Physical Sciences and Mathematics Commons^™

Dielectric Anomalies Of Both Chiral And Achiral Nematogens Near The Isotropic To Mesogenic Phase Transition, Garrett Justin Godfrey

Wayne State University Dissertations

The dielectric properties of nematic liquid crystals were studied in both the achiral and chiral limits. For achiral nematics, the literature documents that pretransitional curvature occurs for polar molecules on both sides of the nematic and isotropic phase transition. This curvature is due to anti-parallel dimer formation. However, past models have failed to quantitatively describe pretransitional curvature. Through a generalization of the order parameter, a macroscopic model has been developed to mathematically describe the pretransitional curvature on the isotropic side of the transition. The new model was fitted to dielectric data from the literature. Meaningful parameter estimates were extracted.

The …

The Relation Between Patient Education And Picc Line Occlusion, Patricia Louise Petroulias

Wayne State University Dissertations

The purpose of this study was to test the feasibility of using an electronic tablet to supplement patient and caregiver education about PICC line maintenance and to compare the percentage of PICC line complications in the intervention group with national percentage rates for patients and caregivers. Newly diagnosed cancer patients who had PICC lines inserted participated in this study. They used an electronic tablet to learn the 10 steps for flushing their PICC lines correctly. They also met with the researcher via FaceTime to review the steps.

A total of 11 patients participated in this quasi-experimental pilot study. They completed …

Multilinear And Multiparameter Pseudo-Differential Operators And Trudinger-Moser Inequalities, Lu Zhang

Wayne State University Dissertations

Pseudo-differential operators play important roles in harmonic analysis, several complex variables, partial differential equations and other branches of modern mathematics. We studied some types of multilinear and multiparameter Pseudo-differential operators. They include a class of trilinear Pseudo-differential operators, where the symbols are in the forms of products of Hormander symbols defined on lower dimensions, and we established the Holder type Lp estimate for these operators. They derive from the trilinear Coifman-Meyer type operators with flag singularities. And we also studied a class of bilinear bi-parameter Pseudo-differential operators, where the symbols are taken from the general Hormander class, and we studied …

Electron Transfer Studies In Langmuir-Blodgett Films Of Metallosurfactants For Current Rectification, Corrosion Mitigation, And Water Oxidation, Sunalee Gonawala Jayasundara Mudiyanselage

Wayne State University Dissertations

The work presented in this dissertation is focused on the design and synthesis of new redox-active amphiphilic architectures to optimize and understand the redox, electronic, and film formation properties for applications in current rectification, corrosion mitigation, and water oxidation. As such, new redox-active, and amphiphilic iron(III), cobalt(III), nickel(II), copper(II), and zinc(II) complexes were synthesized as precursors for Langmuir-Blodgett films used for the aforementioned applications.

For the use in molecular rectification, amphiphilic copper(II) and nickel(II) complexes with [N2O2] ligand environment were synthesized. Homogeneous film formation ability was observed between ~20-25 mN/m pressure, with a film collapse observed at ~35 mN/m for …

Synthesis And Heteroallene Reactivity Of Bis(Aldimino)Pyridine Nickel Complexes In Four Different Oxidation States, Blake Reed

Wayne State University Dissertations

A series of redox non-innocent bis(aldimino)pyridine ligands were synthesized. These were then reacted with nickel(II) salts to form Ni[NNN]X2 complexes. Cyclic voltammograms of these nickel(II) complexes suggest that more reduced states can be achieved. Reduction of these nickel(II) complexes lead to distorted square planar complexes with the halide bent ~20° out of the plane. EPR suggests that spin density is located on the metal as g-values of >2.01 were obtained. This differs from previously reported analogous bis(ketimino)pyridine complexes, which show a ligand-based radical and nickel(II). DFT confirms that as the Npyr-Ni-X angle decreases, spin density on the nickel increases. Because …

Variational Analysis And Stability In Optimization, M. Ebrahim Sarabi

Wayne State University Dissertations

The dissertation is devoted to the study of the so-called full Lipschitzian stability of local solutions to finite-dimensional parameterized problems of constrained optimization, which has been well recognized as a very important property from both viewpoints of optimization theory and its applications. Employing second-order subdifferentials of variational analysis, we obtain necessary and sufficient conditions for fully stable local minimizers in general classes of constrained optimization problems including problems of composite optimization as well as problems of nonlinear programming with twice continuously differentiable data. Based on our recent explicit calculations of the second-order subdifferential for convex piecewise linear functions, we establish …

