Spherical drawing for understanding urban spaces

Drawing, besides being the only tool able to represent ideas that live in our mind, is also a means to represent the perception of the world. The importance that is still dedicated to freehand drawing has led to the proliferation of digital tools for simulating traditional techniques, creating good opportunities that mix manual gesture and virtual world. Spherical drawing is placed in this context: it comes from spherical photography and from digital environment but, to some extent, is bearer of that materiality and abstraction that are sometimes sought to communicate images or interpret real places. The idea is to exploit the potential of an immersive 360° environment for the understanding of urban spaces through graphic-perceptive analyses. This type of representation is very close to the human vision from which perceptual studies derive, so it could contribute to the discipline with considerable advantages. In order to verify the validity of this new procedure, piazza Sempione in the Montesacro district in Rome was chosen as a case study. The contribution includes a series of representations of piazza Sempione that are based on the fragmentation of some visual stimuli, so that they can be recognized and appreciated individually

Spherical drawings for understanding urban spaces

Il disegno, oltre ad essere l’unico strumento in grado di rappresentare le idee che risiedono nella nostra mente, è anche un mezzo attraverso cui rappresentare la percezione del mondo. L’importanza che ancora si dedica al disegno a mano libera ha comportato il proliferare di strumenti digitali di simulazione delle tecniche tradizionali, creando delle interessanti possibilità di commistione tra il gesto manuale e il mondo virtuale. Il disegno sferico si colloca in questo contesto: trae origine dalla fotografia sferica e dall’ambiente digitale ma, in qualche misura, è portatore di quella matericità e astrazione che talvolta si ricerca per comunicare immagini o interpretare luoghi reali. L’idea è quella di sfruttare le potenzialità di un ambiente immersivo a 360° per la comprensione degli spazi urbani attraverso analisi grafico-percettive. Questo tipo di rappresentazione è molto vicina alla visione umana da cui gli studi percettivi derivano, per cui potrebbe contribuire alla disciplina con notevoli vantaggi. Per poter verificare l’effettiva validità di questa nuova procedura è stato scelto come caso studio piazza Sempione nel quartiere Montesacro a Roma. Nel contributo vengono proposte una serie di rappresentazioni di piazza Sempione che si basano sulla scomposizione di alcuni stimoli visivi in modo da poterli riconoscere ed apprezzare singolarmente.Drawing, besides being the only tool able to represent ideas that live in our mind, is also a means to represent the perception of the world. The importance that is still dedicated to freehand drawing has led to the proliferation of digital tools for simulating traditional techniques, creating good opportunities that mix manual gesture and virtual world. Spherical drawing is placed in this context: it come from spherical photography and from digital environment but, to some extent, is bearer of that materiality and abstraction that are sometimes sought to communicate images or interpret real places. The idea is to exploit the potential of an immersive 360° environment for the understanding of urban spaces through graphic-perceptive analyses. This type of representation is very close to the human vision from which perceptual studies derive, so it could contribute to the discipline with considerable advantages. In order to verify the validity of this new procedure, it was chosen piazza Sempione in the Montesacro district in Rome as a case study. The contribution includes a series of representations of piazza Sempione that are based on the fragmentation of some visual stimuli, so that they can be recognized and appreciated individually

DarkSide: Latest results and future perspectives

DarkSide is direct-detection dark-matter experimental project based on radiopure argon. The main goal of the DarkSide program is the detection of rare nuclear elastic collisions with hypothetical dark-matter particles. The present detector, DarkSide-50, placed at Laboratori Nazionali del Gran Sasso (LNGS), is a dualphase time projection chamber (TPC) filled with ultra-pure liquid argon, extracted from underground sources. Surrounding the TPC to suppress the background there are neutron and muon active vetoes. One of argon key features is the capability to distinguish between electron and nuclear recoils, exploiting the different shapes of the signals. DarkSide-50 new results, obtained using a live-days exposure of 532.4 days, are presented. This analysis sets a 90% C.L. upper limit on the dark matternucleon spin-independent cross-section of 1.1 × 10-44 cm2 for a WIMP mass of 100 GeV/c2. The next phase of the project, DarkSide-20k, will be a new detector with a fiducial mass of ∼ 20 tons, equipped with cryogenic silicon photomultipliers (SiPM)

