Changing inter-molecular spin-orbital coupling for generating magnetic field effects in phosphorescent organic semiconductors

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

On the dynamic behaviour of the "click" mechanism in dipteran flight

In this paper, the dynamic behaviour of the "click" mechanism is analysed. A more accurate model is used than in the past, in which the limits of movement due to the geometry of the flight mechanism are imposed. Moreover, the effects of different damping models are investigated. In previous work, the damping model was assumed to be of the linear viscous type for simplicity, but it is likely that the damping due to drag forces is nonlinear. Accordingly, a model of damping in which the damping force is proportional to the square of the velocity is used, and the results are compared with the simpler model of linear viscous damping. Because of the complexity of the model an analytical approach is not possible so the problem has been cast in terms of non-dimensional variables and solved numerically. The peak kinetic energy of the wing root per energy input in one cycle is chosen to study the effectiveness of the "click" mechanism compared with a linear resonant mechanism. It is shown that, the "click" mechanism has distinct advantages when it is driven below its resonant frequency. When the damping is quadratic, there are some further advantages compared to when the damping is linear and viscous, provided that the amplitude of the excitation force is large enough to avoid the erratic behaviour of the mechanism that occurs for small forces. (C) 2011 Elsevier Ltd. All rights reserved.

Selenium determination in tissue samples of Nile tilapia using ultrasound-assisted extraction

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

Tooth replantation after use of euro-coffins solution or bovine milk as storage medium: a histomorphometric analysis in dogs

Purpose: Euro-Collins solution was developed for the preservation of organs for transplantation, whose characteristics have raised interest for its use as a storage medium for avulsed teeth before replantation. This study evaluated histologically and morphometrically the healing process of dog teeth replanted after storage in Euro-Collins solution or bovine milk.Materials and Methods: Eighty roots of 4 young adult mongrel clogs were randomly assigned to 4 groups (n = 20) and the root canals were instrumented and obturated with gutta-percha and a calcium hydroxide-based sealer. After 2 weeks, the teeth were extracted and subjected to the following protocols: GI (negative control), replantation immediately after extraction; GII (positive control), bench-drying for 2 hours before replantation; GIII and GIV, immersion in 10 mL of whole bovine milk and Euro-Collins solution at 4 C, respectively, for 8 hours before replantation. The animals were sacrificed 90 days postoperatively. The pieces containing the replanted teeth were subjected to routine processing for histologic and histometric analyses under light microscopy and polarized light microscopy.Results: Root resorption was observed in all groups. GII exhibited the greatest loss of dental structure (P < .01), and inflammatory resorption was predominant in this group. Storage in milk showed poorer results than immediate replantation and storage in Euro-Collins solution (P < .01). The teeth stored in Euro-Collins solution presented similar extension of root resorption and periodontal ligament reorganization to those of immediately replanted teeth.Conclusions: The findings of this study suggest that the Euro-Collins solution is an adequate storage medium for keeping avulsed teeth for up to 8 hours before replantation.

Occlusal caries prevention in high and low risk schoolchildren. A clinical trial

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

Evaluation of Cu, Mn, and Se in Vegetables Using Ultrasonic Extraction and GFAAS Quantification

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

Levels of copper in Nile tilapia from Brazil

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

Effect of grape pre-drying and static pomace contact on physicochemical properties and sensory acceptance of Brazilian (Bordo and Isabel) red wines

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Kinetics of osmotic dehydration and air-drying of pumpkins (Cucurbita moschata)

Kinetics of osmotic dehydration (OD) and effects of sucrose impregnation on thermal air-drying of pumpkin slices were investigated. A simplified model based on the solution of Fick's Law was used to estimate effective diffusion coefficients during OD and air-drying. In order to take into account shrinkage, average and variable thicknesses were considered. Pumpkin slices were dehydrated in sucrose solutions (40%, 50% and 60%, w/w, 27 degrees C. The effective water diffusion coefficients were higher than the sucrose, and low diffusivity dependence with solution concentration was observed. Samples non-treated and pre-treated in 60% osmotic solutions during one hour were dried in a hot-air-dryer at 50 and 70 degrees C (2 m/s) until equilibrium was achieved. Pre-treatment enhanced mass transfer during air-drying. Great volume reduction was observed in pre and non-treated dried samples. Using variable thickness in the model diminished the relative deviations between predicted and experimental OD and drying data. (C) 2007 Elsevier Ltd. All rights reserved.

Measurements of inclusive W plus jets production rates as a function of jet transverse momentum in p(p)over-bar collisions root s=1.96 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Structural features of silicas prepared in n-heptane/water/ethanol/sodium dodecylsulfate microemulsions

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

Comparison between freeze and spray drying to obtain powder Rubrivivax gelatinosus biomass

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

The Chemical Percolation Devolatilization Model Applied to the Devolatilization of Coal in High Intensity Acoustic Fields

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Mineralogical characterization of clays used in the structural ceramic industry in west of S. Paulo State, Brazil

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

Quality of natural coffee subjected to different rest periods during the drying process

O parcelamento da secagem pode ser eficiente tanto no que diz respeito à qualidade final do café, quanto na redução do consumo específico de energia. Diante disso, objetivou-se, com o presente trabalho, avaliar o efeito do teor de água dos frutos no momento da interrupção da secagem e do período de repouso até a retomada da secagem na qualidade do café natural, por meio da análise sensorial e dos testes de condutividade elétrica e lixiviação de potássio. Frutos de café maduros foram colhidos manual e seletivamente e, em seguida, secados ao sol em terreiros de concreto por dois dias e, então, submetidos à secagem mecânica em secadores de camada fixa. Quando o café atingiu os teores de água de 20%, 17% e 14% (base úmida, bu), a secagem foi interrompida e o café permaneceu em repouso por cinco, quinze e trinta dias e, posteriormente, foi secado em secadores mecânicos até o teor de água de 11% (bu). O controle constituiu-se na secagem completa em terreiro. Observou-se que as combinações entre o menor teor de água e o maior período de repouso e entre o maior teor de água e o menor período de repouso, proporcionam menores valores de lixiviação de potássio. A qualidade da bebida melhora progressivamente com o aumento do período de repouso. A interrupção da secagem com teores de água de 17% e 20% (bu) não altera a qualidade do café natural, comparativamente à secagem completa em terreiro.