bluuebunny/crossref_metadata_2025_split huggingface dataset:
The preparation and properties of fractions from high density polyethylenes
Authors: Williamson G. R. , Wright B. , Haward R. N. 
Published: July 2010

AbstractA number of fractions have been prepared on a large scale from Ziegler 0·945‐density polyethylene and Phillips 0·96‐density polyethylene. Their physical properties have been compared with those of whole polymers having much broader distributions of molecular weight. It is shown that the main effects of narrowing the molecular‐weight distribution of polyethylene are to lower its density, to reduce its tensile yield strength, probably to increase its impact strength, and (with some reservations) to increase its ultimate elongation. Little change is evident in melt index or folding endurance. The effects on stress‐cracking resistance depend upon the type of polymer being considered. The relationship between yield strength and density is independent of intrinsic viscosity and of intrinsic viscosity distribution.
The quaternary liquid system benzene‐furfural‐ISO‐octane‐cyclohexane
Authors: Henty C. J. , McManamey W. J. , Prince R. G. H. 
Published: July 2010

AbstractLiquid‐liquid equilibrium data at 25° are presented for the ternary systems benzene‐furfural‐iso‐octane, benzene‐furfural‐cyclohexane and furfural‐iso‐octane‐cyclohexane and the quaternary system benzene‐furfural‐iso‐octane‐cyclohexane. The correlations developed by Prince1 were found to relate satisfactorily the quaternary equilibrium compositions to the ternary equilibrium data, if a few quaternary tie lines are known. Benzene equilibrium concentrations in the quaternary system can be predicted from relationships obtained for the ternary systems.
Extraction of uranium (VI) from nitric acid solutions by some cyclohexyl‐ and benzyl‐alkylamines
Authors: Sato Taichi 
Published: July 2010

AbstractThe partition of uranium (VI) between nitric acid solutions and benzene solutions of some cyclohexyl‐ and benzyl‐alklamines has been investigated at different concentrations of nitric acid and solvent, and at different temperatures. An infra‐red spectral study has also been made of the organic solutions obtained. The mechanism of uranium extraction in this system is discussed on the basis of the results obtained.
Studies in adsorption. XIX. Measurement of external specific surface of fibres by solution adsorption
Authors: Giles C. H. , Tolia A. H. 
Published: July 2010

AbstractA method of measuring the external specific surface of fibres is described. p‐Nitrophenol in a range of concentrations in dilute solution in a non‐penetrating solvent, preferably n‐hexane or n‐heptane, is applied to air‐dry fibres a t room temperature, and adsorption isotherms are determined by spectrophotometric analysis of the solutions. Preferably three isotherms are measured for short but increasing periods of immersion, e.g., 5, 10 and 20 min., in which adsorption is confined mainly to the external surface of the fibres. The point on each curve corresponding to the first completed monolayer is then determined and the apparent external specific surface calculated. The values rise with time, probably because of slow penetration of the fibre structure by the solution, hut back extrapolation to zero time gives results in good agreement with measurements by microscope. The method is a sensitive one for detecting small degrees of mechanical or chemical damage to fibres and is applicable to many types of fibre; nylon, regenerated cellulose, paper pulp, wool and Terylene polyester fibres have been examined with success. Thcoretical aspects of the results are discussed.
Effects of impurities and additions on the hydration of calcium sulphate plaster slurries
Authors: Schiller K. 
Published: July 2010

AbstractThe consequences of the presence of small quantities of foreign material in a hydrating slurry are investigated. After discussion in a qualitative manner of how the large number of physical and chemical factors which determine the course of the chemical reaction are individually or collectively affected, it is shown, on the basis of a previously published quantitative theory how these effects show up in the conventional thermal hydration curve. Features such as acceleration, retardation, and ‘snap set’ are elucidated. An extended appendix deals with inhibited initial nucleation.
Estimation and determination of sulphate in soils and various other siliceous and calcareous metals
Authors: Keattch C. J. 
Published: July 2010

AbstractA method, based on the use of hypophosphorous and hydriodic acids, is described for determining the sulphate content of soils and various other siliceous and calcareous materials. Also included is a procedure for estimating whether the sulphate content of soils is greater or less than 0.1% (as SO3). Both proposed methods are more rapid than the classical gravimetric procedure.
Equilibrium studies on the solvent extraction of some transition metals with naphthenic acid
Authors: Fletcher A. W. , Flett D. S. 
Published: July 2010

