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Articles 481 - 510 of 2036

Full-Text Articles in Physical Sciences and Mathematics

Synthesis And Characterization Of Redox Non-Innocent Ligand Supported Transition Metal Complexes, Adriana Marie Lugosan Jan 2021

Synthesis And Characterization Of Redox Non-Innocent Ligand Supported Transition Metal Complexes, Adriana Marie Lugosan

Dissertations

Catalysis is an integral part of society, which is often taken for granted. Over the past few years, there has been an increased effort to develop catalysts that are more environmentally friendly, selective, and energy efficient. This work focuses on the development of novel complexes made from a carefully designed non-innocent ligand together with earth-abundant and cost-effective transition metals that can be used to understand fundamental inorganic chemistry principles and serve as model systems. The work reported within validates the utility of this novel class of redox non-innocent ligand to form metal complexes with interesting properties, such as a non-porphyrin …


Secularism, The Oxford Movement, And Religious Aesthetics In John Keble, Christina Rossetti, Adelaide Anne Procter, And Gerard Manley Hopkins, Mary Harmon Jan 2021

Secularism, The Oxford Movement, And Religious Aesthetics In John Keble, Christina Rossetti, Adelaide Anne Procter, And Gerard Manley Hopkins, Mary Harmon

Dissertations

This dissertation examines the relationship between secularism and the development of Oxford Movement poetry. The members of the movement sought to restore pre-Reformation religious practices in the Anglican Church while maintaining its distinctiveness from the Roman Catholic and Orthodox traditions, which led to the development of unique liturgy, architecture, hymns, and poetry, among other art forms. I argue that secularism simultaneously made the movement more possible while also making it more unstable. Secularism gave the theologians and poets of the movement enough freedom to borrow from older Christian traditions, yet the movement failed to revive the Anglican Church (several members …


Hemingway, Sartre, And Secularization: Finding Religion Without God, Marcos Antonio Norris Jan 2021

Hemingway, Sartre, And Secularization: Finding Religion Without God, Marcos Antonio Norris

Dissertations

This dissertation intervenes in the critical debate over Ernest Hemingway’s religious orientation. One camp of Hemingway scholars argues that he was a practicing Catholic, while the other camp argues that Hemingway was an existential atheist. Rather than side with either camp in this binary debate, my research offers a third option that bridges the gap between these opposing positions. Examining Hemingway’s life and works through the eyes of contemporary political philosopher Giorgio Agamben, I argue that Hemingway is, properly speaking, neither a secularist nor a theist, but a secularized theist, whose “religion” takes the form of masculine volition, or sovereign, …


A Comparison Of Instructional Efficiency Models In Third Level Education, Murali Rajendran Jan 2021

A Comparison Of Instructional Efficiency Models In Third Level Education, Murali Rajendran

Dissertations

This study investigates the validity and sensitivity of a novel model of instructional efficiency: the parabolic model. The novel model is compared against state-of-the-art models present in instructional design today; Likelihood model, Deviational model and Multidimensional model. This models is based on the assumption that optimal mental workload and high performance leads to high efficiency, while other models assume that low mental workload and high performance leads to high efficiency. The investigation makes use of two instructional design conditions: a direct instructions approach to learning and its extension with a collaborative activity. A control group received the former instructional design …


Stellar Classification Of Folded Spectra Using The Mk Classification Scheme And Convolutional Neural Networks, John Magee Jan 2021

Stellar Classification Of Folded Spectra Using The Mk Classification Scheme And Convolutional Neural Networks, John Magee

Dissertations

The year 1943 saw the introduction of the Morgan-Keenan (MK) classification scheme and this replaced the existing Harvard Classification scheme. Both stellar classification scheme are fundamentally grounded in the field of spectroscopy. The Harvard Classification scheme classified stars based on stellar surface temperature. The MK Classification scheme introduced the concept of a luminosity class that is intrinsically linked to the surface gravity of a star. Temperature and luminosity class values are estimated directly from the stellar spectrum.

