3,600 research outputs found
The properties of penumbral microjets inclination
We investigate the dependence of penumbral microjets inclination on the
position within penumbra. The high cadence observations taken on 10 November
2006 with the Hinode satellite through the \ion{Ca}{ii} H and G--band filters
were analysed to determine the inclination of penumbral microjets. The results
were then compared with the inclination of the magnetic field determined
through the inversion of the spectropolarimetric observations of the same
region. The penumbral microjet inclination is increasing towards the outer edge
of the penumbra. The results suggest that the penumbral microjet follows the
opening magnetic field lines of a vertical flux tube that creates the sunspot.Comment: 4 pages, 4 figures, A&A Letter in pres
Phase stability of lanthanum orthovanadate at high-pressure
When monoclinic monazite-type LaVO4 (space group P21/n) is squeezed up to 12
GPa at room temperature, a phase transition to another monoclinic phase has
been found. The structure of the high-pressure phase of LaVO4 is indexed with
the same space group (P21/n), but with a larger unit-cell in which the number
of atoms is doubled. The transition leads to an 8% increase in the density of
LaVO4. The occurrence of such a transition has been determined by x-ray
diffraction, Raman spectroscopy, and ab initio calculations. The combination of
the three techniques allows us to also characterize accurately the pressure
evolution of unit-cell parameters and the Raman (and IR)-active phonons of the
low- and high-pressure phase. In particular, room-temperature equations of
state have been determined. The changes driven by pressure in the crystal
structure induce sharp modifications in the color of LaVO4 crystals, suggesting
that behind the monoclinic-to-monoclinic transition there are important changes
of the electronic properties of LaVO4.Comment: 39 pages, 6 tables, 7 figure
Decisiones administrativas y judiciales sobre la maternidad subrogada: análisis de un caso.
Este trabajo versa sobre el desarrollo que se está experimentando en España la eficacia otorgada por vía registral a un medio alternativo de acceder a la filiación como es el recurso en el extranjero a la maternidad subrogada. Para ello, se ha analizado un caso concreto, en el que se pueden ver todas las resoluciones, tanto administrativas como judiciales, a las que se han enfrentado una pareja homosexual que, mediante un contrato de gestación por sustitución, tuvieron a dos niños, y los impedimentos para conseguir su inscripción en el Registro Civil español
Supersonic Evershed flow outside Sunspots
We report on the discovery of mostly horizontal field channels just outside
sunspot penumbrae (in the so-called `moat' region) that are seen to sustain
supersonic flows (line-of-sight component of 6 km s{-1}). The spectral
signature of these supersonic flows corresponds to circular polarization
profiles with an additional, satellite, third lobe of the same sign as the
parent sunspot' Stokes V blue lobe, for both downflows and upflows. This is
consistent with an outward directed flow that we interpret as the continuation
of the magnetized Evershed flow outside sunspots at supersonic speeds. In
Stokes Q and U, a clear signature of a transverse field connecting the two flow
streams is observed. Such an easily detectable spectral signature should allow
for a clear identification of these horizontal field channels in other
spectropolarimetric sunspot data. For the spot analyzed in this paper, a total
of 5 channels with this spectral signature have been unambiguously found
Pulsatile flow in coronary bifurcations for different stenting techniques
The objective of this work is to analyze the local hem
odynamic changes caused in a coronary bifurcation by three different stenting techniques: simple stenting of the main vessel, simple stenting of the main vessel with kissing balloon in the side branch and culotte. To carry out this study an idealized geometry of a coronary bifurcation is
used, and two bifurcation angles, 45º and 90º, are chosen as representative of the wide variety of re
al configurations. In order to quantify the influence of the stenting technique on the local blood flow, both numeri-
cal simulations and experimental measurements are performed. First, steady simulations are carried out with the commercial code ANSYS-Fluent, and then, experimental measurements with PIV (Particle Image Velocimetry) obtained
in the laboratory are used to validate the numerical simulation. The steady computational simulations show a good overall agreement with the experimental data. Second, pulsatile flow is considered to take into account the tran-
sient effects. The time averaged wall shear stress, scillatory shear index and pressure drop obtained numerically are used to compare the behavior of the stenting techniques
Effects of ammonium nitrate, cesium chloride and tetraethylammonium on high-affinity potassium uptake in habanero pepper plantlets (Capsicum chinense Jacq.)
