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It was found that there exists a critical laser energy density for each material , EC , for which selective laser melting process is optimal for material properties .
 process parameter: laser energy density; material: material; manufacturing process: selective laser melting process; concept or principle: material properties
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: laser energy density, material, selective laser melting process, material properties 
Answer:
 process parameter: laser energy density; material: material; manufacturing process: selective laser melting process; concept or principle: material properties