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Using low energy electrons to neutralize electrostatic charges on cryogenic test mass mirrors of future gravitational wave detectors
Get PDFElectrostatic charging is a limiting noise source for gravitational wave detection already at room temperature. The development of a mitigation method compliant with cryogenics is mandatory to preserve the performances envisaged by the upcoming generation of gravitational wave detectors. We have recently proposed the use of selected energy electrons (below few hundreds eV) impinging on the mirror surface to neutralize electrostatic charges of both polarities. Here we present the experimental evidence of the method on a 20nm SiO2/Si substrate
The metrology-meteorology cooperation on thermodynamic environmental issues
Get PDFEnvironmental measurements represent a phenomenal societal and scientific challenge of ever-growing importance in the light of the ongoing and future climate variability. Thermal quantities (temperature of air, sea, snow and soil humidity, permafrost depth) are key among the Essential Climate Variable (ECVs) as defined by the WMO Global Climate Observing System in these areas. In order to accurately capture climatic trends and enable early detection, metrological rigor in terms of sensor calibration and uncertainty budget evaluation are of paramount importance. For this reason, the metrology and meteo/climatological communities have started a decade-long ongoing cooperation through the mutual recognition accords between the WMO and BIPM. This cooperation led to the exchange of representatives in WGs, the co-hosting of a series of joint workshops (“Metrology for Climate Action”), and a general strict cooperation, through the development of new measurement techniques and instruments; the understanding of uncertainty components both for laboratory calibration and for field conditions; the accurate evaluation of quantities of influence; and the development of guidelines, best
practices and recommendations
Insights into earthquake ruptures from analysis of DAS data
Get PDFThe possibility to exploit fibre optic cables through Distributed Acoustic Sensing (DAS) systems is a powerful tool for seismologists, providing spatially continuous recordings of earthquakes. This technology is suitable for the analysis of seismic ruptures, continuously mapping the source properties as observed along the sensed cable. In this study we describe how far-field strain radiation from a circular rupture can be modelled to evaluate the earthquake size and released stress drop during fault slippage. We then fit earthquake signals recorded along a 150km long dark fibre cable deployed offshore the coast of Central Chile sensed by DAS, to evaluate the rupture properties of small to moderate subduction events. We show that stress drop increases for moderate magnitude events, indicating a complexity in the slip pattern and the presence of small scale asperities also at this scale
Artificial intelligence algorithms for prostate cancer prediction by breath analysis
Get PDFBreath analysis is emerging as a promising screening technique. Analysis of volatile organic compounds by artificial intelligence can lead to an early warning bell by noninvasive screening. In this work, we analyze volatile organic compounds from patients who had undergone a prostate cancer exam. We expose a computational methodology to discriminate suspected and full-blown patients. We adopt a sample selection and use oversampling to train a neural network based on a Multi-Layer Perceptron in order to predict real data and simulate performances on further patients undergoing prostate cancer screening
Rapporto tecnico-gestionale "Strumenti per la formazione del personale CNR - Rendicontazione attività di formazione URP anni 2023-2024"
Get PDFNell’ambito della gestione dei corsi di formazione per il personale URP si vuole dare una
panoramica delle attività di formazione previste per i dipendenti del CNR
Comparison of viewing distance between tablet and paper text in accommodative reserve measurement in presbyopes
Get PDFThe use of digital devices is increasing and widespread, especially among presbyopic subjects. This study investigated how the viewing distance of a paper text and a text contained in a tablet changes and how the use of these two different devices affects accommodative reserve in presbyopes. Indeed, the difference in brightness between a paper text and a text presented on a digital device could affect the measurement of accommodative reserve in presbyopes. The results showed that there were no statistical and clinical differences in the presentation of
the two tests. The type of stimulus (paper vs. digital) would not seem to affect accommodative reserve in presbyopic subjects
Brillouin micro spectroscopy and morpho mechanics of a hybrid lens
Get PDFBrillouin spectroscopy, a well established optical technique for the non-destructive, contactless, and label-free readout of mechanical properties, has recently regained prominence in mapping the viscoelastic properties of soft and
biological materials. This study presents a preliminary exploration of the mechanical heterogeneities of a hybrid lens, visualized through a 2D cross-sectional map. Addi
tionally, a critical evaluation of the use of two models for analyzing Brillouin spectra in viscoelastic materials, namely the damped harmonic oscillator and the Lorentzian
models, is provided
Physics and neuroscience synergy in visual analysis
Get PDFA branch of physics named geometrical optic gave birth to Optometry, the science that measures visual function. Even if this physical approach is still essential not all clinical results of visual function can be explained just with physical formulae. More recently the scientific community has started to consider neuroscience as a new method to explain some visual conditions. Aim of this review is to collect some papers to prove the requirement of an interdisciplinary approach to visual functional problems
Implementation of a compact optical architecture for visual psychophysical tests based on spatial light modulators
Get PDFSpatial light modulators (SLM) are increasingly used as active optical elements for wavefront manipulation in holography, adaptive optics, and beam shaping. In this work, we present the implementation and test of a compact optical
system based on a computer-controlled SLM to perform psychophysical tests on visual acuity and contrast sensitivity. The Fourier transform of the desired pattern,
e.g., Snellen optotype or Gabor grating, is encoded and uploaded on the SLM and customized in terms of final size, contrast, orientation, and position. The device is controlled with specific software in order to conduct psychophysical tests and converge quickly towards a threshold estimate. Thanks to its versatility and scalability, the platform can be extended straightforwardly to any visual test, and a preliminary study on the effect of stochastic resonance on contrast sensitivity threshold is here shown and discussed
A consistent description of the monopole resonance in spherical nuclei
Get PDFWe have recently implemented a fully self-consistent model based on Quasiparticle-Vibration Coupling (QPVC model). This can be applied to Giant Resonances of any kind, and can account for the position of the resonance main peak (or centroid) and for the resonance width. In this contribution, we show how this model can solve the problem of the different incompressibilities (K∞) that spherical nuclei display. In other words, we discuss here that the values of K∞ extracted from Sn isotopes and 208Pb turn out to be compatible, so that the famous issue of the “fluffiness” of Sn is set. Ca isotopes and 90Zr are also compatible with the same values of K∞, that are around 225–230 MeV. This conclusion relies on the use of the so-called subtraction method