Sentence examples for are not always valid from inspiring English sources

However, those assumptions are not always valid.

The assumptions of a fast and spherically symmetric wind are not always valid.

That is, impulsive controllers with fixed impulsive gains and intervals are not always valid for different networks.

However these assumptions are not always valid under typical operating conditions of a PEMFC, and particularly so at high current density.

It should be noted here that the obtained mass and stiffness matrices are not always valid for every measured modal parameter.

In this paper, we show that these assumptions are not always valid, and propose sensor node wakeup schemes based on combinatorics block design to address energy-related issues when common assumptions fail.

Since we expected that a registered IA diagnosis in an EMR of the GP is not always valid, an algorithm was developed to improve the validity of the diagnosis IA in the LINH database.

In the first place, some or all of the reacting species are ions and, because of the electrical forces between them, the law expressing their concentrations at equilibrium is not always valid.

However, this approximation is not always valid.

Such assumption is not always valid.

Because of this, the conclusions reached were not always valid.