3 Dark Energy
Mostrando 13-24 de 90 artigos, teses e dissertações.
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13. Nanofibras de carbono verticalmente alinhadas:: estudo do crescimento por microscopia eletrônica de transmissão
This work is about the growth of vertically aligned Carbon Nanofibers - CNFs - grown by Plasma Enhanced Chemical Vapour Deposition - PECVD. Being so, a detailed study of catalyst particle is necessary and Transmission Electron Microscopy - TEM - is fundamental for this knowledge. Some analytical techniques associated to TEM were used: Bright and Dark Field I
Publicado em: 2008
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14. Efeitos da inibição da protoporfirinogênio IX oxidase sobre as trocas gasosas e fluorescência da clorofila a em plantas de soja (Glycine max L. Merrill) / Effects of inhibition of protoporphyrinogen oxidase IX on gas exchange and chlorophyll fluorescence of soybean plants (Glycine max L. Merrill)
The photosynthetic fixation of CO2 depends on the capture of light energy by the harvest complex (chlorophyll b and carotenoids), which transfer the energy to the photosystems reaction centers (chlorophyll a). The electrons transfer chain established between the photosystems generates reducing power necessary for the CO2 fixation in the Calvin cycle. The int
Publicado em: 2008
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15. Ocupação humana e transformação da paisagem na Amazônia brasileira / Human settlement and landscape transformation in the Brazilian Amazon
In this planet, very few environments are free from anthropogenic disturb. The prehistoric populations used to play significant roles for the formation of some kind of landscapes; the consequences of their actions contributed to the present landscape characteristics. At the Amazon, these transformations are inferred from anthropogenic vestiges, such as: (1)
Publicado em: 2008
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16. Efeitos das inomogeneidades da matéria em Cosmologias Aceleradas
Os recentes avanços observacionais da Astronomia e um arcabouço teórico cada vez mais consistente, transformaram a Cosmologia numa das mais excitantes áreas da ciência contemporânea. Nesta tese, modelos homogêneos e inomogêneos contendo matéria escura e diferentes tipos de energia escura são confrontados com dados observacionais recentes. Inicialme
Publicado em: 2007
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17. Hydrogen influence on gallium arsenide thin films prepared by rf-magnetron sputtering technique
We investigate the effect of the hydrogen intentional incorporation on the structural properties of the amorphous gallium arsenide prepared by rf-magnetron sputtering technique. The properties of the non-hydrogenated films are: band gap of 1.4 eV (E04), Urbach energy of 110 meV, stoichiometric composition ([As]/[Ga] = 0.50), and dark conductivity of about 3.
Brazilian Journal of Physics. Publicado em: 2006-09
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18. Photodynamic action of mesoporphyrins on mitochondrial functions and LNCaP cell viability / Ação fotodinamica de meso-porfirinas sobre função mitocondrial e viabilidade de celulas LNCaP
The action of irradiated cationic Fe(III)TMPyP and anionic Fe(III)TPPS4 forms of mesoporphyrins on mitochondrial functions was investigated using experimental conditions that caused minimal effects on mitochondria in the dark. Treatment of mitochondria with 1 µM Fe(III)TMPyP for 2 min decreased the respiratory control by 3% in the dark and 28% after irradia
Publicado em: 2006
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19. MicropropagaÃÃo calogÃnese e irradiaÃÃo da figueira "Roxo de valinhos" / Micropropagation, callogenesis and irradiation of fig plants âRoxo de Valinhosâ
It was carried out three in vitro works with âRoxo de Valinhosâ fig plants. The first one aimed to verify the sensibility of explants to gamma radiation and the plantlets were separated by size (2,5 to 4,5; 5 to 7 and 8 to 10 cm) and were taken to the Nuclear Energy Center, irradiated on the doses 10, 20,30,40 e 50 Gy and cutted separating the bud portion:
Publicado em: 2006
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20. Respostas ao estresse osmótico e hipóxico em traíra, Hoplias malabaricus (Teleostei, Erythrinedae) aspectos fisiológicos e adaptativos.
The stress level, via change in the plasma concentration of cortisol and the physiological and metabolic responses caused by osmotic shock and hypoxia and the effect of cortisol injection on theses responses, were studied in traíra, Hoplias malabaricus, injected and non-injected with cortisol exogenous (IC) and maintained in water similar to it natural envi
Publicado em: 2006
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21. Statefinder revisited
The quality of supernova data will dramatically increase in the next few years by new experiments that will add high-redshift supernova to the currently known ones. In order to use this new data to discriminate between different dark energy models, the statefinder diagnostic was suggested [1] and investigated by Alam et al.[3] in the light of the proposed Su
Brazilian Journal of Physics. Publicado em: 2005-12
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22. Alternative dark energy models: an overview
A large number of recent observational data strongly suggest that we live in a flat, accelerating Universe composed of ~ 1/3 of matter (baryonic + dark) and ~ 2/3 of an exotic component with large negative pressure, usually named Dark Energy or Quintessence. The basic set of experiments includes: observations from SNe Ia, CMB anisotropies, large scale struct
Brazilian Journal of Physics. Publicado em: 2004-03
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23. Tratamento de chorume de aterro sanitario usando eletrolise foto-assistida / Treatment of landfill leachate by photo-assisted electrolysis
Sanitary landfills are the major method used today for the disposal and management of municipal solid waste. Decomposition of waste and rainfall generate leachate at the bottom of landfills, causing groundwater contamination. The leachate is a dark grey, foul smelling solution and it can be considered a complex effluent, often containing organic compounds, h
Publicado em: 2004
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24. Analysis of the energy consumption and sensorial comparison for basil drying under different treatments. / Analise do consumo energetico e comparação sensorial para a secagem de manjericão sob diferentes tratamentos.
Several kind of air treatments are used to dry some products. Air, after some of these treatments, has higher temperatures than ambient temperatures and lower relative humidities, that results in lose of components responsible for color and flavor. This work has as goals the built and instrumentation of a plant to treat ambient air and a tray dryer. The prod
Publicado em: 2003