Diffusion experimental investigations

Edelman, R.B., Portune, O.R, Weilerstein, G., Cochran, T.H., and Haggard, J.B., Jr., An analytical and experimental investigation of gravity effects upon laminar gas jet-diffusion flames, Proc. Combust. Inst., 14,399,1973. 

Gauthier P-J, Condomines M, Hammouda T (1999) An experimental investigation of radon diffusion in an anhydrous andesitic melt at atmospheric pressure Implications for radon degassing from empting magmas. Geochim Cosmochim Acta 63 645-656... 

The mechanism of gas transport through the porous hydrophobic layer of the developed air gas-diffusion electrodes is theoretically and experimentally investigated [5],... 

Gas diffusion in the nano-porous hydrophobic material under partial pressure gradient and at constant total pressure is theoretically and experimentally investigated. The dusty-gas model is used in which the porous media is presented as a system of hard spherical particles, uniformly distributed in the space. These particles are accepted as gas molecules with infinitely big mass. In the case of gas transport of two-component gas mixture (i = 1,2) the effective diffusion coefficient (Dj)eff of each of the... 

Then, ionic diffusion towards self-affine fractal electrode was experimentally investigated by using cyclic voltammetry in a mixture of 30 wt % glycerol and 70 wt % (0.01 M K4[Fe(CN)6] + 0.5 M Na2S04) solution. The cyclic voltammograms obtained... 

Nowak M. and Behrens H. (1997) An experimental investigation on diffusion of water in haplogranitic melts. Contrib. Mineral. Petrol. 126, 365-376. 

Binh et al. (104, 105) performed experimental investigations of surface diffusion under ultra-high vacuum and found that free evaporation must also be considered for temperatures higher than about 0.65 Tm (the melting point) for clean surfaces. They presented a thermal grooving model (106-108) in which free evaporation was considered simultaneously with surface diffusion. In this... 

How easily experimental investigations of cumene cracking by, porous catalysts can suffer from diffusion effects can be demonstrated by use of the data in Table IV. These data were calculated from the criterion (1)... 

Experimental investigations and theoretical computations of SO2 absorption in a spray drier [47] showed that, with an excess of calcium hydroxide absorption is limited only by the gas-phase mass transfer. In addition, the flow in a spray drier could be described by the model of an ideal stirred vessel. Newton et al. [70] considered the subprocesses of mass transfer of SO2 from the gaseous phase to the drop surface, the absorption, the dissociation of SO2, the diffusion of the produced species and the dissolution of calcium hydroxide particles in the drop. 

Jagoda, I., Prado, G., and Lahaye, J., An experimental investigation into soot formation and distribution in polymer diffusion flames, Combust. Flame, 37, 261, 1980. 

Experimental investigations of turbulence diffusion. A factor in transportation of sediment in open channel flow. J Applied Mechanics, 12 A91-A100. 

The first section of this chapter is devoted to the presentation of some diffusion models constructed on the basis of phenomenological considerations. These so-called heuristic models are often cited in the literature and used for the interpretation of experimental results. A special emphasis is to discuss how the mathematical formulae of these models can correlate with experimetal data and moreover to predict diffusion coefficients beyond the ranges experimentally investigated. This latter aspect is of great interest not only from a fundamental point of view but also in many practical fields where the possibility to predict a diffusion process might be a more economic alternative to its experimental investigation. 

Similarly to Fig. 5-4 for other glassy polymer-solvent systems also the predictions of this free-volume theory are in general agreement with experimental data on the temperature dependence of D in the vicinity of Tg2. In particular, the theory predicts a step change in Ed at Tg2, and this is consistent with most experimental investigations of polymer-solvent diffusion at temperatures just above and below the glass transition temperature (6,11,15). 

Further research was performed on alkaline fuel-cell concepts (e.g. characterisation of gas diffusion electrodes) as well as on catalytic burners (reaction kinetics of H2/air mixtures). Experimental investigation of dymanic combustion phenomena was performed. Practical tests were carried out on internal combustion engines, including compression ignition engines (Altman el al., 1997 Schucan, 2000)... 

Owing to their definite structures, most biomolecules have an appreciable permanent dipole moment which must lead to dielectric polarization via the rotational mechanism of preferential orientation. Thus pertinent experimental investigation permits a direct determination of the molecular dipole moments and rotational relaxation times (or rotational diffusion coefficients, respectively). These are characteristic factors for many macro-molecules and give valuable information regarding structural properties such as length, shape, and mass. 

Krooss, B.M., 1987. Experimental investigation of the diffusion of low-molecular weight hydrocarbons in sedimentary rocks Kinetics of the release of light hydrocarbons from source rocks. In Doligez, B. (ed.), 1987. Migration of hydrocarbons in sedimentary basins. 3rd IFP Exploration and Production Research Conference, 1987. Editions Technip, Paris, pp. 329-351... 

Experimental investigations have determined the dififusivity of different gases in various porous soil and overburden materials. The periods calculated for gases to travel a particular distance vary considerably (Table l-II). Mercury vapour diffuses in 15 days through 10 m of sand whereas 5.7 years are required for Kr to pass through 10 m of fine-grained playa sediments. 

Testury, M.H., 1996. Results of geoelectrochemical experimental investigations by means of the diffusion extraction of metals (MDE) and their significance in geophysical prospecting for kimberlite explosion pipes. VINITI, St. Petersburg State Mining Institute, Russia, 12 pp. (in Russian). 

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