摘要:

AbstractThe phase, composition of the previously prepared three hardened highly refractory basic cements (dolomitic magnesite, periclase and dolomitic magnesite chrome) was established by the aid of d.t.a., t.g.a., microscopic examination, electron microscopy and X‐ray analysis.The following properties of these cements were determined: compressive strength, apparent porosity, linear shrinkage and ignition loss. These parameters were measured for each cement after 3 days air curing at ∼ 60% r.h. and after heating these cements to 110°, 450°, 600°, 800° and 1200°C.The variation in these parameters as a function of temperature was correlated in the light of their componen

ISSN:0375-9210    

DOI:10.1002/jctb.5020210501

出版商:John Wiley&Sons, Ltd    

年代:1971

数据来源: WILEY

摘要:

AbstractSodium silicate solutions with a silicon dioxide:sodium monoxide mole ratio of 3.41:1 were dried gently to give amorphous solids. These solids, together with the products obtained by heating them at various temperatures up to ∼ 200°c, were studied by differential thermal analysis, solubility tests and other techniques. The resultant data give some insight into the structural changes which occur in the solid during the drying proce

ISSN:0375-9210    

DOI:10.1002/jctb.5020210502

出版商:John Wiley&Sons, Ltd    

年代:1971

数据来源: WILEY

摘要:

AbstractThe friction and constant drop of a single fibre, acting as a brush, was measured, the fibre acting as its own dynamometer. Under such conditions, no co‐operative effects between adjacent fibres could occu

ISSN:0375-9210    

DOI:10.1002/jctb.5020210503

出版商:John Wiley&Sons, Ltd    

年代:1971

数据来源: WILEY

摘要:

AbstractA method of comparing adsorption data, obtained for samples within a series and having similar surface characteristics, is described. It is shown that the surface interaction with polar molecules increases quite markedly as the polar nature of the surface changes. The use of a non‐polar molecule established that the effects observed were genuin

ISSN:0375-9210    

DOI:10.1002/jctb.5020210504

出版商:John Wiley&Sons, Ltd    

年代:1971

数据来源: WILEY

摘要:

AbstractA study has been made of the stability of porous α‐aluminá‐based catalysts subjected to carbon deposition during the catalytic oxidation of methane. The most important factor in determining the stability, defined as the time taken before mechanical disintegration of the catalyst begins, was found to be the mechanical strength of the alumina. The stability was directly proportional to the mechanical str

ISSN:0375-9210    

DOI:10.1002/jctb.5020210505

出版商:John Wiley&Sons, Ltd    

年代:1971

数据来源: WILEY

摘要:

AbstractThe kinetics of absorption of isobutylene in acetic acid in the presence of concentrated sulphuric acid (98 wt.‐%) as catalyst, which results in the formation of t‐butyl acetate, was studied in a 10‐cm i.d. agitated glass reactor. The solubility of isobutylene in acetic acid and t‐butyl acetate was determined experimentally. The reaction is relatively slow and the diffusional factors could be completely eliminated. The values of the second‐order reaction rate constant were 0.82 and 2.7 cm3mole−1sec−1at 20° and 40°

ISSN:0375-9210    

DOI:10.1002/jctb.5020210506

出版商:John Wiley&Sons, Ltd    

年代:1971

数据来源: WILEY

摘要:

AbstractThe characterisation of hydrocarbon and natural waxes by differential scanning calorimetry is described. It is shown that the determination of the melting, cooling and remelting curves of a wax, and comparison with the corresponding curves of authenticated waxes, affords a rapid and valuable method for the identification of many waxes. Heats of transition of many waxes are also given.

ISSN:0375-9210    

DOI:10.1002/jctb.5020210507

出版商:John Wiley&Sons, Ltd    

年代:1971

数据来源: WILEY