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

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

In ancient Chinese astronomy, they used the earthly branches to express time and direction.

Mr. Ochi is my best friend.

Mr. Adachi is my best friend.

Mr. Chida is my best friend.

Moderate exercise is good for health.

The saffron cod is a winter specialty in Hokkaido.

The structure of this building is very sturdy.

I'm thinking of making a stew with saffron cod for dinner tonight.