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| Registros recuperados: 75 | |
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| Morita, R; Jones, R. |
| The nitrifying bacteria were found to survive 24 weeks in the absence of ammonium without decreasing their number of cell size. Because H sub(2), CO, and CH sub(4) are present in the marine environment, these substrates were investigated as a possible source of the energy of maintenance for the nitrifying bacteria. super(14)CO and super(14)CH sub(4) were found to be oxidized by the nitrifiers. N-serve was found to inhibit the oxidation of CO. Using the nitrifiers' ability to oxide CO, a method for the determination of the nitrification rate was developed. The ability of nitrifiers to oxidize CO may play a significant role in the cycling of CO sub(2) in the marine environment. Whether CO and CH sub(4) oxidation play a role in the survival of nitrifiers in... |
| Tipo: Text |
Palavras-chave: Methane; Carbon dioxide; Survival; Bacteria; Nitrification; Nitrogen cycle; Oxidation; Carbon cycle; Biogeochemistry; Metabolism. |
| Ano: 1984 |
URL: http://archimer.ifremer.fr/doc/1984/acte-975.pdf |
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| Gu, Yuanyuan; Katul, Gabriel G.; Cassar, Nicolas. |
| The significance of the water-side gas transfer velocity for air–sea CO2 gas exchange (k) and its non-linear dependence on wind speed (U) is well accepted. What remains a subject of inquiry are biases associated with the form of the non-linear relation linking k to U (hereafter labeled as f(U), where f(.) stands for an arbitrary function of U), the distributional properties of U (treated as a random variable) along with other external factors influencing k, and the time-averaging period used to determine k from U. To address the latter issue, a Taylor series expansion is applied to separate f(U) into a term derived from time-averaging wind speed (labeled as ⟨U⟩, where ⟨.⟩ indicates averaging over a monthly time scale) as currently employed in climate... |
| Tipo: Text |
Palavras-chave: Carbon dioxide; Gas transfer velocity; Time-averaging; Wind speeds. |
| Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00687/79949/82869.pdf |
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| Bréchet, Laëtitia; Courtois, Elodie A.; Saint-germain, Thomas; Janssens, Ivan A.; Asensio, Dolores; Ramirez-rojas, Irene; Soong, Jennifer L.; Van Langenhove, Leandro; Verbruggen, Erik; Stahl, Clément. |
| Tropical soils are a major contributor to the balance of greenhouse gas (GHG) fluxes in the atmosphere. Models of tropical GHG fluxes predict that both the frequency of drought events and changes in atmospheric deposition of nitrogen (N) will significantly affect dynamics of soil carbon dioxide (CO2) and methane (CH4) production and consumption. In this study, we examined the combined effect of a reduction in precipitation and an increase in nutrient availability on soil CO2 and CH4 fluxes in a primary French Guiana tropical forest. Drought conditions were simulated by intercepting precipitation falling through the forest canopy with tarpaulin roofs. Nutrient availability was manipulated through application of granular N and/or phosphorus (P) fertilizer to... |
| Tipo: Text |
Palavras-chave: Carbon dioxide; Drought; Fertilization; Methane; Nitrogen; Phosphorus; Soil GHG fluxes; Tropical forest. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00595/70694/68903.pdf |
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| Sarradin, Pierre-marie; Caprais, Jean-claude; Briand, Patrick; Gaill, Françoise; Shillito, Bruce; Desbruyeres, Daniel. |
| The objective of this study is to describe the chemical and physical environment surrounding the vent organisms at the Genesis site (EPR, 2640 m). The main chimney is colonized by Riftia pachyptila, fishes Zoarcidae and crabs Bythograeidae. The top of the smoker is covered with tubes of polychaetes Alvinellidae, the frontier zone by limpet gastropods. Temperature measurements and water sampling were made on an axis along the chimney. The environment was characterized using relationships between chemical concentrations and temperature to provide a chemo-thermal model of the site. Discrete temperature ranges were 1-1.6 degrees C in sea water, 1.6-10 degrees C among Riftia plumes (up to 25 degrees C at the tube base), 7-91 degrees C close to the alvinellid... |
| Tipo: Text |
Palavras-chave: Hydrothermal ecosystem; Hydrogen sulphide; Carbon dioxide; Temperature. |
| Ano: 1998 |
URL: http://archimer.ifremer.fr/doc/00186/29764/28200.pdf |
