Development and significance of tectonic foliations in the Hercynian Belt of NW Spain

[Resumen] En este trabajo se presenta un modelo de distribución y desarrollo de foliaciones en rocas pelíticas y samíticas dentro de un orógeno: el Macizo Herciniano del NW d e España. Estas rocas estuvieron sometidas a una deformación polifásica, con tres fases principales, en condiciones que van desde la transición diagénesis-metamorfismo hasta un metamorfismo de alto grado. Las características de las foliaciones asociadas a las distintas fases de deformaci6n varían progresivamente a medida que lo hace el metamorfismo, existiendo, no obstante, algunos saltos bruscos en dichas características, cuya situaci6n coincide con los límites entre algunas de las grandes zonas en que se divide el orógeno. En todo caso, la foliación tect6nica primaria(Sl) muestra un carácter generalizado, mientras que las otras dos (S2 y S3) presentan una distribución más irregular, apareciendo la S2 en relación con las zonas de cizalla asociadas a grandes cabalgamientos y la S3 controlada por la posición de la anisotropía previa dominante. En la formaci6n de estas foliaciones intervino, en general, de manera muy importante la disolución por presión en las áreas menos metamórficas y la recristalización orientada de filosilicatos en las más metamórficas. El análisis de las relaciones cronológicas entre cristalización metamórfica y desarrollo de foliaciones pone de manifiesto una cierta heterogeneidad espacial en el momento de aparición de los episodios metamórficos en relación con los de deformación. Esta heterogeneidad puede explicarse por las alteraciones en las condiciones P, T que produce el emplazamiento de las grandes unidades tectónicas.[Abstract] A model concerning distribution and development of foliations is presented in this paper, for pelitic and psammitic rocks in the Hercynian Belt ofNW Spain. This rocks have undergone three main deformation phases, in conditions ranging from the iagenesis-metamorphism transition to the high grade metamorphism. The features of the foliations associated to the different phases varie progressively with the metamorphism. Nevertheless, sorne abrupt changes in this features can also be found in sorne of the borders between the main tectonic units. Anyhow, the primary tectonic foliation (Si) is generalized, and the other two (S2 and S3) have a more irregular distribution, related to shear zones associated to main thrusts (S2), or to zones with a favourable possition of the main previous anisotropy (for S3)' The deformation mechanisms opperating in the development of this foliations were, mainly, pressure solution in the zones with low metamorphism, and recrystalization of orientated phyllosillicates in those with the higher metamorphism. The analysis of the chronologic relationships between metamorphic crystalization and development of the foliations in different tectonic units shows sorne differences in the age of the metamorphic episodes in relation with the deformation. These inhomogeneities can be explained by the changes in P, T conditions produced by the emplacement of the main tectonic units

The impact of PISA in the Spanish society : the case of written press

En la última década los resultados de los diferentes Informes PISA han avivado el debate sobre la calidad de nuestro sistema educativo, repercutiendo en la opinión pública y en la toma de decisiones en el plano político. En el presente estudio se analiza el impacto que han tenido los resultados de PISA en la sociedad española a través de las noticias publicadas en el periódico «El País» desde el 2001 al 2014, atendiendo a las siguientes cuestiones: a) los subgéneros periodísticos utilizados para hablar de PISA y su autoría; b) la evolución de las noticias desde PISA 2001 hasta PISA 2012; y c) la frecuencia de uso de las competencias evaluadas por PISA como argumento informativo. Los resultados muestran la gran trascendencia de la evaluación PISA en prensa, sobre todo desde la edición del Informe correspondiente al año 2003 y reflejado en su mayoría en artículos de carácter informativo-descriptivo. Por otro lado, se evidencia el tratamiento que hacen los medios de comunicación escrita a las competencias matemática, científica y lectora, dando una mayor relevancia a esta última en los últimos años. Por último, se concluye que la prensa escrita ha sido un gran contribuyente a la hora de trasladar los resultados obtenidos en PISA a la opinión pública, a pesar del uso inadecuado que se hace en ocasiones de los datos sin tener en cuenta las limitaciones del propio estudio

