1,631 research outputs found

    Oscillations above the barrier in the fusion of 28Si + 28Si

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    Fusion cross sections of 28Si + 28Si have been measured in a range above the barrier with a very small energy step (DeltaElab = 0.5 MeV). Regular oscillations have been observed, best evidenced in the first derivative of the energy-weighted excitation function. For the first time, quite different behaviors (the appearance of oscillations and the trend of sub-barrier cross sections) have been reproduced within the same theoretical frame, i.e., the coupled-channel model using the shallow M3Y+repulsion potential. The calculations suggest that channel couplings play an important role in the appearance of the oscillations, and that the simple relation between a peak in the derivative of the energy-weighted cross section and the height of a centrifugal barrier is lost, and so is the interpretation of the second derivative of the excitation function as a barrier distribution for this system, at energies above the Coulomb barrier.Comment: submitted to Physics Letters

    Study of a New Trigger on Multiplicity and Primary Interaction Vertex using the ALICE Silicon Pixel Detector

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    New trigger inputs for the ALICE Central Trigger Processor (CTP) are proposed. They are based on the use of Fast Multiplicity (FM) output signals generated by the ALICE Silicon Pixel Detector (SPD). These can be used for a multiplicity based centrality trigger and for a fast on-line computation of the primary vertex. A simple algorithm for primary vertex location at the trigger level is proposed. The precision that can be achieved with this method on centrality selection and primary vertex location, is discussed for interactions with different pseudo-rapidity density level. The feasibility of background rejection is also considered

    Very Low Alcohol Consumption Is Associated with Lower Prevalence of Cirrhosis and Hepatocellular Carcinoma in Patients with Non-Alcoholic Fatty Liver Disease

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    The role of moderate alcohol consumption in the evolution of NAFLD is still debated. The aim of this study is to evaluate the impact of current and lifelong alcohol consumption in patients with NAFLD. From 2015 to 2020, we enrolled 276 consecutive patients fulfilling criteria of NAFLD (alcohol consumption up to 140 g/week for women and 210 g/week for men). According to their current alcohol intake per week, patients were divided in: abstainers, very low consumers (C1: <70 g/week) and moderate consumers (C2). We created a new tool, called LACU (Lifetime Alcohol Consuming Unit) to estimate the alcohol exposure across lifetime: 1 LACU was defined as 7 alcohol units per week for 1 drinking year. Patients were divided into lifelong abstainers and consumers and the latter furtherly divided into quartiles: Q1-Q4. Stratification according to alcohol intake, both current and cumulative as estimated by LACU, showed that very low consumers (C1 and Q1-Q3) displayed lower frequency of cirrhosis and hepatocellular carcinoma compared to abstainers and moderate consumers (C2 and Q4). We can speculate that up to one glass of wine daily in the context of a Mediterranean diet may be a long-term useful approach in selected NAFLD patients

    Recent experimental results in sub- and near-barrier heavy ion fusion reactions

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    Recent advances obtained in the field of near and sub-barrier heavy-ion fusion reactions are reviewed. Emphasis is given to the results obtained in the last decade, and focus will be mainly on the experimental work performed concerning the influence of transfer channels on fusion cross sections and the hindrance phenomenon far below the barrier. Indeed, early data of sub-barrier fusion taught us that cross sections may strongly depend on the low-energy collective modes of the colliding nuclei, and, possibly, on couplings to transfer channels. The coupled-channels (CC) model has been quite successful in the interpretation of the experimental evidences. Fusion barrier distributions often yield the fingerprint of the relevant coupled channels. Recent results obtained by using radioactive beams are reported. At deep sub-barrier energies, the slope of the excitation function in a semi-logarithmic plot keeps increasing in many cases and standard CC calculations over-predict the cross sections. This was named a hindrance phenomenon, and its physical origin is still a matter of debate. Recent theoretical developments suggest that this effect, at least partially, may be a consequence of the Pauli exclusion principle. The hindrance may have far-reaching consequences in astrophysics where fusion of light systems determines stellar evolution during the carbon and oxygen burning stages, and yields important information for exotic reactions that take place in the inner crust of accreting neutron stars.Comment: 40 pages, 63 figures, review paper accepted for EPJ

    Italian winegrowers’ and wine makers’ attitudes toward climate hazards and their strategy of adaptation to the change

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    This study reports the results of a survey disseminated to Italian winegrowers and wine makers to understand their attitude toward the main climate risk factors on grape and wine productions and their willingness to proactively act in facing the related consequences. A general noticeable concern about the future effects of climate change and variability emerged, even with some differences between stakeholders operating in different geographic and climatic areas. Current signals of adaptation mostly emerged at technological level, but they also included the varietal choice, with evidence to a switch from traditional varieties to others showing better pest and drought tolerance. In addition, some climate-smart cultural practices are considered ranging from water-saving irrigation methods to sustainable energy managemen
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