Dark Matter annihilation energy output and its effects on the high-z IGM

We study the case of DM self annihilation, in order to assess its importance as an energy injection mechanism, to the IGM in general, and to the medium within particular DM haloes. We consider thermal relic WIMP particles with masses of 10GeV and 1TeV and we analyse in detail the clustering properties of DM in a $\Lambda$CDM cosmology, on all hierarchy levels, from haloes and their mass function, to subhaloes and the DM density profiles within them, considering adiabatic contraction by the presence of a SMBH. We then compute the corresponding energy output, concluding that DM annihilation does not constitute an important feedback mechanism. We also calculate the effects that DM annihilation has on the IGM temperature and ionization fraction, and we find that assuming maximal energy absorption, at z ~ 10, for the case of a 1TeV WIMP, the ionization fraction could be raised to $6 \times 10^{-4}$ and the temperature to 10K, and in the case of a 10GeV WIMP, the IGM temperature could be raised to 200K and the ionization fraction to $8 \times 10^{-3}$. We conclude that DM annihilations cannot be regarded as an alternative reionization scenario. Regarding the detectability of the WIMP through the modifications to the 21 cm differential brightness temperature signal ($\delta$Tb), we conclude that a thermal relic WIMP with mass of 1TeV is not likely to be detected from the global signal alone, except perhaps at the 1-3mK level in the frequency range 30MHz < $\nu$ < 35MHz corresponding to 40 < z < 46. However, a 10GeV mass WIMP may be detectable at the 1-3mK level in the frequency range 55MHz < $\nu$ < 119MHz corresponding to 11 < z < 25, and at the 1-10mK level in the frequency range 30MHz < $\nu$ < 40MHz corresponding to 35 < z < 46.Comment: 23 pages, 12 figures, accepted for publication in MNRA

Aportación al estudio de la estructura económica de un monasterio altomedieval. Un prototipo: Sant Pere de Grau d'Escales

La iglesia hoy conocida con el nombre de Sant Pere de Grau d'Escales es la única edificación subsistente del antiguo cenobio de Sant Pere d'Escales y ha llegado hasta nosotros gracias a la acertada restauración que efectuó, en su día, el Servicio de Conservación de Monumentos de la Diputación de Barcelona (foto 1 y 2). Se halla situada en un pequeño valle por el que se desliza el río Aigua d'Ora, afluente del Cardener, encajonado por el Estret de Valielles al norte y las escarpadas alturas del Taravill y Busa por el sur, en territorio que fue antaño del decanato de Lord. Forma parte, en consecuencia, del reducido enclave de Valielles, perteneciente al municipio de Montmajor (prov. de Barcelona)

Lírica y poéticas no-representacionales : dos poetas "peruanos"

Este ensayo explora formas de subjetividad emergentes partiendo de la hipótesis de que éstas se manifiestan de manera anticipada y no del todo articulada en la poesía y en el arte. Vivimos en un momento post-identitario y la lírica se reinventa ante esta exigencia histórica. Los dos poetas estudiados, Rafael Espinosa y Emilio Lafferranderie, ponen en marcha prácticas que superan los usos habituales del discurso poético (identificación, subrogación del yo). Su modo de resistencia consiste en bloquear o dificultar los procesos de identificación que propone el mercado cultural como compensación simbólica al bloqueo de la vida política.Aquest assaig explora formes de subjectivitat emergents partint de la hipòtesi de que aquestes es manifesten de manera anticipada i no del tot articulada en la poesia i l'art. Vivim en un moment postidentitari i la lírica es reinventa davant aquesta exigència històrica. Ambdós poetes estudiats, Rafael Espinosa i Emilio Ladderranderie, posen en marxa pràctiques que superen els usos habituals del discurs poètic (identificació, subrogació del jo). El seu mode de resistència consisteix en bloquejar o dificultar els procesos d'identificació que proposa el mercat cutural com a compensació simbòlica al bloqueig de la vida política.This article explores new, emergent subjectivities assuming that they are experienced/exhibited by poetry and art in anticipatory, non-fully articulated ways. In the post-identity period we live, lyric poetry evolves and is reinvented to confront new historical demands. Both of the studied poets -Rafael Espinosa and Emilio Lafferranderie- enact new practices to go beyond traditional uses of poetic discourse (identification, subrogation of the self). Their practice of resistance blocks or hampers the processes of identification that circulate on the cultural market as symbolic compensations for the blockage of political life

Difusión y Acceso a Datos e Información Científica y Tecnológica en la Normativa de Fondos Públicos para la Innovación en Chile

