Development by Mechanochemistry of La0.8Sr0.2Ga0.8Mg0.2O2.8 Electrolyte for SOFCs

In this work, a mechanochemical process using high-energy milling conditions was employed to synthesize La0.8Sr0.2Ga0.8Mg0.2O3-δ (LSGM) powders from the corresponding stoichiometric amounts of La2O3, SrO, Ga2O3, and MgO in a short time. After 60 min of milling, the desired final product was obtained without the need for any subsequent annealing treatment. A half solid oxide fuel cell (SOFC) was then developed using LSGM as an electrolyte and La0.8Sr0.2MnO3 (LSM) as an electrode, both obtained by mechanochemistry. The characterization by X-ray diffraction of as-prepared powders showed that LSGM and LSM present a perovskite structure and pseudo-cubic symmetry. The thermal and chemical stability between the electrolyte (LSGM) and the electrode (LSM) were analyzed by dynamic X-ray diffraction as a function of temperature. The electrolyte (LSGM) is thermally stable up to 800 and from 900 °C, where the secondary phases of LaSrGa3O7 and LaSrGaO4 appear. The best sintering temperature for the electrolyte is 1400 °C, since at this temperature, LaSrGaO4 disappears and the percentage of LaSrGa3O7 is minimized. The electrolyte is chemically compatible with the electrode up to 800 °C. The powder sample of the electrolyte (LSGM) at 1400 °C observed by HRTEM indicates that the cubic symmetry Pm-3m is preserved. The SOFC was constructed using the brush-painting technique; the electrode-electrolyte interface characterized by SEM presented good adhesion at 800 °C. The electrical properties of the electrolyte and the half-cell were analyzed by complex impedance spectroscopy. It was found that LSGM is a good candidate to be used as an electrolyte in SOFC, with an Ea value of 0.9 eV, and the LSM sample is a good candidate to be used as cathode

Control and automation in chemical engineering : problems

Descripció del recurs: 11 de maig de 2015This book shows a solved problems collection with the aim of covering the knowledge requirements of the students of Chemical Engineering. The book begins with feedback systems, after having seen the block diagrams, until the study of stability using the frequency response. Some problems about control systems that are not based on feedback systems, always applied on Chemical Processes (Chapters 1, 2 and 3). The second part of the book is focused on applying in a practical way the concepts of Automation and Control. The chapter 4 solves discrete systems using pneumatic elements and programmable logic devices (PLCs). Finally, chapter 5 deals with the control of continuous processes using a PLC

A Fuzzy-set hierarchical classification of family firms

Family firms can be thought of as heterogeneous configurations where ownership, governance, management and succession are often intertwined. Previous works have typically used a partial definition of family firm based on one or more of these three aspects. In this empirical work we seek to clarify the definitions and typologies of family firms by using fuzzy sets qualitative comparative analysis (fs/QCA). Based on this methodology, we propose a hierarchical classification of family firms based on necessity and sufficiency conditions, including some possible overlapping among alternative types. We use an international sample of 6,611 companies from different industries and national/legal systems

Citrus psorosis virus movement protein contains an aspartic protease required for autocleavage and the formation of tubule-like structures at plasmodesmata

Plant virus cell-to-cell movement is an essential step in viral infections. This process is facilitated by specific virus-encoded movement proteins (MPs), which manipulate the cell wall channels between neighboring cells known as plasmodesmata (PD). Citrus psorosis virus (CPsV) infection in sweet orange involves the formation of tubule-like structures within PD, suggesting that CPsV belongs to "tubuleforming" viruses that encode MPs able to assemble a hollow tubule extending between cells to allow virus movement. Consistent with this hypothesis, we show that the MP of CPsV (MPCPsV) indeed forms tubule-like structures at PD upon transient expression in Nicotiana benthamiana leaves. Tubule formation by MPCPsV depends on its cleavage capacity, mediated by a specific aspartic protease motif present in its primary sequence. A single amino acid mutation in this motif abolishes MPCPsV cleavage, alters the subcellular localization of the protein, and negatively affects its activity in facilitating virus movement. The amino-terminal 34-kDa cleavage product (34KCPsV), but not the 20-kDa fragment (20KCPsV), supports virus movement. Moreover, similar to tubule-forming MPs of other viruses, MPCPsV (and also the 34KCPsV cleavage product) can homooligomerize, interact with PD-located protein 1 (PDLP1), and assemble tubule-like structures at PD by a mechanism dependent on the secretory pathway. 20KCPsV retains the protease activity and is able to cleave a cleavage-deficient MPCPsV in trans. Altogether, these results demonstrate that CPsV movement depends on the autolytic cleavage of MPCPsV by an aspartic protease activity, which removes the 20KCPsV protease and thereby releases the 34KCPsV protein for PDLP1-dependent tubule formation at PD. IMPORTANCE Infection by citrus psorosis virus (CPsV) involves a self-cleaving aspartic protease activity within the viral movement protein (MP), which results in the production of two peptides, termed 34KCPsV and 20KCPsV, that carry the MP and viral protease activities, respectively. The underlying protease motif within the MP is also found in the MPs of other members of the Aspiviridae family, suggesting that protease-mediated protein processing represents a conserved mechanism of protein expression in this virus family. The results also demonstrate that CPsV and potentially other ophioviruses move by a tubule-guided mechanism. Although several viruses from different genera were shown to use this mechanism for cell-to-cell movement, our results also demonstrate that this mechanism is controlled by posttranslational protein cleavage. Moreover, given that tubule formation and virus movement could be inhibited by a mutation in the protease motif, targeting the protease activity for inactivation could represent an important approach for ophiovirus control.Fil: Robles Luna, Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Biotecnología y Biología Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Biotecnología y Biología Molecular; ArgentinaFil: Peña, Eduardo José. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Biotecnología y Biología Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Biotecnología y Biología Molecular; ArgentinaFil: Borniego, María Belén. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Biotecnología y Biología Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Biotecnología y Biología Molecular; ArgentinaFil: Heinlein, Manfred. Université de Strasbourg; Francia. Centre National de la Recherche Scientifique; FranciaFil: Garcia, Maria Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Biotecnología y Biología Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Biotecnología y Biología Molecular; Argentin

