Digital Commons Network^™

Sequences Of Random Matrices Modulated By A Discrete-Time Markov Chain, Huy Nguyen

Wayne State University Dissertations

In this dissertation, we consider a number of matrix-valued random sequences that are modulated by a discrete-time Markov chain having a finite space.Assuming that the state space of the Markov chain is large, our main effort in this work is devoted to reducing the complexity. To achieve this goal, our formulation uses time-scale separation of the Markov chain. The state-space of the Markov chain is split into subspaces. Next, the states of the Markov chain in each subspace are aggregated into a ``super'' state. Then we normalize the matrix-valued sequences that are modulated by the two-time-scale Markov chain. Under simple …

Electrochemistry Of Bubbles: Developing New Sensors, Promoting Gas Evolution Reactions, And Extraction Of Rare Earth Elements, Ruchiranga R. Ranaweera

Wayne State University Dissertations

This dissertation presents new analytical, electrocatalysis, and separation strategies that utilize bubble behaviors in different electrochemical systems. The first part of this dissertation focuses on the method development for PFAS preconcentration and detection. First, we present the bubble-nucleation-based electrochemical method for the selective and sensitive detection of surfactants. Our method utilizes the high surface activity of surfactant analytes to affect the electrochemical bubble nucleation and then transduces the change in nucleation condition to an electrochemical signal for determining the surfactant concentration. Using this method, we demonstrate the quantitation of perfluorinated surfactants in water, a group of emerging environmental contaminants, with …

Versatility Of Low-Power Wide-Area Network Applications, Dali Ismail

Wayne State University Dissertations

Low-Power Wide-Area Network (LPWAN) is regarded as the leading communication technology for wide-area Internet-of-Things (IoT) applications. It offers low-power, long-range, and low-cost communication. With different communication requirements for varying IoT applications, many competing LPWAN technologies operating in both licensed (e.g., NB-IoT, LTE-M, and 5G) and unlicensed (e.g., LoRa and SigFox) bands have emerged. LPWANs are designed to support applications with low-power and low data rate operations. They are not well-designed to host applications that involve high mobility, high traffic, or real-time communication (e.g., volcano monitoring and control applications).With the increasing number of mobile devices in many IoT domains (e.g., agricultural …

High Mobility N-Type Field Effect Transistors Enabled By Wse2/Pdse2 Heterojunctions, Arthur Bowman Iii

Wayne State University Dissertations

Two-dimensional (2D) semiconductors such as transition metal dichalcogenides (TMDs) have emerged as a promising candidate for post-silicon electronics. Few-layer tungsten diselenide (WSe2), a well-studied TMD, has sown high hole mobility and ON/OFF ratio in field effect transistor (FET) devices. But the n-type performance of WSe2 is still quite limited by the presence of a substantial Schottky Barrier. Palladium diselenide, (PdSe2) is a newly discovered TMD that is of interest because of its high electron mobility, and moderate ON/OFF ratios. However, despite its relatively small bandgap, the n-type performance of few-layer PdSe2 FETs has also been limited by a Schottky barrier, …

An Investigation Of Uncertainties In Intensity Modulated Radiation Therapy, Cory Knill

Wayne State University Dissertations

Introduction: The treatment of cancer using intensity modulated radiation therapy (IMRT) is complex, involving many sub-processes to commission a treatment platform and treat patients. Uncertainties within the individual sub-process can lead to inaccurate treatments and sub-optimal patient outcomes. This research focused on minimizing uncertainties throughout IMRT commissioning and treatments. Methods: Five sub-processes were selected for uncertainty reduction: 1) optimizing radiation-imaging coincidence of the treatment machine, 2) improving the statistical model used to analyze IMRT commissioning data, 3) reducing the effect of ion recombination in IMRT quality assurance measurements, 4) improving the correlation between IMRT quality assurance results and patient-specific delivery …

