Técnicas avanzadas de medida de dispersión cromática a frecuencias ópticas

La fibra óptica a pesar de tener buenas propiedades, también presenta limitaciones, una de estas limitaciones es la dispersión. La dispersión es un fenómeno que introduce un retardo diferente a cada una de las componentes espectrales que se transmiten por la fibra óptica. Este proyecto esta basado en el estudio de este fenómeno y la medida del mismo a partir de métodos conocidos y propuestas de mejoras de estos. Se realiza un estudio matemático genérico del esquema básico de medida que tiene en cuenta todos los parámetros que pueden controlarse de forma externa, con el objetivo de identificar nuevos métodos de medida usando el mismo esquema experimental básico. Además, se monta en el laboratorio y se automatiza uno de los procesos básicos para la realización de las medidas, la determinación de la función de transferencia del modulador Mach-Zehnde

Organisational learning capability, product innovation performance and export intensity

The hypothesis that managerial characteristics which facilitate the organisational learning process can provide firms with a basis for competitive advantage has received a great deal of attention. While there is evidence that organisational learning affects export intensity, we argue that intermediate variables, such as innovation, should be used in order to evaluate its impact in organisations. This study shows that firms with a higher organisational learning capability tend to be more innovative, and for this reason, they are more likely to export a higher share of their production. From a longitudinal perspective, we use structural equation modeling on a database from Italian and Spanish ceramic tile producers, worldwide leaders in terms of technology. The database combines primary and secondary data. The results support our theoretical conjectures. Findings improve our understanding of the antecedents of export intensity and are related to previous research

SHARDS: A global view of the star formation activity at z~0.84 and z~1.23

In this paper, we present a comprehensive analysis of star-forming galaxies (SFGs) at intermediate redshifts (z~1). We combine the ultra-deep optical spectro-photometric data from the Survey for High-z Absorption Red and Dead Sources (SHARDS) with deep UV-to-FIR observations in the GOODS-N field. Exploiting two of the 25 SHARDS medium-band filters, F687W17 and F823W17, we select [OII] emission line galaxies at z~0.84 and z~1.23 and characterize their physical properties. Their rest-frame equivalent widths (EW$_{\mathrm{rf}}$([OII])), line fluxes, luminosities, star formation rates (SFRs) and dust attenuation properties are investigated. The evolution of the EW$_{\mathrm{rf}}$([OII]) closely follows the SFR density evolution of the universe, with a trend of EW$_{\mathrm{rf}}$([OII])$\propto$(1+z)$^3$ up to redshift z~1, followed by a possible flattening. The SF properties of the galaxies selected on the basis of their [OII] emission are compared with complementary samples of SFGs selected by their MIR and FIR emission, and also with a general mass-selected sample of galaxies at the same redshifts. We demonstrate observationally that the UVJ diagram (or, similarly, a cut in the specific SFR) is only partially able to distinguish the quiescent galaxies from the SFGs. The SFR-M$_*$ relation is investigated for the different samples, yelding a logarithmic slope ~1, in good agreement with previous results. The dust attenuations derived from different SFR indicators (UV(1600), UV(2800), [OII], IR) are compared and show clear trends with respect to both the stellar mass and total SFR, with more massive and highly star-forming galaxies being affected by stronger dust attenuation.Comment: Replaced to match the accepted version (24 pages, 1 table, 17 figures). Published in ApJ, 812, 155 (2015): http://stacks.iop.org/0004-637X/812/15

Democracia, financiarización y neoextraccionismo ante los desafíos de la industrialización y el mercado de trabajo

Uno de los desafíos del a democracia es la logran transformación a raíz del proceso de financiarización y su crisis, la alternativa ha sido reformas económicas y planes de austeridad que han socavado en empleo

Evaluation of turbulent dissipation rate retrievals from Doppler Cloud Radar

Turbulent dissipation rate retrievals from cloud radar Doppler velocity measurements are evaluated using independent, in situ observations in Arctic stratocumulus clouds. In situ validation data sets of dissipation rate are derived using sonic anemometer measurements from a tethered balloon and high frequency pressure variation observations from a research aircraft, both flown in proximity to stationary, ground-based radars. Modest biases are found among the data sets in particularly low- or high-turbulence regimes, but in general the radar-retrieved values correspond well with the in situ measurements. Root mean square differences are typically a factor of 4-6 relative to any given magnitude of dissipation rate. These differences are no larger than those found when comparing dissipation rates computed from tetheredballoon and meteorological tower-mounted sonic anemometer measurements made at spatial distances of a few hundred meters. Temporal lag analyses suggest that approximately half of the observed differences are due to spatial sampling considerations, such that the anticipated radar-based retrieval uncertainty is on the order of a factor of 2-3. Moreover, radar retrievals are clearly able to capture the vertical dissipation rate structure observed by the in situ sensors, while offering substantially more information on the time variability of turbulence profiles. Together these evaluations indicate that radar-based retrievals can, at a minimum, be used to determine the vertical structure of turbulence in Arctic stratocumulus clouds

Conocimiento sobre lesiones dentales traumáticas en docentes de educación primaria en escuelas públicas del distrito de “Villa Maria del Triunfo” Lima – Perú 2017

Evalúa el conocimiento sobre lesiones dentales traumáticas en docentes de educación primaria, para lo cual se utilizó como instrumento de recolección de datos una encuesta dirigida a 274 docentes de educación primaria de 14 escuelas públicas del distrito de Villa María del Triunfo. Encontrándose que el 46% de los docentes presentaron un conocimiento aceptable, según sus dimensiones se obtuvo que el conocimiento sobre lesiones de tejido blando y fractura dental fue aceptable (42% y 54% respectivamente) mientras que el conocimiento sobre movilidad y avulsión dental fue insuficiente (47.1% para ambos casos). Así mismo se relacionó el conocimiento y el género de los docentes, obteniendo que el conocimiento es distinto entre hombres y mujeres, y aparentemente las mujeres poseen mejor conocimiento; sin embargo, en la asociación del conocimiento en relación con la edad de los docentes, el conocimiento previo y los años de experiencia docente no se obtuvo diferencias significativas. Por otro lado, los docentes consideran necesario el tratamiento inmediato ante una lesión traumática dental y consideran que el especialista más adecuado es el odontopediatra; sin embargo, no están satisfechos con el conocimiento actual que poseen y ven necesario la capacitación acerca de este tema.Tesi

NEXT-100 Technical Design Report (TDR). Executive Summary

In this Technical Design Report (TDR) we describe the NEXT-100 detector that will search for neutrinoless double beta decay (bbonu) in Xe-136 at the Laboratorio Subterraneo 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 plane performing the energy measurement is composed of Hamamatsu R11410-10 photomultipliers, specially designed for operation in low-background, xenon-based detectors. Each individual PMT will be isolated from the gas by an individual, pressure resistant enclosure and will be coupled to the sensitive volume through a sapphire window. The tracking plane consists in an array of Hamamatsu S10362-11-050P MPPCs used as tracking pixels. They will be arranged in square boards holding 64 sensors (8 times8) with a 1-cm pitch. The inner walls of the TPC, the sapphire windows and the boards holding the MPPCs will be coated with tetraphenyl butadiene (TPB), a wavelength shifter, to improve the light collection.Comment: 32 pages, 22 figures, 5 table