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moving away from its original state when disturbed by an external force and to continue after that force has been withdrawn.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 ?
Arthroscopic Bankart repair is an established option for patients with isolated soft tissue Bankart lesions, yet Burkhart and coworkers reported a near 70% instability recurrence rate following soft tissue stabilization with underlying bony Bankart or Hill-Sachs lesions.
Second, less developed nations experience domestic shocks due to intrinsic instability and self-inflicted policy faults (Kharroubi, 2006).
A new contingency introduced in the CFR's survey for this year is political instability in European Union countries caused by the influx of refugees and migrants, while the report also mentions escalating tensions between Russia and North Atlantic Treaty Organization (NATO) member states.
This intelligent safety stock policy gives better results in terms of instability and cost compared to the automatic policy where orders are placed every time the projected inventory is below the target safety level (Sridharan, 2007; Kabak & Ornek, 2009).
It shows that the main source of work face support resistance is fracture instability of different roofs in the overlying strata and intensity of mine pressure manifestation with different coal seam thicknesses demonstrates different manners of distribution.
FDI in Arab countries was negatively affected, however, in non-oil manufacturing activities, due to revolutions and instability, the paper highlighted.
During follow-up, 32% developed incident instability, 20% incident buckling, 11% worsening instability, and 21% worsening buckling.
Figures indicate that regional instability has helped the nation expand income from its tourism industry by more than 15 per cent in the first four months of 2013.
1) With this paper I add to our understanding of earnings instability by studying whether workers who are employed by volatile firms are paid volatile earnings.
Roughly, no scientific research has been mentioned in the literature regarding the evaluation of pelvic incidence in patients with or without lumbar spinal instability.
Shoulder instability is a commonly encountered problem in young athletes.