A recently demonstrated technique of aerodynamic levitation has been used to study the resonance frequency of liquid droplets. A thin pressurized gas layer supports the droplet avoiding any contact with the environment. Due to the external gravitational field, the measured frequency is different from the one predicted by the classical models for a spherical drop. An ellipsoidal shape has been introduced to take into account the competition between surface and gravitational energies. Results of this model are in good agreement with experiments in terms of volume, as well as density and surface energy, dependence of the oscillation frequency.

International audienceA recently demonstrated aerodynamic levitation technique is used to perform contactless viscosity measurements. Classical models dealing with free oscillations of droplets without gravity cannot correctly describe the correspondence between damping coefficient and viscosity. An energetic approach taking into account the shape of the drop, and the velocity field of the liquid inside the drop, is introduced, leading to good agreement between experimental measurements and known viscosities of glycerol-water mixtures. Nonlinear effects are also investigated and experimental results are compared with the theory of anharmonic oscillations

Durante la década de 1960, se produjeron importantes transformaciones en la arquitectura de Concepción, Chile. El efecto de un terremoto y la puesta en marcha de un renovado Plan Regulador generaron cambios sustanciales en la manera de concebir la arquitectura local. Asimismo, la Iglesia Católica vivió procesos de cambio que repercutieron en su arquitectura. Concepción fue parte de esos cambios y en la totalidad de su área metropolitana se construyeron obras de arquitectura religiosa que trascendieron el paso del tiempo. Estas obras (que además repercutieron en los planteamientos de templos protestantes) trascendieron más allá de su función espiritual, en particular, teniendo un impacto urbano notorio, configurando manzanas y barrios y pasando a ser hitos importantes y apreciados en la ciudad.