Influence of hydrogen peroxide in the tribocorrosion behaviour of a CoCrMo biomedical alloy

This paper studies the influence of hydrogen peroxide (H2O2) in simulated body fluids on the wear and corrosion behaviour of a CoCrMo biomedical alloy. CoCrMo are passive materials commonly used in prosthesis and implants because of its high corrosion resistance and mechanical properties. Hydrogen peroxide is produced by bacteria and leukocytes as a consequence of an inflammatory reaction which may modify the tribo-electrochemical response of metals implanted in the human body. Indeed, the oxidizing environment generated by the presence of the peroxide increases the metal dissolution rate. Electrochemical and tribocorrosion tests were carried out in a PBS solution with different addition of H2O2 (0.5, 2, 4 and 12%).The authors acknowledge Generalitat Valencia for the Gerónimo Forteza financial support and to the Electron Microscopy Service of the UPV for the SEM images

Shrouded wind turbine performance in yawed turbulent flow conditions

Artículo científico. Wind Engineering XX(X):1–7 ©The Author(s) 2021 Reprints and permission: sagepub.co.uk/journalsPermissions.nav DOI: 10.1177/ToBeAssigned www.sagepub.com/Wind turbines represent a growing energy source worldwide. In many cases, operating in turbulent and changing wind direction spots. In this work, we use a wind tunnel to analyse the effect of the turbulence in a wind turbine provided with a Wind Lens flow concentrator, under yaw conditions, for turbulence intensity values of 10% and 15%. Measurements are made of the power coefficient as a function of the Tip Speed Ratio using two types of Wind Lens, CiiB5 and CiiB10, at yaw angles from 0 to 30 . In general, for the turbine with Wind Lens, an increase of the yaw angle causes a reduction of the power coefficient. If the turbine operates with the CiiB10, the stronger the turbulence, the greater performance is obtained. In conclusion, for the case of turbulent flow and yaw = 20 or less, the Wind Lens turbine offers better performance than without the flow concentrator

Genetic algorithm optimization of entanglement

We present an application of a genetic algorithmic computational method to the optimization of the concurrence measure of entanglement for the cases of one dimensional chains, as well as square and triangular lattices in a simple tight-binding approach in which the hopping of electrons is much stronger than the phonon dissipationComment: 26 pages with 13 figures, based on Chapter 3 of the Master thesis of the first author defended at IPICyT, San Luis Potosi, Mx, on 22nd of February 2006, similar to the published version [Fig. 5 left out but contains the Appendix figure

Bound states of dark solitons and vortices in trapped multidimensional Bose-Einstein condensates

We report on the existence and stability of multidimensional bound solitonic states in harmonically trapped scalar Bose-Einstein condensates. Their equilibrium separation, as a measure of the strength of the soliton- soliton or the solitonic vortex-vortex interaction, is provided for varying chemical potential μ. Static bound dark solitons are shown to be dynamically stable in elongated condensates within a range of intermediate (repulsive) interparticle-interaction strength. Beyond this range the snaking instability manifests during the time evolution of the planar solitons and produces the decay into nonstationary vortex states. A subsequent dynamical recurrence of solitons and vortices can be observed at low μ. At equilibrium, the bifurcations of bound dark solitons are bound solitonic vortices. Among them, both two-open and two-ring vortex lines are demonstrated to exist with both counter- and co-rotating steady velocity fields. The latter flow configurations evolve, for high chemical potential, into a stationary three-dimensional (3D)-chain-shaped vortex and a three vortex-antivortex-vortex ring sequence that arrest the otherwise increasing angular or linear momentum respectively. As a feature common to the bifurcated families of vortex states, their excitation spectra present unstable modes with associated oscillatory dynamics. In spite of this, the family of two-open counter-rotating vortices support dynamically stable 3D states

Victimization and peer and parents attachment: The mediating effect of regulatory emotional self-efficacy