AbstractThe extraction of copper, nickel and cobalt from solutions of constant ionic strength by naphthenic acid has been studied as a function of pH, metal and naphthenic acid concentration. The extracted species in benzene solution have been identified as Ni2R4,4RH and Co2R4,4RH while an empirical formula of CuR2RH may be written for the copper complex, where RH represents the naphthenic acid. In the case of the copper however there is indirect evidence for a dimeric complex. The extractions are shown to conform with the general pattern of liquid cation‐exchange as exemplified by the alkyl phosphoric acids and the aromatic sulphonic acids.
Ignition delay of ponderosa pine needles and sphagnum moss
Authors: Mutch R. W. 
Published: July 2010

AbstractControlled experiments demonstrated a significant difference between the ignition delay of ponderosa pine needles and that for sphagnum moss. At a furnace temperature of 320° and a fixed oxygen inlet of 33 c.c./min., sphagnum moss ignited more quickly than ponderosa pine needles. The materials were ground in a Wiley mill and subjected to three methods of sample preparation and two modes of ignition. Delays were determined by two methods: spontaneous ignition and pilot ignition.Particle size distribution, density, moisture content, heat of combustion, and chemical composition of the two fuels were measured to establish, if possible, what parameters influenced the difference in delay of ignition of these fuels.
Effect of vanadium pentoxide on gas‐phase combustion. I. The carbon monoxide‐sulphur dioxide‐oxygen system
Authors: Tipper C. F. H. , Williams B. H. 
Published: July 2010

AbstractThe kinetics of oxidation processes in the system carbon monoxide‐sulphur dioxide‐oxygen in the presence of surfaces, mainly vanadium pentoxide (V) and equimolar V2O5 and K2SO4 (V‐K), have been investigated using a static system. The upper limit of the explosive combustion of ‘wet’ CO was the same with a V, V‐K, KC1 or silica surface, the overall activation energy governing ignition being about 35 kcal. mole−1. Ignition was promoted by the addition of water (or the use of a boric oxide surface) but inhibited by SO2 and packing the vessel. The lower limit pressure was higher with a V‐ than with a V‐K‐surface, but varied little with temperature, and was unaffected by varying the water concentration or by the addition of SO2. Increase in surface/volume ratio raised the limit. The rate of the normal slow oxidation of ‘wet’ CO at pressures above the upper limit was very sensitive to changes in the nature of the surface, the order being V‐K > silica > V > KC1. Addition of SO2 greatly decreased the rate with a V‐surface but increased it with a V‐K‐surface. Packing the vessel had the same effect and with a V‐K‐surface the activation energy fell to about 18 kcal. mole−1. The heterogeneous reaction of SO2 and O2 was much faster on a V‐K‐ than on a V‐surface, the activation energies being 31 and 27 kcal. mole−1 respectively.The elementary steps in the chain mechanism, occurring in the systems under moist conditions, are discussed. It is concluded that, at the lower limit, branching is due to excited CO2 and termination to surface destruction of oxygen atoms, while, at or above upper limit pressures, branching by a process involving O atoms and H2O and the relative rates of reaction of HO2 radicals in the gas phase and at the wall are important. The mixtures undergoing ‘inhibited’ slow oxidation probably contain carbon, suboxides which can terminate chains by reaction with O atoms. SO2 may react with O atoms in the gas phase or with O2 on the surface depending on the conditions.
Reaction kinetics of the formation of hexamethylenetetramine
Authors: Wood R. K. , Stevens W. F. 
Published: July 2010

AbstractNew kinetic data are presented for the reaction between ammonia and formaldehyde to form hexamethylenetetramine. The reaction appears to be first‐order in ammonia concentration, and second‐order in formaldehyde concentration, according to the results of flow experiments made with a single stirred‐tank reactor. Both concentrated and dilute solutions were investigated. Heat of reaction data are also reported.
Influence of silica on the hydration of 3 CaO,SiO2
Authors: Stein H. N. , Stevels J. M. 
Published: July 2010

