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There was a 20 % increase in yield strength when samples were produced under CO2 .
 machanical property: yield strength; concept or principle: samples; material: CO2
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: yield strength, samples, CO2 
Answer:
 machanical property: yield strength; concept or principle: samples; material: CO2