Tribological behavior of functionalized 1-2 layered graphene/uhmwpe composites

In this work we present the evaluation of pristine and functionalized graphene as reinforcements for UHMWPE-based composites. These composites were manufactured by physically blending graphene particles and medical grade UHMWPE powder followed by a thermo-compression process. Mechanical behaviour by means of uniaxial tension and biaxial load by small punch were carried out. Friction coefficient and wear rate were measured. In some cases composites enhanced stiffness and yield stress, although with loss of toughness. This mechanical behaviour was recuperated after a thermal treatment. Small positive changes were obtained with some graphene concentrations respect to the friction coefficient. However, 20 % of reduction in wear rate was obtained when the graphene was functionalized. In general these composites present a good trend to be a potential alternative to the current highly crosslinked polyethylenes.We thank the Ministry of Science and Education of Spain by means of the projects MAT2010-16175) and CONSOLIDER CSD2008-00023 (FUNCOAT) for financial suppor

Influence of processing conditions on microstructural, mechanical and tribological properties of graphene nanoplatelet reinforced UHMWPE

Ultra-high molecular weight polyethylene (UHMWPE) is a relevant thermoplastic in industry and a well-proven standard biomaterial in joint replacements. To enhance its tribological properties while preserving its bulk ones, composite coatings on a UHMWPE substrate were prepared using non-functionalised graphene nanoplatelet (GNP) at reinforcement concentration of 0.1–5 wt% and two mechanical mixing techniques (ball mill or blade mixer) with different consolidation temperatures of 175–240 °C. Changes in morphology and size of the UHMWPE particles before hot-pressing were observed in function of the mechanical mixing techniques applied. Wear rate was affected by graphene content, reaching a minimum at 0.5 wt% GNP, with a reduction of 20 and 15%, for ball milling and blade mixer, respectively. However, blade mixer increased the wear rate by around twice respect the ball milling results, for all the studied materials. The coefficient of friction decreased notably, by ~25%, below 3 wt% GNP content, and hardness increased by 24%, regardless of the mechanical mixing process used. Finally, consolidation temperature had a positive influence on wear rate at temperatures of around 195 °C, which could be related to the free radical scavenger effect of the GNP

El margen de apreciación nacional en los tribunales regionales de derechos humanos: una aproximación consensualista

El trabajo examina la noción del margen de apreciación nacional utilizada por el Tribunal Europeo de Derechos Humanos y la Corte Interamericana de Derechos Humanos desde una perspectiva consensualista, basada en el Derecho internacional público. El margen de apre- ciación nacional es un concepto jurídico indeterminado cuya aplicación depende de diversos factores intrínsecos y extrínsecos. El consenso representa uno de esos elemen- tos de carácter extrínseco y tiene un efecto integrador en la jurisprudencia regional de derechos humanos. En efecto, el desarrollo de los derechos fundamentales en Europa y América va acompañado de un consenso entre los Estados partes de ambos subsistemas regionales de derechos hu- manos. Sin ese necesario consensus generalis, que los tribunales regionales de derechos humanos constatan a través de la práctica de los Estados, la interpretación evolutiva se hace más compleja y la jurisprudencia regional de dere- chos humanos se torna más deferente con la soberanía estatal. El consenso, por tanto, constituye una noción que permite explicar, desde el Derecho internacional público, la aplicación del margen de apreciación nacional por parte del Tribunal Europeo de Derechos Humanos y de la Corte Interamericana de Derechos Humanos.The paper examines the concept of margin of appreciation invoked by the European Court of Human Rights and the Interamerican Court of Human Rights, from a consensualist approach based on Public interna- tional Law. The margin of appreciation is an indeterminate legal concept whose application depends on several intrinsic and extrinsic factors. In this context, the consen- sus, one of these extrinsic factors, produces an integrating effect on the regional human rights jurisprudence. The development of fundamental rights in Europe and America is accompanied by a consensus between States parties to both regional subsystems. Without the necessary consensus generalis, which is confirmed through State practice, the evolutive interpretation of the human rights treaties becomes more complex and regional human rights case-law turns out to be more deferential towards State sovereignty. The consensus allows to explain, from Public international Law, the application of the margin of appreciation by the European Court of Human Rights and the Interamerican Court of Human Rights

La institución del amicus curiae y el arbitraje de inversiones

En los últimos años se viene consolidando la intervención del individuo en el arbitraje de inversiones en calidad de amicus curiae. Este proceso se gestó en el ámbito institucional del TLCAN, donde varias decisiones arbitrales establecieron los primeros precedentes sobre la materia y, con posterioridad, tras la reforma de las reglas procesales y de los APPRI norteamericanos se ha desarrollado una jurisprudencia homogénea que permite, bajo determinadas condiciones, la presentación de observaciones escritas, el acceso a ciertos documentos procesales y la presencia en las audiencias públicas. La última modificación de las Reglas de arbitraje del CIADI ha reconocido todas estas posibilidades en este ámbito, después de que un tribunal arbitral llamado a resolver los casos Aguas de Barcelona I y III ya las hubiera admitido con anterioridad. Sin embargo, en la práctica se aprecian algunas diferencias sustanciales entre la intervención de los terceros como amici curiae en el TLCAN y en el CIADI. A nuestro juicio ello se debe no sólo a la mayor uniformidad del primero, sino también a que los árbitros designados para resolver litigios en el TLCAN poseen una formación jurídica más completa en el common law

