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In discussing arguments which tend to dismiss risk, we identify the hidden premises needed to support these claims. Differences between a prudential model and a scientific model are considered. A ‘reductio ad absurdum’ objection, and fallacies of ambiguity, where ‘insignificant risk’ may be confused with ‘inconsequential risk’, are also discussed. Disagreement over the interpretation of risk has the potential to disrupt the optimum use of medical imaging technology. While communication of risk need not address the underlying philosophical complexities, advice from the radiation protection community must be rooted in an awareness of these issues if inconsistencies are to be avoided. © 2020 Society for Radiological Protection. Published on behalf of SRP by IOP Publishing Limited. All rights reserved.Hybrid nanocomposites reinforced with a mixture of graphene nanoplatelets (GNPs) and carbon nanotubes (CNTs) have shown improvement in filler dispersion while providing a cost-effective alternative to CNT monofiller composites. Depending on their composition, hybrid composites can exhibit electrical performance superior to either of the constituent monofiller composites due to synergistic effects. In this work, we develop a three-dimensional tunneling-based continuum percolation model for hybrid nanocomposites filled with hardcore particles of elliptical GNPs and cylindrical CNTs. Using Monte Carlo simulations, parametric studies of the filler volume, composition and morphology are carried out to analyze the conditions required for synergy in percolation onset and electrical conductivity. Our results suggest that for hybrid systems with well-dispersed fillers, the electrical performance is linked to the number of tunneling junctions per filler inside the percolated network of the nanocomposites. More importantly, hybrid composites filled with specific morphology of GNP and CNT, exhibit synergy in their electrical performance when the monofiller composites of each of those exact fillers have similar percolation onset values. The simulations results are in agreement with relevant experimental data on hybrid nanocomposites. © 2020 IOP Publishing Ltd.For wound healing applications, a scaffold of biocompatible/porous network is crucial to support cell proliferation and spreading. Therefore, -polycaprolactone (PCL) nanofibrous scaffold containing co-dopants of strontium/selenium into hydroxyapatite (HAP) were modified with different contributions of graphene oxide (GO) via the laser ablation technique. The obtained compositions were investigated using XRD, TEM and FESEM. It was obvious that fiber diameters were in the range of from 0.15- 0.30 µm and 0.35-0.83 µm at the lowest and highest concentration of GO respectively, while the maximum height of the roughness progressed to be 393 nm. DX3213B The toughness behavior is promoted from 5.77±0.21 to be 9.16±0.29 MJ/m3 upon GO from lowest to the highest contribution, while the maximum strain at break reached to 148.1±0.49% at the highest concentration of GO. The cell viability indicated that the fibrous scaffold was biocompatible. The investigated of HFB4 cell attachments towards the fibrous compositions showed that with the rising of GO, cells tend to grow intensively through the scaffolds. Furthermore, the proliferation of cells was observed to be rooted in the porous structure and spreading on the surface of the scaffold. This progression of cells with increasing of GO content may provide a simple strategy not only to enhance mechanical properties but also to manipulate a nanofibrous scaffold with proper behaviors for biomedical applications. © 2020 IOP Publishing Ltd.GaSe is a layered semiconductor with an optical band gap tunable by the number of layers in a thin film. This is promising for application in micro/optoelectronics and photovoltaics. However, for that, knowledge about the intrinsic defects are needed, since they may influence device behavior. Here we present a comprehensive study of intrinsic point defects in both bulk and monolayer (ML) GaSe, using an optimized hybrid functional which reproduces the band gap and is Koopmans’ compliant. Formation energies and charge transition levels are calculated, the latter in good agreement with available experimental data. We find that the only intrinsic donor is the interlayer gallium interstitial, which is absent in the case of the ML. The vacancies are acceptors, the selenium interstitial is electrically inactive, and small intrinsic defect complexes have formation energies too high to play a role in the electronic properties of samples grown under quasi-equilibrium conditions. Bulk GaSe is well compensated by the intrinsic defects, and is an ideal substrate. The ML is intrinsically ¬p-type, and p-type doping cannot be compensated either. The opening of the band gap changes the defect physics considerably with respect to the bulk. © 2020 IOP Publishing Ltd.Tuning black phosphorene properties such as structural, electronic and transport are explored via substitutional C-doped. We employed density functional theory (DFT) calculations in combination with non-equilibrium Green’s function (NEGF) for modeling the systems. Our results revealed that substitutional C-doped phosphorene are energetically favorable, and ruled by exothermic process. We also found that C-doping induces a change of the electric properties, such as a semiconductor-to-metal transition for the most lower concentration and \textitzig-zag C-wire. Furthermore, for an \textitarmchair C-wire and the most higher concentration the semiconductor character is kept, meanwhile the direct-to-indirect transition is observed to band gap nature. The band structures show that there exists a dependence of the electronic charge transport with directional character of the C-doped configuration. The findings demonstrated that, the directional doping could play the role for conductance on 2D platform. © 2020 IOP Publishing Ltd.In this work, we set out to develop a model of gas-phase nucleation in a mixture of copper and argon atoms, which can be further used for analysing macro-systems. Processes occurring at the atomic level are described using coefficients obtained by statistical analysis of molecular dynamic (MD) data on interactions of metal clusters with metal and argon atoms. The MD simulation results are compared with those obtained using the proposed macroscopic model. It is found that the coefficients obtained by averaging the interaction data suitably represent the integral value of the heat of condensation, although result in the smoothing of the energy distribution functions of the clusters. Analysis of the evolution of the number of clusters has shown that the values of their increase rate were lower than those obtained by MD simulation. The conclusion is made, that in order to improve the precision of the developed gas-phase condensation model, it should be supplemented by cluster coagulation. © 2020 IOP Publishing Ltd.