[en] Photo-induced effects have been detected by magnetic measurements, Moessbauer spectroscopy and reflectivity. The LIESST effect has been achieved in the spin-crossover system [Fe_xCo_1-x(btr)₂(NCS)₂].H₂O. We investigated the purely photo-induced magnetism of a Prussian Blue analogue Rb_0.52Co[Fe(CN)₆]_0.84, 2.31 H₂O, involving an optical electron transfer from Fe^II to Co^III. Inherent aspects of photomagnetic experiments are described: bulk and surface effects, magnetic and electronic metastabilities of the photo-excited state

No abstract available

[en] The asymmetric wiggler inserted since the end of 1990 on the Super-ACO storage ring in Orsay, has been built to produce high rate and high flux of circularly polarized soft X-rays in the 400-2000 eV range. This insertion device is particularly well suited to measure x-ray absorption spectra corresponding to dipole transitions towards electronic orbitals which are directly responsible for the magnetism (3d states of first row transition metals, 4f states of rare-earths). We report the first magnetic circular x-ray dichroism spectra obtained with this insertion device. They exemplify the wide prospects of this experimental setup. (author)

[en] The synthesis of molecular-based magnets with high Curie temperatures is a challenge for chemists. Within the framework of first-principles methods (the ASW method) we study two well-characterized compounds in the hexacyanochromate (III) family: CsNi[Cr(CN)₆[ and CsMn[Cr(CN)₆[. (orig.)

[en] Highlights: • RSM models optimise drinking water production by enhanced coagulation. • Two surface water catchments were compared: river and reservoir. • Cluster analysis determined baseline and peak organic matter loads at DWTPs. • Sensitivity analysis allowed the interpretations of RSM models outputs. • Peak scenarios were described as episodes particularly important for optimisation. Coagulation is the main process for removing natural organic matter (NOM), considered to be the major disinfection by-products (DBPs) precursor in drinking water production. In this work, k-means clusters analysis were used to classify influent waters from two different surface drinking water treatment plants (DWTPs) located in the Mediterranean region. From this, enhanced coagulation models based on response surface methodology (RSM) were then developed to optimise coagulation at two water catchments (river and reservoir). The cluster analysis classified the water quality of the raw waters into two groups related to baseline and peak organic loads. The developed enhanced coagulation models were based on the turbidity, total organic carbon (TOC) and UV₂₅₄ removals. Sensitivity analysis applied to the models (after predictors selection) determined the factors relative individual contributions for each DWTP scenario. Then, profile plots for enhanced coagulation were studied to identify the optimal levels for each case. Models mean R² were 0.85 and 0.86 in baseline and 0.85 and 0.84 in peak scenario for river and reservoir catchments, respectively. Results of this study indicate that the surface water quality variation in river DWTP is seasonal and is expressed by an increase of turbidity, while in the reservoir DWTP is related to extreme weather events showing high levels of dissolved organic load (TOC and UV₂₅₄). During baseline cases, where raw waters present low levels of organics, the three factors optimal adjustment should be ensured to optimise coagulation. Then, during peak scenarios, where influent waters present high organics, the optimal for enhanced coagulation relies on the correct adjustment of C_d. The presented work provides models for drinking water production aimed to propose the optimum conditions for enhanced coagulation, considering the influent water characteristics under different weather conditions.