Mg-based Nanocomposites For Hydrogen Storage Containing Ti-cr-v Alloys As Additives

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)In this study, we have investigated the synthesis, microstructure and hydrogen storage properties of Mg-based nanocomposites containing different concentrations of TiCrV and TiCr1.2V0.8 alloys. The Mg-based nanocomposites of Mg containing Ti-Cr-V additives were prepared by reactive milling (RM) under hydrogen atmosphere. The structural characterization revealed the presence of the beta-MgH2,gamma-MgH2 and BCC phases in the powders samples after RM. In addition, a very refined and homogenous microstructure with average MgH2 crystallite size of around 10-12 nm was observed, including a nanometric dispersion of the additives in the magnesium hydride matrix. The doping with TiCrV and TiCr1,2V0,8 greatly improves the hydrogen desorption behavior of Mg in comparison with the sample without additive, resulting in the lowest onset temperature (240 degrees C) for the sample containing 5% mol. of TiCrV. Very fast absorption and desorption kinetics at 275 degrees C and 300 degrees C (7 minutes and 5 minutes for full desorption and absorption, respectively) were observed in the samples containing TiCrV and TiCr1,2V0,8 without any notable difference between the type of additive used in comparison with the pure sample. However, a slight reduction in hydrogen capacity is observed in the mixtures than for the pure sample (6.7 wt.% against 7.3 wt.%).1918085CAPESCNPqCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)6th Latin American Conference on Metastable and Nanostructured Materials (NANOMAT)AUG 19-20, 2015Cancun, MEXIC

The strangeness of commonplace: magritte’s poetics beneath a psychoanalytical glance

This article aims to build possible relationships between psychoanalysis and some of the most puzzling works of René Magritte (1898 - 1967), keeping consistent with the curating of an exhibition called "Magritte: The Mystery of the Ordinary". Thus, we dedicated to reading materials of commentators and critics of the painter's work, we also investigated the texts produced by Magritte himself, in which the painter introduces some key-concepts for the understanding of his artistic thinking: aesthetic emotion, poetics, mysteries of the ordinary, uncanny (resounding the Freudian’s Umheimlich). Thereby, we were careful to not produce superficial and reductionist interpretations, which only implement psychoanalysis to the art. Therefore, we aimed to produce a critical interpretation, attentive to details of art works, demonstrating the implications present there and showing possible links between the work of Magritte and psychoanalytic theory

Latex and natural rubber : recent advances for biomedical applications

Recently, latex (NRL) and natural rubber (NR) from Hevea brasiliensis have emerged as promising biomaterials from renewable sources for biomedical applications. Although some attempts at commercial applications have been made, there is a need to comprehensively document the state-of-the-art of these biopolymers for biomedical applications and regenerative medicine. Here we present the recent advances in the development of NRL and NR as biomedical materials with potential properties including biocompatibility and biodegradability. Due to the angiogenic properties of NRL and NR, well-defined functional materials can be used for drug delivery systems (oral/transdermal), scaffolds for skin and bone regeneration, and dressings for wound healing. The incorporation of drugs, nanoparticles, cells, and others into NRL and NR polymer chains offers a wide range of applications such as dressings with antimicrobial activity and sustained release systems. Concluding remarks on the growth of these biomaterials for biomedical applications and regenerative medicine were discussed

Perceptions of the appropriate response to norm violation in 57 societies

An Author Correction to this article: DOI: 10.1038/s41467-021-22955-x.Norm enforcement may be important for resolving conflicts and promoting cooperation. However, little is known about how preferred responses to norm violations vary across cultures and across domains. In a preregistered study of 57 countries (using convenience samples of 22,863 students and non-students), we measured perceptions of the appropriateness of various responses to a violation of a cooperative norm and to atypical social behaviors. Our findings highlight both cultural universals and cultural variation. We find a universal negative relation between appropriateness ratings of norm violations and appropriateness ratings of responses in the form of confrontation, social ostracism and gossip. Moreover, we find the country variation in the appropriateness of sanctions to be consistent across different norm violations but not across different sanctions. Specifically, in those countries where use of physical confrontation and social ostracism is rated as less appropriate, gossip is rated as more appropriate.Peer reviewe

Changes in social norms during the early stages of the COVID-19 pandemic across 43 countries

The emergence of COVID-19 dramatically changed social behavior across societies and contexts. Here we study whether social norms also changed. Specifically, we study this question for cultural tightness (the degree to which societies generally have strong norms), specific social norms (e.g. stealing, hand washing), and norms about enforcement, using survey data from 30,431 respondents in 43 countries recorded before and in the early stages following the emergence of COVID-19. Using variation in disease intensity, we shed light on the mechanisms predicting changes in social norm measures. We find evidence that, after the emergence of the COVID-19 pandemic, hand washing norms increased while tightness and punishing frequency slightly decreased but observe no evidence for a robust change in most other norms. Thus, at least in the short term, our findings suggest that cultures are largely stable to pandemic threats except in those norms, hand washing in this case, that are perceived to be directly relevant to dealing with the collective threat