DarkSide new results and prospects

New results on the scattering cross-section between dark matter particles and nuclei and electrons are presented. They are obtained using a live-days exposure of 532.4 days from the DarkSide-50 experiment, which is a dual-phase liquid-argon time projection chamber (LAr TPC) installed at Laboratori Nazionali del Gran Sasso (LNGS). In this paper, the DarkSide-20k experiment, a LAr TPC with an active (fiducial) mass of 23 t (20 t) to be built at LNGS, is also reviewed. Thanks to its exceptionally low instrumental background, DarkSide-20k will be able to exclude cross sections between weakly interacting massive particles (WIMPs) and nuclei at 90% confidence level down to 2.8×10−48 cm2 (1.2×10−47 cm2) for a WIMP mass of 100 GeV/c2 (1 TeV/c2)

Measurement of the ion fraction and mobility of 218Po produced in 222Rn decays in liquid argon

We report measurements of the charged daughter fraction of 218Po as a result of the 222Rn alpha decay, and the mobility of 218Po+ ions, using radon-polonium coincidences from the 238U chain identified in 532 live-days of DarkSide-50 WIMP-search data. The fraction of 218Po that is charged is found to be 0.37 ± 0.03 and the mobility of 218Po+ is (8.6 ± 0.1) × 10−4 cmVs2

Status and perspective of the DarkSide experiment at LNGS

The DarkSide experiment aims to perform a background-free direct search for dark matter with a dual-phase argon TPC. The current phase of the experiment, DarkSide-50, is acquiring data at Laboratori Nazionali del Gran Sasso and produced the most sensitive limit on the WIMP-nucleon cross section ever obtained with a liquid argon target (2.0 × 10-44 cm2 for a WIMP mass of 100 GeV/c2). The future phase of the experiment will be a 20 t fiducial mass detector, designed to reach a sensitivity of ∼ 1 × 10-47 cm2 (at 1 TeV/c2 WIMP mass) with a background-free exposure of 100 ty. This work contains a discussion of the current status of the DarkSide-50 WIMP search and of the results which are more relevant for the construction of the future detector

Latest results of dark matter detection with the DarkSide experiment

In this contribution the latest results of dark matter direct detection obtained by the DarkSide Collaboration are discussed. New limits on the scattering cross-section between dark matter particles and baryonic matter have been set. The results have been reached using the DarkSide-50 detector, a double-phase Time Projection Chamber (TPC) filled with 40Ar and installed at Laboratori Nazionali del Gran Sasso (LNGS). In 2018, the DarkSide Collaboration has performed three different types of analysis. The so-called high-mass analysis into the range between ∼ 10 GeV and ∼ 1000 GeV is discussed under the hypothesis of scattering between dark matter and Ar nuclei. The low-mass analysis, performed using the same hypothesis, extends the limit down to ∼1.8 GeV. Through a different hypothesis, that predicts dark matter scattering off the electrons inside of the Ar atom, it has been possible to set limits for sub-GeV dark matter masses

DarkSide status and prospects

DarkSide uses a dual-phase Liquid Argon Time Projection Chamber to search for WIMP dark matter. The current detector, DarkSide-50, is running since mid 2015 with a target of 50 kg of Argon from an underground source. Here it is presented the latest results of searches of WIMP-nucleus interactions, with WIMP masses in the GeV-TeV range, and of WIMP-electron interactions, in the sub-GeV mass range. The future of DarkSide with a new generation experiment, involving a global collaboration from all the current Argon based experiments, is presented