Machine learning is a well-established technique in astronomy. Traditionally, a spectrum is treated as a one-dimensional sequence of data. Techniques such as artificial …


Human Age And Gender Classification Using Convolutional Neural Networks, Eamon Kelliher Jan 2021

Human Age And Gender Classification Using Convolutional Neural Networks, Eamon Kelliher

Dissertations

In a world relying ever more on human classification, this papers aims to improve on age and gender image classification through the use of Convolutional Neural Networks (CNN). Age and gender classification has become a popular area of study in the past number of years however there are still improvements to be made, particularly in the area of age classification. This research paper aims to test the currently accepted fact that CNN models are the superior model type for image classification by comparing CNN performance against Support Vector Machine performance on the same dataset. Using the Adience image classification dataset, …


Molecular Mechanism Of Cyanobacteria Circadian Clock Oscillator And Effect Of Co Factors On Its Oscillation, Manpreet Kaur Dec 2020

Molecular Mechanism Of Cyanobacteria Circadian Clock Oscillator And Effect Of Co Factors On Its Oscillation, Manpreet Kaur

Dissertations

The circadian rhythms arise as an adaptation to the environmental 24-hour day and night cycle due to Earth's rotation. These rhythms prepare organisms to align their internal biological activities and day to day behavior or events with the environmental change of the 24-hour day and night cycle. Circadian rhythms are found widely in all living kingdoms of life on Earth. Cyanobacteria are photosynthetic prokaryotes which first used to study these circadian rhythms. Among cyanobacterial species, Synechococcus elongatus PCC 7942 (henceforth, S. Elongatus) is the simplest organism with a durable and sturdy circadian clock and is study as a model organism. …


Coordination, Adaptation, And Complexity In Decision Fusion, Weiqiang Dong Dec 2020

Coordination, Adaptation, And Complexity In Decision Fusion, Weiqiang Dong

Dissertations

A parallel decentralized binary decision fusion architecture employs a bank of local detectors (LDs) that access a commonly-observed phenomenon. The system makes a binary decision about the phenomenon, accepting one of two hypotheses (H0 (“absent”) or H1 (“present”)). The k 1 LD uses a local decision rule to compress its local observations yk into a binary local decision uk; uk = 0 if the k 1 LD accepts H0 and uk = 1 if it accepts H1. The k 1 LD sends its decision uk over a noiseless dedicated channel to a Data Fusion Center (DFC). The DFC combines the …


Drone-Assisted Emergency Communications, Di Wu Dec 2020

Drone-Assisted Emergency Communications, Di Wu

Dissertations

Drone-mounted base stations (DBSs) have been proposed to extend coverage and improve communications between mobile users (MUs) and their corresponding macro base stations (MBSs). Different from the base stations on the ground, DBSs can flexibly fly over and close to MUs to establish a better vantage for communications. Thus, the pathloss between a DBS and an MU can be much smaller than that between the MU and MBS. In addition, by hovering in the air, the DBS can likely establish a Line-of-Sight link to the MBS. DBSs can be leveraged to recover communications in a large natural disaster struck area …


A Deep Machine Learning Approach For Predicting Freeway Work Zone Delay Using Big Data, Abdullah Shabarek Dec 2020

A Deep Machine Learning Approach For Predicting Freeway Work Zone Delay Using Big Data, Abdullah Shabarek

Dissertations

The introduction of deep learning and big data analytics may significantly elevate the performance of traffic speed prediction. Work zones become one of the most critical factors causing congestion impact, which reduces the mobility as well as traffic safety. A comprehensive literature review on existing work zone delay prediction models (i.e., parametric, simulation and non-parametric models) is conducted in this research. The research shows the limitations of each model. Moreover, most previous modeling approaches did not consider user delay for connected freeways when predicting traffic speed under work zone conditions. This research proposes Deep Artificial Neural Network (Deep ANN) and …


Supporting User Interaction And Social Relationship Formation In A Collaborative Online Shopping Context, Yu Xu Dec 2020

