Al/Gf composite foams with SiC-engineered interfaces for the next generation of active heat dissipation materials

Interfacial engineering has been investigated as a method of increasing thermal conductivity in a variety of aluminium/graphite composites but remains unexplored in the few graphite-containing aluminium foams developed to date. In this study, the replication method was used to fabricate aluminium/graphite composite foams by infiltrating with liquid aluminium packed preforms containing SiC-coated oriented graphite flakes and NaCl particles, the latter acting as a templating agent. The effects of interfacial modification caused by the SiC presence were investigated alongside those of NaCl and graphite flake particle sizes. Materials benefit from low pressure drops when large NaCl particles are used. Furthermore, large graphite flakes coated with SiC provide thermal conductivities up to 232 Wm-1K-1, improved mechanical properties and power dissipation capacities up to 2-fold and 6-fold higher than aluminium/graphite composite foams with unmodified interfaces and standard aluminium foams, respectively, making them ideal candidates for active heat sinks in next-generation electronic devices.This work was made possible by funding from the Spanish Agencia Estatal de Investigación (AEI), the Spanish Ministry of Science and Innovation, and the European Union under grant PDC2021-121617-C21 for the development of foams with novel phases that can be integrated into new systems for upcoming filtration applications. The authors would also like to acknowledge the financial support received for the same purpose from the Conselleria d'Innovació, Universitats, Ciència, i Societat Digital of the Generalitat Valenciana through grant GVA-COVID19/2021/097. L.P. Maiorano also acknowledges the financial support from the University of Alicante through grant UAFPU2019-33 “Programa Propio para el fomento de la I+D+i del Vicerrectorado de Investigación y Transferencia de Conocimiento”

Two-sided orthogonal reductions to condensed forms on asymmetric multicore processors

[EN] We investigate how to leverage the heterogeneous resources of an Asymmetric Multicore Processor (AMP) in order to deliver high performance in the reduction to condensed forms for the solution of dense eigenvalue and singular-value problems. The routines that realize this type of two-sided orthogonal reductions (TSOR) in LAPACK are especially challenging, since a significant fraction of their floating-point operations are cast in terms of memory-bound kernels while the remaining part corresponds to efficient compute-bound kernels. To deal with this scenario: (1) we leverage implementations of memory-bound and compute-bound kernels specifically tuned for AMPs; (2) we select the algorithmic block size for the TSOR routines via a practical model; and (3) we adjust the type and number of cores to use at each step of the reduction. Our experiments validate the model and assess the performance of our asymmetry-aware TSOR routines, using an ARMv7 big.LITTLE AMP, for three key operations: the reduction to tridiagonal form for symmetric eigenvalue problems, the reduction to Hessenberg form for non-symmetric eigenvalue problems, and the reduction to bidiagonal form for singular-value problems.The researchers from Universidad Jaume I were supported by project TIN2014-53495-R of MINECO and FEDER, and the FPU program of MECD. The researcher from Universitat Politecnica de Valencia was supported by the Generalitat Valenciana PROMETEOII/2014/003. The researcher from Universitat Politecnica de Catalunya was supported by projects TIN2015-65316-P from the Spanish Ministry of Education and 2014 SGR 1051 from the Generalitat de Catalunya, Dep. d'Innovacio, Universitats i Empresa.Alonso-Jordá, P.; Catalán, S.; Herrero, JR.; Quintana-Ortí, ES.; Rodríguez-Sánchez, R. (2018). Two-sided orthogonal reductions to condensed forms on asymmetric multicore processors. Parallel Computing. 78:85-100. https://doi.org/10.1016/j.parco.2018.03.005S851007

Model Design and Calculation with Polymeric and Composite Materials through Project-Based Learning

[EN] The new educational paradigm requires new active methodologies to fulfil the market demanding needs. Students need to join the competitive labor market with optimal skills to achieve all their professional objectives. That is why the current teaching-learning process requires disruptive changes through the implementation of innovative methodologies such as the Project-Based Learning (PBL). The PBL is a methodology that allows students to acquire the key knowledge and skills through the elaboration of a project that gives response to a real problem. According to the Edgar Dale's Cone of Experience (Dale, 1946) the PBL is an active methodology since it is located at the basis of the pyramid in the layer of: `Direct Purposeful Experience ¿ Go through a Direct Experience¿. Based on Dale¿s results, students will remember 90% of what they do as they perform the project. In light of this, and with the main goal of prepare suitable professionals, in the Mechanical Engineering Degree of the Universitat Politècnica de València, a PBL model has been defined. This model involves the following three subjects: (i) Polymer Matrix Composite Materials Engineering; (ii) Manufacturing processes of polymer matrix composite materials and (iii) Advanced design with polymers: Project with composite materials. All these subjects are taught in the second semester of the 4th year of the Mechanical Engineering Degree. The PBL model, which consists of the design and calculation of a pressure tank by using CAD/CAE tools such as SolidWorks, will be developed concurrently among the three subjects. In this article, the PBL model is defined as well as the steps and considerations that have been followed and taken into account for its definition.This article has been supported by the Vice-rectorate for Digital Resources and Documentation (Vicerrectorado de Recursos Digitales y Documentación) and Vice-Rectorate for Studies, Quality and Accreditation (Vicerrectorado de Estudios, Calidad y Acreditación) under the Call for Learning + Teaching (Convocatoria Aprendizaje + Docencia (A+D 2019)) and Project Code: 1678-A. The authors would like to acknowledge the support of the Institute of Educational Sciences (Instituto de Ciencias de la Educación) of Universitat Politècnica de València, the Evaluation and Monitoring Commission for Educational Innovation and Improvement Projects (Comisión de Evaluación y Seguimiento de Proyectos de Innovación y Mejora Educativa (CESPIME)) and Escuela Politécnica Superior de AlcoyBalart, R.; Montanes, N.; Quiles-Carrillo, L.; Jordá-Gisbert, S.; Sanchis-Gomis, HC.; Sanchis, R. (2020). Model Design and Calculation with Polymeric and Composite Materials through Project-Based Learning. EDULEARN Proceedings (Internet). 3979-3986. https://doi.org/10.21125/edulearn.2020.1076S3979398

