296 research outputs found

    ¿Entre héroes y deidades? actos de sacrificio de la Edad del Hierro grabados en la roca 6 del monte de Porreiras (Noroeste de Portugal)

    Get PDF
    El objetivo de este trabajo es publicar los grabados rupestres del Monte das Porreira 6, situado en Paredes de Coura, en el no de Portugal. El estudio se ha basado en un levantamiento fotogramétrico y el posterior contraste con la determinación de la distancia geométrica. Se trata de una roca profusamente decorada con una larga diacronía de grabados. La fase inicial incluye el arte atlántico clásico, integrado en el Calcolítico Reciente. La segunda fase incluye la representación de équidos, jinetes y puñales con mango de antenas. Basándose en los paralelos de dichas armas, es posible integrar estos motivos entre la Edad de Bronce Final y la Edad de Hierro Inicial. También es posible observar el paso de una gramática abstracta, durante la primera fase, a una gramática figurativa, en la que se puede identificar una narrativa relacionada con los sacrificios humanos y de animales, asociada al uso de puñales con mango de antenas. Estas representaciones evocan un simbolismo que recuerda a los textos de Estrabón y objetos de bronce que contienen escenas de sacrificio. La última fase del grabado indica nuevos cambios simbólicos, con la valorización de acciones aisladas perpetradas por un jinete, portando un arma arrojadiza, que pueden representar a una divinidad o a un héroe.The aim of this work is to publish the rock engravings of Monte das Porreira 6, located in the council of Paredes de Coura, in the Northwest of Portugal. The study was based on photogrammetric surveys and subsequent contrast recurring to geometric distance determination. It is a profusely decorated rock with a long diachrony of carving. The initial phase includes Classical Atlantic Art, integrated in the regional Neo-Chalcolithic period. The second phase includes representation of several types of equids, horsemen, and antenna-hilted daggers. Based on parallels for such weapons, it is possible to integrate these motifs between the Late Bronze Age and an Early Iron Age of North-western Iberia. It is also possible to observe a change from an abstract grammar, during the first phase, to a figurative grammar, in which we can identify a narrative related to human and animal sacrifices, associated with the use of antenna-hilted daggers. These depictions recall a symbolism reminiscent of Strabo’s writings, including bronze objects containing sacrificial scenes. The final phase of engraving indicates new symbolic changes, with valorisation of isolated actions perpetrated by horsemen, carrying throwing weapons, which may be a representation of a deity or hero

    Production of polymer filament-shaped piezoelectric sensors for e-textiles applications

    Get PDF
    This work aims at the development of piezoelectric materials for flexible sensors produced with various geometries, at low cost and high production rates, adequate for the industrial scale. In particular the filament form, appropriate for integration into textiles, is described, but other geometries, such as tape, are also being studied. The filaments are produced by co-extrusion of multiple layers with piezoelectric and electrically conductive polymer composites.Fundação para a Ciência e a Tecnologia (FCT) - PTDC/CTM/108801/200

    Piezoelectric filaments produced by coextrusion

    Get PDF
    Considering the significant interest of both the academic and industrial communities in the fields of i/e-textiles (interactive/electronic textiles), the number of developed applications is far below the expected. This fact is mainly related to the difficulties on the development of production methodologies adequate to industrial scale processes. In this areas the integration of piezoelectric materials, that possess sensing/actuating capabilities, such as poly(vinylidene fluoride), PVDF, and can be processed using conventional processing techniques, is very promising and has encouraged a large number of research works. However, until now, most of the developed production methodologies are difficult to adapt to the industrial scale. This work reports recent developments achieved, in the framework of a research project, on the production of piezoelectric filament by coextrusion of PVDF and electrical conductive layers. The developed production methodology involves a conventional coextrusion line, for which a coextrusion die was designed to produce a multilayer filament. This filament comprises an inner layer of an electrically conductive Polypropylene grade and a middle layer of PVDF and is coated with an electrical conductive ink. The piezoelectric response of the produced filaments will be also presentedFundação para a Ciência e a Tecnologia (FCT)- FCT PTDC/CTM/108801/200

    inTB - a data integration platform for molecular and clinical epidemiological analysis of tuberculosis

