976 resultados para Fe-cr-b
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Se presentan mediciones experimentales de la radiación solar ultravioleta en el rango B del espectro solar (UV-B) y la radiación ultravioleta en el rango total RUV (UV-A+UV-B) en días claros y sin nubes en Heredia, Costa Rica. Se utilizó una radiómetro UV-B, que mide la radiación solar en el rango espectral 280-315 nm, y un radiómetro RUV, que mide la radiación solar en el rango espectral 280-385 nm. La dependencia entre entre UV-B y RUV también fue investigada, y se encontró un excelente grado de asociación entre ambas. Además se detalló que UV-B representa solamente un 5,4% de RUV, a pesar de que UV-B es mil veces más potente que UV-A. Los valores de UV-B medidos in situ fueron comparados con los valores predichos por un modelo atmosférico espectral, el cual utiliza como datos de entrada: la hora del día, la latitud, la altitud, el albedo superficial, la distancia Tierra-Sol, la turbiedad atmosférica y el ozono atmosférico. La comparación entre los valores medidos y predichos dio resultados satisfactorios.
Prevalencia de sobrepeso y obesidad en escolares de b?sica primaria de la ciudad de Santiago de Cali
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Se realiz? un estudio descriptivo, de corte transversal, cuantitativo y no experimental, para identificar la prevalencia de sobrepeso, obesidad y sus variables asociadas en una muestra de 264 escolares de 3 Instituciones Educativas P?blicas y 2 colegios del sector privado. La edad de los escolares oscil? entre los 7,13 y los 11,68 a?os. La edad promedio de los ni?os fue de 9,5 a?os y las de las ni?as 9,4 a?os. Las variables medidas fueron: la fecha de nacimiento, la masa corporal, la estatura, el porcentaje de grasa, la circunferencia de cintura, la presi?n arterial y la dinamometr?a manual. Se calcularon con base en estos valores la edad decimal, el IMC y la clasificaci?n de porcentaje graso. En cuanto a la prevalencia de sobrepeso y obesidad, en el an?lisis global, un 48,4% de la muestra total de ni?os se ubic? en las clasificaciones de porcentaje graso m?s elevadas, que indican sobrepeso y obesidad. La prevalencia en las ni?as fue del 44%. El estrato con mayor prevalencia de sobrepeso y obesidad fue el 4 con 62,6%. El sector con mayor prevalencia fue el p?blico con 48,2%. Lo que sin duda es una alerta sobre la necesidad m?s y mejores de programas de control de peso y composici?n corporal en los colegios y escuelas evaluados, existen problemas cr?nicos de salud presentes y futuros que se pueden evitar con las estrategias de intervenci?n adecuadas. Las diferencias estad?sticas encontradas entre la variable cualitativa clasificaci?n de porcentaje graso y la circunferencia de cintura, el IMC, la presi?n arterial sist?lica, la masa corporal y el porcentaje graso, expresa la influencia que ejerce esa clasificaci?n en el resultado de la variable cuantitativa, y espec?ficamente entre los subgrupos de la clasificaci?n de porcentaje graso. Se obtuvieron altas correlaciones entre la variable cualitativa clasificaci?n de porcentaje graso y las variables cuantitativas masa corporal, porcentaje de grasa corporal, circunferencia de cintura e ?ndice de masa corporal (Rho > 0,600).