Studies of the Spanish adolescent population has concluded that victimization is related to lack of emotional regulation and impulse control. Therefore, if a victim is unable to recognize, understand and regulate their emotions, this can result in rejection by their peers. A cross-sectional study was conducted to examine regulatory emotional self-efficacy as a possible mediator in the association between peer and parents attachment and victimization. Adolescents (n = 563) completed Regulatory Emotional Self-Efficacy, Inventory of Parents and Peer Attachment and Kid at School questionnaires. Structural equation models (SEMs) were used to predict a latent variable of victimization with parents and peer attachment, emphasizing the mediating role of regulatory emotional self-efficacy, as comprised by a positive and a negative aspect. Results showed that peer attachment had an indirect negative effect, through perceived self-efficacy, in managing a positive effect in victimization, while father attachment had an indirect negative affect, through perceived self-efficacy, in managing a negative affect in victimization, and Mother attachment had no statistically significant indirect effect in victimization. This study suggests that the roles of parents and peers, and also between mothers and fathers, are different in relation to the perception of victimization of adolescents. Findings provide relevant information regarding implications for prevention and intervention in victimization

Prevalence of anti-sperm antibodies, risk factors associated and their impact on spermatobioscopy in infertile men

Background: The first immunological correlation with male infertility was reported in 1954 by Wilson and Rumke with the identification of anti-sperm antibodies. The prevalence of anti-sperm antibodies in infertile men varies from 9%-36%, the main cause being the loss of the blood-testicular barrier and otherwise the association with chronic inflammation. It has been shown that immune infertility is found in 15% of patients with varicocele.Methods: A transversal comparative study was carried out with 360 infertile men who were tested for anti-sperm antibodies between January 2011 and July 2018. Two groups were integrated; Group 1, infertile men with positive anti-sperm antibodies >50%, group 2, infertile men with negative anti-sperm <50%. Seminogram parameters were evaluated according to the WHO 5th edition and associated risk factors with anti-sperm antibodies.Results: 360 infertile men were evaluated during the study, 42 were excluded because they did not meet the inclusion criteria, the prevalence of anti-sperm antibodies was 14.5%. Group 1; n=46 (14.5%) and group 2, n=272 (85.5%), the clinical characteristics and the hormonal profile were compared at study admission without significant difference. There was a significant decrease in progressive motility in group 1 (38.7±23.8) vs group 2 (50.1±18.9) p=0.03. Analyzing the risk factors, varicocele was found to be significant 23.7%, OR 2.14 (1.27-3.61) p=0.004 as well as retractable testicle 26.4%, OR 2.13 (1.23-3.70) p= 0.008.Conclusions: The affectation of motility was confirmed, which leads to the suspect varicocele and retractable testicle as risk factors

Propiedades psicométricas del Inventario de Situaciones y Respuestas de Ansiedad Breve (ISRA-B)