    Get PDF
    This deposit is composed by the main article plus the supplementary materials of the publication.Tuberculosis is currently the second highest cause of death from infectious diseases worldwide. The emergence of multi and extensive drug resistance is threatening to make tuberculosis incurable. There is growing evidence that the genetic diversity of Mycobacterium tuberculosis may have important clinical consequences. Therefore, combining genetic, clinical and socio-demographic data is critical to understand the epidemiology of this infectious disease, and how virulence and other phenotypic traits evolve over time. This requires dedicated bioinformatics platforms, capable of integrating and enabling analyses of this heterogeneous data.Instituto Gulbenkian de Ciência, Programa Nacional de Luta contra a Tuberculose, Instituto Nacional de Saúde Ricardo Jorge, Administração Regional de Saúde de Lisboa e Vale do Tejo

    Theoretical simulation of different 3D separator geometries for lithium-ion batteries

    Get PDF
    The battery separator is an essential component of batteries and affects their cycling performance. In this work, the effect of different 3D geometries of the battery separator on battery performance was studied keeping the same volume. It was observed that the different geometries affect the cycling performance, the best geometry being the perforated one that cycled up to 90 C. The cycling performance is affected by parameters such as the separator thickness and the electrolyte volume. Through the control of the battery separator geometry it is possible to obtain high performance lithium-ion batteries.Portuguese Foundation for Science and Technology (FCT): UID/FIS/04650/2019, PTDC/CTMENE/5387/2014, UID/CTM/50025/2013, PTDC/FIS-MAC/28157/2017, grant SFRH/BPD/112547/2015 (C.M.C.) and contract CEECIND/00833/2017 (R.G.), including FEDER funds through the COMPETE 2020 Programme and National Funds through FCT. Financial support from the Basque Government Industry Department under the ELKARTEK and HAZITEK programs is also acknowledged. F. Miranda was also supported by Portuguese funds through the CIDMA - Center for Research and Development in Mathematics and Applications, and the Portuguese Foundation for Science and Technology (“FCT - Fundação para a Ciência e a Tecnologia”), within project UID/MAT/04106/2013

    New eugenol derivatives with enhanced insecticidal activity

    Get PDF
    Eugenol, the generic name of 4-allyl-2-methoxyphenol, is the major component of clove essential oil, and has demonstrated relevant biological potential with well-known antimicrobial and antioxidant actions. New O-alkylated eugenol derivatives, bearing a propyl chain with terminals like hydrogen, hydroxyl, ester, chlorine, and carboxylic acid, were synthesized in the present work. These compounds were later subjected to epoxidation conditions to give the corresponding oxiranes. All derivatives were evaluated against their effect upon the viability of insect cell line Sf9 (Spodoptera frugiperda), demonstrating that structural changes elicit marked effects in terms of potency. In addition, the most promising molecules were evaluated for their impact in cell morphology, caspase-like activity, and potential toxicity towards human cells. Some molecules stood out in terms of toxicity towards insect cells, with morphological assessment of treated cells showing chromatin condensation and fragmentation, which are compatible with the occurrence of programmed cell death, later confirmed by evaluation of caspase-like activity. These findings point out the potential use of eugenol derivatives as semisynthetic insecticides from plant natural products.This research was funded by COMPETE 2020 program, co-financed by the FEDER and the European Union, PTDC/ASP-AGR/30154/2017 (POCI-01-0145-FEDER-030154). The authors also acknowledge the Foundation for Science and Technology (FCT; Portugal), and FEDER-COMPETE/QREN-EU for financial support to the research centers CQ/UM (UIDB/00686/2020), CF-UM-UP (UIDB/04650/2020) and REQUIMTE (UIDB/50006/2020). The NMR spectrometer Bruker Avance III 400 is part of the NationalNMRNetwork and was purchased within the framework of the National Program for Scientific Re-equipment, contract REDE/1517/RMN/2005, with funds from POCI 2010 (FEDER) and the FCT. The authors would also like to thank RIAIDT-USC for the use of their analytical facilities

    Coextrusion of polymeric piezoelectric filaments

    Get PDF
    The difficulties related to the development of industrial scalable production methodologies have limited the number of applications currently available in the field of interactive/electronic textiles, which are far below the anticipated a few years ago. In these areas the integration of piezoelectric materials, that possess sensing/actuating capabilities, such as poly(vinylidene fluoride), PVDF, and can be processed using conventional processing techniques, is very promising and has encouraged a large number of research works. However, until now, most of the developed production methodologies are difficult to adapt to the industrial scale. This work reports recent developments achieved in the framework of a research project, on the production of piezoelectric filament by coextrusion of PVDF and an electrically conductive thermoplastic. The developed production methodology is based on a conventional coextrusion line, for which a coextrusion die was designed to produce a multilayer filament, which comprises an inner layer of an electrically conductive Polypropylene grade and a middle layer of PVDF and is coated with an electrical conductive ink. The sensing capabilities of the produced filaments are also characterized.Fundação para a Ciência e a Tecnologia (FCT)- FCT PTDC/CTM/108801/200

