摘要:

AbstractThe separation of 6·6 mg of229Th from 400 g of233U is described. The process involves the preferential extraction of233U from an aqueous solution in nitric acid into dibutyl carbitol and the purification of the thorium left in the aqueous phase by ion exchange. Thorium recovery was 91% and the thorium was decontaminated from uranium by a factor of at least 4 × 10

ISSN:0021-8871    

DOI:10.1002/jctb.5010190801

出版商:John Wiley&Sons, Ltd    

年代:1969

数据来源: WILEY

摘要:

AbstractA silica sol was frozen and then thawed yielding a suspension of plate‐like silica which when dried gave a sample which was almost entirely composed of micropores. The silica aged when left to stand in the laboratory, but reached a constant value of activity after a period of about six months or less. No apparent change in microporosity occurred during the ageing process.Several selected samples were sintered at temperatures up to 800° at which point virtually all the adsorption capacity of the adsorbent was destroyed leaving adsorption to take place only on the external surfa

ISSN:0021-8871    

DOI:10.1002/jctb.5010190802

出版商:John Wiley&Sons, Ltd    

年代:1969

数据来源: WILEY

摘要:

AbstractThe effect of various additives, and of coating a catalytically active metal surface with polymeric materials, on the formation of autoxidative deposits from hydrocarbon jet fuels at 250–425 °F has been investigated. Various anti‐oxidant additives including alkyl substituted phenols and a phenylenediamine were found to be ineffective in reducing the rate of deposit formation. The use of rust preventive and metal de‐activator additives increased the rate of deposit formation above 350°F. Coating a catalytically active titanium alloy surface with various polymeric materials increased the rate of deposit formation, particularly at temperatures above 35°F. This latter result suggests that these polymeric surfaces are catalytically active for either primary or secondary radical‐producing reactions in the hydrocarbon autoxidation system which leads to the formation o

ISSN:0021-8871    

DOI:10.1002/jctb.5010190803

出版商:John Wiley&Sons, Ltd    

年代:1969

数据来源: WILEY

摘要:

AbstractDiffusion coefficients measured with a flowing junction cell and a wavefront shearing interferometer are reported. These coefficients were correlated with respect to solution concentration for three liquid systems: monoethanolamine‐water, diethanolamine‐water and triethanolamine‐water at 25°. Equations from fundamental electrolytic theory were used as a basis for corre

ISSN:0021-8871    

DOI:10.1002/jctb.5010190804

出版商:John Wiley&Sons, Ltd    

年代:1969

数据来源: WILEY

摘要:

AbstractThe degree of branching of waxes, expressed as the number of branches per 100 carbon atoms, is important because it determines crystallinity, which in its turn influences physical properties. Among several methods available for the study of branching, an infra‐red spectrometric method was chosen. It consisted of the determination of methyl groups. It was also necessary to determine molecular weight.The most serious problem encountered was the variation of the specific absorbance at the chosen frequency (1379 cm−1) with the structural position of the methyl group, which necessitated a thorough qualitative investigation of the branches, using infra‐red, nuclear magnetic resonance and mass spectrometry. It was shown that branches in the Fischer‐Tropsch waxes are almost entirely methyl and that the branching is seemingly distributed statistically along the chains. Calibration was effected with pure n‐ and mono‐methyl paraffins, making the determination of degree of branching possible. This method can be applied to other materials provided that certain structural features about the

ISSN:0021-8871    

DOI:10.1002/jctb.5010190805

出版商:John Wiley&Sons, Ltd    

年代:1969

数据来源: WILEY

摘要:

AbstractXenon‐arc irradiation was used to study the influence of a wide range of radiation intensity on the rate of photo‐oxidation of a sample of air‐blown bitumen as determined by infra‐red spectroscopy. The xenon‐arc was monitored to provide information on its rate of decay, and its range of intensity was compared with that of total solar radiation in Melbourne. Thermal (dark) oxidation rates were also determined at various temperatures. The information obtained is discussed in terms of the mechanism of photo‐oxidation of bitumen and the relation to climatological data. Acceleration factors for oxidation of bitumen in the laboratory for prediction of durability were determined by applying the superposition principle

ISSN:0021-8871    

DOI:10.1002/jctb.5010190806

出版商:John Wiley&Sons, Ltd    

年代:1969

数据来源: WILEY

ISSN:0021-8871    

DOI:10.1002/jctb.5010190807

出版商:John Wiley&Sons, Ltd    

年代:1969

数据来源: WILEY