8186
Additive manufacturing via 3-D printing technologies have become a frontier in materials research , including its application in the development and recycling of permanent magnets .
 Additive manufacturing, 3-D, technologies, materials, recycling, permanent magnets
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, 3-D, technologies, materials, recycling, permanent magnets