Theses and Dissertations

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The impact of a book flood on reading motivation and reading achievement of fourth grade students
(2017-03-22) Andrews, Sherry; Pavonetti, Linda; pavonett@oakland.edu
Reading proficiency makes profound differences in reasoning and the ability to learn new information. Past research has indicated that avid readers demonstrate superior literacy development and a wide-range of knowledge across subjects (Allington, 2011; Guthrie, 2008; Krashen, 2004). In a contrasting trajectory, a child who does not engage in reading has limited exposure to a wide vocabulary (Cunningham & Stanovich, 1997) and a gap in knowledge ensues that adversely impacts literacy into adulthood (Hodgkinson, 1995; Neuman & Celano, 2006). This quasi-experimental study examined the impact of readily accessible books on students’ motivation to read, attitudes towards reading and reading achievement when students are provided daily opportunities to read self-selected materials provided through a book flood. Book floods are designed to provide a large number of books to a classroom with limited books. Thirty-eight fourth grade students from two intact classrooms were assigned as the treatment (n=19) and the control group (n=19). Participants in both the control and treatment group were administered pre- and post-test to measure reading motivation and attitudes towards reading. Participants’ scores from the district mandated assessment were used to measure pre- and post-treatment reading achievement. The fourth-graders in the treatment group were provided 15-minutes daily to read self-selected books from the book flood. Participants in the treatment group recorded and rated the self-selected books in reading logs for a 12-week period. ANCOVA was conducted to compare post-tests results on the Elementary Reading Attitude Survey (M. McKenna & Kear, 1990), the Self-Regulation Questionnaire-Reading Motivation (De Naeghel, Van Keer, Vansteenkiste, & Rosseel, 2012), and the Northwest Evaluation Association Measures of Academic Progress (NWEA, 2003). Analyses of the data indicate significant differences between the control and treatment group on post-test results for recreational autonomous and academic autonomous reading motivation but not on post-test results for attitudes towards recreational and academic reading. Correlation relationships and other descriptive findings are discussed.
Teacher Characteristics and Effective Implementation of the Accelerated Reader program, as reported by Teachers of African American students
(2017-11-08) Johnson, Debra; McMillon, Gwendolyn; ; mcmillon@oakland.edu
How are teacher characteristics related to teaching practices in reading instruction? Melton, Smothers, Anderson, Fulton, Replogue, & Thomas (2004) maintained teachers are the most powerful dynamic in the classroom. African American students often attain lower reading scores than other students. It is important to determine which teacher characteristics may be affecting the reading achievement of African American students when the Accelerated Reading (AR) program is utilized in the classroom. This study examined teacher characteristics and compared them to elements of the Accelerated Reader program and teaching approaches the participants may have used with their African American students to increase their reading achievement scores. The study is necessary to the field of literacy because no study exists that considers the actions of the teachers when they utilize the AR program with their African American students to increase their reading achievement scores. This study reported responses and comments of 25 teacher participants from three different elementary-middle schools. The use of quantitative data from the research-based online SurveyMonkey Pro survey and written comments from participants were considered the most effective methods of data collection and provided a logical approach to gathering information and maintaining the validity of the data. The 42-question survey instrument included multiple choice and free-response answers regarding how the participants implemented the AR program. The hypothesis predicted that the teacher characteristics would be related to all eight elements and all ten approaches. The data analysis was completed with IBM’s SSPS Statistics software, Version 22, to determine statistically significant relationships. The results of the study indicated five teacher characteristics, specifically the participants’ educational level, the participants’ total years of teaching experience, the participants’ years of using AR in the classroom, the years the participants had been teaching the current grade, and the number of school or district AR workshops the participants attended positively correlated with multiple elements of the AR program and many of the teaching approaches the participants used with their African American students to increase their reading achievement scores.
