Marine Sediments
Mostrando 1-12 de 271 artigos, teses e dissertações.
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1. Radionuclídeos como marcadores de um novo tempo: o Antropoceno
On May 2019, the members of the Anthropocene Working Group completed a binding vote to affirm some of the key questions that have been agreed in 2016: the Anthropocene should be considered as a formal chronostratigraphic unit, defined by a Global Boundary Stratotype Section and Point (GSSP), using one of the stratigraphic signals around the mid-twentieth cen
Quím. Nova. Publicado em: 2020-04
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2. ÉTERES DIFENÍLICOS POLIBROMADOS (PBDE) COMO CONTAMINANTES PERSISTENTES: OCORRÊNCIA, COMPORTAMENTO NO AMBIENTE E ESTRATÉGIAS ANALÍTICAS
Flame retardants are substances mixed with numerous materials to inhibit the combustion process, reducing risks and damages caused by fires. Among these substances, polybrominated diphenyl ethers (PBDEs) have been widely used for decades due to their low cost and high efficiency. However, since they are mixed and not chemically bonded to the materials, PBDEs
Quím. Nova. Publicado em: 2018-07
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3. Assessing legacy contaminants in sediments from marine protected areas of the central coast of São Paulo (Brazil)
Resumo A contaminação dos sedimentos superficiais foi avaliada neste estudo em amostras de áreas marinhas protegidas (AMP) da costa central de São Paulo. Quatro campanhas de amostragem foram feitas entre 2013 e 2015 em 10 sítios localizados nos Parques Estaduais Marinho da Laje de Santos e Xixová-Japuí (PEMLS e PEXJ, respectivamente), e Área de Prote
Braz. j. oceanogr.. Publicado em: 2017-12
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4. The effect of heavy metal contamination on the bacterial community structure at Jiaozhou Bay, China
Abstract In this study, determination of heavy metal parameters and microbiological characterization of marine sediments obtained from two heavily polluted sites and one low-grade contaminated reference station at Jiaozhou Bay in China were carried out. The microbial communities found in the sampled marine sediments were studied using PCR-DGGE (denaturing gr
Braz. J. Microbiol.. Publicado em: 2017-03
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5. Barium and its Importance as an Indicator of (Paleo)Productivity
ABSTRACT Barium (Ba) is a trace element which occurs predominantly as barite mineral (BaSO4) in the marine environment. Previous work suggests that barite concentrations are related to the organic carbon flux and marine biological debris in the water column suggesting a direct or indirect involvement in the marine biological cycling. In addition, barite has
An. Acad. Bras. Ciênc.. Publicado em: 2016-12
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6. VALIDAÇÃO DE UM MÉTODO ANALÍTICO PARA DETERMINAÇÃO DE MARCADORES ORGÂNICOS GEOQUÍMICOS EM AMOSTRAS DE SEDIMENTOS MARINHOS
This paper describes the validation of an alternative method for determination of n-alkanes, sterols (OLs) and n-alkanols (ALCs) in marine sediments, through adaptation of clean up. The method reduced the material consumption, the discards produced and working time. The recovery percentages were 60-129% for n-alkanes, 52-67% for OLs and 43-141% for ALCs, acc
Quím. Nova. Publicado em: 2016-09
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7. Multivariate Optimization of a Simultaneous Cloud Point Extraction Procedure of Cd, Cu and Ni from Sediments Samples and Determination by ICP OES
A simultaneous preconcentration method for cadmium, copper and nickel in samples of sediments and determination by inductively coupled plasma optical emission spectrometry was developed. The method is based on the extraction of the metals as complexes formed with 2-(5-bromo-2-pyridylazo)-5-(diethylamino)-phenol (5-Br-PADAP) at cloud point of the nonionic sur
J. Braz. Chem. Soc.. Publicado em: 2016-04
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8. Biomineralization processes of calcite induced by bacteria isolated from marine sediments
Biomineralization is a known natural phenomenon associated with a wide range of bacterial species. Bacterial-induced calcium carbonate precipitation by marine isolates was investigated in this study. Three genera of ureolytic bacteria, Sporosarcina sp., Bacillus sp. and Brevundimonas sp. were observed to precipitate calcium carbonate minerals. Of these speci
Braz. J. Microbiol.. Publicado em: 2015-06
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9. Bryophyte and pteridophyte spores and other palynomorphs in quaternary marine sediments from Campos Basin, southeastern Brazil: Core BU-91-GL-05
This paper presents morphological descriptions and ecological data of cryptogam spores and other non-pollen palynomorphs from Quaternary sediments of Campos Basin, Rio de Janeiro, SE Brazil. The ages were derived from biostratigraphy of planktonic foraminifers and two radiocarbon dates, and suggest that sediment deposition started in the last 140,000 years B
Acta Bot. Bras.. Publicado em: 2015-06
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10. Interlaboratory Comparison of Quantifying Hydrocarbons and Trace Elements in Sediment Samples from a Tropical Estuary
The Marine and Environmental Studies Laboratory at PUC-Rio, in partnership with the PETROBRAS R&D Center (Brazil), conducted an interlaboratory comparison of aliphatic and aromatic hydrocarbons and trace element determinations. The goal of this study was to produce a homogeneous and stable material and obtain consensus concentration values for its use as a r
J. Braz. Chem. Soc.. Publicado em: 2015-02
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11. Production of polypeptide antibiotic from Streptomyces parvulus and its antibacterial activity
A highly potent secondary metabolite producing actinomycetes strain is isolated from marine soil sediments of Visakhapatnam sea coast, Bay of Bengal. Over all ten strains are isolated from the collected soil sediments. Among the ten actinomycetes strains the broad spectrum strain RSPSN2 was selected for molecular characterization, antibiotic production and i
Braz. J. Microbiol.. Publicado em: 08/04/2014
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12. Comparison of growth methods and biological activities of brazilian marine Streptomyces
The present work describes the study of the growth and the cytotoxic and antitumor activities of the extracts of the marine microorganisms Streptomyces acrymicini and Streptomyces cebimarensis, the latter a new strain. Both microorganisms were collected from coastal marine sediments of the north coast of São Paulo state. Growth was performed in a shaker and
Braz. J. Chem. Eng.. Publicado em: 2013-03