Plasma Spectroscopic Techniques Applied to Biological and Environmental Matrices

The purpose of this research was to apply the use of direct ablation plasma spectroscopic techniques, including spark-induced breakdown spectroscopy (SIBS) and laser-induced breakdown spectroscopy (LIBS), to a variety of environmental matrices. These were applied to two different analytical problems. SIBS instrumentation was adapted in order to develop a fieldable monitor for the measurement of carbon in soil. SIBS spectra in the 200 nm to 400 nm region of several soils were collected, and the neutral carbon line (247.85 nm) was compared to total carbon concentration determined by standard dry combustion analysis. Additionally, Fe and Si were evaluated in a multivariate model in order to determine their impacts on the model's predictive power for total carbon concentrations. The results indicate that SIBS is a viable method to quantify total carbon levels in soils; obtaining a good correlation between measured and predicated carbon in soils. These results indicate that multivariate analysis can be used to construct a calibration model for SIBS soil spectra, and SIBS is a promising method for the determination of total soil carbon. SIBS was also applied to the study of biological warfare agent simulants. Elemental compositions (determined independently) of bioaerosol samples were compared to the SIBS atomic (Ca, Al, Fe and Si) and molecular (CN, N2 and OH) emission signals. Results indicate a linear relationship between the temporally integrated emission strength and the concentration of the associated element. Finally, LIBS signals of hematite were analyzed under low pressures of pure CO2 and compared with signals acquired with a mixture of CO2, N2 and Ar, which is representative of the Martian atmosphere. This research was in response to the potential use of LIBS instrumentation on the Martian surface and to the challenges associated with these measurements. Changes in Ca, Fe and Al lineshapes observed in the LIBS spectra at different gas compositions and pressures were studied. It was observed that the size of the plasma formed on the hematite changed in a non-linear way as a function of decreasing pressure in a CO2 atmosphere and a simulated Martian atmosphere.

Understanding the Leadership Capacity and Practice of Assistant Principals

The purpose of this study was to explore the leadership capacities and practices of assistant principals. The research also sought to determine what relationships existed between capacity and practice and to see if there was a difference based on experience, context and personal characteristics. Since the majority of principals first serve as assistant principals, their work and experiences as assistant principals will have significant consequences (Kwan, 2009). The literature has long held and continues to challenge the notion that the role of assistant principal is adequate preparation for the principalship (Chan, Webb, & Bowen, 2003; Harris, Muijs, & Crawford, 2003; Kwan, 2009; Mertz, 2000; Webb & Vulliamy, 1995). Based on empirical findings, this study has affirmed the need to further research and refine the role of the assistant principal. The results indicate that in addition to strengths, there are explicit gaps and missed opportunities in the leadership practices of assistant principals that impact the potential for building a leadership pipeline within schools. The work of the assistant principal is characterized by a proliferation of duties rather than a strategic set of practices that support distributed leadership and sustainability.

Identifying Overweight Risk and Intervening at the Twelve Month Well Child Exam

Childhood obesity is an epidemic that is having devastating effects on the physical and psychological health of children. The core processes of Acceptance and Commitment Therapy (ACT) are explored in this paper relative to how they can be applied as interventions in an early life obesity prevention model. While reviewing research in childhood obesity intervention models, this paper proposes a study that involves conducting behavioral health consultations with mothers whose children are at high risk for becoming overweight.