1603
After sintering , the vertical gradient of porosity disappears .
 manufacturing process: sintering; concept or principle: vertical; machanical property: porosity
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: 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} 
 Entities: sintering, vertical, porosity 
Answer:
 manufacturing process: sintering; concept or principle: vertical; machanical property: porosity