Using Engagement with Instructor Feedback to Nurture First-Year Writing Students’ Self-Efficacy
(2017-11-08) Gabrion, Laura; Leigh, S. Rebecca; leigh23@oakland.edu
Many students enter college with low self-perceptions about their writing skills. Research indicates that first-year writing instructors typically rely on the semi-self-regulated steps of the writing process to help students develop positive feelings about their writing. First-year composition courses employ instructor-provided feedback, whether oral or written or both, as a process for helping students improve their writing skills; therefore, an important consideration for teachers of first-year writing is how to engage students in the feedback provided. One way to make instructor feedback useful and meaningful to students is to create opportunities for conversation between student and instructor in advance of the revision stage. By combining instructor feedback with student-composed revision plans, instructors and students can participate in dialogic feedback that encourages both critical thinking and critical revision (Berzsenyi, 2001; Muldoon, 2009). Dialogic feedback diminishes students’ misinterpretations of instructors’ comments and gives students a better understanding of their writing and which skills to work on as they progress. This study investigated students’ interaction with instructional feedback as a method for impacting students’ self-efficacy in first-year composition. Results suggest that active engagement with instructor feedback has the ability to raise students’ confidence, persistence, and performance and should be considered, consequently, as an integral part of the feedback process.
The Impact of Face-To-Face Versus Online Peer Review on Students' Writing Achievement
(2017-11-08) Hine, Lisa; McEneaney, John; mceneane@oakland.edu
This study examines the impact of type of peer review first year college students participated in, either face-to-face (F2F) or online (OL) and its effect on students' writing achievement. Using a two-way repeated measures design, this research measured students' overall writing score as well as the five key areas of writing: focus and meaning; content and development; organization; language use, voice and style; and mechanics and conventions. Since this design allows for a pre- and post-test of the participants, it was chosen to measure the treatment effect, comparing the type of peer review between groups and its overall impact on students’ final writing achievement. The results suggest that there was not a significant effect based on the format of the peer review (F2F vs. OL) in either students' overall score nor in the five key areas of writing. However, there was statistically significant growth in both overall writing achievement scores over time as well as in the five key areas of writing, indicating that regardless of peer review format, first-year writing students’ writing achievement can improve over the course of one semester.
An Examination of the Effectiveness of Peer Feedback on Chinese University Students’ English Writing Performance
(2018-02-05) Zhang, Xin; McEneaney, John; mceneane@oakland.edu
Effective writing pedagogy in higher education has been a consistent goal of researchers and instructors in the English as a second / foreign language writing practices. Formative peer feedback, a key factor in pedagogical writing practices, has been receiving growing interest (Hu & Lam, 2010). While much remains unknown regarding how the quality of peer feedback and back-feedback affects students’ writing performance, this quantitative study adopted a quasi-experimental control group design to investigate primary pedagogical effects of peer feedback on university students’ writing performance in an EFL context. A total of 198 sophomores majoring in English took part in a 15-week research study. A one-way repeated measures ANCOVA analysis was conducted to examine the comparative effect between the traditional and peer feedback groups. The result revealed that beginning with slightly different writing ability, the peer feedback group significantly made more growth in writing achievement than the traditional feedback group. Further analysis through hierarchical multiple regression analyses showed that both the quality of students’ feedback and the quality of students’ back-feedback were significant predictors of students’ writing performance. Additionally, the quality of students’ back-feedback had a slightly larger impact than that of the quality of students’ feedback. This study provides not only further evidence of the power of formative peer feedback as an effective tool to maximize learning, but also recommends the inclusion of it in the university curriculum to encourage students to direct and monitor their own learning processes and be life-long learners.
Impact of virtual literature circles on Chinese university EFL students' independent English reading
(2018-02-28) Pei, Li; McEneaney, John; mceneane@oakland.edu
The purpose of this study was to examine the impact of virtual literature circles (VLCs) on Chinese university English as a foreign language (EFL) students’ independent English reading. The importance of independent reading for EFL students to develop critical thinking, language proficiency, and good readership was extensively discussed and supported (eg. Day and Bamford, 1998; Krashen, 1989, 1993, 1995; Mason & Krashen, 1997; Ro, 2013; Yamashita, 2013). However, lack of empirically validated approaches hindered the ability of EFL teachers to effectively promote such reading. This study proposed a VLC approach for EFL teachers to engage their students in independent English reading. The VLC approach integrated the use of social media into traditional literature circles. To validate this approach in an EFL environment, VLCs were implemented with a sample of Chinese university EFL students. A quasi-experimental between-subjects posttest design was selected to investigate the effectiveness of the VLC. The 118 research participants were enrolled in four reading classes. Two classes (n=59) were randomly assigned to the VLC treatment and the other two (n=59) to the summary-writing treatment, while reading two American young adult novels outside of school. To measure participant reading experiences and reading achievement, five book-dependent instruments (the Reading Experience Survey, the Written Retell Test, the Vocabulary Acquisition Test, the Reading Comprehension Test, and the Reading Engagement Essay) were developed and administered to all research participants after the eight-week experiment. A one-way MANCOVA showed that, overall, VLC participants outperformed the summary-writing participants on the composite score of the posttest. Univariate analysis revealed that participation in VLCs led to statistically better performance in the Reading Experience Survey and the Reading Comprehension Test. The research provided empirical evidence for the overall effectiveness of the VLC. The findings have important implications for EFL reading instruction and research.