Nonlinear Stochastic Systems And Controls: Lotka-Volterra Type Models, Permanence And Extinction, Optimal Harvesting Strategies, And Numerical Methods For Systems Under Partial Observations, Ky Quan Tran

Wayne State University Dissertations

This dissertation focuses on a class of stochastic models formulated using stochastic differential equations with regime switching represented by a continuous-time Markov chain, which also known as hybrid switching diffusion processes. Our motivations for studying such processes in this dissertation stem from emerging and existing applications in biological systems, ecosystems, financial engineering, modeling, analysis, and control and optimization of stochastic systems under the influence of random environments, with complete observations or partial observations.

The first part is concerned with Lotka-Volterra models with white noise and regime switching represented by a continuous-time Markov chain. Different from the existing literature, the Markov …

New Chemistry For The Growth Of First-Row Transition Metal Films By Atomic Layer Deposition, Joseph Peter Klesko

Wayne State University Dissertations

Thin films containing first-row transition metals are widely used in microelectronic, photovoltaic, catalytic, and surface-coating applications. In particular, metallic films are essential for interconnects and seed, barrier, and capping layers in integrated circuitry. Traditional vapor deposition methods for film growth include PVD, CVD, or the use of plasma. However, these techniques lack the requisite precision for film growth at the nanoscale, and thus, are increasingly inadequate for many current and future applications. By contrast, ALD is the favored approach for depositing films with absolute surface conformality and thickness control on 3D architectures and in high aspect ratio features. However, the …

Studies Toward A Detailed Understanding Of The Intrinsic Properties Of Nucleic Acid Constituents: Gas-Phase Conformations, Energetics, And Glycosidic Bond Stability, Ranran Wu

Wayne State University Dissertations

The gas-phase conformations of the protonated forms of the nucleic acid constituents: nucleosides and mononucleotides, were characterized by infrared multiple photon dissociation (IRMPD) action spectroscopy and theoretical calculations. The IRMPD spectroscopy experiments were performed using a Fourier transform ion cyclotron resonance mass spectrometer (FT-ICR MS) coupled to a free electron laser or a OPO/OPA laser system to measure the IRMPD action spectra over the IR fingerprint and hydrogen-stretching regions.

Theoretical calculations were performed using both mechanic dynamics and high level quantum chemical calculations to optimize structures, compute vibrational frequencies and IR intensities, and to obtain the relative stabilities of optimized …

Multiferroicity In Iron Vanadate, Magnetite And Polyvinylidene Fluoride Nanocomposite Films, Ehab Hamdy Abdelmonaim Abdelhamid

Wayne State University Dissertations

With the increasing demand on cheaper and better performance multifunctional materials for different applications, it is becoming more crucial to have a better understanding of the physics needed to tailor more devices and materials to fit better in every day’s technological needs. Materials which show more than one ferroic order simultaneously –namely, multiferroics– are of particular importance for their potential applications as multiple state memory elements, transducers and electrically tunable microwave devices.

In this work, we studied FeVO4 single crystals as an example on low symmetry multiferroics. We focused on the anisotropy in those crystals in an attempt to nail …

Two-Dimensional Low-Resistance Contacts For High Performance Wse2 And Mos2 Transistors, Hsun Jen Chuang

Wayne State University Dissertations

ABSTRACT

TWO-DIMENSIONAL LOW-RESISTANCE CONTACTS FOR HIGH PERFORMANCE WSe2 and MoS2, TRANSISTORS

by

Hsun-jen Chuang

May 2016

Advisor: Dr. Zhixian Zhou

Major: Physics

Degree: Doctor of Philosophy

Two-dimensional layered materials beyond graphene such as transition metal dichalcogenides (TMDs) have attracted a lot of interests due to their superior property in many aspects. In this work, I am focusing on two TMD materials: WSe2 and MoS2. The main objective this work is to develop novel approaches to fabricating low-resistance ohmic contacts to TMDs for low power, high performance electronic applications. First, we used graphene as electrical contacts for WSe2 field-effect transistor with …

Europium(Ii)-Containing Complexes For Responsive Magnetic Resonance Imaging, Levi Alexander Ekanger

Wayne State University Dissertations

The research projects described in this dissertation are focused on studying the oxidation of EuII-containing complexes within the context of responsive MRI. Prior to this research, EuII had not been explored within the context of oxidation-responsive MRI nor had the use of this ion been reported in vivo. The results of these studies enable predictions about the oxidation-responsive behavior of EuII-containing complexes in vitro and in vivo.

