摘要:

AbstractSilica gels were prepared under various conditions from sodium silicate and two organic silicates. The gels prepared by the hydrolysis of ethanolamine polysilicate were less active than those obtained from sodium silicate, but a gel with a substantial surface area was prepared by the slow hydrolysis in acid solution of isopropyl silicate.Adsorption isotherms of benzene and ethanol were determined gravimetrically on samples of the gels at temperatures between 0° and 35°. Evidence is presented to show that the Brunauer‐Emmett‐Teller (B.E.T.) values of the monolayer capacity for ethanol are more reliable than those for benzene. For most gels, the area occupied by the ethanol molecule in the adsorbed monolayer appears to be close to

ISSN:0021-8871    

DOI:10.1002/jctb.5010110901

出版商:John Wiley&Sons, Ltd    

年代:1961

数据来源: WILEY

摘要:

AbstractAlthough methods have been published for the measurement of traces of H2S in air, no mention is made of their reaction to SO2, which is invariably present in the atmosphere, particularly in industrial areas, in concentrations vastly in excess of that of the H2S. In some cases, the calibration and ultimate limits of detection of the methods are also in doubt. The work described here includes a critical practical appraisal of five alternative methods with respect to interference by SO2, maximum flow rate and limit of detection and their accurate calibration to low levels by both volumetric and gas dilution techniques. Modifications to eliminate interference by SO2are also described.A description is given of a simple portable field apparatus capable of measuring concentrations of H2S down to 10−4p.p.m. in a 2 h. sampling period, together with typical levels found when using i

ISSN:0021-8871    

DOI:10.1002/jctb.5010110902

出版商:John Wiley&Sons, Ltd    

年代:1961

数据来源: WILEY

摘要:

AbstractThe effect of film losses by evaporation on the spreading characteristics of hexadecanol crystals is examined. It is shown that steady‐state pressures lower than the equilibrium spreading pressure are exhibited and that these are dependent on the ratio of crystal perimeter to film area. The results have been used to evaluate the spreading constant over a range of pressure

ISSN:0021-8871    

DOI:10.1002/jctb.5010110903

出版商:John Wiley&Sons, Ltd    

年代:1961

数据来源: WILEY

摘要:

AbstractThe composition of the benzole in the gas during the carbonising cycle of a coke oven has been investigated by gas‐liquid chromatography. The results show that paraffins and naphthenes are mainly produced early in the cycle, whereas the maximum benzene concentration occurs much late

ISSN:0021-8871    

DOI:10.1002/jctb.5010110904

出版商:John Wiley&Sons, Ltd    

年代:1961

数据来源: WILEY

摘要:

AbstractInfra‐red spectroscopy provides a sure, rapid method of identifying textile fibres and pure fabrics. A simple standard method of sample preparation using only a few milligrams of powdered material in a potassium bromide disc is outlined. Representative spectra are published, and the identifying features of each curve are briefly discusse

ISSN:0021-8871    

DOI:10.1002/jctb.5010110905

出版商:John Wiley&Sons, Ltd    

年代:1961

数据来源: WILEY

摘要:

AbstractA number of amino‐ and carboxyl‐substituted diaryl‐phosphine oxides have been prepared and converted into polyamides. Some esters of vinyl‐ and allyl‐phosphonic acid have also been prepared and converted into addition

ISSN:0021-8871    

DOI:10.1002/jctb.5010110906

出版商:John Wiley&Sons, Ltd    

年代:1961

数据来源: WILEY

摘要:

AbstractAn experimental method has been developed which is capable of measuring the unsteady‐state molecular flow of small volumes of gas from a micro‐porous solid such as are encountered under thermal conditions unfavourable to adsorption. Two new computational procedures, which do not use the severe simplifying assumptions of existing methods, are described for evaluating diffusivities from unsteady‐state diffusion data. They are applied to some experimental results on the diffusion rates of several gases from synthetic zeo

ISSN:0021-8871    

DOI:10.1002/jctb.5010110907

出版商:John Wiley&Sons, Ltd    

年代:1961

数据来源: WILEY