Anger and disgust shape judgments of social sanctions across cultures, especially in high individual autonomy societies

When someone violates a social norm, others may think that some sanction would be appropriate. We examine how the experience of emotions like anger and disgust relate to the judged appropriateness of sanctions, in a pre-registered analysis of data from a large-scale study in 56 societies. Across the world, we find that individuals who experience anger and disgust over a norm violation are more likely to endorse confrontation, ostracism and, to a smaller extent, gossip. Moreover, we find that the experience of anger is consistently the strongest predictor of judgments of confrontation, compared to other emotions. Although the link between state-based emotions and judgments may seem universal, its strength varies across countries. Aligned with theoretical predictions, this link is stronger in societies, and among individuals, that place higher value on individual autonomy. Thus, autonomy values may increase the role that emotions play in guiding judgments of social sanctions

Hydrogen storage in mgh2-additives (additives: fe, nb, fe2o3, nb2o5, fef3, nbf5) nanocomposites produced by high energy ball milling and severe plastic deformation

Mg-based nanocomposites are considered promising materials for hydrogen storage in the solid state. In this work, Mg-based nanocomposites containing iron-based (Fe, Fe2O3, FeF3) and niobium-based (Nb, Nb2O5, NbF5) additives were processed by different processing routes involving high energy ball milling and severe plastic deformation techniques. The high energy ball milling techniques are represented here by the reactive milling under hydrogen atmosphere and by the cryogenic milling while the severe plastic deformation technique is represented here by extensive cold rolling. An alternative processing route including a previous short ball milling step before the cold rolling processing was evaluated. The study of the effect of additives according to the chosen processing routes and an extensive characterization of the hydrogen storage properties allowed a better understanding on the mechanisms which are responsible by the kinetics improvements related to the microstructural particularities. The materials prepared by the different processing techniques were characterized by micro and nanostructural analysis techniques such as, among others, x-ray diffraction followed by the Rietveld method, scanning and transmission electron microscopy. The desorption behavior was studied by differential scanning calorimetry and the kinetic behavior was investigated by absorption and desorption cycles. The correlation of the results obtained with the different processing routes showed that the beneficial effect of the additives in promoting the H-sorption kinetics is positively extended independently of the processing route; however, the acting mechanisms depend on strictly on the preparation methods and the combination of one or more factor related to the microstructure. Furthermore, the severe plastic deformation techniques showed a very good potential in comparison with the high energy ball milling techniques in processing Mg-based nanocomposites, resulting in materials with good hydrogen storage properties.Universidade Federal de Sao CarlosNanocompositos a base de magnesio sao considerados materiais muito promissores para a armazenagem de hidrogenio em estado solido. No presente trabalho, nanocompositos a base de magnesio contendo aditivos a base de Ferro (Fe, Fe2O3, FeF3) e Niobio (Nb, Nb2O5, NbF5) foram processados por diferentes rotas de processamento envolvendo tecnicas de moagem de alta energia (MAE) e deformacao plastica severa (SPD). As tecnicas de MAE sao representadas aqui pela moagem reativa (MR) sob atmosfera de hidrogenio e pela moagem criogenica (MC) enquanto que a tecnica de SPD e representada pela laminacao a frio (CR). Uma nova rota alternativa de processamento composta por uma etapa previa curta de moagem antes do processo de laminacao foi avaliada. O estudo da influencia de aditivos conforme a rota de processamento empregada e a intensa caracterizacao das propriedades de armazenagem de hidrogenio permitiu um melhor entendimento sobre os mecanismos responsaveis pelas melhorias cineticas relacionadas com as particularidades microestruturais. Os materiais preparados pelos diferentes tecnicas de processamento foram caracterizados atraves de tecnicas de analise micro e nanoestrutural, incluindo, entre outras, difracao de raios-X (DRX) seguida pelo metodo de Rietveld, microscopia eletronica de varredura e transmissao. O comportamento durante a dessorcao foi estudado por calorimetria diferencial de varredura (DSC) e a cinetica das reacoes foram investigadas atraves de ciclos de absorcao/dessorcao de H2. A correlacao entre os resultados obtidos com as diferentes rotas de processamento demonstraram que o efeito benefico dos aditivos em promover a cinetica das reacoes com o H2 se estende de maneira muito positiva independentemente da rota de processamento usada, porem, os mecanismos de atuacao dependem estritamente dos metodos de preparacao e da combinacao de um ou mais fatores relacionados a microestrutura. Alem disso, as tecnicas de SPD demonstraram um grande potencial frente as tecnicas de MAE no processamento de nanocompositos a base de magnesio, resultando em materiais com otimas propriedades de armazenagem de hidrogenio