Scour morphology at rock-bed sills for different spatial arrangements and geometric configurations

Bed sills are often used for river restoration. This structure typology contributes to stabilize bed slope and, generally, increases the energy dissipation. The erosive process occurring downstream of them is one of the most important issue to be solved and predicted in order to assure the correct hydraulic functioning of bed sills. Therefore, in the last decades, hydraulic engineers adopted innovative solutions, which could conjugate both the hydraulic aspects and the necessity to minimize structures impact on water bodies. In this perspective, rock-bed sills became very popular and widely adopted in river restoration projects. Nevertheless, there is still a lack of knowledge regarding their geometry optimization in terms of both scour depth reduction and equilibrium morphology. Therefore, experimental tests were conducted to simulate different rock-sills arrangements and typologies. This paper furnishes a preliminary analysis of the scour process downstream of rock-bed sills in a wide range of hydraulic and geometric configurations

Scour on Alluvial Bed Downstream of Falling Jets

This paper describes a theoretical approach for predicting the local scour downstream of falling jets, due to grade control structures, with the support of laboratory evidences. A number of 63 runs were con- ducted, varying sediment grain size, discharge, downstream water level and drop height. For each run, the scour hole profile was accurately measured in order to derive the bottom shear stress from the local slope, whence the hydrodynamic characteristics of the flow field at the scour bottom were derived from theoretical analyses. These analyses show that the turbulence structure in the scour hole can be subdivided in three zones: i) the impinging jet zone, ii) the transition region and iii) the wall jet zone in which the mean velocity profile is similar. These considerations allow to compute the bottom shear stress distribution along the scour hole di- rectly from the impact jet momentum at the scour bottom. Through the sediment equilibrium equation, the scour hole shape is computed and the maximum scour depth is derived

Communicating culture: a reinforcement process model

In this article, after laying the conceptual foundations of communication and corporate culture, we revise the disagreement on whether their role in their mutual relationship is a minor or a fundamental one. Then, we define “communication in corporate culture”, as the foundation of the communication-culture system. Building on this idea, we suggest a model for organizational reinforcement. Finally, we define the basic patterns in order to strengthen and reinforce the proposed cycle