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Leachates are effluent produced by decomposition of solid waste, they have complex composition and can be highly toxic. Therefore such percolated liquid should be collected and treated properly to avoid environmental contamination of soil and of water bodies. The objective of this study was to evaluate the toxicity through ecotoxicological tests with Ceriodaphnia dubia (Cladocera - Crustacea) of percolated liquids generated in two different systems of municipal solid waste (MSW) disposal in the city of Natal/ RN: A Sanitary Landfill in the Metropolitan Region of Natal/ RN, and in a dump off area. Furthermore, it was evaluated the possible contamination of the underground water of the dump off area. Two monthly samples were taken at four points between the months of May/2009 and January/2010. The Point "A" corresponds to the end of the pond leachate treatment in ASRMN; The Point "B" corresponds to a containment pond at the dump. The Point "C" is an area near one of the cells of the dump off area where the leachate outcrops; The Point "D" stands for an underground water well at the area. The last point, called "E" was sampled only once and corresponds to the slurry produced by temporary accumulation of solid waste in the open area of the dump. The ecotoxicological tests, acute and chronic, followed the ABNT 13373/2005 rules, with some modifications. The samples were characterized by measuring the pH number, the dissolved oxygen (DO), the salinity, BOD5, COD, Cd, Cu, Pb, Cr, Fe, Mg, Ni, and Zn. At Point A, the average number of EC50-48h ranged between 1.0% and 2.77% (v/v), showing a high toxicity of the leachate to C.dubia in all months. To this point, positive correlations were found between the EC50- 48 with precipitation. Negative correlations were found between the EC50- 48h with salinity. At point B there was no response of the acute exposure of organisms to the test samples. At point C the EC50-48h ranged from 17.68% to 35.36% in just two months of the five ones analyzed, not correlated meaning. Point D, the EC50-48h level ranged between 12.31% and 71.27%, showed a negative correlation with, only, precipitation. Although it was observed toxicity of underground water in the Landfill Area, there was no evidence of water contamination by leachate, however, due to the toxic character of this water, additional tests should be conducted to confirm the quality of water that is used for human supply. At point E there was no acute toxicity. These results support the dangers of inappropriate disposal of MSW to water bodies due to the high toxicity of the leachate produced highlighting the necessity of places of safe confinement and a treatment system more effective to it
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Air pollution can threat the environment and public health, and is assess by pollutant ́s concentration measurements in order to verify whether the limits set by environmental agencies are being respected. However, these measures do not indicate immediately the impacts to living beings. To faced this problem, plants are been investigated as potential bioindicators of air pollution and, among them, stand out bromeliads Tillandsia genus which colonize various substrates,. obtaining water and nutrients from the atmosphere directly. In this context, this research assessed the potential of epiphytic bromeliad Tillandsia recurvata (L.) L. found in urbanized areas of the city of Curitiba - PR as a bioindicator of urban air pollution. According to vehicle traffic, five sample points were selected and classified. Points P1 and P2 were classified as high-traffic vehicle due presenting trucks and urban transport; point P3 was classified as moderate traffic due the predominance of private vehicles and urban transport; and points P4 and P5 were classified as low-traffic, presenting circulation of private vehicles only. There were analyzed the abundance of T. recurvata, morphophysiological parameters (leaf area, leaf specific area, sclerophylly index, percentage dry weight / fresh weight, chlorophyll (a + b), analysis of structural mesophyll organization) and the heavy metals accumulation (Fe, Cd, Cr, Cu, Pb and Zn). The abundance analysis and the results obtained for metals analysis were correlated with the intensity of vehicular traffic, directing the sampling points P1 > P2 = P3 > P4 = P5. This result demonstrate that the abundance of T. recurvata is greater in urban air pollution impacted areas, thus indicating that T. recurvata absorbs and accumulates metals and can be used in biomonitoring of urban air pollution in areas impacted by vehicular traffic. Morphophysiological parameters analyzed shows that the internal plant ́s structure is not significantly impacted by urban air pollution due plant ́s adptations. The presence of absorbing scales, the CAM metabolism pathway and it ́s store water ability, among other features, demonstrate their potential as bio-indicator in urban areas, especially regarding heavy metals accumulation .
