5247
Porosity , density , and defect were characterised at 4 localities within the DED component by microscopy and x-ray tomography .
 Porosity, density, defect, DED, component, microscopy, x-ray tomography
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:
 Porosity, density, defect, DED, component, microscopy, x-ray tomography