1501
Mechanical properties were characterized with a comparison to different materials and methods from literature , showing hardness and flexural modulus up to ∼1800 HV and 400 GPa , respectively .
 concept or principle: Mechanical properties; concept or principle: materials; machanical property: hardness; machanical property: GPa
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: Mechanical properties, materials, hardness, GPa 
Answer:
 concept or principle: Mechanical properties; concept or principle: materials; machanical property: hardness; machanical property: GPa