The objective of this study was to investigate thermal stresses in oxidation protection coatings on carbon-carbon composites. Multilayer coatings with each layer of coating applied at a different temperature, and gradient coatings with continuously varying properties through the thickness of the coating were considered. Particular emphasis was on the prediction of the thermal stresses in the vicinity of geometric discontinuities. For the analysis an incremental generalized plane-strain finite element model that accounts for temperature-dependent material properties and continuously varying properties in the gradient coatings was developed. The model is based on an incremental constitutive equation for linear thermoelastic materials that accounts for the coupling between stresses and the temperature-dependence of the material properties. In addition to the finite element model, an incremental simplified plane stress analysis for the prediction of stresses away from geometric discontinuities was developed. Analyses of carbon-carbon substrates with coatings showed that large stress concentrations in the coatings may be present near the geometric discontinuities. It was found that inserting a compliant layer between the carbon-carbon substrate and the oxidation protection coatings, or inserting a gradient coating with properties varying from those of a compliant material near the carbon-carbon substrate to those of the oxidation protection coating near the oxidation protection coating, could be used to significantly reduce the magnitudes of the stresses in the stress concentrations. The influence of geometric and material parameters on the stresses was studied and for some combinations of parameters stresses near the geometric discontinuities could be reduced to magnitudes that were smaller than the magnitudes of the stresses away from the discontinuities. For coatings applied at different temperatures, the application temperature of the coatings significantly influenced the magnitude of the stresses. The lowest stresses were obtained for gradient coatings for which the application temperature of the gradient coating varied continuously, proportional to the material composition in the gradient coating. / Ph. D.

Ph. D.

A model that simulates test of metal:-plate-connected wood trusses was developed. The truss test model built on previous research efforts to simulate ultimate failure of structural systems. For years, lumber failure models have used failure equations that were derived from design equations. This approach was applied to the strengths of metal plate connected joints. The model uses actual steel properties data for modelling the strength of the joints, and uses the most current lumber data to model the lumber strength and stiffness properties in the trusses. One of the unique features of the model is the use of basic fundamental engineering properties to predict the strengths of the individual components of the structural systems. These general principles allow the model to be used for many truss configurations. This flexibility differs from several current metal plate connected wood truss models in the literature. Although the safety factor for lumber is the smallest of all the truss components, many of the simulated truss failures were controlled by plate failures. The metal plate connected joints were the weakest link in the truss system. To improve the overall strength of a truss, the plates would need to be strengthened. Two different truss configurations were used for the simulations. Both truss simulations performed well, when compared to actual test data. / Ph. D.

A major battle in the struggle for African American civil rights has been the pursuit of educational opportunity. Little has been written about the early civil rights movement in western and southwestern Virginia. There is an especial paucity of information about the efforts of African American Southwest Virginians to improve their educational opportunities. This dissertation addresses that need by centering the study on an individual educator's life during the period 1913-1940 in Pulaski, Virginia. Chauncey Depew Harmon, Senior, was an African American educator born in Pulaski, Virginia, in 1913. Educated at Tuskegee Normal and Industrial Institute during 1929-35, he returned to Pulaski to become principal of Calfee Training School in 1938. With the assistance of the NAACP and the Virginia State Teachers Association, Harmon led one of the earliest campaigns for equalization of teacher salaries and facilities during the 1938-39 school term. In March of 1939, the Pulaski County School Board decided to send its African American high school students to the Christiansburg Industrial Institute, effectively eliminating Harmon's position. Harmon's efforts resulted in a suit, Corbin et al. v. County School Board of Pulaski County, that was one of eleven facility equalization suits supported by the NAACP prior to Brown v. Board of Education. The study is an example of microhistory. Microhistory is the detailed, intensive study of the lives of particular individuals or groups. The study employs accepted methods of historical research. The study is organized chronologically. The outcomes of the study are threefold. First, the study serves to document the youth, education, and, early career of Harmon. Second, the study examines the persons, events, and institutions of the period that played a role in leading up to Harmon's decisions and actions to push for equalization of teacher salaries and school facilities in Pulaski. Finally, the study endeavors to add to the body of knowledge and understanding of the issue of race in American education. / Ed. D.

