152 research outputs found

    Modeling high impedance connecting links and cables below 1 Hz

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    High impedance connecting links and cables are modeled at low frequency in terms of their impedance to ground and to neigbouring connecting links. The impedance is usually considered to be the parallel combination of a resistance and a capacitance. While this model is adequate at moderate and low frequency, it proved to be not satisfactory at very low frequency, in the fractions of Hz range. Deep characterization was carried out on some samples down to 10 uHz, showing that an additional contribution to capacitance can emerge. A model was developed to explain and account for this additional contribution

    CLARO-CMOS, a very low power ASIC for fast photon counting with pixellated photodetectors

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    The CLARO-CMOS is an application specific integrated circuit (ASIC) designed for fast photon counting with pixellated photodetectors such as multi-anode photomultiplier tubes (Ma-PMT), micro-channel plates (MCP), and silicon photomultipliers (SiPM). The first prototype has four channels, each with a charge sensitive amplifier with settable gain and a discriminator with settable threshold, providing fast hit information for each channel independently. The design was realized in a long-established, stable and inexpensive 0.35 um CMOS technology, and provides outstanding performance in terms of speed and power dissipation. The prototype consumes less than 1 mW per channel at low rate, and less than 2 mW at an event rate of 10 MHz per channel. The recovery time after each pulse is less than 25 ns for input signals within a factor of 10 above threshold. Input referred RMS noise is about 7.7 ke^- (1.2 fC) with an input capacitance of 3.3 pF. Thanks to the low noise and high speed, a timing resolution down to 10 ps RMS was measured for typical photomultiplier signals of a few million electrons, corresponding to the single photon response for these detectors

    Large sheath folds in the Brian\ue7onnais of the Ligurian Alps reconstructed by analysis of minor structures and stratigraphic mapping

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    This study presents a geometric and structural analysis of curvilinear sheath folds exposed in blueschist rocks of the Ligurian Alps. Field data are presented in a geological map of the structural synthesis with related geological sections (at the 1:10,000 scale) that illustrate the relationships and evolution of large-scale, sheath folds within metamorphic rocks. We based our analyses on the geometric parameters of more than 40 minor folds, as shape (hinge-Lm1 angle, main axial plane/S1 angle, interlimb angle and hinge curvature), asymmetry, fold hinge/stretching lineation obliquity and structural facing pattern. The summary of the whole data depicts a coherent 3D structure showing several orders of minor folds. Sense of asymmetry of minor folds and stratigraphic order has been used to reconstruct a reliable large-scale structure, and to define the sheath fold shape

    the thrust zone of the ligurian penninic basal contact monte fronte ligurian alps italy

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    ABSTRACTThis paper presents a geological map and interpretative cross-sections, which illustrate the structure of a major fault zone of the Alps, that is, the Ligurian segment of the Penninic Basal Contact (PBC), which led to the emplacement of the orogenic wedge onto the European crust. Chaotic deposits, whose origin is debated, characterize the footwall of this complex thrust zone. The lower part of the sequence containing chaotic deposits consists of low deformed paraconglomerates and exotic megablocks embedded with turbidites. Conversely, the highly deformed upper part of the sequence englobes fragments of substratum-derived succession and is bounded by thrust planes. The nature of these chaotic deposits suggests an origin by gravitational processes related to the unstable front of the advancing wedge associated with offscraping of tectonic slices during the thrusting of allochtonous nappes along the PBC thrust zone

    Influence of the Reward Function on the Selection of Reinforcement Learning Agents for Hybrid Electric Vehicles Real-Time Control

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    The real-time control optimization of electrified vehicles is one of the most demanding tasks to be faced in the innovation progress of low-emissions mobility. Intelligent energy management systems represent interesting solutions to solve complex control problems, such as the maximization of the fuel economy of hybrid electric vehicles. In the recent years, reinforcement-learning-based controllers have been shown to outperform well-established real-time strategies for specific applications. Nevertheless, the effects produced by variation in the reward function have not been thoroughly analyzed and the potential of the adoption of a given RL agent under different testing conditions is still to be assessed. In the present paper, the performance of different agents, i.e., Q-learning, deep Q-Network and double deep Q-Network, are investigated considering a full hybrid electric vehicle throughout multiple driving missions and introducing two distinct reward functions. The first function aims at guaranteeing a charge-sustaining policy whilst reducing the fuel consumption (FC) as much as possible; the second function in turn aims at minimizing the fuel consumption whilst ensuring an acceptable battery state of charge (SOC) by the end of the mission. The novelty brought by the results of this paper lies in the demonstration of a non-trivial incapability of DQN and DDQN to outperform traditional Q-learning when a SOC-oriented reward is considered. On the contrary, optimal fuel consumption reductions are attained by DQN and DDQN when more complex FC-oriented minimization is deployed. Such an important outcome is particularly evident when the RL agents are trained on regulatory driving cycles and tested on unknown real-world driving missions

