Introduction to the study of the iron mining, in the catalan and the Andorran Pyrenees

In the Catalan and in the Andorran Pyrenees, as in the ariegian one, there is an enormous conjunct ofold mining explotations, dedicated to the extraction and to the benefit of the iron minerals. This explotations had his principal apogee during the Middle and the Moderns Ages, and contributed to the development ofthe process ofthe obtainment ofiron called farga catala,na. As it's known, that metaHurgical process was initiality extended in Catalonia and in the Foix Country, and then it was propagated over aH the known world (MATAPERELLO and RIBA, 1993

News media and the emotional public sphere. Introduction

This introduction provides the conceptual and theoretical context that informs a multidisciplinary approach to the relationships between news media and emotions and their influence on the dynamics of the public sphere. It also highlights the importance of the emotional dimension of the public sphere to understand why rationalistic perspectives on both the media and the public sphere do not suffice to capture the complexities of social and political life in contemporary democracies. This Special Section of the International Journal of Communication presents theoretical frameworks, methodological approaches, and empirical research that contribute to our understanding of the relationships and mutual implications of news media, emotions, and the public spher

The XIV International Geological Congress of 1926 in Spain

El XIV Congreso Geológico Internacional de 1926 ha sido el único organizado en España. Se exponen las características principales del mismo, a nivel temático y organizativo. Se analizan cuantitativamente el número de asistentes, las lenguas utilizadas, los países representados, las publicaciones, los autores y su productividad. Se muestra así el significado del congreso en la historia de los mismos, el predominio de geólogos franceses y alemanes, el predominio del trabajo individual y el limitado significado real del congreso en la producción científica de su época. Se analiza también el significado en la Historia de la Geología, ligado a la ciencia “normal” en sentido khuniano, pero no a los grandes temas de debate del momento, así como su significativo papel sociológico. También se analiza su importante papel en la Historia de la Geología en España.The XIV International Geological Congress has been the only one organised in Spain. Its main characteristics, at a thematic and organizative level, are showed. The number of attendants, languages, represented countries, papers, authors and scientific productivity are analysed in a quantitative way. The analysis shows the meaning of the Congress in the history of them, the predominance of frenchs and germans and the individual work, the true mening of the Congress in the scientific production, very limited. The meaning in the history of geology is also analysed, linked to the “standard” science in a khunian sense, but not to the main topics in discusion. Also, the significant sociological role is analysed. Also, the role in the Spain´s history of geology, more important, is analysed.Depto. de Geodinámica, Estratigrafía y PaleontologíaFac. de Ciencias GeológicasTRUEpu

Inhomogeneous electronic structure probed by spin-echo experiments in the electron doped high-Tc superconductor Pr_{1.85}Ce_{0.15}CuO_{4-y}

63Cu nuclear magnetic resonance (NMR) spin-echo decay rate (T_2^{-1}) measurements are reported for the normal and superconducting states of a single crystal of Pr_{1.85}Ce_{0.15}CuO_{4-y} (PCCO) in a magnetic field B_0=9T over the temperature range 2K<T<200K. The spin-echo decay rate is temperature-dependent for T<55K, and has a substantial dependence on the radio frequency (rf) pulse parameters below T~25K. This dependence indicates that T_2^{-1} is strongly effected by a local magnetic field distribution that can be modified by the rf pulses, including ones that are not at the nuclear Larmor frequency. The low-temperature results are consistent with the formation of a static inhomogeneous electronic structure that couples to the rf fields of the pulses.Comment: 4 pages, 4 figure

MOND and the dark baryons

We consider for the first time the implications on the modified gravity MOND model of galaxies, of the presence of dark baryons, under the form of cold molecular gas in galaxy discs. We show that MOND models of rotation curves are still valid and universal, but the critical acceleration a0 separating the Newtonian and MONDian regimes has a lower value. We quantify this modification, as a function of the scale factor c between the total gas of the galaxy and the measured atomic gas. The main analysis concerns 43 resolved rotation curves and allows us to find the best pair (a0 = 0.96 10e-10 m.s-2, c = 3), which is also compatible to the one obtained from a second method by minimizing the scatter in the baryonic Tully-Fisher relation.Comment: 11 pages, 8 figures, accepted in A&

An Evolutionary Sequence of Expanding Hydrogen Shells in Galaxy Discs

Large HI shells, with diameters of hundreds of pc and expansion velocities of 10-20kms-1 are well observed features of local gas rich galaxies. These shells could well be predicted as a result of the impact of OB associations on the ISM, but doubt has been cast on this scenario by the apparent absence of OB stars close to the centres of a large fraction of these shells in recent observations of the SMC. Using Fabry-Perot scanned Halpha emission line mapping of nearby galaxy discs we have detected, in all the HII regions where the observations yield sufficient angular resolution and S:N ratio, dominant Halpha shells with radii a few tens of pc, expanding at velocities of 50-100kms-1. We have applied a simple dynamically consistent framework in which we can extrapolate the properties of the observed Halpha shells to a few 10^7yr after the formation of the OB stars. The framework includes the dynamical inputs of both winds and SNe on the surrounding ISM. The results give quantitative statistical support to the hypothesis that the Halpha emitting shells are generic progenitors of the HI shells. During the time taken for an expanding shell to reach the size of a typical HI shell, the OB association may well lose its most luminous stars so the absence of such stars near the centres of many of the HI shells is well explained in this scenario.Comment: 8 pages, 4 figures, accepted for publication in Astronomy and Astrophysic

Impurities in s=1s=1 Heisenberg Antiferromagnets

The $s=1$ Heisenberg Antiferromagnet is studied in the presence of two kinds of local impurities. First, a perturbed antiferromagnetic bond with $J'\ne J$ at the center of an even-length open chain is considered. Using the density matrix renormalization group method we find that, for sufficiently strong or weak $J'$, a bound state is localized at the impurity site, giving rise to an energy level in the Haldane gap. The energy of the bound state is in agreement with perturbative results, based on $s=1/2$ chain-end excitations, both in the weak and strong coupling limit. In a region around the uniform limit, $J'=J$, no states are found with energy below the Haldane gap. Secondly, a $s=1/2$ impurity at the center of an otherwise even-length open chain is considered. The coupling to the $s=1/2$ impurity is varied. Bound states in the Haldane gap are found {\it only} for sufficiently weak (antiferromagnetic) coupling. For a $s=1/2$ impurity coupled with a strong (antiferromagnetic) bond, {\it no} states are found in the Haldane. Our results are in good qualitative agreement with recent experiments on doped NENP and Y$_2$BaNiO$_5$.Comment: 29 pages, RevTeX 3.0, 12 uuencoded postscript figures include

Establecimiento de un sistema silvopastoril para ovinos como alternativa en la producción intensiva

Cartilla elaborada por el Servicio Nacional de Aprendizaje SENA, a través del Programa SENNOVA, el Semillero de Investigación AGROPEC-SIAS. Busca convertirse en una herramienta útil para aquellos productores Ovino-caprinos interesados en incorporar en sus prácticas, nuevas tecnologías de producción de ganadería sostenible que le aporten a la reconversión del medio ambiente, permitiéndoles enfrentar la escasez de alimentos forrajeros durante condiciones agroclimáticas adversas, como las que se presentan en la región Caribe cada año por la presencia de los largos periodos de verano.Booklet prepared by the National Learning Service SENA, through the SENNOVA Program, the AGROPEC-SIAS Research Seedbed. It seeks to become a useful tool for those sheep-goat producers interested in incorporating in their practices, new technologies of sustainable livestock production that contribute to the reconversion of the environment, allowing them to face the shortage of forage foods during adverse agroclimatic conditions, such as that appear in the Caribbean region every year due to the presence of long summer periods.Definición del sistema silvopastoril -- Características de las especies forrajeras y arbustivas asociados al sistema silvopastoril para la producción ovina -- Características del sistema silvopastoril intensivo en la producción ganadera -- Descripción del establecimiento del sistema silvopastoril intensivo para la producción Ovino caprino – SSPi-O con Leucaena leucocephala asociados con Botón de Oro Tithonia diversifolia y pastos mejoradosna44 página