Manzana 270 en Berlín: un ejemplo de construcción en la tradición de las manzanas regulares berlinesas

Peer Reviewe

«Deus caritas est». Sobre la primera encíclica del Papa Benedicto XVI.

La encíclica Deus caritas est es mucho más que una reflexión sobre el amor cristiano. A través de un lúcido análisis de la cuestión del amor en las fuentes de la civilización occidental, muestra cuánto ha perdido el pensamiento moderno que ha dejado de lado lo que le ofrece la revelación. En continuidad con las encíclicas que abordaron anteriormente la cuestión social, la nueva encíclica señala la necesidad de que la justicia social del Estado no se haga ciega a las exigencias intrínsecas de la fe revelada

Flexible delivery of Er:YAG radiation at 2.94 µm with negative curvature silica glass fibers:a new solution for minimally invasive surgical procedures

We present the delivery of high energy microsecond pulses through a hollow-core negative-curvature fiber at 2.94 µm. The energy densities delivered far exceed those required for biological tissue manipulation and are of the order of 2300 J/cm(2). Tissue ablation was demonstrated on hard and soft tissue in dry and aqueous conditions with no detrimental effects to the fiber or catastrophic damage to the end facets. The energy is guided in a well confined single mode allowing for a small and controllable focused spot delivered flexibly to the point of operation. Hence, a mechanically and chemically robust alternative to the existing Er:YAG delivery systems is proposed which paves the way for new routes for minimally invasive surgical laser procedures

Slow and velocity-tunable beams of metastable He2_2 by multistage Zeeman deceleration

Metastable helium molecules (He$_2^*$) have been generated by striking a discharge in a supersonic expansion of helium gas from a pulsed valve. When operating the pulsed valve at room temperature, 77K, and 10K, the mean velocity of the supersonic beam was measured to be 1900m/s, 980m/s, and 530m/s, respectively. A 55-stage Zeeman decelerator operated in a phase-stable manner was then used to further reduce the beam velocity and tune it in the range between 100 and 150m/s. The internal-state distribution of the decelerated sample was established by photoionization spectroscopy.Comment: 10 pages, 7 figure