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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

On-line chemistry in a mesoscale model assessment of the Toronto emission inventory and lake-breeze effects on air quality /

Plummer, David A. January 1999 (has links)
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.
2

Investigation of the atmospheric importance of organic nitrates through laboratory and field experiments /

O'Brien, Jason Matthew. January 2005 (has links)
Thesis (Ph.D.)--York University, 2005. Graduate Programme in Chemistry. / Typescript. Includes bibliographical references (leaves 199-210). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://wwwlib.umi.com/cr/yorku/fullcit?pNR11608
3

Liquid aerosol photochemistry : a thesis submitted in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Chemistry in the University of Canterbury /

Bones, David L. January 2008 (has links)
Thesis (Ph. D.)--University of Canterbury, 2008. / Typescript (photocopy). Includes bibliographical references (p. 171-177). Also available via the World Wide Web.
4

Photochemical formation and cost-efficient abatement of ozone high-order sensitivity analysis /

Cohan, Daniel Shepherd. January 2004 (has links) (PDF)
Thesis (Ph. D.)--Earth and Atmospheric Sciences, Georgia Institute of Technology, 2005. / Russell, Armistead G., Committee Chair ; Chameides, William L., Committee Member ; Wang, Yuhang, Committee Member ; Noonan, Douglas, Committee Member ; Chang, Michael E., Committee Member. Vita. Includes bibliographical references.
5

Computer modeling of photochemical ozone formation: a simplified approach

Moshiri, Ebrahim 01 January 1984 (has links)
Photochemically produced ozone represents a worldwide enviromental hazard. Controlling ozone formation in polluted air requires control of hydrocarbon and nitrogen oxides precursors. The degree of control can be established with the chemical model of the reacting species. A hydrocarbon-specific photochemical ozone model is developed, based upon a minimum set of chemical equations. This model eliminates the need for the traditional "brute force" approach to integrate systems of tens or even hundreds of simultaneous differential equations. We have sought to develop the full kinetic potential for simplification which this chemical system may have. Key features of the model are reaction of parent hydrocarbon with hydroxyl radical (OH) to produce products, which themselves react with OH or are photodissociated. These basic steps are summarized by three rate parameters which describe NO photooxidation and ultimate accumulation of ozone. Since the mechanism may be solved in a closed form, it is a simple matter to evaluate the rate parameters for any hydrocarbon from smog chamber data. This evaluation can be carried out by analysis of data in NO photooxidation regime, before ozone begins to accumulate. The simple model for NO photooxidation is transformed to give an equation which describes the number of NO conversions per hydrocarbon decay, independent of time or of hydroxyl radical concentration. Comparison of the rate parameters determined from existing smog chamber data for n-butane and propene shows a very good agreement with explicit mechanisms for these extensively studied hydrocarbons. Rate parameters have been determined for a number of less studied hydrocarbons as well.
6

Characterizing the photochemical environment over China

Liu, Zhen 30 March 2012 (has links)
The rapid rising anthropogenic emissions driven by economic growth over China documented by satellite observations and bottom-up inventories have led to severely degraded air quality, and also have been suggested to be linked to the recent upward trends of tropospheric O₃ over the regions downwind of China. Multi-scale modeling analyses facilitated by ground-level, aircraft and satellite observations have been conducted to understand the atmospheric chemistry over China. Analyses using a 1-D photochemical model constrained by measurements at Beijing in August of 2007 suggest that reactive aromatic VOCs are the major source (~75%) of peroxy acetyl nitrate (PAN). Detailed radical budget analyses reveal the very fast ROₓ (OH + HO₂ + RO₂) production, recycling and destruction driven by VOC oxidation and heterogeneous processes. Photoenhanced aerosol surface uptake of NO₂ is found to be the predominant source of nitrous acid (HONO) during daytime (~70%). 3-D regional modeling analyses of tropospheric vertical column densities of glyoxal (CHOCHO) from SCIAMACHY show that anthropogenic emissions of aromatic VOCs are substantially underestimated (by a factor of 5 - 6, regionally varied) over China. Such an underestimation is the main cause of a large missing source of CHOCHO over the region in current global models, and could also partly explain the underestimation of organic aerosols in previous modeling studies.
7

