5,485 research outputs found

    LA PRIMA LEGGE ITALIANA "CONTRO LA VIOLENZA SESSUALE". UN DIBATTITO LUNGO VENT'ANNI (1976 - 1996)

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    La presente ricerca indaga il dibattito sociale, culturale e politico che ha anticipato la legge n. 66 Norme penali contro la violenza sessuale, licenziata dal Parlamento italiano nel febbraio 1996 e che, a quasi settant’anni dall’entrata in vigore del Codice penale Rocco, modificò la normativa vigente in materia di reati sessuali. Quel risultato arrivò a conclusione di un dibattito ventennale che visse due fasi principali: la prima coincise con il decennio degli anni Settanta ed ebbe come protagonista il movimento femminista, la seconda prese avvio all’inizio degli anni Ottanta e spostò il baricentro della discussione all’interno delle aule parlamentari. Nel lavoro di analisi proposto sono state seguite tre direttrici principali. Innanzitutto si è indagato il ruolo giocato dal movimento femminista nell’accendere i riflettori sul tema dello stupro e nel rompere il muro di silenzio che lo aveva relegato a questione privata. In secondo luogo si è tentato di fotografare il fermento sociale e culturale che accompagnò l’iniziativa femminista contribuendo a diffondere nella società civile italiana una nuova consapevolezza sul tema della violenza e degli abusi sessuali. L’attenzione si è infine soffermata sulla pluralità di approcci, punti di vista ed interpretazioni che animarono il dibattito parlamentare sulla riforma in materia di reati sessuali con l’intento di portare alla luce le ragioni più o meno nascoste che per cinque legislature impedirono alle forze politiche di approdare ad una soluzione condivisa.This research aims to investigate the social, cultural and political debate that has anticipated law no. 66 Norme penali contro la violenza sessuale, dismissed by the Italian Parliament in February 1996. That result amended the current law in sex offenses and it was the final step of a twenty-year debate during which the Italian feminist movement played a crucial role. This research has three principle objectives. Firstly, it investigates the role played by the Italian feminist movement in bringing to light the subject of rape and breaking the wall of silence that had relegated it to a private sphere. Secondly, it aims to photograph the social and cultural turmoil raised by the feminist initiative which spread a new awareness about violence and sexual abuses in the Italian civil society. Thirdly, the research analyses the plurality of opinions and points of view that animated the parliamentary debate and prevented political forces from reaching a shared approach on the reform of criminal sex offenses

    Testing the cores of first ascent red-giant stars using the period spacing of g modes

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    In the context of the determination of stellar properties using asteroseismology, we study the influence of rotation and convective-core overshooting on the properties of red-giant stars. We used models in order to investigate the effects of these mechanisms on the asymptotic period spacing of gravity modes (ΔΠ1\Delta \Pi_1) of red-giant stars that ignite He burning in degenerate conditions (M\lesssim2.0 M_{\odot}). We also compare the predictions of these models with Kepler observations. For a given Δν\Delta\nu, ΔΠ1\Delta \Pi_1 depends not only on the stellar mass, but also on mixing processes that can affect the structure of the core. We find that in the case of more evolved red-giant-branch (RGB) stars and regardless of the transport processes occurring in their interiors, the observed ΔΠ1\Delta \Pi_1 can provide information as to their stellar luminosity, within ~10-20%. In general, the trends of ΔΠ1\Delta \Pi_1 with respect to mass and metallicity that are observed in Kepler red-giant stars are well reproduced by the models.Comment: 5pages, 6 figure

    The AGB bump: a calibrator for the core mixing

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    The efficiency of convection in stars affects many aspects of their evolution and remains one of the key-open questions in stellar modelling. In particular, the size of the mixed core in core-He-burning low-mass stars is still uncertain and impacts the lifetime of this evolutionary phase and, e.g., the C/O profile in white dwarfs. One of the known observables related to the Horizontal Branch (HB) and Asymptotic Giant Branch (AGB) evolution is the AGB bump. Its luminosity depends on the position in mass of the helium-burning shell at its first ignition, that is affected by the extension of the central mixed region. In this preliminary work we show how various assumptions on near-core mixing and on the thermal stratification in the overshooting region affect the luminosity of the AGB bump, as well as the period spacing of gravity modes in core-He-burning models.Comment: Submitted to EPJ Web of Conferences, to appear in the Proceedings of the 3rd CoRoT Symposium, Kepler KASC7 joint meeting; 2 pages, 2 figure

