42 research outputs found

    A comparison between faecal sterols and coliform counts in the investigation of sewage contamination in sediments

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    In September 2002, nine sediment samples (0-2 cm) were collected from Botafogo Cove (southwestern part of Guanabara Bay) in order to compare the use of chemical (coprostanol) and biological markers (E. coli and total coliforms) in identifying faecal contamination. The values found (organic carbon - 6.0 to 64.8 mg g-1; coprostanol - 1.4 to 105 µg g-1; E. coli - Em setembro de 2002, foram coletadas nove amostras de sedimento superficial (0-2 cm) na Enseada de Botafogo (sudoeste da Baía de Guanabara/RJ), a fim de comparar o uso de marcadores químicos (coprostanol) e biológicos (E. coli e coliformes totais) na identificação da contaminação fecal da região. Os resultados obtidos (carbono orgânico - 6,0 to 64,8 mg g-1; coprostanol - 1,4 to 105 µg g-1; E. coli - < 30 to 2400 NMP/10g e coliformes totais - 40 to 9300 NMP/10g) foram iguais ou maiores aos observados em outras áreas contaminadas da Baía de Guanabara. Nas estações próximas à linha de costa, as concentrações de coprostanol e as contagens das bactérias confirmaram que o esgoto doméstico se acumulou no sedimento da enseada. As concentrações de coprostanol se mantiveram altas nas estações distantes das fontes de contaminação, porém o material fecal representou uma menor fração do carbono orgânico. Nessas mesmas estações, redução na contagem de colimetria foi proporcionalmente mais alta, provavelmente pela baixa sobrevivência das bactérias devido ao efeito de luz, salinidade e temperatura. durante o transporte e deposição das partículas de esgoto. Portanto, baseando-se nos resultados obtidos, o coprostanol foi um indicador mais adequado da contaminação fecal nos sedimentos da Enseada de Botafogo

    Strength regain in soil aggregate beds by swelling and shrinkage

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    A lightweight approach for designing enterprise architectures using BPMN : an application in hospitals

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    An Enterprise Architecture (EA) comprises different models at different levels of abstraction. Since existing EA design approaches, e.g. MDA, use UML for modeling, the design of the architecture becomes complex and time consuming. In this paper, we present an integrated and lightweight design approach for EA that uses a generic architecture and patterns, expressed in BPMN. The approach facilitates the modeling between the different levels. This has been applied in real cases in hospitals and other domains, demonstrating its feasibility and usability, reducing complexity and time for modeling

    Poly(DL-aspartic acid) and copper(II) acetate monohydrate interactions

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    Trans. Metal Chem., 2007, 32, 1106-110

    A lightweight approach for designing enterprise architectures using BPMN : an application in hospitals

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    An Enterprise Architecture (EA) comprises different models at different levels of abstraction. Since existing EA design approaches, e.g. MDA, use UML for modeling, the design of the architecture becomes complex and time consuming. In this paper, we present an integrated and lightweight design approach for EA that uses a generic architecture and patterns, expressed in BPMN. The approach facilitates the modeling between the different levels. This has been applied in real cases in hospitals and other domains, demonstrating its feasibility and usability, reducing complexity and time for modeling

    Sorption Parameters of Carbendazim and Iprodione in the Presence of Copper Nanoparticles in Two Different Soils

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    Today, metal nanoparticles are being incorporated into soil through several routes, where they could alter the sorption behavior of other contaminants such as pesticides. Therefore, a short assay was carried out through sorption isotherms to evaluate the effect of copper nanoparticles (NCu) and copper sulfate (as the bulk form) at 50, 100, and 200 mg kg−1 on the sorption capacity of two commonly applied fungicides (carbendazim and iprodione) onto two agricultural soils, contrasting in organic matter content (2% and 14%) and texture (sandy and loamy) respectively. The isotherms were well described using the Freundlich model (R2 > 0.95). Interestingly, at low organic matter, the pesticide sorption was notoriously increased in the presence of copper. However, NCu caused a minimal dose-dependent effect compared with their bulk form. Conversely, at high organic matter, the sorption was slightly altered by the presence of NCu. These findings constitute the first evidence that copper nanoparticles applied to agricultural soils can modify the sorption behavior of fungicides, which might increase their permanence in the environment. However, more detailed studies should be carried out in order to understand the interaction mechanisms between NCu/pesticides/soil and consequently their potential environmental risks.UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro en Investigación en Contaminación Ambiental (CICA

