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Full-Text Articles in Physical Sciences and Mathematics

Consequence Based Procedure For Description Logics With Self Restriction, Cong Wang, Pascal Hitzler Jan 2013

Consequence Based Procedure For Description Logics With Self Restriction, Cong Wang, Pascal Hitzler

Computer Science and Engineering Faculty Publications

We present a consequence based classification procedure for the description logics with self restriction constructor. Due to the difficulty of constructing a concept inclusion model for self restriction, we use a different proof by showing that all the completion rules can simulate all the corresponding ordered resolution inferences.


An Analytical Look At Glen Helen Nature Preserve Fall 2013, Audrey E. Mcgowin, Seth W. Brittle, Jacob Doolin, Dustin Estridge, Anna Foote, Shannon Hennley, Megan Huddleson, Robert Johnson, Abraham Kemboi, Carlie Mcgrath, John Mcgrath, Renata Mitton, David Roland, Nicholas Rose Jan 2013

An Analytical Look At Glen Helen Nature Preserve Fall 2013, Audrey E. Mcgowin, Seth W. Brittle, Jacob Doolin, Dustin Estridge, Anna Foote, Shannon Hennley, Megan Huddleson, Robert Johnson, Abraham Kemboi, Carlie Mcgrath, John Mcgrath, Renata Mitton, David Roland, Nicholas Rose

Chemistry Faculty Publications

No abstract provided.


Monitoring The Health Of Glen Helen Nature Preserve: Fall 2012 Sediment And Water, Audrey E. Mcgowin Ph.D., Triet Minh Truong Jan 2013

Monitoring The Health Of Glen Helen Nature Preserve: Fall 2012 Sediment And Water, Audrey E. Mcgowin Ph.D., Triet Minh Truong

Chemistry Student Publications

This poster presents the results for environmental testing in Glen Helen by the Special Topics in Analytical Chemistry course at Wright State University under the direction of Professor Audrey McGowin in Spring 2012. Water quality data are presented for the Yellow Spring in Yellow Springs, Ohio for April and May of 2012. Other test sites range from locations along Yellow Springs Creek to the covered bridge near Little Miami River.

This poster was created by Triet M. Truong.


Traffic Analytics Using Probabilistic Graphical Models Enhanced With Knowledge Bases, Pramod Anantharam, Krishnaprasad Thirunarayan, Amit P. Sheth Jan 2013

Traffic Analytics Using Probabilistic Graphical Models Enhanced With Knowledge Bases, Pramod Anantharam, Krishnaprasad Thirunarayan, Amit P. Sheth

Kno.e.sis Publications

Graphical models have been successfully used to deal with uncertainty, incompleteness, and dynamism within many domains. These models built from data often ignore preexisting declarative knowledge about the domain in the form of ontologies and Linked Open Data (LOD) that is increasingly available on the web. In this paper, we present an approach to leverage such 'top-down' domain knowledge to enhance 'bottom-up' building of graphical models. Specifically, we propose three operations on the graphical model structure to enrich it with nodes, edges, and edge directions. We illustrate the enrichment process using traffic data from 511.org and declarative knowledge from ConceptNet. …


Advancing Data Reuse In Phyloinformatics Using An Ontology-Driven Semantic Web Approach, Maryam Panahiazar, Amit P. Sheth, Ajith Harshana Ranabahu, Rutger Vos, Jim Leebens-Mack Jan 2013

Advancing Data Reuse In Phyloinformatics Using An Ontology-Driven Semantic Web Approach, Maryam Panahiazar, Amit P. Sheth, Ajith Harshana Ranabahu, Rutger Vos, Jim Leebens-Mack

Kno.e.sis Publications

Phylogenetic analyses can resolve historical relationships among genes, organisms or higher taxa. Understanding such relationships can elucidate a wide range of biological phenomena, including, for example, the importance of gene and genome duplications in the evolution of gene function, the role of adaptation as a driver of diversification, or the evolutionary consequences of biogeographic shifts. Phyloinformaticists are developing data standards, databases and communication protocols (e.g. Application Programming Interfaces, APIs) to extend the accessibility of gene trees, species trees, and the metadata necessary to interpret these trees, thus enabling researchers across the life sciences to reuse phylogenetic knowledge. Specifically, Semantic Web …


