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| Registros recuperados: 43 | |
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| Lunven, Michel; Guillaud, Jean-francois; Youenou, Agnes; Crassous, Marie-pierre; Berric, Roger; Le Gall, Erwan; Kerouel, Roger; Labry, Claire; Aminot, Alain. |
| A new Fine Scale Sampler (FSS) was designed and used in the Loire River plume (Bay of Biscay, France) in order to study phytoplankton distribution in highly stratified water columns. The FSS consists of a linear array of 15 sampling bottles, set horizontally at 20 cm intervals. Data acquired from the CTD and fluorescence probe of the FSS enable it to be precisely positioned at the depth of the highest density gradient or at the chlorophyll a maximum. The FSS made it possible to investigate fine scale vertical distribution of phytoplankton and relationships with water density, nutrient concentrations or light availability, for spring and summer conditions. Under spring conditions, the entire upper layer exhibited a dominant diatom population (Chaetoceros... |
| Tipo: Text |
Palavras-chave: Plankton patchiness; Density discontinuity; Sampling; Thin layer; Nutrients; Phytoplankton. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/publication-533.pdf |
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| Andrieux-loyer, Françoise; Aminot, Alain. |
| Phosphorus forms with respect to sediment characteristics, such as grain-size, and major chemical elements, were studied in French coastal marine areas (the Bay of Seine and the Loire and Gironde Estuaries).In the three areas, Fe/Al-bound phosphate (Fe/Al-P) and exchangeable phosphate (exch-P) were significantly related to the proportion of fine fraction (< 63 mum). The special association of these forms with fine particles, as well as the relationships between exch-P, Fe/Al-P and Fe showed that adsorption processes on Fe oxides had taken place. However, for similar Fe concentrations, Bay of Seine sediments showed Fe/Al-P concentrations which were four to five times higher than those found in the Loire and Gironde Estuaries. This was attributed to... |
| Tipo: Text |
Palavras-chave: Coastal areas; Major elements; Phosphorus forms; Grain size; Sediments. |
| Ano: 2001 |
URL: http://archimer.ifremer.fr/doc/2001/publication-469.pdf |
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| Savoye, N; Aminot, Alain; Treguer, Paul; Fontugne, M; Naulet, N; Kerouel, Roger. |
| Two cruises (April and June 1997) were carried out in the Bay of Seine, a nitrate- and ammonium-enriched ecosystem of Western Europe, to identify the major mechanisms that control delta(15)N and VC in spring particulate organic matter (POM). Particulate organic nitrogen (PON) delta(15)N ranged between 0.8 and 5.2parts per thousand in April and between 2.2 and 6.2parts per thousand in June, while particulate organic carbon (POC) delta(13)C ranged between -24.3 and -19.7parts per thousand, and between -20.0 and -16.2parts per thousand during the same periods. During spring 1997, POM was highly dominated by autochthonous phytoplankton. It is shown that the variation of PON delta(15)N is due to both nitrate mixing between river and marine waters and... |
| Tipo: Text |
Palavras-chave: C and N stable isotopes; Phytoplankton; Coastal ecosystem; Nitrate utilization; Bay of Seine. |
| Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/00000/10645/7593.pdf |
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| Labasque, Thierry; Chaumery, Christian; Aminot, Alain; Kergoat, Gilles. |
| The spectrophotometric iodine measurement for oxygen determination by the Winkler method is re-examined for theoretical and operational aspects. It is shown that the selection of an isobestic point for measuring the mixture of iodine and tri-iodide in the solution enhances reliability. The wavelength value of 466 nm was selected after a spectrum study. Then, performances are assessed by mean of statistical approach based on repeated standardization curves at the isobestic point compared with other wavelengths. At 466 nm, the method is linear up to about 1000 mumol kg(-1) of O-2. Optimization and validation of the spectrophotometric method is realized through a robustness study based on factors that may alter the results (temperature, reagent volumes,... |
