A wide family of singularity-free cosmological models

In this paper a family of non-singular cylindrical perfect fluid cosmologies is derived. The equation of state corresponds to a stiff fluid. The family depends on two independent functions under very simple conditions. A sufficient condition for geodesic completeness is provided.Comment: 7 pages, RevTeX

Average power prediction in microcells

A propagation model to estimate the average received power in an urban microcell environment has been developed. This model can be used both in line of sight (LOS) and non line of sight (NLOS) conditions in any regular or irregular microcell structure.Peer ReviewedPostprint (published version

High-frequency collective excitations in molten and glassy Te studied by inelastic neutron scattering

7 págs.; 5 figs.; 1 tab. ; PACS number s : 61.25.Mv, 61.43.Er, 61.20.Lc, 61.12. qhttp://dx.doi.org/10.1103/PhysRevB.73.094201The spectra of collective excitations of liquid and glassy tellurium have been studied by means of inelastic neutron scattering. Here we report on the dynamics of liquid Te as measured at two different temperatures, just above melting (Tm =723 K) and at ∼1000 K as well as the glass that is studied at room temperature. Estimates for the velocity of propagating excitations for both temperatures have been obtained from the experimental data, and a contrasting behavior is found with respect to anomalies shown by the adiabatic sound velocity measured by ultrasound methods. The origin of such differences is finally discussed. © 2006 The American Physical Society.This work was supported in part by Grant No. MAT2002- 04178-C04 SpainPeer Reviewe

The reception in Spain of African literature written in English: Statistical data generation using the specialised bibliographic database BDÁFRICA

El presente artículo examina la recepción de la literatura africana en lengua inglesa en España basándonos en BDÁFRICA, una base de datos bibliográfica que recoge obras de autores nacidos en África y publicadas en español y en España entre 1972 y 2014. Se ofrece una reflexión crítica de las dificultades para definir la literatura africana como objeto de estudio, debido a su complejidad y heterogeneidad. Se propone, además, un conciso recorrido historiográfico por la conformación del canon de dicha literatura que se ha realizado desde Occidente. Asimismo, se demuestra la falta de estudios estadísticos sobre la recepción de literatura africana en lengua inglesa en España. Respondiendo a esta necesidad, el objetivo del artículo es detallar y analizar los datos estadísticos inéditos que proporciona la base de datos, adoptando una metodología descriptiva. Los resultados de este estudio, que aporta datos cuantitativos y cualitativos fiables y novedosos, son originales en tanto en cuanto reflejan y señalan los problemas de la traducción de la literatura africana en lengua inglesa en España. BDÁFRICA, que es gratuita y está disponible en red, pretende ser un recurso y una fuente que estimule el desarrollo de la investigación en literatura poscolonial en España. Sin duda, esta base de datos bibliográfica especializada es una herramienta muy valiosa, especialmente para investigadores, traductores y editoriales interesados en literatura africana.English translation of abstract: This paper explores the reception in Spain of African literature written originally in English by focusing on BDÁFRICA, a bibliographical database of works of fiction by African-born authors published in Spain, in Spanish between 1972 and 2014. It provides a critical reflection on the constraints of defining the object of study when African literature is discussed, due to the complexity and heterogeneity of such literature. It also proposes a concise historiographical journey through the Western canon formation of African literature in English. Additionally, it evidences the lack of quantitative studies on the reception in Spain of African literature in English. To cater to this need, the aim of this paper is to report and analyse the groundbreaking statistical data the database itself provides by following a descriptive approach. The findings of this study, which provides reliable and unprecedented quantitative and qualitative data, are original in the sense that they map and highlight the problems of the reception of African literature in English, and translated in Spain. This shows BDÁFRICA, which is free and available online, as a primary (re)source for work to pave the way for the development of postcolonial literature research in Spain. This specialised bibliographical database is undoubtedly an invaluable tool, especially for researchers, translators and publishing houses interested in African literature.Published versio

BDAFRICA: Design and implementation of a database of Postcolonial African literature published in Spain

