Context. Magnetohydrodynamic (MHD) waves are often reported in the solar atmosphere and usually classified as slow, fast, or Alfvén. The possibility that these waves have mixed properties is often ignored. Aims. The goal of this work is to study and determine the nature of MHD kink waves. Methods. This is done by calculating the frequency, the damping rate and the eigenfunctions of MHD kink wav...

It is proved that irrespective of compressibility tokamak steady states with purely poloidal mass flow can not exist in the framework of either magnetohydrodynamics (MHD) or Hall MHD models. Non-existence persists within single fluid plasma models with pressure anisotropy and incompressible flows.

An optimal control problem for the equations governing the stationary problem of magnetohydrodynamics (MHD) is considered. Control mechanisms by external and injected currents and magnetic fields are treated. An optimal control problem is formulated. First order necessary and second order sufficient conditions are developed. An operator splitting scheme for the numerical solution of the MHD sta...

Global magnetohydrodynamic (MHD) simulations of the Earth's magnetosphere must be coupled with a dynamical ionospheric module in order to give realistic results. The usual approach is to compute the ®eld-aligned current (FAC) from the magnetospheric MHD variables at the ionospheric boundary. The ionospheric potential is solved from an elliptic equation using the FAC as a source term. The plasma...

A complete analytical and numerical treatment of all magnetohydrodynamic waves and instabilities for radially stratified, magnetized accretion disks is presented. The instabilities are a possible source of anomalous transport. While recovering results on known hydrodynamic and both weak-and strong-field mag-netohydrodynamic perturbations, the full magnetohydrodynamic spectra for a realistic acc...

This work revisits the star formation rate (SFR) model of Krumholz and McKee, extends it to the case of a magnetized medium, and verifies it with a set of numerical simulations of driven, supersonic, magneto-hydrodynamic (MHD) turbulence, where collapsing cores are captured with accreting sink particles. The main results are: i) a new physical interpretation of the critical density for star for...

We calculate the relative grain-grain motions arising from interstellar magnetohydrodynamic (MHD) turbulence. The MHD turbulence includes both fluid motions and magnetic fluctuations. While the fluid motions accelerate grains through hydro-drag, the electromagnetic fluctuations accelerate grains through resonant interactions. We consider both incompressive (Alfvén) and compressive (fast and slo...

A recent study by Nakariakov et al. pointed out that the dispersion relation of MHD sausage mode oscillations has been incorrectly applied to coronal loops, neglecting the highly dispersive nature of the phase speed and the long-wavelength cutoff of the wave number. In the light of these new insights we revisit previous observations that have been interpreted in terms of MHD sausage mode oscill...

We developed a three dimensional linear code for simulations of MHD waves in a gravitationally stratified medium with strong gradients of pressure and density in the presence of non-uniform background magnetic field and background flows. The code is suitable for analysis of excitation, propagation, and transformation of MHD waves in realistic models of sunspots. Such a code can be used for prod...

Accelerated atherosclerosis is the major cause of mortality in maintenance hemodialysis (MHD) patients, and endothelial injury associated with MHD might contribute strongly to pathogenesis. The current study was designed to explore possible associations between circulating endothelial cells (CECs) and intima-media thickness of common carotid artery (CCA-IMT) as an indicator of carotid atheroscl...