agglomeration vs concentration

agglomeration

noun
  • The act or process of collecting in a mass; a heaping together. 

  • State of being collected in a mass; a mass; cluster. 

  • An extended city area comprising the built-up area of a central city and any suburbs linked by continuous urban area. 

  • a mass of large volcanic fragments bonded under heat. 

concentration

noun
  • The act, process or product of reducing the volume of a liquid, as by evaporation. 

  • The proportion of a substance in a whole. 

  • The act or process of removing the dress of ore and of reducing the valuable part to smaller compass, as by currents of air or water. 

  • The direction of attention to a specific object. 

  • A field or course of study on which one focuses, especially as a student in a college or university. 

  • The amount of solute in a solution measured in suitable units (e.g., parts per million (ppm)) 

  • The matching game pelmanism. 

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