3533
As flow rates of shielding gas increased from 5 L/min to 25 L/min , the oxygen content in the melt pool decreased from 775 ppm to 375 ppm at low intensity of laser beam ( 73 W/m2 ) , and from 677 ppm to 1470 ppm at high intensity of laser beam ( 725 W/m2 ) .
 As, gas, oxygen, melt pool, laser beam, laser beam
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:
 As, gas, oxygen, melt pool, laser beam, laser beam