A Hybrid Approach To Finding Relevant Social Media Content For Complex Domain Specific Information Needs, Delroy H. Cameron, Amit P. Sheth, Nishita Jaykumar, Gaurish Anand, Krishnaprasad Thirunarayan, Gary Alan Smith Jan 2013

A Hybrid Approach To Finding Relevant Social Media Content For Complex Domain Specific Information Needs, Delroy H. Cameron, Amit P. Sheth, Nishita Jaykumar, Gaurish Anand, Krishnaprasad Thirunarayan, Gary Alan Smith

Kno.e.sis Publications

While contemporary semantic search systems offer to improve classical keyword-based search, they are not always adequate for complex, domain specific information needs. Some complex search situations require knowledge of both ontological concepts as well as 'intelligible constructs' not typically modeled in ontologies. Intelligible constructs convey essential information, which may be important to the holistic information needs of information seekers. Such constructs may include notions of intensity, frequency, interval, dosage, emotion, sentiment, equivalence, synonymy, negation, parts-of-speech, etc. However, few search systems utilize both structured background knowledge (ontologies) and the aforementioned knowledge for query interpretation in domain specific searches. Instead, there is …


Mining Diversified Decision Trees Across Multiple Datasets To Capture Similarities And Alignable Differences, Qian Han Jan 2013

Mining Diversified Decision Trees Across Multiple Datasets To Capture Similarities And Alignable Differences, Qian Han

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This dissertation studies the problem of mining shared and alignable difference knowledge structures across multiple datasets/applications. Shared and alignable difference knowledge structures are important for identifying analogies between application domains and for forming new hypothesis in challenging research applications, and for assessing the degree and types of knowledge-level similarities and differences between application domains for use in learning transfer. Generally speaking, shared knowledge structures characterize underlying datasets and highlight conceptual-level structural similarities among the datasets. This dissertation studies the mining of shared decision trees, which are a special type of shared knowledge structures. We first consider building one shared decision …


The Enhancement Of Peroxide-Cured Fluoroelastomer Rubber To Metal Bonding, Richard Hunter Cooke Iii Jan 2013

The Enhancement Of Peroxide-Cured Fluoroelastomer Rubber To Metal Bonding, Richard Hunter Cooke Iii

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A "combi-cured&" fluoroelastomer (FKM) rubber formulation was designed to yield 100% cohesive rubber failure when cured to cold-rolled steel with derivatives of polymeric silane adhesives. Three different categories of adhesives were tested: Unsaturated Polymeric Silane with Phosphonium Salt (UPSP-D), Unsaturated Polymeric Silane (UPS-L), and Saturated Polymeric Silane (SPS-L). Adhesion Inserts molded using ASTM Method D429 Method C all consistently yielded 100% cohesive rubber failure and showed adhesion strength in the range of 700 to 800 psi after being pulled at 2" per minute until break. After obtaining consistent 100% rubber failure, a design of experiment (DOE) was implemented to determine …


Enhanced Resolution Of The Paleoenvironmental And Diagenetic Features Of The Silurian Brassfield Formation, Lisa Marie Oakley Jan 2013

Enhanced Resolution Of The Paleoenvironmental And Diagenetic Features Of The Silurian Brassfield Formation, Lisa Marie Oakley

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The Brassfield Formation is an early Silurian (Aeronian, Llandoverian) unit of limestone and dolostone with excellent preservation of early reef communities and a diverse invertebrate fauna. A well-preserved outcrop occurs in southwestern Ohio at the Oakes Quarry Park in Fairborn; it contains abundant corals and stromatoporoids that are co-dominant in reef and reef-affected settings. This research provided an enhanced perspective of the Brassfield Formation to better reconstruct its paleoenvironment and better understand its diagenetic features. The depositional and diagenetic features of the Brassfield are described and interpreted using histologic methods and light microscopy. Selected thin sections were treated with carbonate …