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| Woolf, D.k.; Shutler, J.d.; Goddijn‐murphy, L.; Watson, A.j.; Chapron, Bertrand; Nightingale, P.d.; Donlon, C.j.; Piskozub, J.; Yelland, M.j.; Ashton, Ian; Holding, T.; Schuster, U.; Girard-ardhuin, Fanny; Grouazel, Antoine; Piolle, Jean-francois; Warren, M.; Wrobel‐niedzwiecka, I.; Land, P.e.; Torres, R.; Prytherch, J.; Moat, B.; Hanafin, J.; Ardhuin, Fabrice; Paul, Frederic. |
| The contemporary air‐sea flux of CO2 is investigated by the use of an air‐sea flux equation, with particular attention to the uncertainties in global values and their origin with respect to that equation. In particular, uncertainties deriving from the transfer velocity and from sparse upper ocean sampling are investigated. Eight formulations of air‐sea gas transfer velocity are used to evaluate the combined standard uncertainty resulting from several sources of error. Depending on expert opinion, a standard uncertainty in transfer velocity of either ~5% or ~10% can be argued and that will contribute a proportional error in air‐sea flux. The limited sampling of upper ocean fCO2 is readily apparent in the Surface Ocean CO2 Atlas (SOCAT) databases. The effect... |
| Tipo: Text |
Palavras-chave: Carbon dioxide; Air-sea flux; Uncertainty; Transfer velocity; Sampling. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00513/62450/66754.pdf |
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| Legoix, Ludovic. |
| Gas hydrates are fascinating ice-like compounds made of water cages that retain various types of guest molecules. Natural gas hydrates on Earth form below the seafloor and permafrost and contain mainly methane (CH4). Methane from hydrate deposits could be considered as an energy resource. One possible production scenario of CH4 from hydrates is the injection of carbon dioxide (CO2) or carbon dioxide-nitrogen(CO2-N2) mixed gas into the reservoir. Depending on the thermodynamic constraints, the composition of the gas hydrate guest molecules changes: the energy source CH4 is released and the greenhouse gas CO2 is trapped. The aim of the present work is to study the mixed gas hydrates that form in gas hydrate reservoirs after injection of CO2 or CO2-N2 gas... |
| Tipo: Text |
Palavras-chave: Gas hydrates; Methane; Carbon dioxide; Thermodynamic. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00490/60183/63524.pdf |
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| Bakker, Dorothee C. E.; Pfeil, Benjamin; Olsen, Are; Sabine, Christopher L.; Metzl, Nicolas; Hankin, Steven; Koyuk, Heather; Kozyr, Alex; Malczyk, Jeremy; Manke, Ansley; Telszewski, Maciej. |
| Net oceanic uptake of the greenhouse gas carbon dioxide (CO2) reduces global warming but also leads to ocean acidification [Intergovernmental Panel on Climate Change (IPCC), 2007]. Understanding and predicting changes in the ocean carbon sink are critical to assessments of future climate change. Surface water CO2 measurements suggest large year-to-year variations in oceanic CO2 uptake for several regions [Doney et al., 2009]. However, there is much debate on whether these changes are cyclical or indicative of long-term trends. Sustained, globally coordinated observations of the surface ocean carbon cycle and systematic handling of such data are essential for assessing variation and trends in regional and global ocean carbon uptake, information necessary... |
| Tipo: Text |
Palavras-chave: Carbon dioxide; Ocean; Coastal; Synthesis. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00140/25162/23290.pdf |
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| Montalvo, J. F.; García, I.; Esponda, S.C.,; Cesar, M.E.; Alburquerque, O.. |
| Se realizaron cinco muestreos entre enero de 2007 y junio de 2008 a la zona costera del municipio Playa, con el fin de evaluar los contenidos de los compuestos del ciclo del carbono. Los parámetros estudiados en la matriz agua fueron carbón orgánico, pH, alcalinidad total, alcalinidad al carbonato, dióxido de carbono total, dióxido de carbono libre, presión parcial de CO2, y contenidos de bicarbonato y carbonato. Los compuestos de carbono orgánico e inorgánico tuvieron una distribución muy heterogénea, los valores de pH (8,24±0,22) y alcalinidad total (2523±119 μmol/kg) indican que el área tiene un comportamiento alcalino, estos montos fueron similares a los encontrados en aguas de la plataforma marina cubanos y superiores a los consignados para el... |
| Tipo: Journal Contribution |
Palavras-chave: Carbon dioxide; Alkalinity; Carbon cycle; Carbon dioxide; Alkalinity; Carbon cycle; Http://aims.fao.org/aos/agrovoc/c_1302; Http://aims.fao.org/aos/agrovoc/c_8721; Http://aims.fao.org/aos/agrovoc/c_17299. |
