摘要:

AbstractPolymeric substances usually swell less when placed in the vapour of a liquid in a closed vessel than they do in the liquid itself. This is known as ‘Schroeder's Paradox’, and many attempts have been made to explain it. With lightly vulcanised rubber and carbon tetrachloride the paradoxical behaviour is caused by small differences in temperature (of order 0.1 °c) which exist under normal conditions between a liquid and its vapour in a closed vessel; the vapour is normally the warmer of the two. Strict temperature control abolishes the par

ISSN:0021-8871    

DOI:10.1002/jctb.5010160801

出版商:John Wiley&Sons, Ltd    

年代:1966

数据来源: WILEY

摘要:

AbstractExpansion of hardened normal Portland cement in chloride solutions exceeded that in distilled water, but specimens made of ground cement‐clinker were not appreciably affected by the presence of chloride ions. Addition of chloride ions to sulphate solutions caused increased expansion of cement pastes, but the combined effect of chloride and sulphate ions was less than that of the sum of the separate components. Magnesium and calcium chloride were more aggressive than sodium and potassium chloride. In chloride solutions, richer cement pastes were more strongly expanded than poorer ones, in contrast to their behaviour in sulphate solutions.The results are interpreted in terms of the rates of formation of calcium chloroaluminate, the effect of chloride ion on sulphoaluminate crystallisation, slight variations in composition of the chloride phase and leaching of some of the reaction product

ISSN:0021-8871    

DOI:10.1002/jctb.5010160802

出版商:John Wiley&Sons, Ltd    

年代:1966

数据来源: WILEY

摘要:

AbstractReactive styrene dyes, in which a dichloropyrimidine or triazine group is incorporated with the reactive methylene component, have been prepared and evidence for their chemical reaction with polyamide fibre (nylon) given. The corresponding hydroxy‐, amino‐ and substituted‐amino‐styryl‐s‐triazines have been made. The diaminotriazinyl group has also been introduced into the aldehyde component, but attempts to hydrolyse this to give the corresponding dihydroxy derivative were u

ISSN:0021-8871    

DOI:10.1002/jctb.5010160803

出版商:John Wiley&Sons, Ltd    

年代:1966

数据来源: WILEY

摘要:

AbstractPotassium silicate liquors of very similar composition (SiO2/K2O ratios approximately 3.mD4:1) prepared from Aerosil, acid‐washed silica‐gel fines or potash glass have been examined by (a) light scattering, (b) reaction with molybdate and (c) use of the metachromatic effect with pinacyanol chloride. Definite differences between the molecular weights of the samples were obtained from the light‐scattering results. These differences correlated well with the interaction observed between the silicate and pinacyanol chloride and the wet adhesion shown by the silicate; the samples containing more of the very high molecular weight polysilicate showing poor adhesion. The actual molecular weights have been estimated, but the determination of these involved dilutions of the silicate liquors and, over the range of dilution used, the reaction with molybdate showed that rapid depolymerisation of the silicate polyanion occurred on dilution. The results indicate that liquors prepared from potash glass contain more high‐molecular‐weight material than liquors prepared from silica gel o

ISSN:0021-8871    

DOI:10.1002/jctb.5010160804

出版商:John Wiley&Sons, Ltd    

年代:1966

数据来源: WILEY

摘要:

AbstractA detailed investigation on the two‐step conversion of ethanol to butadiene has been carried out in a fluidised bed using a large number of single and binary oxide catalyst systems. Al2O3was the best catalyst among the single oxide catalyst systems whereas Al2O3‐ZnO (60 : 40) was most active among binary oxide catalysts. A maximum conversion of 43.8% was obtained with Al2O3‐ZnO (60 : 40) at a temperatures of 375° and a feed rate of 1.0 ml per h per ml of catalyst, the mole ratio of ethanol to acetaldehyde being 2.

ISSN:0021-8871    

DOI:10.1002/jctb.5010160805

出版商:John Wiley&Sons, Ltd    

年代:1966

数据来源: WILEY

摘要:

AbstractAn equilibrium still, based on the Jones still has been developed to determine vapour‐liquid equilibrium data at low pressures. Results are presented for the system 2‐methylnaphthalene‐n‐decanol at 1.5 mm and 3.0 mm Hg abs. This system can be used for testing vacuum distillation columns operating at low pr

ISSN:0021-8871    

DOI:10.1002/jctb.5010160806

出版商:John Wiley&Sons, Ltd    

年代:1966

数据来源: WILEY

摘要:

AbstractA process has been studied in which Zircaloy‐uranium alloy is dissolved in a mixture of hydrofluoric acid and potassium fluoride. The uranium can be precipitated with an efficiency of 99.9%, as a complex potassium uranium fluoride, together with some of the zirconium in analogous complexes. These precipitates, when dissolved in a mixture of aluminium nitrate and nitric acid, give stable solutions from which uranium may be recovered by solvent extraction with an overall efficiency of 99.7

ISSN:0021-8871    

DOI:10.1002/jctb.5010160807

出版商:John Wiley&Sons, Ltd    

年代:1966

数据来源: WILEY