摘要:

Yeast grown in an inadequately buffered medium may yield a good crop, but the phosphatase content of the yeast obtained is considerably lower than that of yeast grown in a buffered medium. Wide variations in the magnesium concentration of the growth medium have little effect on the phosphatase content of the yeast obtained. Low phosphate concentrations in tomato juice medium result in a yeast with high phosphatase content.

ISSN:1923-4287    

DOI:10.1139/cjr42b-029

出版商:NRC Research Press    

年代:1942

数据来源: NRC

摘要:

The system ethanol-methanol was studied at 40 °C. using the original and also a modified form of the apparatus of Ferguson and Funnell. The total pressure curve is linear and the partial pressure curves agree with Raoult's law within the experimental error.

ISSN:1923-4287    

DOI:10.1139/cjr42b-030

出版商:NRC Research Press    

年代:1942

数据来源: NRC

摘要:

The effect of addition agents on syneresis of silica gel is reviewed. Various methods of measurement of syneresis have been investigated and a convenient method that gave duplicate results agreeing within 1.2% is described. The effect of a series of alcohols—methyl, ethyl, glycol, glycerol, and erythritol—on syneresis has been studied. The results indicate that the total volume of syneretic liquid at equilibrium was the same as that of the control (within the experimental error) and that no adsorption had taken place in the gel itself. The data on the adsorption of the alcohols was determined by analysis of the syneretic liquid for its alcohol concentration by an oxidation method using chromic acid.

ISSN:1923-4287    

DOI:10.1139/cjr42b-031

出版商:NRC Research Press    

年代:1942

数据来源: NRC

摘要:

Studies of nitrile hydrolysis in concentrated acid media have been extended to the hydrolysis of hydrocyanic acid, acetonitrile, and cyanoacetic acid in hydrochloric acid solutions of concentration 1 to 8.5 N. It appears that the hydrolysis of aliphatic nitriles in concentrated sulphuric and hydrochloric acids provides systems of consecutive, irreversible unimolecular reactions over the complete rangeknitrilekamide(more dilute acid) toknitrilekamide(highly concentrated acid), for a sufficient range of acid concentrations. The limit,knitrilekamide, is not attained in hydrobromic acid solutions. The nitriles studied here exhibit a large decrease in activation energy with increase of acid concentration, similar to that observed earlier for propionitrile. The magnitude of the variation of the Arrhenius parameters is specific for each nitrile. For the acetonitrile hydrolysis, the increase in rate with increase of acid concentration largely follows the accompanying activation energy decrease. The relative rates of hydrolysis of different nitriles, at given acid concentration, are not governed by differences in activation energy. The variation of activation energy is briefly discussed in relation to certain other factors.

ISSN:1923-4287    

DOI:10.1139/cjr42b-032

出版商:NRC Research Press    

年代:1942

数据来源: NRC