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| Registros recuperados: 50 | |
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| Dekov, V.m.; Vanlierde, E.; Billstrom, K.; Garbe-schoenberg, C. -d.; Weiss, D. J.; Gatto Rotondo, G.; Van Meel, K.; Kuzmann, E.; Fortin, D.; Darchuk, L.; Van Grieken, R.. |
| Two groundwater-fed river systems (Nete and Demer, Belgium) carry red suspended material that settles on the river bed forming red sediments. The local aquifer that feeds these river systems is a glauconite-rich sand, which provides most of the dissolved Fe to the rivers. The solid component of these systems, i.e., the red suspended material and sediments, has a simple mineralogy (predominantly ferrihydrite), but shows a complex geochemistry pointing out the different processes contributing to the river chemistry: (1) the red sediments have higher transition metal (excluding Cu) and detrital element (e.g., Si, Al, K, Rb, etc.) concentrations than the red suspended matter because of their longer residence time in the river and higher contribution of the... |
| Tipo: Text |
Palavras-chave: Ferrihydrite; Fe-Zn-Sr-Nd-Pb-isotopes; Rivers; Sediments; Suspended matter. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00203/31404/29789.pdf |
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| Injuk, J.; Van Grieken, R.; De Leeuw, G.. |
| The atmospheric input of up to 16 trace and other elements into the North Sea is further assessed from aerosol concentrations measured at a coastal station in Belgium, on ships during two cruises, and on a platform, in the years 1992-1994. The Slinn and Slinn model is used to calculate the dry deposition from the measured aerosol concentrations. The total (dry and wet) deposition into the North Sea environment is estimated to be (in tonnes per year): 560 for V, 1300 for Cr, 650 for Ni, 690 for Cu, 3500 for Zn and 1970 for Pb. The 'giant' particles dominate the fluxes. The atmospheric contribution to the total input into the North Sea, including riverine inputs and direct discharges, are estimated to be 28% for Cu, 29% for Zn and 57% for Pb. The inputs... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Aerosols Experimental data Fallout Heavy metals Measurement Modelling ANE; North Sea. |
| Ano: 1998 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=309 |
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| Hoornaert, S.; Treiger, B.; Van Grieken, R.; Laane, R.W.P.M.. |
| A literature review is given of atmospheric trace metal concentrations in aerosols above the North Sea and the English Channel over the period 1971-1994. Literature data have been gathered and intercompared to look for possible trends in the reported concentrations. Six trace metals are considered: Cd, Cu, Pb, Zn, Ni, and Cr. A distinction is made between measurements in different regions of the North Sea, and between coastal and marine areas. The majority of the data deals with the Southern Bight, providing the most reliable trends. Strong decreasing trends are observed for the Pb and Zn concentrations above the North Sea during the years 1971-1994. For Cd, Cu, Ni, and Cr, much less data are available in the literature. Despite this, also for Cd and Cu a... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1999 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=8158 |
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| Treiger, B.; Injuk, J.; Bondarenko, I.; Van Espen, P.; Van Grieken, R.; Breitenbach, L.; Wätjen, U.. |
| A multivariate statistical evaluation technique, non-linear mapping, is proposed to extract information from a multielement microbeam proton-induced X-ray emission data set. Individual aerosol particles, collected in the North Sea troposphere, were classified according to their composition. Several groups of particles were identified and suggestions were made for their sources. |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1994 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=2683 |
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| Rojas, C.M.; Van Grieken, R.; Maenhaut, W.. |
| During the period from September 1988 to October 1989, 23 flights were carried out over the Dutch Continental Shelf of the North Sea and a total of 108 aerosol filter samples were collected. The samples were analyzed for Na, Mg, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Br and Pb using both particle-induced X-ray emission (PIXE) and energy-dispersive X-ray fluorescence (EDXRF). The results from PIXE exhibited better precision and lower detection limits than those from EDXRF. Therefore the further discussion and interpretation was based on the PIXE data only. It was observed that Si, S, V, Mn, Ni, Cu and Pb were enriched with respect to the earth's crust. It was seen that winds from the sector Southeast-South contributed most significantly to... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1993 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=8422 |
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| Injuk, J.; Van Malderen, H.; Van Grieken, R.; Swietlicki, E.; Knox, J.M.; Schofield, R.. |
