lnstitut für Sensorik und Elektronik
Dauerhafte URI für die Sammlunghttps://irf.fhnw.ch/handle/11654/28068
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Publikation Growth and structural change of combustion aerosols at high relative humidity(American Chemical Society, 01.12.1995) Weingartner, Ernest; Baltensperger, Urs; Burtscher, Heinz01A - Beitrag in wissenschaftlicher ZeitschriftPublikation Hygroscopic properties of carbon and diesel soot particles(Elsevier, 08/1997) Weingartner, Ernest; Burtscher, Heinz; Baltensperger, UrsLaboratory experiments were performed in order to study the hygroscopic properties of freshly produced carbon and diesel soot particles at subsaturations (i.e. at relative humidity < 100%). Wetted carbon aggregates collapsed to a more compact structure. In contrast, the diesel combustion particles exhibited a much smaller restructuring combined with condensational growth. The hygroscopicity of the diesel particles was enhanced when the sulfur content of the fuel was increased or when the particles were subjected to an ozone and UV pre-treatment. By extrapolating the data with a Köhler model critical supersaturations were calculated. Freshly emitted combustion particles are unlikely to act as cloud condensation nuclei whereas an aging of the particles will enhance their nucleation ability.01A - Beitrag in wissenschaftlicher ZeitschriftPublikation Aerosol emission in a road tunnel(Elsevier, 02/1997) Weingartner, Ernest; Keller, Christian; Stahel, Werner; Burtscher, Heinz; Baltensperger, UrsContinuous measurements of aerosol emissions were performed within the scope of emission measurements in the Gubrist tunnel, a 3250 m long freeway tunnel near Zürich, Switzerland, from 20 September to 26 September 1993. The particles in the respirable size range (d < 3 μm) were found to be mainly tail pipe emissions with very small amount of tire wear and road dust. The calculated PM3 emission factor for diesel engines was about 310 mg/km, where the main part (63%) of the diesel vehicles were heavy-duty vehicles. Thirty-one percent of the PM3 emissions from diesel vehicles were black carbon and 0.86% particle bound PAR Due to the high fraction emitted by diesel engines the contribution of gasoline engines could not be evaluated by the statistical model. During their residence time in the tunnel the particles undergo significant changes, resulting in a more compact structure. It is concluded that this is mainly due to adsorption of volatile material from the gas phase to the particle surface.01A - Beitrag in wissenschaftlicher Zeitschrift