Investigation of Running Records and How Teachers Use the Reading Information to Inform Instruction
(2018-03-09) LeBlanc, Joanne Farley; Christ, Tanya; christ@oakland.edu
A qualitative research approach was taken to examine (1) how teachers used running records to identify students’ needs, and (2) how those needs were addressed in subsequent instruction. Participants included three first-grade classroom teachers from across two schools, and one high-, average-, and low-performing reader in each classroom (nine first-grade students in all). Four data sources were collected: (1) brief initial interviews to identify demographic data for teachers and students, (2) video recordings of running record sessions and brief instruction immediately following these sessions, (3) artifacts from the running record sessions, and (4) semi-structured teacher interviews after teachers had time to more deeply analyze the running record assessment data. Data were coded using emergent coding and constant comparative analysis to identify themes and subthemes that reflected how teachers used running records to identify students’ needs and how those needs were addressed in instruction. Findings showed that (1) teachers’ data collection was inconsistent, (2) teachers blurred the line between assessment and instruction by integrating instruction into their assessment, (3) the quality of the in-the-moment analyses of assessment varied across teachers, (4) teachers identified most of their students’ needs when given additional time for analysis, (5) teachers addressed a limited breadth of needs (just chunking and retelling) despite broader student needs being evident, and (6) the quality of instruction was consistently varied. This study extended knowledge in the field about how first-grade classroom teachers use running records for assessment and to guide instruction.
Chinese EFL Learners' Use of Online Reading Strategies
(2019-03-10) Wu, Wen; McEneaney, John E.; mceneane@oakland.edu
Based on Afflerbach and Cho’s (2009) theoretical model of Constructively Responsive Reading on the Internet (CRRI model), this study aims to explore the patterns of reading strategies that 40 proficient, college-level, Chinese English as a Foreign Language (EFL) learners use while reading online. It also seeks to identify the strategies’ relations to reading comprehension. This study utilized an exploratory research design. During the study, the participants were required to complete a 30-minute reading task on a pre-selected website, followed by a comprehension assessment with 20 multiple-choice questions. During the reading task, the participants were asked to verbalize their thinking process. Both their verbalization and online actions were recorded by Camtasia. These recordings served as the primary data and then were coded using Afflerbach and Cho’s (2009) four strategy categories as the coding scheme. Following this, the coded primary data were analyzed quantitatively. The results first indicated that participants’ meaning-making strategy use dominated the whole reading process. Both the self-monitoring and text location strategies served as a supporting role in this reading task; however, the information evaluation strategy was used least often. Additionally, based on the sequential patterns of the participants’ strategy use, three different types of readers were identified: uncertain readers, exploratory readers, and strategic readers. Lastly, the examination of the relationship between strategy use, reader types, and comprehension outcome revealed that both the meaning-making and self-monitoring strategies had a strong effect on the comprehension outcome. The results also showed that the comprehension outcome was significantly different among all three reader types. The comprehension outcomes of the strategic readers ranked highest, followed by the exploratory readers and the uncertain readers. This exploratory study not only provides a quantitative assessment of Afflerbach and Cho’s (2009) theoretical framework, but also extends our understanding of online reading to a different cultural context. The findings of the study have important implications for both practice and research.
