Morphology dependent ultrafast electron dynamics in ultrathin gold films

Ultrafast electron dynamics in 5 nm thick gold films have been investigated as a function of film morphology. The transient reflectivity data reveal a sub-100 fs rise time and a complex relaxation profile on the picosecond timescale. These data are discussed in terms of a modified two-temperature model of the electron dynamics accounting for the initial relaxation of the non-thermal population. The electron–phonon coupling may be sensitive to film morphology. The possible origin of this behaviour is discussed and results are placed in the context of enhanced photochemistry on thin metal films

Z-scan confocal method for indirect focus location

We present a new technique that we have defined as the z-scan confocal method to determine the location and size of the focal spot in a tightly focused ultrashort laser pulse. The method permits accurate positioning of a target in the focal spot with a fast response. The technique is designed to help to automatize the location of an overdense target in focus in a laser plasma experiment and suitable to be implemented in a closed loop configuration setup. The method allows for a fast localization of the focal position and the relative motion of the target with respect to it. As an example of the potential of the technique we have measured the defocusing of a fast rotating disc in several radii to reconstruct the motion of the disc at focus

Caminos Alternativos para la Sostenibilidad y el Buen Vivir

En este texto, las diversas perspectivas presentadas en el marco del desarrollo sostenible plantean un tránsito a la sustentabilidad, y de ahí que se considere como una alternativa al buen vivir. Se plantean propuestas a partir de casos documentados que la sociedad organizada trabaja y que brindan alternativas desde su propia racionalidad y sentir, así como el rol del Estado en los procesos sociales en los territorios rurales. Asimismo, se exponen algunos casos de intervención vía políticas públicas y de cuando la sociedad organizada es autogestionaria, y logra proyectos con resultados de impacto que, si bien no son espectaculares, sí dejan huella en su ámbito local de origen