| 1. |
- Fuzzi, S., et al.
(author)
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The Po Valley Fog Experiment 1989
- 1992
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In: Tellus. Series B: Chemical and Physical Meteorology. - : Stockholm University Press. - 0280-6509. ; 44:5, s. 448-468
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Journal article (peer-reviewed)abstract
- An outline is presented here of the Po Valley Fog Experiment 1989, carried out within the EUROTRAC‐GCE project. This experiment is a joint effort by several European research groups from 5 countries. The physical and chemical behaviour of the fog multiphase system was studied experimentally following the temporal evolution of the relevant chemical species in the different phases (gas, droplet, interstitial aerosol) and the evolution of micrometeorological and microphysical conditions, from the pre‐fog situation through the whole fog evolution, to the post‐fog period. Some general results, useful for describing the general features of the fog system, are presented here, while specific scientific questions on the different processes taking place within the system itself will be addressed in other companion papers of this same issue.
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| 2. |
- Wiedensohler, A., et al.
(author)
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A novel unipolar charger for ultrafine aerosol particles with minimal particle losses
- 1994
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In: Journal of Aerosol Science. - : Elsevier BV. - 0021-8502. ; 25:4, s. 639-649
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Journal article (peer-reviewed)abstract
- A unipolar diffusion charger with minimal particle losses in the ultrafine size range has been developed. This charger uses two radioactive α-sources to produce ions which are drawn into the charging region by an alternating electric field. The aerosol flow in the centre of the charging region is surrounded by a particle-free sheath air flow to prevent particle losses. Charged aerosol particles move in a "zigzag" manner in the charging channel under the influence of the alternating electric field. Positive gas ions, with higher electrical mobilities than ultrafine aerosol particles, homogeneously fill the entire charging region. Here, the aerosol becomes unipolarly charged. The charging efficiency is strongly dependent on the residence time of the particles in the ion cloud. The ion current was measured in the charging region to determine the ion concentration. The residence time of the particles in the ion cloud was calculated for each stream line of the aerosol flow. The losses of ultrafine particles in the charger were experimentally determined. The unipolar charge distribution was measured and calculated by integrating the theoretical charge distribution over all stream lines of the aerosol flow.
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| 3. |
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| 4. |
- Martinsson, Bengt G., et al.
(author)
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Elemental composition of fog interstitial particle size fractions and hydrophobic fractions related to fog droplet nucleation scavenging
- 1992
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In: Tellus. Series B: Chemical and Physical Meteorology. - : Stockholm University Press. - 0280-6509. ; 44:5, s. 593-603
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Journal article (peer-reviewed)abstract
- The cloud nucleation scavenging process was studied during a joint campaign of the EUROTRAC sub‐project Ground‐based Cloud Experiment. It was found that the particle size has a strong influence on the partitioning of particles between the cloud droplet and the interstitial aerosol reservoirs. A new aerosol sampling unit, the relative humidity processing system, was employed for the extraction of particles with a low growth‐ability with respect to increased relative humidity. The system supplied tracer elements on the particle growth‐ability. These elements could be used to identify a factor related to particle hygroscopic properties, which was in effect as a selector of cloud condensation nuclei.
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| 5. |
- Szöcs, G., et al.
(author)
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Species discrimination in five species of winter-flying geometrids (Lepidoptera) based on chirality of semiochemicals and flight season
- 1993
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In: Journal of Chemical Ecology. - 0098-0331. ; 19:11, s. 2721-2735
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Journal article (peer-reviewed)abstract
- Enantiomer separation of (6 Z,9 Z)-cis-3,4-epoxynonadecadiene and (3 Z,9 Z)-cis-6,7-epoxynonadecadiene could be achieved using chiral high-resolution gas chromatography and a cyclodextrin-bond column. (3 Z,9 Z)-(6 R,7 S)-Epoxynonadecadiene was identified from ovipositor extracts of Colotois pen-Naria, while in Erannis defoliaria the 6 S,7 R-enantiomer was found. In field trapping tests pure synthetic enantiomers caught only conspecific males of these species. (3 Z,6 Z,9 Z)-Nonadecatriene was found in both species, while the presence of (3 Z,6 Z,9 Z)-heneicosatriene was indicated in C. Pennaria only. A 10:10:3 blend of (3 Z,9 Z)-(6 R,7 S)-epoxynonadecadiene, (3 Z,6 Z,9 Z)-heneicosatriene, and (3 Z,6 Z,9 Z)-nonadecatriene was found to be optimal for catching C. Pennaria, while E. Defoliaria males were optimally caught by a 1:1 mixture of (3 Z,9 Z)-(6 S,7 R)-epoxynonadecadiene and (3 Z,6 Z,9 Z)-nona-decatriene. (6 Z,9 Z)-(3 S,4 R)-Epoxynonadecadiene was identified from ovipositor extracts of Agriopis (Erannis) aurantiaria. In field tests the pure enantiomer proved to be a highly specific sex attractant for both the late autumn/early winter flying A. Aurantiaria and the late winter/early spring flying A. Leucophearia. Males of Agriopis marginaria, which fly in late winter/early spring, were attracted to (3 Z,9 Z)-(6 S,7 R)-epoxynonadecadiene. The addition of (3 Z,6 Z,9 Z)-nonadecatriene to the S,R-enantiomer increased captures. Optimal catches were recorded with a 10:3 epoxide-hydrocarbon blend. Enantiomer specificity in all species was confirmed in EAG measurements.
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| 6. |
- Tóth, Miklos, et al.
(author)
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Attraction of male turnip moths Agrotis segetum (Lepidoptera : Noctuidae) to sex pheromone components and their mixtures at 11 sites in Europe, Asia, and Africa
- 1992
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In: Journal of Chemical Ecology. - 0098-0331. ; 18:8, s. 1337-1347
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Journal article (peer-reviewed)abstract
- Selected combinations of (Z)-5-decenyl, (Z)-7-dodecenyl, and (Z)-9-tetradecenyl acetates, the pheromone components of the turnip moth AgrotisSegetum were tested for field attractancy at six, two, and three sites in Europe, Asia, and Africa, respectively. At all of the sites in Eurasia and in northern Africa the ternary mixture of the acetates captured most males, while at the sites south of the Sahara in Africa, (Z)-5-decenyl acetate alone was responsible for attraction. Differences in male attraction among the populations studied confirm the existence of significant population variation in the pheromone of A. segetum. Interpretation of the present results together with earlier studies suggests that this variation is more or less continuous in Eurasia and north Africa, while a clearly distinct pheromone type is present in the areas south of the Sahara desert.
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| 7. |
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