The institutionalization of the technical and industrial education in france, 1919-1958

El presente artículo estudia la organización institucional de la enseñanza técnica e industrial en Francia desde 1919, con la Ley Astier, hasta 1958, con el fin de la Cuarta República. Es una época en la que se asiste a la definición de la formación profesional industrial por parte del Estado, aun con la ruptura de 1940 y la instauración del régimen de Vichy, cuyo impacto en la evolución de esta educación es considerable. En este período la problemática institucional, afectada por las exigencias económicas de mano de obra cualificada, se centra en la disyuntiva de si favorecer el aprendizaje tradicional del taller, dirigido al obrero, o reorganizar la escolarización de la enseñanza industrial media dentro de la estructura de la educación secundaria, dirigida al cuerpo de técnicos. Finalmente, durante la Cuarta República, se observa que esta ambigüedad lo único que favorece es reforzar la distancia entre los dos niveles de enseñanza técnica.The present article studies the institutional organization of the technical and industrial education in France from 1919 with the law Astier, until 1958, with the end of the Fourth Republic. It is an epoch in which the State organizes the industrial vocational training, though with the break of 1940 and the establishment of the regime of Vichy, which impact in the evolution of this education is considerable. In this period the politics, influenced by the economic requirements of qualified workers, presents the problem of if to favor the industrial learning of the worker, or of reorganizing the industrial education of technical personnel inside the structure of the secondary education. Finally, during the Fourth Republic, is observed that this ambiguity the only thing that it favors is to reinforce the distance between both levels of technical education

IX Jornadas de lingüística

Celebradas en Cádiz los días 30 de noviembre y 1 de diciembre de 200

High performance of symmetric micro supercapacitors based on silicon nanowires using N-methyl-N-propylpyrrolidinium bis(trifluoromethylsulfonyl)imide as electrolyte

This work describes the development and performance of a symmetric microsupercapacitor made of nanostructured electrodes based on silicon nanowires (SiNWs) deposited using chemical vapor deposition (CVD) on silicon substrates. The performance of the SiNWs micro-supercapacitor employing an aprotic ionic liquid (N-methyl-N-propylpyrrolidinium bis(trifluoromethylsulfonyl)imide) (PYR13TFSI) as an electrolyte was able to deliver a maximal power density of 182 mW cm-2 and a specific energy of 190 µJ cm-2 operating at a wide cell voltage of 4V with a quasi-ideal capacitive behaviour. The lifetime of the device exhibited a remarkable electrochemical stability retaining 75 % of the initial capacitance after several million galvanostatic charge-discharge cycles at a high current density of 1 mA cm-2. Furthermore, a coulombic efficiency of approximately 99 % was obtained after galvanostatic cycling test without structural degradation on the morphology of SiNWs

Dynamics in the center manifold around equilibrium points periodically perturbed three-body problems

A new application of the parameterization method is presented to compute invariant manifolds about the equilibrium points of Periodically Perturbed Three-Body Problems (PPTBP). These techniques are applied to obtain high-order semi-numerical approximations of the center manifolds about the points L1,2 of the Sun-perturbed Earth-Moon Quasi-Bicircular Problem (QBCP), which is a particular case of PPTBP. The quality of these approximations is compared with results obtained using equivalents of previous normal form procedures. Then, the parameterization is used to initialize the computation of Poincaré maps, which allow to get a qualitative description of the periodically-perturbed dynamics near the equilibrium points

Invariant manifolds of a non-autonomous quasi-bicircular problem computed via the parameterization method

The parameterization method (pm) has been used to compute high-order parameterizations of invariant manifolds of vector fields at xed points. This paper extends such approach to invariant manifolds of periodically-perturbed vector fields about a periodic orbit with the same frequency, with a direct application on the libration points of the Sun-Earth-Moon system. The Sun-Earth-Moon environment is modeled by the so-called Quasi-Bicircular Model (qbcp), which is a coherent restricted four-body model that describes the motion of a spacecraft under the simultaneous gravitational influences of the Earth, the Moon, and the Sun. The pm is adapted to account for the explicit time-dependency of the corresponding vector field. This new procedure yields high-order periodic semi-analytical approximations of the center manifolds about the libration points L1;2 of the periodically-perturbed Sun-(Earth+Moon) and Earth-Moon systems. These approximations are then used to initialize the computation of Poincaré maps, which allow to get a qualitative description of the non-autonomous dynamics near the equilibrium points. It is shown that, with this new approach, the semi-analytical description of the center manifolds in a coherent four-body environment is valid in a neighborhood significant enough to be used in practice. In particular, the well-known Halo orbit bifurcation is recovered in all cases

