Thermal effects on the resonance fluorescence of doubly dressed artificial atoms

In this work, robustness of controlled density of optical states in doubly driven artificial atoms is studied under phonon dissipation. By using both perturbative and polaron approaches, we investigate the influence of carrier-phonon interactions on the emission properties of a two-level solid-state emitter, simultaneously coupled to two intense distinguishable lasers. Phonon decoherence effects on the emission spectra are found modest up to neon boiling temperatures ($\sim 30$ K), as compared with photon generation at the Fourier transform limit obtained in absence of lattice vibrations (zero temperature). These results show that optical switching and photonic modulation by means of double dressing, do not require ultra low temperatures for implementation, thus boosting its potential technological applications.Comment: Submitted versio

Disrupted asteroid P/2016 G1. II. Follow-up observations from the Hubble Space Telescope

After the early observations of the disrupted asteroid P/2016 G1 with the 10.4m Gran Telescopio Canarias (GTC), and the modeling of the dust ejecta, we have performed a follow-up observational campaign of this object using the Hubble Space Telescope (HST) during two epochs (June 28 and July 11, 2016). The analysis of these HST images with the same model inputs obtained from the GTC images revealed a good consistency with the predicted evolution from the GTC images, so that the model is applicable to the whole observational period from late April to early July 2016. This result confirms that the resulting dust ejecta was caused by a relatively short-duration event with onset about 350 days before perihelion, and spanning about 30 days (HWHM). For a size distribution of particles with a geometric albedo of 0.15, having radii limits of 1 $\mu$m and 1 cm, and following a power-law with index --3.0, the total dust mass ejected is $\sim$2$\times$10$^7$ kg. As was the case with the GTC observations, no condensations in the images that could be attributed to a nucleus or fragments released after the disruption event were found. However, the higher limiting magnitude reachable with the HST images in comparison with those from GTC allowed us to impose a more stringent upper limit to the observed fragments of $\sim$30 m.Comment: 10 pages, 2 figures Accepted by Astronomical Journal, Nov. 2, 201

Time-resolved photometry of the young dipper RX~J1604.3-2130A:Unveiling the structure and mass transport through the innermost disk

Context. RX J1604.3-2130A is a young, dipper-type, variable star in the Upper Scorpius association, suspected to have an inclined inner disk, with respect to its face-on outer disk. Aims. We aim to study the eclipses to constrain the inner disk properties. Methods. We used time-resolved photometry from the Rapid Eye Mount telescope and Kepler 2 data to study the multi-wavelength variability, and archival optical and infrared data to track accretion, rotation, and changes in disk structure. Results. The observations reveal details of the structure and matter transport through the inner disk. The eclipses show 5 d quasi-periodicity, with the phase drifting in time and some periods showing increased/decreased eclipse depth and frequency. Dips are consistent with extinction by slightly processed dust grains in an inclined, irregularly-shaped inner disk locked to the star through two relatively stable accretion structures. The grains are located near the dust sublimation radius (similar to 0.06 au) at the corotation radius, and can explain the shadows observed in the outer disk. The total mass (gas and dust) required to produce the eclipses and shadows is a few % of a Ceres mass. Such an amount of mass is accreted/replenished by accretion in days to weeks, which explains the variability from period to period. Spitzer and WISE infrared variability reveal variations in the dust content in the innermost disk on a timescale of a few years, which is consistent with small imbalances (compared to the stellar accretion rate) in the matter transport from the outer to the inner disk. A decrease in the accretion rate is observed at the times of less eclipsing variability and low mid-IR fluxes, confirming this picture. The v sin i = 16 km s(-1) confirms that the star cannot be aligned with the outer disk, but is likely close to equator-on and to be aligned with the inner disk. This anomalous orientation is a challenge for standard theories of protoplanetary disk formation.Science & Technology Facilities Council (STFC): ST/S000399/1. ESO fellowship. European Union (EU): 823 823. German Research Foundation (DFG): FOR 2634/1 TE 1024/1-1. French National Research Agency (ANR): ANR-16-CE31-0013. Alexander von Humboldt Foundation. European Research Council (ERC): 678 194. European Research Council (ERC): 742 095. National Aeronautics & Space Administration (NASA). National Science Foundation (NSF). National Aeronautics & Space Administration (NASA): NNG05GF22G. National Science Foundation (NSF): AST-0909182, AST-1 313 422

