Suchergebnisse

The present article discusses the contribution of the tools of the social networks analysis to the intellectual history. Based on the case of important antiimperialistic Latin-American figures of the beginning of the 20th century, it thinks theoretically about the limits and potentials of this method. It focus particularly on the different questions that this methodology raises because of it relation with the historical temporalities, the social spaces, the forms of action and the role of the individual as agent of change in history. ; Este artigo a contribuição das ferramentas que discute da análise de redes sociais à história intelectual que está baseado no caso de figuras latim importante os antiimperialistas americanos de princípios do século de XX. Propõe um téorica de reflexão sobre os limites e potencialidades deste método interdisciplinar. O núcleo de suas análises é centrado particularmente nas questões diferentes que ela ergue esta metodologia em sua relação com os tempos históricos, os espaços sociais, a ação forma e a lista do indivíduo como motor da história. ; Este artículo discute el aporte de las herramientas del análisis de redes sociales a la historia intelectual basándose en el caso de importantes figuras antiimperialistas latinoamericanas de principios del siglo XX. Propone una reflexión teórica sobre los límites y potencialidades de este método interdisciplinario. El meollo de sus análisis se centra particularmente en las distintas interrogantes que plantea esta metodología en su relación con los tiempos históricos, los espacios sociales, las formas de acción y el rol del individuo como motor de la historia.

This article reflects on the consequences of historical change and interdisciplinary research in politicalscience. Taking as point of reference the socio-historical approach to political parties, is a plea forinterdisciplinary research of party genesis. Given the hard work that represents the objectification ofhistorical turn of political science to interpret political processes, insists on the need to develop bothcomparative and located research about the origins of the political formations, illustrating thisproposition through examples as the Partido Aprista Peruano and Acción Democrática of Venezuela.Moreover, this proposal examines the challenges of "historicization" of this discipline in an effort toturn to the past to overcome the theoretical and methodological obstacles related to the study of theprocesses of party genesis. ; El presente artículo reflexiona sobre las consecuencias del giro histórico y de las prácticas interdisciplinarias en ciencias políticas. Tomando como punto de referencia el enfoque sociohistórico de los partidos políticos, constituye un alegato a favor del estudio interdisciplinario de las génesis partidarias. Teniendo en cuenta la ardua tarea que representa la objetivación del giro histórico de las ciencias políticas para interpretar procesos políticos, insiste sobre la necesidad de desarrollar investigaciones a la vez localizadas y comparativas de los orígenes de las formaciones políticas, ilustrando esta proposición a través de los ejemplos del Partido Aprista Peruano y de Acción Democrática de Venezuela. Por otra parte, esta propuesta examina los desafíos que plantea la "historicización" de esta disciplina en su afán de recurrir al pasado para superar los obstáculos teóricos-metodológicos relacionados con el estudio de los procesos de génesis partidarias.

Résumé Cet article se penche sur les réseaux transnationaux et les actions collectives menées par les anciens étudiants de l'université centrale de Caracas, qui furent expulsés du Venezuela en 1929 et que l'historiographie désigne comme la « Génération de 1928 ». Utilisant la méthodologie de l'analyse des réseaux sociaux afin d'examiner les caractéristiques sociopolitiques du réseau égocentré de Rómulo Betancourt, ce travail met en lumière les différentes caractéristiques de l'internationalisation des activités de ces exilés vénézuéliens. Il examine notamment les rivalités existantes pour le contrôle de la résistance contre la dictature de Juan Vicente Gómez.

