| 1. |
- Medina-Silva, Renata, et al.
(författare)
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Microbiota associated with tubes of Escarpia sp. from cold seeps in the southwestern Atlantic Ocean constitutes a community distinct from that of surrounding marine sediment and water
- 2017
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Ingår i: Antonie van Leeuwenhoek. International Journal of General and Molecular Microbiology. - : Springer Science and Business Media LLC. - 0003-6072 .- 1572-9699. ; 111:4, s. 533-550
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Tidskriftsartikel (refereegranskat)abstract
- As the depth increases and the light fades in oceanic cold seeps, a variety of chemosynthetic-based benthic communities arise. Previous assessments reported polychaete annelids belonging to the family Siboglinidae as part of the fauna at cold seeps, with the ‘Vestimentifera’ clade containing specialists that depend on microbial chemosynthetic endosymbionts for nutrition. Little information exists concerning the microbiota of the external portion of the vestimentiferan trunk wall. We employed 16S rDNA-based metabarcoding to describe the external microbiota of the chitin tubes from the vestimentiferan Escarpia collected from a chemosynthetic community in a cold seep area at the southwestern Atlantic Ocean. The most abundant operational taxonomic unit (OTU) belonged to the family Pirellulaceae (phylum Planctomycetes), and the second most abundant OTU belonged to the order Methylococcales (phylum Proteobacteria), composing an average of 21.1 and 15.4% of the total reads on tubes, respectively. These frequencies contrasted with those from the surrounding environment (sediment and water), where they represent no more than 0.1% of the total reads each. Moreover, some taxa with lower abundances were detected only in Escarpia tube walls. These data constitute on the first report of an epibiont microbial community found in close association with external surface of a cold-seep metazoan, Escarpia sp., from a chemosynthetic community in the southwestern Atlantic Ocean.
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| 2. |
- Melo, Clarissa L., et al.
(författare)
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Integration results of soil CO2 flux and subsurface gases in the Ressacada Pilot site, Southern Brazil
- 2017
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Ingår i: 13th International Conference on Greenhouse Gas Control Technologies, GHGT-13. - : Elsevier. ; , s. 3793-3804
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Konferensbidrag (refereegranskat)abstract
- The first CO2 monitoring field lab at the Ressacada Farm, in the Southern region of Brazil, started in 2011 and until 2015 offered an excellent opportunity to run controlled CO2 releases experiments in soil and shallow subsurface through vertical injection wells. This paper focus on the presentation and comparison of the results obtained at the last campaign realized at this site in August 2015. The results integrate a time-lapse monitoring experiment of CO2 migration in both saturated and unsaturated sand-rich sediments and soil, using soil CO2 flux measurements and subsurface gas analyses through CO2 concentrations (ppm) and carbon isotope ratios (delta C-13 of CO2). The CO2 flux results in the studied area showed an increase in the flux values according to the increasing of injection rate and along the campaign are directed to the southwest portion of the area. However, even by injecting large amounts of CO2, fluxes are greatly reduced when it rains. The gas analysis also showed an increase in CO2 concentrations according to the increasing of the injection rate mainly in the superficial levels of the monitoring wells (0.5m and 2m depth). The delta C-13 of CO2 found on the 3rd injection day showed the presence of CO2 injected and demonstrate that the sampling methodology with vacutainer vial was effective, since there is no atmospheric contamination. The correlation of isotopic analysis were consistent with the results of concentrations and CO2 fluxes and thus, it is clear that the CO2 breakthrough occurred from the 3rd day of injection, while were obtained the largest CO2 fluxes, the higher gas concentrations in the subsurface, as well as the industrial origin of delta C-13 of CO2.
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| 3. |
- Melo, Clarissa L., et al.
(författare)
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CO2MOVE Project : The New Brazilian Field Lab Fully Dedicated to CO2 MMV Experiments
- 2017
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Ingår i: 13th International Conference on Greenhouse Gas Control Technologies, GHGT-13. - : Elsevier. ; , s. 3699-3715
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Konferensbidrag (refereegranskat)abstract
- After the Ressacada Project experience acquired from 2011 to 2015 when PUCRS, UNESP and other institutions conducted three controlled CO2 release experiments, PETROBRAS, the national oil company that is sponsoring the project, has launched a new challenge to its partners. The company stimulated the implementation of a new Brazilian experimental site where there will be a deepening of studies in geologically more complex conditions and more challenging from a technological point of view. The choice of an area inside PUCRS campus, in Viamao - Rio Grande do Sul state, was motivated by a predominantly clay subsoil and the privileged location of the site in terms of ease logistics and security, which is required for a project of this size that houses high-tech equipment with significant cost. The CO2MOVE project started at 2015 with the subsurface characterization of the site and the assembly and manufacture of an automated system for CO2 and gas tracers with injection capacity for 5 to 50 kg/ day. Based on physical characterization studies and on numerical modeling that is being developed, the site infrastructure will be completed in the next months with the positioning of vertical injection wells, monitoring wells, and other equipment and monitoring mesh. Monitoring tools should be arranged in an area of approximately 100m(2), occupying the entire region surrounding the injection wells. Fieldwork involving CO2 injection and monitoring should have a 60 days duration of which 15 days are for preliminary surveys (pre-injection), 30 days for injection and CO2 monitoring and the last 15 days for post-injection measurements. Following this work, the collected data will be analyzed in the university labs. Similarly to Ressacada Project, this experiment will run measurements of soil CO2 flux with accumulation chambers, CO2 turbulent fluxes with Eddy Covariance, subsurface gases and groundwater monitoring, and resistivity measurements. Other monitoring methods still not tested by the research team will be held as gas tracers monitoring and laser measurements. (C) 2017 The Authors. Published by Elsevier Ltd.
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