Outward expansion

The earth s atmosphere extends some 600 to 1500 kilometers into space. Two factors are involved in this great extension of the atmosphere. First, above about 100 kilometers, the atmospheric temperature increases rapidly with altitude, causing an outward expansion of the atmosphere far beyond that which would occur were die temperature within the bounds observed at the earth s surface. Second above Ihis dislance. the atmosphere is sufficiently rarefied so that the different atmospheric constituents attain diffusive equilibrium distributions in the gravitational field the lighter... 

During mercerization, the swelling induced by the caustic is inhibited from outward expansion by the presence of the primary wall of the cotton fiber. The changes observed in fiber morphology by mercerization include deconvolution, decrease in the size of the lumen, and a more circular cross section. 

The simplest scheme which might be autocatalytic is indicated in the sketch where the active material is disposed in a hollow shell as indicated in Fig. 8.3a. Suppose that when the firing plug is in place one has just the critical mass for this configuration. If as the reaction proceeds the expansion were to proceed only inward it is easy to see from diffusion theory that v would increase. Of course in actual fact it will proceed outward (tending to decrease v ) as well as inward and the outward expansion would in reality give the dominant effect. However, even if the outward expansion were very small compared to the inward expansion, it has been calculated that this method gives very low efficiency with 12 an efficiency of only about 10 was calculated. 

Missing of a local position at the topmost layers (lower coordination number) due to the inward relaxation of the topmost layers and the outward expansion of the lower layers. 

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