Thesis (Ph. D.)--York University, 1999. Graduate Programme in Earth and Space Science. / Typescript. Includes bibliographical references (leaves 249-265). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://wwwlib.umi.com/cr/yorku/fullcit?pNQ39304.

Thesis (M.S.)--Oregon Graduate Center, 1976.

This research was developed to investigate the potential environmental impacts of poor air quality in Perth. This involved improving existing vegetation maps (through satellite image analysis techniques) for biogenic or forest emissions as a precursor to smog in Perth. Further, to visualise potential environmental impacts associated with poor air quality, a four- dimensional (volumetric over time) animation was created which clearly shows the path and extent of smog in Perth throughout an entire day.Computer mapping of vegetation using Landsat TM data was performed to create an updated inventory of forest types in Perth as input into a photochemical smog model. By improving the inventory of forest cover, the Department of Environmental Protection (DEP) in Perth can calculate up to date biogenic emission estimates for the photochemical smog model.Outputs from the DEP's photochemical smog model were integrated into a Geographical Information System (GIS) and subsequently visualised to show plume movement and potential environmental impact. Two datasets (nitrogen oxides and ozone) were provided to investigate the volumetric and dynamic temporal movement of photochemical smog in Perth on one day, March 16, 1994.Nitrogen oxide sources can range from industry and petroleum refining to motor vehicle exhaust emissions, and are a major precursor to photochemical smog (ozone) formation in Perth. Natural emission sources (forest or biogenic emissions) can also be an important contributing factor to the photochemical smog mix in Perth. Biogenic emissions are comprised of Reactive Organic Chemicals (ROC) or Volatile Organic Compounds (VOC) which act as a catalyst to aid the nitrogen oxide conversion to ozone.Three-dimensional and four-dimensional GIS techniques were used to highlight both plume movement and environmental impact. These two sets of visualisations have differing ++ / chemical levels (higher and lower, respectively) to show movement and interaction effectively. Visualisation of the chemicals allows for a greater understanding of the mostly invisible chemical movement over the course of a day and its potential impact to humans and vegetation.The spatial and temporal interaction of the plumes was investigated by creating a series of animations that can be viewed over the Internet. By using multimedia capabilities, these results can be easily distributed to a wide range of decision makers and people generally interested in smog in Perth.

The gap between hope and happening refers to the experiences of four academic women who work at Milton University (MU), the pseudonym for a regional Australian university. This thesis is concerned with the ways in which discourses circulating within MU shape the performances and discursive positionings of the four women - Alice, Madonna, Veronica and Tamaly (all pseudonyms) - and how, in turn, these women negotiate these discourses. Data are drawn from the women’s narratives, university policy documents and selected institutional texts. A feminist poststructuralist lens interrogates both policies, reflecting different approaches towards gender equity at MU, and discursive practices, constructing the ‘good academic’ at MU. Instead of acts of resistance, what is revealed in this workplace is the continuing covert strategies of marginalization that reproduce women’s positioning on the margins of mainstream academia, indicating the presence of a kind of ‘phallocentnc smog’ emerging from a dominant masculine culture. This thesis finds a gap between the transformative potential of the four women at the micro-social (subjectivity) level and the lack of transformation at the macro-social (workplace) level. This suggests that the women’s abilities to resist and transform phallocentric discourses at the personal/private level are not sustainable at the public level because of the enduring power of normative institutional discourses or the ‘phallocentric smog’. This thesis signals the need for ongoing interrogation of the gap between the hope that feminists have (theory) and the happening for women (practice) in the quest for sustainable equity.

