84 research outputs found

    Novel technique to extract experimental symmetry free energy information of nuclear matter

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    A new method of accessing information on the symmetry free energy from yields of fragments produced in Fermi-energy heavy-ion collisions is proposed. Furthermore, by means of quantum fluctuation analysis techniques, correlations between extracted symmetry free-energy coefficients with temperature and density were studied. The obtained results are consistent with those of commonly used isoscaling techniques.Comment: 6 pages, 3 figures Heavy-ion nuclear reactions at Fermi energies, Nuclear equation of State, Fragmentatio

    Twitter and elections: are tweets, predictive, reactive, or a form of buzz?

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    The popular microblogging social media platform Twitter has been prominently covered in the press for its perceived role in activism, disaster recovery, and elections amongst other things. In the case of elections, Twitter has been used actively by candidates and voters alike in a diverse range of elections around the world including the 2010 UK elections, the 2012 US presidential elections, and the 2013 Italian elections. However, Twitter has often been found to be a poor predictor of electoral success. This article investigates what role tweets play during elections and whether they are more reactive than predictive. Using the specific case of the 2012 US Republican presidential primary elections, this article explores how candidate's Twitter presence affects electoral outcomes and whether the sentiment and frequency of candidate-related tweets is related to campaign success and offline success at the ballot box. This study finds that tweets were more reactive rather than predictive. Additionally, sentiment analysis revealed that tweets were generally neutral towards candidates. An interesting finding of our study is how candidates used Twitter to generate ‘buzz’, political capital that did not translate to success at the ballot box. We specifically explore how Huntsman's daughters used YouTube videos and tweets that were perceived as a ‘backstage’ look into the campaign and ultimately generated high levels of buzz. Though tweets do not seem to be reflective or predictive of an election campaign offline, they are being used for social media campaigns which can and do get covered by traditional media

    A content analysis of gambling operators’ Twitter accounts at the start of the English premier league football season

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    The use of social media is now an established strategy to engage and maintain customer loyalty. The purpose of the present study was to examine the Twitter accounts of ten of the largest online sports betting operators in the UK to determine what marketing strategies were employed. More specifically, this study analyzed 3375 tweets posted by the operators during the opening weekend of the 2018–2019 English Premier League football season using a content analysis methodology. The results demonstrated that multiple strategies, including hashtags, were used to link gambling operator tweets with major sporting events, and the use of numerous promotional campaigns. Notably, over 90% of the tweets contained no responsible gambling information. The quantity and content of social media posts underline the need for a review of the current advertising regulations in the UK. Further research should examine how exposure to sports betting social media marketing influences gambling behavior

    Pushing the high count rate limits of scintillation detectors for challenging neutron-capture experiments

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    One of the critical aspects for the accurate determination of neutron capture cross sections when combining time-of-flight and total energy detector techniques is the characterization and control of systematic uncertainties associated to the measuring devices. In this work we explore the most conspicuous effects associated to harsh count rate conditions: dead-time and pile-up effects. Both effects, when not properly treated, can lead to large systematic uncertainties and bias in the determination of neutron cross sections. In the majority of neutron capture measurements carried out at the CERN n\_TOF facility, the detectors of choice are the C6_{6}D6_{6} liquid-based either in form of large-volume cells or recently commissioned sTED detector array, consisting of much smaller-volume modules. To account for the aforementioned effects, we introduce a Monte Carlo model for these detectors mimicking harsh count rate conditions similar to those happening at the CERN n\_TOF 20~m fligth path vertical measuring station. The model parameters are extracted by comparison with the experimental data taken at the same facility during 2022 experimental campaign. We propose a novel methodology to consider both, dead-time and pile-up effects simultaneously for these fast detectors and check the applicability to experimental data from 197^{197}Au(nn,Îł\gamma), including the saturated 4.9~eV resonance which is an important component of normalization for neutron cross section measurements

    Charge identification of fragments with the emulsion spectrometer of the FOOT experiment

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    The FOOT (FragmentatiOn Of Target) experiment is an international project designed to carry out the fragmentation cross-sectional measurements relevant for charged particle therapy (CPT), a technique based on the use of charged particle beams for the treatment of deep-seated tumors. The FOOT detector consists of an electronic setup for the identification of Z ≄ 3 fragments and an emulsion spectrometer for Z ≀ 3 fragments. The first data taking was performed in 2019 at the GSI facility (Darmstadt, Germany). In this study, the charge identification of fragments induced by exposing an emulsion detector, embedding a C2 H4 target, to an oxygen ion beam of 200 MeV/n is discussed. The charge identification is based on the controlled fading of nuclear emulsions in order to extend their dynamic range in the ionization response

