Additive colour mixing

White light is composed of the additive primary colours of red, green and blue. These primary colours are the ones which cannot be made by mixing any of the other two together. Mixing light of two of these primary colours in equal proportions produces the following colours  

Red + Blue = Magenta Red + Green = Yellow Blue + Green = Cyan 

When visible spectral light is split in a prism or other dispersion medium such as 

Surface absorbs blue and reflects red and green light 

Additive colour mixing applies to the combination of light beams and is therefore the system employed in colour television and other display systems (see Chapter 3). 

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Figure 2.1 (a) Additive colour mixing (b) subtractive colour mixing... 

Additive Colour Mixing used with light, the primary colours being red, green and blue. 

For incomplete absorption of the primary blue light by the LUCO material, also mixed bluish-greenish (i.e. turquoise) colours can be generated. Additive colour mixing of the primary LED-blue with secondary photoluminescence-red results in magenta, a colour not accessible by conventional pn-junction semiconductor devices. 

Colour synthesis The process by which the complete range of visible colours is derived by mixing the three primary wavelengths of light in varying combinations. This is known as additive colour synthesis. 

In most compounding operations, single- and twin-screw extruders are involved at some stage to melt, convey, compress and mix different compounds such as additives, colourants and different polymer types. 

Dissolve 4 5 ml. of aniline in a mixture of 10 ml. of concentrated hydrochloric acid and 20 ml. of water cool the solution to 5°, and diazotise by the addition of 4 g. of sodium nitrite dissolved in 20 ml, of water, observing the usual precautions given on page 181. Dissolve 7 g. of 2-naphthol in 60 ml. of 10% sodium hydroxide solution contained in a 200 ml. beaker, and cool this solution to 5 by external cooling, aided by the direct addition of about 20-30 g. of crushed ice. Now add the diazotised solution very slowly to the naphthol solution, keeping the latter well stirred meanwhile the mixed solutions immediately develop a deep red colour, and the benzeneazonaphthol should... 

For maintenanee of optimum values pH at definition of Rh and Ir used the aeetie buffer mixes, prepared with addition of isopropanole. Colour of eomplexes develops within 2 h at 65 5°C or during 5 min under influenee of mierowave radiation. 

Ice-cream is a product which has been developed since mechanical refrigeration became available. Ice-cream mixes comprise fats (not always dairy), milk protein, sugar and additives such as emulsifiers, stabilizers, colourings, together with extra items such as fruit, nuts, pieces of chocolate, etc., according to the particular type and flavour. The presence of this mixture of constituents means that the freezing... 

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