Sistema para el control de acceso a un centro comercial

Sequential logic systems over the years have allowed an improvement in control and access systems. This article looks for a way to use this type of logic to create an autonomous system in Verilog for the access of people to a shopping mall, which should allow the realization of counts, movement analysis, and temperature detections, which allow avoiding the direct relationship with the security employees, making this way a protection measure for situations like the one that is currently being experienced with the global pandemic. This system, due to its configuration and accessibility, must be easy to understand, therefore the operation of this project is visualized with a traffic light configuration where green represents a positive action of entry, represents an alert or emergency. The system will give a stop signal, either for high temperatures or for people over or equal to the limits.Los sistemas de lógica secuencial a lo largo de los años han permitido un mejoramiento en los sistemas de control y de acceso. Este artículo busca la manera de usar este tipo de lógica para crear un sistema autónomo en Verilog de acceso de personas a un centro comercial, el cual debe permitir la realización de conteos, análisis de movimiento y detecciones de temperatura, que permitan evitar la relación directa con los empleados de seguridad haciendo de esta forma una medida de protección para situaciones como la que se está viviendo actualmente con la pandemia mundial. Este sistema, debido a su configuración y accesibilidad, debe ser de fácil comprensión, por esto el funcionamiento de este proyecto se visualiza con una configuración de semáforo en donde el verde representa una acción positiva de ingreso, mientras que el rojo representa una alerta o emergencia.&nbsp

Reducing depopulation in rural Spain: The impact of immigration

The attraction of foreign-born immigrants to rural areas in developed countries has aroused growing interest in recent years. The central issue in this study is the demographic impact of immigration in rural Spain, focusing on depopulated areas. The economic and demographic consequences of depopulation have become major concerns, and the arrival of international migrants has come to be seen as a possible solution. The aim of this study is to add to a literature in which qualitative research and local or regional perspectives predominate. The present research draws on quantitative findings for a significant part of Spain. The evidence in this study is principally based on population figures for the last years of the 20th century, a period of low immigration to Spain, and the early years of the 21st century, when the inflow of foreign migrants gathered intensity. We also explore the early consequences of the present economic crisis, which began in 2008. The analysis is based on estimates of native and foreign-born population growth for a range of territorial aggregations. Counterfactual techniques are also used. The results show that the arrival of immigrants has so far contributed substantially to reducing and even halting or reversing depopulation. A further series of analyses concentrates on the potential of rural areas to retain immigrants in the long run. The study also recommends a comprehensive policy approach in this regard

Molecular Dynamics Simulation of Polymer-Metal Bonds

Molecular simulation is becoming a very powerful tool for studying dynamic phenomena in materials. The simulation yields information about interaction at length and time scales unattainable by experimental measurements and unpredictable by continuum theories. This is especially meaningful when referring to bonding between a polymer and a metal substrate. A very important characteristic of polymers is that their physical properties do not rely on the detailed chemical structure of the molecular chains but only on their flexibility, and accordingly they will be able to adopt different conformations. In this paper, a molecular simulation of the bonding between vinyl ester polymer and steel is presented. Four different polymers with increasing chain lengths have been studied. Atomic co-ordinates are adjusted in order to reduce the molecular energy. Conformational changes in the macromolecules have been followed to obtain the polymer pair correlation function. Radius of gyration and end-to-end distance distributions of the individual chains have been used as a quantitative measurement of their flexibility. There exists a correlation between flexibility of the molecular chains and the energy of adhesion between the polymer and the metal substrate. Close contacts between the two materials are established at certain points but every atom up to a certain distance from the interface contributes to the total value of the adhesion energy of the system

