Kit ?Energy, Environment and Sustainability?: An educational strategy for a sustainable future. A case study for Guinea-Bissau

Increasing the scientific knowledge of the population through education is a developmentstrategy towards a sustainable future. However, there is no equity in the access to science educationand scientific knowledge. The aim of this paper is to present and analyse a science kit named ?Energy,Environment and Sustainability? (KEAS). Based on research conducted in Guinea-Bissau, it exploresstrategies to promote science education for a sustainable future. The strengths and limitations ofthe KEAS were studied using different data collection methods, including interviews, observation,survey, focus groups and document analysis. The participants were teacher trainers from the Guinea-Bissau School of Education. It is concluded that the KEAS is a feasible and suitable teaching strategyappropriate to the context, having the potential to contribute to learning about the environment andsustainability. Further, it addresses real problems for which students should acquire knowledge andskills in order to be able to make informed choices.C917-B3FD-1A62 | Maria Lu?sa Vieira das Nevesinfo:eu-repo/semantics/publishedVersio

Marked object recognition multitouch screen printed touchpad for interactive applications

The market for interactive platforms is rapidly growing, and touchscreens have been incorporated in an increasing number of devices. Thus, the area of smart objects and devices is strongly increasing by adding interactive touch and multimedia content, leading to new uses and capabilities. In this work, a flexible screen printed sensor matrix is fabricated based on silver ink in a polyethylene terephthalate (PET) substrate. Diamond shaped capacitive electrodes coupled with conventional capacitive reading electronics enables fabrication of a highly functional capacitive touchpad, and also allows for the identification of marked objects. For the latter, the capacitive signatures are identified by intersecting points and distances between them. Thus, this work demonstrates the applicability of a low cost method using royalty-free geometries and technologies for the development of flexible multitouch touchpads for the implementation of interactive and object recognition applications.Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding UID/FIS/04650/2013. The authors thank the FCT for financial support under projects PTDC/EEI-SII/5582/2014 and PTDC/CTM-ENE/5387/2014. P. C., J.O. and V. C. also thank the FCT for the SFRH/BPD/110914/2015, SFRH/BPD/98219/2013 and SFRH/BPD/97739/2013 grants, respectively. Financial support from the Basque Government Industry Department under the ELKARTEK Program is also acknowledged as well as funding by theSpanish Ministry of Economy and Competitiveness (MINECO) through the project MAT2016-76039-C4-3-Rinfo:eu-repo/semantics/publishedVersio

The influence of the dispersion method on the electrical properties of vapor-grown carbon nanofiber/epoxy composites

The influence of the dispersion of vapor-grown carbon nanofibers (VGCNF) on the electrical properties of VGCNF/Epoxy composites has been studied. A homogenous dispersion of the VGCNF does not imply better electrical properties. In fact, it is demonstrated that the most simple of the tested dispersion methods results in higher conductivity, since the presence of well-distributed nanofiber clusters appears to be a key factor for increasing composite conductivity

A new approach for the fabrication of cytocompatible PLLA-magnetite nanoparticle composite scaffolds

Magnetic biomimetic scaffolds of poly(L-lactide) (PLLA) and nanoparticles of magnetite (nFe3O4) are prepared in a wide ratio of compositions by lyophilization for bone regeneration. The magnetic properties, cytotoxicity, and the in vitro degradation of these porous materials are closely studied. The addition of magnetite at 50 °C was found to produce an interaction reaction between the ester groups of the PLLA and the metallic cations of the magnetite, causing the formation of complexes. This fact was confirmed by the analysis of the infrared spectroscopy and the gel permeation chromatography test results. They, respectively, showed a displacement of the absorption bands of the carbonyl group (C=O) of the PLLA and a scission of the polymer chains. The iron from the magnetite acted as a catalyser of the macromolecular scission reaction, which determines the final biomedical applications of the scaffolds—it does so because the reaction shortens the degradation process without appearing to influence its toxicity. None of the samples studied in the tests presented cytotoxicity, even at 70% magnetite concentrations.This work was supported by the Spanish Ministry of Economy and Competitiveness (MINECO) through the project MAT2016-76039-C4-3-R (AEI/FEDER, UE) and from the Basque Government Industry Department under the ELKARTEK, HAZITEK and PIBA programs. Supported by the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding UID/FIS/04650/2013, project POCI-01-0145-FEDER-028237 and grant SFRH/BD/111478/2015 (S.R.) is acknowledged

