Digital Commons Network^™

Antifragility: Disorder As The Wind That Energizes The Fire Within Us, Abdulah Bajaba

Doctoral Dissertations

Today’s business world is more complex and uncertain than ever due to the unpredictable interdependencies caused by factors such as technology and globalization; accordingly, stress-inducing job demands have never been more prevalent. In order to cope with such demands, employees need to go beyond resilience and embrace disorder as a tool for growth. In this dissertation, I introduce the concept of antifragility to the workplace as a psychological resource that utilizes disorder to its advantage. In order to efficiently coincide with today’s complexity and uncertainty, an employee has to gain more than lose from disorder, simply put, s/he has to …

Novice Teachers’ Perceptions Of The Most Effective Instructional Leadership Practices, Schbrett Lewis Myers

Doctoral Dissertations

This quantitative study examined novice teachers’ perceptions of their principals’ most effective instructional leadership practices to ensure a positive school climate. Principals’ perceptions were examined to assess their understandings of novice teachers’ needs and whether principals have the knowledge to support novice teachers’ pedagogical needs. Novice teacher experts (n=11) and principals (n=8) participated in a modified Delphi study of three rounds. A three-part instrument, comprised of a survey, Likert scale (Compass Louisiana Leader Performance Evaluation Rubric), and suggestions were used to assess principals’ and novice teachers’ perceptions. Lawshe’s Content Validity Ratio (CVR) measured validity. Novice teacher experts and principals validated …

A Qualitative Study Identifying A School Leadership Model Promoting And Fostering Technology-Enhanced Teaching And Learning, Lisa Flanders-Dick

Doctoral Dissertations

Technology-enhanced teaching and learning (TETL) is the integration of technology into teaching and learning practices to improve the quality of learning outcomes. This is an essential strategy for improving educational quality. School leaders significantly affect the integration of effective TETL in the classroom. The International Society for Technology in Education (ISTE) provides Standards for Leaders that serve as a framework for innovation in education. Situational Leadership Theory contends that one leadership style cannot be applied to all leadership tasks. This study expands upon the current use of SLT to help derive characteristics needed to develop a school leadership model that …

The Effects Of Disorder In Van Der Waals Materials, Jake Riffle

Doctoral Dissertations

Due to their two-dimensional structure and wide range of electronic behaviors, van derWaals materials have garnered a lot of attention for new technological applications. However, much is still unknown about the consequences that impurities and disorder have on the performance of many new van der Waals materials. In my research I use scanning tunneling microscopy(STM) and electronic transport techniques to study the different types of disorder in three common van der Waals materials: tantalum disulfide (TaS2), black phosphorus (BP), and two-dimensional graphene. In TaS2 I show a sample preparation dependence on the surface state of the bulk crystal and emphasize …

I. Incorporation Of Functionality At The Β-Position For The Zinc-Mediated Chain Extension Reaction Ii. Formal Synthesis Of Heliotridane And Pseudoheliotridane Through A Zinc-Mediated Chain Extension Approach, Nicholas Alexander Arnista

Doctoral Dissertations

The zinc-mediated chain extension reaction has been previously developed to incorporate alkyl or aryl substituents at the β position of the chain-extended product. The incorporation of heteroatom functionality at the β position of the chain-extended product was demonstrated through the use of a functionalized zinc carbenoid species. Silyl ether-functionalized geminal diiodides were used in the chain extension reaction with low to modest yields. Optimization of the chain extension reaction was performed by modification of solvent, reaction temperature, reaction time, and addition of diiodide. The chain extension reaction was performed on several different substrates, such as β-keto esters, β-keto amides, and …

Climatic And Biotic Interactions In Terrestrial Systems During Ancient Warm Periods, Sarah Johnson Widlansky

Doctoral Dissertations

This work focuses on two terrestrial sedimentary records in the western United States that record the ancient greenhouse interval of the early Paleogene (~ 55 million years ago). The Paleogene, and past warm periods in general, offer a means of understanding potential biotic and environmental response to future warming scenarios. Part One of this dissertation establishes a new stable isotope climate record from the Bighorn Basin of Wyoming that is tied to an extensive fossil mammal assemblage (Chapter 1). This new stable isotope record captures carbon isotope excursions (CIEs) associated with the early Eocene hyperthermals ETM2, H2, and potentially I1 …

Heat Transport By Baroclinic Acoustic Streaming, Jacques Abdul Massih

Doctoral Dissertations

Acoustic streaming refers to time-averaged flows generated by time-periodic sound waves. In classic“Rayleigh streaming”, the mean flow is generated by the interaction of a standing acoustic wave with a solid boundary (e.g., a channel wall). Applications of acoustic streaming include inducing fluid mixing in microfluidic medical devices, improving the efficiency of chemical reactions, and enhancing heat transfer. Recently, Chini et al. [J. Fluid Mech., Vol. 744 (2014)] and Michel & Chini [J. Fluid Mech., Vol. 858 (2019)] demonstrated that strong acoustic streaming flows can be generated in gases subjected to an imposed cross-channel temperature gradient. In contrast with Rayleigh streaming, …

Penalized Regression Splines-Based Tests For Comparing Two Time Series With Unequal Lengths, Mirajul Islam

Doctoral Dissertations

The Spline-based modeling has been an established tool for parametric and nonparametricregression modeling because of its continuous progress on theoretical and computational fronts over the last three decades. This thesis explores the idea of penalized spline modeling and goodness of fit testing in the context of time series testing in the frequency domain approach. The comparison of different time series is an important topic in statistical data analysis and has various applications in scientific research. One approach to identifying similarities or dissimilarities between two stationary processes is to compare the spectral densities of both time series. This thesis examines whether …

N-Heterocyclic Carbene Functionalized Single-Chain Nanopartcles Aqueous Catalytic Platform, Xianggeng Liu

Doctoral Dissertations

Single-chain nanoparticles (SCNP) are a class of intramolecular cross-linked polymericnanoparticles with a variety of applications including catalysis, sensors, nanomedicine, and nanoreactors. Such nanoparticles are synthesized by folding or collapsing single polymer molecules. By implementing a single-chain folding technique, the single-chain nanoparticles with uniform degrees of cross-linking are synthesized by parent polymer chains with similar chain lengths and polymer microstructure. Polymer chains that are synthesized by various controlled polymerization techniques can be converted to SCNPs through a variety of covalent chemistry and supramolecular interactions. Based on the expected cross-linking chemistry, related functional groups can be installed either during monomer synthesis or …

Sociocultural Dimensions Of Environmental Stewardship In New Hampshire: Implications For Adult Environmental Education, Ian Patrick Hanley

Doctoral Dissertations

The overarching aim of this dissertation is to expand evidence and theory of adult identity processes in the context of environmental stewardship, as well as to provide knowledge and recommendations to environmental stewardship and environmental education professionals. The intent is to better understand variation in how adult environmental stewards report on and value their own engagement with both sociocultural and natural systems. This line of inquiry stems from the fundamental claim that environmental stewardship activity is not singularly based on environmental content knowledge but is also related to forms of cultural and social engagement. By recognizing these dual aspects of …

Socioscientific Decision-Making In Undergraduate Students: The Role Of Personal Epistemology, Jordan Dana Bader

Doctoral Dissertations

Socioscientific issues (SSIs), or controversial scientific issues with social implications, influence members of society regardless of demographic. SSIs are contentious and ill-structured, meaning they do not have a definitive answer. To properly equip students with the tools needed to handle SSIs, undergraduate science curricula emphasize scientific literacy skills, such as the ability to search, recognize, and utilize accurate scientific information when handling science driven issues outside of the classroom. However, SSIs are influenced by political, social, economic, and cultural stakeholders. Therefore, students may not be basing their SSI decisions off of accurate information. An individual’s personal epistemology is known to …

Water Droplet Machining And Droplet Impact Mechanics, Benjamin Mitchell

Doctoral Dissertations

Water Droplet Machining (WDM) is a new manufacturing process, which uses a series of high-velocity, pure-water droplets to impact and erode metal workpieces, for the purpose of through-cutting, milling and surface profiling. The process is conducted within a vacuum environment to suppress aerodynamic drag and atomization of the waterjet and droplet stream. This preserves droplet momentum and allows for a more efficient transfer of energy between the water and workpiece, than in standard atmospheric pressure. As a new manufacturing technique, parameter-specific details and characteristics of this process are absent from the scientific literature. Furthermore, the erosion mechanisms involved in droplet-solid …

