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The close agreement between the framework 's predictions and the experimental data demonstrates that the surface asperities soften due to frictional heating , while acoustic softening effects are insignificant .
 framework, predictions, experimental data, surface asperities, heating, acoustic softening effects
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:
 framework, predictions, experimental data, surface asperities, heating, acoustic softening effects