Parallaxes of southern extremely cool objects III : 118 L and T dwarfs

We present new results from the Parallaxes of Southern Extremely Cool dwarfs program to measure parallaxes, proper motions and multiepoch photometry of L and early T dwarfs. The observations were made on 108 nights over the course of 8 yr using the Wide Field Imager on the ESO 2.2m telescope. We present 118 new parallaxes of L and T dwarfs of which 52 have no published values and 24 of the 66 published values are preliminary estimates from this program. The parallax precision varies from 1.0 to 15.5mas with a median of 3.8mas. We find evidence for two objects with long term photometric variation and 24 new moving group candidates. We cross-match our sample to published photometric catalogues and find standard magnitudes in up to 16 pass-bands from which we build spectral energy distributions and H-R diagrams. This allows us to confirm the theoretically anticipated minimum in radius between stars and brown dwarfs across the hydrogen burning minimum mass. We find the minimum occurs between L2 and L6 and verify the predicted steep dependence of radius in the hydrogen burning regime and the gentle rise into the degenerate brown dwarf regime. We find a relatively young age of ~2 Gyr from the kinematics of our sample.Peer reviewedFinal Accepted Versio

Search for varying constants of nature from astronomical observation of molecules

The status of searches for possible variation in the constants of nature from astronomical observation of molecules is reviewed, focusing on the dimensionless constant representing the proton-electron mass ratio $\mu=m_p/m_e$. The optical detection of H$_2$ and CO molecules with large ground-based telescopes (as the ESO-VLT and the Keck telescopes), as well as the detection of H$_2$ with the Cosmic Origins Spectrograph aboard the Hubble Space Telescope is discussed in the context of varying constants, and in connection to different theoretical scenarios. Radio astronomy provides an alternative search strategy bearing the advantage that molecules as NH$_3$ (ammonia) and CH$_3$OH (methanol) can be used, which are much more sensitive to a varying $\mu$ than diatomic molecules. Current constraints are $|\Delta\mu/\mu| < 5 \times 10^{-6}$ for redshift $z=2.0-4.2$, corresponding to look-back times of 10-12.5 Gyrs, and $|\Delta\mu/\mu| < 1.5 \times 10^{-7}$ for $z=0.88$, corresponding to half the age of the Universe (both at 3$\sigma$ statistical significance). Existing bottlenecks and prospects for future improvement with novel instrumentation are discussed.Comment: Contribution to Workshop "High Performance Clocks in Space" at the International Space Science Institute, Bern 201

Tools and Strategies for Health Promotion in Urban Context: Technology and Innovation for Enhancing Parish Ecclesiastical Heritage Through Sport and Inclusion

The relationship between the built environment and health is an increasingly important issue in the planning and regeneration of the contemporary city. The contribution reflects on the impact of sport and social inclusion on the population’s health and well-being, moving from the results of a research experience. The project involves the parish ecclesiastical heritage. It proposes methods committed to its regeneration and innovation, aiming to enhance the oratorio sports facilities in a multi-generation, inclusive, and health education perspective. The definition of a multidisciplinary and analytical tool is based on a set of qualitative and quantitative criteria, for assessing the structures in different aspects, to reconsider the pre-existing sport facilities, and suggesting strategies for the renovation and innovation of their spaces and services. The application of the tool to the parish facilities brings extensive reflections on the importance of promotion of physical activity and of the creation of accessible social environments, suggesting strategies for more liveable and healthy community spaces; moreover, it contributes to the definition of systemic strategies and scientific tools for the enhancing of built heritage in the urban context

A robust electro-thermal IGBT SPICE model: Application to short-circuit protection circuit design

An optimized electro-thermal IGBT SPICE model based on the Kraus model was developed to allow reliable simulation at application level. A particular emphasis to the temperature dependence of physical parameters was given for both the on-state and breakdown conditions. The model was experimentally validated in steady state and transient operation on a Field-Stop trench-gate 30 A-600 V commercial IGBT device. The effectiveness of the convergence-accuracy aspects was proved for the proposed model. The application to the short-circuit protection circuit design for a hard switched fault in an inverter motor-drive application was also analysed. The ability of the proposed IGBT model was experimentally verified with a simplified-equivalent circuit where a short condition was forced on the load, enabling the desaturation protection by the IGBT driver. The results show an accurate prediction of the device electro-thermal behaviour under short-circuit conditions, with a possible optimal design of the desaturation circuit parameters when the device experiences hard-switched-fault or fault-under-load events. © 2015 Elsevier Ltd

