The effect of through-thickness compressive stress on mode II interlaminar crack propagation:A computational micromechanics approach

A micromechanics framework for modelling the mode II interlaminar crack onset and propagation in fibre-reinforced composites is presented with the aim of i) modelling the micro-scale failure mechanisms that underlie interlaminar crack propagation, and ii) determining the effect of the through-thickness pressure on mode II fracture toughness. An algorithm for the generation of the fibre distribution is proposed for the generation of three-dimensional Representative Volume Elements (RVEs). Appropriate constitutive models are used to model the different dissipative effects that occur at crack propagation. Numerical predictions are compared with experiments obtained in previous investigations: it is concluded that the proposed micromechanical model is able to simulate conveniently the interlaminar crack propagation and to take into account the effect of the through-thickness pressure on mode II interlaminar fracture toughness

Digital media in primary schools: literacy or technology? Analyzing government and media discourses

This article examines the political and the media discourses concerning the Portuguese governmental program responsible for delivering a laptop named “Magalhães” to all primary school children. The analysis is based on the official documents related to the launch and development of the initiative as well as the press coverage of this topic. The main purpose is to recognize the dominant public discourses and to find out what the media select for the debate in the public sphere. This analysis was done with a particular focus on the critical media literacy framework. The results reveal that the press highlighted the negative aspects of that program and that this framing could have a strong impact on how it was accepted and understood by the public opinion. Analysis also reveals that the governmental initiative was predominantly driven by technological objectives, in particular the access to technology, rather than media literacy objectives.The authors disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This paper is part of a three years project named "Navigating with 'Magalhaes': Study on the Impact of Digital Media in Schoolchildren" funded by FCT - Fundacao para a Ciencia e a Tecnologia (Portuguese Foundation for Science and Technology) and co-funded by FEDER - Fundo Europeu de Desenvolvimento Regional (ERDF: European Regional Development Fund) through COMPETE - Programa Operacional Factores de Competitividade (Operational Competitiveness Programme)

Erratum to: 36th International Symposium on Intensive Care and Emergency Medicine

[This corrects the article DOI: 10.1186/s13054-016-1208-6.]

Energy values of the different molecular systems of graphene/epoxy models for both opening and shearing separation modes

The energy values were obtained through Molecular Dynamics simulations and these have been used for calculating the traction

New dextrin nanomagnetogels as contrast agents for magnetic resonance imaging

This study aims at the production and characterization of a “nanomagnetogel” consisting of superparamagnetic iron oxide nanoparticles (g-Fe2O3) stabilized within a hydrophobized-dextrin nanogel. The nanomagnetogel obtained was extensively characterized with respect to physico-chemical (transmission electron microscopy, cryo-scanning electron microscopy, dynamic light scattering, small angle X-ray scattering), magnetic (relaxometry, MIAplex) and biocompatibility (interaction with cells) properties. The obtained nanomagnetogel formulation, with about 4 mM of iron and a diameter of 100 nm, presents relevant features as a promising magnetic resonance imaging (MRI) contrast agent, noteworthy superparamagnetic behavior, high stability, narrow size distribution and potential for magnetic guidance to target areas by means of an external magnetic field. High values of transverse relaxivity make the nanomagnetogel a promising T2 contrast agent, allowing enhanced lesion detectability through magnetic resonance imaging. The nanomagnetogel demonstrated non-toxicity for 3T3 fibroblast cultures and was efficiently internalized by bone marrow-derived macrophages, therefore having potential as a contrast agent for MRI of the organs associated with the reticuloendothelial system (spleen, liver). The production of the nanomagnetogel is simple and easy to scale up, thus offering great technological potential.The authors thank the Magnisense Corporation for providing a MIAplex reader and CFGCG the EU COST TD1004 Action “Theragnostics Imaging and Therapy”. The authors thank Prof Cid´alia Botelho for the iron analysis by atomic absorbance spectroscopy at the Oporto University – Chemical Engineering Department. C. Gonçalves, J. A. Martins and M. F. M. Ferreira acknowledge FCT Portugal, for post-doc grant SFRH/BPD/ 70524/2010, sabbatical grant SFRH/BSAB/1328/2013 and PhD grant SFRH/BD/63994/2009, respectively