Ground-level ozone (O3) is a secondary pollutant produced by its precursors, such as volatile organic compounds (VOC) and nitrogen oxides (NOx) through complex photochemical reactions in sunlight. This study was aimed to investigate the relationships of surface ozone with its precursors in urban locations. Atmospheric measurements of hydrogen peroxide (H2O2) and nitric acid (HNO3) were conducted at the three sites, namely Nan-Tze, Chien-Chin and Hsiung-Kong, in Kaohsiung City during three consecutive days of fall, winter and spring seasons in 2002-2003, from which the ozone-VOC-NOx sensitive regimes were derived using two methods, namely the indicator ratios of H2O2/HNO3 and O3/HNO3 developed by Sillman (1997), and the extent parameter, E, of SPM (Smog Production Model) developed by Blanchard (1994). Measurements indicate that H2O2 reaches its peak concentration approximately at noon to afternoon (12:00 to 15:00); meanwhile HNO3 reaches its lowest concentration. In general, fall season has highest concentrations on H2O2 and HNO3, followed by spring and winter. The correlation analyses indicate that ozone has positive relationships with temperature and solar insolation, while it has negative relationships with NOx, NO and NO2. According to the indicator ratios of H2O2/HNO3 = 0.3 ¡V 0.6, O3/HNO3 = 12 -16 (Sillman, 1997), results show that VOC-limited regimes occupy about 62.5% and 58.3% at the Hsiung-Kong site, 47.8% and 69.6% at the Nan-Tze site, and 33.3% and 70.8% at the Chien-Chin site in the fall season. Results also show that VOC-limited regimes occupy about 80.9% and 66.7% at the Hsiung-Kong site, 54.2% and 41.7% at the Nan-Tze site, and 70.8% and 45.8% at the Chien-Chin site in the winter, while it is 52.4¢Mand 80.9¢Mat the Hsiung-Kong site, 50.0¢Mand 66.7¢Mat the Nan-Tze site, and 35.7¢Mand 28.6¢Mat the Chien-Chin site in the spring. According to the critical value of extent parameter, Ecrit = 0.7 (Blanchard, 1994), IV results show that VOC-limited regimes pre-dominate at three sites in autumn, winter and spring, all occupying 100% except in that a VOC-limited regime occupies about 91.7% at the Chien-Chin site in spring. In summary, the ozone-VOC-NOx sensitivity results derived from indicator ratios agree fairly well with SPM results, except for the Chien-Chin site in spring. The indicator ratios and Ecrit are frequently considered to be universal under given assumptions. However, these values may vary with meteorology and topography. Further studies are needed to characterize these parameters locally.

ABSTRACT Ground-level ozone (O3) is a secondary pollutant produced by its precursors, such as volatile organic compounds (VOC) and nitrogen oxides (NOx) through complex photochemical reactions in sunlight. This study was aimed to investigate the relationships of surface ozone with its precursors in the urban and rural locations in Pingtung County. Atmospheric measurements of hydrogen peroxide (H2O2) and nitric acid (HNO3) were conducted at the two sites, namely Pingtung city and Chaochou, in Pingtung County during three consecutive days of fall, winter and spring seasons in 2002-2003, from which the ozone-VOC-NOx sensitive regimes were derived using two methods, namely the indicator ratios of H2O2/HNO3 and O3/HNO3 developed by Sillman (1997), and the extent parameter, E, of SPM (Smog Production Model) developed by Blanchard (1994). According to the indicator ratios of H2O2/HNO3 = 0.3 ¡V 0.6, O3/HNO3 = 12 -16 (Sillman, 1997), results at the Pingtung site show that VOC-limited regimes occupy about 68% in autumn, winter and spring. Results at the Chaochou site show that VOC-limited regimes occupy about 52.8% in autumn and winter, while NOx-limited regimes occupy about 54.2% in spring. According to the critical value of extent parameter, Ecrit = 0.7 (Blanchard, 1994), results show that VOC-limited regimes predominate (93.8%) at Pingtung site in winter and spring. Results at the Chaochou site show that VOC-limited regimes predominate (87.5%) in winter, while NOx-limited regimes predominate (58.3%) in spring. In summary, the ozone-VOC-NOx sensitivity results derived from indicator ratios agree fairly well with SPM results. The indicator ratios and Ecrit are frequently considered to be universal under given assumptions. However, these values may vary with meteorology and topography. Further studies are needed to characterize these parameters locally.

Reproduction de : Thèse de doctorat : Structure et dynamique des systèmes réactifs : Lille 1 : 2004. / Les publications en annexe n'ont pas été numérisées. N° d'ordre (Lille 1) : 3568. Résumé en français et en anglais. Titre provenant de la page de titre du document numérisé. Bibliogr. p. 125-128. Liste des communications.