Measurement Of The Cross Section Of Top Quark Pairs Produced In Association With A Photon In Lepton + Jets Events At √S = 13 Tev With Full Runii Cms Data, Nabin Poudyal

Wayne State University Dissertations

The inclusive production cross section of top quark pairs in association with a photon is measured in proton-proton collisions at the LHC with 13 TeV energy using the full RunII data collected by CMS in 2016, 2017, and 2018 with a total corresponding integrated luminosity of 137 fb −1 . The relative fraction of ttγ events normalized to inclusive tt production is measured. The cross section measurement provides important information about the electromagnetic coupling of the standard model top quark and is sensitive to physics beyond the standard model. The analysis is carried out in the in semileptonic decay channel …

Novel Deep Learning Methods For Medical Applications With Limited Data, Kaiyue Zhou

Wayne State University Dissertations

Deep learning has become an increasingly popular trend in recent years with applications in different domains including healthcare and medicine using numeric, spatially 2D and 3D, and time-series based video and audio data. However, data collection being the principal bottleneck for advancement in the life sciences, particularly in genomics, engineering, and healthcare, has led to incomplete and insufficient data, resulting in non-optimal deep learning model performances. Here, we propose solutions to overcome such data limitations when high dimensional medical data with limited sample sizes are present. These solutions include but not limited to multi-class learning, feature compression (\eg, auto-encoder), data …

Induction And Prevention Of Electron Transport In Langmuir-Blodgett Films Of 3d-Based Metallosurfactants: Studies On Current Rectification And Corrosion Inhibition, Aldora Devale Kapuralalage Isuri Weeraratne

Wayne State University Dissertations

The work reported in this thesis focused on the use of redox-active metallosurfactants for current rectification and redox-innocent metallosurfactants for corrosion inhibition. These studies were done based on the hypothesis that redox-active metallosurfactnats can promote electron transport, while redox-innocent metallosurfactants can hinder electron transport. As such, new redox-active phenolate based iron(III), chromium(III), oxovanadium(IV) and redox-innocent gallium(III) and zinc(II) complexes were synthesized and characterized for the aforementioned applications. First, we studied the current rectification ability of a homobimetallic iron(III) hydrophobe with [N4O6] ligand environment. This complex displayed rectification with rectification ratio ranges from 2.6 to 9.8 between -2.0 and 2.0 V …

Pharmaceuticals In The Environment: Health Implications And Environmental Toxicity, Jessica Phillips

Wayne State University Dissertations

Approximately 2.9 billion prescriptions are written annually in the United States, with a multitude of biochemical actions, with 63151 tons used by food producing animals worldwide and an additional 55-77 million prescriptions written for companion animals. With increasing prescription and unknown toxicologic effects of many of these chemicals, zebrafish (danio rerio), an NIH approved human model, were used to model potentially health effects. Significant abnormalities were seen with extended duration metformin exposure from 4 hours post fertilization up to 5 days post fertilization, although short term metformin exposure for 24 hours at 4-5 days post fertilization did not lead to …

The Hatcher-Quinn Invariant And Differential Forms, Joshua Lenwood Turner

Wayne State University Dissertations

An intersection problem consists of submanifolds $P, Q \subset M$ having non-empty intersection. In 1974, Hatcher and Quinn introduced a bordism-theoretic obstruction to finding a deformation of $P$ off of $Q$ by an isotopy. This dissertation studies the problem of finding an analytical expression for the Hatcher-Quinn obstruction---one which involves the language of differential forms. We first introduce the notion of a smooth structure on a set by introducing a system of mappings called plots. By generalizing this to the fibered setting, we use the concept to give a model for the homology of the generalized path space $E$ i.e., …

Synthesis And Reactivity Of Metal Bis(Alkoxide) Complexes In Nitrene Coupling And Polymerization Of Polar Monomers, Duleeka Chamini Wannipurage

