Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network™

Open Access. Powered by Scholars. Published by Universities.®

2014

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 2191 - 2220 of 135657

Full-Text Articles in Entire DC Network

Synthesis Of Au And Ag Catalysts With Controlled Sizes Of Metal Particles, Eleni A. Kyriakidou Dec 2014

Synthesis Of Au And Ag Catalysts With Controlled Sizes Of Metal Particles, Eleni A. Kyriakidou

Theses and Dissertations

The performance of supported metal catalysts largely depends on the structure and composition of the metal particles and the nature of the support. In order to achieve better control over these parameters, synthetic route based on the use of templating agents has been proposed. Among the different templating agents, poly(amidoamine) (PAMAM) dendrimers have attracted a lot of recent attention as nanoparticle stabilizers. In this thesis, Au/G4OH nanocomposites were synthesized in aqueous solutions and used as precursors for the preparation of SiO2-supported Au nanoparticles. Elemental analysis, UV-Vis, and STEM measurements were used to estimate the extent of the Au-dendrimer interactions and …

Go to article

On The Development Of High Strain Rate Experiments For The Characterization Of Engineering Materials, Silas P. Mallon Dec 2014

On The Development Of High Strain Rate Experiments For The Characterization Of Engineering Materials, Silas P. Mallon

Theses and Dissertations

In order to predict the damage accumulation and failure processes associated with highly dynamic events such as blast loading, shock wave loading, and ballistic impact loading, a commensurate understanding of the fundamental constitutive and fracture behavior of materials subjected to such high rate loading conditions is necessary. In this effort, high strain rate experimental facilities consisting of a shock tube apparatus and a torsional split Hopkinson bar apparatus have been designed, constructed, and subsequently used to investigate the mechanical properties of an array of engineering materials subjected to a variety of dynamic loading conditions. Designs for the experimental equipment utilized …

Go to article

Functionalized Graphitic Nanoreinforcement For Cement Composites, Nima Zohhadi Dec 2014

Functionalized Graphitic Nanoreinforcement For Cement Composites, Nima Zohhadi

Theses and Dissertations

Physical and mechanical properties of graphitic nanomaterials, in particular multiwalled carbon nanotubes (MWCNTs) and graphene nano-platelets (GNPs) make them promising candidates for nanoreinforcement of cement composites. The two key challenges associated with the incorporation of MWCNTs and GNPs are to attain uniform dispersion and interfacial bonding within the composite matrix. The effects of three main-stream dispersion techniques (namely, ultrasonication, acid-etching, and surfactant-coating) on the mechanical properties and microstructure of MWCNT- and GNP-cement composites were experimentally studied. Compressive strength tests and different characterization techniques including dynamic light scattering, Raman spectroscopy, Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, and transmission …

Go to article

Marine Population Connectivity: Range Boundaries And Climate Change, Rhiannon Leigh Rognstad Dec 2014

Marine Population Connectivity: Range Boundaries And Climate Change, Rhiannon Leigh Rognstad

Theses and Dissertations

Population connectivity, particularly in open systems, is an important metric for understanding population-level processes on both ecological and evolutionary timescales. In coastal marine systems, adults are typically sedentary and dispersal occurs primarily during a larval stage when individuals are transported in ocean currents. Because coastal marine populations exist as networks of interconnected subpopulations, variation in the magnitude and extent of population connectivity can have profound effects on population dynamics and species distribution limits. Connectivity is a complex process, affected by a multitude of factors, including adult inputs and physical dispersal, which operate at multiple scales and may interact. This dissertation …

Go to article

Culturally Relevant Teaching: A Case Study On Teaching Statistics In The High School Setting, Lashaune Natae Smith Dec 2014

Culturally Relevant Teaching: A Case Study On Teaching Statistics In The High School Setting, Lashaune Natae Smith

Theses and Dissertations

Public school enrollment is increasing for African American, Hispanic, Asian/Pacific Islander, and American Indian/Alaskan Native students. However, minority and immigrant children tend to perform lower academically than White, middle-class students. Hence, there is a growing need to reform pedagogical practices for underachieving student populations to have improved chances for school success. Culturally relevant teaching is an effective approach to addressing the social and academic needs of minority students. The purpose of this study was to examine culturally relevant teaching in high school statistics classrooms of predominantly African American students. Using a qualitative case study research design, this study examined two …