Teacher Knowledge Matters
(2019-10-23) Baxa, Julienne; Christ, Tanya; christ@oakland.edu
The DIGILIT FRAMEWORK Selecting and integrating the use of digital texts or tools in literacy lessons are complex tasks. The DigiLit Framework provides a succinct model to guide planning, reflection, coaching, and formative evaluation of teachers’ successful digital text or tool selection and integration for literacy lessons. For digital text or tool selection, teachers need to consider content accuracy, quality for supporting literacy development, intuitiveness, and user interactivity. For integrating these in instruction, modeling and guided practice should be provided for both literacy skills/strategies and the use of digital text or tool affordances. Also, instruction should capitalize on the digital affordances to transform instruction beyond what is possible with paper and pencil texts or tools. Examples of using the DigiLit framework to evaluate digital text and tool selections and their integration in literacy instruction are provided. DEMYSTIFYING IRI COMPREHENSION DATA: HOW ARE CLASSROOM TEACHERS USING IT? This study examined the classroom practices of nine teachers as they collected, scored, identified comprehension objectives, and used data from informal reading inventories (IRIs) to inform comprehension instruction with 23 students. Using open coding and constant comparative analysis (Corbin & Strauss, 2015), video recorded IRI administrations, post-IRI interviews, follow-up reading lessons, final interviews, and 440 pages of artifacts were analyzed. Data were analyzed for patterns of collection, scoring, comprehension objective identification, and follow-up instruction both within teachers and across teachers. Findings revealed that teachers showed strengths in administering suggested prompts, gaining additional information by asking open-ended questions, completely scoring comprehension sections, and scoring many sections completely accurately. Teachers’ needs were especially evident in the accurate identification of comprehension objectives for upcoming instruction based on IRI data and in how to provide appropriate follow-up instruction based on data from an IRI. Implications include the need to explore individualized professional development given that different teachers had differing strengths and needs as they used IRIs to collect, score, inform objectives and teach comprehension lessons.
The Role of Career Readiness in Humanities Curriculum: An Ethnographic Case Study in Pre- and Post-Tenured Humanities Faculty Course Design
(2021-07-23) Smydra, Rachel Verburg; Nidiffer, Jana; Moore, Shaun; Johnson, Eileen
This qualitative ethnographic single case-study was conducted to investigate what influences pre- and post-tenured humanities faculty course design, the effects of those influences, and their perceptions about career readiness. This study focused on a career readiness initiative at Mid-western Michigan University (MMU), which was built around the National Association of Colleges and Employers’ career competencies. With much of the success of this initiative dependent on faculty, the course design process and career readiness perceptions served as critical areas to explore. Eisner and Vallance’s (1974) education value orientations theory served as a framework for this investigation. Thirteen pre- and post-tenured MMU humanities faculty with at least two years of teaching experience participated in the study. Data collection included one-on-one semi-structured interviews, influence rankings, and document analysis of faculty syllabi and current and archival department/program resources. The data collected were analyzed and coded for insight into different influences, effects of those influences, and perceptions about career readiness. Findings showed students, academic discipline, and the purpose of education resonated as primary influences. In addition, faculty participants demonstrated that they employ meta-orientations by considering different influences concurrently. Influences resonated in faculty decision-making with regard to the following course design elements: content, skills, learning outcomes and themes, and big course questions. Findings also demonstrated that most participants are resistant to the language, branding, and logistics of MMU's career readiness initiative; however, some see the value of career readiness and have implemented aspects of transfer into their courses. These findings have implications for not only administrators who consider strategies to build a culture around career readiness but also for stakeholders concerned about the value of the humanities, the collective humanities disciplines, and ultimately for students who take courses in humanities disciplines.
The Relationship Between State-Trait Anger Expression and Attrition Rates of African Americans in Court Ordered Anger Management Treatment
(2021-10-20) Childers, Kimberly M.; Chaney, Michael; Leibert, Todd; Matthews, Jennifer; Scott, Chaunda
This research examined the relationship between state-trait anger and attrition rates of African Americans in court ordered anger management (COAM). In this study, archival data was collected from African Americans clients sentenced to COAM from 2011-2018 at a university counseling clinic. The results indicated that no relationship exists between state-trait anger and attrition from COAM. Men were found to have higher scores on state anger physical and trait anger reaction. Results also indicated that younger participants were more likely to have higher state anger verbal and state anger physical scores than older participants. These results yielded shed light on the need for appropriate pre-screening, cultural sensitivity, and recognition of possible bias in the referral process from judicial systems for African Americans. The sociopolitical implications of African Americans receiving harsher criminal sanction and possibly inappropriate clinical treatment as part of those sanctions is an area for future research. While the clinical implications for counselor educators and clinicians suggest that additional training is needed to increase advocacy for African American clients in COAM.
