Pulsations in M dwarf stars

We present the results of the first theoretical non-radial non-adiabatic pulsational study of M dwarf stellar models with masses in the range 0.1 to 0.5M_solar. We find the fundamental radial mode to be unstable due to an \epsilon mechanism caused by deuterium (D-) burning for the young 0.1 and 0.2M_solar models, by non-equilibrium He^3 burning for the 0.2 and 0.25M_solar models of 10^4Myr, and by a flux blocking mechanism for the partially convective 0.4 and 0.5M_solar models once they reach the age of 500Myr. The periods of the overstable modes excited by the D-burning are in the range 4.2 to 5.2h for the 0.1M_solar models and is of order 8.4h for the 0.2M_solar models. The periods of the modes excited by He^3 burning and flux blocking are in the range 23 to 40min. The more massive and oldest models are more promising for the observational detection of pulsations, as their ratio of instability e-folding time to age is more favourable.Comment: 5 pages, 4 figures, 2 tables. Accepted for publication in MNRAS Letters on 2011 October 11 Version 2 is the accepted manuscript with changes in boldfac

Contribución al estudio de la historia de Béjar : colección de estudios y documentos

Copia digital. Valladolid : Junta de Castilla y León. Consejería de Cultura y Turismo, 2009-201

Luminescent rare-earth-doped up-converting nanoparticles for Cr3+ sensing in water

Water contamination by heavy metals poses a significant threat to human health and to the environment. Cr3+is a common contaminant in aqueous media; therefore, innovative sensing technologies for reliable detection are in demand. In this study, we demonstrate that NaGdF4: Yb3+, Er3+up-converting nanoparticles can be used as ratiometric luminescence probes to detect low concentrations of Cr3+contaminating ions in water. Excitation in the near-infrared region provides a fluorescence-based detection method with large depth penetration and is autofluorescence-free. Based on this ability, a paper-based sensor was manufactured in which the incorporated up-converting nanoparticles allowed a limit of detection of Cr3+ion concentrations as low as 2 nM. This represents a new step towards the practical application of rare-earth-doped nanoparticles in environmental monitoring, addressing the critical need for efficient detection methods of contaminating ions in waterPID2020-118878RB-I00, PID2019-106211RB-I0

Prevalencia de artritis séptica neonatal en un hospital universitario

Introducción: La artritis séptica neonatal es un padecimiento poco común que se ha relacionado con recién nacidos internados en la unidad de cuidados intensivos neonatal, cuyo principal factor de riesgo es el uso previo de catéter central. Objetivo: establecer la prevalencia de la artritis séptica neonatal en nuestro Hospital. Material y método: estudio observacional descriptivo de prevalencia. Se incluyeron todos los recién nacidos con diagnostico de artritis séptica neonatal internados un la unidad de cuidados intermedios e intensivos neonatal del Hospital Universitario Dr. José Eleuterio González del año 2003 al 2007. Se revisaron los expedientes y se registraron variables generales, factores de riesgo, bacteriología y mortalidad. Resultados: Se diagnosticaron 26 casos de artritis séptica neonatal durante el periodo de tiempo estudiado, solo 20 casos lograron criterios de inclusión: la prevalencia fue de 1.2 casos por cada 1,000 nacidos. La edad gestacional fue 39.2 ± 1.3 semanas, con peso 3193 ± 709 g. El factor de riesgo que se presento con mas frecuencia fue el antecedente de uso previo de catéter en 75% de los casos. Se aisló microorganismo en 80% de los casos, los bacterias grampositivas se aislaron en 80% de los casos; el Staphylococcus aureus fue el microorganismo aislado predominantemente en 75% de los casos. La presentación poliarticular fue en 40% de los casos. La mortalidad fue de 0%. Conclusiones: La prevalencia fue menor a lo reportado en la literatura. Los microorganismos grampositivos continúan siendo los microorganismos predominantes en la artritis séptica neonatal. La mortalidad es baja

Design of a Low-Cost Multiplexer for the Study of the Impact of Soiling on PV Panel Performance

Atmospheric factors, such as clouds, wind, dust, or aerosols, play an important role in the power generation of photovoltaic (PV) plants. Among these factors, soiling has been revealed as one of the most relevant causes diminishing the PV yield, mainly in arid zones or deserts. The effect of soiling on the PV performance can be analyzed by means of I–V curves measured simultaneously on two PV panels: one soiled and the other clean. To this end, two I–V tracers, or one I–V tracer along with a multiplexer, are needed. Unfortunately, these options are usually expensive, and only one I–V tracer is typically available at the site of interest. In this work, the design of a low-cost multiplexer is described. The multiplexer is controlled by a low-cost single-board microcontroller manufactured by ArduinoTM, and is capable of managing several pairs of PV panels almost simultaneously. The multiplexer can be installed outdoors, in contrast to many commercial I–V tracers or multiplexers. This advantage allows the soiling effect to be monitored on two PV panels, by means of I–V indoor tracers. I–V curves measured by the low-cost multiplexer are also presented, and preliminary results are analyzedThis research was funded by the Spanish Ministry of Economy, Industry, and Competitiveness “PVCastSOIL” project No ENE2017-83790-C3-1-2-3-R, in collaboration with the European Regional Development Fun

