Errors in the measurement systems with the inclusion of single-phase loads at 220V in three-phase distribution networks

[EN] This research analyzes the problems presented by the measurement systems in one Phase three wires electrical distribution networks when single-phase loads are connected to 220V and proposes to replace the equation to eliminate the error that occurs in the energy meter. This case of study was given in Ecuador due to the massive inclusion of induction cookers through the change of the energy matrix promoted by the state since this account with more than 90 of hydroelectric energy to meet their electric demand. It is important to explain that this research does not include in the state of the art the problem and the solutions, because of this novelty was presented promptly in Ecuador due to the technical conditions of the energy distribution system, at the voltage level versus the construction voltage of the single-phase loads that in the case of induction, cookers were imported from countries that handle 220V single-phase voltages. This consequence does not present a choice, it is ethical for those responsible for the measurement systems of the Utility, to present a solution to the inconvenience of how it is developed in this investigation.This work was supported by Universitat Politectica de Valencia in Valencia (Spain), the Smart University 2.0 Research Group of the Universidad Catolica de Cuenca (Ecuador), and the Utility CENTROSUR for the data, equipment and laboratory to perform the tests (Ecuador).Toledo, MA.; Álvarez, C.; Morales, DX.; Arias, C. (2019). Errors in the measurement systems with the inclusion of single-phase loads at 220V in three-phase distribution networks. IEEE. 1-7. https://doi.org/10.1109/CHILECON47746.2019.8987564S1

Low carbon sink capacity of Red Sea mangroves

Mangroves forests of Avicennia marina occupy about 135 km2 in the Red Sea and represent one of the most important vegetated communities in this otherwise arid and oligotrophic region. We assessed the soil organic carbon (Corg) stocks, soil accretion rates (SAR; mm y-1) and soil Corg sequestration rates (g Corg m-2 yr-1) in 10 mangrove sites within four locations along the Saudi coast of the Central Red Sea. Soil Corg density and stock in Red Sea mangroves were among the lowest reported globally, with an average of 4 ± 0.3 mg Corg cm-3 and 43 ± 5 Mg Corg ha-1 (in 1 m-thick soils), respectively. Sequestration rates of Corg, estimated at 3 ± 1 and 15 ± 1 g Corg m-2 yr-1 for the long (millennia) and short (last century) temporal scales, respectively, were also relatively low compared to mangrove habitats from more humid bioregions. In contrast, the accretion rates of Central Red Sea mangroves soils were within the range reported for global mangrove forests. The relatively low Corg sink capacity of Red Sea mangroves could be due to the extreme environmental conditions such as low rainfall, nutrient limitation and high temperature, reducing the growth rates of the mangroves and increasing soil respiration rates

Structural and optical characterisation of planar waveguides obtained via sol-gel

8 páginas, 6 figuras, 1 tabla.-- Trabajo presentado a la "International Conference on Applications of Optics and Photonics" celebrada en Braga (Portugal) en Mayo del 2011.Planar waveguides of SiO2:TiO2 (multilayer structure) and SiO2:CeO2 (thick layer) were prepared onto commercial glass substrates using a sol-gel technique combined with dip-coating. These glassy coatings were structural characterised by Transmission Electron Microscopy (TEM) Energy Dispersive X-ray analysis and by Confocal Microscopy. Thicknesses of 1230 nm and 4,15 μm and refractive indices of 1.59 and 1.48 for SiO2:TiO2 (70:30) and SiO2:CeO2 (95:5) waveguides were obtained, respectively, by Spectroscopic Ellypsometry. Losses of 0.8 dB/cm were measured by double prism method in the SiO2:CeO2 system.The authors acknowledge funding from MICINN (TEC2006-10469, CEN 2007-2014, SURFALUX SOL-00030930 and MAT2010-18519), from DGA (Group of Excellence in Laser Material Processing and Characterisation) and XUNTA DE GALICIA (INCITE08PXIB206013PR).Peer reviewe

Ultraintense Femtosecond Magnetic Nanoprobes Induced by Azimuthally Polarized Laser Beams

