724 research outputs found
The reaction in coupled channel chiral models up to next-to-leading order
We study the meson-baryon interaction in S-wave in the strangeness S=-1
sector using a chiral unitary approach based on a next-to-leading order chiral
SU(3) Lagrangian. We fit our model to the large set of experimental data in
different two-body channels. We pay particular attention to the reaction, where the effect of the next-to-leading order
terms in the Lagrangian are sufficiently large to be observed, since at tree
level the cross section of this reaction is zero. For these channels we improve
our approach by phenomenologically taking into account effects of the high spin
hyperonic resonances.Comment: 8 pages, 4 figures, presented at the II Russian-Spanish Congress
"Particle and Nuclear Physics at all Scales and Cosmology", Saint-Petersburg,
October 1-4, 2013. arXiv admin note: text overlap with arXiv:1311.5025; and
with arXiv:hep-ph/0505239 by other author
Minhocas como indicadoras da fertilidade do solo.
Numa área da cordilheira dos Andes se avaliaram diversos parâmetros socioeconômicos e variáveis do solo para verificar suas relações com os processos de transformação da cobertura vegetal e dos usos do solo, e construir possÃveis indicadores do panorama atual após aprox. 120 anos de colonização e perturbação dos ecossistemas colombianos. Se realizaram entrevistas aos agricultores para obter a informação socioeconômica. Em nove janelas selecionadas ao azar, se amostraram algumas variáveis fÃsico-quÃmicas do solo e as comunidades de minhocas em 22 usos do solo. Encontraram-se fortes relações entre produtores com maiores ingrsesos econômicos, alto nÃvel de educação, maior perturbação do solo, solos compactados, e alto uso de fertilizantes. Nas propriedades menores os agricultores tinham menores ingressos e egressos de dinheiro e nÃvel mais baixo de educação, e essas propriedades tinham maiores teores de matéria orgânica, maior riqueza de espécies de minhocas, e os solos estavam menos compactados. Demonstrou-se a importância do trabalho com enfoques interdisciplinares no processo de construção de indicadores, e destacou-se o valor das ferramentas desenvolvidas para predizer a condição atual dos agroecossistemas e a qualidade do solo.Resumo expandido
Las fechas de 'El Faetonte', de Calderón
El objetivo del presente artÃculo es estudiar la controvertida fecha de composición y estreno de 'El Faetonte' y otras comedias relacionadas. En el trabajo se revisa igualmente la fortuna escénica de la pieza posterior a la primera representación, contexto en el que se presta especial atención al segundo montaje de la comedia en vida de Calderón, que ha suscitado debate entre la crÃtica ante la posibilidad de que el propio dramaturgo pudiera haber revisado el texto.
The aim of this paper is to study the date of composition and first performance of El Faetonte and related plays.The paper also examines the staging of the play after the first representation. In this context special attention is given to the second performance of 'El Faetonte' for which the playwright could have modified the original play
Correlation function for the state: Determination of the binding, scattering lengths, effective ranges and molecular probabilities
We perform a study of the correlation functions using
an extension of the local hidden gauge approach which provides the interaction
from the exchange of light vector mesons and gives rise to a bound state of
these components in with a binding energy of about ~MeV. After that,
we face the inverse problem of determining the low energy observables,
scattering length and effective range for each channel, the possible existence
of a bound state, and, if found, the couplings of such a state to each
component as well as the molecular probabilities of each
of the channels. We use the bootstrap method to determine these magnitudes and
find that, with errors in the correlation function typical of present
experiments, we can determine all these magnitudes with acceptable precision.
In addition, the size of the source function of the experiment from where the
correlation functions are measured can be also determined with a high
precision.Comment: 7 pages, 3 figure
Analyzing the impact of demand response and reserves in islands energy planning
Small Islands usually rely on fossil fuels for their energy supply and face common challenges such as high energy costs and carbon dioxide emissions. For these reasons they represent interesting cases for analysing the transition towards a clean and secure energy system. Nevertheless, integrating non-dispatchable Renewable Energy Sources in the power grid causes stability issues and this is particularly true for island grids. Such issue is not fully considered in long-term energy planning; indeed, an important factor that should be considered in order to ensure the reliability of the grid are Reserves. There are different types of Reserves depending on the reactiveness/response time and the duration of the service. In this paper, primary and secondary reserves have been analysed in order to plan the long-term energy transition of the small island of Favignana, Italy by means of the new version of H2RES, a Linear Programming single-objective optimisation model able to provide a long-term capacity investment and dispatching optimisation. It has been found that biomass generators are favoured to both photovoltaic and wind turbines for their ability to provide reserves and also decrease the unpredictability of the supply. Batteries and Electrolysers are also used mostly for reserve provision
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