Intratidal variability and transport of petroleum aromatic hydrocarbons in an anthropized tropical estuarine system: the Suape estuary (8.4S 35W)

A instalação do Complexo Industrial Portuário de Suape (CIPS) modificou algumas características físicas, químicas e biológicas do Estuário de Suape. Este estudo apresenta a primeira caracterização física deste sistema, focando na hidrodinâmica local, transporte de materiais e a influência destes sobre algumas propriedades locais. Os parâmetros físicos também foram associados aos hidrocarbonetos de petróleo dissolvidos e/ou dispersos (HPDDs). Durante um ciclo completo de maré (13 h), foram registrados o nível, fluxo e propriedades da água (salinidade, temperatura, material em suspensão - MS -, clorofila e oxigênio dissolvido), além da velocidade e direção das correntes, usando ADCP e CTD. Os HPDDs foram investigados nas águas superficiais e de fundo, através de espectrofluorescência. Os resultados revelaram uma estrutura vertical homogênea, um regime de maré semidiurno e um padrão térmico diurno. As concentrações de HPDDs na superfície e no fundo são baixas e similares, devido à ação da maré. A fonte mais provável é o CIPS, uma vez que o transporte residual dos hidrocarbonetos de petróleo, da clorofila e do oxigênio dissolvido são no sentido do estuário do Massangana. Um padrão oposto foi observado para o transporte residual da salinidade e MS, no sentido da lagoa. Estes resultados indicam que a hidrodinâmica local é essencial para entender o transporte e troca de materiais entre os vários segmentos do estuário. Estudos mais completos são necessários para se obter conclusões mais consistentes.The Suape Estuary encompasses the Suape Industrial Port Complex (SIPC), a major industrial development in Brazil's Northeast region, which, in order to be implanted, caused drastic environmental changes in this system. This study presents the first physical characterization of the Suape estuarine system, focusing on the local hydrodynamics, material transport and its influence on some specific properties. Physical properties were also associated to dissolved dispersed petroleum hydrocarbons (DDPHs). A study was undertaken during a complete semi-diurnal tidal cycle (13 hr), during which water level, water flow, current velocity and direction, water properties (salinity, temperature, suspended particulate matter - SPM -, chlorophyll and dissolved oxygen) were recorded using ADCP and CTD systems. The DDPHs were investigated in surface and bottom waters, by spectrofluorescence, using Carmópolis oil and chrysene as analytical standards. Results showed a well-mixed vertical structure, a semi-diurnal tide regime and a diurnal thermal pattern. There was no statistical difference between DDPH concentrations at surface and bottom, due to the tide acting as an important homogenizer. DDPHs were low and the main contribution seems to be that from SIPC, as the residual transport of DDPHs, chlorophyll and dissolved oxygen, was towards the Massangana estuary. An opposite pattern was observed for salinity and SPM, whose residual transport was towards the lagoon. The results pointed local hydrodynamics as an essential tool for understanding material transport and exchanges among the estuarine segments. A longer time series should be studied in order to obtain more robust conclusions

3-(2,4-Dibromo­anilino)-2,2-dimethyl-2,3-dihydro­naphtho[1,2-b]furan-4,5-dione: a new substituted aryl­amino nor-β-lapachone derivative

The title compound, C20H15Br2NO3, shows the furan ring to adopt a half-chair conformation and the two ring systems to be approximately perpendicular [dihedral angle = 71.0 (2)°]. In the crystal structure, inter­molecular C—H⋯O contacts link the mol­ecules

Construção de modelos físicos dos orbitais atômicos e moleculares para o ensino de quí

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Chemoselective oxidation of benzophenazines by m-CPBA: n-oxidation vs. oxidative cleavage

Chemoselectivity is observed when a pyran-benzo[a]phenazine and a furan-benzo[a]phenazine from beta-lapachone and nor-beta-lapachone, respectively, were submitted to oxidation by m-CPBA. The pyran phenazine furnished mainly macrolactones, while the furan one led exclusively to a phenazine N-8 oxide. To understand this difference in reactivity, we synthesized a new furan phenazine, with the reactive double bond site less hindered than that of the derivative from nor-beta-lapachone. This furan phenazine, upon oxidation with m-CPBA, furnished mainly the expected macrolactone. These experimental results, along with preliminary analysis based on mechanical molecular calculations of the ground state of the substrates, allowed us to suggest that the observed chemoselectivity has a steric oxidant approach control origin, related to the presence of the geminal methyl groups in the phenazine structure. Several of the synthesized compounds are, herein, reported for the first time

Identification of phlebotomine sand fly (Diptera: Psychodidae) in Atlantic forest fragments and their dispersal to urban area

Abstract The geographical distribution of sand flies in Brazil has been the subject of some studies, yet there is no information about the phlebotomine fauna in João Pessoa, State of Paraíba, Brazil. The aim of this work is to evaluate the occurrence and distribution of sand flies in the Atlantic forest fragments and to evaluate a possible dispersion in 06 nearby districts. Light traps were used during three consecutive nights, supplemented by an aspirator during the dry period and rainy season. A total of 222 sand flies were found, 143 (130 males and 13 females) in the Atlantic forest, and 79 in urban areas. During the entire dry season, three species of phlebotomine sand flies were recorded in 11 forest fragments, Lutzomyia longipalpis, Lu. migonei and Lu. whitmani. During the rainy season, only Lu. longipalpis was found. This was the only species identified in the studied neighborhoods during both seasons. The differences in diversity of sand flies encountered between natural habitats and urban areas may thus be correlated mostly with adaptations to particular habitats and availability of food. One species (Lu. longipalpis) appears to be rapidly adapting to urban areas because of deforestation

Ciclo de Seminários como estratégia para incrementar a divulgação e utilização de publicações da Divisão de Ensino de Química da SBQ e a qualidade de Ensino na Educação Básica Pública

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