Consulta: subjectFacets:"Tracer"
Registros recuperados: 11
Data/hora: 08/06/2024 18:52:18

Hydrodynamic characterization of the Arcachon Bay, using model-derived descriptors
Provedor de dados: 5
Autores: Plus, Martin; Dumas, Franck; Stanisiere, Jean-yves; Maurer, Daniele.
A numerical model (MARS-2D) was developed, with the aim of describing the hydrodynamics that prevail in Arcachon Bay. Direct model results as well as derived mixing and transport time-scales (tidal prism, local and integrated flushing times, age of water masses), were used to understand the behaviour of water masses and exchanges between the Bay and its frontiers. Particular attention was paid to the processes that drive the hydrodynamics (tides, wind and rivers), in order to understand their respective influence. The Arcachon Bay hydrodynamic system appears primarily to be highly influenced by tides; secondarily, by winds. About two third of the lagoon total volume is flushed in and out at each tidal cycle, which represent a mean tidal prism of 384...
Tipo: Text
Palavras-chave: Arcachon Bay; Tracer; Age of seawater; Flushing time; Tidal prism; Residual fluxes; Hydrodynamics.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/publication-6424.pdf

Inventory and distribution of tritium in the oceans in 2016
Provedor de dados: 5
Autores: Oms, Pierre-emmanuel; Bailly Du Bois, Pascal; Dumas, Franck; Lazure, Pascal; Morillon, Mehdi; Voiseux, Claire; Le Corre, Cedric; Cossonnet, Catherine; Solier, Luc; Morin, Pascal.
Tritium concentrations in oceans were compiled from the literature, online databases and original measurements in order to determine the global distribution of tritium concentrations according to latitude and depth in all oceans. The total inventory of tritium decay corrected in 2016 has been estimated using evaluation of the natural and artificial contributions in 23 spatial subdivisions of the total ocean. It is determined equal to 26.8 ± 14 kg including 3.8 kg of cosmogenic tritium. That is in agreement with the total atmospheric input of tritium from nuclear bomb tests and the natural inventory at steady-state estimated from natural production rates in the literature (27.8–29.3 kg in the Earth). We confirm the global increase in tritium according to...
Tipo: Text
Palavras-chave: Radionuclide; Tracer; Database; Background concentration.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00470/58157/60653.pdf

Dissolved Radiotracers and Numerical Modeling in North European Continental Shelf Dispersion Studies (1982–2016): Databases, Methods and Applications
Provedor de dados: 5
Autores: Bailly Du Bois, Pascal; Dumas, Franck; Voiseux, Claire; Morillon, Mehdi; Oms, Pierre-emmanuel; Solier, Luc.
Significant amounts of anthropogenic radionuclides were introduced in ocean waters following nuclear atmospheric tests and development of the nuclear industry. Dispersion of artificial dissolved radionuclides has been extensively measured for decades over the North-European continental shelf. In this area, the radionuclide measurement and release fluxes databases provided here between 1982 and 2016 represent an exceptional opportunity to validate dispersion hydrodynamic models. This work gives accessibility to these data in a comprehensive database. The MARS hydrodynamic model has been applied at different scales to reproduce the measured dispersion in realistic conditions. Specific methods have been developed to obtain qualitative and quantitative results...
Tipo: Text
Palavras-chave: Radionuclide; Tracer; Data collection; Antimony 125 (Sb-125); Tritium (H-3); Dispersion; Modeling; English Channel; North Sea; Biscay Bay.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00633/74521/74348.pdf

Rotavirus VLP2/6: a new tool for tracking rotavirus in the marine environment
Provedor de dados: 5
Autores: Loisy, Fabienne; Atmar, Robert L.; Cohen, Jean; Bosch, Albert; Le Guyader, Soizick.
The potential of rotavirus 2/6-virus-like-particles (VLP2/6) for use as tracers in the marine environment was investigated. The stability of bovine rotavirus (strain RF) and VLP2/6 in natural seawater at 25degreesC for six days was studied. ELISA and western blot methods were used to quantify the particles. The rates of decline of rotavirus particles and VLP2/6 were similar (approximately 0.5 log 10 per day). Western blot analysis showed that the integrity of capsid proteins VP2 and VP6 was conserved during the incubation time. These results demonstrate that VLP2/6 particles have the same stability in seawater as rotavirus particles. Thus, VLP2/6 can be used as a tracer, which should be of particular value for studying the fate of rotavirus particles in...
Tipo: Text
Palavras-chave: Stability; Tracer; Seawater; Virus like particles; Rotavirus.
Ano: 2004
URL: https://archimer.ifremer.fr/doc/2004/publication-330.pdf