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El Programa Nacional de Biling?ismo, actualmente Programa Nacional de Ingl?s1, ha sido Promovido por el Ministerio de Educaci?n Nacional de Colombia desde el a?o 2004. Su principal objetivo es fomentar en los ciudadanos colombianos la capacidad para manejar al menos una lengua extranjera, espec?ficamente el ingl?s. Con esto se busca obtener mano de obra calificada en tiempos de globalizaci?n y brindar las mismas oportunidades a cada colombiano para adquirir esta lengua. Seg?n el Ministerio de Educaci?n Nacional de Colombia: ?Ser biling?e es tener m?s conocimientos y oportunidades para ser m?s competentes y competitivos, y mejorar la calidad de vida de todos los ciudadanos? (MEN, 2005).(Extra?do de una p?gina web) En este trabajo se analiza el discurso dominante que se encuentra en una cartilla taller utilizada en una de las capacitaciones brindadas al cuerpo docente de las instituciones p?blicas, en ella se presenta un material pedag?gico para los niveles de b?sica primaria llamado Bunny Bonita. Tambi?n se utilizan algunos documentos oficiales que dan cuenta del discurso utilizado para presentar los proyectos educativos en Colombia, sobre todo, el discurso relacionado con el Programa Nacional de Ingl?s. El presente trabajo se basa en el modelo de Van Dijk (2010) ?An?lisis Cr?tico Epist?mico del Discurso? ya que sus estrategias de estudio permiten hallar la manera como el conocimiento se construye por parte del discurso de los grupos dominantes. Como resultado, este trabajo muestra por medio del an?lisis de la cartilla de capacitaci?n de Bunny Bonita, que el Programa Nacional de Ingl?s m?s que una soluci?n a los problemas de desigualdad es un proyecto que satisface los intereses de la ?lite colombiana. Adicionalmente muestra c?mo el discurso dominante utilizado es el medio que permite que los colombianos acepten de manera positiva el proyecto y apoyen su ejecuci?n
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En toda relaci?n social el lenguaje es parte fundamental para la interacci?n entre lo sujetos. A partir del lenguaje los seres humanos logran entablar comunicaci?n, expresar pensamientos, sentimientos y posiciones, el lenguaje adquiere significado dependiendo de la persona y la comunidad que lo utilice. En esta construcci?n de sentidos, el discurso como acto de comunicaci?n se desarrolla a partir de las relaciones sociales que rigen el contexto y la construcci?n del discurso. Existen distintas formas de elaborar dicho discurso, partiendo del uso de las estructuras gramaticales hasta la adopci?n de un estilo y la utilizaci?n de distintas formas ret?ricas. Estos elementos se emplean con un prop?sito y dependiendo de lo que se quiera obtener a cambio. De un profesor a un estudiante, de un empleador a su empleado, de un gobernante a su pueblo. Cada sujeto tiene una meta a alcanzar y lo hace a trav?s del discurso que utiliza. En medio de todo esto, es posible que el relato de los hechos y los eventos, as? como la respuesta o concepci?n de una comunidad frente a lo ocurrido pueda manipularse desde el manejo del discurso y la informaci?n que se promueva. Para el an?lisis de este discurso institucional y m?s concretamente del corpus se emplear?n una serie de categor?as de an?lisis propuestas por Teun A. Van Dijk (1994-1999-2000) y John B. Thompson (1993),
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The physicochemical characteristics of three Brazilian pears were investigated using elemental analysis, scanning electron microscopy (SEM), X-ray diffractometry (XRD) and studies of Cr(III) biosorption based on adsorption isotherms. Adsorption of Cr(III) by in natura peat from Santo Amaro das Brotas (Sergipe State) was much greater than by peats from either Ribeirao Preto (São Paulo State) or Itabaiana (Sergipe State), with adsorption capacities (q) of 4.90 +/- 0.01, 1.70 +/- 0.01 and 1.40 +/- 0.01 mgg (1), respectively. Pre-treatments with HCl and NaOH + HCl reduced adsorption by the Santo Amaro clas Brotas peat, showing that adsorption efficiency was associated with the amount of organic matter present. Conversely, increase in the mineral content following pre-treatment increased adsorption of Cr(III) by the Ribeirao Preto and Itabaiana peats. Highest adsorption (retention >95.0%) was achieved at equilibrium pH 4.0 using the Santo Amaro das Brotas peat. Experimental data for the adsorption of Cr(III) from aqueous solution onto this peat were fitted to the Langmuir equation, from which an equilibrium adsorption capacity, q(max), of 5.60 mgg(-1) was obtained, which was close to the experimentally determined value. (c) 2008 Elsevier B.V. All rights reserved.
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Relief shown by hachures. Depths shown by contours.