Supporting User Interaction And Social Relationship Formation In A Collaborative Online Shopping Context, Yu Xu

Dissertations

The combination of online shopping and social media allow people with similar shopping interests and experiences to share, comment, and discuss about shopping from anywhere and at any time, which also leads to the emergence of online shopping communities. Today, more people turn to online platforms to share their opinions about products, solicit various opinions from their friends, family members, and other customers, and have fun through interactions with others with similar interests. This dissertation explores how collaborative online shopping presents itself as a context and platform for users' interpersonal interactions and social relationship formation through a series of studies. …


Dances And Escape Of The Vortex Quartet, Brandon Behring Dec 2020

Dances And Escape Of The Vortex Quartet, Brandon Behring

Dissertations

This dissertation considers the linear stability of a one-parameter family of periodic solutions of the four-vortex problem known as 'leapfrogging' orbits. These solutions, which consist of two pairs of identical yet oppositely-signed vortices, were known to W. Gröbli (1877) and A. E. H. Love (1883) and can be parameterized by a dimensionless parameter related to the geometry of the initial configuration. Simulations by Acheson and numerical Floquet analysis by Tophøj and Aref both indicate, to many digits, that the bifurcation occurs at a value related to the inverse square of the golen ratio. Acheson observed that, after an initial period …


Characterizing Reactive Iron Mineral Coatings And Their Roles In Natural Attenuation At A Site With Historical Contamination, Han Hua Dec 2020

Characterizing Reactive Iron Mineral Coatings And Their Roles In Natural Attenuation At A Site With Historical Contamination, Han Hua

Dissertations

Reactive iron mineral coatings in redox transition zones play an important role in contaminant attenuation. These mineral coatings include poorly crystalline to crystalline iron sulfides, carbonates, and oxyhydroxides, and are a signature of the biogeochemical processes occurring. To better understand these processes, reactive iron mineral coatings are characterized in an 18-m Anaerobic Core collected from a contaminated industrial site. This study targets redox transition zones uncovered in the core. A suite of complementary analyses is applied to distinguish the surface coating mineralogy using X-ray Diffraction, X-ray fluorescence, and field-emission scanning electron microscopy (FESEM) with energy dispersive X-ray analyzer (EDX). In …


The Aging And Impacts Of Atmospheric Soot: Closing The Gap Between Experiments And Models, Ogochukwu Yvonne Enekwizu Dec 2020

The Aging And Impacts Of Atmospheric Soot: Closing The Gap Between Experiments And Models, Ogochukwu Yvonne Enekwizu

Dissertations

The main goal of this dissertation is to generate data and parameterizations to accurately represent soot aerosols in atmospheric models. Soot from incomplete combustion of fossil fuels and biomass burning is a major air pollutant and a significant contributor to climate warming. The environmental impacts of soot are strongly dependent on the particle morphology and mixing state, which evolve continuously during atmospheric transport via a process known as aging. To make predictions of soot impacts on the environment, most atmospheric models adopt simplifications of particle structure and mixing state, which lead to substantial uncertainties. Using an experimentally constrained modeling approach, …


Performance Optimization Of Big Data Computing Workflows For Batch And Stream Data Processing In Multi-Clouds, Huiyan Cao Dec 2020

Performance Optimization Of Big Data Computing Workflows For Batch And Stream Data Processing In Multi-Clouds, Huiyan Cao

Dissertations

Workflow techniques have been widely used as a major computing solution in many science domains. With the rapid deployment of cloud infrastructures around the globe and the economic benefits of cloud-based computing and storage services, an increasing number of scientific workflows have migrated or are in active transition to clouds. As the scale of scientific applications continues to grow, it is now common to deploy various data- and network-intensive computing workflows such as serial computing workflows, MapReduce/Spark-based workflows, and Storm-based stream data processing workflows in multi-cloud environments, where inter-cloud data transfer oftentimes plays a significant role in both workflow performance …


