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Measuring spouses’ ages allows us to explore larger sociological issues about marriage, such as whether narrowing gaps signal gender progress or if a rise in female-older unions reveals a status change. Using Census and American Community Survey data, I test the merits of beauty-exchange and status homogamy theories as explanations for how heterosexual marital age gaps changed over a 40-year period of social and economic revolution. Analyses address questions about how age gaps compared for people with different characteristics, whether similarly aged couples exhibited greater educational and socio-economic homogamy than others, and if the odds of being in age-heterogamous marriages changed. Chapter 4 provides the historical context of U.S. marriages from 1910 on, and shows that while disadvantaged groups retreated from marriage, the percentage of individuals with greater education and income who married remained high. Age homogamy rose over 100 years due to a decline in marriages involving much-older husbands rather than increases in wife-older unions. Results in Chapter 5 show that mean age gaps decreased significantly over time for first-married individuals by most—but not all—characteristics. Gaps narrowed for those who were White, Black, other race, or of Hispanic origin; from any age group; with zero, one, or two wage earners; with any level of education; and from most types of interracial pairs. One exception was that mean age gaps increased between Asian wives and White husbands, and Asian women’s odds of having a much older husband were higher than the odds for racially homogamous women. Those odds increased over time. Findings lent support for status homogamy theory, since same-age couples showed greater educational homogamy than others in any decade, but showed mixed support for beauty exchange. In 2010-14, the median spousal earnings gap was wider in husband-older marriages than age-homogamous ones; however, the reverse was true in 1980. Women-older first or remarriages exhibited the smallest median earnings gaps in 1980 and 2010-14, and women in these marriages contributed a greater percentage of the family income than other women in 2010-14 (43.6% vs 36.9%, respectively). The odds of being in age-heterogamous unions were significantly higher for persons who were remarried, from older age groups, from certain racial backgrounds, in some interracial marriages, less educated, and from lower SES backgrounds. Age and remarriage showed the greatest impact on odds ratios. While age homogamy increased overall, the odds of being a much older spouse (11+ years older) increased dramatically for remarried men and women between 1970 and 1980, and then remained high in 2010-14. Remarried women’s odds of being the much older wife versus a same-age spouse were 20.7 times that of the odds of first-married women in 2010-14. Other results showed that Black men’s odds of being with a much-older wife compared to one around the same age were about 2.5 times that of the odds of White men in each decade. Hispanic men’s odds of being in a first marriage with a much-older wife versus one of the same age were also twice the odds of White men in 1980 and 2010-14. Analyses demonstrated that marital age gaps have, indeed, changed significantly since the second-wave women’s movement, and that while age homogamy increased, the odds of being age heterogamous also shifted for people with different characteristics. / Sociology

no / This paper presents research into perceived quality of vehicle body split lines / gaps. The survey based methodology combined direct attribute evaluation and choice experiments with multiple test cases, based on static images generated from parametric CAD virtual prototypes of a specific vehicle. The study systematically tested for perception without and with awareness and the Hawthorne bias, showing significant effects. Statistical analysis provided clear evidence of the user preference for smaller gap size, and as such supports target and tolerance setting for the body gap.

