Context. The MHD instabilities can generate complex field topologies even if the initial field configuration is a very simple one. Aims. We consider the stability properties of magnetic configurations containing a toroidal and an axial field. In this paper, we concentrate mainly on the behavior of non-axisymmetric perturbations in axisymmetric magnetic configurations. Methods. The stability is ...

this paper is devoted to study of a partial differential equation governing panel motion in supersonic flow. this pde can be transformed to an ode by means of a galerkin method. here by using a criterion which is closely related to the routh-hurwitz criterion, we investigate the mentioned transformed ode from hopf bifurcation point of view. in fact we obtain a region for existence of simple hop...

Growth of Rayleigh-Taylor (R-T) instabilities under the axisymmetric explosion are investigated by two-dimensional hydrodynamical calculations. The degree of the axisymmetric explosion and amplitude of the initial perturbation are varied parametrically to find the most favorable parameter for reproducing the observed line profile of heavy elements. It is found that spherical explosion can not p...

       In this paper an SIS epidemic model with saturated incidence rate and treatment func- tion is proposed and studied. The existence of all feasible equilibrium points is discussed. The local stability conditions of the disease free equilibrium point and endemic equilibrium point are established with the help of basic reproduction number.However the global stabili- ty conditions of these eq...

Herein paper compares the analytical model with the FEM based numerical model of the axisymmetric bending of circular sandwich plates. Also, the paper describes equations of the circular symmetrical sandwich plates bending with isotropic face sheets and the nonlinear elastic core material. The method of constructing an analytical solution of nonlinear differential equations has been described. ...

Several experiments involving two-dimensional and axisymmetric bodies have been carried out in a Trisonic wind tunnel at supersonic speeds to investigate and analyse the measured values of base pressure and to compare them with those from the theoretical methods. The objective of the experiments was to obtain an appropriate method for processing the results of wind tunnel tests on rockets or ai...

This study investigates the stability features of spatially spreading heated jets in viscous regime with real gas effects, using both unsteady two-dimensional axisymmetric simulations and linear analyses steady state time-averaged states. At a Reynolds number $400$ , are found to undergo subcritical Hopf bifurcation, marking start self-sustained oscillations when decreasing temperature ratio $S...

We consider the Hawking-Ellis (Segre-Plebanski) classification of stress-energy tensors, both in test-field limit, and presence back-reaction governed by usual Einstein equations. For test fields it is not too difficult to get a type~IV via quantum vacuum polarization effects. (For example, Unruh state for massless scalar field Schwarzschild background.) However, driven ordinary equations situa...

A mathematical model describing the dynamics  of a  delayed  stage structure prey - predator  system  with  prey  refuge  is  considered.  The  existence,  uniqueness  and bounded- ness  of  the  solution  are  discussed.    All  the  feasibl e  equilibrium  points  are determined.  The   stability  analysis  of  them  are  investigated.  By  employ ing  the time delay as the bifurcation parame...