Photothermal Techniques
Mostrando 1-9 de 9 artigos, teses e dissertações.
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1. Photoacoustic Thermal Characterization of Banana Fibers
Natural fibers are attracting the interest of engineering sectors owing to specific advantages such as lightweight and lower cost as well as an inherent condition of being renewable, biodegradable, recyclable and environmentally correct with respect to CO2 emission. In addition, several natural fibers present mechanical and thermal properties appropriate for
Mat. Res.. Publicado em: 2015-12
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2. Estudo de materiais magnéticos através de técnicas fototérmicas : efeito magnetocalórico e filmes finos / Study of magnetic materials using photothermal techniques : magnetocaloric effect and thin films
The magnetocaloric effect (MCE) has been widely studied because of its possible application in magnetic refrigeration. The search for suitable materials has intensified over the last decade, with a demand not only for the preparation of new materials but also for their complete characterization. The aim of this work is to apply the photothermal techniques to
Publicado em: 2010
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3. Investigation of the theory of coupling compositis in thermal waves fields / Investigação da teoria de acoplamentos de compósitos em campos de ondas térmicas
In this work we elaborate an analytical solution of the temperature field of an opaque material containing two overlapping and parallel subsurface cylinders, illuminated by a modulated light beam. The method is based on the expansion of plane and cylindrical thermal waves, in series of Bessel and Hankel functions. Firstly, the work shows the model of propaga
Publicado em: 2009
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4. Thermal properties of WC-10 wt. (%) Co alloys
In this article, photothermal techniques were used in order to determine some thermal properties: diffusivity, conductivity, effusivity and specific heat capacity of WC-10 wt. (%) Co six samples subjected to different sintering processes. The samples were sintered using high pressure - high temperature (HPHT) sintering system. The open cell photoacoustic (OP
Materials Research. Publicado em: 2008-03
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5. "Estudo das contribuições térmica e eletrônica na variação do índice de refração de materiais dopados com íons emissores" / Study of thermal and electronic contribution to the refractive index variation of materials doped with ions emiters
In this work we have studied the thermal and optical properties of emitters ions by using the thermal lens and z-scan time resolved techniques. It was obtained the thermal lens photothermal spectra of Yb3+ doped samples, and several other photothermal parameters. Also, it was done a study on the optical nonlinearity saturation effects over the determination
Publicado em: 2006
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6. Transient convective heat transfer
In nature, as well as within the human-made thermal systems, the time-variable regimes are more commonly encountered, if not always, than the permanent regimes. Nevertheless, studies in convection are still more frequent in the permanent regimes, undoubtedly due to the related difficulties in calculation in terms of time and cost of computation. One may dist
Journal of the Brazilian Society of Mechanical Sciences and Engineering. Publicado em: 2005-03
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7. Efeito anomalo nas medidas de lente termica em vidros com pontos quanticos de CdTe / Anomalous effect in thermal lens measurements in CdTe quantum dot doped glasses
Semiconductor doped glasses are of great interest because of their non-linear optical properties and short response time due to quantum confinement. In this work, we used the thermal lens technique to determine the thermal diffusivity (a ) and the behavior of the temperature coefficient of the refractive index (dn/dT ) in CdTe doped borosilicate glasses trea
Publicado em: 2005
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8. Photothermal characterization of low density polyethylene food packages
The present work discuss the applicability of photothermal techniques for determining diffusion coefficients of oxygen and carbon dioxide of commercial low-density polyethylene (LDPE). The methodology involves the monitoring of diffused gas by a photoacoustic analyzer. Diffusion coefficients measured for CO2 and O2 were 2.77 x 10-8 cm²/s and 1.68 x 10-7 cm�
Polímeros. Publicado em: 2004-03
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9. New applications of photothermal techniques for studying interfaces. / Novas aplicações de técnicas fototérmicas para o estudo de interfaces.
This work presents the development of new instrumentations based on photothermal phenomena to study solid-liquid and liquid-gas interfaces, including in the latter the effect of surfactants. The work is divided into chapters, each one focusing on the development and/or application of a new technique. Chapter I presents an introduction to photothermal phenome
Publicado em: 2001