Go to article

Influence Of Defects In Epitaxial Graphene Towards Material Growth And Device Performances, Shamaita Shithi Shetu Dec 2014

Influence Of Defects In Epitaxial Graphene Towards Material Growth And Device Performances, Shamaita Shithi Shetu

Theses and Dissertations

Since its invention in 2004, Graphene, a two dimensional array of SP2 bonded carbon atoms has received significant interest by the scientific community due to its unique electrical, optical and mechanical properties. A promising route to the synthesis of large-area graphene, is epitaxial graphene formed by sublimation of silicon atoms from Silicon carbide at elevated temperatures (>1200oC). Although the electronic and mechanical properties of graphene with perfect atomic lattice are outstanding, the structural defects, which may appear during graphene growth, can influence the growth mechanism and material properties. However, deviations from perfection, i.e. introducing dopants in semiconductors often considered …

Go to article

Impacts Of Adolescents' Emotional And Behavioral Concerns And Social Skills On Parenting Stress, Marissa Miller Dec 2014

Impacts Of Adolescents' Emotional And Behavioral Concerns And Social Skills On Parenting Stress, Marissa Miller

Theses and Dissertations

Minimal literature has examined predictors of parenting stress for parents of adolescents and what may contribute to the impact of these predictors, particularly those regarding adolescent behavior. The current study sought to evaluate whether adolescents’ internalizing and externalizing behaviors significantly predicted parenting stress and whether adolescent social skills moderated the relationship. Covariates of gender, age, ethnicity, and socioeconomic status were entered first into a multiple regression moderation model and followed by internalizing and externalizing behaviors, social skills, and interaction terms, respectively. The overall model explained 19 percent of the variance in parenting stress. While internalizing behaviors significantly predicted parenting stress, …

Go to article

Fabrication And Characterization Of Novel Electrodes For Solid Oxide Fuel Cell For Efficient Energy Conversion, Yu Chen Dec 2014

Fabrication And Characterization Of Novel Electrodes For Solid Oxide Fuel Cell For Efficient Energy Conversion, Yu Chen

Theses and Dissertations

Solid oxide fuel cells (SOFCs) have been considered as one of the most promising technologies for future energy conversion since they can in principle be operated with fuels ranging from H2 to any hydrocarbon fuel. However, the system cost and coking (when using hydrocarbon as fuel) issues for the state-of-art electrode materials/designs often limit their further application. The objective of this Ph.D dissertation is aiming at overcoming these problems and accelerating SOFC commercialization. One approach to cost reduction is lowering the SOFC operating temperature to below 800 or even 600 oC, so that inexpensive materials can be used and quick …

Go to article

Characterization Of Electrodeposited Copper Foil Surface Roughness For Accurate Conductor Power Loss Modeling, Michael B. Griesi Dec 2014

Characterization Of Electrodeposited Copper Foil Surface Roughness For Accurate Conductor Power Loss Modeling, Michael B. Griesi

Theses and Dissertations

As computer data rates have increased, designers observed that the standard models for estimating the impact of copper foil surface roughness on conductor loss are limited to a few GHz. The more recent snowball model (a “snowball” estimation of the Huray Model) has demonstrated improved conductor loss predictions up to 50 GHz by estimating the necessary parameters using reasonable assumptions about the geometric surface features of electrodeposited copper foil. Since then, the Huray Model has been incorporated into commercial electromagnetic field simulators. However, a standard method of characterizing the electrodeposited copper foil used in high-speed circuits to directly implement the …

Go to article

Climatic Controls On Organic Matter Decomposition In Boreal Peatlands, Michael J. Philben Dec 2014

Climatic Controls On Organic Matter Decomposition In Boreal Peatlands, Michael J. Philben

Theses and Dissertations

Boreal peatlands currently contain 550 Pg C and are located at high latitudes where mean annual temperatures are expected to increase by as much as 7°C by the end of the century. There is growing concern that warming will stimulate decomposition, transforming peatlands from a sink to a source of atmospheric carbon dioxide and accelerating climate change. A primary goal of this dissertation was to evaluate the effect of climate change on organic matter decomposition in peatlands. This was achieved by developing and employing biochemical tracers to indicate the extent of peat decomposition across a range of naturally occurring climatic …

Go to article

Young, Southern Women's Perceptions Of Stem Careers: Examining Science, Technology, Engineering And Mathematics As A Gendered Construct, Jessica Elizabeth Quinton Dec 2014

Young, Southern Women's Perceptions Of Stem Careers: Examining Science, Technology, Engineering And Mathematics As A Gendered Construct, Jessica Elizabeth Quinton

Theses and Dissertations

Career interests develop over a lifetime and tend to solidify during late adolescence and early adulthood (Lent, Brown, and Hackett, 2002). The primary purpose of the present qualitative study, which is framed in Feminist Standpoint Theory (Haraway, 1988; Harding, 2007; Naples, 2007; Richardson, 2007), is to understand how eighthgrade, young women in a suburban, public, southern, middle school the South Carolina County School District (CCSD) (pseudonym) perceive their accessibility to Science, Technology, Engineering, and Mathematics (STEM) courses and careers. The secondary purpose is to understand these young women’s “perceptions and unconscious beliefs about gender in science and mathematics” and how …

Go to article

Comprehensive Joint Time-Frequency Analysis Toward Condition Based Maintenance Regimes For Electrical And Mechanical Components, David Lee Coats Dec 2014

Comprehensive Joint Time-Frequency Analysis Toward Condition Based Maintenance Regimes For Electrical And Mechanical Components, David Lee Coats

Theses and Dissertations

Based upon a framework of time-frequency analysis, we outline condition based maintenance (CBM), or maintenance only upon evidence of need, for both electrical and mechanical systems. We apply novel time-frequency cross-correlation metrics to helicopter drivetrain systems and electrical cables as remaining useful life assessments by non-destructive and non-invasive tests. In both cases, these metrics for health assessment provide a basis for diagnostic and prognostic analysis of underlying systems and components by performing accelerated condition tests on actual mechanical and electrical systems. We present novel time-frequency domain vibration analysis of a gearbox failure in an AH-64 Apache drivetrain testbed and quantify …

Go to article

Ferric Reductases And Transporters That Contribute To Mitochondrial Iron Homeostasis, Anshika Jain Dec 2014

Ferric Reductases And Transporters That Contribute To Mitochondrial Iron Homeostasis, Anshika Jain

Theses and Dissertations

Iron (Fe) is the fourth most abundant element in the Earth’s crust, yet the availability of Fe to plants is often limited. This is because in most soil types, Fe precipitates as ferric-oxyhydroxy complexes, making it unavailable for uptake by plants. While the mechanisms involved in Fe uptake from the soil are relatively well understood, the mechanisms involved in its further distribution to the aerial portion of the plant and to subcellular compartments are not fully understood. During Fe deprivation, plants up-regulate root Fe acquisition machinery. How plants sense Fe deprivation and tie the Fe status of the plant to …

Go to article

Cationic Metallocene-Containing Polymers: From Synthesis To Applications, Jiuyang Zhang Dec 2014

Cationic Metallocene-Containing Polymers: From Synthesis To Applications, Jiuyang Zhang

Theses and Dissertations

Metallopolymers, with the combination of metals and polymeric framworks, have attracted a lot of attention during the past decades. The development of metallopolymers has been largely driven by the desire to combine the synthetic efficiency and versatility of an organic polymer framework with the unique redox, responsive and catalytic properties of inorganic metals. Among different kinds of metallopolymers, metallocene-containing polymers， have been widely utilized for applications ranging from electrochemical sensors to templates for advanced inorganic catalysts to battery materials, due to their unique physicochemical properties. In the first part of my thesis, we showed controlled/living polymerization strategies to prepare well-defined …

Go to article

Product And Consumer Characteristics As Moderators Of Consumer Response To Sustainable Products, Kealy Carter Dec 2014

Product And Consumer Characteristics As Moderators Of Consumer Response To Sustainable Products, Kealy Carter

