A primary school teacher in south-central Thailand has gone viral on the internet for welcoming students to her classroom in the most heartwarming and fun ways.

While most schools in the country — as well as its Asian neighbors — typically require students to address their teachers formally, Nattaya Nat, 25, connects with her pupils warmly.

In her viral video, Nat, who teaches at Banpruewai School in Chachoengsao province, is seen greeting her students through one of four app-like options: (1) hug, (2) handshake, (3) fist-bump and (4) high-five.

One by one, students enter their classroom through their greeting of choice, with some apparently wishing for more.

In just a week, Nat’s video had more than 3.6 million views and thousands of shares, reactions and comments.

The young teacher has also shared videosa plate fin heat exchanger, a technique for tension expanding hairpin tubes into a fin pack unit, as explained in greater detail in U.S. Pat. No. 4,584,765 was developed. This prior technique was generally carried out on a coil which was first belled by a split collet and pin arrangement, and then expanded. Because of the closeness of the heat exchanger tube rows the bells that were formed are simple, single diameter bells. Further, because of the closeness of the heat exchanger tube rows, the jaw members of the tue clamping fixture were relatively long, thin members. In operation, however, these long, thin jaw members bowed or bent in the transverse direction to the direction of the movement of the expanding bullet during the expansion process. Furthermore, the