摘要:

AbstractThis paper describes the preparation from coal of carbonized briquettes which are highly reactive to sulphur and are promising as a substitute for wood charcoal in the manufacture of carbon disulphide. A description is given of the variables influencing the briquette carbonization process and the way in which they can be controlled to give products of very high reactivity. A comparison has been made of the rate of interaction of various carbons, including the chars, with sulphur and the results are discussed in relation to the factors influencing their reactivity.

ISSN:0021-8871    

DOI:10.1002/jctb.5010010501

出版商:John Wiley&Sons, Ltd    

年代:1951

数据来源: WILEY

摘要:

AbstractMetals and alloys, commonly used as catalysts, are prepared in a finely divided state by atomizing under pressure. The sprayed particles are activated by oxidation, e.g. with sodium hypochlorite solution, washed, dried and reduced with hydrogen.

ISSN:0021-8871    

DOI:10.1002/jctb.5010010502

出版商:John Wiley&Sons, Ltd    

年代:1951

数据来源: WILEY

摘要:

AbstractThe present paper is an endeavour to interpret the experimental results (previously obtained by the present authors) from the point of view of safety in mines in which open acetylene lamps are used as the source of illumination. The danger caused by the formation of CO from acetylene lamps in isolated workings becomes distinctly serious when the oxygen content of the atmosphere falls to 17% or below. At this concentration of 17% oxygen, and operating with two acetylene lamps (2‐in. flames) in an isolated working of 1000‐cu. ft. capacity, the concentration of CO in the working could reach the value of 0.09% after a period of 8 hr. It is estimated that under these conditions the time of exposure required to cause death would be under 2 hr.Tables are provided which enable the concentration of CO in an atmosphere to be estimated under any particular conditi

ISSN:0021-8871    

DOI:10.1002/jctb.5010010503

出版商:John Wiley&Sons, Ltd    

年代:1951

数据来源: WILEY

摘要:

AbstractThe acetyl group of acetamidomesitylene is not split off either by acids or by alkalis under analytical conditions. A laboratory preparation of acetamidomesitylene is described.

ISSN:0021-8871    

DOI:10.1002/jctb.5010010504

出版商:John Wiley&Sons, Ltd    

年代:1951

数据来源: WILEY

摘要:

AbstractDuring research on the indirect determination of moisture in coal, the authors examine the errors possible when using a desiccator, and study the relative values of various desiccants. They conclude that an ordinary desiccator, regardless of the efficiency of the desiccant it contains, is of little use in preventing absorption of moisture by the dried coal, and that it can be abandoned provided that the moisture dishes bear well‐fitting covers, and that the time between drying and weighing is reduced to a minimu

ISSN:0021-8871    

DOI:10.1002/jctb.5010010505

出版商:John Wiley&Sons, Ltd    

年代:1951

数据来源: WILEY

摘要:

AbstractThe submerged‐culture process for the production of penicillin byPenicillium chrysogemanwas investigated in the laboratory. An attempt was made to determine whether there was any rigid relationship between the growth and respiration of the mould and the yield of penicillin, and whether the rate of transfer of oxygen to the liquid phase always limited the yield of penicillin. With these objects in view fermentations were carried out with different types of fermenter, concentrations of medium and strains of the mould. The results indicated that there was no rigid relationship between the various processes. This view was supported by a study of the effect of temperature on the different reactions. With any particular set of conditions, however, changes in the speed of stirring produced effects on growth, respiration and yield of penicillin which appeared to be related. This was doubtless due to the effect of changes in agitation on parallel but relatively independent processes. Our results suggest that the yield of penicillin depends mainly on the suitability of the agitation for its particular enzyme system, and that at present improvements can best be sought by empirical means. Fermenters and fermentation‐systems will show different responses to changes in conditions depending on which part of the enzyme system producing penicillin is limiting its product

ISSN:0021-8871    

DOI:10.1002/jctb.5010010506

出版商:John Wiley&Sons, Ltd    

年代:1951

数据来源: WILEY

摘要:

AbstractThe rational synthesis of polycondensation individuals produced during the formation of phenol‐formaldehyde and allied resins by reactions leading to unequivocal structures has been begun. Three resole structures have been synthesized by methods which offer extension to other intermediates : (i) 2 : 4′‐Dihydroxy‐5‐hydroxymethyldiphenylmethane was synthesized by application of a lithium‐exchange reaction withn‐butyl‐lithium to 5‐bromo‐2 : 4′‐dihydroxydiphenylmethane by way of the 5‐carboxy‐2 :4′‐dihydroxy‐derivative which was reduced to the required compound by lithium aluminium hydride; (ii) 2 : 2′‐dihydroxy‐3 : 5‐bishydroxymethyldiphenylmethane was synthesized from 3 : 5‐dibromo‐2 : 2′‐dihydroxydiphenylmethane by way of 3 : 5‐dibromo‐2 : 2′‐dihydroxy‐3′: 5′‐bishydroxymethyldiphenylmethane, which on controlled reduction with palladium‐hydrogen furnished the required bishydroxymethyl compound; (iii) 2:4: 6‐trishydroxymethylphenol was obtained by reduction of ethyl hydroxytrimesate by lithium aluminium hydride in dioxan.As a contribution towards the problem of ‘ cross‐linking ’ in phenolic resins, I : 2‐di‐(p‐hydroxy‐phenyl)ethane, I: 2‐di‐(o‐hydroxyphenyl)ethane, and I‐o‐hydroxyphenyl‐2‐p‐hydroxyphenylethane, in which the phenolic nuclei are separated by an additional methylene group, have been rationally synthesized with a view to comparison of their reaction with formaldehyde with that of the corresponding dihydroxydiphenylmethanes. The corresponding isomeric dihydroxydiphenylpropanes have also been prepared fo

ISSN:0021-8871    

DOI:10.1002/jctb.5010010507

出版商:John Wiley&Sons, Ltd    

年代:1951

数据来源: WILEY

摘要:

AbstractThe paper discusses the general principles of the kinetics of reactions as carried out in the two main types of continuous process. Comparison is made with the corresponding batch system with regard to the necessary volume of reaction space. It is shown that a correct choice of the type of process can sometimes be used to increase the yield of a reaction. The application of these principles to polymerization is described in outline.

ISSN:0021-8871    

DOI:10.1002/jctb.5010010508

出版商:John Wiley&Sons, Ltd    

年代:1951

数据来源: WILEY