256 research outputs found

    Comparison of inorganic and biohybrid layered silicates as adsorbents and carriers of herbicide imazamox for smart control of Striga and Orobanche spp.weeds

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    Poster presentado en el International Conference on Structural Nano Composites 20-21 May 2014 in Madrid, Spain, pag. 53 (2014) (NANOSTRUC 2014)Parasitic plants as Striga and Orobanche spp. are controlled by the systemic herbicide imazamox, which has to act at early stages of weed seeds germination in the root zone. Imazamox is an ionic herbicide with high water solubility and soil mobility: high risk of water contamination and loss of efficacy.CSIC (JAE-­‐Doc), MINECO (AGL2011-­‐23779), JA (AGR-­‐264 and P11-­‐AGR-­7400) with FEDER-­‐FSE (OP2009-­‐13); BASF for technical imazamox and M.A. Adelino for SW-­CHs samples.Peer Reviewe

    A methodological proposal and tool support for the HL7 standards compliance in the development of health information systems

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    Health information systems are increasingly complex, and their development is presented as a challenge for software development companies offering quality, maintainable and interoperable products. HL7 (Health level 7) International, an international non-profit organization, defines and maintains standards related to health information systems. However, the modelling languages proposed by HL7 are far removed from standard languages and widely known by software engineers. In these lines, NDT is a software development methodology that has a support tool called NDT-Suite and is based, on the one hand, on the paradigm of model-driven engineering and, on the other hand, in UML that is a widely recognized standard language. This paper proposes an extension of the NDT methodology called MoDHE (Model Driven Health Engineering) to offer software engineers a methodology capable of modelling health information systems conforming to HL7 using UML domain models

    Composite Spin Waves, Quasi-Particles and Low Temperature resistivity in Double Exchange Systems

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    We make a quantum description of the electron low temperature properties of double exchange materials. In these systems there is a strong coupling between the core spin and the carriers spin. This large coupling makes the low energy spin waves to be a combination of ion and electron density spin waves. We study the form and dispersion of these composite spin wave excitations. We also analyze the spin up and down spectral functions of the temperature dependent quasi-particles of this system. Finally we obtain that the thermally activated composite spin waves renormalize the carriers effective mass and this gives rise to a low temperature resistivity scaling as T ^{5/2}.Comment: 4 pages, REVTE

    Relación entre la mortalidad materna y la gobernanza de los países iberoamericanos

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    Antecedentes/Objetivos: Pese al aumento de los recursos financieros y ser a menudo el 1er objetivo de los gobiernos, muchos países no están en camino de alcanzar el objetivo de Desarrollo del Milenio relacionado con la reducción de la mortalidad materna (MM). La gobernanza de los países es uno de los determinantes de la MM sobre el que hay disparidad de criterios y escasa literatura sobre el impacto de la misma en la MM. Objetivo: analizar la relación entre los factores de la gobernanza y la mortalidad materna en Iberoamérica, en 2012. Métodos: Estudio transversal ecológico para 2012, que utiliza el país como unidad de análisis sobre relación entre la gobernanza y la MM. Fuentes información: Estadísticas de Naciones Unidas, Banco Mundial, OMS/OPS. Se realizó un modelo de regresión lineal simple, y ajustado por riqueza (PIB). Resultados: Controlado por la riqueza del país, se detectan asociaciones significativas entre la MM con las variables de la gobernanza: Control de la corrupción R2 = 73,2% (p = 0,001), Estado de derecho R2 = 73% (p = 0,001), calidad regulatoria R2 = 70,9% (p = 0,002), efectividad gubernamental R2 = 69,5% (p = 0,003), voz y rendición de cuentas R2 = 68,3% (p = 0,004) y transparencia R2 = 66,8% (p = 0,003). Todas estas variables se asociación inversamente. Conclusiones: La mortalidad materna en 2012 está fuertemente relacionada con la capacidad y calidad gubernamental de los 19 países Iberoamericanos. En concreto, la MM se asocia con 6 de las 7 categorías componentes de la gobernanza. Afrontar la multicausalidad de la MM es un reto, entre los que se debe considerar y analizar el impulso político para la reducción de la corrupción, el desarrollo del estado de derecho, la calidad regulatoria, la efectividad gubernamental, el facilitar la voz y rendición de cuentas y la transparencia.Proyecto Prometeo. SENESCYT, Ecuador

    Oxidation of CO and methanol on Pd-Ni catalysts supported on different chemically-treated carbon nanofibers

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    In this work, palladium-nickel nanoparticles supported on carbon nanofibers were synthesized, with metal contents close to 25 wt % and Pd:Ni atomic ratios near to 1:2. These catalysts were previously studied in order to determine their activity toward the oxygen reduction reaction. Before the deposition of metals, the carbon nanofibers were chemically treated in order to generateoxygen and nitrogen groups on their surface. Transmission electron microscopy analysis (TEM) images revealed particle diameters between 3 and 4 nm, overcoming the sizes observed for thenanoparticles supported on carbon black (catalyst Pd-Ni CB 1:2). From the CO oxidation at different temperatures, the activation energy Eact for this reaction was determined. These values indicated a high tolerance of the catalysts toward the CO poisoning, especially in the case of the catalystssupported on the non-chemically treated carbon nanofibers. On the other hand, apparent activation energy Eap for the methanol oxidation was also determined finding—as a rate determining step—the COads diffusion to the OHads for the catalysts supported on carbon nanofibers. The results here presented showed that the surface functional groups only play a role in the obtaining of lower particlesizes, which is an important factor in the obtaining of low CO oxidation activation energies

    Influence of Olive Oil Mill Waste Amendment on Fate of Oxyfluorfen in Southern Spain Soils

