1198
Similar to , the authors found that a decreasing cell size and an increasing gradient density has a positive effect on the structural performance .
 machanical property: cell size; machanical property: density; process characterization: structural performance
Please list all entity words in the text that fit the category.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} 
Answer:
 machanical property: cell size; machanical property: density; process characterization: structural performance