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Nomenclatura Unesco > (25) Ciencias de la Tierra y Espacio > (2501) Ciencias de la atmósfera > (2501.13) Auroras

Mostrando recursos 1 - 20 de 15,634

1. Printed mGreat Britain. Pergamon Press plc Sondrestrom and EISCAT radar observations of poleward-moving amoral forms - R. M. Robinson; C. R. Clauer; Ix La Beaujardi~e; J. D. Kelly; E. Friis-christensens; M. Lockwood I
Abstract-During many magnetospheric substorms, the aurora1 oval near midnight is observed to expand poleward in association with strong negative perturbations measured by local ground magnetometers. We show Sondrestrom and EISCAT incoherent scatter adar measurements during three such events. In each of the events, enhanced ionization produced by the precipitation moved northward by several degrees of latitude within 10-20 min. The electric fields measured uring the three events were significantly different. In one event the electric field was southward everywhere within the precipitation region. In the other two events a reversal in the meridional component of the field was observed. In...

2. Search Engine for Punjabi - Tanjyot Aurora; Brahmaleen Kaur
The World Wide Web (WWW), helps to share information globally, the amount information has outgrown billions of databases. Its size, heterogeneity and human –oriented semantics pose a serious obstacle in search for desired information. Traditional search engines like Google help naïve users to access web resources and perform only word based indexing and searching may provide with irrelevant documents that are presented to user. Addition of semantics to search engine solves the two problems associated with search engines low precision and low recall. Work has been done in English and Hindi dialect but not much work has been done for...

Abstract. Optical observations of a dayside auroral brightening sequence, by means of all-sky TV cameras and meridian scanning photometers, have been combined with EISCAT ion drift observations within the same invariant latitude- MLT sector. The observations were made during a January 1989 campaign by utilizing the high F region ion densities during the maximum phase of the solar cycle. The chaPacteristic intermittent optical events, covering ~300 km in east-west extent, move eastward (antisunward) along %he poleward boundary of the persistent back•ound aurora at velocities of ~1.5

4. Spatial and temporal regulation of Condensins I and II in mitotic chromosome assembly in human cells - Takao Ono; Yuda Fang; David L. Spector; Tatsuya Hirano
Two different condensin complexes make distinct contributions to metaphase chromosome architecture in vertebrate cells. We show here that the spatial and temporal distributions of condensins I and II are differentially regulated during the cell cycle in HeLa cells. Condensin II is predominantly nuclear during interphase and contributes to early stages of chromosome assembly in prophase. In contrast, condensin I is sequestered in the cytoplasm from interphase through prophase and gains access to chromosomes only after the nuclear envelope breaks down in prometaphase. The two complexes alternate along the axis of metaphase chromatids, but they are arranged into a unique geometry...

5. 1874 to arbitrate the dispute between - Prime Minister Mackenzie Was
livid, not simply at what he considered a British attempt to interfere in Canadian internal matters, but because of the implication that British Columbia might have a legitimate grievance to arbitrate. He railed at the perfidiousness of British Columbians. According to Margaret Ormsby, Mackenzie’s “relations with provincial politicians were soon to leave him with the impression that British Columbians were a race apart, skilled in dissembling and adept at refusing to make plain statements of fact and candid declarations of policy. ” His views were founded on his belief that British Columbians had total “disregard for the interests of the...

6. Events of enhanced convection and related dayside auroral activity - J. Moen; M. Lockwood; W. F. Denig; U. P. Lovhaug; B. Lybekk; A. Egel; D. Opsvik; E. Friis-christensen
Abstract. In this paper we study the high-latitude plasma flow variations associated with a periodic (-8 min) sequence of auroral forms moving along the polar cap boundary, which appear to be the most regularly occuring dayside auroral phenomeno• under conditions of southward directed interplanetary magnetic field. Satellite data on auroral particle precipitation and ionospheric plasma drifts from DMSP F10 and F11 are combined with ground-based optical and ion flow measurements for January 7, 1992. Ionospheric flow measurements of 10-s resolution over the range of invariant latitudes from 71 ø to 76 ø were obtained by operating both the European incoherent...

