Emergence of granular-sized magnetic bubbles through the solar atmosphere. II. Non-LTE chromospheric diagnostics and inversions

Magnetic flux emergence into the outer layers of the Sun is a fundamental mechanism for releasing energy into the chromosphere and the corona. In this paper, we study the emergence of granular-sized flux concentrations and the structuring of the corresponding physical parameters and atmospheric diagnostics in the upper photo- sphere and in the chromosphere. We make use of a realistic 3D MHD simulation of the outer layers of the Sun to study the formation of the Ca II 8542 line. We also derive semi-empirical 3D models from non-LTE inversions of our observations. These models contain depth-dependent information of the temperature and line-of-sight stratification. Our analysis explains the peculiar Ca II 8542 profiles observed in the flux-emerging region. In addition, we derive detailed temperature and velocity maps describing the ascent of magnetic bubbles from the photosphere to the chromosphere. The inversions suggest that, in active regions, granular-sized bubbles emerge up to the lower chromosphere where the existing large-scale field hinders their ascent. We report hints of heating when the field reaches the chromosphere.Comment: Submitted to ApJ, 10 Figure

Comercio colonial canario, siglo XVIII. Nuevo índice para su cuantificación: La contabilidad del Colegio de San Telmo, 1708-1776

II Coloquio de Historia Canario-Americana, (1977) Tomo II; Cuadros, tablas, gráficos y apéndice; 14 p.En el estudio del comercio colonial hispanoamericano diversas investigaciones han desvelado o van dando a conocer la distinta importancia y la aportación de los diferentes puertos españoles y americanos. Sobre los canarios, que contaban ya con excelentes estudios para una primera cuantificación y aproximación, vuelve a centrarse la atención, según veo en el programa de este Coloquio y sé por trabajos en vías de realización. En este contexto, me he interesado desde hace tiempo en el análisis del comercio colonial, hasta ahora ceñido al virreinato de Nueva España, quiero ofrecer en estas Sesiones una nueva perspectiva del comercio canario-americano en el siglo XVIII, fruto del trabajo de archivo que los alumnos de tercer curso de Historia Universal de la Universidad de Sevilla realizaron bajo mi dirección. La dificultad de formación de series estadísticas completas en la Edad Moderna hace que todo índice que para ello se ofrezca sea bien acogido y apreciado, pese a las limitaciones lógicas que, en distinto grado, puedan ofrecerPeer reviewe

Gamow-Siegert functions and Darboux-deformed short range potentials

Darboux-deformations of short range one-dimensional potentials are constructed by means of Gamow-Siegert functions (resonance states). Results include both Hermitian and non-Hermitian short range potentials which are exactly solvable. As illustration, the method is applied to square wells and barriers for which the transmission coefficient is a superposition of Fock-Breit-Wigner distributions. Resonance levels are calculated in the long lifetime limit by means of analytical and numerical approaches. The new complex potentials behave as an optical device which both refracts and absorbs light waves.Comment: 20 pages, 15 figures, LaTeX fil

Design of a Secure Transmission System for Secure Key Injection During Initialization Phase of IOT Devices

In the last decade society has experienced an exponential growth in the number of devices connected to the Internet. Recently, new gadgets called Internet of Things devices have appeared in our homes. Although they often lack a physical interface to directly interact with them, they are able to read information from sensors and autonomously communicate with servers, performing decisions accordingly. However, most of the domestic devices that are being commercialized do not implement strict security policies, potentially leading to security breaches that compromise the user’s privacy. The following work provides an alternative to the WPS technology in the initial setup phase of these devices, in which the gadget has to be loaded with the Wi-Fi key so it can connect to the Internet. The use of infrared technology implementing a Diffie-Hellman key exchange protocol to inject this key makes the process much safer, without compromising the cost of the device or the user experience