摘要:

AbstractThe number of possible fibre‐forming high polymers is very great, but the screening of these materials by various tests reduces them to a quite small group of substances suitable for general textile use.The range of available synthetic fibres is discussed and some indication is given of the criteria useful in examining a new fibre‐forming polymer in order to decide its textile util

ISSN:0021-8871    

DOI:10.1002/jctb.5010041001

出版商:John Wiley&Sons, Ltd    

年代:1954

数据来源: WILEY

摘要:

AbstractUranium oxide (U3O8, triuranium octaoxide) of high purity is obtained from pitchblende by converting the uranium into uranyl nitrate, which is extracted by ether containing 3% (w/v) of nitric acid. The ethereal extract is passed through a column of activated cellulose, which retains the impurities present, giving a solution containing pure uranyl nitrate. The recovery of uranium is quantitative (over 99–9%), and the product is of sufficiently high purity to be used as an analytical and spectrographic standar

ISSN:0021-8871    

DOI:10.1002/jctb.5010041002

出版商:John Wiley&Sons, Ltd    

年代:1954

数据来源: WILEY

摘要:

AbstractPhenols, naphthols and benzoic acid can be condensed with boron triacetate under suitable conditions to yield pure orthoborates. With salicylic acid, condensation takes place through the phenolic group, leaving the carboxyl group unaffected. It had been previously reported by Pictet&Geleznoff that dicarboxylic acids condensed with boron triacetate, but this has not been confirmed in the present work.

ISSN:0021-8871    

DOI:10.1002/jctb.5010041003

出版商:John Wiley&Sons, Ltd    

年代:1954

数据来源: WILEY

摘要:

AbstractDistribution coefficients at 25° for nicotine between water and three organic solvents for low nicotine concentrations have been determined. The liquid‐liquid equilibrium at 25° for the system nicotine‐water‐carbon tetrachloride has been investigated, and it is shown that the system is solutropic, with a horizontal tie‐line at 38 wt.‐%

ISSN:0021-8871    

DOI:10.1002/jctb.5010041004

出版商:John Wiley&Sons, Ltd    

年代:1954

数据来源: WILEY

摘要:

AbstractRecent work has shown that oxalic acid is capable of replacing sulphuric acid, in whole or part, in the superphosphate process.The most promising method of manufacturing cheap oxalic acid on a large scale is by nitric acid oxidation of plant wastes, provided that most of the nitric acid can be recovered for re‐use. With wood and straw waste, oxalic acid yields of up to 85% are obtained at optimum conditions of temperature, catalyst concentration and reaction time. However, the loss of nitric acid is sufficiently low only when fuming nitric acid is used. In this case the ratio of oxalic acid produced to nitric acid lost is 7:1. The nitric acid lost is converted largely into nitrous oxide and this conversion appears to be connected with the oxidation of the lignin fraction of the sawdus

ISSN:0021-8871    

DOI:10.1002/jctb.5010041005

出版商:John Wiley&Sons, Ltd    

年代:1954

数据来源: WILEY

摘要:

AbstractThe sulphuration of trialkylethylenes with hydrogen sulphide‐sulphur dioxide at 0° (Peachey process) results in disubstitutive cross‐linking of the olefins, yielding dialkenyl tetrasulphides. At higher temperatures substitutive—additive cross‐linking occurs and alkyl alkenyl polysulphides are formed. Dialkenyl tetrasulphides are similarly formed by causing the olefin to react with sulphur at room temperature in the presence of zinc oxide and zinc dibutyldithiocarbamate, low concentrations of hydrogen sulphide acting as a catalyst for this reaction. At higher temperatures the reaction is also exclusively disubstitutive, a feature connected with the function of zinc compounds in influencing the cross‐linking reaction. The sulphuration of olefins with tetramethylthiuram disulphide at 140° shows a similar influence of zin

ISSN:0021-8871    

DOI:10.1002/jctb.5010041006

出版商:John Wiley&Sons, Ltd    

年代:1954

数据来源: WILEY

摘要:

AbstractCalibration curves of optical densities against concentrations at the selected wavelengths of 14.98, 4.65 and 3.3 μ for each of the gases carbon dioxide, carbon monoxide and propane respectively, with nitrogen as diluent, are presented. Deviations from Beer's law are apparent and result in appreciable errors in analysing mixtures of these gases. Correction curves are provided that allow accuracies in analysis of within 0.1, 0.2 and 0.4% for propane, carbon dioxide and carbon monoxide respectively, which shows an improvement on results of previously published work on similar mixtures

ISSN:0021-8871    

DOI:10.1002/jctb.5010041007

出版商:John Wiley&Sons, Ltd    

年代:1954

数据来源: WILEY

摘要:

AbstractA precipitation process is described for converting crude thorium oxalate or crude thorium phosphate into substantially pure thorium nitrate.The process is based on the use of a sulphuric acid‐oxalic acid mixture to ‘leach’ the bulk of the phosphate from a thorium oxalate complex. A phosphate concentrate can be treated similarly, but is first treated with oxalic acid to convert it into an oxalate complex. Residual phosphate and sulphate are removed from the acid‐treated products by precipitation of thorium oxalate under specified conditions. Residual lanthanons, together with any remaining impurities, are separated from thorium by precipitation of a granular form of thorium ‘peroxynitrate’. Variables in the process have been studied and material flow sheets, based on laboratory investigations, are presented. If mechanical losses are ignored the yield of thorium from monazite exceeds 90%.Application of the process to any type of thorium oxalate or phosphate concentrate is discussed, and details are given of the analytical determination in various thorium compounds of small quantities of phosphorus, cerium and mixed

ISSN:0021-8871    

DOI:10.1002/jctb.5010041008

出版商:John Wiley&Sons, Ltd    

年代:1954

数据来源: WILEY

ISSN:0021-8871    

DOI:10.1002/jctb.5010041009

出版商:John Wiley&Sons, Ltd    

年代:1954

数据来源: WILEY