194 research outputs found

    El Modelo HIRLAM de predicción del INM

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    α-Titanium phosphate intercalated with propylamine: An alternative pathway for efficient europium(III) uptake into layered tetravalent metal phosphates

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    Abstractα-Ti(HPO4)2·H2O (α-TiP) and its propylamine intercalation product, Ti(HPO4)2·2C3H7NH2·H2O (α-TiPPr), have been synthesized and characterized. Later, their sorption capacity for europium(III) was investigated, and this purpose was accomplished by treating α-TiP and α-TiPPr with europium(III) nitrate solutions at different concentrations until the equilibrium is reached. All samples were characterized, among others, by powder X-ray diffraction (PXRD), scanning and transmission electron microscopies (SEM, TEM, STEM-EDX, SAED), thermogravimetric analysis (TGA), and photoluminescence (PL) measurements. The results show that the Eu3+ uptake is limited to surface when α-TiP is used as sorbent. Nevertheless, the Eu-retention is considerably enhanced with α-TiPPr as a consequence of an ion-exchange process into the interlayer space of the layered titanium phosphate (involving propylammonium cations, C3H7NH3+, and hexahydrate europium(III) species, [Eu(H2O)6]3+), and the crystal structure of a hypothetical final product, α-[Eu(H2O)6]2/3Ti(PO4)2·[(H2O)6]1/3, has been proposed by using DFT calculations

    Genetic fuzzy schedules for charging electric vehicles

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    This work tackles the problem of scheduling the charging of electric vehicles in a real-world charging station subject to a set of physical constraints, with the goal of minimising the total tardiness with respect to a desired departure date given for each vehicle. We model a variant of the problem that incorporates uncertainty in the charging times using fuzzy numbers. As solving method, we propose a genetic algorithm with tailor-made operators, in particular, a new chromosome evaluation method based on generating schedules from a priority vector. Finally, an experimental study avails the proposed genetic algorithm both in terms of algorithm convergence and quality of the obtained solutions.Acknowledgements. This work was supported by the Spanish Government [Grant Nos.TIN2016-79190-R, MTM2014-55262-P]

    OWL-POLAR : semantic policies for agent reasoning

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    The original publication is available at www.springerlink.comPostprin

    Green and blue materials for the ceramic industry from pink MgCoxNi1-xSiO4 (0 ≤ x ≤ 1) solid solutions

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    In this study, MgCoxNi1-xSiO4 (0.0 ≤ x ≤ 1.0) solid solutions with an olivine structure were synthetized via the chemical coprecipitation method and materials with a smaller M(II) (M = Co, Ni) amount than Co2SiO4 and Ni2SiO4 compounds were obtained. At 1200 °C, the Co(II) and Ni(II) were randomly distributed in the MgCoxNi1-xSiO4 (0.0 ≤ x ≤ 1.0) solid solutions with the olivine structure, but the occupation of Co(II) and Ni(II) ions in M1 (4a) octahedral sites was obtained at a higher level than in M2 (4c) octahedral sites. The Mg(II) ions prefer the M2 sites. This preference explains the main contribution of the M1 sites in spectra of octahedral Co(II) ions and the M1-O and M2-O distances jointly explain the pink colour of the MgCoxNi1-xSiO4 (0.0 ≤ x ≤ 1.0) solid solutions, while the colour of Co2SiO4 is blue. Spectra can be interpreted as the sum of Ni(II) and Co(II) ions in octahedral sites. When these solid solutions are enamelled, the pink colouring changes to green or blue because of the presence of tetrahedral Co(II).Funding for open access charge: CRUE-Universitat Jaume

    Morphine leads to global genome changes in H3K27me3 levels via a Polycomb Repressive Complex 2 (PRC2) self-regulatory mechanism in mESCs