The Synthesis Of Benzyloxy Substituted Dp-Ppvs, Ryan Oostendorp Jan 2013

The Synthesis Of Benzyloxy Substituted Dp-Ppvs, Ryan Oostendorp

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The alkyne 1-(benzyloxy)-4-(propargyloxy)benzene was reacted with 2,5-di(carboethoxy)3,4-diphenylcyclopentadienone to yield diethyl 5-((4-(benzyloxy)phenoxy)methyl)-2,3-diphenylterephthalate. The terephthalate was reduced with lithium aluminum hydride to produce 5-((4-(benzyloxy)phenoxy)methyl)-1,4-di(hydroxymethyl)-2,3-diphenylbenzene. The diol was reacted with thionyl chloride to yield the monomer 5-((4-(benzyloxy)phenoxy)methyl)-1,4-di(chloromethyl)-2,3-diphenylbenzene that has a pendent protected phenol function. The new compounds were characterized by melting point, IR, 1H NMR, 13C NMR spectroscopy and elemental analysis. Polymerization of the dichloro monomer via a Gilch polymerization yielded poly[(2,3-diphenyl-(5-((4-(benzyloxy)phenoxy)methyl)-1,4-phenylene) vinylene]. The polymer was characterized by IR, 1H NMR spectroscopy, TGA and DSC. The polymer was insoluble in most solvents but partially soluble in chlorinated solvents. The solid polymer fluoresced a …


Semsos : An Architecture For Query, Insertion, And Discovery For Semantic Sensor Networks, Joshua Kenneth Pschorr Jan 2013

Semsos : An Architecture For Query, Insertion, And Discovery For Semantic Sensor Networks, Joshua Kenneth Pschorr

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With sensors, storage, and bandwidth becoming ever cheaper, there has been a drive recently to make sensor data accessible on the Web. However, because of the vast number of sensors collecting data about our environment, finding relevant sensors on the Web and then interpreting their observations is a non-trivial challenge. The Open Geospatial Consortium (OGC) defines a web service specification known as the Sensor Observation Service (SOS) that is designed to standardize the way sensors and sensor data are discovered and accessed on the Web. Though this standard goes a long way in providing interoperability between sensor data producers and …


Two Fundamental Building Blocks To Provide Quick Reaction Capabilities For The Department Of Defense, Daniel Alan Uppenkamp Jan 2013

Two Fundamental Building Blocks To Provide Quick Reaction Capabilities For The Department Of Defense, Daniel Alan Uppenkamp

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The Department of Defense (DoD) has a need for long-term development efforts in conjunction with short-term development efforts. Ideally, Quick Reaction Capabilities (QRC) would be able to make use of the same processes that are used for Acquisition Programs (AP) with a few modifications to accommodate the accelerated schedule. Unfortunately, APs have a more fundamental problem with both the development process and the development framework. In August of 2007, the agile development process and modular, open source framework discussed in this thesis were two key factors that enabled the Air Force Research Laboratory (AFRL) to successfully deploy AngelFire in support …


Student Fact Book, Fall 2013, Thirty-Seventh Annual Edition, Wright State University, Office Of Student Information Systems, Wright State University Jan 2013

Student Fact Book, Fall 2013, Thirty-Seventh Annual Edition, Wright State University, Office Of Student Information Systems, Wright State University

Wright State University Student Fact Books

The student fact book has general demographic information on all students enrolled at Wright State University for Fall Semester, 2013.