This paper analyzes the regulatory framework in the public funds of the National Innovation System in Chile regarding diffusion and access to scientific and technological data. The results show several failures in the innovation regulatory framework. Concerning data diffusion, most funds do not clearly define who should carry out the diffusion activities, do not promote sufficiently the diffusion of non-confidential information and show little interest in defining and planning diffusion activities. Regarding data sharing, it should be clearly specified the means in which R+D+i data and process are to be delivered. In addition, open access requirements to researchers present serious deficiencies, while compliance of commitments, although show better results, should further improve

Alfares, hornos y producción de cerámica en la Cataluña Medieval y Moderna: una reflexión para su estudio

[spa] A lo largo de la última década, numerosas excavaciones arqueológicas -preventivas en su mayoría-han permitido la recuperación y el estudio de algunasestructuras de cocción de cerámica de cronologías medievalesy postmedievales que se añaden al panorama conocido afinales del siglo XX. Sin embargo, se constata la ausencia enel ámbito catalán de visiones de síntesis que aúnen esfuerzospor superar el localismo propio e inevitable de las memoriasde excavación en favor de una interpretación más ampliaacerca de la ocupación del territorio y de las estrategias deproducción.En este trabajo, que no pretende ser exhaustivo, presentamosun somero estado de la cuestión en relación con el estudiode las estructuras de cocción y los talleres de producción decerámica en la Cataluña de época medieval y moderna quenos permita ahondar en los problemas de fondo que dichasactividades plantean. Nuestro objetivo, pues, es poner sobrela mesa una reflexión acerca de la actividad alfarera y delmodelo de implantación de centros de producción en unterritorio determinado, así como a la propia evolución de loshornos durante los siglos medievales y modernos en aras deuna mayor adecuación técnica.[eng] During the last ten years, archaeological -mainly preventive- fieldwork allowed finding out some kilns from medieval and modern times that complete the panorama known until the end of 20th Century. Even though, it should be pointed out that a global state of the art about firing structures lacked for medieval and modern Catalonia. There is a strong need for some synthesis views making an effort to join results and exchange data in order to overcome the unavoidable localisms of emergency fieldwork for a better understanding of landscape occupation and craftsmanship strategies. Therefore, this paper aims to present a global -although non exhaustive- view on this matter in order to highlight some items concerning pottering activities, firing structures and workshops in Medieval and Modern Catalonia in order to deep into the main issues of such activities. Accordingly, our main goal is to propose some questions and reflexions for debate concerning pottery craftsmanship and its model of layout throughout the landscape; as well as the evolution of kilns during medieval and modern periods so as to achieve a better technical improvement. Within this piece of research, the location of this kind of manufacturing sites is discussed in order to detect some patterns of setting and developing throughout medieval and modern times, bearing in mind their rooting in the roman period. What we can observe is that there seems to be a continued process, with no interruption, that leads from the roman pottery producing centres, mainly specialized in amphorae production and settled on the Coastal Catalonian Plane, to the medieval cave-dwelling workshops specialized in reduced cooking wares. These inland settlements, deal with the production of specialized wares according to the new demand of these Centuries until social changes during the end of Middle Ages, gradually forced their disappearance in favour of new ways of pottery-making related to the new enhancement of cities and the improvement of urban world. To sum up, pottery production can be considered quite a good reflect of social changes and it points towards the way in what societies occupy the landscape and interact with the natural environment. From the archaeological standpoint, scholars are given a boost to approaching to this subject in a deep insight that globally considers this kind of sites as a whole. Furthermore, we spotlight the strong need of detailed excavation field-works in order to gather as much information as possible from these sites in order to understand the entire productive process, focusing in the excavation of kilns, but as well in workshops and annexe areas, which frequently are much complex

DC-Voltage-Ratio Control Strategy for Multilevel Cascaded Converters Fed With a Single DC Source

Recently, a multilevel cascaded converter fed with a single DC source has been presented. An analysis of the steady-state working limits of this type of converter is presented in this paper. Limits of the maximum output voltage and the minimum and maximum loading conditions for stable operation of the converter are addressed. In this paper, a way to achieve any DC voltage ratio (inside the stable operation area of the converter) between the H-bridges of the single-DC-source cascaded H-bridge converter is presented. The proposed DC-voltage-ratio control is based on a time-domain modulation strategy that avoids the use of inappropriate states to achieve the DC-voltage-ratio control. The proposed technique is a feedforward-modulation technique which takes into account the actual DC voltage of each H-bridge of the converter, leading to output waveforms with low distortion. In this way, the dc voltage of the floating H-bridge can be controlled while the output voltage has low distortion independently of the desired DC voltage ratio. Experimental results from a two-cell cascaded converter are presented in order to validate the proposed DC-voltage-ratio control strategy and the introduced concepts.Ministerio de Ciencia y Tecnología TEC2006-03863Junta de Andalucía EXC/2005/TIC-117