1196
However , the sample protected by N2 contained many flaky nitrides , whose presence improved the microhardness but reduced the ultimate tensile strength ( UTS ) and plasticity .
 concept or principle: sample; material: N2; material: nitrides; concept or principle: microhardness; machanical property: ultimate tensile strength; machanical property: UTS; machanical property: plasticity
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: sample, N2, nitrides, microhardness, ultimate tensile strength, UTS, plasticity 
Answer:
 concept or principle: sample; material: N2; material: nitrides; concept or principle: microhardness; machanical property: ultimate tensile strength; machanical property: UTS; machanical property: plasticity