Sabiia Seb
PortuguêsEspañolEnglish
Embrapa
        Busca avançada

Botão Atualizar


Botão Atualizar

Ordenar por: RelevânciaAutorTítuloAnoImprime registros no formato resumido
Registros recuperados: 9
Primeira ... 1 ... Última
Imagem não selecionada

Imprime registro no formato completo
Autonomously profiling the nitrate concentrations in the ocean : the Pronuts project ArchiMer
D'Ortenzio, Fabrizio; Le Reste, Serge; Lavigne, Heloise; Besson, F.; Claustre, H.; Coppola, Laurent; Dufour, A.; Dutreuil, Vincent; Laes, Agathe; Leymarie, Edouard; Malarde, Damien; Mangin, A.; Migon, Christophe; Morin, P.; Poteau, A.; Prieur, L.; Raimbault, P.; Testor, Pierre.
Tipo: Text
Ano: 2012 URL: http://archimer.ifremer.fr/doc/00114/22555/20243.pdf
Imagem não selecionada

Imprime registro no formato completo
Determination of iron-porphyrin-like complexes at nanomolar levels in seawater ArchiMer
Vong, Lilita; Laes, Agathe; Blain, Stéphane.
A new method for the non-specific determination of iron-porphyrin-like complexes in natural waters has been developed. It is based on the chemiluminescent oxidation of the luminol in the presence of dioxygen (O-2) at pH 13. The method has been implemented in a FIA manifold that allowed the direct injection of seawater. The limit of detection is 0.11 nM of equivalent hemin (Fe-protoporphyrin IX). Fe2+, Fe3+, H2O2, siderophore (deferoxamin mesylate), humic acid and phytic acid did not interfere when the), were present at the concentrations expected in seawater. Metal free porphyrin and Mg, Cu, Co porphyrin complexes did not induce a significant chemiluminescent signal. Poisoned unfiltered samples could be stored for several weeks before analyses. The new...
Tipo: Text Palavras-chave: Chemiluminescence; Complexation; Flow injection; Seawater; Porphyrin; Iron.
Ano: 2007 URL: http://archimer.ifremer.fr/doc/2007/publication-3298.pdf
Imagem não selecionada

Imprime registro no formato completo
Developing Autonomous Observing Systems for Micronutrient Trace Metals ArchiMer
Grand, Maxime M.; Laes, Agathe; Fietz, Susanne; Resing, Joseph A.; Obata, Hajime; Luther, George W.; Tagliabue, Alessandro; Achterberg, Eric P.; Middag, Rob; Tovar-sánchez, Antonio; Bowie, Andrew R..
Trace metal micronutrients are integral to the functioning of marine ecosystems and the export of particulate carbon to the deep ocean. Although much progress has been made in mapping the distributions of metal micronutrients throughout the ocean over the last 30 years, there remain information gaps, most notable during seasonal transitions and in remote regions. The next challenge is to develop in situ sensing technologies necessary to capture the spatial and temporal variabilities of micronutrients characterized with short residence times, highly variable source terms, and sub-nanomolar concentrations in open ocean settings. Such an effort will allow investigation of the biogeochemical processes at the necessary resolution to constrain fluxes, residence...
Tipo: Text Palavras-chave: Trace metals; Micronutrients; In situ chemical analyzers; In situ sensors; GEOTRACES; OceanObs'19; Ocean observing time series.
Ano: 2019 URL: https://archimer.ifremer.fr/doc/00482/59337/62116.pdf
Imagem não selecionada