Theses and Dissertations

This dissertation consists of two essays. In both, product sustainability is broadly focused on the environmental and social performance (Luchs et al. 2010) of a product. The first essay explores the role of firm sustainability reputation in behavioral intentions for sustainable products. Additionally, this essay applies construal level theory (Liberman and Trope 1998; Vallacher and Wegner 1985, 1987) and addresses the situation that exists wherein sales of sustainable products produced by firms founded under sustainability principles are more stable than those produced by traditional firms (Clifford and Martin 2011). The second essay introduces a measure of consumer perceived product sustainability …

Go to article

Metformin Arrests Growth And Induces Apoptosis Of Neuroblastoma Cells, Nadia Al-Sammarraie Dec 2014

Metformin Arrests Growth And Induces Apoptosis Of Neuroblastoma Cells, Nadia Al-Sammarraie

Theses and Dissertations

Neuroblastoma is one of the most common solid neoplasms in children, which affects sympathetic neurons with a wide range of genetic abnormalities, especially MYCN amplification, a molecular marker of poor prognosis. Despite advance therapy, still the mortality rate for advance disease is high with frequent relapse and resistance to cytotoxic therapy with evidence of p53 mutation. Metformin, an oral hypoglycemic medication, is a relatively safe and cost effective drug with wide clinical applications, mainly for treatment of Type 2 diabetes. Recent studies have showed promising anticancer effect of metformin on various cancer types, especially on p53 mutant cells. In our …

Go to article

A Theory Of Reward Stability, Justice Evaluations And Group Cooperation, Hyomin Park Dec 2014

A Theory Of Reward Stability, Justice Evaluations And Group Cooperation, Hyomin Park

Theses and Dissertations

The objective of this dissertation is to introduce a theory of the stability of rewards, justice evaluations and group cooperation with the results from three empirical tests of the theory. According to justice theory, rewards from exchange relations produce justice evaluations among individuals, leading to emotional and behavioral reactions. Specifically, unjust rewards cause lower levels of justice evaluations, positive emotions, and cooperative behaviors. Prospect theory and research on negativity bias posit the asymmetry between negative and positive events: negative events have a stronger effect than the same size of positive events on individuals’ perception. Combining the previous arguments, the theory …

Go to article

Analysis Of Hurricane Preparedness Levels And Evacuation Intent For South Carolina Coastal Residents, Wesley Chad Seigler Dec 2014

Analysis Of Hurricane Preparedness Levels And Evacuation Intent For South Carolina Coastal Residents, Wesley Chad Seigler

Theses and Dissertations

Many communities across the nation, especially those in coastal areas, are experiencing extensive growth and expansion. This growth and the associated need for additional infrastructure, goods and services, and basic human needs often place people and the things they value in harm’s way due to the threat of a natural disaster. In order to properly prepare and mitigate disaster impacts, individuals and communities must view disasters as events that will likely occur at least once during their lifetime rather than simply outside possibilities. Residents of coastal communities must prepare for potential impacts from hurricanes and resulting storm surges and must …

Go to article

How School Leadership Develops Parental Involvement Strategies With Social Capital In Four South Carolina Middle Schools, Anthony Neil Boatwright Dec 2014

How School Leadership Develops Parental Involvement Strategies With Social Capital In Four South Carolina Middle Schools, Anthony Neil Boatwright

Theses and Dissertations

Passed in 2001, the No Child Left Behind (NCLB) mandate requires schools to have a comprehensive plan for addressing parental involvement. Identifying successful practices to increase social capital and academic achievement in lower socio-economic schools appears to be the area that is having the most impact. Principals can contribute to higher success rates by generating productive partnerships between the school and parents/guardians. The purpose of this study is to describe the parental involvement strategies that four successful South Carolina (SC) middle school principals used and to identify successful practices being implemented to increase social capital and academic achievement. The researcher …

Go to article

A Soul Composed Of Harmonies: George Herbert's Life, Writings, And Choral Settings Of His English Poetry, Benjamin Todd Ebner Dec 2014

A Soul Composed Of Harmonies: George Herbert's Life, Writings, And Choral Settings Of His English Poetry, Benjamin Todd Ebner

Theses and Dissertations

George Herbert’s poetry is among the greatest religious poetry written in the English language. His introspective and nuanced understanding of the human soul and his beautiful style of writing have earned him his place among the great poets. His catalogue is filled with poems ready to be set to music, and dozens of them have been. However, there is no document that seeks to gather an annotated list of these compositions in one place. Further, while a few of these compositions are performed often, there are dozens of other worthy compositions that should be heard on a more wide and …

Go to article

Innovation Among Georgian Journalism Educators: A Network Analysis Perspective, Ana Keshelashvili Dec 2014

Innovation Among Georgian Journalism Educators: A Network Analysis Perspective, Ana Keshelashvili

Theses and Dissertations

Rapid developments in technology in recent years have disrupted the media’s traditional role as a main informer for citizens. The changes have challenged journalism educators worldwide, pushing them to innovate and experiment. One purpose of this dissertation is to examine adoption of innovations by journalism educators in Georgia, a small post-Soviet country with partly free media and lack of professional outlets, that has been and still is a beneficiary of Western aid for media development. Employing innovation diffusion theory and the network analysis perspective, this dissertation uses a census of journalism educators and journalism program leaders in Georgia to understand …

Go to article

Novel Biofabrication Technologies To Recapitulate In Vivo Geometries In Collagen Hydrogels, Veronica Rodriguez-Rivera Dec 2014

Novel Biofabrication Technologies To Recapitulate In Vivo Geometries In Collagen Hydrogels, Veronica Rodriguez-Rivera

Theses and Dissertations

Tissue engineering and regenerative medicine aims to restore form and function to tissues that have been lost or damaged due to disease, congenital defect, or trauma. Biomaterials suitable to restore these complex tissues need to provide a balance between chemical and mechanical properties, providing accurate cell-matrix interaction and induce in vivo behaviors such as proliferation, differentiation and migration. It also requires that physical and chemical cues be presented to the body in the proper temporal and spatial pattern. The extracellular matrix exerts forces that are transmitted through focal adhesion causing changes in the cell behavior. The hypothesis for this dissertation …

Go to article

Understanding The Evolutionary History Of Biochemical Innovation, Madeline Opal St. Julien Dec 2014

Understanding The Evolutionary History Of Biochemical Innovation, Madeline Opal St. Julien

Theses and Dissertations

The serine protease (SP) gene family is an ecologically important gene family because of observed involvement in innate immunity, digestive processes, and embryological development of arthropods. In the past decade, all genes of the serine protease family have been classified in a number of arthropods, with the exception of crustacean. Possible evolutionary mechanisms have been observed based off of varying selectional pressures acting on recent SP expansions in respect to varying diets. Daphnia is the first crustacean to have its genome sequenced, and their genomes were analyzed in this study to elucidate the expansion and divergence of the SP gene …

Go to article

Gestational Weight Gain, Pregnancy Outcomes, And Use Of Perinatal Health Services, Lujing Zhan Dec 2014

Gestational Weight Gain, Pregnancy Outcomes, And Use Of Perinatal Health Services, Lujing Zhan

Theses and Dissertations

This dissertation consists of three studies that were undertaken to better understand 1) the role of gestational weight gain (GWG) during early pregnancy on subsequent blood pressure changes and the risk of pregnancy-induced hypertension (PIH), 2) the causal effect of GWG in both early and mid-late pregnancy on the subtypes of preterm births, and 3) the impact of personal capital on the use of perinatal health services (i.e., prenatal care use and preconception care counseling). The first two studies were based on the data from the 1988 National Maternal and Infant Health Survey and the third study employed the data …

Go to article

Practical Concurrency Support For Web Service Transactions, Emad Alsuwat Dec 2014

Practical Concurrency Support For Web Service Transactions, Emad Alsuwat

Theses and Dissertations

Traditional database concurrency control methods use locking, timestampordering, and optimistic-ordering to achieve DB consistency. However, these approaches are not suitable for long-running Web Service Compositions (WSCs) due to associated performance degradation. Our hypothesis asserts that, using transactional semantic and ordering information, the execution time of a WSC can be reduced, thus allowing the use of traditional database concurrency control methods while avoiding unacceptable performance degradation. Our solution is based on the following approaches: § We model a WSC as WS-BPEL specification, i.e., a partial order of WS transactions. § We allow some of the WS transactions in the WSC to …

Go to article

Going Up The Country: A Comparison Of Elite Ceramic Consumption Patterns In Charleston And The Carolina Frontier, Rebecca E. Shepherd Dec 2014

Going Up The Country: A Comparison Of Elite Ceramic Consumption Patterns In Charleston And The Carolina Frontier, Rebecca E. Shepherd

Theses and Dissertations

The 18th century colonial world is characterized by a dramatic increase in the consumption of goods identified as the “consumer revolution.” During this period fashionable material culture and the social performances associated with their use became universally recognized symbols of group membership. This thesis uses archaeological evidence to explore variation in the degree of participation in the consumer revolution between urban and rural settings in late eighteenth-century South Carolina. The data used for this research will be taken from excavated ceramic assemblages of two domestic archaeological sites, both of which were homes owned consecutively by the wealthy Brewton and Motte …

Go to article

A Phenomenological Study Of Student Engagement In United States History Classrooms, Emily Louvette Manigault Dec 2014

A Phenomenological Study Of Student Engagement In United States History Classrooms, Emily Louvette Manigault

Theses and Dissertations

The purpose of this phenomenological study is to explore the relationship between student engagement and the perception of academic achievement (learning) by teachers and students in an urban high school social studies course. Over the past several years, educational leaders and researchers have tried to find a cause for a number of issues in public education, including low academic achievement, increasing student drop-out rates and the decline of positive perceptions of schools in general. As a result, there has been increasing research done on the level of engagement that students experience during their schooling. Much of the research has focused …

Go to article

The Influence Of Organizational Climate On The Use And Quality Of Evidence-Based Practices In School Mental Health, Katherine Knies Dec 2014

The Influence Of Organizational Climate On The Use And Quality Of Evidence-Based Practices In School Mental Health, Katherine Knies

Theses and Dissertations

Organizational climate is defined as the reflection of workers’ perceptions of, and emotional responses to, the characteristics of their work environment (Glisson & James, 2002). While previous research explored the importance of organization climate for the adoption of evidence-based practices (EBPs) in mental health settings, there is a dearth of organizational climate focused research in school mental health settings (SMH). The current study examines the influence of organizational climate on two separate dependent variables: the extent to which EBPs were used and the quality of clinician delivery for the evidence-based practices used in a quality improvement intervention for SMH practitioners. …

Go to article

Measurement Of Polarization Observables PZ, PSZ, And PCZ In Double-Pion Photoproduction Off The Proton, Yuqing Mao Dec 2014

Measurement Of Polarization Observables PZ, PSZ, And PCZ In Double-Pion Photoproduction Off The Proton, Yuqing Mao

Theses and Dissertations

Meson production from excited nucleons is important in the study of baryon resonances and pion photoproduction is attracting much attention. To date a rather large amount of unpolarized cross-section measurements have been reported for both single- and double-pion photoproduction. However, polarization observables provide complementary information as they probe different combinations of transition amplitudes. The database for polarization observables remains quite sparse. Double-pion photoproduction have been studied in Hall B at Jefferson Lab with linearly polarized tagged photon beams incident on longitudinally polarized protons. The experiment covered center-of-mass energies between 1.4 GeV and 2.3 GeV. The target was a FROzen Spin …

Go to article

Toward A Theory Of Safe Passage: Agentic Practices Of Women Writers Who Teach, Lillian Gordon Reeves Dec 2014

Toward A Theory Of Safe Passage: Agentic Practices Of Women Writers Who Teach, Lillian Gordon Reeves

Theses and Dissertations

Past studies show that narrative is an effective tool for guiding teachers to develop teacher identity, to recognize their practical knowledge, and to engage in teacher transformation, especially during initial teacher training and the early years of their career. Consequently, other researchers have identified how narrative studies inform what we know about teachers’ identities, their practical knowledge, and their transformations during initial training and early career teaching. However, we do not know how narrative functions in the experiences of teachers beyond initial teacher training and early career teaching. This study intends to fill this gap in the research. In this …

Go to article

First Prev Next Last