2,508 research outputs found

    Ground currents in a photovoltaic power plant: Theoretical approach and experimental tests

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    Arrays of photovoltaic (PV) modules, mounted on metallic structures, always create stray capacitances between active conductors and ground. Thus, leakage currents flowing in these ground capacitances are formed. If the number of PV modules array is high, these currents can reach some amperes. Noticeable leakage currents can cause several problems related to the proper operation of electrical installation and appliances and to the safety of people. In this work, the problem of the ground currents in PV arrays is firstly studied from a theoretical point of view. Suitable equivalent circuits are presented. Then, the set-up and the results of a field measurement for the estimation of the leakage currents in an operating PV power plant are reported

    Rheological and physical characterization of PEDOT: PSS/graphene oxide nanocomposites for perovskite solar cells

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    In this work, the influence of graphene oxide (GO) doped Poly(3,4 ethylenedioxythiophene):poly (styrenesulfonate)(PEDOT:PSS) thin nanocomposite on an indium–tin-oxide (ITO) anode, as hole transport layer (HTL) in perovskite solar cells, was investigated. Different concentrations of GO were added into the PEDOT:PSS in order to enhance its conductivity. In particular, the influence of GO content on the rheological and thermal properties of Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS)/GO nanocomposites was initially examined. The GO filler was prepared by using modified Hummers method and dispersed into PEDOT:PSS in different quantity (ranging from 0.05 to 0.25 %wt/wt). The obtained nanocomposite solutions were analyzed by rheological characterizations in order to evaluate the influence of the GO filler on the viscosity of the PEDOT:PSS matrix. The wettability of solutions was evaluated by Contact Angle (CA) measurements. The quality of GO dispersion into the polymer matrix was studied using Scanning electron microscopy (SEM) and X-ray diffraction (XRD). Thermal characterizations (DSC and TGA) were, finally, applied on nanocomposite films in order to evaluate thermal stability of the films as well as to indirectly comprehend the GO influence on PEDOT:PSS-water links

    Management of self-inflicted orchiectomy in psychiatric patient. Case report and non-systematic review of the literature

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    Introduction: Self-inflicted orchidectomy and auto-castration, also known as “Eshmun complex” is a rare phenomenon. The aim of our study it to present the management of a patient who performed a self orchiectomy and propose a non-systematic review of literature about self-orchiectomy. Material and method: A 27-years old male Patient with psychiatric disorder was admitted to our ward to have been cutted his scrotum with scissors and cut away his left testicle causing active bleeding from the left spermatic artery. The patient underwent emergency surgery with clamping of the spermatic cord and hemostasis of the wound. Results: After surgery the clinical condition of the patient remained good during whole hospitalization. Urgent psychiatric evaluation was performed in order to administer proper therapy for acute management. To best of our knowledge, only 11 cases of self-orchidectomy are reported in literature and all of them except 1 case, underwent surgical exploration. Conclusions: Self-orchidectomy is an extremely rare phenomenon, often associated with psychiatric disorders, compounded by the use of drugs. In our opinion, emergency surgery should be the first choice of treatment, offering diagnostic and hemostatic purpose in a single act, aimed to prevent acute and postacute complications

    Predictors of DAPSA Response in Psoriatic Arthritis Patients Treated with Apremilast in a Retrospective Observational Multi-Centric Study (2023-02-07)

