1570
The amounts and morphologies of hydrogen micropores and solidification microvoids varied from the top , middle , and bottom of the wall sample because of the distinct microstructure and second-phase distribution in each section .
 morphologies, solidification, sample, microstructure, distribution
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:
 morphologies, solidification, sample, microstructure, distribution