ISSN:0021-8871    

DOI:10.1002/jctb.5010050709

出版商:John Wiley&Sons, Ltd    

年代:1955

数据来源: WILEY

摘要:

AbstractSome methods for the preparation of 2:3:4:5‐tetramethylphenol have been investigated, the most useful being the Gattermann reaction with 2:3:5‐trimethylphenol followed by Clemmensen reduction. Hydrogenolysis of phenol alcohols over copper chromite catalyst has been shown to give methyl‐substituted phenols without rearrangement; nuclear chlorine does not interfere and is not removed during the hydrogenolysis. Several compounds of interest in the study of the phenol–formaldehyde reaction have been p

ISSN:0021-8871    

DOI:10.1002/jctb.5010050701

出版商:John Wiley&Sons, Ltd    

年代:1955

数据来源: WILEY

摘要:

AbstractThe recovery of wool from sheepskin pieces by digestion in warm water and with bacterial and mould proteases and papain has been investigated on a laboratory scale. The influence of conditions of pre‐shrinkage of the skin in hot water, temperature of digestion, pH, presence of buffers and other salts, and other factors have been studied. The wools recovered from the digested skin pieces have been examined to ascertain the extent of wool damage, if any. The optimum conditions have been found for each method and the advantages and disadvantages of the different methods compared. The possible use of the various methods on a large scale is discusse

ISSN:0021-8871    

DOI:10.1002/jctb.5010050702

出版商:John Wiley&Sons, Ltd    

年代:1955

数据来源: WILEY

摘要:

AbstractA large number of glyoxaline‐2‐thiols and some 2‐alkylthioglyoxalines react with 2:6‐di‐chloroquinone chloroimide at pH 8 to give coloured products which are in most cases soluble in chloroform. The mechanism of the reactions is briefly

ISSN:0021-8871    

DOI:10.1002/jctb.5010050703

出版商:John Wiley&Sons, Ltd    

年代:1955

数据来源: WILEY

摘要:

AbstractMild steel corrosion probes have been used to determine the relation between surface temperature and amount of iron corroded by the flue gases of relatively low moisture content from a diffusion flame of carbon monoxide, to which additions of sulphur dioxide were made. Complementary measurements have been made of the percentage conversion of sulphur dioxide to sulphur trioxide and of the rates of acid build‐up on a dewpoint meter. Over the temperature range employed, corrosion showed a maximum at 66°to 70°, and humidity of combustion air was found to have a significant effect on corrosion.From the dewpoint meter readings and other data, theoretical rates of acid deposition on the corrosion probe have been calculated and these and the experimental values are compared and discus

ISSN:0021-8871    

DOI:10.1002/jctb.5010050704

出版商:John Wiley&Sons, Ltd    

年代:1955

数据来源: WILEY

摘要:

AbstractAn earlier study showed that the tensile strengths of rubber samples were distributed in a doubly exponential curve. Use is made of this fact and recently published statistical concepts in setting up a more reliable criterion for the acceptance of a rubber compound based on the tensile strength. Further the number of determinations required can be judged, thereby reducing the amount of testing necessary. The equations and constants for three to six samples are given and the method of calculation illustrated so that comparable sets of figures can be calculated for other sample sizes. The calculations to find the proportion of samples meeting a fixed specification or tolerance range are included.

ISSN:0021-8871    

DOI:10.1002/jctb.5010050705

出版商:John Wiley&Sons, Ltd    

年代:1955

数据来源: WILEY

摘要:

AbstractFive commercial coal‐tar pitches, an air‐blown pitch and a straight‐run bitumen have been fractionated by solvent extraction and precipitation, and the molecular weights and elementary composition of the products have been determined. All five normal pitches are similar as regards the lower end of their molecular‐weight‐distribution curves, 50% by weight ranging from 150 to 350. The distributions of the upper 50% are also continuous, but the top molecular weight varies from 1400 in the low‐temperature carbonization pitch to about double that figure in the horizontal‐retort pitch. The molecular weights of bitumen and air‐blown pitch extend to above 5000.The coke‐oven pitch fractions all consist predominantly of condensed aromatic molecules, mainly hydrocarbon in nature, exhibiting only a limited degree of methyl substitution. The horizontal‐retort pitch is slightly less aromatic. The vertical‐retort pitch, though containing low‐molecular‐weight paraffins, increases in aromaticity with increasing molecular weight. The low‐temperature carbonization pitch fractions all have lower carbon/hydrogen ratios than those of the other pitches.Ultracentrifuging of tars and their solutions has failed to reveal any significant amount of disperse phase. Pitch is considered to be a supercooled liquid whose physical properties can be adequately explained without r

ISSN:0021-8871    

DOI:10.1002/jctb.5010050706

出版商:John Wiley&Sons, Ltd    

年代:1955

数据来源: WILEY

摘要:

AbstractA method has been devised for the determination of ozone at high dilutions, which does not require complete absorption of the ozone by the reagent and is independent of the volume of air passed. It is based on the measurement of the oxidation potential of a bromine–hydrobromic acid electrode, which is not affected by the oxides of nitrogen or other oxidizing substances in the concentrations which occur in the atmosphere. The results are compared with those obtained by the potassium iodide–starch paper method and the limitations of the different techniques are discus

ISSN:0021-8871    

DOI:10.1002/jctb.5010050707

出版商:John Wiley&Sons, Ltd    

年代:1955

数据来源: WILEY

摘要:

AbstractA method of removing the soluble part of a gas mixture by foam is described. The foam bed is formed by passing the mixture through a porous plate over which a suitable absorbent liquid is caused to flow. The process is illustrated by some results from experiments designed to remove carbon dioxide from the air. It is shown that high coefficients of absorption are obtained and that for the conditions specified the method is superior to the use of the conventional packed tower.

ISSN:0021-8871    

DOI:10.1002/jctb.5010050708

出版商:John Wiley&Sons, Ltd    

年代:1955

数据来源: WILEY