107 research outputs found
Chiral plasma instability and primordial Gravitational wave
It is known that cosmic magnetic field, if present, can generate anisotropic
stress in the plasma and hence, can act as a source of gravitational waves.
These cosmic magnetic fields can be generated at very high temperature, much
above electroweak scale, due to the gravitational anomaly in presence of the
chiral asymmetry. The chiral asymmetry leads to instability in the plasma which
ultimately leads to the generation of magnetic fields. In this article, we
discuss the generation of gravitational waves, during the period of
instability, in the chiral plasma sourced by the magnetic field created due to
the gravitational anomaly. We have shown that such gravitational wave will have
a unique spectrum. Moreover, depending on the temperature of the universe at
the time of its generation, such gravitational waves can have a wide range of
frequencies. We also estimate the amplitude and frequency of the gravitational
waves and delineate the possibility of its detection by future experiments like
eLISA.Comment: 8 pages, 2 figure
The National Immigrant Survey of Spain. A new data source for migration studies in Europe
Spain has recently become the destination for large numbers of international migrants and now ranks as a key focal point for international migration in Europe. Currently, approximately one in ten residents in Spain are foreigners, up more than tenfold from figures holding at the outset of this century. Migration has now become a major social and political issue in the country. In order to provide reliable data about migrants in Spain for researchers and policy makers, acting on a proposal of a research team working within the context of the Population and Society Research Network (GEPS), the Spanish Statistical Office has recently carried out an extremely ambitious survey of foreign-born persons currently living in Spain. In the course of the survey, nearly 15,500 persons were interviewed regarding a large array of issues pertaining to their migration experience. Important documentation, including the project report, the methodological specifications of the survey, and the anonymized micro data have recently been made available to the scientific community and to policy makers at the website of the Instituto Nacional de EstadĂstica. The purpose of this paper is to describe this data source, its content, its methodological underpinnings, and the way the fieldwork and data cleaning were carried out. Examples of preliminary results will be presented so as to underscore the potential this survey affords for researchers everywhere.immigrant survey, international migration, migrant strategies, migration data set, migration studies, migratory networks, Spain
Assessing the Competitive Behaviour of Firms in the Single Market: A Micro-based Approach
This Report analyses and compares a number of indicators related to the evolution of the competitive behaviour of firms in the Single Market, from 1999 to 2007, in a selected number of both manufacturing and services industries and eight EU countries: Belgium, Germany, France, Italy, Poland, Romania, Spain and Sweden. A novelty of the approach is that the analysis is derived from firm-level observable data, which allow to grasp not only information on the average changes taking place in each industry and across countries, but also the distribution and sources of these changes in terms of individual firms' pricing behaviour and market shares, an information which is impossible to gather in detail from aggregate, traditional sector-level measure
Assessing the Competitive Behaviour of Firms in the Single Market: A Micro-based Approach
This Report analyses and compares a number of indicators related to the evolution of the competitive behaviour of firms in the Single Market, from 1999 to 2007, in a selected number of both manufacturing and services industries and eight EU countries: Belgium, Germany, France, Italy, Poland, Romania, Spain and Sweden. A novelty of the approach is that the analysis is derived from firm-level observable data, which allow to grasp not only information on the average changes taking place in each industry and across countries, but also the distribution and sources of these changes in terms of individual firms' pricing behaviour and market shares, an information which is impossible to gather in detail from aggregate, traditional sector-level measure
