The phrase "are necessary for efficient" is correct and usable in written English.
It can be used when discussing the importance of certain elements or factors that contribute to efficiency in a process or system.
Example: "The resources and tools provided are necessary for efficient project management."
Alternatives: "are essential for effective" or "are required for optimal".
The second and third items are necessary for efficient analysis from a statistical viewpoint.
Thus, error control techniques are necessary for efficient video transmission over error prone channels.
While such habits are necessary for efficient scientific work within any specialty discipline, they constitute barriers to alternative conceptions.
Thus, we suggest that alterations in the nuclear structure may facilitate cellular reorganizations that are necessary for efficient migration.
Membranes possessing high permeability to water vapor and high liquid entry pressure (LEP) are necessary for efficient membrane distillation (MD) desalination.
New strategies are necessary for efficient separation, purification and enrichment in biotechnology, medicine, and food technology as well as in the chemical and petrochemical industries.
Thus some arousal is thought to be necessary for efficient performance, but too much arousal leads to anxiety or stress, which degrades performance.
Species of economic importance have been extensively studied in order to discover the biological peculiarities that have the determining roles in abundance and distribution; knowledge of such characteristics, of course, is necessary for efficient fishing.
Thus, surface modification of SPIO nanoparticles is necessary for efficient cell labeling.
Screening for microbes capable of co-fermentation is necessary for efficient conversion of lignocellulosic biomass into ethanol with enhanced productivity.
This is necessary for efficient energy storage in connection with the two-phase heat transfer fluid water/steam.
