Search results for "O2"

Selective aqueous oxidation of aromatic alcohols under solar light in the presence of TiO2 modified with different metal species

2022

AbstractA set of metals modified TiO2 photocatalysts were prepared starting from titanium tetraisopropoxyde and different metal precursors to study the influence of the addition of the various foreign agents on the physico-chemical and photocatalytic properties of the catalysts. The powders were characterized by X-ray diffraction, Raman spectroscopy, specific surface area measurements, scanning electron microscopy, energy dispersive X-ray spectroscopy, UV–Vis diffuse reflectance spectroscopy, photoluminescence, temperature programmed desorption after CO2 adsorption. The photocatalytic activity was evaluated using as probe reactions the partial oxidation of three aromatic alcohols: benzyl al…

Sintesi e caratterizzazione di polveri e film di TiO2

2006

2D Slab Models of Nanotubes Based on Tetragonal TiO2 Structures: Validation over a Diameter Range

2021

This research was funded by the M-ERA.NET project ?Multiscale computer modelling, synthesis and rational design of photo(electro)catalysts for efficient visible-light-driven seawater splitting? (CatWatSplit). Institute of Solid State Physics, University of Latvia as the Center of Excel-lence has received funding from the European Union?s Horizon 2020 Framework Program H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under Grant Agreement No. 739508, project CAMART2.

Selective oxidative dehydrogenation of ethane over SnO2-promoted NiO catalysts

2012

[EN] Ni-Sn-O mixed oxides catalysts have been investigated for the oxidative dehydrogenation of ethane. The catalysts were prepared through the evaporation of aqueous solutions of nickel nitrate and tin oxalate and finally calcined in air at 500 degrees C for 2 h. These materials have been characterized by several techniques (N-2-adsorption, X-ray diffraction, High-Resolution Electron Microscopy, temperature programmed reduction, X-Ray Photoelectron Spectroscopy, Fourier Transformed Infrared Spectroscopy of adsorbed CO and O-18/O-16 isotope exchange). The addition of just a tiny amount of tin highly increases the selectivity to ethylene (from ca. 40% to 80-90%). Thus, high selectivity to et…

Modification of the Selectivity Properties of Tubular Ceramic Membranes after Alkaline Treatment

2017

International audience; This work focuses on the selectivity modification of ceramic membranes after a mild alkaline treatment. Filtration of pure saltwater solutions was carried out with commercial titania membranes before and after the treatment. After treatment, the rejection of NaF significantly decreased, while the rejection of NaCl and NaBr increased. Additionally, NaI and Na 2 SO 4 remained close to zero. Pore size and electrical charge being almost unchanged, only significant modifications in the dielectric effects can explain this modification of selectivity. Therefore, the surface chemistry and the interaction (nature and magnitude) with the solvent and with the species present in…

Andamento stagionale del flusso di emissione di CO2 dal suolo in risposta al contenuto di umidità all'interno di un agroecosistema mediterraneo

2014

Total soil respiration as the sum of two biotic component, autotrophic and heterotrophic respiration, is influenced by various environmental factor, in particular soil temperature and soil moisture. In arid and semi arid regions, soil moisture is a major driver of soil respiration during periods of drought stress. Hence, the aim of this work was to evaluate the effect of soil moisture on soil CO2 efflux. Measurements were made every two weeks between January 2008 and June 2010 using a portable soil respiration instrument fitted with a soil respiration chamber (IRGA) CIRAS 1 (PP Systems, Hitchin, UK).The Simultaneously with soil respiration measurements, soil temperature (T) and soil volumetri…

State selective electron injection in non-aggregated titanium phthalocyanine sensitised nanocrystalline TiO2 films

2004

We describe a novel titanium phthalocyanine that shows no aggregation when anchored to nanocrystalline TiO2 films through its axial carboxylated ligand without the use of co-adsorbents; state selective electron injection into the TiO2 is demonstrated, resulting in efficient photocurrent generation in dye sensitised photoelectrochemical solar cells. Palomares Gil, Emilio J, epagil@alumni.uv.es

Chromatographic Air Analyzer Microsystem for the Selective and Sensitive Detection of Explosive-related Compounds

2014

Abstract The detection of explosives and explosive-related compounds is of major importance for the monitoring of explosive- contaminated sites. Current methods need to become cheaper and portable while maintaining a high sensitivity and selectivity level. In that sense, a silicon micro-analytical platform consisting of a three-dimensional micro-preconcentrator based on a hydrophobic zeolite, coupled to a silicon spiral micro-column was built. A chemical gas sensor acted as a miniaturized gas detector. This system allowed selective detection of orthonitrotoluene (ONT), an explosive-related compound at the sub-ppm level in the presence of toluene and moisture.

Use of supercritical CO2 and N2 as dissolved gases for the atomization of ethanol and water

2012

Supercritical dissolved gas atomization (SDGA) is an atomization process in which a gas at temperatures and pressures above the critical point is used as the atomizing medium. The concept of SDGA has been applied mainly using CO 2 as atomizing gas in various processes developed for the production of fine particles of pharmaceuticals, polymers, and chemical products and for the atomization of fuels. In this work, SDGA, using ethanol and water as the liquids to be atomized, has been experimentally studied. The spray characteristics, in terms of droplet size and distribution, have been investigated using a laser diffraction analyzer. Ethanol has been chosen due to the large miscibility with CO…

Effects of ocean acidification on embryonic respiration and development of a temperate wrasse living along a natural CO2 gradient

2016

Volcanic CO2 seeps provide opportunities to investigate the effects of ocean acidification on organisms in the wild. To understand the influence of increasing CO2 concentrations on the metabolic rate (oxygen consumption) and the development of ocellated wrasse early life stages, we ran two field experiments, collecting embryos from nesting sites with different partial pressures of CO2 [pCO2; ambient (400 µatm) and high (800-1000 µatm)] and reciprocally transplanting embryos from ambient- to high-CO2 sites for 30 h. Ocellated wrasse offspring brooded in different CO2 conditions had similar responses, but after transplanting portions of nests to the high-CO2 site, embryos from parents that sp…