2445
However , a yield strength increase of 22 % was observed in the composite compared with the strength of unreinforced sample of equivalent density .
 yield strength, composite, strength, sample, density
Please list all entity words in the text that fit the category. Output format is "word1, 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:
 yield strength, composite, strength, sample, density