RESUMO
Cloud computing has become a popular delivery model service, offering several advantages. However, there are still challenges that need to be addressed when applying the cloud model to specific scenarios. Two of such challenges involve deploying and executing applications across multiple providers, each comprising several services with similar functionalities and different capabilities. Therefore, dealing with application distributions across various providers can be a complex task for a software architect due to the differing characteristics of the application components. Some works have proposed solutions to address the challenges discussed here, but most of them focus on service providers. To facilitate the decision-making process of software architects, we previously presented PacificClouds, an architecture for managing the deployment and execution of applications based on microservices and distributed in a multi-cloud environment. Therefore, in this work, we focus on the challenges of selecting multiple clouds for PacificClouds and choosing providers that best meet the microservices and software architect requirements. We propose a selection model and three approaches to address various scenarios. We evaluate the performance of the approaches and conduct a comparative analysis of them. The results demonstrate their feasibility regarding performance.
RESUMO
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.