Metallic glass/PVDF magnetoelectric laminates for resonant sensors and actuators: a review

Among magnetoelectric (ME) heterostructures, ME laminates of the type Metglas-like / PVDF (magnetostrictive+piezoelectric constituents) have shown the highest induced ME voltages, usually detected at the magnetoelastic resonance of the magnetostrictive constituent. This ME coupling happens because of the high cross-correlation coupling between magnetostrictive and piezoelectric material, and is usually associated with a promising application scenario for sensors or actuators. In this work we detail the basis of the operation of such devices, as well as some arising questions (as size effects) concerning their best performance. Also, some examples of their use as very sensitive magnetic fields sensors or innovative energy harvesting devices will be reviewed. At the end, the challenges, future perspectives and technical difficulties that will determine the success of ME composites for sensor applications are discussed.J.G., A.L. and J.M.B. would like to thank the financial support from the Basque Government under ACTIMAT and MICRO4FAB projects (Etortek program) and Research Groups IT711-13 project. A. Lasheras wants to thank the Basque Government for financial support under FPI Grant. Technical and human support provided by SGIker (UPV/EHU, MICINN, GV/EJ, ESF) is gratefully acknowledged. P.M., N.P. and S. L.-M. thank the Portuguese Fundação para a Ciência e Tecnologia (FCT) for financial Sensors 2017, 13 19 support under Strategic Funding UID/FIS/04650/2013 and project PTDC/EEI-SII/5582/2014, including FEDER funds, UE. P. Martins acknowledges also support from FCT (SFRH/BPD/96227/2013 grant). Financial support from the Spanish Ministry of Economy and Competitiveness (MINECO) through the project MAT2016-76039-C4-3-R (AEI/FEDER, UE) (including the FEDER financial support) is also acknowledgedinfo:eu-repo/semantics/publishedVersio

Environmentally friendly carrageenan-based ionic-liquid driven soft actuators

UID/FIS/04650/2020 UID/QUI/0686/2020 LA/P/0008/2020 PID2019-106099RB-C43/AEI/10.13039/501100011033A naturally derived polymer based on iota carrageenan and different ammonium and imidazolium based ionic liquids (ILs) are used for the development of environmentally friendly soft actuators. The influence of IL content and type and solvent evaporation temperature on the morphological and physico-chemical properties of the materials was evaluated, together with the effect on actuator functional response. Independently of the IL content and type, and the solvent evaporation temperature, a non-porous structure is obtained. The incorporation of the IL within the polymer matrix does not affect the thermal stability but leads to a decrease in the Young modulus for the different IL/carrageenan samples. The highest influence was observed by using the [Ch][DHP] IL at a filler content of 40% w/w with a decrease in the Young modulus from 748 MPa for the neat polymer to 145 MPa for the [Ch][DHP]/carrageenan sample. Furthermore, the ionic conductivity of the samples increases with increasing IL content, with the highest values being 2.9 × 10-6 S cm-1 and 1.2 × 10-6 S cm-1 for the samples with 40% w/w of [Bmim][FeCl4] and [Ch][DHP], respectively. Regarding the soft actuator performance, the maximum displacement was obtained for the [Ch][DHP]/carrageenan sample with an IL content of 40% w/w, showing a maximum displacement of 5.8 mm at a DC applied voltage of 9 V.publishersversionpublishe

Indirect X-ray detectors based on inkjet-printed photodetectors with a screen-printed scintillator layer