7. INFERRING THE STRUCTURE OF THE SOLAR CORONA AND INNER HELIOSPHERE DURING THE MAUNDER MINIMUM USING GLOBAL THERMODYNAMIC MAGNETOHYDRODYNAMIC SIMULATIONS - Pete Riley; Roberto Lionello; Jon A. Linker; Andre Balogh; Jürg Beer; Paul Charbonneau; Nancy Crooker; Marc Derosa; Mike Lockwood; Matt Owens; Ken Mccracken; Ilya Usoskin; S. Koutchmy
Observations of the Sun’s corona during the space era have led to a picture of relatively constant, but cyclically varying solar output and structure. Longer-term, more indirect measurements, such as from 10Be, coupled by other albeit less reliable contemporaneous reports, however, suggest periods of significant departure from this standard. The Maunder Minimum was one such epoch where: (1) sunspots effectively disappeared for long intervals during a 70 yr period; (2) eclipse observations suggested the distinct lack of a visible K-corona but possible appearance of the F-corona; (3) reports of aurora were notably reduced; and (4) cosmic ray intensities at Earth...

8. VARIABILITY OF DAYSIDE CONVECTION AND MOTIONS OF THE CUSP/CLEFT AURORA - M. Lockwood L; J. Moen; S. W. H. Cowley; A. D. Farmer; U. P. Lvhaug; H. Liihr; V. N. Davda I
Abstract. We present measurements of the ionospheric plasma flow over the range of invariant latitudes 71-76 ø, observed at 10-second resolution using both the EISCAT radars, with simultaneous observations of the 630 nm cusp/cleft aurora made by a meridian-scanning photometer at Ny]klesund, Svalbard. A major increase inthe trans-auroral voltage from 5 to 40 kV (associated with sunward convection in the early afternoon sector) is found to follow a southward motion of the aurora and coincide with the onset of regular transient auroral breakup events. It is shown that these observations are consistent with recent theoretical work on how ionospheric flows...

9. Simultaneous observations of reconnection pulses at Cluster and their effects on the cusp aurora observed at the Chinese Yellow River Station
signatures were observed. During this interval, simultaneous and conjugated all‐sky

10. Modeling
the observed proton aurora and ionospheric convection responses to changes in the IMF clock angle: 2. Persistence of ionospheric convection

11. Printed in Great Britain. Pergamon Press plc AURORAL AND PLASMA FLOW TRANSIENTS AT MAGNETIC NOON - M. Lockwood; P. E. Sandholt; A. D. Farmer; S. W. H. Cowley; B. Lybekk; V. N. Davda
Abstract-We present observations of a transient event in the dayside aurora1 ionosphere at magnetic noon. F-region plasma convection measurements were made by the EISCAT radar, operating in the beamswinging “Polar ” experiment mode, and simultaneous observations of the dayside aurora1 emissions were made by optical meridian-scanning photometers and all-sky TV cameras at Ny Alesund, Spitzbergen. The data were recorded on 9 January 1989, and a sequence of bursts of flow, with associated transient aurora, were observed between OX:45 and 11:00 U.T. In this paper we concentrate on an event around 09:05 U.T. because that is very close to local magnetic...

12. Two Types of Aurora on Mars as Observed by MAVEN's Imaging UltraViolet Spectrograph - Schneider; Deighan; Jain; Stiepen, Arnaud; et al.

