Physical Sciences and Mathematics Commons^™

Exploring The Chemistry Of Cyclopentadienyl-Cobalt-Cyclobutadiene (Cpcocb) Complexes And Synthesis Of Side-Chain Cpcocb Polymers, Preeti Chadha

Electronic Thesis and Dissertation Repository

Synthetic metallopolymers have acquired ample attention recently due to their potential applications as precursors to functional soft materials. Organometallic polymers combine the best of both organic and inorganic polymers. Polyferrocenes comprise the major portion of organometallic polymers. Therefore, quest for new monomeric precursors to organometallic polymers has expediated. One efficient method for obtaining main-chain metallopolymers is by the ring opening polymerization (ROP) of strained cyclic metallacylophanes(MCPs). Organometallic polymers containing cyclopentadienyl-cobalt-cyclobutadiene (CpCoCb) have been targeted since early 1990’s due to their isoelectronic nature (cf. ferrocene) with three major groups working in this area. The early CpCoCb containing polymers were prepared …

Structure And Strength: Anisotropic Polyvinyl Alcohol Hydrogels And Spider Mite Silk Fibres, Stephen Hudson

Electronic Thesis and Dissertation Repository

Polyvinyl alcohol (PVA) is a hydrophilic, biocompatible polymer which can be made into physically cross-linked hydrogels by freezing and thawing PVA solution. These hydrogels can be made with anisotropic mechanical properties closely matching those of porcine aorta, making them a promising material for producing artificial heart valves and heart valve stents.

Small- and ultra small-angle neutron scattering has been used to study the structure of isotropic and anisotropic PVA hydrogels at length-scales of 2 nm to 10 μm. By supplementing the neutron data with data from atomic force microscopy, a large range of length-scales have been probed, within which structural …

Models, Techniques, And Metrics For Managing Risk In Software Engineering, Andriy Miranskyy

Electronic Thesis and Dissertation Repository

The field of Software Engineering (SE) is the study of systematic and quantifiable approaches to software development, operation, and maintenance. This thesis presents a set of scalable and easily implemented techniques for quantifying and mitigating risks associated with the SE process. The thesis comprises six papers corresponding to SE knowledge areas such as software requirements, testing, and management. The techniques for risk management are drawn from stochastic modeling and operational research.

The first two papers relate to software testing and maintenance. The first paper describes and validates novel iterative-unfolding technique for filtering a set of execution traces relevant to a …

Numerical Simulations Of Composition Changes In The High Latitude Thermosphere During Disturbed Conditions, Albert T. Russell

Electronic Thesis and Dissertation Repository

The closure of magnetospheric currents in the high latitude ionosphere makes the
high latitude thermosphere a very dynamic environment. The composition and dynamics
of this region become even more complex during geomagnetic disturbances
as the electric fields from the magnetosphere now have the ability to substantially
alter the winds and composition of this region. This complexity is especially apparent
in mass spectrometer observations of composition changes, with heavier gases
(N₂,O₂, andAr) showing substantial enhancements while lighter gases (He and O)
normally exhibit moderate to severe depletions. Quantifying the changes in atomic
and molecular oxygen can be …

Magnetic Diffusion In Star Formation: From Clouds To Cores To Stars To Disks, Wolfgang B. Dapp

Electronic Thesis and Dissertation Repository

We investigate magnetic diffusion on scales from molecular clouds over prestellar and
protostellar cores down to young stellar objects (YSOs) and their surrounding protoplanetary disk.
In Chapter 2, we present thin-sheet simulations that exhibit long-lived magnetic-tension-driven oscillations, founded in the interaction of the cloud's magnetic field with that anchored in an external medium. In contrast with "local" simulations in a periodic box, where turbulence decays away in approximately a sound crossing time, and needs to be continually replenished by driving, our simulation has "global" aspects, and retains some kinetic energy indefinitely. We provide an analytical explanation for these modes, that …

The Effect Of The Environment On The Corrosion Products And Corrosion Rates On Gas Transmission Pipelines, Brent Sherar