In 1965, a study funded by the Carnegie Corporation identified 21 functions considered to comprise a basic student personnel program at any two-year college. Many changes have occurred in the two-year college over the past 29 years. Two-year colleges experienced continuous growth and expansion during the 1970s, wrestled with budget cuts and retrenchment in the 1980s, and faced an uncertain future in the 1990s. The purpose of this study was to conduct a survey to determine if differences existed: (a) between 1965 and 1994 in student personnel functions at large and small two-year colleges, (b) between large and small two-year colleges in student personnel functions purportedly offered in 1994, (c) between large and small two-year colleges in the scope and quality of student personnel functions provided in 1994, and (d) between large and small two-year colleges in ten selected institutional factors in 1994. The Basic Services Questionnaire (BSQ) was developed and administered to a random national sample of 200 principal student affairs officers stratified by size of college. The survey required responses to 28 student personnel functions, perceptions of the scope and quality of these functions, and ten selected institutional factors. The Chi Square Test of Independence and the Multivariate Analysis of Variance were utilized to analyze the data. The results of the study confirmed that the 21 basic student personnel functions identified in the 1965 Carnegie study were provided in 1994 by both large and small colleges, that seven additional functions were identified as basic student personnel functions provided by two-year colleges in 1994, and that the majority of the 238 student personnel functions provided at both large and small two-year colleges were perceived to be provided with the same scope and quality in 1994. The results of this study could be used by principal student affairs officers as both a model for implementation and evaluation of student personnel programs at their colleges. / Ph. D.

Lenticular-sheet (LS) images induce the sensation of object depth through motion parallax and stereopsis, which is based on retinal disparity. To achieve the three-dimensional effect, some sacrifice of image quality must be made. A study is described which investigated the tradeoff between depth and image quality that is inherent in LS imaging by asking subjects to evaluate stimuli that varied on these attributes. Four different scenes were generated as experimental stimuli to encompass a range of typical LS images. The length of camera travel in taking the 20 photographs necessary to produce a single image determined the overall amount of depth in the image, while varying the pivot point allowed the degree of foreground and background disparity to be altered. Preference evaluations were conducted using the method of free-modulus magnitude estimation. Generally, subjects preferred images which had smaller amounts of camera travel, and they tended to dislike excessive amounts of foreground disparity. However, differences were scene-dependent, so post-hoc analyses were performed to determine sources of significance in main effects and interactions. The most preferred image was also determined for each scene by selecting the image with the highest mean rating. In a second experiment, these most preferred LS images for each scene were shown to subjects along with their analogous two-dimensional (2D) photographic versions. Results indicate that observers from the general population looked at the LS images longer than they did at the 2D versions and rated them higher on the attributes of quality of depth and attention-getting ability, although the LS images were rated lower on sharpness. No difference was found in overall quality or likeability. When paired comparisons were made, preference results were scene-dependent. Finally, a recall task showed no difference in the ability to remember details based on the type of image. These results show that consumers prefer LS images when they satisfy the viewer’s image quality requirements and that these images can be beneficial in attracting and maintaining consumer attention. Recommendations, in the form of design implications, are made which can help the LS image developer meet these image quality requirements. / Ph. D.

This dissertation involves an empirical reexamination of US growth with the purpose of explaining growth usually attributed to advances in productivity. First, retaining the assumption of exogenous technological progress, I attempt to improve upon existing empirical models through new functional form assumptions. Next, I employ recent models of endogenous growth. Later chapters explore the issues of nonstationarity and international dependence. A significant generalization of the Gumbel Exponential distribution is developed and applied to the statistical modeling of economic growth. My chief objective is to characterize more accurately recent growth experience so that we may determine the most effective policy actions. Current empirical studies of growth behavior have concentrated on a cross sectional approach. I believe, in addition, much can be learned about individual growth processes through a time series approach. This approach avoids many complicated issues in cross sectional analysis including changes in institutions within and between countries. Better understanding the nature of growth in a particular country and relating this process to other nations should yield valuable insight into the nature of growth, convergence and divergence and provide implications for public policy. Many empirical studies have downplayed the crucial issue of examining the data in order to find the most appropriate econometric model specification. Through misspecification testing, we can identify and avoid faulty assumptions. Instead of viewing our data set as uncooperative, we should value the rich information our data contain. If our usual specification assumptions are invalid, more information can be extracted from our series through the inclusion of additional variables or through a Maximum Likelihood approach based upon an alternative distribution. This is the approach I follow in reexamining commonly utilized US input and output series. Utilizing the statistical and graphical abilities of the computer packages GAUSS and MATLAB, I am able to examine both graphically and analytically the validity of various assumptions about the underlying distributions of the data. With this approach, I can show that the Solow Residual contains a great deal of additional information about the dynamic pattern of growth of macroeconomic aggregates. / Ph. D.

