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The earthquake (Ml=5.8; Mw=6.3) that shook L’Aquila (Abruzzo region, Italy) on 6 April 2009 and caused huge widespread damage in the other 56 municipalities of the seismic crater has also provided important input to reflect proactively on the need to avoid the repetition of similar tragedies, learning from the ca-lamities that have occurred. In fact, L’Aquila and the other municipalities hit by the earthquake represent an open-air analysis laboratory to reveal and directly see the weak points of the different buildings on the field which did not adequately resist the shocks. In order to provide important data for social utility, in this paper we illustrate the steps which constitute a GIS procedure that we have thought in order to evaluate the relationship between the period of construction and the outcomes of compliance with building safety stand-ards. Through sequential activities which have enabled us to also produce three-dimensional scenarios – of immediate communicative impact and able to show details for interdisciplinary analysis and strategical planning – we have portrayed the urban evolution of L’Aquila per period of construction and mapped the level of damage to the buildings. The relational analysis and quantitative data have permitted us to show that in the case of L’Aquila the major percentages of “unusable buildings”, and also these together with “condemned buildings due to external risks” concern the structures erected until 1955 and then in the 1956-1975 period, followed by the ones constructed in the periods of 1976-1988 and 1989-1994. Similar results, in conjunction with other specific information, can offer the possibility to define and apply the consolida-tion measures necessary to tackle future earthquakes in an appropriate way, without a passive sense of res-ignation and with a deeper awareness of seismic risk.

While a significant part of the population is concentrated in urban areas, the influence of cityscape parameters on human heat stress remain poorly understood. Yet we agree to develop urban spaces (street, square, district ...) in a way to provide best possible quality of life. In order to do so, quantitative and qualitative references are required. To fill this gap the HES-SO † - hepia/leea ‡ has developed an innovative portable monitoring system that can be easily deployed in various outdoor and indoor environments. The monitoring equipment is embedded into a backpack that is carried during ‘climatic urban walks’ that can be reproduced at different times of the day or seasons so to yield a detailed and dynamic description of the climatic context of a portion of the city from the pedestrian point of view.

Gestione del rischio, non più gestione delle catastrofi. È questo il nuovo indirizzo, dettato al livello internazionale, che deve seguire le aree più esposte ai disastri ambientali del pianeta. Gli ultimi tragici episodi (dal terremoto del Centro Italia del 2016-2017, alle devastanti alluvioni del 2018, fino alle recenti eruzioni dell’Etna con relative scosse sismiche in Sicilia) non fanno che ribadire che l’Italia deve convivere con rischi ambientali di ogni genere, visto che, purtroppo, possiede un lunghissimo catalogo storico di eventi, spesso catastrofici, in grado di sconvolgere popolazioni e trasformare il territorio nel breve e nel lungo periodo., Semestrale di studi e ricerche di geografia, N. 1 (2019): Scenari Fluviali: rappresentazioni, pratiche e visioni

International audience; Luminescent concentrators (LC) enable breaking the limit of geometrical concentration imposed by the brightness theorem. They enable increasing the brightness of Lambertian light sources such as (organic) light-emitting diodes. However, for illumination applications, light emitted in the high-index material needs to be outcoupled to free space, raising important light extraction issues. Supported by an intuitive graphical representation, we propose a simple design for light extraction: a wedged output side facet, breaking the symmetry of the traditional rectangular slab design. Angular emission patterns as well as ray-tracing simulations are reported on Ce:YAG single crystal concentrators cut with different wedge angles, and are compared with devices having flat or roughened exit facets. The wedge output provides a simple and versatile way to simultaneously enhance the extracted power (up to a factor of 2) and the light directivity (radiant intensity increased by up to 2.2.)

Semestrale di studi e ricerche di geografia, N. 1 (2018)

