245 research outputs found

    Influence of LV Neutral Grounding on Global Earthing Systems

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    International Standards define a Global Earthing System as an earthing net created interconnecting local Earthing Systems (generally through the shield of MV cables and/or bare buried conductors). In Italy the Regulatory Authority for Electricity and Gas requires Distributors to guarantee the electrical continuity of LV neutral conductor. This requirement has led to the standard practice of realizing “reinforcement groundings” along the LV neutral conductor path and at users’ delivery cabinet. Moreover, in urban high load scenarios (prime candidates to be part of a Global Earthing System), it is common that LV distribution scheme creates, trough neutral conductors, an effective connection between grounding systems of MV/LV substations, modifying Global Earthing System consistency. Aim of this paper is to evaluate the effect, in terms of electrical safety, of the above mentioned LV neutral distribution scheme when an MV-side fault to ground occurs. At this purpose simulations are carried out on a realistic urban test case and suitable evaluation indexes are proposed

    A Practical Method to Test the Safety of HV/MV Substation Grounding System

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    The adequacy of a Grounding System (GS) to the safety conditions has to be periodically tested by measurements. The test methods and techniques used to verify the electrical characteristics of the GS include the measurements of step and touch voltages. The goal of the test is to verify that touch voltage and step voltage remain below a safe value in all the zones of the installation. The measurements can present some operational difficulties. The purpose of this paper is to present the procedure, step-by-step, of a practical method of measuring touch/step voltages in grounding systems located in urban or industrial areas with reduced accessibility. The suggested method uses auxiliary current electrodes located at short distances. This paper demonstrates by test measurements done in a real case that the method provides conservative results

    Epigenetics of human cutaneous melanoma: setting the stage for new therapeutic strategies

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    Cutaneous melanoma is a very aggressive neoplasia of melanocytic origin with constantly growing incidence and mortality rates world-wide. Epigenetic modifications (i.e., alterations of genomic DNA methylation patterns, of post-translational modifications of histones, and of microRNA profiles) have been recently identified as playing an important role in melanoma development and progression by affecting key cellular pathways such as cell cycle regulation, cell signalling, differentiation, DNA repair, apoptosis, invasion and immune recognition. In this scenario, pharmacologic inhibition of DNA methyltransferases and/or of histone deacetylases were demonstrated to efficiently restore the expression of aberrantly-silenced genes, thus re-establishing pathway functions. In light of the pleiotropic activities of epigenetic drugs, their use alone or in combination therapies is being strongly suggested, and a particular clinical benefit might be expected from their synergistic activities with chemo-, radio-, and immuno-therapeutic approaches in melanoma patients. On this path, an important improvement would possibly derive from the development of new generation epigenetic drugs characterized by much reduced systemic toxicities, higher bioavailability, and more specific epigenetic effects

    Performance of the ALICE experiment at the CERN LHC

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    ALICE is the heavy-ion experiment at the CERN Large Hadron Collider. The experiment continuously took data during the first physics campaign of the machine from fall 2009 until early 2013, using proton and lead-ion beams. In this paper we describe the running environment and the data handling procedures, and discuss the performance of the ALICE detectors and analysis methods for various physics observables

    Copernicus Ocean State Report, issue 6

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    The 6th issue of the Copernicus OSR incorporates a large range of topics for the blue, white and green ocean for all European regional seas, and the global ocean over 1993–2020 with a special focus on 2020

    Multiplicity dependence of jet-like two-particle correlation structures in p-Pb collisions at 1asNN=5.02 TeV

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    Two-particle angular correlations between unidentified charged trigger and associated particles are measured by the ALICE detector in p\u2013Pb collisions at a nucleon\u2013nucleon centre-of-mass energy of 5.02 TeV. The transverse-momentum range 0.7 < pT,assoc < pT,trig < 5.0 GeV/c is examined, to include correlations induced by jets originating from low momentum-transfer scatterings (minijets). The correlations expressed as associated yield per trigger particle are obtained in the pseudorapidity range |\u3b7| < 0.9. The near-side long-range pseudorapidity correlations observed in high-multiplicity p\u2013Pb collisions are subtracted from both near-side short-range and away-side correlations in order to remove the non-jet-like components. The yields in the jet-like peaks are found to be invariant with event multiplicity with the exception of events with low multiplicity. This invariance is consistent with the particles being produced via the incoherent fragmentation of multiple parton\u2013parton scatterings, while the yield related to the previously observed ridge structures is not jet-related. The number of uncorrelated sources of particle production is found to increase linearly with multiplicity, suggesting no saturation of the number of multi-parton interactions even in the highest multiplicity p\u2013Pb collisions. Further, the number scales only in the intermediate multiplicity region with the number of binary nucleon\u2013nucleon collisions estimated with a Glauber Monte-Carlo simulation
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