Numerical simulation of electrical problems in a vacuum disjuntor

A vacuum circuit breaker is a device that allows the cutting of electrical power. This device consists essentially of two electrodes, one of them being mobile and is subject to a mechanical force produced by a spring, giving rise to the contact between the two electrodes. The current passing between two electrodes is determined by the extension of the contact zone. Moreover, the passage of current generated Laplace forces in areas bordering the contact, but not yet in contact. Due to the curved geometry of the electrodes, these Laplace forces are opposite and therefore cause the repulsion of the electrodes. This means that for a given power we have to evaluate the electric potential, the magnetic field corresponding to the contact zone

NUMERICAL SIMULATIONS OF COUPLED PROBLEMS IN A VACUUM DISJUNTOR

In this work we carried out the modelling, the discretization and the numerical simulation of a vacuum breaker. We present a mathematical model of the multi-physical problem involving mechanical, electrical and electromagnetic phenomena. The finite element method is employed in conjunction with a technique of domain decomposition to solve the mechanical problem and the electrical problem while a direct integration of the Biot-Savart formula allows to compute an approximation of the magnetic field, hence the Lorentz-Laplace forces

Numerical Simulation of Flow Structures in the Presence of Alternate and Transverse Bars: Application to the Loire River (France)

Hydrodynamic

Implementation of a novel approach accounting for the influence of vegetation on sediment transport in GAIA

Hydrodynamic

Numerical modelling of graded sediment transport based on the experiments of Wilcock and Crowe (2003)

Water Qualit

A Study of Hate Speech in the North and South: Politicians as Communicative Agents

Hate speech as a political tool of extremism has been on the rise in the Global North and Global South. Its appeal gains audience, support, and strength every day in numerous countries. The geographical spaces may be different, but the geopolitical social locations of groups, members, and individuals reveal similar inequalities and aggressions. Considering this context, we intend to contribute with an assessment of hate speech via a case study - a politician’s statements in the Netherlands with a brief parallel with a Brazilian scenario. Centrally, our paper approaches two different domains of hate speech. One domain of hate speech is its discursive framing, taken as a major source of representations, and the other is its interpretation in the context of legal systems. Agency is what connects the two domains. That is, we will address institutional agents and legal interpretation of politicians’ speeches. To have an understanding of the subject matter, we need to understand the collective representations involved. In simple terms, we connect (legal) interpretation and (collective) representation to deal with hate speech cases performed by agents. These agents are addressed in hate speech laws both within the Netherlands and within the UN - also considering speech aggression in the Brazilian political scenario. Finally, addressing the agents and the framed speech acts involved seem to be relevant steps to broaden our understanding of the criminalization of hate speech and its propagation inside human societies, observing that we can resignify our frames and the agents around us as part of a bigger community

Processus et intérêts des partis dans les négociations commerciales entre le Mercosur et le Canada = Process and party interests in the Mercosur-Canada trade negotiations

Depuis 2018, le Canada et les pays du Mercosur négocient un accord de commerce de nouvelle génération. Cette négociation commerciale n’est pas sans défis. En effet, il s’agit d’une négociation entre une fédération (le Canada) et un regroupement de pays (Mercosur), qui inclut deux fédérations qui ont leurs propres logiques de négociation. L’objectif de cet article est d’exposer de manière comparée la complexité des processus de négociations et les intérêts des pays du Mercosur, avec un accent sur le Brésil, et du Canada, dans le cadre de ces négociations commerciales. Il cherche également à décrire comment se déroulent les négociations afin de mieux comprendre la dynamique en place et les effets possibles sur les résultats de la négociation. Les principales conclusions sont à l’effet que les relations commerciales entre les pays du Mercosur et le Canada sont de faible intensité et que les arbitrages finaux risquent d’être difficiles. Dans le cas du Canada, il est loin d’être certain que les agriculteurs sous gestion de l’offre en matière agricole, tout comme plusieurs premiers ministres provinciaux, accepteront des concessions en matière agricole pour un meilleur accès au marché des pays du Mercosur. Du côté du Mercosur, c’est le secteur industriel, notamment au Brésil et en Argentine, qui a tendance à résister aux concessions. Contrairement au Canada, l’intérêt stratégique de l’ensemble des pays du bloc converge vers l’ouverture du marché agricole

Negative regulation of EB1 turnover at microtubule plus ends by interaction with microtubule-associated protein ATIP3

International audienceThe regulation of microtubule dynamics is critical to ensure essential cell functions. End binding protein 1 (EB1) is a master regulator of microtubule dynamics that autonomously binds an extended GTP/GDP-Pi structure at growing microtubule ends and recruits regulatory proteins at this location. However, negative regulation of EB1 association with growing microtubule ends remains poorly understood. We show here that microtubule-associated tumor suppressor ATIP3 interacts with EB1 through direct binding of a non-canonical proline-rich motif. Results indicate that ATIP3 does not localize at growing microtubule ends and that in situ ATIP3-EB1 molecular complexes are mostly detected in the cytosol. We present evidence that a minimal EB1-interacting sequence of ATIP3 is both necessary and sufficient to prevent EB1 accumulation at growing microtubule ends in living cells and that EB1-interaction is involved in reducing cell polarity. By fluorescence recovery of EB1-GFP after photobleaching, we show that ATIP3 silencing accelerates EB1 turnover at microtubule ends with no modification of EB1 diffusion in the cytosol. We propose a novel mechanism by which ATIP3-EB1 interaction indirectly reduces the kinetics of EB1 exchange on its recognition site, thereby accounting for negative regulation of microtubule dynamic instability. Our findings provide a unique example of decreased EB1 turnover at growing microtubule ends by cytosolic interaction with a tumor suppressor. INTRODUCTION Microtubules (MTs) are polarized structures that continuously switch between periods of polymerization and depolymerization at their growing (plus) ends. This process, termed MT dynamic instability, allows rapid reorganization of the MT cytoskeleton during essential cell functions such as cell polarity and migration, mitosi

Genetic variation among major human geographic groups supports a peculiar evolutionary trend in PAX9

A total of 172 persons from nine South Amerindian, three African and one Eskimo populations were studied in relation to the Paired box gene 9 (PAX9) exon 3 (138 base pairs) as well as its 59and 39flanking intronic segments (232 bp and 220 bp, respectively) and integrated with the information available for the same genetic region from individuals of different geographical origins. Nine mutations were scored in exon 3 and six in its flanking regions; four of them are new South American tribe-specific singletons. Exon3 nucleotide diversity is several orders of magnitude higher than its intronic regions. Additionally, a set of variants in the PAX9 and 101 other genes related with dentition can define at least some dental morphological differences between Sub-Saharan Africans and non-Africans, probably associated with adaptations after the modern human exodus from Africa. Exon 3 of PAX9 could be a good molecular example of how evolvability works