scholarly journals Role of the Hall Current in Magnetohydrodynamic Dynamos

2003 ◽  
Vol 584 (2) ◽  
pp. 1120-1126 ◽  
Author(s):  
Pablo D. Mininni ◽  
Daniel O. Gomez ◽  
Swadesh M. Mahajan
Keyword(s):  
Hall Current

Role of casson fluid on MHD natural convective flow towards vertically inclined plate with hall current

2018 ◽  
Author(s):  
D. V. V. Krishna Prasad ◽  
G. S. Krishna Chaitanya ◽  
R. Srinivasa Raju
Keyword(s):  
Convective Flow ◽  
Hall Current ◽  
Casson Fluid ◽  
Inclined Plate

ROLE OF THE HALL EFFECT ON THE MAGNETOROTATIONAL INSTABILITY

2010 ◽  
Vol 19 (06) ◽  
pp. 695-700
Author(s):  
CECILIA BEJARANO ◽  
DANIEL GÓMEZ
Keyword(s):  
Hall Effect ◽  
Hall Current ◽  
Instability Criterion ◽  
Dimensional Model ◽  
Magnetorotational Instability ◽  
One Dimensional ◽  
Ionization Fraction ◽  
Cold Plasmas ◽  
Instability Growth

Within the framework of magnetohydrodynamics, the Hall effect might become significant either in fully ionized low density plasmas or in cold plasmas with a low ionization fraction. We address the role of the Hall current in the development of the magnetorotational instability. The instability criterion and the instability growth rate are derived from a one-dimensional model.

scholarly journals Coupling Large Eddies and Waves in Turbulence: Case Study of Magnetic Helicity at the Ion Inertial Scale

Atmosphere ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 203 ◽  
Author(s):  
Annick Pouquet ◽  
Julia E. Stawarz ◽  
Duane Rosenberg
Keyword(s):  
Turbulent Flows ◽  
Hall Current ◽  
Cascade Range ◽  
Magnetic Helicity ◽  
Helical Growth ◽  
Simple Scaling ◽  
Large Eddies ◽  
The Ideal

In turbulence, for neutral or conducting fluids, a large ratio of scales is excited because of the possible occurrence of inverse cascades to large, global scales together with direct cascades to small, dissipative scales, as observed in the atmosphere and oceans, or in the solar environment. In this context, using direct numerical simulations with forcing, we analyze scale dynamics in the presence of magnetic fields with a generalized Ohm’s law including a Hall current. The ion inertial length ϵ H serves as the control parameter at fixed Reynolds number. Both the magnetic and generalized helicity—invariants in the ideal case—grow linearly with time, as expected from classical arguments. The cross-correlation between the velocity and magnetic field grows as well, more so in relative terms for a stronger Hall current. We find that the helical growth rates vary exponentially with ϵ H , provided the ion inertial scale resides within the inverse cascade range. These exponential variations are recovered phenomenologically using simple scaling arguments. They are directly linked to the wavenumber power-law dependence of generalized and magnetic helicity, ∼ k − 2 , in their inverse ranges. This illustrates and confirms the important role of the interplay between large and small scales in the dynamics of turbulent flows.

scholarly journals Quantum model of the magnetic field of the Hot Expanding Earth

2020 ◽  
Vol 196 ◽  
pp. 02024
Author(s):  
Vladimir Kuznetsov
Keyword(s):  
Magnetic Field ◽  
Crucial Role ◽  
Hall Current ◽  
Double Electric Layer ◽  
Weak Field ◽  
Quantum Model ◽  
The Earth ◽  
Earth Magnetic Field ◽  
The Magnetic Field

Principally new quantum model of the magnetic field of the Hot Earth [1] is proposed here. The model proceeds from the generation scheme of the Earth magnetic field (EMF) reported at the conference in 2019 [2], where crucial role of quantum entanglement (QE) of the inner G-core matter for EMF generation under the Hall effect was first evidenced. With regard to my impact into geodynamics of the Hot Earth [3] and quantum geophysics [4] the improved version of [2] is presented here. The justification for the model of EMF generation given in the encyclopedia of Geomagnetism [5] due to the daily rotation of the DEL (double electric layer), exciting a weak field and its amplification by the Hall current is first used here.

Thermal instability of a compressible finite-Larmor-radius Hall plasma in a porous medium

1996 ◽  
Vol 55 (1) ◽  
pp. 35-45 ◽  
Author(s):  
R. C. Sharma ◽  
Sunil
Keyword(s):  
Magnetic Field ◽  
Porous Medium ◽  
Thermal Instability ◽  
Hall Current ◽  
Larmor Radius ◽  
Vertical Magnetic Field ◽  
Finite Larmor Radius ◽  
Medium Permeability ◽  
Hall Plasma

The thermal instability of a compressible plasma in a porous medium is considered in the presence of a uniform vertical magnetic field to include the Hall-current and finite-Larmor-radius effects. The system is found to be stable for (cp/g) β < 1, where cp, β and g are the specific heat at constant-pressure, the uniform adverse temperature gradient and the acceleration due to gravity respectively. The uniform vertical magnetic field, Hall-current and finite. Laimor-radius effects introduce oscillatory modes in the system for (cp/g) β ≤ 1, which were non-existent in their absence. The Hall current and finite Larmor radius (FLR) individually have destabilizing and stabilizing effects respectively on the system. In their simultaneous presence there is competition between the destabilizing role of the Hall current and the stabilizing role of the FLR, and each succeeds in stabilizing a certain wavenumber range. In the absence of a magnetic field (and hence the absence of an FLR and Hall current), the destabilizing effect of medium permeability is seen, but in the presence of a magnetic field (and hence the presence of an FLR and Hall current), the medium permeability may have a stabilizing or a destabilizing effect on the thermal instability of the plasma. The effect of compressibility is found to postpone the onset of thermal instability in plasma.

Role of dactinomycin in the improved survival of children with Wilms' tumor

JAMA ◽  
1966 ◽  
Vol 195 (12) ◽  
pp. 1005-1009 ◽  
Author(s):  
D. J. Fernbach
Keyword(s):  
Wilms Tumor
Sign in / Sign up

Export Citation Format

Share Document