Boosting the performance of the ASTRI SST-2M prototype: reflective and anti-reflective coatings

ASTRI is a Flagship Project of the Italian Ministry of Education, University and Research, led by the Italian National Institute of Astrophysics, INAF. One of the main aims of the ASTRI Project is the design, construction and verification on-field of a dual mirror (2M) end-to-end prototype for the Small Size Telescope (SST) envisaged to become part of the Cherenkov Telescope Array. The ASTRI SST-2M prototype adopts the Schwarzschild-Couder design, and a camera based on SiPM (Silicon Photo Multiplier); it will be assembled at the INAF astronomical site of Serra La Nave on mount Etna (Catania, Italy) within mid 2014, and will start scientific validation phase soon after. The peculiarities of the optical design and of the SiPM bandpass pushed towards specifically optimized choices in terms of reflective coatings for both the primary and the secondary mirror. In particular, multi-layer dielectric coatings, capable of filtering out the large Night Sky Background contamination at wavelengths $\lambda \gtrsim 700$ nm have been developed and tested, as a solution for the primary mirrors. Due to the conformation of the ASTRI SST-2M camera, a reimaging system based on thin pyramidal light guides could be optionally integrated aiming to increase the fill factor. An anti-reflective coating optimized for a wide range of incident angles faraway from normality was specifically developed to enhance the UV-optical transparency of these elements. The issues, strategy, simulations and experimental results are thoroughly presented.Comment: 4 pages, 6 figures. In Proceedings of the 33rd International Cosmic Ray Conference (ICRC2013), Rio de Janeiro (Brazil). All ASTRI contributions at arXiv:1307.463

La creazione di valore nelle strategie di disinvestimento: evidenze dal contesto europeo

Obiettivo del paper: Analizzare il ruolo della performance pre-disinvestimento nella creazione di valore delle scelte di disinvestimento nei paesi dell\u2019Europa Continentale, evidenziando eventuali interazioni con la presenza di \u201cblockholder\u201d e con il grado di correlazione tra il core business dell\u2019impresa che disinveste e il business disinvestito. Metodologia: Analisi econometrica su un campione di 147 operazioni realizzate in 13 paesi dell\u2019Europa Continentale. Risultati: La performance precedente l\u2019operazione, che consente di distinguere tra strategie di disinvestimento di tipo reattivo e proattivo, modera la relazione tra le determinanti di creazione di valore identificate dalla letteratura (risoluzione di conflitti di agenzia tramite il controllo esercitato dal blockholder e rifocalizzazione sul core business) e performance post-disinvestimento. Quando la performance prima dell\u2019operazione \ue8 elevata, l\u2019effetto della presenza di blockholder sulla performance postdisinvestimento \ue8 meno positivo, mentre l\u2019impatto della scarsa correlazione tra business \ue8 meno negativo. Limiti della ricerca: A causa della scarsa numerosit\ue0 campionaria non \ue8 stato possibile esplorare eventuali differenze tra le diverse modalit\ue0 di disinvestimento. Implicazioni pratiche: Il management delle imprese deve riconoscere che il disinvestimento, se usato secondo una logica proattiva, pu\uf2 avere anche un\u2019accezione positiva, e che la performance delle operazioni di disinvestimento non \ue8 indipendente dai risultati che l\u2019impresa ha realizzato nel periodo precedente all\u2019operazione stessa. Di conseguenza, i manager devono individuare il momento pi\uf9 adeguato per implementare le scelte di disinvestimento. Originalit\ue0 del paper: Lo studio contribuisce in modo originale alla letteratura sul disinvestimento, con un particolare focus sulle determinanti della performance del disinvestimento nei paesi dell\u2019Europa Continentale e sulla moderazione esercitata dalla performance pre-disinvestimento quale indicatore della tipologia di disinvestimento (reattivo vs. proattivo)

Turbulence-driven ion beams in space plasmas

The description of the local turbulent energy transfer and the high-resolution ion distributions measured by the Magnetospheric Multiscale mission together provide a formidable tool to explore the cross-scale connection between the fluid-scale energy cascade and plasma processes at subion scales. When the small-scale energy transfer is dominated by Alfv´enic, correlated velocity, and magnetic field fluctuations, beams of accelerated particles are more likely observed. Both space observations and numerical simulations suggest the nonlinear wave-particle interaction as one possible mechanism for the energy dissipation in space plasmas

Phase-synchronization, energy cascade, and intermittency in solar-wind turbulence.

The energy cascade in solar wind magnetic turbulence is investigated using MESSENGER data in the inner heliosphere. The decomposition of magnetic field time series in intrinsic functions, each characterized by a typical time scale, reveals phase reorganization. This allows for the identification of structures of all sizes generated by the nonlinear turbulent cascade, covering both the inertial and the dispersive ranges of the turbulent magnetic power spectrum. We find that the correlation (or anticorrelation) of phases occurs between pairs of neighboring time scales, whenever localized peaks of magnetic energy are present at both scales, consistent with the local character of the energy transfer process

Using gamification to incentivize sustainable urban mobility.

Sustainable urban mobility is an important dimension in a Smart City, and one of the key issues for city sustainability. However, innovative and often costly mobility policies and solutions introduced by cities are liable to fail, if not combined with initiatives aimed at increasing the awareness of citizens, and promoting their behavioural change. This paper explores the potential of gamification mechanisms to incentivize voluntary behavioural changes towards sustainable mobility solutions. We present a service-based gamification framework, developed within the STREETLIFE EU Project, which can be used to develop games on top of existing services and systems within a Smart City, and discuss the empirical findings of an experiment conducted in the city of Rovereto on the effectiveness of gamification to promote sustainable urban mobility

In Vivo Distribution of Corneal Epithelial Dendritic Cells in Patients With Glaucoma

The purpose of this study was to evaluate dendritic cell (DC) distribution, morphology, and DC density in the entire cornea of medically controlled glaucoma patients (MCGP), using in vivo confocal microscopy (IVCM).Fifty MCGP were enrolled, 15 patients with dry eye, and 15 healthy subjects served as controls. Patients were asked to complete the Ocular Surface Disease Index (OSDI) questionnaire and then underwent tear film break-up time (BUT), corneal staining, and Schirmer test (ST) I and then IVCM. In vivo confocal microscopy evaluated the limbal and central DC density, the DCs morphology and distribution. Relationships among DC density, OSDI score, and corneal staining were analyzed.Medically controlled glaucoma patients were divided into 2 groups; group 1 (29 eyes) was tested with one drug; group 2 (21 eyes) was tested with ≥2 drugs. Dendritic cells were significantly higher at limbus than at central cornea in both groups. Limbal DCs were found in the 86.7%, 89.7%, 90.4%, and 93.3% of eyes in controls, groups 1 and 2, and DED; central corneal DCs were found in the 26.6%, 75.9%, 80.9%, and 86.6% of eyes in controls, groups 1 and 2, and DED. Dendritic cell density was higher in glaucoma groups and DED than in controls (P < 0.001). Group 2 and DED presented DC density significantly higher compared with group 1 (P < 0.05). In group 1 DC density was higher in patients taking preserved drugs than in those taking preservative-free drugs (P < 0.05). Dendritic cell density was higher in DED than in group 2 (P < 0.05). Dendritic cell density significantly correlated with corneal staining and OSDI (P < 0.001).Dendritic cells increase in the entire cornea of MCGP, with a higher density at limbus. These modifications may take part in the induction of the glaucoma-related ocular surface disease