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Traffic Contribution to the Local Air Pollution
Smolík, Jiří ; Bízek, V. ; Schwarz, Jaroslav ; Ždímal, Vladimír ; Ondráček, Jakub ; Džumbová, Lucie ; Mašková, Ludmila
Particles emitted from the road transport represent one of the major aerosol source in the city environment. Due to the fact that increased aerosol concentrations are connected with higher morbidity and mortality, it is necessary to characterize and quantify these emissions in order to evaluate their effect on human health and environment. Road transport emissions include direct particle emissions from exhausts from attrition of brake lining, tires and roads and resuspended particles and indirect emissions in the form of secondary particles produced by chemical reactions of gaseous emissions.
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Modelování úniku a disperze nebezpečného plynu
Jaňour, Zbyněk ; Bezpalcová, Klára ; Erhart, Jakub ; Kellnerová, Radka ; Šeděnková, Hana
Liquefied industrial gases and liquefied energy gases are transported, stored and used in steadily increasing amounts.Since the vapours of many of these chemicals are either toxic or flammable or both, there is heightened concern amongst public and regulatory bodies on potential hazards in a case of accidental releases. The objective of this contribution is to present the concept and result of a wind tunnel study of the dispersion of pollution clouds in a atmospheric boundary layer. Scaling laws, which have to be fulfilled in order to ensure model/prototype similitary, have been developed. Examples of the method application have been demonstrated.
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Wind tunnel modelling of flow and dispersion in the street canyon
Bezpalcová, Klára ; Leitl, B. ; Jaňour, Zbyněk
There used method of physical moddeling,which is successful in solution of the atmospheric boundary layer problems.The first step was to estabilish charakteristics of the boundary layer in thewind tunnel.The measurement was done on a very simple model of a steet canyon. Atfirst there was measured a flow field and its charakteristics as the mean velocity,the intensity of turbulence and the shear stress by the method of the Laser DopplerAnemometry. Flame Ionization Detector was used for measurements of the concentration of apassive contamination from a line source. There was estimated the critical Building Reynolds Numberfor this setup on the basis of the measurement of concentration. Finally themeasured dimensionless concentration was used to estimete a concentration ofthe air pollution in a real street in a urban area and this estimate was compared with the pollutant limits.
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