Effect of the anionic counterpart: Molybdate vs. tungstate in energy storage for pseudo-capacitor applications

Nickel-based bimetallic oxides (BMOs) have shown significant potential in battery-type electrodes for pseudo-capacitors given their ability to facilitate redox reactions. In this work, two bimetallic oxides, NiMoO4 and NiWO4, were synthesized using a wet chemical route. The structure and electrochemical properties of the pseudo-capacitor cathode materials were characterized. NiMoO4 showed superior charge storage performance in comparison to NiWO4, exhibiting a discharge capacitance of 124 and 77 F·g−1, respectively. NiMoO4, moreover, demonstrates better capacity retention after 1000 cycles with 87.14% compared to 82.22% for NiWO4. The lower electrochemical performance of the latter was identified to result from the redox behavior during cycling. NiWO4 reacts in the alkaline solution and forms a passivation layer composed of WO3 on the electrode, while in contrast, the redox behavior of NiMoO4 is fully reversible

A Metabolomic Approach to the Study of Wine Micro-Oxygenation

Wine micro-oxygenation is a globally used treatment and its effects were studied here by analysing by untargeted LC-MS the wine metabolomic fingerprint. Eight different procedural variations, marked by the addition of oxygen (four levels) and iron (two levels) were applied to Sangiovese wine, before and after malolactic fermentation

Metabolic constituents of grapevine and grape-derived products

The numerous uses of the grapevine fruit, especially for wine and beverages, have made it one of the most important plants worldwide. The phytochemistry of grapevine is rich in a wide range of compounds. Many of them are renowned for their numerous medicinal uses. The production of grapevine metabolites is highly conditioned by many factors like environment or pathogen attack. Some grapevine phytoalexins have gained a great deal of attention due to their antimicrobial activities, being also involved in the induction of resistance in grapevine against those pathogens. Meanwhile grapevine biotechnology is still evolving, thanks to the technological advance of modern science, and biotechnologists are making huge efforts to produce grapevine cultivars of desired characteristics. In this paper, important metabolites from grapevine and grape derived products like wine will be reviewed with their health promoting effects and their role against certain stress factors in grapevine physiology

A Hybrid Electrochemical Energy Storage Device Using Sustainable Electrode Materials

2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim A new electrochemical energy storage device, comprising a faradaic rechargeable pseudo-capacitor type electrode with a non-faradaic rechargeable capacitor electrode, is successfully developed for potential applications in smart electric grids. Mapping new electrodes possessing both high energy and power densities as well as long cycle life is vital for the sustainable energy management. In this work, we present a new approach to design electrodes, fabricated from sustainable resources by hybridizing calcined eggshell capacitor anode with a mixed binary metal oxide pseudo-capacitor cathode. Calcium carbonate (calcite), obtained from the biowaste-derived eggshell, is an effective electrode material and operates via accumulation of ions on the electrode surface, providing a high discharge capacitance of 100 F/g through a non-faradaic process. The calcite present in eggshells is found to be a valuable renewable resource which can be utilized for energy storage through suitable process design. Otherwise, such potentially useful materials (eggshells) are generally discarded as landfill. The mixed binary metallic oxide (NiO/Co3O4) showed a typical pseudocapacitive behaviour associated with both charge transfer reactions and electrostatic means provided a high discharge capacitance of 225 F/g. The fabricated prototype hybrid device provides an energy density 35 Wh/Kg at a power density 420 W/Kg. The charge storage characteristics of the hybrid device depend heavily on the current rate employed. The design and fabrication of new sustainable electrode materials provides an understanding of materials and their electrochemical performance in the high-voltage window

An experimental set up to study the micro-mechanisms of stress corrosion cracking

International audienceAn experimental setup is presented. It aims at studying stress corrosion cracking in a U-notch aluminum alloy sample at a small scale, intermediate between the polycrystal (1mm) and the micro beam (10µm). Digital Image Correlation (DIC) is used to determine the amount of plasticity introduced before crack initiation from the notch tip. The elastic displacement field is also measured by DIC, and numerically calculated, in order to obtain the Stress Intensity Factor (SIF) during crack propagation. The plasticity introduced, at the load level necessary for obtaining initiation, is negligible. It is less than 0.5% at the tip of the notch and less than 0.2% for the rest of the sample. First stress corrosion cracking results show that the SIF values during crack propagation are in between 4 and 6 MPa √ m, being consistent with a SCC intergranular brittle fracture according to the literature. The intergranular nature of the crack is confirmed by a SEM observation of the final fracture surface.Un montage expérimental est présenté. Il est conçu pour l'étude de la fissuration par corrosion sous contrainte, à petite échelle, à partir de micro entailles. Les échantillons ont une taille intermédiaire entre les éprouvettes polycristallines classiques (quelques mm) et les micro-poutres (10 µm). La technique de "corrélation d'images numériques" (CIN) est utilisée pour quantifier la déformation plastique induite par le chargement mécanique nécessaire à l'amorçage de la fissuration depuis le fond d'entaille. Les champs de déplacement élastiques sont aussi mesurés et calculés par "éléments finis" pour obtenir le facteur d'intensité des contraintes (K). La plasticité introduite par le chargement mécanique initial est faible: moins de 0.5% à la pointe de l'entaille, et moins de 0.2% dans le reste de l'échantillon. Les premiers essais de fissuration donnent des valeurs de K entre 4 et 6 MPa √ m, en accord avec la littéra-ture. La nature intergranulaire de la fissuration est confirmée par des observations en microscopie à balayage de faciès de rupture.

Histone deacetylase 3 is required for centromeric H3K4 deacetylation and sister chromatid cohesion.

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Combination of several mass spectrometry ionization modes: A multiblock analysis for a rapid characterization of the red wine polyphenolic composition

cited By 11International audienceIn the present study, direct flow injection mass spectrometry was investigated for rapid characterization of the polyphenolic composition of red wines. Atmospheric pressure chemical ionization (APCI) and electrospray ionization (ESI) (in both positive and negative ion modes) have been simultaneously used for a more comprehensive analysis of the samples studied. In this way, four mass spectra have been recorded for each wine. Each spectrum was considered as a fingerprint related to the chemical composition. This methodology was applied to a large number of Beaujolais wines from different grades and different vintages.This data set was processed using a chemometrical multiblock analysis, which allowed to synthesize the whole information collected. The results obtained showed that the wine fingerprints address the composition of the main polyphenolic compounds present in the red wines and can discriminate groups of wines showing different polyphenolic compositions. Multiblock analysis appears as a very promising tool to deal with several data tables of multivariate signals in order to define, by combining the whole information, the best operating protocol according to the desired analytical objectives. © 2010 Elsevier B.V

New compounds obtained by evolution and oxidation of malvidin 3-O-glucoside in ethanolic medium

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