Thesis (M.S. Ed.)--Northern Illinois University, 2001. / Includes bibliographical references (leaves [33]-45).

Thesis (Ph.D.)--Hong Kong University of Science and Technology, 2006. / Includes bibliographical references (leaves 116-133). Also available in electronic version.

Thesis (Ph. D.)--Drexel University, 2007. / Includes abstract and vita. Includes bibliographical references (leaves 150-159).

Thesis (Ph. D.)--University of Texas at Austin, 2007. / Vita. Includes bibliographical references.

Thesis (M. Sc.)--University of Canterbury, 2006. / Typescript (photocopy). Includes bibliographical references (leaves 61-73). Also available via the World Wide Web.

Thesis (M.S.)--West Virginia University, 2007. / Title from document title page. Document formatted into pages; contains viii, 52 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 45-47).

Thesis (Ph. D.)--University of Nevada, Reno, 2008. / "August 2008." Includes bibliographical references. Online version available on the World Wide Web.

Formic acid and nitric acid have been found to contribute to aerosol formation and are key components of acidity in the troposphere. Tropospheric measurements of these species are often limited, resulting in major uncertainties when assessing their effects on the climate. Current global chemistry-transport models significantly under-predict formic acid concentrations, particularly in the mid-to-high latitudes of the Northern Hemisphere. Furthermore, large discrepancies exist in the role played by dinitrogen pentoxide on nitric acid production between two recently documented models assessing the global nitric acid budget. In order to accurately constrain the budget of these acids in the mid-to-high latitudes of the Northern Hemisphere, it is crucial that these uncertainties are addressed. In this work, airborne measurements of formic acid, nitric acid and dinitrogen pentoxide are presented from across different regions of the Northern Hemisphere to investigate direct and indirect sources contributing to the formic acid and nitric acid regional budgets. Measurements were collected using a Chemical Ionisation Mass Spectrometer (CIMS) fitted to the Facility for Atmospheric Airborne Measurements (FAAM) BAe-146 aircraft. Formic acid measurements within the European Arctic during March and July 2012 would indicate ocean sources dominate over terrestrial sources irrespective of seasonality. CH2I2 photolysis and oxidation was hypothesised as a marine source of formic acid. Modelled estimates would indicate the CH2I2 reaction route may represent a significant summer marine source of formic acid within the Fenno-Scandinavian Arctic. Additionally, low altitude aircraft measurements taken within the Fenno-Scandinavian Arctic over regions occupied by wetlands in August 2013 were used to calculate a formic acid surface flux. Results would suggest formic acid emission from wetlands may represent up to 37 times greater than its globally inferred estimate. A flux measurement conducted over a comparable region in September 2013 observed a negative flux, indicating a change of this region from a net source to a net sink of formic acid. The inconsistency of this regional wetland source confirms the need for in-depth studies on formic acid emission from wetlands, in order to better understand its contribution to the regional and global formic acid budget. In a separate study, significant daytime elevations of N2O5 and HNO3 concentrations were observed within identified biomass burning plumes off the eastern coast of Canada. In-plume correlations between N2O5 and HNO3 concentrations observed within these environments suggest N2O5 was acting as additional daytime source of gaseous HNO3 when subjected to photolytically-limited conditions. This result has important implications to ozone production and provides evidence for an additional daytime source of nitric acid, which must be included in chemistry models calculating the global nitric acid budget.

No description available.

Orientador: Carlos Frederico de Oliveira Graeff / Banca: Wendel Andrade Alves / Banca: Francisco Carlos Lavarda / O Programa de Pós-Graduação em Ciência e Tecnologia de Materiais, PosMat, tem carater institucional e integra as atividades de pesquisa em materiais de diversos campi da Unesp / Resumo: O óxido nítrico (NO) é um radical livre com inúmeras funções fisiológicas, tais como regulação da pressão sanguínea e sistema nervoso. O desenvolvimento de Sistemas de Liberação Controlada (SLC) de NO no organismo são de grande importância em tratamentos de diversas patologias, bem como para a indústria farmacêutica. A espectroscopia de ressonância paramagnética (RPE) foi utilizada para detecção e caracterização da taxa de liberação de NO. Esta é uma técnica amplamente utilizada no estudo de entes paramagnéticos existentes em sistemas biológicos. Os SLCs de NO foram desenvolvidos a partir da incorporação do agente aprisionador de NO, FeDETC, nas matrizes biocompatíveis de látex e siloxanopoli(oxipropileno) (PPO). O foco deste trabalho é obter membranas para liberação controlada de NO que sejam capazes de liberar NO localmente através de estímulos externos. A matriz de PPO apresentou forte sinal de NO, resistência mecânica e estabilidade igual às melhores matrizes sólidas já obtidas em nosso laboratório. Mantendo a matriz de PPO em ambiente sem iluminação e à temperatura ambiente, o NO permanece aprisionado ao FeDETC por até 45 dias nas primeiras sínteses e 33 dias nas últimas sínteses. Em experimentos feitos com a matriz de látex foi observado que o NO permanece complexado ao FeDETC até 61 dias e 45 dias para amostras estocadas no escuro à temperatura ambiente e sob temperatura de 50C. Em ambas matrizes, foi observado que a taxa de liberação de NO do sistema pode também ser acelerada através da aplicação de um campo magnético ou através do aumento de temperatura. Estas características fazem do PPO e látex , matrizes ideais para construção de SLCs de NO. / Abstract: Nitric oxide (NO) is a free radical species with multiples physiological functions, such as the regulation of blood pressure and nervous system. The development of drug delivery systems (DDS) of NO in the body are of great importante in the treatment of varios diseases, as well as for the pharmaceutical industry. Electron Paramagnetic Resonance (EPR) technique, was used for NO detection and characterization of the NO delivery kinetics. This is a technique widely used in the study of paramagnetic entities existing in biological systems. NO DDSs were developed based in trap FeDETC incorporated in siloxane-poly(oxypropylene) (PPO) and latex biocompatible matrix. The focus of this work is to obtain membranes for controlled release of NO that are able to release NO locally by external stimuli. The PPO400 and PPO2000 DDS presents a stronger EPR signal, strength and highest stability, equal to the best solid matrices already obtained in our laboratory, e. g. latex matrix. Keeping the matrix in PPO enviromment without lighting and temperature, the NO remains trapped in FeDETC for up to 45 days in the first synthesis and summaries for the last 33 days. In experiments made with the latex matrix was observed that NO remains trapped in FeDETC until 61 or 45 days for samples stored in the dark at room temperature and samples left at the greenhouse 50C. In both matrices was observed that the kinetics of NO release of NO release of the system can also be accelerated by applying modulated magnetic field of 40G or by increasing temperature. These characteristics make the PPO and latex, matrices ideal for building DDS NO. / Mestre