Operational modal analysis of a spar-type floating platform using frequency domain decomposition method

System identification of offshore floating platforms is usually performed by testing small-scale models in wave tanks, where controlled conditions, such as still water for free decay tests, regular and irregular wave loading can be represented. However, this approach may result in constraints on model dimensions, testing time, and costs of the experimental activity. For such reasons, intermediate-scale field modelling of offshore floating structures may become an interesting as well as cost-effective alternative in a near future. Clearly, since the open sea is not a controlled environment, traditional system identification may become challenging and less precise. In this paper, a new approach based on Frequency Domain Decomposition (FDD) method for Operational Modal Analysis is proposed and validated against numerical simulations in ANSYS AQWA v.16.0 on a simple spar-type structure. The results obtained match well with numerical predictions, showing that this new approach, opportunely coupled with more traditional wave tanks techniques, proves to be very promising to perform field-site identification of the model structures

Progress on the experimental set-up for the testing of a floating offshore wind turbine scaled model in a field site

This document describes design and realization of a small-scale field experiment on a 1:30 model of spar floating support structure for offshore wind turbines. The aim of the experiment is to investigate the dynamic behaviour of the floating wind turbine under extreme wave and parked rotor conditions. The experiment has been going on in the Natural Ocean Engineering Laboratory of Reggio Calabria (Italy). In this article, all the stages of the experimental activity are presented, and some results are shown in terms of motions and response amplitude operators. Finally, a comparison with corresponding results obtained using ANSYS AQWA software package is shown, and conclusions are drawn. The presented experimental set-up seems promising to test offshore floating structures for marine renewable energy at a relatively large scale in the Natural Ocean Engineering Laboratory field site

Investigation of Ni/4H-SiC diodes as radiation detectors with low doped n-type 4H-SiC epilayers

Abstract The development of SiC minimum ionising particle (MIP) detectors imposes severe constrains in the electronic quality and the thickness of the material due to the relatively high value of the energy required to produce an electron–hole pair in this material by MIP against the value for Si. In this work, particle detectors were made using semiconductor epitaxial undoped n-type 4H-SiC as the detection medium. The thickness of the epilayer is on the order of 40 μm and the detectors are realised by the formation of a nickel silicide on the silicon surface of the epitaxial layer (Schottky contact) and of the ohmic contact on the back side of 4H-SiC substrate. The low doping concentration (≅6×10 13 cm −3 ) of the epilayer allows the detector to be totally depleted at relatively low reverse voltages (≅100 V). We present experimental data on the charge collection properties by using 5.486 MeV α-particles impinging on the Schottky contact. A 100% charge collection efficiency (CCE) is demonstrated for reverse voltages higher than the one needed to have a depletion region equal to the α-particle extrapolated range in SiC. The diffusion contribution of the minority change carriers to CCE is pointed out. By comparing measured CCE values to the outcomes of drift–diffusion simulation, values are inferred for the hole lifetime within the neutral region of the charge carrier generation layer

Lateral IBIC analysis of GaAs Schottky diodes

Abstract Charge collection efficiency (CCE) profiles of a semi-insulating (SI) gallium arsenide LEC (Liquid Encapsulated Czochralski) Schottky diode have been investigated by lateral Ion Beam Induced Charge collection (IBIC) technique. A focussed 2.4 MeV proton microbeam was scanned over the cleaved surface of a SI-GaAs diode and the charge collection efficiency was evaluated as a function of the ion beam position at different bias voltages. By fitting the CCE profiles with the equations derived by the Shockley–Ramo–Gunn's theorem, drift lengths of electrons and holes were obtained. Experimental results are consistent with previous OBIC (Optical Beam Induced Current) and SP (Surface Potential) measurements and confirm the model based on the formation of a Mott barrier due to the enhanced electron capture cross section in high field conditions

Insufficient access to harm reduction measures in prisons in 5 countries (PRIDE Europe): a shared European public health concern

