Digital Commons Network^™

Precambrian Evolution Of The Salalah Crystalline Basement From Structural Analysis And 40Ar/39Ar Geochronology, Hanadi Abulateef Al-Doukhi

Doctoral Dissertations

"The Salalah Crystalline Basement (SCB) is the largest Precambrian exposure in Oman located on the southern margin of the Arabian Plate at the Arabian Sea shore. This work used remote sensing, detailed structural analysis and the analysis of ten samples using ⁴⁰Ar/³⁹Ar age dating to establish the Precambrian evolution of the SCB by focusing on its central and southwestern parts. This work found that the SCB evolved through four deformational events that shaped its final architecture: (1) Folding and thrusting event that resulted in the emplacement of the Sadh complex atop the Juffa complex. This event resulted …

The Role Of Potential Antioxidant In Medicinal Drug-Induced Oxidative Stress, Weili Fan

Doctoral Dissertations

"Most medicinal drugs have adverse effects. Among the most commonly used of these drugs are several types, known as "oxidative drugs". These are believed to cause adverse effects that induce oxidative stress, an imbalance of generation and detoxification of reactive oxygen species. So it is a reasonable assumption that the antioxidant might alleviate the toxicity induced by these drugs. N-acetylcysteine (NAC), a synthetic thiol, is a free-radical scavenger and a precursor of glutathione (the main endogenous antioxidant). However, the negative charge of NAC at physiological pH limits its bioavailability. N-acetylcysteineamide (NACA) is neutral in charge and is believed to have …

Investigating And Modeling Tar-Mats In A Kuwaiti Carbonate Reservoir And Their Role In Understanding Oil Reserves And Recovery Economics, Abdullah Owidah Almansour

Doctoral Dissertations

"Tar-mat columns exist in many carbonate reservoirs in the Middle East. Historically, tar-mats have been thought to impede primary oil extraction, thus necessitating further improved oil recovery (IOR) technology applications. However, this research considers tar-mats as potential sources for unlocking extremely difficult crude oil, less than 5 ⁰API. The main objective of the study was to understand the qualitative physical and chemical properties of extremely viscous tar-mat oil and the quantitative potential of tar-mats to extract difficult oil.

The physical and chemical geneses of the tar-mat oil were analyzed utilizing several experimental geochemical techniques, including rock evaluation pyrolysis, liquid extracts …

Radio Frequency Interference (Rfi) Modeling Of Complex Modules In Mobile Devices And System-Level Modeling For Transient Esd Simulation, Tianqi Li

Doctoral Dissertations

"The thesis is composed of three papers, which cover the systematic modeling of radio-frequency-interference (RFI) and electro-static-discharge (ESD) problems happened in mobile devices.

In the first paper, an averaging technique is developed, for phase resolved scanning over random fields generated by multiple uncorrelated stochastic sources. This method can separate the field contribution of each noise source and resulting field patterns as if the out-of-interest sources were turned off. The scanned data can be used for emission source localization, far-field pattern calculation and Huygens's box modeling.

In the second paper, using Huygens's Equivalent Theorem a systematic approach for the modeling of …

The Effects Of Explicit Listening Strategy Instruction On The Listening Comprehension Of English As Second Language (Esl) Community College Students, Yi Guan

Doctoral Dissertations

This mixed methods study explored the effects of explicit listening strategy instruction on the beginning-level ESL learner's listening comprehension at a community college in Northern California. Most previous studies measured the effectiveness of listening strategy instruction by comparing students' test scores, but little research explored the students' listening strategy development and their perceptions of the strategy instruction. Furthermore, no prior research exists on the effects of listening strategy instruction among community college students.

The researcher employed the concurrent triangulation approach, collecting and analyzing both quantitative and qualitative data simultaneously. Data sources included interviews, a listening test, background surveys, and classroom …

Bay Area Student Involvement In The Environmental And Food Justice Movements: A Narrative Of Motivations, Experiences, And Community Impact, Laura E. Solof

Doctoral Dissertations

Many California public school students lack exposure to any formal, academic curriculum that emphasizes environmental awareness and activism. This may result in a population of adults who believe they know more about the environment than they actually do, lack the skills to compete in an expanding green job market, lack creativity and the ability to problem-solve, suffer from obesity, depression, anxiety, and attention disorders, and unknowingly contribute to the ever-increasing problems of air and water pollution, land and habitat destruction, and other environmental injustices. Community organizations and university programs are filling this much-needed gap in student environmental education, as they …

An Investigation Of Special Education Teachers' Perceptions Of The Effectiveness Of A Systematic 7-Step Virtual Worlds Teacher Training Workshop For Increasing Social Skills, Natalie Christina Nussli

Doctoral Dissertations

This study describes how a systematic 7-Step Virtual Worlds Teacher Training Workshop promoting inquiry, experiential learning, and sociocultural theory guided the enculturation of 18 special education teachers into three-dimensional virtual worlds. The main purpose was to enable these teachers to make informed decisions about the usability of virtual worlds for students with social skills challenges, such as students with autism. Mixed-methods data analysis and triangulation were based on the analysis of seven instruments. Six of the seven steps of the intervention received high ratings indicating its viability for teachers' professional development opportunities

Teachers Adapting Common Core Informational-Text Writing Instruction For Students With Mild To Moderate Disabilities, Diana Hawley

Doctoral Dissertations

With the adoption of the Common Core State Standards, students must now become skilled at using different types of writing to help them critique text and process information. They also are required to write informational text. Informational-text writing is challenging for students with mild to moderate disabilities, including students with language-learning disabilities, who often struggle with aspects of language necessary for learning to read and write. These students show striking challenges with productivity, grammatical and spelling accuracy, and sentence complexity, with differences in performance by genre (Koutsoftas & Gray, 2012; Scott & Windsor, 2000; Troia, Lin, Cohen, & Monroe, 2011). …

Advanced Earth Observation For Humanitarian Information Extraction, Chandi Witharana

Doctoral Dissertations

Advanced Earth observation (EO) is increasingly recognized as an indispensible tool to support rigorous and robust decision making in crisis management. In crisis scenarios, EO data need to be streamed through time-critical workflows for delivering reliable and effective information to civil protection authorities. In this context, the over arching goal of this research is to closely examine the integral segments of routing EO-based rapid mapping workflows to understand prevailing shortfalls and to devise novel approaches to catalyze conditioned geoinformation delivery to cater increasing user demand. This study envisions three interconnected objectives, which are primarily fuelled by very high spatial resolution …

Engineering Analysis Of Minimally Invasive Mitral Valve Repair, Thuy Pham

Doctoral Dissertations

Surgical treatment for severe functional MR often involves mitral annuloplasty to improve leaflet apposition and ultimately downsize the dilated mitral valve. However, the high rate of operative mortalities of up to 6 ~12% have limited the more expanded use of this procedure. Recently, minimally invasive percutaneous transvenous mitral annuloplasty (PTMA) approaches using entirely catheter-based methods have been developed to reduce procedural morbidity and mortality. One of the approaches is to utilize the proximal location of the coronary sinus (CS) to the mitral annulus (MA) to percutaneously deploy a PTMA device within CS vessel. When the device contracts, it indirectly reshapes …

Thermodynamics Of A Rotating Detonation Engine, Craig A. Nordeen

Doctoral Dissertations

A practical thermodynamic cycle model of a rotating detonation engine (RDE) is developed for the purpose of predicting performance and understanding flow field behavior. The cycle model is based on a heuristic analysis of a RDE numerical simulation. The model is compared to the simulation and to laboratory experiment with good results.

The RDE constrains a detonation wave to rotate inside a cylindrical annulus, has no moving parts and requires a single ignition sequence. Thrust is produced continuously and at high frequency. The simplicity of the RDE offers the possibility of a practical detonation engine with efficiencies that exceed conventional …

Gifted Students’ Perceptions Of The Influence Of A Gifted Middle School Program On The Development Of Their Achievement Orientation, Micah N. Bruce-Davis

Doctoral Dissertations

In social cognitive theory, the development of self-perceptions is a complex process involving personality and environment. While educators may have little influence on students’ personality traits, they can attend to environmental components that support the development of positive self-perceptions. Developing positive self-perceptions has been identified as a key precursor to developing achievement behaviors. Achievement orientations are viewed as positive learning orientations with students focused on learning new material in comparison to a standard of excellence. Motivational variables such as achievement goals, self-efficacy beliefs, and intelligence beliefs have been connected to the development of an achievement orientation. These motivational variables have …

Biological Activities Of Influenza Virus Subpopulations: Characterization Of Infectious, Interferon-Inducing And Interferon Induction-Suppressing Particles, Christopher P. Malinoski

Doctoral Dissertations

This dissertation explores the complex nature of the influenza virus quasispecies. Influenza populations exist as a mixture of mostly replication-deficient biologically-active particles. These particles are measured and quantified based upon the phenotype they manifest upon entry into the host. Three subpopulations are characterized: infectious, interferon-inducing, and interferon induction-suppressing particles.

It has been observed that only 5 out of every 100 particles of influenza are infectious. A novel biological assay was developed and, for the first time, directly demonstrated that infectious particles are the progenitors of all other virus particles. From the disparity observed to exist between the numbers of physical …

A Two-Step Estimation Procedure And A Goodness-Of-Fit Test For Spatial Extremes Models, Hongwei Shang

Doctoral Dissertations

Parametric max-stable processes are increasingly used to model spatial extremes. Since the dependence structure is specified for block maxima, the data used for inference are block maxima from all sites. To improve the estimation efficiency, we propose a two-step approach with composite likelihood that utilizes site-wise daily records in addition to block maxima. Besides the parameter estimation, there is no formal model checking and diagnosis method for spatial extremes modeling yet. Model diagnosis in practice has been informal and mostly based on visual checking tools such as residual plot and quantile-quantile plot. We proposed a goodness-of-fit test for max-stable processes …

Engineered Osmosis For Sustainable Water And Energy: Novel Nanofiber-Supported Thin-Film Composite Membrane Design & Updated Flux Model Proposal, Ngoc Thi Nhu Bui

Doctoral Dissertations

Engineered osmosis (EO) is a state-of-the-art technology which harnesses the natural phenomenon of osmosis to address global issues related to water and energy. In this process, an osmotic pressure drives water across a semi-permeable membrane from a dilute feed solution to a concentrated draw solution. EO has the potential to sustainably produce fresh water at low energy cost, generate electricity and recover high-value dissolved solids. However, EO has not progressed beyond conceptualization and lab scale studies due to obstacles in membrane design, draw solution recovery, system integration, scale-up, and definitive process economics. This study focuses on addressing the primary obstacle …

Localization And Dynamics Of Myosin Vb In Mammalian Cells, Eun-Ji Kim

Doctoral Dissertations

The myosin superfamily is a large and diverse family of proteins that are capable of binding to actin filaments and generating mechanical forces by hydrolyzing ATP. Myosins perform a diverse set of functions in cell, including endocytosis, exocytosis, movement of pigment granules or mRNA, and cell motility. More specifically, Class-V myosins are a group of barbed-end directed motors that have been implicated in organelle transport. For example, in vitro motility assays suggest that myosin Va is a processive motor with a step size of 36 nm and moves at the speed of 0.6 µm/sec, which is consistent with a functional …

An Integrated Plasma Spectroscopic And Capacitive Sensing Platform For Water Quality Diagnostics, John William Sweeney

Doctoral Dissertations

Even in modern times, the consumption of polluted water continues to inflict tremendous suffering on millions of people worldwide that is largely preventable with adequate sanitation practices, routine water quality diagnostics, and treatment. However, conventional water quality monitoring practices remain a time consuming endeavor, where water samples collected on-site are transported to off-site laboratories for evaluation with laboratory-scale chemical analysis devices. While considerable efforts have been made to miniaturize these devices for in-field use, many of the devices reported in the literature provide an incomplete assessment of a water contaminant's environmental impact by focusing on identifying its chemical composition and …

