530 research outputs found
Hagamos los Centros Educativos más verdes: la huella ecológica del Instituto "Vega del Táder" de Molina de Segura en el curso 2004
Reaching Out: The Basque Transnational Body in the Poetry of Kirmen Uribe
In this paper we explore the contribution of Kirmen Uribe, a Basque writer, artist and cultural activist, to the process of political reconciliation in the Basque country, a socially transforming compromise brought about by the dissolution of the Basque terrorist organization ETA in October 20th, 2011. Uribe achieved literary recognition and public notoriety within the Iberian cultural landscape with the publication of his novel Bilbao-New York-Bilbao in 2008, for which he received the Spanish National Literature Prize for Narrative in the following year. However, we argue that it is with his earlier collection of poems Bistatean Heldu Eskutik ‘Meanwhile Take my Hand,’ originally published in Euskara—the Basque language—in 2001, that Uribe initiates a strong, symbolic act towards reconciliation in Basque social relations. Using a methodological framework built on the juxtaposition of transnational and affect studies, we analyze the transformational thrust of an affective, reconciliatory language in Uribe’s poems. Building on Deleuze and Guattari’s notion of a minor literature, we first consider how this affective language overflows and deterritorializes the traditional geographical and discursive boundaries of Basque cultural nationalism; then, we analyze the production of Uribe’s poetic expression within a specific temporality, in which Basque society demanded the end of violence in the Basque country; and, finally, we argue that this poet’s self-conscious poetics of affect provides a cultural model for the democratization of the Basque social body reterritorialized in the transnational realm
A comparative study of the cathodic behaviour of EuCl3 in two imidazolium chloride ionic liquids, the 1-butyl-3-methylimidazolium (C4mimCl) and the 1-ethyl-3methylimidazolium (C2mimCl), on a glassy carbon electrode.
Producción CientíficaThis work presents a comparative study of the electrochemical behaviour, on a glassy carbon electrode, of dissolved EuCl3 in two chlorobasic ionic liquids, the 1-ethyl-3-methylimidazolium chloride, C2mimCl, and the 1-buthyl-3-methylimidazolium chloride, C4mimCl, over the temperature ranges 363–398 K and 343–363 K respectively. In both media, the electro-reduction of EuCl63 − takes place via only one electrochemical step EuCl63 −/EuCl64 −. The electrochemical system EuCl64 −/Eu(0) has not been observed within the electrochemical window of both ILs, due to the prior reduction of the respective imidazolium cation from the solvents, which inhibits the electro-extraction of Eu(0) from the media on the GC electrode.
The paper describes how several electrochemical techniques (e.g. cyclic voltammetry (CV), convolutive potential sweep voltammetry (CPSV), steady state voltammetry (SSV), chronopotentiometry (CP) and chronoamperometry (CA)) have been used experimentally: i) verifying assumptions used in their theoretical analysis, and ii) ensuring reproducible conditions at the electrode/electrolyte interface, with the aim to obtain high-precision measurements of the diffusion coefficient of EuCl63 −. In order to know if there are discrepancies between the obtained data, a two-way analysis of variance, ANOVA, has been carried out. The analysis has shown that with a 95% confidence level there are no significant differences between the diffusion coefficients obtained by the different techniques. On the other hand, the diffusion coefficient of EuCl63 − increases with the temperature following the Arrhenius law, being the activation energy for diffusion 40.4 ± 2.6 and 60.2 ± 1.8 kJ mol− 1 in C2mimCl and C4mimCl respectively. The dimensionless Schmidt numbers, defined as the ratio between solvent viscosity and solute diffusivity (Sc = ν/D), have also been calculated to characterise the solute global mass transport through its environment.
On the GC electrode, the electro-reduction of EuCl63 − to EuCl64 − is a quasi-reversible process. Accurate values of the kinetic parameters (i.e. the intrinsic rate constant of charge transfer, k0, and the charge transfer coefficient, α), as well as the reversible half wave potential, Er1/2, have been obtained for the first time in the mentioned ionic liquids, by simulation of the cyclic voltammograms and logarithmic analysis of the voltammograms and convoluted curvesJunta de Castilla y León, VA171U1
Amperometric biosensor for oxalate determination in urine using sequential injection analysis
Producción CientíficaAn amperometric flow biosensor for oxalate determination in urine samples after enzymatic reaction with oxalate oxidase immobilized on a modified magnetic solid is described. The solid was magnetically retained on the electrode surface of an electrode modified with Fe (III)-tris-(2-thiopyridone) borate placed into a sequential injection system preceding the amperometric detector. The variables involved in the system such as flow rate, aspired volumes (modified magnetic suspension and sample) and reaction coil length were evaluated using a Taguchi parameter design. Under optimal conditions, the calibration curve of oxalate was linear between 3.0–50.0 mg·L−1, with a limit of detection of 1.0 mg·L−1. The repeatability for a 30.0 mg·L−1 oxalate solution was 0.7%. The method was validated by comparing the obtained results to those provided by the spectrophotometric method; no significant differences were observed.CONACyT (Project 178607)Ministerio de Ciencia e Innovación (MCINN AN2010-00234)Junta de Castilla y León (Project VA023A10-2
El video como herramienta docente
Como se deduce del resumen de la conferencia que la Dra. Galindo impartirá en la III Jornada de Docencia de la SEQA, que se celebrará en Valencia el 5 de septiembre, actualmente son muchas las herramientas que están alterando el paradigma de la enseñanza presencial. Desde hace años venimos oyendo que las TICs están alterando el proceso enseñanza aprendizaje en todos los ámbitos y niveles educativos. Con el fin de incorporarnos a los cambios que esto supone, podemos incluir en este momento youtube entre nuestras herramientas de trabajoUniversidad de Valladolid PID1617/01
Introducción al estudio de procesos electroquímicos para Trabajos de Fin de Grado (TGF) o de Máster (TFM)
En este artículo aportamos una vía que puede servir para enfocar el problema de los TFGs y TFMs, con un grado de experimentación aceptable.
