摘要:

AbstractThe suitability of clinker‐activated high‐slag cement mortars for use in brickwork construction and in rendered finishes, has been investigated. The study was carried out on a slag cement composed of 80% granulated slag, 15% clinker and 5% raw gypsum; its specific surface area was 4000 cm2/g. It was found that the slag cement mortars and cement‐lime mortars of the proportions commonly used in practice, have higher water‐retentivity than the corresponding mortars of ordinary Portland cement, and that their strengths are comparable to those of the latter

ISSN:0375-9210    

DOI:10.1002/jctb.2720240902

出版商:John Wiley&Sons, Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractThe coating properties and ion‐exchange performance of powdered ion‐exchange resins were examined in a small test facility. Satisfactory resin coatings were obtained with cation : anion resin ratios in the range 1 : 1 to 3 : 1, but a 9 : 1 resin ratio resulted in a high pressure drop across the coating. The “settled resin volume” proved to be a reliable guide to the coating performance of resin slurries. The ion‐exchange capacity of the cation resin increased from 2.5 to 2.8 equiv./kg as the sodium concentration in the influent decreased from 49 to 0.5 mg 1−1. Within the ranges examined, resin ratio, resin loading and flowrate had no significant effect on cation capacity. The ion‐exchange capacity of the anion resin for chloride ions was 2.2 to 2.3 equiv/kg at ambient temperature but exposure of the resin for four days at 80 °C reduced the capacity to 1.6 equiv./kg; four days at 90 °C reduced the capacity to less than 1 equiv./kg. The thermal stability of the powdered anion resin was markedly less than that quoted elsewhere for anion bead resin. The stability of the floc was al

ISSN:0375-9210    

DOI:10.1002/jctb.2720240903

出版商:John Wiley&Sons, Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractWheno‐dichlorobenzene was carboxylated with carbon monoxide in presence of water at high pressure the conversions to phthalic acid and benzoic acid at the optimum reaction conditions were 6.20% and 35.80% respectively without any catalyst, while with a catalyst (nickel iodide on silica gel; Ni : SiO2= 50 : 50) these conversions were 8.90% and 39.85% respectively. Use of catalyst reduced the optimum temperature and pressure for the conversion to phthalic acid, while it reduced the optimum pressure and residence period for the conversion to benzoic aci

ISSN:0375-9210    

DOI:10.1002/jctb.2720240904

出版商:John Wiley&Sons, Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractThe sintering of platinum black catalyst in different atmospheres, namely, nitrogen, oxygen and hydrogen was studied in the temperature range 300‐600 °C.The rate of sintering was found to differ in different atmospheres; it is the least in oxygen, whereas in nitrogen the sintering seems to be much facilitated and in hydrogen the rapid de‐activation becomes much more pronounced.Analysis of the kinetic results showed that the sintering process follows the first order equation in nitrogen andin vacuo, and follows the second order equation in oxygen and hydrogen atmospheres.The activation energy of the sintering process, calculated from the Arrhenius equation, was found to be 2.9, 3.7 and 13 k cal/mol in hydrogen, oxygen and nitrogen respectively, as obtained from the activity measurements, and 3, 3.5 and 12.5 respectively, as obtained from the surface measurements. An interpretation was given for the high activation energy of sintering in nitrogen in view of compound formation on the sur

ISSN:0375-9210    

DOI:10.1002/jctb.2720240905

出版商:John Wiley&Sons, Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractIn the present investigation, the effect of three process variables viz., air rate, temperature and time of oxidation has been studied to determine the possibility of making paving bitumens from North Rumaila Crude Oil. In order to have flexibility in the choice of proper feedstock for bitumen production, the effect of these process parameters was studied on three different vacuum residues. Air rate and temperature of oxidation were optimised to produce a bitumen product having less temperature susceptibility. The composition studies of typical feeds and oxidised products indicate that mainly “saturates” components get converted to “asphaltics” on air

ISSN:0375-9210    

DOI:10.1002/jctb.2720240906

出版商:John Wiley&Sons, Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractThe effect of pigment volume concentration upon the leaching of soluble pigments from insoluble binders has been studied and the results used to extend a previously described1theoretical treatment. The number of interconnecting holes between the cavities left after solution of the pigment from the insoluble binder is assumed to be related to the pigment volume concentration in a similar way to the number of contacts made by smooth spheres regularly packed at the same solids content. An empirical equation is used to relate the number of contacts made between spheres to their density of packing, and consequently to relate the number of interconnecting holes between cavities to the pigment volume concentration.Predictions based on the resulting relationship are compared with the leaching characteristics measured for three different coating compositions, each made with a range of pigment volume concentrations using two different vinyl resins and two grades of copper (I) oxide pigment. The predicted variations with pigment volume concentration of initial leaching rate, and of initial rates of decrease in leaching rates, hold reasonably well for pigment volume fractions between 0.30 and 0.80, the full range studied. Longer term leaching behaviour appears predictable only for paints of pigment fractions above about 0.45; anomalies below this figure are attributed to lack of pigment solution.Statistical analysis of experimental leaching rate data indicate that the initial leaching rates are unaffected within limits by the type of binder and pigment. The two copper oxide pigments used behaved similarly. However, the kind of binder used does affect the rate of decrease in leaching rate. The experimental data is consistent with the theoretical model employed and with the concept that the thickness of binder separating pigment particles and hence the interconnecting hole size remains approximately constant irrespective of pigment volume concentration.

ISSN:0375-9210    

DOI:10.1002/jctb.2720240907

出版商:John Wiley&Sons, Ltd    

年代:1974

数据来源: WILEY

摘要:

AbstractMany sterilisation techniques are available which rely on physical chemical processes, the final choice being dictated by the particular application. The electrohydraulic discharge technique was investigated with the aim of optimising bacterial inactivation in a variety of aqueous fluids. Discharges were produced between two submerged electrodes by the rapid release of electrical energy stored in a capacitor. Variations in optical density of the fluid undergoing treatment greatly influenced the degree of cellular inactivation and it is postulated that U.V. radiation from the discharge is the principal bactericidal agent.

ISSN:0375-9210    

DOI:10.1002/jctb.2720240908

出版商:John Wiley&Sons, Ltd    

年代:1974

数据来源: WILEY

ISSN:0375-9210    

DOI:10.1002/jctb.2720240901

出版商:John Wiley&Sons, Ltd    

年代:1974

数据来源: WILEY