摘要:

AbstractAn apparatus for the detection and estimation of low concentrations of chloride by means of a cell‐comprising silver chloride and lead sulphate electrodes is described. The method is quick and convenient and the accuracy is of the order of ± 10% down to 1 p.p.m. or less. It is particularly suitable for the determination of small amounts of chloride in boiler water since other anions commonly present do not interfe

ISSN:0368-4075    

DOI:10.1002/jctb.5000670101

出版商:John Wiley&Sons, Ltd    

年代:1948

数据来源: WILEY

摘要:

AbstractThe sources of errors likely to arise in the estimation of minute quantities of SO3in gases containing much larger quantities of SO2are discussed with particular reference to boiler flue gases. A laboratory method is described whereby these difficulties in estimation may be eliminated, as demonstrated by the results obtained on a synthetic gas mixture of known SO2and SO3content.

ISSN:0368-4075    

DOI:10.1002/jctb.5000670102

出版商:John Wiley&Sons, Ltd    

年代:1948

数据来源: WILEY

摘要:

AbstractThe reaction between hydrogen and pyrites under suitable conditions gives good yields of hydrogen sulphide; practically the whole of the labile sulphur of pyrites can be removed from the ore, leaving ferrous sulphide. Under the conditions described in this paper, the rate of formation of hydrogen sulphide from pyrites increases to a maximum and then falls off according to the exponential law. The optimum conditions for the reaction are: (a) temperature of reaction should be 625‐650°, (b) space velocity of hydrogen should be 40‐50 volumes hydrogen per volume of pyrites at kiln temperatures of 625‐650°. Corrosion of plant materials is greatly diminished by using mild steel “servarized” by aluminium. Size of pyrites has little effect on reaction time if the lumps of ore are not greater than 1 1/2 in. More than 90% of the arsenic in pyrites is removed as arsenious sulphide, which passes over suspended in the

ISSN:0368-4075    

DOI:10.1002/jctb.5000670103

出版商:John Wiley&Sons, Ltd    

年代:1948

数据来源: WILEY

摘要:

AbstractAn investigation of the utilization of the sulphur content of byproduct ferrous sulphide from the hydrogenation of pyrites, is described. The reaction of ferrous sulphide with steam or sulphur dioxide to produce hydrogen sulphide or sulphur is considered to be impracticable. It is shown that the exothermic combustion of ferrous sulphide yields sulphur dioxide in concentrations suitable for sulphuric acid manufacture cither by Chamber or Contact processes. It is at least as easy to burn the ferrous sulphide, obtained as in Part I of this paper, in a small‐scale burner of the hand‐fired type, as it is to burn pyri

ISSN:0368-4075    

DOI:10.1002/jctb.5000670104

出版商:John Wiley&Sons, Ltd    

年代:1948

数据来源: WILEY

摘要:

AbstractThe analyses of a series of natural waters are given, together with the results of a standard test for initial action on lead. Correlation between the calcium carbonate saturation index, the organic content and the degree of initial action on lead of these waters is attempted.

ISSN:0368-4075    

DOI:10.1002/jctb.5000670105

出版商:John Wiley&Sons, Ltd    

年代:1948

数据来源: WILEY

摘要:

AbstractData presented for a range of vulcanized rubbers prepared under different conditions show that while olefinic unsaturation becomes reduced by vulcanization in the proportion of one double bond for each sulphur atom combined with a C5H‐unit, the original H/C ratio of 8/5 is not altered. The loss of unsaturation is somewhat modified when zinc oxide or certain accelerators are also present. Oxygen has a slight inhibiting effect on vulcanization; hydrogen sulphide and mercaptans markedly catalyse the vulcanization reaction without, apparently, affecting the efficiency of the sulphur cross‐linking reaction.In confirmation of the results of Hull, Olsen, and France1, a small proportion of zinc oxide or a soluble zinc soap promotes a reaction between sulphur and mercapto groups whereby di‐ and poly‐sulphides arc formed with liberation of hydrogen sulphide. The same type of activity is shown by some of the nitrogenous accelerators commonly used in rubber vulcanization. Substantial conversion of mercapto groups into polysulphidc linkages is therefore to be expected when vulcanization is conducted in the presence of these auxiliary sub