| Ano: 2009 |
URL: http://hdl.handle.net/1834/3390 |
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| Rentería, W.; Ortega, J.. |
| La fertilización de los océanos con hierro han sido presentada como solución a corto plazo para poder reducir CO2 de la atmósfera. Esta afirmación presentada hace 20 años ha liderado y ha despertado un controversial debate sobre las posibles consecuencias en el clima. La bioquímica del hierro es un sistema complejo y su estudio en el océano es relativamente nuevo en comparación con los otros nutrientes, sin embargo, este sistema ha sido descrito en varios estudios que ayudan en la compresión de la afirmación intrincada sobre los beneficios de la fertilización con hierro. El objetivo de este estudio es describir los aspectos relacionados con los fundamentos de la fertilización con hierro, discutiendo acerca de la afirmación de la limitación de hierro y la... |
| Tipo: Journal Contribution |
Palavras-chave: Iron; Pollution effects; Carbon dioxide. |
| Ano: 2012 |
URL: http://hdl.handle.net/1834/4715 |
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| Koné, Yéfanlan José-Mathieu; Seu-Anoi, N.M.. |
| Les données de CO2 obtenues pendant deux campagnes dans les lagunes Aby et Ebrié montrent que ces écosystèmes sont très hétérogènes en terme de dynamique de CO2. Alors que la lagune Ebrié est sursaturée de CO2 vis-à-vis de l'atmosphère , la lagune Aby quant à elle est sous saturée en CO2 à cause d'une forte production phytoplanctonique caractérisée par des valeurs élevées de chlorophylle a dans la colonne d'eau. Ces résultats ne permettent pas par conséquent de conclure si les lagunes sont des sources ou des puits de CO2. Cependant, ils mettent en exergue l'importance de ces milieux dans les bilans globaux de CO2 surtout dans les régions tropicales. Ils soulignent aussi l'importance de la diversité des écosystèmes côtiers dans le cycle global du carbone. |
| Tipo: Journal Contribution |
Palavras-chave: Jets; Carbon dioxide; Coastal lagoons. |
| Ano: 2010 |
URL: http://hdl.handle.net/1834/5773 |
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| Homem Junior,Antonio Carlos; Nocera,Bruno Faleiros; Faleiros,Lucas Figueiredo; Almeida,Marco Túlio Costa; Paschoaloto,Josimari Regina; Perez,Henrique Leal; D’Áurea,André Pastori; Ezequiel,Jane Maria Bertocco. |
| Abstract: The objective of this work was to evaluate the partial replacement of corn grains by soybean hulls, in high-grain diets, and its effect on the feeding behavior and ruminal fermentation parameters of feedlot sheep. Eight rumen-cannulated crossbred sheep were assigned to four treatment groups composed of a control, to fed a diet of 50% corn silage and 50% concentrate, and to three groups fed high-grain diets, as follows: 85% corn (Diet85), 75% corn plus 10% soybean hulls (Diet75), and 65% corn plus 20% soybean hulls (Diet65). High-grain diets reduced rumination time and provided a higher degradation of feed dry matter, a higher-propionic acid concentration, a lower-acetic acid concentration, a lower methane and carbon dioxide gas production, and a... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Carbon dioxide; Dry matter degradation; Ingestive behavior; Methane gas; Short-chain fatty acids. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2019000103500 |
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| LOURENÇO,A.A.; MOTA,R.V.; SANCHES,J.L.; MARQUES,R.F.; MARCHI,S.R.. |
| ABSTRACT: This research aimed to study weed interference relationship on morphogenesis, yield, and greenhouse gas production potential of Urochloa ruziziensis under pasture renovation conditions. The experimental design was a randomized block design with four replications. Treatments consisted of seven coexistence periods: 0, 15, 30, 45, 60, 75, and 90 days after emergence (DAE). The following morphological parameters were analyzed: number of tillers, number of leaves, photosynthetically active leaf blade biomass, fresh stem biomass, dead material biomass, and total dry biomass. In vitro analyses of methane (CH4) and carbon dioxide (CO2) production were also carried out. The results were submitted to analysis of variance by the F-test, and the test of... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Pasture renovation; Weed competition; Morphogenesis; Carbon dioxide; Methane. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582019000100272 |
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| Registros recuperados: 75 | |
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