3 Dark Energy
Mostrando 1-12 de 90 artigos, teses e dissertações.
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1. Thermal, structural and optical properties of magnetic BiFeO3 micron-particles synthesized by coprecipitation method: heterogeneous photocatalysis study under white LED irradiation
Abstract Bismuth ferrite, BiFeO3 (BFO) prepared via a coprecipitation method, was used as an effective photocatalyst for the degradation of methylene blue (MB) using a white light-emitting diode (LED-50 W) lamp. The as-prepared material was characterized by TGA, XRD, SEM-EDX, FTIR, and UV-vis-DRS techniques. The effects of experimental key parameters such as
Cerâmica. Publicado em: 2022
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2. Carbon Dioxide Biofixation and Production of Spirulina sp. LEB 18 Biomass with Different Concentrations of NaNO3 and NaCl
ABSTRACT Microalgae are efficient at using solar energy to turn CO2 and nutrients into biomass containing lipids, proteins, carbohydrates and other compounds that may be used to produce bioproducts for human and animal consumption and pharmaceutical use. The aim of this study was to assess the effect of the NaNO3 and NaCl concentration on the growth kinetics
Braz. arch. biol. technol.. Publicado em: 08/10/2018
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3. Improvement of yield of the edible and medicinal mushroom Lentinula edodes on wheat straw by use of supplemented spawn
The research evaluated the interactions of two main factors (strain / types of spawn) on various parameters with the purpose to assess its effect on yield and biochemical composition of Lentinula edodes fruiting bodies cultivated on pasteurized wheat straw. The evaluation was made with four strains (IE-40, IE-105, IE-124 and IE-256). Different types of spawn
Braz. J. Microbiol.. Publicado em: 2014-06
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4. Eletrodos porosos contendo TiO2 e WO3 : propriedades eletroquímicas e atividade fotocatalítica para remoção do corante Rodamina 6G e do hormônio 17 a-etinilestradiol em solução aquosa / Porous electrodes containig TiO2 and WO3 : eletroctrochemical properties and photocatalytic activity for removal of Rodhamine 6G dye and 17 alfa -ethynylestradiol
Porous films electrodes containing TiO2 and WO3 were deposited on SnO2:F (FTO) conducting glass from aqueous suspensions with TiO2 Degussa P25®, WO3 precursors and polyethylene glycol, followed by heating (450°C, 30 min). The maximum absorption was respectively observed at 390 and 480 nm for TiO2 and WO3 samples; intermediate values were obtained for the m
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 02/07/2012
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5. Turbulência em cosmologia: análise de dados simulados e observacionais usando computação de alto desempenho / Turbulence in cosmology: analysis of simulated and observational data using high performance computing
Recent results from the study of the Large-Scale Structure evolution suggest that the process of structure formation may have similarities with the dynamics of a turbulent fluid. The scaling law for the energy distribution in a turbulent fluid shows an inertial range of power -5/3, known as the Kolmogorov s law. This thesis presents an evaluation of the grav
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 26/05/2011
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6. Domain wall, stiff matter and ultra-relativistic particles from a generalized double-component dark energy model
This letter discusses a modified Friedmann-Robertson-Walker cosmology in which the equation of state behaves like p = 3ηa m ρn -ρ,(η,m,n) ∈ . Many interesting features are revealed in particular the manifestation of domain wall, cosmic string, stiff matter, dust and radiation/ultra-relat
Brazilian Journal of Physics. Publicado em: 2010-06
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7. Dual-curing, self-adhesive resin cement: influence of the polymerization modes on the degree of conversion and microhardness
RelyX TM Unicem, dual-curing self-adhesive resin cement, was tested in order to evaluate the degree of conversion (DC) and Vickers microhardness (VMH). The specimens were prepared into 4 groups (GR). For GR1, the specimens were irradiated with 500 mW.cm-2 during 20 seconds while for GR3 the same intensity was used but the irradiation time was 40 seconds. The
Materials Research. Publicado em: 2010-06
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8. Observational Constraints in Interacting Dark Energy Models / Vínculos observacionais em modelos de energia escura interagente
In the present work the possibility of a dark energy interacting with dark matter has been investigated. We considered a flat Friedmann-Robertson-Walker space-time with two alternative interacting dark energy models. In the first, the interaction term, appearing in the energy conservation equations was introduced by purely phenomenological reasons. In the se
Publicado em: 2009
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9. Preparação e caracterização de eletrodos de titanatos para aplicação em conversão de energia solar / Preparation and characterization of titanate electrodes for solar energy conversion
Thin porous films electrodes of titanates H2Ti2O5, H2Ti4O9 and H2Ti8O17 were prepared and investigated. The titanates were synthesized through solid state reactions by heating mixtures of TiO2 and K2CO3; after HCl treatment for ion exchange, the samples were rinsed with water. X-ray diffraction and scanning electron microscopy indicated that, depending on th
Publicado em: 2009
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10. Influence of vinasse application in saturated hydraulic conductivity and runoff / Influência da aplicação de vinhaça na condutividade hidráulica do solo saturado e no escoamento superficial
The production of alcohol used as fuel is increasing every year due to the need to replace the sources of fossil fuels, which is finite, and on the other hand alcohol is a renewable energy source. But the production of this fuel generates large quantities of waste and the vinasse draws most attention by its high value as fertilizer, primarily by the amount o
Publicado em: 2009
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11. Microstructure and composition of rare earth-transition metal-aluminium-magnesium alloys
The determination of the microstructure and chemical composition of La0.7-xPr xMg0.3Al 0.3Mn0.4Co0.5 Ni3.8 (0 < x < 0.7) metal hydride alloys has been carried out using scanning electron microscopy (SEM), energy dispersive X ray analysis (EDX) and X ray diffraction analysis (XRD). The substitution of La with Pr changed the grain structure from equiaxial to c
Materials Research. Publicado em: 2008-03
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12. Acelaração do universo e criação gravitacional de matéria escura fria: novos modelos e testes observacionais
Recent astronomical observations (involving supernovae type Ia, cosmic background radiation anisotropy and galaxy clusters probes) have provided strong evidence that the observed universe is described by an accelerating, flat model whose space-time properties can be represented by the FriedmannRobertsonWalker (FRW) metric. However, the nature of the substanc
Publicado em: 2008