摘要:

AbstractA study was made of the effects of variations in concentration (0.125–0.75 saturated) and temperature (3–50°C) on the amounts of sodium incorporated in crystals of calcium sulphate dihydrate formed by the hydration of calcium sulphate hemihydrate in solutions of sodium chloride. The incorporation of sodium was favoured by reducing the temperature and increasing the concentration of sodium chloride. Samples of dihydrate containing sodium gave X‐ray diffraction patterns with additional peaks that were attributed to the presence of a compound of calcium sulphate containing sodium but resembling the hemihydrate crystallographically. This compound appeared to occur as inclusions within the grains of dih

ISSN:0375-9210    

DOI:10.1002/jctb.5020251002

出版商:John Wiley&Sons, Ltd    

年代:1975

数据来源: WILEY

摘要:

AbstractThe distribution of isomers in mononitration of toluene is demonstrated to be dependent upon the properties of the solvents involved. An empirical model has been derived to relate the isomer ratio with the dipole moments and dielectric constants of the solvents. Based on this observation, an investigation into the effect of electric field on the distribution of isomers in continuous mononitration of toluene has been carried out.

ISSN:0375-9210    

DOI:10.1002/jctb.5020251003

出版商:John Wiley&Sons, Ltd    

年代:1975

数据来源: WILEY

摘要:

AbstractNew cyclohexenyl alkenyl ketones are prepared by the reaction of various methyl cyclohexenyl carboxylates and vinylmagnesium chloride; for example, 1‐(4′‐methyl‐3′‐cyclohexene‐1′‐yl)‐1‐oxo‐4‐pentene is obtained from methyl 4‐methyl‐3‐cyclohexene‐1‐carb

ISSN:0375-9210    

DOI:10.1002/jctb.5020251004

出版商:John Wiley&Sons, Ltd    

年代:1975

数据来源: WILEY

摘要:

AbstractA systematic study has been made of the synthesis of dipropylaniline from aniline and n‐propanol using H2SO4and HCl as catalysts. With both catalysts, the optimum temperature, pressure, residence period, mole ratio of aniline to n‐propanol and mole ratio of aniline to H+(catalyst) for the synthesis are 245°C, 600 lb/in2, 2 h, 1:3 and 1:0.305 respectively. Very high pressure has practically no influence on the reaction and it helps only to form undesirable tarry matter. The maximum conversions of aniline to dipropylaniline under these optimum conditions are 45.53 and 46.57% with H2SO4and HCl respectively. The conversion of aniline to propylaniline is always found to be greater than conversion to dipropylaniline. At the optimum conditions for the synthesis of dipropylaniline, conversions of aniline to propylaniline are 47.75% with H2SO4and 51.55% with

ISSN:0375-9210    

DOI:10.1002/jctb.5020251005

出版商:John Wiley&Sons, Ltd    

年代:1975

数据来源: WILEY

摘要:

AbstractThe u.v. absorption spectra of 22 monosubstituted and 19 disubstituted benzoic acids have been studied in water or aqueous dioxan over a pH range of about 1–8. The isosbestic points have been measured and the results are discusse

ISSN:0375-9210    

DOI:10.1002/jctb.5020251006

出版商:John Wiley&Sons, Ltd    

年代:1975

数据来源: WILEY

摘要:

AbstractPlatinum/charcoal and nickel/chromium oxide catalysts for the isotopic exchange of deuterium between hydrogen and water vapour were prepared under optimum experimental conditions. The catalytic activity determination of both indicated higher activity for Pt/charcoal than for Ni/Cr2O3. BET measurements of the specific surface area and pore structure showed higher values for Pt/charcoal than for Ni/chromia. Chemisorption data of both catalysts allowed the determination of the specific metallic surface area, the degree of dispersion and the average particle size of the supported metals. A comparison between the results of the catalytic activity, BET measurements and chemisorption was made and indicated close agreement.

ISSN:0375-9210    

DOI:10.1002/jctb.5020251007

出版商:John Wiley&Sons, Ltd    

年代:1975

数据来源: WILEY

摘要:

AbstractIn the hydrogenolysis of methoxy‐substituted benzylic alcohols side reactions of demethoxylation and ring saturation can occur under mild conditions which depend on the activity of the palladium–carbon catalyst used. Chromato‐graphic and spectroscopic examination of reaction products is desirable to find the extent of by‐product fo

ISSN:0375-9210    

DOI:10.1002/jctb.5020251008

出版商:John Wiley&Sons, Ltd    

年代:1975

数据来源: WILEY

摘要:

AbstractThe densities of the urea synthesis solution in chemical equilibrium have been measured over the ranges 2.04 ⪕ NH3/CO2⪕ 6.3, H2O/CO2=0, 150 ⪕T⪕TcriticalandPbuble–point⪕P⪕ 900 atm. In the temperature and composition range of, respectively, 150 ⪕T⪕ (Tcritical–20°C) and 2.7 ⪕ NH3/CO2⪕ 6.3, it is possible to describe accurately the experimental results by means of an empirical equation based on regression analysis. Experiments suggest that at high temperatures near critical conditions the chemical composition of the urea synthesis solution becomes a str

ISSN:0375-9210    

DOI:10.1002/jctb.5020251009

出版商:John Wiley&Sons, Ltd    

年代:1975

数据来源: WILEY

摘要:

AbstractBy means of chemostat culture and automatic control of pH and dissolved oxygen tension the penicillin fermentation was controlled so that the partial pressure of carbon dioxide (Pco2) in the gas phase was the only variable. This reveals that under the conditions used carbon dioxide strongly inhibits penicillin production. The synthesis rate (units/mg dry mycelium x h) was decreased about 50% by aPco2of 0.08 atm.

ISSN:0375-9210    

DOI:10.1002/jctb.5020251010

出版商:John Wiley&Sons, Ltd    

年代:1975

数据来源: WILEY

摘要:

AbstractA simple, non‐aseptic, submerged aerobic fermentation was sought in which microbial protein could be synthesised from non‐protein nitrogen, at the expense of barley carbohydrate, to supplement the protein content of barley grain for non‐ruminant feeding. Screening of 23 isolates of fungi in shake flask cultures showed that microbial protein could be successfully produced by a number of different species in a medium containing barley as a source of carbohydrate. Protein synthesis was markedly affected by the addition of different sources of non‐protein N to the fermentation; and (NH4)2SO4or urea proved to be good N sources in this respect.Aspergillus oryzaewas selected as the most suitable species for protein synthesis, based on its performance when supplemented with the various N sources. The growth rate ofA. oryzaein stirred culture was such that high yields of mycelial protein could be achieved within 24 h from a culture inoculated with a spore suspension. Under the conditions of growth used in these experiments there appeared to be little advantage in adding more than 2% barley to the medium. Higher yields of protein could be achieved at barley concentrations in excess of 2%, but only if the incubation period was extended. The tolerance ofA. oryzaeto low pH values was exploited to enable fungal cultures to be grown under non‐aseptic conditions. Good yields of protein were obtained in 40 litre cultures grown at pH 3.5 in a modified domestic washing machine. Although protein yields were poor, non‐aseptic growth was also sucesssful at pH 3.5 in 1000 litre cultures grown in an agricultural feed‐

ISSN:0375-9210    

DOI:10.1002/jctb.5020251011

出版商:John Wiley&Sons, Ltd    

年代:1975

数据来源: WILEY