3161
Present paper also reports on the hierarchical microstructure features of the 316L material processed by EBM® characterized by optical and electron microscopy .
 concept or principle: microstructure; material: material; process characterization: optical; process characterization: electron microscopy
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: manufacturing standard, machanical property, manufacturing process, material, engineering feature, process parameter, machine or equipment, application, process characterization, enabling technology, biomedical, concept or principle 
Text: {0} 
 Entities: microstructure, material, optical, electron microscopy 
Answer:
 concept or principle: microstructure; material: material; process characterization: optical; process characterization: electron microscopy