SPATIO-TEMPORAL PATTERNS OF JUVENILES IN EU PURSE SEINE FLEET CATCHES TARGETING TROPICAL TUNAS OVER THE PERIOD 1990-2019

The knowledge of the juvenile distribution in fisheries is essential to better manage the fishing effort on a stock. The exploration of a large dataset which covers 30 years of the purse seine fishery sampling enabled to study the spatio-temporal dynamic of the juvenile catches of the yellowfin and bigeye tunas. Results showed the existence of several areas of prime importance in terms of catch and concentration in juveniles with seasonal variations. Thus, the south of the fishing ground (Cape Lopez) was fished during winter month and the north during summer months (Cape Verde, Senegal y Mauritania). Offshore coastal zone and Gulf of Guinea were fished almost all along the year. This seasonal pattern is quite stable since the 90s but the proportion of juveniles in schools associated with floating objects tended to increase in both species. This preliminary study opened the way for further research on this important component of the fish stocks. La connaissance de la répartition des juvéniles dans les pêcheries est essentielle pour mieux gérer l'effort de pêche sur un stock. L'exploration d'un vaste jeu de données couvrant 30 ans d'échantillonnage de la pêcherie à la senne a permis d'étudier la dynamique spatio-temporelle des captures de juvéniles d'albacore et de thon obèse. Les résultats ont montré l'existence de plusieurs zones de première importance en termes de capture et de concentration des juvéniles avec des variations saisonnières. Ainsi, le sud de la zone de pêche (Cap Lopez) était pêché pendant les mois d'hiver et le nord pendant les mois d'été (Cabo Verde, Sénégal et Mauritanie). La zone côtière offshore et le golfe de Guinée ont été pêchés presque toute l'année. Bien que ce schéma saisonnier soit stable depuis les années 1990, la proportion de juvéniles dans les bancs associés à des objets flottants avait tendance à augmenter pour ces deux espèces. Cette étude préliminaire a ouvert la voie à d'autres recherches sur cette composante importante des stocks de poissons. El conocimiento de la distribución de los juveniles en las pesquerías es esencial para gestionar mejor el esfuerzo pesquero en un stock. La exploración de un gran conjunto de datos que abarca 30 años de muestreo de la pesquería de cerco permitió estudiar la dinámica espacio-temporal de las capturas de juveniles de rabil y patudo. Los resultados mostraron la existencia de varias zonas de importancia primordial en cuanto a la captura y concentración de juveniles con variaciones estacionales. Así, el sur del caladero (Cabo López) se pescaba durante el mes de invierno y el norte durante los meses de verano (Cabo Verde, Senegal y Mauritania). En la zona costera y en el golfo de Guinea se pescaba casi todo el año. Esta pauta estacional es bastante estable desde los años 90, pero la proporción de juveniles en los cardúmenes asociados a objetos flotantes tendió a aumentar en ambas especies. Este estudio preliminar abrió el camino a nuevas investigaciones sobre este importante componente de los stocks de peces.Versión del edito

Spatio-temporal patterns of juveniles in EU Purse sein fleet catch targetting tropical tunas over the period 1990-2019

The knowledge of the juvenile distribution in fisheries is essential to better manage the fishing effort on a stock. The exploration of a large dataset which covers 30 years of the purse seine fishery sampling enabled to study the spatio-temporal dynamic of the juvenile catches of the yellowfin and bigeye tunas. Results showed the existence of several areas of prime importance in terms of catch and concentration in juveniles with seasonal variations. Thus, the south of the fishing ground (Cape Lopez) was fished during winter month and the north during summer months (Cape Verde, Senegal y Mauritania). Offshore coastal zone and Gulf of Guinea were fished almost all along the year. This seasonal pattern is quite stable since the 90s but the proportion of juveniles in schools associated with floating objects tended to increase in both species. This preliminary study opened the way for further research on this important component of the fish stocks.Versión del edito

Pt(II) coordination complexes as visible light photocatalysts for the oxidation of sulfides using batch and flow processes

A new catalytic system for the photooxidation of sulfides based on Pt(ii) complexes is presented. The catalyst is capable of oxidizing a large number of sulfides containing aryl, alkyl, allyl, benzyl, as well as more complex structures such as heterocycles and methionine amino acid, with complete chemoselectivity. In addition, the first sulfur oxidation in a continuous flow process has been developedJ. A. would also like to thank the MICINN for their ‘Ramón y Cajal’ contract and the European Research Council (ERC-CG, contract number 647550

An analysis of existing production frameworks for statistical and geographic information: Synergies, gaps and integration

The production of official statistical and geospatial data is often in the hands of highly specialized public agencies that have traditionally followed their own paths and established their own production frameworks. In this article, we present the main frameworks of these two areas and focus on the possibility and need to achieve a better integration between them through the interoperability of systems, processes, and data. The statistical area is well led and has well-defined frameworks. The geospatial area does not have clear leadership and the large number of standards establish a framework that is not always obvious. On the other hand, the lack of a general and common legal framework is also highlighted. Additionally, three examples are offered: the first is the application of the spatial data quality model to the case of statistical data, the second of the application of the statistical process model to the geospatial case, and the third is the use of linked geospatial and statistical data. These examples demonstrate the possibility of transferring experiences/advances from one area to another. In this way, we emphasize the conceptual proximity of these two areas, highlighting synergies, gaps, and potential integration. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

Listado de especies de peces (excluyendo túnidos) capturadas de forma accesoria por la flota de cerco tropical española en el área ICCAT

El objetivo principal del presente estudio es mostrar una lista verificada de las capturas accesorias de peces (excluidas las especies de túnidos) por parte de la flota española de cerco tropical en el área de ICCAT. Se ha identificado un total de 76 especies de peces (excluidas las especies de túnidos) durante el período de estudio (2003-2017). También se han identificado dos taxones que necesitan confirmación (Kajikia audax y Makaira mazara)