1,721,003 research outputs found
HYDROSOLUBLE COMPOSITIONS OF STABILIZED COLLAGENASE AND THE PROCESS FOR THEIR PREPARATION
No full textA High-Frequency (95 GHz) Electron Paramagnetic Resonance Study of B-doped TiO2 photocatalysts
No full textA high-field and high-frequency (HF, 95 GHz) electron paramagnetic resonance (EPR) study has been carried on B-doped TiO2. Several paramagnetic species are observed both in the dark and under UV irradiation which are resolved employing the high resolution of HFEPR. The behaviour of the EPR signals may be interpreted in terms of a sensitization of the B-doped TiO2 to visible light. A paramagnetic species interacting with a B atom is found. The Hamiltonian parameters of this species carry important information on its electronic structure. The analysis of the hyperfine values reveals that the spin density is mainly centred on the B and asymmetrically distributed in two p B orbitals. Insights into the B local structure in the semiconductor are gained
Surface Phases and Photocatalytic Activity Correlation of Bi2O3/Bi2O4-x Nanocomposite
No full textUV-visible radiations were used to induce surface modifications in Bi2O3 leading to the formation of Bi2O3/Bi2O4-x nanocomposite. Despite the complexity of the degradation mechanisms, which depend on the nature of the pollutants, our results indicate that Bi2O3/Bi2O4-x-based materials are very promising as photocatalysts
A convenient chemoenzymatic synthesis of (R)-(-) and (S)-(+)-homo-beta-proline
No full textBoth enantiomers of the heterocyclic GABA analogue homo-b-proline (3-pyrrolidineacetic acid) were synthesized by a chemoenzymatic method involving the use of two enantiocomplementary enzymes in the disymmetric hydrolyses of 3-nitromethylglutaric acid diethyl este
Heavy metal salts of succinic acid hemiesters with hyaluronic acid or hyaluronic acid esters, a process for their preparation and relative pharmaceutical compositions
No full textPhotocatalytic decolourization of dyes on NiO–ZnO nano-composites
No full textNiO–ZnO nanocomposite photocatalysts were synthesized by co-precipitation/co-gel formation techniques using potassium hydroxide (KOH), sodium carbonate (Na2CO3) and oxalic acid (H2C2O4) as precipitating agents. X-Ray diffraction (XRD) analysis was employed for the determination of crystallite size and phase purity, while BET surface areas were estimated by nitrogen physisorption analysis. The photocatalytic activities of the NiO–ZnO nanocomposites, evaluated using the photo-decolourization of two structurally different dyes, methyl orange and methylene blue, were correlated with the variation in the crystallite size of the constituents of the composites. All the three synthesized nanocomposites showed appreciable activity for the decolourization of dyes. NiO–ZnO nanocomposite derived by KOH exhibited maximum activity for the decolourization of both the dyes and the decolourization rate of methylene blue was found to be comparable with that of Degussa P-25 TiO2. Finally, the activity of the most active NiO–ZnO composite with relatively large crystallite sizes was compared with the pure components and their physical mixture, synthesized by the identical synthetic route, in the same molar ratio as that of nanocomposite
A short and convenient chemoenzymatic synthesis of both enantiomers of 3-phenylGABA and 3-(4-chlorophenyl)GABA (Baclofen)
No full textBoth enantiomers of the pharmacologically active GABA analogues 4-amino-3-phenyl and 4-amino-3-(4-chlorophenyl) butyric acid (Baclofen) with high enantiomeric excesses were synthesized by a chemoenzymatic method involving a-chymotrypsin mediated kinetic resolutions of the corresponding 3-phenyl- and 3-(4-chlorophenyl)-4-nitrobutyric acid methyl ester precursor
Stabilized metal nanoparticles embedded into porous oxides: a challenging approach for robust catalysts
No full textStabilized metal nanoparticles embedded into porous oxides: a challenging approach for robust catalyst
CVD Co3O4 nanopyramids: a nano-platform for the photo-assisted H2 production
No full textSpinel-type Co3O4 nanopyramids grown by CVD starting from Co(hfa)2•TMEDA display attractive features for hydrogen production by photo-reforming of methanol solutions, especially in the presence of oxygen in the reaction medium. To the best of our knowledge, this is the first example of photo-activated H2 generation by means of supported cobalt oxide nanosystems
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