scholarly journals CALCULATION OF THE RATE OF NET ON-OFFSHORE SEDIMENT TRANSPORT ON THE BASIS OF FLUX CONCEPT

1984 ◽  
Vol 1 (19) ◽  
pp. 91 ◽  
Author(s):  
Ichiro Deguchi ◽  
Toru Sawaragi
Keyword(s):  
Sediment Transport ◽  
Water Depth ◽  
Sediment Concentration ◽  
Suspended Load ◽  
Spatial Variations ◽  
Sediment Flux ◽  
Bed Load ◽  
Two Dimensional ◽  
Dimensional Model ◽  
Two Dimensional Model

Time and spatial variations of sediment concentration of both bed load and suspended load in the process of two-dimensional beach deformation were investigated experimentally. At the same time, the relation between the velocities of water-particle and sediment migration was analyzed theoretically. By using those results,a net rate of on-offshore sediment_ transport in the process of two-dimensional model beach deformation qf was calculated on the basis of sediment flux. It is found that Qf coincides fairly well with .the net rate of on-offshore sediment transport calculated from the change of water depth.

scholarly journals ON-OFFSHORE SEDIMENT TRANSPORT RATE IN THE SURF ZONE

1980 ◽  
Vol 1 (17) ◽  
pp. 72 ◽  
Author(s):  
Toru Sawaragi ◽  
Ichiro Deguchi
Keyword(s):  
Sediment Transport ◽  
Surf Zone ◽  
Suspended Load ◽  
Transport Rate ◽  
Bed Load ◽  
Relative Importance ◽  
Two Dimensional ◽  
Sediment Transport Rate

In this paper, models of the distribution of net on-offshore sediment transport based on two-dimensional equilibrium beach profiles and an equation of continuity of sediment transport are proposed. Various parameters of net on-offshore sediment transport in those models are discussed. Furhter, the relative importance of bed load and suspended load in the two-dimensional beach deformation are examined by measuring both of them on model beach experiments.

scholarly journals A NUMERICAL MODEL FOR SEDIMENT TRANSPORT

1978 ◽  
Vol 1 (16) ◽  
pp. 103
Author(s):  
J.P. Lepetit ◽  
A. Hauguel
Keyword(s):  
Sediment Transport ◽  
Numerical Model ◽  
Time Scale ◽  
Local Scour ◽  
Two Dimensional ◽  
Dimensional Model ◽  
Propagation Equation ◽  
Coastal Structure ◽  
Two Dimensional Model ◽  
The Impact

We introduce here a numerical two dimensional model for sediment transport which permits to compute the impact of a coastal structure on the bottom evolution. The introduction of current disturbance and some assumptions using difference of time scale between current and bottom evolutions permits to obtain a propagation equation driving the bottom evolution. The model has been calibrated in the case of the local scour around a jetty. At last, it has been applied to the bottom evolution in the vicinity of the new port of Dunkerque.

QUASI-THREE-DIMENSIONAL MATHEMATICAL MODELING OF MORPHOLOGICAL PROCESSES BASED ON EQUILIBRIUM SEDIMENT TRANSPORT

2000 ◽  
Vol 11 (07) ◽  
pp. 1425-1436 ◽  
Author(s):  
MY. M. CHARAFI ◽  
A. SADOK ◽  
A. KAMAL ◽  
A. MENAI
Keyword(s):  
Sediment Transport ◽  
Three Dimensional ◽  
Sediment Concentration ◽  
Suspended Load ◽  
Bed Load ◽  
Change Rate ◽  
Sediment Mass ◽  
Load Transport ◽  
Bed Load Transport ◽  
Morphological Processes

A quasi-three-dimensional mathematical model has been developed to study the morphological processes based on equilibrium sediment transport method. The flow velocities are computed by a two-dimensional horizontal depth-averaged flow model (H2D) in combination with logarithmic velocity profiles. The transport of sediment particles by a flow water has been considered in the form of bed load and suspended load. The bed load transport rate is defined as the transport of particles by rolling and saltating along the bed surface and is given by the Van Rijn relationship (1987). The equilibrium suspended load transport is described in terms of an equilibrium sediment concentration profile (ce) and a logarithmic velocity (u). Based on the equilibrium transport, the bed change rate is given by integration of the sediment mass-balance equation. The model results have been compared with a Van Rijn results (equilibrium approach) and good agreement has been found.

Commitment to pro- versus counter-attitudinal behavior and the dynamics of social representations

2002 ◽  
Vol 61 (1) ◽  
pp. 34-44 ◽  
Author(s):  
Eric Tafani ◽  
Lionel Souchet
Keyword(s):  
Higher Education ◽  
Social Representations ◽  
Cognitive Restructuring ◽  
Social Representation ◽  
Two Dimensional ◽  
Dimensional Model ◽  
Social Actions ◽  
The Social ◽  
Two Dimensional Model ◽  
Students Attitudes

This research uses the counter-attitudinal essay paradigm ( Janis & King, 1954 ) to test the effects of social actions on social representations. Thus, students wrote either a pro- or a counter-attitudinal essay on Higher Education. Three forms of counter-attitudinal essays were manipulated countering respectively a) students’ attitudes towards higher education; b) peripheral beliefs or c) central beliefs associated with this representation object. After writing the essay, students expressed their attitudes towards higher education and evaluated different beliefs associated with it. The structural status of these beliefs was also assessed by a “calling into question” test ( Flament, 1994a ). Results show that behavior challenging either an attitude or peripheral beliefs induces a rationalization process, giving rise to minor modifications of the representational field. These modifications are only on the social evaluative dimension of the social representation. On the other hand, when the behavior challenges central beliefs, the same rationalization process induces a cognitive restructuring of the representational field, i.e., a structural change in the representation. These results and their implications for the experimental study of representational dynamics are discussed with regard to the two-dimensional model of social representations ( Moliner, 1994 ) and rationalization theory ( Beauvois & Joule, 1996 ).

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