Wayne State University Dissertations

The nitrene homocoupling to produce azoarenes was done using two different iron (II) alkoxide complexes, Fe(OCtBu2(3,5-Ph2C6H3)2(THF)2 and Fe[OO]Ph(THF)2. Due to the steric bulkiness of HOCtBu2(3,5-Ph2C6H3 ligand, this complex exhibited selectivity for the bis(alkoxide) ligation; no tris(alkoxide) complexes were observed. As a result, both bulky and non-bulky aryl nitrenes are coupled with Fe(OCtBu2(3,5-Ph2Ph)2(THF)2, albeit the coupling of the less bulky substrates requires higher temperatures and longer reaction times. Stoichiometric reactions of Fe(OCtBu2(3,5-Ph2C6H3)2(THF)2 with non-bulky aryl azides led to the observation of the iron(III) tetrazene radical anion complexes, that can produce azoarene products after heating. Tetrazene complexes likely serve as a “masked …

Accumulation-Type Ohmic Van Der Waals Contacts To Nearly Intrinsic Wse2, Upendra Rijal

Wayne State University Dissertations

We report the fabrication of ohmic van der Waals (vdW) contacts to WSe2 using degenerately p-doped MoS2 (p+-MoS2) as a contact-metal. We demonstrate in WSe2 field-effect transistors (FETs) that accumulation-type ohmic contacts and high device performance are achieved without electrostatically gating the drain/source contact regions despite the nearly intrinsic nature of WSe2. Back-gated WSe2 FETs with p+-MoS2 bottom-contacts (which screen the back-gate electric field in the drain/source regions) exhibit linear output characteristics, a high on/off ratio of 108, and a high two-terminal field-effect mobility up to ~200 cm2V-1s-1 at room temperature. Our theoretical modeling reveals that the p+-MoS2/WSe2 vdW contact …

Solving And Applications Of Multi-Facility Location Problems, Anuj Bajaj

Wayne State University Dissertations

This thesis is devoted towards the study and solving of a new class of multi-facility location problems. This class is of a great theoretical interest both in variational analysis and optimization while being of high importance to a variety of practical applications. Optimization problems of this type cannot be reduced to convex programming like, the much more investigated facility location problems with only one center. In contrast, such classes of multi-facility location problems can be described by using DC (difference of convex) programming, which are significantly more involved from both theoretical and numerical viewpoints.In this thesis, we present a new …

New Conforming Finite Elements Based On The De Rham Complexes For Some Fourth-Order Problems, Qian Zhang

Wayne State University Dissertations

In this dissertation, we discuss the conforming finite element discretization of high-order equations involving operators such as $(\curl\curl)^2$, $\grad\Delta\div$, and $-\curl\Delta\curl$. These operators appear in various models, such as continuum mechanics, inverse electromagnetic scattering theory, magnetohydrodynamics, and linear elasticity. Naively discretizing these operators and their corresponding eigenvalue problems using the existing $H^2$-conforming element would lead to spurious solutions in certain cases. Therefore, it is desirable to design conforming finite elements for equations containing these high-order differential operators.

The $\curl\curl$-conformity or $\grad\curl$-conformity requires that the tangential component of $\curl \bm u_h$ is continuous. Recall that the N\'ed\'elec element requires only the …

Thermal Atomic Layer Deposition Of Titanium Nitride Films: Synthesis And Characterization Of Novel Titanium Precursors, Anuththara Chalani Upeksha Abesinghe Arachchige

Wayne State University Dissertations

Due to the continuous miniaturization of microelectronic devices, robust deposition techniques are required which can provide continuous and conformal thin films even in high aspect ratio structures. Atomic Layer Deposition (ALD) is an excellent choice of deposition technique as it is capable of providing perfect film coverage. Because of its self-limited growth mechanism, ALD can afford sub-nanometer thickness control. Precursors used in ALD should be volatile, thermally stable at the deposition temperature, and highly reactive towards the co-regent. Traditionally, ALD has been used to grow metal oxide films. However, the microelectronics industry now demands ALD for metals and metal nitrides. …