AbstractAmorphous silica accelerates the hydration rate of 3CaO,SiO2. This acceleration can be explained by assuming that the silica, by lowering calcium‐ and hydroxyl‐ion concentrations during the first minutes of the hydration, increases the conversion rate of a first protective hydrate layer into another less protective one.In Portland cement pastes, not only hydration of alite but also consumption of sulphate are accelerated, as judged by calorimetric experiments.
The effect of oxidation on the reactivity of nuclear graphite towards air
Authors: Blake A. R. 
Published: July 2010

AbstractThe changes in the reactivity of nuclear graphite towards air following thermal and radiolytic oxidation, have been examined. The increase in reactivity on thermal oxidation is independent of the initial reactivity, and results are reported from which predictions of the reactivity of oxidised graphite can be made. The rate of reactivity rise with radiolytic burn‐off is greater than for thermal burn‐off, but the limiting reactivity at high burn‐off is similar. The difference in the oxidation rates of the various specimens examined is apparently associated with the properties of the initially accessible surface and not with a bulk condition.
Self‐heating of esparto grass
Authors: Rothbaum H. P. 
Published: July 2010

AbstractMoist esparto grass self‐heats less easily than hay, but, as in the latter case, microbiological heating is most likely to lead to further chemical heating at a relative humidity of approximately 96%. Esparto grass has a considerably smaller moisture content than hay when in equilibrium with this R.H. and these results therefore confirm the importance of R.H. in initiating spontaneous combustion.
Autoxidation of monoethenoid fatty acids and esters: Catalytic oxidation of ethylene glycol dioleate
Authors: Skellon J. H. , Whiteley P. 
Published: July 2010

AbstractThe preparation of ethylene glycol dioleate is described, and its union with gaseous oxygen at 55, 85 and 120° has been investigated. The reactivity of the ester with oxygen is compared with previously published data for the monoesters and for ethylene glycol dielaidate.
The thermal decomposition of dye—clay mineral complexes
Authors: Ramachandran V. S. , Kacker K. P. 
Published: July 2010

AbstractClay minerals such as kaolinite, illite, nontronite and montmorillonite were complexed with methylene blue, Malachite green and piperidine and their behaviour when heated was followed by differential thermal and thermogravimetric analysis. The results indicated that organic cations adsorbed on the broken bonds being easily accessible to oxygen are oxidised exothermally between 150 and 500°. The cations adsorbed in the interlayer are oxidised in the range 500 to 800° and this corresponds to the temperature at which the (OH) water is expelled from the clay minerals.
Electrical resistivity of a polyvinyl chloride‐dibutyl phthalate plastisol
Authors: Warfield R. W. , Rosen A. H. 
Published: July 2010

AbstractElectrical volume resistivity techniques have been employed to study the hardening and properties of a polyvinyl chloride‐dibutyl phthalate plastisol. It is shown that resistivity measurements can be employed to follow the hardening of plastisol systems and yield information useful in elucidating the nature of the hardening process. This process appears to occur in two stages. In order to obtain the maximum extent of hardening, it is necessary to conduct the final stage in the hardening process at a temperature above the glass transition temperature of the polymeric component. Plasticised systems exhibit a non‐linear dependence of resistivity vs temperature.
The reaction of cyanuric chloride with gelatins and animal glues
Authors: Leach A. A. 
Published: July 2010

AbstractThe conditions for the reaction of cyanuric chloride with solutions of gelatins and animal glues have been examined. The compound was shown to be a very efficient crosslinking agent; as little as 1.2 moles of reagent per 105 g. of protein were required to double the viscosity of a gelatin solution. Insoluble gel networks were readily formed. For commercial applications the products obtained were unsatisfactory. Increased gel strengths were obtained on crosslinking solutions of gelatins and glues of low initial gel strengths and viscosities. With materials of higher initial gel strength and viscosity, either no increase, or a decrease, in gel strength was observed. These phenomena are discussed in the light of the observations by Stainsby et al.6 on the factors governing the rigidity of gelatin gels.
Concentration of the fluorozirconate ion by ion flotation
Authors: Rice N. W. , Sebba F. 
Published: July 2010

