Earth construction in Algeria between tradition and modernity

This paper was accepted for publication in the journal Proceedings of the Institution of Civil Engineers: Construction Materials and the definitive published version is available at http://dx.doi.org/10.1680/jcoma.15.00048.In the south of Algeria, many indigenous settlements have been built using local earth construction techniques; in the north, despite the availability of suitable earth, only a few rural contemporary settlements have been built using ‘improved’ earth construction. This paper adopts a case study approach to examine and compare structural deficiencies of two earth-built housing settlements in different regions in Algeria. In the indigenous earth settlement in the south, where adobe was used in combination with local timber and stones, the dwellings exhibit many structural defects. Stabilisation of the soil and introduction of modern materials in the contemporary rammed earth settlement in the north has not, however, helped produce structurally adequate dwellings. These dwellings also exhibited many cracks and debonding of rendering, and thus did not fulfil the requirements and aspirations of their occupants. The study concludes that for a potentially successful earth building scheme there are inter-related factors that should be considered: selection of an appropriate soil and construction technique, implementation of a suitable structural design, construction and post-completion processes, availability of relevant skills and provision of adequate training on the construction technique

Space QUEST mission proposal: experimentally testing decoherence due to gravity

Models of quantum systems on curved space-times lack sufficient experimental verification. Some speculative theories suggest that quantum correlations, such as entanglement, may exhibit different behavior to purely classical correlations in curved space. By measuring this effect or lack thereof, we can test the hypotheses behind several such models. For instance, as predicted by Ralph et al [5] and Ralph and Pienaar [1], a bipartite entangled system could decohere if each particle traversed through a different gravitational field gradient. We propose to study this effect in a ground to space uplink scenario. We extend the above theoretical predictions of Ralph and coworkers and discuss the scientific consequences of detecting/failing to detect the predicted gravitational decoherence. We present a detailed mission design of the European Space Agency's Space QUEST (Space—Quantum Entanglement Space Test) mission, and study the feasibility of the mission scheme.© 2018 The Author(s