| X-ray emission techniques for bulk and individual particle analysis (EDXRF, EPXMA, micro-PIXE) were combined and applied in atmospheric research on the North Sea area as part of a field-study on air-sea exchange processes of particulate matter. The atmospheric loading for a number of elements was determined by EDXRF, yielding bulk concentrations for Mg, Al, Si, S, Cl, K, Ca, Cr, Mn, FE, Ni,Cu, Zn, BR and Sr. From these EDXRF data, deposition rates were derived and, based on a classical multivariate statistical approach, different aerosol sources were identified. Complementary to this work, EPXMA combined with automated image analysis was applied to individual size-segregated aerosol particles to determine their inorganic composition, physical size and... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1993 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=2711 |
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| Maenhaut, W.; Raemdonck, H.; Selen, A.; Van Grieken, R.; Winchester, J.W.. |
| By using a polyester sailboat as sampling platform, a series of duplicate aerosol samples was collected by cascade impactors on a trip from Panama to Tahiti in 1979. Elemental analysis mainly by particle-produced X-ray emission (PIXE) indicated, in the samples collected between Panama and the Galapagos Islands, the presence of a substantial crustal component (0.4 µg/m³), fine Cu (0.4 ng/m³ and Zn (0.6 ng/m³), and excess fine S and K (100 and 2.4 ng/m³, respectively in addition to the major sea salt elements. The crustal component and fine Cu and Zn are suggested to result from natural continental sources (i.e., eolian dust transport from the American continents and perhaps geothermal emissions). Samples collected west of the Galapagos Islands in the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Aerosols IS; Equatorial Pacific. |
| Ano: 1983 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3398 |
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| Rojas, C.; Otten, P.; Van Grieken, R.; Laane, R.W.P.M.. |
| A mathematical approach based on the Monin-Obukhov similarity theory is used to predict the wind speed, friction velocity and drag coefficient, which are then introduced in the well-known deposition model of Slinn and Slinn (1980), to calculate the dry deposition of heavy metals into the North Sea. This model is perfectly suitable for aircraft sampling considering the fact that usually due to safety reasons, flights at the reference height used in deposition models (10m), are not possible. To check this approach, deposition velocities were calculated based on the airborne concentrations of Cu, Cd, Zn and Pb obtained by sampling with the aid of an aircraft over the Dutch continental shelf of the North Sea. Results are in agreement with those found in the... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1991 |
URL: http://www.vliz.be/imisdocs/publications/262330.pdf |
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| Noone, K.J.; Johnson, D.W.; Taylor, J.P.; Ferek, R.J.; Garrett, T.; Hobbs, P.V.; Durkee, P.A.; Nielsen, K.; Öström, E.; O'Dowd, C.; Smith, M.H.; Russell, L.M.; Flagan, R.C.; Seinfeld, J.H.; De Bock, L.; Van Grieken, R.; Hudson, J.G.; Brooks, I.; Gasparovic, R.F.; Pockalny, R.A.. |
| A case study of the effects of ship emissions on the microphysical, radiative, and chemical properties of polluted marine boundary layer clouds is presented. Two ship tracks are discussed in detail. <i>In situ</i> measurements of cloud drop size distributions, liquid water content, and cloud radiative properties, as well as aerosol size distributions (outside-cloud, interstitial, and cloud droplet residual particles) and aerosol chemistry, are presented. These are related to remotely sensed measurements of cloud radiative properties. The authors examine the processes behind ship track formation in a polluted marine boundary layer as an example of the effects of anthropogenic particulate pollution on the albedo of marine stratiform clouds. |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Aerosols; Air pollution; Albedo; Atmosphere; Atmosphere; Atmospheric boundary layer; Boundary layers; Cloud cover; Clouds; Man-induced effects; Marine environment; Marine pollution; Particulates; Remote sensing; Ships. |
| Ano: 2000 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=8839 |
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| Otten, P.; Injuk, J.; Van Grieken, R.. |
| Air sampling on a series of 10 cruises, spanning the whole area of the North Sea, yielded detailed spatial distributions of atmospheric concentrations of Al, Si, S, Cl, P, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, and Pb determined by EDXRF. A strong influence of the air mass history on the heavy metal concentrations was demonstrated for the whole sampling period of 5 years. Factor analysis performed on all samples collected with a stack filter unit resulted in the identification of three factors for the coarse particle fraction (sulphate particles with trace metals, sea salt particles and soil dust or metallurgic particles containing Fe) and four factors for the fine particle fraction (sea salt, sulphate with Pb and Zn), trace metal particles with Cu, Ni, Zn... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1994 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3896 |