13. Revisiting the theory and usage of junction capacitance: Application to high efficiency amorphous/crystalline silicon heterojunction solar cells - Kleider, Jean-Paul; Alvarez, José; Brézard-Oudot, Aurore; Gueunier-Farret, Marie-Estelle; Maslova, Olga
International audience

14. 1 UK Lunar Science Missions: MoonLITE & Moonraker - Yang Gao; Mark Taylor; Jim Clemmet; Dave Parker; Ian A; Andrew J. Ball; Lionel Wilson; Alex Da Silva Curiel; Phil Davies; Martin Sweeting; Adam Baker
been preparing a 'smallsat ' approach to achieving a low-cost lunar mission for more than a decade – including various activities, such as the earlier ESA study on LunarSat and currently hardware contribution to the Chandrayaan-1 mission. With the recent successes in GIOVE-A, TOPSAT & BEIJING-1, alongside participation in Aurora & Chandrayaan-1, Surrey have developed capabilities for providing affordable engineering solutions to space exploration. SSTL/SSC was recently funded by UK Particle Physics and Astronomy Research Council (PPARC) to undertake a study on low-cost lunar mission concepts that could address key scientific questions. This paper presents some key results from this...

15. Problemas derivados de la ausencia de armonización en la Unión Europea: residencia fiscal societaria, sucesiones internacionales e Impuesto sobre el Patrimonio - Ribes Ribes, Aurora
El trabajo aborda las distintas problemáticas derivadas de la ausencia de armonización en la Unión Europea, por lo que respecta a la residencia fiscal de las personas jurídicas, y a los Impuestos sobre el Patrimonio y sobre Sucesiones y Donaciones. Detectadas las distorsiones y aspectos susceptibles de mejora, la autora apunta posibles soluciones a fin de perfeccionar la regulación en vigor.

16. Reflexiones acerca de un futuro Convenio multilateral en el ámbito de la Unión Europea - Ribes Ribes, Aurora
Al hilo de la Acción 15 del Proyecto BEPS (Base erosion and profit shifting), liderado por la OCDE y el G-20, la autora plantea la posibilidad de adoptar un Convenio modelo en materia de renta y patrimonio en el ámbito de la Unión Europea, como preludio de un Tratado multilateral europeo para evitar la doble imposición internacional y la evasión fiscal.

17. El Reglamento español de procedimientos amistosos en materia de imposición directa: propuestas de mejora - Ribes Ribes, Aurora
Con ocasión de la Acción 14 del Proyecto BEPS (Base erosion and profit shifting), auspiciado por la OCDE y el G-20, vuelve a cobrar relevancia la necesidad de incrementar la eficacia de los mecanismos alternativos de resolución de conflictos en el ámbito internacional tributario. El presente trabajo analiza pormenorizadamente la regulación española de la fase interna del procedimiento amistoso, denuncia las deficiencias existentes y aporta propuestas de mejora, desde la reflexión crítica.

18. Saturn’s aurora observed by the Cassini camera at visible wavelengths - Dyudina, Ulyana A.; Ingersoll, Andrew P.; Ewald, Shawn P.; Wellington, Danika
The first observations of Saturn’s visible-wavelength aurora were made by the Cassini camera. The aurora was observed between 2006 and 2013 in the northern and southern hemispheres. The color of the aurora changes from pink at a few hundred km above the horizon to purple at 1000–1500 km above the horizon. The spectrum observed in 9 filters spanning wavelengths from 250 nm to 1000 nm has a prominent H-alpha line and roughly agrees with laboratory simulated auroras. Auroras in both hemispheres vary dramatically with longitude. Auroras form bright arcs between 70° and 80° latitude north and between 65° and 80°...

19. Older adults with cognitive and mobility-related limitations: Social deprivation and forms of care received - Fontaine, Roméo; Pino, Maribel; Jean-Baptiste, Marine; Philibert, Aurore; Briant, Nicolas; Joël, Marie-Eve
A paraître

20. $rec.titulo - Marsh Arts (family Coenagrionidae; Marsh Darts
Marsh darts are slender and small damselflies with varied colouration. These non-iridescent damselflies rest with wings closed over thei r body. The wings are transparent and rounded at the tip. The long and slender abdomen is slightly longer than the h ind w ing. Some o f the smal les t damselflies like the Golden Dartlet (Ischnura aurora) is from this family. Marsh Darts are found throughout the world. World over, this family is represented by about 1147 species. Within Indian limits, 65 species are known and in peninsular India 25 species are recorded. The marsh darts breed in a...

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