High-precision analysis of binary stars with planets. I. Searching for condensation temperature trends in the HD 106515 system

We explore the probable chemical signature of planet formation in the remarkable binary system HD 106515. The A star hosts a massive long-period planet with 9 MJup detected by radial velocity. We also refine stellar and planetary parameters by using non-solar-scaled opacities when modeling the stars. Methods. We carried out a simultaneous determination of stellar parameters and abundances, by applying for the first time non-solar-scaled opacities in this binary system, in order to reach the highest possible precision. Results. The stars A and B in the binary system HD 106515 do not seem to be depleted in refractory elements, which is different when comparing the Sun with solar-twins. Then, the terrestrial planet formation would have been less efficient in the stars of this binary system. Together with HD 80606/7, this is the second binary system which does not seem to present a (terrestrial) signature of planet formation, and hosting both systems an eccentric giant planet. This is in agreement with numerical simulations, where the early dynamical evolution of eccentric giant planets clear out most of the possible terrestrial planets in the inner zone. We refined the stellar mass, radius and age for both stars and found a notable difference of 78% in R compared to previous works. We also refined the planet mass to mp sini = 9.08 +/- 0.20 MJup, which differs by 6% compared with literature. In addition, we showed that the non-solar-scaled solution is not compatible with the classical solar-scaled method, and some abundance differences are comparable to NLTE or GCE effects specially when using the Sun as reference. Then, we encourage the use of non-solar-scaled opacities in high-precision studies such as the detection of Tc trends.[abridged]Comment: 9 pages, 10 figures, A&A accepted. arXiv admin note: text overlap with arXiv:1507.0812

Experimental approval of the extended flat bands and gapped subbands in rhombohedral multilayer graphene

Graphene layers are known to stack in two stable configurations, namely ABA or ABC stacking, with drastically distinct electronic properties. Unlike the ABA stacking, little has been done to experimentally investigate the electronic properties of ABC graphene multilayers. Here, we report the first magneto optical study of a large ABC domain in a graphene multilayers flake, with ABC sequences exceeding 17 graphene sheets. The ABC-stacked multilayers can be fingerprinted with a characteristic electronic Raman scattering response, which persists even at room temperatures. Tracing the magnetic field evolution of the inter Landau level excitations from this domain gives strong evidence to the existence of a dispersionless electronic band near the Fermi level, characteristic of such stacking. Our findings present a simple yet powerful approach to probe ABC stacking in graphene multilayer flakes, where this highly degenerated band appears as an appealing candidate to host strongly correlated states.Comment: 8 pages, 4 figure

Evaluación biomecánica de la carga final de la tenodesis de bíceps

El interés en las diferentes técnicas de tenodesis artroscópica se ha incrementado en los últimos 10 años. Sin embargo, hay muy poca información publicada sobre sus propiedades biomecánicas y clínicas. El objetivo del presente estudio es analizar una de las propiedades biomecánicas de dos tipos diferentes de tenodesis artroscópicas de bíceps: PITT vs Sutura con Arpones. Material y métodos: 15 especímenes cadavéricos frescos congelados se aleatorizaron para ambas técnicas. Una vez realizada la cirugía, los húmeros con el tendón fijado al Ligamento Transverso, se montaron en una máquina de prueba de materiales en paralelo para llevar a cabo el protocolo de carga hasta el fallo a una velocidad de 1.25 mm/sec. Se obtuvo la carga final (N) y se consideró la variable principal. Se compararon ambas técnicas mediante el test paramétrico de la t de Student. Resultados: Ambos tipos de reparaciones mostraron cargas finales adecuadas: 175,46±40,4 N la sutura con arpones y 142,79±30,9 N la técnica PITT (p>0.05). Conclusión: La Sutura con Doble Arpón y PITT demostraron una resistencia satisfactoria inicial sin diferencias significativas entre ambos grupos. Ambas técnicas son útiles a la hora de abordar la patología del bíceps, aunque la técnica PITT es más rápida, económica y accesible

Caracterización y cartografía fitoclimáticas del bosque nativo subantártico en la Isla Grande de Tierra del Fuego (Patagonia, Argentina)

Isla Grande de Tierra del Fuego is especially peculiar in phytoclimatic terms, situated as it is at an extreme southerly latitude, surrounded by large water masses and close to the great mass of Antarctic ice. Its main peculiarities in this sense are the coolness of its summers and a very narrow temperature range. As a result, the woodland landscapes in the parts with forest cover are dominated by microphyllous broadleaf physiognomies, both evergreen and deciduous, of the Nothofagus genus. This paper reports a more in-depth investigation of the hitherto little-known phytoclimatic conditions in that territory which included calibration and validation of a model of phytoclimatic suitability that addresses the principal plant physiognomic units and phytoclimatic mapping. It discusses the causes behind the presence of broadleaf formations in thermal conditions which in the northern hemisphere would allow only coniferous formations or no tree formations at all, and also the edaphic peculiarities that may explain the presence of a evergreen species like Nothofagus betuloides in subantarctic mixed forests.La Isla Grande de Tierra del Fuego presenta una muy marcada originalidad fitoclimática por su posición en latitudes muy australes, estar rodeada por grandes masas de agua y por su cercanía a la gran masa de hielo polar antártica. Esta originalidad se traduce en un escaso calor estival y una oscilación térmica muy reducida como principales peculiaridades, dando lugar en sus porciones arboladas a paisajes boscosos dominados por fisionomías planifolias de carácter micrófilo, tanto perennifolias como caducifolias del género Nothofagus. Este trabajo profundiza en las hasta hoy escasamente conocidas condiciones fitoclimáticas de este territorio, mediante la calibración y validación de un modelo de idoneidad fitoclimática respecto de las principales unidades fisionómicas de vegetación y el establecimiento de una cartografía fitoclimática. Se discuten las causas que provocan la existencia de formaciones planifolias en condiciones térmicas que darían lugar a formaciones aciculifolias o desarboladas en el hemisferio Norte, así como las particularidades edáficas que condicionan la presencia de la estrategia perennifolia representada por Nothofagus betuloides en los bosques mixtos subantárticos

