67 research outputs found

    A New automatic system of cell colony counting

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    The counting process of cell colonies is always a long and laborious process that is dependent on the judgment and ability of the operator. The judgment of the operator in counting can vary in relation to fatigue. Moreover, since this activity is time consuming it can limit the usable number of dishes for each experiment. For these purposes, it is necessary that an automatic system of cell colony counting is used. This article introduces a new automatic system of counting based on the elaboration of the digital images of cellular colonies grown on petri dishes. This system is mainly based on the algorithms of region-growing for the recognition of the regions of interest (ROI) in the image and a Sanger neural net for the characterization of such regions. The better final classification is supplied from a Feed-Forward Neural Net (FF-NN) and confronted with the K-Nearest Neighbour (K-NN) and a Linear Discriminative Function (LDF). The preliminary results are shown

    An evaluation of the Diamat HPLC analyser for simultaneous determination of haemoglobins A2 and F

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    The authors describe a modification of the instrumental parameters of the Diamat fully automated HPLC system for Hb A2 assay (Bio-Rad Laboratories, Milan, Italy) in order to obtain simultaneous determination of Hb A2 and Hb F

    Muonic atom X-ray spectroscopy for non-destructive analysis of archeological samples

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    The implementation in the RIKEN-RAL negative muons facility of a new muon beamline monitoring and novel digital data acquisition system for gamma and X-ray spectroscopy are presented. This work also shows the high potential of the muonic atoms X-ray spectroscopy technique in non-destructive elemental characterization of archaeological samples

    Dark sectors 2016 Workshop: community report

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    This report, based on the Dark Sectors workshop at SLAC in April 2016, summarizes the scientific importance of searches for dark sector dark matter and forces at masses beneath the weak-scale, the status of this broad international field, the important milestones motivating future exploration, and promising experimental opportunities to reach these milestones over the next 5-10 years

    US Cosmic Visions: New Ideas in Dark Matter 2017: Community Report

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    This white paper summarizes the workshop "U.S. Cosmic Visions: New Ideas in Dark Matter" held at University of Maryland on March 23-25, 2017.Comment: 102 pages + reference

    Characterizing the Sardinia candidate site for the Einstein Telescope

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    Due to its unique geophysical features and to the low density population of the area, Sos Enattos is a promising candidate site to host the Einstein Telescope (ET), the third-generation Gravitational Wave Observatory. The geophysical characterization of the Sos Enattos former mine, close to one of the proposed ET corners, started in 2010 with the deployment of seismic and environmental sensors underground. Since 2019 a new extensive array of seismometers, magnetometers and acoustic sensors have been installed in three stations along the underground tunnels, with one additional station at the surface. Beside a new geological survey over a wider area, two boreholes about 270 m deep each were excavated at the other two corners, determining the good quality of the drilled granite and orthogneiss rocks and the absence of significant thoroughgoing fault zones. These boreholes are instrumented with broadband seismometers that revealed an outstanding low level of vibrational noise in the low-frequency band of ET-LF (2-10Hz), significantly lower than the Peterson's NLNM and resulting among the quietest seismic stations in the world in that frequency band. The low seismic background and the reduced number of seismic glitches ensure that just a moderated Newtonian noise subtraction would be needed to achieve the ET target sensitivity. Geoelectrical and active seismic campaigns have been carried out to reveal the features of the subsurface, revealing the presence of small-sized fractured areas with limited water circulation. Finally, temporary arrays of seismometers, magnetometers and acoustic sensors are deployed in the area to study the local sources of environmental noise

    Array analysis of seismic noise at the Sos Enattos mine, the Italian candidate site for the Einstein Telescope

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    The area surrounding the dismissed mine of Sos Enattos (Sardinia, Italy) is the Italian candidate site for hosting Einstein Telescope (ET), the third-generation gravitational wave (GW) observatory. One of the goals of ET is to extend the sensitivity down to frequencies well below those currently achieved by GW detectors, i.e. down to 2 Hz. In the bandwidth [1,10] Hz, the seismic noise of anthropogenic origin is expected to represent the major perturbation to the operation of the infrastructure, and the site that will host the future detector must fulfill stringent requirements on seismic disturbances. In this paper we describe the operation of a temporary, 15-element, seismic array deployed in close proximity to the mine. Signals of anthropogenic origin have a transient nature, and their spectra are characterized by a wide spectral lobe spanning the [3,20] Hz frequency interval. Superimposed to this wide lobe are narrow spectral peaks within the [3,8] Hz frequency range. Results from slowness analyses suggest that the origin of these peaks is related to vehicle traffic along the main road running east of the mine. Exploiting the correlation properties of seismic noise, we derive a dispersion curve for Rayleigh waves, which is then inverted for a shallow velocity structure down to depths of ≈≈ 150 m. This data, which is consistent with that derived from analysis of a quarry blast, provide a first assessment of the elastic properties of the rock materials at the site candidate to hosting ET

    Observation of gravitational waves from the coalescence of a 2.5−4.5 M⊙ compact object and a neutron star

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    Search for eccentric black hole coalescences during the third observing run of LIGO and Virgo

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    Despite the growing number of confident binary black hole coalescences observed through gravitational waves so far, the astrophysical origin of these binaries remains uncertain. Orbital eccentricity is one of the clearest tracers of binary formation channels. Identifying binary eccentricity, however, remains challenging due to the limited availability of gravitational waveforms that include effects of eccentricity. Here, we present observational results for a waveform-independent search sensitive to eccentric black hole coalescences, covering the third observing run (O3) of the LIGO and Virgo detectors. We identified no new high-significance candidates beyond those that were already identified with searches focusing on quasi-circular binaries. We determine the sensitivity of our search to high-mass (total mass M>70 M⊙) binaries covering eccentricities up to 0.3 at 15 Hz orbital frequency, and use this to compare model predictions to search results. Assuming all detections are indeed quasi-circular, for our fiducial population model, we place an upper limit for the merger rate density of high-mass binaries with eccentricities 0<e≤0.3 at 0.33 Gpc−3 yr−1 at 90\% confidence level
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