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The droplets were found to have a slight impact on the molten pool behaviours , which produces stable molten pool shapes .
 concept or principle: droplets; concept or principle: impact; concept or principle: molten pool; concept or principle: molten pool
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: droplets, impact, molten pool, molten pool 
Answer:
 concept or principle: droplets; concept or principle: impact; concept or principle: molten pool; concept or principle: molten pool