Effect of electron inertia on radiative instability of rotating two-component gaseous plasma

2012 ◽  
Vol 90 (12) ◽  
pp. 1209-1221 ◽  
Author(s):  
A.K. Patidar ◽  
R.K. Pensia ◽  
V. Shrivastava
Keyword(s):  
Magnetic Field ◽  
Thermal Conductivity ◽  
Growth Rate ◽  
Electrical Resistivity ◽  
Heat Loss ◽  
Loss Function ◽  
Mode Analysis ◽  
Electron Inertia ◽  
Radiative Instability ◽  
Jeans Criterion

The problem of radiative instability of homogeneous rotating partially ionized plasma incorporating viscosity, porosity, and electron inertia in the presence of a magnetic field is investigated. A general dispersion relation is obtained using normal mode analysis with the help of relevant linearized perturbation equations of the problem. The modified Jeans criterion of instability is obtained. The conditions of Jeans instabilities are discussed in the different cases of interest. It is found that the simultaneous effect of viscosity, rotation, finite conductivity, and porosity of the medium does not essentially change the Jeans criterion of instability. It is also found that the presence of arbitrary radiative heat-loss function and thermal conductivity modified the conditions of Jeans instability for longitudinal propagation. It is found that, for longitudinal propagation, the conditions of radiative instability are independent of magnetic field, viscosity, rotation, finite electrical resistivity, and electron inertia, but for the transverse mode of propagation it depends upon finite electrical resistivity and strength of magnetic field and is independent of viscosity, electron inertia, and rotation. From the curves we find that viscosity has a stabilizing effect on the growth rate of instability but the thermal conductivity and density-dependent heat-loss function has a destabilizing effect on the instability growth rate.

scholarly journals Effect of Radiative Heat-Loss Function and Finite Larmor Radius Corrections on Jeans Instability of Viscous Thermally Conducting Self-Gravitating Astrophysical Plasma

2012 ◽  
Vol 2012 ◽  
pp. 1-14 ◽  
Author(s):  
Sachin Kaothekar ◽  
R. K. Chhajlani
Keyword(s):  
Thermal Conductivity ◽  
Heat Loss ◽  
Loss Function ◽  
Radiative Heat ◽  
Gravitational Instability ◽  
Mode Analysis ◽  
Instability Criterion ◽  
Larmor Radius ◽  
Astrophysical Plasma ◽  
Radiative Heat Loss

The effect of radiative heat-loss function and finite ion Larmor radius (FLR) corrections on the self-gravitational instability of infinite homogeneous viscous plasma has been investigated incorporating the effects of thermal conductivity and finite electrical resistivity for the formation of a star in astrophysical plasma. The general dispersion relation is derived using the normal mode analysis method with the help of relevant linearized perturbation equations of the problem. Furthermore the wave propagation along and perpendicular to the direction of external magnetic field has been discussed. Stability of the medium is discussed by applying Routh Hurwitz’s criterion. We find that the presence of radiative heat-loss function and thermal conductivity modify the fundamental Jeans criterion of gravitational instability into radiative instability criterion. From the curves we see that temperature dependent heat-loss function, FLR corrections and viscosity have stabilizing effect, while density dependent heat-loss function has destabilizing effect on the growth rate of self-gravitational instability. Our result shows that the FLR corrections and radiative heat-loss functions affect the star formation.

Thermal Instability of Self-Gravitating Partially-Ionized Gaseous Plasma

2011 ◽  
Vol 8 (1) ◽  
pp. 181-187
Author(s):  
Ram K. Pensia ◽  
V. Shrivastava ◽  
Vishal Kumar ◽  
Ashok K. Patidar ◽  
Vikas Prajapat
Keyword(s):  
Magnetic Field ◽  
Thermal Conductivity ◽  
Heat Loss ◽  
Radiative Heat ◽  
Longitudinal Mode ◽  
Thermal Mode ◽  
Radiative Heat Loss ◽  
Gaseous Plasma ◽  
Jeans Instability ◽  
Partially Ionized

The effect of radiative heat-loss function on the Jeans instability of an infinitely conducting, homogeneous partially ionized gaseous plasma is investigated. It is assumed that the medium is carrying a uniform magnetic field in the presence of porosity and thermal conductivity. With the help of relevant linearized perturbation equations of the problem, a general dispersion relation is obtained for a such medium using the normal analysis technique, which is reduced for both the transverse and the longitudinal mode of propagation. The longitudinal mode is found to be modified by Alfven speed and parameter of porosity. The thermal mode is obtained separately having the effects of thermal conductivity and arbitrary radiative heat-loss functions. The effect of collision with neutrals and magnetic field have a stabilizing effect, while thermal conductivity has destabilizing influence on the Jeans instability of gaseous plasma. In the transverse mode of propagation, we find the condition of radioactive instability depends on thermal conductivity, magnetic field and the porosity of the medium.