| Tipo: Text |
Palavras-chave: Isobestic point; Sea water; Spectrophotometry; Dissolved oxygen. |
| Ano: 2004 |
URL: http://archimer.ifremer.fr/doc/2004/publication-1694.pdf |
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| Aminot, Alain; Kerouel, Roger. |
| The paper reviews the methods described in the literature for the determination of total dissolved free primary amines (TDFPA) by fluorescence. A wide set of reaction conditions can be found, but they rely on few experiments for their validation. Among fluorogenic compounds, o-plithaldialdehyde (OPA) is more sensitive than fluorescamine and was thus examined here. However, the use of mercaptoethanol (ME) in the reaction (as ail additional derivatization compound) is able to generate unreliable results, in particular when standardization relies on glycine. We suggest replacing ME with 3-mercaptopropionic acid (MPA) which induces more stable and comparable fluorescence among amine Compounds. A systematic study was therefore undertaken to define reagent... |
| Tipo: Text |
Palavras-chave: Fluorescence; Determination; Seawater; Total dissolved free primary amines. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-2274.pdf |
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| Menesguen, Alain; Aminot, Alain; Belin, Catherine; Chapelle, Annie; Guillaud, Jean-francois; Joanny, Michel; Lefebvre, Alain; Merceron, Michel; Piriou, Jean-yves; Souchu, Philippe. |
| In order to be able to count the cases of coastal eutrophication and to propose methods to monitor as well as to reduce these phenomena, first of all it is necessary to precisely define the word eutrophication itself. Instead of the strict etymological definition, that is to say a progression of the enrichment of a medium, we will rather retain the concept of a state enriched at a point such as it causes harmful effects on the ecosystem, and nuisances to man's activities. Based on the average chemical equations of the organic matter synthesis/degradation in the sea, this operational definition thus puts forwards the harmful consequences of enrichment, i.e. the production of an excessive algal biomass, sometimes unbalanced from the point of view of... |
| Tipo: Text |
Palavras-chave: Alexandrium; Phaeocystis; Monostroma; Ulva; Dilution plume; Water trapping; Anoxia; Nitrogen and phosphorus loadings; Red tides; Phytoplankton blooms; Green tides; Eutrophication; Alexandrium; Phaeocystis; Monostroma; Ulva; Panache de dilution; Confinement; Anoxie; Phosphate; Nitrate; Apports terrigènes; Eaux colorées; Blooms phytoplanctoniques; Marées vertes; Eutrophisation. |
| Ano: 2001 |
URL: http://archimer.ifremer.fr/doc/2001/rapport-22.pdf |
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| Aminot, Alain; Kerouel, Roger; Le Guellec, Anne-marie; Bodennec, Guy; Quemeneur, Michelle; Marty, Yanic. |
| Ce travail est effectué dans le cadre du programme général concernant l'étude des rejets urbains en mer, sous la responsabilité de Jean-François GUILLAUD. Il constitue, dans ce programme, le premier volet de l'étude des paramètres entrant dans la chimie des cycles naturels, par la recherche d'une définition aussi précise que possible de la composition des effluents urbains brut et épuré et de leur évolution journalière. |
| Tipo: Text |
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| Ano: 1986 |
URL: http://archimer.ifremer.fr/doc/00082/19295/16890.pdf |
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| Daniel, Anne; Kerouel, Roger; Aminot, Alain. |
| Following previous work, the production of reference material for nutrients in seawater, using pasteurization as a preservation method, was carried out seven times between 2006 and 2010 in the framework of inter-laboratory exercises. The preparation of samples from natural seawater allowed to become depleted in nutrients then spiked, bottled and pasteurized, is described. Five main nutrients are involved in this study: ammonium, nitrite, nitrate, phosphate and silicate. Bottles are in glass for the ammonium samples and in plastic for the other nutrients. Pasteurization was performed at 80 ± 3 °C for 2 h. Samples were controlled for homogeneity and stability at 3–5 month interval, before and after the period allocated for each exercise and a third time... |