Effect of Impurity Scattering on the Nonlinear Microwave Response in High-Tc Superconductors

We theoretically investigate intermodulation distortion in high-Tc superconductors. We study the effect of nonmagnetic impurities on the real and imaginary parts of nonlinear conductivity. The nonlinear conductivity is proportional to the inverse of temperature owing to the dependence of the damping effect on energy, which arises from the phase shift deviating from the unitary limit. It is shown that the final-states interaction makes the real part predominant over the imaginary part. These effects have not been included in previous theories based on the two-fluid model, enabling a consistent explanation for the experiments with the rf and dc fields

Simultaneous Surface Plasmon Resonance and X-ray Absorption Spectroscopy

We present here an experimental set-up to perform simultaneously measurements of surface plasmon resonance (SPR) and X-ray absorption spectroscopy (XAS) in a synchrotron beamline. The system allows measuring in situ and in real time the effect of X-ray irradiation on the SPR curves to explore the interaction of X-rays with matter. It is also possible to record XAS spectra while exciting SPR in order to detect the changes in the electronic configuration of thin films induced by the excitation of surface plasmons. Combined experiments recording simultaneously SPR and XAS curves while scanning different parameters can be carried out. The relative variations in the SPR and XAS spectra that can be detected with this set-up ranges from 10-3 to 10-5, depending on the particular experiment

KELT-17: a chemically peculiar Am star and a hot-Jupiter planet

Context. The detection of planets orbiting chemically peculiar stars is very scarcely known in the literature. Aims. To determine the detailed chemical composition of the remarkable planet host star KELT-17. This object hosts a hot-Jupiter planet with 1.31 MJup detected by transits, being one of the more massive and rapidly rotating planet hosts to date. We aimed to derive a complete chemical pattern for this star, in order to compare it with those of chemically peculiar stars. Methods. We carried out a detailed abundance determination in the planet host star KELT-17 via spectral synthesis. Stellar parameters were estimated iteratively by fitting Balmer line profiles and imposing the Fe ionization balance, using the program SYNTHE together with plane-parallel ATLAS12 model atmospheres. Specific opacities for an arbitrary composition and microturbulence velocity vmicro were calculated through the Opacity Sampling (OS) method. The abundances were determined iteratively by fitting synthetic spectra to metallic lines of 16 different chemical species using the program SYNTHE. The complete chemical pattern of KELT-17 was compared to the recently published average pattern of Am stars. We estimated the stellar radius by two methods: a) comparing the synthetic spectral energy distribution with the available photometric data and the Gaia parallax, and b) using a Bayesian estimation of stellar parameters using stellar isochrones. Results. We found overabundances of Ti, Cr, Mn, Fe, Ni, Zn, Sr, Y, Zr, and Ba, together with subsolar values of Ca and Sc. Notably, the chemical pattern agrees with those recently published of Am stars, being then KELT-17 the first exoplanet host whose complete chemical pattern is unambiguously identified with this class. The stellar radius derived by two different methods agrees to each other and with those previously obtained in the literature.Comment: 5 pages, 8 figures, 2 tables, A&A accepte

Environmental monitoring of marine aquaculture facilities

Aquaculture, like any other productive activity which uses natural resources, can have an impact on the environment. Both the magnitude and dimension of this influence are related to the type of culture being carried out, and the geographic location of the farm. The present study focuses on the environmental impact associated with aquaculture activities (both inland and off-shore), and identifies the best indicators in the water column and the seabed, in order to further our knowledge of the environmental impact of this activity, thus helping to improve the design of aquaculture environmental monitoring.Aunque la acuicultura marina, en comparación con otros sectores productivos y otras actividades que se desarrollan en el litoral, origine un efecto menor sobre el medio ambiente, es obvio que puede producir algún impacto, y por ello, para asegurar el respeto a los valores medioambientales del entorno y cumplir correctamente los principios del desarrollo sostenible, lo importante es conocer cuáles pueden ser esos impactos, para tratar de corregirlos o, según los casos, minimizarlos. En el presente estudio se trata de establecer los indicadores ambientales para el seguimiento de la actividad, tanto en instalaciones en mar abierto como en instalaciones en tierra, contribuyendo a mejorar el diseño de programas de vigilancia ambiental para cada tipo de instalación.Instituto Español de Oceanografí