ISSN:0021-8871    

DOI:10.1002/jctb.5010010101

出版商:John Wiley&Sons, Ltd    

年代:1951

数据来源: WILEY

摘要:

AbstractPoints of technique in the use of the Fuoss‐Mead osmometer, as modified by Masson and Melville, are discussed. In particular, a new criterion is described for the impermeability of the membrane to solute. Older criteria are critically reviewed. Problems of extrapolation of reduced osmotic pressurev. concentration curves are considered, and tentative explanations given for the negative slope sometimes observe

ISSN:0021-8871    

DOI:10.1002/jctb.5010010102

出版商:John Wiley&Sons, Ltd    

年代:1951

数据来源: WILEY

摘要:

AbstractExperiments with polystyrene are described (a) to illustrate the difference between viscosity‐average and number‐average differential distribution curves and (b) to test the nature and the efficiency of the fractionation process. The viscosity‐molecular weight relationship for dilute solutions of high polymers is critically reviewed. Evidence is presented which suggests that during fractionation successive fractions have differing distributions. This indicates a lack of precision in the evaluation of the andKof the Houwink equation, and the absence of objectivity in the method of plotting differential distribution curvesviatheir stepwise and integral c

ISSN:0021-8871    

DOI:10.1002/jctb.5010010103

出版商:John Wiley&Sons, Ltd    

年代:1951

数据来源: WILEY

摘要:

AbstractAn expression is developed for the passage of material through rotating cylindrical kilns or driers, relating the time of passage to the other important variables—slope, length, diameter, and rate of rotation of the kiln, feed rate and rill angle of the material. The expression is derived from fundamentals, and is in accord with previously published empirical relations. It is thought that the derivation will promote a better understanding of the mechanism of the movement of materials in rotary kilns and drier

ISSN:0021-8871    

DOI:10.1002/jctb.5010010104

出版商:John Wiley&Sons, Ltd    

年代:1951

数据来源: WILEY

摘要:

AbstractRelatively simple correlations of the important variables associated with allowable vapour rates in packed columns are presented. These are similar to those already used for the same purpose in connexion with plate columns. The suggested method of calculation of limiting velocity is simpler than those methods derived from correlations of a more complex type which are described in the literature on packed columns; it is nevertheless adequate for preliminary design of columns operating at atmospheric pressure or below.

ISSN:0021-8871    

DOI:10.1002/jctb.5010010105

出版商:John Wiley&Sons, Ltd    

年代:1951

数据来源: WILEY

摘要:

AbstractIt is shown that 2‐ and 4‐tolylsuccinimides, on nitration, form derivatives where the nitro groups occupy positionsmetato the acylamino group, whereas 3‐tolylsuccinimide nitratesortho‐parato the acylamino group; hence the methyl radical is the directing agent in these co

ISSN:0021-8871    

DOI:10.1002/jctb.5010010106

出版商:John Wiley&Sons, Ltd    

年代:1951

数据来源: WILEY

摘要:

AbstractUsing a buffered pyridine electrolyte, sulphur gives a regular polarographic wave suitable for its quantitative determination. A method based on this principle has been developed for the determination of ‘true’ free sulphur in rubber. The method has been compared with gravimetric and volumetric processes, and found to give slightly lower results than either of these, since sulphur combined in any form in the acetone extract is not included. It is particularly suited to routine replicate determinations as it is considerably quicker than older meth

ISSN:0021-8871    

DOI:10.1002/jctb.5010010107

出版商:John Wiley&Sons, Ltd    

年代:1951

数据来源: WILEY

摘要:

AbstractA spinning‐band column which is specially adapted for the vacuum fractionation of fatty‐acid esters is described. Plate‐efficiency tests carried out at 760 mm. and in the range 3.0‐0.5 mm. show that the lowest value for the H.E.T.P. is 2.64 cm. at atmospheric pressure, this value increasing at the lower pressures. Distillation curves for ester mixtures show that the column is very suitable for analytical ester fractionation at pressures of the order

ISSN:0021-8871    

DOI:10.1002/jctb.5010010108

出版商:John Wiley&Sons, Ltd    

年代:1951

数据来源: WILEY

摘要:

AbstractA simple and inexpensive method adaptable to most electric furnaces of reasonable internal dimensions is described. The furnace is converted into an air‐bath of very quick response, controlled with a simple and easily adjustable form of gas‐expansion thermostat. High temperatures may be maintained with very small fluctuation, and trouble from temperature gradients made negligi

ISSN:0021-8871    

DOI:10.1002/jctb.5010010109

出版商:John Wiley&Sons, Ltd    

年代:1951

数据来源: WILEY

摘要:

AbstractThe paper describes an apparatus embodying, in a single unit which can be assembled in a few minutes, all the components necessary to condense, separate automatically and return the solvent and take off the water in azeotropic distillations.The apparatus is suitable for reactions on any reasonable scale using various solvents lighter or heavier than water. Difficulty has been experienced with benzene, but means are suggested for overcoming it.

ISSN:0021-8871    

DOI:10.1002/jctb.5010010110

出版商:John Wiley&Sons, Ltd    

年代:1951

数据来源: WILEY