9037
This has been primarily attributed to poor bonding between printed layers since the lower layers cool below the glass transition temperature ( Tg ) before the next layer is deposited .
 concept or principle: bonding; concept or principle: glass transition temperature; process characterization: Tg; process parameter: layer
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: bonding, glass transition temperature, Tg, layer 
Answer:
 concept or principle: bonding; concept or principle: glass transition temperature; process characterization: Tg; process parameter: layer