Solid Oxide Fuel Cells based on Lanthanum Tungstates Electrolytes

Lanthanum tungstate with composition La27W4NbO55- (LWNO) has been tested as proton conductor electrolyte for Solid Oxide Fuel Cells (SOFCs). For this purpose, different electrodes and composite electrodes are considered, including: La0.8Sr0.2MnO3-, La0.6Sr0.4Co1-xFexO3-, La0.5Sr0.5Cr0.5Mn0.5O3-, SrFe0.75Nb0.25O3- and NiO. Chemical compatibility between the cell components is investigated by X-ray powder diffraction (XRPD) and energy dispersive spectroscopy (EDS). Furthermore, area specific resistance (ASR) of the different electrodes is determined in symmetrical cells by impedance spectroscopy. XRPD and EDS analysis do not reveal significant bulk reactivity between most of these electrodes and LWNO electrolyte in the typical operating temperature range of a SOFC (600-900 ºC). However, minor interdiffusion of elements at the electrolyte/electrode interface affects both the ohmic losses and electrode polarization of the cells. ASR values are significantly improved by using a buffer layer of Ce0.8Gd0.2O1.9, between the electrolyte and electrode materials, to prevent reactivity. A single cell with 350 µm thick electrolyte, NiO-Ce0.8Gd0.2O1.9 anode and La0.6Sr0.4Co0.8Fe0.2O3- cathode, generates maximum power densities of 140 and 18 mWcm-2 at 900 and 650 ºC, respectively.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Compatibility and performance of SOFCs based on lanthanum tungstates

Rare-earth tungstates with general composition “Ln6WO12” have attracted great attention in last few years due to their relatively high mixed proton-electron conductivity [1, 2]. One of the main ad-vantages of these electrolytes, compared to the traditional perovskites based on BaCeO3, is that they exhibit high tolerance towards CO2 and H2S environments. Therefore, this material is a potential electrolyte for proton conducting solid oxide fuel cells (PC-SOFC). In this work, the lanthanum tungstate with com-position La27W4NbO55-δ (LWNO) has been tested as proton conductor electrolyte [3]. For this purpose, different electrodes and composite electrodes have been considered, including: La0.8Sr0.2MnO3-δ, La0.6Sr0.4Co1-xFexO3-δ, La0.5Sr0.5Cr0.5Mn0.5O3-δ, SrFe0.75Nb0.25O3-δ and NiO. Chemical compatibility between the cell compo-nents is investigated by X-ray powder diffraction (XRPD) and energy dispersive spectroscopy (EDS). Furthermore, area specific resistance (ASR) of the different electrodes is determined in symmetrical cells by impedance spectroscopy. XRPD and EDS analysis do not reveal significant bulk reactivity between most of these electrodes and LWNO electrolyte in the typical operating temperature range of a SOFC (600-900 ºC). However, minor interdiffusion of elements at the electrolyte/electrode interface affects both the ohmic losses and electrode polarization of the symmetric cells. ASR values are significantly improved by using a buffer layer of Ce0.8Gd0.2O1.9, between the electrolyte and electrode materials, to prevent reactivity. A single cell with 350 µm thick electrolyte, NiO-Ce0.8Gd0.2O1.9 anode and La0.6Sr0.4Co0.8Fe0.2O3-δ cathode, generates maximum power densities of 140 and 18 mWcm-2 at 900 and 650 ºC, respectively. Hence, lanthanum tungstates could be competitive proton conductors for PC-SOFCs with similar performance to those based on BaZrO3 if thin film electrolytes are used.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Perceveid Social Support in middle school students

