Octupole correlations in 110Xe

The observation of large quadrupole moments led to the suggestion that some nuclei might have spheroidal shapes, while others present a reflection-asymmetric shape, as for example pear shape. Nuclei around N=Z=56, in the vicinity of the double-magic nucleus 100Sn, are expected to show some of the largest octupole correlations in the whole Segré chart, indeed the experimentally deduced B(E3; 3- → 0+) strength in 114Xe is one the largest measured so far. In this contribution the preliminary results of the extended level scheme of 110Xe, which is expected to have even larger octupole correlations, will be presented. The 110Xe was populated via the 54Fe(58Ni,2n) fusion-evaporation reaction at the Accelerator laboratory of the University of Jyväskylä. After the separation of the fusion-evaporation products in MARA, the 110Xe was implanted into a DSSD to further clean the in-beam gamma rays via the recoil alpha tagging technique. The gamma rays emitted from the excited 110Xe levels were measured by the gamma-ray array Jurogam3.ope

Costi esterni del trasporto e liberalizzazione del settore ferroviario.

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A Multiphysics Co-Simulation Framework of a Gas Engine and Three-Way Catalyst toward a Complete Vehicle Design Model

In view of the increasingly stringent emission regulations, the automotive sector needs considerable support from the development of robust and reliable engine and aftertreatment models. Accurate reproduction of engine-out and tailpipe pollutants plays a crucial role in complying with these legislations. Given the difficulty in characterizing some critical phenomena, frequently caused by strong dynamics and related to experimental uncertainties, communication between several calibrated and reliable models is mandatory. This is certainly valid for powertrains that will be powered with alternative gas fuels such as natural gas, bio-methane and hydrogen in the future. This paper describes a methodology to co-simulate a 1D CNG HD 6-cyl engine model and a 1D quasi-steady three-way catalyst model in a global framework for high-fidelity virtual prototyping of the vehicle system. Through the implementation of a dedicated control logic in MATLAB/Simulink, the modeling architecture allows for the reproduction of the engine performance parameters together with the evaluation of the TWC pollutants’ conversion efficiency. An extensive database of experimental tests was used to assess the model response. The latter was validated in multiple steady-state operating conditions of the engine workplan. Using a semi-predictive combustion model, the validation was carried out over a wide range of different air-to-fuel ratios and during fast rich/lean transitions to evaluate the formation and conversion phenomena of the main chemical species, both engine-out and tailpipe. Subsequently, the complete model was validated in dynamic conditions throughout a WHTC, accurately reproducing the cut-off phases and their sudden accelerations. The numerical–experimental agreement on pollutant reproduction is generally good and globally below 3%. Larger deviations occur in extremely rich conditions and in CH4 emission evaluation due to the lack of information related to the combustion process and chemical mechanisms involving the Pd surface

An extreme negative sea level in the Mediterranean Basin: San Giorgio case study compared with Adriatic Sea

The aim of this paper is to discuss the case of an extreme negative sea level phenomenon that occurred along Sicily Island’s coasts (Italy). Sea level time series associated to six stations that are part of the Italian tide gauge network have been analysed. By deriving the tidal residual and by evaluating meteorological parameters’ trends, it was possible to give an explanation to this phenomenon

Icarus : In-situ monitoring of the surface degradation on a near-Sun asteroid

Icarus is a mission concept designed to record the activity of an asteroid during a close encounter with the Sun. The primary science goal of the mission is to unravel the nontrivial mechanism(s) that destroy asteroids on orbits with small perihelion distances. Understanding the destruction mechanism(s) allows us to constrain the bulk composition and interior structure of asteroids in general. The Icarus mission does not only aim to achieve its science goals but also functions as a technical demonstration of what a low-cost space mission can do. The proposed space segment will include a single spacecraft capable of surviving and operating in the harsh environment near the Sun. The spacecraft design relies on the heritage of missions such as Rosetta, MESSENGER, Parker Solar Probe, BepiColombo, and Solar Orbiter. The spacecraft will rendezvous with an asteroid during its perihelion passage and records the changes taking place on the asteroid's surface. The primary scientific payload has to be capable of imaging the asteroid's surface in high resolution using visual and near-infrared channels as well as collecting and analyzing particles that are ejected from the asteroid. The payload bay also allows for additional payloads relating to, for example, solar research. The Icarus spacecraft and the planned payloads have high technology readiness levels and the mission is aimed to fit the programmatic and cost constraints of the F1 mission (Comet Interceptor) by the European Space Agency. Considering the challenging nature of the Icarus trajectory and the fact that the next F-class mission opportunity (F2) is yet to be announced, we conclude that Icarus is feasible as an F-class mission when certain constraints such as a suitable launch configuration are met. A larger mission class, such as the M class by the European Space Agency, would be feasible in all circumstances.Peer reviewe

