6808
The effect of the protective atmosphere on the microstructure and mechanical performance of AISI 316L deposited parts was investigated by building samples using a simple nitrogen shielding gas or using a nitrogen-filled build chamber .
 concept or principle: microstructure; application: mechanical; concept or principle: samples; manufacturing process: simple; material: nitrogen; concept or principle: gas; process parameter: build chamber
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: microstructure, mechanical, samples, simple, nitrogen, gas, build chamber 
Answer:
 concept or principle: microstructure; application: mechanical; concept or principle: samples; manufacturing process: simple; material: nitrogen; concept or principle: gas; process parameter: build chamber