AbstractThe conditions for concentrating the fluorozirconate ion by ion flotation with aminium salts as collector were studied. The effect of changed bubble rate, concentration of collector and zirconiumfluoride ratios as well as change of pH were examined and collection into a solvent was also studied. Maximum recovery was 80%.
The oxidation of uranium dioxides
Authors: Walker D. E. Y. 
Published: July 2010

AbstractThe oxidation of three types of uranium dioxide (UO2) material has been investigated in the 120—360° range.In UO2 powders, of surface area greater than about 2 m.2/g., oxidation was diffusion‐controlled up to U3O7 which oxidised to U3O8 above about 240°. The activation energies were in the range 20—27 kcal./mole.For material with very low surface‐area, both electrolytic UO2 powder (0.0405 m.2/g.) and sintered pellets (5 cm.2g.) were oxidised by nucleation and growth controlled processes. The growth activation energies for the two materials were 32.19 and 26.38 kcal./mole respectively. Considerable differences occurred in the oxidation rate of pellets from batch to batch.Material with intermediate surface‐area comprising sintered powder (0.135 m.2/g.) and crushed sintered pellets (0.095 m.2/g.) gave oxidation curves which were hybrid between the other two types above. At a high enough temperature (∼ 420°), the 0.095 m.2/g. material showed a completely sigmoid ‘nucleation’ type of curve.X‐Ray diffraction studies were performed at intermediary stages in the oxidations to trace the presence of the γ‐UO2 phase, and suggestions are put forward to explain the above differences in behaviour.
Volume‐area distributions for micropores
Authors: Irving James P. , Butt John B. 
Published: July 2010

AbstractA comparison of micropore size distributions in the range below 100 Å has been made for a silica gel sample, using the results of exact and approximate Barrett, Joyner & Halenda computations and of the recently proposed method of Dollimore & Heal. A number of discrepancies were noted between the results of the computations; in particular, while total surface areas obtained from the determinations of Barrett, Joyner & Halenda were within 2% of the BET surface area, the value from the Dollimore & Heal computation was about 20% smaller.The various methods which have been proposed for pore size distribution are essentially the same in theory; discrepancies such as those noted in this work are attributed to the differing values of adsorbed multilayer thickness used in the calculations. Although there is little agreement among the published correlations of multilayer thickness for nitrogen adsorption, the Halsey eqauation which is employed by Dollimore & Heal, lies well above other correlations and must be regarded as of questionable value in distribution computations. A satisfactory multilayer thickness correlation should provide a means of accounting for the effects of pore structure and non‐ideal adsorption; the approach suggested by Mingle & Smith may be promising in this direction.
Diffusion and dissolution of the hydroxybenzoic acids in water
Authors: Mullin J. W. , Cook T. P. 
Published: July 2010

AbstractSingle spheres of o‐, m‐ and p‐hydroxybenzoic acid have been dissolved into a water stream (Re range 100—1000) and the data are correlated by a relationship of the form
equation image
The meta‐isomer (ϕ = 0.80) behaves differently from the ortho‐ and para‐isomers (ϕ = 0.71) and it is suggested that this is due to the influence of surface effects on the dissolution process. A quantity termed the ‘work of replacement’, which can be calculated from surface tensions and wetting angles, has been defined to give a measure of the influence of these effects.Solubility, density, viscosity and diffusivity data are presented for saturated aqueous solutions of the three hydroxybenzoic acids. Differences in diffusivity of the isomers are explained by considering the effects of dimerisation due to hydrogen bonding.
The thermal decomposition of zinc di‐(4‐methylpentyl‐2) dithiophosphate
Authors: Ashford J. S. , Bretherick L. , Gould P. 
Published: July 2010

AbstractThe thermal decomposition in glass of a purified sample of zinc OO‐di‐(4‐methylpentyl‐2) dithiophosphate (phosphorothiolothionate) has been investigated under a variety of conditions. The volatile decomposition products have been quantitatively analysed by gas—liquid chromatography (GLC). The types of compound present include olefins, saturated and unsaturated thiols and sulphides, and saturated disulphides, which were separated and identified by a combination of GLC and mass spectrometry. The olefin fraction was analysed in detail by capillary GLC. A mechanism to account for the observed decomposition products is proposed and discussed.
Mercury removal from hydrogen gas streams
Authors: Logan W. R. 
Published: July 2010

