deoxidation vs sapping

deoxidation

noun
  • The process of extracting the oxygen content of a dissolved oxide, or of removing dissolved oxygen, with the aid of a reducing agent. 

sapping

noun
  • The act by which something is sapped or depleted. 

  • The act of excavating trenches. 

  • The act of being struck with a sap or club. 

How often have the words deoxidation and sapping occurred in a corpus of books? (source: Google Ngram Viewer )