Crowding of Polymer Coils and Demixing in Nanoparticle-Polymer Mixtures

The Asakura-Oosawa-Vrij (AOV) model of colloid-polymer mixtures idealizes nonadsorbing polymers as effective spheres that are fixed in size and impenetrable to hard particles. Real polymer coils, however, are intrinsically polydisperse in size (radius of gyration) and may be penetrated by smaller particles. Crowding by nanoparticles can affect the size distribution of polymer coils, thereby modifying effective depletion interactions and thermodynamic stability. To analyse the influence of crowding on polymer conformations and demixing phase behaviour, we adapt the AOV model to mixtures of nanoparticles and ideal, penetrable polymer coils that can vary in size. We perform Gibbs ensemble Monte Carlo simulations, including trial nanoparticle-polymer overlaps and variations in radius of gyration. Results are compared with predictions of free-volume theory. Simulation and theory consistently predict that ideal polymers are compressed by nanoparticles and that compressibility and penetrability stabilise nanoparticle-polymer mixtures.Comment: 18 pages, 4 figure

NUEVAS APORTACIONES AL CATÁLOGO FAUNÍSTICO DE LOS QUIRONOMIDOS (DIPTERA: CHIRONOMIDAE) DEL PARQUE NACIONAL DE DOÑANA (SW DE ESPAÑA)

Twenty one species of chironomids have been recorded from Doñana National Park. Amongst these, 12 records are new for the area and 4 for the Iberian península. Total number of chironomid species known in the area rises to 35. A complete list of species including comments on their ecology and biogeography is includedEn los muestreos realizados para la ejecución del presente trabajo se han capturado ejemplares de 21 especies, de ellas 12 son nuevas citas para el Parque Nacional de Doñana y 4 para la Península Ibérica. Con la mencionada aportación, el número de especies de Quironómidos citados para el Parque asciende a 35. Se presenta una relación de las 21 especies capturadas con consideraciones de tipo ecológico y comentarios sobre las implicaciones biogeográficas de las especies más interesantes

Concept note for ICCAT ecoregion workshop identification of regions in the ICCAT convention area for supporting the implementation of ecosystem based fisheries management

The overall aim of the workshop is to advance in the identification of candidate ecologically meaningful regions that can serve as a basis to produce a more integrated ecosystem-based advice, and thereby support the implementation and operationalization of ecosystem-based fisheries management (EBFM) in the International Commission for the Conservation of Atlantic Tunas (ICCAT) convention area. The candidate regions should have boundaries that make ecological sense, and are practical in informing fisheries management. The workshop will gather CPC national scientists and external experts from different scientific disciplines (e.g. biogeography, oceanography, ecology, fisheries and fisheries management in the ICCAT area) to develop a “proof of concept” for broad-scale regionalization of the ICCAT convention area.L'objectif général de l'atelier est de progresser dans l'identification de possibles régions écologiquement significatives qui peuvent servir de base pour produire un avis écosystémique plus intégré, et ainsi soutenir la mise en œuvre et la mise en marche de la gestion des pêcheries basée sur les écosystèmes (EBFM) dans la zone de la Convention de la Commission internationale pour la conservation des thonidés de l'Atlantique (ICCAT). Les régions candidates doivent avoir des limites qui ont un sens écologique, et qui sont pratiques pour renseigner la gestion des pêcheries. L'atelier réunira des scientifiques nationaux des CPC et des experts externes de différentes disciplines scientifiques (par exemple, la biogéographie, l'océanographie, l'écologie, la pêche et la gestion des pêcheries dans la zone de l'ICCAT) afin de développer une preuve conceptuelle pour une régionalisation à grande échelle de la zone de la Convention ICCATEl objetivo global del taller es avanzar en la identificación de posibles regiones ecológicamente significativas que puedan servir como base para formular un asesoramiento basado en el ecosistema más integrado, apoyando la implementación y puesta en marcha de la ordenación pesquera basada en el ecosistema (EBFM) en la zona del Convenio de la Comisión Internacional para la Conservación del Atún Atlántico (ICCAT). Las regiones candidatas deberían tener límites que tengan sentido ecológico y que sean prácticas para aportar información a la ordenación pesquera. El taller reunirá a científicos nacionales de las CPC y a expertos externos de diversas disciplinas (por ejemplo, biogeografía, oceanografía, ecología, pesca y ordenación pesquera en la zona de ICCAT) para desarrollar una demostración conceptual para una regionalización a gran escala de la zona del Convenio de ICCAT.Versión del edito