Software As A Service: The Mediating Role Of Consequences Of Saas Diffusion On Firm Performance, Cristina Marie-Mccarthy Recchia

Wayne State University Dissertations

ABSTRACTSOFTWARE AS A SERVICE: THE MEDIATING ROLE OF CONSEQUENCES OF SAAS DIFFUSION ON FIRM PERFORMANCE by CRISTINA MARIE-MCCARTHY RECCHIA DECEMBER 2021 Advisor: Dr. Ratna Babu Chinnam Major: Industrial Engineering Degree: Doctor of Philosophy There are ample studies that support a positive link between information technology and firm performance. Bharadwaj (2000) and Chae (2014, 2018) are two examples that provided a foundation for this work. These scholars looked at how capabilities associated with information technology contribute to improved financial performance using a specific set of financial ratios. In addition, there are studies that examine a positive link between Software-as-a-Service (SaaS) and …

A Review Of Sample Size And Design Efficacy In Crossover Design In Peer-Reviewed Psychology Research, Kyle Moxley

Wayne State University Dissertations

A REVIEW OF SAMPLE SIZE AND DESIGN EFFICACY IN CROSSOVER DESIGN IN PEER-REVIEWED PSYCHOLOGY RESEARCHby KYLE C. MOXLEY November 2021 Advisor: Dr. Shlomo S. Sawilowsky Major: Education Evaluation and Research Degree: Doctor of Philosophy The present study seeks to investigate the efficacy of crossover research designs, and the application of crossover designs, in the field of behavioral sciences. Under ideal conditions, crossover designs are assumed to be more efficacious than parallel studies in that participants are given both treatments. However, the presence of carryover effects from treatments may influence outcomes (Jones & Kenward, 2014). To prevent carryover effects, researchers frequently …

Methods For Ad Hoc And Conversational Entity Retrieval From Knowledge Graphs, Fedor Nikolaev

Wayne State University Dissertations

The recent years have witnessed the increase in popularity of knowledge graphs in various applications, such as information extraction and retrieval systems, and intelligent assistants. Traditionally, retrieval from knowledge graphs is performed by submitting queries in SPARQL, a rigid query language based on triple patterns and logical operations. In this work, we propose several approaches to ad hoc and conversational entity retrieval that transcend the limitations of this approach by allowing the user to either submit queries using natural language in an ad hoc retrieval setting or have a conversation with an intelligent retrieval system by asking a series of …

Improved Contacts And Device Performance In Mos2 Transistors Using 2d Semiconductor Interlayers, Kraig Andrews

Wayne State University Dissertations

The rapid growth of modern electronics industry over the past half-century has been sustained by the continued miniaturization of silicon-based electronics. However, as fundamental limits approach, there is a need to search for viable alternative materials for next-generation electronics in the post-silicon era. Two-dimensional (2D) semiconductors such as transition metal dichalcogenides (TMDs) have attracted much attention due to their atomic thickness, absence of dangling bonds and moderately high carrier mobility. However, achieving low-resistance contacts has been major impediment in developing high-performance field-effect transistors (FETs) based on 2D semiconductors. A substantial Schottky barrier (SB) is often present at the metal/2D-semicondcutor interface, …

Non-Canonical Targets, Reaction Kinetics, And Cellular Potency Of Amino Acid-Linked Platinum(Ii) Compounds, Bett Kimutai

Wayne State University Dissertations

DNA serve as an ideal target where drugs such as cisplatin (cisPt) bind and exert their anticancer activities. CisPt is known to preferentially coordinate with DNA leading to formation of cisPt-deoxyguanosine (dGuo) adducts. The adducts distort the DNA structure and contribute to inhibition of DNA-mediated cellular functions and ultimately cancer cell death. Despite its utilization as an anticancer drug, cisPt has a number of drawbacks, which include toxic side effects and cellular resistance. Resistance occurs through processes such as repair of damaged DNA and inactivation of cisPt present in the cell. To overcome these challenges, the aim of this thesis …

