Search results for "CATA"
showing 10 items of 13753 documents
La mediación intralingüística : propuestas didácticas
2020
Resumen: Los principales objetivos de este artículo son definir el concepto demediación intralingüística y presentar propuestas didácticas para practicar y/o evaluaresta actividad de lengua en los niveles B1, B2 y C1. Nuestro trabajo se enmarca en elcontexto de las Escuelas Oficiales de Idiomas de Cataluña. La publicación de los RealesDecretos 1041/2017 y 1/2019 impuso a las EEOOII evaluar la mediación lingüística.Como asesoras técnicas coordinadoras de las pruebas de certificación en las EEOOIIcatalanas, llevamos a cabo una investigación para definir el concepto de mediación,desarrollar los currículos, determinar las características de las tareas de mediaciónintralingüística y elaborar cri…
Ternary transition metals sulfides in hydrotreating catalysis.
2007
International audience; Pure microcrystalline barium molybdate BaMoO4 and barium tungstate BaWO4 materials were prepared by molten flux reaction using alkali metal nitrates as reaction media. The obtained crystals have rhombic shape and expose mostly (111) crystallographic planes. Their mean size depends on the flux temperature and the nature of the alkali metal cation. Monomeric molybdate and tungstate used as precursors yield target products already at 673 K whereas if polymerized ammonium oxosalts were used, then higher temperatures were necessary to obtain barium salts. The optimal temperature for the preparation of pure crystals with well defined shape was found to be near 773 K. UV–vi…
Photocatalytic and Catalytic Oxidation of 2-Propanol over Au/TiO2-CeO2 Catalysts
2016
Photocatalytic and catalytic oxidation of 2-propanol (representative VOC’s compound) were compared over mixed (Au)TiO2-CeO2-based catalysts. The role of support in Au catalyzed oxidation reaction under photo and dark conditions was studied. In the photocatalytic oxidation CeO2 had a negative effect on the performance towards the alcohol conversion of both TiO2-CeO2 and Au/TiO2-CeO2 catalysts, being Au/TiO2 the most active system. On the contrary mixed TiO2-CeO2 and Au/TiO2- CeO2 samples showed a higher catalytic oxidation efficiency for 2-propanol conversion compared to the single oxides.
Colloquium: Nonequilibrium effects in superconductors with a spin-splitting field
2018
This Colloquium discusses the recent progress in understanding the properties of spin-split superconductors under nonequilibrium conditions. Recent experiments and theories demonstrate a rich variety of transport phenomena occurring in devices based on such materials that suggest direct applications in thermoelectricity, low-dissipative spintronics, radiation detection, and sensing. This text discusses different experimental situations and presents a theoretical framework based on quantum kinetic equations. This framework provides an accurate description of the nonequilibrium distribution of charge, spin, and energy, which are the relevant nonequilibrium modes, in different hybrid structure…
Superparamagnetic recoverable flowerlike Fe3O4@Bi2O3 core–shell with g-C3N4 sheet nanocomposite: synthesis, characterization, mechanism and kinetic s…
2019
In the present research study, a simple method was developed for the synthesis of three-dimensional flowerlike Fe3O4@Bi2O3 core–shell with g-C3N4 sheet nanocomposites. The X-ray diffraction, Fourier transform infrared spectroscopy, scanning electronic microscopy, transmission electron microscope, vibrating sample magnetometer, dynamic laser scattering analyzer and UV–Vis diffuse reflection spectroscopy were employed for the characterization of structure, purity and morphology of the resultant samples. The degradation of indigo carmine as a model of organic dye pollutant is applied for photo-catalytic activity. The parameters which are affecting the efficiency of various parameters, such as;…
Production of Nano-Sized Co<sub>3</sub>O<sub>4</sub> by Pyrolysis of Organic Extracts
2016
The most promising application field of materials based on nano-sized Co3O4 is catalysis. The method of production is one of the factors, which greatly affects the catalytic activity of Co3O4 catalysts. The aim of this research is to study possibilities of a new promising extractive-pyrolytic method (EPM) for the production of Co3O4 nanopowders and silica- and ceria-supported Co3O4 nanocomposites. Solutions of cobalt hexanoate in hexanoic acid and trioctylammonium tetrachlorocobaltate in toluene preliminary produced by solvent extraction were used as precursors. The precursors’ thermal stability, phase composition, morphology and the magnetic properties of the final products of pyrolysis we…
Luminescence of F2 and F3 + centres in LiF crystals irradiated with 12 MeV 12C ions
2018
Dependences of the nanohardness and photoluminescence of F 2 and F 3 + centers on the depth in LiF crystals irradiated with 12 MeV 12 C ions to fluences 10 10 -10 15 ions/cm 2 were studied using laser scanning confocal microscopy, luminescent spectroscopy, and the nanoindentation method. The nanohardness measurements showed a significant hardening effect at the end of the ion run with the dominant contribution of defects formed by the mechanism of elastic collisions. The observed attenuation of the luminescence intensity at high fluences is associated with the intense nucleation of dislocations as traps for aggregate color centers.
Synthesis of ZnO–Ag2CO3–Fe3O4@rGO core–shell structure: magnetically separable photocatalyst for degradation of MB using the Box–Behnken design
2020
In this work, a simple microwave method was utilized to prepare ZnO sheet linked with Fe3O4@rGO core–shell and of Ag2CO3 through formation of the quadri-photocatalytic with high activity. The microstructure, morphology, spectroscopic, and magnetic characteristics of the prepared samples were assessed using XRD, SEM, PL, TEM, FT-IR, DLS, and VSM analysis. The photocatalytic activity of the material was evaluated for photodegradation of methylene blue dye under the UV and visible light with home-made photoreactor. The response surface method in a Box–Behnken design was utilized to design the experiments. The parameters affecting the efficiency of the degradation including, pH (5–9), photocata…
Rhodamine (B) photocatalysis under solar light on high crystalline ZnO films grown by home-made DC sputtering
2018
Abstract ZnO thin films were deposited by home-made DC sputtering of zinc target under mixed gases (Argon, Oxygen) plasma on glass substrates. Films were deposited by varying oxygen partial pressure (PO2) from 0.09 to 1.3 mbar in the deposition chamber, at a fixed substrate temperature of 100 °C. The samples were characterized by photoluminescence (PL), X-ray diffraction (XRD), optical transmissions (UV–vis), scanning electron microscopy (SEM) and electrical (Hall effect) measurements. The results indicate that by varying the oxygen pressure in the deposition chamber, the films show a precise and well defined photoluminescence emissions for each range of pressure covering almost the entire …