instability


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Related to instability: hemodynamic instability, Microsatellite instability, mental instability, shoulder instability

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moving away from its original state when disturbed by an external force and to continue after that force has been withdrawn.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 ?
We found that 72 patients had documented signs of instability, including ligamentous injuries, fibrous capsule ruptures of C1-C2, or trauma to the dens-related capsula.
Given all the available data on the low prevalence of detrusor instability and the similarly low rate of surgical failure because of the misdiagnosis of detrusor instability, Dr.
The flow ratios of the two streams were adjusted until an interfacial instability was observed, and then the experiment was repeated at a different processing temperature.
Export instability in literature is defined as the short-run fluctuations in export earnings corrected for trend.
FDI in Arab countries was negatively affected, however, in non-oil manufacturing activities, due to revolutions and instability, the paper highlighted.
In a review of the literature, unaddressed capsular laxity and Bankart lesions (12) have been cited as the most common pathologies associated with continued instability after surgical stabilization procedures (Table 2).
At 60 months, 17% reported knee buckling in the past 3 months, 29% reported slipping or "shifting, slipping, or going to give way, but didn't actually do so," and 37% reported instability (buckling and/or slipping), said Dr.
Accusing some political parties of conspiring to create instability, she said whenever there is instability, it affects progress and development and indirectly aggravates the woes of the poor.
Oman is benefiting from instability in the Middle East.
BEIRUT: Head of Lebanon's Economic Committee Adnan Kassar reiterated Monday warnings that the economy is at the mercy of political bickering and instability.
According to a literature review in the August 2012 issue of the Journal of the American Academy of Orthopaedic Surgeons, most incidences of shoulder joint instability are the result of traumatic contact injuries like force or falling on an outstretched arm; a direct blow to the shoulder area; forceful throwing, lifting or hitting; or contact with another player.
Clinton mentioned about the link between inequality and instability.