Rayleigh diffusion

There are two types of light diffusion Rayleigh and Raman. Energies of diffused and excited photons are equal. Thus, Rayleigh diffusion and excitation occurs at the same wavelengths. 

S. Dumartin, M. Thibeau, and B. Oksengorn. Depolarisation du rayonnement Rayleigh diffuse par un milieu forme de molecules isotropes essai de calcul de Teffet de symmetrie croissante de I environnement moleculaire avec densite. Compt. Rend. Acad. Sci. Paris, ser. B, 277 884-887 (1970). 

M. Thibeau, B. Oksengorn, and B. Vodar. Etude theorique et experimentale de la depolarisation du rayonnement Rayleigh diffuse par les gaz rares comprimes. J. Phys. (Paris), 29 287-296 (1968). 

Particles greatly submicronic (a < 0.3). For a < 0.3, the optical model of the Rayleigh diffusion is used. Particles diffuse light as much forward as backward. 

There are two types of light difhision Rayleigh and Raman. Rayleigh diffusion occurs at wavelength equal to that of the excitation one. Thus, energy of the diffused photons is equal to the energy of the excitation photons. 

Usually one should not start the emission spectrum before or at the excitation wavelength in order to avoid recording Rayleigh diffusion. 

Froger, A. and Rosengard, A. Rayleigh diffusion measurements and calculations for SF, condensation in a supersonic nozzle expansion, Rarefied Gas Dynamics,II (H.Oguchi, ed.) Univ.of Tokyo Press, pp.759-766 (1984). 

Homogeneity variation of the medium causing Rayleigh diffusion... 

Circulation of fluid is promoted by surface tension gradients but inhibited by viscosity, which slows the flow, and by molecular diffusion, which tends to even out the concentration differences. The onset of instabibty is described by a critical Marangoni number (Mo), an analogue of the Rayleigh... 

Thus, for the investigation of buried polymer interfaces, several techniques with molecular resolution are also available. Recently NMR spin diffusion experiments [92] have also been applied to the analysis of a transition zone in polymer blends or crystals and even the diffusion and mobility of chains within this layer may be analyzed. There are still several other techniques used, such as radioactive tracer detection, forced Rayleigh scattering or fluorescence quenching, which also yield valuable information on specific aspects of buried interfaces. They all depend very critically on sample preparation and quality, and we will discuss this important aspect in the next section. 

Lord Rayleigh [310] modeled transport in a homogeneous suspension of spheres placed in a square lattice. In terms of diffusion coefficients, his solution was... 

The force Rayleigh scattering method was developed by Nagashima s group. Thermal diffusivity can be measured in a contact-free manner within a time interval of 1 ms, with a small temperature rise of 0.1 K and with a small volinne of about 10 mm The sample needs to be colored by an admixture of a dye for suitable absorption of a heating laser beam. The principle is schematically shown in Fig. 32. Two beams of equal intensity divided by means of abeam splitter cross in the sample to create... 

Kdhler, W and Schdfer, R, Polymer Analysis by Thermal-Diffusion Forced Rayleigh Scattering. Vol. 151, pp. 1-59. 

W. J. Goux, L. A. Verkruyse, S. J. Salter 1990, (The impact of Rayleigh-Benard convection on NMR pulsed-field-gra-dient diffusion measurements), J. Mag. Reson. 88, 609. 

Rayleigh parameters, two-pathway excitation, coherence spectroscopy, 155-159 Reaction-diffusion equations, multiparticle collisions, reactive dynamics, 108-111 Reaction rates ... 

JA Wesson, H Takezoe, H Yu, SP Chen. Dye diffusion in swollen gels by forced Rayleigh scattering. J Appl Phys 53 6513-6519, 1982. 

TDFRS Thermal diffusion forced Rayleigh scattering... 

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