X Rays Diffraction
Mostrando 13-24 de 102 artigos, teses e dissertações.
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13. Encapsulation of naproxen in nanostructured system: structural characterization and in vitro release studies
Nanoparticles were produced by solvent emulsification evaporation method with the following characteristics: nanometric size (238 ± 3 nm), narrow polydispersity index (0.11), negative zeta potential (-15.1 mV), good yield of the process (73 ± 1.5%), excellent encapsulation efficiency (81.3 ± 4.2%) and spherical shape. X-rays diffraction demonstrated the l
Química Nova. Publicado em: 2011
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14. Estruturas magneticas do EuSe por difração magnetica de raios-X / Magnetic structures of EuSe by magnetic X-ray diffraction
Esta dissertação apresenta um estudo das estruturas magnéticas em um filme de EuSe por difração magnética de raios-X. Usamos um filme de EuSe de 3200 Å , com uma alta qualidade cristalina e crescido por epitaxia de feixe molecular sobre um substrato de BaF2(111). A difração magnética de raios-X revelou um diagrama de fases exibindo uma forte hister
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 30/07/2010
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15. Caracterização de vidros niobofosfatos para aplicação em selagem em célula a combústivel de óxido sólido / Characterization of niobophosphate glasses for solid oxide fuel cell (SOFC) sealing
Solid oxide fuel cells (SOFC) are devices which generate d.c. power by the oxidation of hydrogen molecules. These devices can have a multilayer plane design containing a cathode, an anode, a solid electrolyte, and a sealing material. The sealing, which is the subject of this study, has to be chemically stable at relatively SOFC operational condition in oxi-r
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 16/03/2010
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16. Synthesis and characterization of polystyrene - layered double hydroxide nanocomposites via in situ polymerization / Sintese e caracterização de nanocompositos de poliestireno - hidroxido duplo lamelar via polimerização in situ
Over the past decade, polymer nanocomposites have attracted considerable interests in both academia and industry. This fact has connection with notable improvement in several properties these new materials have demonstrated with a small amount of nano-reinforcements. Some superior properties of polymer nanocomposites include barrier resistance and flame reta
Publicado em: 2010
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17. Study of pre-formulation, pharmaceutical development and characterization of solid dosage forms of olanzapine / Estudo de pré-formulação, desenvolvimento farmacotécnico e caracterização de formas farmacêuticas sólidas da olanzapina
Among manufacturing processes available, direct compression is indicated for OLZ because this drug is moisture sensitive. Before drug developement, preformulation investigations involving physical and chemical properties of drug and excipient combined and separated must be performed. Thus, drug solubility profile, thermal analysis techniques, mainly DSC and
Publicado em: 2010
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18. Estudo estrutural de nanossistemas semicondudores e semicondutores implantados por difração de raios-X de n-feixes / Structural study of semiconductors nanosystems and implanted semiconductors by means of n-beams X-ray diffraction
In this paper, X-ray multiple diffraction (MD) associated with the advantages of synchrotron radiation appears as a high-resolution microprobe and it is used to obtain relevant contributions to the study of structural properties of semiconductor materials, as they present themselves nanosystems epitaxial or implanted with ions. The study and detection of neg
Publicado em: 2010
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19. Crescimento de nanofios auto-sustentados de arseneto de índio por epitaxia por feixes moleculares
This Thesis reports the experimental and theoretical works related to the growth and characterization of free-standing gallium indium arsenide nanowires grown by Molecular Beam Epitaxy (MBE). The growth mechanisms of free-standing nanowires remain barely known and explored in its fundamental aspects. The theoretical models of the formation of free-standing n
Publicado em: 2010
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20. Effect of zinc crystals size on galvanized steel deformation and electrochemical behavior
Hot-dip galvanized steel sheets with different spangle sizes were deformed by means of rolling and tension. The change of preferential crystallographic orientation and of superficial characteristics due to the deformation was analyzed by means of both X-rays diffraction and optical and scanning electronic microscopy. A correlation between such changes and th
Materials Research. Publicado em: 2009-09
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21. Electrospinning and characterization of polyamide 66 nanofibers with different molecular weights
Polyamide 66 (PA66) nanofibers of different molecular weights were obtained by electrospinning of formic acid solutions. An ionic salt, NaCl, was also added to the solutions to increase the conductivity. PA66 concentrations between 15-17 wt.(%)/v and electrical fields between 2.0 and 2.5 kV/cm were the best conditions to produce the smallest nanofibers; howe
Materials Research. Publicado em: 2009-06
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22. DEVELOPING A VERSATILE MONOCHROMATIZATION SYSTEM FOR X-RAYS / DESENVOLVIMENTO DE UM SISTEMA DE MONOCROMATIZAÇÃO VERSÁTIL PARA RAIOS-X
The investigation of the dynamics of the interaction of high-energy X-rays and molecules of biological interest requires the energy of the X-rays to be well defined, so that one can establish the dependence of the molecular ionization and fragmentation patterns as functions of the incident beam energy. For this purpose, a versatile system for the monochromat
Publicado em: 2009
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23. Synthesis of nanostructured boron nitride and its potentially for application in cosmetology / Sínteses e caracterização de nitreto de boro nanoestrutrado com potencialidade de aplicação em cosmetologia
Regular use of appropriate cosmetics is an important resource for the maintenance of the skin health and, consequently, its beauty. The effect of ultraviolet rays is harmful to the health of the skin and can result in increase of the cancer incidence, aging and other undesirable cutaneous changes. The effects of the infra-red rays are less described in the s
Publicado em: 2009
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24. Estudo e caracterização de matérias-primas para o desenvolvimento de blocos sílico-calcários
The types of products manufactured calcium silicate blocks are very diversified in its characteristics. They include accessory bricks, blocks, products in dense material, with or without reinforcements of hardware, great units in cellular material, and thermal insulating products. The elements calcium silicate are of great use in the prefabricated constructi
Publicado em: 2009