Uncertain what component used in the circuit

hello... im a first year student .. i want to do a project of active power filter to filter the harmonics using current injection

ive found a circuit from internet to study .. but the problem is.. how should i implement it into PCB or into electronics component because i dont really know what component should i buy for the system. Ive emailed the author but none of reply i get.

I attach the picture of the circuit. Hope you guys can help explain it to me. Thanks..

the author is the only hope for you....
lets wait...

ive sent the in a few months back... but hes not replying (