Inert gas can be found which is inexpensive and common. For example, carbon dioxide is sometimes used in gas mixtures for GMAW because it is not reactive to the weld pool created by arc welding. But it is reactive to the arc. The more carbon dioxide that is added to the inert gas, such as argon, will increase your penetration. The amount of carbon dioxide is often determined by what kind of transfer you will be using in GMAW. The most common is spray arc transfer, and the most commonly used gas mixture for spray arc transfer is 90% argon and 10%
Longest-lasting light bulbs have been so infrequently turned off, this is the precise reason for their longevity. Most of the wear and tear that leads to burnouts in incandescent light bulbs is caused by turning them on and off, not by burning them. Each time the bulb is turned on and off, the filament is heated and cooled. This causes the material of the filament to expand and contract, in turn causing micro stress cracks to develop. The more the light is turned on and off, the larger these cracks grow, until eventually the filament breaks at some point, in non-spectacular fashion, thus