We report a novel scheme to generate laser-induced, ultrafast, intense (Tesla scale), spatially isolated, magnetic fields. Three-dimensional particle-in-cell simulations show that a femtosecond azimuthally polarized infrared vector beam, aimed at a conducting circular aperture, produces an intense axially polarized tip-shaped femtosecond magnetic field, extending over micrometer distances and being isolated from the electric field. Our results are backed up by an analytic model, demonstrating the underlying physics and guiding for optimal parameters. In particular, we find the conditions under which the magnetic nanoprobe is substantially enhanced, reaching 4 T when driven by a 1011 W/cm2 laser field, which reflects a selective enhancement by a factor of ∼6. Our scheme offers a promising tool to control, probe, and tailor magnetic nanodomains in femtosecond time scales through pure magnetic interaction by using structured laser beams.The authors thank Luis López, Eduardo Martı́nez, and Victor J. Raposo for fruitful discussions. The authors thank the support from Ministerio de Economı́a y Competitividad (FIS2015-71933- REDT), Xunta de Galicia/ FEDER (ED431B 2017/64 and ED431E 2018/08), and Ministerio de Ciencia, Innovación y Universidades (EQC2018-0041 17-P). C.H.-G. acknowledges support from a 2017 Leonardo Grant for Researchers and Cultural Creators, BBVA Foundation. C.H.-G., E.C.J., and L.P. acknowledge support from Junta de Castilla y León (SA046U16, SA287P18) and Ministerio de Economı́a y Competitividad (FIS2016-75652-P). M.B. is funded by the FPU grant program of MECD. The authors acknowledge the OSIRIS Consortium, consisting of UCLA and IST (Lisbon, Portugal) for the use of OSIRIS, for providing access to the OSIRIS framework

!Agree Studio: a Platform to Edit and Validate Ws-Agreement Documents

The widespread use of SLA-regulated Cloud services, in which the violation of SLA terms may imply a penalty for the parties, have increased the importance and complexity of systems supporting the SLA lifecycle. Although these systems can be very different from each other, ranging from service monitoring platforms to auto-scaling solutions according to SLAs, they all share the need of having machine-processable and semantically valid SLAs. in this paper we present iAgree studio, the first application, up to our knowledge, that is able to edit and semantically validate agreement documents that are compliant with the WS–Agreement specification by checking properties such as its consistency, and the compliance between templates and agreement offers. in addition, it reports explanations when documents are not valid. Moreover, it allows users to combine the validation and explanation operations by means of a scenarios develope

Emprendimiento y creación de empresas: una perspectiva de estudiantes universitarios

Las actitudes y características personales de los emprendedores condicionan el tipo de emprendimiento que, a su vez, puede condicionar el éxito futuro de la empresa creada. Sobre esas actitudes y características se puede influir con diversas actuaciones que potencien el emprendimiento, siempre y cuando se ajusten previamente al perfil del sujeto sobre el que se actúa para obtener los resultados deseados. Este trabajo busca detectar los diferentes perfiles de los potenciales emprendedores, clasificarlos tanto por su actitud ante la creación de empresas como por sus características innovadoras, determinando los factores endógenos y exógenos que motivan sus comportamientos y que condicionarán el modo de actuar de todas aquellas instituciones que pretenden fomentar el espíritu emprendedor y la creación de tejido empresarial. Para ello, se realizó una encuesta sobre características personales y valoración del entorno a estudiantes de Administración y Dirección de empresas, entendiendo que en un futuro próximo van a estar en el mercado laboral, estableciendo o asesorando los emprendimientos, por lo que sus características probablemente indiquen muchas de las tendencias futuras

