Showing 1 - 10 of 19
The quasi-equilibrium or maximum entropy approximation is applied in order to derive constitutive equations from kinetic models of polymer dynamics. It is shown in general and illustrated for an example how canonical distribution functions are obtained from the maximum entropy principle, how...
Persistent link: https://www.econbiz.de/10011060168
The main goal of this paper is a rigorous consideration of the stress problem in some simple models of granular piles. Discrete models are considered and the transition to the continuous description is accomplished in order to find the coarse-grained average stress. Some phenomenological rules...
Persistent link: https://www.econbiz.de/10010588735
We discuss the kinetic representation of gases and the derivation of macroscopic equations governing the thermomechanical behavior of a dilute gas viewed at the macroscopic level as a continuous medium. We introduce an approach to kinetic theory where spatial distributions of the molecules are...
Persistent link: https://www.econbiz.de/10010591790
The method of invariant manifold is developed for a derivation of reduced description in kinetic equations of dilute polymeric solutions. It is demonstrated that this reduced description becomes universal in the limit of small Deborah and Weissenberg numbers, and it is represented by the...
Persistent link: https://www.econbiz.de/10010873916
Diffusion of transported particles in the intracellular medium is described by means of a generalized diffusion equation containing forces due to the cytoskeleton network and to the protein motors. We find that the enhanced diffusion observed in experiments depends on the nature of the force...
Persistent link: https://www.econbiz.de/10011057194
We present a kinetic theory for one-dimensional inhomogeneous systems with weak long-range interactions. Starting from the Klimontovich equation and using a quasilinear theory valid at order 1/N in a proper thermodynamic limit N→+∞, we obtain a closed kinetic equation describing the...
Persistent link: https://www.econbiz.de/10011057970
Previous thermodynamic analyses of shear-induced shift of the spinodal line in diluted polymer solutions in plane Couette flows are extended here to the entangled regime by using the reptation model. The most significant difference with respect to the dilute regime is a shift of the critical...
Persistent link: https://www.econbiz.de/10011058744
Measurement of the resistance to a stretching motion, the so-called elongational viscosity ηe, has proven to be difficult for dilute polymer solutions, although it is important for a large number of applications. We attempt to deduce ηe of dilute solutions of flexible polymers in two different...
Persistent link: https://www.econbiz.de/10011058980
We study the evaporation of stars from globular clusters using the simplified Chandrasekhar model [S. Chandrasekhar, Dynamical friction. II. The rate of escape of stars from clusters and the evidence for the operation of dynamical friction, Astrophys. J. 97 (1943) 263]. This is an analytically...
Persistent link: https://www.econbiz.de/10011059461
When considering the hydrodynamics of Brownian particles, one is confronted to a difficult closure problem. One possibility to close the hierarchy of hydrodynamic equations is to consider a strong friction limit. This leads to the Smoluchowski equation that reduces to the ordinary diffusion...
Persistent link: https://www.econbiz.de/10011060369