摘要:

The rate of dehydration of copper sulphate pentahydrate has been determined over a range of low pressures of water vapor. It has been found that as the pressures are increased, the rate at first drops very rapidly; this drop is followed by a period of marked acceleration, which is followed in turn by a gradual decline. Copper sulphate pentahydrate has been found to be similar in this respect to manganous oxalate dihydrate, which has been hitherto regarded as unique in its behavior. The observed effects are probably due to amorphous to crystalline transitions occurring during induction periods, the durations of which have also been found to depend on water vapor pressure.

ISSN:0008-4042    

DOI:10.1139/v53-015

出版商:NRC Research Press    

年代:1953

数据来源: NRC

摘要:

The fission yield of I131has been investigated using improved extraction techniques and disintegration rate measurements. The value obtained for the fission yield is (3.1 ± 0.1)%. This is relative to a Ba140reference fission yield of 6.1%. The half-life for I131has been determined and found to be 8.05 ± 0.01 days.

ISSN:0008-4042    

DOI:10.1139/v53-016

出版商:NRC Research Press    

年代:1953

数据来源: NRC

摘要:

Feedingdl-tyrosine-2-C14to sprouting barley resulted in the formation of radioactive hordenine and N-methyltyramine in the roots. Isolation and degradation of these alkaloids showed that all the activity was located in the α-carbon atom of the side chain, thus indicating that tyrosine is a precursor of N-methyltyramine and hordenine.

ISSN:0008-4042    

DOI:10.1139/v53-017

出版商:NRC Research Press    

年代:1953

数据来源: NRC

摘要:

The main products of this reaction were hydrogen cyanide and polymer that contained approximately 32% nitrogen. Yields of these substances increased to constant values with increase of acetylene flow rate. Some cyanogen and methane were also formed. The yield of cyanogen passed through a maximum with increased flow rate of acetylene, but the methane yields were quite erratic.

ISSN:0008-4042    

DOI:10.1139/v53-018

出版商:NRC Research Press    

年代:1953

数据来源: NRC

摘要:

Extraction of wheat straw holocellulose with 4% potassium hydroxide removed a polysaccharide fraction containingD-xylose (77.2%),L-arabinose (6.9%), and uronic acid anhydride (7.9%). Hydrolysis of this polysaccharide with dilute acid produced a degraded polysaccharide which was precipitated by ethanol after removing freeD-xylose from the hydrolyzate by fermentation withHansenulasuaveolans. Prolonged hydrolysis of the degraded polysaccharide yielded an aldobiuronic acid which was shown to be 3-(xylopyranosyl)-α-D-glucuronopyranoside. The β-isomer of this compound was synthesized fromD-glucurone andD-xylose and its structure was confirmed by degradative studies after methylation. The enzyme β-glucuronidase did not hydrolyze the α- or β-isomers of this aldobiuronic acid.

ISSN:0008-4042    

DOI:10.1139/v53-019

出版商:NRC Research Press    

年代:1953

数据来源: NRC

摘要:

An advantage of determining cobalt with 1-nitroso-2-naphthol is that the reagent is relatively stable and forms a very stable cobalt complex. Also this cobalt complex has maximum absorption in the visible spectrum which allows determination visually or with ordinary colorimeters.The procedure is based on decreasing the iron interference by the removal of part of the iron as phosphate and on a simple purification of the carbon tetrachloride solution of the 1-nitroso-2-naphthol cobalt complex which eliminates traces of palladium, iron, etc.The method has the same order of accuracy as theo-nitrosocresol method but preparation of reagents and the analysis in general require less time.

ISSN:0008-4042    

DOI:10.1139/v53-020

出版商:NRC Research Press    

年代:1953

数据来源: NRC

摘要:

The diffusion coefficient of polyisobutylene inn-heptane has been found to decrease at first, then to increase with increasing molecular weight.

ISSN:0008-4042    

DOI:10.1139/v53-021

出版商:NRC Research Press    

年代:1953

数据来源: NRC

摘要:

Silver acetate-d3and bromine react readily in the dry state in a sealed tube to give methyl-d3bromide in high yield. This method is more convenient than the reduction of carbon dioxide to deuterated methyl alcohol with lithium aluminum deuteride, followed by the conversion of the alcohol into the halide, or other methods hitherto reported.

ISSN:0008-4042    

DOI:10.1139/v53-022

出版商:NRC Research Press    

年代:1953

数据来源: NRC

摘要:

The photolysis of acetone – hydrogen chloride mixtures has been investigated at 150 °C. and at room temperature. A strong suppression of ethane formation with a corresponding large increase in the formation of methane results from additions of relatively very small amounts of hydrogen chloride to acetone. The importance of the reactionsandhas been demonstrated. The collision yield of reaction (1) at 28 °C. is 2 × 10−4, and, therefore, the upper limit for E1is 5.1 kcal. per mole. The effects observed at 150° and 28° indicate that, on the assumption of a zero activation energy and a steric factor of unity for combination of methyl radicals, E1 = 2.1 ± 1 kcal. per mole, andP1is approximately 7 × 10−3.

ISSN:0008-4042    

DOI:10.1139/v53-023

出版商:NRC Research Press    

年代:1953

数据来源: NRC

摘要:

Additions of carbon tetrachloride to acetone show in photolysis an apparent anomaly: methane formation is strongly increased and the formation of ethane correspondingly lowered. In this manner a hydrogen abstraction reaction is simulated. The cause of the anomaly and its bearing on the photolysis of acetone with other chlorinated methanes has been investigated.

ISSN:0008-4042    

DOI:10.1139/v53-024

出版商:NRC Research Press    

年代:1953

数据来源: NRC