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Many metal L-PBF systems also have optional laser power and melt-pool sensing to determine the state of part with the possibility of detecting a failure before it damages the machine .
 material: metal; machine or equipment: L-PBF systems; process parameter: laser power; application: sensing; concept or principle: failure; machine or equipment: machine
Please list all entity words in the text that fit the category.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} 
Answer:
 material: metal; machine or equipment: L-PBF systems; process parameter: laser power; application: sensing; concept or principle: failure; machine or equipment: machine