Electronic Thesis and Dissertation Repository

This thesis reports a series of investigations examining external corrosion processes along gas transmission pipelines. TransCanada PipeLines Ltd. (TCPL) has developed six proposed corrosion scenarios to describe external pipeline corrosion, based primarily on corrosion products and corrosion rates (CRs) observed at field sites. The six proposed corrosion scenarios can be divided into two groups: abiotic and biotic. The three abiotic corrosion scenarios are (1) anaerobic corrosion, (2) aerobic corrosion, and (3) anaerobic corrosion turning aerobic; while (4) anaerobic corrosion with microbial effects, (5) aerobic corrosion turning anaerobic with microbial effects, and (6) anaerobic corrosion with microbial effects turning aerobic comprise …

Arrangements Of Submanifolds And The Tangent Bundle Complement, Priyavrat Deshpande

Electronic Thesis and Dissertation Repository

Drawing parallels with the theory of hyperplane arrangements, we develop the theory of arrangements of submanifolds. Given a smooth, finite dimensional, real manifold $X$ we consider a finite collection $\A$ of locally flat codimension $1$ submanifolds that intersect like hyperplanes. To such an arrangement we associate two posets: the \emph{poset of faces} (or strata) $\FA$ and the \emph{poset of intersections} $L(\A)$. We also associate two topological spaces to $\A$. First, the complement of the union of submanifolds in $X$ which we call the \emph{set of chambers} and denote by $\Ch$. Second, the complement of union of tangent bundles of these …

Coupled Heat And Water Transport In Frozen Soils, Ranjeet M. Nagare

Electronic Thesis and Dissertation Repository

The effect of freezing on soil temperature and water redistribution was examined in four Mesocosms maintained at different initial water content profiles. An innovative experimental setup involving use of a frozen base layer acting as a proxy to permafrost beneath an active layer made up of packed and undisturbed peat cores was used. The experimental setup was successfully validated for its ability to maintain one dimensional change in temperature and soil water content in frozen soil. There was a substantial amount of water redistribution towards the freezing front, enough to create an impermeable frozen, saturated zone within 15 cm of …

Uncertainty Estimation Of Extreme Precipitations Under Climate Change: A Non-Parametric Approach, Tarana A. Solaiman

Electronic Thesis and Dissertation Repository

Assessment of climate change impacts on hydrology at watershed scale incorporates (a) downscaling of global scale climatic variables into local scale hydrologic variables and (b) assessment of future hydrologic extremes. Atmosphere-Ocean Global Climate Models (AOGCM) are designed to simulate time series of future climate responses accounting for human induced green house gas emissions. The present study addresses the following limitations of climate change impact research: (i) limited availability of observed historical information; (ii) limited research on the detection of changes in hydrologic extremes; and (iii) coarse spatio-temporal resolution of AOGCMs for use at regional or local scale. Downscaled output from …

Design And Syntheses Of Fluorescent Cytosine Analogues, David W. Dodd

Electronic Thesis and Dissertation Repository

The avid hybridization of peptide nucleic acid (PNA) to DNA and RNA along with the molecule’s biological stability has led it to be used in both antisense and antigene capacities. PNA acts against translation via a steric blockade mechanism. It is therefore reasonable to assume that increased heteroduplex stability could lead to increased potency. Two ways of doing this were explored. I) N-Terminal attachment of a platinous chloride chelating moiety to PNA complementary to Xenopus noggin was synthesized with the objective of selective, covalent platination of the target transcript in vivo. Phenotypes consistent with knockdown of the selected …

Characteristic Polynomial Of Arrangements And Multiarrangements, Mehdi Garrousian

Electronic Thesis and Dissertation Repository

This thesis is on algebraic and algebraic geometry aspects of complex hyperplane arrangements and multiarrangements. We start by examining the basic properties of the logarithmic modules of all orders such as their freeness, the cdga structure, the local properties and close the first chapter with a multiarrangement version of a theorem due to M. Mustata and H. Schenck.

In the next chapter, we obtain long exact sequences of the logarithmic modules of an arrangement and its deletion-restriction under the tame conditions. We observe how the tame conditions transfer between an arrangement and its deletion-restriction.

In chapter 3, we use some …

An Analytical And Numerical Treatment Of Inclined Elliptical Orbits About A Kerr Black Hole, Peter G. Komorowski

Electronic Thesis and Dissertation Repository

Since its publication in 1915, Einstein's theory of general relativity has yielded significant results; they include: analytical solutions to the Einstein field equations; improved analysis of orbital dynamics; and the prediction of gravitational wave (GW) radiation. Gravitation is the weakest of the fundamental interactions; and theoretical models of GW generation and propagation show that its detection poses a significant technical challenge. Unlike the study of electromagnetic radiation, experiments within the laboratory are virtually impossible; so astronomical sources of GW, such as binary black hole systems, offer an alternative. But GW detection remains difficult. The matched filtering techniques used to discriminate …

Late Pleistocene Climate And Proboscidean Paleoecology In North America: Insights From Stable Isotope Compositions Of Skeletal Remains, Jessica Z. Metcalfe

Electronic Thesis and Dissertation Repository

This thesis uses the carbon, nitrogen, and oxygen isotope compositions of mammoth (Mammuthus) and mastodon (Mammut) skeletal remains to reconstruct paleoclimate and paleoecology in Late Pleistocene North America. Analytical methods, sampling strategies, environmental adaptations and seasonal behaviors of proboscideans were investigated.

Reliable and reproducible results are crucial for a study of this nature. A persistent methodological problem in the isotope analysis of structural carbonate in bioapatite was solved by reacting bioapatite under “sealed vessel” conditions.

Growth rate determinations are critical for designing sampling strategies and interpreting results. Histological and isotopic measurements demonstrated variations in enamel growth …

Strategies For Waveform Tomography Of Long-Offset, 2-D Exploration Seismic Data, Andrew J. Brenders

Electronic Thesis and Dissertation Repository

Waveform Tomography, combines starting models from traveltime tomography with tomographic waveform inversion. This approach to inversion recovers a “best fit” velocity model by iteratively minimizing the misfit between the observed, frequency-domain waveform data and modelled, synthetic waveforms. The method is both computationally efficient and an improvement over ray-based tomographic methods. Synthetic benchmark studies and experiments with long-offset, 2-D, exploration seismic field data, demonstrate that Waveform Tomography can yield accurate, high resolution velocity models, vital in seismic exploration for hydrocarbons.

I first present an application of Waveform Tomography to long-offset, 2-D, synthetic marine seismic data using the 2004 BP velocity benchmark. …

Impact Of Geomagnetically Induced Currents On Power Transformers, Jonathan E. Berge

Electronic Thesis and Dissertation Repository

This thesis deals with the impact of Geomagnetically Induced Current (GIC) on power transformers in electrical power systems. A simulator to calculate the flows of GIC in an electrical power network, based on an assumed or measured induced geoelectric potential is proposed. This simulator includes all needed mapping techniques to handle a system that cover a large geographical area.

A correlation between GIC and the reactive power absorbed in the core of the saturated transformer is proposed. That correlation is used to estimate GIC in a transformer utilizing existing reactive power measuring infrastructure within the electrical grid without the need …

Descent Systems, Eulerian Polynomials And Toric Varieties, Letitia Mihaela Golubitsky

Electronic Thesis and Dissertation Repository

It is well-known that the Eulerian polynomials, which count permutations in S_n by their number of descents, give the h-polynomial/h-vector of the simple polytopes known as permutohedra, the convex hull of the Sn -orbit for a generic weight in the weight lattice of Sn . Therefore the Eulerian polynomials give the Betti numbers for certain smooth toric varieties associated with the permutohedra. In this thesis we derive recurrences for the h-vectors of a family of polytopes generalizing this. The simple polytopes we consider arise as the orbit of a non-generic weight, namely a weight fixed by only the simple reflections …

Thermodynamics, Hydrodynamics And Critical Phenomena In Strongly Coupled Gauge Theories, Christopher Pagnutti

Electronic Thesis and Dissertation Repository

The gauge theory / string theory correspondence has led to great progress in the study of strongly-coupled gauge theories. In this work, we start with a detailed treatment of some simple examples of this correspondence in order to establish some of the concepts and techniques are used on a more complicated system. We then consider a (3+1)-dimensional theory of gravity with a translationally invariant horizon, that is assumed to be dual to a (2+1)-dimensional non-conformal gauge theory at finite temperature. We study the thermodynamics of this model and find that there exists an exotic type of second-order phase transition wherein …

Confidence Interval Estimation For Continuous Outcomes In Cluster Randomization Trials, Julia Taleban

Electronic Thesis and Dissertation Repository

Cluster randomization trials are experiments where intact social units (e.g. hospitals, schools, communities, and families) are randomized to the arms of the trial rather than individuals. The popularity of this design among health researchers is partially due to reduced contamination of treatment effects and convenience. However, the advantages of cluster randomization trials come with a price. Due to the dependence of individuals within a cluster, cluster randomization trials suffer reduced statistical efficiency and often require a complex analysis of study outcomes.

The primary purpose of this thesis is to propose new confidence intervals for effect measures commonly of interest for …

Finding Faulty Functions From The Traces Of Field Failures, Syed Shariyar Murtaza

Electronic Thesis and Dissertation Repository

Corrective maintenance, which rectifies field faults, consumes 30-60% time of software maintenance. Literature indicates that 50% to 90% of the field failures are rediscoveries of previous faults, and that 20% of the code is responsible for 80% of the faults. Despite this, identification of the location of the field failures in system code remains challenging and consumes substantial (30-40%) time of corrective maintenance. Prior fault discovery techniques for field traces require many pass-fail traces, discover only crashing failures, or identify faulty coarse grain code such as files as the source of faults. This thesis (which is in the integrated article …

Pushing The Boundaries In Gradient And Shim Design For Mri, Parisa Hudson

Electronic Thesis and Dissertation Repository

High performance gradient and shim coils are highly interested for high-field magnetic resonance imaging and spectroscopy to correct for large B₀ inhomogeneities created by the magnetic susceptibility differences between tissues, bone, and air. In chapter two, complete sets of high-performance gradient and shim coils are designed using two different methods: the minimum inductance and the minimum power target field methods. A quantitative comparison of shim performance in terms of merit of inductance, ML, and merit of resistance, MR, is made for shim coils designed using the minimum inductance and the minimum power design algorithms. The coils designed …

Bulk Density Of Small Meteoroids, Jean-Baptiste Kikwaya Eluo

Electronic Thesis and Dissertation Repository

The purpose of our work is to determine the bulk density of meteoroids. Unlike previous works which focused either on the dynamical properties of the meteoroids (deceleration), ignoring fragmentation; or on fitting solely the lightcurves, neglecting the dynamics of the meteoroids, we use both the photometry and astrometry to constrain our model. Our model, based on the dustball model, considers the meteoroid to be a collection of grains held together by a lower boiling point 'glue'. It uses conservation of energy and momentum to model the change in velocity and the light production as a function of time. The free …

New Synthetic Methodologies Directed Toward Pharmacologically Active Compounds As Well As Silole Based Chromophores For Analytical And Optoelectronic Applications, Mahmoud M. Abd Rabo Moustafa

Electronic Thesis and Dissertation Repository

The development of new and efficient synthetic methodologies to prepare heterocyclic compounds has received great attention over the years due to their importance in the pharmaceuticals and fine chemicals industries. Described herein are several novel syntheses of a variety of heterocycles including siloles, azaindoles, piperideines, piperidines and tetrahydropyrans.

A one-pot, two-step methodology involving Tamao’s reductive cyclization followed by Negishi cross coupling was utilized to synthesize several new series of silole-based chromophores. The property studies revealed new electropolymerized poly(thienyl-silole)s with enhanced photoefficiency for all-polymer solar cells. In addition, a new procedure is developed for the synthesis of the first dissymmetric silole …

Hemodynamics In The Stenosed Carotid Bifurcation With Plaque Ulceration, Emily Y. Wong

Electronic Thesis and Dissertation Repository

The presence of irregular plaque surface morphology or ulceration of the atherosclerotic lesion has been identified as an independent risk factor for ischemic stroke. Doppler ultrasound (DUS) is the most commonly performed non-invasive technique used to assess patients suspected of having carotid artery disease, but currently does not incorporate the diagnosis of plaque ulceration. Advanced Doppler analyses incorporating quantitative estimates of flow disturbances may result in diagnostic indices that identify plaque ulcerative conditions. A technique for the fabrication of DUS-compatible flow phantoms was developed, using a direct-machining method that is amenable to comprehensive DUS investigations. In vitro flow studies in …

Architecture Supporting Computational Trust Formation, Chern Har Yew

Electronic Thesis and Dissertation Repository

Trust is a concept that has been used in computing to support better decision making. For example, trust can be used in access control. Trust can also be used to support service selection. Although certain elements of trust such as reputation has gained widespread acceptance, a general model of trust has so far not seen widespread usage. This is due to the challenges of implementing a general trust model. In this thesis, a middleware based approach is proposed to address the implementation challenges.

The thesis proposes a general trust model known as computational trust. Computational trust is based on research …

Algorithmic Contributions To The Theory Of Regular Chains, Wei Pan

Electronic Thesis and Dissertation Repository

Regular chains, introduced about twenty years ago, have emerged as one of the major

tools for solving polynomial systems symbolically. In this thesis, we focus on different

algorithmic aspects of the theory of regular chains, from theoretical questions to high-

performance implementation issues.

The inclusion test for saturated ideals is a fundamental problem in this theory.

By studying the primitivity of regular chains, we show that a regular chain generates

its saturated ideal if and only if it is primitive. As a result, a family of inclusion tests

can be detected very efficiently.

The algorithm to compute the regular GCDs …

The Impact Of Climate And Transport On The Compositions And Textures Of Heavy Minerals In Modern Rivers Of New Zealand, Alexandre Aubin

Electronic Thesis and Dissertation Repository

The types, abundances and textures of heavy minerals in the 63-125 μm fraction of modern river sands were investigated in order to assess the controls of climate, tectonic setting, source composition, recycling, transport and diagenesis on the nature of sedimentary systems. Two rivers on the South Island of New Zealand were selected for detailed study; the Haast is a high-flow river located in the high precipitation region near the west coast, whereas the Ahuriri River has lower flow rates and is located in a drier region in the central South Island. In both river systems, the Zircon-Tourmaline-Rutile (ZTR) index increases …

Advanced Topics On State Complexity Of Combined Operations, Yuan Gao

Electronic Thesis and Dissertation Repository

State complexity is a fundamental topic in formal languages and automata theory. The study of state complexity is also strongly motivated by applications of finite automata in software engineering, programming languages, natural language and speech processing and other practical areas. Since many of these applications use automata of large sizes, it is important to know the number of states of the automata. In this thesis, we firstly discuss the state complexities of individual operations on regular languages, including union, intersection, star, catenation, reversal and so on. The state complexity of an operation on unary languages is usually different from that …

Descending Central Series Of Free Pro-P-Groups, German A. Combariza

Electronic Thesis and Dissertation Repository

In this thesis, we study the first three cohomology groups of the quotients of the descending central series of a free pro-p-group. We analyse the Lyndon-Hochschild- Serre spectral sequence up to degree three and develop what we believe is a new technique to compute the third cohomology group. Using Fox-Calculus we express the cocycles of a finite p-group G with coefficients on a certain module M as the kernel of a matrix composed by the derivatives of the relations of a minimal presentation for G. We also show a relation between free groups and finite fields, this is a new …

Cost-Efficient Variable Selection Using Branching Lars, Li Hua Yue

Electronic Thesis and Dissertation Repository

Variable selection is a difficult problem in statistical model building. Identification of cost efficient diagnostic factors is very important to health researchers, but most variable selection methods do not take into account the cost of collecting data for the predictors. The trade off between statistical significance and cost of collecting data for the statistical model is our focus. A Branching LARS (BLARS) procedure has been developed that can select and estimate the important predictors to build a model not only good at prediction but also cost efficient. BLARS method is an extension of the LARS variable selection method to incorporate …

Survival Analysis Of Microarray Data With Microarray Measurement Subject To Measurement Error, Juan Xiong

Electronic Thesis and Dissertation Repository

Microarray technology is essentially a measurement tool for measuring expressions of genes, and this measurement is subject to measurement error. Gene expressions could be employed as predictors for patient survival, and the measurement error involved in the gene expression is often ignored in the analysis of microarray data in the literature. Efforts are needed to establish statistical method for analyzing microarray data without ignoring the error in gene expression. A typical microarray data set has a large number of genes far exceeding the sample size. Proper selection of survival relevant genes contributes to an accurate prediction model. We study the …