Sentence examples for is often not valid from inspiring English sources

If migrants fall seriously ill, they have little choice but to go back to their villages; their government-subsidised rural medical insurance is often not valid in a different province (or even, until last year, in a different part of Henan).

This hypothesis is often not valid: AC losses induce temperature increases.

This assumption is often not valid due to channel estimation errors and/or feedback delays.

In this work, theoretical and experimental evidence is presented to show that a Bruggeman exponent of 1.5 is often not valid for real electrodes or separator materials.

Hence the common perception (based upon all our experience in conventional enzymology) that enzymes are more efficient catalysts than chemical catalysts is often not valid in non-aqueous enzymology.

For conventional well testing which is carried out over several days or several weeks, reservoir properties are usually assumed to be constant, but this assumption is often not valid for analyzing long-term transient pressure data acquired from a permanent down-hole gauge, which can record down-hole transient pressure data for several years.

These assumptions are often not valid in case of NORM (Naturally Occurring Radioactive Materials) where long term lack of secular equilibrium in the uranium and/or thorium decay series is often observed.

For short fibre polymer composites such as chopped strand mat laminates (CSM), glass mat thermoplastics (GMT) and sheet moulding compounds (SMC), conventional methods to measure fracture energy are often not valid since linear elastic fracture mechanics (LEFM) criteria are not fulfilled.

In a meta-analysis, this is often not a valid assumption.

The prolonged, intense use of chemotherapy is often not a valid option due to adverse side effects compromising any clinical benefits and decreasing client compliance [ 51].

An intention to cure is valid for HD, however it is often not for NHL.