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    Background: To date, only a few real-world-setting studies evaluated apremilast effectiveness in psoriatic arthritis (PsA). The aims of this retrospective observational study are to report long-term Disease Activity Index for Psoriatic Arthritis (DAPSA) response of apremilast in PsA patients and to analyze the predictors of clinical response. Methods: All PsA consecutive patients treated with apremilast in fifteen Italian rheumatological referral centers were enrolled. Anamnestic data, treatment history, and PsA disease activity (DAPSA) at baseline, 6 months, and 12 months were recorded. The Mann–Whitney test and chi-squared tests assessed the differences between independent groups, whereas the Wilcoxon matched pairs signed-rank test assessed the differences between dependent samples. Logistic regressions verified if there were factors associated with achievement of DAPSA low disease activity or remission at 6 and 12 months. Results: DAPSA low disease activity or remission rates at 6 and 12 months were observed, respectively, in 42.7% (n = 125) and 54.9% (n = 161) patients. Baseline DAPSA was inversely associated with the odds of achieving low disease activity or remission at 6 months (odds ratio (OR) 0.841, 95% confidence interval (CI) 0.804–0.879; p < 0.01) and at 12 months (OR 0.911, 95% CI 0.883–0.939; p < 0.01). Conclusions: Almost half of the PsA patients receiving apremilast achieved DAPSA low disease activity or remission at 6 and 12 months. The only factor associated with achievement of low disease activity or remission at both 6 and 12 months was baseline DAPSA

    Anxiety and depression in keratotic oral lichen planus: a multicentric study from the SIPMO

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    Objectives: Oral lichen planus with exclusive keratotic reticular, papular, and/or plaque-like lesions (K-OLP) is a clinical pattern of OLP that may be associated with a complex symptomatology and psychological alteration. The aim of the study was to evaluate the prevalence of anxiety (A) and depression (D) in patients with K-OLP, analyzing the potential predictors which can affect mental health status. Methods: Three hundred K-OLP patients versus 300 healthy controls (HC) were recruited in 15 Italian universities. The Numeric Rating Scale (NRS), Total Pain Rating Index (T-PRI), and Hamilton Rating Scales for Depression and for Anxiety (HAM-D and HAM-A) were administered. Results: The K-OLP patients showed statistically higher scores in the NRS, T-PRI, HAM-D, and HAM-A compared with the HC (p-value < 0.001**). A and D were found in 158 (52.7%) and 148 (49.3%) K-OLP patients. Strong linear correlations were identified between HAM-A, HAM-D, NRS, T-PRI, and employment status and between HAM-D, HAM-A, NRS, T-PRI, employment status, and female gender. Multivariate logistic regression revealed that HAM-D and HAM-A showed the greatest increase in the R2 value for A and D in the K-OLP patients, respectively (DR2 = 55.5% p-value < 0.001**; DR2 = 56.5% p-value < 0.001**). Conclusions: The prevalence of A and D is higher in the K-OLP patients compared with the HC, also found in K-OLP subjects without pain, suggesting that the processing of pain may be in a certain way independent of the processing of mood. Clinical relevance: Mood disorders and pain assessment should be carefully performed in relation to K-OLP to obtain a complete analysis of the patients

    INFN What Next: Ultra-relativistic Heavy-Ion Collisions

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    This document was prepared by the community that is active in Italy, within INFN (Istituto Nazionale di Fisica Nucleare), in the field of ultra-relativistic heavy-ion collisions. The experimental study of the phase diagram of strongly-interacting matter and of the Quark-Gluon Plasma (QGP) deconfined state will proceed, in the next 10-15 years, along two directions: the high-energy regime at RHIC and at the LHC, and the low-energy regime at FAIR, NICA, SPS and RHIC. The Italian community is strongly involved in the present and future programme of the ALICE experiment, the upgrade of which will open, in the 2020s, a new phase of high-precision characterisation of the QGP properties at the LHC. As a complement of this main activity, there is a growing interest in a possible future experiment at the SPS, which would target the search for the onset of deconfinement using dimuon measurements. On a longer timescale, the community looks with interest at the ongoing studies and discussions on a possible fixed-target programme using the LHC ion beams and on the Future Circular Collider.Comment: 99 pages, 56 figure

