic Time Headway Prediction And Analysis: A Deep Learning Approach, Saumik Sakib Bin Masud Dec 2020

Traffic Time Headway Prediction And Analysis: A Deep Learning Approach, Saumik Sakib Bin Masud

Theses and Dissertations

In the modern world of Intelligent Transportation System (ITS), time headway is a key traffic flow parameter affecting ITS operations and planning. Defined as “the time difference between any two successive vehicles when they cross a given point”, time headway is used in various traffic and transportation engineering research domains, such as capacity analysis, safety studies, car-following, and lane-changing behavior modeling, and level of service evaluation describing stochastic features of traffic flow. Advanced travel and headway information can also help road users avoid traffic congestion through dynamic route planning, for instance. Hence, it is crucial to accurately model headway distribution …


Thermal And Spectroscopic Investigations On Polymer-Based Nanofibers, Omosola Oriretan Dec 2020

Thermal And Spectroscopic Investigations On Polymer-Based Nanofibers, Omosola Oriretan

Theses and Dissertations

Nanofibers of Poly (ethylene oxide), PEO, Poly (vinylpyrrolidone) PVP, Co-nanofiber of PEO-PVP and PEO nanocomposite of various Fullerene compositions were prepared by dissolving PEO, PVP and Fullerene in water. The Fullerene nanoparticles were added to the PEO solutions, the mixtures were homogenized under high power sonication. The PEO solutions, PVP solutions, the co-polymer solutions of PEO-PVP and the PEO -Fullerene solutions were centrifugally spun using Force spinning™ machine. The obtained nanofibers and the nanocomposites were subjected to FTIR analysis, Raman analysis and various heating and cooling cycles with heating and cooling rates ranging from 10C/min to 600C/min using differential scanning …


Chemical Modification And In Silico Validation Of Medicinally Privileged Molecular Scaffolds As Kras And Sars-Cov-2 Protease Inhibitors, Precious M. Okwuchukwu Dec 2020

Chemical Modification And In Silico Validation Of Medicinally Privileged Molecular Scaffolds As Kras And Sars-Cov-2 Protease Inhibitors, Precious M. Okwuchukwu

Theses and Dissertations

Coronavirus disease was declared a global pandemic by WHO in March 2020, cancer is the second leading cause of death by a disease. Several scientists around the world are working relentlessly to discover an effective remedy to eradicate these deadly diseases. A natural polyphenol (magnolol) has been isolated from a tree Magnolia grandiflora (family Magnoliaceae) found on UTRGV campuses. This research is focused on design of a series of chemically modified sulfonyl derivatives based on the isolated magnolol framework and other medicinally privileged molecular scaffolds framework that can effectively bind to the COVID-19 main protease, SARS- CoV-2 3CL protease …


Effects Of Elevated Temperature On 8-Hydroxy-2'-Deoxyguanosine Expression, Dna Damage And Cellular Apoptosis In The American Oyster (Crassostrea Virginica), Md Faizur Rahman Dec 2020

Effects Of Elevated Temperature On 8-Hydroxy-2'-Deoxyguanosine Expression, Dna Damage And Cellular Apoptosis In The American Oyster (Crassostrea Virginica), Md Faizur Rahman

Theses and Dissertations

Global temperature increases due to anthropogenic activities. The effects of rising temperature are well documented in aquatic organisms. The American oyster is an ideal shellfish species to study on global warming and oxidative DNA damage. In this study, We observed the effects of high temperature on heat shock protein-70 (HSP70), 8-hydroxy-2’-deoxyguanosine (8-OHdG), ssDNA, dsDNA, caspase-3 (CASP3), BAX and γH2AX, a molecular marker of DNA damage, protein expressions in gills of oysters. Immunohistochemical results showed that elevated temperatures (28 and 32°C) significantly increased HSP70, 8-OHdG, dsDNA, γH2AX, BAX and CASP3 protein expressions in gills of oysters compare to control (24°C). In …


Bivariate Markov Chain Model Of Irritable Bowel Syndrome (Ibs) Subtypes And Abdominal Pain, Ricardo Reyna Jr. Dec 2020

Bivariate Markov Chain Model Of Irritable Bowel Syndrome (Ibs) Subtypes And Abdominal Pain, Ricardo Reyna Jr.