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EFEITO DA APLICAÇÃO CONTINUADA DE BIOSÓLIDO NA COMPARTIMENTALIZAÇÃO DE METAIS EM SOLO CULTIVADO COM BANANA (MUSA SPP). MA040 Germana Breves Rona1; Fernanda Ardilha1; Fernanda Serrenho1; Sarai de Alcantara1; Daniel Vidal Perez2; Luiz A.S. Melo3., germanarona@hotmail.com 1Instituto de Química/UFRJ, Av. Brig. Trompovsky, s/nº, Cidade Universitária, CEP 21949-900, Rio de Janeiro (RJ); 2Embrapa Solos, R. Jardim Botânico, 1024, CEP: 22460-000, Rio de Janeiro (RJ). 3Embrapa Meio Ambiente, Caixa Postal 69, CEP: 13820-000, Jaguariúna (SP) (INTRODUÇÃO) O lodo de esgoto é rico em matéria orgânica e nutrientes, podendo substituir, ainda que parcialmente, os fertilizantes minerais. Graças a essas características, esse resíduo pode desempenhar importante papel na produção agrícola e na manutenção da fertilidade do solo. Entretanto, esse composto apresenta materiais pesados em sua composição. Assim torna-se necessário ponderar as variações das formas disponíveis desses elementos. Nesse sentido, a extração seqüencial é uma metodologia que permite avaliar o destino principal de dado metal no solo em função de suas preferências de ligação química na matriz organomineral. No entanto, essa análise consome muito tempo e reagente. A possibilidade de relacionar essa extração complexa com uma mais simples seria interessante. É o objetivo do presente trabalho, portanto, avaliar a relação entre uma metodologia de extração seqüencial e os dois métodos de extração simples mais usados no Brasil, Mehlich 1 e DTPA. (METODOLOGIA) As amostras foram coletadas em um ensaio instalado no campo experimental da Embrapa-Meio Ambiente (Jaguariúna, SP) em um Argissolo Vermelho- Amarelo. O delineamento experimental foi o de blocos ao acaso com 5 repetições. Os tratamentos estudados foram: 1. fertilização mineral (NPK), com base na análise de solo; 2. aplicação de lodo de esgoto com base na sua concentração de nitrogênio e mantendo a metade da quantidade aplicada na fertilização mineral (N/2); 3 aplicação de lodo de esgoto mantendo a quantidade de N aplicada na fertilização mineral (N); 4. duas vezes a concentração de lodo de esgoto aplicada no tratamento 3 (2N). Dois tipos de lodo foram aplicados: entre 2000 e 2004 usou-se lodo originário da região de Barueri (SP), tipicamente industrial.; em 2005 foi aplicado lodo originário do município de Jundiaí (SP), que pode ser considerado de característica doméstica. Ambos foram fornecidos pela SABESP, na forma adequada para aplicação agrícola. As amostras de solo foram coletadas na profundidade de 0-20 cm no ano de 2006. A extração seqüencial foi a descrita por Wasserman et al. (2005). As extrações simples, DTPA e Mehlich 1 seguiram a metodologia da Embrapa (1997). A determinação de Fe, Cu, Zn e Cr foi realizada por ICP-OES (PE OTIMA 3000). (RESULTADOS) As extrações simples de Fe, Cu, Zn e Cr correlacionaram-se positiva e significativamente com as principais fases do solo ligadas à biodisponibilidade. Os elementos Fe e Zn, extraídos tanto por Mehlich 1, como por DTPA, correlacionaram-se com mais significânica com a Fase 1, ligada à CTC do solo. Já os elementos Cu e Cr, correlacionaram-se melhor com a Fase 3, relacionada à matéria orgânica. O Mn extraído por DTPA apresentou melhor correlação com a Fase 1. (CONCLUSÃO) Todos os metais analisados apresentaram uma tendência em aumentarem sua concentração total em função da dose de lodo aplicada. As fases 1 e 3 apresentam importância neste sentido, sendo este um motivo de grande preocupação, por serem frações biodisponíveis, podendo agravar seriamente, os riscos de contaminação pelos metais em questão. No entanto, as concentrações encontradas são bem menores que aquelas recomendadas pela CONAMA no375/2006. Agradecimentos: CNPq, FAPERJ, FUJB, Embrapa
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Sediment contamination by metals poses risks to coastal ecosystems and is considered to be problematic to dredging operations. In Brazil, there are differences in sedimentology along the Large Marine Ecosystems in relation to the metal distributions. We aimed to assess the extent of Al, Fe, Hg, Cd, Cr, Cu, Ni, Pb and Zn contamination in sediments from port zones in northeast (Mucuripe and Pecem) and southeast (Santos) Brazil through geochemical analyses and sediment quality ratings. The metal concentrations found in these port zones were higher than those observed in the continental shelf or the background values in both regions. In the northeast, metals were associated with carbonate, while in Santos, they were associated with mud. Geochemical analyses showed enrichments in Hg, Cd, Cu, Ni and Zn, and a simple application of international sediment quality guidelines failed to predict their impacts, whereas the use of site-specific values that were derived by geochemical and ecotoxicological approaches seemed to be more appropriate in the management of the dredged sediments. (C) 2012 Elsevier Ltd. All rights reserved.
