Anisotropic thermal emission from magnetized neutron stars

The thermal emission from isolated neutron stars is not well understood. The X-ray spectrum is very close to a blackbody but there is a systematic optical excess flux with respect to the extrapolation to low energy of the best blackbody fit. This fact, in combination with the observed pulsations in the X-ray flux, can be explained by anisotropies in the surface temperature distribution.We study the thermal emission from neutron stars with strong magnetic fields in order to explain the origin of the anisotropy. We find (numerically) stationary solutions in axial symmetry of the heat transportequations in the neutron star crust and the condensed envelope. The anisotropy in the conductivity tensor is included consistently. The presence of magnetic fields of the expected strength leads to anisotropy in the surface temperature. Models with toroidal components similar to or larger than the poloidal field reproduce qualitatively the observed spectral properties and variability of isolated neutron stars. Our models also predict spectral features at energies between 0.2 and 0.6 keV.Comment: 18 pages, 19 figures, version accepted for publication in A&

Pulsar kicks by anisotropic neutrino emission from quark matter

We discuss an acceleration mechanism for pulsars out of their supernova remnants based on asymmetric neutrino emission from quark matter in the presence of a strong magnetic field. The polarized electron spin fixes the neutrino emission from the direct quark Urca process in one direction along the magnetic field. We calculate the magnetic field strength which is required to polarize the electron spin as well as the required initial proto-neutron star temperature for a successfull acceleration mechanism. In addition we discuss the neutrino mean free paths in quark as well as in neutron matter which turn out to be very small. Consequently, the high neutrino interaction rates will wash out the asymmetry in neutrino emission. As a possible solution to this problem we take into account effects from colour superconductivity.Comment: 6 pages, 3 figures, poster contribution at the conference "Nuclear Physics in Astrophysics III",Dresden,March 26-31,200

Evolution of Protoneutron Stars

We study the thermal and chemical evolution during the Kelvin-Helmholtz phase of the birth of a neutron star, employing neutrino opacities that are consistently calculated with the underlying equation of state (EOS). Expressions for the diffusion coefficients appropriate for general relativistic neutrino transport in the equilibrium diffusion approximation are derived. The diffusion coefficients are evaluated using a field-theoretical finite temperature EOS that includes the possible presence of hyperons. The variation of the diffusion coefficients is studied as a function of EOS and compositional parameters. We present results from numerical simulations of protoneutron star cooling for internal stellar properties as well as emitted neutrino energies and luminosities. We discuss the influence of the initial stellar model, the total mass, the underlying EOS, and the addition of hyperons on the evolution of the protoneutron star and upon the expected signal in terrestrial detectors.Comment: 67 pages, 25 figure

The Emotional Self-Efficacy Scale: Adaptation and Validation for Young Adolescents

Emotional self-efficacy (ESE) is an important aspect of emotional functioning, with current measures for children and adolescents focused on the measurement of self-beliefs in relation to the management of emotions. In the present study, we report the psychometric properties of the first adaptation of the Emotional Self-Efficacy Scale for youth (Youth-ESES) that measures additional aspects of ESE, such as perceiving and understanding emotions and helping others modulate their emotions. Participants were 192 young adolescents aged 11 to 13 years from a U.K. state school. They completed the Youth-ESES and measures of ability emotional intelligence (EI) and cognitive ability. Results support the same four-factor structure that has been previously documented using the adult version of the ESES, with the four subscales being largely independent from cognitive ability and only moderately related to ability EI. However, the four subscales were less differentiated in the present study compared with adult data previously published, suggesting that there is a strong general factor underlying young adolescents’ ESE scores. Overall, the results suggest that the adapted Youth-ESES can be reliably used with youth, and that confidence in how a young person feels about his or her emotional functioning remains distinct from emotional skill

Optimización robusta en aplicaciones aeronáuticas con la combinación de cálculo estocástico y algoritmos evolutivos

ResumenLas incertidumbres son un problema cotidiano en la ingeniería aeroespacial y en sus aplicaciones. Los métodos de optimización robusta utilizan, normalmente, y para asegurar la robustez de las soluciones, la generación aleatoria de los valores con incertidumbres así como criterios de selección multi-punto para la determinación del óptimo. Desde un punto de vista computacional, la aplicación a problemas de fluido-dinámica (CFD) o interacción fluido-estructura (FSI) puede ser extremadamente cara. Este trabajo presenta el acoplamiento entre el cálculo estocástico y los algoritmos evolutivos para la definición de un procedimiento de optimización robusta. Se propone, en primer lugar, una metodología para el cálculo estocástico, que a continuación se aplica a la solución de problemas de optimización. Estos métodos propuestos se han aplicado a dos tipos de problemas; un problema de CFD y otro de FSI orientados a la reducción de la resistencia aerodinámica y del fenómeno de estabilidad estructural conocido por «flutter», respectivamente.AbstractUncertainties are a daily issue to deal with in aerospace engineering and applications. Robust optimization methods commonly use a random generation of the inputs and take advantage of multi-point criteria to look for robust solutions accounting with uncertainty definition. From the computational point of view, the application to coupled problems, like fluid-dynamics (CFD) or fluid-structure interaction (FSI), can be extremely expensive. This work presents a coupling between stochastic analysis techniques and evolutionary optimization algorithms for the definition of a stochastic robust optimization procedure. At first, a stochastic procedure is proposed to be applied into optimization problems. The proposed method has been applied to both CFD and FSI problems for the reduction of drag and flutter, respectively

Decision-making in school-age sport measured through a digital tool.

