7360
The retention of a large number of unmelted particles leads to inferior geometrical quality and mechanical properties of printed pure Al parts .
 concept or principle: particles; concept or principle: quality; concept or principle: mechanical properties; material: Al
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: particles, quality, mechanical properties, Al 
Answer:
 concept or principle: particles; concept or principle: quality; concept or principle: mechanical properties; material: Al