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Registros recuperados: 56 | |
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Luz,Cynthia Fernandes Pinto da; Barth,Ortrud Monika; Silva,Cleverson Guisan. |
Four samples of the surface sediments of the Lagoa do Campelo lake bottom were collected in a transect of 500 m by 500 m from edge to edge, in a northeast/southwest direction, the dominant wind direction in the region. The analysis of pollen grains, fern spores and algae were used to evaluate their spatial deposition and level of deterioration. In total, 58 types of pollen grains were identified, mainly from herbs as Cyperaceae, Poaceae and Typhaceae. Pollen grains occurred in all the analyzed sediments. The area of highest concentration was the northeast side of the lake. The southwest side showed the highest pollen grain and fern spore degradation and mechanical damage, probably as they were carried across the lake by wind-driven currents, confirming the... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Palynomorphs; Sedimentation; Recent Holocene; Lagoa do Campelo; Rio de Janeiro State. |
Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062005000400009 |
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MAHIQUES,MICHEL M. DE; FIGUEIRA,RUBENS C.L.; ALVES,DANIEL P.V.; ITALIANI,DIANA M.; MARTINS,CRISTINA C.; DIAS,JOÃO M.A.. |
The role played by human activity in coastline changes indicates a general tendency of retreating coasts, especially deltaic environments, as a result of the recent trend of sea level rise as well as the blockage of the transfer of sediments towards the coast, especially due to the construction of dams. This is particularly important in deltaic environments which have been suffering a dramatic loss of area in the last decades. In contrast, in this paper, we report the origin and evolution of an anthropogenic delta, the Valo Grande delta, on the south-eastern Brazilian coast, whose origin is related to the opening of an artificial channel and the diversion of the main flow of the Ribeira de Iguape River. The methodology included the analysis of coastline... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Anthropic activity; Delta; Sedimentation; Lagoon. |
Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652014000401597 |
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Mahiques,Michel M.; Fukumoto,Marina M.; Silveira,Ilson C.A.; Figueira,Rubens C.L.; Bícego,Marcia C.; Lourenço,Rafael A.; Mello-e-Sousa,Silvia H.. |
A first evaluation of the sedimentary changes, including accumulation of inorganic and organic carbon on the upper slope off Southeastern Brazil under different climatic conditions, based on the analysis of a sedimentary core, is here presented. Results indicate that sedimentation rate as well sedimentary characteristics, including the nature of the organic carbon deposited during the LGM (Last Glacial Maximum), were different from the present deposition, indicating higher primary productivity during the LGM, to be accounted for by the higher values of marine organic carbon. Nevertheless, the higher values of Accumulation Rate of calcium carbonate and organic carbon can be credited to the higher values of the sedimentation rates. Conditions prevailing... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Sedimentation; Accumulation rate; Upper slope; Southeastern Brazil. |
Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652007000100018 |
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Mahiques,Michel M.; Sousa,Silvia H.M.; Burone,Leticia; Nagai,Renata H.; Silveira,Ilson C.A.; Figueira,Rubens C.L.; Soutelino,Rafael G.; Ponsoni,Leandro; Klein,Daniel A.. |
The aim of this work was to generate an inventory of the data on radiocarbon datings obtained from sediments of the São Paulo Bight (southern Brazilian upper margin) and to analyze the data in terms of Late Quaternary sedimentary processes and sedimentation rates. A total of 238 radiocarbon datings from materials collected using differents ampling procedures was considered for this work. The sedimentation rates varied from less than 2 to 68 cm.kyr-1. The highest sedimentation rate values were found in a low-energy (ría type) coastal system as well as in the upwelling zones of Santa Catarina and Cabo Frio. The lowest rates were found on the outer shelf and upper slopes. Our results confirm the strong dependency of the shelf currents, with an emphasis to the... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Continental margin; Quaternary; Radiocarbon; Sea-level; Sedimentation. |
Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652011000300006 |
