Based on the mechanism of heat generation at the welding interface, welding methods for thermoplastics can be classified as external and internal heating methods, as shown in Fig 1. Fig. 1. Classification of welding methods for semi-finished polymeric materials.
ritalin is the brand name of the drug methylphenidate hydrochloride doctors prescribe ritalin to treat attention deficit hyperactivity disorder adhd and a sleep disorder known as narcolepsy
1 Cocainea powerful illegal stimulant drug produced from the coca leaf, one of the most abused illegal drugs in America.  Ritalin(methylphenidate), often referred to as R-Balling the abuse of drugs used in treating attention deficit syndrome is a growing problem in America.