Rapid prototyping of electrochemical lateral flow devices: stencilled electrodes

A straightforward and very cost effective method is proposed to prototype electrodes using pressure sensitive adhesives (PSA) and a simple cutting technique. Two cutting methods, namely blade cutting and CO2 laser ablation, are compared and their respective merits are discussed. The proposed method consists of turning the protective liner on the adhesive into a stencil to apply screen-printing pastes. After the electrodes have been printed, the liner is removed and the PSA can be used as a backing material for standard lateral flow membranes. We present the fabrication of band electrodes down to 250 μm wide, and their characterization using microscopy techniques and cyclic voltammetry. The prototyping approach presented here facilitates the development of new electrochemical devices even if very limited fabrication resources are available. Here we demonstrate the fabrication of a simple lateral-flow device capable of determining glucose in blood. The prototyping approach presented here is highly suitable for the development of novel electroanalytical tools.This work has been funded by the Spanish Ministry of Economy through the DADDi2 project (Grant TEC2013-48506). MK acknowledges funding through the Beatriu de Pinós program (BP-DGR-2013), supported by the Secretary for Universities and Research of the Ministry of Economy and Knowledge of the Government of Catalonia and the Cofund programme of the Marie Curie Actions of the 7th R&D Framework Programme of the European Union. We acknowledge support by the CSIC Open Access Publication Initiative through its Unit of Information Resources for Research (URICI)Peer reviewe

Contribution to Theme A of the Benchmark Workshop: Effect of Concrete Swelling on the Equilibrium and Displacements of an Arch Dam

The Kariba dam is undergoing concrete expansion as a result of an alkali-aggregate reaction. The model adopted to simulate the process is explained in the paper; it is based on the model first proposed by Ulm et al, as later modified by Saouma and Perotti. It has been implemented in the commercial finite element code Abaqus and applied to solve the benchmark problem. The parameters of the model were calibrated using the data recorded up to 1995. The calibrated model was then used for predicting the evolution of the dam up to the present date. Apart from this prediction the paper offers a number of conclusions, such as the fact that the stress level appears to have a major influence on the expansion process; and it presents some suggestions to improve the formulation of the benchmark, such as providing temperature data and widening the locations and conditions of the data employed in the calibratio

Optimised design of foundations for wind towers

Environmental, political, and other considerations are leading to the installation of growing numbers of wind turbines for electricity generation. The present paper concentrates on onshore installations, in which the turbine is placed at the end of a tower founded on the ground. A serious problem with the foundation or its connection with the tower entails a global failure. A worrying percentage of the towers built before 2010 is ill designed, often with obvious manifestations of the design problem. On the other hand the new designs attempt to optimise material quantities and costs while providing an adequate behaviour under the demands imposed. Principia has gathered considerable experience in both the identification and remediation of the problems experienced by older foundations and the optimisation of new designs. The problem is particularly suitable for numerical simulations with Abaqus and the paper provides the necessary concepts and methodological approach for a reliable and satisfactory solution. More specifically, the concrete geometry is meshed with solid elements. Surface elements including rebar layers are embedded. Other parts of the structure as the steel cylinder, welded studs, anchorage bars, etc. are also included. The concrete behaviour is described with the Abaqus concrete damaged plasticity model. Abaqus/Explicit is used because of the strong non-linearities, mainly caused by concrete cracking and crushing. The methodology allows assessing the suitability of the design for ultimate, serviceability and fatigue limit states

El papel de los convertidores CC/CC en las comunicaciones por luz visible

XXIV Seminario Anual de Automática, Electrónica Industrial e Instrumentación 2017 (SAAEI'17), Valencia (España)Las comunicaciones inalámbricas en luz visible (CLV) se han propuesto como una alternativa a las clásicas comunicaciones inalámbricas basadas en el uso del congestionado espectro de RF (Radiofrecuencia). La idea es utilizar los sistemas de iluminación basados en LEDs para compatibilizar las funciones de iluminación y transmisión de datos. Numerosos estudios y pruebas se han realizado ya, pero todos ellos con dispositivos que manejaban potencias bastante modestas. El objetivo de este trabajo es analizar las distintas formas en las que la electrónica de potencia puede ayudar a incrementar la potencia de las CLVs, manteniendo rendimientos energéticos altos. Todas las soluciones que se van a proponer se basan en el uso de convertidores CC/CC conmutadosEste trabajo ha sido financiado por el Gobierno Español mediante el Proyecto MINECO-17-DPI2016-75760-R y el contrato predoctoral FPU14/03268, por el Gobierno del Principado de Asturias por el proyecto FC-15-GRUPIN14-143 y por los “European Regional Development Fund (ERDF) grants

