Optimisation of post-drawing treatments by means of neutron diffraction

The mechanical properties and the durability of cold-drawn eutectoid wires (especially in aggressive environments) are influenced by the residual stresses generated during the drawing process. Steelmakers have devised procedures (thermomechanical treatments after drawing) attempting to relieve them in order to improve wire performance. In thiswork neutron diffraction measurements have been used to ascertain the role of temperature and applied force – during post-drawing treatments – on the residual stresses of five rod batches with different treatments. The results show that conventional thermomechanical treatments are successful in relieving the residual stresses created by cold-drawing, although these procedures can be improved by changing the temperature or the stretching force. Knowledge of the residual stress profiles after these changes is a useful tool to improve the thermomechanical treatments instead of the empirical procedures used currently

Plastically-Induced Volume Deformation of Nanocrystalline α-Fe with a '110' Columnar Structure

Volume changes accompanying the plastic deformation at 300 K of nanocrystalline samples of α-Fe with a columnar grain structure possessing a ⟨11¯0⟩ random fiber texture has been obtained from molecular dynamics (MD) simulations. The samples were strained in tension along the common axial direction of the columnar grains. After removal of the elastic volume change, the evolution of plastic volume strain was obtained. Small but non-negligible volume dilations or contractions are observed depending on size (samples of very small grain size show volume contraction). The rate of volume change is high during the first 10% plastic deformation and continues at a low pace thereafter; the first 10% deformation represents a transient in the stress–strain behavior too. The complex behavior observed is reasonably explained by the superposition of contributions from different plastically-induced structural changes to the mass density change: Mainly from changes of grain size, grain boundary structure, dislocation density and density of point-defects. The results are of interest for the development of crystal plasticity theories not restricted by the volume conserving assumption

Las Criptomonedas, el blockchain y su comparativa con las divisas

El nacimiento de las criptomonedas está cambiando el paradigma tradicional de los medios de pago. El origen del Bitcoin en el año 2008 pretendía sustituir las divisas tradicionales caracterizadas por la centralización hacia un sistema descentralizado. Este trabajo pretende aproximar los conceptos esenciales de las criptomonedas para favorecer la comprensión de este fenómeno creciente al lector. Determinaremos si el Bitcoin es considerado como una divisa o como una commodity seguido de una comparativa de este sistema con el sistema de divisas tradicional. En definitiva, y ante el creciente interés de la sociedad en la inversión en criptomonedas como medio especulativo, proporcionaremos una decisión sobre el mercado más favorable para invertir (el mercado FOREX o el mercado de las criptomonedas) teniendo en cuenta tanto las rentabilidades como los riesgos que llevan asociados. <br /

A further study of the kinetics of recrystallization and grain growth of cold rolled TWIP steel

Over last decades, the twinning - induced plasticity Fe-Mn-C (TWIP) steels have been the focus on huge amount of research works due to their prominent strength – ductility compounding which develops from the occurrence of extended mechanical twinning during plastic deformation under mechanical loads (Grässel and Frommeyer, 1998; Frommeyer et al., 2000; Cornette et al., 2005; Scott et al., 2006; Bouaziz et al., 2008; Hamada et al., 2010; Bouaziz et al., 2011; De Cooman et al., 2011; Galán et al., 2012; Gil Sevillano and De las Cuevas, 2012; Chen et al., 2013; De las Cuevas et al., 2014; Ghasri-Khouzani and McDermid, 2015; Pierce et al., 2015; De las Cuevas and Gil Sevillano, 2017). In TWIP steels, the fully austenitic microstructure can be retained by means of high level alloying with elements such as Mn, Al and Si. Al and Si are mainly used to adjust the magnitude of the stacking fault energy, gSFE, of austenite (Frommeyer et al., 2000). Furthermore, they also strengthen the steel by solid solution hardening and stabilize austenite owing to their ability of slowing down the precipitation of carbides, especially cementite, leaving more carbon available for the enrichment of austenite (Leslie and Rauch, 1978)

Proyecto constructivo de centro de turismo rural en Cuellar (Segovia).

