摘要:

AbstractThe relationship [η] =KMaand unperturbed dimensions of the copolyesters poly(ethylene terephthalate‐co‐ethylene isophthalate) with 7.5% and 25% isophthalic structures in the main chain were determined. The experimental data proved the influence of the amount of isophthalic structures upon the values ofKandafrom the relation between intrinsic viscosity and molecular weight and on the values for unperturbed dimens

ISSN:0264-3413    

DOI:10.1002/jctb.5040350102

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractPhosphate rock contains up to 1% lanthanide (rare earths) oxides present in isomorphous substitution for Ca2+. Lanthanum, cerium and neodymium form about 80% of the total. When the rock is leached with H2SO4the lanthanides are mostly (about 70%) lost in the gypsum residue. When the rock is leached with HNO3or HC1, more than 80% can be recovered without interference with fertiliser production. At an annual production of 130 million tons, phosphate rock represents an important source of lanthanides. The different methods of recovery are reviewed.

ISSN:0264-3413    

DOI:10.1002/jctb.5040350103

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractDuring direct vapour phase dehydrogenation of ethanol, a copper‐on‐silica catalyst lost much of its activity in 100 h. Analysis with X‐ray diffraction, scanning electron microscopy and X‐ray photoemission showed that both sintering and carbon deposition accompanied the drop in activity. In catalysts in which chromia was also present copper was found to be in a more highly dispersed form which was more resistant to sintering. The chromia catalyst accumulated carbon comparably to those containing copp

ISSN:0264-3413    

DOI:10.1002/jctb.5040350104

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractEquilibrium conditions of adsorption of a basic dye on hardwood sawdust were studied using the Langmuir and Freundlich isotherms. Two sets of experiments were carried out at different particle sizes and temperatures. The adsorption of the basic dye on hardwood was found to conform with the two isotherms. The capacity of hardwood for the adsorption of basic dye was found to increase by decreasing the particle size and increasing the temperature. The cost of hardwood adsorbent is only 8.4% that of activated carbon.

ISSN:0264-3413    

DOI:10.1002/jctb.5040350105

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractDecolourisation of a dilute solution of a basic dyestuff was carried out by using hardwood sawdust as adsorbent. At 80°C 85% decolourisation occurred within 100 min at an initial concentration (Co) of 200 mg dm−3. There was a 44% reduction in contact time when the temperature was raised from 25 to 80°C. The rate parameter for different initial dye concentrations was found to follow the equation: kco=4.20Co0.88and the rate parameter for different mean diameterdmfollowed the equationkdm=4.1 (l/dm)0.135. The activation energy of the process was 9.83 kJ mol−1which shows that the rate controlling step is intraparticle diff

ISSN:0264-3413    

DOI:10.1002/jctb.5040350106

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractA quantitative estimation of the effect of sodium hydroxide on the solubility of gypsum in the presence of lime at 30, 60 and 100°C is given. At 30°C the solubility of gypsum was promoted by a 0.0146M solution of sodium hydroxide which at a concentration as low as 0.0029M raised the sulphate ion concentration at 60 and 100°C. At the three temperatures studied the solubility curves of gypsum first rose slowly then more rapidly around 0.02 to 0.08M NaOH. In the range 0.08 to 1M NaOH solution, a constant value of the sulphate ion concentration was measured which corresponded to the complete dissolution of gypsum, even in the presence of lime. The solubility curve of gypsum was lowered slightly at 30°C in a supersaturated lime solution and was depressed by concentrations lower than or equal to 0.02M NaOH solutions at 60 and 10

ISSN:0264-3413    

DOI:10.1002/jctb.5040350107

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractThe fundamental aspects of the extraction and stripping of platinum (II) from its chloride solution by Aliquat 336 diluted with toluene have been studied. The extraction and stripping was at 99.5 and 97.6% equilibrium within 30 s and 20 min respectively. The percentage extraction increased slightly with decreasing hydrochloric acid concentration. In 0.1 mol dm−3hydrochloric acid, 1.0 volume percent Aliquat 336 in toluene could load 9.8 mmol dm−3of platinum (II). The percentage stripping of platinum (II) from Pt(II)‐load organic solvent increased with increasing sodium bisulphite concentration. The enthalpy changes of extraction and of stripping were 12.8 and 114.9 kJ mol−1respectively. Both of the reactions were endo

ISSN:0264-3413    

DOI:10.1002/jctb.5040350108

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

ISSN:0264-3413    

DOI:10.1002/jctb.5040350101

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY