Digital Commons Network^™

Development And Evaluation Of A Thermochemistry Concept Inventory For College-Level General Chemistry, David A. Wren

Dissertations

The research presented in this dissertation culminated in a 10-item Thermochemistry Concept Inventory (TCI). The development of the TCI can be divided into two main phases: qualitative studies and quantitative studies. Both phases focused on the primary stakeholders of the TCI, college–level general chemistry instructors and students. Each phase was designed to collect evidence for the validity of the interpretations and uses of TCI testing data. A central use of TCI testing data is to identify student conceptual misunderstandings, which are represented as incorrect options of multiple– choice TCI items. Therefore, quantitative and qualitative studies focused heavily on collecting evidence …

Ultrafast Dynamics And Two-Photon Absorption Properties Of Chromophores At Interfaces, Semere Ghebru Bairu

Dissertations

Materials with large two-photon absorption (2PA) cross-sections found applications in several areas such as sensor protection, 3D micro/nano fabrication, photodynamic therapy, optical data-storage, multi-photon sensing, multi-photon microscopy and imaging. Several successful research strategies were developed in literature to achieve 2PA materials with enhanced cross-sections. However, the obtained cross-sections are far from adequate and there is a need to develop new strategies. In a parallel development, numerous research efforts were focused on studying the dynamics of interfacial charge-transfer (ICT) across chromophoresemiconductor interfaces, especially in the context of dye-sensitized solar cells. While investigating the fundamentals of ICT, it was found that these …

New Approaches On Deinking Evaluations, Roland Gong

Dissertations

Paper recycling in the U.S. is the most successful program of environmental sustainability. Approximately two thirds of consumed paper products were recycled, according to the EPA and AF&PA. However, domestic mills only applied one third of recycled fibers into new products, which is much lower than reported in China (67%). The domestic recycle mills claimed that outdated facilities, poor recycled fiber quality and high manufacturing cost are the major issues. They also said that these recycle mills have been put in a “no-win” position, which threatens the whole recycling loop eventually. A case study about Chinese recycle mills has been …

In Situ Quenching And Post-Polymerization Modification Of Telechelic Polyisobutylene, Todd Raymond Hartlage

Dissertations

Polyisobutylene (PIB) is a saturated hydrocarbon elastomer that can only be produced by cationic polymerization. The water-initiated, chain transfer controlled synthesis conducted on an industrial scale produces monofunctional PIB with mixed olefin end groups. Living cationic techniques produce mono- and di-functional telechelic PIB. In situ quenching is the process of adding functional molecules to the polymerization reactor after all monomer is consumed. These quencher species bond to the chain ends, installing their latent functionality onto the polymer chain. To date, all quenchers utilized have been soft π-nucleophiles.

In the first project, free thiols, both aromatic and aliphatic, are shown to …

A Pattern In The Lusternik-Schnirelmann Category Of Rational Spaces, Julie Dare Houck

Dissertations

The Lusternik-Schnirelmann (or LS) category of a space is one less than the number of contractible open sets with which we can cover the space. If we look at the LS categories of the skeleta of a CW complex, we find a sequence of dimensions where the LS category changes. I discuss whether certain of these "category sequences" (defined in the paper, "Categorical Sequences", by Nendorf, Scoville, and Strom) could be realized as the categorical sequences of rational spaces. I first reduce from looking at all rational spaces to only Postnikov sections of finite wedges of spheres. Using the Leray-Serre …

The Characterization Of Algae Grown On Nutrient Removal Systems And Evaluation Of Potential Uses For The Resulting Biomass, Kristin Hampel

Dissertations

Eutrophication resulting from excess nutrient loads is a major environmental issue that affects surface water quality and causes surplus primary production, thereby reducing dissolved oxygen concentrations. A method for managing nutrients in surface waters involves absorption of excess nutrients by deliberately cultivating benthic algal turf biomass, then harvesting it for a variety of uses, including biofuels, soil amendments, or feed supplements, thus coupling nutrient removal to additional economic drivers.

The goals of this work are to (1) evaluate the composition of algal biomass grown to remove surface water nutrients, (2) compare biomass grown at different geographic locations and in dissimilar …

Anxiety-Reducing Strategies In The Classroom, Robin K. Buchler

Dissertations

This case study research explored how sixth grade students experience and respond to anxiety prior to, during, and after receiving 10 sessions of instruction in anxiety-reducing strategies in the classroom compared to a group of similar students who do not receive instruction in anxiety-reducing strategies in the classroom. Three research-based strategies were taught: (a) progressive muscle relaxation, (b) breathing exercises, and (c) positive self- talk. Qualitative data were collected through journals the students kept, pre-questionnaires and post-questionnaires, observation notes, and field notes. Four strong themes, in the words of the students, were identified: (a) “I like it” – demonstrating autonomy; …

An Embodied Perspective Of Expertise In Solving The Problem Of Making A Geologic Map, Caitlin Norah Callahan

Dissertations

The task of constructing a geologic map is a cognitively and physically demanding field-based problem. The map produced is understood to be an individual’s two-dimensional interpretation or mental model of the three-dimensional underlying geology. A popular view within the geoscience community is that teaching students how to make a geologic map is valuable for preparing them to deal with disparate and incomplete data sets, for helping them develop problem-solving skills, and for acquiring expertise in geology. Few previous studies have focused specifically on expertise in geologic mapping. Drawing from literature related to expertise, to problem solving, and to mental models, …

Iterative Solvers For Large, Dense Matrices, Eowyn Wilhelmina Cenek

Dissertations

Stochastic Interpolation (SI) uses a continuous, centrally symmetric probability distribution function to interpolate a given set of data points, and splits the interpolation operator into a discrete deconvolution followed by a discrete convolution of the data. The method is particularly effective for large data sets, as it does not suffer from the problem of oversampling, where too many data points cause the interpolating function to oscillate wildly. Rather, the interpolation improves every time more data points are added. The method relies on the inversion of relatively large, dense matrices to solve Annx = b for x. Based on the probability …

Biophysical Understanding Of Novel Synthetic Amyloid-Β (Aβ) Prions In Alzheimer's Disease, Amit Kumar

Dissertations

Oligomers of amyloid-β (Aβ) peptide are the primary toxic agents that play a pivotal role in the pathogenesis of Alzheimer’s disease (AD). Oligomers are the intermediates formed during the Aβ aggregation process leading up to insoluble fibrils. It is important to know that oligomers can also be formed via pathways that do not lead to fibril formation. Such ‘off-pathway’ oligomers would have significantly longer half-lives than the ‘on-pathway’ ones, which may result in prolonged toxicity to neuronal cells. Furthermore, neither the mechanism of neurotoxicity nor the potential mechanisms of propagation and proliferation to neighboring cells are well understood. Moreover, recent …

The Effect Of Asian Origin, Culture And Learning Beliefs On High School Students' Physical Science Learning Beliefs, Xiaolan Li

Dissertations

Asian Americans have been recognized as the model minority in the United States since the 1960s. Students from Asian countries are winning in international competitions, especially in science and mathematics. Modern Western scholars working within the constructivist learning theory advocate malleable intelligence and effort, which actually corresponds to Asian learning beliefs and learning behaviors. This research is designed to test if American high school students and Chinese students from the mainland of China who are motivated to attend American universities are different in their learning beliefs of physical science and what accounts for the difference if there is any.

Relation Between The Adsorption Behavior And Bulk Complexation In Oppositely Charged Polyelectrolyte-Surfactant Systems: Effect Of Polyelectrolyte Concentration, Molecular Weight, Charge Localization And Backbone Rigidity/Hydrophobicity, Vipul Suhas Padman

Dissertations

Due to a wide range of applications, much emphasis has been placed on understanding the physicochemical behavior of polyelectrolyte/surfactant complexes, both at air-water interface and in the bulk. However, the correlation between the adsorption behavior and complexation in the bulk is less explored. In this research, this correlation is investigated and its dependence on polyelectrolyte concentration, molecular weight, charge localization and backbone rigidity and hydrophobicity is studied. The polyelectrolyte concentration is normalized with respect to it critical overlap concentration in order to compare the polymer in same concentration regime. Different polyelectrolyte systems were used to analyze the polyelectrolyte structural effect: …

The Role Of Distress Tolerance In Aggressive Behavior, Anne Winston Mcintyre

Dissertations

Berkowitz (1989) proposed that the degree of negative affect experienced following a frustrating event determines whether one will respond aggressively, suggesting that one possesses a certain amount of tolerance for distressing emotions. However, little research has been conducted on the relation between distress tolerance and aggression. Moreover, no published study has examined the relation between distress tolerance and behavioral aggression using a multi-modal assessment approach, nor examined the potential mediating role of negative affect in the relation between distress tolerance and aggression. To address this gap in the literature, college students (N = 87) aged 18 to 49 years (M …

The Effect Of Online Discussion Forums On Student Learning And Student Perception Of Learning In A Science Course At The Community College Level, Rachel Syring Ryan

Dissertations

Institutions of higher education are feeling the pressure to offer a greater number of courses through alternative methods of instructional delivery including hybrid and online courses in an attempt to meet the needs of their students. Among institutions of higher education, community colleges have become a forerunner in online education, in many cases incorporating the development of online education into the institution’s strategic plan. To some educators, hybrid course offerings provide the best of face-to-face education with electronic transfer of information. One of the greatest challenges which exists in the development of a hybrid course is the development of instructional …

Synthesis And Characterization Of Polyisobutylene-Block-Polyamides As Novel Thermoplastic Elastomers, Lauren Renee Kucera

Dissertations

Academic research has focused on two main areas of the living carbocationic polymerization (LCP) of isobutylene (IB): (1) the in-depth study and understanding of mechanistic features of the polymerization, and (2) the utilization and manipulation of the unique aspects of PIB in order to produce practically useful polymeric materials. The research included in this dissertation focuses mainly on the latter objective. This work details three main areas of research: (1) the copolymerization of PIB and polyamides (PA) to form novel thermoplastic elastsomers (TPEs), (2) the mechanical, physical and thermal properties of the novel PIB-PA materials, and (3) the use of …

Design, Development, And Psychometric Analysis Of A General, Organic, And Biological Chemistry Topic Inventory Based On The Identified Main Chemistry Topics Relevant To Nursing Clinical Practice, Corina E. Brown

Dissertations

This two-stage study focused on the undergraduate nursing course that covers topics in general, organic, and biological (GOB) chemistry. In the first stage, the central objective was to identify the main concepts of GOB chemistry relevant to the clinical practice of nursing. The collection of data was based on open-ended interviews of both nursing and chemistry teaching faculty as well as practicing nurses. From the resulting interviews, three themes emerged: topics that were Important--had a direct application in nursing clinical practice; topics that were Foundational--not directly important for nursing clinical practice but facilitated the understanding of the important topics; and …

Evaluation Of The Effect Of A Digital Mathematics Game On Academic Achievement, Christine M. Wale

Dissertations

Digital games are widely popular and interest has increased for their use in education. Digital games are thought to be powerful instructional tools because they promote active learning and feedback, provide meaningful contexts to situate knowledge, create engagement and intrinsic motivation, and have the ability individualize instruction. However, claims about the potential benefits of digital games in education have outpaced quality empirical research on their effectiveness in K-12 settings. The purpose of this study was to investigate the effectiveness of a mathematics digital game, Ko’s Journey, on seventh grade students’ mathematics achievement as defined by a researcher-constructed test aligned with …

The Dimensions Of Self-Regulated Learning And Academic Achievement In College Students, Nasar Said

Dissertations

The purpose of this study was to first investigate the factor structure of a data set, which included the measures of: (a) executive functions, (b) metacognitive strategies, (c) time management, and (d) academic self-efficacy in a sample of undergraduate students (N = 45) . A second purpose was to explore whether there were differences between low-achieving (n = 21) and high-achieving college students (n = 24) in terms of the scores on the underlying factors identified in the factor structure that presumably will align with the measures of executive functions, metacognitive strategies, time management, and academic self-efficacy or some type …

Dynamics Of Perceptual Organization In Complex Visual Search: The Identification Of Self Organized Criticality With Respect To Visual Grouping Principles, Attila Jozsef Farkas

Dissertations

The current project applies modern quantitative theories of visual perception to examine the effect of the Gestalt Law of proximity on visual cognition. Gestalt Laws are spontaneous dynamic processes (Brunswik & Kamiya, 1953; Wertheimer, 1938) that underlie the principles of perceptual organization. These principles serve as mental short-cuts, heuristic rule-of-thumb strategies that shorten decision-making time and allow continuous, efficient processing and flow of information (Hertwig & Todd, 2002). The proximity heuristic refers to the observation that objects near each other in the visual field tend to be grouped together by the perceptual system (Smith-Gratto & Fisher, 1999). Proximity can be …

The Effect Of Preschool On Reaching Achievement Among Kindergarten Students, Reisha Monique Mckinney

Dissertations

As early childhood education continues to move to the forefront of public policy debate, more attention is being paid to early literacy. Strickland and Riley-Ayers (2006) indicated that early literacy and early learning opportunities play a vital role in academic achievement. This study invested whether there were statistically significant relationships between preschool attendance based on the reading and language arts scores from the Georgia Kindergarten Inventory Developing Skills test.

The study also determined if there were differences in the reading and language arts for those who attended preschool and those who did not based on free/reduced and full paid lunch. …

The Perceptions Of The Effectiveness Of Making Middle Grades Work, Darryl Rene Porter

Dissertations

Many school districts throughout the United States utilize educational programs in their schools to improve student achievement. The Southern Regional Education Board recognized that to improve graduation rates in high school, students’ academic performance in middle schools needed to be improved, which gave rise to the Making Middle Grades Work initiative. The researcher conducted this study to determine the perceptions of the effectiveness of Making Middle Grades Work initiative. Participants in this study included 114 teachers and 18 administrators. The participants indicated their perceptions of the effectiveness of the Making Middle Grades Work initiative by responding to questions on a …

Using Brief Experimental Analyses To Identify Effective Math Interventions For Early Elementary Students, Chelsi Ronatta Clark

Dissertations

athematics difficulties, this study aimed to use a brief experimental analysis (BEA) to identify effective interventions within a response to intervention (RTI) framework. Participants included four lower elementary school students who exhibited marked problems in mathematics. The effects of mathematics interventions to increase mathematic computational fluency and accuracy were assessed during the BEA. The intervention that produced the greatest gains during the BEA was compared to the intervention that produced the least gains during an extended analysis phase. It was hypothesized that: (a) during a BEA of math interventions, students will demonstrate differential responding across interventions; (b) during a BEA …

Prekindergarten And Kindergarten Teachers' Perceptions Of Demographic Determinants And Academic Success, Melanie Ellen Boyle

Dissertations

The purpose of this study was to examine kindergarten and prekindergarten teachers' perceptions of academic success for children based on the type of care children received prior to beginning kindergarten, as well as other demographics, which could cause variations in academic success. The researcher used a seven section multi-method survey instrument, which included teacher demographic questions, Likert-scale perception questions, and one open-ended question. Sections of inquiry included: Common Core, general academic risk factors for students, barriers to overall academic success, student demographics, and promotion of academic success for students. The survey instrument was distributed to prekindergarten and kindergarten teachers in …

Bifurcation And Chaos Of Nonlinear Vibro-Impact Systems, Yu Guo

Dissertations

Vibro-impact systems are extensively used in engineering and physics field, such as impact damper, particle accelerator, etc. These systems are most basic elements of many real world applications such as cars and aircrafts. Such vibro-impact systems possess both the continuous characteristics as continuous dynamical systems and discrete characteristics introduced by impacts at the same time. Thus, an appropriately developed discrete mapping system is required for such vibro-impact systems in order to simplify investigation on the complexity of motions. In this dissertation, a few vibro-impact oscillators will be investigated using discrete maps in order to understand the dynamics of vibro-impact systems. …

The Impact Of Computer Efficacy On The Success Of The Nontraditional Community College Student, Amy Renee Henson

Dissertations

The purpose of this research was to determine the extent that computer-related factors affect the success of nontraditional college students. Since nontraditional students typically have fewer skills than traditionally-aged students, they may be less efficacious regarding their ability to use technology. Unfortunately, such reduced confidence may adversely affect the entire college experience for students, and ultimately, successful employment. The simple process of obtaining information on campus websites may be daunting enough; however, when students enter the classroom, they often find that course requirements include considerable amounts of computer use. Therefore, in addition to learning specific course content, nontraditional students must …

The Message 2.0: Perceptions Of Success From Members Of The Founding Class Of Mc Squared Stem High School, Jeffrey D. Mcclellan

Dissertations

This dissertation examines the methods of learning from the student’s perspective in order to understand what made the first graduating class of MC Squared successful. The conceptual model of student success composed of non-academic factors of motivation, social connectedness, and self-management was used for the lens from which to understand the six students in depth. Through the research, it was uncovered that diversified learning environments, a mastery based assessment system, and an unwavering acceptance of students within a challenging and supportive environment are essential to the success achieved at MC Squared STEM High School. Lastly, the seminal contribution of this …

A Robust Estimate For The Bifurcating Autoregressive Model With Application To Cell Lineage Data, Tamer M. E. Elbayoumi

Dissertations

The bifurcating autoregressive model (BAR) is commonly used to model binary tree data. One application for this model relates to cell lineage data in biology. The purpose of studying the cell lineage process is to know whether the observed correlations between related cells are due to similarities in the environmental, inherited effects, or a combination of both of them. Because outliers in this kind of data are quite common, the need for a robust estimation procedure is necessary. A weighted L1 (WL1) estimate for estimating the parameters of the BAR model is considered. When the weights are constant, the estimate …

Examining Antarctica From A Geodynamic Perspective: Backstripping, Ice Thickness, Tectonics And Erosion, Travis Gary Hayden

Dissertations

I have applied the principles of basin analysis and geodynamics to several cores recovered from on or near the Antarctic continent to answer 2 independent questions about the tectonic evolution of Antarctica; as well as estimate the thickness of the Antarctic Ice Sheet at the Last Glacial Maximum.

I developed, and applied a modification of the backstripping modeling technique to compensate for the loading and erosion of glacial ice at the AND-1B site by combining a backstripping driven inverse model, with a driven ice-load model. This modification allowed me to identify and constrain the timing of major pulses of subsidence …

Organic Solar Cells Based On High Dielectric Constant Materials: An Approach To Increase Efficiency, Khalil Jumah Tawfiq Hamam

Dissertations

The efficiency of organic solar cells still lags behind inorganic solar cells due to their low dielectric constant which results in a weakly screened columbic attraction between the photogenerated electron-hole system, therefore the probability of charge separating is low. Having an organic material with a high dielectric constant could be the solution to get separated charges or at least weakly bounded electron-hole pairs. Therefore, high dielectric constant materials have been investigated and studied by measuring modified metal-phthalocyanine (MePc) and polyaniline in pellets and thin films. The dielectric constant was investigated as a function of temperature and frequency in the range …

Concept Graphs: Applications To Biomedical Text Categorization And Concept Extraction, Said Bleik

Dissertations

As science advances, the underlying literature grows rapidly providing valuable knowledge mines for researchers and practitioners. The text content that makes up these knowledge collections is often unstructured and, thus, extracting relevant or novel information could be nontrivial and costly. In addition, human knowledge and expertise are being transformed into structured digital information in the form of vocabulary databases and ontologies. These knowledge bases hold substantial hierarchical and semantic relationships of common domain concepts. Consequently, automating learning tasks could be reinforced with those knowledge bases through constructing human-like representations of knowledge. This allows developing algorithms that simulate the human reasoning …