The extraction and recovery of trace organic material from semi-solid and solid matrices is often the slowest and most error-prone step of an analytical method. The conventional liquid extraction techniques for solids and semi-solids materials (Soxhlet) have two main disadvantages. The first, large volumes of organic solvent are required, which can lead to sample contamination and "losses" due to volatilization during concentration steps. The second, to achieve an exhaustive extraction can require several hours to days. With the development of sophisticated instrumentation with detection limits in the picogram and femtogram levels, pressure is finally felt within the analytical community to develop and validate sample preparation procedures which can be used to rapidly isolate trace level organics from complex matrices.Because of its applicability to solid, semi-solid, and liquid matrices microwave-assisted (MAE) extraction has emerged as a powerful sample preparation technique. The objective of this research was to evaluate directly focused microwave energy for the isolation of systemic fungicide residues from woody plant tissues.The hallmark of microwave extraction (MAE) is accelerated dissolution kinetics as a consequence of the rapid heating processes that occur when a microwave field is applied to a sample. The current popularity of MAE resides mainly on its applicability to a wide range of sample types because the selectivity can be easily manipulated by altering solvent polarities.Propiconazole is a systemic fungicide, used to combat the fungal pathogen Ophiostoma ulmi, the casual agent of Dutch elm disease (DED). It was successfully extracted from treated Ulmus americana (elm tree) using MAE with a percent recovery of 395% in 15 minutes. Until now, techniques for rapid and efficient extraction of polar material from wood were non-existent. This work produces results much quicker than Supercritical Fluid Extraction (SFE). The influence of pH, microwave power, and time on extraction efficiency was also investigated. The extraction methodology was optimized and statistically validated.This MAE method combined with GC-MS was used to study the diffusion patterns and degradation of propiconazole in tree bark over extended time periods. Because of the complex nature of woody plant systems, it was realized that a more theoretical means must be used to determine the degradation rate of propiconazole in water systems. As a result, propiconazole was reacted with water under controlled temperature and pH conditions; to measure the degradation rate of propiconazole.The internal pH of elm sap is about 6.0; the slightly acidic environment and natural enzymes within the xylem vessels are known to catalyze the degradation of propiconazole (1). Novartis Inc. has marketed propiconazole as having fungicidal effects in injected elms for nearly two years. Our degradation studies have indicated much shorter lifetimes. To confirm our fate studies, the activation energy for the degradation reaction of propiconazole was calculated. This information provided valuable insight into revising dosage and treatment frequency for maximum protection of the elm against Dutch elm disease. Anti-fungal activity among metabolites was also explored. This is the first reported use of MAE to monitor the degradation of systemic pesticides in woody plant material. / Ph. D.

The number of college freshmen enrolled in developmental courses is an indicator that many American high school graduates are not adequately prepared for college. Research has indicated that from 30% to 69% of high school graduates who entered college are required to take at least one developmental course. The purpose of this study was to examine the high school experiences of freshmen college students, specifically, the roles their high school teachers, high school guidance counselors, the parents, and they themselves played in preparing them for college. Data were analyzed to explore differences by race (majority v. minority), gender and type of English class (regular v. developmental). The participants were freshmen students enrolled in college developmental English and general English courses at one community college and one four year college. In order to answer the research questions presented in this study, participants completed a 60-item questionnaire. Fifteen items addressed areas that the research questions investigated (i.e. role of high school teachers, guidance counselors, parents, self). The research questions were examined through a series of analysis of variance tests. Results revealed significant differences by race, gender, type of class and interactions between the effects. The data provide the basis for making recommendations to high school administrators and local school boards which, when implemented will better prepare high school students for the academic rigors of college courses. / Ed. D.