Organic photodetectors (PDs) based on printing technologies will allow to expand the current field of PD applications toward large-area and flexible applications in areas such as medical imaging, security, and quality control, among others. Inkjet printing is a powerful digital tool for the deposition of smart and functional materials on various substrates, allowing the development of electronic devices such as PDs on various substrates. In this work, inkjet-printed PD arrays, based on the organic thin-film transistor architecture, have been developed and applied for the indirect detection of X-ray radiation using a scintillator ink as an X-ray absorber. The >90% increase of the photocurrent of the PDs under X-ray radiation, from about 53 nA without the scintillator film to about 102 nA with the scintillator located on top of the PD, proves the suitability of the developed printed device for X-ray detection applicationsThe authors thank FEDER funds through the COMPETE 2020 Programme and National Funds through FCT-Portuguese Foundation for Science and Technology under Strategic Funding UID/FIS/04650/2013 and projects PTDC/EEI-SII/5582/2014, PTDC/CTM-ENE/5387/2014 and in the framework of EuroNanoMed 2016 call, Project LungChek ENMed/0049/2016. J.O. and V.C. thank the FCT for the SFRH/BD/98219/2013 and SFRH/BPD/97739/2013 grants, respectively. The authors acknowledge funding by the Spanish Ministry of Economy and Competitiveness (MINECO) through the project MAT2016-76039-C4-3-R. Financial support from the Basque Government Industry Department under the ELKARTEK program is also acknowledged. The authors thank Iain McCulloch and Martin Heeney from Flexink for providing the OSC. Dirk Rittrich (Department Layer Deposition at Fraunhofer ENAS) is acknowledged for the FIB/SEM analysis and the sample preparation. R.D.R acknowledges the DFG Unit FOR1317 SMINT, the Cluster of Excellence, and the Tomsk Polytechnic University Competitiveness Enhancement Program grant TPU CEP_IHTP_73\2017. This work was performed in the context of the European COST Action MP1302 Nanospectroscopy.info:eu-repo/semantics/publishedVersio

Thermal, dielectrical and mechanical response of α and β-poly(vinilydene fluoride)/Co-MgO nanocomposites

Nanocomposites of the self-forming core-shell Co-MgO nanoparticles, which were of approximately 100 nm in diameter, and poly(vinylidene fluoride) (PVDF) polymer have been prepared. When the polymer is crystallized in the α-phase, the introduction of the nanoparticles leads to nucleation of the γ-phase of PVDF, increasing also the melting temperature of the polymer. With the introduction of the Co-MgO particles, the dielectric constant of the material slightly increases and the storage modulus decreases with respect to the values obtained for the pure polymer

Tailoring porous structure of ferroelectric poly(vinylidene fluoride-trifluoroethylene) by controlling solvent/polymer ratio and solvent evaporation rate

Ferroelectric macroporous poly(vinylidene fluoride-trifluoroethylene) membranes have been produced by isothermal crystallization from the solution at different temperatures starting from different diluted solutions of the co-polymer in dimethylformamide. In this way pore architecture, consisting in interconnected spherical pores can be obtained. The mechanism and kinetics of solvent evaporation was investigated and related to the evolution of the polymer microstructure. The mechanism underlying the pattern formation has been discussed on the light of the Flory-Huggins (FH) lattice theory, grain boundary effects and the Cahn-Hilliard equation for mass conservation systems. It was also observed that the temperature or initial concentration of the crystallization process does not affect the phase, ferroelectric transition temperature or the melting temperature of the polymer.The authors thank the Portuguese Foundation for Science and Technology (FCT) Grants PTDC/CTM-NAN/112574/2009, PTDC/CTM/73030/2006, PTDC/CTM/69316/2006 and NANO/NMed-SD/0156/2007. V.F., C.M.C. and V.S. thank the FCT for the SFRH/BD/44289/2008, SFRH/BD/68499/2010, SFRH/BPD/63148/2009 grants, respectively. JLGR acknowledge the funding from the Programa de Apoyo a la Investigacion y Desarrollo (PAID-00-09) of the Universidad Politecnica de Valencia for a short stay in Universidade do Minho, Braga, the support of the Spanish Ministry of Science through project No. MAT2010-21611-C03-01 (including the FEDER financial support) and funding for research in the field of Regenerative Medicine through the collaboration agreement from the Conselleria de Sanidad (Generalitat Valenciana), and the Institute de Salud Carlos III (Ministry of Science and Innovation). The authors wish also thank the CeNTI - Centre for Nanotechnology and Smart Materials, Rua Fernando Mesquita, 2782, 4760-034 Vila Nova de Famalicao, Portugal for allowing the use of some experimental equipment.California, A.; Cardoso, VF.; Costa, CM.; Sencadas, V.; Botelho, G.; Gómez Ribelles, JL.; Lanceros-Mendez, S. (2011). Tailoring porous structure of ferroelectric poly(vinylidene fluoride-trifluoroethylene) by controlling solvent/polymer ratio and solvent evaporation rate. EUROPEAN POLYMER JOURNAL. 47(12):2442-2450. https://doi.org/10.1016/j.eurpolymj.2011.10.005S24422450471