摘要:

The separation of multicomponent hydrocarbon mixtures spreading on a water surface is related to the spreading coefficients of the hydrocarbons, taking into account relative volatilities and solubilities. In both synthetic and crude oil systems, the separation can be explained by the differences in spreading coefficients.

ISSN:0037-2366    

DOI:10.1080/00372367508058994

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

Recent increases in the price of plastics, following the trend of the oil industry, have focused attention on the problem of their recovery—similar to that of metals, glass, etc.—from industrial and municipal waste. Since plastics generally differ little in their physical properties, neither electromagnetic methods nor flotation are suitable for the purpose in hand, but specific gravity is the most promising separation parameter in spite of the relatively small differences involved. (All plastics fall within the 0.9 to 2.3 g/cm3range.) Single-step separation of multicomponent mixtures is feasible by means of a magnetohydrodynamic (MHD) technique based either on a constant or on a pulsating field, and also by means of magnetohydroctatic (MHS) techniques. The effectiveness of the MHD jigging method was demonstrated in experiments on a five-component mixture, carried out in a laboratory trough using a pulsating field with given periodicity. A 5-cm bed was stratified in 30 sec into fractions of sp. gr. 1.06, 1.21, 1.30, 1.37, and 1.40 g/cm3. The main object of the study was experimental determination of the stroke of the expulsive force, in an electrolyte solution, ensuring the most effective stratification. Certain possibilities are being considered for an MHD jig separator equipped with sintered permanent magnets. Experiments were carried out which showed the feasibility of precision separation of lightweight and heavy plastics according to mass density using a MHS technique with a sensitivity up to 10−2g/cm3. The feasibility was also demonstrated of the separation of metals (copper and aluminum) and plastics (polyvinyl chloride and polystyrene) in a single process and a single operation.

ISSN:0037-2366    

DOI:10.1080/00372367508058995

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

Sedimentation field-flow fractionation (SFFF) is an elution-centrifugation method which operates with an equilibrium solute layer thickness of the order of 10 μ. Retention is a function of molecular weight and density, thereby making it possible to obtain both fractionation and molecular weight values for particles and macromolecules. Equations for the characteristics of this method are given. Experimental data are obtained for bacteriophage T2 and compared with theoretical predictions. The molecular weight determined from these data are (227 ± 11) × 106and (236 ± 7) × 106for two different dilutions. Finally, it is noted that the potential speed and accuracy of the method are attractive, and are based largely on the small sedimentation layer thickness.

ISSN:0037-2366    

DOI:10.1080/00372367508058996

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

Papers impregnated with titanic molybdate have been used to chromatograph various cations in sodium nitrate solutions of 0.1 to 4Mconcentrations. Various important separations are listed. The movement of the cations is proportional to the activity of the developing medium. Various plots are made to discuss the theoretical behavior of movement of cations on these papers.

ISSN:0037-2366    

DOI:10.1080/00372367508058997

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

Various reported studies of the effect of sample size on efficiency in gel permeation chromatography are not in complete agreement. In particular there is conflicting experimental evidence as to the existence of a lower limit in sample size below which no further increase in efficiency is observed. This study reports efficiency studies in terms of plate number and resolution for polystyrene in chloroform for sample sizes less than those commonly studied. The results support the existence of such a lower limit on sample size.

ISSN:0037-2366    

DOI:10.1080/00372367508058998

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

A simple and rapid spectrophotometric determination of uranium(VI) is described. The uranium(VI)N-m-tolyl-o-methoxybenzohydroxamic acid complex is extracted with chloroform at pH 5.3 to 5.5 from aqueous solution. Maximum absorption of orange-red extract occurs at 510 nm. The colored complex obeys Beer's law over the range 0.3 to 20 ppm of uranium. The effect of acidity, reagent concentration, and diverse ions on the visible absorption of extracted complex has been studied.

ISSN:0037-2366    

DOI:10.1080/00372367508058999

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

Shortly after the ultracentrifuge was developed, it was realized that molecular-weight distributions (MWDs) of polymers could be obtained from sedimentation equilibrium experiments. Although numerous attempts have been made to obtain MWDs from sedimentation equilibrium experiments, the results were not very satisfactory, and most MWDs were obtained from sedimentation velocity experiments. Only recently have some satisfactory methods been developed for sedimentation equilibrium experiments. These methods were restricted to ideal, dilute solutions and to ultracentrifuge cells with sector-shaped centerpieces. Both of these restrictions can now be removed. Methods for correcting for nonideal behavior are shown. Procedures for obtaining MWDs from sector—or nonsector—shaped centerpieces are shown. These procedures are illustrated with real examples, and a comparison between MWDs obtained by sedimentation velocity, sedimentation equilibrium, and gel permeation chromatography experiments is shown.

ISSN:0037-2366    

DOI:10.1080/00372367508059000

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

This is a scanned image of the original Editorial Board page(s) for this issue.

ISSN:0037-2366    

DOI:10.1080/00372367508058993

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor