Physical Sciences and Mathematics Commons^™

Progress Towards The Total Synthesis Of Amphidinolide C, Nicholas A. Morra

Electronic Thesis and Dissertation Repository

A second generation catalyst for the Mukaiyama oxidative cyclization for the formation of trans-THF rings is described. Co(nmp)₂, displays increased stability to the reaction conditions, resulting in lower catalyst loadings, lower reaction temperatures, and significantly higher purity and yields of the products. Three procedures have been developed with this new water-soluble catalyst that greatly simplifies the post-reaction purification, making this procedure the premier method of forming trans-THF rings.

This new catalyst has been applied towards the total synthesis of the potently bioactive macrocycle, Amphidinolide C. Herein we report the successful synthesis of several fragments of the …

Synthesis Of (±)-Quebrachamine, Tetrahydroisoquinocarbazoles, And Progress Towards Biselide A And E, Barbora Morra

Electronic Thesis and Dissertation Repository

A variety of methodologies developed in our research group have inspired the three separate projects reported. First, the total synthesis of (±)-quebrachamine was performed in 13 steps and 17.8% overall yield. Highlights of the synthesis include an efficient preparation of a functionalized indole core via a [3+2] annulation cycloaddition reaction between a functionalized nitrile and donor-acceptor cyclopropane and a photo induced 9-membered ring closure.

Secondly, we have reported the most efficent and highest yielding route to several tetrahydroisoquinocarbazoles, where the core was prepared in six steps from tryptophol in 51% overall yield. This work highlights for the first time the …

Molecular Dynamics Simulations Of Peptide-Mineral Interactions, Susanna Hug

Electronic Thesis and Dissertation Repository

We present molecular dynamics (MD) simulations providing information about the mechanisms of biomineralization. We focus on osteopontin-related peptides, which inhibit the growth of calcium oxalate monohydrate (COM) the primary constituent of kidney stones.

First, we performed two ab initio MD simulations: aspartic acid (Asp) and the dimer of aspartic acid and phosphoserine (Asp-pSer) interacting with a fully hydrated COM crystal slab exposing the {100} face. For Asp we found that one of the carboxyl and the amine group both interact with the crystal surface but neither forms a stable contact during the simulation. Asp-pSer interacts preferably with its carboxyl groups …

Scanning Probe Microscopy Studies Of The Properties Of Conducting Polymers, Kevin D. O'Neil

Electronic Thesis and Dissertation Repository

Electronically conducting polymers (ECPs) have been growing in interest as important materials for a variety of different applications such as charge storage devices and photovoltaics. However, in all of these applications, the performance of conducting polymers are strongly dependent upon their local properties such as morphology, local conductivity and carrier mobility, local chemical composition, etc. All polymer materials feature a distribution of these parameters and therefore, they are considered heterogeneous. In this work, we use atomic force microscopy (AFM) and its related techniques such as current-sensing AFM (CS-AFM), Kelvin probe force microscopy (KFM) and phase imaging (PI-AFM) to directly investigate …

Multi-Core Unit Propagation In Functional Languages, Jonathan Alexander Leaver

Electronic Thesis and Dissertation Repository

Answer Set Programming is a declarative modeling paradigm enabling specialists in diverse disciplines to describe and solve complicated problems. Growth in high performance computing is driving ever smarter and more scalable parallel answer set solvers. To improve on today's cutting-edge, researchers need to develop increasingly intelligent methods for analysis of a solver's runtime information. Reflecting on the solver's search state typically pauses its progress until the analysis is complete. This work introduces methods from the domain of parallel functional programming and immutable type theory to construct a representation of the search state that is both amenable to introspection and efficiently …

Magnetic Properties And Defects In Iron Implanted Strontium Titanate Single Crystals And Thin Films, Misha Chavarha

Electronic Thesis and Dissertation Repository

Physical vapor deposition was used to grow good quality crystalline stoichiometric SrTiO₃ thin films on Si(001) substrate using a systematic approach starting from understanding of kinetics and thermodynamics of the system and finishing with the development of procedure for high quality SrTiO₃/Si interface. Growth of optimized SrTiO₃ perovskite structure on Si requires careful transformation of a thin interfacial SrSix layer into the initial SrTiO₃ lattice cells. The critical aspects of the growth, such as low temperature and low oxidant partial pressure, are explained in details. Crystallinity and stoichiometry of SrTiO₃ were verified using powder …

Ozone Measurements And Transport, Mohammed Kedir Osman

Electronic Thesis and Dissertation Repository

Ozone intrusions from the stratosphere to the troposphere occur as part of the Brewer-Dobson circulation, but the details of the microphysics of the process are unresolved. This research mainly focuses on near-tropopause regions, and examines stratospheric ozone intrusions into the troposphere across this stable zone. My research objective is to identify the small-scale atmospheric dynamical features responsible for the intrusion of stratospheric ozone into the troposphere, and to determine their relative importance from case to case.

Windprofiler radars, together with frequent ozonesonde launches, have been used to detect stratospheric ozone intrusions. This work has been supplemented by numerical simulation via …

Confidence Intervals For Comparison Of The Squared Multiple Correlation Coefficients Of Non-Nested Models, Li Tan Jr.

Electronic Thesis and Dissertation Repository

Multiple linear regression analysis is used widely to evaluate how an outcome or responsevariable is related to a set of predictors. Once a final model is specified, the interpretation of predictors can be achieved by assessing the relative importance of predictors.

A common approach to predictor importance is to compare the increase in squared multiple correlation for a given model when one predictor is added to the increase when another predictor is added to the same model.

This thesis proposes asymmetric confidence-intervals for a difference between two correlated squared multiple correlation coefficients of non-nested models. These new proceduresare developed by …

Hyperpolarized Noble Gas Magnetic Resonance Imaging And Dynamic Spectroscopy For Investigation Of Rat Models Of Lung Inflammation, Matthew S. Fox

Electronic Thesis and Dissertation Repository

Imaging of the lungs using non-ionizing approaches such as hyperpolarized ³He and ¹²⁹Xe magnetic resonance imaging (MRI) is a useful tool both for research and clinical applications. This work focused on development of ¹²⁹Xe MRI techniques to investigate inflammation in rat lungs. A rodent model of inflammation, specifically radiation-induced lung injury (RILI) was developed using a collimated ⁶⁰Co source. A quantitative MRI technique measuring absolute ventilated lung volume (|VLV|) was performed using ¹²⁹Xe and ³He. Following a comparison between |VLV| values obtained from rats using the previously established ³He method and those obtained …

Studies Of Aftershock Sequences Of Large Subduction Zone Earthquakes, Armick Ivanian

Electronic Thesis and Dissertation Repository

Amongst the different types of earthquakes, it is observed that the mega-thrust earthquakes, which occur in subduction zones, are the most devastating. The aftershock sequences following the mega-thrust earthquakes can also increase the level of seismic hazard, even in remote areas away from the mainshock fault zone. This thesis examines the statistical parameters of aftershock sequences of large subduction zone earthquakes that have occurred in the western and eastern Pacific Ocean. These parameters are vital for seismic hazard assessment of regions located near subduction zones. The results show that, on average, the Gutenberg-Richter exponent—the b-value—is markedly higher in the …

A Geobiological Investigation Of The Mazon Creek Concretions Of Northeastern Illinois, Mechanisms Of Formation And Diagenesis, Andrea S. Fernandes

Electronic Thesis and Dissertation Repository

Siderite concretions from the mid-Pennsylvanian Francis Creek Shale of the Mazon Creek area, in northeastern Illinois, contain exceptionally preserved soft-tissue fossils. Scanning electron microscopy, energy dispersive spectroscopy, time of flight-secondary ion mass spectrometry and micro-x-ray diffraction on polychaete worm, jellyfish and holothurian samples highlighted detrital clay and quartz grains in siderite cement. The worm and jellyfish are pyritised and surrounded by pyrite halos, whereas the holothurian is preserved as a weathered impression. Specimens possessed either microbial textures or framboidal pyrite, in carbon-enriched zones. The carbon-enriched zones contained organic compounds, indicating that extensive degradation associated with high temperature diagenesis did not …

Effects Of Chemical And Mechanical Weathering Processes On The Degradation Of Plastic Debris On Marine Beaches, David A. Cooper

Electronic Thesis and Dissertation Repository

Plastics are an integral part of everyday life, and the use of plastic products for consumer goods, food packaging, recreational and commercial fishing and medical and sanitary applications continues to increase. The durability, low cost, light weight and hydrophobic nature of plastic make it a desirable material for numerous applications; however, these same characteristics make plastic debris in natural environments a pervasive problem. Increases in plastic use and low economic incentive for recovery, result in accumulation of debris in marine environments. Degradation of plastics through chemical weathering occurs in the open ocean or along shorelines where polymers are exposed to …

Miniaturized Fractionation And Purification Of Analytes Of Interest In Complex Mixtures: Protein Enrichment And Purification With Capillary Electrophoresis And Identification Of Pesticide Chemicals In Bio-Oils, Christina J. Booker

Electronic Thesis and Dissertation Repository

The ability to isolate and detect an analyte of interest is vital for many different facets of life today, from disease detection to environmental safety. The goal of the method development discussed within this thesis is to isolate and identify unique analytes from complex matrices and to do so in a scaled down approach. Removal of an analyte from a diverse background of molecules is often required for successful detection and determination of analyte properties. As well, many samples are only available at low volumes and at trace levels so miniaturized techniques that only require small sample volumes are designed …

Relationships Between Earthquake Ground Motions And Modified Mercalli Intensity, Andrea Sweny

Electronic Thesis and Dissertation Repository

With widespread Internet use, web-based earthquake reports are a valuable source of felt intensitydata with broad geographical coverage. Paired with ground motion data, Internet surveys like theUSGS Did You Feel It? (DYFI) website can be used to derive relationships between ground motionparameters and Modified Mercalli Intensity (MMI). These are particularly important for regionswith sparse seismographic coverage where the quality and density of intensity data may be superiorto ground motion data. MMI-ground motion relationships are also needed to infer ground motionsof historical earthquakes.

Using well-documented earthquakes in across North America, we analyze correlations betweenfelt intensity and ground motions, including peak ground …

Syntheses, Hydrogen Bonding, And Metal Coordination Studies Of New Ferrocene Peptide Conjugates, Craig D. Colquhoun

Electronic Thesis and Dissertation Repository

The main goal of the research was the synthesis of new ferrocene peptideconjugates, to study the role of hydrogen bonding interactions, and the coordinationproperties of these systems. Ferrocene peptide conjugates have been extensivelystudied as models of protein secondary structures. Of particular interest weredisubstituted ferrocene derivatives such as ferrocene dicarboxylic acid, which have beenshown to be important in the design of peptide mimics. The inter-ring spacing betweentwo cyclopentadienyl rings in ferrocene has shown to be appropriate for forminghydrogen bonds between conjugated peptide chains, which are attached to the twocyclopentadienyl rings. Inter-ring spacing has proven to be of great importance for theformation …

Socially Responsible Investment In A Changing World, Desheng Wu

Electronic Thesis and Dissertation Repository

Socially responsible investment funds make up a growing segment of the investment world. This work considers the impact of including SRI in an investor portfolio both normally and during crisis times. Regimes are identified using Markov switching models. This study is based on return data of four indices, namely, the MSCI World Index, S&P 500, Eurostoxx 50, and the socially responsible index - Advanced Sustainable Performance Index (ASPI). The approaches used are portfolio optimization, GARCH and Markov switching models. Our work shows that a socially responsible index is a good asset to keep in a portfolio. Our simulation results suggest …

Molecular Dynamics Studies Of Interactions Of Phospholipid Membranes With Dehydroergosterol And Penetrating Peptides, Amir Mohsen Pourmousa Abkenar

Electronic Thesis and Dissertation Repository

We have performed molecular modeling of membrane and peptide systems by employing the classical molecular dynamics method and force field parameterizations. In this thesis, our main interest is the interaction of sterols as well as peptides with membranes. The thesis consists of three related projects. The first project focuses on cholesterol (CHOL) and dehydroergosterol (DHE) interacting with palmitoyl-oleoyl phosphatidylcholine (POPC) lipid bilayers. We study the effects of both sterols on the bilayer and compare them with each other. We first study the condensing and ordering effect of these sterols. Then, we study their orientations within the bilayer and relate them …

Transition Metal Complexes With Reactive Trimethylsilylchalcogenolate Ligands: Precursors For The Preparation Of Ternary Nanoclusters, Chhatra Bahadur Khadka

Electronic Thesis and Dissertation Repository

The Co²⁺ and Mn²⁺ complexes (N,N´-tmeda)Co(ESiMe₃)₂ (E = S, 1a; E = Se, 1b), (3,5-Me₂C₅H₃N)₂Co(ESiMe₃)₂ (E = S, 2a; E = Se, 2b), [Li(N,N´-tmeda)]₂[(N,N´-tmeda)Mn₅(μ-ESiMe₃)₂(ESiMe₃)₄(μ₄-E)(μ₃-E)₂] (E = S, 3a; E = Se, 3b), [Li(N,N´-tmeda)]₂[Mn(SSiMe₃)₄] (4), [Li(N,N´-tmeda)]4[Mn₄(SeSiMe₃)₄(μ_{3 …}

Study Of Malaria Transmission Dynamics By Mathematical Models, Yanyu Xiao

Electronic Thesis and Dissertation Repository

This Ph.D thesis focuses on modeling transmission and dispersal of one of the most common infectious disease, Malaria. Firstly, an integro-differential equation system is derived, based on the classical Ross-Macdonald model, toemphasize the impacts of latencies on disease dynamics. The novelty lies in the fact that different distributionfunctions are used to describe the variance of individual latencies. The theoretical results of this projectindicate that latencies reduce the basic reproduction number. Secondly, a patch model is derived to examine how travels of human beings affects the transmission and spread of Malaria. Due to coexistence of latency and dispersal, the model turns …

Thermal Plume Transport From Sand And Gravel Pits Potential Thermal Impacts On Cool-Water Streams, Jeffrey M. Markle

Electronic Thesis and Dissertation Repository

Potential thermal impacts from below-water-table aggregate extraction on a cool-water stream were investigated by monitoring thermal plumes, moving through an unconfined glacial-outwash aquifer, and assessing their subsurface persistence. The growing demand for aggregate and increased pressure to pursue extraction in ecologically sensitive areas has driven the need for this work. During a 10-year period, ground and surface water temperatures were measured monthly, including two periods of intensive monitoring (22 months and 2.5 years). The aquifer hydraulic conductivity (K) is quantified at the laboratory and field scale. The mean K’s from the multi-scale tests depend on test-support volume and …

Quantum Coherence And Interference In Metallic Photonic Crystals And Hybrid Systems, Ali Hatef

Electronic Thesis and Dissertation Repository

In the first part of the thesis, we study the absorption coefficient of quantum dots doped in metallic photonic crystals under different circumferences. We study numerically the temporal evolution of the absorption coefficient profile where a probe field is applied to monitor the absorption process in two cases, when quantum dots are embedded lightly and densely. We also studied the effect of a changing plasma frequency on the absorption profile of quantum dots two possible field configurations. We show that the changes in plasma energy can take the system from the absorption region to the transparent and gain region.

As …

Bifurcations And Stability In Models Of Infectious Diseases, Bernard S. Chan

Electronic Thesis and Dissertation Repository

This work is concerned with bifurcation and stability in models related to various aspects of infections diseases.

First, we study the dynamics of a mathematical model on primary and secondary cytotoxic T-lymphocyte responses to viral infections by Wodarz et al. This model has three equilibria and the stability criteria of them are discussed. We analytically show that periodic solutions may arise from the third equilibrium via Hopf bifurcation. Numerical simulations of the model agree with the theoretical results. These dynamical behaviours occur within biologically realistic parameter range.

After studying the single-strain model, we analyze the bifurcation dynamics of an …

Investigating Interfacial Reactions Of Silver-Containing Films Using Novel Methods, Sarah Danielle Pretty

Electronic Thesis and Dissertation Repository

This thesis presents work on the mechanism and kinetics of the surface film reactions involving the conversion of aqueous species on solid surfaces, and specifically, the reactions of iodide and bromide on silver oxide on silver substrate. These reactions provide a method of immobilizing unwanted halides and are particularly suited to control of hazardous radioactive iodine. Potential applications of this research include nuclear reactor safety and post-accident radioiodine management, and the safe production and use of the medical isotope ¹³¹I.

The aqueous-solid conversion of reaction Ag₂O with X^-(aq) to form AgX on a Ag substrate …

Reactivity Of Dimethylplatinum (Ii) Complexes, Muhieddine A. Safa

Electronic Thesis and Dissertation Repository

This thesis describes a study of dimethylplatinum(II) and dimethylplatinum(IV) complexes containing bidentate nitrogen donor ligands. This work deals with oxidative addition, and reductive elimination chemistry, and it focuses on synthesis, characterization, and reaction mechanisms in studies of these complexes.

The compound [PtMe₂(bpe)], bpe = 1,2-bis(2-pyridyl)ethane, is easily oxidized to give octahedral organoplatinum(IV) complexes and the subsequent chemistry is profoundly influenced by the accompanying strain induced in the 7-membered Pt(bpe) chelate ring. On reaction of [PtMe₂(bpe)] with HCl, the initial product [PtHClMe₂(bpe)] undergoes reductive elimination of methane to form [PtClMe(bpe)]. In contrast, methyl …

Trust-Based Service Selection, Zainab Aljazzaf

Electronic Thesis and Dissertation Repository

Service Oriented Architecture (SOA) is an architectural style that builds enterprise solutions based on services. In SOA, the lack of trust between different parties affects the adoption of such architecture. Trust is as significant a factor for successful online interactions as it is in real life communities, and consequently, it is an important factor that is used as a criterion for service selection. In the context of online services and SOA, the literature shows that the field of trust is not mature. Trust definition and the consideration of the essentials of trust aspects do not reflect the true nature of …

High Power Systems For Dynamic Field Control And Shielding In The Mr Environment, Dustin W. Haw

Electronic Thesis and Dissertation Repository

This thesis addresses several aspects of gradient and shim coil design and fabrication. New design techniques are coupled with experimental construction methods to expand small animal insert gradient and shim technology. The design techniques are also applied to other areas of magnetic resonance hardware.

A custom 2-axis gradient insert coil is designed and fabricated for the purpose of eddy current characterization. The construction tolerances were examined via bench top inductance measurements and eddy currents measurement inside a 7.0 T head-only MR system. A great deal of freedom is available when positioning shielding coils with respect to their corresponding primary coils …

Real Options Models In Real Estate, Jin Won Choi

Electronic Thesis and Dissertation Repository

Our aim in this thesis is to investigate the usefulness of real options analysis, taking case studies of problems in real estate. In the realm of real estate, we consider the following three problems. First, we consider the valuation and usefulness of presale contracts of condominiums, which can be viewed as similar to call options on condominiums. Secondly, we consider the valuation of farm land from the perspective of land developers, who may think of farm land as being similar to call options on subdivision lots. Third, we consider the valuation of opportunities to install solar panels on properties, in …

Generalized Exponential Models With Applications, Iman Mabrouk

Electronic Thesis and Dissertation Repository

We introduce a generalized exponential model whose exact moments and normalizing constant are obtained in terms of Meijer’s generalized hypergeometric G-function. Actually, several widely utilized statistical distributions such as the gamma, Weibull and half-normal constitute particular cases thereof. The generalized inverse Gaussian distribution, which was popularized in the late seventies by Ole Barndor_Neilsen, is also extended by incorporating an additional parameter in its density function, the moments of the resulting distribution being expressed in terms of Bessel functions. A number of data sets were then fitted with diverse exponential-type models for comparison purposes. Additionally, it is shown that the …

Convection Due To Spatially Distributed Heating, Mohammad Zakir Hossain

Electronic Thesis and Dissertation Repository

Convection in an infinite horizontal slot subject to spatially distributed heating has been investigated for a wide range of Prandtl numbers. The primary flow response consists of convection in the form of rolls. When heating wave number alpha is sufficiently large the convection is found to be limited to a layer adjacent to lower wall and a uniform conductive layer emerges at upper section of the slot.

Conditions leading to the emergence of secondary convection have been identified using linear stability of the above primary convection. The secondary convection gives rise to longitudinal, or transverse, or oblique rolls; or to …

Seismic Microzonation Of Great Toronto Area And Influence Of Building Resonances On Measured Soil Responses, Dimitar Genchev Mihaylov

Electronic Thesis and Dissertation Repository

A pilot seismic microzonation of the Greater Toronto Area (GTA) is used to establish the conditions and limitations of geophysical methods for site response investigations in city conditions. Maps of fundamental soil resonant frequencies, amplifications at these frequencies and interpolated average shear wave velocity of top 30 m of soil profile (VS- 30) used in soil classification were compared to the maps of drift thickness and surficial geology for the GTA. The non-applicability of the interpolated VS-30 map for site classification between measured test points is indicated. It is also shown that the soil response cannot be estimated properly using …