13,200 research outputs found

    Nuclear re-interaction effects in quasi-elastic neutrino nucleus scattering

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    The quasi-elastic neutrino-nucleus cross section has been calculated by using a Fermi gas model corrected to consider the re-scattering between the emitted nucleon and the rest nucleus. As an example of the relevance of this effect we show results for the muon production cross section on 16O target.Comment: 7 pages, 4 Postscript figures, Contribution to NuInt01 Workshop, KEK, Tsukuba, Japa

    Second random-phase approximation with the Gogny force. First applications

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    We present the first applications of the second random-phase-approximation model with the finite-range Gogny interaction. We discuss the advantages of using such an interaction in this type of calculations where 2 particle-2 hole configurations are included. The results found in the present work confirm the well known general features of the second random-phase approximation spectra: we find a large shift, several MeV, of the response centroids to lower energies with respect to the corresponding random-phase-approximation values. As known, these results indicate that the effects of the 1 particle-1 hole/2 particle-2 hole and 2 particle-2 hole/2 particle-2 hole couplings are important. It has been found that the changes of the strength distributions with respect to the standard random-phase-approximation results are particularly large in the present case. This important effect is due to some large neutron-proton matrix elements of the interaction and indicates that these matrix elements (which do not contribute in the mean-field calculations employed in the conventional fit procedures of the force parameters) should be carefully constrained to perform calculation

    Low-lying magnetic excitations of doubly-closed-shell nuclei and nucleon-nucleon effective interactions

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    We have studied the low lying magnetic spectra of 12C, 16O, 40Ca, 48Ca and 208Pb nuclei within the Random Phase Approximation (RPA) theory, finding that the description of low-lying magnetic states of doubly-closed-shell nuclei imposes severe constraints on the spin and tensor terms of the nucleon-nucleon effective interaction. We have first made an investigation by using four phenomenological effective interactions and we have obtained good agreement with the experimental magnetic spectra, and, to a lesser extent, with the electron scattering responses. Then we have made self-consistent RPA calculations to test the validity of the finite-range D1 Gogny interaction. For all the nuclei under study we have found that this interaction inverts the energies of all the magnetic states forming isospin doublets.Comment: 19 pages, 13 figures, 7 tables, accepted for publication in Phys. Rev.

    George Washington

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    Portrait of George Washington, facing right. Includes facsimile of Washington\u27s signature.https://egrove.olemiss.edu/skipwith/1019/thumbnail.jp

    Les baobabs de Madagascar : Quel cadre réglementaire pour leur conservation ?

