Classification according to structure

Part 2 of the Colour Indexf Third Edition, classifies dyestuffs according to their constitution in effect by reference to the chromophore present in the dye molecule. Only those dyes whose structure has been declared or published appear in Part 2 whereas all known commercial dyes are classified according to application or usage in Part 1. 

The categories marked ( ) are not classified as to chromophore since sulphur dyes for example are mixtures of indeterminate structures and azoic and oxidation bases are Ingrain dyes (section 2.4.2.8) and are sold as components, the final dye being produced on the substrate by chemical processes. 

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Inhibition of PDE5 is a very broad field, and several reviews covering PDE5 inhibitors have appeared [15]. Instead of trying to cover all known inhibitors, a classification according to structural type is attempted. At least three main classes can be recognized ... 

In (2.5) and (2.6), e, /x, a, and a are the constitutive parameters that characterize the electric and magnetic properties of the material. Hence, s is the electric permittivity, /i the magnetic permeability, a the electric conductivity, and a the equivalent magnetic resistivity. The variation of the constitutive parameters as a function of diverse field characteristics (such as intensity, position, direction, and frequency) leads to their classification according to structure and behavior. 

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