Experimental investigation on steady granular flows interacting with an obstacle down an inclined channel: study of the dead zone upstream from the obstacle. Application to interaction between dense snow avalanches and defence structures

An experimental investigation with dry granular flows passing over an obstacle down a rough inclined channel has been performed. The aim is to improve our understanding of the interaction between dense snow avalanches and defence structures. Specific attention was directed to the study of the zone of influence upstream from the obstacle, linked to the formation of a dead zone. The dead zone length <i>L</i> was systematically measured as a function of the obstacle height <i>H</i> and the channel inclination <i>&#x03B8;</i>, for several discharges. In a whole range of channel inclinations, all the data are shown to collapse into a single curve when properly scaled. The scaling is based on the introduction of a theoretical deposit length (depending on <i>H</i>, <i>&#x03B8;</i> and the internal friction angle of the material, <i>&#x03C6;</i>) and a Froude number of the flow depending on the obstacle height

Pre and Post Synaptic NMDA Effects Targeting Purkinje Cells in the Mouse Cerebellar Cortex

N-methyl-D-aspartate (NMDA) receptors are associated with many forms of synaptic plasticity. Their expression level and subunit composition undergo developmental changes in several brain regions. In the mouse cerebellum, beside a developmental switch between NR2B and NR2A/C subunits in granule cells, functional postsynaptic NMDA receptors are seen in Purkinje cells of neonate and adult but not juvenile rat and mice. A presynaptic effect of NMDA on GABA release by cerebellar interneurons was identified recently. Nevertheless whereas NMDA receptor subunits are detected on parallel fiber terminals, a presynaptic effect of NMDA on spontaneous release of glutamate has not been demonstrated. Using mouse cerebellar cultures and patch-clamp recordings we show that NMDA facilitates glutamate release onto Purkinje cells in young cultures via a presynaptic mechanism, whereas NMDA activates extrasynaptic receptors in Purkinje cells recorded in old cultures. The presynaptic effect of NMDA on glutamate release is also observed in Purkinje cells recorded in acute slices prepared from juvenile but not from adult mice and requires a specific protocol of NMDA application

Modélisation numérique de l'effet d'un obstacle sur les écoulements de fluides à seuil par la méthode SPH

[Departement_IRSTEA]EEE [TR1_IRSTEA]23 - ALTEAURISK / DYNAL [Encadrant_IRSTEA]Naaim M.We study the influence of an obstacle on a yield-stress fluid flow. Such fluid follows a Herschel-Bulkley flow curve. Solutions of the flow equations are computed by the SPH (Smoothed Particle Hydrodynamics) method. This technique is first validated by comparison to classical well-documented flows. First results are obtained for steady flows. In that case, we study the influence on the speed, on the formation of a rigid zone and on the local pressure upstream the structure. In some cases, zones of accelerated flow can be observed . The length of the rigid zone is proportional to the obstacle height. Then, we study transitory flows. Some cumulated momentum is numerically "measured" downstream the structure to estimate the absorbed momentum due to the presence of the obstacle. Finally, a study concerning the maximum pressure value and the duration of the pressure rise is carried out upstream the obstacle.Nous étudions l'influence d'un obstacle sur l'écoulement d'un fluide à seuil. Ces fluides sont modélisés par une loi de type Herschel-Bulkley et nous résolvons les équations du mouvement par la méthode particulaire SPH (Smoothed Particle Hydrodynamics). Cette technique est validée par comparaison à des écoulements bien documentés. Les premiers résultats sont obtenus pour des écoulements permanents. Nous étudions dans ce cas les variations de vitesse, la formation d'une zone rigide, la position de la surface libre et la pression engendrée en amont de l'obstacle. Dans certains cas, on peut observer des zones de d'écoulement accéléré. La longueur de la zone rigide en amont de l'obstacle croît proportionnellement à la hauteur de la singularité. Nous étudions ensuite des écoulements transitoires. Nous avons " mesuré " numériquement une quantité de mouvement cumulée en aval de l'obstacle afin d'estimer ce qui était absorbé par l'ouvrage. Une étude concernant la pression maximale et le temps de montée de la sollicitation en amont de l'obstacle a été menée

Investigations expérimentales sur des écoulements granulaires permanents interagissant avec un obstacle en canal incliné : étude de la zone morte en amont de l'obstacle. Application à l'interaction entre les avalanches de neige dense et les structures de protection