Twitris: Socially Influenced Browsing, Ashutosh Sopan Jadhav, Wenbo Wang, Raghava Mutharaju, Pramod Anantharam, Vinh Nguyen, Amit P. Sheth, Karthik Gomadam, Meenakshi Nagarajan, Ajith Harshana Ranabahu Jan 2013

Twitris: Socially Influenced Browsing, Ashutosh Sopan Jadhav, Wenbo Wang, Raghava Mutharaju, Pramod Anantharam, Vinh Nguyen, Amit P. Sheth, Karthik Gomadam, Meenakshi Nagarajan, Ajith Harshana Ranabahu

Kno.e.sis Publications

In this paper, we present Twitris, a semantic Web application that facilitates browsing for news and information, using social perceptions as the fulcrum. In doing so we address challenges in large scale crawling, processing of real time information, and preserving spatio-temporal-thematic properties central to observations pertaining to real time events. We extract metadata about events from Twitter and bring related news and Wikipedia articles to the user. In developing Twitris, we have used the DBPedia ontology.


Adaptive Semantic Annotation Of Entity And Concept Mentions In Text, Pablo N. Mendes Jan 2013

Adaptive Semantic Annotation Of Entity And Concept Mentions In Text, Pablo N. Mendes

Kno.e.sis Publications

The recent years have seen an increase in interest for knowledge repositories that are useful across applications, in contrast to the creation of ad hoc or application-specific databases.
These knowledge repositories figure as a central provider of unambiguous identifiers and semantic relationships between entities. As such, these shared entity descriptions serve as a common vocabulary to exchange and organize information in different formats and for different purposes. Therefore, there has been remarkable interest in systems that are able to automatically tag textual documents with identifiers from shared knowledge repositories so that the content in those documents is described in a …


Compensation In Al-Doped Zno By Al-Related Acceptor Complexes: Synchrotron X-Ray Absorption Spectroscopy And Theory, Jiraroj T-Thienprasert, S. Rujirawat, W. Klysubun, J. N. Duenow, T. J. Coutts, S. B. Zhang, David C. Look, Sukit Limpijumnong Jan 2013

Compensation In Al-Doped Zno By Al-Related Acceptor Complexes: Synchrotron X-Ray Absorption Spectroscopy And Theory, Jiraroj T-Thienprasert, S. Rujirawat, W. Klysubun, J. N. Duenow, T. J. Coutts, S. B. Zhang, David C. Look, Sukit Limpijumnong

Physics Faculty Publications

The synchrotron x-ray absorption near edge structures (XANES) technique was used in conjunction with first-principles calculations to characterize Al-doped ZnO films. Standard characterizations revealed that the amount of carrier concentration and mobility depend on the growth conditions, i.e. H2 (or  O2)/Ar gas ratio and Al concentration. First-principles calculations showed that Al energetically prefers to substitute on the Zn site, forming a donor AlZn, over being an interstitial (Ali). The measured Al K-edge XANES spectra are in good agreement with the simulated spectra of AlZn, indicating that the majority of Al atoms …


Extending Positive Class Results Across Multiple Instructors And Multiple Classes Of Modeling Instruction, Eric Brewe, Adrienne L. Traxler, Jorge De La Garza, Laird H. Kramer Jan 2013

Extending Positive Class Results Across Multiple Instructors And Multiple Classes Of Modeling Instruction, Eric Brewe, Adrienne L. Traxler, Jorge De La Garza, Laird H. Kramer

Physics Faculty Publications

We report on a multiyear study of student attitudes measured with the Colorado Learning Attitudes about Science Survey in calculus-based introductory physics taught with the Modeling Instruction curriculum. We find that five of six instructors and eight of nine sections using Modeling Instruction showed significantly improved attitudes from pre- to postcourse. Cohen’s d effect sizes range from 0.08 to 0.95 for individual instructors. The average effect was d = 0.45, with a 95% confidence interval of (0.26–0.64). These results build on previously published results showing positive shifts in attitudes from Modeling Instruction classes. We interpret these data in light …


Effect Of Sample History On Dissolution Rates Of Gypsum {010} Surfaces, Dennis Stefan Renier Lennaerts Jan 2013

Effect Of Sample History On Dissolution Rates Of Gypsum {010} Surfaces, Dennis Stefan Renier Lennaerts