In this paper, the multipactor RF breakdown in a parallel-plate waveguide partially filled with a ferrite slab magnetized normal to the metallic plates is studied. An external magnetic field is applied along the vertical direction between the plates in order to magnetize the ferrite. Numerical simulations using an in-house 3-D code are carried out to obtain the multipactor RF voltage threshold in this kind of structures. The presented results show that the multipactor RF voltage threshold at certain frequencies becomes considerably lower than for the corresponding classical metallic parallel-plate waveguide with the same vacuum gap ; This work was supported in part by the European Space Agency under Novel Investigation in Multipactor Effect in Ferrite and other Dielectrics used in high power RF Space Hardware under Contract AO 1-7551/13/NL/GLC, in part by the Spanish Government under Coordinated R&D Project TEC2013- 47037-5-R and Project TEC2014-55463-C3-3-P, and in part by the European Commission (ERDF). The review of this paper was arranged by Editor R. Carter. ; Gonzalez Iglesias, D.; Gomez, A.; Gimeno Martinez, B.; Fernández, O.; Vegas, A.; Casas, F.; Anza Hormigo, S. (2016). Analysis of Multipactor RF Breakdown in a Waveguide Containing a Transversely Magnetized Ferrite. IEEE Transactions on Electron Devices. 63(12):4939-4947. doi:10.1109/TED.2016.2614370 ; S ; 4939 ; 4947 ; 63 ; 12

In this paper, the multipactor RF breakdown in a parallel-plate waveguide partially filled with a ferrite slab magnetized normal to the metallic plates is studied. An external magnetic field is applied along the vertical direction between the plates in order to magnetize the ferrite. Numerical simulations using an in-house 3D code are carried out to obtain the multipactor RF voltage threshold in this kind of structures. The presented results show that the multipactor RF voltage threshold at certain frequencies becomes considerably lower than for the corresponding classical metallic parallel-plate waveguide with the same vacuum gap. ; This work was supported by the European Space Agency (ESA) under Novel Investigation in Multipactor Effect in Ferrite and other Dielectrics used in high power RF Space Hardware Contract AO 1-7551/13/NL/GLC, and partially by the Spanish Government (under coordinated R&D projects TEC2013-47037-C5-R and TEC2014-55463-C3-3-P).

[EN] This paper reports on the experimental measurement of power threshold levels for the multipactor effect between samples of ferrite material typically used in the practical implementation of L-and S-band circulators and isolators. For this purposes, a new family of wideband, nonreciprocal rectangular waveguide structures loaded with ferrites has been designed with a full-wave electromagnetic simulation tool. The design also includes the required magnetostatic field biasing circuits. The multipactor breakdown power levels have also been predicted with an accurate electron tracking code using measured values for the secondary electron yield (SEY) coefficient. The measured results agree well with simulations, thereby fully validating the experimental campaign. ; This work was supported in part by the European Space Agency (ESA) through the Research Project Novel Investigation in Multipactor Effect in Ferrite and Other Dielectrics Used in High Power RF Space Hardware under Contract AO 1-7551/13/NL/GLC, in part by the Ministerio de Economia y Competitividad (Spanish Government) through Research and Development under Project TEC2016-75934-C4-1-R and Project TEC2016-75934-C4-2-R, and in part by the European Regional Development Fund under Project TEC2014-55463-C3-3-P. ; Vague Cardona, JJ.; Melgarejo-Lermas, JC.; Boria Esbert, VE.; Guglielmi, M.; Moreno Cambroreno, MDR.; Reglero Mangada, MS.; Mata-Sanz, R. (2019). Experimental Validation of Multipactor Effect for Ferrite Materials Used in L- and S-Band Nonreciprocal Microwave Components. IEEE Transactions on Microwave Theory and Techniques. 67(6):2151-2161. https://doi.org/10.1109/TMTT.2019.2915546 ; S ; 2151 ; 2161 ; 67 ; 6

This paper reports on the experimental measurement of power threshold levels for the multipactor effect between samples of ferrite material typically used in the practical implementation of L- and S-band circulators and isolators. For this purposes, a new family of wideband, nonreciprocal rectangular waveguide structures loaded with ferrites has been designed with a full-wave electromagnetic simulation tool. The design also includes the required magnetostatic field biasing circuits. The multipactor breakdown power levels have also been predicted with an accurate electron tracking code using measured values for the secondary electron yield (SEY) coefficient. The measured results agree well with simulations, thereby fully validating the experimental campaign. ; This work was supported by European Space Agency (ESA) through research project "Novel Investigation in Multipactor Effect in Ferrite and other Dielectrics used in High Power RF Space Hardware" (ref. AO 1-7551/13/NL/GLC), and by MINECO (Spanish Government) under R&D projects TEC2016-75934-C4-1-R, TEC2016-75934-C4-2-R and the ERDF co-funded project TEC2014-55463-C3-3-P.