instability

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instability

1. tendency to variable or unpredictable behaviour
2. Physics a fast growing disturbance or wave in a plasma

instability

[‚in·stə′bil·əd·ē]
(control systems)
A condition of a control system in which excessive positive feedback causes persistent, unwanted oscillations in the output of the system.
(physics)
A property of the steady state of a system such that certain disturbances or perturbations introduced into the steady state will increase in magnitude, the maximum perturbation amplitude always remaining larger than the initial amplitude.

instability

In a structure, the sudden loss of stiffness that limits its load-carrying capability, and in some cases results in the structure’s failure.

instability

instabilityclick for a larger image
i. A state of the atmosphere in which a parcel of air will continue to rise, if for any reason, it is pushed up. Any instability in the atmosphere means turbulent conditions exist. The environmental lapse rate (ELR) in this case will be higher than both dry and saturated adiabatic lapse rates. Dry adiabatic lapse rate (DALR) is the rate of decrease of temperature with height of a parcel of dry air lifted adiabatically. Its value is 3°/1000 ft. Saturated adiabatic lapse rate (SALR) is the lapse rate of a parcel of saturated air and its value is 1.5°/1000 ft.
ii. A tendency of a body to continue moving away from its original state when disturbed by an external force and to continue after that force has been withdrawn.
iii. The failure of structures, such as the buckling of plates and panels under compression, and the failure of struts under end loads.
References in periodicals archive ?
The fact that we now know that these KH instabilities in CMEs are so far only observable in the extreme ultraviolet, at a temperature of 11 millionelvin, will also help us in modeling CME behavior," said University of Warwick researcher Claire Foullon.
The bubble instabilities induced by various flow rates of the cooling air at different TUR and BUR values are presented in this section.
In these circumstances, the Federal Reserve needed to take further steps to head off potential instabilities that would threaten the economic expansion.
It means that high applied voltage suppresses the axisymmetric instabilities and favors the whipping instability because the electric field normal to the jet produced by the surface charge is actually slightly larger than the tangential electric field.
7, 8) were the first to present the results of bubble instabilities for a single layer film of LDPE and polystyrene (PS)/HDPE blends by recording the bubble behavior through still pictures.
Gross instabilities are readily apparent, whereas finer instabilities affect film properties such as clarity.
The lesson to me would be that the atmospheric system clearly has inherent instabilities, and it can clearly change in extremely short times.
Bindschadler, however, contends scientists donht know enough about the potential instabilities in the ice sheet to rule out collapse in the next century.
RouteDynamics provides this IP routing visibility, enabling companies to identify and perform real-time diagnosis of routing instabilities.
Instabilities in the plasma's behavior tend to build up until they enable the plasma to break out of confinement.
3 brace is already being recommended by orthopedists across the country as a leading-edge aid for ACL/PCL and MCL/LCL instabilities.
Instead, small instabilities, or perturbations, develop along the boundary between the two regions, creating flow pathways.