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    Background: Environmentally induced epigenetic changes can lead to health problems or disease, but the mechanisms involved remain unclear. Morphine can pass through the placental barrier leading to abnormal embryo development. However, the mechanism by which morphine causes these effects and how they sometimes persist into adulthood is not well known. To unravel the morphine-induced chromatin alterations involved in aberrant embryo development, we explored the role of the H3K27me3/PRC2 repressive complex in gene expression and its transmission across cellular generations in response to morphine. Results: Using mouse embryonic stem cells as a model system, we found that chronic morphine treatment induces a global downregulation of the histone modification H3K27me3. Conversely, ChIP-Seq showed a remarkable increase in H3K27me3 levels at specific genomic sites, particularly promoters, disrupting selective target genes related to embryo development, cell cycle and metabolism. Through a self-regulatory mechanism, morphine downregulated the transcription of PRC2 components responsible for H3K27me3 by enriching high H3K27me3 levels at the promoter region. Downregulation of PRC2 components persisted for at least 48 h (4 cell cycles) following morphine removal, though promoter H3K27me3 levels returned to control levels. Conclusions: Morphine induces targeting of the PRC2 complex to selected promoters, including those of PRC2 components, leading to characteristic changes in gene expression and a global reduction in H3K27me3. Following morphine removal, enhanced promoter H3K27me3 levels revert to normal sooner than global H3K27me3 or PRC2 component transcript levels. We suggest that H3K27me3 is involved in initiating morphine-induced changes in gene expression, but not in their maintenance.This study was supported by grants from the Spanish Health Department ISCIII (DTS 18/00142) and University of the Basque Country. IM was supported by fellowship from Basque Government, and MA and IU were supported by fellowship from the University of the Basque Country (UPV/EHU)

    A review of undulated sediment features on Mediterranean prodeltas: distinguishing sediment transport structures from sediment deformation

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    Most Mediterranean prodeltas show undulated sediment features on the foresets of their Holocene wedges. These features have been described all along the Mediterranean for the last 30 years and interpreted as either soft sediment deformation and incipient landsliding, and more recently, as sediment transport structures. We perform a review and detailed analysis of these undulated sediment features using ultrahigh-resolution seismic and bathymetric data as well as geotechnical information and hydrodynamic time series and hydrographic transects. In this study we show that the characteristics of the sediment undulations (configuration of the reflections down section and between adjacent undulations and overall morphologic characteristics) are incompatible with a genesis by sediment deformation alone and do not show evidence of sediment deformation in most cases. Various processes in the benthic boundary layer can be invoked to explain the variety of features observed in the numerous areas displaying sediment undulations

    Structural and Proton Conductivity Studies of Fibrous π-Ti2O(PO4)2·2H2O: Application in Chitosan- Based Composite Membranes

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    Although the fibrous polymorphic modification of titanium phosphate, π-Ti2O(PO4)2·2H2O (π-TiP) is known for decades, its crystal structure has remained unsolved. Herewith we report the crystal structure of π-TiP at a room temperature, determined from the synchrotron radiation powder X-ray diffraction, and corroborated by 31P solid state NMR and the accurate density functional theory calculations. In contrast to the previously reported ρ-TiP polymorph, the as-synthesized hydrated phase crystallizes in the monoclinic system (P21/c, a = 5.1121(2) Å, b = 14.4921(9) Å, c = 12.0450(11), β = 115.31(1)°, Z=4) and is composed of corner-sharing titanium octahedra and phosphate units arranged in a pattern distinct of ρ-TiP polymorph. The unit cell was confirmed by SAED, while the formation of planar packing imperfections and stacking faults along the [101] was revealed by HRTEM analysis. In situ dehydration study of π-TiP, monitored by high-temperature powder X-ray diffraction, led to a new anhydrous monoclinic [P21/c, a = 5.1187(13) Å, b = 11.0600(21) Å, c = 14.4556(26), β = 107.65(2)°, Z=4) phase that crystallizes at 500°C. The latter resembles the packing fashion of the parental π-TiP, albeit titanium atoms are present both in distorted tetrahedral and octahedral coordination environments. Anhydrous π-TiP was found to partially rehydrate at room temperature adopting reversibly the structure of the initial phase. The studies carried out under different conditions of leaching and impregnation with H3PO4 showed that π-TiP exhibits an extrinsic proton conductivity (1.3·10−3 S·cm−1 at 90 °C and 95% RH) due to the presence of protonated phosphate species bounded on the particles surface, as revealed by 31P MAS-NMR spectroscopy data. The composite membranes of Chitosan (CS) matrices filled with H3PO4-impregnated π-TiP solid show an increment of proton conductivity up to 4.5·10–3 S·cm–1, at 80 °C and 95% RH, 1.8-fold higher than those of bare CS membranesMAT2016-77648-R and PID2019-110249RB-I00), Junta deAndalucía (FQM-113) M. Bazaga-García thanks Junta de Andalucía for her Postdoc PAIDI grant and R. M. P. Colodrero thanks UMA Research Plan for her financial support
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