Photochemical smog in greater Cape Town

Loewenheim, L January 1988 (has links)
Bibliography: leaves 124-131. / Photochemical smog is the name given to a complex sequence of chemical reactions that occurs in the presence of sunlight. These reactions comprise a mix of organic and inorganic compounds, including a number of toxic secondary pollutants such as ozone (O3) and peroxyacetyl nitrate. These substances are commonly referred to as oxidants and are the result of numerous reactions of primary pollutants or precursors (including nitrogen oxides (NOx) and non- methane hydrocarbons (NHHC)) emitted from vehicle exhausts and to some extent industry, O3 is the major constituent of the photochemical oxidants, and its concentration is often used to determine the severity of photochemical smog. Limited research on photochemical smog in Cape Town has been undertaken, and this study has concentrated on providing a more detailed understanding of photochemical precursor and oxidant levels in the urban atmosphere of Greater Cape Town. This was approached by the investigation and assessment of the spatial and temporal behaviour of photochemical pollutants, making use of automatic monitor data collected from 1984 to 1986, and supplemented by data collected during a spatial survey in April and Hay of 1987. Precursor levels were found to be strongly influenced by the seasonal cycle of the weather and were highest in winter when stable atmospheric conditions prevailed, particularly during morning rush hours, O3 behaviour was complex and lacked any definite relationship to season or to selected meteorological variables, although the limited data indicated high levels during the early spring months. Peak levels were generally experienced on fair weather days during the early afternoon hours at the time of maximum ultraviolet radiation, O3 levels did not exceed the USEPA 1-hour standard of 0.12ppm during 1985 and 1986. The spatial distribution of precursor and oxidant concentrations showed the NOx levels to be spatially dependent, following the major arterial roads. NHHC levels were spatially less well defined than NOx, and O3 levels were spatially relatively uniform, exhibiting depletion due to scavenging by nitric oxide (NO) in areas close to main traffic routes. High NOx levels were experienced predominantly in the city centre, while the suburbs tended to experience the higher O3 levels. Cape Town was not considered to have a photochemical smog problem of the same magnitude as Los Angeles or Sydney, ( due to a number of factors which contributed to the complex situation (such as high NO levels, relatively low NMHC levels and strong winds in summer). However in the Northern Suburbs, the absence of high NO levels together with additional NMHC emissions from nearby industry led to the recognition of this area as one of potential photochemical smog formation.
8

EVALUATION OF AIR QUALITY USING AN ANALYTICAL METHOD FOR TOXIC ORGANIC VAPORS IN INDUSTRIAL EMISSIONS.

Broach, Rhonda Lee. January 1982 (has links)
No description available.
9

Dopad spotřeby domácností na životní prostředí / Envirnomental impact of household consumption

Mach, Radomír January 2021 (has links)
The main goal of this dissertation thesis is to quantify the environmental burden associated with household consumption in the Czech Republic. Emissions of three groups of gases were selected to express the burden on the environment, namely emissions causing climate change, acidification and the formation of photosmog. These emissions arise from the consumption of fuels in households, and they are usually referred to as direct household emissions. Or they arise in the production and distribution of goods and services, and they are usually referred to as indirect household emissions. Although indirect emissions come from combustion in energy production and other industrial processes and agricultural activities, not from households, they are a consequence of household demand for final products. Therefore, such emissions are considered to be a consequence of household consumption. The resulting emission values are given for the average household and households divided into expenditure deciles. Emissions increase with expenditure per household member in total consumption and in individual consumption groups across all deciles. In the case of climate change-related emissions, more than half come from heating (41%) and electricity (21%). For acidification, heating (31%) and food (24%) are the dominant...

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