This paper presents the analysis of the mechanical and durable properties of recycled aggregate c... more This paper presents the analysis of the mechanical and durable properties of recycled aggregate concrete (RAC) for using in concrete. The porosity of recycled coarse aggregates is known to influence the fresh and hardened concrete properties and these properties are related to the specific mass of the recycled coarse aggregates, which directly influences the mechanical properties of the concrete. The recycled aggregates were obtained from construction and demolition wastes (CDW), which were divided into recycled sand (fine) and coarse aggregates. Besides this, a recycled coarse aggregate of a specific mass with a greater density was obtained by mixing the recycled aggregates of the CDW with the recycled aggregates of concrete wastes (CW). The concrete was produced in laboratory by combining three water-cement ratios, the ratios were used in agreement with NBR 6118 for structural concretes, with each recycled coarse aggregates and recycled sand or river sand, and the reference concre...
The industrial development which has provided a significant progress in the improvement of the li... more The industrial development which has provided a significant progress in the improvement of the life quality has also brought some problems to the environment. In this context, the mobility industry has generated several types of pollutants. Among these pollutants stands out the ...
This article presents the optical networks tecnology and it's challenges. Futherly, this revi... more This article presents the optical networks tecnology and it's challenges. Futherly, this review focus on tree of themain problems related to all-optical networks aiming the main references on related literature. It is: the RWA problem, the placement converters and survivability networks. Resumo. Este artigo apresenta a tecnologia de redes ópticas transparentes e seus desafios. Em particular, o artigo descreve três
The rise in atmospheric pollution caused by gases such as ammonia has led many researchers to con... more The rise in atmospheric pollution caused by gases such as ammonia has led many researchers to conduct studies aimed at decreasing or treating the emissions of such polluting gases. The present work attempted to study the adsorption of ammonia in the fixed bed of activated carbon as a means to treat its emissions. The effects of the initial concentration of ammonia (C0) and of the bed temperature (TL) on the adsorption of ammonia by the activated carbon were also considered. Adsorption capacity of activated carbon was determined using data from the breakthrough curves and from a balance of mass in the bed. Adsorption capacities were obtained employing the Langmuir and Freudlich isotherms. The results showed that within the NH3 concentration range of 600-2400 ppm, adsorption capacity varied from 0.6 to 1.8 mg NH3/g carbon at 40 degrees C, from 0.2 to 0.7 mg NH3/g carbon at 80 degrees C and from 0.15 to 0.35 mg NH3/g carbon at 120 degrees C. These numbers highlight the tendency toward a lower adsorption capacity with the decrease in temperature. As to mass of the bed, this latter variable had no significant influence over adsorption capacity.
This paper presents the analysis of the mechanical and durable properties of recycled aggregate c... more This paper presents the analysis of the mechanical and durable properties of recycled aggregate concrete (RAC) for using in concrete. The porosity of recycled coarse aggregates is known to influence the fresh and hardened concrete properties and these properties are related to the specific mass of the recycled coarse aggregates, which directly influences the mechanical properties of the concrete. The recycled aggregates were obtained from construction and demolition wastes (CDW), which were divided into recycled sand (fine) and coarse aggregates. Besides this, a recycled coarse aggregate of a specific mass with a greater density was obtained by mixing the recycled aggregates of the CDW with the recycled aggregates of concrete wastes (CW). The concrete was produced in laboratory by combining three water-cement ratios, the ratios were used in agreement with NBR 6118 for structural concretes, with each recycled coarse aggregates and recycled sand or river sand, and the reference concre...
The industrial development which has provided a significant progress in the improvement of the li... more The industrial development which has provided a significant progress in the improvement of the life quality has also brought some problems to the environment. In this context, the mobility industry has generated several types of pollutants. Among these pollutants stands out the ...
This article presents the optical networks tecnology and it's challenges. Futherly, this revi... more This article presents the optical networks tecnology and it's challenges. Futherly, this review focus on tree of themain problems related to all-optical networks aiming the main references on related literature. It is: the RWA problem, the placement converters and survivability networks. Resumo. Este artigo apresenta a tecnologia de redes ópticas transparentes e seus desafios. Em particular, o artigo descreve três
The rise in atmospheric pollution caused by gases such as ammonia has led many researchers to con... more The rise in atmospheric pollution caused by gases such as ammonia has led many researchers to conduct studies aimed at decreasing or treating the emissions of such polluting gases. The present work attempted to study the adsorption of ammonia in the fixed bed of activated carbon as a means to treat its emissions. The effects of the initial concentration of ammonia (C0) and of the bed temperature (TL) on the adsorption of ammonia by the activated carbon were also considered. Adsorption capacity of activated carbon was determined using data from the breakthrough curves and from a balance of mass in the bed. Adsorption capacities were obtained employing the Langmuir and Freudlich isotherms. The results showed that within the NH3 concentration range of 600-2400 ppm, adsorption capacity varied from 0.6 to 1.8 mg NH3/g carbon at 40 degrees C, from 0.2 to 0.7 mg NH3/g carbon at 80 degrees C and from 0.15 to 0.35 mg NH3/g carbon at 120 degrees C. These numbers highlight the tendency toward a lower adsorption capacity with the decrease in temperature. As to mass of the bed, this latter variable had no significant influence over adsorption capacity.
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Papers by Christiano Rodrigues