Assessing the Competitive Behaviour of Firms in the Single Market: A Micro-based Approach
This Report analyses and compares a number of indicators related to the evolution of the competitive behaviour of firms in the Single Market, from 1999 to 2007, in a selected number of both manufacturing and services industries and eight EU countries: Belgium, Germany, France, Italy, Poland, Romania, Spain and Sweden. A novelty of the approach is that the analysis is derived from firm-level observable data, which allow to grasp not only information on the average changes taking place in each industry and across countries, but also the distribution and sources of these changes in terms of individual firms' pricing behaviour and market shares, an information which is impossible to gather in detail from aggregate, traditional sector-level measures.european union,eu,setzer,wolff,van den Noord,euro area,money,heterogeneity,money holdings
A lingvisztikai-orális és a vizuális kommunikáció néhány összefüggése
Ferdinand de Saussure (1) svájci nyelvĂ©sz munkássága nemcsak a nyelvtudomány Ă©s a nyelv termĂ©szetĂ©re vonatkozĂł gondolkodás törtĂ©netĂ©ben jelentett fordulatot, hanem erĹ‘teljesen hatott a szemiotika mint önállĂł diszciplĂna (ki)fejlĹ‘dĂ©sĂ©re is. Legnagyobb Ă©rdeme, hogy a nyelvet rendszerkĂ©nt fogta fel Ă©s vizsgálta, továbbá a nyelvi jelensĂ©g jobb megĂ©rtĂ©se Ă©rdekĂ©ben bevezette a ’langue’, ’langage’ Ă©s ’parole’ fogalmakat
A felsőfokú szakképzés helyzete az oktatási rendszerben Franciaországban és Magyarországon
Egy kĂ©pzĂ©stĂpus mindig az adott ország kĂ©pzĂ©si struktĂşrájába beágyazott, saját tradĂciĂłkkal rendelkezĹ‘ entitás. Az eurĂłpai uniĂłs felsĹ‘oktatási tĂ©rsĂ©g kialakulásával párhuzamosan nem szűnnek Ă©s szűntek meg teljesen a nemzeti sajátosságok: a kĂĽlönbözĹ‘ rendszerek egymás mellett Ă©lĂ©sĂ©nek Ă©kes bizonyĂtĂ©kát kapjuk, ha az egyetemi szintű kĂ©pzĂ©sek nulladik fokának is tekintett felsĹ‘fokĂş szakkĂ©pzĂ©s rendszerĂ©t vizsgáljuk, amely az oktatás egysĂ©ges nemzetközi osztályozási rendszerĂ©ben (ISCED) az 5B szinten helyezkedik el
Synthèse sur la modélisation thermo-hygro-aéraulique des bâtiments dans l’Annexe 41 de l’Agence Internationale de l’Energie
IMPACT DE LA POLLUTION URBAINE SUR LES MATÉRIAUX DU PATRIMOINE CULTUREL
10 p. (version du 9 juin 2006, mis en forme)National audienceQu'il soit extrait d'une carrière ou produit industriellement, un matériau est soumis à l'action de l'environnement dès sa mise en oeuvre. Ce sont les interactions successives entre l'environnement et le matériau qui vont entraîner un changement de son aspect et de ses caractéristiques. En d'autres termes, le matériau subit une altération c'est-à -dire un vieillissement. Dans un premier temps, les interactions matériaux-atmosphères créent des modifications qui intéressent la surface du matériau. Par la suite, l'altération progresse vers la profondeur entraînant ainsi une perte de matière plus conséquente. La progression de l'altération dépend des propriétés intrinsèques du matériau et de l'agressivité du milieu. Généralement, un environnement urbain montre des concentrations fortes en polluants gazeux et particulaires. Les gaz sont capables de générer des acides plus ou moins forts qui vont interagir avec le substrat entraînant une perte de matière par dissolution ou bien la formation d'encroûtement. Quant aux particules, elles peuvent catalyser des réactions de sulfatation, favoriser la fixation d'eau ou encore entraîner par leur dépôt un noircissement progressif des façades. Ces altérations engendrent des coûts d'entretien et de restauration considérable qui préoccupent de plus en plus les pouvoirs publics. Des normes en matière de qualité de l'air ont été fixées pour la santé et les écosystèmes mais restent à établir pour la préservation des matériaux du patrimoine culturel. Par ailleurs, la formulation par les industriels de matériaux à encrassement réduit trouvera certainement des applications dans le domaine de la conservation des matériaux du patrimoine
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