Visible spectroscopy of the new ESO Large Program on trans-Neptunian objects and Centaurs: final results

A second large programme (LP) for the physical studies of TNOs and Centaurs, started at ESO Cerro Paranal on October 2006 to obtain high-quality data, has recently been concluded. In this paper we present the spectra of these pristine bodies obtained in the visible range during the last two semesters of the LP. We investigate the spectral behaviour of the TNOs and Centaurs observed, and we analyse the spectral slopes distribution of the full data set coming from this LP and from the literature. We computed the spectral slope for each observed object, and searched for possible weak absorption features. A statistical analysis was performed on a total sample of 73 TNOs and Centaurs to look for possible correlations between dynamical classes, orbital parameters, and spectral gradient. We obtained new spectra for 28 bodies, 15 of which were observed for the first time. All the new presented spectra are featureless, including 2003 AZ84, for which a faint and broad absorption band possibly attributed to hydrated silicates on its surface has been reported. The data confirm a wide variety of spectral behaviours, with neutral--grey to very red gradients. An analysis of the spectral slopes available from this LP and in the literature for a total sample of 73 Centaurs and TNOs shows that there is a lack of very red objects in the classical population. We present the results of the statistical analysis of the spectral slope distribution versus orbital parameters. In particular, we confirm a strong anticorrelation between spectral slope and orbital inclination for the classical population. A strong correlation is also found between the spectral slope and orbital eccentricity for resonant TNOs, with objects having higher spectral slope values with increasing eccentricity.Comment: 11 pages, 9 figure

Brain and Spinal Cord Interaction: Protective Effects of Exercise Prior to Spinal Cord Injury

We have investigated the effects of a spinal cord injury on the brain and spinal cord, and whether exercise provided before the injury could organize a protective reaction across the neuroaxis. Animals were exposed to 21 days of voluntary exercise, followed by a full spinal transection (T7–T9) and sacrificed two days later. Here we show that the effects of spinal cord injury go beyond the spinal cord itself and influence the molecular substrates of synaptic plasticity and learning in the brain. The injury reduced BDNF levels in the hippocampus in conjunction with the activated forms of p-synapsin I, p-CREB and p-CaMK II, while exercise prior to injury prevented these reductions. Similar effects of the injury were observed in the lumbar enlargement region of the spinal cord, where exercise prevented the reductions in BDNF, and p-CREB. Furthermore, the response of the hippocampus to the spinal lesion appeared to be coordinated to that of the spinal cord, as evidenced by corresponding injury-related changes in BDNF levels in the brain and spinal cord. These results provide an indication for the increased vulnerability of brain centers after spinal cord injury. These findings also imply that the level of chronic activity prior to a spinal cord injury could determine the level of sensory-motor and cognitive recovery following the injury. In particular, exercise prior to the injury onset appears to foster protective mechanisms in the brain and spinal cord

El paisaje eólico de la llanura aluvial de San Juan (Llanura Manchega Central)

[Resumen] El campo dunar de la Llanura aluvial de San Juan, esta caracterizado por la presencia dedunas arcillosas, limosas o limo-arcillosas. Morfologicamente, son dunas de tipo parabólico y otras con aspecto "cónico", "transverso" o "longitudinal", construidas por paleovientos efectivos que provenían del W y SW. Finalmente, se discute la edad y origen de estos complejos dunares.[Abstract] The dunes of the San Juan alluvial plain consists most characteristically of clayey, silty, and clayeysilty dunes, which morphologically are most commonly of parabolic type , but dome-shaped, transverse and linear dunes are present as well. These were built up by effective winds coming from the Wand SW. Finally, both the age and genesis of these dunes is discússed