Molecular Dynamics Simulations of Lead and Lithium in Liquid Phase

Pb17Li is today a reference breeder material in diverse fusion R&D programs worldwide. Extracting dynamic and structural properties of liquid LiPb mixtures via molecular dynamics simulations, represent a crucial step for multiscale modeling efforts in order to understand the suitability of this compound for future Nuclear Fusion technologies. At present a Li-Pb cross potential is not available in the literature. Here we present our first results on the validation of two semi-empirical potentials for Li and Pb in liquid phase. Our results represent the establishment of a solid base as a previous but crucial step to implement a LiPb cross potential. Structural and thermodynamical analyses confirm that the implemented potentials for Li and Pb are realistic to simulate both elements in the liquid phase

YouTube doctors confronting COVID-19: Scientific–medical dissemination on YouTube during the outbreak of the coronavirus crisis

Producción CientíficaThe coronavirus crisis has highlighted the consumption of social media and online video platforms in search of an alternative discourse to that provided by traditional media. The objective of this article is to find an approach to education and scientific dissemination on COVID-19 present in the Spanish context of YouTube, focusing on the content analysis of audiovisual texts generated by creators from the medical and biomedical fields. A methodological orientation was used for this based on the Grounded Theory, which was applied to five case studies whose informative material on SARS-CoV-2 exceeded ten million views as of March 2021. The results reveal the existence of a group of medical professionals in the Spanish YouTube sphere who, since the COVID-19 outbreak, have been involved in the construction of an alternative discourse around the health crisis and its evolution that pursues a high standard of audiovisual quality, scientific rigor, and educational ability.Ministerio de Ciencia e Innovación y Ministerio de Universidades - FEDER (CAS19/00226 and PID2019-104689RB-I00)

The relationship between landscape patterns and human-caused fire occurrence in Spain

Aim of study: Human settlements and activities have completely modified landscape structure in the Mediterranean region. Vegetation patterns show the interactions between human activities and natural processes on the territory, and allow understanding historical ecological processes and socioeconomic factors. The arrangement of land uses in the rural landscape can be perceived as a proxy for human activities that often lead to the use, and escape, of fire, the most important disturbance in our forest landscapes. In this context, we tried to predict human-caused fire occurrence in a 5-year period by quantifying landscape patterns. Area of study: This study analyses the Spanish territory included in the Iberian Peninsula and Balearic Islands (497,166 km2). Material and Methods: We evaluated spatial pattern applying a set of commonly used landscape ecology metrics to landscape windows of 10x10 sq km (4751 units in the UTM grid) overlaid on the Forest Map of Spain, MFE200. Main results: The best logistic regression model obtained included Shannon’s Diversity Index, Mean Patch Edge and Mean Shape Index as explicative variables and the global percentage of correct predictions was 66.3 %. Research highlights: Our results suggested that the highest probability of fire occurrence at that time was associated with areas with a greater diversity of land uses and with more compact patches with fewer edges

Experimental performance of a novel scraped surface heat exchanger for latent energy storage for domestic hot water generation

In this work, a novel design of a real scale Scraped Surface Heat Exchanger (SSHE) for solar LTES has been developed and experimentally tested. The main issue in PCM heat exchangers is the growth of a solid layer at the heat transfer walls during the latent energy extraction/discharging, that lowers heat transfer. The removal of the solidified PCM through scraping increases the heat transfer rate with nearly constant heat flux. Those characteristics make it suitable for domestic hot water generation. Discharging tests have been performed in scraping and no scraping modes (SM and nSM). The heat release rate in SM has shown to be between two and three times higher than in nSM. Moreover, in SM there is a complete extraction of the available latent energy (11.9 MJ) in a short period, compared to nSM. Additionally, a performance comparison between the developed SSHE and those available in open literature has been done. The results of heat release density (4 kW/m2) and overall heat transfer coefficient (1000 W/m2K) have shown similar values, though the scraping mechanism, the rotational speed, the size and their energy capacity are different. The developed design is an appropriate technology to increase the efficiency in solar LTES.The authors gratefully acknowledge to European Regional Development Fund and Ministerio de Ciencia e Innovación - Agencia Estatal de Investigación for the financial support of the project ALTES: “Active Latent Thermal Energy Storage”, Ref. PGC2018-100864-B-C21. We are also grateful to the company Outheway for the technical support in the design and manufacturing of scraper rotative heat exchanger. The present publication was first presented at the 16th Conference on Sustainable Development of Energy, Water and Environment Systems SDEWES conference, Dubrovnik, Croatia, 10–15 October 2021

