摘要:

Abstract1Mineral aggregates used in asphalt mixtures become reduced in size during mixing, consolitation and under traffic action. Laboratory and field investigations were made into the factors affecting this process. Each factor in turn was treated as a variable and its influence upon stability evaluated. Five aggregates—norite, dolerite, basalt, dolomite and quartzite—were chosen and are described petrologically.2Successive crushing tests on the chosen aggregates show that final gradings were reached, after which there was little further size‐reduction under load and only a small increase in bulk density. This final grading is shown to be influenced by the original grading and the type of stone used.3An examination of the crushing characteristics of the aggregates indicates decrease in crushing resistance when flaky particles are present in quantity. The degree of comminution of each aggregate type was tested, and was found to be closely connected with the degree of lubrication given to the aggregate by the binder, which in turn is controlled by its viscosity.4Aggregate type influences stability, which usually increases with mix density, but experiments show that strength of an aggregate is not the controlling factor in giving maximum stability; aggregate shape and size are both important. It is concluded that maximum stability results from the use of an aggregate whose physical properties are intermediate between the very hard and the very

ISSN:0021-8871    

DOI:10.1002/jctb.5010030802

出版商:John Wiley&Sons, Ltd    

年代:1953

数据来源: WILEY

摘要:

AbstractThe study of the chlorination of α‐chloroethylbenzene (1′‐chloroethylbenzene) in the presence of iodine as catalyst has been continued in more detail. With concentrations of 2.0% by weight of iodine instead of 0.2% as employed previously, much higher amounts of chlorine react by substitution, and less addition takes place. The formation of styrene dichloride (1′:2′‐dichloroethylbenzene), which results from the use of high iodine concentrations at 20°, is prevented by carrying out the reaction at 0°.Yields of nuclear‐monochlorinated α‐chloroethylbenzene are about 88% of the theoretical. Styrene dichloride, which gives rise to α‐ and β‐chlorostyrene in the monochlorostyrene obtained on dehydrochlorination, can be estimated in the chlorination product by inf

ISSN:0021-8871    

DOI:10.1002/jctb.5010030803

出版商:John Wiley&Sons, Ltd    

年代:1953

数据来源: WILEY

摘要:

AbstractEquations relating temperature and pressure for adiabatic compression and expansion of polystyrene are derived from Spencer&Gilmore's equation of state for equilibrium conditions.The temperature changes determined experimentally are larger than expected and the results are correlated if a constant in the equation of state is altered.Compressions and expansions are found to be essentially reversible and adiabatic for the time scale of the experiments and for the time scale occurring in injection moulding.

ISSN:0021-8871    

DOI:10.1002/jctb.5010030804

出版商:John Wiley&Sons, Ltd    

年代:1953

数据来源: WILEY

摘要:

AbstractFrom a general energy balance and Spencer&Gilmore's equation of state, energy relationships are developed for steady and non‐steady flow of high polymers. Use of the equations to determine the temperature variations in an injection‐moulding cycle is indicated and the equations, together with one previously determined for non‐flow conditions, are applied to an idealized injection‐moulding process. The resulting calculations for polystyrene, neglecting heat transfer, indicate that large temperature variations take place during a cycle. Consequently, any analysis of the process must take into account the energy conversions taking place. The thermal energy supplied to the polymer by viscous friction is shown to be an appreciable fraction of the total r

ISSN:0021-8871    

DOI:10.1002/jctb.5010030805

出版商:John Wiley&Sons, Ltd    

年代:1953

数据来源: WILEY

摘要:

AbstractTernary and quaternary phase‐equilibrium data are presented for the system benzene‐n‐hexane‐ethylenediamine and benzene‐n‐hexane‐ethylenediamine‐water at 20°. This system is solutropic, (i.e. the distribution ratio is reversed in it); to distinguish it from other solutropic systems the term molar solutrope has been proposed, which refers to systems that show a change in sign of the gradient of the tie lines on a molar plot. One other system which has been found to be molar solutropic is acetone‐ethylene glycol‐benzene at 27°.Ethylenediamine is capable of extracting benzene fromn‐hexane and of producing 100%n‐hexane (raffinate) and 85% benzene (extract) as products. The addition of water to the solvent improves the purity of the extract, and at 16% of water a product of 97% pur

ISSN:0021-8871    

DOI:10.1002/jctb.5010030806

出版商:John Wiley&Sons, Ltd    

年代:1953

数据来源: WILEY

摘要:

AbstractThe value of aqueous inhibitor solutions for the temporary protection of steel has been investigated, and inorganic pastes and organic emulsions have been developed for protecting steel against atmospheric corrosion.Heavy inhibitor‐salt deposits afford some protection, but bentonite pastes give much longer protection and may have practical applications. The thixotropic properties of bentonite and other materials are particularly valuable when the pastes are applied to inclined surfaces; application may be by brushing, dipping, or spraying.The further rusting of steel surfaces can be suppressed by the use of bentonite/nitrite pastes, a useful practical application where the cost of de‐rusting a rusted surface might be unecono

ISSN:0021-8871    

DOI:10.1002/jctb.5010030807

出版商:John Wiley&Sons, Ltd    

年代:1953

数据来源: WILEY

摘要:

AbstractA study has been made of the effect of changes in reaction conditions on the decomposition ofn‐primary alcohols over cobalt catalysts in the presence of hydrogen or mixtures of hydrogen and carbon monoxide. The increases in reaction rate with increases in temperature and space velocity are similar for the alcohol decomposition and Fischer‐Tropsch synthesis reactions. With the exception of ethyl alcohol, the most stable of the alcohols, alcohols decompose in synthesis gas (CO + 2H2) at 150° at a rate comparable with that of the synthesis reaction. From an examination of the products of decomposition, it would appear that the main reaction is dehydration of the alcohol. Although the formation of higher hydrocarbons by chain growth takes place during the reaction, especially in the presence of small quantities of carbon monoxide, chain growth from an alcohol which has been desorbed from the surface is not considered to be an important step in the synthesis reaction. The results are consistent with the conception that alcohols are the true primary products of the synth

ISSN:0021-8871    

DOI:10.1002/jctb.5010030808

出版商:John Wiley&Sons, Ltd    

年代:1953

数据来源: WILEY

摘要:

AbstractThe corrosion characteristics of wrought aluminium and a number of wrought and cast alloys when immersed in typical public supply waters under stagnant or slowly moving water conditions have been investigated. Most of the tests have been carried out at room temperature but tests have also been made at temperatures up to 80°. Corrosion‐time curves have been drawn, using pitting depth and loss of weight as measures of corrosion.Changes in the composition of the waters caused greater differences than changes in alloys, but the order of attack was similar in all waters tested. Corrosive attack was most severe in the harder waters, the typical form of attack being the development of deep pits covered by mounds of corrosion product consisting mainly of aluminium hydroxide (‘nodular pitting’)Experiments with synthetic waters have shown that this form of pitting develops when calcium bicarbonate, chlorides, copper salts and dissolved oxygen are present together in the water. These constituents are all normally present in various proportions in public supply waters. A mechanism accounting for the development of the pits is pr

ISSN:0021-8871    

DOI:10.1002/jctb.5010030809

出版商:John Wiley&Sons, Ltd    

年代:1953

数据来源: WILEY

ISSN:0021-8871    

DOI:10.1002/jctb.5010030801

出版商:John Wiley&Sons, Ltd    

年代:1953

数据来源: WILEY