Análisis de propiedades del transporte de humedad en bloques de hormigón

The moisture absorption properties in the concrete blocks have a significant influence on the performance of the penetration of rainwater. Knowledge of these properties is necessary to have technical information that allows the construction of walls with long life. In this paper we conducted a comparative analysis of two structural concrete blocks in relation to their physical properties and moisture transport: open porosity, specific mass and the initial rate of absorption (IRA), the total absorption and uptake versus time, obtaining the sorptivity as code for measuring the absorption accurate and reliable. The results obtained show that the sorptivity in the case of concrete block D2 is not applicable and presents the absorption average curve versus time as a characterization parameter with great potential, once can be observed the behavior of the blocks from the initial time to saturation, showing the characteristics between the different block types analyzed.Las propiedades de absorción de humedad de los bloques de hormigón tienen influencias significativas en el comportamiento a la penetración de agua de lluvia. El conocimiento de estas propiedades es necesario para poder contar con información técnica que permita la construcción de paredes con vida útil prolongada. En el presente articulo se realizó un análisis comparativo de dos bloques de hormigón estructurales en relación a sus propiedades físicas y de transporte de humedad: porosidad abierta, masa especifica así como la tasa inicial de absorción (IRA), absorción total y la absorción en función del tiempo, con la obtención de la sorptividad como código de medición preciso y confiable. Los resultados mostraron que la sorptividad no es aplicable en el caso de los bloques de hormigón D2 y se presenta la curva media de absorción en función del tiempo como un nuevo parámetro de caracterización que permite analizar el comportamiento y las peculiaridades de los bloques desde el instante inicial hasta la saturación

The Science Performance of JWST as Characterized in Commissioning

This paper characterizes the actual science performance of the James Webb Space Telescope (JWST), as determined from the six month commissioning period. We summarize the performance of the spacecraft, telescope, science instruments, and ground system, with an emphasis on differences from pre-launch expectations. Commissioning has made clear that JWST is fully capable of achieving the discoveries for which it was built. Moreover, almost across the board, the science performance of JWST is better than expected; in most cases, JWST will go deeper faster than expected. The telescope and instrument suite have demonstrated the sensitivity, stability, image quality, and spectral range that are necessary to transform our understanding of the cosmos through observations spanning from near-earth asteroids to the most distant galaxies