4392
Despite the variety of experimental and modelling efforts devoted to the subject , no studies directly observe the interactions between individual powder particles and the liquid pool of metal at a high enough temporal frequency to characterize these discrete contact events .
 concept or principle: experimental; enabling technology: modelling; material: powder particles; material: metal; application: contact
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: experimental, modelling, powder particles, metal, contact 
Answer:
 concept or principle: experimental; enabling technology: modelling; material: powder particles; material: metal; application: contact