5,583 research outputs found
Nuclear shape dependence of Gamow-Teller distributions in neutron-deficient Pb isotopes
We study Gamow-Teller strength distributions in the neutron-deficient even
isotopes (184-194)Pb in a search for signatures of deformation. The microscopic
formalism used is based on a deformed quasiparticle random phase approximation
(QRPA) approach, which involves a self-consistent quasiparticle deformed Skyrme
Hartree-Fock (HF) basis and residual spin-isospin forces in both the
particle-hole and particle-particle channels. By analyzing the sensitivity of
the Gamow-Teller strength distributions to the various ingredients in the
formalism, we conclude that the beta-decay of these isotopes could be a useful
tool to look for fingerprints of nuclear deformation.Comment: 20 pages, 11 figures. To be published in Physical Review
Local Structure of Cu2+ in the (C2H5NH3)2MCl4:Cu2+ (M: Cd, Mn) Layer Perovskites. Influence of Hydrostatic Pressure in the 0-60 kbar Range*
UniMOOC: colaborative work, innovating in education
Desde que en 2007-2008 se pusiera en práctica por vez primera la metodología MOOC (Cursos Abierto Online y Masivo), el proceso de innovación educativa se ha acelerado gracias a iniciativas tan potentes como Udacity, Coursera o MITx. Su impacto potencial en el mundo universitario y de la enseñanza en general han llevado a replantear el futuro de la educación a gran escala. El éxito de los MOOCs ha sido exponencial, desde los 50 matriculados en el curso de David Wiley sobre Educación Abierta (año 2007) hasta los más de 2.5 millones de inscritos en Coursera en 2012. Hasta este punto, se ha vivido un proceso de reafirmación y apuesta por el modelo tanto por parte de la sociedad como de las instituciones educativas de mayor prestigio en el mundo. A pesar de encontrarnos aun en un marco metodológico claramente experimental, ya nadie puede negar el éxito cosechado por los MOOCs y el previsible futuro que parece aguardarles. En este documento se presenta el caso UniMOOC como el primer MOOC para emprendedores en español, un proyecto que comienza a definirse en la primavera de 2012, y que cuenta con una proyección orientada a alcanzar los 60.000 alumnos en su primera edición.In 2007-2008 appeared for the very first time the MOOC phenomenon (Massive Open Online Course). Since then educational innovation process has accelerated due to initiatives like Udacity, Coursera or MITx. The potential impact of MOOCs in every educational grade has forced to rethink the future of universities and schools. The success of MOOCs has been exponential: the 2007 David Wiley's Open Education MOOC involved 50 students; in 2012 were more than 2.5 millions of courserians inscribed in at least one of the thousands MOOCs offered in Coursera. To gain the current success it has been necessary the society recognition and the support from the main educational institutions of the world. Nowadays the educational community is still in the first stage of the MOOC methodology, but what it has achieved in a few years aim to a favourable future. In this paper we present UniMOOC Project, like the first Spanish MOOC for entrepreneurships. This Project started to define in Spring of 2012, and it is projected to reach more than 60.000 users in its first edition
Tourism Growth and Economic Development: Academic and Non-Academic Perspectives
This article explores the complex relationship between tourism growth and economic development from academic and non-academic perspectives. The former mainly highlights the positive influence of tourism while recognizing biases and limitations that may arise from using different methodologies, variables, or temporary scenarios in research. However, non-academic stakeholders, such as the media and politicians, offer unverified and biased opinions that can influence public perceptions and lead to failed investments. This article provides recommendations to foster a balanced conversation between the two perspectives, with a broader dissemination of academic results and a recognition of the difficulties in analyzing the relationship between tourism and economic development, such as the mobility of stakeholders.This study has been carried out within the framework of the following research projects: "Digital Transition and Innovation in the Labor Market and Mature Sectors. Taking Advantage of AI and Platform Economy (DILATO)", with reference TED2021-129600A-I00 funded by MCIN/AEI /10.13039/501100011033 and by European Union Next GenerationEU/PRTR; and "Innovation and sustainability in tourism competitiveness after COVID-19" with reference TUR-RETOS2022-049 funded by MICT/SET and by European Union NextGenerationE
Economic crises and market performance—A machine learning approach
This note analyzes the relationship between economic crises and tourism performance in Spain during the period 1970–2013 using machine learning techniques. Specifically, a regression tree is estimated to confirm that, although the dynamics of Spanish tourism performance is influenced by the general variables established by the literature, the crisis periods disrupt the natural functioning of these dynamics, provoking disturbances that affect the tourism market position of destinations to a greater extent than expected. Conversely, to other econometric techniques, machine learning approach allows us to achieve greater flexibility and enriches the information, estimating the interrelations and thresholds operating in this context
Competitiveness and overtourism: a proposal for an early warning system in Spanish urban destinations
The tourism industry is undergoing accelerated changes that pose significant challenges for both destination and business managers as well as for researchers of the tourism phenomenon. Two of these challenges that are particularly relevant are the emergence of the sharing economy and its influence on the degree of overtourism perceived in the tourist destinations. This paper addresses the subject through the use of machine learning techniques. The findings show that machine learning techniques are especially well-suited tools for dealing with these kinds of tourism issues. The findings also show that for the Spanish case, tourism competitiveness is a key predictor of overtourism
Bioaccumulation of pharmaceuticals in moluscs and fishes from a Mediterranean coastal lagoon (Mar Menor SE Spain)
beta-decay in neutron-deficient Hg, Pb, and Po isotopes
The effect of nuclear deformation on the energy distributions of the
Gamow-Teller strength is studied in neutron-deficient Hg, Pb, and Po even
isotopes. The theoretical framework is based on a self-consistent deformed
Skyrme Hartree-Fock mean field with pairing correlations between like nucleons
in BCS approximation and residual spin-isospin interactions treated in the
proton-neutron quasiparticle random phase approximation. After a systematic
study of the Gamow-Teller strength distributions in the low excitation energy
region, relevant for beta-decay, we have identified the best candidates to look
for deformation signatures in their beta-decay patterns. beta+ half-lives and
total Gamow-Teller strengths B(GT+) and B(GT-) are analyzed as well.Comment: 18 pages, 7 figures, to appear in Phys. Rev.
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