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Araya-Vargas,Alexander; Busutil,Linnet; García-Rojas,Andrea; Pereira-Chaves,José Miguel; Piedra-Castro,Liliana. |
ABSTRACT Marine sponges fulfill many critical functions to coral reefs. In turn, variations in the community structure of the poriferans may indicate changes in the environmental conditions of the ecosystems where they live. However, their study has been scarce in the Caribbean of Costa Rica, mainly in the ecological field. Therefore, the community structure of these organisms was evaluated in four reef patches (Perezoso, Pequeño, Coral Garden, and the 0.36) and it was determined whether it could be explained by sedimentation, substrate, and depth. Relative abundance (RA) and relative coverage (RC) for each species, sponge density, and diversity indices (species richness, Shannon heterogeneity, Pielou's evenness, and Simpson's dominance) were calculated... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Porifera; Coral reef; Sedimentation; Substrate; Depth. |
Ano: 2020 |
URL: http://www.scielo.org.co/scielo.php?script=sci_arttext&pid=S0122-97612020000100039 |
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Luna,Christine Lamenha; Lopes,Carlos Edison; Massarani,Giulio. |
The aim of this work was use flocculation/sedimentation and flotation for recovery of spores of the Bacillus sphaericus. Microorganism was produced batchwise using culture medium based skimmed milk, corn steep liquor and mineral salts. The best results of flocculation were obtained using CaCl2.2H2O, FeCl3.6H2O, Al2(SO4)3 and tannin as flocculating agents, with optimal flocculation concentrations of 1,500, 3,000, 2,000 and 1,700ppm, respectively. Flocculent suspensions were characterized based on floc diameter and density. Settling tests were performed in batch at different concentrations of the cellular suspensions and revealed high recovery of the solids in suspension in all cases. Flotation tests were accomplished using a mechanical agitated flotation... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Bacillus sphaericus; Flocculation; Sedimentation; Flotation. |
Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132005000400008 |
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Costa,Gustavo Henrique Gravatim; Masson,Igor dos Santos; Freita,Lidyane Aline de; Roviero,Juliana Pelegrini; Mutton,Márcia Justino Rossini. |
The objective of this study was to evaluate the effect of Moringa oleifera Lam. leaf extract on the sedimentation of impurities in the treatment of sugarcane juice and the effects on sugar quality and on the clarified juice. The experimental design used was a 4x2 factorial arrangement with four replications. The main treatments performed included the extracted original sugarcane juice, the synthetic polyelectrolyte (Flomex 9076), the leaf extract, and a control. The secondary treatments consisted of the sugarcane varieties RB92579 and RB867515. The clarification process used was simple defecation, in which the flocculating agents and the juice, limed and heated, were poured simultaneously into a decanter. The microbiological and chemico-technological... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Simple defecation; Polyelectrolyte; Biomolecule; Sedimentation; Sucroenergetic sector. |
Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-20612014000100029 |
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Dias, Nelson Wellausen; Batista, Getulio; Targa, Marcelo dos Santos; Novo, Evlyn Marcia Leão Moraes; Barbosa, Claudio Clemente. |
As águas do rio Paraíba do Sul apresentam um alto nível de degradação ambiental em função do despejo direto de efluentes domésticos sem tratamento e de contaminações de origem difusa (sedimentos, nutrientes e matéria orgânica) provenientes do carreamento de solo erodido, fertilizantes, pesticidas, herbicidas e dejetos de animais para os canais de drenagem. Comparativamente, a água do reservatório de Paraibuna possui qualidade de água significativamente superior aos demais trechos do Rio Paraíba do Sul devido ao fato de estar a montante dos principais centros urbanos do Vale do Paraíba. Entretanto as águas que abastecem esta represa são provenientes de duas bacias (Paraibuna e Paraitinga) com características de cobertura e uso do solo bastante distintas que... |
Tipo: Article |
Palavras-chave: Represas; Sedimentação; Sensoriamento remoto hiperespectral; Hyperspectral remote sensing; Reservoirs; Sedimentation. |
Ano: 2006 |
URL: http://hdl.handle.net/2315/41 |
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OLIVEIRA, M. D. de; CALHEIROS, D. F.. |