Modeling Mass Transfer And Chemical Reaction In Industrial Nitrocellulose Manufacturing Processes, Francis Patrick Sullivan Dec 2020

Modeling Mass Transfer And Chemical Reaction In Industrial Nitrocellulose Manufacturing Processes, Francis Patrick Sullivan

Dissertations

A series of models are proposed to describe the production of military grade nitrocellulose from dense cellulose materials in mixtures of nitric acid, sulfuric acid, and water. This effort is conducted to provide a predictive capability for analyzing the rate and extent of reaction achieved under a range of reaction conditions used in the industrial nitrocellulose manufacturing process for sheeted cellulose materials. Because this capability does not presently exist, nitrocellulose producers have historically relied on a very narrow range of cellulose raw materials and resorted to trial and error methods to develop processing conditions for new materials. This tool enables …


Small-Scale Dynamics Of Photospheric Magnetic Activities And Their Chromospheric Responses, Jiasheng Wang Dec 2020

Small-Scale Dynamics Of Photospheric Magnetic Activities And Their Chromospheric Responses, Jiasheng Wang

Dissertations

The evolution of photospheric magnetic fields is considered as the fundamental source of forming atmospheric structures and triggering most solar activities, including flares and mass ejections on various scales (CMEs, jets, etc.). With the implementation of high-resolution observational instruments, small-scale details of magnetic features are recognized that can provide important information regarding the evolution in active regions and the connection between photospheric magnetic reconnection and jet-like ejections in the quiet Sun. This research takes advantage of the exceptionally high-resolution measurements of vector magnetic field and imaging observations by the Goode Solar Telescope, and UV/EUV imaging observations from space-based instruments. The …


Blast Shock-Wave Characterization In Experimental Shock Tubes, Sudeepto Kahali Dec 2020

Blast Shock-Wave Characterization In Experimental Shock Tubes, Sudeepto Kahali

Dissertations

Blast-induced traumatic brain injuries have affected U.S. soldiers deployed for extended periods in the gulf and Afghanistan wars. To identify the biomechanical and biochemical mechanisms of injury, critical in the identification of diagnostic and therapeutic tools, compressed gas-driven shock tubes are used by investigators to study shockwave-animal specimen interactions and its biological consequences. However, shock tubes are designed and operated in a variety of geometry with a range of process parameters, and the quality of shock wave characteristics relevant to field conditions and therefore the study of blast-induced traumatic brain injuries suffered by soldiers is affected by those conditions. Lab-to-lab …


Semantic, Integrated Keyword Search Over Structured And Loosely Structured Databases, Xinge Lu Dec 2020

Semantic, Integrated Keyword Search Over Structured And Loosely Structured Databases, Xinge Lu

Dissertations

Keyword search has been seen in recent years as an attractive way for querying data with some form of structure. Indeed, it allows simple users to extract information from databases without mastering a complex structured query language and without having knowledge of the schema of the data. It also allows for integrated search of heterogeneous data sources. However, as keyword queries are ambiguous and not expressive enough, keyword search cannot scale satisfactorily on big datasets and the answers are, in general, of low accuracy. Therefore, flat keyword search alone cannot efficiently return high quality results on large data with structure. …


Countering Internet Packet Classifiers To Improve User Online Privacy, Sina Fathi-Kazerooni Dec 2020

Countering Internet Packet Classifiers To Improve User Online Privacy, Sina Fathi-Kazerooni

Dissertations

Internet traffic classification or packet classification is the act of classifying packets using the extracted statistical data from the transmitted packets on a computer network. Internet traffic classification is an essential tool for Internet service providers to manage network traffic, provide users with the intended quality of service (QoS), and perform surveillance. QoS measures prioritize a network's traffic type over other traffic based on preset criteria; for instance, it gives higher priority or bandwidth to video traffic over website browsing traffic. Internet packet classification methods are also used for automated intrusion detection. They analyze incoming traffic patterns and identify malicious …


Novel Applications Of Mass Spectrometry For Quantitation And Reaction Mechanism Elucidation, Pengyi Zhao Dec 2020

Novel Applications Of Mass Spectrometry For Quantitation And Reaction Mechanism Elucidation, Pengyi Zhao

Dissertations

Mass spectrometry (MS) has been growing as one of the most widely used tools in the field of analytical chemistry. Various applications have been developed to harness the high sensitivity and specificity of mass spectrometric analysis. In this dissertation, two major challenges are addressed. By developing mass spectrometric-based methods, absolute quantitation of proteins/peptides have been achieved. Elucidation of various reaction mechanisms are also enabled. These are the focuses of this dissertation.

