77 research outputs found

    Superconducting density of states at the border of an amorphous thin film grown by focused-ion-beam

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    We present very low temperature Scanning Tunneling Microscopy and Spectroscopy (STM/S) measurements of a W based amorphous thin film grown with focused-ion-beam. In particular, we address the superconducting properties close to the border, where the thickness of the superconducting film decreases, and the Au substrate emerges. When approaching the Au substrate, the superconducting tunneling conductance strongly increases around the Fermi level, and the quasiparticle peaks do not significantly change its position. Under magnetic fields, the vortex lattice is observed, with vortices positioned very close to the Au substrate.Comment: To appear in Journal of Physics: Conference serie

    Comparative Life Cycle Assessment of gypsum plasterboard and a new kind of bio-based epoxy composite containing different natural fibers

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    [DE] A comparative LCA from cradle to grave between traditional plasterboard, for drywall applications, and different composite boards, made by natural fiber and a bio-based epoxy resin (Supersap CLR), was carried out. The goal of the study was to determine whether the composites based on such a resin combined with natural fibers could be an eco-friendly alternative to plasterboard in the building sector. Moreover, the impacts related to each of the fibers used are also assessed separately from cradle to gate in order to get a better understanding of its influence. Both the results obtained through the IPC. GWP 100a method and the recipe endpoint show a remarkable difference between the plasterboard and all the different composites, the composites offering a 50% reduction in the CO2 emissions. The calculations performed regarding the impacts related to the different fibers showed only small differences between them.The authors gratefully thank the Spanish Ministry of Economy, Industry and Competitiveness, for funding the project BIA2013-41537-R (BIAEFIREMAT 'Development of new sustainable eco-materials and building systems for the building industry, based on the use of residues and renewable raw materials'). The project is co-funded by the European Regional Development Fund and it is included in the R+D National Programme for Research Aimed at the Challenges of Society.Quintana, A.; Alba Fernández, J.; Rey Tormos, RMD.; Guillén Guillamón, IE. (2018). Comparative Life Cycle Assessment of gypsum plasterboard and a new kind of bio-based epoxy composite containing different natural fibers. Journal of Cleaner Production. 185:408-420. https://doi.org/10.1016/j.jclepro.2018.03.042S40842018

    Caracterización preliminar de emisiones de gases de efecto invernadero (CH4 y CO2) procedentes de volcanes de fango del Golfo de Cádiz

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    Mud volcanism represents an important migration pathway for methane and other gases from deeper reservoirs to the surface; however most submarine sources remain poor quantified. During SUBVENT2 cruise, water column over several mud volcanoes were surveyed for gas seepage characterization. Water samples of ROV Niskin and Rosette-CTD Niskin bottles were recovered above the Bonjardim, El Cid, Las Negras, Mercator, Algacel, Mvseis, Madrid and Yuma mud volcanoes, and at three newly discovered, mud volcano like structures, to quantify overall gases release fluxes from seabed. CO2 and CH4 concentrations were measured by potentiometric titration and using a gas chromatograph, respectively, in order to understand the relationship between physicochemical and geological processes. Gases concentrations decreased from shallower to deeper mud volcanoes. Values varied widely within 50 to 200 nM for CH4 and between 400 to 1500 μatm for fCO2. Greenhouse gases variations were large influenced by water column depth, temperature, salinity and possibly by anaerobic oxidation of methane (AOM). Our observations suggest that the emission of methane and carbon dioxide from the mud volcanoes structures studied here may be relevant at the present as a part of the carbon global cycle.Versión del edito

    Nanoscale superconducting properties of amorphous W-based deposits grown with focused-ion-beam

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    We present very low temperature Scanning Tunneling Microscopy and Spectroscopy (STM/S) measurements in W-based amorphous superconducting nanodeposits grown using a metal-organic precursor and focused-ion-beam. The superconducting gap closely follows s-wave BCS theory, and STS images under magnetic fields show a hexagonal vortex lattice whose orientation is related to features observed in the topography through STM. Our results demonstrate that the superconducting properties at the surface of these deposits are very homogeneous, down to atomic scale. This, combined with the huge nanofabrication possibilities of the focused-ion-beam technique, paves the way to use focused-ion-beam to make superconducting circuitry of many different geometries

    Cycloaddition of alkynes to diimino Mo3S4 cubane-type clusters: a combined experimental and theoretical approach

