Electrons
Mostrando 13-24 de 833 artigos, teses e dissertações.
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13. O CONCEITO DE VALÊNCIA EM LIVROS DIDÁTICOS DE QUÍMICA GERAL ENTRE AS DÉCADAS DE 1890 E 1940
This paper aims to investigate the presentation of the concept of valence in college-level, general chemistry textbooks published in the USA between the 1890s and the 1940s. The delimited period covers the emergence of theories about atomic structure, electronic distribution and chemical bonding. Transition from the classical concept of valence (as the combi
Quím. Nova. Publicado em: 2019-02
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14. Impact of Alloy Composition and Thermal Stabilization on Martensitic Phase Transformation Structures in CuAlMn Shape Memory Alloys
Alloys of CuAlMn are known as cheap, high strength shape memory alloys with an excellent damping capacity within their austenitic-martensitic phase transformation, compared to alloy systems like NiTi, CuZnAl or MnCu. But CuAlMn alloys have disadvantage due to generation of voids by a high shrinkage which further increases the existing proneness to stress cra
Mat. Res.. Publicado em: 19/07/2018
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15. Electrical and optical numerical modeling of DP-PPV based polymer light emitting diode
Abstract In this paper, an in-depth study of the electrical and optical characteristics of Polymer Light Emitting Diodes ITO/PEDOT: PSS/DP-PPV derivatives/Al(Ca) is presented. Three polymer materials are considered; poly(2,3-diphenyl-5-(4-heptyloxy-4'-oxytrimethylenediphenyl)-phenylenevinylene) (P1), poly(2,3-diphenyl-5-[4-(4-pentylcyclohexyl)phenoxy]-propyl
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2018-06
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16. Investigating Space Radiation Environment Effects on Communication of Razaksat-1
ABSTRACT: This study attempted to identify whether space radiation sources could have affected the communication on RazakSAT-1 that was orbiting in a Low Earth Orbit-Near Equatorial (LEO-NEqO). Data on galactic cosmic rays (GCR), trapped protons, trapped electrons, and solar energetic particles (SEPs) obtained from Space Environment Information System (SPENV
J. Aerosp. Technol. Manag.. Publicado em: 03/05/2018
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17. EXPLAINING THE GEOMETRY OF SIMPLE MOLECULES USING MOLECULAR ORBITAL ENERGY-LEVEL DIAGRAMS BUILT BY USING SYMMETRY PRINCIPLES
The built of qualitative energy-level molecular diagrams for different geometries of simple molecules allow to explain the preferred geometry. The diagrams are built using simple symmetry principles and explain, on basis of the number of nonbonding electrons, for example, why the molecule of water is bent and not linear and ammonia is pyramidal and not plana
Quím. Nova. Publicado em: 2018-05
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18. Improvement of power efficiency of hybrid white OLEDs based on p-i-n structures
ABSTRACT In this article, hybrid white organic light-emitting diodes (WOLEDs) under p-i-n structures have been investigated in terms of power efficiency. By using tris(8-hydroxy quinolinato) aluminum (Alq3) doped with 8-hydroxy-quinolinato lithium (Liq) as an n-type and WHI112 doped with molybdenum trioxide (MoO3) as a p-type, the typical device structure of
Matéria (Rio J.). Publicado em: 05/03/2018
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19. O MÉTODO DE HYLLERAAS PARA ÁTOMOS DE DOIS ELÉTRONS
The quantum mechanics of two electrons atoms, as suggested by E. A. Hylleraas in the period between 1928-1930, is discussed in the present work. Hylleraas introduced explicit correlations in the wavefunction by treating the coordinates between the electrons as an independent variable of the problem, an approach that gives very precise energy values. Solution
Quím. Nova. Publicado em: 2017-10
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20. Ethylene Glycol Electro-Oxidation on Platinum-Free Surfaces: How the Composition of PdRuRh Surfaces Influences the Catalysis
In this work we performed electrochemical (cyclic voltammetry and chronoamperommetry) and spectroelectrochemical studies (in situ Fourier transform infrared (FTIR)) in PdRuRh electrodeposits in acidic media in presence of ethylene glycol (0.5, 1.0 and 2.0 mol L-1). The electrochemical results show that the ethylene glycol oxidation is sensitive to the compos
J. Braz. Chem. Soc.. Publicado em: 2017-06
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21. Study of PtPd Bimetallic Nanoparticles for Fuel Cell Applications
Bimetallic nanoparticles are of special interest for their potential applications for fuel cells, mainly for portable power applications. Among the bimetallic systems, Pt-Pd bimetallic nanoparticles have received great interest as they can be widely used as effective catalysts for various electrochemical reactions. In this work, Pt-Pd alloy bimetallic nanopa
Mat. Res.. Publicado em: 15/05/2017
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22. A Sensitive Voltammetric Determination of Anti-Parkinson Drug Pramipexole Using Titanium Dioxide Nanoparticles Modified Carbon Paste Electrode
In this study, a facile sensor based on TiO2 nanoparticles modified carbon paste electrode was developed for voltammetric determination of pramipexole in pharmaceutical formulations and biological samples. Surface of the fabricated electrode have been characterized using field emission scanning electron microscopy. Under the optimized experimental conditions
J. Braz. Chem. Soc.. Publicado em: 2017-04
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23. MATHEMATICAL MODELING OF THE ELECTRIC CURRENT GENERATION IN A MICROBIAL FUEL CELL INOCULATED WITH MARINE SEDIMENT
Abstract Microbial fuel cells (MFC) are electrochemical devices that utilize the ability of some microorganisms to oxidize organic matter and transfer electrons resulting from their metabolism to an insoluble acceptor. The goal of the present study was to model the kinetics of electrical current generation from an MFC inoculated with marine sediment. For thi
Braz. J. Chem. Eng.. Publicado em: 2017-01
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24. Characterization of basic oxygen furnace slag and granite waste mixtures to Portland cement production
Abstract The aim of this paper is to analyze mixtures of basic oxygen furnace slag and granite waste in order to produce Portland cement. X-ray patterns were carried out in both the basic oxygen furnace slag and granite waste. Then, mixtures were prepared to obtain the binary basicity of 0.5, 0.9 and 1.2. The mixtures were melted at 1500ºC. Two cooling step
REM, Int. Eng. J.. Publicado em: 2016-12