Profile penetration

Fig. 4 Corrosion inside a pipe (bore 100 mm, wall thickness 6.3 mm), projection technique at 160 kV (double wall penetration), profile plot with calibrated wall thickness loss...

The contact an e or adhesion tension of a binder solution with respecd to a powder can be determined from the slope of the penetration profile. Washburn tests can also be used to investigate the influence of powder preparation on penetration rates. The Bartell cell is related to the Washburn test except that adhesion tension is determined by available gas pressure which opposes penetration. [Bartell Osterhof, Ind. Eng. Chem., 19, 1277 (1927).]... 

Toll, R., Jacobi, U., Richter, H., Lademann, J., Schaefer, H., and Blume-Peytavi, U. (2004) Penetration profile of microspheres in follicular targeting of terminal hair follicles. Journal of Investigative Dermatology, 123 (1), 168-176. 

The apparently simple picture presented by Fig. 25 changes, however, both at higher and lower doping levels. Figure 26 shows SIMS penetration profiles at 200°C for three different donor concentrations (Johnson, 1988). While these do not have exactly the ideal Fickian shape of Fig. 5, they can be at least roughly fitted by this shape the depths at which the concentration has fallen to a tenth its extrapolated surface value yield the effective... 

Figure 5.3 Schematic representation of the penetration profile for bulk, grain boundary, and dislocation diffusion in a polycrystalline solid. The initial part of the curve is bell shaped, and the part due to short-circuit diffusion is made up of linear segments. The insets show the distribution of the tracer in the sample.

Figure 5.5 Penetration profiles typical of bulk diffusion (a), (b), and (c) illustrate gradually increasing heating times.

The random-walk model of diffusion can also be applied to derive the shape of the penetration profile. A plot of the final position reached for each atom (provided the number of diffusing atoms, N, is large) can be approximated by a continuous function, the Gaussian or normal distribution curve2 with a form ... 

Radioactive 180 was diffused into a poly crystalline pellet of ZnO at 900°C for 48 h. The diffusion profile had a marked tail showing that extensive grain boundary diffusion had occurred. The variation of the concentration of the radioactive isotope with depth for the tail of the penetration profile is given in the following table. Calculate the grain boundary diffusion coefficient, Dgb, of 180 if the bulk diffusion coefficient at 900°C is 5.53 x 10-21 m2 s-1 and the grain boundary width is taken as 1 nm. 

In general, upon exposure to UV radiant energy, a photoinitiator can generate free radicals or ions, as pointed out earlier. These are generated at a rapid rate, and their depth profile corresponds to the inverse photon penetration profile. Similar to electron penetration, the final cure profile often deviates from the initial radical or ion distribution, since they can live much longer than the exposure time. The mechanisms of the processes for the generation of reactive species are discussed in detail in Davidson. ... 

The most useful tool for the study of penetration is the electron microprobe, which was first used for this purpose by Cannon and Welling (14). They have shown the buildup of relatively thick layers of lead compounds around pellets exposed to exhaust originating from heavily leaded fuels. More recently, penetration profiles in pellets have been published for exhaust produced by fuels with lower amounts of lead. Figure 8 shows such a profile in a pellet exposed to exhaust with 0.5 g Pb/gal for 400 hr. Note, that at the exterior of the pellet, lead concentration (by weight) has... 

The relative penetration of lead, zinc, phosphorus, and sulfur into the washcoat is seen in Fig. 12 at a comer where the washcoat is relatively thick. Lead and sulfur penetrate over 100 /urn, phosphorus between 30 and 50 /tm, and zinc less than 2 p.m. All of the elements, except zinc, penetrate down into the deep crack and laterally into the washcoat. This supports again the supposition that zinc arrives at the surface in particulates, while lead, phosphorus, and sulfur arrive as gaseous entities. However, the penetration profiles do not prove the modes of deposition conclusively. Contaminant concentrations expressed in terms of lead... 

FIGURE 17.1 Human epidermal penetration profiles of estradiol (n = 6) from ultradeformable liposomes from passive delivery and electroporation (5 pulses of 100 V, 100 ms, and 1 min spacing). 

Toll, R., et al. (2004) Penetration profile of microspheres in follicular targeting of terminal hair follicles. J Invest Dermatol 123,168-76. 

Depth of penetration Millimeter range or less, in dependence of acceleration voltage (penetration profile ) Centimeter range... 

Figure 19.4. Penetration profiles for yoghurt gels produced from milks with different degrees...

Rflc-venlafaxine 10 and its sila analogue rac-11 have similar physicochemical properties (pi Ca = 9.7, log P = 3.1 in n-octanol/water, log P = 0.9 at pH 7.4) indicating that venlafaxine and sila-venlafaxine could have a similar brain penetration profile. The in vitro pharmacological studies of venlafaxine, sila-venlafaxine and their enantiomers (used as hydrochlorides) for their efficacy in monoamine reuptake inhibition demonstrated differences in activity and also in inhibition profile (06JOM(691)3589, 06OM1188). With respect to serotonin, noradrenaline and dopamine reuptake inhibition potency these... 

For the 25 freeze-thaw cycles, it was found that plastic fillers did not change the chloride penetration profile of concrete. More cycles are needed to confirm this result and to explore effects with a larger number of cycles. 

The contact angle or adhesion tension of a binder solution with respect to a powder can be determined from the slope of the penetration profile. Washburn tests can also be used to investigate the... 

Reaction condition Only thin films, thicker films need higher beam energy (penetration profile ) Diffusion of oxygen must be prevented... 

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