Measurement Of [Special Characters Omitted] (Pp[Special Characters Omitted]Tt) In The[Special Characters Omitted]+ Jets Channel Using 4.7 Fb-1 Of Data From The Atlas Experiment Of The Large Hadron Collider, Anirvan Sircar

Doctoral Dissertations

The top quark is the heaviest of the known elementary particles in the Standard Model. Top quark decay can result into various final states; therefore, careful study of its production rate and other properties is very important for particle physics. With the shutdown of the Tevatron, The Large Hadron Collider (LHC) is the only facility currently capable of studying top quark properties. The data obtained by proton-proton collisions in the LHC is recorded by two general purpose detectors, ATLAS and CMS. The results in the dissertation are from the ATLAS detector. A new measurement is reported of &sgr;(pp [special …

Modeling And Control Of Nanoparticle Bloodstream Concentration For Cancer Therapies, Scarlett S. Bracey

Doctoral Dissertations

Currently, the most commonly used treatments for cancerous tumors (chemotherapy, radiation, etc.) have almost no method of monitoring the administration of the treatment for adverse effects in real time. Without any real time feedback or control, treatment becomes a "guess and check" method with no way of predicting the effects of the drugs based on the actual bioavailability to the patient's body. One particular drug may be effective for one patient, yet provide no benefit to another. Doctors and scientists do not routinely attempt to quantifiably explain this discrepancy. In this work, mathematical modeling and analysis techniques are joined together …

Multi-Segment Multi-Criteria Approach For Selection Of Trenchless Construction Methods, Ashikul Islam

Doctoral Dissertations

The research work presented in this thesis has two broad objectives as well as five individual goals. The first objective is to search and determine the minimum cost and corresponding goodness-of-fit by using a different combination of methods that are capable of resolving the problem that exists in multiple segments. This approach can account for variations in unit price and the cost of the design and the inspection associated with multiple methods. The second objective is to calculate the minimum risk for the preferred solution set. The five individual goals are 1) reduction in total cost, 2) application of Genetic …

Positive Hysteresis, Negative Hysteresis, And Oscillations In Visual Perception, Dobromir Dotov

Doctoral Dissertations

The present work addresses a particular problem that humans and other animals need to deal with while making their way through their environments. The environment always affords much more possibilities for action than one could engage in. How does an animal become attuned to one property of the environment and then switch to another one when the circumstances begin to change? What happens when one forces a human participant in an environment as much deprived of possibilities for action as could be possible? The conceptual and mathematical tools of dynamical systems theory and synergetics allow a good expression of the …

A Mechanochemical Study Into The Growth And Shape Maintenance Of Rod-Shaped Bacteria, Akeisha Belgrave

Doctoral Dissertations

Rod-shaped bacteria grow in length without changing their width [1, 2]. A major feature of bacterial cell growth is the remodeling of the cell wall, the primary structure giving the bacterium its shape and structural integrity. In many rod-shaped bacteria, the process by which the cell wall gets larger as the cell grows involves severing bonds that link the existing cell wall material together in order to insert and bind new material. Coordination between severing and insertion is likely necessary in order to prevent the cell wall from rupturing due to the large pressure difference between the inside and outside …

Reliable Integrated Circuits Design And Test At Sub-45nm Technologies, Jifeng Chen

Doctoral Dissertations

The rapid scaling of CMOS technology into the 45nm feature node or below enables the design of higher performance chips through the construction of complex and powerful circuitry. Under area and power constraints similar to those of the past, circuit performance can raise to multi-GHz. The major impulse is that current design can provide an abundance of functionalities with a compacted layout of millions of transistors in a small chip area. However, shrinking transistor dimensions and highly condensed design layout inevitably raise reliability issues including a notable impact on performance, e-specially aging effects and process variations. The timing uncertainties introduced …

Scan Statistics For Normal Data, Xiao Wang

Doctoral Dissertations

In this dissertation we derive accurate approximations and inequalities for the distribution of fixed window scan statistics for observations from a continuous model. Employing the R algorithms for multivariate normal and t probabilities developed by Genz and Bretz (2009), these approximations and inequalities are applied to normal observations, with mean and variance being both known and unknown. These approximations are utilized to investigate the performance of fixed window scan statistics for detecting a local shift in the process mean for iid normal data. Both one and two dimensional scan statistics are investigated. To detect a local change of unknown size …

The Top Lyapunov Exponent Of Symplectic Stochastic Differential Equations: Theory And Numerics, Alex Baldenko

Doctoral Dissertations

We calculate the top Lyapunov exponent for solutions to linear stochastic differ- ential equations with non-commuting drift and diffusion matrices. In particular we consider (1) a class of Rd-valued stochastic differential equations arising in the study of the noisy harmonic oscillator (2) Sp(2, R)-valued stochastic differential equations are considered. Additionally, numerical bounds are provided and simulation techniques are discussed with an example.

Social And Linguistic Factors In The Development Of Children With Autism, Emma C. Kelty-Stephen

Doctoral Dissertations

There is an ongoing debate in the literature over the main source of information that children use when acquiring and developing language. Theories either support a computational linguistic perspective – in which children are thought to use aspects of language itself and their ability to perceive patterns to acquire language – or a social perspective, in which children are thought to use their ability to jointly attend with communication partners in order to acquire language. It is difficult to tease apart these sources of information in typically-developing children, but children with autism spectrum disorders have difficulty with both joint attention …

Multiple Testing Under Dependence With Approximate Posterior Likelihood And Related Topics, Sairam D. Rayaprolu

Doctoral Dissertations

This dissertation studies large-scale multiple testing which plays an important role in many areas of modern science and technology, such as biomedical imaging and genomic data processing. It has long been recognized that statistical dependence in data poses a significant challenge to large-scale multiple testing. Failure to take the dependence into account can result in severe drop in performance of multiple testing. In particular, the detection power of large-scale multiple tests is known to suffer under dependence when the False Discovery Proportion must be controlled. However, it often happens that the dependence structure is unknown and only a single, albeit …

Probabilistic And Dynamical Models Of Belief Update: Effects Of Experimentally Induced Implicit Bias, Stephanie Petrusz

Doctoral Dissertations

Organisms undertake actions on the basis of perceptions. Perceptions serve as the basis for what an agent takes to be the case; that is, for the agent’s beliefs. However, the idea of belief is freighted with notions of fallibility and subjectivity, since belief is often considered insofar as it is distinct from knowledge. Here, an attempt is made to link belief more closely with perception and action. This linkage is shown by considering the role belief plays in determining behavior, which is distinct from the role belief plays in language-based philosophical accounts of content and intention. These two notions …

Topological And Isotopic Equivalence With Applications To Visualization, Ji Li

Doctoral Dissertations

There is contemporary interest to preserve appropriate topological characteristics during geometric modeling. Here we focus upon topological equivalence (by home- omorphism) and isotopic equivalence (by ambient isotopy). Homeomorphism is an equivalence relation used for static images, while ambient isotopy requires a homeomorphism at each value of the time parameter, which is particularly applicable for time varying models. We provide sufficient conditions that guarantee these equivalences for geometric approximations of Bezier curves, as one of the fundamental computational representations. We also present further generalization beyond any curve approximation algorithm to establish broad criteria for a sequence of piecewise linear curves to …

Multiple Crossing Fixed-Size Sequential Confidence Regions For The Mean Vector And Regression Parametes Under Multivariate Normality, Sankha V. Muthu Poruthotage

Doctoral Dissertations

This dissertation introduces a novel sequential sampling methodology. The strategy for termination associated with this methodology is called multiple crossing stopping rule. Properties of the multiple crossing stopping rule are illustrated analytically as well as by simulations. Comparisons are made between the multiple crossing methodology and some of the existing methodologies, and relative merits are discussed. First, the proposed methodology is discussed in the context of estimating the mean of a normal population with a fixed-width confidence interval. Efficiency, and asymptotic consistency of the multiple crossing methodology is proven. The coverage probabilities are discussed by the means of extensive simulations. …