Physical Sciences and Mathematics Commons^™

Air-Processed Polymer Photovoltaics: Advanced Morphological Characterization And Synthesis Of New Materials For Increased Light Absorption, Levi Moore

Dissertations

Organic photovoltaics (OPVs) have undergone intense development in recent years due to their potential to produce inexpensive, flexible, lightweight, and portable solar cells utilizing organic photoactive materials. Polymer-based OPVs have recently surpassed the 10 % in laboratory-scale devices, but require strict processing conditions in inert environments. Materials and processing methods that are workable in air are therefore desired. In addition to the light-absorbing and charge transport properties of the active layer materials, the morphology, crystallinity and orientation of the components of the phase-separated blend are paramount in determining OPV device performance This dissertation explores the processing of the model polymer …

Radial Basis Function Differential Quadrature Method For The Numerical Solution Of Partial Differential Equations, Daniel Watson

Dissertations

In the numerical solution of partial differential equations (PDEs), there is a need for solving large scale problems. The Radial Basis Function Differential Quadrature (RBFDQ) method and local RBF-DQ method are applied for the solutions of boundary value problems in annular domains governed by the Poisson equation, inhomogeneous biharmonic equation, and the inhomogeneous Cauchy-Navier equations of elasticity. By choosing the collocation points properly, linear systems can be obtained so that the coefficient matrices have block circulant structures. The resulting systems can be efficiently solved using matrix decomposition algorithms (MDAs) and fast Fourier transforms (FFTs). For the local RBFDQ method, the …

Ecological And Oceanographic Influences On Leatherback Turtle Behavior And Scyphozoan Jellyfish Distributions In The Gulf Of Mexico, Katrina Aleksa

Dissertations

Leatherback turtles (Dermochelys coriacea) are a wide-ranging, oceanic species that feed exclusively on gelatinous zooplankton. Leatherback have been spotted in the Gulf of Mexico (GoM) for several decades and consistently had a high level of interactions with longline fisheries. However, no quantitative studies have been performed to address the spatiotemporal distribution of these turtles in the GoM. This research determines 1) leatherback movements and high-use areas in the GoM, 2) their association with oceanographic features, 3) the distribution and density of two abundant medusae in the northern GoM and any association with biophysical parameters, and 4) the body …

3d Printing Concrete Structures And Verifying Integrity Of Their G-Code Instructions: Border Wall A Case Study, Jason Breland

Dissertations

Thanks to advances in Additive Manufacturing (AM) technology and continued research by academics and entrepreneurs alike, the ability to “3d print” permanent concrete structures such as homes or offices is now a reality. Generally, AM is the process that allows for a 3d model of an object to be converted into hardware instructions to generate that object layer by layer using a malleable medium such as a plastic. Specifically, large scale concrete AM can now generate a structure, such as a building, layer by layer more quickly and efficiently than traditional construction methods [6, 39]. This innovative, semi-autonomous process promises …

Historical Change Of Seagrasses In The Mississippi And Chandeleur Sounds, Linh Thuy Pham

Dissertations

Seagrasses are important coastal resources facing numerous stressors, and losses have been documented from local to global assessments. Under the broad theme of habitat loss and fragmentation, a study of historical change in total area and landscape configuration of seagrasses in the Mississippi and Chandeleur Sounds was conducted. Mapping data was collated from a multitude of previous projects from 1940 to 2011.

Comparisons of seagrass area among various studies that used different mapping methods can result in overestimation of area change and misleading conclusions of change over time. The vegetated seagrass area (VSA) data were generalized to a common resolution …

Barrier Properties Of Polymer Nanocomposites With Graphene Oxide And Its Derivatives: Mechanism And Applications In Anticorrosive Coatings, Yidan Guan

Dissertations

Metallic devices made from steel or aluminum are subjected to deterioration by environmental contaminants over time. As one of the corrosion control methods, organic coatings show many advantages due to their low cost, versatility, decoration aesthetics and effective protections. Corrosion protection theories and failure modes of organic coatings are still not fully understood due to complicated interactions in the coating-metal-environment system, however, it is widely agreed that the barrier nature of polymeric materials towards aggressive species, such as oxygen, water, electrolyte, plays a key role. Improved barrier property of polymer nanocomposites (PNCs) with two-dimensional (2D) carbon filler, graphene and graphene …

