The part of a sentence "insufficient certain" is not correct and is not commonly used in written English.
A more grammatically correct phrase could be "insufficiently certain" or "not certain enough." These phrases mean that something is not definite or clear enough. Example: The witness's testimony was insufficiently certain, leading the jury to have doubts about the defendant's guilt.
Furthermore, the electrical conductivity is insufficient for certain applications (e.g. lightning strike protection, signal transfer, grounding).
Cu/Ti3SiC2/C composites are a new promising material system that combines advantages of copper-graphite composites and Ti3SiC2, but the mechanical properties, wear resistance, and other performance parameters of these materials remain insufficient under certain conditions [6].
Despite their utility, peptides are, however, insufficient for certain protein interaction studies and functional assays.
These few paired samples were insufficient for certain analyses, such as comparing differences across age groups and sex.
The ITS region has been most commonly used [ 19, 47- 49], although it is recognised as insufficient in certain genera [ 131].
Large-amplitude low-frequency protein movements, such as those that are induced by ligand binding events or those that have to overcome an energy barrier, however, are strongly nonharmonic, so that NMA descriptions may be insufficient in certain cases.
Mr. Vilar's defense team said that he had received poor legal help, that there was insufficient evidence of certain crimes of which he was accused, and that the judge at trial had not instructed the jury properly.
Most of these methods have practical limitations or provide insufficient results in certain conditions.
Unfortunately, even if suitable recordings are available they might still be insufficient to retrieve certain environmental sounds.
Though raised in Nazi Germany, Cardinal Ratzinger wrote this about the Nazi Holocaust: "it cannot be denied that a certain insufficient resistance to this atrocity on the part of Christians can be explained by an inherited anti-Judaism present in the hearts of not a few Christians".