The Lower Coastal Plain of the southeastern United States is a major wood producing region. The region is characterized by a combination of nearly-level topography, poorly-drained soils, and high rainfall, which results in a perched water table in some soils that inundates the surface several times each year. Harvesting timber under wet site conditions often results in extensive soil compaction, rutting, soil displacement, and waterlogging. Forest managers are concerned that these visually-displeasing soil disturbances may cause site damage and reduced productivity. These concerns were addressed in an operational-scale field experiment conducted in South Carolina. The objectives of this experiment were to determine: (i) if soil disturbance changes key soil properties and processes; (ii) if soil disturbance reduces loblolly pine productivity; and, (iii) if disturbance can be mitigated with site preparation practices? Three 20-ha, 20-yr-old loblolly pine (Pinus taeda L.) plantations were harvested under wet and dry conditions to create a broad gradient in soil disturbance. Within each harvested plantation, a subset of 3-ha plots were site prepared by either bedding, or mole-plowing plus bedding, then all sites were established as 3rd -rotation pine plantations. Prior to site preparation, each plot was classified and mapped using a 5 by 5 soil disturbance (none to churned) by organic debris (none to slash piles) classification matrix. Within each plot, data were collected on several soil physical, chemical, and biological properties over a 2-yr period following site preparation. Key soil properties were integrated into a Soil Quality Index (SQI) and compared to aboveground productivity of 2-yr-old loblolly pine trees growing on closely-spaced (30 by 30 cm) bioassay plots planted across the gradient of soil disturbance. The soil physical properties were used to determine the least limiting water range (LLWR), the range in soil water content within which root growth is not limited. Soil compaction and deep rutting reduced the LLWR. Retention of logging slash improved the LLWR for compacted and rutted soils. Site preparation improved the quality of the soil physical environment across all levels of soil disturbance. Soil disturbance had no effect on soil chemical or biological properties as evidenced by no change in soil pH, ECEC, base saturation, available P, or net N mineralization with disturbance. The base saturation exceeded 80 % on all sites, with Ca saturation controlling soil pH. The high base saturation buffered any redox-induced changes in soil chemistry that would have resulted from disturbance. The results showed that high fertility is an important mechanism for buffering the potentially-negative effects of soil disturbance on the soil nutritional environment. Site preparation changed soil chemical properties, but the changes were probably associated with tillage effects on organic matter and clay content, not redox processes. The SQI showed that surface soil compaction and deep rutting reduced soil quality, mainly by decreasing the LLWR and aeration depth. Site preparation mitigated the effects of most disturbances on soil quality, evidenced by similar aboveground biomass production among soil disturbance classes after bedding. A regression model was developed for predicting aboveground biomass production as a function of SQI. SQI explained 73 % of the variation in aboveground biomass production. The regression model showed that compression tracks and rutting decreased aboveground biomass production compared to undisturbed soils. The long-term effect of these disturbances on productivity will depend on natural soil recovery processes. However, these early results suggest that compaction and rutting should be minimized on similar sites, especially if sites will not be bedded before reforestation. The mole-plow / bedding treatment increased aboveground biomass production, indicating that this experimental treatment may be a viable practice for enhancing productivity. / Ph. D.

This study examines social structural effects on student mathematics preparation and identification with a science, technology, engineering, or mathematics (STEM) field, as well as the social psychological factors that may mediate those effects. Using demographic, academic, attitudinal, and school policy data from the Educational Longitudinal Study of 2002 (ELS: 2002) for over 14,000 students from a nationally representative sample, this research tests a model of mathematics course taking and selection of a STEM field linking social identity and self processes with academic decision making. Using structural equation modeling (SEM) to assess the relationships between the latent and observed variables, specifically examining mathematics self-efficacy and social support variables and how they mediate the effects of background variables and prior mathematics achievement on mathematics course taking and subsequent choice of a STEM major, the initial model tests the use of advanced mathematics course taking as a proxy to a college major in a STEM field. This study further develops a second model linking social identity and mathematics course taking using the nested structure of the data to consider the role of school grouping policies on mathematics course taking. Hierarchical linear modeling (HLM) is employed to measure the effects of individual socio-economic level, race, gender, and coping resources within schools with different course selection and ability grouping policies on high school mathematics course taking. The results of structural equation modeling supported most formulations of the conceptual model and showed significant effect of coping resources on mathematics course taking and subsequent STEM matriculation. Furthermore, females showed lower mathematics self-efficacy and were less likely to enter a STEM field of study than males although they experienced higher levels of social support and math course taking. Findings from the hierarchical linear models suggested that students’ mathematics course taking was related to coping variables, but it varied by course enrollment policy at the school level. The effects of school policy were not consistent across racial groups. The study had both theoretical and practical significance, providing insights for increased diversity in STEM majors as well as policy implications at the high school level. / Ph. D.

