Bi Symmetry
Mostrando 1-11 de 11 artigos, teses e dissertações.
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1. Impedance and Modulus Spectroscopy Characterization of Tb modified Bi0.8A0.1Pb0.1Fe0.9Ti0.1O3 Ceramics
In this paper we present the impedance spectroscopy of ternary solid solutions of BiFeO3, TbFeO3 and PbTiO3, prepared by solid-state reaction method. The preliminary structural studies were carried out by x-ray diffraction technique, showing the formation of polycrystalline sample with ABO3 type of perovskite structure with hexagonal symmetry for Bi0.8Tb0.1P
Mat. Res.. Publicado em: 16/02/2016
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2. Estudo das transiÃÃes de fase do RbBi0,31 3Nd0,02 W8/3O9, submetido a variaÃÃes de pressÃo hidrostÃtica e temperatura. / Studies of phase transitions of RbBi0,313Nd0,02W8/3O9 submit variation of hydrostatic pressure en temperature
Tungsten bronzes has attracted great attention owing to it is interesting physical properties. Hexagonal tungsten of the form AxWO3 (with A = K, Rb, Cs), are well know superconductors. The RbBi1/3W8/3O9 (RBW) material, belongs to the valence balanced hexagonal tungsten materials with ABxW3-xO9 stoichiometry (with A = Cs, K, Rb, Tl, and B = Bi, Nd, Ta, Zr, Sc
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 16/02/2009
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3. Structural and dielectric properties of ZrO2 added (Na1/2Bi1/2)TiO3 ceramic
Polycrystalline samples of ZrO2 added (Na1/2Bi1/2)TiO3 were prepared using high-temperature solid-state reaction method at 1050ºC and subsequent sintering at 1090ºC in air atmosphere. Rietveld analyses of XRD data indicated the formation of a single-phase hexagonal structure with R3c symmetry. Dielectric studies revealed the relaxor behaviour. The addition
Brazilian Journal of Physics. Publicado em: 2009-06
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4. Medidas de assimetria bivariada e dependência local. / Measures of bivariate asymmetry and local dependence.
Esta tese trata de dois assuntos importantes na teoria de risco: o fenômeno da dependência local e a identificação e mensuração de assimetrias apresentadas pelos dados. A primeira parte trata de dependência local, sendo abordadas algumas medidas já analisadas na literatura. Versões locais dos coeficientes de Kendall e Spearman , baseadas na distribu
Publicado em: 2008
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5. Estudo da convergência no método de elementos finitos aplicado a dispositivos eletromagnéticos não lineares. / Survey on the convergence of non-linear finite element method applied to electromagnetic devices in two-dimension.
This work presents a study on the convergence of non-linear finite analysis applied to the modeling of electromagnetic devices with plane symmetry. Three aspects have been thoroughly investigated which have influence on the convergence performance, namely: the relaxation factor in the Newton-Raphson algorithm, the model of the magnetization curve and the cho
Publicado em: 2007
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6. Aplicação de métodos tomográficos na reconstrução bi-dimensional de propriedades de chamas / Application of the tomographyc methods on bidimensional reconstruction of the flame properties
Fundamentally, flame diagnosis by tomographic imaging deals with reconstructing an image from its projections. In the strict sense of the word, a projection at a given angle is the integral of the image in the direction specified by that angle. However, in a loose sense, projection means the information derived from the emitted energies, at some angle, when
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 16/02/2006
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7. Estudo de materiais a base de bismuto (III) : sistema Bi2O3-V2O5 modificado pela incorporação de metais alcalinos terrosos
In the present work, we have studied a material with unusual properties, bismuth vanadate, BiVO4. The synthesis of this material was performed through the oxide method and the non-hydrolytic sol-gel method. This was done, in order to obtain information about the influence of these methods on the structural, thermal, compositional, morphological, and color ch
Publicado em: 1995
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8. Regulation of aspartate transcarbamoylase synthesis in Escherichia coli: analysis of deletion mutations in the promoter region of the pyrBI operon.
The catalytic and regulatory polypeptide chains of Escherichia coli aspartate transcarbamoylase are encoded by the pyrB and pyrI genes, respectively, which constitute a single transcriptional unit in the pyrBI operon. The DNA sequence immediately preceding the first structural gene, pyrB, contains a short open reading frame that could encode a 44-amino acid
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9. Three-dimensional structure of the rotavirus haemagglutinin VP4 by cryo-electron microscopy and difference map analysis.
The three-dimensional structure of the rotavirus spike haemagglutinin viral protein 4 (VP4) has been determined to a resolution of 26 A by cryo-electron microscopy and difference analysis of intact virions and smooth (spikeless) particles. Native and spikeless virions were mixed prior to cryo-preservation so that both structures could be determined from the
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10. Nucleotide sequence analysis of Tn4551: use of ermFS operon fusions to detect promoter activity in Bacteroides fragilis.
The Bacteroides pBI136 clindamycin resistance (Ccr) determinant from the composite transposon Tn4551 was cloned onto the shuttle plasmid pFD160, and the regions necessary for expression in Bacteroides fragilis were determined. These results suggested that transcriptional regulatory signals required for Ccr were located in the Tn4551 direct repeat sequence (D
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11. Disulfide bridge-mediated folding of Sindbis virus glycoproteins.
The Sindbis virus envelope is composed of 80 E1-E2 (envelope glycoprotein) heterotrimers organized into an icosahedral protein lattice with T=4 symmetry. The structural integrity of the envelope protein lattice is maintained by E1-E1 interactions which are stabilized by intramolecular disulfide bonds. Structural domains of the envelope proteins sustain the e