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Fondo Margaritainés Restrepo
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Errores de edición
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Case Description: An 82-years old Hispanic woman with a past medical history significant for pulmonary thromboembolism on oral anticoagulation, rheumatoid arthritis, and hypertension developed a new onset thrombocytopenia. Clinical Findings: Small clonal B-cells populations (SCBP) also known as monoclonal B-cell lymphocytosis was found as part of the workup for an idiopathic thrombocytopenia and lead ultimately to the diagnosis of parotid primary follicular lymphoma coexisting with Warthin tumor involving the bone marrow in a small extent and oncocytic papilloma located in the maxillary sinus. Treatment and Outcome: Patient was treated with Rituximab monotherapy with improvement on her platelet count. Clinical relevance: Although it is unclear the role of this clonal cells, they may work as a possible diagnostic tool for occult lymphomas. Further prospective studies are needed to confirm this possible association.
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Leachates are effluent produced by decomposition of solid waste, they have complex composition and can be highly toxic. Therefore such percolated liquid should be collected and treated properly to avoid environmental contamination of soil and of water bodies. The objective of this study was to evaluate the toxicity through ecotoxicological tests with Ceriodaphnia dubia (Cladocera - Crustacea) of percolated liquids generated in two different systems of municipal solid waste (MSW) disposal in the city of Natal/ RN: A Sanitary Landfill in the Metropolitan Region of Natal/ RN, and in a dump off area. Furthermore, it was evaluated the possible contamination of the underground water of the dump off area. Two monthly samples were taken at four points between the months of May/2009 and January/2010. The Point "A" corresponds to the end of the pond leachate treatment in ASRMN; The Point "B" corresponds to a containment pond at the dump. The Point "C" is an area near one of the cells of the dump off area where the leachate outcrops; The Point "D" stands for an underground water well at the area. The last point, called "E" was sampled only once and corresponds to the slurry produced by temporary accumulation of solid waste in the open area of the dump. The ecotoxicological tests, acute and chronic, followed the ABNT 13373/2005 rules, with some modifications. The samples were characterized by measuring the pH number, the dissolved oxygen (DO), the salinity, BOD5, COD, Cd, Cu, Pb, Cr, Fe, Mg, Ni, and Zn. At Point A, the average number of EC50-48h ranged between 1.0% and 2.77% (v/v), showing a high toxicity of the leachate to C.dubia in all months. To this point, positive correlations were found between the EC50- 48 with precipitation. Negative correlations were found between the EC50- 48h with salinity. At point B there was no response of the acute exposure of organisms to the test samples. At point C the EC50-48h ranged from 17.68% to 35.36% in just two months of the five ones analyzed, not correlated meaning. Point D, the EC50-48h level ranged between 12.31% and 71.27%, showed a negative correlation with, only, precipitation. Although it was observed toxicity of underground water in the Landfill Area, there was no evidence of water contamination by leachate, however, due to the toxic character of this water, additional tests should be conducted to confirm the quality of water that is used for human supply. At point E there was no acute toxicity. These results support the dangers of inappropriate disposal of MSW to water bodies due to the high toxicity of the leachate produced highlighting the necessity of places of safe confinement and a treatment system more effective to it
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A novel route to prepare highly active and stable N2O decomposition catalysts is presented, based on Fe-exchanged beta zeolite. The procedure consists of liquid phase Fe(III) exchange at low pH. By varying the pH systematically from 3.5 to 0, using nitric acid during each Fe(III)-exchange procedure, the degree of dealumination was controlled, verified by ICP and NMR. Dealumination changes the presence of neighbouring octahedral Al sites of the Fe sites, improving the performance for this reaction. The so-obtained catalysts exhibit a remarkable enhancement in activity, for an optimal pH of 1. Further optimization by increasing the Fe content is possible. The optimal formulation showed good conversion levels, comparable to a benchmark Fe-ferrierite catalyst. The catalyst stability under tail gas conditions containing NO, O2 and H2O was excellent, without any appreciable activity decay during 70 h time on stream. Based on characterisation and data analysis from ICP, single pulse excitation NMR, MQ MAS NMR, N2 physisorption, TPR(H2) analysis and apparent activation energies, the improved catalytic performance is attributed to an increased concentration of active sites. Temperature programmed reduction experiments reveal significant changes in the Fe(III) reducibility pattern with the presence of two reduction peaks; tentatively attributed to the interaction of the Fe-oxo species with electron withdrawing extraframework AlO6 species, causing a delayed reduction. A low-temperature peak is attributed to Fe-species exchanged on zeolitic AlO4 sites, which are partially charged by the presence of the neighbouring extraframework AlO6 sites. Improved mass transport phenomena due to acid leaching is ruled out. The increased activity is rationalized by an active site model, whose concentration increases by selectively washing out the distorted extraframework AlO6 species under acidic (optimal) conditions, liberating active Fe species.