a transparent plastic varnish with nanoparticulate magnetic additives

For the purpose of preparing TCCs (= transparent and electrical conducting coatings), metallic and ferromagnetic nano-additives were dispersed into a transparent varnish and the obtained dispersions were coated on transparent plastic substrates. During hardening of the dispersion the magnetic nano- additives were aligned by a magnetic field. The resulting coatings have electrical pathways along lines of nano-additive chains and are highly transparent in the areas between the lines. Therefore, the electrical conductivity is anisotropic, and it depends on the alignment of the nano- additives (i.e. on the distance between the nano-additives within the chains and the length of the lines) as well as on the thickness of an oxide and/or solvent shell around the nano-additives. The transparency depends also on the alignment and here especially on the thickness and the distance between the formed lines. The quality of the alignment in turn, depends on the magnetic properties and on the size of the particles. We used commercial plastic varnishes, which form electrically isolating (≥ 10− 12 S/m) and transparent (about 90% transparency) coatings, and the following magnetic additives: Co-, Fe-, CoPt3, CoPt3@Au- and Fe@Au-nanoparticles as well as CoNi-nanowires. Coatings with Fe@Au-nanoparticles show the best results in terms of the electrical conductivity (10− 5 S/m–10− 6 S/m) at transparencies above 70%. Furthermore, in addition to the magnetic nano-additives, transparent additives (Al2O3-particles) and non-magnetic, but better conducting additives (carbon- nanotubes) were added to the varnish to increase the transparency and the electrical conductivity, respectively

Communities of shared interests and cognitive bridges: the case of the anti-vaccination movement on Twitter

This paper presents an analysis of the anti-vaccination movement’s referencing of research articles on the topic of vaccination in the social media network Twitter. Drawing on the concept of bibliographic coupling, the paper demonstrates how Twitter users can be coupled based on articles mentioned on Twitter. The sample applied consists of 113 open access journal articles. The combination of tweeter coupling with the respective stance of Twitter accounts vis-à-vis vaccination makes possible the creation of a network graph of tweeters mentioning this corpus of articles. In addition to a common interest in the scientific literature, the findings show distinct communities of shared interests within the anti-vaccination movement, and demonstrate that tweeter coupling can be used to map these distinctive interests. The emergence of Twitter accounts serving as cognitive bridges within and between communities is noted and discussed with regard to their relative positions in the network. This paper’s results extend the knowledge on the application of altmetric data to study the interests of non-scientific publics in science; more specifically, it adds to the understanding of the potentials of open science and science–society interactions arising from increased access by non-scientists to scientific publications.</p

Laser-guided corrosion control: a new approach to tailor the degradation of Mg-alloys

Despite corrosion being commonly seen as a problem to be avoided, applications such as batteries or biodegradable implants do benefit from corrosion‐like phenomena. However, current strategies address corrosion control from a global perspective for a whole component, without considering local adaptations to functionality specifications or inhomogeneous environments. Here, a novel concept is presented: the local control and guidance of corrosion through a laser surface treatment. Immersion tests in saline solution of AZ31 magnesium alloy samples show degradation rates reduced up to 15 times with the treatment, owing to a fast passivation after the induced microstructural modifications. By controlling the treatment conditions, the degradation can be restricted to delimited regions and driven towards specific directions. The applicability of the method for the design of tailored degradation biomedical implants is demonstrated and uses for cathodic protection systems and batteries can also be anticipated