3978
Microstructure characterisation , in particular a detailed study of precipitates , was carried out using optical and scanning electron microscopy .
 Microstructure, precipitates, optical, scanning electron microscopy
Please list all entity words in the text that fit the category. Output format is "word1, 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} 
Answer:
 Microstructure, precipitates, optical, scanning electron microscopy