Current Sheet Regulation of Solar Near-Relativistic Electron Injection Histories

We present a sample of three large near-relativistic (>50 keV) electron events observed in 2001 by both the ACE and the Ulysses spacecraft, when Ulysses was at high-northern latitudes (>60°) and close to 2 AU. Despite the large latitudinal distance between the two spacecraft, electrons injected near the Sun reached both heliospheric locations. All three events were associated with large solar flares, strong decametric type II radio bursts and accompanied by wide (>212°) and fast (>1400 km s-1) coronal mass ejections (CMEs). We use advanced interplanetary transport simulations and make use of the directional intensities observed in situ by the spacecraft to infer the electron injection profile close to the Sun and the interplanetary transport conditions at both low and high latitudes. For the three selected events, we find similar interplanetary transport conditions at different heliolatitudes for a given event, with values of the mean free path ranging from 0.04 AU to 0.27 AU. We find differences in the injection profiles inferred for each spacecraft. We investigate the role that sector boundaries of the heliospheric current sheet (HCS) have on determining the characteristics of the electron injection profiles. Extended injection profiles, associated with coronal shocks, are found if the magnetic footpoints of the spacecraft lay in the same magnetic sector as the associated flare, while intermittent sparse injection episodes appear when the spacecraft footpoints are in the opposite sector or a wrap in the HCS bounded the CME structure.

Los indígenas sanapanás, Carlos Casado y las fotografias de de Sanctis

El español Carlos Casado del Alisal se estableció en la ciudad de Rosario en el año 1857, y configuró un importante número de empresas dedicadas a la producción del trigo, del quebracho colorado de la zona del Chaco Paraguayo, y en especial a la exportación de ambos recursos desde el Puerto de Rosario a Europa y a los Estados Unidos. En este artículo nos referimos a la colaboración que hizo el español republicano Matías Alonso Criado al facilitar a Casado la llegada de la Orden Salesiana a la zona costera del Chaco con la finalidad de "educar" a los indígenas sanapanás. Para elaborar este artículos hemos consultado el Archivio della Sacra Congregazione degli Affari Ecclesiastici Straordinari del Archivio Segreto Vaticano (en adelante A.S.V., A.E.S.).

Circumsolar energetic particle distribution on 2011 November 3

Late on 2011 November 3, STEREO-A, STEREO-B, MESSENGER, and near-Earth spacecraft observed an energetic particle flux enhancement. Based on the analysis of in situ plasma and particle observations, their correlation with remote sensing observations, and an interplanetary transport model, we conclude that the particle increases observed at multiple locations had a common single source active region and the energetic particles filled a very broad region around the Sun. The active region was located at the solar backside (as seen from Earth) and was the source of a large flare, a fast and wide coronal mass ejection, and an EIT wave, accompanied by type II and type III radio-emission. In contrast to previous solar energetic particle events showing broad longitudinal spread, this event showed clear particle anisotropies at three widely separated observation points at 1AU, suggesting direct particle injection close to the magnetic footpoint of each spacecraft, lasting for several hours.We discuss these observations and the possible scenarios explaining the extremely broad particle spread for this event.

Multi-Eruption Solar Energetic Particle Events Observed by SOHO/ERNE

In the last two decades of studying the Solar Energetic Particle (SEP) phenomenon, intensive emphasis has been put on how and when and where these SEPs are injected into interplanetary space. It is well known that SEPs are related to solar flares and CMEs. However, the role of each in the acceleration of SEPs has been under debate since the major role was taken from flares ascribed to CMEs step by step after the skylab mission, which started the era of CME spaceborn observations. Since then, the shock wave generated by powerful CMEs in between 2-5 solar radii is considered the major accelerator. The current paradigm interprets the prolonged proton intensity-time profile in gradual SEP events as a direct effect of accelerated SEPs by shock wave propagating in the interplanetary medium. Thus the powerful CME is thought of as a starter for the acceleration and its shock wave as a continuing accelerator to result in such an intensity-time profile. Generally it is believed that a single powerful CME which might or might not be associated with a flare is always the reason behind such gradual events.

