[1] The aerosol characterization experiment performed within the Large-Scale BiosphereAtmosphere Experiment in Amazonia-Smoke, Aerosols, Clouds, Rainfall and Climate (LBA-SMOCC) field experiment carried out in Rondônia, Brazil, in the period from September to November 2002 provides a unique data set of size-resolved chemical composition of boundary layer aerosol over the Amazon Basin from the intense biomassburning period to the onset of the wet season. Three main periods were clearly distinguished on the basis of the PM 10 concentration trend during the experiment: (1) dry period, with average PM 10 well above 50 mg m À3 ; (2) transition period, during which the 24-hour-averaged PM 10 never exceeded 40 mg m À3 and never dropped below 10 mg m À3 ; (3) and wet period, characterized by 48-hour-averaged concentrations of PM 10 below 12 mg m À3 and sometimes as low as 2 mg m À3 . The trend of PM 10 reflects that of CO concentration and can be directly linked to the decreasing intensity of the biomass-burning activities from September through November, because of the progressive onset of the wet season. Two prominent aerosol modes, in the submicron and supermicron size ranges, were detected throughout the experiment. Dry period size distributions are dominated by the fine mode, while the fine and coarse modes show almost the same concentrations during the wet period. The supermicron fraction of the aerosol is composed mainly of primary particles of crustal or biological origin, whereas submicron particles are produced in high concentrations only during the biomass-burning periods and are mainly composed of organic material, mostly water-soluble, and $10% of soluble inorganic salts, with sulphate as the major anion. Size-resolved average aerosol chemical compositions are reported for the dry, transition, and wet periods. However, significant variations in the aerosol composition and concentrations were observed within each period, which can be classified into two categories: (1) diurnal oscillations, caused by the diurnal cycle of the boundary layer and the different combustion phase active during day (flaming) or night (smouldering); and (2) day-to-day variations, due to alternating phases of relatively wet and dry conditions. In a second part of the study, three subperiods representative of the JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 112, D01201, doi:10

A comprehensive chemical aerosol characterisation was carried out at K-puszta, Hungary, from 24 May until 29 June 2006. Up to 11 June it was unusually cold at the site, but from 12 June onwards it was warm. PM 2.5 and PM 10 samplers with Nuclepore polycarbonate filters and quartz fibre filters were deployed in parallel for mostly day and night collections. All samples were analysed for the particulate mass (PM) by weighing. The Nuclepore polycarbonate filters were analysed for up to 29 elements by particle-induced x-ray emission spectrometry (PIXE) and for major anions and cations by ion chromatography. The quartz fibre filters were analysed for organic and elemental carbon by a thermal-optical transmission technique. The atmospheric concentrations of the PM and most species and elements were higher during the warm period than during the cold one. Aerosol chemical mass closure calculations were done for the PM 2.5 and PM 10 aerosols. As gravimetric PM data we used the data from the Nuclepore polycarbonate filters. For reconstituting this PM, eight aerosol components were considered. Organic matter contributed by far the most to the PM 2.5 and PM 10 PM; it was responsible for 40-50% of the average PM. Noteworthy were the much larger percentages of crustal matter during the warm period than during the cold one. In the PM 2.5 aerosol, crustal matter accounted for 17% of the average PM during the warm period, but only for 3.1% during the cold period. For the PM 10 aerosol, the percentages were 28% in the warm period and 10% in the cold one.

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This paper describes an experimental investigation of heat transfer inside a CFR spark ignition engine operated at a constant engine speed of 600 rpm. The heat flux is directly measured under motored and fired conditions with a commercially available thermopile sensor. The heat transfer during hydrogen and methane combustion is compared examining the effects of the compression ratio, ignition timing and mixture richness. Less cyclic and spatial variation in the heat flux traces are observed when burning hydrogen, which can be correlated to the faster burn rate. The peak heat flux increases with the compression ratio, but the total cycle heat loss can decrease due to less heat transfer at the end of the expansion stroke. An advanced spark timing and increased mixture richness cause an increased and advanced peak in the heat flux trace. Hydrogen combustion gives a heat flux peak which is three times as high as the one of methane for the same engine power output.

A comprehensive chemical aerosol characterization was carried out at a kerbside in downtown Budapest in spring 2002. Several filter samplers were deployed in parallel for day and night collections, and a total of 23 parallel collections were made. All samples were analysed for the particulate mass (PM) by weighing. Depending on the sampler type and/or collection substrate, further analyses were performed for up to 46 elements by a combination of particle-induced x-ray emission (PIXE) spectrometry and instrumental neutron activation analysis (INAA), for major anions and cations by ion chromatography and for organic carbon and elemental carbon by a thermal-optical transmission technique. Some of the elements measured could clearly be associated with traffic-related sources, e.g. Cu and Sb were attributed to emissions from brake linings. Aerosol chemical mass closure calculations were made for the separate fine (<2 µm) and coarse (2-10 µm) size fractions and also for the PM 10 aerosol. For reconstituting the gravimetric PM, eight aerosol types were considered, and three aerosol types were deduced from the PIXE/INAA elemental data set. Organic matter and elemental carbon were the dominant aerosol types in the fine fraction; they explained on average 43 and 21%, respectively, of the fine PM. The coarse PM consisted mainly of crustal matter (49%) and organic matter (30%). The large contribution from crustal matter (road dust) to the coarse fraction is consistent with other data from kerbside sites in Europe.