ISSN:0021-8871    

DOI:10.1002/jctb.5010051010

出版商:John Wiley&Sons, Ltd    

年代:1955

数据来源: WILEY

摘要:

AbstractWhen an equimolar mixture of dimethylphosphoramidic dichloride and hexamethylphosphoramide is heated (120–200°), radical exchange (NMe2for Cl) takes place and tetramethylphosphorodiamidic chloride is formed. This radical exchange follows a first‐order reaction at 120°. An equimolar mixture of the dichloride and the amide undergoes polymerisation at room temperature, and after 6–8 days solidifies to a crystalline mass. This mass appears to be a mixture of a salt‐like addition product of the dichloride and the amide approaching a hexameric state, and the unchanged dichloride and amide. On heating, it undergoes radical exchange with the formation of tetramethylphosphorodiamidic chloride which yields bisdimethylaminophosphonous anhydride (schradan) on treatment with potassium hydroxide in

ISSN:0021-8871    

DOI:10.1002/jctb.5010051001

出版商:John Wiley&Sons, Ltd    

年代:1955

数据来源: WILEY

摘要:

AbstractThe isomer distribution in the C6‐hydrocarbons from synthesis products has been shown to be markedly dependent on the temperature at which synthesis is effected, and it has been established that this result is not due to secondary isomerization of the initial reaction product

ISSN:0021-8871    

DOI:10.1002/jctb.5010051002

出版商:John Wiley&Sons, Ltd    

年代:1955

数据来源: WILEY

摘要:

AbstractThe size of gas bubble produced from an open‐ended tube immersed in a liquid can be derived by equating surface tension and buoyancy forces. The equations do not apply, however, when the gas flow is large as in many industrial fermentations, and porous elements are therefore often used to provide many orifices and a low gas‐flow through each. Even this technique fails if a mycelial growth is formed during the fermentation because the bubbles coalesce in the fermenter. Mechanical agitation was examined by the author by measuring gas‐to‐liquid transfer rates using paper pulp to imitate the mycelium, since this was found to interfere chemically with the reaction. Without agitation, the paper pulp reduced the transfer rate by a factor of twenty. With simple paddle agitation in conjunction with a sparge ring, the effect of pulp was reduced to a factor of seven but with a high‐speed agitator used with an open tube gas inlet, the factor was reduc

ISSN:0021-8871    

DOI:10.1002/jctb.5010051003

出版商:John Wiley&Sons, Ltd    

年代:1955

数据来源: WILEY

摘要:

AbstractAn ultracentrifugal examination of groundnut protein treated with various bases has been made. It has been shown that only bases with a dissociation constant higher than about 10−1cause an appreciable reduction in the molecular weight of the protein and are suitable for fibre formation with the protei

ISSN:0021-8871    

DOI:10.1002/jctb.5010051004

出版商:John Wiley&Sons, Ltd    

年代:1955

数据来源: WILEY

摘要:

AbstractWhen reactions in non‐isothermal systems are treated kinetically, complicated differential equations arise, as well as ‘integral rate constants’ of the form\documentclass{article}\pagestyle{empty}\begin{document}$ \mathop \smallint \limits_o^t $\end{document}k(t)dt. Methods are described for evaluating the integrals and for solving numerically the differential equations which are obtained for both reversible and irreversible reac

ISSN:0021-8871    

DOI:10.1002/jctb.5010051005

出版商:John Wiley&Sons, Ltd    

年代:1955

数据来源: WILEY

摘要:

AbstractAn isopiestic technique has been used for observing the static control of humidity by saturated salt solutions and by paired salt hydrates. Many new values within the range 7% to 60% relative humidity at 25°C have been obtained, using saturated solutions of highly soluble salts. Difficulties encountered in using paired salt hydrates to control humidity at low levels have been described

ISSN:0021-8871    

DOI:10.1002/jctb.5010051006

出版商:John Wiley&Sons, Ltd    

年代:1955

数据来源: WILEY

摘要:

AbstractA method of evaluating the temperature drop across a condensate film is evolved, based on the fact that for many substances the group of physical constants (k3p2λg/μ)1/4appearing in the Nusselt equation is nearly independent of temperature. A graphical solution will give the desired temperature drop, thus eliminating trial‐and‐error me

ISSN:0021-8871    

DOI:10.1002/jctb.5010051007

出版商:John Wiley&Sons, Ltd    

年代:1955

数据来源: WILEY

摘要:

AbstractThe effects of a number of factors on the rate of solution of oxygen in fresh and saline water were investigated experimentally to provide information about re‐aeration in a polluted estuary.It was shown that stirring the water at different speeds with impellers or forcing air streams of different velocities tangentially over the surface caused relatively gradual changes in the rates of solution, measured as exit coefficients, until the surface became visibly disturbed. Thereafter there was a much more rapid increase in rate of solution with increasing rate of stirring or wind velocity.Increasing the height and frequency of stable progressive waves and the height of choppy waves generated mechanically in the water caused an approximately linear increase in rate of solution.Under different conditions of surface agitation the rate of solution increased linearly with increasing temperatures in the range 0–35°. The temperature coefficients, defined as the increase in rate of solution expressed as a percentage of the value at 20°, per degree Centigrade increase in temperature had a mean value of 2.37.Oil films on the surface of the water caused little effect until the thickness of the film exceeded 10−4cm. A soluble surface contaminant, on the other hand, caused considerable reductions in the rate of solution, which increased with increasing concentration of the contaminant but which tended to a limitin

ISSN:0021-8871    

DOI:10.1002/jctb.5010051008

出版商:John Wiley&Sons, Ltd    

年代:1955

数据来源: WILEY

摘要:

AbstractThe specific gravity‐temperature coefficients of a wide range of coal tars were correlated with the specific gravity (S.G.) by the formula\documentclass{article}\pagestyle{empty}\begin{document}$$ d({\rm S}{\rm .G}{\rm .})/{\rm d}t = 0.001778 - 0.000980({\rm S}{\rm .G}{\rm .}) $$\end{document}A similar relationship for coal tar distillates could not be derived, but it was found possible to correlate their coefficients with their mean (or 50%) boiling points as\documentclass{article}\pagestyle{empty}\begin{document}$$ d({\rm S}{\rm .G}{\rm .})/{\rm d}t = 0.001477 - 0.000322\,\log (T - 60). $$\end{document}The data for pure hydrocarbons are in agreement with this empirical relationshi

ISSN:0021-8871    

DOI:10.1002/jctb.5010051009

出版商:John Wiley&Sons, Ltd    

年代:1955

数据来源: WILEY