Influence Of Conformational Restriction On The Antibacterial Activity And Ribosomal Selectivity Of Aminoglycoside Antibiotics, Michael Gabriel Pirrone

Wayne State University Dissertations

The ever-increasing threat posed by multidrug-resistant infectious bacteria necessitates

the development of novel antibiotics. Aminoglycoside antibiotics are growing in interest due to

their broad spectrum of activity, lack of known drug related allergies, low manufacturing cost,

and their well-studied mechanism of action. The simplification of rational drug design due to the

well-studied mechanism of action is the key to overcoming the issues presented by these drugs,

namely ototoxicity and nephrotoxicity.

A study of the effect of the conformation of the aminoglycoside ring I side chain is

described wherein it was discovered that an increase in a particular conformation augments the …

Reflection And Reverberation In Neutron Star Low-Mass X-Ray Binaries, Benjamin Coughenour

Wayne State University Dissertations

Neutron star low-mass X-ray binaries (NS LMXBs) are systems which consist of a NS and a low-mass companion star. They are naturally variable on a variety of timescales, and are even classified by their X-ray spectral variability on the timescales of hours to days. The most luminous NS LMXB sources are known as ‘Z’ sources, because they trace out a characteristic ‘Z’ shape when plotted on a color-color or hardness-intensity diagram. The physical mechanisms causing this variability are not well understood. To try to address this, we model spectra taken from different positions on a hardness-intensity diagram of two Z …

Exploring The Scope And Limitations Of The Oxidative Deamination Of N-Acetyl Neuraminic Acid, Mohammed Bakr Hawsawi

Wayne State University Dissertations

Sialic acids are molecules of importance in the fields of carbohydrate chemistry and glycoscience, and their diversity make them even more attractive to scientific research. Modifications of sialic acid derivatives may lead to several biological and chemical features that can be utilized for medicinal purposes. The modern drug therapy is dependent on the chemical discoveries of potent and effective molecules. N-Acetyl neuraminic acid is the parent and most common molecule in sialic acid family that received considerable attention in glycochemical research. This dissertation explores the scope as well as the limitations of the Zbiral oxidative deamination of N-acetyl neuraminic acid …

Sociotechnical Systems Approach For Designing Effective Pre-College Stem Programs For Adult Students, Ifeoma Okechukwu

Wayne State University Dissertations

In the context of its external environment, sociotechnical systems (STS) are tools for restructuring an organization’s components into inter-related and interdependent social and technical subsystems for improving the organization’s performance and the well-being of its actors. The theory of STS states that the optimal performance and effectiveness of an organization lies in the joint optimization of the social (all human-based elements) and the technical (the tools and technology for doing work) subsystems. Many technical industries know the benefits of STS, however the concept has a minimal presence in education, in spite of education’s many challenges such as improving the graduation …

The Wedge Family Of The Cohomology Of The C-Motivic Steenrod Algebra, Hieu Trung Thai

Wayne State University Dissertations

Computing the stable homotopy groups of the sphere spectrum is one of the most important problems of stable homotopy theory. Focusing on the 2-complete stable homotopy groups instead of the integral homotopy groups, the Adams spectral sequence appears to be one of the most effective tools to compute the homotopy groups. The spectral sequence has been studied by J. F. Adams, M. Mahowald, M. Tangora, J. P. May and others.

