1,663 research outputs found
On the changes in the physical properties of the ionized region around the Weigelt structures in Eta Carinae over the 5.54-yr spectroscopic cycle
We present HST/STIS observations and analysis of two prominent nebular
structures around the central source of Eta Carinae, the knots C and D. The
former is brighter than the latter for emission lines from intermediate or high
ionization potential ions. The brightness of lines from intermediate and high
ionization potential ions significantly decreases at phases around periastron.
We do not see conspicuous changes in the brightness of lines from low
ionization potential (<13.6 eV) that the total extinction towards the Weigelt
structures is that the total extinction towards the Weigelt structures is AsubV
=2/0. that the total extinction towards the Weigelt structures is AV = 2.0.
Weigelt C and D are characterized by an electron density of that the total
extinction towards the Weigelt structures is AV = 2.0. Weigelt C and D are
characterized by an electron density of 10exp6.9 cm-3 that does not
significantly change throughout the orbital cycle. The electron temperature
varies from 5500 K (around periastron) to 7200 K (around apastron). The
relative changes in the brightness of He I lines are well reproduced by the
variations in the electron temperature alone. We found that, at phases around
periastron, the electron temperature seems to be higher for Weigelt C than that
of D. The Weigelt structures are located close to the Homunculus equatorial
plane, at a distance of about 1240 AU from the central source. From the
analysis of proper motion and age, the Weigelt complex can be associated with
the equatorial structure called the Butterfly Nebula surrounding the central
binary system.Comment: 19 pages, 18 figure
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Management of functional neurological disorder.
Functional neurological disorder (FND) is a common cause of persistent and disabling neurological symptoms. These symptoms are varied and include abnormal control of movement, episodes of altered awareness resembling epileptic seizures and abnormal sensation and are often comorbid with chronic pain, fatigue and cognitive symptoms. There is increasing evidence for the role of neurologists in both the assessment and management of FND. The aim of this review is to discuss strategies for the management of FND by focusing on the diagnostic discussion and general principles, as well as specific treatment strategies for various FND symptoms, highlighting the role of the neurologist and proposing a structure for an interdisciplinary FND service
A Study of the Export Financing System in the Philippines
How much support is the Philippine government giving to its export sector by means of its financing schemes? Are the small and indirect exporters given preference or assistance? How supportive is the entire export financing system in the country to the attainment of an export-driven development strategy? These questions are the primary concern of this paper. Based on a survey sample of seven commercial banks, it examines the various components of the Philippine export financing system. A review of the Philippine trade policies and its export profiles is provided.financial market, financial economy, financial sector, export commodities, financial services
Mullitización de mezclas de arcilla caolinítica e hidróxido de aluminio
Se calcinaron mezclas de arcilla caolinítica e hidróxido de aluminio, los ensayos se realizaron entre 900 y 1400°C, a distintos tiempos de calentamiento. Los compuestos obtenidos se estudiaron por técnicas de difracción de rayos X, dejándose establecido que se produce reacción entre la agregada y la liberada, para formar mullita a temperaturas inferiores a 1400°C, cuando la mezcla se precalienta varias horas a temperaturas próximas a los 1000°C. Se confirmó el fenómeno de nucleación de mullita, por tratamientos térmicos similares en mezclas de ácido silícico e hidróxido de aluminio puros. Es de interés tecnológico lograr la transformación total a mullita, de mezclas arcilla alúmina, a temperaturas no mayores de 1400°C. Por esto, el presente trabajo tuvo por fin comprobar si la que se forma durante el calentamiento del puede entrar en la reacción de mullitización del caolín, combinándose con la sílice remanente.Mixtures of kaolin clay and aluminium hydroxide were heated to temperatures between 900 and 1400°C for different periods. The heat treated samples were studied by X-ray diffraction techniques. It was clearly shown that the added reacts with the free to form mullite at temperatures below 1400°C when the mixtures were preheated for several hours at temperatures approaching 1000°C. Through similar heating treatments in mixtures of silicic acid and pure aluminium hydroxide, the mullite nucleation phenomenon was confirmed. It is of technological interest to achieve the total transformation to mullite of the clay-alumina mixtures by heating to temperatures not exceeding 1400°C. It was the aim of the present investigation to observe the reaction between the form ed from and the silica freed from the kaolin to form mullite
Contribution of agronomic traits for sugar yield in sweet sorghum genotypes
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