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    A heterocyclic ligand 4,40-di-tert-butyl-2,20-bipyridine (dbbpy) has been coordinated to the Mo3S4 cluster unit affording the complex [Mo3S4Cl3(dbbpy)3]+ ([1]+) in a one-step ligand-exchange protocol from [Mo3S4(tu)8(H2O)]Cl4 4H2O (tu = thiourea). The new cluster was isolated as [1]PF6 and [1]Cl salts in high yields and the crystal structure of the latter determined by X-ray analysis. The synthetic procedure was extended to tungsten to afford [W3S4Cl3(dbbpy)3]+ ([2]+). Kinetic and NMR studies show that [1]+ reacts with several alkynes to form dithiolene species via concerted [3+2] cycloaddition reactions whereas [2]+ remains inert under similar conditions. The different rates for the reactions of [1]+ are rationalised by computational (DFT) calculations, which show that the more electron-withdrawing the substituents of the alkyne the faster the reaction. The inertness of [2]+ is due to the endergonicity of its reactions, which feature DGr values systematically 5–7 kcal mol 1 more positive than for those of [1]+

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    An accurate understanding of the mechanisms underlying an individual's response to rt-PA treatment is critical to improve stroke patients' management. We thus reviewed the literature in order to identify biochemical and genetic factors that have been associated with safety and efficacy of rt-PA administration after stroke

    Kinetics Aspects of the Reversible Assembly of Copper in Heterometallic Mo3CuS4 Clusters with 4,4′-Di-tert-butyl-2,2′- bipyridine

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    Treatment of the triangular [Mo3S4Cl3(dbbpy)3]Cl cluster ([1]Cl) with CuCl produces a novel tetrametallic cuboidal cluster [Mo3(CuCl)S4Cl3(dbbpy)3][CuCl2] ([2][CuCl2]), whose crystal structure was determined by X-ray diffraction (dbbpy = 4,4′-di-tert-butyl-2,2′-bipyridine). This species, which contains two distinct types of Cu(I), is the first example of a diimine-functionalized heterometallic M3M′S4 cluster. Kinetics studies on both the formation of the cubane from the parent trinuclear cluster and its dissociation after treatment with halides, supported by NMR, electrospray ionization mass spectrometry, cyclic voltammetry, and density functional theory calculations, are provided. On the one hand, the results indicate that addition of Cu(I) to [1]+ is so fast that its kinetics can be monitored only by cryo-stopped flow at −85 °C. On the other hand, the release of the CuCl unit in [2]+ is also a fast process, which is unexpectedly assisted by the CuCl2 − counteranion in a process triggered by halide (X−) anions. The whole set of results provide a detailed picture of the assembly−disassembly processes in this kind of cluster. Interconversion between trinuclear M3S4 clusters and their heterometallic M3M′S4 derivatives can be a fast process occurring readily under the conditions employed during reactivity and catalytic studies, so their occurrence is a possibility that must be taken into account in future studies

    Distribution of Pestivirus exposure in wild ruminants in Spain

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    A large‐scale study was carried out to determine the prevalence of antibodies against Pestivirus species in wild ruminants and describe their spatial variation in mainland Spain. Serum samples of 1,874 wild ruminants from different regions of this country were collected between the years 2000 and 2017. A total of 6.6% (123/1,874) animals showed antibodies against Pestivirus by both blocking ELISA (bELISA) and virus neutralization tests (VNT). The prevalence of antibodies against pestiviruses was different both among species and regions. Seroprevalence by species was 30.0% (75/250) in Southern chamois (Rupicapra pyrenaica), 7.0% (25/357) in fallow deer (Dama dama), 2.5% (10/401) in red deer (Cervus elaphus), 2.4% (8/330) in Iberian wild goat (Capra pyrenaica), 1.1% (4/369) in roe deer (Capreolus capreolus) and 0.8% (1/130) in mouflon (Ovis aries musimon), not detecting seropositivity (0/37) in Barbary sheep (Ammotragus lervia). The results confirm that exposure to pestiviruses was detected throughout mainland Spain, with significantly higher seroprevalence in Northern regions associated with the presence of Southern chamois. This indicates an endemic circulation of pestiviruses in Southern chamois and a limited circulation of these viruses in the remaining wild ruminant species during the last two decades, thus suggesting that non‐chamois species are not true Pestivirus reservoirs in Spain. Nonetheless, the high spatial spread of these viruses points out that new epidemic outbreaks in naïve wild ruminant populations or transmission to livestock may occur, evidencing the usefulness of monitoring pestiviruses in wild ruminants, especially at the wildlife–livestock interface.info:eu-repo/semantics/acceptedVersio

    On the determinants of local government debt: Does one size fit all?

