We present a simple resonant Hamiltonian model for the vertical response of a stellar disk to the growth of a bar perturbation. As a bar perturbation grows stars become trapped in vertical Inner Lindblad resonances and are lifted into higher amplitude orbits. The vertical structure of a boxy and peanut shaped bulge as a function of radius and azimuthal angle in the galaxy plane can be predicted...

A perturbation of relative humidity is used as a trigger to start the convection in a two-dimensional numerical model of a cumulus cloud. The effects of varying the width and depth of the perturbation are studied. The rate of growth; eventual cloud height, liquid water content, and updraft strength are strongly dependent on depth of the impulse; but for realistically shallow depths, these value...

We consider an inertial model of chemotactic aggregation generalizing the Keller-Segel model and we study the linear dynamical stability of an infinite and homogeneous distribution of cells (bacteria, amoebae, endothelial cells,...) when inertial effects are accounted for. These inertial terms model cells directional persistance. We determine the condition of instability and the growth rate of ...

Instability of high frequency wave, such as, Langmuir wave (LW) is studied using fluid model in collisional and streaming dusty plasma with dust charge fluctuation. In irradiated dusty plasma, dust charge fluctuation is considered to be due to the combined effect of LW perturbation and photoelectron emission. The piled up electrons on a dust grain due to LW perturbation can be swept out by phot...

in this paper robust pid control of fully-constrained cable driven parallel manipulators with elastic cables is studied in detail. in dynamic analysis, it is assumed that the dominant dynamics of cable can be approximated by linear axial spring. to develop the idea of control for cable robots with elastic cables, a robust pid control for cable driven robots with ideal rigid cables is firstly de...

in this paper, finite element elastic contact analysis of a functionally graded (fg) hollow brake disk in contact with pad, subjected to rotation, contact pressure and frictional heat is presented. the material properties vary through the thickness according to a power-law characterised by a grading index, n. the material property is purely steel at the core part and gradually moves and approac...

in this paper, we investigate a singular perturbation problem including a fourth order o.d.e. with general linear boundary conditions. firstly, we obtain the necessary conditions of solution of o.d.e. by making use of fundamental solution, then by compatibility of these conditions with boundary conditions, we determine that, for given perturbation problem, whether boundary layer is formed or not.

We have shown previously that different patterns of growth (including classical Gompertzian, exponential, and hyperexponential) can be described based on the Gompertzian difference equation, In G(t+s) = a+b In G(t) [G(t), tumor size at time t; s, constant time interval of a stroboscopic set of tumor size measurements], by the initial or intrinsic growth rate, a, and the exponential rate of grow...

We have shown previously that different patterns of growth (including classical Gompertzian, exponential, and hyperexponential) can be de scribed based on the Gompertzian difference equation, In G(t + s) = a + b In G(t) [G(t), tumor size at time t: s, constant time interval of a stroboscopie set of tumor size measurements], by the initial or intrinsic growth rate, a, and the exponential rate of...

In this article, the effects of viscous dissipation and inertial force on the velocity and temperature distributions of the mixed convection laminar flow in a vertical channel partly filled with a saturated porous medium have been studied. In this regard, the Brinkman–Forchheimer extended Darcy model was adopted for the fluid flow in the porous region. In addition, three different viscous dissi...