Abstract   The present paper is devoted to implementation of the immersed boundary technique into the Fourier pseudo-spectral solution of the vorticity-velocity formulation of the two-dimensional incompressible Navier-Stokes equations. The immersed boundary conditions are implemented via direct modification of the convection and diffusion terms, and therefore, in contrast to some other similar ...

Structure–function studies of rhodopsin kinase (RK; EC 2.7.1.125) require a variety of mutants. Therefore, there is need for a suitable system for the expression of RK mutant genes. Here we report on a study of expression of the RK gene in baculovirus-infected Sf21 cells and characterization of the enzyme produced as purified to near homogeneity. Particular attention has been paid to the posttr...

We show that while Runge-Kutta methods cannot preserve polynomial invariants in general, they can preserve polynomials that are the energy invariant of canonical Hamiltonian systems. Mathematics Subject Classification. 65P10, 65L06. Received May 21, 2008. Published online July 8, 2009. All Runge-Kutta (RK) methods preserve arbitrary linear invariants [12], and some (the symplectic) RK methods p...

The algebraic flux correction (AFC) schemes presented in this work constrain a standard continuous finite element discretization of nonlinear hyperbolic problem to satisfy relevant maximum principles and entropy stability conditions. desired properties are enforced by applying limiter antidiffusive fluxes that represent the difference between high-order baseline scheme property-preserving appro...

We consider the solution of initial value problems (IVPs) of large systems of ordinary differential equations (ODEs) for which memory space requirements determine the choice of the integration method. In particular, we discuss the space-efficient sequential and parallel implementation of embedded Runge–Kutta (RK) methods. We focus on the exploitation of a special structure of commonly appearing...

Spectral deferred correction (SDC) methods for solving ordinary differential equations (ODEs) were introduced by Dutt, Greengard and Rokhlin, [3]. In this paper, we study the properties of these integral deferred correction methods, constructed using high order integrators in the prediction and correction loops, and various distributions of quadrature nodes. The smoothness of the error vector a...

An iterative method LSMR is presented for solving linear systems Ax = b and leastsquares problems min ‖Ax−b‖2, with A being sparse or a fast linear operator. LSMR is based on the Golub-Kahan bidiagonalization process. It is analytically equivalent to the MINRES method applied to the normal equation ATAx = ATb, so that the quantities ‖Ark‖ are monotonically decreasing (where rk = b−Axk is the re...

In this paper‎, ‎we suggest a fifth order convergence three-step method for solving system of nonlinear equations‎. ‎Each iteration of the method requires two function evaluations‎, ‎two first Fr'{e}chet derivative evaluations and two matrix inversions‎. ‎Hence‎, ‎the efficiency index is $5^{1/({2n+4n^{2}+frac{4}{3}n^{3}})}$‎, ‎which is better than that of other three-step methods‎. ‎The advant...