Pollen count count is by using a Burkard Trap, also known as the seven-day volumetric spore trap. This device works by facing towards the wind and drawing in air by using a pump. The pollen particles drawn in by the pump are then trapped by a sticky wax film that is attached to a rotating drum. The drum slowly rotates one turn over the course of seven days while collecting particles. The tape is removed after one week and cut into day-length sections. Pollen count Pollen count is the measurement of the number of grains of pollen in a cubic meter of
Enteric coating However, as the solvents for such solutions are organic solvents, there's a concern about the toxicity potential of the traces of the residual solvents in the tablet coating. The first form of gastro-resistant coating was introduced by Unna in 1884 in the form of keratin-coated pills, although it was later discovered that they weren't able to withstand gastric digestion. Salol was also used by Ceppi as one of the first forms of enteric coating. However, the first material that was extensively used as enteric coating agent was shellac, since its introduction in 1930. Properly treated or hydrolyzed shellac showed different