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The recoil momentum transfer produced by irradiation of a flat tin (Sn) target with pulses of high-power CO 2 laser with intensity ranging from 10 7 to 10 10 W cm −2 has been studied. Momentum measurements were performed using a ballistic pendulum, capable of measuring momenta as small as 0.001 g • cm s −1 . It has been established that the recoil momentum monotonically increases with the laser energy and asymptotically reaches the power scaling law p ∼ I α with α = 0.96 ± 0.07. Results are compared with previously published theoretical studies.

The objective of the study was to examine the structure of typical Ukrainian chernozem developed on loess, which (I) had been fertilized by standard crop rotation since 1912 with farm yard manure at the rate of 16 t ha-1 and (II) had not been fertilized with farm yard manure by sugar beet monoculture since 1929. After harvest of winter wheat and sugar beet, the samples of undisturbed structure were taken from 5 layers of both profiles: 0-8, 10-18, 20-28, 30-38, and 40-48 cm. The morphological analysis of the structure of the investigated chernozem revealed that the most visible differences between the soil structures of the two pedons occurred in their superficial layers. The 0-18 cm layer of the soil in the experiment I had an aggregate structure, whereas analogous layer of the soil in experiment II was much more compacted. Below about 30 cm from the ground level both pedons had very similar structure. For the soil in the experiment I an appropriate crop rotation and regular supplies of organic matter allowed for preservation of a favourable structure even in the upper layers - in contrast to the soil in the experiment II.

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