4,566 research outputs found

    Universal geometrical scaling of the elliptic flow

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    The presence of scaling variables in experimental observables provide very valuable indications of the dynamics underlying a given physical process. In the last years, the search for geometric scaling, that is the presence of a scaling variable which encodes all geometrical information of the collision as well as other external quantities as the total energy, has been very active. This is motivated, in part, for being one of the genuine predictions of the Color Glass Condensate formalism for saturation of partonic densities. Here we extend these previous findings to the case of experimental data on elliptic flow. We find an excellent scaling for all centralities and energies, from RHIC to LHC, with a simple generalization of the scaling previously found for other observables and systems. Interestingly the case of the photons, difficult to reconcile in most formalisms, nicely fit the scaling curve. We discuss the possible interpretations of this finding in terms of initial or final state effects.Comment: 6 pages, 4 figures, accepted for publication in Phys Rev

    Estudio comparado de la genitalia de dos poblaciones españolas de Cataglyphis (Hym., Formicidae), grupo albicans de color negro

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    El estudio de la genitalia masculina de dos poblaciones de Cataglyphis grupo albicans de color negro, de Tarifa (Cádiz) y Bellaterra (Barcelona), inicialmente consideradas por diferencias de coloración como C. albicans y C. ibericus, respectivamente, pone de manifiesto diferencias importantes entre ellas, coincidentes con el estudio enzimático (De Haro y otros, 1995). Este estudio enzimático motivó la consideración provisional de las poblaciones orientales ibéricas como pertenecientes a C. albicans, dados 10s problemas que planteaba su identidad con la población marroquí C . albicans ruber. La población de Tarifa se consideró un taxón nuevo, no quedando aclarada la situación taxómica de C. ibericus. Estudios geográficamente mis extensos aclararán si estas poblaciones ibéricas forman parte de una clina morfológica y qué taxón o taxones constituyen.The study of male genitalia of two populations of Cataglyphis group albicans, black colour, from Tarifa (Cádiz) and Bellaterra (Barcelona), previously considered by differences in colour as C. albicans and C . ibericus, respectively, show important differences, in coincidence with enzymatic study (De Haro et al., 1995). In these enzymatic studies, the eastern iberian populations were provisionally considered as C. albicans, due to the problems showed by their identity with the morocco population C . albicans ruber. The Tarifa population was considered a new taxon, with no explanation about the taxonomic situation of C . ibericus. Further studies with greater geographical extension will clear up the existence of a possible morphological cline in the iberian populations and which taxon or taxons they constitute

    On Balance: Intelligence Democratization in Post-Franco Spain

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    The article of record as published may be found at http://dx.doi.org/10.1080/08850607.2018.146658

    FIRST "Winged" and X-shaped Radio Source Candidates: II. New Redshifts

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    We report optical spectroscopic observations of X-shaped radio sources with the Hobby-Eberly Telescope and Multiple-Mirror Telescope, focused on the sample of candidates from the FIRST survey presented in Paper I (Cheung 2007). A total of 27 redshifts were successfully obtained, 21 of which are new, including that of a newly identified candidate source of this type which is presented here. With these observations, the sample of candidates from Paper I is over 50% spectroscopically identified. Two new broad emission-lined X-shaped radio sources are revealed, while no emission lines were detected in about one third of the observed sources; a detailed study of the line properties is deferred to a future paper. Finally, to explore their relation to the Fanaroff-Riley division, the radio luminosities and host galaxy absolute magnitudes of a spectroscopically identified sample of 50 X-shaped radio galaxies are calculated to determine their placement in the Owen-Ledlow plane.Comment: emulateapj style, 10 pages, 4 figures, 2 tables; ApJS accepted with minor revision from submitted version (v1

    Correlation between Mn oxidation state and magnetic behavior in Mn/ZnO multilayers prepared by sputtering

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    Compositional, microstructural, and magnetic characterization of ZnO 30 Å/Mn x n multilayers prepared by sputtering is presented to study the observed ferromagnetism in the Mn-ZnO system. The nominal Mn layer thickness, x, is varied from 3 to 60 Å, while the number of bilayers, n, is increased to maintain the total amount of Mn constant. Microstructure information was deduced from x-ray reflectivity, Mn oxidation state was determined by x-ray absorption spectroscopy, and magnetic properties were measured over a temperature range of 5–400 K. Magnetic behavior of these samples is found to be related to the Mn layer thickness x. Multilayers with x 30 Å exhibit ferromagnetism with a Curie temperature above 400 K, while mostly paramagnetic behavior is obtained for x15 Å. Magnetic behavior is discussed in terms of electronic and structural parameters of samples. Mn-ZnO interface effect is related to the ferromagnetic order of the samples, but it is not a sufficient condition. The essential role of the Mn oxidation state in the magnetic behavior of this system is pointed out. It is shown a correlation between the obtained ferromagnetism and a Mn oxidation state close to 2+.Ministerio de Educación y Ciencias de España-MAT2003-01880 y MAT2006-0100

    Direct laser interference patterning of bioceramics: a short review

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    Bioceramics are a great alternative to use in implants due to their excellent biocompatibility and good mechanical properties. Depending on their composition, bioceramics can be classified into bioinert and bioactive, which relate to their interaction with the surrounding living tissue. Surface morphology also has great influence on the implant biological behavior. Controlled texturing can improve osseointegration and reduce biofilm formation. Among the techniques to produce nano- and micropatterns, laser texturing has shown promising results due to its excellent accuracy and reproducibility. In this work, the use of laser techniques to improve surface morphology of biomaterials is reviewed, focusing on the application of direct laser interference patterning (DLIP) technique in bioceramics.This study was funded by FCT-Portugal through the following projects-UID/EEA/04436/2013, COMPETE 2020 with the code POCI-01-0145-FEDER-00694 and LaserMULTICER (POCI-01-0145-FEDER-031035) and by Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq), Brazil through the project-CNPq/UNIVERSAL/421229/2018-7. B.H. acknowledges the support of the Alexander von Humboldt Foundation
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