Pompéi. Villa de Diomède

Dans la continuité du programme initié en 2013, l’objectif de la deuxième campagne menée sur la Villa de Diomède était de mettre en évidence la chronologie du bâtiment et son rapport aux espaces environnants. Pour ce faire, l’étude archéologique a été centrée sur les façades est et sud de la villa, afin d’éclaircir le rapport à la rue (via delle Tombe) et aux tombes adjacentes. Il convenait d’explorer davantage l’évolution de la villa en fonction des rapports de propriété et d’occupation de l..

Structural insights into chaperone addiction of toxin-antitoxin systems

International audienceSecB chaperones assist protein export by binding both unfolded proteins and the SecA motor. Certain SecB homologs can also control toxin-antitoxin (TA) systems known to modulate bacterial growth in response to stress. In such TA-chaperone (TAC) systems, SecB assists the folding and prevents degradation of the antitoxin, thus facilitating toxin inhibition. Chaperone dependency is conferred by a C-terminal extension in the antitoxin known as chaperone addiction (ChAD) sequence, which makes the antitoxin aggregation-prone and prevents toxin inhibition. Using TAC of Mycobacterium tuberculosis, we present the structure of a SecB-like chaperone bound to its ChAD peptide. We find differences in the binding interfaces when compared to SecB–SecA or SecB-preprotein complexes, and show that the antitoxin can reach a functional form while bound to the chaperone. This work reveals how chaperones can use discrete surface binding regions to accommodate different clients or partners and thereby expand their substrate repertoire and functions

Study on INTOC Waterproofing Technology for Basement of High-Rise Buildings

International audienceThe seepage or water leaks in general and the seepage of the basement of high-rise buildings are common problems in the world. In Vietnam, for more than 20 years, INTOC products have shown high efficiency in basement waterproofing through surveys of several constructions. However, research on these products is hardly available. In this study, the author conducted a number of experiments on an INTOC product, positive and negative sides’ waterproofing effects as well as the influence of the product on the adhesion between reinforcement and concrete. The results showed that when applying the product on the concrete samples of grade M300 and M400 at water pressures of 10 and 12 daN/cm2, there wasn’t any seepage flow through the waterproofing layer. The waterproofing slurry on the reinforced surface didn’t affect its adhesion with concrete. The waterproofing layer has a very small surface tension, so it is hydrophobic and resists capillary permeability, and hence has small wetting properties

Study on INTOC Waterproofing Technology for Basement of High-Rise Buildings

International audienceThe seepage or water leaks in general and the seepage of the basement of high-rise buildings are common problems in the world. In Vietnam, for more than 20 years, INTOC products have shown high efficiency in basement waterproofing through surveys of several constructions. However, research on these products is hardly available. In this study, the author conducted a number of experiments on an INTOC product, positive and negative sides’ waterproofing effects as well as the influence of the product on the adhesion between reinforcement and concrete. The results showed that when applying the product on the concrete samples of grade M300 and M400 at water pressures of 10 and 12 daN/cm2, there wasn’t any seepage flow through the waterproofing layer. The waterproofing slurry on the reinforced surface didn’t affect its adhesion with concrete. The waterproofing layer has a very small surface tension, so it is hydrophobic and resists capillary permeability, and hence has small wetting properties

Evolution of compactive shear localization bands: geological data and numerical models

International audienceCompactive shear bands with different ratio of compactive to shear inelastic deformation were recently studied in detail in different regions within the porous rocks. Among them are nicely exposed networks of conjugate cataclastic bands formed in a single tectonic event in the "Bassin du Sud-Est" (Provence, France) in Cretaceous sandstones. Microanalysis of the material within the bands shows that they underwent mainly thrust-sense shearing with a minor compactive component. The most striking feature of the evolution of these bands is their thickening at the flanks by incorporation of the intact host rock into the deformation bands and formation of new strands. This feature as well as the general band pattern was reproduced in 2-D finite-difference models where the hardening modulus h grew with inelastic deformation. This growth causes strengthening of the material within the initial bands (resulting from deformation bifurcation) and considerably slows down its inelastic deformation after it reaches a maximal value defined by all the constitutive parameters and most of all by the rate of increase in h. The strengthening above a certain level results in the band widening due to the accretion at its edges of material not yet deformed as it becomes involved in compactive shearing. The inelastic deformation is therefore the most rapid along the band flanks, while the thickening with time of the band core part mainly undergoes elastic unloading starting from some stage. The initial band spacing depends on the initial h value h0 and increases with h0 in accordance with predictions from bifurcation theory. During deformation, the spacing reduces due to the propagation of bands that largely saturate the model/layer, resulting in a band pattern that resembles the natural band networks. The increase of h imposed in the models appears therefore as both an important and realistic property that can also be derived from available experimental rock testing data. On the other hand, it is difficult to constrain with sufficient AGU Abstract Browser http://abstractsearch.agu.org/meetings/2011/FM/sections/T/sessions/T... 1 sur 3 05/01/2015 19:08 precision the evolution of h with deformation based only such data. Therefore the adjustment/calibration of the constitutive models based on the reproduction of natural deformation patterns in numerical simulations appears as an important tool

A Chernov bound for robust tolerance design and application

International audienceWithin an industrial manufacturing process, tolerancing is a key player. The dimensions uncertainties management starts during the design phase, with an assessment on variability of parts not yet produced. For one assembly step, we can gain knowledge from the tolerance range required for the parts involved. In order to assess output uncertainty of this assembly in a reliable way, this paper presents an approach based on the deviation of the sum of uniform distributions. As traditional approaches based on Hoeffding inequalities do not give accurate results when the deviation considered is small, we propose an improved upper bound. We then discuss how the stack chain geometry impacts the bound definition. Finally, we show an application of the proposed approach in tolerance design of an aircraft sub-assembly. The main interest of the technique compared to existing methodologies is the management of the confidence level and the emphasis of the explicit role of the balance within the stack chain

A statistical approach for robust tolerance design

Within an industrial manufacturing process, tolerancing is a key player. The dimensions uncertainties management starts during the design phase, with an assessment on variability of parts not yet produced. For one assembly step, we can gain knowledge from the tolerance range required for the parts involved. In order to assess output uncertainty of this assembly in a reliable way, this paper presents an approach based on the deviation of the sum of uniform distributions. As traditional approaches based on Hoeffding inequalities do not give accurate results when the deviation considered is small, we propose an improved upper bound. We then discuss how the stack chain geometry impacts the bound definition. Finally, we show an application of the proposed approach in tolerance design of an aircraft sub-assembly. The main interest of the technique compared to existing methodologies is the management of the confidence level and the emphasis of the explicit role of the balance within the stack chain

Fatigue effects of discontinuous cyclic loading on the mechanical characteristics of sandstone

International audienc