The EuII-containing cryptate 1.33 was used to evaluate EuII-based positive contrast enhancement after intravenous, intraperitoneal, and subcutaneous injections. The transitory behavior of the positive contrast enhancement correlated with reported levels of oxygenation and …

Crossed Beam Imaging Of The Reaction Dynamics Of Halogen Atoms With Selected Hydrocarbons, Yuanyuan Shi

Wayne State University Dissertations

This dissertation presents results of applying dc slice imaging in crossed molecular beams to probe the dynamics of the reactions of halogen atoms (chlorine and fluorine) with polyatomic hydrocarbons and alcohols such as deuterated propanes, butane isomers, pentane, alkenes and propanol. The full velocity-flux contour maps of the radical products were measured with 157nm single photon ionization at various collision eneriges. Secondary and tertiary abstractions were found in Cl with normal and deuterated propanes and butane isomers and show distinct differences. The differences were explained in terms of the nature of abstraction sites, energy disposal of the radical product, and …

Modeling Bedrock Transmissivity; Implications For Contaminant Transport In An Overlying Glacial Aquifer System, Amanda Pruehs

Wayne State University Theses

This study evaluated alternative representations of bedrock surface and bedrock transmissivity on advective transport predictions in an 11 km x 15 km x 116 m groundwater model. Bedrock topography, initially based on a map by Kunkle (1961), was reinterpreted using data from 227 additional bedrock penetrations drilled in the last 55 years. Varying assumptions of hydraulic conductivity were employed to model a range of bedrock conductivity from 1 to 3 orders of magnitude less than the overlying glacial aquifer system. MODPATH forward particle tracking and MT3DMS advective-dispersive transport modeling were employed to explore the influence of bedrock configuration and conductivity …

Modified Synthesis Of Ligands For Lanthanide Ions, Lauren Elizabeth Hopper

Wayne State University Theses

Ligands of relevance to lanthanide ions have been synthesized and modified with respect to pKa and thermal conditions (both microwave and non-microwave). Microwave-assistance has been used previously to accelerate the rates of reactions of ligand syntheses, primarily as a thermal component in agreement with the Arrhenius equation. The modified syntheses of intermediates for lanthanide complexes presented in this thesis enable rapid synthesis of common intermediates—DO2A-methyl ester, DO2A-ethyl ester, and DO2A t-butyl ester—that previously required days to synthesize. Additionally, this modified synthesis can be performed with or without microwave irradiation, suggesting that the thermal component of the rate acceleration is not …

Big Data Management Using Scientific Workflows, Andrii Kashliev

Wayne State University Dissertations

Humanity is rapidly approaching a new era, where every sphere of activity will be informed by the ever-increasing amount of data. Making use of big data has the potential to improve numerous avenues of human activity, including scientific research, healthcare, energy, education, transportation, environmental science, and urban planning, just to name a few. However, making such progress requires managing terabytes and even petabytes of data, generated by billions of devices, products, and events, often in real time, in different protocols, formats and types. The volume, velocity, and variety of big data, known as the "3 Vs", present formidable challenges, unmet …

Cohomology Operations On Random Spaces, Matthew John Zabka

Wayne State University Dissertations

Topology has recently received more attention from statisticians as some its tools have been applied to understanding the shape of data. In particular, a data set can generate a topological space, and this space’s topological structure can give us insight into some properties of the data. This framework has made it necessary to study random spaces generated by data. For example, without an understanding of the probabilistic properties of random spaces, one cannot conclude with any degree of confidence what the tools of topology tell us about a data set. While some results are known about the cohomological structure of …

Feature Grouping Using Weighted L1 Norm For High-Dimensional Data, Karthik Kumar Padthe`

Wayne State University Theses

Building effective prediction models from high-dimensional data is an important problem in several domains such as in bioinformatics, healthcare analytics and general regression analysis. Extracting feature groups automatically from such data with several correlated features is necessary, in order to use regularizers such as the group lasso which can exploit this deciphered grouping structure to build effective prediction models. Elastic net, fused-lasso and Octagonal Shrinkage Clustering Algorithm for Regression (oscar) are some of the popular feature grouping methods proposed in the literature which recover both sparsity and feature groups from the data. However, their predictive ability is affected adversely when …

