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This article addresses the deployment and characterization of a piezoelectric-pneumatic material-jetting ( PPMJ ) additive manufacturing process to print graphene-based nanocomposites with 3D structures .
 additive manufacturing process, print, 3D structures
Please list all entity words in the text that fit the category. Output format is "word1, 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:
 additive manufacturing process, print, 3D structures