The Rayleigh-Taylor instability plays an important role in the dynamics of several astronomical objects, in particular, in supernovae (SN) evolution. In this paper we develop an analytical approach to study the stability analysis of spherical expansion of the SN ejecta by using a special transformation in the co-moving coordinate frame. We first study a non-stationary spherical expansion of a g...

in this article, we demonstrate an analytic-numeric solution for some dynamical systems using the multistagehomotopy perturbation method. the method yields results that are in complete agreement with their numericalcounterparts.

In the present study, some perturbation methods are applied to Duffing equations having a displacement time-delayed variable to study the stability of such systems. Two approaches are considered to analyze Duffing oscillator having a strong delayed variable. The homotopy perturbation method is applied through the frequency analysis and nonlinear frequency is formulated as a function of all the ...

in this study a nonlinear asymmetric instability analysis carried out to study primary atomization of annular liquid sheets emanating from the prefilming airblast atomizer using a perturbation method and potential flow assumption. in this direction, firstly governing equations derived according to potential flow assumption and conservation equations while dynamic and static boundary condition a...

Human perturbations affect many aquatic ecosystems globally. We use age‐structured matrix population models to explore how growth rates in short‐lived freshwater fish are affected by recurrent environmental river ecosystems. Simulations summarized reveal species‐specific fitness characteristics contribute sustainability habitats subject perturbation. Deterministic calculations used estimate tim...

Objectives: To check and compare the effectiveness of modified agility and perturbation training over conventional physical therapy in patients with knee osteoarthritis. Methods: Subjects were screened on the basis of inclusion and exclusion criteria and a total of 50 subjects were recruited for the study. They were randomly divided into Group A and group B with n=25 each. Results: Group ...

Here, a new method called Aboodh transform homotopy perturbation method(ATHPM) is used to solve nonlinear partial dierential equations, we presenta reliable combination of homotopy perturbation method and Aboodh transformto investigate some nonlinear partial dierential equations. The nonlinearterms can be handled by the use of homotopy perturbation method. The resultsshow the eciency of this me...

objectives: to check and compare the effectiveness of modified agility and perturbation training over conventional physical therapy in patients with knee osteoarthritis. methods: subjects were screened on the basis of inclusion and exclusion criteria and a total of 50 subjects were recruited for the study. they were randomly divided into group a and group b with n=25 each. results: group receiv...