213 research outputs found
Images and visual motifs of Spanish economic power: the IBEX court and the banking crisis (2011–2013)
The media help to construct the visual and iconographic imagery of economic power in the dialectical tension between what they show and what they leave out of view. Images such as unemployment queues, graphs, and portraits of the powerful appear assiduously on the front pages of the press, revealing different visual motifs essential to understanding the narrative of the economy, with its inheritances, mutations and hierarchies, which point to its relationship with other spheres of power such as the monarchy or politics. This article attempts to decipher the codes of visual representation of the economic sphere in Spain through the qualitative analysis of front-page photographs published in El País, El Mundo and La Vanguardia from 2011 to 2013, a period marked by the banking and financial crisis, civil protests, or the judicial prosecution of figures such as Rodrigo Rato. The methodology used combines visual analysis and comparative iconography with theoretical foundations of social semiotics and visual communication, as well as interviews with photojournalists and chiefs of staff. Finally, the results conclude that both economic leaders and the media codify their photographs using specific visual motifs to project a distant and proactive image of the banking elite, which is only disrupted when previously revered figures of the economic elite fall from grace in corruption cases. And also, that in the dialectic of the visible and the invisible of economic power there are hidden historical moments that can never be photographed.Los medios de comunicación ayudan a construir el imaginario visual e iconográfico del poder económico en la tensión dialéctica entre lo que muestran y lo que dejan fuera de campo. Imágenes como las colas del paro, los gráficos y los retratos de los poderosos aparecen asiduamente en las portadas de prensa revelando diferentes motivos visuales esenciales para comprender la narrativa de la economía, con sus herencias, mutaciones y jerarquías, que evidencian su relación con otros ámbitos del poder como la monarquía o la política. Este artículo intenta descifrar los códigos de representación visual del ámbito económico en España a través del análisis cualitativo de las fotografías de portada publicadas en El País, El Mundo y La Vanguardia de 2011 a 2013, período marcado por la crisis bancaria y financiera, las protestas civiles o el procesamiento judicial de figuras como Rodrigo Rato. La metodología utilizada combina el análisis visual y la iconografía comparada con fundamentos teóricos de la semiótica social y la visual communication, además de entrevistas a fotoperiodistas y jefes de gabinete. Finalmente, en los resultados se concluye que tanto los líderes económicos como los media codifican sus fotografías empleando motivos visuales concretos para proyectar una imagen distante y proactiva de la élite bancaria, que solo se trastoca cuando figuras antes veneradas de la élite económica caen en desgracia por casos de corrupción. Y también que en la dialéctica de lo visible y lo invisible del poder económico quedan ocultos momentos históricos que nunca podrán ser fotografiados
Atmospheric lepton fluxes at ultrahigh energies
In order to estimate the possibility to observe exotic physics in a neutrino
telescope, it is essential to first understand the flux of atmospheric
neutrinos, muons and dimuons. We study the production of these leptons by
high-energy cosmic rays. We identify three main sources of muons of energy E >
10^6 GeV: the weak decay of charm and bottom mesons and the electromagnetic
decay of unflavored mesons. Contrary to the standard assumption, we find that
eta mesons, not the prompt decay of charm hadrons, are the dominant source of
atmospheric muons at these energies. We show that, as a consequence, the ratio
between the neutrino and muon fluxes is significantly reduced. For dimuons,
which may be a background for long-lived staus produced near a neutrino
telescope, we find that pairs of E ~ 10^7 GeV forming an angle above 10^-6 rad
are produced through D (80%) or B (10%) meson decay and through Drell-Yan
proceses (10%). The frequency of all these processes has been evaluated using
the jet code PYTHIA.Comment: 10 pages, 4 figures; published versio
Applications of Infrared Thermography in sports. A review
La termografía infrarroja (TI) registra el calor irradiado de un cuerpo, que es emitido en un rango del espectro electromagnético que la visión humana no es capaz de identificar. La respuesta térmica depende de una serie de ajustes fisiológicos específicos como la homeostasis corporal y salud del deportista, lo cual permite establecer interesantes aplicaciones en el deporte. El objetivo de este trabajo ha sido revisar la literatura en torno a las aplicaciones de la TI en el ámbito del deporte, y proponer las características óptimas del registro en relación al evaluado, las condiciones ambientales y la cámara utilizada. Concluimos que la principal contribución de la TI en el ámbito del deporte es ayudar a identificar signos de lesión antes de que la lesión se produzca, permitiéndonos actuar de manera preventiva durante el proceso de entrenamiento
Stability of negative ionization fronts: regularization by electric screening?
We recently have proposed that a reduced interfacial model for streamer
propagation is able to explain spontaneous branching. Such models require
regularization. In the present paper we investigate how transversal Fourier
modes of a planar ionization front are regularized by the electric screening
length. For a fixed value of the electric field ahead of the front we calculate
the dispersion relation numerically. These results guide the derivation of
analytical asymptotes for arbitrary fields: for small wave-vector k, the growth
rate s(k) grows linearly with k, for large k, it saturates at some positive
plateau value. We give a physical interpretation of these results.Comment: 11 pages, 2 figure
Freezing/melting of water in the confined nanospace of carbon materials: Effect of an external stimulus
Freezing/melting behavior of water confined in the nanopores of activated carbon materials has been evaluated using differential scanning calorimetry (DSC) at different water loadings, and after the application of an external stimulus. Under atmospheric pressure conditions, the DSC scans show a depression in the freezing/melting point of confined water compared to the bulk system. Interestingly, water confined in narrow micropores (pores below 0.7 nm) does not exhibit any phase transition, i.e. it is non-freezable water. Inelastic neutron scattering (INS) data confirm the presence of a distorted molecular assembly in narrow micropores, whereas synchrotron X-ray powder diffraction data (SXRPD) demonstrate the non-freezable nature of the water confined in these narrow-constrictions. Similar experiments under high-pressure CH4 give rise to a completely different scenario. Under high-pressure conditions methane hydrates are formed with a water-to-hydrate yield of 100% for the under-saturated and saturated samples, i.e. in the presence of an external stimulus even water in narrow micropores is prone to experience a liquid-to-solid phase transition. These results confirm the beneficial role of carbon as a host structure to promote nucleation and growth of methane hydrates with faster kinetics and a higher yield compared to the bulk system and to other porous materials.The authors would like to acknowledge financial support from the MINECO (MAT2016-80285-p), Generalitat Valenciana (PROMETEOII/2014/004), H2020 (MSCA-RISE-2016/NanoMed Project), Spanish ALBA synchrotron (Projects 2018022707 & 2019023322) and Oak Ridge beam time availability (Project IPTS-20843.1)
Behaviour of the antioxidant tert-butylhydroquinone on the storage stability and corrosive character of biodiesel
AbstractThe behaviour of the antioxidant tert-butylhydroquinone (TBHQ) on the storage stability of biodiesel was investigated. Storage conditions were simulated through static immersion corrosion tests in biodiesel (with and without TBHQ) using copper coupons. Measurements of oxidation stability (Rancimat induction period) and metal release at different stages of corrosion were performed. After 24h of the static immersion test, the neat and TBHQ-doped biodiesels presented induction times below the EN 14214 limit (6h). Copper release was more intense in the neat biodiesel which evidenced that TBHQ retarded the corrosion process as a corrosion inhibitor. Ion trap–time-of-flight mass spectrometry (IT–TOF-MS) revealed the presence of considerable amounts of tert-butylquinone (TBQ) in the TBHQ-doped biodiesel exposed to the corrosion process. As TBHQ molecules adsorb at the copper surface to inhibit corrosion, these molecules are catalytically oxidised to TBQ. IT–TOF-MS also indicated the formation of new molecules of high molecular weight only presented in the TBHQ-doped biodiesel deteriorated by the corrosion process. MS2 spectra gave clear evidence of the formation of new complexes between free radicals of long-chain molecules (fatty acid derivatives) and TBQ radicals during biodiesel deterioration
O epitélio respiratório em ratos Wistar após 48 horas de exposição contínua ao ruído de baixa frequência
ABSTRACTPrevious studies show that exposure to low frequency noise (LFN) (≤500Hz, including infrasound) produces irreversible lesions in Wistar rat respiratory epithelia. Recovery periods for LFN-induced lesions have thus become an object of interest. Changes in the respiratory epithelia of Wistar rats after continuous short-term exposure to LFN are described. Twelve rats were exposed to continuous LFN for 48hrs, and 10 age-matched rats were kept in silence. Animals were treated in accordance with 86/609/CE. After exposure ceased, two rodents were sacrificed immediately, and another two after 6, 12, 24, 48hrs, and 7 days of post-exposure silence. Respiratory epithelial fragments were prepared for light and scanning/ transmission electron microscopy. Six hours after exposure, intense and irregular cellular tumefaction was visible and rosetta structures, formed by secretory cells (SC) centered on a brush cell (BC), were identifiable. Cilia were shorter and shaggy. BC microvilli tended to group, losing the uniform distribution seen in controls. Twelve hours after exposure, cell balooning was still present, BC shape was highly irregular and microvilli were grouped. SC microvilli were still shorter than controls. Seven days after exposure, controls and exposed were indistinguishable. LFN-induced epithelial lesions seem to be reversible if recovery periods are respected.REV PORT PNEUMOL 2003; IX (6): 473-47
Gluon self-energy in a two-flavor color superconductor
The energy and momentum dependence of the gluon self-energy is investigated
in a color superconductor with two flavors of massless quarks. The presence of
a color-superconducting quark-quark condensate modifies the gluon self-energy
for energies which are of the order of the gap parameter. For gluon energies
much larger than the gap, the self-energy assumes the form given by the
standard hard-dense loop approximation. It is shown that this modification of
the gluon self-energy does not affect the magnitude of the gap to leading and
subleading order in the weak-coupling limit.Comment: 21 pages, 6 figures, RevTeX, aps and epsfig style files require
Experimental evidence for fast cluster formation of chain oxygen vacancies in YBa2Cu3O7-d being at the origin of the fishtail anomaly
We report on three different and complementary measurements, namely
magnetisation measurements, positron annihilation spectroscopy and NMR
measurements, which give evidence that the formation of oxygen vacancy clusters
is on the origin of the fishtail anomaly in YBa2Cu3O7-d. While in the case of
YBa2Cu3O7.0 the anomaly is intrinsically absent, it can be suppressed in the
optimally doped state where vacancies are present. We therefore conclude that
the single vacancies or point defects can not be responsible for this anomaly
but that clusters of oxygen vacancies are on its origin.Comment: 10 pages, 4 figures, submitted to PR
Wear and surface residual stress evolution on twin-disc tests of rail/wheel steels
Twin disc tribological tests were performed in wheel and rail materials, with specimens
taken from a Spanish AVE train wheel and a UIC60 rail, in a program intended to characterize their
contact fatigue behavior. The X-ray diffraction technique was used to characterize the residual stress
distribution at the initial and damaged stages, as well as in intermediate stages, since existing
residual stresses in the surface layers of the railways steels and its evolution during contact loading
can have a major influence on crack initiation and propagation
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