Effect of Finite Larmor Radius on the Rayleigh-Taylor Instability of Two Component Magnetized Rotating Plasma

1998 ◽  
Vol 53 (12) ◽  
pp. 937-944 ◽  
Author(s):  
P. K. Sharma ◽  
R. K. Chhajlani
Keyword(s):  
Magnetic Field ◽  
Growth Rate ◽  
Normal Mode Analysis ◽  
Mode Analysis ◽  
Larmor Radius ◽  
Horizontal Magnetic Field ◽  
Finite Larmor Radius ◽  
Neutral Particles ◽  
Rayleigh Taylor Instability ◽  
Superposed Fluids

Abstract The Rayleigh-Taylor (R-T) instability of two superposed plasmas, consisting of interacting ions and neutrals, in a horizontal magnetic field is investigated. The usual magnetohydrodynamic equations, including the permeability of the medium, are modified for finite Larmor radius (FLR) corrections. From the relevant linearized perturbation equations, using normal mode analysis, the dispersion relation for the two superposed fluids of different densities is derived. This relation shows that the growth rate unstability is reduced due to FLR corrections, rotation and the presence of neutrals. The horizontal magnetic field plays no role in the R-T instability. The R-T instability is discussed for various simplified configurations. It remains unaffected by the permeability of the porous medium, presence of neutral particles and rotation. The effect of different factors on the growth rate of R-T instability is investigated using numerical analysis. Corresponding graphs are plotted for showing the effect of these factors on the growth of the R-T instability.

Thermal conductivity and electrical resistivity of c-axis oriented polycrystalline (BI,Pb)2Sr2Ca2Cu3Ox in a magnetic field

1994 ◽  
Vol 235-240 ◽  
pp. 1509-1510 ◽  
Author(s):  
K. Mori ◽  
A. Tanaka ◽  
K. Nishimura ◽  
J. Sakurai ◽  
T. Sasaki ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
Oriented Polycrystalline

Jeans Instability of Rotating Viscoelastic Fluid in the Presence of Magnetic Field

2015 ◽  
Vol 70 (1) ◽  
pp. 39-45 ◽  
Author(s):  
Praveen Kumar Sharma ◽  
Shraddha Argal ◽  
Anita Tiwari ◽  
Ram Prasad Prajapati
Keyword(s):  
Magnetic Field ◽  
Growth Rate ◽  
Viscoelastic Fluid ◽  
Normal Mode Analysis ◽  
Mode Analysis ◽  
Viscous Effects ◽  
Strongly Coupled ◽  
Weakly Coupled ◽  
Viscoelastic Effects ◽  
Jeans Instability

AbstractThe Jeans instability of rotating viscoelastic fluid in the presence of uniform magnetic field is investigated using the generalised hydrodynamic (GH) model. A general dispersion relation is derived with the help of linearised perturbation equations using the normal mode analysis, which is further discussed for axis of rotation parallel and perpendicular to the direction of the magnetic field in both the weakly coupled (hydrodynamic) and strongly coupled (kinetic) limits. The onset criterion of Jeans instability for magnetised rotating viscoelastic fluid is obtained, which remains unaffected by the presence of rotation and magnetic field but depends upon viscoelastic effects. The graphical illustrations are depicted to see the influence of rotation, Mach number, shear and viscous effects, and sound speed on the growth rate of Jeans instability. It is found that all these parameters have stabilising influence on the growth rate of Jeans instability; hence, they are capable of collapsing to a self-gravitating, rotating, magnetised viscoelastic medium.