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Mineral dissolution plays a significant role in geochemical processes such as carbon sequestration and isotope geochemistry. While factors such as temperature, pressure, and solution chemistry have been widely studied, the effects of sample history and surface morphology on dissolution rates have been studied to a lesser extent. This research focuses on the dissolution of cleaved, polished, and reacted samples of the atomically flat natural {010} cleavage plane of gypsum (CaSO4·2H2O) to further investigate upon the effect of sample history. Gypsum was chosen as the mineral of interest because of its planar crystal surface and relatively fast dissolution rate. Chemical dissolution …


Cyclic Voltammetric And Square Wave Anodic Stripping Voltammetric Analysis Of Lead And Cadmium Utilizing The Novel Titanium Dioxide/ Zirconium Dioxide/ Tween 80 Carbon Paste Composite Electrode, Phuong Khanh Quoc Nguyen Jan 2013

Cyclic Voltammetric And Square Wave Anodic Stripping Voltammetric Analysis Of Lead And Cadmium Utilizing The Novel Titanium Dioxide/ Zirconium Dioxide/ Tween 80 Carbon Paste Composite Electrode, Phuong Khanh Quoc Nguyen

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Heavy metals, particularly Lead (Pb) and Cadmium (Cd), had been long identified as hazardous pollutants in the environment. Joining the continuous effort to alleviate this dilemma, a new electro-chemical sensor has been developed to assess the level of Pb and Cd in aqueous environment. The current work describes the utilization of two different electro-analytical techniques, cyclic voltammetry (CV) and square wave anodic stripping voltammetry (SWASV), in conjunction with the novel Titanium Dioxide/ Zirconium Dioxide/ Tween 80 (TiO2/ ZrO2/ Tween 80) carbon paste composite electrode to qualitatively and quantitatively analyze Pb and Cd. In this dissertation, along with a comprehensive literature …


A Large Scale Distributed Syntactic, Semantic And Lexical Language Model For Machine Translation, Ming Tan Jan 2013

A Large Scale Distributed Syntactic, Semantic And Lexical Language Model For Machine Translation, Ming Tan

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The n-gram model is the most widely used language model (LM) in statistical machine translation system, due to its simplicity and scalability. However, it only encodes the local lexical relation between adjacent words and clearly ignores the rich syntactic and semantic structures of the natural languages. Attempting to increase the order of an n-gram to describe longer range dependencies in natural language immediately runs into the curse of dimensionality. Although previous researches tried to increase the order of n-gram on a large corpus, they did not see obvious improvement beyond 6-gram. Meanwhile, other LMs, such as syntactic language models and …


Post-Emplacement Leaching Behaviors Of Nano Zero Valent Iron Modified With Carboxymethylcellulose Under Simulated Aquifer Conditions, Leslie Lavinia Williams Jan 2013

Post-Emplacement Leaching Behaviors Of Nano Zero Valent Iron Modified With Carboxymethylcellulose Under Simulated Aquifer Conditions, Leslie Lavinia Williams

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Nanoscale particles of zero valent iron stabilized with carboxymethylcellulose (CMC-nZVI) have been shown to degrade chlorinated hydrocarbons efficiently in bench-scale investigations. The remediation of contaminated sites by subsurface injection of stabilized nZVI in a slurry form has been investigated at pilot scale and field scale with conflicting results concerning transport of stabilized nZVI and its long-term stability for in situ degradation of chlorinated hydrocarbons. Changes in the hydraulic conductivity in porous media have also been reported following injection of stabilized nZVI slurry in both large tank experiments and in field studies. This study investigated the leaching behavior of CMC-nZVI post-emplacement …


Adaptive Semantic Annotation Of Entity And Concept Mentions In Text, Pablo N. Mendes Jan 2013

Adaptive Semantic Annotation Of Entity And Concept Mentions In Text, Pablo N. Mendes

Browse all Theses and Dissertations

The recent years have seen an increase in interest for knowledge repositories that are useful across applications, in contrast to the creation of ad hoc or application-specific databases.

