Alkanes
Mostrando 1-12 de 258 artigos, teses e dissertações.
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1. 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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2. Biodiesel: An Overview II
The crescent number of scientific articles published per year shows that research on biodiesel continues to play an important role to support the growing demand for this biofuel. The second edition of Biodiesel: An Overview presents the worldwide research in the last 15 years. Microalgae biomass is the most studied raw material alternative in this period and
J. Braz. Chem. Soc.. Publicado em: 2021-07
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3. Thermal and Catalytic Fast Pyrolysis of Oily Extracts of Microalgae: Production of Biokerosene
Three different microalgae species, Desmodesmus sp., Nannochloropsis oculata and Halamphora coffeaeformis were grown under controlled conditions. The resulting dry biomass was characterized by TG-DTA (thermogravimetry-differential thermal analysis) and extracted with three solvents having different polarities. The extracts gross mass yields varied from 2% us
J. Braz. Chem. Soc.. Publicado em: 2021-04
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4. Impactos da mudança de vegetação local no aporte de matéria orgânica para um estuário tropical preservado (Estuário do Rio Itapicuru – BA)
Estuaries are major areas of organic matter (OM) deposition, playing an important role in the global carbon cycle. The Itapicuru's river estuary (IRE) is in the North Coast of Bahia (Brazil), in na Environmental Protected Area. Although it presents preserved conditions, some environmental changes caused by human activities can be observed. This study evaluat
Quím. Nova. Publicado em: 15/08/2019
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5. Organic matter composition related to methane ebullitive flux of an urban coastal lagoon, Southeastern Brazil
In 2016, Brazil emitted 18.25 Tg of methane. Some of these emissions occur through continental aquatic ecosystems, locations of fate and accumulation of organic and inorganic matter. Thus, the aim of this study is to evaluate the origin of organic matter in Rodrigo de Freitas Lagoon, an eutrophic, coastal and chocked lagoon in Rio de Janeiro, Brazil, through
Quím. Nova. Publicado em: 15/08/2019
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6. THERMODYNAMIC ANALYSIS AND MODELING OF BRAZILIAN CRUDE OIL AND ASPHALTENE SYSTEMS: AN EXPERIMENTAL MEASUREMENT AND A PC-SAFT APPLICATION
ABSTRACT Asphaltenes represent the heaviest fraction of crude oils, being recognized by their tendency to self-associate and precipitate. Asphaltene precipitation and subsequent deposition can cause problems in all stages of production. The objective of this paper is to model Brazilian crude oil and asphaltene systems using the PC-SAFT equation of state. Asp
Braz. J. Chem. Eng.. Publicado em: 15/07/2019
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7. Insecticidal activities and mechanism of extracts from neem leaves against Oxya chinensis
RESUMO Nesse estudo, folhas "neem" foram extraídas com sucesso com éter de petróleo, 95% de etanol e água, e as atividades inseticidas desses extratos foram medidas contra larvas de Oxya chinesis. Os resultados mostram que extrato com 95% de etanol deram o maior resultado de extração e atividade inseticida e foi então extraído utilizando mais cinco d
Arq. Bras. Med. Vet. Zootec.. Publicado em: 2019-02
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8. Variation of cuticular chemical compounds in three species of Mischocyttarus (Hymenoptera: Vespidae) eusocial wasps
Abstract The social wasps have a remarkable system of organization in which chemical communication mediate different behavioral interactions. Among the compounds involved in this process, cuticular hydrocarbons are considered the main signals for nestmate recognition, caste differentiation, and fertility communication. The aims of this study were to describe
Rev. Bras. entomol.. Publicado em: 2017-09
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9. Distribution and Sources of Aliphatic and Polycyclic Aromatic Hydrocarbons in Surface Sediments of Itajaí-Açu Estuarine System in Brazil
The Itajaí-Açu estuarine system, located in southern Brazil, has great economic importance due to the presence of two ports (Itajaí and Navegantes). This system is affected by industrial and dredging activities, which can cause the remobilization of pollutants accumulated over time in the sediment. In this context, hydrocarbons were assessed in twelve sur
J. Braz. Chem. Soc.. Publicado em: 2017-04
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10. Cuticular n-alkane in leaves of seven Neotropical species of the family Lecythidaceae: a contribution to chemotaxonomy
ABSTRACT Biosynthesized from very long-chain fatty acid wax precursors, n-alkanes make a valuable contribution to the taxonomy of plants. The alkane components of foliar epicuticles of seven Neotropical species of Lecythidaceae were investigated: Bertholletia excelsa, Cariniana legalis, Couroupita guianensis, Eschweilera alvimii, Eschweilera ovata, Gustavia
Acta Bot. Bras.. Publicado em: 13/03/2017
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11. Chemical cuticular signature of leafcutter ant Atta sexdens (Hymenoptera, Formicidae) worker subcastes
ABSTRACT In leafcutter ants the division of labour is associated to worker size variation clustered in four subcastes. In this work we used Atta sexdens Forel (1908) as a model to test the hypothesis that each subcaste expresses its own chemical signature comprised of cuticular lipids. To assess it, we extracted epicuticular compounds by using nonpolar solve
Rev. Bras. entomol.. Publicado em: 2016-12
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12. 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