Resumo A carbonatação tem sido alvo de preocupação de construtores e pesquisadores, pois, ao diminuir o pH da solução intersticial do concreto, pode favorecer a despassivação e posterior corrosão das armaduras do concreto armado. Dentre os fatores que influenciam a carbonatação está a utilização de materiais pozolânicos, como o metacaulim. Entretanto, não há um consenso quanto à contribuição positiva ou negativa da presença destas adições. O presente trabalho avaliou a influência do metacaulim nas propriedades mecânicas, na porosidade e, principalmente, na carbonatação do concreto, a partir da adição de 0%, 5%, 10% e 15% de metacaulim, em relação à massa do cimento. De acordo com os resultados obtidos, observou-se que a adição de metacaulim, apesar de não ter influenciado significativamente na porosidade, conferiu ao concreto uma maior resistência à compressão axial, uma diminuição da absorção capilar e retardou o avanço da frente de carbonatação no concreto.

Abstract Carbonation has been a concern of constructors and researchers because, by lowering the pH of the interstitial solution of the concrete, it can favor the post-deposition and subsequent corrosion of reinforced concrete reinforcement. Among the factors that influence carbonation is the use of pozzolanic materials, such as metakaolin. However, there is no consensus as to the positive or negative contribution of these additions. This work evaluated the influence of metakaolin on the mechanical properties, porosity and in particular on the carbonation of concrete, from the addition of 0%, 5%, 10% and 15% of metakaolin, in relation to the cement mass. From the results, it was observed that the addition of metakaolin, while not significantly influencing the porosity, gave the concrete a greater resistance to axial compression, a decrease in the capillary absorption and delayed the advance of the carbonation front in the concrete.

RESUMEN El objetivo de este trabajo es evaluar la eficiencia y el cambio de productividad de las Cooperativas de Crédito de Paraná. El análisis consideró 45 unidades (cada cooperativa estudiada), cada una con 10 variables en cada período (8 inputs y 2 outputs). Esta evaluación ha tenido en cuenta los datos de la cooperativa de crédito trimestral, de enero de 2009 a julio de 2015 (27 períodos). La metodología incluía Análisis de Envoltura de Datos (DEA), Análisis de Componentes Principales (PCA) y Indice de Malmquist (MI). Los resultados mostraron que las DMUs 453, 498 y 517 se consideraron 100% eficientes en todos los períodos, considerando como puntos de referencia. No hubo casos en que una DMU no se considerara 100% eficiente en al menos una observación. El MI mostró que la diferencia entre el mayor y el menor promedio fue significativa (variando entre 19.837 para DMU 251 y 0.926 para DMU 450). El promedio entre todos los MI fue 4,735 con una desviación estándar de 3,547, evidenciando las diferentes medidas de eficiencia entre cada DMU en comparación con las otras.

ABSTRACT The aim of this paper is to evaluate the efficiency and productivity change of Paraná's Credit Union. The analysis considered 45 units (each credit union researched), each of one with 10 variables in each period (8 inputs and 2 outputs). This evaluation has taken into account quarterly credit union's data, from January 2009 to July 2015 (27 periods). The methodology included Data Envelopment Analysis (DEA), Principal Components Analysis (PCA) and Malmquist Index (MI) techniques. The results showed that DMUs 453, 498 and 517 were considered 100% efficient in all periods, making them ideal benchmarks. There was no case that a DMU was not considered 100% efficient in at least one observation. The MI showed that the difference between the biggest and the smallest average was significant (varying between 19.837 for DMU 251 and 0.926 for DMU 450). The average between all MI was 4,735 with a standard deviation of 3,547, evidencing the different measures of efficiency between each DMU when compared to the others.

The influence of environmental and biological factors on the efficacy of Bacillus thuringiensis serovar israelensis and B. sphaericus as mosquito larvicides are reviewed. The importance of strain dependence, cultivating media/methods, mosquito species/specificity, formulations and their relation to mosquito feeding habits, as well as temperature, solar exposure, larval density and concomitant presence of other aquatic organisms are addressed with reference to the present status of knowledge in Brazil.