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.
'First degree' burns are least severe, 'second degree' are intermediate, and 'third degree' are the most severe. They may be caused by heat, severe cold, radiation, electricity, and chemicals. Common sense precautions can prevent most incidents of burn injury. Burn injury may seem like a hazard that welders face every working day. After all, they are using a process that involves molten metal and high temperature welding arcs.