Stress, coping et inondations (la santé mentale des inondés de la Somme)

Les inondations de la vallée de la Somme, survenues en 2001, ont été l'occasion d'évaluer l'existence de troubles psychiques chez les inondés au travers d'une étude de type transversale exposés / non exposés, réalisée deux ans après les faits. Les résultats nous ont confirmé, par ailleurs, l'existence de plusieurs stratégies d'ajustement face aux inondations. Les principales utilisées sont les stratégies dites actives (ou positives) : 76 % des individus pour la " recherche de soutien social ", ou encore 50% pour la " résolution de problèmes ". Il est a noté que ces stratégies ont été utilisées de manière exclusives ou combinées et ont protégé les sinistrés des troubles dépressifs. Les stratégies dites passives (ou négatives), moins fréquentes, ont engendré par opposition des éléments de détresse psychologique (stress, trouble anxieux, insomnie) et nous montrent une inadaptation à la situation vécue. Cette étude a finalement permis de déterminer le profil d'une population dont la santé mentale est à risque dans ce contexte, ce qui offre de nouvelles perspectives dans la prise en charge médicopsychologique des inondésAMIENS-BU Santé (800212102) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Complete oxidation of formaldehyde at low temperature using Cerium modified birnessite-Like MnO2: effect of calcination temperature

International audienc

Influence of the preparation method on the activity of copper-manganese oxides for toluene total oxidation

International audienceCopper manganese oxides were prepared either by a co-precipitation method using metal nitrates as precursors, tetramethylammonium hydroxide (TMAH) as precipitant or by a redox-precipitation method using manganese acetate and copper nitrate as precursors, permanganate of potassium as oxidant. Copper manganese oxides synthesized by the redox method and calcined at 300 °C were also doped with Pt and Pd (0.5 wt%). The materials were characterized by ICP-OES, X-ray powder diffraction, N2 adsorption/desorption analysis, temperature-programmed reduction, X-ray photoelectron spectroscopy and time-of-flight secondary-ion mass spectrometry. The catalyst properties were assessed in total oxidation of toluene and compared with those of the corresponding single oxides and of a commercial Hopcalite catalyst. Copper manganese oxides were proved to be more active than the single oxides whatever the method of preparation used. CuMnOx prepared via redox method were more active than the catalyst prepared by co-precipitation and compared favorably with the commercial Hopcalite. The overall characterization results revealed that the redox method can ensure a good dispersion of copper in close interaction with manganese preserving more active sites at the outermost layers of the catalyst in comparison with the catalyst obtained via co-precipitation. However all the catalysts deactivate to some extent at the earlier stages of the reaction before to reach a steady-state. For redox catalysts calcined at 300 °C, although the dispersion of trace amount of noble metals does not ensure a better activity, adding Pt allows to get a better resistance to deactivation. Additionally it is to be noticeable that the catalyst using redox-precipitation method calcined at 200 °C outperforms the commercial hopcalite overtime on stream

Preferential dissolution of copper from Cu-Mn oxides in strong acid medium: Effect of the starting binary oxide to get new efficient copper doped MnO2 catalysts in toluene oxidation

This work investigated the concept of preferential dissolution of copper in HNO3 10 M at 20 °C from two starting Cu-Mn oxides to acquire novel copper doped MnO2 like polymorphs. On purpose two starting Cu-Mn oxides were tested: a nanocristalline CuMn2O4 spinel phase with a SSA of 47 m2/g and a weak amorphous Cu-Mn oxide with a Mn/Cu atomic ratio of 4.8 (SSA: 166 m2/g). The physico-chemical properties of the final copper doped MnO2 like oxides were discussed in terms of the nature of the starting oxides and of the operating conditions applied for the acid treatment. Finally, these new copper doped γ/ε MnO2 like oxides were assessed in toluene oxidation and their catalytic performances were compared with those of α-MnO2 and ε-MnO2 catalysts. The copper doped MnO2 obtained from the weak amorphous Cu-Mn oxide exhibited the highest activity in terms of T50(CO2). This highest activity was related to a high density of Cu-O-Mn interactions at the outermost layers of the catalyst as assessed by ToF-SIMS results