4.9 X 101

4 X 10-2

1.2 X 10-1

the living matter of the biosphere (Vernadsky includes this part into the biosphere). The temperature T0 is the temperature of this part. Since we assume that it is in thermal equilibrium with biota then, without loss of generality, we can say that T0 = T = 287 K. A specific exergy of one weight unit of living matter is ex = Ex/B.

It is very important that the specific exergy depends not only on the relative element composition of both the living matter and the crust (i.e. the percentage content of different chemical elements in these systems, in the biosphere and in the crust), but, to a significant degree, its value depends on the ratio r = M/M0, i.e. on the relative value of crust matter involved in the fast (in comparison with geological times) global biogeochemical cycles. It will become clear if we rewrite Eq. (7.1) as ex = KW + o-(ln r - 1) H----(7.2)

Taking into account that all concentrations in Vinogradov's table are evaluated in the relative weight units (%) and using formula (7.2), we can calculate the values of K, a and s*\ Kw = 777, a = 395, s0 = 130. All these values are measured in J/g of living matter.

Let us calculate the specific exergy for different values of r. The first simplest hypothesis is the assumption that the total amount of matter does not change in the course of transition from the non-living state to the living one, i.e. the peculiar conservation law of matter has been realised and M = M0, i.e. r = 1. In other words, there is dynamic equilibrium between biota and crust, i.e. between the living and non-living matter of the biosphere. The latter is understood in Vernadsky's wide sense, where the whole matter of crust has been involved into the "Big Living Cycle". According to Vernadsky the Earth's crust is a result of the biosphere's activity, the trace of the past biospheres.

By setting r = 1 in Eq. (7.2) we obtain immediately that specific exergy of 1 g of living matter is equal to 512 J/g.

The specific exergy can be presented as the sum ex = £n=i (ex)1, where (ex)1 is the contribution of partial exergy, corresponding to ith element, into the total exergy. Let us compare these contributions (see Table 11.2).

In fact, the main contribution belongs to hydrogen (~ 71%) (i.e. water, carbo-hydrates, etc.). The second place is occupied by carbon (~ 21%). Then come silicon, aluminium

Table 11.2

Partial specific exergy for different chemical elements (in J/g of living matter)

Table 11.2

Partial specific exergy for different chemical elements (in J/g of living matter)


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