45,158 research outputs found

    Las galeras en la política militar española en el Mediterráneo durante el siglo XVI

    Get PDF
    Las galeras fueron el instrumento marítimo más efectivo en la lucha naval en el Mediterráneo durante el siglo XVI. Aunque la monarquía hispánica trató de competir en este campo con el imperio turco, finalmente, se tuvo que contentar con desarrollar una estrategia defensiva. El autor analiza la decadencia de las galeras después de 1574, matizando la tesis de Gilmartin.Les galeres foren l'instrument marítim més efectiu en la lluita naval a la Mediterrània durant el segle XVI. Tot i que la monarquia hispànica va intentar competir en aquest camp amb l'imperi turc, finalment, es va haver d'acontentar a desenvolupar una estratègia defensiva. L'autor analitza la decadència de les galeres després de 1574, tot matisant la tesi de Gilmartin.The galleys were the most effective maritime instrument in the naval fight in the Mediterranean Sea during the 16th century. Although the Hispanic monarchy tried to compete with the Turkish Empire, finally, it had to be content by developing a defensive strategy. The author analyzes the decay of the galleys after 1574, changing Gilmartin thesis slightly

    Near-barrier Fusion Induced by Stable Weakly Bound and Exotic Halo Light Nuclei

    Get PDF
    The effect of breakup is investigated for the medium weight 6^{6}Li+59^{59}Co system in the vicinity of the Coulomb barrier. The strong coupling of breakup/transfer channels to fusion is discussed within a comparison of predictions of the Continuum Discretized Coupled-Channels model which is also applied to 6^{6}He+59^{59}Co a reaction induced by the borromean halo nucleus 6^{6}He.Comment: 6 pages, 3 figures. A talk given at the FUSION06: International Conference on Reaction Mechanisms and Nuclear Structure at the Coulomb barrier, March 19-23, 2006, San Servolo, Venezia, Ital

    Relativistic Winds from Compact Gamma-Ray Sources: II. Pair Loading and Radiative Acceleration in Gamma-ray Bursts

    Get PDF
    We consider the effects of rapid pair creation by an intense pulse of gamma-rays propagating ahead of a relativistic shock. Side-scattered photons colliding with the main gamma-ray beam amplify the density of scattering charges. The acceleration rate of the pair-loaded medium is calculated, and its limiting bulk Lorentz factor related to the spectrum and compactness of the photon source. One obtains, as a result, a definite prediction for the relative inertia in baryons and pairs. The deceleration of a relativistic shock in the moving medium, and the resulting synchrotron emissivity, are compared with existing calculations for a static medium. The radiative efficiency is increased dramatically by pair loading. When the initial ambient density exceeds a critical value, the scattering depth traversed by the main gamma-ray pulse rises above unity, and the pulse is broadened. These considerations place significant constraints on burst progenitors: a pre-burst mass loss rate exceeding 10^{-5} M_\odot per year is difficult to reconcile with individual pulses narrower than 10 s, unless the radiative efficiency is low. An anisotropic gamma-ray flux (on an angular scale \Gamma^{-1} or larger) drives a large velocity shear that greatly increases the energy in the seed magnetic field forward of the propagating shock.Comment: 19 pp., LaTeX (aaspp4.sty), revised 12/23/99, Ap. J. in press; summary section added and several minor improvements in presentatio

    Two neutron decay of 16Be

    Full text link
    Recently, the first example of two-neutron decay from the ground state of an unbound nucleus, 16^{16}Be, was seen. Three-body methods are ideal for exactly treating the degrees of freedom important for these decays. Using a basis expansion over hyperspherical harmonics and the hyperspherical R-matrix method, we construct a realistic model of 16^{16}Be in order to investigate its decay mode and the role of the two-neutron interaction. The neutron-14^{14}Be interaction is constrained using shell model predictions. We obtain a ground state for 16^{16}Be that is over-bound by approximately 1 MeV with a width of approximately 0.23 MeV. This suggests, that for such systems, the three-body force needs to be repulsive.Comment: 4 pages, 1 figure, contribution to the proceedings for the 21st International Conference on Few Body Problems in Physics, Chicago, Illinois, US

    Healthcare assistants: distributional losses as a consequence of NHS modernisation?

    Get PDF
    This paper examines the labour process of Healthcare Assistants (HCAs) at a National Health Service (NHS) hospital trust (TUH) in the context of the NHS modernisation agenda. It determines whether application of the modernisation agenda is formalised at TUH and considers how HCAs are affected. The paper is based upon 60 interviews with HCAs, structured questionnaires completed by all interview respondents, observation of HCAs and interviews with non-clinical managers. The findings show that elements of the modernisation agenda are informally implemented at TUH to the detriment of HCAs. HCAs experience distributional losses in the form of intensification as nurses deflect duties to HCAs and insulate themselves from adverse effects. HCAs resist, using selective absence when pressures mount. They ameliorate losses by re-internalising their work as a job with caring elements not a genuine caring role. They rationalise their altered behaviour towards patients by blaming the regime's treatment of them as a subordinated group
    • …
    corecore