| Tipo: Text |
Palavras-chave: Pasteurization; Nutrients; Seawater; Inter-laboratory exercises. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00058/16905/15066.pdf |
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| Aminot, Alain. |
| Dans le cadre de l'extension du RNO aux Antilles, un exercice d"intercomparaison des laboratoires pressentis pour effectuer les analyses du volet « hydrologie » a été organisé par l'IFREMER fin 2000-début 2001. L'exercice comportait l'analyse de cinq paramètres : salinité, nitrate, nitrite, ammonium et phosphate. Chacun des paramètres devait être analysé à deux niveaux de concentration. Les participants étaient au nombre de 3. Chaque laboratoire a reçu deux flacons de 250 ml pour la salinité et huit flacons de 150 ml pour les nutriments (un flacon par paramètre et par niveau). Les laboratoires étaient informés qu'ils devaient analyser les échantillons dans un délai de six semaines environ après réception, ce qui limitait les risques de dérive potentielle... |
| Tipo: Text |
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| Ano: 2001 |
URL: http://archimer.ifremer.fr/doc/00018/12911/9866.pdf |
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| Aminot, Alain; Kerouel, Roger. |
| A segmented flow automated method with on-line photo-oxidation for the determination of dissolved organic phosphorus + soluble reactive phosphorus (DOP + SRP) in seawater and fresh water is described here. A low-power lamp was used for a compact, easy-to-handle and low-ozone-producing manifold. The influence of seawater matrix components was studied in detail using natural seawater and salt solutions spiked with DOP model compounds. Bromide was found to be the most inhibitory species in seawater. The work shows that most salt solutions referred to as artificial seawater are not satisfactory model matrices to test the actual seawater matrix effect. Since DOP recovered in undiluted seawater samples was about half that obtained in fresh water samples, the... |
| Tipo: Text |
Palavras-chave: Measurement; Fresh water; Seawater; Total dissolved phosphorus; Dissolved organic phosphorus. |
| Ano: 2001 |
URL: http://archimer.ifremer.fr/doc/2001/publication-1678.pdf |
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| Aminot, Alain; Kerouel, Roger; Birot, Dominique. |
| A version of the orthophthaldialdehyde-fluorescence ammonium determination for flow injection analysis (FIA) is presented here, with a view to its use for in situ, low-power consumption systems, Thus, the reaction temperature was limited to 30 degreesC and FIA was used in stop-Bow mode (3 min stop). The calibration is linear up to 50 mu mol l(-1), but concentrations up to 100 mu mol l(-1) can be measured. Repeatability is around 1% in the range of 0.5-4 mu mol l(-1) and the detection limit is about 0.03 mu mol l(-1) Over the salinity range of 5-35 (seawater practical salinity scale) the salt effect is almost negligible (within +/- 2%); and below salinity of 5 it increases to a maximum of -9% in fresh water compared to seawater. Hydrogen carbonate,... |
| Tipo: Text |
Palavras-chave: In situ; Fluorometry; Flow injection analysis; Determination; Ammonium. |
| Ano: 2001 |
URL: http://archimer.ifremer.fr/doc/2001/publication-1722.pdf |
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| Lunven, Michel; Guillaud, Jean-francois; Crassous, Marie Pierre; Youenou, Agnes; Gohin, Francis; Huret, Martin; Danielou, Marie-madeleine; Kerouel, Roger; Labry, Claire; Aminot, Alain. |
| Inscrite dans le cadre du Grand Défi Golfe de Gascogne, la campagne VILOIR a été réalisée du 19 au 26 Juin 2003 à bord du Côtes de la Manche avec pour objectif l’étude en période estivale des structures hydrologiques et phytoplanctoniques des panaches de la Loire et de la Vilaine. Elle fait suite, sur la même thématique, à la campagne hivernale NUTRIGAS (2001) et à la campagne printanière GASPROD (2002). |
| Tipo: Text |
Palavras-chave: Surveillance; Littoral; Phytoplancton; Phycotoxines; Bretagne; Pays de Loire. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/00144/25494/23648.pdf |
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| Aminot, Alain; Guillaud, Jean-francois; Andrieux, Francoise. |
