Unsteady axisymmetric flow by the method of discrete vortices

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Preface to 2009 EURING Analytical Meeting proceedings

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Luiz Bernardo Pericás: Caio Prado Júnior, uma biografia política, Boitempo, São Paulo, 2016, pp. 504, ISBN 978-85-7559-448-3.

Per i testi della sezione "Recensioni" non è di norma previsto un abstract

Tolérance aux défauts de type court-circuit d'interrupteurs de puissance en SiC utilisés dans un convertisseur DC/DC entrelacé

International audienceL'optimisation de la fiabilité des convertisseurs DC-DC est cruciale pour que la chaine de traction d'un véhicule à pile à combustible puisse fournir, sans interruption, la puissance énergétique demandée par la charge. Pour atteindre cet objectif, un algorithme de détection du défaut est requis afin de l'identifier et le localiser avant que ses effets ne causent l'arrêt du système. Les composants, passifs ou actifs, qui constituent les convertisseurs statiques sont l'une des sources à l'origine de ces défauts. Dans cet article, le défaut de type court-circuit d'interrupteurs de puissance est considéré et un contrôle tolérant aux fautes est proposé. Une architecture modulaire est, par ailleurs, suggérée qui associe plusieurs briques génériques « Pile à Combustible + Convertisseur DC-DC » dans le but d'augmenter l'opérabilité et la disponibilité du système même en mode dégradé. Ainsi, pour améliorer d'avantage les performances du convertisseur, la technologie en carbure de silicium est adoptée

Experiments of a twenty cell PEFC operating under fault conditions with diode by-pass circuit for uninterrupted power delivery

International audienceThe work presents the results of experiments related to the electrical and dynamical behaviour of a 500W, twenty cell Polymer Electrolyte Fuel Cell (PEFC) stack operated under fault condition and connected to an anti-parallel diode acting as a by-pass. The stack is placed in an experimental set-up that reproduces the electrical coupling in series of two fuel cells. The results allow the evaluation of the by-pass diode solution in the case of specific degraded working modes such as the break of the gas reactant feeding. The experiments presented in this article constitute an extrapolation and a complementary investigation of the preliminary results already achieved on a two cell PEFC stack and which had demonstrated the capability of the reverse diode to electrically isolate a fuel cell stack under fault. The proposed experiments focus on the dynamic behaviour of the stack under degraded working modes and point out the key-role of the fuel cell stack impedance in the triggering of the anti-parallel diode switching

Action palliative par le convertisseur statique en cas de défaillance d'un générateur PAC modulaire de puissance

International audienceLa montée en puissance des piles à combustible se heurte à des difficultés d'ordre mécanique et fluidique, limitant l'assemblage en série de cellules unitaires pour les piles de forte puissance. Aussi, à l'heure actuelle, est-il plus aisé de concevoir des générateurs pile à combustible associant plusieurs piles unitaires, dits " multi-stack ". L'approche multi-stack permet en outre de gérer d'éventuelles défaillances pouvant intervenir sur l'une des piles en fonctionnement. Cet article présente des actions de soulagement de la pile défaillante possibles par intervention sur les convertisseurs statiques de puissance d'interface et permettant le rétablissement de cette pile défaillante vers son état sain

On the Use of Train Braking Energy Regarding the Electrical Consumption Optimization in Railway Station

AbstractNowadays, many projects have been conducted in order to reduce CO2 emissions, with the objective of reducing energy consumption. In the context of the urban railway area, the energy consumption is huge. It is respectively split into 70% for the traction and 30% for station consumers. Many works have already been carried out on traction systems, but very few of them were oriented towards the station energy problematic. This paper describes the project led by “Efficacity” Institute which concerns the use of the braking energy to manage and optimize the railway station energy consumption.Efficacity investigates energetic concepts in order to store the braking energy of the trains with a stationary electrical saving system, and to reutilize it for the power supply of electric and thermal consumers or actuators in a railway station thanks to a microgrid. The idea is to store train braking energy in hybrid storage system (composed of batteries and super-capacitors cells) and to restate it judiciously at different moments of the day (during peak or low energy consumption hours) to various kind of station loads

