Search results for "Estructura"
showing 10 items of 368 documents
Dry Mechanochemical Synthesis of Highly Luminescent, Blue and Green Hybrid Perovskite Solids
2019
A simple method to obtain bright photoluminescent wide bandgap mixed‐halide 3D perovskites is reported. The materials are prepared by dry mechanochemical synthesis (ball‐milling) starting from neat binary precursors, and show enhanced photoluminescence upon the addition of an adamantane derivative in the precursors' mixture. The structural characterization suggests that the additive does not participate in the crystal structure of the perovskite, which remains unvaried even with high loading of amantadine hydrochloride. By simple stoichiometric control of the halide precursors, the photoluminescence can be finely tuned from the UV to the green part of the visible spectrum. Photoluminescence…
Operation and first results of the NEXT-DEMO prototype using a silicon photomultiplier tracking array
2013
NEXT-DEMO is a high-pressure xenon gas TPC which acts as a technological test-bed and demonstrator for the NEXT-100 neutrinoless double beta decay experiment. In its current configuration the apparatus fully implements the NEXT-100 design concept. This is an asymmetric TPC, with an energy plane made of photomultipliers and a tracking plane made of silicon photomultipliers (SiPM) coated with TPB. The detector in this new configuration has been used to reconstruct the characteristic signature of electrons in dense gas, demonstrating the ability to identify the MIP and "blob" regions. Moreover, the SiPM tracking plane allows for the definition of a large fiducial region in which an excellent e…
Pulsed-field studies of the magnetization reversal in molecular nanomagnets
2004
We report experimental studies of crystals of Mn12 molecular magnetic clusters in pulsed magnetic fields with sweep rates up to 4x10^3 T/s. The steps in the magnetization curve are observed at fields that are shifted with respect to the resonant field values. The shift systematically increases as the rate of the field sweep goes up. These data are consistent with the theory of the collective dipolar relaxation in molecular magnets.
The next generation nuclear instruments: AGATA and NEDA, and nuclear structure studies near N=Z line
2017
The first part of this thesis is devoted to the development of a large array of neutron detectors NEDA (NEutron Detector Array) and their conceptual design using Monte-Carlo simulations. Prior to the development of NEDA, the neutron detection with liquid scintillators is discussed in Chapter 2. In Chapter 3, the design criteria and simulations of NEDA are discussed. NEDA aims to build a neutron detector array with high efficiency, based on liquid scintillators. NEDA will be coupled to the high-purity γ-ray detector arrays, like AGATA, EXOGAM, to be used as a trigger or complementary detector in the contemporary nuclear physics experiments, which aim to investigate the structure of the exoti…
Twisted-Light-Ion Interaction: The Role of Longitudinal Fields.
2017
The propagation of light beams is well described using the paraxial approximation, where field components along the propagation direction are usually neglected. For strongly inhomogeneous or shaped light fields, however, this approximation may fail, leading to intriguing variations of the light-matter interaction. This is the case of twisted light having opposite orbital and spin angular momenta. We compare experimental data for the excitation of a quadrupole transition in a single trapped $^{40}$Ca$^+$ ion by Schmiegelow et al, Nat.\ Comm.\ 7, 12998 (2016), with a complete model where longitudinal components of the electric field are taken into account. Our model matches the experimental d…
Arte funerario y astrología: La Pira de Luis I
1991
LOS FUNERALES DE EPOCAS ANTIGUAS TENDIERON A USAR ELOCUENTES IMAGENES ASTROLOGICAS QUE HACEN REFERENCIA AL MAS ALLA. EL ARTICULO ANALIZA EL CATAFALCO DE LUIS I (1724), PRIMERA EXHIBICION COMPLETA DE IMAGENES ASTROLOGICAS EN EL ARTE EFIMERO DEL MEXICO COLONIAL. (A.B.C./ L.A.G.)
Más allá del acero: Otros metales y sus usos en la arquitectura del siglo XXI
2009
[ES] El protagonismo que ostentan los metales como compuestos básicos para el desenvolvimiento cotidiano de la vida humana resulta evidente e irrefutable. Del mismo modo que una mayoría de las actividades diarias que realizamos serían imposibles sin el apoyo que nos brinda el metal, un amplio porcentaje de la arquitectura de la última centuria también hace descansar sus fundamentos en la solidez de una estructura metálica. Más allá del hierro como predecesor y del acero como digno sucesor, la constructiva recurre asimismo con asiduidad a otros metales para conformar con ellos la imagen final del edificio, redundando en ésta componentes tanto técnicos como expresivos de los que son responsab…