These knowledge repositories figure as a central provider of unambiguous identifiers and semantic relationships between entities. As such, these shared entity descriptions serve as a common vocabulary to exchange and organize information in different formats and for different purposes. Therefore, there has been remarkable interest in systems that are able to automatically tag textual documents with identifiers from shared knowledge repositories so that the content in those documents is described in a …


Synthesis And Characterization Of Graphene Oxide/Sulfur Nanocomposite For Lithium-Ion Batteries, Aaron Joseph Blake Jan 2013

Synthesis And Characterization Of Graphene Oxide/Sulfur Nanocomposite For Lithium-Ion Batteries, Aaron Joseph Blake

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The growing need for clean and efficient energy storage systems has recently peaked due to concerns of climate change and increased global energy consumption. However, efficiently integrating renewable resources such as solar and wind energy into society will require a complex electrical energy storage (EES) system capable of storing and expending significant amounts of energy. A battery based on the lithium/sulfur couple can yield a theoretical specific energy of 2600Wh/kg, which is about five times higher than that offered by present Li-ion batteries, and hence, is a promising and attractive technology. Despite recent developments in addressing various issues inherent to …


A Geophysical Investigation To Locate Missing Graves Utilizing Ground Penetrating Radar, Electromagnetic, And Magnetic Methods, Jared Wyatt Shank Jan 2013

A Geophysical Investigation To Locate Missing Graves Utilizing Ground Penetrating Radar, Electromagnetic, And Magnetic Methods, Jared Wyatt Shank

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Old cemeteries often have graves that are unmarked because gravestones are missing or degraded and the graves are in areas for which maps or other historical documents are incomplete. This is the case for one cemetery in southwestern Ohio, known as Stevenson Cemetery, which contains graves of Revolutionary War and War of 1812 veterans. The immediate goal of this study is to locate unmarked graves in this cemetery using geophysical techniques. The broader goal is to evaluate three geophysical techniques to determine the effectiveness of each.

The three geophysical techniques evaluated in this study are magnetics, electro-magnetics, and ground-penetrating radar. …


Anomalies In Sensor Network Deployments: Analysis, Modeling, And Detection, Giovani Rimon Abuaitah Jan 2013

Anomalies In Sensor Network Deployments: Analysis, Modeling, And Detection, Giovani Rimon Abuaitah

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A sensor network serves as a vital source for collecting raw sensory data. Sensor data are later processed, analyzed, visualized, and reasoned over with the help of several decision making tools. A decision making process can be disastrously misled by a small portion of anomalous sensor readings. Therefore, there has been a vast demand for mechanisms that identify and then eliminate such anomalies in order to ensure the quality, integrity, and/or trustworthiness of the raw sensory data before they can even be interpreted.

Prior to identifying anomalies, it is essential to understand the various anomalous behaviors prevalent in a sensor …


Design And Fabrication Of An Eddy Current Brake Dynamometer For Efficiency Determination Of Electric Wheelchair Motors, Wesley Brin Jan 2013

Design And Fabrication Of An Eddy Current Brake Dynamometer For Efficiency Determination Of Electric Wheelchair Motors, Wesley Brin

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Electric wheelchairs have a considerable impact on improving the quality of life for the millions of disabled persons around the world. These modern pieces of technology offer freedom and mobility for disabled persons to interact with the world outside of their homes. The goal of this project is to assist in advancements of conventional electric wheelchairs. This includes replacing the heavy, bulky, and inefficient lead acid batteries and worm gear drive systems with lithium-ion batteries and wheel hub motors in order to decrease weight and size, and increase efficiency. This master thesis research is focused on designing, fabricating, and testing …


The Synthesis And Characterization Of 1,3-Bisphenylsulfonylacetone, 2,5-Dicarboethoxy-3,4-Di(4-Methylphenyl)Cyclopentadienone Dimer, And Dp-Ppv Polymers And Oligomers, Mark Robert Duffy Jan 2013

