Multi-Scale Dynamic Study of Secondary Impact During Drop Testing of Surface Mount Packages

This dissertation focuses on design challenges caused by secondary impacts to printed wiring assemblies (PWAs) within hand-held electronics due to accidental drop or impact loading. The continuing increase of functionality, miniaturization and affordability has resulted in a decrease in the size and weight of handheld electronic products. As a result, PWAs have become thinner and the clearances between surrounding structures have decreased. The resulting increase in flexibility of the PWAs in combination with the reduced clearances requires new design rules to minimize and survive possible internal collisions impacts between PWAs and surrounding structures. Such collisions are being termed ‘secondary impact’ in this study. The effect of secondary impact on board-level drop reliability of printed wiring boards (PWBs) assembled with MEMS microphone components, is investigated using a combination of testing, response and stress analysis, and damage modeling. The response analysis is conducted using a combination of numerical finite element modeling and simplified analytic models for additional parametric sensitivity studies.

THE EFFECT OF SCHOOL CLIMATE (STUDENT AND TEACHER ENGAGEMENT) ON STUDENT PERFORMANCE

Title of Dissertation: THE EFFECT OF SCHOOL CLIMATE (STUDENT AND TEACHER ENGAGEMENT) ON STUDENT PERFORMANCE Kenneth L. Marcus, Doctor of Education, 2016 Directed By: Dr. Thomas Davis, Assistant Professor, Education Policy and Leadership, Department of Teaching and Learning, Policy and Leadership This quantitative research study was designed to compute correlations/relationships of student engagement and student achievement of fifth grade students. Secondary information was collected on the relationship of FARMS, type of school, hope, and well-being on student achievement. School leaders are charged with ensuring that students achieve academically and demonstrate their ability by meeting identified targets on state and district mandated assessments. Due to increased pressure to meet targets, principals implement academic interventions to improve student learning and overlook the benefits of a positive school climate. This study has provided information on the impact of school climate on student achievement. To conduct this study, the researcher collected two sets of public fifth grade data (Gallup Survey student engagement scores and DSA reading, mathematics, and science scores) to determine the relationship of student performance and school climate. Secondary data were also collected on teacher engagement and the percentage of students receiving FARMS to determine the effect on students. The findings from this study reinforced the belief that school climate can have a positive effect on student achievement. This study contributed quantitative data about the relationship between school climate and school achievement.

The Impact of Childhood Sexual Abuse on Later Parenting Self-Perceptions: The Moderating Effect of Family Support

Childhood sexual abuse has been found to be a risk factor for developing negative parenting self-perceptions later in life. Given this established relationship, it is crucial to investigate factors that may mitigate negative outcomes, such as family support. The present study used secondary analysis of a dataset of 265 predominantly African-American and low-income mothers. This study examined differences in parenting self-perceptions among mothers who experienced childhood sexual abuse and those who did not. Analyses revealed that mothers who experienced childhood sexual abuse did not differ in terms of parenting self-perceptions from non-sexually-abused mothers. After controlling for depression, there was no moderating effect of family support; however, a main effect for family support was observed. The results indicate that depression plays a larger role in mothers’ parenting self-perceptions than childhood sexual abuse, and that family support is beneficial for all mothers, regardless of sexual abuse status. Clinical implications are discussed.