Phase matching effects in high harmonic generation at the nanometer scale

Plasmon resonances are known to amplify the electromagnetic fields near metallic nanostructures, providing a promising scheme to generate extreme-ultraviolet harmonics using low power drivings. During high-order harmonic generation (HHG), the driving and harmonic fields accumulate a phase difference as they propagate through the target. In a typical set-up –a laser focused into a gas jet– the propagation distances amount to several wavelengths, and the cumulative phase-mismatch affects strongly the efficiency and properties of the harmonic emission. In contrast, HHG in metallic nanostructures is considered to overcome these limitations, as the common sources of phase mismatch –optical density and focusing geometry– are negligible for subwavelength propagation distances. We demonstrate that phase matching still plays a relevant role in HHG from nanostructures due to the non-perturbative character of HHG, that links the harmonic phase to the intensity distribution of the driving field. Our computations show that widely used applications of phase matching control, such as quantum path selection and the increase of contrast in attosecond pulse generation, are also feasible at the nanoscale.Junta de Castilla y León (SA046U16) and MINECO (FIS2013-44174-P, FIS2016-75652-P, FIS2015-71933-REDT, SEV-2015-0522, FIS2013-46768-P, FIS2016-79508-P). M. Blanco is funded by FPU grant program of MECD. C. H.-G. is funded by Marie Curie International Outgoing Fellowship within the EU Seventh Framework Programme for Research and Technological Development (2007–2013), grant Agreement No. 328334. A. Chacón and M. Lewenstein also acknowledge support from Adv. ERC grant OSYRIS, Generalitat de Catalunya (SGR 874, CERCA Program), and Fundació Privada Cellex

Transformaciones de haz mediante microlentes selfoc activas

[EN]: In this paper light propagation in an active selfoc microlens with complex refractive index and gradient parameter are examined. The ray-transfer matrix of an active material regarded as a diffraction-free first order optical system is presented to describe the beam transformations in active selfoc microlenses. Results concerning Gaussian beam transformationsand on-axis irradiance through the active selfoc microlens are discussed and commented. © Sociedad Española de Óptica.[ES]: En este trabajo se estudia la propagación de la luz a través de una microlente selfoc activa con un índice de refracción y parámetro de gradiente complejos. La matriz de transferencia de rayos, vista como un sistema óptico de primer orden libre de efectos de difracción, es introducida para describir las transformaciones que puede sufrir un haz en microlentes selfoc activas. Por último se presentan y comentan los resultados correspondientes a las transformaciones de haces Gaussianos y a la irradiancia en eje a través de la microlente selfoc activa.This work has been sponsored by Xunta de Galicia/Feder (INCITE08PXIB206013PR), Ministerio de Ciencia e Innovación (MAT2010-18519) and CDTI (SURFALUX SOL-00030930), Spain. Besides, Ana I. Gomez-Varela wants to acknowledge the financial support from the FPU (Formación de Profesorado Universitario) grant 2009 (Ministerio de Educación, Spain).Peer Reviewe

Deficits in executive functions but not in decision making under risk in individuals with problematic social-network use.

Background: The tendency to strive for immediate gratification by neglecting potential negative long-term outcomes characterizes addictive behaviors, such as substance use or gaming disorder. Problematic socialnetwork use is currently discussed as another potential addictive behavior, which is considered to result from an imbalance between affective and cognitive processes, indicated by traits such as increased impulsivity and/ or decreased executive functions and decision-making abilities. Methods: This study investigates the respective functions in social-network users by use of the Cards and Lottery Task (CLT) – a decision-making task under risk conditions in which options contain conflicting immediate and long-term outcomes at the same time. A sample of German and Spanish participants (N = 290) performed the CLT aswell as the Modified Card Sorting Test (MCST), Barratt Impulsiveness Scale (BIS), the short Internet Addiction Test specified for social-networking (sIAT-SNS), and screeners on other potentially problematic behaviors. Results: Comparing extreme groups based on sIAT-SNS scores (1SD above/below mean), individuals with problematic social-network use (n = 56), as compared to those with non-problematic social-network use (n = 50), showed increased attentional impulsivity and reduced executive functions. No differences were observed in decision-making performance. Conclusion: The findings indicate that problematic social-network use is related to attentional rather than general decision-making deficits. Furthermore, problematic social-network use is likely to co-occurwith other problematic Internet-use behaviors, particularly gaming or shopping.pre-print455 K