Características colorimétricas de una pantalla con tecnología OLED

En este trabajo se han presentado las características colorimétricas de una pantalla OLED, valorando la luminancia, rango dinámico, constancia de primarios, aditividad y dependencia de canales, además de comprobar si puede aplicarse un método físico de caracterización. También, se ha evaluado la gama de color reproducible por este dispositivo considerando el sólido de color teórico asociado al mismo. Se ha comprobado que esta pantalla OLED presenta una buena constancia de cromaticidad de los primarios, pero un nivel de aditividad bajo, hecho que no garantiza que pueda utilizarse el método de caracterización GOG directamente, sino que tenga que realizarse una modificación para asegurar una buena caracterización. También, se ha comprobado que la gama real de colores es más pequeña que la gama de color teórica obtenida a partir del blanco de la pantalla. No obstante, este trabajo es un estudio preliminar que debería completarse con el estudio de diferentes dispositivos basados en tecnología OLED con el fin de conocer adecuadamente sus propiedades colorimétricas.

Avaliação de um biorreator rotativo para fermentação em estado sólido

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Produção de enzimas celulolíticas por fermentação em estado sólido em bioreator de leito fixo

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Produção de lipase por fermentação em estado sólido em biorreator de leito fixo

Pós-graduação em Engenharia e Ciência de Alimentos - IBILCE

Fabricação e caracterização metalográfica e mecânica de tiras de ligas metálicas fundidas e tixolaminadas no estado semi-sólido de diferentes intervalos de solidificação

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Produção de ligninases por basidiomicetos através de fermentação em estado sólido, caracterização e aplicação das enzimas

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Desenvolvimento de um biorreator rotativo para produção de enzimas celulolíticas por fermentação em estado sólido

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Produção de ligno-hemi-celulases por fermentação em estado sólido e avaliação dos efeitos da aplicação das enzimas na composição química e estrutura do bagaço e da palha de cana

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Cinética de crescimento do fungo termófilo Myceliophthora thermophila M. 7.7 em cultivo no estado sólido

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação da influência da fermentação fúngica em estado sólido na obtenção de compostos fenólicos a partir de resíduos de café

Pós-graduação em Engenharia e Ciência de Alimentos - IBILCE

Produção de celulases fúngicas por fermentação em estado sólido: ampliação de escala de biorreatores de leito fixo

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Avaliação técnico-econômica da produção de enzimas celulolíticas por fermentação em estado sólido

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação técnico-econômica da produção de enzimas celulolíticas por fermentação em estado sólido

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Obtenção de Mo2C com adição de Co por reação gás-sólido em reator de leito fixo

Sulfur compounds emissions have been, on the late years, subject to more severe environmental laws due to its impact on the environment (causing the acid rain phenomena) and on human health. It has also been object of much attention from the refiners worldwide due to its relationship with equipment’s life, which is decreased by corrosion, and also with products’ quality, as the later may have its color, smell and stability altered by the presence of such compounds. Sulfur removal can be carried out by hydrotreating (HDT) which is a catalytic process. Catalysts for HDS are traditionally based on Co(Ni)-Mo(W)/Al2O3. However, in face of the increased contaminants’ content on crude oil, and stricter legislation on emissions, the development of new, more active and efficient catalysts is pressing. Carbides of refractory material have been identified as potential materials for this use. The addition of a second metal to carbides may enhance catalytic activities by increasing the density of active sites. In the present thesis Mo2C with Co addition was produced in a fixed bed reactor via gas-solid reaction of CH4 (5%) and H2(95%) with a precursor made of a mix of ammonium heptamolybdate [(NH4)6[Mo7O24].4H2O] and cobalt nitrate[Co(NO3)2.6H2O] at stoichiometric amounts. Precursors’ where analyzed by XRF, XRD, SEM and TG/DTA. Carboreduction reactions were carried out at 700 and 750°C with two cobalt compositions (2,5 and 5%). Reaction’s products were characterized by XRF, XRD, SEM, TOC, BET and laser granulometry. It was possible to obtain Mo2C with 2,5 and 5% cobalt addition as a single phase at 750°C with nanoscale crystallite sizes. At 700°C, however, both MoO2 and Mo2C phases were found by XRD. No Co containing phases were found by XRD. XRF, however, confirmed the intended Co content added. SEM images confirmed XRD data. The increase on Co content promoted a more severe agglomeration of the produced powder. The same effect was noted when the reaction temperature was increased. The powder synthesized at 750°C with 2,5% Co addition TOC analysis indicated the complete conversion from oxide material to carbide, with a 8,9% free carbon production. The powder produced at this temperature with 5% Co addition was only partially converted (86%)

Effect of staining solutions and repolishing on color stability of direct composites

OBJECTIVES: The purpose of this study was to assess the color change of three types of composite resins exposed to coffee and cola drink, and the effect of repolishing on the color stability of these composites after staining. MATERIALS AND METHODS: Fifteen specimens (15 mm diameter and 2 mm thick) were fabricated from microhybrid (Esthet-X; Dentsply and Filtek Z-250; 3M ESPE) and high-density hybrid (Surefil; Dentsply) composites, and were finished and polished with aluminum oxide discs (Sof-Lex; 3M ESPE). Color of the specimens was measured according to the CIE L*a*b* system in a refection spectrophotometer (PCB 6807; BYK Gardner). After baseline color measurements, 5 specimens of each resin were immersed in different staining solutions for 15 days: G1 - distilled water (control), G2 - coffee, G3 - cola soft drink. Afterwards, new color measurement was performed and the specimens were repolished and submitted to new color reading. Color stability was determined by the difference (ΔE) between the coordinates L*, a*, and b* obtained from the specimens before and after immersion into the solutions and after repolishing. RESULTS: There was no statistically signifcant difference (ANOVA, Tukey's test; p>0.05) among the ΔE values for the different types of composites after staining or repolishing. For all composite resins, coffee promoted more color change (ΔE>3.3) than distilled water and the cola soft drink. After repolishing, the ΔE values of the specimens immersed in coffee decreased to clinically acceptable values (ΔE<3.3), but remained signifcantly higher than those of the other groups. CONCLUSIONS: No signifcant difference was found among composite resins or between color values before and after repolishing of specimens immersed in distilled water and cola. Immersing specimens in coffee caused greater color change in all types of composite resins tested in this study and repolishing contributed to decrease staining to clinically acceptable ΔE values.