Cavitation Resistance of Elastomeric Coatings Deposited by Different Methods

In this study a fluid elastomer was applied by two different methods on a martensitic stainless steel substrate, in order to obtain coatings for protection against cavitation. The investigations regarding the resistance to cavitation erosion of the elastomeric coatings were carried out by the indirect vibratory method using the values of the cumulative erosion (material loss) developed during a testing period of 600 minutes with a 20 kHz ultrasonic vibrator at a peak-to-peak amplitude of 50 μm. The experimental results obtained in the laboratory have been processed statistically. They clearly pointed out that the deposition method significantly influences the cavitation resistance of the elastomer.

Studying the present-day dynamics of Lena delta by space images

The dynamics of Lena delta coastline since the late XX century up to the present time have been studied using Landsat satellite data. The comparison of different-time images of morphologically different segments of the delta coastline has shown the major portion of the delta to be stable. Minimal changes have been recorded near the mouths of the branches carrying a minor portion of the Lena runoffthe Olenekskaya and Tumatskie. In the eastern part of the delta, near the mouths of copious branches Trofimovskaya and Bykovskaya, no changes have taken place, as well as in its western part, which is represented by a part of abrasion marine terrace embraced by the delta. In the southwestern part, in the Olenek delta, the delta coastline has been eroded with the erosion material transported eastward by along-shore current. Near the mouths of the Tumatskaya branch, the forms of marine accumulation are unstable, and the marine terrace in the northeastern part of the delta shows a minor local erosion. The periods of erosion in different delta areas are not synchronous and the eroded zones are not large in size. No increment in the land, nor shore progradation have been seen.

EFFICIENCY OF INTERO MODEL TO PREDICT SOIL EROSION INTENSITY AND SEDIMENT YIELD IN KHAMSAN REPRESENTATIVE WATERSHED (WEST OF IRAN)

Application of empirical models is inevitable because of the complexity of process,features, spatial and temporal variation of soil erosion and non-existence or lack ofassociated data. In the present study, maximum outflow and soil erosion intensitywere predicted for Khamsan representative watershed in West of Iran, using IntEromodel. The results of production of erosion material in the river basin (W year),coefficient of the deposit retention (Ru) and real soil losses (G year) were thencompared with the measured soil erosion, SDR and sediment yield data inKhamsan watershed. The intensity of the erosion process were medium in studiedwatershed. The predicted data were compared with the measured sediment yield ofstudied watershed and verified the acceptable results of the IntEro model inKhamsan representative watershed. The results showed that the peak flow is 27.50m3s-1 for a return period of 100 years. The value of Z coefficient of 0.876 indicatesthat the river basin belongs to the second destruction category out of five. Thecalculated net soil loss from the river basin was 12263.44 m3 per year, specific282.81 m3km-2 per year. The strength of the erosion process is strong, andaccording to the erosion type, it is surface erosion.