97 research outputs found
Remarkable hydrogen storage properties of MgH2 doped with VNbO5
The present work concerns the catalytic effect of VNbO5, a ternary oxide prepared via a solid-state
route, on the sorption performance of MgH2. Three doped systems, namely 5, 10 and 15 wt% VNbO5–
MgH2 have been prepared by ball milling and thoroughly characterized. Hydrogen sorption, evaluated by
temperature programmed desorption experiments, revealed a significant reduction of the desorption
temperature from 330 1C for the un-doped sample (prepared and tested for comparison) to 235 1C for
the VNbO5-doped sample. Furthermore, more than 5 wt% of hydrogen can be absorbed in 5 minutes at
160 1C under 20 bar of hydrogen, which is remarkable compared to the 0.7 wt% achieved for the
un-doped system. The sample doped with 15 wt% of additive, showed good reversibility: over 5 wt% of
hydrogen with negligible degradation even after 70 consecutive cycles at 275 1C and 50 cycles at
300 1C. The kinetics analysis carried out by Kissinger’s method exhibited a considerable reduction of the
activation energy for the desorption process. Finally, pressure-composition-isotherm experiments
conducted at three different temperatures allowed estimating the thermodynamic stability of the system
and shed light on the additive role of VNbO5
Can Artificial Ecosystems Enhance Local Biodiversity? The Case of a Constructed Wetland in a Mediterranean Urban Context
Constructed wetlands (CW) are considered a successful tool to treat wastewater in many countries: their success is mainly assessed observing the rate of pollution reduction, but CW can also contribute to the conservation of ecosystem services. Among the many ecosystem services provided, the biodiversity of CW has received less attention. The EcoSistema Filtro (ESF) of the Molentargius-Saline Regional Natural Park is a constructed wetland situated in Sardinia (Italy), built to filter treated wastewater, increase habitat diversity, and enhance local biodiversity. A floristic survey has been carried out yearly 1 year after the construction of the artificial ecosystem in 2004, observing the modification of the vascular flora composition in time. The flora of the ESF accounted for 54 % of the whole Regional Park’s flora; alien species amount to 12 %; taxa of conservation concern are 6 %. Comparing the data in the years, except for the biennium 2006/2007, we observed a continuous increase of species richness, together with an increase of endemics, species of conservation concern, and alien species too. Once the endemics appeared, they remained part of the flora, showing a good persistence in the artificial wetland. Included in a natural park, but trapped in a sprawling and fast growing urban context, this artificial ecosystem provides multiple uses, by preserving and enhancing biodiversity. This is particularly relevant considering that biodiversity can act as a driver of sustainable development in urban areas where most of the world’s population lives and comes into direct contact with nature
Bentonite as a refining agent in waste cooking oils recycling: flash point, density and color evaluation
Clarification of waste recycled cooking oil (WCO) is very important in order to refine the intermediate regenerated base resulting from the previous steps. Bentonite has been historically employed as a filling material for oil refining filters due to its easy availability and its cheap price. In the present communication our early results from the filtration of degummed WCO through a pad of bentonite are presented. In particular, the variation of density, flash point and color have been monitored prior and after the filtration process and compared with samples of non-filtered WCO. An early classification of the bentonite employed has been conducted on the basis of FT-IR and XRD measurements
CO2 Hydrogenation Induced by Mechanochemical Activation of Olivine With Water Under CO2 Atmosphere
A study on the mechanochemical activation of the olivine in presence of H2O and under CO2 atmosphere have been approached, focusing both on the structural nature of the transformation and the conversion of CO2 to methane and light hydrocarbons. The mechanochemical process was carried out by high energy laboratory mills, with milling vials properly modified in order to be used as batch reactors. Chemical reactivity and reaction rates were investigated under different experimental conditions, evidencing increased performance with respect to the thermally activated process reported in literature. Mechanical treatment induced H2O and olivine activation, with consequent release of molecular H2 which, in turn, allowed hydrogenation of activated CO2. This last reaction also led, through a competitive process, to the precipitation of carbonate phases, whose composition and structural features were dependent of the CO2/H2O ratio.Fil: Farina, Valeria. Università Degli Studi Di Sassari; ItaliaFil: Gamba, Nadia Soledad. Comisión Nacional de Energía Atómica. Gerencia de Área de Aplicaciones de la Tecnología Nuclear. Gerencia de Investigación Aplicada; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología - Nodo Bariloche | Comisión Nacional de Energía Atómica. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología - Nodo Bariloche; ArgentinaFil: Gennari, Fabiana Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Gerencia de Área de Aplicaciones de la Tecnología Nuclear. Gerencia de Investigación Aplicada; ArgentinaFil: Garroni, Sebastiano. Università Degli Studi Di Sassari; ItaliaFil: Torre, Francesco. Università Degli Studi Di Cagliari; ItaliaFil: Taras, Alessandro. Università Degli Studi Di Sassari; ItaliaFil: Enzo, Stefano. Università Degli Studi Di Sassari; ItaliaFil: Mulas, Gabriele. Università Degli Studi Di Sassari; Itali