One of the remaining problems associated with the photo-degradation of organic species in the atmosphere, is concerned with the mechanisms of C₅ and larger fragments. In this respect the 2-pentoxy radical has been chosen as a model radical. The subsequent mechanisms for it are thought to be similar to those for all other larger species. The photolysis of 2-pentyl nitrite in the near ultraviolet (UV) region at 328-383 nm resulted in the formation of 2-pentoxy radicals and nitric oxide with the quantum yield of 0.97 ± 0.08 at 298-393K, consistent with the assumption that the quantum yield was unity for alkyl nitrites. In the present work, <I>tert-</I>butyl nitrite has been shown to be unity. The reactions of the model radical were investigated in inert (CF₄), and oxygen atmospheres, by end product analysis using on-line gas-liquid chromatography. The expected reaction routes were: decomposition, oxidation (β-H atom abstraction), and 1,5-H shift isomerisation which would produce acetaldehyde, 2-pentanone and acetone respectively. Its reaction scheme was evaluated by comparing the experimental with model results, derived by the Gear Algorithm. The estimated or calculated rate constants in the literature were "brute force" adjusted to adapt the modelling results to the experimental results. Our investigations suggested, among the rate constants for the 2-pentoxy radical: k_dec9.2 x 10³s^-1: CH₃CH(O)(CH₂)₂CH₃ → n-CH₃CHO + n-C₃H_7,k₀₂ 7.0 x 10⁵M^-1s^-1: CH₃CH(O)(CH₂)₂CH₃+0₂ → CH₃C(O)(CH₂)₂CH₃ + HO₂, and k_isom 1.4 x 10⁴s^-1; CH₃CH(O)(CH₂)₂CH₃ → CH₃CH(OH)(CH₂)₂CH₂) The 1,5-H shift isomerisation is relatively fast. The Arrhenius parameters of these rate constants were also modified.

Se denomina smog a la niebla o dispersión coloidal de un líquido en aire, altamente tóxica por su elevada concentración en óxidos de azufre y nitrógeno, los que le confieren características ácidas por la presencia de los ácidos sulfúrico y nítrico. El pH de estas nieblas puede llegar a valores de 2. Las nieblas producidas por las reacciones fotoquímicas son llamadas comúnmente smog fotoquímico. El mismo se forma por la presencia de hidrocarburos y όxidos de nitrógeno en presencia de la luz solar. En la reacción se forman ozono, derivados nitro de los hidrocarburos, compuestos orgánicos como el formaldehido, etc. Sobre la base de que la fuente principal de NO× la constituye los procesos de cοmbustíόn de hidrocarburos (principalmente gases de escape de los automóviles), las cantidades producidas en los centros con alta densidad de población suelen ser tan grandes que el único control para evitar este tipo de nieblas debe tener como premisa la limitación de los HC y NOx que alcancen la atmósfera. Respecto a su toxicidad, es bien conocido que ocasiona problemas respiratorios graves y que además la niebla concentra otros contaminantes como compuestos orgánicos y pesticidas. Esta problemática se ve intensificada por las características geográficas y meteorológicas (zona de alta presión) de algunas ciudades que impiden la dispersión de los contaminantes. Las reacciones que dan lugar al smog fotoquímico son muy complejas y aún no se ha logrado la compresión total del sistema. El objetivo que se persigue en su estudio es obtener un modelo que permita predecir el grado de disminución de smog que se alcanzaría con las medidas de control de emisión de los contaminantes. Tales modelos permitirían programar y evaluar las estrategias a adoptar para controlar la contaminación del aire y elegir las formas más eficientes de transporte, crecimiento urbano y aprovechamiento de los recursos urbanos. / Tesis digitalizada en SEDICI gracias a la Biblioteca Central de la Facultad de Ciencias Exactas (UNLP).

Zugl.: Diss. phil.-naturwiss. Fak. Univ. Bern, 1996. / Die Arbeit enstand im Rahmen des Nationalfondsprojektes "Simulation meteorologischer und chemischer Prozesse während Sommersmoglagen über dem Schweizer Mittelland" Bibliogr.: p. 191-194.