Research on school climate has among its purposes to contribute to improving the quality of education, one of the main challenges of the Mexican educational system, particularly at the level of basic education. Our aim was to explore the relationships between the dimensions of school climate of perceived social the support teacher-student, support student-student and opportunities for autonomy and academic performance. The study was non-experimental and correlational. The sample consisted of 325 students from a middle school in northeastern Mexico, with a mean age of 13.4 years who responded to a scale of perceived school climate. The results show that students perceive great teacher support associated with student-student support and opportunities for autonomy. In addition, we found that academic achievement related to teacher support and opportunities for autonomy. These data are consistent with the country´s educational policy, which emphasizes the teacher´s role as facilitator of student learning to improve learning outcomes and the quality of education.Fil: Rodriguez, María Concepción. Universidad Autónoma de Nuevo León; MéxicoFil: Vivas, Jorge Ricardo. Universidad Nacional de Mar del Plata. Facultad de Psicología. Centro de Investigación en Procesos Básicos, Metodologías y Educación; ArgentinaFil: Comesaña, Ana. Universidad Nacional de Mar del Plata. Facultad de Psicología. Centro de Investigación en Procesos Básicos, Metodologías y Educación; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; ArgentinaFil: Ramirez, Laura Minerva. Universidad Autónoma de Nuevo León; MéxicoFil: Peña, José Armando. Universidad Autónoma de Nuevo León; Méxic

La Corona y la propuesta de candidato a Presidente del Gobierno: nuevas prácticas y viejas normas

El modelo de elección del Presidente del Gobierno diseñado por la Constitución, conserva toda su vigencia, al haber superado las difíciles pruebas de resistencia a las que, hasta el presente, ha sido sometido. Aun así, en vistas de la experiencia acumulada, quizá sea oportuno proponer la introducción de algunas correcciones que impidan que se fuercen las previsiones constitucionales, de acuerdo con intereses espurios. Mas ninguna de ellas afecta a al cometido que desempeña la Corona en dicho procedimiento, dado que su actuación, apegada escrupulosamente a la Constitución y orientada, en todo momento, a la promoción del interés general, se ha demostrado invaluable. A este respecto, no debemos olvidar que se trata de un procedimiento esencialmente diseñado para situar en su centro a los grupos políticos con representación parlamentaria, que son sus protagonistas naturales, y no a ninguna institución, pretendidamente arbitral, sustitutiva o auxiliar de los mismos. Corresponde, por tanto, a aquéllos, como es propio que suceda en toda democracia parlamentaria, alcanzar el acuerdo y otorgar su confianza al candidato que mejor consideren. Y nadie podrá sustituir su criterio, ni privarlos de su responsabilidad.The constitutional model of election of the President of the Government in Spain retains all its validity, having overcome the difficult tests of resistance to which it has hitherto been subjected. Even so, in view of the accumulated experience, it may be appropriate to propose the introduction of some corrections that prevent the constitutional provisions from being forced, in accordance with spurious interests. But none of them affects the role played by the Crown in this procedure since its performance, scrupulously adhering to the Constitution and oriented at all times to the promotion of general interest, has proved invaluable. In this respect we must not forget that this is a procedure essentially designed to place political groups with parliamentary representation, which are its natural protagonists, and not to any institution, allegedly as an arbitrator, substitute or an auxiliary. It is therefore up to them, as it is proper to happen in any parliamentary democracy, to reach agreement and give their confidence to the candidate they consider best. And no one can substitute their criteria, nor deprive them of their responsibility

Distributed feedback lasers based on dichromated poly(vinyl alcohol) reusable surface-relief gratings

A simple, low-cost and versatile holographic method to produce reusable surface-relief gratings on dichromated poly(vinyl alcohol) (DCPVA) films, with periods Λ ≥ 270 nm and modulation depths up to 300 nm, is reported. DCPVA presents processing advantages with respect to other photoresists, such as dichromated gelatine, i.e. higher light sensitivity, simpler fabrication process and better batch to batch reproducibility. The successful use of these DCPVA relief gratings as distributed feedback (DFB) laser resonators is demonstrated. Second-order DFB devices emitting in the wavelength range 577-614 nm have been easily prepared by coating a dye-doped polymer film on top of the resonators.We thank the Spanish Government (MINECO) and the European Union (FEDER) for grant no. MAT2011-28167-C02

