摘要:

AbstractPrevious workers have shown that inhibitors having relatively strong oxidising anions, such as chromate and nitrite, passivate iron both in the presence of air and in de‐aerated solutions. Evidence is presented to show that while this may be so in 0.1M solutions, the behaviour in de‐aerated dilute solutions ranging from 200 to 1600 p.p.m. of inhibitor is quite different. Further, the action of nitrite is essentially different from that of chromate, in that, in the absence either of dissolved oxygen or of a pre‐immersion oxide film, nitrite is impotent in preventing corrosion of

ISSN:0021-8871    

DOI:10.1002/jctb.5010111201

出版商:John Wiley&Sons, Ltd    

年代:1961

数据来源: WILEY

摘要:

AbstractA method of compacting silica gel powder is described together with details of the surface changes that accompany such a process. The strength of discs of this material in vacuum and in the presence of different pressures of various gases and vapours are given. Carbon tetrachloride at room temperature has no effect. Nitrogen at liquid nitrogen temperature (−195.8°) causes a small decrease in strength. Water‐vapour at room temperature even in small quantities causes a sharp fall in stre

ISSN:0021-8871    

DOI:10.1002/jctb.5010111202

出版商:John Wiley&Sons, Ltd    

年代:1961

数据来源: WILEY

摘要:

AbstractA streamline jet of absorbing liquid has been used to investigate the rate of uptake of carbon dioxide into water and into commercial carbolates at temperatures in the range 30—60°. The ratio of absorption rates with and without chemical reaction has been correlated with reaction rate constant, hydrogen‐ion concentration and flow factors. In addition, the rate of change of liquid‐film transfer coefficient with temperature has been shown to be similar for all carb

ISSN:0021-8871    

DOI:10.1002/jctb.5010111203

出版商:John Wiley&Sons, Ltd    

年代:1961

数据来源: WILEY

摘要:

AbstractThe hydrogenation of benzene vapour has been studied in a flow system using a ‘practical’ nickel‐on‐silica catalyst between 40° and 275° at atmospheric pressure. The reaction rate dependence was zero‐order with respect to benzene partial pressure in the range 60—150 mm. investigated and second‐order with respect to hydrogen. The apparent activation energy changes from 2.0 ± 0.2 kcal./mol. to around 0.9 ± 0.1 kcal./mol. to −19.5 ± 0.5 kcal./mol. in three distinct temperature regions.The results are discussed in terms of a possible rate limitation and it is suggested that, above 170°, cyclohexane once formed at the surface may possibly be dehydrogenated, since the energetics are favourable. The rate‐controlling step in the mechanism may be the transfer of hydrogen molecules from a van der Waals layer to the catalyst surface where, on dissociation, these react with C6H8(ads.) to give C6H10(ads.) and finally C6H12.A brief study of catalyst poisoning by water v

ISSN:0021-8871    

DOI:10.1002/jctb.5010111204

出版商:John Wiley&Sons, Ltd    

年代:1961

数据来源: WILEY

摘要:

AbstractThe influence of some non‐ionic organic additives, dissolved in the water used for mixing cement pastes, on cement hydration was determined by isothermal calorimetry. The additives, all poly‐alcohols, exert a retarding action on cement hydration. Glycerol has, in addition, a particular influence on the crystallisation of ettringite and calcium hydroalumino‐monosulphate, accelerating the consumption of sulphate

ISSN:0021-8871    

DOI:10.1002/jctb.5010111205

出版商:John Wiley&Sons, Ltd    

年代:1961

数据来源: WILEY

摘要:

AbstractElectrolytes with monomer and polymer organic cations act predominantly like the corresponding sodium salts in the same concentration. Electrolytes with organic anions vary in action from a retardation of ettringite crystallisation only (sodium oleate) to a complete inhibition of all hydration reactions during the first days polymer anions especially have a very strong effect.The results are in accordance with the concept of a positive surface charge on hydrating cement particles as well as on the hydration products.

ISSN:0021-8871    

DOI:10.1002/jctb.5010111206

出版商:John Wiley&Sons, Ltd    

年代:1961

数据来源: WILEY

摘要:

AbstractEquilibrium distribution data at 20° are presented for three ternary liquid systems having aliphatic amines as solutes. For the low range of solute concentrations considered, the distribution ratio for each system varies appreciably. This is shown to be due largely to the effect of partial dissociation of the solute amines in the aqueous phase, and the equilibrium data are correlated successfully from a consideration of this effect

ISSN:0021-8871    

DOI:10.1002/jctb.5010111207

出版商:John Wiley&Sons, Ltd    

年代:1961

数据来源: WILEY