Results 261 to 270 of about 1,689,762 (301)

A Multivariable Analysis of the Plasma Vertical Instability in Tokamaks

Proceedings of the 45th IEEE Conference on Decision and Control, 2006
For more than a decade the vertical position instability intrinsic to vertically elongated tokamak plasmas has been relatively well understood. Controllers that stabilize this instability have been in routine use at experimental devices since the 1980' s.
Michael L. Walker 0004, David A. Humphreys   +1 more
openaire   +1 more source

Plasma modelling for the control of vertical instabilities in tokamaks

Nuclear Fusion, 1989
A linearized non-rigid MHD consistent displacement model is shown to be adequate to the study of the vertical stability of a plasma in an air core or iron core tokamak. This simple but accurate approach, which can be extended to the study of shape and radial position control, can be used in determining the limits of validity of the linear approximation
ALBANESE, Raffaele, COCCORESE, VINCENZO, RUBINACCI, GUGLIELMO   +2 more
openaire   +2 more sources

On feedback stabilization of the tokamak plasma vertical instability

Automatica, 2009
For more than a decade the instability intrinsic to vertically elongated tokamak plasmas has been relatively well understood. Controllers that stabilize this instability have been in routine use at experimental devices since the 1980's. However, most analysis of this instability has used low order approximations, often just one state, from which ...
Michael L. Walker 0004, David A. Humphreys   +1 more
openaire   +2 more sources

Vertical Instability in Spondylolisthesis

Spine, 2003
Lateral radiographs of the lumbar spine were taken of 40 patients with lumbar spondylolisthesis. These radiographs were taken in the neutral, flexion, and extension positions for both erect and recumbent postures, and also in the prone and supine positions with traction applied via a traction table.To define and demonstrate the presence of "vertical ...
Chow, DHK, Luk, KDK, Holmes, A
openaire   +4 more sources

Control of the vertical instability in advanced tokamak

Fusion Engineering and Design, 1998
The control of vertical instability is studied for DN divertor plasmas in a tokamak with both passive and active control coils. The characteristic parameter of the vertical instability and a second damp stable operating region of the feedback gain are found. The favorable effects of higher triangularity and hollow profile on the critical elongation are
F.Z. Li, Q.D. Gao, J.H. Zhang
openaire   +1 more source

Instability of a vertical riser in the wake of an upstream vertical riser

Applied Ocean Research, 2010
The static solution and its associated dynamic stability of a vertical riser situated in the wake of an upstream riser is investigated in the paper. Both the upstream and downstream risers are top-tensioned and pinned at the bottom ends on the seabed. Due to the wake effects, the downstream riser is subject to mean lift force as well as drag along its ...
openaire   +3 more sources

Baroclinic Instability in Vertically Discrete Systems

Journal of the Atmospheric Sciences, 1988
The Charney-Phillips (1953) standard vertical grid for quasi-geostrophic models is compared with the Lorenz (1960) vertical grid (which departs from the standard grid by carrying horizontal velocity and potential temperature at same levels) in the framework of the quasi-geostrophic potential vorticity equation and baroclinic instability.
Akio Arakawa, Shrinivas Moorthi
openaire   +1 more source

Thermal Instability of a Magnetofluid in a Vertical Rectangular Channel

The Physics of Fluids, 1968
The onset of the instability of an incompressible, viscous and electrically conducting fluid heated from below and confined within a vertical, rectangular channel is investigated when a uniform magnetic field is applied normally to one side of the channel. The condition for the stability revealed by the critical Rayleigh number is found to be dependent
openaire   +2 more sources

Double-diffusive instabilities in a vertical slot

Journal of Fluid Mechanics, 1999
A fluid stably stratified by a salinity gradient and enclosed between two vertical boundaries can become unstable when it is subjected to a temperature difference between the walls. The linear stability of such a fluid in a vertical slot is investigated.
Kerr, Oliver S., Tang, Kit Yee
openaire   +1 more source

SORET INSTABILITY IN A VERTICAL BRINKMAN POROUS ENCLOSURE

Numerical Heat Transfer, Part A: Applications, 2001
This paper presents an analytical and numerical study of the influence of the Soret effect on the onset of convection in a vertical porous layer subject to uniform heat fluxes along the vertical walls. In the formulation of the problem use is made of the Brinkman-extended Darcy model, which is relevant to sparsely packed porous media.
openaire   +1 more source