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    7 páginas.-- 1 figura.-- 3 tablas.-- 37 referencias.--Oxyfluorfen herbicide residues have been previously reported in surface and ground water in the Guadalquivir river basin in Spain. Soil factors and processes (sorption, dissipation, and leaching) influencing the potential offsite transport of oxyfluorfen to surface and ground water were characterized in laboratory experiments for two soils from Southern Spain. The influence of olive-oil mill waste amendment on the soil processes was also determined. Oxyfluorfen sorption in unamended soils was not significantly affected by soil active components (organic matter and clay fraction). However, a significant increase in soil sorption of the herbicide was observed upon amendment. Laboratory half-life values for oxyfluorfen in unamended sandy clay loam and silty clay soils at 40% moisture content and 25°C were 29 and 19 days, respectively, and it increased by a factor of four upon amendment. Oxyfluorfen's mobility along soil profile increased with the amendment in leaching studies at 25°C, suggesting that dissolved organic matter of amendment can play an important role enhancing soil vertical movement of the pesticide. The increase in soil adsorption and persistence observed with olive-oil mill waste amendment can promote its losses by runoff following winter application, whereas vertical movement of oxyfluorfen can be enhanced following spring application when olive-oil mill waste amendment is also applied.This work has been partially financed by research projects P06-AGR-565, P07-AGR-03077, and AGR-264 from Junta de Andalucia, all of them cofinanced with EU FEDER-FSE funds (Operative Program 2003/06 and 2007/11). This work has been specially supported by I-Link 0025 research project from CSIC. We are grateful to Dow Agrosciences LLC, Indianapolis, IN for supplying 14C-labeled oxyfluorfen. Authors also thank to Dra. L. Cox and Dr. R. Celis for manuscript valuable support, comments and suggestions.Peer reviewe

    Theory of carrier mediated ferromagnetism in dilute magnetic oxides

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    We analyze the origin of ferromagnetism as a result of carrier mediation in diluted magnetic oxide semiconductors in the light of the experimental evidence reported in the literature. We propose that a combination of percolation of magnetic polarons at lower temperature and Ruderman-Kittel-Kasuya-Yosida ferromagnetism at higher temperature may be the reason for the very high critical temperatures measured (up to ~700 K).Comment: 10 pages, 3 figures; formulae and references added, discussion extende

    Conductance as a Function of the Temperature in the Double Exchange Model

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    We have used the Kubo formula to calculate the temperature dependence of the electrical conductance of the double exchange Hamiltonian. We average the conductance over an statistical ensemble of clusters, which are obtained by performing Monte Carlo simulations on the classical spin orientation of the double exchange Hamiltonian. We find that for electron concentrations bigger than 0.1, the system is metallic at all temperatures. In particular it is not observed any change in the temperature dependence of the resistivity near the magnetical critical temperature. The calculated resistivity near TcT_c is around ten times smaller than the experimental value. We conclude that the double exchange model is not able to explain the metal to insulator transition which experimentally occurs at temperatures near the magnetic critical temperature.Comment: 6 pages, 5 figures included in the tex

    Seasonal herbicide monitoring in soil, runoff and sediments of an olive orchard under conventional tillage

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    Trabajo presentado en la EGU General Assembly 2016 (European Geosciences Union), celebrada en Viena del 12 al 17 de abril de 2015.Several pollution episodes in surface and groundwaters with pesticides have occurred in areas where olive crops are established. For that reason, it is necessary to know the evolution of some pesticides in olive trees plantation depending on their seasonal application. This is especially important when conventional tillage is used. A monitoring of two herbicides (terbuthylazine and oxyfluorfen)in the first cm of soil and, in runoff and sediment yield was carried out after several rainfall events. The rainfall occurred during the study was higher in winter than in spring giving rise more runoff in winter. However, no differences in sediment yields were observed between spring and winter. Terbuthylazine depletion from soil is associated to the first important rainfall events in both seasons (41 mm in spring and 30 mm in winter). At the end of the experiment, no terbuthylazine soil residues were recovered in winter whereas 15% of terbuthylazine applied remained in spring. Oxyfluorfen showed a character more persistent than terbuthylazine remaining 48% of the applied at the end of the experiment due to its low water solubility. Higher percentage from the applied of terbuthylazine was recovered in runoff in winter (0.55%) than in spring (0.17%). Nevertheless, no differences in terbuthylazine sediments yields between both seasons were observed. That is in agreement with the values of runoff and sediment yields accumulated in tanks in both seasons. Due to the low water solubility of oxyfluorfen very low amount of this herbicide was recovered in runoff. Whereas, in sediment yields the 39.5% of the total applied was recovered. These data show that the dissipation of terbuthylazine from soil is closely related with leaching processes and in less extent with runoff. However, oxyfluorfen dissipation is more affected by runoff processes since this herbicide is co-transported in sediment yields.P08-AGR-03643, P11-AGR-7400, JA (AGR-264) partially finnanced with FEDER-FSE (OP 2007-13) and FACCE-JPI (Designchar4food).Peer Reviewe

    Fluctuation induced hopping and spin polaron transport

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    We study the motion of free magnetic polarons in a paramagnetic background of fluctuating local moments. The polaron can tunnel only to nearby regions of local moments when these fluctuate into alignment. We propose this fluctuation induced hopping as a new transport mechanism for the spin polaron. We calculate the diffusion constant for fluctuation induced hopping from the rate at which local moments fluctuate into alignment. The electrical resistivity is then obtained via the Einstein relation. We suggest that the proposed transport mechanism is relevant in the high temperature phase of the Mn pyrochlore colossal magneto resistance compounds and Europium hexaboride.Comment: 8 pages, 3 figure
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