Potassium (K+) is an essential nutrient and the most abundant cation in plant cells. Plants have a wide variety of transport systems for K+ acquisition that catalyze K+ uptake across a wide spectrum of external K+ concentrations and mediate K+ movement within the plant, as well as its release into the environment. The KUP/HAK/KT transporter family plays a key role in K+ homeostasis in plant cells. The present study demonstrates that habanero pepper plantlets have a clear pattern of K+ uptake when resupplemented with K+ after K+ starvation. Habanero pepper plantlets, re-supplemented with a solution containing low concentrations of K+ after 72, 96 or 120 h of K+ starvation were able to decrease the amount of K+ in the solution at different time points. To study the effect of NH4+, we added different concentrations of NH4NO3 to the medium solution and demonstrated that NH4+ inhibited K+ uptake in a dose-dependent manner. When the plantlets were subjected to K+ starvation for 72 h and then resupplemented with 50 or 100 μM K+, exposure to K+ channel blockers (10 mM CsCl and 20 mM TEA) decreased their K+ uptake compared with the control treatment. A model demonstrating the process of K+ uptake through an NH4+-insensitive component was proposed.Key words: Potassium, high affinity transporters, channel blockers, ammonium
Estados de ánimo y rendimiento deportivo en fútbol : ¿existe la ventaja de jugar en casa?
Los estados de ánimo previos a la competición han sido asociados con la selección de deportistas y el rendimiento deportivo. Recientes investigaciones parecen haber demostrado que la relación entre el estado de ánimo precompetitivo y el rendimiento, podría estar mediado por una serie de variables como son la duración del evento, el tipo de deporte e incluso la localización del partido (Terry, 1997). En el presente estudio, tenemos intención de observar cómo los estados de ánimo, previos a la competición, influyen en el rendimiento de un equipo de fútbol durante toda la temporada, y si esta relación está mediada por la variable localización del partido. Según los resultados obtenidos, la variable localización del partido parece mediar en la relación existente entre estados de ánimo y rendimiento, siendo los partidos jugados fuera de casa donde más se manifiestan los estados de ánimo y su consiguiente influencia en el rendimiento.Emotional states, previous to competition, have been associated to competition outcomes and athletes selection. Recent investigations have demonstrated that some variables could being mediating the relationships between emotional states and competition outcome, such as duration of the event, type of sport and game location (Terry, 1997). The present study's intention is to observe how the emotional states, previous to competition, relate to competition performance, in a soccer team during a season. Also, we are interested in the possible mediating role of game location. The study results, seem to confirm that game location mediate the relationship between emotional states and performance, with home matches having the more positive emotional states and performance
Effect of EtOH/H₂O ratio and pH on bis-sulfur silane solutions for electrogalvanized steel joints based on anaerobic adhesives
International Conference on Advanced Computational Engineering and Experimenting (ACE-X 2010),Presented in part at the 4th International Conference on Advanced Computational Engineering and Experimenting (ACE-X 2010), Paris, France, 8–9 July 2010.A minimum hydrolysis time is required to get an adequate crosslinking between a silane film and a metallic substrate and that depends on the contents of silane, ethanol, and water in the silane solution. The objectives for this work are: 1) to study the effect of different ratios of ethanol/water on the hydrolysis time for a 1% bis-sulfur silane solution at pH 6, by attenuated total reflectance infrared spectroscopy. The different solutions studied correspond to different ratios of silane/ethanol/water by volume. The study was done following appearance of the siloxane and silanol groups and the disappearance of the ethoxysilane groups. 2) Also studied was the adhesion and corrosion behaviour of bis-sulfur silane (bis[3-(bis[3-(triethoxysilyl)propyl]disulfide, DS) in solutions of ethanol/water at pH 4 and 6 and γ-methacryloxypropyltrimethoxysilane (MPS) coatings obtained by a two-step process on galvanized steel samples. This coated surface was analysed by reflection absorption infrared spectroscopy (FTIR-RA), scanning electron miscroscopy (SEM), and polarization curves. Results obtained at pH 6 were compared with the ones for pH 4. Single lap shear tests were used to contrast the behaviour of anaerobic adhesives on electrogalvanized steel silanized samples. It was observed that higher hydrolysis time was necessary to get good adhesion behaviour if the solution was prepared at pH 4, while at pH 6 the best behaviour was observed for short hydrolysis times
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