Lime treated soil erodibility investigated by EFA erosion testing

Erosion is susceptible to reduce the overall stability of a structure under hydraulic and static loads, but also can lead to the development of a fast breach. In parallel, dikes and levees builders and designers have not so many ways to improve initial properties of materials available on site, for the construction or restoration of hydraulic embankments. In this context, soil treatment with lime is a relevant procedure that is reported to improve the mechanical properties and erosion behavior of silty and clayey soils. This study focuses on the changes induced by lime treatment on the erosion resistance of a silty soil, and the evolution of relevant erosion parameters with curing time. EFA (Erosion Function Apparatus) tests on a silty soil from Marche-les-Dames (Belgium) were performed on the native soil, and after 2.5 % lime addition at several curing times (1, 7 and 28 days). After 1 day curing time, a slight increase in the soil erosion resistance is recorded, whereas after seven days submitted to a water flow velocity above 3 m/s, the soil passes from a medium to a low erodibility level. After 28 days, the soil has a very low erodibility for the same water velocity

Efficacy and acceptability of transcranial direct current stimulation (tDCS) for major depressive disorder: An individual patient data meta-analysis

We evaluated the efficacy and acceptability of transcranial direct current stimulation (tDCS) for treating acute depressive episodes using individual patient data that provide more precise estimates than aggregate data meta-analysis. A systematic review of placebo-controlled trials on tDCS as only intervention was conducted until December-2018. Data from each study was collated to estimate odds ratio (OR) and number needed to treat (NNT) of response and remission, and depression improvement. Endpoints were pre-determined. Nine eligible studies (572 participants), presenting moderate/high certainty of evidence, were included. Active tDCS was significantly superior to sham for response (30.9% vs. 18.9% respectively; OR = 1.96, 95%CI [1.30–2.95], NNT = 9), remission (19.9% vs. 11.7%, OR = 1.94 [1.19–3.16], NNT = 13) and depression improvement (effect size of β = 0.31, [0.15–0.47]). Moreover, continuous clinical improvement was observed even after the end of acute tDCS treatment. There were no differences in all-cause discontinuation rates and no predictors of response were identified. To conclude, active tDCS was statistically superior to sham in all outcomes, although its clinical effects were moderate

Definition and epidemiology of treatment resistance in psychiatry

The current chapter discusses different aspects of treatment resistance in mental disorders. We will first describe the prevalence and disease burden of mental disorders, then we will have a closer look at treatment outcomes in psychiatry, and next we will focus on treatment resistance, its impact and strategies for improvement. It will become clear that, despite the rapidly increasing knowledge base for psychiatric treatments, there are still many unknowns and points for improvement. The aim of this chapter is to introduce the major elements of this discussion needed to appreciate the more specific aspects that will be treated in the subsequent chapters that focus on specific disorders.</p

Application d'un produit polymère à la consolidation des sables carbonatés

L'injection est un procédé de construction de plus en plus utilisé pour l'étanchement ou la consolidation des sols. Le choix du produit d'injection dépend des caractéristiques du sol et de l'objectif du traitement. Les coulis de ciment, injectés sous pression, sont couramment utilisés. Cependant, l'utilisation de produits chimiques peut être plus avantageuse grâce, principalement, à leur faible viscosité assurant une meilleure pénétrabilité des terrains à injecter.Cet article décrit les travaux réalisés avec un nouveau produit polymère utilisé pour la consolidation des sables carbonatés. Ces formations présentent des caractéristiques mécaniques faibles à très faibles, et le traitement envisagé permet d'augmenter leur résistance mécanique.L'expérimentation, utilisant en grande partie l'essai de compression simple, porte sur des échantillons de sable préalablement injectés. Des valeurs de la résistance de 3,5 à 4 MPa sont régulièrement obtenues dès quelques heures de conservation dans l’eau. L’amélioration de la résistance mécanique est étudiée en fonction des principaux paramètres liés aux problèmes d'injection