Nitriding is often used to increase the surface hardness of metals.

High temperature and high pressure are required to nitridate this metal.

It's high temperature today, it's hard to go out.

He almost died of suffocation, but fortunately he was saved.

Your cooperation is needed for this project.

I need you.

This metal is very hard.

He has the ability to change into a wolf.

In this lake, denitrification is actively taking place.

This soil is active in denitrification, releasing nitrogen into the atmosphere.