Vernacular housing practices in Burkina Faso: Representative models of construction in Ouagadougou and walls hygrothermal efficiency

peer reviewedIn Burkina Faso, particularly in Ouagadougou, the walls of the houses are made of several local materials. The choice of a material implies a suitable constructive technique and an appropriate architecture. The walls are either earth-based, i.e. Compressed Earth Blocks (CEBs) or Adobe, or based on cement-based materials such as hollow concrete blocks. This paper proposes a description of the vernacular construction practices according to the material used for the walls and tries to explore the hygrothermal behaviour of various wall compositions. A hygrothermal simulation of a hollow concrete blocks wall and a CEBs wall using the WUFI®Pro software is carried out in order to compare the humidity flux passing through interior surface of each wall and to analyze the influence of integrated moisture in the calculation of heat flow. It is shown that, for CEBs wall, both thermal and hygrothermal simulation of heat flow give similar results. © 2017 The Authors. Published by Elsevier Ltd

X-ray Cluster Cosmology

Sensitive, wide-area X-ray surveys which would be possible with the WFXT will detect huge samples of virialized objects spanning the mass range from sub-groups to the most massive clusters, and extending in redshift to beyond z=2. These samples will be an excellent dataset for carrying out many traditional cosmological tests using the cluster mass function and power spectrum. Uniquely, WFXT will be able not only to detect clusters but also to make detailed X-ray measurements for a large number of clusters and groups right from the survey data. Very high quality measurements of the cluster mass function and spatial correlation over a very wide range of masses, spatial scales, and redshifts, will be useful for expanding the cosmological discovery space, and in particular, in searching for departures from the "concordant" Lambda-CDM cosmological model. Finding such departures would have far-reaching implications on our understanding of the fundamental physics which governs the Universe.Comment: ASTRO2010 decadal survey science white pape