Development of Digital Shearography for Complex Defects Inspection
(2021-11-09) Zhang, Boyang; Yang, Lianxiang; Barber, Gary; Qu, Hongwei; Narainen, Roderigue
Digital shearography measures the first derivative of the object surface deformation, which has the advantages of high sensitivity, full field, non-contact, realtime and anti-disturbance. It is widely used in materials inspection in industry. The information acquisition methods of the first derivative distribution are mainly divided into the intensity method and the phase shift method. The intensity method is to directly obtain the first derivative phase distribution by subtracting the light intensity map. The phase shift method to obtain phase information can be divided into temporal phase shift and spatial phase shift. Most digital shearography systems are single camera based and can only capture one image every shoot. However, unpredictable defects like the narrow crack and minor flaws could induce incomplete detection due to some limitations. There are two major issues on the measurement, one is the defect with the irregular shape which is not sensitive to the digital shearography, another is the deformation made of defects that is much smaller than the resolution of cameras. Digital Shearography measures the first derivative of deformation on the object surface because the shearing direction determines the derivative direction being measured, tests using multiple shearing directions are sometimes required to detect all kinds of defects. When the deformation is long and narrow as a crack while the shearing direction is perpendicular to the crack growing direction, digital shearography has the best sensitivity. In opposite, if the crack growing direction is parallel to the shearing direction, digital shearography is not able to find it out. Irregular shape defects detection is a tough challenge for digital shearography. Another challenge is the defects that are too small for the field of view. The limited pixels can miss the defects due to the low signal to noise ratio. To increase the sensitivity of detecting minor defects, a small field of view measurement is needed but it is time consuming in a large surface area inspection. The new development can be divided into three categories: 1) Modified Michelson interferometer based dual shearing digital shearography. 2) Spatial light modulator based dual shearing direction shearography. 3) Polarized digital shearography for simultaneous dual sensitive measurement. The basic theory, optical path analysis, preliminary studies, results analysis and research plan are shown in detail in this dissertation.
How Faculty Use Online Social Spaces to Develop Their Teaching Practices: An Ethnographic Study of The #Ungrading Online Community
(2021-11-09) Moore, Christina Marie; Nidiffer, Jana; Sule, Thandi; Nichols Hess, Amanda
In higher education, faculty often teach in isolation, wondering if their practices reach and inspire students. If their institutions have teaching and learning centers, faculty might engage in discussions with colleagues within and beyond their disciplines, complemented by programming that builds their pedagogical knowledge. But many faculty members either do not have access to such programming because their institution lacks it, their schedule does not allow for it, or the programming does not connect with their interests and needs. Some faculty turn to online spaces such as social networking sites (e.g. Twitter, Facebook, and LinkedIn) to listen to and connect with other faculty, exchange teaching ideas, and refine practices accordingly. My study analyzed the conditions in which online teaching-based communities thrive and the experiences of faculty within them, focusing on two questions: how do faculty develop their teaching practices and identities in online communities of practice and personal learning networks, and why do they engage in this teaching development in online spaces. This digital ethnography observed an active Twitter-based conversation on ungrading, the practice of minimizing, eliminating, and critically examining grading constructs. Complemented with observing a related book club’s activities and analyzing faculty’s personal blogs, publications, and presentations, this dissertation described the culture of “Teaching Twitter” generally and #ungrading specifically. Results found that faculty on Twitter valued participating on the periphery of these communities, sometimes engaging more in these spaces over time and other times using Twitter as a starting point to engage in smaller communities of practice. They gravitated toward Twitter to find other teaching-centered faculty practicing ungrading, as such faculty can be difficult to find at one’s institution alone. Twitter and related online spaces provided faculty the autonomy and flexibility they need in teaching-related professional development. Faculty and faculty developers can apply the results of this study to create more online, social opportunities for teaching development.