ISSN:0368-4075    

DOI:10.1002/jctb.5000670106

出版商:John Wiley&Sons, Ltd    

年代:1948

数据来源: WILEY

摘要:

AbstractYeasts have been exposed to SO2in nutrient solutions with two concentrations of dextrose; chosen so as to induce the same rate of growth in the yeast, but to combine with quite different proportions of the SO2added. It was found that the behaviour of the yeast was related to the concentration of “free” (i.e. iodinetitratable) SO2, and not to the amounts “ combined “ or added. In another experiment, a correlation was demonstrated between the rate of growth of yeasts in concentrated orange juice and the concentration of free SO2, but not with the combined or total SO2; in this experiment however, larger quantities of free SO2were involved than in the first.It is concluded that in relation to the preservative action of SO2the quantities added and going into combination are irrelevant, such action being exerted only through the proportion remaining “free.” It is nevertheless clear that there are present in fruit juices factors which reduce the effectiveness even of the

ISSN:0368-4075    

DOI:10.1002/jctb.5000670107

出版商:John Wiley&Sons, Ltd    

年代:1948

数据来源: WILEY

摘要:

AbstractIn connexion with the production of lubricating oils by the polymerization of unsaturated oils and spirits, prevous workers have studied the polymerization of pure olefins of various types. For the most part these studies have been restricted to olefins of short chain‐length, and in no case has the oxidation stability of the resulting oils by an accepted test, such as that of the Air Ministry, been reported. Since olefin‐polymer oils usually fail to meet the requirements for high‐grade aviation oils only in respect of their oxidation stability, this is a notable omission. The short investigation reported in the present paper was undertaken to determine for one type of olefin whether increase in chain length was accompanied by increase in oxidation stability of the olefin‐poly

ISSN:0368-4075    

DOI:10.1002/jctb.5000670108

出版商:John Wiley&Sons, Ltd    

年代:1948

数据来源: WILEY

摘要:

AbstractDespite the deactivating influence of the chlorine atoms the trichloroacettoluidides, on nitration, substituteo‐p‐and the nucleus is actually activated since it readily furnishes dinitro‐compounds in each

ISSN:0368-4075    

DOI:10.1002/jctb.5000670109

出版商:John Wiley&Sons, Ltd    

年代:1948

数据来源: WILEY

摘要:

AbstractA. niger, growing in the presence ofp‐aminobenzoic acid and its lower alkyl esters, departs significantly from linearity in media of approximatepH3 to 5, containing nitrate nitrogen. This effect is not observed where media are ofpH6 to 7 or nitrogen is supplied solely as the ammonium ion or the freepara‐amino grouping is acetylated or with the correspondingottho‐ or meta‐aminobenzoate. The non‐linear growth rates can be interpreted in terms of an initial phase, a phase of secondary inhibition and a period of outgrowth. Inhibition in the initial phase is appreciably less at higherpHlevels.P. roquefortigrowing in the presence of esters ofp‐aminobenzoic acid in media wherepHrises during growth shows an accelerating curve. This effect is associated with a marked loss of inhibitory power atpHgreater than about 5·7. A similar acceleration is seen with methyl N‐acctyl‐p‐aminobenzeate but has not been found with methylp‐hydroxybenzoate. None of the free aminobenzoic acids departs from the linear growth curve with this organism.B. fulvagives an acceleration in the presence of methylp‐aminobenzoate under the same conditions ofpHand nitrate nitrogen as cause secondary inhibition ofA. niger.In contrast to the other two organisms the less acid media (pH5 and 7) are relatively more inhibitory, this being associated with absence of acceleration such as is seen under the more acid conditions. The three aminobenzoic acids giv

ISSN:0368-4075    

DOI:10.1002/jctb.5000670110

出版商:John Wiley&Sons, Ltd    

年代:1948

数据来源: WILEY