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| 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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| Van Malderen, H.; Hoornaert, S.; Van Grieken, R.. |
| Aerosol samples have been collected over the Southern Bight of the North Sea from an aircraft. In this way, 96 samples were taken for single-particle analysis during 16 flights. Almost 45,000 individual particles were analyzed with electron probe X-ray microanalysis. More than 5,000 of these were found to contain significant concentrations of one or more of the heavy metals Cr, Pb, and Zn. With the help of hierarchical, nonhierarchical, and fuzzy clustering techniques, various heavy metal-containing particle types could be identified. Significant differences in abundances were detected in the North Sea heavy metal aerosol, depending on the origin of the air masses. In samples with continental influence 50 times more Zn- and Pb-containing particles were... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1996 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3150 |
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| Xhoffer, C.; Wouters, G.; Van Grieken, R.. |
| Five pairs of North Sea bulk waters and their corresponding surface microlayer samples were investigated for their particulate matter content and chemically analyzed and characterized by electron probe X-ray microanalysis and laser microprobe mass analysis. Multivariate techniques as hierarchical and nonhierarchical clustering in association with principal component analysis was performed on a data set containing more than 3,000 individual particles. This classification procedure yielded eight different particle types. Differences in particle type abundances for the microlayer and bulk water were observed. They were apportioned to their most probable sources. The results were compared with atmospheric and riverine particle data. The domination of the major... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1992 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=2909 |
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| Otten, P.; Bruynseels, F.; Van Grieken, R.. |
| Ammonia is important in the atmosphere because it neutralizes acidic species. The relative importance of different inorganic ammonium compounds (chloride, nitrate and sulfate) in marine air chemistry was studied by single-particle characterization with the laser microprobe mass analyser. Standard aerosols were generated as a reference for compound identification, based on the fingerprint spectra obtained, and calculation of the relative sensitivity achieved for different ions in a marine aerosol matrix. The relative sensitivity for ammonium was low. Aerosol samples were collected in the Southern Bight of the North Sea under different meteorological conditions and examined for their ammonium compounds. Samples collected during an inversion period with... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Absorption spectroscopy; Aerosols; Ammonium compounds. |
| Ano: 1987 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3256 |
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| Ganor, E.; Levin, Z.; Van Grieken, R.. |
| Aerosol particles were collected aboard a ship in Haifa and Tel Aviv, Israel, during the summer time. The aerosol particles (6170) were analyzed as individual particles and classified according to their chemical composition, size, number concentration per cubic centimeter and morphology. Most of the aerosol particles could be classified into four groups. The first contains gypsum from the sea and from industrial sources brought in by land breezes. A second group is characterized by continental aluminosilicate and quartz. A third group consists of sea salt mixed with sulphate particles. The fourth group is characterized by an abundance of sulphate particles, some of which are ammonium sulphate brought by the land breezes. The particles were identified as... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1998 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=304 |
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| Injuk, J.; Van Grieken, R.. |
| A literature review of the atmospheric concentration rates and dry and wet deposition fluxes of particulate Cd, Cr, Cu, Pb and Zn to the North Sea and adjacent areas is given. The results of direct measurements of dry and wet deposition fluxes are compared to indirect estimates and to modelling values. This work points out the large uncertainties in results of different studies on atmospheric input of trace elements into the North Sea. The current knowledge about the dependence of the deposition velocity upon the particular size and about the processes controlling wet deposition fluxes, and the quality and completeness of the emission data are still adequate for describing the environmental cycle and impact of heavy metals in the North Sea. |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1995 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=2981 |
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| Registros recuperados: 50 | |
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