ISSN:0021-8871    

DOI:10.1002/jctb.5010151210

出版商:John Wiley&Sons, Ltd    

年代:1965

数据来源: WILEY

摘要:

AbstractAn outline of the causes and nature of fading of organic colouring matters is given. Atmospheric fading, in absence of light, is produced by nitrogen oxides in urban air, especially with blue and violet disperse dyes on some hydrophobic fibres, but sulphur dioxide and ozone can also cause fading. Light fading occurs with all dyes; some of the factors which affect it are discussed, including the physical state of the dye, the chemical and the physical nature of the fibre, the temperature and humidity of the atmosphere, and the quality and intensity of the illumination. The hue of many soluble dyes becomes redder on fading. The types of fading rate are described; the fading of many dyes is rapid at first, but later it slows to a constant rate, so that a dye, which by normal testing methods has low fastness, may yet withstand prolonged exposure.

ISSN:0021-8871    

DOI:10.1002/jctb.5010151201

出版商:John Wiley&Sons, Ltd    

年代:1965

数据来源: WILEY

摘要:

AbstractThe need for a selective method for the removal of urea from urine is enhanced by the success of electrodialysis for removing electrolytes from urine. An investigation has been made of the capacities of an activated charcoal and an ion‐exchange resin (Amberlite IR‐120) for removal of urea from aqueous solution and from urine. In the charcoal column studies, determinations were made of the service time, the shape and thickness of the wavefront, and adsorbent capacity.The values of the adsorbent capacity of 6–14 and 50–200 mesh activated carbon are approximately 0.027 g. of urea/cm.3gross volume of carbon. For column lengths of the order of the thickness of the wavefront, approximately 0.6 of the capacity is used before the effluent urea concentration reaches 5% of the influent concentration. On the average, one chloride ion is removed from urine for each 1.3 molecules of urea adsorbed. The capacity of the activated carbon in removing urea from aqueous solution is approximately 10% greater than that for removal of urea from urine. The capacities of Amberlite IR‐120 ion‐exchange resin are 0.023 and 0.090 g. of urea/cm.3gross volume of resin for removal of urea from urine and from aqueous solution, r

ISSN:0021-8871    

DOI:10.1002/jctb.5010151202

出版商:John Wiley&Sons, Ltd    

年代:1965

数据来源: WILEY

摘要:

AbstractSome organic solvents, miscible with water, become partially miscible in the presence of either glucose or fructose, and the partition ratios of these sugars between the resulting phases then differ. This difference is considered as the basis for a separation of the glucose and fructose of invert sugar. An examination of binodal curves and tie‐lines of the two systems: solvent‐water‐glucose and solvent‐water‐fructose has been made in respect of eleven organic solvents. Among these n‐propanol and t‐butanol were found the most suitable for the separation of glucose and fructose. The concentrations of sugars in their solvent‐rich phases are much greater with these two solvents than in the corresponding phases of the best solvents partially miscible with water in absence of sugars. The quantities of the two alcohols needed to process a given weight of sugars are, correspondingly, very much smaller. About 40 theoretical stages would be needed to produce glucose and fructose of 90% purity.In the one liquid‐liquid extraction column used, fractionation of glucose and fructose was small, possibly because of the low rates of diffusion of the sugars, or because of column characteristics.Glucose was the more effective sugar in making the solvent and water partially miscible, except with aqueous 2,6‐dimethylpyridine, when fructose was more effective.An improved method of preparation of 2‐methyl‐1,4‐dioxan, one of the solvents examined in

ISSN:0021-8871    

DOI:10.1002/jctb.5010151203

出版商:John Wiley&Sons, Ltd    

年代:1965

数据来源: WILEY

摘要:

AbstractThe relative dating of palaeontological specimens may be assisted by an analysis for selected elements: methods for the determination of fluorine, phosphate, iron and carbonate are described and assessed. Some examples of the application of such analyses are discussed.

ISSN:0021-8871    

DOI:10.1002/jctb.5010151204

出版商:John Wiley&Sons, Ltd    

年代:1965

数据来源: WILEY

摘要:

AbstractGood recovery (∼90%) of aluminium contaminated with up to 7% beryllium from a 2:1 molar aluminium/beryllium mixture is possible by flotation of the oxalate complexes at pH 4 with long‐chain fatty amines (especially tetradecylami

ISSN:0021-8871    

DOI:10.1002/jctb.5010151205

出版商:John Wiley&Sons, Ltd    

年代:1965

数据来源: WILEY

摘要:

AbstractOn the basis of a previously proposed mechanism to explain hydration of plaster, the changes of concentration in the liquid medium are calculated. Separate evidence based on conductivity measurements and radio‐tracer methods are give

ISSN:0021-8871    

DOI:10.1002/jctb.5010151206

出版商:John Wiley&Sons, Ltd    

年代:1965

数据来源: WILEY

摘要:

AbstractThe nature, identity and physical characteristics of the component particles of 14 representative British fly ashes have been studied, with the purpose of relating them to the pozzolanic properties of the ashes. In this paper data are presented on the chemical and mineralogical analyses, specific surfaces and particle size distribution of the ashes. The particles have been classified into characteristic types by microscopical examination, and centrifugal float‐and‐sink methods of density separation have been used to study the distribution of these types in the various ashes. The mineralogical origin of the particles is studied by comparing them with particles produced by passing particles of representative coal minerals through a fl

ISSN:0021-8871    

DOI:10.1002/jctb.5010151207

出版商:John Wiley&Sons, Ltd    

年代:1965

数据来源: WILEY

摘要:

AbstractThe pozzolanic activities of 14 representative British fly ashes have been compared by determining the crushing strengths of their lime mortars cured for periods of 7–730 days. The mortars differed considerably both in the crushing strengths attained and in the rates at which these strengths were developed. The relations between the crushing strengths and the carbon content, glass content, silica and alumina content, density, and specific surface of the ashes have been examined, as such factors have been suggested in the literature as parameters of pozzolanic activity. For short periods of cure, none of these factors was found to correlate closely with crushing strength; the best correlation was that given by the specific surface of the ashes, as determined from the particle size analysis. For long periods of cure, the best correlation was given by the SiO2or the (SiO2+ Al2O3) content of the ashes. The activity of an ash was found to reside in its siliceous particles and was determined by their particle size characteristics. The chemical compositions of these particles lay within a fairly narrow range and differences in composition within this range were found to have no significant influence on activit

ISSN:0021-8871    

DOI:10.1002/jctb.5010151208

出版商:John Wiley&Sons, Ltd    

年代:1965

数据来源: WILEY

摘要:

AbstractActivation of quartz by copper sulphate on the soap flotation has been studied by varying activator concentration, collector concentration and pH to find the equilibrium conditions of flotation and non‐flotation. The results are presented as contact curves. Increasing oleic acid raised the lower critical pH, but excess of oleic acid and of hydroxide depressed flotation. It is postulated that ‘hydroxyoleate of copper’ is responsible for flotation.Deactivation studies were made by complexing and sequestering the copper with amines, amino‐acids, etc. Increasing deactivator concentrations increase the lower critical pH due to the reduction in the concentration of cupric ions. The usefulness of a new reagent, ascorbic acid, for depression was

ISSN:0021-8871    

DOI:10.1002/jctb.5010151209

出版商:John Wiley&Sons, Ltd    

年代:1965

数据来源: WILEY