Measuring production-dissolution rates of marine biogenic silica by Si-30-isotope dilution using a high-resolution sector field inductively coupled plasma mass spectrometer
Provedor de dados: 5
Autores: Fripiat, Francois; Corvaisier, Rudolph; Navez, Jacques; Elskens, Marc; Schoemann, Veronique; Leblanc, Karine; Andre, Luc; Cardinal, Damien.
Regional and seasonal variability of the Si dissolution: production ratios in the surface ocean have not been well assessed. Here, we propose a new method for determining these rates, using the Si-30-isotopic dilution technique with a high-resolution sector field inductively coupled plasma mass spectrometer (HR-SF-ICP-MS). Relative analytical precision of the isotopic measurement is better than 1%, similar to that obtained by thermal ionization-quadrupole mass spectrometry (TIMS). Accuracy and reproducibility of the isotopic measurements have been checked on artificial and natural solutions by intercomparison between two HR-SF-ICP-MS instruments and one TIMS. Measurements of real Si production and dissolution rates are illustrated for two contrasted...
Tipo: Text
Palavras-chave: Isotopic fractionation; Southern ocean; Acid uptake; Waters; Phytoplankton; Environments; Biosilica; Recovery; Balance; Tracer.
Ano: 2009
URL: https://archimer.ifremer.fr/doc/00205/31607/30033.pdf

Bacterivory by benthic organisms in sediment : Quantification using 15N-enriched bacteria
Provedor de dados: 5
Autores: Pascal, P.y.; Dupuy, C; Mallet, C; Richard, P; Niquil, N.
The fate of benthic bacterial biomass in benthic food webs is a topic of major importance but poorly described. This paper describes an alternative method for evaluation of bacterial grazing rate by meiofauna and macrofauna using bacteria pre-enriched with stable isotopes. Natural bacteria from the sediment of an intertidal mudflat were cultured in a liquid medium enriched with 15NH4Cl. Cultured bacteria contained 2.9% of 15N and were enriched sufficiently to be used as tracers during grazing experiments. Cultured bacteria presented a biovolume (0.21 &amp;#956;m3) and a percentage of actively respiring bacteria (10%) similar to those found in natural communities. The number of Operational Taxon Units found in cultures fluctuated between 56 and 75% of that...
Tipo: Text
Palavras-chave: Tracer; Stable isotope; Sediment; Grazing; Bacteria.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/2008/publication-4296.pdf

On the distribution of silicic acid as a frontal zone tracer in the Indian sector of the Southern Ocean
Provedor de dados: 5
Autores: Prego, R; Park, Yh; Barciela, Mc; Morvan, J; Poncin, J; Treguer, P.
The subantarctic frontal zone surveyed during the April-May 1991 SUZIL cruise in the Crozet-Kerguelen Amsterdam area shows a strong horizontal (north to south) gradient of dissolved silicate, increasing with depth, from 5 to 10 mu molSi kg(-1) at 100 m, and 10 to 70 mu molSi kg(-1) at 600 m. The northern limit of this frontal zone, which is formed by the confluence of the Subtropical and Subantarctic Fronts, is delimited at the surface by the 2 mu molSi kg(-1) silicate isoline. Silicate-salinity diagrams also allow different water regimes to be positioned relative to the frontal zone. This sloping interface is between two water bodies, one to the north with more saline subtropical waters of less concentrated silicate than the southern one, corresponding to...
Tipo: Text
Palavras-chave: Silicate; Tracer; Frontal zone; Silicate-salinity diagram; Crozet Basin; Southern Ocean.
Ano: 1999
URL: https://archimer.ifremer.fr/doc/00239/35063/34593.pdf