    Multiplicity dependence of jet-like two-particle correlations in p-Pb collisions at sNN\sqrt{s_{NN}} = 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-Pb collisions at a nucleon-nucleon centre-of-mass energy of 5.02 TeV. The transverse-momentum range 0.7 <pT,assoc<pT,trig< < p_{\rm{T}, assoc} < p_{\rm{T}, trig} < 5.0 GeV/cc is examined, to include correlations induced by jets originating from low momen\-tum-transfer scatterings (minijets). The correlations expressed as associated yield per trigger particle are obtained in the pseudorapidity range η<0.9|\eta|<0.9. The near-side long-range pseudorapidity correlations observed in high-multiplicity p-Pb 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--parton 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-Pb collisions. Further, the number scales in the intermediate multiplicity region with the number of binary nucleon-nucleon collisions estimated with a Glauber Monte-Carlo simulation.Comment: 23 pages, 6 captioned figures, 1 table, authors from page 17, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/161

    Anisotropic flow of charged hadrons, pions and (anti-)protons measured at high transverse momentum in Pb-Pb collisions at sNN=2.76\sqrt{s_{\rm NN}}=2.76 TeV

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    The elliptic, v2v_2, triangular, v3v_3, and quadrangular, v4v_4, azimuthal anisotropic flow coefficients are measured for unidentified charged particles, pions and (anti-)protons in Pb-Pb collisions at sNN=2.76\sqrt{s_{\rm NN}} = 2.76 TeV with the ALICE detector at the Large Hadron Collider. Results obtained with the event plane and four-particle cumulant methods are reported for the pseudo-rapidity range η<0.8|\eta|<0.8 at different collision centralities and as a function of transverse momentum, pTp_{\rm T}, out to pT=20p_{\rm T}=20 GeV/cc. The observed non-zero elliptic and triangular flow depends only weakly on transverse momentum for pT>8p_{\rm T}>8 GeV/cc. The small pTp_{\rm T} dependence of the difference between elliptic flow results obtained from the event plane and four-particle cumulant methods suggests a common origin of flow fluctuations up to pT=8p_{\rm T}=8 GeV/cc. The magnitude of the (anti-)proton elliptic and triangular flow is larger than that of pions out to at least pT=8p_{\rm T}=8 GeV/cc indicating that the particle type dependence persists out to high pTp_{\rm T}.Comment: 16 pages, 5 captioned figures, authors from page 11, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/186

    Centrality dependence of charged particle production at large transverse momentum in Pb-Pb collisions at sNN=2.76\sqrt{s_{\rm{NN}}} = 2.76 TeV

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    The inclusive transverse momentum (pTp_{\rm T}) distributions of primary charged particles are measured in the pseudo-rapidity range η<0.8|\eta|<0.8 as a function of event centrality in Pb-Pb collisions at sNN=2.76\sqrt{s_{\rm{NN}}}=2.76 TeV with ALICE at the LHC. The data are presented in the pTp_{\rm T} range 0.15<pT<500.15<p_{\rm T}<50 GeV/cc for nine centrality intervals from 70-80% to 0-5%. The Pb-Pb spectra are presented in terms of the nuclear modification factor RAAR_{\rm{AA}} using a pp reference spectrum measured at the same collision energy. We observe that the suppression of high-pTp_{\rm T} particles strongly depends on event centrality. In central collisions (0-5%) the yield is most suppressed with RAA0.13R_{\rm{AA}}\approx0.13 at pT=6p_{\rm T}=6-7 GeV/cc. Above pT=7p_{\rm T}=7 GeV/cc, there is a significant rise in the nuclear modification factor, which reaches RAA0.4R_{\rm{AA}} \approx0.4 for pT>30p_{\rm T}>30 GeV/cc. In peripheral collisions (70-80%), the suppression is weaker with RAA0.7R_{\rm{AA}} \approx 0.7 almost independently of pTp_{\rm T}. The measured nuclear modification factors are compared to other measurements and model calculations.Comment: 17 pages, 4 captioned figures, 2 tables, authors from page 12, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/284
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