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Surface Processes
Published in F.G.H. Blyth, M. H. de Freitas, A Geology for Engineers, 2017
F.G.H. Blyth, M. H. de Freitas
Youth, maturity and old age constitute a ‘cycle’ of erosion which, to be completed, requires the river to remove all the material supplied to it by the degrading slopes. If the rate of supply is equal to its rate of removal, linear slopes of constant angle can be expected (Fig. 3.11c). When the rate of removal exceeds the rate of supply convexo-concave slopes result.
Formation and physical properties of soils
Published in Fethi Azizi, Applied Analyses in Geotechnics, 1999
The geological process of soil formation is based on rock weathering which can occur either chemically when the minerals of a rock are altered through a chemical reaction with rainwater, or mechanically through climatic effects such as freeze-thaw cycles and erosion (see for instance Bell, 1993).
Erosion performance of detonation gun deposited WC–12Co, Stellite 6 and Stellite 21 coatings on SAE213-T12 steel
Published in Tribology - Materials, Surfaces & Interfaces, 2020
Prashant Kumar Singh, S. B. Mishra
Figure 9 shows the plot of erosion rate against the cumulative mass of erodent for WC–Co, Stellite 6 and Stellite 21 coatings on SAE213-T12 steel at 30° and 90° impact angles. The uncoated sample of SAE213-T12 boiler steel has shown the characteristic behaviour of ductile material by giving higher erosion at 30° impact angle as compared to that at 90° impact angle, associated with plastic deformation as the main phenomenon of material removal (Figures 9 and 10). During the initial four to five cycles of erosion test i.e. the incubation period, the variations in erosion rate are more and thereafter due to the work-hardening effect the surface becomes smooth and uniform causing a reduction in erosion rate variation. The erodent particles also get embedded in the material during the initial cycle of erosion tests and result in the variation of the erosion rate (increases when embedded and decreases when removed) of the coating [33]. The variation is more in case of steel material as it is comparatively softer and ductile than the coatings.
Ten reasons to set up sediment budgets for river management
Published in International Journal of River Basin Management, 2018
Roy M. Frings, Wilfried B. M. Ten Brinke
Sediment budgets help to identify the essential morphological problems for river management. Without sediment budget it may be hard to judge whether observed erosion or deposition phenomena represent a problem that calls for action, or are just part of a more-or-less natural cycle of erosion and sedimentation that can be left without management operations.