1. (General Engineering) tungsten-electrode inert gas welding: a method of welding in which the arc is maintained by a tungsten electrode and shielded from the access of air by an inert gas. Compare MIG welding.
A prescription for a controlled drug is valid for 28 days from the date given on the prescription. usually six months unless it's a controlled i.e. morphine, pethidine and methadone. These medicines are often misused, so have stricter legal controls on their supply to prevent them being obtained illegally. A prescription for a controlled drug is valid for 28 days from the date given on the prescription.
Your prescription can be found on the box on your contact lenses. This is law that your lens prescription must be there and you use it to place your order online. Your prescription is valid for a minimum of 1 year from the date your eye care doctor gives you the prescription. In some states it's 2 years.