This dissertation demonstrates how the study of young adult fiction can be illuminated by a working knowledge of contemporary literary theories, viewing these theories as strategies, approaches to interpretation. The text reflects the author’s education in theory, his belief that a basic knowledge of theory provides a rich repertoire of new ways of reading, and his consideration of the ways in which theory can be used by both teachers and students in secondary and university classrooms. The text introduces literary theory to those who have little or no experience with it, explaining how theory establishes and explores relationships among author, reader, text, and cultural contexts. Its conversational style encourages readers to explore the practical applications of theory in their work. Each chapter discusses one theory and demonstrates its application in a close reading of one young adult text: Formalism (Virginia Hamilton’s M. C. Higgins, the Great); archetypal theory (Gary Paulsen’s Dogsong); structuralism/semiotics (Bruce Brooks’ The Moves Make the Man); poststructuralism/deconstruction (Lois Lowry’s The Giver); reader-response theories (Walter Dean Myers’ Fallen Angels); feminism (Budge Wilson’s short story collection The Leaving); black aesthetics (Ernest Gaines’ A Lesson Before Dying); cultural studies (M. E. Kerr’s Night Kites); and the application of several theories to Katherine Patterson’s Jacob Have I Loved. The concluding chapter sets the voices of theorists and teachers into conversations about the implications for theory in the English classroom. / Ph. D.

The purpose of this study was to compare the dimensions of personal development of black male high school student athletes with black male high school student nonathletes to determine the relationship between participation in interscholastic athletics and the degree of students’ personal development. The study drew upon the recent literature in the sociology of sports to ascertain the impact of sports participation on personal development. Specific questions directed toward the problem sought to uncover characteristics that discriminate between black male high school student athletes and black male high school student nonathletes in levels of confidence, sexual identity, and conceptions about body and appearance. The Erwin Identity Scale, a portion of the Iowa Student Development Inventories, and a demographic questionnaire were used to measure personal development. These instruments gathered information from both black male students who had been members of athletic teams as well as those who had never participated. Scores were tabulated on the three subscales of the EIS and the demographic variables. Results of the study indicated that there was a significant difference between black male athletes and black male nonathletes when considering the three subscales jointly, with athletes scoring significantly lower on two of the three subscales. More specifically, there was a significant difference between groups on the subscales confidence and sexual identity, with athletes showing lesser development. An analysis of the significance of the relationship between the groups and five demographic variables indicated that athlete status had a significant relationship with age only. Additional findings indicated that confidence can be explained by athlete status; that sexual identity can be explained by athlete status and GPA; and that conceptions about body and appearance can be explained by GPA. Student services personnel must recognize these differences and develop programs to meet the developmental and special needs of black male high school students, especially the black male high school athlete. / Ed. D.

The purposes of this study were to examine the relationships among creativity, motivational orientation, and perceived parenting style in gifted and nongifted adolescents; to compare gifted and nongifted adolescents in creativity, motivational orientation, and perceived parenting style; and to establish preliminary validation for the Perceptions of Parenting Scale (POPS). The Multidimensional Stimulus Fluency Measure (MSFM), the Student Self-Evaluation of Creativity (SSEC), the Scale of Intrinsic Versus Extrinsic Orientation in the Classroom (IEOS), the Cornell Socialization Inventory (CSI), and the POPS were administered to 37 gifted and 57 nongifted sixth- through twelfth-grade students. IQ scores were obtained from school records. Results indicated a positive relationship between intrinsic motivation and self-reports of creativity. For the gifted, self-reports of creativity correlated positively with original fluency on the MSFM, and IQ was positively related to maternal negative affect and general control in the preschool and primary years. IQ was negatively related to maternal deprivation of privileges in the nongifted. For the nongifted, IEOS scores were negatively related to maternal control through reward in the preschool and primary years. For the gifted, IEOS scores were positively related to maternal consistency, confidence in child, and past autonomy. Self-reports of creativity correlated positively with maternal confidence in child. For the gifted, SSEC scores correlated positively with maternal consistency and with paternal and maternal allowance of autonomy. SSEC scores correlated negatively with maternal reward for the gifted. Several POPS scales correlated highly with the CSI factors. Chi-square results indicated that gifted students were more intrinsically motivated than nongifted students. MANOVA and t-test results revealed that gifted students scored higher than nongifted students on measures of IQ, self-reports of creativity, intrinsic motivation, paternal achievement demands, and past and present paternal and past maternal negative affect; nongifted students scored higher than gifted students on measures of perceived paternal indulgence and maternal instrumental companionship; females rated their mothers as higher than males in present negative affect, past affective companionship, and past and present control; and high school students reported greater past paternal control and punishment than did middle school students. / Ph. D.