Background: Prisoners constitute a high-risk population, particularly for infectious diseases. The aim of this study was to estimate the level of infectious risk in the prisons of five different European countries by measuring to what extent the prison system adheres to WHO/UNODC recommendations. Methods: Following the methodology used in a previous French survey, a postal/electronic questionnaire was sent to all prisons in Austria, Belgium, Denmark and Italy to collect data on the availability of several recommended HIV-HCV prevention interventions and HBV vaccination for prisoners. A score was built to compare adherence to WHO/UNODC recommendations (considered a proxy of environmental infectious risk) in those 4 countries. It ranged from 0 (no adherence) to 12 (full adherence). A second score (0 to 9) was built to include data from a previous French survey, thereby creating a 5-country comparison. Results: A majority of prisons answered in Austria (100 %), France (66 %) and Denmark (58 %), half in Belgium (50 %) and few in Italy (17 %), representing 100, 74, 89, 47 and 23 % coverage of the prison populations, respectively. Availability of prevention measures was low, with median adherence scores ranging from 3.5 to 4.5 at the national level. These results were confirmed when using the second score which included France in the inter-country comparison. Overall, the adherence score was inversely associated with prison overpopulation rates (p = 0.08). Conclusions: Using a score of adherence to WHO/UNODC recommendations, the estimated environmental infectious risk remains extremely high in the prisons of the 5 European countries assessed. Public health strategies should be adjusted to comply with the principle of equivalence of care and prevention with the general community

Craving in opioid use disorder : from neurobiology to clinical practice

Funding: Indivior UK Ltd.Opioid use disorder (OUD) is a major public health issue that has reached epidemic levels in some parts of the world. It is a chronic and complex neurobiological disease associated with frequent relapse to drug taking. Craving, defined as an overwhelmingly strong desire or need to use a drug, is a central component of OUD and other substance use disorders. In this review, we describe the neurobiological and neuroendocrine pathways that underpin craving in OUD and also focus on the importance of assessing and treating craving in clinical practice. Craving is strongly associated with patients returning to opioid misuse and is therefore an important treatment target to reduce the risk of relapse and improve patients’ quality of life. Opioid agonist therapies (OAT), such as buprenorphine and methadone, can significantly reduce craving and relapse risk, and it is essential that patients are treated optimally with these therapies. There is also evidence to support the benefits of non-pharmacological approaches, such as cognitive behavioral therapy and mindfulness-based interventions, as supplementary treatments to opioid agonist therapies. However, despite the positive impact of these treatments on craving, many OUD patients continue to suffer with negative affect and dysphoria. There is a clear need for further studies to progress our understanding of the neurobiological basis of craving and addiction and to identify novel therapeutic strategies as well as to optimize the use of existing treatments to improve outcomes for the growing numbers of patients affected by OUD.Publisher PDFPeer reviewe

position paper per un programma di eliminazione della epatite c nella popolazione a rischio dei consumatori di sostanze e dei detenuti

The data recently published in scientific literature identify in substance abuse the most important risk factor for the transmission of HCV. Another population at risk is represented by detainees, mainly because most of them have a history of substance use. Treatment of the population at risk (substance users and detainees) must become a priority for health systems both to ensure fairness of access to care and to achieve the public health goal of eliminating HCV. The programs to take charge should be multi-disciplinary, flexible, tailored, evidence-based, disseminated homogeneously throughout the national territory, and supported by procedures and guidelines including harm reduction actions, as suggested by the WHO

Milestones to reach Hepatitis C Virus (HCV) elimination in Italy : from free-of-charge screening to regional roadmaps for an HCV-free nation

Although Italy has been on track for Hepatitis C Virus (HCV) elimination since 2019, it fell off track due to the decrease in the number of treated patients. HCV elimination in Italy will be possible if immediate action is taken. A health policy was implemented beginning in 2021, consisting of screening among key populations and birth cohorts (1969-1989), estimated to have a high prevalence of undiagnosed individuals. The active screening requires regional governance that manages the processes' complexity integrating a well-organized network between territory assistance and hospital to achieve an effective HCV care cascade. This document aims to support the regional decision-making process by defining paths for screening and linkage-to-care. Implementing active screening strategies beyond a risk-based approach is required as a General Practitioners' task. Simplified paths must be drawn for the key populations screening. The infrastructure built for COVID-19 vaccination could be used also for HCV screening. According to a multidisciplinary care delivery, screening should be supplemented with rapid linkage-to-care and treatment of newly diagnosed patients. The realization of the proactive screening during the first two years is vital because it will define the tracks for the whole HCV cost-effective screening of 1948-1988 birth cohorts in Italy

La terapia farmacologica dell'alcolismo: l'acamprosato e il nalmefene gli ultimi due farmaci anti-alcol approvati dagli organismi regolatori per la pratica clinica. Parte IV

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