Systematic study of the dynamics about and between the Libration Points of the Sun-Earth-Moon System

A new approach is proposed for systematic detection and refinement of natural connections EML12 of the Earth-Moon system and SEML12 of Sun-Earth-Moon. It is structured around the Quasi-Bircircular Problem, a restricted coherent and periodic four-body dynamical model of the Sun-Earth-Moon system. The dynamics about the Libration points are described by high-order periodic semi-analytical expansions obtained via the parametrization method

Systematic study of the dynamics about and between the Libration Points of the Sun-Earth-Moon System

A new approach is proposed for systematic detection and refinement of natural connections EML12 of the Earth-Moon system and SEML12 of Sun-Earth-Moon. It is structured around the Quasi-Bircircular Problem, a restricted coherent and periodic four-body dynamical model of the Sun-Earth-Moon system. The dynamics about the Libration points are described by high-order periodic semi-analytical expansions obtained via the parametrization method

Entrainment of the Mammalian Cell Cycle by the Circadian Clock: Modeling Two Coupled Cellular Rhythms

The cell division cycle and the circadian clock represent two major cellular rhythms. These two periodic processes are coupled in multiple ways, given that several molecular components of the cell cycle network are controlled in a circadian manner. For example, in the network of cyclin-dependent kinases (Cdks) that governs progression along the successive phases of the cell cycle, the synthesis of the kinase Wee1, which inhibits the G2/M transition, is enhanced by the complex CLOCK-BMAL1 that plays a central role in the circadian clock network. Another component of the latter network, REV-ERBα, inhibits the synthesis of the Cdk inhibitor p21. Moreover, the synthesis of the oncogene c-Myc, which promotes G1 cyclin synthesis, is repressed by CLOCK-BMAL1. Using detailed computational models for the two networks we investigate the conditions in which the mammalian cell cycle can be entrained by the circadian clock. We show that the cell cycle can be brought to oscillate at a period of 24 h or 48 h when its autonomous period prior to coupling is in an appropriate range. The model indicates that the combination of multiple modes of coupling does not necessarily facilitate entrainment of the cell cycle by the circadian clock. Entrainment can also occur as a result of circadian variations in the level of a growth factor controlling entry into G1. Outside the range of entrainment, the coupling to the circadian clock may lead to disconnected oscillations in the cell cycle and the circadian system, or to complex oscillatory dynamics of the cell cycle in the form of endoreplication, complex periodic oscillations or chaos. The model predicts that the transition from entrainment to 24 h or 48 h might occur when the strength of coupling to the circadian clock or the level of growth factor decrease below critical values

SiNWs-based electrochemical double layer micro-supercapacitors with wide voltage window (4V) and long cycling stability using a protic ionic liquid electrolyte

The present work reports the use and application of a novel protic ionic liquid (triethylammonium bis(tri fluoromethylsulfonyl)imide; NEtH TFSI) as an electrolyte for symmetric planar micro-supercapacitors based on silicon nanowire electrodes. The excellent performance of the device has been successfully demonstrated using cyclic voltammetry, galvanostatic charge-discharge cycles and electrochemical impedance spectroscopy. The electrochemical characterization of this system exhibits a wide operative voltage of 4 V as well as an outstanding long cycling stability after millions of galvanostatic cycles at a high current density of 2 mA cm. In addition, the electrochemical double layer micro-supercapacitor was able to deliver a high power density of 4 mWcm in a very short time pulses (a few ms). Our results could be of interest to develop prospective on-chip micro-supercapacitors using protic ionic liquids as electrolytes with high performance in terms of power and energy densities