Colour techniques

As a decorative finish on steel and zinc-base alloys for a variety of domestic and ornamental articles. The finish may be protected by clear lacquers or may be coloured by metal colouring techniques for use on, for example, door handles, luggage trim, etc. 

Ab initio Cl study of isotope separation of U2 using a 365 two-colour technique... 

C. Bohne, M. G. Fan, Z-J. Li, J. Lusztyk, and J. C. Scaiano, Photochromic processes in spiro(l,3,3-trimethylindolo-2,2 -naphth[l,2-b]-l,4-oxazine) studied using two-laser two-colour techniques, J. Chem. Soc., Chem. Common. 1990,571-572. 

Pointillism Method of oil painting with numerous small dots of two or more pure colours which, at a distance, produce the effect of mixed colour. Technique pioneered by the French Impressionist painter Georges Seurat. 

Canham LT, Aston R (2012) Method of protecting skin from UV radiation using a dermatological composition having porous silicon. US Patent 8128912 B2 Canham LT, Loni A, Godfrey A (2010) Colouring techniques. Intemational Patent WO/2010/ 038065... 

We will use here a node colouring technique for all three types of allocation. Formally the assignment problem can be stated as ... 

Plastics may be coloured using a mass colouration technique, or with specific polymers it may be possible to surface dye. Mass colouration is the method normally employed, and colourants are incorporated into the polymer along with other additives such as stabilisers or lubricants. 

Select the techniques to be used. Decisions on the number of trials is invariably coloured by cost, but always check they are balanced otherwise it may be false economy... 

Raman spectrometry is another variant which has become important. To quote one expert (Purcell 1993), In 1928, the Indian physicist C.V. Raman (later the first Indian Nobel prizewinner) reported the discovery of frequency-shifted lines in the scattered light of transparent substances. The shifted lines, Raman announced, were independent of the exciting radiation and characteristic of the sample itself. It appears that Raman was motivated by a passion to understand the deep blue colour of the Mediterranean. The many uses of this technique include examination of polymers and of silicon for microcircuits (using an exciting wavelength to which silicon is transparent). 

Sulfur dissolves in liquid ammonia to give intensely coloured solutions. The colour is concentration-dependent and the solutions are photosensitive.Extensive studies of this system by several groups using a variety of spectroscopic techniques, primarily Raman,... 

During the past 20 y numerous other highly coloured halogen cations have been characterized by Raman spectroscopy. X-ray crystallography, and other techniques, as summarized in Table 17.18. Typical preparative routes involve direct oxidation of the halogen (a) in the absence of solvent, (b) in a solvent which is itself the oxidant (e.g. AsFs) or (c) in a non-reactive solvent (e.g. SO2). Some examples are listed below ... 

Tungsten bronzes can be prepared by a variety of reductive techniques but probably the most general method consists of heating the normal tungstate with tungsten metal. They are extremely inert chemically, being resistant both to alkalis and to acids, even when hot and concentrated. Their colours depend in the proportion of M and W present. In the case of sodium... 

Requirements for cans for beer and soft drinks differ from those for food cans in that (a) only low tin and iron contents can be tolerated in the product and (t>) the anticipated shelf-lives are much shorter. Specialised lacquering techniques including striping the seams are used to give complete cover to the metal. For soft drinks it is sometimes possible to select colouring matters and acids least likely to give rise to corrosion troubles, and rapid methods of testing formulations have been devised . Steel quality is also controlled by special tests. 

In acid-base titrations the end point is generally detected by a pH-sensitive indicator. In the EDTA titration a metal ion-sensitive indicator (abbreviated, to metal indicator or metal-ion indicator) is often employed to detect changes of pM. Such indicators (which contain types of chelate groupings and generally possess resonance systems typical of dyestuffs) form complexes with specific metal ions, which differ in colour from the free indicator and produce a sudden colour change at the equivalence point. The end point of the titration can also be evaluated by other methods including potentiometric, amperometric, and spectrophotometric techniques. 

In an alternative procedure designed to deal with minute volumes of liquid, Walter38 set up a layer cell based upon the technique employed in instant colour photographic films, Such a cell designed to determine potassium ions made use of two layer assemblies terminating in valinomycin electrodes, so that with a standard potassium chloride solution added to one assembly, and the... 

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