Se trataría de llevar a cabo el estudio electroquímico de un sistema redox (soluble-soluble) en disolución acuosa o en un disolvente tipo RTIL (Room Temperature Ionic Liquids) o NADES (Natural Deep Eutectic Solvents). Ello implica la determinación de los parámetros que controlan el proceso: El coeficiente de difusión (D) y la constante de velocidad estándar de intercambio de electrones (k0). La comparación de ambos valores nos indicará el fenómeno controlante lo que puede completarse con otros criterios de reversibilidad
Chromium(VI) removal from aqueous solution by magnetite coated by a polymeric ionic liquid-based adsorbent
An evaluation of the chromium(VI) adsorption capacity of four magnetite sorbents coated with a polymer phase containing polymethacrylic acid or polyallyl-3-methylimidazolium is presented. Factors that influence the chromium(VI) removal such as solution pH and contact time were investigated in batch experiments and in stirred tank reactor mode. Affinity and rate constants increased with the molar ratio of the imidazolium. The highest adsorption was obtained at pH 2.0 due to the contribution of electrostatic interactions.Junta de Castilla y León Proyecto VA171U1
Electrodeposition of Indium on W and Cu electrodes in the Deep Eutectic Solvent choline chloride-ethylene glycol (1:2).
Producción CientíficaA procedure for drying the deep eutectic solvent (DES) choline chloride - ethylene glycol, ChCl-EG (1:2), based on the use of molecular sieves has been developed, being the final water content of the electrolyte 145±5 ppm.
In this dried DES, the stability of InCl and InCl3 as well as the electrochemical behaviour of their solutions has been investigated using electrochemical techniques, X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM). Experiments performed under a N2 atmosphere show that InCl3, dissolved in the rich chloride media as InClp 3-p, is reduced on a tungsten electrode to indium metal via only one electrochemical step.
Conversely, InCl undergoes the following disproportionation reaction when dissolved in the eutectic ChCl-EG (1:2)
3InCl(s) + (p − 3)Cl− ⇌ 2In(0) + InClp − 3 p
generating In(0) and giving place to identical electrochemical signals as those obtained after the addition of InCl3 to the DES.
On a tungsten electrode, nucleation and crystal growth of In plays an important role in the electrodeposition process. Chronoamperometric results were consistent with instantaneous three dimensional nucleation on a finite number of active sites with diffusion controlled growth of the nuclei, whatever the applied overpotential and temperature. Mass transport towards the electrode is a diffusion process, and the following empirical expression for the temperature dependence of the diffusion coefficient was calculated.
LnD = −(3.58 ± 0.22)–(3665 ± 76) T − 1
The electro-reduction of In(III) solutions was also investigated at a copper substrate. The resulting cyclic
voltammograms evidenced the formation of In-Cu intermetallic compounds. Hence, In-Cu alloy films were obtained by continuous potentiostatic electrolysis and intensiostatic pulse electrolysis. The obtained samples, characterized by XRD and SEM, revealed the formation of the metastable CuIn phase that could be transformed into Cu11In9 by thermal annealing.Consejería de Educación of the Junta de Castilla y León Project VA171U14 for financial support. S. García, also thanks the youth employment operative programme (European Social Fund, ESF, and youth employment initiative, YEI)
Dispersive solid phase extraction based on butylamide silica for determination of sulfamethoxazole in milk samples by capillary electrophoresis
A new method based on the combination of dispersive solid-phase extraction and capillary electrophoresis is proposed for the determination of sulfamethoxazole in milk samples. Butylamide silica was synthesized and used as extractant. Factors involved in sample treatment method such as: butylamide silica amount, NaOH concentration in methanol, sample volume, and dispersion time were evaluated using a Taguchi parameter design. Under optimal conditions, average recoveries ranged from 73 to 85% with a limit of detection of 0.05 mg L 1 were achieved. The proposed method is a useful technique for cleanup milk samples.Junta de Castilla y León Proyecto VA171U1
Intercalary diaphysometafisary humeral reconstruction with nonvascularized peroneal graft and external fixation
Para la reconstrucción de los defectos óseos, tras la resección marginal intercalar causada por la escisión de tumores benignos o malignos de baja intensidad, se han propuesto diversas técnicas operatorias. La reconstrucción ósea intercalar con injerto autólogo peroneal no vascularizado es una de las más recomendadas. Se presentan dos pacientes, en edad pediátrica, uno de sexo masculino y otro femenino, con padecimiento de quiste óseo solitario multicameral y osteocondroma, respectivamente. Los exámenes humorales realizados resultaron normales. Los estudios radiográficos mostraron características propias de estas lesiones: imágenes redondeadas irregulares, radiotransparentes y radiodensas alternantes, esclerosis de sus bordes corticales adelgazadas intactas. Sometidos a intervenciones quirúrgicas para reconstrucción humeral intercalar diafisometafisaria con injerto peroneal no vascularizado. Para estabilizar el injerto, se utilizó la fijación externa con pines metálicos transfixiantes acoplados a un marco rígido metálico. La fase posoperatoria trascurrió sin dificultades. Seguimiento riguroso hasta la remodelación ósea y rehabilitación completa, nueve meses posteriores a las intervenciones quirúrgicas
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