Inactive sulphur

Dipentene, the inactive form of limonene, not only occurs naturally in essential oils, but results by the action of heat on several other ter-penes, and to a considerable extent by the action of sulphuric acid on pinene. 

It can be obtained artificially by treating sabinene or thujene with dilute sulphuric acid, when the resulting alcohol is optically inactive. The natural alcohol, isolated from juniper berry oil, has the following characters —... 

The best method for producing it artificially is to condense salicylic acid and methyl alcohol by means of sulphuric acid. It is a colourless oil, optically inactive, and possessing an intense wintergreen odour. It has the following characters —... 

Metal deactivator To form inactive protective films on metal surfaces which otherwise might catalyse oxidation and corrosion reactions Trialkyl and triaryl phosphites, organic dihydroxyphosphines, some active sulphur compounds, diamines in lubricating greases, mercaptobenzothiazole and phosphites... 

Corrosion by sulphur additives Sulphur compounds occur naturally in most lubricants and many oil additives contain sulphur. In a properly formulated lubricant these sulphur compounds should be inactive at ambient temperature. At elevated temperatures they may decompose to give more active materials which can stain and corrode metals, particularly silver and copper. However, these same sulphur compounds have many beneficial qualities this is why they are not removed com.pletely in refining and why they are used as additives. 

Mincing, cooking and maturing expose meat products to oxidative stress for a long time so that antioxidants added for lipid protection are slowly destroyed on storage. Onion juice is a powerful antioxidant in meat products, more efficient than garlic juice. Lipid hydroperoxides are reduced to inactive hydroxyl derivatives by reaction with sulphur compounds present in those juices. 

An amorphous form of sulphur which is insoluble in rubber. It is used in rubber compounds which have to be stored for some considerable time in the uncured state without loss of tack, e.g., repair materials for tyres and belting. Since this form of sulphur is insoluble in the rubber it cannot bloom to the surface. The use of insoluble sulphur also gives some degree of scorch control since it is inactive until it reverts to the soluble form. Insulation... 

The catalytic conversion of heavy hydrocarbons, such as heavy oil or sulphurous organic residues, from the oil industry via steam reforming is not feasible because solid carbon starts to be deposited at temperatures above 800 °C, which renders the catalyst inactive in a short period of time and, furthermore, blocks the gas flow in the reactor. Heavy hydrocarbons are, therefore, converted to hydrogen using partial oxidation (POX). Note that in refineries the term gasification is more commonly used partial oxidation is the scientific terminology. 

The pharmacokinetics of amezinium metilsulphate in man have been reported [413-415]. The first step of metabolism consists in demethylation affording the pharmacologically inactive, uncharged 5-amino-2-phenyl-3(2//)-pyridazinone hydroxylated pyridazinones and sulphuric acid conjugates thereof have been isolated [413],... 

Tho only part of the nitre system, if it may be so termed, which appears open to objection, or whioh may be cavilled at, is the contact of the nitric and sulphurous acids at a high temperature, and in consequence the, possible decomposition of tho nitrlo aoid either into nitrons oxide or nitrogen, both totally inactive, and for the required,purpose wholly useless gases. That such a circumstance has taken place is inferred from a fact which occurred jc actual practice. A set of burners were worked to their utmost consumption they became. very hot, and required much more nitrate to keep the chamber in proper working order than previously. It would be difficult, in fact almost impossible, to prove the truth of such an opinion but, nevertheless, it is... 

Although sulphur in the compact form appears to be a comparatively inactive clement, yet when in a fine state of division it reacts with many metals, and at elevated temperatures it combines directly with nearly all other elements (exceptions being nitrogen, iodine, beryllium, gold, platinum and iridium) to form stable binary compounds, the reactions often occurring with great vigour. 

The earliest attempt to nitrate cellulose in mixtures comprising inactive substances was made by Rogovin and Paradnia [46]. The experiments were aimed at investigating the possibility of replacing the large excess of sulphuric acid which does... 

Pt-Re-S/Si02 catalysts under the same conditions are inactive. The Pt-Ir-S/Si02 catalysts behave slightly differently a larger proportion of the total conversion is due to the sulphur-free metallic surface. The catalysts containing Ir are faster than the Re-containing ones but the selectivity to Cs+ is lower. 

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