    Constraining angular momentum transport processes in stellar interiors with red-giant stars in the open cluster NGC6819

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    Clusters are excellent test benches for verification and improvement of stellar evolution theory. The recent detection of solar-like oscillations in G-K giants in the open cluster NGC6819 with Kepler provides us with independent constraints on the masses and radii of stars on the red giant branch, as well as on the distance to clusters and their ages. We present, for NGC6819, evolutionary models by considering rotation-induced mixing ; and the theoretical low-l frequencies of our stellar models.Comment: Submitted to EPJ Web of Conferences, to appear in the Proceedings of the 3rd CoRoT Symposium, Kepler KASC7 joint meeting; 2 pages, 1 figur

    Frequency and wavenumber selective excitation of spin waves through coherent energy transfer from elastic waves

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    Using spin-wave tomography (SWaT), we have investigated the excitation and the propagation dynamics of optically-excited magnetoelastic waves, i.e. hybridized modes of spin waves and elastic waves, in a garnet film. By using time-resolved SWaT, we reveal the excitation dynamics of magnetoelastic waves through coherent-energy transfer between optically-excited pure-elastic waves and spin waves via magnetoelastic coupling. This process realizes frequency and wavenumber selective excitation of spin waves at the crossing of the dispersion relations of spin waves and elastic waves. Finally, we demonstrate that the excitation mechanism of the optically-excited pure-elastic waves, which are the source of the observed magnetoelastic waves, is dissipative in nature.Comment: 5 pages, 4 figure

    Laser-driven quantum magnonics and THz dynamics of the order parameter in antiferromagnets

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    The impulsive generation of two-magnon modes in antiferromagnets by femtosecond optical pulses, so-called femto-nanomagnons, leads to coherent longitudinal oscillations of the antiferromagnetic order parameter that cannot be described by a thermodynamic Landau-Lifshitz approach. We argue that this dynamics is triggered as a result of a laser-induced modification of the exchange interaction. In order to describe the oscillations we have formulated a quantum mechanical description in terms of magnon pair operators and coherent states. Such an approach allowed us to} derive an effective macroscopic equation of motion for the temporal evolution of the antiferromagnetic order parameter. An implication of the latter is that the photo-induced spin dynamics represents a macroscopic entanglement of pairs of magnons with femtosecond period and nanometer wavelength. By performing magneto-optical pump-probe experiments with 10 femtosecond resolution in the cubic KNiF3_3 and the uniaxial K2_2NiF4_4 collinear Heisenberg antiferromagnets, we observed coherent oscillations at the frequency of 22 THz and 16 THz, respectively. The detected frequencies as a function of the temperature ideally fit the two-magnon excitation up to the N\'eel point. The experimental signals are described as dynamics of magnetic linear dichroism due to longitudinal oscillations of the antiferromagnetic vector.Comment: 25 pages, 10 figure

    NGC 6819: testing the asteroseismic mass scale, mass loss, and evidence for products of non-standard evolution

