Electronic structure and dimerization of a single monatomic gold wire

The electronic structure of a single monatomic gold wire is presented for the first time. It has been obtained with state-of-the-art ab-initio full-potential density-functional (DFT) LMTO (linearized muffin-tin orbital) calculations taking into account relativistic effects. For stretched structures in the experimentally accessible range the conduction band is exactly half-filled, whereas the band structures are more complex for the optimized structure. By studying the total energy as a function of unit-cell length and of a possible bond-length alternation we find that the system can lower its total energy by letting the bond lengths alternate leading to a structure containing separated dimers with bond lengths of about 2.5 \AA, largely independent of the stretching. However, first for fairly large unit cells (above roughly 7 \AA), is the total-energy gain upon this dimerization comparable with the energy costs upon stretching. We propose that this together with band-structure effects is the reason for the larger interatomic distances observed in recent experiments. We find also that although spin-orbit couplings lead to significant effects on the band structure, the overall conclusions are not altered, and that finite Au_2, Au_4, and Au_6 chains possess electronic properties very similar to those of the infinite chain.Comment: (14 pages, 5 figures; Elsevier Preprint style elsart.sty

Nuevos datos sobre la sedimentación terciaria en La Mancha (Ciudad Real)

Los datos obtenidos de la investigación geofísica y perforación de sondeos en la parte occidental de La Mancha han permitido determinar la estructura del sustrato del Neógeno: un conjunto de fosas controladas por fallas, que se generaron en periodos de tectónica distensiva. Se han separado tres  unidades litoestratigráficas: Unidad detrítica de la base, Unidad lutítica roja intermedia y Unidad carbonatada superior

Fission program at n_TOF

Since its start in 2001 the n_TOF collaboration developed a measurement program on fission, in view of advanced fuels in new generation reactors. A special effort was made on measurement of cross sections of actinides, exploiting the peculiarity of the n_TOF neutron beam which spans a huge energy domain, from the thermal region up to GeV. Moreover fission fragment angular distributions have also been measured. An overview of the cross section results achieved with different detectors is presented, including a discussion of the 237Np case where discrepancies showed up between different detector systems. The results on the anisotropy of the fission fragments and its implication on the mechanism of neutron absorption, and in applications, are also shown

Nuevos datos sobre la sedimentación terciaria en La Mancha (Ciudad Real)

Los datos obtenidos de la investigación geofísica y perforación de sondeos en la parte occidental de La Mancha han permitido determinar la estructura del sustrato del Neógeno: un conjunto de fosas controladas por fallas, que se generaron en periodos de tectónica distensiva. Se han separado tres  unidades litoestratigráficas: Unidad detrítica de la base, Unidad lutítica roja intermedia y Unidad carbonatada superior

Molecular gas at supernova local environments unveiled by EDGE

CO observations allow estimations of the gas content of molecular clouds, which trace the reservoir of cold gas fuelling star formation, as well as to determine extinction via H$_2$ column density, N(H$_2$). Here, we studied millimetric and optical properties at 26 supernovae (SNe) locations of different types in a sample of 23 nearby galaxies by combining molecular $^{12}$C$^{16}$O (J = 1 $\rightarrow$ 0) resolved maps from the EDGE survey and optical Integral Field Spectroscopy from the CALIFA survey. We found an even clearer separation between type II and type Ibc SNe in terms of molecular gas than what we found in the optical using H$\alpha$ emission as a proxy for current SF rate, which reinforces the fact that SNe Ibc are more associated with SF-environments. While A$_V$ at SN locations is similar for SNe II and SNe Ibc, and higher compared to SNe Ia, N(H$_2$) is significantly higher for SNe Ibc than for SNe II and SNe Ia. When compared to alternative extinction estimations directly from SN photometry and spectroscopy, we find that our SNe Ibc have also redder color excess but showed standard Na I D absorption pseudo-equivalent widths ($\sim$1 \AA). In some cases we find no extinction when estimated from the environment, but high amounts of extinction when measured from SN observations, which suggests that circumstellar material or dust sublimation may be playing a role. This work serves as a benchmark for future studies combining last generation millimeter and optical IFS instruments to reveal the local environmental properties of extragalactic SNe.Comment: MNRAS accepted, 17 pages, 8 Figures, 4 Table

Contenido de aminoácidos libres en frutos de chirimoyo durante la maduración

El chirimoyo es un fruto tropical que crece en algunos países de América y en una serie de selectivas áreas del sur de España, siendo una fuente rica de aminoácidos libres. Los efectos de las temperaturas después de la postrecolección de este fruto han sido estudiadas. La firmeza del fruto se ha determinado con un medidor de textura y los aminoácidos libres se determinaron por cromatografía en columna de intercambio iónico, utilizando un autoanalizador de aminoácidos. El chirimoyo se caracterizó por un alto contenido en prolina y citrulina. El ácido glutámico y la glutamina estaban también presentes pero en pequeñas cantidades. La citrulina y la prolina se incrementaron durante la maduración; el aumento dependió de la temperatura de almacenamiento

Experimental evidences of a large extrinsic spin Hall effect in AuW alloy

We report an experimental study of a gold-tungsten alloy (7% at. W concentration in Au host) displaying remarkable properties for spintronics applications using both magneto-transport in lateral spin valve devices and spin-pumping with inverse spin Hall effect experiments. A very large spin Hall angle of about 10% is consistently found using both techniques with the reliable spin diffusion length of 2 nm estimated by the spin sink experiments in the lateral spin valves. With its chemical stability, high resistivity and small induced damping, this AuW alloy may find applications in the nearest future

Note: "Lock-in accelerometry" to follow sink dynamics in shaken granular matter

Understanding the penetration dynamics of intruders in granular beds is relevant not only for fundamental Physics, but also for geophysical processes and construction on sediments or granular soils in areas potentially affected by earthquakes. While the penetration of intruders in two dimensional (2D) laboratory granular beds can be followed using video recording, it is useless in three dimensional (3D) beds of non-transparent materials such as common sand. Here we propose a method to quantify the sink dynamics of an intruder into laterally shaken granular beds based on the temporal correlations between the signals from a reference accelerometer fixed to the shaken granular bed, and a probe accelerometer deployed inside the intruder. Due to its analogy with the working principle of a lock in amplifier, we call this technique Lock in accelerometry (LIA). During Earthquakes, some soils can lose their ability to sustain shear and deform, causing subsidence and sometimes substantial building damage due to deformation or tumblin