The physical supply chain relies on three components to transport products: the pallet, the package, and unit load stabilizers. The interactions between these three components can be investigated to understand the relationship between them to find potential optimization strategies. The relationship between corrugated boxes and pallets have been previously investigated and have found that the relationship can be used to reduce the quantity of material used in unit loads and can also reduce the cost per unit load if the package and pallet are designed using a systems approach. Although corrugated boxes are a common form of packaging, plastic pails are also used in packaging for liquids and powders, but they have not been previously investigated. To understand the interactions between the wooden pallet and plastic pails, physical tests were conducted and then used to create and validate a finite element model. The experiments were carried out in three phases. The first phase included physical testing of plastic pails where the deckboard gap and overhang support conditions would be isolated by using a rigid deckboard scenario. The second phase also used physical tests to investigate plastic pails but instead used flexible deckboards and used an overhang support condition and a 3.5 in. gap support condition. The third phase of experiments would develop and validate a finite element model to further understand the impact of deckboard gaps and overhang depending on the location of the gap. Previous physical experiments were used to create and validate the finite element model. Nonlinear eigen buckling analysis was used to model the plastic pail buckling failure that was seen in physical testing. The model based on the physical experiments was able to predict the behavior of the plastic pail within a range of 5-12% variation with higher variation being introduced when the flexible deckboard is introduced. The finite element model was then used to model a range of deckboard gap sizes and overhang sizes as well as different locations for deckboard gaps. The results of the experiments indicate that the percent of pail perimeter that is supported directly on the pallet impacts the compression strength of the plastic pail. Decreasing the quantity of support decreases the compression strength of the plastic pail in a linear pattern. The location of the deckboard gap also influenced the compression strength because of the quantity of pail being supported being altered. The results of the experiments can be used by industry members to provide guidelines on unit load design to prevent plastic pail failure. Industry members can also use the results as a baseline investigation and further the finite element model by incorporating their own plastic pail design. / Doctor of Philosophy / The physical movement of products relies on three main elements: pallets, packaging, and stabilizers for unit loads. Examining how these components interact helps uncover their relationships and potential strategies for optimization. Previous studies have explored the connection between corrugated boxes and pallets, revealing ways to reduce material usage and costs through a systems-based design approach. While corrugated boxes are commonly studied, plastic pails, used for liquids and powders, have not received similar attention. To understand the dynamics between wooden pallets and plastic pails, physical tests were conducted. The physical experiments illustrated the importance of investigating the relationship within unit loads but there are limitations that exist when doing physical experimentation such as time and materials. A finite element model is a mathematical model that can be used to simulate physical phenomenon to further understand physical interactions without having to conduct physical experiments. Using the results of the physical experiments that were conducted, a finite element model was developed to further investigate the system that exists between pails and pallets. The experiments occurred in three phases. The first phase focused on isolating deckboard gap and overhang support conditions using a rigid deckboard scenario in plastic pail testing. In the second phase, a pallet with flexible deckboards was used to explore overhang and a 3.5-in. gap support condition. The third phase involved creating and validating a finite element model to better grasp the impact of deckboard gaps and overhang, considering gap location. Previous physical experiments guided the model's development and validation. Nonlinear eigen buckling analysis simulated plastic pail buckling failure observed in physical tests. The model predicted plastic pail behavior within a 5-12% variation range, with greater variation when using flexible deckboards. This model explored various deckboard gap and overhang sizes, along with different gap location and found that the quantity of unsupported perimeter that the pail experiences affects the quantity of load that the pail can experience before achieving failure. These results are impactful to industry members because it quantifies the impact that pallets can have on their package. Understanding the interactions between the package and the pallet can also be used to create unit loads that are safer by quantifying the buckling load of plastic pails. Investigating plastic pails and the interactions between pallet components can lead to creating safer and better design unit loads in the industry.

The purpose of this study was to determine the perceptions of mentors regarding the impact of a school-based mentoring program and to identify which research-based best practices were used to achieve these impacts. School accountability measures have brought many changes to education. Since the implementation of No Child Left Behind there has been focused attention on student performance on standardized state testing. To ensure that every student met grade level content standards, schools have implemented collaborative planning through professional learning communities to improve instructional practices, regular meetings to track student performance data, and an increased focus on teacher and school leader evaluations to name a few. Despite the positive impacts of all these efforts, there are still gaps in the academic performance levels of identified student reporting groups. To eliminate these achievement gaps, many school leaders are implementing school-based mentoring programs to help meet the socio-emotional needs of their students. A convergent parallel mixed-methods design was used for this study. The researcher gathered quantitative data from a survey developed in a previous study which sought to "unpack how mentoring has its documented, beneficial effects and to refine understanding of best practice" (Tolan, McDaniel, Richardson, Arkin, Augenstern, and Dubois, 2020, p. 2104). The survey was used to identify the practices used by a school-based mentoring program. These survey data were supported by qualitative data collected during semi-structured recorded interviews. The interviews were used to discover the perceptions of the mentors on the impacts of the mentoring program as well as the practices used by the program. The two types of data were used to compare the findings from one another. The findings of this study demonstrated the mentor's fierce belief in the effectiveness of the program. The mentor's shared that they help students develop the ability to advocate for themselves. This finding contrasted with the existing research which discussed mentor's advocating for the mentee. The mentor's felt one of the impacts was helping student to identify and manage the emotions they dealt with in their daily lives. Finally, the mentor's shared that the mentoring program helped students develop prosocial behaviors such as empathy, social problem solving, and cooperation. / Doctor of Education / School leaders are dedicated professionals who work tirelessly to ensure that teachers are prepared to meet the needs of every student. Over the last twenty years there has been renewed attention on school accountability measures from both the state and federal governments. Despite these well-intentioned efforts and the incredible efforts of school leaders there remains significant gaps in the performance of students from the identified reporting groups; such as racial categories, students from low-income households, students with disabilities, and English Language learners. School leaders continue to search for additional resources to help meet the needs of these students. These efforts have led many school leaders to implement school-based mentoring programs. This mixed-methods study sought to identify the perceptions of mentors on the impacts of a school-based mentoring program, as well as which practices were used to achieve these impacts, in a diverse school division in central Virginia. Quantitative data was collected through a survey which sought to determine the practices used by the school-based mentoring program and whether they aligned with the research-based best practice identified in a study by Tolan et al. (2020). Qualitative data was gathered through semi-structured interviews to uncover the perceptions of the mentors on the impacts of the program and to confirm the use of research-based best practices. These two data sets were compared to confirm the findings. The study found that the school-based mentoring program taught students to effectively advocate for themselves. This contrasted with the research-based best practices identified by Tolan et al. (2020) which called for mentors to advocate for students. A second finding was that one of the impacts identified by mentors was that the mentoring program helped students develop empathy, social problem-solving skills, and cooperation. The third finding was that the mentors taught students to identify, name, and then develop the skills necessary to manage the emotions students were struggling with in their lives. Mentors perceived that these skills built upon one another leading students to develop healthy relationships with both peers and school personnel, ultimately leading to increased academic engagement and performance.