    Advances and new ideas for neutron-capture astrophysics experiments at CERN n_TOF

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    This article presents a few selected developments and future ideas related to the measurement of (n,Îł) data of astrophysical interest at CERN n_TOF. The MC-aided analysis methodology for the use of low-efficiency radiation detectors in time-of-flight neutron-capture measurements is discussed, with particular emphasis on the systematic accuracy. Several recent instrumental advances are also presented, such as the development of total-energy detectors with Îł-ray imaging capability for background suppression, and the development of an array of small-volume organic scintillators aimed at exploiting the high instantaneous neutron-flux of EAR2. Finally, astrophysics prospects related to the intermediate i neutron-capture process of nucleosynthesis are discussed in the context of the new NEAR activation area

    Advances and new ideas for neutron-capture astrophysics experiments at CERN n_TOF

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    This article presents a few selected developments and future ideas related to the measurement of (n,Îł) data of astrophysical interest at CERN n_TOF. The MC-aided analysis methodology for the use of low-efficiency radiation detectors in time-of-flight neutron-capture measurements is discussed, with particular emphasis on the systematic accuracy. Several recent instrumental advances are also presented, such as the development of total-energy detectors with Îł-ray imaging capability for background suppression, and the development of an array of small-volume organic scintillators aimed at exploiting the high instantaneous neutron-flux of EAR2. Finally, astrophysics prospects related to the intermediate i neutron-capture process of nucleosynthesis are discussed in the context of the new NEAR activation area

    Increasing the energy flexibility of existing district heating networks through flow rate variations

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    The possibility of recovering waste and renewable heat in urban areas has made district heating networks one of the key infrastructures for decarbonising the heating sector in Europe. The ability to shift the heat production over time is an important asset to improve the competitiveness of both new and existing networks. To this purpose, the present study evaluates the flexibility potential provided by the water volume enclosed in the network pipelines using the district heating network of Verona (Italy) as a case study. Given the users heat demand in two representative weeks, computer simulations were carried out to calculate the network's thermal response to circulating flow rate variations. The latter were designed to cause an early or late shift in the daily peak thermal load. The local temperature drop at the users substations compared to the current situation was used as a relative discomfort indicator. The simulations were carried out using the model NeMo, which has been attached as supplementary material to this publication. The simulation results show that the network pre-charge strategy achieves significant benefits in terms of both peak shaving and load shifting with a limited impact on discomfort for the users. Furthermore, the paper shows that the available storage capacity of the network is significantly influenced by the duration of the flow adjustment, by the average velocity of the heat carrier fluid and by the daily heat demand pattern. Finally, it is shown that the energy flexibility of the network also depends on its topology. In this regard, the article provides preliminary indications on the number and position of the bypass pipes needed to implement the proposed flow rate variations. In conclusion, the article shows that the thermal inertia of the heat carrier fluid is an interesting source of flexibility for existing networks, and the results highlight its potential and limitations

    Flow rate control in standing column wells: A flexible solution for reducing the energy use and peak power demand of the built environment

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    Standing column wells offer a generous and flexible solution to improve the energy efficiency of the built environment. As these systems behavior is strongly affected by groundwater advection, the acute challenge of predicting their thermal evolution with both accuracy and computational efficiency has so far hindered the development of design tools and optimized control strategies. In this work, a powerful simulation algorithm is implemented and applied to the performance assessment of multi-borehole standing column well systems located in a heterogeneous geological environment and operating under various constant and dynamic flow rate control strategies. The iterative algorithm relies on the non-stationary convolution technique to simulate the underground components, and the EnergyPlus approach to represent the heat pump efficiency at full and part loads. The findings suggest that using higher flow rates in peak conditions is a key element that minimizes auxiliary assistance and power demand. Complementary variable flow rate control aiming to maintain a 2 °C temperature difference across the plate heat exchanger has shown to alleviate groundwater usage and generate at least 8%–11% annual energy savings compared with constant flow. This operating strategy allowed the systems to deliver 197–246 W/m with a heating seasonal performance factor of 3.59. These results were achieved through 34 annual simulations having hourly time steps that were performed with the proposed algorithm in a total of 4 h 17 min, compared to 11 days for a single simulation using a numerical reference model
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