El presente proyecto tiene por objeto definir las obras necesarias de Rehabilitacion a realizar en el edificio de viviendas situado en la Avda. de Camilo Jose Cela no 6 de Cuellar (Segovia), para la construccion de un parador de turismo rural y pertenece al nucleo historico del municipio de Cuellar,ocupa un solar de planta poliedrica. Segun su registro en el Catastro, el año de construccion del inmueble es el 1910, y su uso local principal es Industrial en el caso de la Planta Baja, y Residencial en el caso de las Plantas Primera y Segund

Desarrollo de competencias digitales de estudiantes universitarios en contextos informales de aprendizaje

The purpose of this article is to explore the perception of university students about the development of digital skills in informal educational contexts. To this end, a sequential mixed research was conducted with university students from a private institution in the city of Cali, Colombia. The data collection techniques consisted of an electronic questionnaire and two discussion groups. Among the main results, it was found that students have a heterogeneous perception regarding the development of the different areas of digital skills, being stronger those related to the interaction and the creation/ edition of graphic content. The lowest values were reported for security competencies and problem solving. The students referred a wide number of digital practices that they had learned autonomously, through interaction with other individuals, with web resources and from trial-error personal experiences. However, these competences are not usually transferred to the academic field. Finally, some proposals are presented. They can be considered as articulating axes for the development of digital competences inside and outside the classroom.Este artículo busca evidenciar la percepción de estudiantes universitarios sobre el desarrollo de competencias digitales por fuera de los contextos educativos formales. Para ello, se llevó a cabo una investigación mixta secuencial con ingresantes universitarios de una institución privada de la ciudad de Cali, Colombia. Como técnicas de recolección de información se implementaron un cuestionario electrónico y dos grupos de discusión. Entre los principales resultados se encontró que los estudiantes tienen una percepción heterogénea respecto al desarrollo de las distintas áreas de la competencia digital, siendo más fuertes las relacionadas con la interacción y la creación/edición de contenidos gráficos. Las de menor desarrollo son las competencias de seguridad y resolución de problemas. Los estudiantes dan cuenta de un amplio número de prácticas digitales que han aprendido de forma autónoma, a través de la interacción con otros sujetos, con recursos propios de la web y a partir de experiencias personales de ensayo y error, pero estas competencias no suelen transferirse al ámbito académico. Finalmente, se presentan algunas propuestas que pueden plantearse como ejes articuladores del desarrollo de competencias digitales dentro y fuera del aula

Childhood Cancer and the Family: A Pilot Proposal for Comprehensive Intervention at the Time of Diagnosis

Childhood cancer has a great impact on children and their environment. To minimize this, countries such as Canada and the USA have protocols in the field of social work, although these are scarce in Europe and especially in Spain. This paper aims to develop a pilot protocol in Aragon (Spain) for the practice of onco-pediatric social work in one of the hardest moments: the diagnosis. For its elaboration, a previous study was carried out in three phases, which provided data on the disease and its impact on the family and children and a methodological basis for the intervention from social work, all considering the participation of the agents involved as a fundamental element. Variables have been identified that influence the impact on the family support network and its quality of life at the time of diagnosis of childhood cancer. In addition, different indicators have been explored, based on the reality of these families. Finally, a pilot proposal for a comprehensive family intervention protocol in the diagnosis of childhood cancer has been elaborated. This work is intended to be a guide for intervention and delimitation of quality standards to be considered when dealing with the diagnosis of childhood cancer

Defect-induced tuning of polarity-dependent adsorption in hydrophobic–hydrophilic UiO-66

Structural defects in metal–organic frameworks can be exploited to tune material properties. In the case of UiO-66 material, they may change its nature from hydrophobic to hydrophilic and therefore affect the mechanism of adsorption of polar and non-polar molecules. In this work, we focused on understanding this mechanism during adsorption of molecules with different dipole moments, using the standard volumetric adsorption measurements, IR spectroscopy, DFT + D calculations, and Monte Carlo calculations. Average occupation profiles showed that polar and nonpolar molecules change their preferences for adsorption sites. Hence, defects in the structure can be used to tune the adsorption properties of the MOF as well as to control the position of the adsorbates within the micropores of UiO-66.</p