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Chemical characterization and source apportionment of individual aerosol particles over the North Sea and the English Channel using multivariate techniques OMA
Xhoffer, C.; Bernard, P.; Van Grieken, R.; Van der Auwera, L..
More than 25,000 individual aerosol particles in 51 particulate matter samples, all taken from a research vessel over the North Sea and the English Channel, in a time range of 4 years, were analyzed by automated electron probe X-ray microanalysis (EPXMA). Multivariate methods were used to reduce the total data set. Single-particle analysis combined with hierarchical cluster analysis yields nine major particle types. The North Sea aerosol is predominantly composed of sea salt, sulfur-rich particles, silicates and calcium sulfate particles. Their abundance is dependent on meteorological conditions and sample location. Differences between all samples were studied on the basis of the abundance variations by using principal component analysis. Three factors...
Tipo: Info:eu-repo/semantics/article
Ano: 1991 URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=2915
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Electron microprobe analysis of suspended matter in the Angola Basin OMA
Bernard, P.; Eisma, D.; Van Grieken, R..
Electron microprobe analysis of suspended-matter samples collected at different water depths at ten stations in the Angola Basin indicated that at each station, from top to bottom, the elementary composition of the suspended matter was very similar and differed from the composition of the suspended matter at the adjacent stations. This indicates that the downward settling of the suspended matter is much faster than the horizontal transport and mixing by the currents. Assuming that the suspended matter settles in the form of flocs, or is scavenged by settling flocs, the suspended matter can indeed reach the bottom in a shorter period than needed for the currents to cover the distance between adjacent stations. Comparison with sediment trap data from the...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Biochemical composition; Ocean basins; Sediment traps; Sedimentation; Suspended particulate matter.
Ano: 1999 URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3977
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Elemental concentrations and heavy metal pollution in sediments and suspended matter from the Belgian North Sea and the Scheldt estuary OMA
Van Alsenoy, V.; Bernard, P.; Van Grieken, R..
The elemental composition of sediment and suspended matter samples from the Belgian coastal and offshore regions of the Southern Bight of the North Sea and from the Scheldt estuary has been determined using X-ray fluorescence and atomic absorption spectrometry.Special attention was given to the heavy metals of the black and grey lists. The bulk sediment and the clay/silt fraction were analyzed. The average heavy metal contents in the fraction <63 µm were comparable to the levels in the suspended matter. Different normalization techniques led to the identification of two different populations of sediments. Most of the sediments were enriched in Cd, Cr, Hg, Pb and Zn but no enrichment was found for Cu and Ni. Comparing these data with older data indicates...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Heavy metals; Pollution; Sediments; Suspended particulate matter.
Ano: 1993 URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=2789
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Geochemistry of suspended matter from the Baltic Sea: 1. Results of individual particle characterization by automated electron microprobe OMA
Bernard, P.; Van Grieken, R.; Brügmann, L..
Automated electron probe X-ray microanalysis was used to characterize some 15.000 individual suspension particles from 50 samples of suspended matter collected from different depths at 18 stations throughout the Baltic Sea and the transient area to the North Sea. For each particle, 14 minor and major elements were determined and size information data were obtained. To process this huge amount of results, multivariate analysis techniques were invoked: the particles were classified into specific types and the abundance variations of these groups were studied.It appeared that 80% of all investigated particles contained mostly silicon, and seemed to consist of quartz, and K-rich and Fe-rich aluminosilicates. The abundance of BaSO<sub>4</sub>...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Authigenic minerals Automation Chemical oceanography Electron microscopy Sediment composition Suspended particulate matter ANE; North Sea.
Ano: 1989 URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3160
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On suspended barite and the oxygen minimum in the Southern Ocean OMA
Dehairs, F.A.; Goeyens, L.; Stroobants, N.; Bernard, P.; Goyet, C.; Poisson, A.; Chesselet, R..
Particulate Ba profiles were measured in the Indian sector of the southern ocean. The largest fraction (>80%) of this barium is present as barite microcrystals. The profiles of total barium are characterized by a subsurface maximum between 200 and 500 m depth in the vicinity of the oxygen minimum. Highest barium values are found just south of the Polar Front, while lowest values occur close to the Antarctic Divergence. Between the divergence and the Polar front a tight inverse relationship is observed between oxygen in the oxygen minimum and barium in the barium maximum. This relationship disappears north of the Polar Front. Since suspended barite is known to be of biological origin, the correlation of barite with oxygen suggests that the observed...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Barite Oxygen PS; Southern Ocean.
Ano: 1990 URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3076
Registros recuperados: 5
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