Kinetics and hydrogen storage performance of Li-Mg-N-H systems doped with Al and AlCl3
Recent investigations showed the formation of new amide-chloride phases between LiNH2 and AlCl3 after milling and/or heating under hydrogen pressure. These phases exhibited a key role in the improvement of the hydrogen storage properties of the LiNH2-LiH composite. In the present work, we studied the effects of Al and AlCl3 additives on the hydrogen storage behavior of the Li-Mg-N-H system. The dehydrogenation kinetics and the reaction pathway of Al and AlCl3 modified LiNH2-MgH2 composite were investigated through a combination of kinetic measurements and structural analyses. During the first cycle, the addition of Al catalytically accelerates the hydrogen release at 200 °C. In the subsequent cycles, the formation of a new phase of unknown nature is probably responsible for both increased equilibrium hydrogen pressure and decreased dehydrogenation rate. In contrast, AlCl3 additive reacts with LiNH2-MgH2 through the milling and continues during heating under hydrogen pressure. Addition of AlCl3 leads to the formation of two cubic structures identified in the Li-Al-N-H-Cl system, which improves dehydrogenation rate by modifying the thermodynamic stability of the material. This study evidences positive effect of cation and/or anion substitution on hydrogen storage properties of the Li-Mg-N-H system.This study has been partially supported by bilateral collaboration Project MINCyT-MA
Estudio de plomo isotópico del lingote depositado en el Museo Minero de Riotinto hallado en Masa Planes (Minas de Riotinto, Huelva - España)
Lead was a necessary element for Roman
metallurgical work, so being able to determine its
origin is very important to know the commercial
circuits of commodities in the Roman world. On
February 27th, 2015, a Roman lead ingot was
found in Planes Lode (Riotinto Mines, Huelva,
Spain), within the area of the Riotinto Project led
by Atalaya Mining, we take the opportunity to
thank this Company for supporting this Project.
It`s the first lead ingot found in Riotinto with a
known locationEl plomo fue un elemento necesario para los
trabajos metalúrgicos romanos, por lo que poder
determinar su origen es muy importante para
conocer los circuitos comerciales de las materias
primas en el mundo romano. El 27 de febrero de
2015 se encontró un lingote romano de plomo en
Masa Planes (Minas de Riotinto, Huelva-España),
dentro del área del Proyecto Riotinto liderado por
Atalaya Mining, aprovechamos para agradecer a
esta compañía el apoyo para este proyecto. Siendo
el primer lingote de plomo hallado en Riotinto con
una ubicación conocid
Mesoporous Titania powders: the role of precursors, ligand addition and calcination rate on their morphology, crystalline structure and photocatalytic activity
We evaluate the influence of the use of different titania precursors, calcination rate, and ligand addition on the morphology, texture and phase content of synthesized mesoporous titania samples, parameters which, in turn, can play a key role in titania photocatalytic performances. The powders, obtained through the evaporation-induced self-assembly method, are characterized by means of ex situ X-Ray Powder Diffraction (XRPD) measurements, N2 physisorption isotherms and transmission electron microscopy. The precursors are selected basing on two different approaches: the acid-base pair, using TiCl4 and Ti(OBu)4, and a more classic route with Ti(OiPr)4 and HCl. For both precursors, different specimens were prepared by resorting to different calcination rates and with and without the addition of acetylacetone, that creates coordinated species with lower hydrolysis rates, and with different calcination rates. Each sample was employed as photoanode and tested in the water splitting reaction by recording I-V curves and comparing the results with commercial P25 powders. The complex data framework suggests that a narrow pore size distribution, due to the use of acetylacetone, plays a major role in the photoactivity, leading to a current density value higher than that of P25
Cardiovascular toxicity in patients with chronic myeloid leukemia treated with second-generation tyrosine kinase inhibitors in the real-life practice: Identification of risk factors and the role of prophylaxis
No abstract availabl
Low low-density lipoprotein (LDL), cholesterol and triglycerides plasma levels are associated with reduced risk of arterial occlusive events in chronic myeloid leukemia patients treated with ponatinib in the real-life. A Campus CML study
not available (letter
Variants within the immunoregulatory CBLB gene are associated with multiple sclerosis
A genome wide association scan of ~6.6 million genotyped or imputed variants in 882 Sardinian Multiple Sclerosis (MS) cases and 872 controls suggested association of CBLB gene variants with disease, which was confirmed in 1,775 cases and 2,005 controls (overall P =1.60 × 10-10). CBLB encodes a negative regulator of adaptive immune responses and mice lacking the orthologue are prone to experimental autoimmune encephalomyelitis, the animal model of MS
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