This qualitative case study analyzes the underrepresentation of minority students in Advanced Placement (AP) courses in Virginia high schools and examines the influences that encourage school leaders to lessen the existing gaps at their assigned schools. Data from a division in southeastern Virginia summarizing each school's minority representation in its AP courses were analyzed. After identifying the schools' minority representation levels, qualitative research methods were used to determine the impact, if any, of school leaders on student participation rates. Additionally, qualitative data from individual interviews were considered to determine if school leaders who had a higher representation of minority populations at their schools demonstrated intentional actions to address AP participation in their schools. The results of this study indicate that principals believed that all capable students should have access to AP courses and that teachers and counselors influence students' decisions to enroll in AP courses. Additionally, principals found that sharing data reflecting their school's representation rates helped justify the need to improve student participation in AP courses. Principals with high participation rates placed importance on communicating to students the opportunities obtained by participating in AP courses and expected school staff to encourage students with potential to participate in more rigorous courses. Principals with higher minority representation rates in advanced courses were also found to frequently remind a variety of stakeholders to encourage students to participate in AP courses. Furthermore, principals with higher minority representation in AP programs used more "we," "us," and "our" statements and references to a team approach when asked about their work. Finally, this study found that specialized academies create environments where stronger student representation rates can occur in AP courses for all student groups. The results of the study have the potential to impact high school leaders as they seek to improve outcomes for the students they serve. / Ed. D.

Les tokamaks visent à réaliser la fusion contrôlée de noyaux de deutérium et de tritium par le confinement magnétique d'un plasma chaud. L'interaction entre le plasma et les parois a été étudiée en détail pour le tokamak Tore Supra. Au cours des décharges, le plasma interagit fortement avec le limiteur, formé de milliers de tuiles en composite carbone/carbone. L'érosion de ces tuiles par les flux de particules du plasma mène à la formation de co-dépôts de carbone et de deutérium qu'il est essentiel de limiter. Nous avons effectué une étude multi-échelle, principalement avec les différents outils de la microscopie électronique, sur des tuiles provenant du limiteur de Tore Supra. Une analyse des co-dépôts a permis de mettre en évidence leur topographie en forme de pointes, orientées dans une même direction quelque soit la position de la tuile sur le limiteur. L'étude de la surface de tuiles appartenant à des zones majoritairement érodées a révélé la présence d'une striation périodique de surface. Ces deux phénomènes ont été mis en relation avec la direction des flux et l'effet de la gaine faiblement magnétisée de Tore Supra a été mis en évidence. L'analyse des dépôts présents dans les interstices entre les tuiles a révélé une physique propre à ces interstices permettant la formation de dépôts en profondeur. Des nanoparticules graphitiques sphériques ont été observées, signe d'une croissance homogène locale en phase plasma. Nous avons développé des méthodes de mesure des volumes de dépôt et des volumes érodés, menant à l'établissement d'un bilan carbone et à l'évaluation de la masse de deutérium piégé, en bon accord avec les mesures in-situ réalisées dans Tore Supra. / Tokamaks are devices aiming at achieving controlled fusion of deuterium and tritium by magnetically confining a hot plasma. The interaction between the plasma and the inner walls is a crucial issue and has been studied in detail in Tore Supra. During discharges the plasma strongly interacts with limiter, designed with thousands of carbon tiles (C/C composite). The plasma particle fluxes erode the tiles, leading to co-deposition of carbon and deuterium that should be limited. We have performed a multi-scale study of tiles extracted from the Tore Supra limiter, mainly using electron microscopy. The analysis of the co-deposits has revealed a tip-shaped topography, tips being oriented in the same direction wherever the tile over the limiter. Analyses of tiles extracted from erosion-dominated zones have revealed the presence of a periodic ripple on their surfaces. Both phenomena have been related with the direction of ion fluxes and the effect of the weakly magnetized sheath of Tore Supra has been shown. Analyses of the deposits inside the gaps in-between the tiles have revealed the existence of specific processes leading to the formation of deposits deeply inside the gaps. Graphitic nano-particles have been observed, showing the existence of local homogeneous growth processes. Finally, by measuring the deposit volume and the C/C composite eroded volume we have obtained an inventory of both carbon and deuterium which is consistent with the analyses of Tore Supra in-situ measurements.