510 research outputs found

    Atmospheric nitrogen input into the North Sea: organic nutrient detection

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    The levels of gaseous organic nitrogen compounds (alkyl nitrates - ANs) together with identification of the possible sources of these compounds in the air were studied. Seasonal trends were investigated by conducting the sampling campaigns during the spring, summer and winter time. The air-mass backward trajectories (BWTs) were calculated for the sampling periods by Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model (Draxler and Rolph, 2003). These BWTs were considered for the determination of the influence of the Atlantic Ocean, the North Sea and the continent as possible sources of ANs. An adapted set-up for low and high volume samplings, extraction and minimized clean-up, identification and quantification capabilities resulting from the complementary use of GC-ECD and GC-MS methods is reported. The AN levels were found to be in the range of a few to 7400 pg.m-3 in the air. The AN fraction consisted of primarily the 2C4, C5 and C6 isomers, which contribute largely to the total AN level. The N-fluxes by ANs were more pronounced for the summer periods than for the winter/spring months, organic nitrates were the most abundant in the Atlantic/Channel/UK air-masses

    Fluxo de gases de efeito estufa em solos do pampa Gaúcho sob silvicultura.

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    Dissertação (Mestrado) - em Mestre em Ciências Biológicas, programa de Pós-Graduação Stricto Sensu em Ciências Biológicas da Universidade Federal do Pampa. Orientador: Frederico Costa Beber Vieira

    1,2,6-thiadiazinones as novel narrow spectrum calcium/calmodulin-dependent protein kinase kinase 2 (CaMKK2) inhibitors

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    We demonstrate for the first time that 4H-1,2,6-thiadiazin-4-one (TDZ) can function as a chemotype for the design of ATP-competitive kinase inhibitors. Using insights from a co-crystal structure of a 3,5-bis(arylamino)-4H-1,2,6-thiadiazin-4-one bound to calcium/calmodulin-dependent protein kinase kinase 2 (CaMKK2), several analogues were identified with micromolar activity through targeted displacement of bound water molecules in the active site. Since the TDZ analogues showed reduced promiscuity compared to their 2,4-dianilinopyrimidine counter parts, they represent starting points for development of highly selective kinase inhibitors

    Análise das condições de moradia das famílias de baixa renda do município de Campinas (SP).

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    Neste estudo, foram analisadas características do responsável familiar (RF) e dos domicílios das famílias pertencentes ao Cadastro Único (CadÚnico) do município de Campinas, para captar uma visão atual da realidade social das famílias de baixa renda. Foram utilizados os dados do CadÚnico para o município de Campinas, disponibilizados pela Secretaria Municipal de Assistência Social, Pessoa com Deficiência e Direitos Humanos (SMASDH). Foram consideradas variáveis do responsável familiar e da moradia. Os resultados demonstram que as famílias cadastradas no CadÚnico enfrentam condições socioeconômicas extremamente desfavoráveis: a renda média das famílias é de R130,00mensaise70 130,00 mensais e 70% delas ganham menos de R 200,00 mensais; são majoritariamente chefiadas por mulheres (88%) e, na média, compostas por até três pessoas; 50% dispõem de somente 1 dormitório para 2 residentes; 96% dos RF indicaram que a moradia é particular permanente e 98% das moradias são feitas de alvenaria (indicadores positivos); 73% das famílias residem em moradias com piso de cerâmica e 24%, com piso de cimento; 15% vivem em residência sem medidor de energia elétrica. Nossos resultados fornecem evidências de que as famílias cadastradas no CadÚnico sobrevivem em situação econômica desfavorável, a qual afeta negativamente sua saúde física e mental. Essas famílias de baixa renda têm menor probabilidade de ter recursos ou resiliência para lidar com impactos negativos e maior probabilidade de viver em moradias com estruturas ineficientes.Evento online. CIIC 2021

    Diffractive Contribution to the Elasticity and the Nucleonic Flux in the Atmosphere

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    We calculate the average elasticity considering non-diffractive and single diffractive interactions and perform an analysis of the cosmic-ray flux by means of an analytical solution for the nucleonic diffusion equation. We show that the diffractive contribution is important for the adequate description of the nucleonic and hadronic fluxes in the atmosphere.Comment: 10 pages, latex, 2 figures (uuencoded PostScript

    Polycyclic Aromatic Hydrocarbons (PAHs) and nitrated analogs associated to particulate matter emission from a Euro V-SCR engine fuelled with diesel/biodiesel blends

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    © 2018 Among the new technologies developed for the heavy-duty fleet, the use of Selective Catalytic Reduction (SCR) aftertreatment system in standard Diesel engines associated with biodiesel/diesel mixtures is an alternative in use to control the legislated pollutants emission. Nevertheless, there is an absence of knowledge about the synergic behaviour of these devices and biodiesel blends regarding the emissions of unregulated substances as the Polycyclic Aromatic Hydrocarbons (PAHs) and Nitro-PAHs, both recognized for their carcinogenic and mutagenic effects on humans. Therefore, the goal of this study is the quantification of PAHs and Nitro-PAHs present to total particulate matter (PM) emitted from the Euro V engine fuelled with ultra-low sulphur diesel and soybean biodiesel in different percentages, B5 and B20. PM sampling was performed using a Euro V – SCR engine operating in European Stationary Cycle (ESC). The PAHs and Nitro-PAHs were extracted from PM using an Accelerated Solvent Extractor and quantified by GC–MS. The results indicated that the use of SCR and the largest fraction of biodiesel studied may suppress the emission of total PAHs. The Toxic Equivalent (TEQ) was lower when using 20% biodiesel, in comparison with 5% biodiesel on the SCR system, reaffirming the low toxicity emission using higher percentage biodiesel. The data also reveal that use of SCR, on its own, suppress the Nitro-PAHs compounds. In general, the use of larger fractions of biodiesel (B20) coupled with the SCR aftertreatment showed the lowest PAHs and Nitro-PAHs emissions, meaning lower toxicity and, consequently, a potential lower risk to human health. From the emission point of view, the results of this work also demonstrated the viability of the Biodiesel programs, in combination with the SCR systems, which does not require any engine adaptation and is an economical alternative for the countries (Brazil, China, Russia, India) that have not adopted Euro VI emission standards
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