Structural And Biochemical Characterization Of The Allosteric Regulation Of Photoreceptor Phosphodiesterase, Richa Garg

Doctoral Dissertations

ABSTRACT

Structural and Biochemical Characterization of the Allosteric Regulation of Photoreceptor Phosphodiesteraseby Richa Garg

The photoreceptor phosphodiesterase (PDE6) is the central enzyme in the visual signaling pathway. Cone PDE6 is a homodimer consisting of a catalytic dimer (Pα’α’) and two cone-specific inhibitory γ-subunits (Pγ’). Rod PDE6 is a heterotetramer which consists of a catalytic dimer (Pαβ) with two rod-specific Pγ subunits. The PDE6 differs from other phosphodiesterases (PDEs), in its unique inhibitory Pγ subunit and its activation by α-subunit of the G-protein (Gα). Regulation of PDE6 activity is a key factor in determining the electric response upon light stimulations. PDE6 …

Melanin Pigments As Antibacterial Agents, Tahmineh Rahmani Eliato

Doctoral Dissertations

In this dissertation I investigated the structural properties of melanin biopigment from different sources as an antibacterial and endotoxin bonding agent. I extracted melanin from Equus ferus hair with acid hydrolysis (termed EquusMel) and characterized it by microscopic and spectroscopic techniques. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) revealed that EquusMel is mainly elliptical in shape with a mesoporous and layered structure within the individual particles. Wide-angle (WAXS) and small-angle (SAXS) X-ray scattering measurements demonstrated a semicrystalline multilayered structure with order spacing of 45.2 Å. Pore size distribution determined by the Barrett–Joyner–Halenda (BJH) method showed primary pores within …

A Memory-Based Approach To Multiple Document Comprehension, Allison Sonia-Bolduc

Doctoral Dissertations

Multiple document (MD) comprehension is of growing interest in the Internet age, in which reading material is readily available from multiple sources. However, comprehension research has typically been dominated by studies investigating single documents (Bråten et al., 2019; McNamara & Magliano, 2009). This dissertation applies a memory-based approach traditionally used in research on single document comprehension to a MD context, with the goal of understanding the on-line processing and integration of information from multiple documents. Expository-style passages were created in which the first half contained information that was either consistent or inconsistent with a target sentence in the second half. …

Compound, Elemental, And Isotopic Perspectives On Mercury Mobilization During Thaw In A Discontinuous Permafrost Zone, Maria F. Fahnestock

Doctoral Dissertations

Arctic ecosystems are a major global sink for both carbon (C) and mercury (Hg), both of which are influenced by anthropogenic activities. The accelerated climate-change-induced warming documented in the Arctic has led to permafrost thaw resulting in landscape evolution from hydrological, vegetation and microbial shifts. All of these resulting changes have the potential to influence how Hg, a toxic contaminant, is mobilized and re-cycled in this ecosystem. In this body of work, I investigate patterns of Hg speciation, elemental abundances, and stable isotopes across the thaw gradient in a permafrost peatland and interconnected freshwater lakes in Abisko, Sweden to assess …

Query-Specific Subtopic Clustering In Response To Broad Queries, Sumanta Kashyapi

Doctoral Dissertations

Information Retrieval (IR) refers to obtaining valuable and relevant information from various sources in response to a specific information need. For the textual domain, the most common form of information sources is a collection of textual documents or text corpus. Depending on the scope of the information need, also referred to as the query, the relevant information can span a wide range of topical themes. Hence, the relevant information may often be scattered through multiple documents in the corpus, and each satisfies the information need to varying degrees. Traditional IR systems present the relevant set of documents in the form …

Interventions Towards Sustainable Watershed Management As Demonstrated By Hydrologic Simulation, Shan Zuidema

Doctoral Dissertations

Increasing population, changing climate, and on-going legacies of environmental mismanagement motivate our need for deeper understanding of the process and limits of adaptation towards sustainable management of water resources. Movements towards open-science and transdisciplinary research have enabled deeper assessments of the co-evolution of human society and changing landscapes. Policies and decisions enabling environmental restoration or sustainable resource use have been actively pursued for decades. The social barriers that prevent adaptations to succeed are deep and entrenched, but equally important are the physical barriers. Successful adaptations in water resource management need to explicitly consider the joint interactions of intervention magnitude, or …

Evaluation Of Curing Effects On Cold In-Place Recycled (Cir) Materials, Chibuike Ogbo

Doctoral Dissertations

Most cold In-place recycled (CIR) construction use asphalt emulsion or foamed asphalt with or without active fillers as a stabilizing agent. To ensure the CIR layer gains appreciable stiffness and strength to support traffic, the stabilizing agents have to undergo curing (to gradually develop strength). If traffic is allowed on the CIR layer before sufficient strength and structural capacity is gained, premature damage will occur. Lack of a fast and reliable procedure to determine the extent of in-situ curing significantly increases the risk of such damage. Present construction specifications rely on empirically based time recommendations to ensure sufficient curing. Current …

Rational Design And Synthesis Of Antifreeze-Protein Inspired Polymers For Anti-Icing Coatings And Cryopreservation Applications, Mohamamd Mousazadehkasin

Doctoral Dissertations

Certain organisms living in cold regions have adapted different strategies to survive in harshly cold temperatures. Some of them use freeze-avoiding strategies in which they can prevent freezing by controlling the concentration of sugars (et. sucrose, trehalose) or polyols (glycerol), regulation of the ice nucleator, and dehydration. Other organisms have adapted to this extremely cold condition by producing antifreeze (gly)proteins (AF(G)Ps) which exhibit ice recrystallization inhibition (IRI), thermal hysteresis activity (THA), and dynamic ice crystal shaping. These proteins discovered in Antarctic fish in 1960 for the first time have been reported in bacteria, fungi, insects, and plants. AF(G)Ps and their …

The Active Tail In The Mms Era: An Ion Perspective, Anthony Jason Rogers

Doctoral Dissertations

The Earth's magnetic field has a complex and dynamic relationship with the greater solar system. The solar wind and interplanetary magnetic field extend the influence of the Sun's atmosphere to the orbit of Earth and well beyond, carrying charged particles in a constant stream of varying density and velocity. These solar influences carry energy which interacts with every object they encounter, including the Earth and its magnetic field.

The primary mechanism for the energetic interaction and exchange of energy between the Earth's magnetic field and the solar wind is called Magnetic Reconnection, a process by which two opposing magnetic fields …

Bridging The Career Transitional Gap Between Field Experts And University Instructors: Factors Affecting New Faculty Members’ Feelings Of Preparedness Of Teaching In Higher Education, Amy Hogan

Doctoral Dissertations

This quantitative study determined factors affecting preparedness for higher education teachers who have transitioned from their expert-level fieldwork into academia. It is a common practice for new university faculty members to be recruited from their areas of expertise as clinicians and practitioners (Eret et al., 2018; Freeman & DiRamio, 2016; Savage & Pollard, 2016). Transitioning from a chosen field into a novice teacher can carry varying weights depending on university teaching appointments. Having the qualities of an experienced practitioner is highly desired to fill faculty roles, but the expertise as a practitioner does not necessarily develop the teaching skills (Eret …

Effect Of Endogenous And Exogenous Agents In Platelet Adhesion, Sowjanya Dokku

Doctoral Dissertations

Platelet adhesion is regulated by both activators, such as adenosine diphosphate, and inhibitors, such as nitric oxide (NO). Both agents are released on platelet activation, so that platelets initiate both positive and negative feedback systems. In vivo platelet adhesion models generally consider the effects of platelet activators and inhibitors separately. The goal of this study was to create an environment in which interplay between positive and negative feedback can be observed together and in which the roles of endogenous and exogenous platelet activators are distinguishable. The results are expected to be applicable to the design of stents, which are susceptible …

Epileptogenic Focus Localization By Novel Analysis Of Lntracranial Eeg In The Frequency Domain, Omar Ali Alamoudi

Doctoral Dissertations

The gold standard for localization of the epileptogenic zone (EZ) continues to be the visual inspection of electrographic changes during seizure onset by experienced EEG readers. Development of an epileptogenic focus localization tool that can accurately delineate the EZ from the analysis of interictal (seizure-free) period is still an open question of great significance for improved diagnosis (e.g., presurgical evaluation) and treatment (e.g., surgical) outcome. We developed an EZ localization algorithm (LA) based on novel analysis of the power in a narrow frequency band of the recorded signals from the brain, that is, using a simple univariate periodogram-type power measure, …

Parallel Computing Framework And Gpu Performance Modeling, Wenjing Xu

Doctoral Dissertations

During the past decades, High-Performance Computing (HPC) has been widely used in various industries. In particular, the exponential growth of GPU (graphics processing unit) is a key technology that has helped promoting the development of artificial intelligence in real-world use cases. When we use GPU to accelerate parallel applications, its programmability, resource management, and scheduling are non-trivial jobs to obtain optimized performance. Therefore, how to effectively exploit GPU resources and improve program performance has been a hot research topic recently.

Benchmark does not always provide a good picture of the performance and details of the parallel applications. The various kinds …

Security-Related Technostress Trifecta On Employees’ Security Counterproductive Behaviors, Bao Duong

Doctoral Dissertations

Information security technology has become more important in preventing and protecting organizational digital assets, and employees are often considered the last line of defense. However, employees at all levels have to face and deal with the complexity, overload, and uncertainty of information security technology in their jobs every day. Although information security technology could benefit the organization and individual employees as it is critical to building and strengthening protection mechanisms for organizational digital assets and employees’ data, it could also negatively affect employees’ emotions and work accomplishments.

This study examines the two effects of psychological techno-stress responses (security-techno distress and …

Distributed Fiber-Optic Temperature Sensors For Applications In The Steel Industry, Muhammad Roman

Doctoral Dissertations

"Steelmaking facilities require continuous temperature measurements throughout the manufacturing process to ensure consistent product quality and high productivity. Motivated by the limitations of conventional temperature sensors, distributed fiber-optic sensors (DFOS) were developed and deployed for various applications in the steel industry. Fiber-optic sensors offer various advantages over conventional sensors, such as the miniaturized size of the optical fiber, immunity to electromagnetic interferences, capability for multiplexing and distributed sensing, and the ability to withstand harsh environments.

Firstly, high-resolution Rayleigh backscattering based DFOS were demonstrated as potential solutions for temperature measurements in steelmaking processes by performing experimental simulations. Additionally, aluminum casting experiments …

Bioinspired Phenolic Compounds For Biomedical Devices, Zhen Tian

Doctoral Dissertations

In this dissertation, I investigated the metal-chelating ability and redox activity of phenoliccompounds from different sources for biomedical applications. Eumelanins are the naturally occurring biopigments that can be found in skin, hair, eyes, or brain of many living organisms. Various functional groups in eumelanin permit it to binding metal ions via comproportionation reaction. I investigated the structure-property relationship of eumelanin by X-ray scattering and electrochemical techniques. I reported the mesoscale structure of eumelanins and its impact on the charge transport. X-ray scattering suggests that eumelanin pigments exhibit the semi-crystalline structure with ordered d-spacings. These unique mesoscale structures further influence the …

The Effects Of Curriculum-Integrated Explicit Learning Strategy Instruction On Reading Comprehension For English As A Second Language (Esl) Learners At The Community College, Sylvia Chaiyeon Lee

Doctoral Dissertations

Reading skills are critical for English as a Second Language (ESL) students in higher education to achieve academic success. However, effective ways to promote student success in ESL reading courses are under-researched. Identifying factors that may enhance the quality and outcomes of learning ESL reading is essential. One such factor identified by previous research is learning strategies. Explicit instruction on learning strategies may lessen the problems and difficulties that international students encounter. Explicit strategy instruction can bring a systematic scaffold into a language learning process, guide students toward proper learning strategies, and promote constructive cognitive processing during learning.

This study …

Genocide In East Turkestan: Exploring The Perspectives Of Uyghurs In The Diaspora And Their Resistance To Chinese State Violence, Lina Semyonovna Lenberg

Doctoral Dissertations

The Uyghurs of Xinjiang Uyghur Autonomous Region—or East Turkestan, as many Uyghurs call their Indigenous homeland in northwestern China, are a Muslim ethnic group whose culture and identity are being systematically destroyed by the Chinese state. Since 2016, Uyghurs have been imprisoned in China’s “re-education camps” on an enormous scale, numbering up to three million. Uyghurs have experienced discrimination and marginalization in China for many years, yet relatively little attention has been given to what has now become a set of gross human rights violations amounting to crimes against humanity and genocide. The purpose of this study was twofold. First, …