Wed, 20 Aug 2008 22:02:07 BST CiteULike: elorenz Liu http://www.citeulike.org/user/elorenz/author/Liu CiteULike.org en-gb Copyright © 2004-2008 citeulike.org http://www.citeulike.org/user/elorenz/article/1305096 <i>Nature, Vol. 396, No. 6706. (5 November 1998), pp. 21-22.</i> Nonlinear dynamics: Jamming is not just cool any more Andrea Liu Sidney Nagel doi:10.1038/23819 Nature, Vol. 396, No. 6706. (5 November 1998), pp. 21-22. 2007-05-18T10:34:26-00:00 1998 Nature 396 6706 21 22 el00126 http://www.citeulike.org/user/elorenz/article/2298253 <i>Journal of Computational Physics, Vol. 220, No. 1. (20 December 2006), pp. 139-154.</i><br /><br />The aggregation of red blood cells (RBC) induced by the interactions between RBCs is a dominant factor of the in vitro rheological properties of blood, and existing models of blood do not contain full cellular information. In this work, we introduce a new three-dimensional model that couples Navier-Stokes equations with cell interactions to investigate RBC aggregation and its effect on blood rheology. It consists of a depletion mediated aggregation model to describe the interactions of RBCs and an immersed continuum model to track the deformation/motion of RBCs in blood plasma. To overcome the large deformation of RBCs, the meshfree method is used to model the RBCs. Three important phenomena in blood rheology are successfully captured and studied via this approach: the shear rate dependence of blood viscosity, the influence of cell rigidity on blood viscosity, and the Fahraeus-Lindqvist effect. As a microscopic illustration of the shear-rate dependence of the blood's viscoelasticity, the disaggregation of an RBC rouleau at shear rates varying between 0.125 and 24 s-1 is modeled. Lower RBC deformability and higher shear rates above 0.5 s-1 are found to facilitate disaggregation. The effective viscosities at different shear rates and for cells with different deformabilities are simulated. The numerical results are shown to agree with the reported experimental measurements. The Fahraeus-Lindqvist effect is, for the first time, studied through three-dimensional numerical simulations of blood flow through tubes with different diameters and is shown to be directly linked to axial-migration of deformable cells. This study shows that cell-cell interaction and cell deformability have significant effects on blood rheology in capillaries. Rheology of red blood cell aggregation by computer simulation Yaling Liu Wing Liu doi:10.1016/j.jcp.2006.05.010 Journal of Computational Physics, Vol. 220, No. 1. (20 December 2006), pp. 139-154. 2008-01-28T16:17:00-00:00 2006 Journal of Computational Physics 220 1 139 154 el00102 http://www.citeulike.org/user/elorenz/article/2050077 <i>Physical Review E, Vol. 65, No. 5. (22 May 2002), 051925.</i><br /><br />A lattice Boltzmann method for simulating the viscous flow in large distensible blood vessels is presented by introducing a boundary condition for elastic and moving boundaries. The mass conservation for the boundary condition is tested in detail. The viscous flow in elastic vessels is simulated with a pressure-radius relationship similar to that of the pulmonary blood vessels. The numerical results for steady flow agree with the analytical prediction to very high accuracy; and the simulation results for pulsatile flow are comparable with those of the aortic flows observed experimentally. The model is expected to find many applications for studying blood flows in large distensible arteries; especially in those suffering from atherosclerosis; stenosis; aneurysm; etc. Lattice Boltzmann method for simulating the viscous flow in large distensible blood vessels Haiping Fang Zuowei Wang Zhifang Lin Muren Liu doi:10.1103/PhysRevE.65.051925 Physical Review E, Vol. 65, No. 5. (22 May 2002), 051925. 2007-12-03T14:32:46-00:00 2002 Physical Review E 65 5 051925 American Physical Society el00082 http://www.citeulike.org/user/elorenz/article/1543332 <i>Chemical Journal of Chinese Universities-Chinese, Vol. 20, No. 12. (1999), pp. 1948-1950.</i><br /><br />Shear thickening implies that the viscosity of a fluid increases with increasing rates of shear, In the past work reported, all shear thickening phenomena were observed in concentrated solid/liquid colloidal suspension, In this paper, the shear thickening was observed in colloidal dispersion gel, with very lower volume fraction, of partially hydrolyzed polyacrylamide (PHPA)/aluminum citrate. Colloidal dispersion gels are made of low concentrations of polymer and crosslinker. Polymer mass fractions normally range from 0.01% to 0.12%, In this concentration regime, there is not enough polymer to form a continuous network, so a conventional bulk type gel cannot form. Instead of a solution of separate gel bundles forms, and it is a mixture of predominantly intramolecular and minimal intermolecular crosslinks, In the work reported here, the colloidal dispersion gels are made of PHPA of 0.03%, KCl of 0.5%, thiourea of 0.1% and Al3+ with a mass fractions range of 0-0.003%, the Al3+ : PHPA mass ratio changes from 0 to 0.1, The critical shear rates(CSR) for the onset of shear thickening are about 200 s(-1) for all CDC systems studied, i. e., the Al3+ : PHPA mass ratio don't affect the CSR, In the lower shear regime than CSR shear thinning was observed and in the higher shear regime than CSR the shear thickening was observed. The shear thickening may be explained with cluster-formation mechanism. Shear thickening in colloidal dispersion gel of partially hydrolyzed polyacrylamide/aluminum citrate WG Hou WQ Zhu SY Liu DJ Sun YG Sheng Chemical Journal of Chinese Universities-Chinese, Vol. 20, No. 12. (1999), pp. 1948-1950. 2007-08-08T13:27:43-00:00 1999 Chemical Journal of Chinese Universities-Chinese 20 12 1948 1950 el00056