摘要:

AbstractShifts in the frequency of certain peaks in the i.r. spectrum of kaolinite during mullite formation were correlated withX‐ray analysis data for the high‐temperature phases. The method provides a means of following the high‐temperature reactions of these minerals, and is rapid, requires only small amounts of sample (mg), and is accurate even for samples of low crystall

ISSN:0021-8871    

DOI:10.1002/jctb.5010190301

出版商:John Wiley&Sons, Ltd    

年代:1969

数据来源: WILEY

摘要:

AbstractBy combustion of a mixture of silicone oil and chloroplatinic acid and organic solvents, Pt–SiO2catalysts with Pt concentrations between 37 and 90% have been prepared and their activity in benzene hydrogenation has been tested in a static system. The special structural characteristics conferred on the catalysts by the combustion method, i.e. small Pt particles with smooth round surfaces well separated by silica, ensure good resistance to de‐activation by exposure to elevated temperatures as well as to atmospheres with high humidity at low temperatu

ISSN:0021-8871    

DOI:10.1002/jctb.5010190302

出版商:John Wiley&Sons, Ltd    

年代:1969

数据来源: WILEY

摘要:

AbstractA study has been made of the stability of potassium ethyl xanthate in solutions containing alkyltrimethyl ammonium halides. It has been shown that the presence of these compounds leads to an increased rate of decomposition, if the solution is in contact with an atmosphere that contains oxygen and its pH is between 6 and 12. Under other conditions, the stability of the xanthate is unaffected by the presence of the co‐solute. It is concluded that the quaternary ammonium compounds catalyse reaction between oxygen and xanthate, and it suggested that at least two different types of oxygenative reaction take plac

ISSN:0021-8871    

DOI:10.1002/jctb.5010190303

出版商:John Wiley&Sons, Ltd    

年代:1969

数据来源: WILEY

摘要:

AbstractThermodynamic functions of disulphur decafluoride have been calculated over the range 200–1000°k. The results from a possible equilibrium reaction of disulphur decafluoride have been used to calculate an approximate value for the heart of formation of disulphur decafluori

ISSN:0021-8871    

DOI:10.1002/jctb.5010190304

出版商:John Wiley&Sons, Ltd    

年代:1969

数据来源: WILEY

摘要:

AbstractThe vapour pressure of acetylacetone has been measured over the temperature range 297–398°k. The results are summarised as:Heat capacity measurements have been carried out on the enol form of acetylacetone over the temperature range 80–300° k. An estimate has been made of heat capacity values below 80° k. Entropy, enthalpy and free energy values have been derived and are listed at ten degree intervals. The melting point (254·80°0·05° k) and heat of fusion (144·8°0·5 abs.Jg−1) of the enol form have been determined. The results have been used in conjunction with previously published data to evaluate the entropies and the heats, entropies and free energies of formation of the keto and enol forms of acetylacetone in the gaseous and liquid phas

ISSN:0021-8871    

DOI:10.1002/jctb.5010190305

出版商:John Wiley&Sons, Ltd    

年代:1969

数据来源: WILEY

摘要:

AbstractThe reactions of histidine were studied with the aim of converting this amino acid to 4‐vinylimidazole, but a commercially attractive scheme could not be develope

ISSN:0021-8871    

DOI:10.1002/jctb.5010190306

出版商:John Wiley&Sons, Ltd    

年代:1969

数据来源: WILEY

摘要:

AbstractThe density, congealing point, and hardness were considered in relation to crystallinity, determined by an infra‐red spectrometric method, of a series of waxes which are fractions from crude Fischer–Tropsch wax. Values ranging between 65 and 93, expressed as molecular percentages of crystalline material present, have been obtained. Data on molecular weights and physical properties were available. Smooth curves could be drawn for the variations of density, congealing point and hardness (or rather penetration) with molecular weight, but only for the more highly crystalline waxes. Two waxes, with crystallinities below 75, were found to have abnormally low congealing points and densities and to be abnormally soft, in relation to their molecular weights. This can be explained in terms of the less dense packing of molecules in the amorphous state.The effect of crystallinity on density was examined more closely, and a set of equations expressing the relationship between these entities and molecular weight was derived. These contain an unknown factor, however, which is dependent upon molecular weight distribut

ISSN:0021-8871    

DOI:10.1002/jctb.5010190307

出版商:John Wiley&Sons, Ltd    

年代:1969

数据来源: WILEY

摘要:

AbstractA modified Dvorák&Boublík&recirculation still was used for the determination of isothermal vapour–liquid equilibrium data for the binary system ethanol–n‐octane at four temperatures. Liquid activity coefficients, γ, were evaluated, and log γ values were correlated by a three‐constant Redlich–Kister equation. Binary azeotrope exists at all four temperatures and the mole fraction of ethanol in the azeotrope increases with increasin

ISSN:0021-8871    

DOI:10.1002/jctb.5010190308

出版商:John Wiley&Sons, Ltd    

年代:1969

数据来源: WILEY

ISSN:0021-8871    

DOI:10.1002/jctb.5010190309

出版商:John Wiley&Sons, Ltd    

年代:1969

数据来源: WILEY