Due to construction and functional characteristics above described, with the internal reflux column it is possible to get selective the separation of components of extremely complex mixtures, with similar chemico-physical characteristics, not economically separable otherwise.
Uniform numbers in American football are unusual compared to those in other sports. They are displayed in more locations on the uniform; they are universally worn on both the front and back of the jersey; and in many cases TV numbers are displayed on either the jersey sleeves, the shoulder pad, or occasionally on the helmets.
The football helmet is a piece of protective equipment used mainly in American football and Canadian football. It consists of a hard plastic shell with thick padding on the inside, a face mask made of one or more plastic-coated metal bars, and a chinstrap.