Ultraviolet Spectrum
Mostrando 13-24 de 142 artigos, teses e dissertações.
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13. Caracterização de minério de ferro por espectroscopia de reflectância difusa
The identification and quantification of the mineralogical phases present in iron ore is of crucial importance, both for quality control and well as for mine planning, processing, etc.. The element iron is usually found in the form of oxides or hydroxides, such as hematite (α- Fe2O3), goethite (α-FeOOH) and magnetite (Fe3O4), and their colors are a
Publicado em: 2010
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14. Polimerização via radical livre fotoiniciada de sistemas multicomponentes para utilização em dispositivos oftalmicos : aspectos opticos e mecanicos / Free radical polymerization photoinitiated of multicomponent systems for us e in ophthalmic devices : optical and mechanical aspects
The current market calls for materials presenting good optical properties which satisfy consumers and users in general and that can be easily handled and processed. Generally, a polymer must present good optical properties, impact resistance and hardness - all compatible in their use as ophthalmic lenses. For quite a long period of time, ophthalmic lenses ma
Publicado em: 2009
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15. Ordem-desordem: uma avaliação estrutural do Ba(ZrxTi1-x)O3 / Order-disorder: an evaluation structural of Ba(ZrxTi1x)O3
This work have as aim, the synthesis of ceramic powders of Ba(ZrxTi1x)O3 (x = 0, 0.25, 0.50, 0.75 and 1) by the polymeric precursor method and investigate the degree of structural order-disorder of these systems by different characterization techniques, such as: thermogravimetric analysis (TA), differential thermal analysis (DTA), X-ray diffraction (XRD), Ra
Publicado em: 2009
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16. Caracterização de Ametistas Naturais
This research intends to investigate the formation of color in samples of natural amethyst from different origins after submitting them to gamma irradiation, as well to develop an identification method of uncolored crystals with potential for development of color. The techniques of infrared spectroscopy, ultraviolet-visible spectroscopy and atomic emission s
Publicado em: 2008
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17. Síntese de bisporfirinas contendo o espaçador 2,2-bipiridina: modelos na elaboração de sensores luminescentes de íons metálicos / Synthesis of bisporphyrins held together by the 2,2-bipyridine spacer: models in the elaboration of luminescent sensors for metal ions
In this work have been synthesized bisporphyrins held together by means of amide linkage at the 4,4position of 2,2-bipyridine, reacting the mono-functionalised aminophenyl-porphyrin (NH2PTriPP) and 4,4-diacid chloride bipyridine (DACBipy). A preliminary study was conducted for the establishment of the reaction conditions for the attainment of mono(nitropheny
Publicado em: 2008
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18. Propriedades eletrônicas e estruturais de nanotubos de dióxido de titânio por primeiros princípios
In this work, we perform first-principles calculations based on the Density Functional Theory (DFT) to study structural and electronic properties of TiO2 nanotubes. Firstly, we address structural aspects. For this purpose we consider a model in which the nanotubes are obtained by rolling up layers of anatase TiO2 oriented in the (001) direction. The stabilit
Publicado em: 2007
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19. Síntese, caracterização e avaliação do perfil de liberação "in vitro" de hidrogéis do álcool polivinílico ph sensitivos processados por métodos físico-químico
In this study hydrogels of poly(vinyl alcohol) (PVA) processed by chemical method and gamma radiation were obtained in order to evaluate the pH responsive behaviour of those systems as well the utilization for the targeted drug delivery in the gastrointestinal tract of Human. The rheological properties of PVA solutions with different hydrolysis degree and we
Publicado em: 2007
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20. Thermoluminescence, electron paramagnetic resonance and color centers properties of diopside / Propriedades de termoluminescência, de ressonância paramagnética eletrônica e de centros de cor de diopsídio
Diopside of chemical formula, CaMgSi2O6, a natural silicate mineral has been investigated concerning its Thermoluminescence (TL), Electron Paramagnetic Resonance (EPR) and Reflectance properties. Synthetic, pure or doped diopside, produced in the laboratory, has been investigated. Samples annealed at 600 `GRAUS´ C for one hour, to eliminate previously induc
Publicado em: 2007
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21. Caracterização elétrica de células solares de tripla tecnologia de matérias e sensores / Electrical characterization of triple junction solar cells - GAINP/GAAS/GE
Triple junction solar cells use a combination of semiconductor materials to more efficiently capture photons in the range of 300nm to 1800nm of sun solar spectrum. Minimum average conversion efficiency AM0 for first generation TJ solar cell for space use is 26,0%. The GaInP, GaAs and Ge were select because of their collective ability to match bandgap energie
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 24/03/2006
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22. Glandula harderiana de ratos wistar como modelo para o estudo de efeitos fotodinamicos
The present work shows, experimentally, that the use of harderian glands of Wistar rats for the study of photodynamic applied to the diagnosis (PDD - of the English, Photo Dynamic Diagnosis) and medical treatment is possible (PDT - of the English, Photo Dynamic Therapy). In the case, the photodynamic action has as photo-sensitizer protoporphirin IX (PpIX), a
Publicado em: 2004
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23. Modelagem quântica de inibidores enzimáticos. / Quantum modelling of enzimatic inhibitors.
We have made a structural and electronic characterization of the enzyme inhibitors E-64 and CA030 using quantum chemistry techniques. Geometry optimizations are performed in the ab initio level with the Hartree-Fock and Density Functional Theory methods and these structures are then compared with crystallographic results obtained from the Protein Data Bank.
Publicado em: 2002
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24. Caracterização otica em materiais transparentes e sua relação com o confortoambiental em edificação
In this work, the characterization and analysis of the solar radiation transmission through transparent materials appropriated for buildings façades is presented. Materials such as reflective sputtered glasses, polycarbonates and commercial polymeric films for solar control on float glass are studied. The electrocromic glass type, promissory new material un
Publicado em: 1998