Time and memory: Camí de sirga and Les veus del Pamano

In this article, I will examine how historical memory is recovered and, in particular, how the issue of time is dealt with. I will explore how literary language, with its ability to penetrate and create contaminated situations, is the most suitable vehicle for presenting historical memory in a less ideological and emotional way and how it offers a means of reconstructing, filling in or setting straight the records provided in official accounts. Finally, I will argue that literature can be used to recover or recreate these official accounts and, in so doing, to give voice to previously suppressed memories, figures and realities

Lecturas polifónicas de los epistolarios de Jorge Guillén y Pedro Salinas

This article addresses Jorge Guillén and Pedro Salinas’ epistolary voice, two fundamental poets in the renewal of Spanish literature around 1927. Both excelled in their letter writing activity. The article discusses some of the similarities and differences we can detect in their correspondence, especially in the letters Guillén sent to his wife, Germaine Cahen, and the letters of Pedro Salinas in general. Letter writing, together with prose and poetry, is a significant part of Guillén and Salinas’ literary and vital projects, and it helps us better know hidden aspects of their writing. Salinas expresses a “perfect forever”, while Guillén is close to a “real human tremor”

Structure of the vacuum states in the presence of isovector and isoscalar pairing correlations

The long standing problem of proton-neutron pairing and, in particular, the limitations imposed on the solutions by the available symmetries, is revisited. We look for solutions with nonvanishing expectation values of the proton Δp, the neutron Δn, and the isoscalar Δ0 gaps. For an equal number of protons and neutrons we find two solutions with Δp = ± Δn, respectively. The behavior and structure of these solutions differ for spin saturated (single l shell) and spin unsaturared systems (single j shell). In the former case the BCS results are checked against an exact calculation.Facultad de Ciencias Exacta

Cross sections for the excitation of isovector charge-exchange resonances in 208Tl

The Glauber approximation for the treatment of heavy-ion scattering, has already been shown to give reliable predictions for the reaction cross section in the particular case of intermediate energy charge-exchange processes. In the present work, we couple a Glauber-type model to microscopic Random Phase Approximation calculations of the charge-exchange excitations of $^{208}$Pb. The aim is to solve the longstanding question whether the very elusive charge-exchange isovector monopole has been really identified in the past experiments, or other multipoles were prevalent in the observed spectra.Comment: text + 4 figures; accepted for publication in Phys. Rev.

A comparative study of magnetic and electrical properties of BiFeO3 mutiferroic ceramics sintered by electric field assisted-methods: Spark plasma sintering and flash sintering

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AC VS. DC flash sintering: Influence of field frequency on flash processes

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Reaction flash sintering for producing high quality functional ceramics within seconds

For ceramic materials, it has been recently shown in literature that applying a small electric field and a small DC current through a sample produces sudden sintering (within seconds) at relatively low temperatures. This method is known as Flash Sintering and it has been applied to number of materials. In this work it is shown that both chemical reaction and sintering can be combined into a single flash sintering experiments. This new approach is known as Reaction Flash Sintering. To demonstrate the feasibility of this method, a multiferroic material, BiFeO3, is prepared from a stoichiometric mixture of Bi2O3 and Fe2O3 oxides. Thus, in a single process, dense nanostructured BiFeO3 ceramics are obtained by applying an electric field of 50 V cm-1 and with a current limit of 35 mA mm-2 within seconds at a furnace temperature of about 625 °C. The resulting materials were pure-phase perovskites without any evidence of secondary phases, sillenite or mullite, that are commonly present in materials prepared by conventional procedures. Moreover, samples were electrically insulating, as measured by complex impedance spectroscopy. It is shown here that the synthesis of pure single-phase ceramics of complex oxides from stoichiometric mixtures of single oxides is possible by reaction flash sintering, even for materials difficult to prepare by conventional procedures. This discovery is a breakthrough in materials preparation

Structure of the vacuum states in the presence of isovector and isoscalar pairing correlations

The long standing problem of proton-neutron pairing and, in particular, the limitations imposed on the solutions by the available symmetries, is revisited. We look for solutions with nonvanishing expectation values of the proton Δp, the neutron Δn, and the isoscalar Δ0 gaps. For an equal number of protons and neutrons we find two solutions with Δp = ± Δn, respectively. The behavior and structure of these solutions differ for spin saturated (single l shell) and spin unsaturared systems (single j shell). In the former case the BCS results are checked against an exact calculation.Facultad de Ciencias Exacta