摘要:

AbstractA description is given of an apparatus designed to allow the continuous recording of the Theological properties of gels. Advantages and disadvantages of the apparatus arc mentioned and the variations in behaviour between gelatin and agar gels and high sugar‐high methoxyl gels observed, from results obtained using the apparatus, are discusse

ISSN:0368-4075    

DOI:10.1002/jctb.5000660901

出版商:John Wiley&Sons, Ltd    

年代:1947

数据来源: WILEY

摘要:

AbstractThe paper describes a study of the fineness characteristics of. a wide range of fillers used in the production of bituminous road surfacings. The object of this study was to find a simple characteristic of the filler which could be directly related to the behaviour of filler‐binder mixtures, both at low filler concentrations which occur in many types of thin surfacing, and at high filler concentrations which occur in dense surfacings of the “asphalt” type. An investigation is then described into the flow properties of a number of filler‐binder systems containing both tar and bitumen binders, over a range of filler concentration from zero to the greatest amount which gave a cohesive mixture. The filler property found to be most simply related to these flow properties is the value of the fractional volume voids in the tightly‐compacted dry filler. The determination of this value is described and it is shown that from it the “optimum binder content” of any filler may be readily calculated. It is also shown that the relation between viscosity and filler concentration of any filler‐binder system may be most simply interpreted if the concentration of filler is expressed in terms of the degree of packing of the filler as calculated from the fraction

ISSN:0368-4075    

DOI:10.1002/jctb.5000660902

出版商:John Wiley&Sons, Ltd    

年代:1947

数据来源: WILEY

摘要:

AbstractThe rate of heat flow from a metal wall to a boiling fluid has been measured for water, toluene, ethyl alcohol and nitric acid. It has been shown that, where more than about 10% of the feed liquid is converted to vapour, the rate of heat transfer is not affected by mass velocity. It is also shown that boiling is not confined to any one zone in a vertical tube evaporator, but probably extends throughout the tube length.

ISSN:0368-4075    

DOI:10.1002/jctb.5000660903

出版商:John Wiley&Sons, Ltd    

年代:1947

数据来源: WILEY

摘要:

AbstractMethods for estimating coating weights on tinplate by removing the tin coating quantitatively were critically examined. The action of several stripping reagents on both hot‐dipped and electrolytic tinplates was studied by measuring weight losses after various periods of immersion and by metallographic examinations of the stripped specimens. Hydrochloric acid inhibited with antimony trichloride was the only reagent which completely removed the tin coating and the alloy layer from hot‐dipped plates and this reagent is recommended for determining total coating weights on hot‐dipped and electrolytic plates. Alkaline potassium iodate is a satisfactory alternative reagent for electrolytic plates. Coating weights determined with these two reagents agreed closely with those determined by iodimetric titrations of tinplate digests provided the latter results were corrected for iodine consumption by the baseplate. Plumbite and bismuthate stripping reagents were found to be unsatisfa

ISSN:0368-4075    

DOI:10.1002/jctb.5000660904

出版商:John Wiley&Sons, Ltd    

年代:1947

数据来源: WILEY

摘要:

AbstractTorsion tests have been used to investigate thermally reversible strain in plasticized p.v.c. in relation to the conditions under which it is produced. The initial set, on cooling after release of the applied strain, increases with the time, temperature and extent of deformation and rapidity of cooling, but under the experimental conditions was almost wholly recoverable on re‐heating. Cooling Under strain increases the initial set, and recovery then begins at the commencement of re‐heating; otherwise it starts at a higher temperature the slower the cooling after release. Recovery per unit temperature rise reaches a maximum just below the straining temperature at a position depending on straining time and rate of cooling, but not on composition within wide limits. Even opposed strains introduced successively at diminishing temperatures are separately recoverable on re‐heating. A qualitative explanation of the phenomena is proposed which assumes the presence of associations covering a wide range of stabil

ISSN:0368-4075    

DOI:10.1002/jctb.5000660905

出版商:John Wiley&Sons, Ltd    

年代:1947

数据来源: WILEY

摘要:

AbstractAn electronic circuit is described by which the following cycle of operations automatically occurs on initiation; the pre‐spark starts, the spectrograph shutter opens after a fixed time, the plate remains exposed for the required period, then the shutter closes just prior to switching off the spark and finally the apparatus is reset. By choosing suitable values of the components, a multi‐position selector switch enables a choice of pre‐spark and the exposure times to be made. It is claimed that this device eliminates some of the tedium of routine spectrograph analysis, saves the operator's time and eliminates some of the personal

ISSN:0368-4075    

DOI:10.1002/jctb.5000660906

出版商:John Wiley&Sons, Ltd    

年代:1947

数据来源: WILEY

摘要:

AbstractThe development of a pyrotechnic insecticidal smoke generator is described. The work is concerned mainly with the formulation of suitable pyrotechnic compositions in which a mixture of sucrose and potassium chlorate is used as the vaporizer and DDT as the insecticide. A method for determining the efficiency of such compositions is described, and the reliability of the method has been confirmed by the isolation from the cloud of almost the whole of the amount of the DDT present, as determined by analysis. The stabilization of the compositions to heat is discussed, and brief mention is made of entomological trials.

ISSN:0368-4075    

DOI:10.1002/jctb.5000660908

出版商:John Wiley&Sons, Ltd    

年代:1947

数据来源: WILEY

摘要:

AbstractA concentration method, employing precipitation by means of a mixture of 8‐hydroxyquinoline, tannic acid and thionalide, is described for the simultaneous recovery of Co, Ni, Mo, Cr, V, Be, Ge, Sn, Pb, Ti, and Zn, from solution in a form suitable for spectrographic analysis. Combined spectrographic and chemical errors seldom exceed ± 10% for individual determinations. The ranges covered arc 2–50 μg. for Co, Ni, Mo, Cr and V, and 5–100 μg, for the other elements except Zn, where the range is 0·2–4 mg. Details are given for the application of the method to the determination of trace constituents in plant materials and soil extracts. The use of other organic reagents in conjunction with 8‐hydroxyquinoline is a

ISSN:0368-4075    

DOI:10.1002/jctb.5000660909

出版商:John Wiley&Sons, Ltd    

年代:1947

数据来源: WILEY