    Effects of drying/rewetting on soil aggregate dynamics and implications for organic matter turnover

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    Drying and rewetting (D/W) of soil have significant impacts on soil organic matter (SOM) turnover. We hypothesised that frequent D/W cycles would release the labile organic matter locked away in soil aggregates, increasing the priming effect (PE) (acceleration or retardation of SOM turnover after fresh substrate addition) due to preferential utilisation by microbes. 13C-labelled lignocellulose was added to the soil, and the effects of 0, 1, or 4 cycles of D/W were evaluated at 5 °C and 25 °C after a 27-day incubation of undisturbed soil cores from a temperate forest (Araucaria araucana). Following the incubation, macroaggregates (' 250 μm), microaggregates (250–53 μm), and silt + clay materials (' 53 μm) were separated. For each aggregate size class, three organic matter (OM) fractions (light (fPOM ' 1.6 g cm−3), occluded (oPOM 1.6–2.0 g cm−3), and heavy (Hf ' 2.0 g cm−3) were determined. D/W cycles caused macroaggregates to increase and a decrease in microaggregates (' 15%) at warm temperatures, and preferential use of the novel particulate organic matter (13C labelled), formerly protected fPOM. CO2 efflux was three times higher at 25 °C than at 5 °C. The D/W cycles at 25 °C had a strong negative impact on cumulative CO2 efflux, which decreased by approximately − 30%, induced by a negative PE of −50 mg C kg−1 soil with 1 D/W cycle and − 100 mg C kg−1 soil with 4 D/W cycles, relative to soil under constant soil moisture receiving 13C-labelled lignocellulose, but no cycles. Increasing the temperature and the number of D/W cycles caused a decrease in substrate use efficiency of particulate lignocellulose. In conclusion, D/W cycles at warm temperatures accelerated OM turnover due to preferential use from fPOM, increasing macroaggregates at the expense of microaggregates. A novel pathway of OM release and PE due to the D/W cycles is discussed. © 2020, Springer-Verlag GmbH Germany, part of Springer Nature

    The TOAR database on observations of surface ozone (and more)

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    In support of the first Tropospheric Ozone Assessment Report (TOAR) a relational database of global surface ozone observations has been developed and populated with hourly measurement data and enhanced metadata. A comprehensive suite of ozone data products including standard statistics, health and vegetation impact metrics, and trend information, are made available through a common data portal and a web interface. These data form the basis of the TOAR analyses focusing on human health, vegetation, and climate relevant ozone issues.Cooperation among many data centers and individual researchers worldwide made it possible to build the world’s largest collection of in-situ hourly surface ozone data covering the period from 1970 to 2015. By combining the data from almost 10,000 measurement sites around the world with global metadata information, new analyses of surface ozone have become possible, such as the first globally consistent characterisations of measurement sites as either urban or rural/remote. Exploitation of these global metadata allows for new insights into the global distribution, and seasonal and long-term changes of tropospheric ozone and they enable TOAR to perform the first, globally consistent analysis of present-day ozone concentrations and recent ozone changes with relevance to health, agriculture, and climate.This presentation will provide a summary of the TOAR surface observations database including recent additions of ozone precursor and meteorological data. We will demonstrate how the database can be accessed and the data can be used, and we will discuss its limitations and the potential for closing some of teh remaining data gaps
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