The phrase "are required for several" is correct and usable in written English.
It can be used when discussing necessary conditions or components needed for multiple items or situations.
Example: "These resources are required for several projects to ensure their successful completion."
Alternatives: "are necessary for multiple" or "are essential for various".
High quality single crystal diamond (SCD) substrates are required for several different important current applications.
UG2AG and AG2UG links are required for several functionalities of WUSNs, such as network management and data retrieval.
As a particular social software contribution to this area, Gärdenfors (2012) characterized how much cognition and communication are required for several kinds of cooperation, from simple flocking behavior, through reciprocal altruism ("I'll scratch your back if you scratch mine"), up to fully fledged teamwork.
Changes to the two existing algorithms, which are required for several reasons, would be too extensive.
GTPases are required for several developmental events such as organization of the actin cytoskeleton and signaling by c-Jun N-terminal kinase and p38 kinase cascades [ 49, 50].
Reticulocytes and mononucleated red blood cells are markers for diseases associated with abnormal red blood cell turnover [ 3]. White blood cells (WBCs), or leukocytes, are required for several hematological tests as well as DNA sequencing.
Strengthening of prestressed hollow core slabs is required for several reasons to maintain their structural integrity.
Dehydroepiandrostenedione (DHEA), a 17-ketosteroid hormone produced by adrenal glands, gonads and including gastrointestinal tract is required for several physiological processes.
A good agreement between the calculated and experimental data validates the nuclear model approaches with increased predictive power to supplement and extend the nuclear database that is required for several applications.
The reported results show that the surface, sub-surface, and bulk chemical oxygen vacancies can be correlated to the observed defects and the H2O/H* species can be used to tailor the band bending of the ZnO NRs which might be required for several applications.