The Synthesis And Characterization Of 1,3-Bisphenylsulfonylacetone, 2,5-Dicarboethoxy-3,4-Di(4-Methylphenyl)Cyclopentadienone Dimer, And Dp-Ppv Polymers And Oligomers, Mark Robert Duffy

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An SN2 reaction between 1,3-dichloroacetone and benzenesulfinic acid sodium salt was carried out to produce 1,3-bis(phenylsulfonyl)acetone. A crystal structure for 1,3-bis(phenylsulfonyl)acetone was obtained. The SN2 reaction was followed by a condensation reaction with benzil but this did not yield a condensation product. A photo-active compound, 2,5-dicarboethoxy-3,4-di(4-methylphenyl)cyclopentadienone, was synthesized and was shown to undergo a unique, solid-state dimerization. Several reactions involving the ester functions were carried out but these did not yield the expected products, instead, structural rearrangements seemed to predominate. An asymmetric cyclopentadienone, 2-carbomethoxy-5-methyl-3,4-diphenylcyclopentadienone, was synthesized and it was reacted with norbornadiene to produce methyl 4-methyl-2,3-diphenylbenzoate. The benzoate was reduced …


Quantitative Analysis Of The Polarity Reversal Pattern Of The Earth's Magnetic Field And Self-Reversing Dynamo Models, Patrick Shane Craig Jan 2013

Quantitative Analysis Of The Polarity Reversal Pattern Of The Earth's Magnetic Field And Self-Reversing Dynamo Models, Patrick Shane Craig

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The geologic record documents that the Earth's magnetic field has reversed 284 times over the past 160 Myr. This study uses two methods to analyze the scaling properties of the pattern of geomagnetic reversals and to analyze the scaling properties of reversals output by two mathematical self-reversing dynamo models, the Rikitake (1958) two-disk dynamo and the magnetohydrodynamic (MHD) model of Driscoll and Olson (2011). The first analysis method plots the duration versus cumulative probability for geomagnetic polarity intervals ranging between 0.01 and 35 Myr. The Kolmogorov-Smirnov statistic is used to determine the optimal minimum value of xmin at which power …


Palaeoecological Analysis Of The Decline In Stromatolite Abundance During The Ordovician Period, Noran Mhm El-Sherif Jan 2013

Palaeoecological Analysis Of The Decline In Stromatolite Abundance During The Ordovician Period, Noran Mhm El-Sherif

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A stromatolite is a laminated benthic microbial deposit. Its uniqueness arises from being present since the Precambrian to the present. Stromatolites recorded a peak time during the Mesoproterozoic, subsequently they witnessed abrupt rises and falls in abundance with the steepest decline in the Ordovician period, from which it never recovered from. There is no consensus yet regarding the reasons behind the decline of stromatolites. Thus the decline of these microbial deposits remains an enigma. Additionally, a literature gap exists regarding the reasons that specifically led to the Ordovician decline. Accordingly, the focus of this literature-based MSc. thesis is to find …


Iodo Containing Sulfone And Sulfonamide Based Poly(Arylene Ether)S, Fadwa G. Constandinidis Jan 2013

Iodo Containing Sulfone And Sulfonamide Based Poly(Arylene Ether)S, Fadwa G. Constandinidis

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In an ongoing project involving the synthesis of functionalized poly(arylene ether)s that carry pendent phenyl sulfonyl groups, the introduction of an iodo group was desired. The effects of fluorine position on the electrophilic iodination of the 2,4-, 2,6-, and 2,5- and 3,5-isomers of difluorodiphenylsulfone, DFDPS were studied. The relative reactivity, toward EAS, was probed via 13C NMR spectroscopy and verified experimentally by iodination with N-iodosuccinimide. The product mixtures and corresponding structures indicated that intermediate stability did not always correlate to reactivity. Model studies were also conducted on DFDPS isomers that successfully carry in iodo groups in a pendent …