Learning by Doing: A Case Study Exploring Mentor Teachers' Experience in a Teacher Preparation Program Through The Lens of Communities of Practice and Transformative Learning
(2021-11-10) Horne, Sara Marie; Carver, Cindy; Smith, Julia; Nidiffer, Jana
This study explores the learning theories communities of practice (Lave & Wenger, 1991) and transformative learning theory (Mezirow, 1978) in the context of mentor teaching. The landscape of teacher education preparation programs is shifting its focus to practice-based teacher education, with the inclusion of high-leverage teaching practices. This study delves into four mentor teachers’ experiences. Through a case study approach, this work examines how a change in teacher education programs impacts the mentor teachers’ experience. The learning theories, communities of practice, and transformative learning, were used as the lens with which to analyze the data. Monthly surveys, individual interviews, and a group interview were used as data instruments. The data demonstrated ways in which mentoring is a disorientating experience, as well as ways in which communities of practice and transformative learning work together to foster a transformative experience for mentor teachers
Experimental Implementation of a New Durability / Accelerated Life Testing Time Reduction Method
(2021-11-13) Baseski, Igor; Mourelatos, Zissimos P.; Latcha, Michael; Drignei, Dorin; Wang, Xia
Fatigue can be defined as a cyclic degradation process resulting in a failure at lower stress levels than the ultimate load. Fatigue reliability is defined as the probability that a structure will perform its intended function throughout its lifetime without any fatigue failure. Durability testing aims to predict fatigue damage in order to estimate the remaining useful life (RUL) based on fatigue. The latter is a useful metric in design for life-cycle cost. The objective of this research is to develop a new durability time reduction method to experimentally estimate the fatigue life of a vehicle component or system with accuracy using a short duration test. We assume that the loading random process (e.g. terrain configuration) is stationary and ergodic so that a single time trajectory can quantify the loading statistics. For the single time trajectory of the load process, we measure the corresponding output stress trajectory at a specified location on the structure. The latter is cycle counted using the 4-point rainflow counting algorithm. The cycle counting identifies all signal (stress) peaks and valleys using a peak picking algorithm and uses them to identify the range of all individual fatigue damage cycles and the time they occur based on a chosen fatigue damage model. Using this information (range of each cycle and the time it occurs), we build a synthetic signal exhibiting the same fatigue damage cycles in the sequence they occur in the actual stress signal. The sequence can be important in order to properly account for the cumulative damage accumulation. Finally, based on the fact that the cycle damage is independent of the time it occurs, we compress the synthetic signal so that its Power Spectral Density (PSD) does not exceed an upper limit dictated by the durability equipment. This proposed durability approach achieves therefore, the same cumulative damage with the original signal in a much shorter testing time. We demonstrate the new durability approach with two examples, and validate it experimentally using a commonly used Belgian block terrain excitation on the suspension coil spring of a military HMMWV (High Mobility Multi-purpose Wheeled Vehicle).
