Sulphur supply

Volkov, I. I. and Rozanov, A. G. (1983). The sulphur supply in oceans. Part I Reservoirs and fluxes. In The Global Biogeochemical Sulphur Cycle, SCOPE 19 (M. V. Ivanov and J. R. Freney, eds). Wiley, Chichester. 

The selenium content of a plant is dependent on the plant species and on whether it is grown in seleniferous or non-seleniferous soil. Generally, Se content in plants increases with the level of Se available and decreases with the sulphur supply. Se concen-... 

A more recent approach in plant diagnostic techniques is the study of relationships between seed yield as affected by sulphur supply, and the total sulphur concentration in seed. Although the range of sulphur concentrations found in seeds is often narrower than in leaves, significant correlations were obtained between total sulphur concentrations in seed and yield, and critical values have been derived for upland rice, cowpea, and wheat. Piper-Steenbjerg effects have been noticed in some pot experiments, and it-has been observed that nitrogen deficiency depressed grain sulphur concentrations to values... 

The total level of glucosinolates is determined by aUeles at several QTLs, discussed above, and by several environmental factors. As would be expected, nitrogen and sulphur supply... 

CH =C(CH3)C02Me. Colourless liquid b.p. lOO C. Manufactured by healing acetone cyanohydrin with methanol and sulphuric acid. It is usually supplied containing dissolved polymerization inhibitor, on removal of which it is readily polymerized to a glass-like polymer. See acrylate resins. 

Sulphur is used in the manufacture of matches and fireworks, as a dust insecticide and for vulcanising rubber. Most of the world supply of sulphur, however, is used for the manufacture of sulphuric acid (p. 296). 

Hydrogen sulphide bums in air with a blue flame yielding sulphur dioxide, but if the air supply is limited, preferential combustion to form sulphur occurs ... 

About 150 ml. of concentrated sulphuric acid is placed in the larger funnel and 100 ml. of concentrated hydrochloric acid in the smaller separatory funnel. The latter is raised until the capillary tube is above the sulphuric acid, the capillary tube is filled with concentrated hydrochloric acid, and the stopper replaced. The rate of evolution of hydrogen chloride is controlled by regulation of the supply of hydro chloric acid this will continue until a volume of hydrochloric acid equal to that of the concentrated sulphuric acid has been used. The diluted sulphuric acid should then be removed and the apparatus recharged. The yield is 31-33 g. of hydrogen chloride per 100 ml. of concentrated hydro chloric acid. If more than an equal volume of hydrochloric acid is employed, the yield of gas decreases and continues to be formed for a tune after the stopcock has been closed. 

Other sources of hazard arise from the handling of such chemicals as concentrated acids, alkalis, metallic sodium and bromine, and in working with such extremely poisonous substances as sodium and potassium cyanides. The special precautions to be observed will be indicated, where necessary, in the experiments in which the substances are employed, and will also be supplied by the demonstrator. The exercise of obvious precautions and cautious handling will in most cases reduce the danger to almost negligible proportions. Thus, if concentrated sulphuric acid should be accidentally spilled, it should be immediately washed with a liberal quantity of water or of a solution of a mild alkali. 

The student should read Sections 1,10 to 1,16 carefully before commencing any experimental work. A supply of melting point capillaries is prepared as described in Section 11,10 (compare Fig. 77, R , I). The apparatus illustrated in Fig. 77. 10, 2, a is assembled with concentrated sulphuric acid as the bath liquid the thermometer selected should have a small bulb. The melting points of pure samples of the following compounds are determined in the manner detailed in Section 11,10 —... 

J. M. Lancaster, "New Developments and Growth in Wodd Fertilizer Demand, Supply and Trade," British Sulphur Corporation, Ltd., Fertilizer Latin American International Conference, Caracas, Venezuela, Apr. 1989. 

Probably the most useful characteristic of the high-silicon irons is their ability to withstand sulphuric acid at all temperatures and concentrations. The maximum rate of corrosion which can develop has been reported to be 0-482mm/y in 30% sulphuric acid at boiling point", and this falls to a minimum rate of 0-025 mm/y when the acid concentration exceeds 60% and the temperature is at boiling point (Fig. 3.64). The former Ministry of Supply... 

Aeration Control of aeration is more difficult. Aeration here means the amount of oxygen supplied either as such or, more commonly, in air. In some situations, it may not require a large amount of air bubbled through a solution to accommodate even a modest rate of corrosion of a small test-piece. Figure 19.2 shows the relationship between the rate of supply of air used for aeration and the rate of corrosion of Monel alloy in 5% sulphuric acid. 

The nitration of some heterocyclic compounds by nitric acid in sulphuric acid has been studied by Katritzky et al.s0 d and the results are exactly as expected in that electron-supplying substituents in the ring favour reaction on the conjugate acid whereas electron-withdrawing substituents produce reaction on the free base. Rate coefficients and the kinetic parameters for nitration of pyridine derivatives (and some benzene analogues)50 are given in Table 4a. 

The oil companies supplying the rubber industry claim that there is no effect on ageing properties when sulphur is present in an oil (up to 6% is possible). They claim that the refining removes the active mercaptans and sulphides and the remainder of the sulphur is complexed into polycyclic compounds and there is no evidence that this type of sulphur has any effect on cure. This claim may be true in some circumstances. However, it is known from practical experience that with certain polymers and compounds the claim is incorrect, especially when the high sulphur oils are used as test media. Oils supplied to the same oil specification from oil fields in different parts of the world, and meeting all the requirements of the specification may, because of widely different sulphur levels, have serious effects on high temperature ageing. 

Fish silage is usually produced from fish offals (heads, intestines, skin, etc.) or waste fish. The enzymes present in fish viscera decompose these tissues and the liquid protein hydrolyzate is the final product [9-11]. To avoid bacteria growth a pH about 2 is required and a relevant amount of organic or inorganic acid is added, usually it is sulphuric acid. The idea was to supply a certain amount of post-coagulation sludge for silage production [12]. 

Parr instruments Not supplied 1108 For sulphur, chlorine, etc. determination... 

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