Imprime registro no formato completo
Impact of environmental factors on in situ determination of iron in seawater by flow injection analysis ArchiMer
Laes, Agathe; Vuillemin, Renaud; Leilde, Bernard; Sarthou, Géraldine; Bournot Marec, Claudie; Blain, Stéphane.
A sensitive method for iron determination in seawater has been adapted on a submersible chemical analyser for in situ measurements. The technique is based on flow injection analysis (FIA) coupled with spectrophotometric detection. When direct injection of seawater was used, the detection limit was 1.6 nM, and the precision 7%, for a triplicate injection of a 4 nM standard. At low iron concentrations, on line preconcentration using a column filled with 8-hydroxyquinoline (8HQ) resin was used. The detection limit was 0.15 nM (time of preconcentration = 240 s), and the precision 6%, for a triplicate determination of a I nM standard, allowing the determination of Fe in most of the oceanic regimes, except the most depleted surface waters. The effect of...
Tipo: Text Palavras-chave: Temperature and pressure effects; Submersible chemical analyser; Seawater; In situ measurements; Iron; Flow injection analysis.
Ano: 2005 URL: http://archimer.ifremer.fr/doc/2005/publication-1209.pdf
Imagem não selecionada

Imprime registro no formato completo
New instruments to monitor coastal sea water masses according to European Water Framework Directive, Trophimatique project ArchiMer
Repecaud, Michel; Degres, Yves; Bernard, Nathalie; Allenou, Jean-pierre; Aoustin, Yannick; Arrondeau, Jean-pierre; Bouget, Jean-francois; Bucas, Karenn; Daniel, Anne; Guillaud, Jean-francois; Hamon, Michel; Jegou, Paul; Laes, Agathe; Le Roux, Dominique; Le Piver, David; Quemener, Loic; Rolin, Jean-francois; Rudelle, Tiphaine; Legrand, Jacques; Vuillemin, Renaud.
The automated monitoring of physico-chemical parameters in the coastal zone has been using large buoys and fixed infrastructures. A better understanding of many estuaries is needed in order to fulfil the agenda and requirements of the European Water Framework Directive. In order to address the fluxes of nutrients as well as algal blooms and low oxygen events, the "TROPHIMATIQUE" project has developed a new generation of instruments able to be deployed in sea waters. The smaller size of the new instruments is intended to facilitate the maintenance. A new multi-parameter probe has been developed. The measurements of all nutrients are performed thanks to the CHEMINI flow injection analysers for nitrate, ammonia, silicate and phosphate. A sampler using similar...
Tipo: Text
Ano: 2009 URL: http://archimer.ifremer.fr/doc/00107/21807/20276.pdf
Imagem não selecionada

Imprime registro no formato completo
On the nature of dissolved copper ligands in the early buoyant plume of hydrothermal vents ArchiMer
Cotte, Laura; Omanovic, Dario; Waeles, Mathieu; Laes, Agathe; Cathalot, Cecile; Sarradin, Pierre-marie; Riso, Ricardo D..
Environmental contextCopper released by deep-sea hydrothermal vents has been recognised to be partly stabilised against precipitation by its complexation with strong Cu binding ligands. Yet, the sources and nature of these compounds in such environments are still not fully understood. This study shows that the Cu ligands detected are hydrothermally sourced and could be mainly inorganic sulfur species. AbstractThe apparent speciation of Cu in the early buoyant plume of two black smokers (Aisics and Y3) from the hydrothermal vent field Lucky Strike (Mid-Atlantic Ridge) was investigated using competitive ligand exchange-adsorptive cathodic stripping voltammetry (CLE-AdCSV). We have assessed the apparent Cu-binding ligand concentration ([L]) and the...
Tipo: Text
Ano: 2018 URL: https://archimer.ifremer.fr/doc/00444/55558/57208.pdf
Imagem não selecionada

