Lisbon's Vasco da Gama Bridge is the longest in Europe, spanning a total distance of 10.7 miles. Taking three years to complete, the bridge opened for traffic in 1998 to celebrate the 500th anniversary of Vasco da Dama's discovery of the maritime route from Europe to India.
The arc temperature may be upto 20,000 K. Although TIG welding produces the highest quality welds, it is a slow and expensive process. Metal inert gas welding process (MIG) is economical with consumable electrode fed at a predetermined rate. Plasma arc welding (PAW) has made substantial progress in utilising the high heat energy of an ionised gas stream.
As a result, the flame emits yellow light. This type of flame is, therefore, called luminous flame. For example, the flame of a kerosene lamp. In kerosene lamp the fuel does not undergo complete combustion due to the insufficient supply of oxygen. Now let us study structure of a paraffin wax candle. flame is a hot, luminous gas or vapor. Gaseous substances burn with a flame. Those solid and liquid fuels which can vaporize on being heated also burn with a flame. Depending on the amount of oxygen available for burning the flames can be of two types: 1  Non-luminous or blue flame.