Decapping protein EDC4 regulates DNA repair and phenocopies BRCA1

BRCA1 is a tumor suppressor that regulates DNA repair by homologous recombination. Germline mutations in BRCA1 are associated with increased risk of breast and ovarian cancer and BRCA1 deficient tumors are exquisitely sensitive to poly (ADP-ribose) polymerase (PARP) inhibitors. Therefore, uncovering additional components of this DNA repair pathway is of extreme importance for further understanding cancer development and therapeutic vulnerabilities. Here, we identify EDC4, a known component of processing-bodies and regulator of mRNA decapping, as a member of the BRCA1-BRIP1-TOPBP1 complex. EDC4 plays a key role in homologous recombination by stimulating end resection at double-strand breaks. EDC4 deficiency leads to genome instability and hypersensitivity to DNA interstrand cross-linking drugs and PARP inhibitors. Lack-of-function mutations in EDC4 were detected in BRCA1/2-mutation-negative breast cancer cases, suggesting a role in breast cancer susceptibility. Collectively, this study recognizes EDC4 with a dual role in decapping and DNA repair whose inactivation phenocopies BRCA1 deficiency.España, Ministerio de Economía y Competitividas CB06/07/0023, SAF2012-31881, SAF2013-45836-R and SAF2015-64152-

Perylenediimide-based distributed feedback lasers with holographic relief gratings on dichromated gelatine

One dimensional second-order distributed feedback (DFB) lasers consisting of polystyrene (PS) films doped with a perylenediimide laser dye, deposited over dichromated gelatine (DCG) photoresist layers with solvent resistant relief gratings recorded by holographic lithography, are reported. The advantage of using the grating on DCG in the final device is that the fabrication process is simplified and the grating pattern better preserved, since no etching methods to transfer the grating to another substrate are needed. A very simple model, proposed to explain the experimental waveguide properties, has allowed identifying the waveguide mode at which DFB emission appears, which was the key to optimize the device performance. In the frame of this model, the thickness of the PS and DCG films could be adjusted in order to minimize the laser threshold and to control its wavelength tuneability. The performance of these lasers is comparable to that of recently reported devices based on the same active material, but deposited over high-quality DFB gratings engraved on SiO2 by nanoimprint lithography.We thank support from the Spanish Government (MINECO) and the European Community (FEDER) through Grant Nos. MAT2008-06648-C02 and MAT-2011-28167-C02, as well as to the University of Alicante. M.G.R. was supported by a CSIC fellowship within the program JAE

Segurança humana e os problemas colaterais da água

Human security basically refers to the obligations that governments have for guaranteeing survival, the means of life and the dignity of their citizens. The solution of the problems that affect the population is function of the States, especially those connected with the utilities that permit improvement of life quality. The meager access to drinkable water has become the second cause of children mortality in the planet. Current studies show that 1.8 million children die every year as consequence of the vast health problems that arise from the consumption of unfit to drink water. The purpose of this paper is to delineate the concept of human security, describing the problems related to the use and supply of water in the world and finally bring up the Colombia situation as a hydric power, and its management of water resources such as moors and rivers, as well as the provision of potable water services.La seguridad humana se refiere fundamentalmente a la obligación que los gobiernos tienen de asegurar la supervivencia, los medios de vida y la dignidad de sus ciudadanos. La solución de problemas que afectan la población es función de los Estados, en especial los relacionados con servicios públicos que permitan mejorar la calidad de vida. El acceso deficiente al agua potable se ha convertido en la segunda causa de muerte infantil del planeta. Estudios actuales muestran que 1,8 millones de niños mueren al año como consecuencia de graves problemas de salud derivados del consumo de agua insalubre. El presente artículo tiene como objetivo delimitar los alcances del concepto de seguridad humana, avanzando hacia la problemática en cuanto al uso y abastecimiento del agua en el mundo, y la situación que enfrenta Colombia como potencia hídrica de cara la conservación de los páramos y otras fuentes de recursos hídricos, como también en la prestación del servicio de agua potable.A segurança humana refere-se, essencialmente, à obrigação dos governos de garantir a sobrevivência, subsistência e a dignidade dos seus cidadãos. A solução dos problemas que afetam a população é uma função dos Estados, particularmente os que estão relacionados com os serviços públicos que possibilitam melhorar a qualidade de vida. O escasso acesso à água potável tornou-se a segunda maior causa de mortalidade infantil no mundo. Estudos atuais mostram que 1,8 milhões de crianças morrem a cada ano como consequência de sérios problemas de saúde por consumir água contaminada. O objetivo deste artigo é o de definir o alcance do conceito de segurança humana, direcionando-o para o problema do uso e fornecimento de água no mundo e a situação que enfrenta a Colômbia como potência hídrica com vistas à conservação da Região dos Páramos e de outras fontes de recursos hídricos, bem como o fornecimento de água potável