Vivere alla quota zero

"Vivere la quota zero" significa favorire la fruizione ampliata e diffusa del comparto urbano di Via Medici del Vascello, periferia sud-est di Milano, un’area attualmente in stato di degrado e abbandono, attraverso la creazione di una “infrastruttura aperta” costituita da spazi pubblici di incontro e socializzazione atti a ospitare attività outdoor per il benessere e il tempo libero per un’utenza diversificata per età, cultura, esigenze e stili di vita. La proposta progettuale propone la valorizzazione del comparto adottando una logica di consumo di suolo zero e di riduzione della volumetria totale del lotto, introducendo una connotazione, oggi mancante, in linea con le attuali tendenze di rigenerazione urbana fondata sul concetto di “città sana” attraverso l'introduzione di elementi di connessione con quartieri limitrofi e le infrastrutture esistenti, la collocazione di funzioni fruibili h24, l' incentivazione della fruizione ciclopedonale e il potenziamento della sicurezza grazie all'interazione sociale. La metodologia su cui si fonda la proposta ha visto una fase preliminare di analisi del contesto urbano e studio di fattibilità tecnica, sociale, economica, finalizzate alla verifica della fruibilità del lotto alla "quota zero". Tali analisi hanno consentito la focalizzazione degli obiettivi dell'intervento e la definizione di quattro ipotesi alternative, successivamente valutate sulla base degli stessi obiettivi. Da qui, l’individuazione dello scenario metaprogettuale più rispondente, tale da creare i presupposti per un'azione partecipata e concertata con utenti e Committenti, supportato da una prima verifica di fattibilità economica e da un'analisi costi-benefici, in vista di ulteriori approfondimenti progettuali e strategie insediative diversificate."Vivere la quota zero" means to promote an extensive and widespread use of an area - which is now degraded and abandoned - through the creation of an "open infrastructure". The area will be organized and designed by a network of public spaces, where people can meet and socialize and where outdoor activities and performances can take place, in order to become a meeting point for the district and the city, where everyone, at any age and at any hour of the day, can spend leisure time. The proposal includes: the development of the area through the connection with the nearest neighboring districts and the existing infrastructures, the placement of activities for leisure and wellness that can be used h24, an improvement of cycle and pedestrian mobility and of safety. The methodology that led to the final pro- posal started from a preliminary phase of analysis of the urban context and a feasibility study which led to the definition of the objecti- ves and of four different design hypothesis. The evaluation of these proposals ended in the identification of the scenario closer to the objectives, mainly composed by five functional areas (Sport, Music, Administration, Socialization and fab lab). The squares - conceived as fundamental places for the public life - and the paths at the ground level cross the area and keep together the whole system, sometimes passing through the buildings, other times 'digging' them

Vivere alla quota zero

"Vivere la quota zero" means to promote an extensive and widespread use of an area - which is now degraded and abandoned - through the creation of an "open infrastructure". The area will be organized and designed by a network of public spaces, where people can meet and socialize and where outdoor activities and performances can take place, in order to become a meeting point for the district and the city, where everyone, at any age and at any hour of the day, can spend leisure time. The proposal includes: the development of the area through the connection with the nearest neighboring districts and the existing infrastructures, the placement of activities for leisure and wellness that can be used h24, an improvement of cycle and pedestrian mobility and of safety. The methodology that led to the final pro- posal started from a preliminary phase of analysis of the urban context and a feasibility study which led to the definition of the objecti- ves and of four different design hypothesis. The evaluation of these proposals ended in the identification of the scenario closer to the objectives, mainly composed by five functional areas (Sport, Music, Administration, Socialization and fab lab). The squares - conceived as fundamental places for the public life - and the paths at the ground level cross the area and keep together the whole system, sometimes passing through the buildings, other times 'digging' them