The phrase "again been employed" is correct and usable in written English.
It can be used when referring to something that has been used or applied once more after a previous instance.
Example: "The method has again been employed in the latest research to achieve better results."
Alternatives: "once more utilized" or "reapplied again".
In particular, the following selection criteria, previously used in the CHAOS-4 model (Olsen et al. 2014), have again been employed: Dark regions only (sun at least 10° below the horizon).
Motivated by our success with α-mannosidosis and based on the observation that the active sites of β-mannosidase are conserved from Bacteroides thetaiotaomicron to mammals, homology modeling has once again been employed as a powerful and reliable method for building 3D structural models of the enzyme for the four species (cow, goat, human and mouse).
With Trump, the wasting-away policy is again being employed.
Nickel plating can again be employed to increase its wear resistance.
"Take 'em right up to the Super Bowl; so what?" Carroll said, a proposition that would surely delight Commissioner Paul Tagliabue of the Humongous Football League where Carroll was once (and might again be) employed.
Finally, a unique question asking whether participants would like to see each of their partners again was employed as a measure of romantic interest, in a dichotomous response scale (i.e. yes/ no).
A useful myth had been employed again.
It would now appear that within 15 years of that, the same deceptive, unaccountable and undemocratic strategy has been employed again.
Time and again, that madness has been employed to undermine efforts to create what the senator characterizes as "a more just, more equal, more free, more caring and more prosperous America".
(5.3) Once again, different methods have been employed.
Again NNRI is employed for the purpose of resampling.
