A context-free e-free grammar with regular restrictions is a context-free £-free grammar G over which a context-free rule r or G is applicable on a string x only if x e y(r) where y(r) is a regular set. It is known from [1] that the context-free £-free grammars with regular restrictions are as powerful as Chomsky's grammars of the type 0. It is shown, that the same result holds for the grammars...

As a droplet moves, due to evaporation at the surface, the droplet size is gradually reduced. Due to decreasing the size of the droplets moving in the spray core, the surface charges become closer and the repulsive force between the charges increases. When the Coulombic force overcomes the surface tension force (Rayleigh instability) the droplet breaks into smaller droplets (Coulomb fission). T...

In this paper we present interactive techniques for physics-based simulation and realistic rendering of rivers using Smoothed Particle Hydrodynamics. We describe the design and implementation of a grid-less data structure to efficiently determine particles in close proximity and to resolve particle collisions. Based on this data structure, an efficient method to extract and display the fluid fr...

The effect of extracellular polymeric substances (EPS) of Gram-positive Bacillus subtilis and Gram-negative Pseudomonas putida on Cu(II) adsorption was investigated using a combination of batch adsorption, potentiometric titrations, Fourier transform infrared spectroscopy. Both the potentiometric titrations and the Cu(II) adsorption experiments indicated that the presence of EPS in a biomass sa...

This work is devoted to numerical modeling and simulation of flows of granular materials, with application to geophysical flows such as avalanches and debris flows. We consider an incompressible viscoplastic fluid, described by a rheology with pressure dependent yield stress, in a two-dimensional setting with a free surface. The regularization method is used to deal with the singularity of the ...

Instabilities of a thin viscous film flowing down a uniformly heated plane are investigated in this study. The heating generates a surface tension gradient that induces thermocapillary stresses on the free surface. Thus, the film is not only influenced by gravity and mean surface tension but also the thermocapillary force is acting on the free surface. Moreover, the heat transfer at the free su...

Free-surface turbulence, albeit constrained onto a two-dimensional space, exhibits features that barely resemble predictions of simplified two-dimensional modeling. We demonstrate that, in a three-dimensional open channel flow, surface turbulence is characterized by upscale energy transfer, which controls the long-term evolution of the larger scales. We are able to associate downscale and upsca...

Effect of air cushion layer right before impact of a rigid body onto water surface has been investigated in this paper. The study is mainly focused on evaluation of cushioning pressure and the resulting free surface elevation. The air flow is assumed to be an irrotational flow which is governed by Laplace equation. The air problem and the resulting response of the water free surface are suppose...

the johor strait is an estuarine system located on the coast of the state of johor in malaysia.the western part of johor strait is a shallow estuarine located between causeway and pulai river. ahydrodynamic model was calibrated based on the environmental fluid dynamic code (efdc) from 4th to 17th of october, 2009. in this calibration, the efdc hydrodynamic model was configured to simulate time ...