Accelerated testing methods to analyse long term stability of a Phase Change Material under the combined effect of shear stress and thermal cycling

The long-term stability of a Phase Change Material (PCM) is a key point for its selection in energy storage devices. This work studies the suitability of a commercial paraffin wax in an active scraped surface heat exchanger for solar energy storage purposes. In these devices, the continuous scraping of inner walls during solidification removes PCM and increases the released heat. Hence, the PCM is affected by a high level of shear stress. In order to study a potential degradation of the paraffin, a novel accelerated procedure has been designed for obtaining samples with a different number of thermal and scraping cycles. The procedure allows to evaluate the effect of shear stresses, thermal cycles and their combined effects separately. Up to 3000 cycles have been generated, which accounts for around 8 years of continuous daily work in the heat exchanger. The measurements through Differential Scanning Calorimetry, rheometry and thermal conductivity analysis have shown that neither the thermal nor the scraping cycling have a significant impact on the paraffin thermo-physical properties. According to the findings reported in this work, paraffin wax RT44HC can be successfully used in scraped surface heat exchangers. It is expected that other commercial paraffins would be also suitable since most of them share the fact of being blends of alkanes and other hydrocarbons.The authors gratefully acknowledge to European Regional Development Fund and Ministerio de Ciencia e Innovación - Agencia Estatal de Investigación for the financial support of the project ALTES: “Active Latent Thermal Energy Storage”, Ref. PGC2018-100864-B-C21

Observation protocol as a professional development tool for in-service teachers

This work has been funded by Cabildo de Tenerife (Spain)

Creative and collective writing in the context of the new cultural practices

Se plantea en este artículo el cambio profundo que, en la nueva cultura del siglo XXI, ha sufrido el concepto de creación colectiva, por influencia de Internet. Las redes sociales, la cultura participativa, la convergencia de los medios y otros factores han favorecido nuevos modos de expresión, al margen de la escritura académica o profesional, como ha sido el caso de la ficción-manía. Sobre el concepto de creación colectiva se está escribiendo mucho, a propósito de la épica y de otros temas literarios y debe ser “iluminado” a la luz de lo que Internet o los nuevos fenómenos, como el auge de las sagas fantásticas o la ficción-manía, están suponiendo. Así, lo que actualmente se denomina escritura colaborativa es en realidad un concepto que ha ido evolucionando de forma acompasada con las poéticas y las prácticas sociales de la lectura en los últimos tiempos. Revisamos los rasgos de estas nuevas prácticas y se analizan las implicaciones para la educación del siglo XXI.The deep change that, in the new culture of the 21st century, has suffered the concept of collective creation, under the influence of the Internet is proposed in this article. Social networking, participatory culture, the convergence of media and other factors have favored new ways of expression, apart from academic or professional writing, as it has been the case of the fan fiction. There is a lot of studies nowadays on the concept of collective creation, with regard to epic and other literary topics and should be “enlightened” in the light of what Internet or new phenomena, such as the rise of fantasy sagas or the fan fiction, are involving. So, what is currently referred to as collaborative writing is actually a concept that has evolved in a measured way with the poetic and social practices of reading in last times. We review the features of these new practices and examine the implications for the education of the 21st century.peerReviewe

El hallazgo de moneda califal de Fontanar (Córdoba)

Análisis del hallazgo de dírhams califales aparecidos en el Fontanar, en los arrabales occidentales de Córdoba.This text deals witn the analysis of dirhams from the Caliphate age found in El Fontanar, in the western outskirts of Córdoba