In this work we use the Energetic and Relativistic Nucleus and Electrons ERNE instrument on board Solar and Heliospheric Observatory SOHO to present an empirical study to show the possibility of multiple accelerations in SEP events. In the beginning we found 18 double-peaked SEP events by examining 88 SEP events. The peaks in the intensity-time profile were separated by 3-24 hours. We divided the SEP events according to possible multiple acceleration into four groups and in one of these groups we find evidence for multiple acceleration in velocity dispersion and change in the abundance ratio associated at transition to the second peak. Then we explored the intensity-time profiles of all SEP events during solar cycle 23 and found that most of the SEP events are associated with multiple eruptions at the Sun and we call those events as Multi-Eruption Solar Energetic Particles (MESEP) events. We use the data available by Large Angle and Spectrometric Coronograph LASCO on board SOHO to determine the CME associated with such events and YOHKOH and GOES satellites data to determine the flare associated with such events. We found four types of MESEP according to the appearance of the peaks in the intensity-time profile in large variation of energy levels. We found that it is not possible to determine whether the peaks are related to an eruption at the Sun or not, only by examining the anisotropy flux, He/p ratio and velocity dispersion. Then we chose a rare event in which there is evidence of SEP acceleration from behind previous CME. This work resulted in a conclusion which is inconsistent with the current SEP paradigm. Then we discovered through examining another MESEP event, that energetic particles accelerated by a second CME can penetrate a previous CME-driven decelerating shock. Finally, we report the previous two MESEP events with new two events and find a common basis for second CME SEPs penetrating previous decelerating shocks. This phenomenon is reported for the first time and expected to have significant impact on modification of the current paradigm of the solar energetic particle events.

Nationalismin vaikutus lähetykseen

Kirjallisuusarvostelu

Lähetys ja ykseys

Kirjallisuusarvostelu

A Test Bed Applied Mobile Robot Navigation

It is presented a test bed applied to studies on dynamics, control, and navigation of mobile robots. A cargo ship scale model was chosen, which can be radio-controlled or operated autonomously through an embedded control system. A control program, which manages on board mission execution, is implemented on a microcontroller. Navigation is based on an electronic compass, which includes automatic compensation for pitch and roll motions. Heading control loop is based on this sensor, and on a rudder positioning system. A propulsion control system is also implemented. Typical manoeuvres as the turning test and "zig-zag", were implemented and tested. They are included on a manoeuvre library, and can be accessed independently or in combined modes. The embedded system is also in charge of signal acquisition and storing during the missions. It is possible to analyse experiments on identification of ship dynamics, control, and navigation, through the data transferred to a PC by serial communication. Navigation is going to be improved by including inertial sensors on board, and a DGPS. Preliminary tests are aimed to ship identification, and manoeuvrability, using free model tests. Future steps include extending this system for developing other mobile robots as, ROVs, AUVs, and aerial vehicles.

Saksa protestanttisen lähetystyön synnyinmaana ja islamilaisen muuttoliikkeen kohdemaana

Kirjallisuusarvostelu

Extraits de comptes royaux, du XVe et du XVIe s. principalement relatifs aux chanceliers et aux secrétaires du roi, par Galland.

Missions étrangères.

Extraits pour l'hist d'Aragon par Galand.

Missions étrangères.

Shi wei.

Double.Impression plus nette.

綸音特典Lun yin te dian.Édit solennel.

Relatif à un voyage fait par l'Empereur (1705).

Chinois 4935

Contient : I太平萬年書Tai ping wan nian shu.Traités sur le système du monde ; II南京羅主教神道碑記Nan jing luo zhu jiao shen dao bei ji.Épitaphe du R. P. Alexandre Ciceri, évêque de Nanking

妄推吉凶辯Wang zhui ji xiong bian.Réfutation de Yang Guang xian et des devins.

Par le P. Verbiest (1669) ; texte avec annotations dans la marge supérieure. Gravé de nouveau à Canton, au Da yuan tang.

天工開物Tian gong kai wu.Traités des industries diverses.

Par Song Ying xing, de Feng xin ; préface de l'auteur (1637). Texte avec figures nombreuses : nourriture, vêtement, condiments, terre cuite, fer, voitures et bateaux, métaux, armes, pierres précieuses, etc.18 livres en 3 sections.