Penetration, of the core

When dealing with porous particles, penetration of the core by water or solvents should be avoided. This can be accomplished using the evaporative efficiency of a fluidised bed, although care should be taken to avoid spray-drying of the coating solution. Other possible side-effect phenomena inside the fluidised bed (Nienow... 

One part of the splitting, due to the difference of the Coulomb integrals J, and Jv, can be easily interpreted as resulting from the difference in the interaction of an inner Is electron with an outer 2s electron or 2p electron. This effect was recognized in the days of the old quantum theory, being described as resulting from greater penetration of the core of the atom (the nucleus plus the inner electrons) by the more eccentric orbits of the... 

In photoabsorption spectroscopy, the distinction can also be made in a different way the probability that an electron on a Rydberg orbit is ejected depends on its penetration of the core, which scales as 1/n 3. On the other hand, the Auger electron has a constant probability Tauger of being ejected. Thus, if we observe a Rydberg series of autoionising resonances in photoabsorption, then the total width rn of the nth member is given by... 

The valence orbitals are not, in fact, external to the cores each function vanishes only at infinity. There is definite penetration of the core region by the valence electrons. 

The normalized distance (rp /p) — l from the interface is a measure of the effective depth of penetration of the core field into the cladding. We plot this quantity as a function of Kin Fig. 14-3(a), taking g = e for the lower curve and 0 = 0.1 for the upper curve. For example, when V = 2.5 we deduce from the rj curve that about 84 % of total fundamental-mode power flows within the... 

Previously derived results for the charge-density profile and polarization profile in this model solution, valid only for small fields, were used. Although these did not consider the penetration of the electrons into the solution, the change in the field is small. A Harrison-type pseudopotential84 was used to represent the effect of core electrons of the solution species on the metal electrons. 

The earlier evaluation of the core radius was in terms of Bohr s impulse condition (see Sect. 2.3.3) at (relatively) high energies. This gives the core radius as 30 A at a particle energy of 10 MeV/amu. For much lower energies, this relation is unrealistic, since electrons ejected in glancing collisions penetrate... 

If there were penetration of the water in the core of the micelle. 

If, even if there were no penetration of the water in the interior of the core of the micelle, a part of the hydrocarbon chains were exposed to the micelle-water interface. 

Frechet and co-workers [32] studied the ability of the dendrimer shell to provide site isolation of the core porphyrin moiety, using benzene-terminated dendrimers Zn[G-n]4P (i.e. 6). From the cyclic voltammograms in CH2C12, the interfacial electron transfer rate between the porphyrin core and the electrode surface decreased with increasing dendrimer generation. However, small molecules like benzyl viologen could still penetrate the shell of 6 to access the porphyrin core as observed from the quenching of porphyrin fluorescence. Their results also revealed that the dendritic shell did not interfere electrochemically or photochemically with the porphyrin core moiety. 

Organic molecules are solubilized by the organic constituents of a micelle. In small micelles the molecules lie close to the interface, while in large microemulsions considerable penetration into the core is observed (1.). Inorganic materials are quite polar and have little interaction with the organic components of the micelle. However, the micelle counterions,... 

Figure 5.6 shows profiles of NO3 concentration measured with microsensors in soil cores taken from ricefields by Revsbech and co-workers (Liesack et al., 2000). During illumination of the cores, O2 generated in the floodwater penetrated to a depth of 2-3 mm and a clear peak of was apparent, produced in... 

Figure 13.3.7 shows scanning electron microscopy (SEM) photographs of the surface of the polyethylene particle after the silica particles were peeled off. The specimen was prepared in the following way. After the composite particles were potted in epoxy resin, the dried resin block was cut using a microtome to produce fine sections. The fracture surface appearance of the polyethylene was then observed under a microscope. The mean depth penetration into the surface of the core particles could be measured using the SEM photographs. Silica 0.3 pan in diameter was embedded in the surface of the polyethylene particles at a depth of 0.03 xm. In... 

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