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    Avec les lĂ©muriens, les baobabs sont certainement reconnus dans le monde comme l’un des groupes les plus emblĂ©matiques de Madagascar. La Grande Île abrite six espĂšces endĂ©miques dont trois ‘En Danger’ sur la liste rouge de l’UICN et trois ‘Quasi - menacĂ©es’. Cet article se propose de passer en revue les dispositions mises en place ainsi que les opportunitĂ©s et limites de la conservation et de la gestion durable des baobabs endĂ©miques de Madagascar. En ratifiant les conventions internationales sur la diversitĂ© biologique (CDB) et sur le commerce international des espĂšces menacĂ©es (CITES), Madagascar s’est engagĂ© Ă  assurer la conservation et la gestion durable des baobabs, plus particuliĂšrement celles des espĂšces menacĂ©es. Cependant, selon l’ArrĂȘtĂ© n° 2915/87 du 7 septembre 1987 sur les produits accessoires des forĂȘts, les baobabs de Madagascar sont considĂ©rĂ©s comme des produits forestiers non ligneux pouvant ĂȘtre exploitĂ©s et aucune disposition n’a Ă©tĂ© prise pour gĂ©rer durablement leur exploitation. La prĂ©sence des baobabs est confirmĂ©e dans 35 zones protĂ©gĂ©es mais, Ă  l’exception de l’AllĂ©e des Baobabs et de la Montagne des Français, les baobabs ne sont pas considĂ©rĂ©s comme des cibles de conservation mais davantage comme des Ă©lĂ©ments profitant d’une protection intrinsĂšque en faisant partie intĂ©grante d’habitats ciblĂ©s pour la conservation. Seule Adansonia grandidieri bĂ©nĂ©ficie de mesures de conservation rĂ©gionales par la mise en place du Dinan’ny Menabe et de la stratĂ©gie de conservation de l’espĂšce dans la RĂ©gion du Menabe. Or les pressions observĂ©es actuellement et les prospectives portant sur l’aire de distribution des deux autres espĂšces classĂ©es ‘En Danger’ que sont A. perrieri et A. suarezensis justifient la mise en place de stratĂ©gies de conservation.With lemurs, baobabs are the most emblematic species of Madagascar internationally. Seven species of the nine existing in the world are Madagascan endemic. This fact testifies the high rate of the biodiversity of the island. Having signed a number of international conventions, Madagascar intends to underline its commitment to the management and conservation of its natural resources. The international system of conservation framing is used for the implementation of national strategy. Thus, in addition to the international system of conservation systems such as the CBD, IUCN or CITES, baobabs of Madagascar are considered as non - timber forest products according to Decree N. 2915/87 of 7 September 1987 related to products accessories forest even if no term is clearly stipulated in this text. Moreover, there is no regulatory framework or specific text about conservation or exploitation of baobabs in Madagascar. Protected areas are then the only protection structures for baobabs. All species of Malagasy baobabs are represented in protected areas but their representation differs depending on the distribution of each species. Except for two protected areas, the baobab is not yet among the specific targets of conservation of protected areas in Madagascar. Adansonia grandidieri is an exception. It benefits indeed from two regional frameworks that specify measures to protect the species and priority activities to be undertaken for the species with the Dinan'ny Menabe and the regional conservation strategy for the species validated in 2013. At the local level, tools and instruments governing the management transfer could constitute framing elements for the management of baobabs. Some species have in fact non-negligible economic values without forgetting the cultural and religious values of some baobab trees. The implementation of the strategy for the conservation of each species is necessary at all levels especially in protected areas as three species are classified as ‘Endangered’ by IUCN. The conservation is necessary to ensure both sustainability of the species and integrity of all uses of baobabs

    Correlations and charge distributions of medium heavy nuclei

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    The effects of long- and short-range correlations on the charge distributions of some medium and heavy nuclei are investigated. The long-range correlations are treated within the Random Phase Approximation framework and the short-range correlations with a model inspired to the Correlation Basis Function theory. The two type of correlations produce effects of the same order of magnitude. A comparison with the empirical charge distribution difference between 206Pb and 205Tl shows the need of including both correlations to obtain a good description of the data.Comment: 20 pages, Latex, accepted for publication in Jour. Phys.

    Receipt from Peal and Co. to Robert Goelet

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    https://digitalcommons.salve.edu/goelet-personal-expenses/1262/thumbnail.jp

    An automatic visual analysis system for tennis

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    This article presents a novel video analysis system for coaching tennis players of all levels, which uses computer vision algorithms to automatically edit and index tennis videos into meaningful annotations. Existing tennis coaching software lacks the ability to automatically index a tennis match into key events, and therefore, a coach who uses existing software is burdened with time-consuming manual video editing. This work aims to explore the effectiveness of a system to automatically detect tennis events. A secondary aim of this work is to explore the bene- fits coaches experience in using an event retrieval system to retrieve the automatically indexed events. It was found that automatic event detection can significantly improve the experience of using video feedback as part of an instructional coaching session. In addition to the automatic detection of key tennis events, player and ball movements are automati- cally tracked throughout an entire match and this wealth of data allows users to find interesting patterns in play. Player and ball movement information are integrated with the automatically detected tennis events, and coaches can query the data to retrieve relevant key points during a match or analyse player patterns that need attention. This coaching software system allows coaches to build advanced queries, which cannot be facilitated with existing video coaching solutions, without tedious manual indexing. This article proves that the event detection algorithms in this work can detect the main events in tennis with an average precision and recall of 0.84 and 0.86, respectively, and can typically eliminate man- ual indexing of key tennis events
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