In Chapters 2 to 4, a novel quantitation method is developed, titled as coulometric mass spectrometry (CMS). The strength of this method is that no reference standard or isotope-labeled …


Convergence Of The Boundary Integral Method For Interfacial Stokes Flow, Keyang Zhang Dec 2020

Convergence Of The Boundary Integral Method For Interfacial Stokes Flow, Keyang Zhang

Dissertations

Boundary integral numerical methods are among the most accurate methods for interfacial Stokes flow, and are widely applied. They have the advantage that only the boundary of the domain must be discretized, which reduces the number of discretization points and allows the treatment of complicated interfaces. Despite their popularity, there is no analysis of the convergence of these methods for interfacial Stokes flow. In practice, the stability of discretizations of the boundary integral formulation can depend sensitively on details of the discretization and on the application of numerical filters. A convergence analysis of the boundary integral method for Stokes flow …


Development Of Novel Membranes For Nanocarbon Enhanced Separation With Application In Biofuels And Solvent Recover, Oindrila Gupta Dec 2020

Development Of Novel Membranes For Nanocarbon Enhanced Separation With Application In Biofuels And Solvent Recover, Oindrila Gupta

Dissertations

Pharmaceutical industries historically have had one of the highest amounts of solvent waste generated per unit of drug manufactured. Energy requirements and carbon footprint of current solvent recycling processes tend to be quite high, and the incineration of the solvents for waste disposal produces toxic air emissions. Also, rapidly increasing demand for energy and strict regulation on engine pollutant emissions have necessitated the use of alcohol as carbon-neutral fuels. Thermal distillation is one of the most common methods for the separation of alcohol-water mixtures. However, its application is limited due to energy requirements and high operating costs, and heating to …


Addressing Ad-Blocking Challenges In Online Publishing: A Data Science Approach, Shuai Zhao Dec 2020

Addressing Ad-Blocking Challenges In Online Publishing: A Data Science Approach, Shuai Zhao

Dissertations

The revenue of online display advertising is expected to reach 389 billion U.S. dollars globally in 2021. However, the fast increase in ad-blocker usage impacts publishers' ad revenue and the ad-supported free web. Faced with this problem, many online publishers choose either to cooperate with ad-blocker software companies to show acceptable ads or to build a wall that requires users to whitelist (i.e., turn off ad-blockers) for content access. This dissertation aims to deepen the understanding of existing counter-ad-blocking strategies and further explore how to address ad-blocking challenges through a data science approach.

The dissertation starts with investigating and identifying …


Response Of Deep Aquifers To Climate Variability, Karem Fathy Abdelgaber Abdelmohsen Dec 2020

Response Of Deep Aquifers To Climate Variability, Karem Fathy Abdelgaber Abdelmohsen

Dissertations

Our recent analysis of Temporal Gravity Recovery and Climate Experiment (GRACE) solutions over the largest aquifer system in Africa (the Nubian Sandstone Aquifer System: NSAS) revealed that while the response of deep aquifers to climatic variations remains a relatively slow process that takes thousands to tens of thousands of years, there is a much faster response in aquifers that are characterized by dense networks of faults, fractures and karst as is the case with the NSAS. This rapid groundwater flow, when it occurs, is detected as an increase in GRACETWS over areas downgradient and distant (hundreds of km) from …


Saudi Elementary Mathematics Teachers’ Knowledge For Teaching Fractions, Mona Khalifah A Aladil Dec 2020

