55 research outputs found

    From bare to renormalized order parameter in gauge space: structure and reactions

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    The physical reason why one can calculate with similar accuracy, as compared to the experimental data, the absolute cross section associated with two-nucleon transfer processes between members of pairing rotational bands, making use of simple BCS (constant matrix elements) or of many-body (Nambu-Gorkov (NG), nuclear field theory (NFT)) spectroscopic amplitudes, is not immediately obvious. Restoration of spontaneous symmetry breaking and associated emergent generalised rigidity in gauge space provides the answer, and points to a new emergence: a physical sum rule resulting from the intertwining of structure and reaction processes and closely connected with the central role induced pairing interaction plays in structure together with the fact that successive transfer dominates Cooper pair tunnelling

    Testing two-nucleon transfer reaction mechanism with elementary modes of excitation in exotic nuclei

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    Nuclear Field Theory of structure and reactions is confronted with observations made on neutron halo dripline nuclei, resulting in the prediction of a novel (symbiotic) mode of nuclear excitation, and on the observation of the virtual effect of the halo phenomenon in the apparently non-halo nucleus 7^7Li. This effect is forced to become real by intervening the virtual process with an external (t,p) field which, combined with accurate predictive abilities concerning the absolute differential cross section, reveals an increase of a factor 2 in the cross section due to the presence of halo ground state correlations, and is essential to reproduce the value of the observed dσ(7d \sigma(^7Li(t,p)9^9Li)/dΩ\Omega.Comment: Submitted to CERN proceedings for the 14th International Conference on Nuclear Reaction mechanisms, Varenna, June 15 - 19, 201

    Cooper pair transfer in nuclei

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    The second order DWBA implementation of two-particle transfer direct reactions which includes simultaneous and successive transfer, properly corrected by non-orthogonality effects is tested with the help of controlled nuclear structure and reaction inputs against data spanning the whole mass table, and showed to constitute a quantitative probe of nuclear pairing correlations

    Presenza di un «Potyvirus» sul Carciofo (<i>Cynara scolymus</i> L.) in Sardegna

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    A latent virus of artichoke has been isolated in Sardinia (Italy). The virus causes characteristic local lesions on Gomphrena globosa L. and Chenopodium amaranticolor Coste et Reyn., and systemic symptoms on Nicotiana benthamiana Domin. and N. clevelandii Gray. In artichoke crude sap the virus has a longevity in vitro of 20-30 hours, a dilution-end point between 10-3 and 10-4 and a thermal inactivation point between 55 and 60°C. The purification of the virus has been obtained from artichoke with two cicles of differential centrifugation followed by sucrose density gradient centrifugation. The purified suspensions had an ultraviolet light (UV) ab sorption spectrum typical of the nucleoproteins with Emax = 260-262 nm; Emin = 246 nm; and a ratio E280/E260 of 0,85 which suggests a RNA content of the virus of about 5,5%. Electron microscope observation showed that negative stained partially purified virus suspensions are composed of filamentous parti cles with a normal lenght (NL) of 730 nm and a mode of the lenght distributions of 729 nm; moreover, ultrathin sections of tissue fragments from leaves of mechanically inocu1ated Nicotiana benthamiana contained cytoplasmic inclusions of the pinwheel type. In serological tube tests, partially purified virus suspensions reacted with homologous serum (titre 1 : 1024) and a serum immune to an ALV (Artichoke Latent Virus) from Bari. These results have been substantially confirmed by serological tests with the method of «antibody coating of virus parti cles » by immune electron microscopy. I t is obvious that a latent potyvirus is widespread in artichoke growing in Sardinia. However, it cannot be exc1uded the possible occurrence in artichoke plants of a latent carlavirus too

    Reperimento del virus dell'«arricciamento maculato» il del carciofo (AMCV) in Sardegna

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    A virus disease of «Masedu» of artichoke has been observed, in a serious form, in southern Sardinia (Italy). Affected plants are stunted with leaves heavily mottled, crinkled and laciniated. On the basis of the herbaceous hosts reactions, physical properties «in vitro», spectrophotometry, electron microscopy and serology, the virus recovered from diseased plants is identified as an isolate of AMCV, belonging to «Tombusvirus» group, serologically undistinguishable from the italian type isolate

    Influenza del Potyvirus latente del carciofo «Spinoso sardo» sulla produitività delle piante in pieno campo: 2. risultati relativi al secondo anno di impianto

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    In order to evaluate the influence of the artichoke latent Potyvirus (ALV) on plant productivity, a comparative field trial between virus-freed by meristem-tip culture and naturally Infected «Spinoso sardo» plants has been repeated for the second year in Sardinia. On the whole the results corroborate those of the first year: the latent infection doesn't affect the earliness and the number of heads per plant; whereas it negatively influences the weight, the diamater and the stem length of the heads

    Il Risanamento degli agrumi dal viroide dell'Exocortite mediante il microinnesto

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    Nearly all old line citrus trees growing in Sardinia (Italy) are infected by citrus exocortis viroid (CEV). The technique of shoot-tip grafting has proved effective in recovering various citrus cultivars free of this viroid

    Application of Octacalcium Phosphate with an Innovative Household-scale Defluoridator Prototype and Behavioral Determinants of its Adoption in Rural Communities of the East African Rift Valley

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    Natural fluoride contamination of drinking water is a serious issue that affects several countries of the world. Its negative health impact is well documented in the East African Rift Valley, where water consumption with fluoride ((Formula presented.)) concentration greater than 1.5 mg/L can cause fluorosis to people. Within the framework of the European Union (EU) Horizon 2020 FLOWERED project, we first designed an effective defluoridation device based on innovative application of octacalcium phosphate (OCP) and then explored its acceptance within rural communities. The prototype (FLOWERED Defluoridator Device [FDD]) essentially is composed of a 20-L tank and a recirculating pump that guarantees the interaction between water and OCP. The device is powered by a car battery for a fixed pumping working time using a fixed amount of OCP for every defluoridation cycle. The results of tests performed in the rural areas of Tanzania show that a standardized use of the prototype can lower the dissolved (Formula presented.) from an initial concentration of 21 mg/L to below the World Health Organization (WHO) drinkable limit of 1.5 mg/L in 2 h without secondary negative effects on water quality. The approximate cost of this device is around US220,whereasthatofOCPisabout220, whereas that of OCP is about 0.03/L of treated water. As with any device, acceptance requires a behavioral change on behalf of rural communities that needed to be investigated. To this end, we piloted a survey to explore how psychological and socioeconomic factors influence the consumption of fluoride-free water. Results show that the adoption of FDD and OCP is more appealing to members of the rural communities who are willing to pay more and have a high consumption of water. Moreover, we suggest that given the low level of knowledge about fluorosis diseases, the government should introduce educational programs to make rural communities aware of the negative health consequences. Integr Environ Assess Manag 2020;00:1–15. © 2020 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC)
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