Waves and structure interaction using multi-domain couplings for Navier-Stokes solvers in OpenFOAM®. Part II: Validation and application to complex cases

In this work, we present several applications of the 2D-3D multi-domain couplings for Navier-Stokes models developed and validated in its companion (Di Paolo et al., submitted). The methodology is used to carry out some relevant simulations which include long regular and irregular waves, solitary wave propagation on a shallow foreshore, focused wave group transformation on a planar beach, wave impact on a cylinder and finally, the numerical twin of a complex laboratory experiment to analyse the performance of a perforated breakwater under wave action. Results agree well with the full 3D simulations and laboratory experiments and demonstrate the feasibility of using the 2D-3D coupled methodologies presented in Part I to successfully replace full 3D modelling. For all the cases considered, the application of coupled methodologies have resulted in a drastic reducing of the computational time without decreasing the accuracy of the full solution

Maximizing the Profit for Industrial Customers of Providing Operation Services in Electric Power Systems via a Parallel Particle Swarm Optimization Algorithm

[EN] Integration of renewable energy sources require an increase in the flexibility of power systems. Demand response is a valuable flexible resource that is not currently being fully exploited. Small and medium industrial consumers can deliver a wide range of underused flexibility resources associated with the electricity consumption in their production processes. Flexible resources should compete in liberalized operation markets to ensure the reliability of the system at a minimum cost. This paper presents a new tool to assist industrial demand response to participate in operation markets and optimize its value. The tool uses a combined physical-mathematical modelling of the industrial demand response and a Parallel Particle Swarm Optimization algorithm specifically tuned for the proposed problem to maximize the profit. The main advantages of the proposed tool are demonstrated in the paper through its application to the participation of a meat factory in the Spanish tertiary reserve market during a whole year using a quarter-hourly time resolution. The enhanced performance of the proposed tool with respect to previous methodologies is shown with these four flexible processes examples, where the maximum available profit obtained in the simultaneous consideration of all different flexible processes is computed. The flexible processes are technical and economically characterized in a way that makes the tool valid for most of the processes in the industry.This work was supported in part by the Primeros Proyectos de Investigacion under Grant PAID-06-18, in part by the Vicerrectorado de Investigacion, Innovacion y Transferencia de la Universitat Politecnica de Valencia (UPV) Valencia-Spain, Generalitat Valenciana through the Research Project under Grant AICO/2019/001, in part by the Spanish Administration under Grant FPU2016/00962, in part by the AEI/10.13039/501100011033 (Ministerio de Ciencia, Innovacion y Universidades, Spanish Government) through the Research Projects under Grant ENE-2016-78509-C3-1-P and Grant RED2018-102618-T, and in part by the EU FEDER Funds.Rodríguez-García, J.; Ribó-Pérez, DG.; Álvarez, C.; Peñalvo-López, E. (2020). Maximizing the Profit for Industrial Customers of Providing Operation Services in Electric Power Systems via a Parallel Particle Swarm Optimization Algorithm. IEEE Access. 8:24721-24733. https://doi.org/10.1109/ACCESS.2020.2970478S2472124733

Resilience in Sports: Sport Type, Gender, Age and Sport Level Differences.

There seems to be a broad consensus that there is a positive correlation between resilience and sport performance. However, different studies show divergent results on the role played by certain variables in this relationship. This study aimed to analyze the possible relationships between resilience levels and the practiced sport according to gender, age, and competitive level of the athletes in 1047 competitive athletes from five different sports (handball, basketball, volleyball, athletics, and judo). Resilience was assessed with the Spanish version of the Brief Resilience Scale (BRS). Results of independent samples t-tests or analysis of variance (ANOVA) showed no significant differences on the level of resilience according to the practiced sport or the competitive level. However, the analyses of covariance (ANCOVA) showed that they were related to the gender and age of the athletes, being higher in males than in females, and there was a positive correlation with age. These results seem to suggest the convenience of using differentiated strategies, according to gender and age, when working on all those protective factors that could allow the athlete to perform better when facing adversity in the competitive environmentpost-print384 K