In 1999, Morel and Voevodsky introduced motivic homotopy theory. One of its consequences is the realization that almost any object studied in classical algebraic topology could be given a motivic …

Effective Field Theory And Machine Learning Approaches To Controlling Nonperturbative Uncertainties In Flavor Physics, Ayesh Gunawardana

Wayne State University Dissertations

The radiative decay $\bar{B}\to X_s\gamma$ and semileptonic heavy meson decay $D\to \pi l \nu$ are important flavor physics probes of new physics. However, these decays are plagued with nonperturbative uncertainties that are needed to be controlled to obtain a theoretically clean description. In this dissertation, we provide effective field theory and machine learning approaches to controlling these uncertainties.\par

In $\bar B\to X_s\gamma$, the largest uncertainty on the total rate and the CP asymmetry arises from resolved photon contributions. These appear first at order $1/m_b$ and are related to operators other than $Q_{7\gamma}$ in the effective weak Hamiltonian. One of the …

Reactions Of First-Row Transition Metal Complexes In Bis(Alkoxide) Ligand Environments With Diazoalkanes: Formation Of Carbenes Versus Reductive Coupling To Form Bridging Tetrazenes, Amanda Grass

Wayne State University Dissertations

This dissertation focuses on the design and reactions of novel late transition metal carbene complexes featuring alkoxide ligand environments. The high-valent cobalt carbene Co(OR)2(=CPh2) (OR = OCtBu2Ph), featuring short Co=C bond of 1.773(3) Å, was previously reported from the reaction of Co(OR)2(THF)2 with diphenyldiazoalkane. Magnetic and spectroscopic (EPR) studies demonstrated Co(OR)2(=CPh2) to be a low-spin S = ½ complex. Computational studies, in agreement with experimental data, suggested that the electronic structure of Co(OR)2(=CPh2) lies between intermediate spin Co(III) anti-ferromagnetically coupled to a carbene radical and a Co(IV) alkylidene. This dissertation began with investigation of this complex in carbene transfer reactivity. …

Exploring Jet Transport Coefficients In The Quark-Gluon Plasma, Amit Kumar

Wayne State University Dissertations

The modifications of hard jets play an essential role as multi-scale probes of the properties of the Quark-Gluon Plasma (QGP) produced in high-energy heavy-ion collisions. In this thesis, we explore the interplay between the soft and hard scales involved in the modification of jet partons as they propagate through the QGP. First, we focus on a regime where the exchanged momenta between the hard parton and the medium are at a high enough scale that QCD perturbation theory can be applied. Based on the assumption that the multiple scatterings inside the plasma are incoherent in the high-energy and high-virtuality phase …

Variational Analysis In Second-Order Cone Programming And Applications, Hang Thi Van Nguyen

Wayne State University Dissertations

This dissertation conducts a second-order variational analysis for an important class on nonpolyhedral conic programs generated by the so-called second-order/Lorentz/ice-cream cone. These second-order cone programs (SOCPs) are mathematically challenging due to the nonpolyhedrality of the underlying second-order cone while being important for various applications. The two main devices in our study are second epi-derivative and graphical derivative of the normal cone mapping which are proved to accumulate vital second-order information of functions/constraint systems under investigation. Our main contribution is threefold:

- proving the twice epi-differentiability of the indicator function of the second-order cone and of the augmented Lagrangian associated with …

Parahydrogen Hyperpolarized Multi-Nuclear Contrast Agents For Potential Mri Applications, Nuwandi Maduranga Ariyasingha Uragoda Wiyannalage

Wayne State University Dissertations

ABSTRACT

PARAHYDROGEN HYPERPOLARIZED MULTI-NUCLEAR CONTRAST AGENTS FOR POTENTIAL MRI APPLICATIONS

by

NUWANDI M. ARIYASINGHA

December 2020

Advisor: Dr. Eduard Chekmenev

Major: Chemistry (Physical)

Degree: Doctor of Philosophy

There have been numerous studies to develop fast, cost effective hyperpolaried (HP) contrast agents with higher polarization values that can be potentially employed for magnetic resonance clinical imaging. Some of the currently used contrast agents are based on 129Xe hyperpolarized nucleus. However, one of the problems associated with this approach, is the high cost of the produced hyperpolarized contrast agents. In addition, the other important practical problem is that the currently used clinical …