The relationship between teachers' participation in 4MAT learning style training and their perception of teacher efficacy was investigated three ways. Teachers who participated in 4MAT Fundamentals training were surveyed, observed, and interviewed. The Gusky and Passaro (1994) teacher efficacy scale was given to 120, K-12 teachers at 4MAT training sites. The survey was administered three times: before the workshop, immediately after the workshop and one month after the teachers had returned to their classrooms. The scale measured two teacher efficacy factors: (a) internal teacher efficacy -- perception of personal influence and impact on teaching and learning situations; and (b) external teacher efficacy -- perception of the influence and impact of elements that lie outside the classroom on teaching and learning situations. In addition, the teachers at one learning style training site were observed to determine how readily they adopted learning style terminology. Finally, six teachers were interviewed three times each to determine if factors found by Ashton (1984) to be associated with a high level of teacher efficacy were present. Perceptions of internal teacher efficacy increased significantly from pre- to post workshop administrations. After the teachers had been in the classroom for one month, internal teacher efficacy scores were lower than immediately after the workshop but still significantly higher than before the workshop. The training had no significant impact on external teacher efficacy scores. An interaction was found between teachers' level of previous knowledge and the reported gain in internal teacher efficacy. Those teachers with little previous knowledge of learning style theory and methodology showed higher levels of gain in internal teacher efficacy immediately after the workshop and on the one-month follow-up survey. The teachers' discourse during interviews and behavior during the workshops reflected all the elements Ashton outlined as associated with teacher efficacy: a belief in students' potential to learn and develop, awareness of the classroom as a social setting, and use of reflective behavior. These data also suggested that the maintenance of a high level of efficacy was influenced by the support of colleagues, modeling of instructional techniques, and validation of teachers' ideas concerning practice. It was also noted that teachers adapted 4MAT methodology idiosyncratically. These findings suggest that knowledge of learning style theory and practice can be valuable to teachers. It appears that examining the impact of learning style training on teachers' attitudes and behaviors may provide meaningful insights into why interest in learning style concepts continues despite an inconclusive research base. / Ph. D.

Slightly more than two million teachers will be needed for the nation's classrooms within the next decade. Consequently, some states have begun to look to their ready supply of paraeducators, also known as teacher assistants, as a pipeline for supplying qualified teachers. These paraeducators who make the career change to teachers are more likely to remain in hard-to-supply geographic areas and to increase the diversity of the teaching force. This study explored the lived experiences of five minority women who successfully negotiated the transition process to become professional teachers. Phenomenological interviewing, within the hermeneutic phenomenology tradition, was the methodology used for data collection. To understand how these paraeducators attained their aspiration, testimonies of their experiences were developed from a series of extended interviews and presented as reconstructed narratives. The transcribed narratives identified common themes that were linked with research on personal and professional development of minority women seeking to make a career change. The discussion of these narratives revealed transitional paths shaped by pain tempered by perseverance and goal-setting. The five women's working to achieve their goal, encased in a common time frame, began with an experience that propelled them on their journey. Four common elements emerged as beneficial in supporting attainment of their professional goals: (a) leadership support; (b) financial support; (c) family support; and (d) personal power. / Ed. D.

