Digital comfort amidst precarity: New middle classes’ experience of well-being and hardship in pandemic times in Brazil

During the pandemic, digital platforms had a boom in revenue or subscriptions. Despite their increasing relevance, few studies explore how different social strata experience such access. Based on 31 in-depth interviews in Rio de Janeiro, Brazil, this article discusses the meanings and practices of digital consumption among the ‘new middle class.’ By focusing on three platforms—ride-sharing apps, food delivery apps, and audio-visual streaming—we interrogate how digital consumption has shaped experiences of well-being and hardship during pandemic times and how it relates to social mobility. We argue that digital platforms brought comfort amidst precarity as mechanisms for accessing relaxing and fun moments while responding to structural issues of Brazilian megacities. Our data also suggest these digital platforms enhance middle-class symbolic status related to individualised and private practices, though collectiveness is still present in participants’ liminal class experience

An assessment of composite repair system in offshore platform for corroded circumferential welds in super duplex steel pipe

The main aim of this study is to assess the effectiveness of a composite repair system in severely corroded circumferential welds in super duplex stainless steel pipes as a preventive measure against the premature corrosion damage at the welds. Artificial defects were fabricated on the super duplex steel tube in order to reproduce the localized corrosion damage defects found in real welded joints. Three kinds of through thickness defects were considered: 25%, 50% and 96% of the perimeter of the pipe. The performance of the repaired pipe was assessed by hydrostatic tests as per ISO 24817 standard. The results showed that the composite repair system can sustain the designed failure pressure even for the pipe damaged with through-wall defect up to 96% of the perimeter of the pipe. Hence, the composite repair system can be used as a preliminary tool to protect the unexpected or premature failure at the welds and maintain an adequate level of mechanical strength for a given operating pressure. This composite repair system can assure that the pipe will not leak until a planned maintenance of the line. Nevertheless, further work is still desirable to improve the confidence in the long-term performance of bonded composite

Prolongamento da vida útil de chicória orgânica acondicionada em diferentes embalagens e refrigeração.

nais do XI Congresso Brasileiro de Agroecologia, São Cristóvão, Sergipe

Phase-field modeling of eutectic structures on the nanoscale: the effect of anisotropy

This is a post-peer-review, pre-copyedit version of an article published in Journal of Materials Science. The final authenticated version is available online at: https://doi.org/10.1007/s10853-017-0853-8A simple phase-field model is used to address anisotropic eutectic freezing on the nanoscale in two (2D) and three dimensions (3D). Comparing parameter-free simulations with experiments, it is demonstrated that the employed model can be made quantitative for Ag-Cu. Next, we explore the effect of material properties, and the conditions of freezing on the eutectic pattern. We find that the anisotropies of kinetic coefficient and the interfacial free energies (solid-liquid and solid-solid), the crystal misorientation relative to pulling, the lateral temperature gradient, play essential roles in determining the eutectic pattern. Finally, we explore eutectic morphologies, which form when one of the solid phases are faceted, and investigate cases, in which the kinetic anisotropy for the two solid phases are drastically different

Thermodynamic modeling by the calphad method and its applications to innovative materials

International audienceAmong the different steps leading to a multi-scale lifetime prediction for aero-engine components and other industrial components, one seems to be apart from the other mechanical engineering concerns: thermodynamic and microstructural modeling. Here is given an introduction to the CALPHAD method [19, 27], explaining how it actually models the thermodynamic properties of multicomponent systems. Then, a number of applications are described, while emphasizing the relevance of using the CALPHAD method for the purpose of developing integrated engineering methods. Finally, the importance of building thermodynamic databases creates a high need for the development of ab initio calculations, as well as high-throughput experiments and, generally speaking, combinatorial materials science