PGM-Free Biomass-Derived Electrocatalysts for Oxygen Reduction in Energy Conversion Devices: Promising Materials

Biomass is a low-cost, abundant and renewable resource that can be used to manufacture porous carbon-based materials for a variety of applications. Different mesoporous carbon supports can be obtained from the various synthetic approaches that are aimed at increasing the specific surface area and functionalization. Currently, most of the biomass is used for energy recovery. The circular economy approach could lead to the development of cheap and sustainable materials, and turning of wastes into a precious resource. In this review, we provide the recent advances in the field of electrochemistry for porous carbon materials derived from biomass, which offers wider applications in proton exchange membrane fuel cells (PEMFCs), anion exchange membrane fuel cells (AEMFCs) and Zn-air batteries (ZABs). The focus is on understanding the required properties of the materials and the role of synthetic pathways in platinum group metal (PGM) free electrocatalysts. The most promising materials are evaluated towards the oxygen reduction reaction (ORR) in PEMFC, AEMFC, and ZAB. The results achieved showed that the expected performances on these energy conversion devices still lack for deployment in practice, especially if compared with commercially available PGM-free electrocatalysts. This review article provides insights on how to improve the actual electrocatalytic activity of biomass-derived materials. Graphical Abstract: [Figure not available: see fulltext.

Exploring Twitter as a game platform; strategies and opportunities for microblogging-based games

Recent years have seen the massive daily engagement of players with games that are integrated with online social networking sites, such as Facebook. However, few games have successfully created engaging experiences through integration with microblogging websites. In this paper, we explore the opportunities and challenges in using Twitter as a platform for playing games, through the case study of the game Hashtag Dungeon, a dungeon-crawling game that uses Twitter for collaborative creation of game content. Two studies were carried out. A quantitative user study with 32 participants demonstrated that players found the game engaging and rewarding. A follow-up qualitative study with 8 participants suggests that Twitter integration in this game is meaningful, but that there are concerns over the impact of the game on players’ Twitter profiles. Based on findings from both studies, we propose strategies for the design of Microblogging-based games, and discuss wider implications of social media integration in games

Tuning the redox properties of Co-N4 macrocyclic complexes for the catalytic electrooxidation of glucose

Graphite electrodes modified with four different cobalt N4 macrocyclics, namely Co tetrapentapyridinophthalocyanine, (CoTPenPyrPc), Co tetrapyridinoporphyrazine (CoTPyPz), Co octa(hydroxyethylthio)phthalocyanine (CoOEHTPc) and Co tetranitrophthalocyanine (CoTNPc) exhibit catalytic activity for the oxidation of glucose in alkaline media. The purpose of this work is to establish correlations between the catalytic activity of these complexes and their redox potential. The activity of the different modified electrodes was tested by linear voltammetry under hydrodynamic conditions using the rotating disk technique. Tafel plots constructed from mass-transport corrected currents give slopes ranging from 0.080 to 0.160 V/decade for the different catalysts which suggests that a first one-electron step is rate controlling with the symmetry of the energy barrier depending on the nature of the ligand of the Co complex. A plot of log I versus the Co(II)/(I) formal potential gives a volcano curve that also includes catalysts studied previously. This illustrates the concept that the formal potential of the catalyst needs to be tuned to a certain value for achieving maximum activity. A theoretical interpretation of these results is given in terms of Langmuir isotherms for the adsorption of glucose on the Co sites of the surface-confined metal complexes

Tabletop Roleplaying Games as Procedural Content Generators

Tabletop roleplaying games (TTRPGs) and procedural content generators can both be understood as systems of rules for producing content. In this paper, we argue that TTRPG design can usefully be viewed as procedural content generator design. We present several case studies linking key concepts from PCG research -- including possibility spaces, expressive range analysis, and generative pipelines -- to key concepts in TTRPG design. We then discuss the implications of these relationships and suggest directions for future work uniting research in TTRPGs and PCG.Comment: 9 pages, 2 figures, FDG Workshop on Procedural Content Generation 202

Dynamic modeling of the reactive twin-screw co-rotating extrusion process: experimental validation by using inlet glass fibers injection response and application to polymers degassing

International audienceIn this paper is described an original dynamic model of a reactive co-rotating twinscrew extrusion (TSE) process operated by the Rhodia company for the Nylon-66 degassing finishing step. In order to validate the model, dynamic experiments have been performed on a small-scale pilot plant. These experiments consist in a temporary injection of glass fibers at the inlet of the extruder after it has reached a given operating point. The outlet glass fibers mass fraction time variation is then measured. This experiment does not lead to the RTD measurement. As a matter of fact, due to the high quantity of glass fibers that is introduced, the behavior of the flow through the extruder is perturbed so that the glass fibers cannot be considered as an inert tracer. The dynamic model that we have published elsewhere (Choulak et al., Ind. Eng. Chem. Res., 2004, 43(23), 7373-7382) is adapted to take into account this nonlinear behavior of the extruder with respect to the glass fibers injection and is favorably compared to experimental results. The description of the degassing operation is also included in the model. The model allows simulations of the complete dynamic behavior of the process. When the steady state is reached, the good position of the degassing vent with respect to the partially and fully filled zones positions can also be checked, thus illustrating the way the model can be used for design purposes

Childhood asthma outcomes during the COVID-19 pandemic: Findings from the PeARL multi-national cohort.

BACKGROUND: The interplay between COVID-19 pandemic and asthma in children is still unclear. We evaluated the impact of COVID-19 pandemic on childhood asthma outcomes. METHODS: The PeARL multinational cohort included 1,054 children with asthma and 505 non-asthmatic children aged between 4-18 years from 25 pediatric departments, from 15 countries globally. We compared the frequency of acute respiratory and febrile presentations during the first wave of the COVID-19 pandemic between groups and with data available from the previous year. In children with asthma, we also compared current and historical disease control. RESULTS: During the pandemic, children with asthma experienced fewer upper respiratory tract infections, episodes of pyrexia, emergency visits, hospital admissions, asthma attacks and hospitalizations due to asthma, in comparison to the preceding year. Sixty-six percent of asthmatic children had improved asthma control while in 33% the improvement exceeded the minimal clinically important difference. Pre-bronchodilatation FEV1 and peak expiratory flow rate were improved during the pandemic. When compared to non-asthmatic controls, children with asthma were not at increased risk of LRTIs, episodes of pyrexia, emergency visits or hospitalizations during the pandemic. However, an increased risk of URTIs emerged. CONCLUSION: Childhood asthma outcomes, including control, were improved during the first wave of the COVID-19 pandemic, probably because of reduced exposure to asthma triggers and increased treatment adherence. The decreased frequency of acute episodes does not support the notion that childhood asthma may be a risk factor for COVID-19. Furthermore, the potential for improving childhood asthma outcomes through environmental control becomes apparent

Video game discourses and implications for game-based education

Increasingly prevalent educational discourses promote the use of video games in schools and universities. At the same time, populist discourses persist, particularly in print media, which condemn video games because of putative negative effects on behaviour and socialisation. These contested discourses, we suggest, influence the acceptability of games and limit critical analysis of their effectiveness as pedagogic tools. This article focuses on the representation of video games in media discourse. We present insights from a small-scale study of the construction of video game discourses in the UK print media in 2013, and discuss three areas that emerged. First, the assumptions inherent in the representation of the ‘video game’; second, the implied lack of agency in the behaviour of ‘the gamer’; and third, the way in which blame is manipulated. Finally, we consider the implications for game-based education