Imprime registro no formato completo
Rhythms and Community Dynamics of a Hydrothermal Tubeworm Assemblage at Main Endeavour Field - A Multidisciplinary Deep-Sea Observatory Approach ArchiMer
Cuvelier, Daphne; Legendre, Pierre; Laes, Agathe; Sarradin, Pierre-marie; Sarrazin, Jozee.
The NEPTUNE cabled observatory network hosts an ecological module called TEMPO-mini that focuses on hydrothermal vent ecology and time series, granting us real-time access to data originating from the deep sea. In 2011-2012, during TEMPO-mini's first deployment on the NEPTUNE network, the module recorded high-resolution imagery, temperature, iron (Fe) and oxygen on a hydrothermal assemblage at 2186 m depth at Main Endeavour Field (North East Pacific). 23 days of continuous imagery were analysed with an hourly frequency. Community dynamics were analysed in detail for Ridgeia piscesae tubeworms, Polynoidae, Pycnogonida and Buccinidae, documenting faunal variations, natural change and biotic interactions in the filmed tubeworm assemblage as well as links with...
Tipo: Text
Ano: 2014 URL: http://archimer.ifremer.fr/doc/00200/31164/29564.pdf
Imagem não selecionada

Imprime registro no formato completo
Sources and transport of dissolved iron and manganese along the continental margin of the Bay of Biscay ArchiMer
Laes, Agathe; Blain, S; Laan, P; Ussher, S; Achterberg, E; Treguer, Paul; De Baar, H. J. W..
Dissolved iron (DFe; <0.2 mu m) and dissolved manganese (DMn; <0.2 mu m) concentrations were determined in the water column of the Bay of Biscay (eastern North Atlantic Ocean) in March 2002. The samples were collected along a transect traversing from the European continental shelf over the continental slope. The highest DFe and DMn concentrations (2.39 nM and 6.10 nM, respectively) were observed in the bottom waters on the shelf at stations closest to the coast. The release of trace metal from resuspended particles and the diffusion from pore waters were probably at the origin of elevated DFe and DMn concentrations in the Bottom Boundary Layer (BBL). In the slope region, the highest total dissolvable iron (TDFe), DFe and DMn values (24.6 nM, 1.58 nM...
Tipo: Text
Ano: 2007 URL: http://archimer.ifremer.fr/doc/2007/publication-2689.pdf
Imagem não selecionada

Imprime registro no formato completo
Sulfate minerals control dissolved rare earth element flux and Nd isotope signature of buoyant hydrothermal plume (EMSO-Azores, 37°N Mid-Atlantic Ridge) ArchiMer
Chavagnac, Valerie; Ali, Hassan Saleban; Jeandel, Catherine; Leleu, Thomas; Destrigneville, Christine; Castillo, Alain; Cotte, Laura; Waeles, Mathieu; Cathalot, Cecile; Laes, Agathe; Pelleter, Ewan; Nonnotte, Philippe; Sarradin, Pierre-marie; Cannat, Mathilde.
While hydrothermal vents are now thought to be a major source of dissolved iron to the oceans, they have always been considered to be a sink for the dissolved rare-earth elements (DREEs). However, true dissolved REE observations in hydrothermal plumes are still lacking. Here we report for the first time the DREE concentrations and neodymium isotopic compositions (DεNd) of buoyant hydrothermal fluids at Lucky Strike (Mid-Atlantic Ridge). We find that 27 to 62% of total hydrothermal DREEs are rapidly scavenged by anhydrite precipitation at the onset of buoyant plume formation. After this initial loss, all DREEs behave quasi-conservatively within the buoyant plume. Dissolved phase εNd (DεNd) in the evolving plume are identical to black smoker DεNd of +9.0 and...
Tipo: Text Palavras-chave: Black smokers; Rare earth elements; Neodymium isotopes; Hydrothermal; Sulfate minerals; EMSO-Azores.
Ano: 2018 URL: https://archimer.ifremer.fr/doc/00456/56733/58511.pdf
Registros recuperados: 9
Primeira ... 1 ... Última
 

Empresa Brasileira de Pesquisa Agropecuária - Embrapa
Todos os direitos reservados, conforme Lei n° 9.610
Política de Privacidade
Área restrita

Embrapa
Parque Estação Biológica - PqEB s/n°
Brasília, DF - Brasil - CEP 70770-901
Fone: (61) 3448-4433 - Fax: (61) 3448-4890 / 3448-4891 SAC: https://www.embrapa.br/fale-conosco

Valid HTML 4.01 Transitional