Introducción y objetivos La ansiedad es la reacción emocional más estudiada, que nos pone en alerta ante la posibilidad de obtener un resultado negativo, por lo que resulta adaptativa en la gran mayoría de las ocasiones, aunque también está en la base de los trastornos emocionales más prevalentes. Por ello, su evaluación ha generado mucha investigación y transferencia. El Inventario de Situaciones y Respuestas de Ansiedad (ISRA) fue desarrollado en España, incluye 22 situaciones (S) y 24 respuestas (R) de ansiedad, que al cruzarlas se forman 224 reactivos (del tipo «en tal S, experimento esta R»). Desde hace más de tres décadas ha sido ampliamente utilizado en la investigación, así como en la práctica, y se han publicado estudios sobre sus propiedades psicométricas en diferentes países. Una versión más breve (ISRA-B) de 46 ítems, sin contenidos cruzados S × R, sino una escala de 22 S y otra de 24 R, con las que evalúan las mismas ocho facetas de la ansiedad, ha mostrado buenas propiedades psicométricas también; sin embargo, existen menos publicaciones psicométricas en población española. El objetivo de este estudio fue analizar las propiedades psicométricas del ISRA-B en España. Método Para ello se contó con 3, 346 voluntarios (36.4% hombres), con edades de 15 a 94 años (media: 30.3; DE: 14.6). Resultados Los resultados confirmaron excelente consistencia interna para Total (.94) y subescala R (.91), buena para S (.89) y sistemas de respuesta Fisiológico (.86) y Cognitivo (.84), y aceptable para Motor (.70). También se encontró buena estabilidad test-retest al cabo de un mes (.78) y buena validez externa al correlacionar .87 con el ISRA original. La estructura factorial del ISRA-B obtenida se adecuó al modelo de Lang de tres sistemas de R y al modelo de Endler de interacción S × R, en los que se basa. Asimismo, se presentan los datos normativos, por sexo y grupo. Conclusión Se concluye que el ISRA-B es válido y confiable, mejora su aplicabilidad respecto al ISRA original, conservando sus propiedades psicométricas. Introduction and objectives: Anxiety is the most studied emotional reaction, which alerts us of the possibility of obtaining a negative result, making it adaptive in the vast majority of cases, although it is also one of the underlying factors of the most prevalent emotional disorders. Therefore, its assessment has generated a lot of research and transfer. The Inventory of Situations and Responses of Anxiety (ISRA) was developed in Spain and it includes 22 situations (S) and 24 responses (R) of anxiety, by which 224 items are formed by crossing them (i.e., «in such Situation, I experience this Reaction»). For more than three decades, it has been widely used in research and practice, and its psychometric properties have been published in different countries. A shorter, 46-item version (ISRA-B), with a 22 S scale plus another of 24 R was developed. The same eight facets of anxiety were assessed, showing good psychometric properties as well. However, there are few publications on the psychometric data using Spanish population. The objective of this study was to analyze the psychometric properties of ISRA-B in Spain. Methods: Three thousand three hundred and forty six volunteers (36.4% men), aged 15 to 94 years (mean: 30.3; SD: 14.6) were included. Results: The results confirmed excellent internal consistency for the Total (.94) and the Responses subscale (0.91), good for the Situations (0.89), as well as the Physiological (, 86) and Cognitive (0.84) response systems, and acceptable for the Motor (0.70). Good test-retest stability was also found after two months (0.78) and good external validity when correlated with the original ISRA (0.87). The results confirm the factor structure of the ISRA-B, adjusted to Lang''s triple response system model and to Endler''s S × R interaction model, on which it is based. Likewise, the normative data are presented, differentiated by sex and group. Conclusions: It is concluded that the ISRA-B is a valid and reliable instrument, which improves its applicability compared to the original ISRA by simplifying its format and number of items, while preserving its psychometric properties

On the isolated dwarf galaxies: from cuspy to flat dark matter density profiles and metallicity gradients

The chemodynamical evolution of spherical multi-component self-gravitating models for isolated dwarf galaxies is studied. We compare their evolution with and without feedback effects from star formation processes. We find that initially cuspy dark matter profiles flatten with time as a result of star formation, without any special tuning conditions. Thus the seemingly flattened profiles found in many dwarfs do not contradict the cuspy profiles predicted by cosmological models. We also calculate the chemical evolution of stars and gas, to permit comparisons with observational data.Comment: Accepted the 28/01/1

Magnification by Galaxy Group Dark Matter Halos

We report on the detection of gravitational lensing magnification by a population of galaxy groups, at a significance level of 4.9 sigma. Using X-ray selected groups in the COSMOS 1.64 deg^2 field, and high-redshift Lyman break galaxies as sources, we measure a lensing-induced angular cross-correlation between the samples. After satisfying consistency checks that demonstrate we have indeed detected a magnification signal, and are not suffering from contamination by physical overlap of samples, we proceed to implement an optimally weighted cross-correlation function to further boost the signal to noise of the measurement. Interpreting this optimally weighted measurement allows us to study properties of the lensing groups. We model the full distribution of group masses using a composite-halo approach, considering both the singular isothermal sphere and Navarro-Frenk-White profiles, and find our best fit values to be consistent with those recovered using the weak-lensing shear technique. We argue that future weak-lensing studies will need to incorporate magnification along with shear, both to reduce residual systematics and to make full use of all available source information, in an effort to maximize scientific yield of the observations.Comment: 6 pages, 3 figures, Accepted by Ap