Saudi Elementary Mathematics Teachers’ Knowledge For Teaching Fractions, Mona Khalifah A Aladil

Dissertations

Recent reform efforts in Saudi Arabia attend to mathematics instruction with a great deal of emphasis to improve Saudi mathematics education. Studies in different countries have confirmed that teachers’ mathematical knowledge for teaching plays an important role in mathematical quality of instruction and students’ achievement (e.g., Ball, 1990; Baumert et al., 2010; Hill, Rowan, & Ball, 2005). Yet few studies about mathematics teachers’ knowledge for teaching have been conducted in the Saudi context. This study investigates Saudi elementary mathematics teachers’ knowledge for teaching in the content strand of rational numbers with an emphasis on fractions, which is an important step …


A Library Of Low Molecular Weight Fluorescent Probes For The Detection Of Cu(Ii) And Fe(Iii) Ions, Ashley Johnson Dec 2020

A Library Of Low Molecular Weight Fluorescent Probes For The Detection Of Cu(Ii) And Fe(Iii) Ions, Ashley Johnson

Dissertations

This dissertation reports the synthesis and photophysical properties of a family of rhodamine dyes (compounds 3.9-3.13 and 4.6). The rhodamine dyes are prepared in two steps, and fully characterized by ESI-MS (Low and High resolution), X-Ray crystallography, NMR spectroscopy, and FT-IR spectroscopy. The coordination environment of the low molecular weight fluorescent probes (LMFPs) was systematically changed to investigate the thermodynamic behavior between the LMFPs and an array of metal ions (Cu2+, Fe2+, and Hg2+ ions) in protic and aprotic solvent systems. Upon coordinating to metal ions, the π-conjugation of the LMFPs changed, resulting in …


Practical Adhesion Measurements In Organic Coatings; Advancing Understanding And Mechanical Methods Development, Diana Gottschalk Dec 2020

Practical Adhesion Measurements In Organic Coatings; Advancing Understanding And Mechanical Methods Development, Diana Gottschalk

Dissertations

“Adhesion” can be considered either a mechanical or chemical phenomenon. The mechanical interpretation describes the difficulty of separating surfaces and is useful for quantifying performance within applications that depend on bulk and interfacial properties. Chemical adhesion describes interfacial resistance to chemical attack and does not depend on bulk properties. Predicting chemical failure through mechanical measurement is confounded by the influence of bulk properties. However, the prospect is attractive because of the robust tolerance for sample geometries, allowing experiments to resemble an end-use system. The present work's primary goal was to elevate mechanical methods to provide a detailed interfacial characterization of …


Hierarchical Aggregation Of Multidimensional Data For Efficient Data Mining, Safaa Khalil Alwajidi Dec 2020

Hierarchical Aggregation Of Multidimensional Data For Efficient Data Mining, Safaa Khalil Alwajidi

Dissertations

Big data analysis is essential for many smart applications in areas such as connected healthcare, intelligent transportation, human activity recognition, environment, and climate change monitoring. Traditional data mining algorithms do not scale well to big data due to the enormous number of data points and the velocity of their generation. Mining and learning from big data need time and memory efficiency techniques, albeit the cost of possible loss in accuracy. This research focuses on the mining of big data using aggregated data as input. We developed a data structure that is to be used to aggregate data at multiple resolutions. …


On The Local Theory Of Profinite Groups, Mohammad Shatnawi Dec 2020

On The Local Theory Of Profinite Groups, Mohammad Shatnawi

Dissertations

Let G be a finite group, and H be a subgroup of G. The transfer homomorphism emerges from the natural action of G on the cosets of H. The transfer was first introduced by Schur in 1902 [22] as a construction in group theory, which produce a homomorphism from a finite group G into H/H' an abelian group where H is a subgroup of G and H' is the derived group of H. One important first application is Burnside’s normal p-complement theorem [5] in 1911, although he did not use the transfer homomorphism explicitly to prove it. …