Thermal conductivity and electrical resistivity of Nb-Ti (HT-50) as a function of temperature and magnetic field

Cryogenics ◽  
1981 ◽  
Vol 21 (1) ◽  
pp. 47-50 ◽  
Author(s):  
E.I. Dyachkov ◽  
R. Herzog ◽  
I.S. Khukhareva ◽  
A. Nichitiu
Keyword(s):  
Magnetic Field ◽  
Thermal Conductivity ◽  
Electrical Resistivity

scholarly journals Influence of magnetic field on electrical and thermal transport in the hole doped ferromagnetic manganite: La0.9Na0.1MnO3

RSC Advances ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 1726-1733 ◽  
Author(s):  
Rajasree Das ◽  
Amit Chanda ◽  
Ramanathan Mahendiran
Keyword(s):  
Magnetic Field ◽  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
Thermal Transport ◽  
Field Dependent

Magnetic field dependent electrical resistivity (ρ), thermal conductivity (κ) and thermopower (S) of polycrystalline La0.9Na0.1MnO3 have been reported and the possible mechanisms are discussed.

Magnetogravitational instability of a rotating anisotropic plasma with finite-ion-Larmor-radius corrections and generalized polytropic laws

1998 ◽  
Vol 60 (4) ◽  
pp. 673-694 ◽  
Author(s):  
G. D. SONI ◽  
R. K. CHHAJLANI
Keyword(s):  
Magnetic Field ◽  
Electrical Resistivity ◽  
Dispersion Relation ◽  
Normal Mode Analysis ◽  
Transverse Mode ◽  
Mode Analysis ◽  
Larmor Radius ◽  
Anisotropic Pressure ◽  
Axis Of Rotation ◽  
The Magnetic Field

The gravitational instability of an infinite homogeneous, finitely conducting, rotating, collisionless, anisotropic-pressure plasma in the presence of a uniform magnetic field with finite-ion-Larmor-radius (FLR) corrections and generalized polytropic laws is investigated. The polytropic laws are considered for the pressure components in directions parallel and perpendicular to the magnetic field. The method of normal-mode analysis is applied to derive the dispersion relation. Wave propagation is considered for both parallel and perpendicular axes of rotation. Longitudinal and transverse modes of propagation are discussed separately. The effects of rotation, finite electrical resistivity, FLR corrections and polytropic indices on the gravitational, firehose and mirror instabilities are discussed. The stability of the system is discussed by applying the Routh–Hurwitz criterion. Extensive numerical treatment of the dispersion relation leads to several interesting results. For the transverse mode of propagation with the axis of rotation parallel to the magnetic field, it is observed that rotation stabilizes the system by decreasing the critical Jeans wavenumber. It is also seen that the region of instability and the value of the critical Jeans wavenumber are larger for the Chew–Goldberger–Low (CGL) set of equations in comparison with the magnetohydrodynamic (MHD) set of equations. It is found that the effect of FLR corrections is significant only in the low-wavelength range, and produces a stabilizing influence. For the transverse mode of propagation with the axis of rotation parallel to the magnetic field, the finite electrical resistivity removes the polytropic index [nu] from the condition for instability. The inclusion of rotation alone or FLR corrections alone or both together does not affect the condition for mirror instability. The growth rate of the mirror instability is modified owing to uniform rotation or FLR corrections or both together. We note that the condition of mirror instability depends upon the polytropic indices. We also note that neither the mirror instability nor the firehose instability can be observed for the isotropic MHD set of equations.

On the Boundedness of the Dimensionless Index of Performance of a Nernst Effect Generator

1963 ◽  
Vol 30 (2) ◽  
pp. 291-294
Author(s):  
S. W. Angrist
Keyword(s):  
Magnetic Field ◽  
Thermal Conductivity ◽  
Electrical Resistivity ◽  
Magnetic Fields ◽  
Dimensionless Quantity ◽  
Nernst Effect ◽  
Strong Magnetic Fields ◽  
Weak Magnetic Fields ◽  
Effect Generator

The author, in an earlier paper, analyzed a Nernst effect generator by the usual thermodynamic methods and found that a bound of unity arises on the dimensionless quantity θT where θ is given as the square of the product of the Nernst coefficient and magnetic field divided by the thermal conductivity and electrical resistivity. By application of the appropriate equations of semiconductor theory this bound is shown to be justified for four limiting cases: Weak magnetic fields considering both extrinsic and intrinsic materials, and strong magnetic fields considering both extrinsic and intrinsic materials.

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