Thermal Waves
Mostrando 13-24 de 24 artigos, teses e dissertações.
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13. Um estudo simplificado da percepção pública dos benefícios e riscos de centrais termonucleares - sugestões para a comunicação de valor com o público / Public perception on the benefits and risks of nuclear power plants_a simplified study
Public acceptance of the nuclear based electricity generation depends on many variables that can be affected by circumstances and interests, which although seemingly not close to the issue, can strongly influence the final outcome. Explicit or consented positions assumed by opinion makers and some segments of society are subject to episodic waves of interact
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 09/03/2007
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14. Estudo de frentes mesosféricas na região equatorial / Study of mesospheric fronts in the equatorial region
An extensive study on mesospheric fronts was carried out by means of mesospheric airglow image observation at at São João do Cariri, PB (7,4oS; 36,5oW) from July 2004 to December 2005. All sky airglow images, meteor radar wind and TIMED/SABER satellite temperature data were used in order to investigate physical scenario of the mesospheric front. Three diff
Publicado em: 2007
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15. Estudo de vidros fosfatos dopados com terras raras para aplicação em fibras ópticas e guias de ondas planares / Estudo de vidros fosfatos dopados com terras raras para aplicação em fibras ópticas e guias de ondas planares
In this work, the thermal and optical properties is of the system P2O5 - ZnO - Al2O3 - AO - PbO - La2O3 (mol %) + XEr2O3 [A = Ba; Mg; X = 0; 1; 2; 3; 4; 5 (wt %)] was studied aiming at applications in optical fibres and planar waves-guides, as optical amplifiers. Such system is unknown and of low cost if compared with others, for example, those made with tel
Publicado em: 2006
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16. "Obtenção de vidros fosfatados contendo Ferro por meio do aquecimento em fornos de microondas" / CHARACTERIZATION OF IRON PHOSPHATE GLASSES PREPARED BY MICROWAVE HEATING
Phosphate glasses have been investigated since the fifties, because they are relatively easy to prepare, have low melting temperatures (1000°C 1200°C), and low glass transition. However, these glasses were very sensitive to humidity, showing a very low chemical durability. Iron phosphate glasses have been prepared by melting inorganic precursors in conv
Publicado em: 2006
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17. 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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18. Ignitor: physics and progress towards ignition
Thermonuclear ignition condition for deuterium-tritium plasmas can be achieved in compact, high magnetic field devices such as Ignitor. The main scientific goals, the underlying physics basis, and the most relevant engineering solutions of this experiment are described. Burning plasma conditions can be reached either with ohmic heating only or with small amo
Brazilian Journal of Physics. Publicado em: 2004-12
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19. The role of alpha particles in the emission of plasma waves inside solar ejecta
The enhancement of the resonant instability of right-hand polarized electromagnetic ion cyclotron waves by alpha particles for physical parameters corresponding to coronal mass ejections is studied. We focus on the effects of alpha thermal anisotropy and relative He++/H+ abundance on growth and absorption rates. The first parameter governs directly wave emis
Brazilian Journal of Physics. Publicado em: 2002-06
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20. The effect of the ferrofluid magnetic particle concentration on the thermal diffusivity
Thermal diffusivity results obtained with the collinear mirage technique, are reported for different concentrations surfacted ferrofluid and for a set of acid ferrofluids with variable pH values. The collinear mirage technique was used because the materials are semitransparent and have low thermal diffusivities. The results show that, as the ferrofluid magne
Braz. J. Phys.. Publicado em: 2001-09
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21. 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
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22. Caracterização de vidros e vitro-cerâmicas com composição 2Na2O1CaO3SiO2 / Characterization of glasses and glass-ceramics with composition 2Na2O1CaO3SiO2
Glass with composition 2Na2O1CaO3SiO2, undergoes homogeneous crystal nucleation between 450 and 56OoC. The nuclei are essentially spherical and presumable have the same composition as the glass matrix. Measuriments of density, X-ray diffraction, thermal analysis by differential scanning calorimetry (DSC), ultrasonics by pulse-echo method, optical absorption,
Publicado em: 1990
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23. Order and disorder in fluid motion.
The development of complex states of fluid motion is illustrated by reviewing a series of experiments, emphasizing film flows, surface waves, and thermal convection. In one dimension, cellular patterns bifurcate to states of spatiotemporal chaos. In two dimensions, even ordered patterns can be surprisingly intricate when quasiperiodic patterns are included.
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24. Piezoelectric Theory of Enzymic Catalysis as Inferred from the Electromechanochemical Principles of Bioenergetics
Starting from the electromechanochemical principles of bioenergetics formulated by Green and Ji, a theory is proposed which describes enzymic catalysis in terms of piezoelectricity in semiconductors. The choice of this particular physical effect for describing catalytic processes is founded on the following experimental observations: most of the amino-acid r