International audienceAn experimental investigation with dry granular flows passing over an obstacle down a rough inclined channel has been performed. The aim is to improve our understanding of the interaction between dense snow avalanches and defence structures. A specific attention was directed to the study of the zone of influence upstream from the obstacle, linked to the formation of a dead zone. The dead zone length L was systematically measured as a function of the obstacle height H and the channel inclination q, for several discharges. In a whole range of channel inclinations, all the data are shown to collapse into a single curve when properly scaled. The scaling is based on the introduction of a theoretical deposit length (depending on H, q and the internal friction angle of the material, j) and a Froude number of the flow depending on the obstacle height

Simulation SPH de l'effet des obstacles sur les écoulements granulaires

International audienceThis paper presents the SPH (Smoothed Particles Hydrodynamics) numerical method adapted to complex rheology and free surface flow. It has been developped to simulate the local effect of a simple obstacle on a granular flow. We have introduced this specific rheology to the classical formalism of the method and thanks to experimental devices, we were able to validate the results. Two viscosity values have been simultaneously computed to simulate "plugs" and "dead zone" with the same code. First, some experiments have been done on a simple inclined slope to show the accuracy of the numerical results. We have fixed the mass flowrate to see the variations of the flow depth according to the channel slope. Then we put a weir to block the flow and we analysed the dependence between the obstacle height and the length of influence upstream from the obstacle. After having shown that numerical results were consistent, we have studied speed profiles and pressure impact on the structure. Also results with any topography will be presented. This will have a great interest to study real flow over natural topography while using the model for decision help

A gestão coletiva de direitos de autor no Brasil e União Européia : o princípio da transparência no ambiente digital

Orientador: Prof. Dr. Marcos WachowiczDissertação (mestrado) - Universidade Federal do Paraná, Setor de Ciências Jurídicas, Programa de Pós-Graduação em Direito. Defesa : Curitiba, 10/06/2020Inclui referências: p. 131-135Resumo: A gestão coletiva de direitos de autor constitui a principal forma de garantir o recebimento dos royalties advindo da execução pública de obras musicais. O instituto é responsável por garantir a proteção dos direitos de autor nos casos que é difícil o titular realizar o controle sozinho. No entanto, o sistema apresenta um grande problema com a falta de transparência na relação entre os titulares das obras e as associações de gestão coletiva. O presente trabalho busca definir o que seria transparência para o este sistema a partir da análise da legislação brasileira e europeia: a Lei 12.853/13 e a Diretiva 2014/26/UE. Entretanto, estas legislações são insuficientes, uma vez que não apresentam mecanismos efetivos de fiscalização. Casos como o IFPI Simulcasting e Radio OI x ECAD ilustram a dificuldade do Direito de acompanhar as novas tecnologias, em especial o streaming. Busca-se uma alternativa ao problema da fiscalização, apresentando a própria tecnologia como opção. As novas plataformas e serviços permitem que os titulares possam gerir suas obras, se tornando fiscais da gestão de direitos. As associações de gestão coletiva deixam de ser o centro da gestão, permitindo que os titulares e interessados saibam como os direitos são arrecadados e distribuídos, garantindo uma maior eficiência do sistema e colocando o autor-criador como sujeito ativo na gestão de seus direitos. Palavras-chave: Gestão Coletiva; Transparência; Fiscalização; Direito Autoral; Streaming.Abstract: The collective management of copyright is the main way to guarantee the receipt of royalties arising from the public performance of musical works. The institute is responsible for ensuring the protection of copyright in cases where it is difficult for the owner to carry out the control alone. However, the system presents a major problem with the lack of transparency in the relationship between the owners of the works and the collective management associations. The present work aims to define what would be transparency for this system based on the analysis of Brazilian and European legislation: Law 12.853/13 and Directive 2014/26/EU. However, these legislation are insufficient, as they do not have effective enforcement mechanisms. Cases such as IFPI Simulcasting and Radio OI x ECAD illustrate the difficulty of the Law to keep up with new technologies, especially streaming. An alternative to the isupervision problem is sought, presenting technology itself as an option. The new platforms and services allow right holders to manage their works, becoming inspectors of rights management. Collective management organizations are no longer the center of management, allowing holders and stakeholders to know how rights are collected and distributed, ensuring greater efficiency of the system and placing the author-creator as an active subject in the management of their rights. Keywords: Collective Management; Transparency; Supervision; Copyright; Streamin