561 research outputs found

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    Intelligence territoriale et éducation au développement durable:une vision systémique de l'éducation au développement durable au service du territoire

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    International audienceCet article pose les bases d'une recherche sur la territorialisation de l'éducation au développement durable. Il s'agit d'étudier les conditions de mise en oeuvre d'une éducation au développement durable territorialisée qui intègre toutes les dimensions du développement durable (économique, environnementale, sociale, culturelle). Cette EDD devant être capable d'associer toutes les catégories d'acteurs territoriaux dans une perspective de co-production de compétences au service de projets de développement locaux, condition de l'émergence de territoires apprenants. L'approche dans une perspective systémique, s'adosse aux travaux de l'intelligence territoriale, ellemobilise les méthodologies du diagnostic territorial et de l'ingénierie de formation

    Deformation of the N=Z nucleus 76Sr using beta-decay studies

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    A novel method of deducing the deformation of the N=Z nucleus 76Sr is presented. It is based on the comparison of the experimental Gamow-Teller strength distribution B(GT) from its beta decay with the results of QRPA calculations. This method confirms previous indications of the strong prolate deformation of this nucleus in a totally independent way. The measurement has been carried out with a large Total Absorption gamma Spectrometer, "Lucrecia", newly installed at CERN-ISOLDE.Comment: Accepted in Phys. Rev. Letter

    Spectroscopy of 34,35Si^{34,35}Si by β\beta decay: sd-fp shell gap and single-particle states

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    The 34,35Alβ^{34,35}Al\beta decays were studied at the CERN on-line mass separator ISOLDE by βγ,βγγ\beta-\gamma, \beta-\gamma-\gamma and βnγ\beta-n-\gamma measurements, in order to corroborate thelow-level description of 34Si^{34}Si and to obtain the first information on the level structure of the N=21 isotope 35Si^{35}Si. Earlier observed γ\gamma lines in 34Al^{34} Al decay were confirmed and new gamma transitions following both beta decay and β\beta-delayed neutron emission were established. The first level scheme in 35Si^{35}Si, including three excited states at 910, 974 and 2168 keV, is consistent with Jπ=3/2J^{\pi} =3/2^{-} and 3/2+3/2^{+} for the first two states respectively. Beta-decay half-life of T1/2=38.6(4)T_{1/2} = 38.6 (4) ms and beta-delayed neutron branching PnP_{n} value (Pn=41(13)(P_{n} =41(13) %) were measured unambiguously. The significance of the single-particle energy determination at N=21, Z=14, for assessing the effective interaction in sd-fp shell-model calculations, is discussed and illustrated by predictions for different n-rich isotopes

    Study of (n,xng) reactions on 238U

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    Prompt-gamma spectroscopy and time-of-flight techniques were used to measure (n,xn gamma) cross-sections on several nuclei of interest for nuclear reactors. Experiments were performed at the GELINA facility which provides a pulsed white neutron beam of maximum energy about 20 MeV. Preliminary results concerning 238U will be presented. This work was supported by PACEN/GEDEPEONand by the European Commission within the Sixth Framework Programme through I3-EFNUDAT (EURATOMcontract no. 036434) and NUDAME (Contract FP6-516487), and within the Seventh Framework Programme through EUFRAT (EURATOM contract no. FP7-211499) and through ANDES (EURATOM contract no. FP7-249671).JRC.D.4-Standards for Nuclear Safety, Security and Safeguard

    Shape study of the N = Z nucleus Kr-72 via beta decay

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    10 pags.; 11 figs.; 2 tabs.; PACS number(s): 23.40.Hc, 29.30.Kv, 27.50.+e, 21.10.Pc; Open Access funded by Creative Commons Atribution Licence 3.0The beta decay of the N = Z nucleus Kr-72 has been studied with the total absorption spectroscopy technique at ISOLDE (CERN). A total B(GT) = 0.79(4)g(A)(2)/4 pi has been found up to an excitation energy of 2.7 MeV. The B(GT) distribution obtained is compared with predictions from state-of-the-art theoretical calculations to learn about the ground state deformation of Kr-72. Although a dominant oblate deformation is suggested by direct comparison with quasiparticle random phase approximation (QRPA) calculations, beyond-mean-field and shell-model calculations favor a large oblate-prolate mixing in the ground state. Published by the American Physical SocietyJ.A.B. acknowledges the predoctoral grant BES-2008-009412 associated with the research project FPA2007-62170 funded by Ministerio de Ciencia e Innovacion (Spain). This work has ´ been partly supported by the Spanish Ministerio de Economía y Competitividad (MINECO) through projects FPA2012- 32443, FPA2011-24553, FPA2011-29854-C04-01, FPA2013- 41267-P, FPA2014-52823-C2-1-P and FIS2011-23565, by STFC-UK (Grant No. ST/F012012/1) and by the European Union by means of the European Commission within its Seventh Framework Programme (FP7) via ENSAR (Contract No. 262010)Peer Reviewe

    Spin-isospin excitations and beta+/EC half-lives of medium-mass deformed nuclei

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    A selfconsistent approach based on a deformed HF+BCS+QRPA method with density-dependent Skyrme forces is used to describe beta+ decay properties in even-even deformed proton rich nuclei. Residual spin-isospin forces are included in the particle-hole and particle-particle channels. The quasiparticle basis contains neutron-neutron and proton-proton pairing correlations in the BCS approach, while neutron-proton pairing interaction is treated as a residual force in QRPA. We discuss the sensitivity of Gamow-Teller strength distributions and beta+/EC half-lives to deformation, pairing and the strength of the particle-particle interaction. The dependence on deformation is also compared to that of spin M1 strength distributions.Comment: 16 pages, 5 figure
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