Construction of interactive Card Game as appliance for the learning in discipline Transport\u27s Systems in Civil Engineering course of Universidade Federal do Paraná

The objective of this research is to present and discuss the results with the inclusion of an educational alternative – Construction of Card Games – in order to enhance students learning in the discipline of Systems Transports in the Civil Engineering course of UFPR, when compared with classes that did not perform the activity. Through this discipline sought to assess if the students would be able, with the proposed approach, of absorb new knowledge and more interesting, without compromising the traditional programmatic content. For this, the decks were made in class times. The results, by the final ratings of discipline, when compared with three other classes in the same discipline, taught by other professors who did not develop the activities, show that this tool contributed in some way to the improvement of the traditional methodology, seen that among the groups showed the highest average compared to others, with positives results for learning

The use of a new automatic device for patients' assessment at Triage in Emergency Department

Objectives: To assess time saving in an Emergency Department arising out of the introduction of automatic devices (Carescape™ V100) to measure vital signs compared to the manual devices. Methods: We performed a prospective, observational study of eligible patients referring to Sant'Andrea Hospital Emergency Department during the entire month of October 2009, randomly assigned into two groups. In the first group of 476 patients vital signs measurements were detected with manual devices, while in the second group of 477 patients with automatic device Carescape™ V100. Results: Data indicated that the comparison of the total time between the two groups gave a significant difference (1993 vs 1518 min, p < 0.001). No differences were found with respect to age, sex and priority codes. Significant differences were also found when comparing the subgroups of the same acuity categories: white codes 4.33 vs 2.27 (min), p < 0.05; green codes 4.28 vs 3.37 (min), p < 0.001; yellow codes 3.92 vs 2.72 (min), p < 0.001. Conclusions: Our data demonstrated a statistical significance between the two groups with a difference of 475 minutes spent in Triage procedures including vital signs measurements. In conclusion time saved by vital signs automatic device could allow ED physicians to make a qualified approach with an earlier diagnosis and a more rapid and effective therapy, possibly improving patients' outcomes. ABSTRACT of data concerning vital signs quality assessment, because we did not compare the two methods in the same patient and we did not correlate Triage priority evaluation with patients' outcomes. In the future further studies should be specifically aimed to address this issue. In conclusion time saved by vital signs automatic device could allow ED physicians to make a qualified approach to patient with an earlier diagnosis and a more rapid and effective therapy, possibly improving patients' outcomes

Análise do sistema de transporte da cidade de curitiba a partir da ótica da do índice de vulnerabilidade social (IVS) / Analysis of the system of transport of the city of curitiba from the optical of the index of social vulnerability (IVS)

Os sistemas de transporte possuem três dimensões fundamentais segundo a ótica da mobilidade sustentável: ambiental, econômica e social. Esse último, foco deste artigo. Em países em desenvolvimento como o Brasil, em que os núcleos urbanos se formaram de modo acelerado e desordenado, atenção especial é necessária aos elementos da dimensão social, cuja negligencia pode resultar em exclusão social por conta da falta de acessibilidade a oportunidades, tais como, estudo, emprego, saúde e lazer. Nesse sentido, o uso de Índices que avaliam os aspectos sociais pode apresentar contribuições essenciais na avaliação, monitoramento e planejamento de cidades mais inclusivas. Esse artigo utiliza o IVS – índice de Vulnerabilidade Social, como fundo para a análise do sistema de transporte de Curitiba, constatando que os meios de transporte que exigem menor custo de aquisição e manutenção são predominantes em regiões com maior vulnerabilidade social, enquanto carros e estacionamentos predominam em áreas de menor vulnerabilidade social.