Energy Gap
Mostrando 13-24 de 195 artigos, teses e dissertações.
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13. Espectroscopia óptica de baixo custo: uma estratégia para a introdução de conceitos de física quântica no ensino médio
Resumo Neste artigo, reportamos a confecção e discutimos a aplicabilidade de um espectrômetro óptico de baixo custo como recurso didático para a introdução de conceitos de Física Quântica no ensino médio. O protótipo foi desenvolvido usando grade de difração comercial, lentes convergentes (lupas), webcam e o software Tracker para extração dos
Rev. Bras. Ensino Fís.. Publicado em: 29/04/2019
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14. Dispositivo vestível para medição da iluminância pupilar
Resumo Dados de exposição do olho humano à luz podem auxiliar pesquisadores e profissionais de projeto a entenderem melhor o desempenho de edifícios, relativamente ao bem-estar e saúde de seus usuários. Entretanto, as tecnologias de detecção existentes para avaliar condições internas de iluminação a partir de um ponto de vista fixo e medir as qua
Ambient. constr.. Publicado em: 2019-04
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15. Recombination Study of Dye Sensitized Solar Cells with Natural Extracts
Natural dyes can be used in dye sensitized solar cells (DSSCs) to generate low-cost devices, although with low light harvesting because of energy losses from the recombination process. This study investigates recombination reactions in DSSCs with natural dyes extracted from eggplants, plums, and hibiscus flowers. Titanium dioxide films were coated on a fluor
J. Braz. Chem. Soc.. Publicado em: 2019-02
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16. SYNTHESIS, ELECTRONIC AND SPECTRAL PROPERTIES OF NEW 1,3,4-THIADIAZOLE COMPOUNDS AND THE SPECTRAL ANALYSIS OF THEIR CONFORMERS USING DENSITY FUNCTIONAL THEORY
In this study, new 1,3,4-thiadiazole compounds were synthesised and characterised by FT-IR, 1H-NMR, UV-vis spectroscopy and elemental analysis, Furthermore, the relationship between the electronic and spectral data of the 16 conformers of each compound was investigated by theoretical calculations; the theoretical data were compared with the experimental resu
Quím. Nova. Publicado em: 2019-02
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17. Electric power load in Brazil: view on the long-term forecasting models
Abstract Paper aims This paper aims to discuss how the energy load forecasts used by the System Operator and the main agents of the sector are made, and for what purposes, besides discuss the forecast deviations of the ONS’s and EPE’s models and their consequences and costs to the agents involved. Originality Fill a gap in the Brazilian literature wh
Prod.. Publicado em: 08/10/2018
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18. Ga Dopant Induced Band Gap Broadening and Conductivity Enhancement in Spray Pyrolysed Zn0.85Ca0.15O thin Films
Ga doped Zn0.85Ca0.15O thin films were prepared by spray pyrolysis method and studied the impact of Ga doping concentration on the physical properties of these films. XRD analysis confirmed the structural purity and polycrystalline nature of the films and composition analysis verified the incorporation of dopants in the structures. Optical transmission in th
Mat. Res.. Publicado em: 03/09/2018
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19. Síntesis y caracterización de fotocatalizadores de hierro soportado sobre zeolitas microporosas
ABSTRACT ZSM11 and BETA zeolitic materials were synthesized by the hydrothermal method and were further impregnated with a 6 wt% of iron and characterized by different physicochemical techniques in order to be employed in the photocatalytic degradation of methyl orange (MO). Matrices structures and crystallinity were verified by X Ray Diffraction (XRD) and F
Matéria (Rio J.). Publicado em: 19/07/2018
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20. Structural, Thermal, Optical, and Photoacoustic Study of Mechanically Alloyed Nanocrystalline SnTe
A nanostructured SnTe phase was produced by mechanical alloying after 2 h of milling. Part of the as-milled powder was annealed and its X-ray diffraction (XRD) pattern was recorded. The XRD patterns of the as-milled and annealed samples were refined using the Rietveld method. After annealing, partial decomposition of the SnTe phase was observed and corrobora
Mat. Res.. Publicado em: 07/06/2018
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21. Band Structure, Charge Distribution and Optical Properties of AlPxSb1-x Ternary Semiconductor Alloys
The present contribution studies on the composition dependence of the electronic and optical properties of the zinc-blende alloy system AlPxSb1-x. The calculations are performed using a pseudopotential approach under the virtual crystal approximation. Features such as electronic band structure, energy band-gaps, refractive index, dielectric constants and val
Mat. Res.. Publicado em: 21/05/2018
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22. Optical and Structural Study of ZnO Thin Films Deposited by RF Magnetron Sputtering at Different Thicknesses: a Comparison with Single Crystal
Optical characterizations of preferred orientation (002) ZnO thin films, prepared by RF magnetron sputtering under pure argon plasma, with different thicknesses have been investigated, where grain size and resistivity increase with thickness. Energy band gap and refractive indices have been calculated. A correlation between band gap values and crystalline qu
Mat. Res.. Publicado em: 16/04/2018
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23. Physiochemical and Optical Properties of GdF3:Pr@LaF3@SiO2 Microspheres
The polyol-based co-precipitation process was employed for synthesis of GdF3:Pr (core) and GdF3:Pr@LaF3 (core-shell) microspheres (MSs). Subsequently, an amorphous silica layer was deposited surrounding the core-shell MSs, which was verified from high-resolution transmission electron microscopy (TEM), energy dispersive X-ray analysis (EDX) and FTIR results.
Mat. Res.. Publicado em: 12/04/2018
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24. Preparation and Characterizations of Monocrystalline Na Doped NiO Thin Films
In the present work, the effect of Na doping on optical, structural and electrical properties of Na doped NiO thin films were studied. The spray pneumatic method was used to deposit the Na doped NiO thin films in the range 0 to 5 wt.%, it are investigated at a substrate temperature of 420 °C with NiO solution 0.1 M. Firstly in the XRD specra, as found that
Mat. Res.. Publicado em: 05/03/2018