Living in the Hutt Space: Immersive process in the Star Wars Role-Play community of Second Life

Immersive virtual settings are evolving to become new “spaces of life”. Humans inhabit these different virtual worlds through their avatars, and tend to gather into communities. However, the behavioral factors underlying the cognitive process of immersion in virtual worlds are still far to be understood. We here investigated these factors using the Star Wars Role-Play community of the virtual setting of Second Life as a model. More specifically, our studies focused on the immersion process in the “Hutt Space”, a portion of the Star Wars Galaxy ruled by the alien species of the Hutts, which combines the trademark aspects of Star Wars universe. Using both quantitative and qualitative methods, we identified some of the factors which favor the immersion process. Our results suggest that the different behavioral factors contributing to the immersion process can be organized in three structuring dimensions: commitment, cohesion, and coherence. We also unveil a compensatory mechanism between appearance and behavioral factors in creation and maintenance of social groups in virtual worlds. Finally, we point out some of the behavioral aspects of the evolution from passive media engagement (spectators), to active media engagement (actors), and suggest a theoretical framework to investigate how human inhabit immersive virtual spaces.     

Multi-physics steady-state analysis of OECD/NEA modular high temperature gas-cooled reactor MHTGR-350

This paper presents the application results of MCS/GAMMA+ to multi-physics analysis of OECD/NEA modular high temperature gas-cooled reactor (MHTGR) benchmark Phase I Exercise 3. It is a part of international R&D efforts lead by the Next Generation Nuclear Plant (NGNP) US project to improve the neutron-physics and thermal-fluid simulation of (high temperature gas-cooled reactors) HTGRs, one of the next generations of safer nuclear reactors. Accurate and validated analysis tools are indeed a crucial requirement for safety analysis and licensing of nuclear reactors. To guide this effort, a numerical benchmark on the MHTGR was created by the NGNP project and formally approved in 2012 for international participation by the OECD/NEA. The benchmark defines a common set of exercises and the comparison of solutions obtained with different analysis tools is expected to improve the understanding of simulation methods for HTGRs. The coupled neutronics/thermal-fluid solution presented in this paper was obtained with the neutron transport Monte Carlo code MCS developed by Ulsan National Institute of Science and Technology and the thermal-fluid code GAMMA+ developed by Korean Atomic Energy Research Institute. The purpose of this paper is to present the GAMMA+/MCS coupled system, the calculation methodology, and the obtained solutions.     

Spheroid model study comparing the biocompatibility of Biodentine and MTA

The primary objective of this study was to assess the biological effects of a new dentine substitute based on Ca₃SiO₅ (Biodentine?) for use in pulp-capping treatment, on pseudo-odontoblastic (MDPC-23) and pulp (Od-21) cells. The secondary objective was to evaluate the effects of Biodentine and mineral trioxide aggregate (MTA) on gene expression in cultured spheroids. We used the acid phosphatase assay to compare the biocompatibility of Biodentine and MTA. Cell differentiation was investigated by RT-qPCR. We investigated the expression of genes involved in odontogenic differentiation (Runx2), matrix secretion (Col1a1, Spp1) and mineralisation (Alp). ANOVA and PLSD tests were used for data analysis. MDPC-23 cells cultured in the presence of MTA had higher levels of viability than those cultured in the presence of Biodentine and control cells on day 7 (P = 0.0065 and P = 0.0126, respectively). For Od-21 cells, proliferation rates on day 7 were significantly lower in the presence of Biodentine or MTA than for control (P < 0.0001). Col1a1 expression levels were slightly lower in cells cultured in the presence of MTA than in those cultured in the presence of Biodentine and in control cells. Biodentine and MTA may modify the proliferation of pulp cell lines. Their effects may fluctuate over time, depending on the cell line considered. The observed similarity between Biodentine and MTA validates the indication for direct pulp-capping claimed by the manufacturers.     

Does a cycle training course improve cycling skills in children?

Introduction

The aim of this study was to determine the short-term effects of cycle training on basic cycling skills in children from the 4th grade of elementary school. Furthermore, the influence of gender, socio-economic status (SES) and initial cycling skills level on the effects of the cycle training was investigated.

