1938
For a brittle material , shear failure is not desirable and layer-by-layer can be much preferred and even might act as protective mechanism .
 material: brittle material; machanical property: shear failure; concept or principle: layer-by-layer; material: be; material: as; concept or principle: mechanism
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:
 material: brittle material; machanical property: shear failure; concept or principle: layer-by-layer; material: be; material: as; concept or principle: mechanism