9 research outputs found
Manual do estagiário e do bolsista: 2010.
Este trabalho que visa oferecer orientações sobre os procedimentos de estágio na Embrapa Arroz e Feijão.bitstream/CNPAF-2010/29875/1/doc-253.pd
Photothermally modulated magnetic resonance applied to the study of the magnetic phase transition in gadolinium thin films
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento CientÃfico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de NÃvel Superior (CAPES)We explore the photothermally modulated magnetic resonance technique to investigate gadolinium thin films deposited on fused quartz substrate, as a function of thickness and thermal treatment, around the magnetic phase transition temperature. It has been observed that the maximum amplitude of the photothermally modulated magnetic resonance (PM-MR) signal takes place near the phase transition temperature, similarly to the magnetocaloric effect, for which Gd has been the prototype material. The reason is that both depend on the temperature derivative of the magnetization, which maximizes at the phase transition. Besides, there is a narrowing of transition with thermal treatment, confirming that thermal treatment stabilizes the film structure. For frequency scan measurements, the heat diffusion in a two-layer system was considered, and a depth profile study was carried out in order to investigate heterogeneities along the film thickness. From the PM-MR response as a function of the modulation frequency it was possible to estimate the thermal properties of the Gd film. Magnetization, X-ray and electron spin resonance measurements were used to complement the analysis and support the conclusions. (c) 2011 Elsevier B.V. All rights reserved.520936343640Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento CientÃfico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de NÃvel Superior (CAPES)FAEPEX-UnicampFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento CientÃfico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de NÃvel Superior (CAPES
Enhanced and tunable white light emission from Ag nanoclusters and Eu3+-co-doped CaBAl glasses
Evaluation of the thermal diffusivity of vegetable oils during frying by Thermal Lens Spectrometry
In this work we report on the use of the Thermal Lens
method to verify the evolution of the thermal diffusivity of sunflower and
soybean vegetable oils utilized in preparation of twenty five snacks
portions. Our results show that the thermal diffusivity for sunflower oil
does not change between 1 and 25 portions of fried snacks. By another hand,
the soybean thermal diffusivity exhibits a little decrease for higher
portion of fried snacks, indicating that for this oil the triglyceride level
is reduced as a degradation process
Evaluation of the thermal diffusivity of vegetable oils during frying by Thermal Lens Spectrometry
Temperature and wavelength dependence of the thermo-optical properties of tellurite and chalcogenide glasses
The refractive index and the temperature coefficient of the optical path length change of tellurite (80TeO) were determined as a function of temperature (up to 150 °C) and wavelength (in the range between 454 and 632.8 nm). The tellurite glass exhibits the usual refractive index dispersion in the wavelength range analyzed, while anomalous refractive index dispersion was observed for the chalcogenide glass between 454 and 530 nm. The dispersion parameters were determined by means of the single-effective oscillator model. In addition, a strong dependence of the temperature coefficient of the optical path length on the photon energy and temperature was found for the chalcogenide glass. The latter was correlated to the shift of the optical band gap (or electronic edge) with temperature, which was interpreted by the electron-phonon interaction model