AbstractType 13X molecular sieve and chromic acid on silica gel have been examined as sorbents for the removal of mercury vapour from hydrogen at atmospheric pressure and, chiefly, ambient temperature. The molecular sieve had a very low capacity for mercury. Chromic acid on silica gel had a much higher capacity but this was much reduced by the presence of water vapour in the hydrogen.
An apparatus for determining high‐pressure liquid‐vapour equilibrium data. I. The methanol—ethanol system
Authors: Butcher K. L. , Robinson W. I. 
Published: July 2010

AbstractAn apparatus for determining high‐pressure liquid–vapour equilibrium data has been developed and proved to operate satisfactorily. The apparatus operates isothermally. Results have been obtained for the ethanol–methanol system at the following temperatures: 100°, 120°, 140° and 160°. The results are shown to be thermodynamically consistent within the limits of the accuracy of their determination. The ‘ideal activity coefficients’ (i.e. calculated assuming that the gas phase behaviour is ideal) are correlated with the mole fraction of the component in the liquid phase by Margules‐type equations (1) and (2). The accuracy of these equations is greater than predictions based on fugacities.From equations (5), (6) and (1) or (2) in the paper it is possible to estimate any pair of liquid‐vapour equilibrium compositions for any specified pressure P and temperature T. Alternatively, for a specified P and liquid composition, the corresponding T and vapour composition may be calculated.
Removal of trace amounts of strontium from aqueous solutions by ion flotation. I. Batch experiments
Authors: Davis B. M. , Sebba F. 
Published: July 2010

AbstractThe most suitable conditions for the removal of strontium ions from aqueous solution by ion flotation have been investigated. The optimum conditions for pH, gas flow rate, concentration of strontium carrier and that of the collector as well as effect of interference by foreign ions were determined. The most suitable collector was found to be α‐sulphopalmitic acid and removal of strontium above 99.9% was achieved. These data were required as a preliminary to an investigation into the conditions for a continuous process which was subsequently developed.
Extraction of cobalt (II) from hydrochloric acid solutions by long‐chain aliphatic amines
Authors: Sato Taichi 
Published: July 2010

AbstractThe partition of cobalt (II) between hydrochloric acid solutions and organic solutions of long‐chain aliphatic amines has been investigated under different conditions. The extracted species has been examined spectro‐photometrically, and an infra‐red study has also been made of the organic phases. The mechanism of extraction is discussed on the basis of the results obtained, and in addition a structure is proposed for the complex formed in this extraction system.
Surface tension of collector‐frother mixtures
Authors: Malati M. A. , Yousef A. A. 
Published: July 2010

AbstractThio‐compound collectors and frothers produce, in aqueous solution, a smaller lowering of surface tension than other collectors. the surface tension of a solution of a collector‐frother mixture is intermediate between those of the individual reagent solutions, when the concentrations of both are in the vicinity of surface saturation, but when the mixture solution is very dilute, the lowering of the surface tension may be equal to the sum of the lowerings due to both reagents.
Effect of calcination temperature on the properties of magnesium oxides for use in magnesium oxychloride cements
Authors: Harper F. C. 
Published: July 2010

AbstractA comparison is made of the properties of magnesium oxides prepared from basic magnesium carbonates and Indian and Greek rock magnesites. the density increased with burning temperature and the reactivity decreased. the effect of this on the properties of oxychloride cements is shown.Iodine number is shown to be a good index of reactivity and specific surface (air permeability) to indicate the amount of chloride solution needed to make a workable mix with an oxide.
Electrodeposition at rotating cathodes from acidified copper sulphate solution
Authors: Kimber G. M. , Napier D. H. , Smith D. H. 
Published: July 2010

AbstractThe variation of the relationship between polarisation and current density at a rotating copper cathode in an electrolyte of copper sulphate and sulphuric acid has been observed under conditions and concentrations similar to those employed in the plating industry, and during the formation of thick deposits. The effect of the following parameters was studied: time of electrolysis, agitation, temperature and composition of electrolyte, and the consequent effects upon the structure of the resulting deposits were noted.The possible effects of the co‐deposition of hydrogen at the cathode is discussed in relation to the structure of the copper at high current density.