uFREASI: user-FRiendly Elemental dAta procesSIng. A free and easy-to-use tool for elemental data treatment

Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) allows the quantification of trace and ultra-trace elements (mg/kg to fg/kg) by separating elements as a function of their massto-charge ratios (m/z) after ionisation into an argon plasma. In spite of being rigorous and accurate, the "Results" modules provided by many manufacturers are often uneasy to use and operators have little control on the calculation. Moreover, the large amount of raw data generated makes the manual treatment very long and not reliable using a "home-made" spreadsheet. The user-FRiendly Elemental dAta procesSIng (uFREASI) software presented in this paper follows a configurable step-by-step procedure allowing a quick and reliable data treatment plus an automatic uncertainty propagation. The concentration calculation is performed using the ordinary least square method after an external calibration. The software proposes many options to correct and to monitor the signal, to warrant both quality and understanding of data treatment. uFREASI is supported by Windows, Mac OS X and Linux 2 operating system, is open and extensible, and is freely downloadable at http://www.ipgp.fr/~tharaud/uFREASI

High resolution NMR unraveling Cu substitution of Mg in hydrotalcitesethanol reactivity

cited By 1International audienc

Highly productive iron molybdate mixed oxides and their relevant catalytic properties for direct synthesis of <i>1,1</i>-dimethoxymethane from methanol

The one-step gas phase conversion of methanol to 1,1-dimethoxymethane (DMM) was studied over highly productive iron molybdate mixed oxides in a fixed-bed reactor working at atmospheric pressure. When placing the Fe-Mo-O catalyst under a reaction mixture highly concentrated in methanol, the DMM selectivity was drastically boosted. This specific and unique feature encouraged us to extensively characterize this family of particular catalysts. LEIS analysis revealed the presence of both Mo and Fe species on the outermost atomic layer of the catalysts. X-ray photoelectron spectroscopy (XPS) and in situ EPR measurements showed that the Fe centres are responsible for the redox properties. The acidic properties of the FeMo mixed oxides were then attributed to anionic vacancies acting as Lewis acid sites produced by dehydroxylation of the catalyst surface. XPS analysis also showed that oxygen from the gas phase was responsible for reoxidation of the catalyst surface with regeneration of the active sites, which suggests a Mars-van Krevelen mechanism. The good catalytic performances were then attributed to a synergistic effect between Mo and Fe species. A Mo/Fe molar ratio of 3.2 for an optimal remarkable yield in DMM of 50% was found

Presentation and evaluation of the IPSL-CM6A-LR climate model

This study presents the global climate model IPSL-CM6A-LR developed at Institut Pierre-Simon Laplace (IPSL) to study natural climate variability and climate response to natural and anthropogenic forcings as part of the sixth phase of the Coupled Model Intercomparison Project (CMIP6). This article describes the different model components, their coupling, and the simulated climate in comparison to previous model versions. We focus here on the representation of the physical climate along with the main characteristics of the global carbon cycle. The model's climatology, as assessed from a range of metrics (related in particular to radiation, temperature, precipitation, and wind), is strongly improved in comparison to previous model versions. Although they are reduced, a number of known biases and shortcomings (e.g., double Intertropical Convergence Zone [ITCZ], frequency of midlatitude wintertime blockings, and El Nino-Southern Oscillation [ENSO] dynamics) persist. The equilibrium climate sensitivity and transient climate response have both increased from the previous climate model IPSL-CM5A-LR used in CMIP5. A large ensemble of more than 30 members for the historical period (1850-2018) and a smaller ensemble for a range of emissions scenarios (until 2100 and 2300) are also presented and discussed