The phrase "are mainly generated" is correct and usable in written English.
It can be used when discussing the primary sources or methods of production for something, often in a scientific or analytical context.
Example: "The results of the experiment are mainly generated from the data collected over the past year."
Alternatives: "are primarily produced" or "are chiefly created."
The equatorial spread-F (ESF) is a phenomenon of ionopheric irregularities which are mainly generated by the generalized Rayleigh Taylor (R T) instability mechanism in conjunction with the other physical mechanisms, originated at the bottom side of the F-layer in the equatorial region after sunset.
Ofcom has said it believes silent calls are mainly generated by telephone marketing, market research, debt recovery, and "number scanning" - where numbers are checked to see if they are working.
Data on justifications are mainly generated from interviewees' interpretations of their own tastes.
The findings are mainly generated from interviews with 19 participants, representing a certain migration group in certain social contexts.
Carbonyls in cigarette smoke are mainly generated by combustion of a number of tobacco constituents [5], mostly carbohydrates.
Those social benefits are mainly generated in the re-use preparation process and distribution activities, whereas the re-use scenario displays a worse performance in energy consumption.
Second, it is generally accepted that the MMN is mainly generated in the auditory cortex [26], with overlapping sources for processing complex stimuli [27].
"Food waste" and "waste cardboard" were mainly generated from "101) Lodging" and "100) Eating and drinking".
In these areas, progress is mainly generated in collaboration and almost never in isolation.
In conventional vehicles, noise is mainly generated from the internal combustion engine.
The magnetic field is mainly generated around the bottleneck structure by feeding current through the wire.