Nostalgia and the Dialectics of Contemporary Feminisms in The Handmaid's Tale

In this article, we turn our gaze to the television series The Handmaid's Tale to examine different critical aspects of nostalgia in relation to contemporary and previous feminist debates. Our purpose is to analyze not only the series' different approaches to nostalgia but also to question the type of feminism the female dystopia attempts to recuperate. We enquire into the political capacity of the show's nostalgia to advance the complex debate on the subject of feminism. In our opinion, the series articulates a conservative recuperation of old feminist debates centered on the female subject (motherhood, rape, pornography, prostitution, etc.) not only due to the threat of the recent misogynistic backlash but also in response to the growth of political power from the LGBTQI movement and the subsequent displacement of traditional feminist issues. Nevertheless, despite falling short of contributing to an intersectional and structural critique of gender injustices, the show constitutes a stimulating catalyst in the fight and debate regarding the improvement of women's lives against the advances of retrograde attitudes and policies in current times. Ultimately, the series defies any monolithic understanding of nostalgia as either amnesiac and regressive or as reflective, inspiring, and recuperative regarding gender

Identificación y modelización de tendencias en emisiones contaminantes

El objetivo de este trabajo es el análisis de tendencias para emisiones contaminantes en España y número de horas o días en que los que se superan los umbrales de concentración permitidos por la ley (Directiva 1999/30/CE y Real Decreto 1073/2002 ) en España , Francia y Portugal. El análisis de tendencias es un área de gran relevancia en la actualidad y existen diferentes herramientas y enfoques para abordarlo. El tipo concreto de datos (reales o enteros) de que trate, además del conocimiento físico.químico del problema, será también relevante a la hora de optar por una u otra alternativa. En este trabajo se han utilizado dos herramientas: el análisis de tendencias estocásticas basado en series temporales para las emisiones contaminantes, y el basado en un modelo jerárquico bayesiano de procesos no homogéneos de Poisson unido a gráficos EWMA para las ocasiones (horas o días) en los que se superan los límites establecidos. Las especies químicas contaminantes que serán objeto de este análisis son: SO2 , NOx , PM10 , PAHs, dioxinas y VOCs y el periodo estudiado será el comprendido entre 1995 y 2008; las predicciones realizadas con ayuda de los modelos ajustados para cada tipo de datos llegarán al año 2020. Las bases de datos utilizadas para este trabajo son las siguientes: EMEP (European Monitoring and Evaluation Programme), disponible en la página web www.emep.int, que ofrece gran cantidad de datos sobre emisiones y concentraciones en los países de la Convención de Transmisión a Larga Distancia de Contaminantes Atmosféricos; estaciones españolas; agregación que se ha realizado; comparativa con Francia y Portuga

