Search results for "Estructura"
showing 10 items of 368 documents
Characterization of a medium size Xe/TMA TPC instrumented with microbulk Micromegas, using low-energy gamma-rays
2014
NEXT-MM is a general-purpose high pressure (10 bar, $\sim25$ l active volume) Xenon-based TPC, read out in charge mode with an 8 cm $\times$8 cm-segmented 700 cm$^2$ plane (1152 ch) of the latest microbulk-Micromegas technology. It has been recently commissioned at University of Zaragoza as part of the R&D of the NEXT $0\nu\beta\beta$ experiment, although the experiment's first stage is currently being built based on a SiPM/PMT-readout concept relying on electroluminescence. Around 2 million events were collected during the last months, stemming from the low energy $\gamma$-rays emitted by a $^{241}$Am source when interacting with the Xenon gas ($\epsilon$ = 26, 30, 59.5 keV). The localized…
Present Status and Future Perspectives of the NEXT Experiment
2014
Gómez Cadenas, Juan José et al.
NEXT-100 Technical Design Report (TDR). Executive summary
2012
[EN] In this Technical Design Report (TDR) we describe the NEXT-100 detector that will search for neutrinoless double beta decay (ßß0v) in 136XE at the Laboratorio Subterráneo de Canfranc (LSC), in Spain. The document formalizes the design presented in our Conceptual Design Report (CDR): an electroluminescence time projection chamber, with separate readout planes for calorimetry and tracking, located, respectively, behind cathode and anode. The detector is designed to hold a maximum of about 150 kg of xenon at 15 bar, or 100 kg at 10 bar. This option builds in the capability to increase the total isotope mass by 50% while keeping the operating pressure at a manageable level. The readout pla…
Initial results of NEXT-DEMO, a large-scale prototype of the NEXT-100 experiment
2013
NEXT-DEMO is a large-scale prototype of the NEXT-100 detector, an electroluminescent time projection chamber that will search for the neutrinoless double beta decay of Xe-136 using 100-150 kg of enriched xenon gas. NEXT-DEMO was built to prove the expected performance of NEXT-100, namely, energy resolution better than 1% FWHM at 2.5MeV and event topological reconstruction. In this paper we describe the prototype and its initial results. A resolution of 1.75% FWHM at 511 keV (which extrapolates to 0.8% FWHM at 2.5 MeV) was obtained at 10 bar pressure using a gamma-ray calibration source. Also, a basic study of the event topology along the longitudinal coordinate is presented, proving that it…
Radiopurity control in the NEXT-100 double beta decay experiment: procedures and initial measurements
2013
[EN] The "Neutrino Experiment with a Xenon Time-Projection Chamber" (NEXT) is intended to investigate the neutrinoless double beta decay of Xe-136, which requires a severe suppression of potential backgrounds. An extensive screening and material selection process is underway for NEXT since the control of the radiopurity levels of the materials to be used in the experimental set-up is a must for rare event searches. First measurements based on Glow Discharge Mass Spectrometry and gamma-ray spectroscopy using ultra-low background germanium detectors at the Laboratorio Subterraneo de Canfranc (Spain) are described here. Activity results for natural radioactive chains and other common radionucl…
Optimal measurement setup for damage detection in piezoelectric plates
2009
[EN] An optimization of the excitation-measurement configuration is proposed for the characterization of damage in PZT-4 piezoelectric plates, from a numerical point of view. To perform such an optimization, a numerical method to determine the location and extent of defects in piezoelectric plates is developed by combining the solution of an identification inverse problem, using genetic algorithms and gradient-based methods to minimize a cost functional, and using an optimized finite element code and meshing algorithm. In addition, a semianalytical estimate of the probability of detection is developed and validated, which provides a flexible criterion to optimize the experimental design. Th…
ESTRUCTURAS ORGANIZATIVAS EN EMPRESAS DE INTERNACIONALIZACIÓN ACELERADA: EVIDENCIA EMPÍRICA
2014
Las pequeñas y medianas empresas internacionales pueden clasificarse en tradicionales, y empresas de internacionalización acelerada o born global. A pesar de que existe una variedad importante de investigaciones en el tema, ninguna ha establecido si existen diferencias entre la organización formal de una empresa de internacionalización acelerada y una empresa internacional tradicional. Mediante un estudio de casos a nivel comparativo, se establecen dos empresas internacionales tradicionales en la industria turística y de alimentos, y se analizan sus estructuras formales, con respecto a dos empresas en las mismas industrias con características de born global. Se determinan diferencias en los…
From entrepreneurial and innovation ecosystems to the social economy ecosystem
2023
Despite the broad academic and political interest aroused by the ecosystem concept, little scientific attention has been paid to its social dimension and especially to the social economy enterprises ecosystems. This paper aims to conceptualize the latter by establishing its defining features and its goals, and to provide empirical evidence from two worldwide known social economy ecosystems, one in the Valencia region of Spain and the other in the Emilia Romagna region of Italy. The results show that the balance between the economic objectives and the creation of social value and social innovation, collective social entrepreneurship and specific institutional components are key features of s…
Dimensionalidad De La Responsabilidad Social Empresarial Percibida Y Sus Efectos Sobre La Imagen Y La Reputación: Una Aproximación Desde El Modelo De…
2008
ResumenLa literatura de marketing sugiere que las acciones y programas de responsabilidad social empresarial podrían mejorar la imagen y la reputación de las empresas ante los ojos de sus consumidores y ser una importante fuente de ventaja competitiva para las mismas. Sin embargo, poco se sabe acerca las percepciones de estos stakeholders al respecto y sobre sus efectos en dichas variables. Para conocerlos, se llevó a cabo una revisión de la literatura, en donde se planteo un modelo teórico de relaciones estructurales el cual es contrastado empíricamente a través del análisis de su estructura de covarianzas. Para tal objetivo, se utiliza una muestra de 358 consumidores jóvenes de telefonía …
Dibujando una nueva cartografía de la colonialidad Sur-Norte en época de crisis: la reproducción de la episteme y el estilo de vida europeo en las mi…
2018
El artículo analiza la migración de cualificados españoles a los espacios de Educación Superior ecuatoriana desde 2010 a 2016, con el objetivo de entender la experiencia de movilidad cualificada española hacia Ecuador. Para ello se ha utilizado una metodología cualitativa a través de entrevistas semiestructuradas a españoles y ecuatorianos que trabajan en los espacios de la Educación Superior. Además, se ha complementado con encuestas online autoadministradas y con observación participante. Se concluye que entre España y Ecuador se han creado espacios de circularidad promovidos por un contexto de crisis económica en España y por una gran inversión en la Educación Superior ecuatoriana. Sin e…