Effects Of Folding On Mineral Cpos In Gneiss: Implications For Lower Crustal Seismic Anisotropy, Alexia K. Sarnowsky

Wayne State University Theses

Isotropic seismic properties are not sufficient to distinguish between many rock types believed to make up the middle and lower continental crust. Seismic anisotropy is the directional dependence of seismic velocity, which we can use to improve our understanding of the composition and structure of the middle and lower continental crust. Our rationale is that seismic anisotropy in the middle and lower crust is controlled by the crystallographic preferred orientation (CPO) of minerals. The effects of folding on mineral CPO in a folded gneiss from the Coweeta Group in North Carolina is used for this study, and we should be …

Dense Periodical Patterns In Photonic Devices: Technology For Fabrication And Device Performance, Sabarish Chandramohan

Wayne State University Dissertations

For the fabrication, focused ion beam parameters are investigated to successfully fabricate dense periodical patterns, such as gratings, on hard transition metal nitride such as zirconium nitride. Transition metal nitrides such as titanium nitride and zirconium nitride have recently been studied as alternative materials for plasmonic devices because of its plasmonic resonance in the visible and near-infrared ranges, material strength, CMOS compatibility and optical properties resembling gold. Coupling of light on the surface of these materials using sub-micrometer gratings gives additional capabilities for wider applications. Here we report the fabrication of gratings on the surface of zirconium nitride using gallium …

Substrate Effects And Dielectric Integration In 2d Electronics, Bhim Prasad Chamlagain

Wayne State University Dissertations

The ultra-thin body of monolayer (and few-layer) two dimensional (2D) semiconducting materials such as transitional metal dichalconiges (TMDs), black phosphorous (BP) has demonstrated tremendous beneficial physical, transport, and optical properties for a wide range of applications. Because of their ultrathin bodies, the properties of 2D materials are highly sensitive to environmental effects. Particularly, the performance of 2D semiconductor electronic devices is strongly dependent on the substrate/dielectric properties, extrinsic impurities and absorbates. In this work, we systematically studied the transport properties of mechanically exfoliated few layer TMD field-effect transistors (FETs) consistently fabricated on various substrates including SiO2,Parylene –C, Al2O3, SiO2 modified …

An Automated System To Measure The Quantum Efficiency Of Ccds For Astronomy, Rebecca Ann Coles

Wayne State University Dissertations

We describe a system to measure the Quantum Efficiency in the wavelength range of 300nm to 1100nm of 40x40 mm n-channel CCD sensors for the construction of the 3.2 gigapixel LSST focal plane. The technique uses a series of instruments to create a very uniform flux of photons of controllable intensity in the wavelength range of interest across the face the sensor. This allows the absolute Quantum Efficiency to be measured with an accuracy in the 1% range. This system will be part of a production facility at Brookhaven National Lab for the basic component of the LSST camera.

Synthesis And Characterization Of Transition Metal Phosphide Nanoparticles For Catalytic Applications: Model Catalysts For Hydrodesulfurization And Electrocatalysts For The Oxygen Evolution Reaction, Don Malinda Ruchira Liyanage

Wayne State University Dissertations

Transition metal phosphides are emerging as efficient catalysts for different processes. Although binary phases have been extensively studied recently researchers have explored the synergism afforded by bimetallic ternary transition metal phosphides. The conventional catalyst preparation methods (temperature programmed reduction or solvothermal synthesis) yield inhomogeneous samples, preventing a detailed understanding of how active site density impacts catalytic activity and mechanism. In contrast, solution-phase arrested-precipitation reactions produce uniform nanoparticles with an excellent control on size, morphology and composition.

This dissertation describes the synthesis of ternary transition metal phosphide nanoparticles (Ni2-xCoxP and Ni2-xRuxP) by solution-phase arrested-precipitation reactions and evaluation of their composition-dependent catalytic …

Facile Synthesis Of Tertiary Aliphatic Amine– Containing Cyclic Motif Via Neutral Aminyl Radical Cyclization, Heng Chen

Wayne State University Theses

Tertiary amine–containing cyclic motifs are prevalent in natural products and pharmaceutical lead targets. Inspired by these biological active molecules, one focus in our lab is the development of neutral aminyl radical chemistry in the synthesis of tertiary aliphatic amine–containing cyclic compounds. In this project, I investigated the mono- and tandem cyclization of aminyl radical with different types of olefins (terminal olefin, enone, and styrenyl). The effect of the hydrogen atom donor and the limitation of the reaction will be discussed.

