摘要:

AbstractExperiments on the removal of water and wetting liquids from a bed of high‐rank coal using a development of Bartell's method showed that the receding contact angle was nearly zero.Observations of drops of water on coal surfaces confirmed that on polished plates the receding contact angle was low: for high‐ and medium‐rank coals it was about 10°, for a low‐rank coal near to zero. For cleaved plates or rough surfaces the receding angle was indistinguishable from zero. The advancing contact angle, on the other hand, was between 60° and 85° on polished plates, depending on coal rank.Fuel oil on the coal surface increased the receding contact angle considerably. Potassium permanganate treatment gave a zero receding angle but a finite advancing angle.The implications of contact hysteresis for dewatering and froth flotation are discussed. It is concluded that knowledge of both advancing and receding angles is necessary to understand these

ISSN:0021-8871    

DOI:10.1002/jctb.5010080401

出版商:John Wiley&Sons, Ltd    

年代:1958

数据来源: WILEY

摘要:

AbstractTensile tests have been carried out on polytetrafluoroethylene, polycaprolactam, polyvinyl chloride and polytrifluoromonochloroethylene at four temperature levels ranging from +20° to −196°C.The tensile strength of polytetrafluoroethylene increased from 1·44 × 103lb./sq. in. at room temperature to 13·8 × 1033lb./sq. in. at −196°c while the tensile strengths of polycaprolactam, polyvinyl chloride and polytetrafluoroethylene correspondingly increased from 9·5 × 103, 7·7 × 103and 6·3 × 103 lb./sq. in. to 27·9 × 103, 19·7 × 103and 16·2 × 103lb./sq. in. respectively. The moduli of elasticity we

ISSN:0021-8871    

DOI:10.1002/jctb.5010080402

出版商:John Wiley&Sons, Ltd    

年代:1958

数据来源: WILEY

摘要:

AbstractA theory is developed for the production of salt by the evaporation of sea‐water. The theory leads to simultaneous differential equations, solutions of which were evaluated on a differential analyser, for both steady‐state and transient conditions.The steady‐state solutions provide data which can be used in the design of a saltfield, particularly in the determination of the ‘concentrating’ area required to provide an adequate supply of concentrated brine to feed the ‘crystallizing’ area from which the salt is ultimately recovered.The transient solutions show the behaviour of the saltfield after flooding with fresh brine, and also after a sudden change is made in the rate of flow through the system. The latter studies are of interest from the operating, rather than design,

ISSN:0021-8871    

DOI:10.1002/jctb.5010080403

出版商:John Wiley&Sons, Ltd    

年代:1958

数据来源: WILEY

摘要:

AbstractFour commercially available, thermally cured polyester resins were subjected to γ‐irradiation at dosages of 1·0 × 106to 5·0 × 107rad. and the effects of the irradiations on physical properties were examined. The greatest effects were on tensile strength and Young's modulus in which 20% improvement was noted. There were no significant changes in hardness or heat distortion properties. Styrene‐modified polyester syrups can be completely cured by irradiation at 5·0 × 106to 1·0 × 107rad. but the properties of the cured products are not significantly superior to those of materials cured by conventiona

ISSN:0021-8871    

DOI:10.1002/jctb.5010080404

出版商:John Wiley&Sons, Ltd    

年代:1958

数据来源: WILEY

摘要:

AbstractResults are given of an investigation, usingX‐ray powder photography for identification, of the effects of temperature, concentration, order of addition and excess of either of the reagents used on the nature of precipitates and their calcination products. Some clarification of the interrelationships of the various forms of alumina is adduce

ISSN:0021-8871    

DOI:10.1002/jctb.5010080405

出版商:John Wiley&Sons, Ltd    

年代:1958

数据来源: WILEY

摘要:

AbstractThe potentials of steel, aluminum, brass and copper rods overcoated with various paints were measured in sea‐water over a period of time. The potentials obtained in all cases were determined by the substrate metal rather than the paint coating used. It is concluded that essentially one is measuring the potential of bare local anodes. The potential‐time curves on copper, brass and aluminum have the same characteristics as those on st

ISSN:0021-8871    

DOI:10.1002/jctb.5010080406

出版商:John Wiley&Sons, Ltd    

年代:1958

数据来源: WILEY

摘要:

AbstractSix fractions have been obtained from a technical cellulose acetate and their molecular weights determined osmotically. Viscosity data are presented for the fractions in acetone, methyl acetate, acetic acid, aniline and pyridine at 25° and values of K and a in the expression [n] = KMaare given. Although logarithmic plots of [n] againstMare fairly well represented by straight lines, some scatter is observed and a possible tendency to downward curvature at higher molecular weights. Reasons for scatter and curvature are discussed and it is suggested that a linear relationship between [n] andMmay apply at lower molecular weights, the chains being considerably extended. At higher molecular weights some coiling of chains is possible. There seems to be no clearly defined relationship between the values of K and a and the solvent power of the solvent. Values of a for basic solvents are in agreement with predictions based on the ability of such solvents to break‐intramolecular polymer bonds but those for acidic solvents are n

ISSN:0021-8871    

DOI:10.1002/jctb.5010080407

出版商:John Wiley&Sons, Ltd    

年代:1958

数据来源: WILEY

摘要:

AbstractAn account is given of the laboratory preparation of aluminium dilaurate using a continuous process. The effect, on the quality of the soap produced, of changing variables such as concentration and proportions of the reacting solutions, degree of agitation and time and temperature of reaction, has been found. It is shown that the product of the best quality, when judged by the consistency and storage stability of gels in hydrocarbons, is obtained when the reaction pH is kept within the range 3.5–4.0.The process was later successfully transferred to a pilot plan

ISSN:0021-8871    

DOI:10.1002/jctb.5010080408

出版商:John Wiley&Sons, Ltd    

年代:1958

数据来源: WILEY

摘要:

AbstractAn account is given of the laboratory preparation of aluminium dinonanoate, the aluminium soap of 3: 5: 5‐trimethylhexanoic acid, using a continuous process. The effect, on the composition and quality of the soap produced, of changing variables such as concentration and proportions of the reacting solutions, degree of agitation and time and temperature of reaction, has been found. It is shown that the product of the best quality, when judged by the consistency and storage stability of gels in hydrocarbons, is produced when the reaction pH is kept within the range 3.6 to 4.0. The conclusions from the laboratory preparations were later confirmed on pilot‐plant sc

ISSN:0021-8871    

DOI:10.1002/jctb.5010080409

出版商:John Wiley&Sons, Ltd    

年代:1958

数据来源: WILEY

摘要:

AbstractA comparison of the sulphite oxidation and polarographic methods of determining oxygen‐transfer rates has been made. It has been found that the former behaves as a gas‐film‐, and the latter a liquid‐film‐controlled process. A start has been made on a rational approach to scale‐up of fermenters, based on the mass‐transfer rate and degree of turbulence. The effects of mould mycelium, anti‐foam and of surface‐active age

ISSN:0021-8871    

DOI:10.1002/jctb.5010080410

出版商:John Wiley&Sons, Ltd    

年代:1958

数据来源: WILEY