El objetivo de este estudio ha sido doble. Por un lado, diseñar y crear un software de evaluación de toma de decisiones en edad escolar, en base a aspectos espacio-temporales, contextualizado en voleibol, denominado “Juego Interactivo de Voleibol”. Por otro lado, analizar y establecer su fiabilidad y validez. El software diseñado se aplicó a una muestra de 132 escolares (64 niños y 68 niñas) de entre 10 y 13 años, de los centros educativos públicos de Educación Primaria y Secundaria de las localidades sevillanas de Arahal y Paradas (España). Para determinar la fiabilidad se estudió la consistencia interna a través del coeficiente alfa de Cronbach. Para calcular el número óptimo de repeticiones se utilizó el Coeficiente de Correlación Intraclase. La validez se comprobó en base a la evaluación de un grupo de 5 expertos. Los resultados indicaron que este nuevo software de evaluación alcanza altos niveles de fiablidad y validezThe aim of this study was twofold. On the one hand, the design and creation of an evaluation software for decision-making in school-age children based on spatial-temporal aspects in the context of volleyball called ‘Interactive Volleyball Game’. On the other hand, the analysis and establishment of its reliability and validity. The designed software was applied to a sample of 132 students (64 boys and 68 girls) aged between 10 and 13 years in public Elementary and Secondary Education schools of Seville towns, Arahal and Paradas (Spain). To determine the reliability, internal consistency was studied through Cronbach's alpha. The intraclass correlation coefficient (ICC) was also analyzed to calculate the optimal number of repetitions for future research. The validity was tested based on the assessment of a group of 5 experts. The results indicated that this new evaluation software reaches high levels of reliability and validit

Bipolar querying of valid-time intervals subject to uncertainty

Databases model parts of reality by containing data representing properties of real-world objects or concepts. Often, some of these properties are time-related. Thus, databases often contain data representing time-related information. However, as they may be produced by humans, such data or information may contain imperfections like uncertainties. An important purpose of databases is to allow their data to be queried, to allow access to the information these data represent. Users may do this using queries, in which they describe their preferences concerning the data they are (not) interested in. Because users may have both positive and negative such preferences, they may want to query databases in a bipolar way. Such preferences may also have a temporal nature, but, traditionally, temporal query conditions are handled specifically. In this paper, a novel technique is presented to query a valid-time relation containing uncertain valid-time data in a bipolar way, which allows the query to have a single bipolar temporal query condition

Nitration of primary amines to form primary nitramines (Review)

Poster presentation at 19th Seminar on New Trends in Research of Energetic Materials; Pardubice, Czech Republic; 20/04/2016-22/04/2016The nitration of primary amines to form primary nitramines is a rarely reported synthetic procedure which proceeds through a minimum of two steps. This is in stark contrast to the nitration of alcohols and secondary amines which is readily achievable by a number of methods in a single step. In general the primary amine must initially be activated to nitration as direct exposure to nitrating media tends to result in the formation of an ionic nitrate salt. This activation may be achieved through the use of a multitude of protecting groups that are stable to the nitrating conditions used thereafter. The review presented here is an attempt to bring together the published literature on this often overlooked synthetic procedure in energetic materials chemistry

Superelastic behavior and elastocaloric effect in a Ni51.5Fe21.5Ga27.0 ferromagnetic shape memory single crystal under compression

Ni51.5Fe21.5Ga27.0 single crystals have been subjected to different heat treatments resulting in a different degree of L21 ordering. Superelastic response has been measured at different temperatures in compression mode. The mechanical behavior strongly depends on axis orientation. In the [001] direction, perfect superelasticity over a wide range of temperatures is found. For the [110] orientation, the material fails by brittle fracture short above austenite transformation finish temperature, Af. A linear dependence of the critical stress with temperature has been found in agreement with Clausius-Clapeyron equation. The slope does not significantly change with the degree of order, but it is notably affected by the crystal orientation. The microstructure of the samples after mechanical tests has been studied by transmission electron microscopy. The superelastic cycling produces dislocations with a Burgers vector that suggests local microplastic deformation of the martensitic phase. Finally, the adiabatic temperature change has been used to chacterize the elastocaloric effect in this alloy. The adiabatic cooling is found to be larger in the [110] than in the [001] orientation at 240 K. However, the brittleness of [110] samples avoid testing the adiabatic temperature change at room temperature. The adiabatic cooling in [001] orientation decreases systematically with temperature, which is related to decrease of the strain and entropy change of transformation