Abslract. Neutron differential elastic-and inelastic-scattering cross sections of '"Rh are measured for incident energies of -1.5 to IOMeV. The measurements are made with sufficient detail to well define the energy-averaged behaviour of the elastic-scattering process. Neutrons corresponding to excitations of groups of levels at 3 3 4 i 13, 5 3 6 i IO, 648 i 25, 796 i 20, 864 f 22, 1120 i 22, 1279 i 60, 1481 i 27 and 1683 f 39 keV aTe observed and the corresponding cross sections determined. Assuming the target nucleus is reasonably approximated by a simple one-phonon vibrator, spherical-optical,dispersive-optical, and coupled-channels models are deduced from the data base. Physical aspects of these models are compared with theoretical predictions and the sptematics of similar model parametrizations in this mass-energy region.
Results are presented for experimental laser-scanning investigations of the statistical characteristics of wind-driven ocean waves. The method involves counting the number of specular points during scanning of the sea surface by a narrow laser beam on a moving ship. The data analyzed are the set of specular points recorded along a track traced out by the laser beam as a result of the motion of the ship and the scanning beam. A prominent feature is the large-scale variability of the number of specular points and the self-similar nature of the process over a rather wide range of spatial scales. A fractal analysis of the process shows a clear power-law interval in the spatial spectrum of the distribution of specular points.
An important part of the general problem of the Arctic climate change is the monitoring of the Fram Strait, which lies between Greenland and Spitsbergen. For this reason it is reasonable to apply acoustic methods which are proven to be effective in acoustic ocean thermometry, acoustic tomography, etc. Knowledge of the main peculiarities of sound signal propagation in this region is needed to estimate the feasibility of applying remote acoustic methods. To this end computer simulation of sound signal propagation in the Fram Strait environment was performed, based on oceanographic data obtained by the R/V POLARSTERN expedition. The presence of stable eigenrays in Fram Strait environmental conditions is demonstrated, typical values of acoustic signal travel time fluctuations due to environmental variations are determined, and the temperature effect on the signal travel time variation is considered. Sensitivity estimates for measurement of the average ocean temperature across Fram Strait is considered in two approaches: by calculating travel time changes along selected stable eigenrays, and by determining the cumulative sum of the whole envelope of the signals passed along water-borne paths.
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