Considerando os usos gerais dos principais sistemas aquáticos no Brasil, os impactos causados por processos de erosão/assoreamento são pontos importantes a serem considerados em programas de pesquisa, básica e aplicada, na área de Limnologia, devido a sua importância na alteração da qualidade da água.O aumento do aporte de material em suspensão, além de causar assoreamento dos rios, altera as características físicas e químicas da água, modificando a qualidade óptica da água e a temperatura (Alabaster & Lloyd, 1982). O sedimento em suspensão pode aderir à superfície dos ovos de peixes, impedindo as trocas de oxigênio e dióxido de carbono, aderir às brânquias e prejudicar as funções de respiração e excreção, e depositar-se cobrindo plantas e locais de... |
Tipo: Folhetos |
Palavras-chave: Alteração; Característica; Assoreamento; Impacto; Rio Taquari; Characteristic; Sedimentation; Impact; Taquari river; Água; Limnologia; Pantanal; Limnology; Water. |
Ano: 2002 |
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/810731 |
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Hussenot, Jerome; Lefebvre, Sébastien; Brossard, Nicolas. |
Marine land-based fish farms located in coastal wetlands (salt-pond zones, lagoon banks, etc.), whether extensive or intensive, send farm effluents directly to the sea or after short periods of stocking in retention reservoirs. The aims of our investigation have been to compare the efficiency of current and potential water treatment procedures in open-air. Wastewater retention ponds in commercial farms (Atlantic coasts of France) are efficient in removing up to 1 metric ton of particulate material (dry weight) per hectare and per day (faeces and unconsumed feed), but are inefficient in reducing dissolved wastes, both organic (urea, amino acids, protein) and inorganic (total ammonia nitrogen, phosphates). Forthcoming outdoor technology to treat these forms... |
Tipo: Text |
Palavras-chave: Traitement de l'eau; Effluent; Décantation; Sédimentation; Écumage; Microalgue; Huître; Water treatment; Effluent; Aquaculture; Sedimentation; Foam fractionation; Microalgae; Oyster. |
Ano: 1998 |
URL: https://archimer.ifremer.fr/doc/1998/publication-873.pdf |
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Francis, Jason M.; Daniell, James J.; Droxler, Andre W.; Dickens, Gerald R.; Bentley, Samuel J.; Peterson, Larry C.; Opdyke, Bradley N.; Beaufort, Luc. |
The Gulf of Papua (GoP) has become a focal point for understanding the deposition and accumulation of siliciclastic and carbonate material along and across a low-latitude continental margin. Although studies have addressed submarine geomorphological features on the inner and middle shelves, as well as processes that may have led to their formation, the seafloor of adjacent slope regions remains poorly documented. This study presents and interprets results from approximately 13,000 line-km of multibeam bathymetry, 9500 line-km of 3.5 kHz seismic, and 122 sediment cores that were collected from the GoP shelf edge and slope, primarily on two cruises (PANASH and PECTEN). Bathymetric maps, in conjunction with the seismic profiles and cores, were used to make... |
Tipo: Text |
Palavras-chave: Great barrier reef; New Guinea; Platform margin; Foreland basin; OF Papua; Sedimentation; Shelf; Bank; Circulation; Australia. |
Ano: 2008 |
URL: https://archimer.ifremer.fr/doc/00208/31938/30356.pdf |
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Sultan, Nabil; Cochonat, Pierre; Canals, M; Cattaneo, Antonio; Dennielou, Bernard; Haflidason, H; Laberg, J; Long, D; Mienert, J; Trincardi, F; Urgeles, R; Vorren, T; Wilson, C. |
The Costa target areas exhibit the variability of slope instabilities needed to improve our understanding of sediment physical and mechanical properties in areas prone to sliding. That is why in this project, we have analysed the different slope failures events from different parts of the Costa target areas, which reflect diverse triggering mechanisms. The aim of the first part of this study was to identify the geotechnical response of the sediment to different external mechanisms (earthquake, rapid sedimentation and gas hydrate melting). We have focused on the relation between external mechanisms and the consequence change in the in-situ stress state and the physical, mechanical, and elastic properties of the sediment. In the second part of the paper, the... |
Tipo: Text |
Palavras-chave: Slope instability; Sensitivity; Sedimentation; Hydrate; Earthquake. |
Ano: 2004 |
URL: http://archimer.ifremer.fr/doc/2004/publication-700.pdf |
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Registros recuperados: 56 | |
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