Low Solar Activity
Mostrando 13-24 de 27 artigos, teses e dissertações.
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13. Preparation, structural and electrochemical properties of V2O5-WO3 xerogel composite / Obtenção, caracterização e estudos das propriedades de compósitos formados por xerogéis de pentóxido de vanádio e óxido de tungstênio
Vanadium pentoxide xerogel has a bi-dimensional structure which is suitable for intercalation of a variety of ions, organic compounds, and even polymeric species. In addition, when associated with other metal oxides such as WO3 and MoO3, it presents an important role in catalysis, since the resulting oxides act as promoters in catalytic reduction of the NOx
Publicado em: 2007
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14. Relação sol-terra estudada através de anéis de crescimento de coníferas do holoceno recente e do triássico / Sun-earth relationship studied by tree growth rings in conifers from holocene and triassic
The study of the Sun and of its energy flux variations is recent and fully experimental. For this reason , if is very important develop studies in order to understand the past and predict the future using natural records at the Earth surface to monitor solar variations and their effects on climate. The studies about the Sun s variations and Sun-Earth-Climate
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 30/08/2006
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15. Dependência das propriedades da região-D ionosférica com o ciclo de atividade solar / Dependence of ionospheric D region properties on solar activity cycle
The goal of this work is to provide new clues for a better understanding of the quiescent ionosphere during different solar activity conditions. For that we study the lower ionospheric response to external perturbations, as solar X-rays emitted during flares. We use solar X-ray fluxes provided by GOES satellites, and ionospheric SPA (Sudden Phase Anomalies)
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 06/07/2006
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16. Dependência das propriedades da região-D ionosférica com o ciclo de atividade solar / Dependence of ionospheric D region properties on solar activity cycle
O objetivo desta dissertação é contribuir para o melhor entendimento da ionosfera quiescente em diferentes condições de atividade solar. Para tanto, estudamos a sua resposta a eventos perturbadores externos constituídos pelas emissões em raios-X durante explosões solares. Utilizamos os fluxos em raios-X obtidos como satélite GOES e os eventos ionosf
Publicado em: 2006
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17. Sun-earth relationship studied by tree growth rings in conifers from holocene and triassic / Relação sol-terra estudada através de anéis de crescimento de coníferas do holoceno recente e do triássico
The study of the Sun and of its energy flux variations is recent and fully experimental. For this reason , if is very important develop studies in order to understand the past and predict the future using natural records at the Earth surface to monitor solar variations and their effects on climate. The studies about the Sun s variations and Sun-Earth-Climate
Publicado em: 2006
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18. A influência dos parâmetros do vento solar na emissão de AKR durante tempestades magnéticas / The influence of the solar wind parameters on the AKR emission during magnetic storms
Several phenomena could be better studied and even disclosed after the development of the satellites and spacecrafts. Auroral Kilometric Radiation (AKR) is one of these phenomena. AKR was first detected only about thirty years ago; its typical frequencies are too low to penetrate earthward across the ionosphere. This radiation is generated through wave-parti
Publicado em: 2006
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19. Protetor solar: desenvolvimento farmacotÃcnico e avaliaÃÃo da eficÃcia e seguranÃa
Besides its physiologic functions, the skin has an important social function, as it could be associated with good health and well-being. Day by day, the skin is exposed to many hazardous factors, such as solar radiation. The understanding about harmful effects caused by excessive sun exposition increased the consumption of sunscreen lotions. Simultaneouls, i
Publicado em: 2005
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20. Ionospherica F-layer nocturnal zonal drift studies over Brazilian region / Estudos das derivas zonais da camada F da ionosfera noturna sobre a região brasileira
This study focused on the nocturnal zonal plasma drifts of the ionosphere (F layer) at equatorial and low latitude regions of the Brazil. The analysis is interpreted using the simple plasma drift model (coupled ionosphere-electric field model of Eccles, 1998) and monochromatic digital images of the OI630nm emission, which allow direct visualization of the io
Publicado em: 2005
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21. Sizing procedure of solar heating systems for agricultural products drying / Metodologia de dimensionamento de sistemas de aquecimento solar para secagem de produtos agricolas
A solar collector design procedure was proposed for sizing solar assisted crop-drying systems using empiric correlations, previously found, to determine the solar fraction supplied by the system. A case study of an in-bin crop drying was accomplished in the city of Campinas - SP with pre-heating of the air through a solar collector complemented by convention
Publicado em: 2004
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22. Sobre a relação entre rotação, atividade crosmosférica e abundância de lítio em estrelas subgigantes
The connection between rotation, CaII emission flux and lithium abundance is analyzed for a sample of subgiant stars, with evolutionary status was determined from the Toulouse-Geneve code and HlPPARCOS trigonometric parallax measurements. We noted that the distribution of rotation and CaII emission flux, as a function of effective temperature, shows a discon
Publicado em: 2003
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23. Estudos da deriva zonal e dinâmica das bolhas de plasma na região tropical / Zonal drifts and dynamical study of the plasma bubbles over the tropical region
All-sky airglow OI 630 nm images obtained at Cachoeira Paulista in the period from January 1989 to December 1991 and January 1995 to December 1997 are analysed to study the nocturnal and seasonal dynamic behavior, as well as bifurcation variations of plasma bubbles during high and low solar activity. Also, all-sky images from São João do Cariri and Cachoei
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 19/02/2002
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24. Estudos da deriva zonal e dinâmica das bolhas de plasma na região tropical / Zonal drifts and dynamical study of the plasma bubbles over the tropical region
All-sky airglow OI 630 nm images obtained at Cachoeira Paulista in the period from January 1989 to December 1991 and January 1995 to December 1997 are analysed to study the nocturnal and seasonal dynamic behavior, as well as bifurcation variations of plasma bubbles during high and low solar activity. Also, all-sky images from São João do Cariri and Cachoei
Publicado em: 2002