Traceability of bovine meat and bone meal in poultry by stable isotope analysis
Provedor de dados: 89
Autores: Carrijo,AS; Pezzato,AC; Ducatti,C; Sartori,JR; Trinca,L; Silva,ET.
Bovine meat and bone meal (MBM) was widely used in animal diets until outbreaks of Bovine Spongiform Encefalopathy (BSE) occurred in some countries. It has not been confirmed yet whether or not BSE may be transmitted to man through chicken meat originated from poultry that had been fed diets containing MBM. Therefore, consumers nowadays express preference for meat originated from birds fed exclusively vegetable diets. This study analyzed samples of major breast muscle (Pectoralis major) using mass spectrometry of stable isotopes (carbon and nitrogen) as a means to assess the presence of MBM in broiler diets, a technique that might be used in the certification of poultry quality. A total of 150 day-old chicks were reared in five randomized treatments with...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Authentication; Carbon-13; Isotopic determination; Nitrogen-15; Tracer.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-635X2006000100010

Air-assisted boom sprayer and spray deposition on bean plants
Provedor de dados: 63
Autores: Bauer,Fernando Cesar; Raetano,Carlos Gilberto.
The development of safe pesticide application techniques with low volume rates, frequency and spray drift, along with the need to obtain better control level of crop pest control levels, justify the air-assistance in boom sprayers. The aim of this research was to evaluate the spray deposition on bean plants with different nozzles and volume rates by air-assisted and non-assisted sprayers. A completely randomized experiment was carried out using copper oxide as a tracer (50% metalic copper) for deposit evaluation. The artificial targets were fixed on the upper and under-side of the leaflets, at the top and lower third of the same plants under the spray boom. After application, targets were washed individually with an extracting solution of nitric acid (1.0...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Phaseolus vulgaris; Application technique; Tracer; Boom sprayer.
Ano: 2003
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162003000200002

Choice of tracers for the evaluation of spray deposits
Provedor de dados: 63
Autores: Palladini,Luiz Antonio; Raetano,Carlos Gilberto; Velini,Edivaldo Domingues.
Tracer substances, used to evaluate spraying effectiveness, ordinarily modify the surface tension of aqueous solutions. This study aimed to establish a method of using tracers to evaluate distribution and amount of spray deposits, adjusted to the surface tension of the spraying solution. The following products were tested: 0.15% Brilliant Blue, 0.15% Saturn Yellow in 0.015% Vixilperse lignosulfonate, and 0.005% sodium fluorescein, and mixtures of Brilliant Blue plus Saturn Yellow and Brilliant Blue plus sodium fluorescein at the same concentrations. Solutions were deposited on citrus leaves and stability was determined by measuring fluorescence and optical density of solutions without drying, dried in the dark and exposed to sunlight for 2, 4 and 8 h....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Pesticide application; Deposition assessment; Tracer; Citrus trees.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162005000500005

Lambda-cyhalothrin efficiency on fruit borer control and quali-quantitative spraying aspects in a pinecone crop
Provedor de dados: 64
Autores: Morais,Jacqueline Lavinscky Costa; Castellani,Maria Aparecida; Raetano,Carlos Gilberto; Macêdo,Juliana Alves de; Nery,Moisés Silva; Moreira,Gabriela Luz Pereira.
ABSTRACT In Brazil, the state of Bahia is one of the largest pinecone (Annona squamosa L.) growers; nevertheless, fruit borer (Cerconota anonella L.) presence limits production. This research aimed to test the efficiency of lambda-cyhalothrin in controlling fruit borer using different spray volumes; additionally, this research tested qualitative and quantitative operational aspects. Trials were carried out in pinecone orchards in Caraíbas-BA, Brazil. Pesticide efficiency was tested by a randomized block experiment with six treatments and five replications. Treatments consisted of lambda-cyhalothrin application (1.5 g a.i. 100 L-1 water) with a surfactant (0.03% v v-1) at spray volumes of 100, 200, 268, 382 and 488 L ha-1 and one control (without spray)....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Annona squamosa; Cerconota anonella; Tracer; Spray application technology.
Ano: 2016
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-70542016000300288