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    This paper analyzes the factors that directly influence levels of debt in Spanish local governments. Specifically, the main objective is to find out the extent to which indebtedness is originated by controllable factors that public managers can influence, or whether it hinges on other variables beyond managers’ control. The importance of this issue has intensified since the start of the crisis in 2007, due to the abrupt decline of revenues and, simultaneously, to the stagnation (or even increase) in the levels of costs facing these institutions face. Results can be explored from multiple perspectives, given that the set of explanatory factors is also multiple. However, the most interesting result relates to the varying effect of each covariate depending on each municipality’s specific debt level, which suggests that economic policy recommendations should not be homogeneous across local governments

    Tolerancia a diferentes factores antinutritivos en lechones alimentados con guisantes de invierno (Pisum sativum) y alberjón (Vicia narbonensis) en la fase estárter

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    Se realizaron dos ensayos para evaluar el efecto de dietas con diferentes niveles de factores antinutritivos: inhibidores de tripsina y quimotripsina (UTI, UQI respectivamente, como unidades) de guisantes de invierno y ¿Glutamyl-S-Ethenyl-Cysteine de alberjón, en el rendimiento de lechones durante el periodo estárter. En cada uno se utilizaron 192 machos castrados, híbridos Duroc x (Large-White x Landrace), con 11,23 y 11,55 kg de peso medio respectivamente, e igual diseño: cuatro tratamientos y ocho réplicas cada una de seis lechones. Los tratamientos del Ensayo 1 fueron: Control: harina de soja 47 y soja extrusionada (0,97 UTI-1,94 UQI/mg de pienso); P-CAR: soja extrusionada y guisante Cartouche (1,62 UTI-3,16 UQI/mg de pienso); P-ICE: soja extrusionada y guisante Iceberg (3,09 UTI-4,95 UQI/mg de pienso); P-LUN: soja extrusionada y guisante Luna (3,19 UTI-5,56 UQI/mg de pienso). Los lechones del tratamiento P-CAR crecieron significativamente más que el resto, con igual consumo y conversión. No hubo diferencias entre Control, P-ICE y P-LUN. El pienso del Ensayo 2 incluía diferentes niveles de alberjón: 0%, 5%, 15% y 25%, y en consecuencia de ¿Glutamyl-S-Ethenyl-Cysteine (1,52% del grano). Los lechones del tratamiento 5% comieron y crecieron más, con igual conversión que los del tratamiento 0%. El rendimiento empeoró con porcentajes del 15% o mayores. Se concluye que lechones de 40 a 61 días de vida mantienen o mejoran el rendimiento con la ingesta de inhibidores de proteasas que exceden 3,28 y 2,86 veces, UTI y UQI respectivamente, los de una dieta de soja, y que la inclusión de 5% de alberjón en el pienso aumenta el consumo y el crecimiento. Two trials were conducted to evaluate the effect of diets with different levels of anti-nutritional factors: trypsin (TIU) and chymotrypsin (CIU) inhibitors units of peas and ¿Glutamyl-S-Ethenyl-Cysteine (GEC) of narbon vetch, in productive performance of pigs from 40 to 61 days of age. 192 barrows were used in each test, Duroc hybrid x (Large White x Landrace), with 11.23 and 11.55 kg body weight respectively, and the same experimental design: four treatments and eight replicates with six piglets in each case. In trial 1 treatments were: Control: soybean meal 47 and soybean extruded (0.97 TIU-1.94 CIU/mg feed); P-CAR: soybean extruded and pea Cartouche (1.62 TIU-3.16 CIU/mg feed); P-ICE: soybean extruded and pea Iceberg (3.09 TIU-4.95 CIU/mg feed); P-LUN: soybean extruded and pea Luna (3.19 TIU-5.56 CIU/mg feed). The piglets of P-CAR treatment grew significantly faster than the others, with the same intake and feed conversion. No significant differences between Control, P-ICE and P-LUN. In trial 2 the feedstuff had different levels of narbon vetch: 0%, 5%, 15% and 25%, and consequently of ¿Glutamyl-S-Ethenyl-Cysteine (1.52% of the grain). The piglets that consumed the treatment of 5% had higher intake and growth, and the same conversion that piglets feeding with the treatment of 0%. The performance worsened significantly with increasing 15%. We conclude that piglets in starter period maintain or improve the performance with intake of proteases inhibitors in feedstuff that exceed 3.28 (TIU) and 2.86 (CIU) times those of a control diet, and that the inclusion of 5% of narbon vetch in feedstuff increases feed intake and growth
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