    Proximal Gamma Ray Spectroscopy for monitoring Soil Water Content in vineyards

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    Soil Water Content (SWC) is a key information in precision agriculture for obtaining high levels of efficiency and health of crops, while reducing water consumption. In particular, for the case of vineyards, due to the recent extreme temperature fluctuations, the knowledge of the SWC of the entire field becomes crucial to allow a timely intervention with emergency irrigation to preserve plant health and yield. Unlike electromagnetic SWC measurements, that are punctual and gravimetric measurements, that are punctual and also time-consuming, the Proximal Gamma Ray Spectroscopy (PGRS) technique can provide field-scale, non-invasive, and real-time measurements of SWC. This is achievable through an in-situ NaI detector, continuously recording photons resulting from the radioactive decay of 40K in the soil, which are attenuated proportionally based on the amount of stored water. Given the inverse proportionality between soil moisture and photons detected by the gamma ray sensor, the SWC value can be easily obtained. In this study we investigate the performance of PGRS applied to the case of study of a vineyard at the farm “Il Poggione” located in Montalcino (Siena, Italy). The effectiveness of the results obtained is supported by different tests: first the validation allowed to compare the PGRS measurement (5.8 ± 1.5)% with a gravimetric measurement (9.0 ± 2.5)%, highlighting a 1-σ agreement; then by the rainfall recognition capability indeed, in correspondence to the most significant rainfall event (18 mm) the SWC value before and after the rain increased of 7.8%. Moreover, the integration of the in-situ system with an agrometeorological station resulted in a Web App, allowing for real time data storage and thus facilitating data management, spectrum analysis, and display for both gamma ray sensor and agrometeorological station results, enabling comprehensive studies of environmental parameters (e.g., temperature, air humidity). This research underlines the potential of PGRS as a precise, real-time, and field scale SWC monitoring tool not only in vineyards but for cultivated fields in general. Further refinements concerning the gamma ray spectra analysis and broader applications in environmental monitoring are envisaged for improved agricultural practices. This study was supported by the project STELLA (Sistema inTEgrato per Lo studio del contenuto d'acqua in agricoLturA) (CUP: D94E20002180009) funded by the Tuscany region under the program POR FESR 2014/2020

    Foreign body ingestion in children. Definition of a nomogram to predict surgical or endoscopic intervention

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    Background and aims: Foreign body ingestion (FBI) in children requires early identification to prevent adverse outcomes and may necessitate endoscopic or surgical intervention. This study aims to develop a nomogram that identifies children who require urgent surgical or endoscopic intervention by using the patient's medical history and clinical parameters collected at admission. Methods: This study is a retrospective review (01/2015-12/2020) of a multicenter case series of children admitted for FBI. Data from 5864 records from 24 hospitals in Italy were analyzed. Logistic regression models were used to establish the probability of requiring surgical or endoscopic intervention based on patient history and clinical characteristics. The nomogram representing the results from the multivariable model was reported to examine the propensity for surgery/endoscopy. Results: The study identified a significant association between intervention and various factors, including type of foreign body (blunt: reference category, disk battery (odds ratio OR:4.89), food bolus (OR:1.88), magnets (OR:2.61), sharp-pointed (OR:1.65), unknown (OR:1.02)), pre-existing diseases or conditions (OR 3.42), drooling (OR 10.91), dysphagia (OR 5.58), vomiting (OR 3.30), retrosternal pain (OR 5.59), abdominal pain (OR 1.58), hematemesis (OR 2.82), food refusal/poor feeding (OR 2.99), and unexplained crying (OR 2.01). The multivariable regression model showed good calibration and discrimination ability, with an area under the ROC curve of 0.77. Conclusions: This study developed the first nomogram to predict the probability of the need for surgical or endoscopic intervention in children with FBI, based on the information collected at admission. The nomogram will aid clinicians in identifying children who require early intervention to prevent adverse outcomes

    Mass testing of the JUNO experiment 20-inch PMTs readout electronics

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    The Jiangmen Underground Neutrino Observatory (JUNO) is a multi-purpose, large size, liquid scintillator experiment under construction in China. JUNO will perform leading measurements detecting neutrinos from different sources (reactor, terrestrial and astrophysical neutrinos) covering a wide energy range (from 200 keV to several GeV). This paper focuses on the design and development of a test protocol for the 20-inch PMT underwater readout electronics, performed in parallel to the mass production line. In a time period of about ten months, a total number of 6950 electronic boards were tested with an acceptance yield of 99.1%

    Validation and integration tests of the JUNO 20-inch PMTs readout electronics

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    The Jiangmen Underground Neutrino Observatory (JUNO) is a large neutrino detector currently under construction in China. JUNO will be able to study the neutrino mass ordering and to perform leading measurements detecting terrestrial and astrophysical neutrinos in a wide energy range, spanning from 200 keV to several GeV. Given the ambitious physics goals of JUNO, the electronic system has to meet specific tight requirements, and a thorough characterization is required. The present paper describes the tests performed on the readout modules to measure their performances.Comment: 20 pages, 13 figure
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