For the Hangings when did it affect elie

I think the hanging of the young boy Pipel affects Elie the most. As Elie witnesses the hanging of the young Pipel, he feels that it is his God who is hanging on the gallows. The death of the pipel is related to the death of Elie's faith in his God. Elie identifies with the death of the young Pipel because he undergoes a similar slow, painful spiritual death.

thank you would pipel be dehumazation ?

Yes, Pipel's death would fit under that. Killing children is about the worst humanity can stoop to.