The purpose of this study is to determine whether the City Public Schools" Leadership Academy has met its primary goal of preparing public school administrators to serve the school division. This study is built on research that reveals that there are a number of principal preparation programs available for future school leaders that do not adequately prepare the applicants for leadership roles. Collaborative partnerships between school divisions and colleges and universities are being formed in order to prepare public school leaders for the administrative demands of today's public schools, challenged by the mandates of the No Child Left Behind legislation. In particular, school divisions are forming grow-your-own leadership academies in order to meet the need for filling positions that are being vacated by retiring administrators. This study utilizes mixed-methodologies comprised of quantitative and qualitative data. Eleven completers of the City Public Schools" Leadership Academy who obtained administrative positions in the division during the 2004-2006 school years were a part of the study. In addition, their supervisors participated in the study. The research highlights, in quantitative data, the survey responses of ten novice administrators who were completers of the City Public Schools" Leadership Academy. Seminars that the novice administrators experienced were based on the six Interstate School Leaders Licensure Consortium (ISLLC) standards. Thus, the survey and interview questions were adapted from the ISLLC standards. Adding richness to the study is the data that was generated in the form of in-depth interviews with the eight principals and five supervisors of the novice administrators. Findings revealed that the novice administrators had an overall perception that the City Public Schools" Leadership Academy prepared them to be school leaders. Although the supervisors felt, that the novice administrators were prepared, there were a few areas where they felt the program was in need of improvement. Additional findings gave school leaders a basis from which to make programmatic decisions that should result in a more effective leadership training program. / Ph. D.

The primary role of the principal has expanded over the past two decades from one of manager to one of manager and instructional leader. With the expanded role of instructional leader, the principal of the twenty-first century is faced with increased levels of accountability for student achievement as evidenced by national legislation, revised state standards, and an ever-increasing scrutiny by shareholders. Six years ago research indicated that approximately one fourth of practicing principals were eligible for retirement in the next three to four years (Lauder, 2000). School districts across the country are finding it more and more difficult to attract qualified candidates with the requisite instructional leadership skills for available principal positions and have chosen to address this crisis by creating principal preparation programs aligned with current needs and based on key practices. The purpose of this qualitative case study was to determine whether school personnel who participate in AAA Public School's leadership training program are better prepared for the principalship than those school personnel who did not participate in this leadership training program. Data collection included (a) focus group interview comprised of a random sample of assistant principals and principals who had participated in the leadership training program (N = 6), (b) focus group interview comprised of a random sample of assistant principals and principals who had not participated in the leadership training program (N = 6), (c) focus group interview with the population of assistant superintendents who evaluate principals (N = 4), (d) leadership academy training documents, and (e) observations. Study results found that administrators who participated in this leadership training program were better prepared, more confident in their leadership, and were more knowledgeable in the roles and responsibilities which principals face. / Ph. D.

The development of Infrared Spectrometry as a High Performance Liquid Chromatographic detector is presented. Early work with both a conventional dispersive instrument and a Fourier Transform Infrared (FTIR) Spectrometer is presented coupled via a flow cell to size exclusion chromatography. These were used for the analysis of the non-volatile components produced in the liquefaction of coal. Additional work is presented for the coupling of FTIR to analytical scale normal phase chromatography via a flow cell technique. Analysis of both model mixtures as well as a complex process solvent used in the liquefaction process is discussed. Use of deuterochloroform as an improved IR transparent solvent is demonstrated. Work with microbore (1 mm i.d.) columns coupled with on-line flow cell detection is presented. Modification of the flow cell design for microbore compatability is shown as well as the benefits of microbore columns for fiow cell FTIR. Detection limits as amount injected for both analytical and microbore scale HPLC-FTIR are shown. / Ph. D.

The purpose of this qualitative study was to develop a better understanding of how eight preservice teachers perceived the culturally diverse students they encountered during their one-year teaching internship. Their personal and professional experiences with diversity were investigated in order to identify the direct and indirect influences they brought to a culturally diverse classroom. The data for this study consisted of narratives from their one-year teaching internship and their home, schooling, and college experiences with cultural diversity. Each preservice teacher was interviewed twice. The issues that emerged from their narratives were individually presented to give a clear picture of how they each perceived classroom cultural diversity. From their narratives, it is clear that how each of these preservice teachers perceived culturally diverse students was largely influenced by their life histories and experiences with cultural diversity. Cultural preparation in college acquired great significance as they each reflected on their preparation to teach in culturally diverse settings. None of them felt prepared to teach culturally diverse students. Instead, they indicated a preference of working in school settings that exhibited students similar to their own backgrounds. Classroom cultural diversity was seen as presenting special challenges, none of them felt prepared to handle. The implications from this study suggest that more preparation on how to work within culturally diverse classrooms is needed prior to, and during the student teaching internship. / Ph. D.