摘要:

AbstractThe sorption of sulphur dioxide by a series of laboratory‐made paper handsheets of typical furnishes was investigated. The gas phase SO2concentrations used approached those found in city atmospheres. It was found that at fixed gas phase SO2concentration, increase in temperature decreased the “pick‐up” rate. Copper and manganese ions were found to catalyse the fixation of sulphur dioxide but iron ions were found to be much less effective in this respect. Experiments conducted to assess the effect of light indicated that the rate of “pick‐up” was increased when the samples were exposed to sunlight; an effect most marked in the samples containi

ISSN:0375-9210    

DOI:10.1002/jctb.5020230602

出版商:John Wiley&Sons, Ltd    

年代:1973

数据来源: WILEY

摘要:

AbstractInvestigations on various types of molecular sieve zeolites have been carried out by differential thermal analysis. The smoothness of the d.t.a. curve at the region of zeolitic water loss is a criterion for a particular type of molecular sieve. Inflection in this region indicates the presence of either non zeolitic material or of more than one type of molecular sieve. Quality of any molecular sieve zeolite can thus be effectively assessed by differential thermal analysis.

ISSN:0375-9210    

DOI:10.1002/jctb.5020230603

出版商:John Wiley&Sons, Ltd    

年代:1973

数据来源: WILEY

摘要:

AbstractThe thermal decomposition of both pure and doped cadmium carbonate has been studied. Doping was effected by adding 1, 5 and 10 atom‐% of Al3+, Li+, Zn2+, Ca2+, and Ba2+. Differential thermal analysis, as well as the kinetics of isothermal decomposition of the various carbonates, has been investigated between 310 and 560 °C. The decomposition of both the pure and doped samples was found to obey Mampel's theory. Rate constants were evaluated and found to be appreciably affected by the presence of foreign ions. Application of the Arrhenius equation gave an activation energy of 22.5 kcal/mol for pure cadmium carbonate which is comparable with the standard enthalpy of the reaction which is 22.0 kcal/mol. On the other hand, in applying the Arrhenius equation to the rate constant of the doped samples, no straight lines could be obtained indicating a continuous decrease in the activation energy with a rise of temperature. The activation energies were found to vary between 4.0 and 44.0 kcal/mol. Discussion is presented to account for the effect of the various dopes on the mechanism of thermal decompositi

ISSN:0375-9210    

DOI:10.1002/jctb.5020230604

出版商:John Wiley&Sons, Ltd    

年代:1973

数据来源: WILEY

摘要:

AbstractSpecific surface areas and pore structure studies were carried out on pure and doped cadmium carbonate heated at different temperatures. Doping with a different valency cation than the host ion was found to influence appreciably both the extent and location of the surface. Results could be interpreted in terms of anion vacancy mechanism, in which these vacancies could be created in the case of Li+doping and could be annealed in the case of Al3+doping, thus affecting “material” transport which in turn is reflected in changes in the extent and location of the surface. In this respect Al3+ions might act as “inhibitors” for material transport and thus lead to a “stabilised” pore structure. The results implicitly suggest that “material” transport is more significant in affecting the pore structure than changes in the rates of isotherma

ISSN:0375-9210    

DOI:10.1002/jctb.5020230605

出版商:John Wiley&Sons, Ltd    

年代:1973

数据来源: WILEY

摘要:

AbstractA semipermeable membrane of sulphonated polyvinylidene fluoride was used as the basis of a membrane electrode for the measurement of the activity of calcium ions in solution. By following the change in calcium ion activity as calcium sulphate dihydrate crystallised from aqueous solution, an equation for the rate of crystallisation was derived.

ISSN:0375-9210    

DOI:10.1002/jctb.5020230606

出版商:John Wiley&Sons, Ltd    

年代:1973

数据来源: WILEY

摘要:

AbstractThe activity of the calcium ion was measured by means of a membrane electrode during the crystallisation of calcium sulphate dihydrate from an aqueous solution in which were dissolved additives previously shown to retard this crystallisation. Evidence was thus obtained that the additives did not act by reducing the thermo‐dynamic activity of the calcium ion and so must influence the kinetics of the crystallisation, probably by adsorption on subcritical embryo

ISSN:0375-9210    

DOI:10.1002/jctb.5020230607

出版商:John Wiley&Sons, Ltd    

年代:1973

数据来源: WILEY

摘要:

Abstractα‐BaO.Al2O3.4H2O has been synthesised and studied by infrared, X‐ray and thermal analytical techniques. The compound of approximate formula BaO.Al2O3.0.5H2O, described in Part III, forms as a dehydration product, and appears to be identical with the compound β‐BAH2described by other workers. A possible explanation for the discrepancy in water content is di

ISSN:0375-9210    

DOI:10.1002/jctb.5020230608

出版商:John Wiley&Sons, Ltd    

年代:1973

数据来源: WILEY

摘要:

AbstractA method of determining the rate of the initiation reaction in the liquid phase oxidation of propionaldehyde is described.

ISSN:0375-9210    

DOI:10.1002/jctb.5020230609

出版商:John Wiley&Sons, Ltd    

年代:1973

数据来源: WILEY

摘要:

AbstractThe liquid phase oxidation of cyclohexanone to adipic acid by air in the presence of acetic acid as a solvent and cobalt acetate or manganese acetate as a catalyst was investigated at a temperature of 60 to 100 °C, and at essentially atmospheric pressure. Succinic acid and glutaric acid were the major by‐products. Under the most suitable set of conditions (cyclohexanone, 1.2M; cobalt acetate, 7 × 10−3M; superficial air velocity, 2.5 cm/s, temperature, 80 °C; period of reaction, 5 h), the overall conversion of cyclohexanone was 61 % and the yield of adipic acid and diabasic acids was 69.3% and 85.6% respec

ISSN:0375-9210    

DOI:10.1002/jctb.5020230610

出版商:John Wiley&Sons, Ltd    

年代:1973

数据来源: WILEY

摘要:

AbstractAn n.m.r. method is developed for the quantitative analysis of the components in the compositions obtained in a process for the production of methyl acrylate. The average error of the method is about ± 2.0%

ISSN:0375-9210    

DOI:10.1002/jctb.5020230611

出版商:John Wiley&Sons, Ltd    

年代:1973

数据来源: WILEY