2-D Modeling of Moisture and Heat Diffusion in Adhesively Bonded Joints
(2021-11-15) Gerini Romagnoli, Marco; Nassar, Sayed A.; Yang, Lianxiang; Gu, Randy; Dembinski, Roman
In this dissertation research, a novel two-dimensional model is proposed for adhesively-bonded Single Lap Joints (SLJ) under combined mechanical loads and moisture/heat diffusion. Governing partial differential equations of the constitutive stress-diffusion model are formulated and solved numerically. Various scenarios for individual and combined diffusion of moisture and heat through the joint substrates and directly into the adhesive layer are analyzed. The resulting location-dependent material model is fed into the governing partial differential equations. Shear and peel stresses in the adhesive layer are investigated. Results are presented, with a focus on the improvements brought by the capability of the proposed model to predict the effects of diffusive patterns that are perpendicular to the axial tensile-shear load.Moisture diffusion across the joint width is found to have a significant effect on the shear stress distribution for structural epoxy adhesives with high elastic modulus. Numerical comparison with a linear Finite Elements Analysis is provided. Material properties are derived from experimental testing of commercially available two-component epoxy and polyurethane adhesives. This document is organized as follows: Chapter One "Introduction and Literature Review" includes a description of the analytical, numerical, and experimental work that serves as foundation for this dissertation. A previous one-dimensional analytical model is revised, and the motivations driving this research effort are illustrated. Chapter Two "Modeling of Heat and Moisture Diffusion" lays the groundwork for the analysis of diffusive patterns in the joint substrates and in the adhesive layer. Multiple scenarios of moisture and heat diffusion are explored, and their effect on the elastic properties of the adhesive is investigated. Governing partial differential equations are derived, and solution strategies are discussed. Chapter Three "Elastic Model" includes the formulation of coupled stress-diffusion partial differential equations for the shear and peel stresses in the adhesive layer, resulting from the application of an external tensile-shear load on the two adherends. Equilibrium considerations, stress-strain, and strain-displacement relationships are used to generate the constitutive equations, with adequate assumptions and simplifications. Chapter Four "Elastic Modulus of Structural Adhesives: Relationship to Bulk Material Temperature" contains the experimental procedure and results for the bulk adhesive tests. The elastic moduli of two-component epoxy and polyurethane adhesives are measured using a DMA Q800, and a linear law relating temperature to material properties is inferred. Chapters Five, Six, and Seven present the results of the shear and peel stress models for adhesive joints subjected to two-dimensional moisture-only, heat-only, and combined moisture/heat diffusion, respectively. A convergence study is performed on the two-dimensional solution to the heat equation governing moisture and heat diffusion in the adhesive layer. Stress gradients along the length and width of the bondline are analyzed, and the results are compared to the previous one-dimensional coupled stress-diffusion model. The results of the two-dimensional model are compared with a Finite Elements Analysis in Chapter Eight "FEA Comparison". Chapter Nine "Conclusions and Future Work" summarizes the major findings of this dissertation research, and outlines the potential for future work.
Solution Methodology for Constrained Eigenvalue Problems and Its Applications with Experimental Validation in Structural Characteristics Identification
(2021-11-15) Chen, Longhan; Gu, Randy; Yang, Lianxiang; Mourelatos, Zissimos P.; Spagnuolo, Anna
A numerical reverse algorithm was developed in this dissertation to find some unknown parameters of an object. For example, if the natural frequency of an object is known, find the mass of the particle placed at a specific place in the object. There is nos such direct formula or algorithm that can solve this kind of problem, we can use the reverse algorithm to solve it. Since the objective function can be built after the structure's stiffness matrix and mass matrix were obtained using the finite element method, and the structure's natural frequencies are known, this kind of problem becomes a constrained eigenvalue problem. The constrained eigenvalue problem can be solved by minimizing the objective function and executed using numerical methods. In this dissertation, we developed Newton's iteration to solve it and also developed the Genetic Algorithm as an alternative algorithm when Newton's iteration cannot find unknown parameters. Several numerical examples, such as beam, plane frame, three-dimensional frame, and plate structure, were chosen to test the proposed algorithm's feasibility, accuracy, and solving time. Furthermore, some groups of experimental validation were also provided to testify to it.
What Is the Relationship Between Early Childhood Teacher Turnover, Adult Staff Resilience and Resilient Leadership Practices at Licensed Early Childhood Centers?
(2021-11-15) Arakelian, Tamara Labadie; Ricks-Doneen, Julie; Oden, Sherri; Wakabayashi, Tomoko; Klein, Suzanne
This research investigated the relationship between adult resilience, resilient leadership practices, and variables that reflected turnover to learn if increasing adult resilience or resilience leadership practices is an avenue to reduce turnover of high quality early childhood education teachers. The areas of adult resilience and resilient leadership practices that were measured include relationships, initiative, internal beliefs, and self-control as itemized in the Devereux Adult Resilience Survey (DARS) and Devereaux Resilience Leadership Survey (DERLS). One-hundred and eighty-five adultsparticipated by completing a survey that gathered their individual information including demographic information like age, information related to turnover like how long they anticipated working at the current center, and responses to the DARS and DERLS. Administrators were also asked to provide center information, like whether turnover was the lower, the same, or higher than the previous year. Those who submitted a survey worked in early childhood centers from an urban area in a Midwestern State of American. The 185 adults who submitted a survey included 99 teachers and 86 administrators from 82 different licensed centers. They ranged in age from 25 to 63 years. A quantitative analysis included factor analysis that established composite variables for each of the DARS and DERLS areas. Statistical significance was analyzed using chi-square, one-way ANOVA, logistic regression, and linear regression. The researcher found many significant relationships. For example, centers with staff with higher DARS ratings had lower turnover and center directors with research recommended qualifications also significantly predicted turnover at the center. Applications include investing in early childhood at each of Bronfenbrenner’s ecological systems to build the resilience of early childhood professionals.