Theses and Dissertations

Researchers use stochastic models like continuous-time Markov chains (CTMC) to model progression of morbidities of public health impact, like HIV and Hepatitis C. Most of the research in that area is done for a single disease. In this research, we use a bivariate continuous-time Markov chain (CTMC) to model progression of co-morbidities. In particular, we use a bivariate CTMC to model the joint progression of Irritable Bowel Syndrome (IBS) and abdominal pain. Symptoms of IBS are known to change throughout the duration of the disorder. Hence, patients are normally asked to make a journal of the stool type, symptoms, and …


Artificial Intelligence In A Main Warehouse In Panasonic: Los Indios, Texas, Edison Antonio Trejo Hernandez Dec 2020

Artificial Intelligence In A Main Warehouse In Panasonic: Los Indios, Texas, Edison Antonio Trejo Hernandez

Theses and Dissertations

The Panasonic Company warehouse is located in Los Indios Texas. The warehouse presents the limitation of the great distances between its headquarters and the Main Warehouse for supplying the branches and main customers, which requires a considerable amount of time to maintain effective communication in the inventory area. In addition, during an online review, it can be confirmed that the website is disabled, contradicting its corporate policy.

The structure of the thesis proposal is arranged in four chapters from the Introduction, Statement of the Problem and Purposes; Previous Studies and Definition of the literature; the Research Methodology and the resources …


Principal Instructional Leadership Behavior As Perceived By Middle School Principals In The Rio Grande Valley Of Texas, Joseph R. Villarreal Dec 2020

Principal Instructional Leadership Behavior As Perceived By Middle School Principals In The Rio Grande Valley Of Texas, Joseph R. Villarreal

Theses and Dissertations

The purpose of this study is to determine which of the 10 leadership functions contained in the PIMRS, as identified by Hallinger (1983), are demonstrated by principals in Rio Grande Valley middle schools that received Texas Education Agency distinctions for closing performing gaps, compared to those middle schools in the Rio Grande Valley that did not. The study aimed to determine if there was a significant difference been the principal instructional leadership behaviors at middle schools recognized for closing performance gaps compared to those that were not recognized. The results showed that there did not exist a significant difference between …


Pre-Entrance Factors And Student Success In An A.A.S. Nursing Program, Connie Marshall Dec 2020

Pre-Entrance Factors And Student Success In An A.A.S. Nursing Program, Connie Marshall

Electronic Theses and Dissertations

The purpose of this study was to evaluate the relationship of pre-entrance factors and the success of students in an Associate of Applied Science (A.A.S.) degree nursing program at a community college in East Tennessee. The criterion variable was success in the nursing program. Success was defined as academic success in all nursing courses and completion of the nursing program to graduation. The predictor variables of pre-entrance factors were gender, age, Health Education Systems, Incorporated (HESI) A2 scores, Pell Grant eligibility, pre-nursing GPA, and prior licensure. The data for this non-experimental secondary analysis were derived from the electronic database in …


Financial Terms In License Agreements, Jorge L. Contreras Dec 2020

Financial Terms In License Agreements, Jorge L. Contreras

Utah Law Faculty Scholarship

This chapter in the forthcoming casebook Intellectual Property Licensing and Transactions: Theory and Practice (2020, forthcoming), discusses the financial terms of IP licensing agreements including fixed payments, running royalties, sublicensing income, milestone payments, equity compensation and cost reimbursement, as well as most-favored and audit clauses. Numerous areas of recent controversy are addressed including the establishment of royalty rates through the entire market value rule (EMVR) versus the smallest salable patent practicing unit (SSPPU) rule, royalties for bundled rights, rules of thumb discredited by the courts, royalty escalation clauses and more. Examples are drawn primarily from biotechnology, high-tech and copyright licensing …