Methods

Five participating schools were randomly assigned to the intervention (n = 3) or control condition (n = 2). Children's cycling skills were assessed, using a practical cycling test, at baseline and immediately after the intervention. At baseline, all participating children received a short parental questionnaire on child's demographic and family factors. After the pre-test, cycle training took place only in the intervention schools. Repeated measure analyses were conducted to evaluate the effectiveness of the cycle training.

Results

The cycle training had a statistically significant effect on children's total cycling skill (F = 46.9, p < 0.001). On mounting the bicycle and start to cycle (F = 2.6, p = 0.11), cycling one handed (F = 2.0, p = 0.16), and cycling on a sloping surface (F = 1.5, p = 0.23), no statistically significant effects were detected. On all other cycling skills, time × condition interaction effects were statistically significant. Gender, SES and initial cycling skills level had no significant influence on the effects of the cycle training.

Conclusion

This study showed that a cycle training of only three sessions was effective to improve children's cycling skills at short term and that cycle training within a traffic-free environment seems to be a useful first step in the development of safe cycling behaviors.     

LusSy: An open tool for the analysis of systems-on-a-chip at the transaction level

We describe a toolbox for the analysis of Systems-on-a-chip written in SystemC at the transaction level. The tool is able to extract information from SystemC code, and to build a set of parallel automata that capture the semantics of a SystemC design, including the transaction-level specific constructs. As far as we know, this provides the first executable formal semantics of SystemC. Being implemented as a traditional compiler front-end, it is able to deal with general SystemC designs. The intermediate representation is now connected to existing formal verification tools via appropriate encodings. The toolbox is open and other tools will be used in the future.     

The Effect of Shear Mixing Speed and Time on the Mechanical Properties of GNP/Epoxy Composites

The aim of this study was to examine the effect of shear mixing speed and time on the mechanical properties of graphene nanoplatelet (GNP) composites. Shear mixing is cited in the literature as one method of making a good dispersion of nanofillers in a polymer that breaks down agglomerates into smaller particles and in the case of GNP can exfoliate layers of graphene. In this paper 0.1 to 5 wt% GNP was mixed with epoxy at different speeds and for different lengths of time. The composites were then cured and the tensile strength and Young’s modulus was measured. Optical microscopy was performed to examine the dispersion of the GNP in the epoxy. The results show that the shear mixing speed and time affect the size of agglomerates, which has an impact on the mechanical properties of the composite. At 3000 rpm and 2 h of mixing the average size of agglomerate was 26.3 μm (30 % reduction compared to that of 1000 rpm and 1 h duration), the tensile strength of epoxy was not affected by the addition of GNP, while a 12 % increase was recorded for the Young’s modulus. It is also found that functionalisation of the surface of the GNP improves the bond formed between the GNP and the resin that enhances its mechanical properties with no effect on the size of the agglomerates. Acetone was used to improve the GNP dispersion and found that shear mixing 5 wt% of GNP with acetone increases the Young’s modulus up to 3.02 from 2.6 GPa for the neat epoxy, an almost 14 % rise.     

Influence of the surface properties of concrete on the adhesion of coating: Characterization of the interface by peel test and FT-IR spectroscopy

The understanding of the adhesion between protective coating and concrete is essential to ensure the aesthetic of buildings. Polyurea (PU) based coating are mainly deposited on the surface of concrete, several days after demoulding. However, their adhesion on concrete depends on different interlinked parameters. This study is based on the development of specific peel tests. A strengthened and porous membrane is introduced into the layer of liquid coating before its crosslinking. This methodology ensures a reproducible debonding of the coating/concrete system to measure the fracture energy. The fracture loci are then characterized by Fourier Transformed Infra-Red (FT-IR) spectroscopy. Results show that humid conditions of curing and long-term ageing strongly decrease the adhesion of coating. This weak adhesion is related to the presence of large crystals of portlandite, the growth of efflorescence or the kinetics of carbonation that could close the porosity or induce a weak interface. The type of the mould is also significant because it could induce the tearing of the extreme surface of concrete during demoulding. This tearing increases the roughness and the open porosity that enhances the fracture energy. Finally, this study demonstrates that the adhesion of PU coating is mainly conditioned by the mechanical anchorage at the surface of concrete.