Deformation of polycrystalline TRIP stainless steel micropillars

The deformation mechanisms of the metastable austenite phase of a transformation induced plasticity (TRIP) stainless steel, AISI 301LN, have been investigated by compression of multicrystalline micropillars of different crystallographic orientations, with particular attention on the strain-induced phase transformation from austenite to martensite. Intergranular shearing and twinning were observed to be the primary deformation mechanisms, with a predominant orientation developed in the austenitic phase, combined with limited planar slip within single grains of austenite. The phase transformation from austenite to ¿ and ¿’-martensite was clearly observed adjacent to the sheared regions using TEM-EBSD techniques. The ¿-martensite phase was found to be preferentially located in the regions near the grain boundaries which experienced higher shear stresses during compression.Peer ReviewedPostprint (author's final draft

Intrinsic hardness of constitutive phases in WC–Co composites:Nanoindentation testing, statistical analysis, WC crystal orientation effectsand flow stress for the constrained metallic binder

The intrinsic hardness of the constitutive phases in WC–Co composites is investigated by combining experimental and statistical analysis nanoindentation techniques. It is done on the basis of considering the cemented carbide material as effectively heterogeneous at the microstructure scale, i.e. consisting of three phases defined by either different chemical nature (carbides and binder) or distinct carbide crystal orientation (i.e. with surface normal perpendicular to either basal or prismatic planes). As main outcome, experimentally measured and statistically significant intrinsic hardness values for the defined phases (WC and constrained metallic binder) are analyzed and determined. Besides the evidence of crystal anisotropy for the WC phase, they permit to identify and account the expected strengthening of the plastic-constrained metallic binder, a critical input parameter for hardness and toughness modelling as well as for microstructural design optimization of ceramic composites reinforced by ductile metallic ligamentsPeer ReviewedPostprint (author's final draft

Geomagnetic Field’s Intensity in Europe for the last 2000 years: the SCHA.DI.00-F geomagnetic model

El modelo direccional europeo de campo geomagnético SCHA.DI.00 válido para los últimos dos mil años ha sido completado mediante la introducción de la paleointensidad. Este modelo, SCHA.DI.00, fue desarrollado a partir de las curvas bayesianas de variación paleosecular existentes en Europa mediante el uso de la técnica de armónicos esféricos en un casquete (SCHA). El modelo regional mejora dentro de la zona de estudio (el continente Europeo) los diferentes modelos globales de campo geomagnético en el pasado. El objetivo de este estudio será usar la reciente base de datos de paleointensidad de Europa de los últimos dos mil años para generar un modelo de campo geomagnético completo (declinación, inclinación e intensidad): el modelo SCHA.DI.00-F.The SCHA.DI.00 directional model for the geomagnetic field in Europe for the last 2000 years has been updated by modelling the palaeointensity. This model, SCHA.DI.00, was developed from available Bayesian European Palaeosecular Variation Curves using the regional Spherical Cap Harmonic Analysis technique. The comparison of the palaeosecular variation curves, given by the regional model, with available archaeomagnetic data not used in its development showed an improvement with respect to the fit obtained by global archaeomagnetic models. In this paper advantage is taken of recently published palaeointensity databases to develop a complete (direction and intensity) regional archaeomagnetic model for the last 2000 years valid for the European region: the SCHA.DI.00– F model.Depto. de Mineralogía y PetrologíaFac. de Ciencias GeológicasTRUEMinisterio de Educación y Ciencia (MEC)pu

A Middle Palaeolithic wooden digging stick from Aranbaltza III, Spain

Aranbaltza is an archaeological complex formed by at least three open-air sites. Between 2014 and 2015 a test excavation carried out in Aranbaltza III revealed the presence of a sand and clay sedimentary sequence formed in floodplain environments, within which six sedimentary units have been identified. This sequence was formed between 137±50 ka, and includes several archaeological horizons, attesting to the long-term presence of Neanderthal communities in this area. One of these horizons, corresponding with Unit 4, yielded two wooden tools. One of these tools is a beveled pointed tool that was shaped through a complex operational sequence involving branch shaping, bark peeling, twig removal, shaping, polishing, thermal exposition and chopping. A use-wear analysis of the tool shows it to have traces related with digging soil so it has been interpreted as representing a digging stick. This is the first time such a tool has been identified in a European Late Middle Palaeolithic context; it also represents one of the first well-preserved Middle Palaeolithic wooden tool found in southern Europe. This artefact represents one of the few examples available of wooden tool preservation for the European Palaeolithic, allowing us to further explore the role wooden technologies played in Neanderthal communities

Mapa escolar de Cataluña

Facilitar una descripción de la situación actual en Catalunya en lo referente a escolarización y evaluar la demanda escolar previsible durante los próximos años. Servicios Educativos (presencia territorial del Departament d'Ensenyament, Servicios Educativos de ayuda a la Escuela). Los Centros docentes y la escolarización en Catalunya (descripción comarcal). Previsión de censo, previsión de escolarización, datos referentes a ámbitos territorales de alcance subcomarcal y datos referentes a municipios. Para reflejar la situación actual se suministran datos que muestran tanto los niveles de escolarización conseguidos en los últimos años en las diferentes etapas de que se componen la Enseñanza Primaria y Secundaria en Catalunya, como los diferentes tipos de Centros educativos en los cuales se imparten dichas Enseñanzas. En cuanto a la previsión para los próximos años, se concreta en una estimación del censo escolar para el período 1990-2001, y también en una previsión de la demanda escolar. Censo de 1986. Centre d'Informació i Documentació de Catalunya. Departament d'Ensenyament.CataluñaES

Cement-Rock Interface Subjected to scCO2

Storing CO2 in deep underground reservoirs has been an important progress in reducing pollution to the atmosphere and standing against climate change. The accumulated gas in these reservoirs is in a supercritical state (scCO2) and in contact with the cement plug during its useful life. Ordinary cement paste cannot stop the carbonation of the system and can lead into CO2 escape paths to other reservoirs or to the surface in a short period of time. In view of this problem, a chemical and microstructural characterization of modified cement with glass microspheres and bacterial nano-cellulose is presented. Using this data, we simulate the carbonation process in reservoir conditions with a chemo-poromechanical model implemented in a finite element code. Results show an increase in properties of the modified cement samples in the experimental and simulation stages