Organic Carbon
Mostrando 1-12 de 1307 artigos, teses e dissertações.
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1. WSOC and Its Relationship with BC, Levoglucosan and Transition Metals in the PM2.5 of an Urban Area in the Amazon
Water-soluble organic carbon (WSOC) makes up a large mass fraction of the organic carbon in the aerosol and can influence important cloud processes in the atmosphere. The capacity of WSOC to form metallic complexes with transition metals is well known; however, its influence on the aerosol of urban areas in the Amazon region is not very well known. In this s
Journal of the Brazilian Chemical Society. Publicado em: 2022
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2. Recent Developments on Palladium-Catalyzed Carbonylation Reactions in Renewable Solvents
Palladium-catalyzed carbonylation reaction has surfaced as a robust tool for insertion of the carbonyl group into organic molecules, and in the last decades enormous progress has been made. Nowadays, a plethora of methodologies is available to synthesize all kinds of carbonyl compounds. However, the focus has shifted during recent years to address rising con
Journal of the Brazilian Chemical Society. Publicado em: 2022
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3. How does organic carbon operate in the pore distribution of fine-textured soils?
RESUMO A qualidade do solo é importante para proporcionar uma condição adequada à produção de alimentos, fibras e energia sem alterações significativas no ambiente. Índices de fragilidade do solo têm sido apresentados como indicadores de qualidade do solo (exemplo, porosidade do solo e estoques de carbono), devido à fácil modificação pelo manej
Revista Brasileira de Engenharia Agrícola e Ambiental. Publicado em: 2022
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4. Biomarkers in Source Rocks from Barreirinha Formation (Devonian): Distribution and Paleoenvironment Significance
The Barreirinha Formation-Upper Devonian, is the main petroleum source rock of the Amazon Basin, deposited during the great Devonian Transgression, contributing to significant accumulations of organic matter (OM) in anoxic conditions, which allowed its preservation. The present work had the objective of characterizing the molecular composition of biomarkers
Journal of the Brazilian Chemical Society. Publicado em: 2022
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5. Spectroscopic techniques combined with chemometrics to study organic matter in tropical soils with different degrees of pedogenetic evolution
Understanding of the organomineral interactions in soil can elucidate the humic substances (HS) formation and the humification process. This study aimed to structurally characterize the humic acids (HA) formed in tropical soils with different pedogenesis degrees. The HA fraction was extracted from soil samples in the superficial horizons of an Inceptisol and
Química Nova. Publicado em: 2022
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6. Supercritical Carbon Dioxide Effect on Lipase-Catalyzed Geranyl Acetate Synthesis
This work provides a general insight on lipase-catalyzed synthesis of geranyl acetate through esterification of geraniol with acetic acid. Although this reaction is relatively well known, the replacement of organic solvents by supercritical fluids is fairly recent and the role of CO2 is still not completely understood. Therefore, reactions were performed wit
Journal of the Brazilian Chemical Society. Publicado em: 2022
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7. SOIL CARBON STOCKS AND COMPARTMENTS OF ORGANIC MATTER UNDER CONVENTIONAL SYSTEMS IN BRAZILIAN SEMI-ARID REGION
RESUMO O objetivo deste estudo foi avaliar o efeito da conversão da vegetação nativa secundária (VN) em sistemas convencionais (agricultura e pastagem) no carbono orgânico total (COS) e carbono das frações da matéria orgânica particulada (MOP) e, matéria orgânica associada aos minerais (MOAM) no semiárido brasileiro. O estudo foi realizado nos mu
Revista Caatinga. Publicado em: 2022
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8. Multifractal and joint multifractal analysis of soil invertebrate fauna, altitude, and organic carbon
RESUMO Os objetivos deste estudo foram avaliar o grau de multifractalidade da distribuição espacial da altitude, concentração de carbono orgânico e diversidade da fauna de invertebrados, e caracterizar o grau de associação joint multifractal dessas variáveis. A amostragem do solo foi realizada a cada 20 m em um transecto de 2.540 m, totalizando 128 p
Revista Brasileira de Engenharia Agrícola e Ambiental. Publicado em: 2022
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9. Soil attributes and spatial variability of soil organic carbon stock under the Atlantic Forest, Brazil
Resumo Para explorar os atributos físicos e químicos do solo e espacializar o estoque de carbono orgânico do solo em um trecho de Floresta Atlântica (Estacional Semidecidual Submontanal, Espírito Santo, Brasil), este estudo avaliou quatro camadas de solo (0-5, 5-10, 10-20 e 20-40 cm), as inter-relações dos atributos físicos e químicos e a espacializ
Ciência Florestal. Publicado em: 2022
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10. Photo-Fenton-Based Degradation of Methylene Blue Dye Using Hydroxyapatite Nanoparticles Doped with Fe3O4/γ-Fe2O3
In this study, we evaluated the catalytic properties of hydroxyapatite (HA) nanoparticles (NPs) doped with Fe3O4/γ-Fe2O3 for the degradation of methylene blue (MB) dye using a photo-Fenton process at pH 2.5, 7.0, and 9.0. The HA NPs were characterized using X-ray diffraction, scanning electron microscopy, Fourier-transform infrared spectrometry, Raman spect
Journal of the Brazilian Chemical Society. Publicado em: 2022
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11. Soil carbon stocks and labile fractions of organic matter under agroforestry system in breast of pernambucan altitude
Resumo O intenso preparo e revolvimento do solo em cultivos, com o tempo, reduz a quantidade e a qualidade da matéria orgânica do solo. Diante desse contexto, este trabalho teve como objetivo determinar os estoques de carbono do solo e frações lábeis sob sistema agroflorestal (SAF) e topossequências em brejo de altitude, em Taquaritinga do Norte, Perna
Ciência Florestal. Publicado em: 2022
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12. Study of Crystallization and Composition on Silicon Oxycarbide (SiOC) and Silicon Boron Oxycarbide (SiBOC) Ceramics Obtained from Alkoxysilanes Precursors
This work deals on the preparation of silicon oxycarbide (SiOC) and silicon boron oxycarbide (SiBOC) ceramics from pyrolysis involving alkoxysilanes with different organic groups. Boron content, organic substituent and annealing time were evaluated on crystallization and composition of resulting ceramics. B-free precursors composed of methyltriethoxysilane (
J. Braz. Chem. Soc.. Publicado em: 2021-06