Ferrofluid
Mostrando 13-21 de 21 artigos, teses e dissertações.
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13. Stochastic Molecular Dynamics of colloidal particles
Colloidal particles move in the carrier liquid under the action of several forces and torques. When the particles carry a dipole moment, electric or magnetic, as in ferrofluids, the rotational and translational motions are coupled because the field on a particle depends on the spatial and directional distribution of the others and the force and torque on it
Brazilian Journal of Physics. Publicado em: 2004-06
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14. Preparation of a ferrofluid using cyclodextrin and magnetite
Um ferrofluido foi obtido a partir da magnetita e da beta-ciclodextrina, com a formação de um complexo de inclusão. A caracterização físico-química do complexo magnétita: beta-ciclodextrina foi realizada através de espectroscopia de absorção na região do infravermelho com transformada de Fourier, difração de raios X, análise térmica (TG/DTA),
Journal of the Brazilian Chemical Society. Publicado em: 2003-12
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15. Analysis of a porous exponential slider bearing lubricated with a ferrofluid considering slip velocity
A porous exponential slider bearing was studied with a ferrofluid lubricant whose flow is governed by Jenkins flow behaviour considering slip velocity at the porous interface. Expressions for dimensionless pressure, load capacity, friction on the slider, coefficient of friction and the position of the centre of pressure were obtained. Computed values were di
Journal of the Brazilian Society of Mechanical Sciences and Engineering. Publicado em: 2003-09
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16. 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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17. Ferrofluid hydrodynamics: waves, jets and free drops
A novel approach to hydrodynamical studies uses the bulk force properties of magnetic liquids to probe the dynamics of (i) freely suspended drops; and (ii) unstable surface waves and jets. The fluid dynamics are imaged by a fast CCD camera, allowing thorough analysis of these time-dependent phenomena. Ferrofluid drops are freely suspended in air by using mag
Braz. J. Phys.. Publicado em: 2001-09
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18. Interfacial instabilities in confined ferrofluids
We investigate the flow of two immiscible, viscous fluids in the confined geometry of a Hele-Shaw cell. We consider that one of the fluids is a ferrofluid and that an external magnetic field is applied. The interfacial instabilities which arise between the fluids are studied for various situations: (a) different cell geometries (radial, rectangular); (b) fro
Braz. J. Phys.. Publicado em: 2001-09
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19. Surface waves and wave resistance in magnetic fluids
We present here the experimental determination of the dispersion relation of surface waves of a ferrofluid submitted to a steady vertical magnetic field. The results are compared to a linear theory where all the magnetic characteristics of the fluid have been taken into account. The knowledge of the dispersion equation is then used to analyse the capillary-w
Braz. J. Phys.. Publicado em: 2001-09
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20. Estados críticos orientacionais em cristais líquidos liotrópicos induzidos por campos magnéticos. / Orientations critical states in lyotropic liquid crystals induced by magnetic fields.
Liquid crystalline structures are found in materials made from molecules which are anisotropic in shape; such material are characterized mainly by a long range orientational order. In the nematic phase, the rodlike molecules tend to align parallel to each other. The average orientation defines a unit vector, called director n. Lyotropic liquid crystals are u
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 19/12/2000
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21. Espectroscopia de lente termica : propriedades termicas de cristais liquidos
Liquid Crystals are fluids that present intermediate properties between solid and liquid, and consist of a molecular arrange with structural order. These systems are classified as Thermotropic Liquid Cristals, Lyotropie Liquid Crystals and Plastic Crystals. Since their discovery, these systems have shown to be an important area of condensed matter research.
Publicado em: 1997