Development Of A Dreissena Bioassay To Assess The Toxicity Of Contaminants Across Two Life-History Stages, Caroline Joyce Addis

Wayne State University Theses

Dreissenid mussels (Dreissena polymorpha and D. bugensis) have rapidly become widespread and ubiquitous in North America since their introduction into the Great Lakes in the 1980s. The resulting environmental and economic impacts of their invasion have been extensive, negatively affecting biodiversity and costing millions of dollars in control efforts and damage to power generation and water treatment facilities. Although dreissenids are often associated with negative impacts, they may present a practical tool for toxicology studies. The typically sessile behavior of the benthic adults coupled with the planktonic nature of the veligers allow for a more complete evaluation of water quality …

Portable X-Ray Fluorescence Measurement Viability In Organic Rich Soils: Pxrf Response As A Function Of Organic Matter Presence, Roozbeh Ravansari

Wayne State University Theses

Portable X-Ray fluorescence provides a cost effective method for producing rapid geochemical data. With advancements in X-Ray generation and detection technology, pXRF has become feasible for use on pedologic materials. Factors affecting pXRF soil measurements such as heterogeneity, moisture content, object geometry, and matrix interferences are widely recognized. However, the influence of organic matter on pXRF soil measurements is poorly understood.

This study examined the influence of organic matter fraction on pXRF trace metal measurements in a soil matrix. Incremental addition of three organic matter surrogates (cellulose, graphite powder, and confectioner’s sugar) was used to investigate the influence of increasing …

Consensus Regularized Selection Based Prediction, Ping Wang

Wayne State University Theses

Integrating regularization methods within a regression framework has become a popular choice for researchers to build predictive models with lower variance and better generalization. Regularizers also aid in building interpretable models with high-dimensional data which makes them very appealing. Regularizers in general are unique in nature as they cater to data specific features such as correlation, structured sparsity, and temporal smoothness. The problem of obtaining a consensus among such diverse regularizers is extremely important in order to determine the optimal regularizer for the model. This is called the consensus regularization problem which has not received much attention in the literature, …

In Vitro And In Vivo Measurments Of Serotonin For Ecological And Mental Health Via Fast Scan Cyclic Voltammetry, Matthew Nicholas Jackson

Wayne State University Theses

Fast Scan Cyclic Voltammetry has been proven to be a highly valuable technique in analysis and detection of neurotransmitters. With this technique, two novel applications are being explored to protect natural water sources as well as furthering the efficacy of antidepressants. Despite setbacks, promising data has been collected to further understand the mechanisms involved in the phototactic response observed in Daphnia Magna. Electrochemical modification of carbon fiber microelectrodes has proven to be inefficient as a means to effectively differentiate between serotonin and its metabolite. As such, this unsuccessful attempt has further narrowed down the list of candidates to electrochemically differentiate …

Integration Of Deterministic And Stochastic Models In A 1,4-Dioxane Contaminated Glacial Aquifer System, Washtenaw County, Michigan, Lena Kristin Pappas

Wayne State University Theses

Hybrid models incorporating stochastic variability within a deterministic hydrostratigraphic framework provide an effective way to assess uncertainty in flow and transport model predictions. This study evaluated the distribution of groundwater flow and contaminant transport pathways in two ensembles of spatially variable hydraulic conductivity (K) distributions. The models comprised a 360 ft-thick sequence of Pleistocene glacial sediments in in an approximately 8 mi2 area across Washtenaw County, Michigan. Conditioned K fields were generated using Sequential Gaussian Simulation (SGS) and Sequential Indicator Simulation (SIS) constructed using indicator classes based on natural gamma ray logs from 77 monitoring wells. K fields were modeled …

Interactive Refinement Of Hierarchical Object Graphs, Ebrahim Khalaj

Wayne State University Theses

Developers need to understand the runtime structure of object-oriented code, and abstract object graphs can help. To extract abstract object graphs that convey design intent in the form of object hierarchy, additional information is needed to express this hierarchy in the code using ownership types, but adding ownership type qualifiers after the fact involves manual overhead, and requires developers to switch between adding qualifiers in the code and looking at abstract object graphs to understand the object structures that the qualifiers describe. We describe an approach where developers express their design intent by refining an object graph directly, while an …