| The Bay of Seine receives the French river with the highest nutrient concentrations, especially phosphorus. Dissolved (phosphate) and particulate phosphorus fluxes have been determined from fortnightly serial data collected by the Port Autonome de Rouen. These determinants exhibit behaviour opposite to that of the river flow: phosphate concentration decreases hyperbolically and particulate phosphorus increases linearily. An approach based on the rate of domestic effluent treatment agrees well (20%) with the measured phosphate flux. The determination of the main particulate phosphorus forms (adsorbed, apatite, non-apatite inorganic, organic) was undertaken over the whole estuarine salinity range. The speciation of particulate phosphorus exhibits a great... |
| Tipo: Text |
Palavras-chave: PHOSPHORUS; SPECIATION; FLUX; ESTUARY; SEINE. |
| Ano: 1993 |
URL: http://archimer.ifremer.fr/doc/00100/21126/18746.pdf |
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| Aminot, Alain; Guillaud, Jean-francois; Kerouel, Roger. |
| The data of hydrology, nutrients and chlorophyll obtained in the Bay of Seine over the period 1978-1994, from 14 océanographie cruises, are synthetised and illustrated by an atlas. The Bay is a typical example of a coastal area influenced by a large river. In winter, the nutrient input is drained off into the eastern Channel. In spring, nutrients are consumed intensively. Silicate is the first that drops to limiting levels. The spring bloom generally begins in the centre-east of the Bay. Chlorophyll a can reach up to 40-70 µg/l during the year, values typical of eutrophic coastal areas. Despite the regular increase of nitrogen inputs, the biomass (as chlorophyll) has not significantly changed over a fifteen year period. |
| Tipo: Text |
Palavras-chave: Chlorophyll; Nutrients; Hydrology; Bay of Seine; Chlorophylle; Nutriments; Hydrologie; Baie de Seine. |
| Ano: 1997 |
URL: http://archimer.ifremer.fr/doc/1997/rapport-1428.pdf |
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| Coverly, Stephen; Kerouel, Roger; Aminot, Alain. |
| Modern instruments together with the use of standard reference materials have improved the accuracy and long-term reproducibility of the analysis of nutrients (ammonium, nitrate, nitrite, phosphate and silicate) in sea water using segmented-flow analysis, so that errors arising from matrix effects become more significant. Colorimetric detectors with bubble-through flowcells have become widely used for seawater analysis in recent years and their associated matrix effects are described. A re-examination of all categories of matrix effects, whose main origin is salinity, was thus undertaken to assess how much they are liable to alter the data. Interferences were classified into four types, each of which was examined in order to show its influence on the... |
| Tipo: Text |
Palavras-chave: Nutrient; Determination; Seawater; Estuarine water; Segmented-flow analysis; Matrix effects. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00057/16843/14530.pdf |
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| El Sayed, Mohamed A.; Aminot, Alain. |
| Extractable organic copper using C18 Sep-Pak cartridges was investigated in seawater after laboratory experiment showed that the (C18 Sep-Pak) cartridges were reliable, in open and coastal waters with normal levels of dissolved organic carbon, for the separation of a specific fraction of organo-copper complexes.Given that the Sep-Pak cartridges retain the hydrophobic fraction of the dissolved organic matter, this extraction technique was applied for studying the characteristics of this particular hydrophobic dissolved organic copper fraction (hDOCu) in the north-western Mediterranean waters. Surface distribution of hDOC is influenced by organic matter input from the river Rhone and its estuary as well as the physical processes affecting the primary... |
| Tipo: Text |
Palavras-chave: Mediterranean sea; Seawater; Dissolved organic matter; Copper compounds. |
| Ano: 2000 |
URL: http://archimer.ifremer.fr/doc/2000/publication-1681.pdf |
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| Registros recuperados: 43 | |
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