Electroluminescent diodes are popular sources due to their low cost, their reliability, and their excellent luminous efficiency. However, the power density of lambertian sources such as LED cannot be improved with linear optics which makes them not suited to laser pumping.We propose to increase the LED power density by one order of magnitude by coupling them in luminescent concentrators (LC). We studied these luminescent concentrators as illuminating sources using LC made of cerium doped YAG crystals (Ce:YAG) and we analyzed their performances using ray tracing simulations. For a deeper understanding of the challenge of extracting trapped rays in luminescent concentrators, a fully analytical model is also presented and used to study the influence of simple geometrical modifications such as wedging or roughening the luminescent concentrators’ output face. A significant increase of the light intensity was experimentally observed as well as a shrinking of the angular distribution.Finally, we set up a full organic structure with a LED source associated to thin film luminescent concentrators in order to pump micrometer-sized multimode waveguides. We demonstrated a one-order of magnitude amplification compared to a direct pumping with the same power density. It makes the LED/concentrator light source well suited for integrated optics and opens new perspectives whenever transposed at a nanometer scale., Les diodes électroluminescentes sont aujourd’hui des sources lumineuses populaires grâce à leur prix réduit, leur longévité, et leur excellent rendement lumineux. Elles restent pourtant mal adaptées au pompage laser en raison d’une densité de puissance trop faible et d’une émission lambertienne rendant impossible l’augmentation de leur brillance à l’aide d’un système optique linéaire.Nous proposons une méthode d’amplification innovante par couplage des LED dans des concentrateurs luminescents (LC) pour augmenter la densité de puissance de près d’un ordre de grandeur. Des LC monocristallins de YAG dopé cérium ont été testés puis analysés grâce à des simulations par tracé de rayons. Un modèle analytique offrant une compréhension avancée de la problématique de l’extraction des rayons piégés dans les LC a aussi été proposé et appliqué à l’étude de modifications géométriques simples que sont le biseau et le dépoli de la face de sortie des concentrateurs. Une amélioration significative de l’intensité extraite ainsi qu’un resserrement du profil angulaire d’émission ont ainsi été observés.Finalement, nous avons mis en place une structure toute organique pour le pompage de guides micrométriques où le couplage des LED est réalisé dans des concentrateurs en couche mince. Une amplification d’un ordre de grandeur de la densité de puissance par pompage indirect par concentrateur est vérifiée expérimentalement, ce qui ouvre la voie vers une utilisation du couple LED/concentrateur en tant que source pour la photonique intégrée.

Electroluminescent diodes are popular sources due to their low cost, their reliability, and their excellent luminous efficiency. However, the power density of lambertian sources such as LED cannot be improved with linear optics which makes them not suited to laser pumping. We propose to increase the LED power density by one order of magnitude by coupling them in luminescent concentrators (LC). We studied these luminescent concentrators as illuminating sources using LC made of cerium doped YAG crystals (Ce:YAG) and we analyzed their performances using ray tracing simulations. For a deeper understanding of the challenge of extracting trapped rays in luminescent concentrators, a fully analytical model is also presented and used to study the influence of simple geometrical modifications such as wedging or roughening the luminescent concentrators output face. A significant increase of the light intensity was experimentally observed as well as a shrinking of the angular distribution. Finally, we set up a full organic structure with a LED source associated to thin film luminescent concentrators in order to pump micrometer-sized multimode waveguides. We demonstrated a one-order of magnitude amplification compared to a direct pumping with the same power density. It makes the LED/concentrator light source well suited for integrated optics and opens new perspectives whenever; Les diodes électroluminescentes sont aujourd’hui des sources lumineuses populaires grâce leur prix réduit, leur longévité, et leur excellent rendement lumineux. Elles restent pourtant mal adaptées au pompage laser en raison dune densité de puissance trop faible et dune émission lambertienne rendant impossible l'augmentation de leur brillance laide d'un système optique linéaire. Nous proposons une méthode d'amplification innovante par couplage des LED dans des concentrateurs luminescents (LC) pour augmenter la densité de puissance de près d'un ordre de grandeur. Des LC monocristallins de YAG dopé cérium ont été testés puis analysés grâce à des simulations par tracé de rayons. Un modèle analytique offrant une compréhension avancée de la problématique de l'extraction des rayons piégés dans les LC a aussi été proposé et appliqué l'étude de modifications géométriques simples que sont le biseau et le dépoli de la face de sortie des concentrateurs. Une amélioration significative de l'intensité extraite ainsi qu'un resserrement du profil angulaire d'émission ont ainsi été observés. Finalement, nous avons mis en place une structure toute organique pour le pompage de guides micrométriques où le couplage des LED est réalisé dans des concentrateurs en couche mince. Une amplification d'un ordre de grandeur de la densité de puissance par pompage indirect par concentrateur est vérifiée expérimentalement, ce qui ouvre la voie vers une utilisation du couple LED/concentrateur en tant que source pour la photonique intégrée.

International audience; By power scaling of LEDs pump concentrators we demonstrated a visible light source (centered at 550 nm) producing 294 W with a radiance of 668 W/cm 2 /sr in the air. Using more than 1100 LEDs, this setup represents one order of magnitude improvement in terms of output power and brightest of LED pump concentrator ever reported. We pushed further the concept of low cost high brightness light source using this concentrator to pump a very simple Nd:YAG laser in free running mode and in passively Q-switched regime using a Cr:YAG saturable absorber. Output energies up to 263 µJ with a pulse duration of 33 ns have been obtained at 1064 nm, leading to a peak power of 8 kW in a TEM00 mode.

This paper deals with the mechatronic design and control of a 3-RPS (Revolute-Prismatic-Spherical) parallel manipulator, which moving platform has three d.o.f.s, one translation and two rotations. Each of the three legs connects the fixed with the moving platform through a revolute and a spherical joint, respectively, while each prismatic joint consists of a DC electromechanical actuator. A prototype was built and experimentally tested by devoting particular attention to the control of the electric drives, as based on the technique of the Path-Step-Diagrams, which is commonly used for controlling pneumatic cylinders.

International audience