1666
After systematic characterization of porosity and microstructure , it was discovered that porosity is highest at lower laser energy and decreases at higher laser energy and also laser energy density alteration resulted in production of dense parts .
 machanical property: porosity; concept or principle: microstructure; machanical property: porosity; concept or principle: laser energy; concept or principle: laser energy; process parameter: laser energy density; manufacturing process: production
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:
 machanical property: porosity; concept or principle: microstructure; machanical property: porosity; concept or principle: laser energy; concept or principle: laser energy; process parameter: laser energy density; manufacturing process: production