Dielectric Relaxation
Mostrando 13-24 de 46 artigos, teses e dissertações.
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13. Estudo da relaxação dielétrica de filmes ultrafinos de poliestireno sulfonado / Dielectric relaxation studies of ultrathin film of sulfonated polystyrene
Ionômeros são polímeros carregados que possuem uma variedade de propriedades elétricas e que recentemente vêm sendo aplicados como camadas de transporte em dispositivos poliméricos. Em particular, camadas ultrafinas de ionômeros são depositadas entre o eletrodo e o polímero eletrônico em OLEDs para aumentar a eficiência da injeção de cargas. Ent
Publicado em: 2009
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14. Fenómenos de relajación interfacial en compuestos epoxi/aluminio
Interfacial dielectric relaxation has been studying in composite materials made with epoxy resin and aluminum. Electric modulus, which has been proposed for the description of systems with relaxation process, presents advantages in comparison to the classic approach of the real and imaginary part of dielectric permittivity. In composite polymer materials, re
Matéria (Rio de Janeiro). Publicado em: 2008-06
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15. PROPRIEDADES TÉRMICAS, DIELÉTRICAS E VIBRACIONAIS DE ORMOSIL S BASEADOS EM PDMS E TEOS DOPADOS COM MDS / THERMAL, DIELECTRIC PROPERTIES AND VIBRACIONAIS OF ORMOSIL S BASED IN DOPED PDMS AND TEOS WITH MDS
In this work have been investigated the dielectric and vibrational properties of the ORMOSIL membranes based on PDMS and TEOS doped with MDS using the Dierential Scanning Calorimetry (DSC), impedance, Raman and infrareds spectroscopy technics. Such membranes are hybrid organic-inorganic materials with potential application in PEMFC (Proton Exchange Membrane
Publicado em: 2008
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16. Relaxação em sistemas moleculares complexos / Relaxation in complex molecular systems
In this Thesis are presented studies by Molecular Dynamics simulations on some molecular systems presenting complex dynamics behavior (i.e., relaxation process caracterized by multiple time scales), including saccharides aqueous solutions, double helix DNA systems, air/water interfaces containing surfactants, and supercooled water. These systems, although cl
Publicado em: 2005
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17. High frequency dielectric relaxation in lanthanum modified PbTiO3 ferroelectric ceramics
Dielectric measurements of lanthanum modified lead titanate ceramics were carried out in a frequency and temperature range of 70 ´ 10(6)Hz - 2 ´ 10(9)Hz and 300 K - 420 K, respectively. Dielectric relaxation appears around 7 ´ 10(8)Hz at room temperature, and the maximum of the dielectric relaxation was around 393 K, the transition temperature (Tc). The r
Materials Research. Publicado em: 2004-06
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18. Aerogel de Sílica: caracterização estrutural e estudo da propriedade da água adsorvida na superfície. / Silica Aerogels: structural characterization and property study of adsorbed water on the surface.
The synthesis of glasses using the sol-gel method appeared recently of great interest either from the technological or from the scientific point of view. We describe the process used to obtain pure vitreous silica (gel formation → hypercritical drying → densification) as well as some physical and chemical characteristics of the various products fab
Publicado em: 1992
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19. Medidas dielétricas em cristal de KCN a ultrabaixas freqüências / Dielectric measurements of KCN crystal at ultra-low frequencies
Dielectric measurements were performed at low frequencies (10-2- 40Hz) with an ultra-low frequency bridge in KCN crystals , as well as at high frequencies (50-10-4 Hz) employing a commercial capacitance bridge (General Radio). The dielectric loss curves show a good adjustment between the high and low frequencies. We obtain dielectric loss peaks in a window o
Publicado em: 1985
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20. Espectroscopia entre 10 e 4000 centímetros pot. Aplicação aos modos vibracionais da sodalita natural brasileira / The influence of capture centers on the dielectric relaxation of KI:M++ crystals
Encontrou-se que a relaxação dielétrica dos dipolos impureza-vacância em KI dopado com pequenas quantidades de KCl é extremamente diferente da relaxação dielétrica na matriz KI não contendo íons Cl-. Os novos picos de relaxação, atribuídos à presença do Cl- na vizinhança imediata do íon divalente, tem um tempo de relaxação 103 vezes menor
Publicado em: 1983
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21. The influence of capture centers on the dielectric relaxation of Ki:M ++. / Influência de centros de captura na relaxação dielétrica de cristais de Ki:M++.
Encontrou-se que a relaxação dielétrica dos dipolos impureza-vacância em KI dopado com pequenas quantidades de KCl é extremamente diferente da relaxação dielétrica na matriz KI não contendo íons Cl‾.Os novos picos de relaxação, atribuídos à presença do Cl‾ na vizinhança imediata do íon divalente, tem um tempo de relaxação 103 vez
Publicado em: 1976
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22. Dielectric spectroscopy as a sensor of membrane headgroup mobility and hydration.
Dielectric spectroscopy is based on the response of the permanent dipoles to a driving electric field. The phospholipid membrane systems of dimyristoylphosphatidylcholine and dioleoylphosphatidylcholine can be prepared as samples of multilamellar liposomes with a well known amount of interlamellar water. For optimal resolution in dielectric spectroscopy one
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23. Dielectric Relaxation of Water and Water-Plasticized Biomolecules in Relation to Cellular Water Organization, Cytoplasmic Viscosity, and Desiccation Tolerance in Recalcitrant Seed Tissues1
To understand the relationship between the organization of cellular water, molecular interactions, and desiccation tolerance, dielectric behaviors of water and water-plasticized biomolecules in red oak (Quercus rubra) seeds were studied during dehydration. The thermally stimulated current study showed three dielectric dispersions: (a) the relaxation of loose
American Society of Plant Physiologists.
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24. Characterization of DNA degradation using direct current conductivity and dynamic dielectric relaxation techniques
The purpose of this study was to evaluate DNA degradation upon thermal heating using dielectric relaxation and direct current (DC) conductivity methods. Herring sperm DNA, human growth hormone (HgH) plasmid DNA, and secreted alkaline phosphatase (SEAP) plasmid DNA were used as the examples. DNA was heated at 80°C for 1 hour. The dielectric relaxation spectr
Springer-Verlag.