The Impact Of High School Career Academies On Student Academic Achievement And Engagement, Daisy Rodriguez Dec 2020

The Impact Of High School Career Academies On Student Academic Achievement And Engagement, Daisy Rodriguez

Seton Hall University Dissertations and Theses (ETDs)

The purpose of this study is to examine the effectiveness of high school career academies in comparison to the traditional, comprehensive high school educational program with respect to student academic achievement and student engagement in one large urban high school in Central New Jersey. It is the intent of this researcher to determine if either of the educational structures and approaches significantly impacts the achievement and engagement levels of students in the high school under investigation.

Student math and ELA state test scores and student engagement scores were analyzed using quantitative methods. To ascertain the degree of effectiveness this reform …


Inference And Estimation In Change Point Models For Censored Data, Kristine Gierz Dec 2020

Inference And Estimation In Change Point Models For Censored Data, Kristine Gierz

Mathematics & Statistics Theses & Dissertations

In general, the change point problem considers inference of a change in distribution for a set of time-ordered observations. This has applications in a large variety of fields and can also apply to survival data. With improvements to medical diagnoses and treatments, incidences and mortality rates have changed. However, the most commonly used analysis methods do not account for such distributional changes. In survival analysis, change point problems can concern a shift in a distribution for a set of time-ordered observations, potentially under censoring or truncation.

In this dissertation, we first propose a sequential testing approach for detecting multiple change …


The Relationship Between Virginia Title 1 Spending And Minority Male Graduation Rates: A Longitudinal Study, Anastacio B. Marin Dec 2020

The Relationship Between Virginia Title 1 Spending And Minority Male Graduation Rates: A Longitudinal Study, Anastacio B. Marin

Educational Leadership & Workforce Development Theses & Dissertations

Over the past two decades, education funding in the United States has been redistributed to schools that lack sufficient financial resources to meet the needs of students (Boyle & Lee, 2015). The No Child Left Behind (NCLB) Act of 2001, the reauthorized Elementary and Secondary Education Act (ESEA), was enacted to increase academic accountability and achievement throughout the nation’s public-school systems. Nationwide, there is a persistent achievement gap between historically marginalized students and their affluent peers. This gap is evident in the Commonwealth of Virginia when measuring student proficiency on End of Course Assessments (EOCAs). For schools serving a large …


Climate Change Games As Boundary Objects: Fostering Dialogic Communication Within Stakeholder Engagement, Megan L. Mckittrick Dec 2020

Climate Change Games As Boundary Objects: Fostering Dialogic Communication Within Stakeholder Engagement, Megan L. Mckittrick

English Theses & Dissertations

Rising waters and the increasing devastation of flood events make coastal resilience a significant issue in the Hampton Roads region of Virginia, particularly in the city of Norfolk. Enhancing resilience requires ongoing stakeholder engagement designed to invite dialogue while encouraging cross-jurisdictional collaboration and comprehensive problem-solving. Climate change games have been employed to support these endeavors. This dissertation provides a response to the following research questions: 1) What is the origin of the climate change game genre? 2) Why are key stakeholders in coastal resilience using climate change games? And 3) how do these games operate for these key stakeholders? To …


Synthesis, Characterization, Spectroscopic, And Mesomorphic Studies Of New Schiff Base Ligands And Titanium, Cobalt, Nickel And Copper Metal Centers, Raj K. Gurung Dec 2020

Synthesis, Characterization, Spectroscopic, And Mesomorphic Studies Of New Schiff Base Ligands And Titanium, Cobalt, Nickel And Copper Metal Centers, Raj K. Gurung