Electrophilic Cleavage And Functionalization Of Polyisobutylenes Bearing Unsaturations In The Backbone And Synthesis Of Polymers For This Process, Christopher Campbell

Dissertations

In the first project, we demonstrated a new reaction, which is a subset of the Friedel‑Crafts alkylation reaction, in which the alkylating carbocation undergoes a cleavage reaction prior to reaction with the aromatic substrate. This reaction was discovered by the observation that when a PIB containing a large amount of coupled fraction was subjected to a mixture of protic and Lewis acids (HCl/TiCl₄) in the presence of an alkoxybenzene compound, the coupled fraction was quantitatively converted to its constituent monofunctional chains, which became functionalized by the alkoxybenzene.

In the second project, a commercial polymer, poly(isobutylene-co-isoprene) (butyl …

A Case Study In The Application Of Model-Based Systems Engineering To Laboratory Research Science, Brad Crochet

Dissertations

This dissertation presents an exploration of the application of Model-Based Systems Engineering (MBSE) tools and methods to the design and execution of sophisticated laboratory experiments. An experiment to measure the first excited state diffusion coefficient, recently attempted by the author, is used as an example. Several MBSE analysis methods are applied, retrospectively, to the process by which the experiment in question was planned and executed. The potential for increased efficiency in managing the diverse types of information associated with such laboratory experiments is demonstrated, as well as possible further avenues for future research.

A Hybrid Parallel Approach To High-Performance Compression Of Big Genomic Files And In Compresso Data Processing, Sandino N. Vargas Pérez

Dissertations

Due to the rapid development of high-throughput low cost Next-Generation Sequencing, genomic file transmission and storage is now one of the many Big Data challenges in computer science. Highly specialized compression techniques have been devised to tackle this issue, but sequential data compression has become increasingly inefficient and existing parallel algorithms suffer from poor scalability. Even the best available solutions can take hours to compress gigabytes of data, making the use of these techniques for large-scale genomics prohibitively expensive in terms of time and space complexity.

This dissertation responds to the aforementioned problem by presenting a novel hybrid parallel approach …

Statistical And Clinical Equivalence Of Measurements, Puntipa Wanitjirattikal

Dissertations

This study proposes a test for statistical equivalence of two measurements. Typically, a new measurement process Υ is compared to an existing or standard measurement process Χ. We are assuming that Χ and Υ are measurements on the same scale. The paired t-test may be used to check for significant difference between (Χ, Υ) pairs. However, the paired t-test is intended to detect shift-type relationships of the form Υ=Χ+δ1 and may have low power for scale-type relations of the form Υ=γΧ.

We propose a test that has reasonable power to …

An Lntegrated Approach (Remote Sensing, Hydrogeology, Geotechnical, And Geoinformatics) To Assess And Monitor Fossil Aquifers And Associated Land Deformation Over The Arabian Peninsula, Abdullah Ghurmullah Saeed Othman

Dissertations

Deformational features such as subsidence, sinkholes, fissures, settling and cracks in buildings and structures, and earthquakes are being reported from many of the world’s arid lands, in areas where fossil aquifers are being excessively exploited. Using the Lower Mega Aquifer System (LMAS) in Arabia as a test site, I applied an integrated approach (remote sensing, geodesy, GIS, geology, hydrogeology, and geotechnical) to identify nature, intensity, spatial distribution, and factors controlling the observed deformation in the central (Al-Qassim and Ha'il regions; area: 16×10⁴ km²) and the northern (Wadi As-Sirhan Basin; area: ~10.9×10⁴ km²) Arabia. A four -fold approach was adopted to …

Ldentifying And Characterizing Cognitive Factors Significant To Practicing And Learning Meteorology, Peggy M. Mcneal

Dissertations

To see the world as a meteorologist, one must understand and interpret atmospheric processes through representations depicted on two-dimensional weather charts and maps that encode large amounts of spatial and numerical data. This is a cognitively demanding and spatially challenging task, especially for students with burgeoning levels of meteorology knowledge, who lack the expertise of practiced meteorologists that read such charts and maps with ease. With little prior work informing meteorology and meteorology education through a cognitive science lens, this study surveys the literature and follows models of discipline-based education and cognitive science research to identify the discrete intelligence factors …

Diagnostics For Choosing Between Stratified Logrank And Stratified Wilcoxon, Jhoanne Marsh C. Gatpatan

Dissertations

Martinez and Naranjo (2010) proposed a pretest for choosing between Logrank or Wilcoxon test in a two - sample case. However, in the presence of covariates, comparing two populations without adjusting for covariates would yield misleading results. In this study, we propose several pretests that will help the analyst decide to use stratified Logrank or stratified Wilcoxon tests in comparing two survival curves after covariates have been taken into account. Power performance of each adaptive test was done through simulations under PH and non-PH cases.

High Performance Computing Techniques For Analyzing Risky Decision Making, Vinay B. Gavirangaswamy

Dissertations

The process or activity of making choices when subject to gain or loss can be understood as risky decision making (RDM). Risky Decisions consists of outcomes of decisions that may probabilistically result in unfavorable results. Every organism that lives faces this challenge and recent research suggests that there is a computational process involved in making these decisions. This has led to new approaches in the study of RDM. My dissertation is towards contributing to expand on the existing knowledge of RDM processes.

The core contribution of my work is an analysis and development of high performance computing techniques that improves …

Color-Connected Graphs And Information-Transfer Paths, Stephen Devereaux

Dissertations

The Department of Homeland Security in the United States was created in 2003 in response to weaknesses discovered in the transfer of classied information after the September 11, 2001 terrorist attacks. While information related to national security needs to be protected, there must be procedures in place that permit access between appropriate parties. This two-fold issue can be addressed by assigning information-transfer paths between agencies which may have other agencies as intermediaries while requiring a large enough number of passwords and rewalls that is prohibitive to intruders, yet small enough to manage. Situations such as this can be represented by …

Structures Of Derived Graphs, Khawlah Hamad Alhulwah

Dissertations

One of the most familiar derived graphs are line graphs. The line graph L(G) of a graph G is the graph whose vertices are the edges of G where two vertices of L(G) are adjacent if and only if the corresponding edges of G are adjacent. One of the best- known results on the structure of line graphs deals with forbidden subgraphs by Beineke. A characterization of graphs whose line graph is Hamiltonian is due to Harary and Nash-Williams. Iterated line graphs of almost all connected graphs were shown to be Hamiltonian by Chartrand. The girth of a graph G …

A Deep Learníng-Based Data Minimization Algorithm For Big Genomics Data In Support Of Lot And Secure Smart Health Services, Mohammed Aledhari

Dissertations

In the age of Big Genomics Data, institutes such as the National Human Genome Research Institute (NHGRI),1000-Genomes project, and the international cancer sequencing consortium are faced with the challenge of sharing large volumes of data between internationallydispersed sample collectors, data analyzers, and researchers, a process that up until now has been plagued by unreliable transfers and slow connection speeds. These occur due to the inherent throughput bottlenecks of traditional transfer technologies. One suggested solution is using the cloud as an infrastructure to solve the store and analysis challenges. However, the transfer and share of the genomics datasets between biological laboratories …

Interactions Between Amyloid-Beta And Microglial Cells, Lisa Gouwens

Dissertations

Alzheimer’s disease (AD), the most common cause of dementia, is a neurodegenerative condition characterized by loss of memory and intellectual abilities. Intracellular plaques of aggregated amyloid-beta (Ab) protein are a well-known pathology associated with AD. Although symptoms usually appear late in life, the accumulation of Ab begins decades earlier and causes activation of microglia, the brain’s immune cells. The ensuing inflammation contributes significantly to neurodegeneration. Determination of the particular form of Ab that causes the most damage in the brain is one of the major questions in the AD field. My research focused on the interactions of microglia with monomers, …

Mathematical Models For Polymer-Nematic Interactions, Ensela Mema

Dissertations

This dissertation considers a mathematical model that consists of a nematic liquid crystal layer sandwiched between two parallel bounding plates, across which an external field may be applied. Particular attention is paid to the effect of an applied field on the layer as well as the interaction between the liquid crystal molecules and the molecules of the substrate. The system studied may be considered as a simple model of a Liquid Crystal Display (LCD) device, and the results obtained are discussed and interpreted within this context.

The first part of this dissertation considers a study that investigates how the number …

Public Perceptions Of The Functions Of Natural And Engineered Infrastructure In Coastal Hazards Mitigation: The Cases Of Two Communities In The Raritan Bayshore, New Jersey, Jaime D. Ewalt Gray

Dissertations

Emerging United States (U.S.) federal policies call for more comprehensive integration of both engineered and natural infrastructure in mitigating coastal hazards. For such policies to be effectively implemented, the mitigation functions of and relationship between natural infrastructure and engineered infrastructure must be understood and their integrated use accepted by affected actors, especially residents living in at-risk coastal communities. Little is known about public perceptions of the functions of engineered and natural infrastructure in coastal hazard mitigation and the interactions between these two types of infrastructure. This study analyzes perceptions based on semi-structured interviews of 14 residents in Laurence Harbor, Middlesex …

A Conversation Centric Approach To Understanding And Supporting The Coordination Of Social Group-Activities, Richard P. Schuler

Dissertations

Despite the widespread and large variety of communication tools available to us such as, text messaging, Skype, email, twitter, Facebook, instant messaging, GroupMe, WhatsApp, Snapchat, etc., many people still routinely find coordinating activities with our friends to be a very frustrating experience. Everyone, has at least once, encountered the difficulties involved with deciding what to do as a group. Some friends may be busy, others may have already seen the movie that the others want to see, and some do not like Mexican food. It is a challenge everyone has faced and continue to face. This is a result of …

Topics On Multiple Hypotheses Testing And Generalized Linear Model, Yalin Zhu

Dissertations

In applications such as studying drug adverse events (AE) in clinical trials and identifying differentially expressed genes in microarray experiments, the data of the experiments usually consists of frequency counts. In the analysis of such data, researchers often face multiple hypotheses testing based on discrete test statistics. Incorporating this discrete property of the data, several stepwise procedures, which allow to use the CDF of p-values to determine the testing threshold, are proposed for controlling familiwise error rate (FWER). It is shown that the proposed procedures strongly control the FWER and are more powerful than the existing ones for discrete data. …

Roles Of Cosolvents On Protein Stability, Zhaoqian Su

Dissertations

The function of a protein is determined by its three-dimensional structure which emerges from the delicate balance of forces involving atoms of the protein and the solvent. This balance can be perturbed by changing temperature, pressure, pH and by adding organic molecules known as cosolvents to the solution. Despite the wide use of cosolvents to perturb protein structures in the lab and in living systems, their molecular mechanisms are still not well established. Understanding these mechanisms is a problem of substantial interest, with potential application to the design of new drugs to target proteins. In this dissertation, we probe the …

Thermochemistry Of Fluorinated Aldehydes And Corresponding Radicals;Thermochemistry And Kinetics Of Diethyl Ether And Ethyl Oxirane Relative To Reactions Under Atmospheric And Combustion Conditions, Douglas Lee Purnell Jr.

Dissertations

Fundamental thermochemical properties including enthalpies (ΔH°f 298), entropies (S°(T)), heat capacities (Cp(T)), and bond dissociation energies (BDEs) for several common and complex hydrocarbon fuel species are determined using computational chemical methods. ΔH°f 298 values are calculated using isodesmic reactions with the CBS-APNO, CBS-4M, CBS-QB3, G2, G3, G4, Weizmann-1 (W1U) and M06-2X, ωB97X, B3-LYP with basis set 6-31G+ (d,p) and 6-31G++(d,p) calculation methods. Structures, moments of inertia, vibrational frequencies, and internal rotor potentials are calculated for contributions to entropies and heat capacities. Kinetic rate parameters are calculated for hydrogen abstraction and …

Annotation Of Multimedia Learning Materials For Semantic Search, Sheetal Rajgure

Dissertations

Multimedia is the main source for online learning materials, such as videos, slides and textbooks, and its size is growing with the popularity of online programs offered by Universities and Massive Open Online Courses (MOOCs). The increasing amount of multimedia learning resources available online makes it very challenging to browse through the materials or find where a specific concept of interest is covered. To enable semantic search on the lecture materials, their content must be annotated and indexed. Manual annotation of learning materials such as videos is tedious and cannot be envisioned for the growing quantity of online materials. One …

Direct Computations Of Marangoni Driven Flows Using A Volume Of Fluid Method, Ivana Seric

Dissertations

The volume of fluid (VoF) interface tracking methods have been used for simulating a wide range of interfacial flows. An improved accuracy of the surface tension force computation has enabled the VoF method to become widely used for simulating flows driven by the surface tension force. A general methodology for the inclusion of variable surface tension coefficient into a VoF based Navier-Stokes solver is developed. This new numerical model provides a robust and accurate method for computing the surface gradients directly by finding the tangent directions on the interface using height functions. The implementation applies to both temperature and concentration …

Programming Frameworks For Mobile Sensing, Hillol Debnath

Dissertations

The proliferation of smart mobile devices in people’s daily lives is making context-aware computing a reality. A plethora of sensors available in these devices can be utilized to understand users’ context better. Apps can provide more relevant data or services to the user based on improved understanding of user’s context. With the advent of cloud-assisted mobile platforms, apps can also perform collaborative computation over the sensing data collected from a group of users. However, there are still two main issues: (1) A lack of simple and effective personal sensing frameworks: existing frameworks do not provide support for real-time fusing of …

Anodic Nanocatalysts For Formic Acid Fuel Cells: An Electrochemical Study, Tamanna F. Shanta Mcfarland

Dissertations

Direct formic acid fuel cells (DFAFCs) have been reported as a prominent source of alternative green energy and solution to imminent energy crisis for the last two decades. The challenge to commercialize DFAFCs is primarily the utilization of cost effective, high performance and durable anodic catalyst for formic acid oxidation (FAO). Consequently, this dissertation addresses the extensive electrochemical study of a number of nanomaterials towards the potential use as electrocatalysts for FAO. Morphology and elemental analyses of the prepared nanomaterials were obtained using electron microscopy techniques.

After a general introduction and overall review of this dissertation (Chapter I), studies of …

Cellulose Reinforced Thermoplastic Composites By In-Situ Ring-Opening Polymerization, Shahab Kashani Rahimi

Dissertations

Over the past two decades, the increasing concern about the negative environmental impacts of synthetic materials has led to rising interests in utilizing renewable natural resources to develop polymer materials with comparable properties and performance to their synthetic counterparts. One of the major fields of interest is polymer composites where the replacement of synthetic fibers with bio renewable natural fibers is of great potential. However, the processing difficulties, in terms of fiber dispersion and thermal stability have limited the application of cellulosic fibers to polymers with low processing temperatures which are mostly hydrophobic polymers. As a result, the true reinforcing …

Electrogenerated Chemiluminescent Studies Of 9,10-Diphenylanthracene, Rubrene, Tris(2,2'-Bipyridine)Ruthenium(Ii) Species, And Their Derivatives For Sensitive Detection Of Biomolecules, Pradip Bastola

Dissertations

This dissertation explored and investigated the coreactant electrogenerated chemiluminescent (ECL) properties of unmixed and mixed systems of highly efficient ECL emitters, such as 9,10-diphenylanthracene (DPA), rubrene (RUB), and tris(2,2′-bipyridine)ruthenium(II) [(Ru(bpy)₃²⁺)] species as well as their water-soluble derivatives, which can serve as ECL labels for sensitive bioanalysis of single or multiple analytes. The screening of most favorable common ECL coreactants, their concentration effects along with the effect of working electrode materials on ECL behavior, and energy transfer related interactions between ECL emitters were systematically investigated. In addition, a strategy for improvement of ECL signals with the use of …