1985
The effect of variations in layer height ( layer scaling ) , energy and time on the temperature and stress evolution was investigated .
 concept or principle: variations; process parameter: layer height; process parameter: layer; process parameter: temperature; machanical property: stress; concept or principle: evolution
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: variations, layer height, layer, temperature, stress, evolution 
Answer:
 concept or principle: variations; process parameter: layer height; process parameter: layer; process parameter: temperature; machanical property: stress; concept or principle: evolution