Chemistry & Biochemistry Theses & Dissertations

Transition metal complexes with Schiff base ligands offer a wide application in the field of development of catalysis and material. The straightforward synthesis allowed the structural modification and helped to optimize in various application of such complexes. Titanium-containing complexes have been reported to be important for their catalytic and material applications through the coordination of a tetradentate Schiff base ligand, viz. N, N’-ethylene bis(salicylideneiminate) dianion (salen). Studies reporting the characterization of achiral titanium(IV) salen complexes are scarce due to their intricate nature. Such complexes would be comparatively less expensive and easier to prepare synthetically and thus could represent an …


Measurement Of Pion-Pion Final State Interactions In Η → Π +Π −Γ With Clas At Jefferson Lab, Torri C. Jeske Dec 2020

Measurement Of Pion-Pion Final State Interactions In Η → Π +Π −Γ With Clas At Jefferson Lab, Torri C. Jeske

Physics Theses & Dissertations

Decays of pseudoscalar mesons proceed from the chiral anomaly, which arises from spontaneous chiral symmetry breaking. In the limit of massless quarks (chiral limit), the η → π +π −γ the decay width is determined solely by the box anomaly term in the Wess Zumino Witten Lagrangian. Since the physical quarks are not massless, the decay region of the η meson is far from the chiral limit and thus proper inclusion of the momentum dependence is essential to reproduce the measured decay width. Several theoretical frameworks have been proposed to describe these interactions. We report a new measurement of the …


Conical Orbital Mechanics: A Rework Of Classic Orbit Transfer Mechanics, Cian Anthony Branco Dec 2020

Conical Orbital Mechanics: A Rework Of Classic Orbit Transfer Mechanics, Cian Anthony Branco

Mechanical & Aerospace Engineering Theses & Dissertations

Simple orbital maneuvers obeying Kepler’s Laws, when taken with respect to Newton’s framework, require considerable time and effort to interpret and understand. Instead of a purely mathematical approach relying on the governing relations, a graphical geometric conceptual representation provides a useful alternative to the physical realities of orbits. Conic sections utilized within the full scope of a modified cone (frustum) were employed to demonstrate and develop a geometric approach to elliptical orbit transformations. The geometric model in-question utilizes the rotation of a plane intersecting the orbital frustum at some angle β (and the change in this angle) in a novel …


Partial Shadow Impact On Loss-Of-Load Probability Of Photovoltaic Power System., M. El-Maghraby, Mohamed Adel El-Sayes Dec 2020

Partial Shadow Impact On Loss-Of-Load Probability Of Photovoltaic Power System., M. El-Maghraby, Mohamed Adel El-Sayes

Mansoura Engineering Journal

This paper studies the shadow impact on the loss-of-load probability, the most significant reliability indices, of the photovoltaic power system (PVPS). A suggested index is derived to reflect the shadow impact, denoted by the "Reductive Index". Novel mathematical model is excecuted to estimate the reduction in the daily output energy of PVPS according to this index and the period of shadow continuity. This reduction results in an equivalent reduction in the solar cells array size. So, the maximum permissible reduction in the solar cells array size can be determined on having an arbitrary loss of-load probability level with its change …


Analytical Study Of Turbulent Boundary Layer Development On Rough Surface With Adverse Pressure Gradient., Samir Hanna, Berge Djebedjian Dec 2020

Analytical Study Of Turbulent Boundary Layer Development On Rough Surface With Adverse Pressure Gradient., Samir Hanna, Berge Djebedjian

Mansoura Engineering Journal

One of the purposes of this investigation is to throw some additional light on the question of how to correlate between the experimental data from different sources and the theoretical approaches for the study of incompressible turbulent boundary layers development on rough surface. Moreover, the study developed included the presence of adverse pressure gradient; as well as a discussion about the effect of surface roughness on the boundary layer parameters which control the flow behaviour. On the basis of Zancow experimental work with rough surface and the velocity law of Rotta, this study has been developed. In order to obtain …