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Physics the condition of a system when some or all of the quantities describing it are independent of time but not necessarily in thermodynamic or chemical equilibrium

(in some contexts, stationary state), in physics, a state of a physical system in which some quantities significant for characterizing the system (different quantities in different cases) do not vary with time. For example, the state of flow of a fluid is a steady state if the rate of motion and other characteristics remain invariant at each point in space. In quantum mechanics, a state in which the energy has a specific and time-invariant value is called a stationary state. (SeeOPEN SYSTEMS and PRIGOGINETHEOREM regarding steady states in thermodynamics.) The state of a system is quasi-stationary (in thermodynamics, quasi-static) if those quantities that, if constant, would make the state a steady state change slowly with time. Here, the relations between various properties of the system remain approximately the same as in a steady state.

the state to which a mechanism or system returns after the occurrence of a transient produced by a perturbation or an initial deviation in the system’s coordinates.

Examples of steady states in linear systems include the rotation of an engine at some fixed rate with a constant load applied to the shaft, harmonic oscillations in an oscillatory circuit, and the operation of an automatic control system with constant perturbations and control inputs. The steady state of a dynamic system is characterized by having the forces acting on the system compensated by a corresponding counteraction. For example, the motion of a rotating mechanism is described by the equation Md = Mr, where Md is the driving torque and Mr is the resisting torque. For a body being heated, Qh = Qd, where Qh and Qd represent, respectively, the amount of heat absorbed by the body during heating and the amount dissipated to the environment. In an oscillatory circuit, Ws = Wh, where Ws and Wh are, respectively, the amount of energy supplied from a power source during one period of the oscillation and the amount evolved as heat in the resistance of the circuit.

[′sted·ē ′stāt]
(physics)
The condition of a body or system in which the conditions at each point do not change with time, that is after initial transients or fluctuations have disappeared.
References in periodicals archive ?
4a shows the time-frequency spectrum of a synthetic signal of a healthy VSD-fed IM, and with Gaussian noise added, where it can be clearly noted that the frequency increases in the startup transient and remains stable at 50 Hz at the steady state by using the STFT technique.
I recommend you give steady state a try for at least two weeks and see if that's what's superior for you.
By decreasing the injection interval to 21 days, the paliperidone serum concentrations will increase to a new steady state
For consumption and capital stock, the steady state values were larger than the transitional path values.
When CDA is activated it takes approximately one second for the fueling rate to match levels from the steady state map.
To solve for any stationary non-steady-state equilibrium time path of the economy from an arbitrary current state to the steady state, we follow the time path iteration (TPI) method of Auerbach and Kotlikoff (1987).
* Determine whether there is a different V[O.sub.2] kinetic response for exercise increments to steady state for different incremental magnitudes, and the same magnitude from different baseline intensities;
In this section we present the Steady State Kalman filter and Lainiotis Filter.
(b) For any m [member of] [s, S], there exists w [member of] [0,1] such that m is a steady state of the corresponding equation (20).
At the unintended steady state, policy is no longer active: It has instead switched to being passive.
Figure 2 shows the dynamic logarithmic gains in responses of the metabolite concentrations to an infinitesimal change at t=0 in each independent variable in the methionine cycle at the nominal steady state under the regulation of CBS by AdoMet, i.e., when [X.sub.1]=53.5, [X.sub.2]=138, [X.sub.3]=12.8, and [X.sub.4]=0.884.

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