Wide applications

X-rays find wide applications in X-ray photography and in crystallography. Prolonged exposure of the human body to the rays induces a dangerous form of dermatitis, and even sterility, but controlled exposures are applied to alleviate cancer. 

The X-ray TV introscope can find wide application in engineering, atomic, chemical, heat power, oil and gas industries. 

For the mechanism of this reaction, see Robinson and Robinson,1918, H3i 639 1924, 145, 827.) The reaction is of wide application for example, the use of methyl-phenyl-hydrazine, CsH5(CHj)> -iN H, in the above reaction gives i-methyl-2-phenylindole, whereas pyruvic acid, CH CO COOH, when converted to its phenylhydrazone and then indolised, gives indole-2-carboxylic... 

Oximes (compare Section III,74,B). The following procedure has wide application. Dissolve 0-5 g. of hydroxylamine hydrochloride in 2 ml. of water, add 2 ml. of 10 per cent, sodium hydroxide solution and 0-2 g. of the aldehyde (or ketone). If the latter is insoluble, add just sufficient alcohol to the mixture to give a clear solution. Heat the mixture under reflux for 10-15 minutes, and then cool in ice. If crystals separate, filter these off, and recrystallise from alcohol, dilute alcohol, benzene or light petroleum (b.p. 60-80°). If no solid separates on cooling, dilute with 2-3 volumes of water, filter the precipitated sohd, and recrystallise. 

Apart from using an environmentally friendly solvent, it is also important to clean up the chemical reactions themselves by reducing the number and amount of side-products formed. For this purpose catalysts are a versatile tool. Catalysts have been used for thousands of years in processes such as fermentation and their importance has grown ever since. In synthetic oiganic chemistry, catalysts have found wide applications. In the majority of these catalytic processes, organic solvents are used, but also here the use of water is becoming increasingly popular . 

Since allylation with allylic carbonates proceeds under mild neutral conditions, neutral allylation has a wide application to alkylation of labile compounds which are sensitive to acids or bases. As a typical example, successful C-allylation of the rather sensitive molecule of ascorbic acid (225) to give 226 is possible only with allyl carbonate[l 37]. Similarly, Meldrum s acid is allylated smoothly[138]. Pd-catalyzed reaction of carbon nucleophiles with isopropyl 2-methylene-3,5-dioxahexylcarbomite (227)[I39] followed by hydrolysis is a good method for acetonylation of carbon nucleophiles. 

On the other hand, in spite of some interesting tinctorial properties, it does not seem that thiazolo dyes received wide application in the texlile industry because they suffer from lack of stability to light and chemical agents. 

The Type K thermocouple (Table 11.59) is more resistant to oxidation at elevated temperatures than the Type E, J, or T thermocouple, and consequently finds wide application at temperatures above 500°C. It is recommended for continuous use at temperatures within the range — 250 to 1260°C in inert or oxidizing atmospheres. It should not be used in sulfurous or reducing atmospheres, or in vacuum at high temperatures for extended times. 

The material of this chapter and, for that matter, of the two preceding chapters has wide applicability in the area of technology and manufacture. To do justice to this facet of the subject would require a book in itself, so we must settle for a few paragraphs concerned with industrial applications. 

The above examples illustrate reactions at an electron-deficient carbon atom. Other 1,1-bielectrophiles allow the direct introduction of a heteroatom into the resultant heterocycle. The most widely applicable and versatile methods for the synthesis of 1,2,5-thiadiazoles and 1,2,5-selenadiazole rely on this approach. 

On the whole, the cycloaddition of alkynes to nitrile N-oxides is one of the most important routes to isoxazoles, but in spite of its potentially wide application, its synthetic utility is less than that of the corresponding reaction with alkenes for the following reasons. (1)... 

A final method of /3-lactam 3,4-bond formation which has found fairly wide application is based on carbenlc insertion (78T1731 p. 1739). The carbenic centre can be generated by photolysis of a diazo compound as in the case of (158) (72JA1629, 79CC846) or from organometalllc precursors, for example (159) (71ACS1927). 

A wide variety of /3-lactams are available by these routes because of the range of substituents possible in either the ketene or its equivalent substituted acetic acid derivative. Considerable diversity in imine structure is also possible. In addition to simple Schiff bases, imino esters and thioethers, amidines, cyclic imines and conjugated imines such as cinnamy-lidineaniline have found wide application in the synthesis of functionalized /3-lactams. A-Acylhydrazones can be used, but phenylhydrazones and O-alkyloximes do not give /3-lactams. These /3-lactam forming reactions give both cis and /raMS-azetidin-2-ones some control over stereochemistry can, however, be exercised by choice of reactants and conditions. 

An alternative K-value formulation that has received wide application to mixtures containing polar and/or nonpolar compounds is... 

Cathodic Protection This electrochemical method of corrosion control has found wide application in the protection of carbon steel underground structures such as pipe lines and tanks from external soil corrosion. It is also widely used in water systems to protect ship hulls, offshore structures, and water-storage tanks. 

Good Good 90 S.9 Wide application in food and pharmaceutical industries... 

Development of extraction-free photometric procedures for the determination of traces of metals for which hygienic and environmental regulations have been established is an urgent problem. For solution of this problem we used as an organic reagent l-(2- pyridylazo)-naphtol-2 (PAN) which forms intensely coloured complex compounds with many metals and is frequently used for their extraction-photometric determination however these procedures did not find wide application in water analysis due to lack of selectivity and necessity of using organic solvents. 

The use of microwave irradiation as an energy source for chemical reactions and processes has been extensively investigated during recent years and has found wide application in various fields of chemistry and technology. The following presentation focuses on the scope and potential of microwaves in chemical analysis. 

The reduction of dimensions also reduces volumes which are accessible to the detector. Thus, detection principles related to geometric dimensions of the detector cell ai e not ideally suited for coupling to microsystems, whereas surface sensitive principles, such as electrochemical methods or optical methods utilizing the evanescent field of a waveguide, or methods which can be focussed on a small amount of liquid, such as electrochemiluminescence (ECE), ai e better suited. This is why electrochemiluminescence detectors ai e combined to microsystems. Moreover ECE has found wide applications in biochemistry because of its high sensitivity, relatively simplicity and feasibility under mild conditions. 

Tetracycline antibiotics have found wide application in animal industries for treatment, preventive maintenance and stimulation of growth of large horned livestock owing to what their residue amounts can be present at milk and meat of animals. Residue amounts of antibiotics are not toxic, however, capable to cause allergic reactions and to promote development of tolerance of the some people pathogenic bacterias. According with the legislative requirements of a number of the European countries it is forbidden to deliver to the population production polluted residual contents of tetracyclines. 

The main idea of research is application of accessible, simple and express methods that don t need expensive reagent techniques for analysis of phanuaceutical products based on bischofite. The determination of metal ions such as Mg, Zn, Cu, Fe by complex-formation titrations using a widely applicable chelating agent, EDTA, have been studied as a function of pH, complexing agents and indicators. The analysis consists of four parts ... 

Select a material of construction that has a wide application range... 

Fluid couplings have a proven record of reliability and ease of operation. They thus have found wide application wherever a light load start and capticily control of drives is required as in fans and pumps. 

One of the most widely applicable and most commonly used methods of purification of liquids or low melting solids (especially of organic chemicals) is fractional distillation at atmospheric, or some lower, pressure. Almost without exception, this method can be assumed to be suitable for all organic liquids and most of the low-melting organic solids. For this reason it has been possible in Chapter 4 to omit many procedures for purification of organic chemicals when only a simple fractional distillation is involved - the suitability of such a procedure is implied from the boiling point. 

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