    Solid polymer electrolytes based on lithium bis(trifluoromethanesulfonyl)imide/poly(vinylidene fluoride -co-hexafluoropropylene) for safer rechargeable lithium-ion batteries

    Get PDF
    The increasing use of electronic portable systems and the consequent energy demand, leads to the need to improve energy storage systems. According to that and due to safety issues, high-performance non-flammable electrolytes and solid polymer electrolytes (SPE) are needed.SPE containing different amounts of lithium bis(trifluoromethanesulfonyl) imide (LiTFSI) into a poly(vinylidene fluoride-co-hexafluoropropylene), PVDF-HFP, polymer matrix have been prepared by solvent casting. The addition of LiTFSI into PVDF-HFP allows to tailor thermal, mechanical and electrical properties of the composite.In particular, the ionic conductivity of the composites increases with LiTFSI content, the best ionic conductivities of 0.0011 mS/cmat 25 degrees C and 0.23 mS/cmat 90 degrees C were obtained for the PVDF-HFP/LiTFSI composites with 80 wt % of LiTFSI.This solid electrolyte allows the fabrication of Li metallic/SPE/C-LiFePO4 half-cells with a discharge capacity of 51.2 mAh/ g at C/20. Further, theoretical simulations show that the discharge capacity value depends on the lithium concentration and percentage of free ions and is independent of the solid polymer electrolyte thickness. On the other hand, the voltage plateau depends on the SPE thickness. Thus, a solid electrolyte is presented for the next generation of safer solid-state batteries.The authors thank the FCT (Fundação para a Ciência e Tecnologia) for financial support under the framework of Strategic Funding grants UID/FIS/04650/2013, UID/EEA/04436/2013 and UID/QUI/0686/2016; and project no. PTDC/FIS-MAC/28157/2017. The authors also thank the FCT for financial support under grant SFRH/BPD/112547/2015 (C.M.C.). Financial support from the Basque Government Industry Department under the ELKARTEK and HAZITEK programs is also acknowledged. JMMD and JLGR acknowledge funding by the Spanish Ministry of Economy and Competitiveness (MINECO) through the project MAT2016-76039-C4-1 and 3-R (including the FEDER financial support) CIBER-BBN is an initiative funded by the VI National R&D&i Plan 2008–2011, Iniciativa Ingenio 2010, Consolider Program, CIBER Actions and financed by the Instituto de Salud Carlos III with assistance from the European Regional Development Fund

    Eugenol β-amino/β-alkoxy alcohols with selective anticancer activity

    Get PDF
    Eugenol, 4-allyl-2-methoxyphenol, is the main constituent of clove essential oil and has demonstrated relevant biological activity, namely anticancer activity. Aiming to increase this activity, we synthesized a series of eugenol β-amino alcohol and β-alkoxy alcohol derivatives, which were then tested against two human cancer cell lines, namely gastric adenocarcinoma cells (AGS) and lung adenocarcinoma cells (A549). An initial screening was performed to identify the most cytotoxic compounds. The results demonstrated that three β-amino alcohol derivatives had anticancer activity that justified subsequent studies, having been shown to trigger apoptosis. Importantly, the most potent molecules displayed no appreciable toxicity towards human noncancer cells. Structure-activity relationships show that changes in eugenol structure led to enhanced cytotoxic activity and can contribute to the future design of more potent and selective drugs.This research was funded by FCT under project PTDC/ASP-AGR/30154/2017 (PO-CI-01-0145- FEDER-030154) of COMPETE 2020, co-financed by FEDER and EU. FCT-Portugal and FEDERCOMPETE/ QREN-EU also gave financial support to the research centres CQ/UM (UIDB/00686/2020) and REQUIMTE (UIDB/50006/2020). The NMR spectrometer Bruker Avance III 400 (part of the National NMR Network) was financed by FCT and FEDER. Renato B. Pereira acknowledges PRIMA Foundation (H2020- PRIMA 2018—Section 2, Project MILKQUA) and FCT (PTDC/QUI-QFI/2870/2020) for the funding
    corecore