Performance Evaluation of a VLC Transmitter Based on the Split of the Power

IEEE Applied Power Electronics Conference and Exposition, San Antonio, (Estados Unidos de Norteamérica), marzo de 2018Visible Light Communication (VLC) has gained relevance during last years. It consists in using High-Brightness LEDs (HB-LEDs) both for lighting and for transmitting information changing the light intensity rapidly. However, there are some bottlenecks that are slowing down the deployment of this technology. One of the most important problems is that the HB-LED drivers proposed for addressing high data rates in VLC achieve poor power efficiency. Since these HB-LED drivers must be able to reproduce fast current waveforms, the use of Linear Power Amplifiers (LPAs) has been adopted, which clearly damage the power efficiency of HB-LED lighting. In order to alleviate this problem, a HB-LED driver made up of two DC-DC power converters is presented in this work. One of them is responsible for performing the communication functionality by operating at high switching frequency (10 MHz), whereas the second one fulfills the illumination functionality by ensuring a certain biasing point. The split of the power allows to minimize the power delivered by the fast-response DC-DC power converter. Thus, the efficiency can be maximized for scenarios with changing conditions (i.e., mobile transmitter and/or receiver, presence of mobile obstacles, etc.). In this sense, how the lighting level and the communication signal power affect both the power efficiency and the communication efficiency is deeply analyzed. The implemented prototype achieves an overall efficiency around 90%. In addition, the proposed VLC transmitter is able to reproduce a wide range of digital modulation schemes, including Orthogonal Frequency Division Multiplexing (OFDM

Effect of Concrete Swelling on the Equilibrium and Displacements of an Arch Dam

The Kariba dam is undergoing concrete expansion as a result of an alkali-aggregate reaction. The model adopted to simulate the process is explained in the paper; it is based on the model first proposed by Ulm et al, as later modified by Saouma and Perotti. It has been implemented in the commercial finite element code Abaqus and applied to solve the benchmark problem. The parameters of the model were calibrated using the data recorded up to 1995. The calibrated model was then used for predicting the evolution of the dam up to the present date. Apart from this prediction the paper offers a number of conclusions, such as the fact that the stress level appears to have a major influence on the expansion process; and it presents some suggestions to improve the formulation of the benchmark, such as providing temperature data and widening the locations and conditions of the data employed in the calibratio

Simulation of Temperatures and Stresses during Construction of a RCC Dam

Se describen las variaciones de temperaturas y de tensiones durante la construcción de presas de hormigón compactado. The curing of concrete is an exothermic process. The heat of hydration generated induces temperature increases in the concrete, which will disappear in the long term by heat conduction in the concrete mass and thermal exchanges with the environment. The problem is of particularly interest for large concrete masses, as is the case of dams, because the time involved in the heat diffusion process grows with the square of the dimensions and a hotter dam interior implies the possibility of cracking the exposed surfaces of the dam. The Cuira dam, currently being built in Venezuela using roller compacted concrete, is a 134 m high, arch-gravity dam. In support of the design, different strategies were analysed, including various combinations of cooling of the water and the aggregate in order to achieve acceptable results. The calculations were conducted with Abaqus, taking into account all the necessary mechanical and thermal characteristics, as well as the relevant non-linearities. The analyses led to the conclusion that no cooling was required, even taking into account the stress state imposed by an early and rapid filling of the reservoir

Imaging approaches to assess the therapeutic response of gastroenteropancreatic neuroendocrine tumors (GEP-NETs): current perspectives and future trends of an exciting field in development

Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) are a family of neoplasms with a complex spectrum of clinical behavior. Although generally more indolent than carcinomas, once they progress beyond surgical resectability, they are essentially incurable. Systemic treatment options have substantially expanded in recent years for the management of advanced disease. Imaging plays a major role in new drug development, as it is the main tool used to objectively evaluate response to novel agents. However, current standard response criteria have proven suboptimal for the assessment of the antiproliferative effect of many targeted agents, particularly in the context of slow-growing tumors such as well-differentiated NETs. The aims of this article are to discuss the advantages and limitations of conventional radiological techniques and standard response assessment criteria and to review novel imaging modalities in development as well as alternative cancer- and therapy-specific criteria to assess drug efficacy in the field of GEP-NETs