An Optimal Asynchrophasor in PMU Using Second Order Kalman Filter
(2021-11-15) Alqahtani, Nayef Mohammed S; Zohdy, Mohamed; Ganesan, Subramaniam; Kobus, Christopher; Elsayed, Suzan
Phasor Measurement Units (PMU) are very costly according to energy regulator and utility companies. Utility operators work on alternative solutions to reduce the error rate and operation costs of PMU. In this paper, we sought to optimize the PMU to reduce the level of error using Second-Order Kalman Filter (SOKF). Consequently, this optimization is based on minimizing the number of errors when receiving the signal from access points or from the main access point. We derived a simple mathematical model to estimate the phase coming from the PMU.PMUs provide Global Positioning System (GPS) time stamped synchronized measurements of voltage and currents with the phase angle of the system at certain points along the grid system. Those synchronized data measurements were extracted in form of amplitude and phase from various locations of the power grid to monitor and control the power system conditions. A PMU device is a crucial part of the power equipment in terms of the cost and operative point of view. However, such ongoing development and improvement to PMUs' principal work is essential to the network operators to enhance the grid quality and the operating expenses. A MATLAB model was created to implement the proposed method in the presence of Gaussian and non-Gaussian noise. It is based on an Asyncrhophasor technique resulting in a phase error minimization when receiving the signal from access point or from the main access point. The results show the proposed SOKF method outperforming the existing model as tested using Mean Square Error (MSE). The SOKF method was replaced with a synchronization unit into the PMU structure to clarify the significance of the proposed new PMU. This paper's proposed method leads to lower costs and less complex techniques to optimize the performance of PMU using SOKF
Preclinical Studies: Treatment of Multiple Sclerosis and Retinal Degenerative Disease Using Stem Cells
(2021-11-15) Cormier, Christina Frances; Chaudhry, G.; Govind, Chhabi; Svinarich, David; Perez-Cruet, Mick
Pluripotent stem cells (PSCs) isolated from an embryo or generated by ectopic expression of transcription factors can self-renew indefinitely and differentiate into all cell types found in the body. PSCs have the highest potential for cell therapies, but they face ethical concerns and technical and safety challenges, including teratoma formation. In contrast, mesenchymal stem cells (MSCs) isolated from adult and perinatal sources do not pose ethical and moral dilemmas. While MSCs isolated from adult sources, such as bone marrow, require invasive procedures, their use may also cause graft verse host disease. Therefore, we have focused on MSCs isolated from perinatal sources such as the umbilical cord (UC). These cells have advantages over adult MSCs in that they are highly proliferative, do not display HLA-DR markers, and thus are not likely to be immunogenic. We tested the therapeutic efficacy of UC-derived MSCs and their derivatives in preclinical studies to treat multiple sclerosis (MS) and retinal degenerative disease (RDD). The specific aims were to 1. production of MSCs for preclinical studies; 2. treatment of MS using MSCs and NSCs; and 3. treatment of RDD using MSCs and RPC. Our results showed that MSC-derived neural stem cells (NSCs) countered the inflammatory response, provided neural protection, and induced neurogenesis in the experimental autoimmune encephalomyelitis (EAE) mouse model of MS. Likewise, MSC-derived retinal progenitor cells (RPCs) survived, integrated, and migrated into various neural layers of the retina in the rd12 mouse model of retinitis pigmentosa (RP). RPCs promoted retinal structure, function, neural protection, and regeneration of the retina resulting in vision improvement. These highly promising findings are likely to facilitate clinical studies for treating MS and RDD.

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