Human heart rate, controlled by complex feedback mechanisms, is a vital index of systematic circulation. However, it has been shown that beat-to-beat values of heart rate fluctuate continually over a wide range of time scales. Herein we use the relative dispersion, the ratio of the standard...

Kinetic representation of fluid dynamics is essential for describing flows far beyond the Navier–Stokes regime. Existing lattice Boltzmann models suffer from discrete rotation artifacts at high Knudsen number (Kn). In this paper, we present a new approach that directly addresses this issue and...

We discuss the hypothesis that, in addition to the known critical point in water (below which two fluid phases — a lower-density gas and a higher-density liquid — coexist), there exists a “second” critical point at low temperatures (below which two liquid phases — a higher-density...

We use the lattice Boltzmann method (LBM) for analysis of high and moderate Knudsen number phenomena. Simulation results are presented for microscale Couette and Poiseuille flows. The slip velocity, nonlinear pressure drop, and mass flow rate are compared with previous numerical results and/or...

We describe a general algorithmic concept for grid refinement in the lattice Boltzmann method. Unlike most of the previously known approaches, the present one is based on volumetric formulation so that conservation laws are exactly guaranteed.

In this paper we develop a lattice Boltzmann model for the generalized Burgers–Huxley equation (GBHE). By choosing the proper time and space scales and applying the Chapman–Enskog expansion, the governing equation is recovered correctly from the lattice Boltzmann equation, and the local...

Viruses self-assemble from identical capsid proteins and their genome consisting, for example, of a long single stranded (ss) RNA. For a big class of T=3 viruses, capsid proteins have long positive N-terminal tails. We explore the role played by the Coulomb interaction between the brush of...

We study a solution of long polyanions (PA) with shorter polycations (PC) and focus on the role of Coulomb interaction. A good example is solutions of DNA and PC which are widely studied for gene therapy. In the solution, each PA attracts many PCs to form a complex. When the ratio of total...

In a recent experiment, a single DNA double helix is stretched and relaxed in the presence of spermidine, a short positive polyelectrolyte, and the pulling force is measured as a function of DNA extension. In a certain range of spermidine concentration, a force plateau appears whose value shows...

We investigated the effects of interstitial air on the impact bifurcations of period doubling motion in vertically vibrated grains beds. The impact of grains on the container bottom undergoes a series of subharmonic bifurcations as the vibration intensity increases. With the presence of air, the...