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    We present an extensive peakbagging effort on Kepler data of \sim50 red giant stars in the open star cluster NGC 6819. By employing sophisticated pre-processing of the time series and Markov Chain Monte Carlo techniques we extracted individual frequencies, heights and linewidths for hundreds of oscillation modes. We show that the "average" asteroseismic parameter δν02\delta\nu_{02}, derived from these, can be used to distinguish the stellar evolutionary state between the red giant branch (RGB) stars and red clump (RC) stars. Masses and radii are estimated using asteroseismic scaling relations, both empirically corrected to obtain self-consistency as well as agreement with independent measures of distance, and using updated theoretical corrections. Remarkable agreement is found, allowing the evolutionary state of the giants to be determined exclusively from the empirical correction to the scaling relations. We find a mean mass of the RGB stars and RC stars in NGC 6819 to be 1.61±0.02M1.61\pm0.02\,\textrm{M}_\odot and 1.64±0.02M1.64{\pm}0.02\,\textrm{M}_\odot, respectively. The difference ΔM=0.03±0.01M\Delta M=-0.03\pm0.01\,\textrm{M}_\odot is almost insensitive to systematics, suggesting very little RGB mass loss, if any. Stars that are outliers relative to the ensemble reveal overmassive members that likely evolved via mass-transfer in a blue straggler phase. We suggest that KIC 4937011, a low-mass Li-rich giant, is a cluster member in the RC phase that experienced very high mass-loss during its evolution. Such over- and undermassive stars need to be considered when studying field giants, since the true age of such stars cannot be known and there is currently no way to distinguish them from normal stars.Comment: 21 pages, 11 figure

    The extended halo of NGC 2682 (M 67) from Gaia DR2

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    Context: NGC 2682 is a nearby open cluster, approximately 3.5 Gyr old. Dynamically, most open clusters should dissolve on shorter timescales, of ~ 1 Gyr. Having survived until now, NGC 2682 was likely much more massive in the past, and is bound to have an interesting dynamical history. Aims: We investigate the spatial distribution of NGC 2682 stars to constrain its dynamical evolution, especially focusing on the marginally bound stars in the cluster outskirts. Methods: We use Gaia DR2 data to identify NGC 2682 members up to a distance of ~150 pc (10 degrees). Two methods (Clusterix and UPMASK) are applied to this end. We estimate distances to obtain three-dimensional stellar positions using a Bayesian approach to parallax inversion, with an appropriate prior for star clusters. We calculate the orbit of NGC 2682 using the GRAVPOT16 software. Results: The cluster extends up to 200 arcmin (50 pc) which implies that its size is at least twice as previously believed. This exceeds the cluster Hill sphere based on the Galactic potential at the distance of NGC 2682. Conclusions: The extra-tidal stars in NGC 2682 may originate from external perturbations such as disk shocking or dynamical evaporation from two-body relaxation. The former origin is plausible given the orbit of NGC 2682, which crossed the Galactic disk ~40 Myr ago.Comment: 9 pages, 5 figures, accepted for publication on A&

    Characterization and in Vivo Biological Performance of Biosilicate

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    After an introduction showing the growing interest in glasses and glass-ceramics as biomaterials used for bone healing, we describe a new biomaterial named Biosilicate. Biosilicate is the designation of a group of fully crystallized glass-ceramics of the Na2O-CaO-SiO2-P2O5 system. Several in vitro tests have shown that Biosilicate is a very active biomaterial and that the HCA layer is formed in less than 24 hours of exposure to simulated body fluid (SBF) solution. Also, in vitro studies with osteoblastic cells have shown that Biosilicate disks supported significantly larger areas of calcified matrix compared to 45S5 Bioglass, indicating that this bioactive glass-ceramic may promote enhancement of in vitro bone-like tissue formation in osteogenic cell cultures. Finally, due to its special characteristics, Biosilicate has also been successfully tested in several in vivo studies. These studies revealed that the material is biocompatible, presents excellent bioactive properties, and is effective to stimulate the deposition of newly formed bone in animal models. All these data highlight the huge potential of Biosilicate to be used in bone regeneration applications.Universidade Federal de São Paulo, Dept Biosci, BR-11060001 Santos, SP, BrazilUniv Fed Sao Carlos, Dept Mat Engn, Vitreous Mat Lab, BR-13565905 Sao Carlos, SP, BrazilUniv Fed Sao Carlos, Dept Physiotherapy, BR-13565905 Sao Carlos, SP, BrazilUniversidade Federal de São Paulo, Dept Biosci, BR-11060001 Santos, SP, BrazilWeb of Scienc
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