An association football (soccer) match is presided over by a referee, whom the Laws of the Game give full authority to enforce the Laws of the Game in connection with the match to which he has been appointed (Law 5). The referee is oftentimes assisted by two assistant referees, and sometimes by a fourth official.
Barfoed's test. Barfoed's test is a chemical test used for detecting the presence of monosaccharides. It is based on the reduction of copper(II) acetate to copper(I) oxide (Cu2O), which forms a brick-red precipitate.
A barcode scanner is a device that is used to read the printed barcodes. A barcode consists of a series of parallel, adjacent bars and spaces that are decoded with the intensity of the light reflected by them. When the scanning is initialized, the scanner lens reads the entire code with the help of the light source and converts the code into 0s and 1s.