Patchy saturation

A patchy saturation is given when fluids are not uniformly mixed. Effective modulus values cannot be estimated from Reuss averaging (lowest level) an upper limit is given by Voigt s averaging ... 

Lebedev, M., Toms-Stewart, J., Clenell, B., Pervukhina, M., Shulakova, V., Patterson, L., Muller, T., Gurevich, B., Wenzlau, F., 2009. Direct laboratory observation of patchy saturation and its effects on ultrasonic velocities. Lead. Edge 28, 24-27. SEG, Tulsa, OK, USA. 

Direct measurements of ambient supersaturations in clouds have been extremely challenging. Not only does one try to measure a small deviation from saturation, but clouds are frequently patchy with supersaturated regions next to subsaturated ones corresponding to dry entrained masses. Previous measurements have indicated that ambient supersaturations are usually less than 1% and almost never exceed 2% (Warner 1968). A median value of 0.1% was reported in these measurements. Most of our knowledge of these supersaturations is based on theoretical calculations using measurements of atmospheric conditions and are rather similar to that presented here as an example. Ranges of supersaturations expected in various cloud types are given in Table 17.3. 

The light and CO2 saturated rate of O2 evolution showed a salt induced decline. This inequivocally demonstrates a non-stomatal effect of salinity on photosynthesis. However, the decline of the light saturated rate of O2 evolution in salt stressed plants was smaller than expected on the basis of A(pi) relationship. These results seem to indicate that some of the non-stomatal effects, as detected by depression of A(p ) curves, are only apparent and could be attributed to patchy stomatal closure. Furthermore, the rate of O2 evolution showed a significant enhancement increasing the partial pressure of CO2 from 50 mbar to 100 mbar (data not shown). These evidences confirm for salt stress other previous observation on the effect of ABA (8, 10, 19) and on the effect of water stress (9 10,... 

Singly bondable association sites— Assumes each association site saturates after sharing in a single association bond. This approximation is not valid for patchy colloids with large patch sizes [43]. 

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