BepiColombo-Mission Overview and Science Goals

BepiColombo is a joint mission between the European Space Agency, ESA, and the Japanese Aerospace Exploration Agency, JAXA, to perform a comprehensive exploration of Mercury. Launched on 20th October 2018 from the European spaceport in Kourou, French Guiana, the spacecraft is now en route to Mercury. Two orbiters have been sent to Mercury and will be put into dedicated, polar orbits around the planet to study the planet and its environment. One orbiter, Mio, is provided by JAXA, and one orbiter, MPO, is provided by ESA. The scientific payload of both spacecraft will provide detailed information necessary to understand the origin and evolution of the planet itself and its surrounding environment. Mercury is the planet closest to the Sun, the only terrestrial planet besides Earth with a self-sustained magnetic field, and the smallest planet in our Solar System. It is a key planet for understanding the evolutionary history of our Solar System and therefore also for the question of how the Earth and our Planetary System were formed. The scientific objectives focus on a global characterization ofMercury through the investigation of its interior, surface, exosphere, and magnetosphere. In addition, instrumentation onboard BepiColombo will be used to test Einstein's theory of general relativity. Major effort was put into optimizing the scientific return of the mission by defining a payload such that individual measurements can be interrelated and complement each other.Peer reviewe

Double-γ\gamma measurement and its implications on 0νββ0\nu\beta\beta decay: a feasibility study

reservedNeutrinoless double-beta decay is a second-order decay process of atomic nuclei suggested by theories beyond the Standard Model. This decay would constitute the first observation of lepton-number conservation symmetry violation in the laboratory, showing that neutrinos are their own antiparticles. The neutrinoless double-beta decay rate depends on a Nuclear Matrix Element (NME), which is a key parameter to design experiments and fully exploit their results. Unfortunately, for each of the neutrinoless double-beta candidate nuclides the corresponding NME presents large uncertainties. A recent publication showed a very good correlation between the matrix elements of neutrinoless double-beta and double-gamma decay from the Double Isobaric Analog State (DIAS) of the initial double-beta state, i.e. the state carrying the same wavefunction except for a rotation in the isospin space, into the final double-beta state. Therefore, we could attack the lack of experimental data on the NME values by studying the two-photon decay process. The only neutrinoless double-beta candidate for which the DIAS is known is the 48Ca isotope, which therefore constitutes the ideal study case to start with. Given the very small double-gamma decay rate expected for this nucleus, it is essential to characterize the contributions of all the competing processes and determine the optimal setup and data processing methods to maximise the double-gamma detection efficiency. For this reason a dedicated custom simulation program based on the GEANT4 framework was developed, in order to simulate the experimental setup and its response to the radiation emitted in the 48Ti nuclear de-excitation. After validating the setup and the simulation outputs, different analysis methods were implemented to suppress the decay processes competing with the double-gamma decay. Promising results concerning both the identification of the double-gamma events and the associated NME extraction were obtained, supporting the feasibility of an experiment aimed at measuring this exotic process in 48Ti. When performed, this measurement will provide the first experimental constraints on the 48Ca neutrinoless double-beta decay NME.Neutrinoless double-beta decay is a second-order decay process of atomic nuclei suggested by theories beyond the Standard Model. This decay would constitute the first observation of lepton-number conservation symmetry violation in the laboratory, showing that neutrinos are their own antiparticles. The neutrinoless double-beta decay rate depends on a Nuclear Matrix Element (NME), which is a key parameter to design experiments and fully exploit their results. Unfortunately, for each of the neutrinoless double-beta candidate nuclides the corresponding NME presents large uncertainties. A recent publication showed a very good correlation between the matrix elements of neutrinoless double-beta and double-gamma decay from the Double Isobaric Analog State (DIAS) of the initial double-beta state, i.e. the state carrying the same wavefunction except for a rotation in the isospin space, into the final double-beta state. Therefore, we could attack the lack of experimental data on the NME values by studying the two-photon decay process. The only neutrinoless double-beta candidate for which the DIAS is known is the 48Ca isotope, which therefore constitutes the ideal study case to start with. Given the very small double-gamma decay rate expected for this nucleus, it is essential to characterize the contributions of all the competing processes and determine the optimal setup and data processing methods to maximise the double-gamma detection efficiency. For this reason a dedicated custom simulation program based on the GEANT4 framework was developed, in order to simulate the experimental setup and its response to the radiation emitted in the 48Ti nuclear de-excitation. After validating the setup and the simulation outputs, different analysis methods were implemented to suppress the decay processes competing with the double-gamma decay. Promising results concerning both the identification of the double-gamma events and the associated NME extraction were obtained, supporting the feasibility of an experiment aimed at measuring this exotic process in 48Ti. When performed, this measurement will provide the first experimental constraints on the 48Ca neutrinoless double-beta decay NME

Cu decay into neutron-rich Zn isotopes: shell structure near 78Ni - β-decay study of 75Cu

Doubly-magic nuclei are the cornerstone of our current understanding of the nuclear shell model. These nuclei have spherical shapes and are more tightly bound than any other in the nuclear chart. Just recently, this selected club has accepted its newest member, the very exotic 78Ni. The neighbouring nuclei around doubly-magic ones are expected to show similar, however weaker, characteristics. For this reason, an experiment was conducted at ISOLDE Decay station (IDS) to study the decay of neutron-rich Cu isotopes into Zn isotopes just above the two double magic 68Ni and 78Ni. In this work part of the collected data were analyzed and, in particular, the level scheme of 75Zn was expanded