Association between sleep-disordered breathing and breast cancer aggressiveness

Background Sleep-disordered breathing (SDB) has been associated with cancer aggressiveness, but studies focused on specific tumors are lacking. In this pilot study we investigated whether SDB is associated with breast cancer (BC) aggressiveness. Methods 83 consecutive women <65 years diagnosed with primary BC underwent a home respiratory polygraphy. Markers of SDB severity included the apnea-hypopnea index (AHI) and the 4% oxygen desaturation index (ODI4). The Ki67 proliferation index, lack of hormone receptors (HR-), Nottingham Histological Grade (NHG), and tumor stage were used as markers of BC aggressiveness. The association between SDB and molecular subtypes of BC was also assessed. Results The mean (SD) age was 48.8 (8.8) years and body mass index was 27.4 (5.4) Kg/m2. 42 women (50.6%) were post-menopausal. The median (IQR) AHI was 5.1 (2–9.4), and ODI4 was 1.5 (0.5–5.8). The median (IQR) AHI did not differ between the groups with Ki67>28% and Ki6728% and Ki67<29% (51.2% vs 52.3%, p = 0.90), HR- and HR+ (58.3% vs 49.1%, p = 0.47), NHG categories (p = 0.89), different tumor stages (p = 0.71), or molecular subtypes (p = 0.73). These results did not change when the ODI4 was used instead of the AHI. Conclusion Our results do not support an association between the presence or severity of SDB and BC aggressiveness.Asociación de Neumología y Cirugía Torácica del Sur (NEUMOSUR) 1/201

El estatus jurídico del embrión humano en la legislación ecuatoriana a la luz del análisis de la sentencia del caso Artavia Murillo y otros (Fecundación in vitro) vs. Costa Rica

The legal status of the human embryo is a matter which major debates have arisen in relation to its position in law, specifically if it is considered a "rights holder". In order to determine the position of the Ecuadorian legislation on the subject, in this thesis, we analyzed the different theories about the beginning of life, in addition to the legal treatment has been given to the human embryo along the history of law, the position of national and international laws and jurisprudence on the issue. In this sense, we have contrasted the analysis with the decision of the Inter-American Court of Human Rights, affirmed in the judgment of Artavia Murillo and others vs. Costa Rica, to conclude, that in Ecuador, the human embryo does not have the legal status of a right holder.El estatus jurídico del embrión humano, es una cuestión de la cual se han originado grandes debates, en relación a su posición en el derecho; específicamente si se lo considera “persona titular de derechos”. Con el objetivo de determinar la postura de la legislación ecuatoriana en el tema, en el presente trabajo, se ha analizado las diferentes teorías acerca del inicio de la vida, además del tratamiento jurídico que se le ha otorgado al embrión humano a lo largo de la historia del derecho, la posición de las leyes nacionales e internacionales, así como la jurisprudencia respecto al tema. En este sentido, se ha contrastado el análisis a la luz de la sentencia del caso Artavia Murillo y otros vs. Costa Rica, emitida por la Corte IDH, para concluir, que en el Ecuador, el embrión humano no posee el estatus jurídico de una persona titular de derechos

Viabilidad del uso de la radiación solar concentrada al proceso de sinterización de cobre

En la actualidad, el proceso de sinterizado, así como la práctica totalidad de los procesos que se llevan a cabo en la industria, depende de las energías convencionales. Este trabajo pretende demostrar la viabilidad del uso de una fuente de energía renovable como es la Energía Solar Térmica en el sinterizado de cobre. Con objeto de realizar en el futuro una evaluación de las fuerzas conductoras y de la trayectoria del material transportado en función de las características del sistema y de la radicación incidente, se opta por diseñar distintos dispositivos experimentales de empaquetamiento basados en modelos de partículas ideales, en este caso cilindros, con los que se pretende simplificar la geometría del sistema real basado en partículas compactadas, siendo evaluados experimentalmente en el Homo Solar de la Plataforma Solar de Almería. Las muestras tratadas en atmósferas ligeramente reductoras, desarrollan cuellos bien definidos y muestran una reducción de porosidad, lo que permite demostrar la viabilidad del proceso

Evaluación continua a través del Moodle para involucrar al alumnado en su proceso de aprendizaje

El artículo presenta los resultados de un estudio orientado a conocer los efectos de un sistema de evaluación continua voluntaria usando la plataforma Moodle y un amplio banco de actividades, basadas en trabajos individuales y colaborativos, que el alumnado puede escoger. El objetivo de proponer este sistema de evaluación es doble. Por un lado, se persigue involucrar al alumnado ausente en el seguimiento de la evaluación continua mediante un entorno virtual. Por otro lado, se quiere motivar al alumnado en general en su aprendizaje a través de actividades continuas y orientadas a la práctica. El estudio se ha llevado a cabo en el contexto de una asignatura formada por dos grupos de los estudios de Administración y Dirección de Empresas de la Universidad de Barcelona. Como indicadores de bondad del sistema se han considerado la participación del alumnado en las actividades de evaluación y las notas finales. Los resultados han puesto de manifiesto la capacidad del sistema de involucrar al alumnado que asiste a clase en la realización de un mínimo de actividades y mejorar su aprendizaje, así como la incapacidad de involucrar significativamente al alumnado que no asiste a clase. Como conclusiones del estudio se apuntan la importancia de diseñar un buen modelo de feed-back y apostar más por tareas pensadas desde los enfoques de la evaluación auténtica