Este trabajo demuestra que no existe un repositorio que incluya los autores poscoloniales africanos publicados hasta el momento en España y que permita, por ende, realizar estudios cuantitativos y cualitativos del impacto de esta literatura con la precisión deseable. Esto supone una carencia tanto para investigaciones académicas como para el sector editorial a la hora de analizar tendencias de selección y recepción en el mercado. Ante esta situación, el objetivo primordial de este trabajo es diseñar e implementar una base de datos, basada en MySQL y delimitada por unos parámetros muy concretos, que recoja todas las obras de autores africanos publicadas en castellano en España entre 1972 (año en que España se unió al sistema ISBN) y 2014. Tras determinar unos criterios de diseño y unos protocolos de compilación específcos, el desarrollo metodológico se ha dividido en cuatro fases: recopilación, almacenamiento, tratamiento y difusión de los datos. Así, la base de datos BDÁFRICA consigue un doble objetivo: por un lado, proporciona a los investigadores datos fables en los que basar sus estudios y, por otro, permitiría ofrecer por primera vez datos estadísticos de la evolución de la publicación de obras de autores africanos en España en los últimos 42 años.English version of abstract: This paper evidences the absence of a repository or database that scompiles the publications of Postcolonial African writing in Spain, thus precluding comprehensive quantitative or qualitative studies on the impact of these works. This is a significant obstacle for both academic research and the book market, which up to now has been unable to analyse market selection and reception trends. To cater for this need, the aim of this paper is to describe the design and implementation of a relational database, based on MySQL and set up using specific and accurate parameters, that includes all the literary works penned by African writers and published in Spain and in Spanish from 1972 (when Spain first joined the ISBN system) to 2014. After determining a number of specific design criteria and compilation protocols, the methodology has been divided into four steps: data collection, storage, statistical processing and online dissemination. Thus, the database BDAFRICA achieves a twofold objective: firstly, it provides researchers with unbiased data as a framework for their studies, and secondly, it offers unprecedented statistics on the evolution of the publication of African literature in Spain over the last 42 years.Published versio

Non-singular radiation cosmological models

In this paper we analyse the possibility of constructing singularity-free inhomogeneous cosmological models with a pure radiation field as matter content. It is shown that the conditions for regularity are very easy to implement and therefore there is a huge number of such spacetimes.Comment: 13 pages, LaTex, ws-mpla, to appear in Modern Physics Letters

Monitoring of an embankment dam in southern Spain based on Sentinel-1 Time-series InSAR

Sentinel-1A/B data were freely provided by ESA through Copernicus Programme. Data have been processed by SARPROZ (Copyright (c) 2009-2020 Daniele Perissin). The satellite orbits are from ESA Quality Control Group of Sentinel-1. Research was supported by: (a) ESA Research and Service Support for providing hardware resources employed in this work, (b) ReMoDams project ESP2017-89344-R (AEI/FEDER, UE) from Spanish Ministry of Economy, Industry and Competitiveness, PAIUJA-2019/2020 and CEACTEMA from University of Jaen (Spain), and RNM-282 research group from the Junta de Andalucia (Spain), (c) ERDF through the Operational Programme for Competitiveness and Internationalisation -COMPETE 2020 Programme within project >, and by National Funds through the FCT -Fundacao para a Ciencia e a Tecnologia (Portuguese Foundation for Science and Technology) as part of project UID/EEA/50014/2013, (d) The Ministry of Education, Youth and Sports from the National Programme of Sustainability (NPU II) project > (Czech Republic), and (e) Slovak Grant Agency VEGA under projects No. 2/0100/20.Deformation monitoring is a common practice in most of dams to ensure their structural health and safety status. Systematic monitoring is frequently carried out by means of geotechnical sensors and geodetic techniques that, although very precise an accurate, can be time-consuming and economically costly. Remote sensing techniques are proved to be very effective in assessing deformation. Changes in the structure, shell or associated infrastructures of dams, including adjacent slopes, can be efficiently recorded by using satellite Synthetic Aperture Radar Inteferometry (InSAR) techniques, in particular, Muti-Temporal InSAR time-series analyses. This is a mature technology nowadays but not very common as a routine procedure for dam monitoring. Today, thanks to the availability of spaceborne satellites with high spatial resolution SAR images and short revisit times, this technology is a powerful cost-effective way to monitor millimeter-level displacements of the dam structure and its surroundings. What is more, the potential of the technique is increased since the Copernicus C-band SAR Sentinel-1 satellites are in orbit, due to the high revisit time of 6 days and the free data availability. ReMoDams is a Spanish research project devoted to provide the deformation monitoring of several embankments dams using advances time-series InSAR techniques. One of these dams is The Arenoso dam, located in the province of Cordova (southern Spain). This dam has been monitored using Sentinel-1 SAR data since the beginning of the mission in 2014. In this paper, we show the processing of 382 SLC SAR images both in ascending and descending tracks until March 2019. The results indicate that the main displacement of the dam in this period is in the vertical direction with a rate in the order of -1 cm/year in the central part of the dam body.ESA Research and ServiceReMoDams project (AEI/FEDER, UE) from Spanish Ministry of Economy, Industry and Competitiveness ESP2017-89344-RCEACTEMA from University of Jaen (Spain)Junta de Andalucia European Commission RNM-282ERDF through the Operational Programme for Competitiveness and Internationalisation -COMPETE 2020 Programme POCI-01-0145FEDER-006961National Funds through the FCT -Fundacao para a Ciencia e a Tecnologia (Portuguese Foundation for Science and Technology) UID/EEA/50014/2013Ministry of Education, Youth and Sports from the National Programme of Sustainability (NPU II) project "IT4Innovations excellence in science" (Czech Republic) LQ1602Vedecka grantova agentura MSVVaS SR a SAV (VEGA) 2/0100/20PAIUJA-2019/202

Arqueología: imagen y proyección social

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