5822
Results show that , to achieve near-full density parts , the energy absorption ( Qa ) by the local powder bed should be approximately 3–8 times greater than the energy consumption ( Qc ) , and this finding applies to all materials investigated .
 density, energy absorption, powder bed, be, materials
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:
 density, energy absorption, powder bed, be, materials