bluuebunny/crossref_metadata_2025 huggingface dataset:
The reaction between anhydrous ethyleneimine and water
Authors: Pascoe P. F. , Sherbrogk‐Gox W. A.
Published: July 2010

It has been demonstrated by several physical measurements that one molecule of anhydrous ethyleneimine reacts with two molecules of water. The reaction product appears to be a chelated ethanolamine‐hydrate which is remarkably stable even in the vapour phase. On prolonged heating the chelate ring opens and a mixture of ethanolamine and water is obtained. The chelated hydrate has the previously unknown structure of a chelate ring held together solely hydrogen bonds.

Sodium hydroxide converts part of the chelate into anhydrous ethyleneimine, which can be recovered distillation. Chelated ethanolamine‐hydrate and anhydrous ethyleneimine behave differently towards certain solvents. Solid sodium hydroxide in the presence of such selective solvents converts the aqueous solution of the chelated ethanolamine‐hydrate effectively to anhydrous ethyleneimine.

The conversion of β‐aminoethylsulphuric acid ester or of β‐chlorethylamine hydrochloride into ethyleneimine occurs in two stages via the chelated ethanolamine‐hydrate as intermediate. The mechanism of this reaction is discussed.
Determination of nickel and iron carbonyls in town gas
Authors: Densham A. B. , Beale P. A. A. , Palmer R.
Published: July 2010

Methods for determining nickel and iron carbonyls in town gas are reviewed and two new procedures are described. The limitations of the glass jet method are discussed. An improved chemical method involves absorption by iodine monochloride in acetic acid followed by a colorimetric finish; sensitivities are 0.006 p.p.m. for nickel carbonyl and 0.01–0.03 p.p.m. for iron carbonyl. Atomic‐absorption spectroscopy provides a very rapid method of analysis; the sensitivities are 0.002 p.p.m. for nickel carbonyl and 0.01 p.p.m. iron carbonyl.
The effect of carbon‐arc intensity on asphalt oxidation
Authors: Wright J. R. , Gampbell P. G. , Fridinger T. L.
Published: July 2010

Films of two air‐blown asphalts were exposed to the carbon arc at different intensities to determine the effect of radiant‐energy intensity on the rate of asphalt oxidation. The oxidation rates were established by measuring the changes in infra‐red absorption in the carbonyl band as a function of exposure time. It was found that: (a) the asphalt oxidation rate increased with the intensity of the carbon arc, (b) the radiant energy output of the accelerated weathering machine tends to level off at the higher voltage settings, and (c) at the maximum voltage adjustment switch setting of the accelerated weathering machine used, the incident‐radiant flux does not equal or exceed that which can be absorbed by asphalt.
The electrochemical oxidation of propane at room temperature
Authors: José V. R. , Long V. D.
Published: July 2010

Propane at room temperature and atmospheric pressure has been oxidised catalytically at the anode of a galvanic cell comprising two porous carbon electrodes immersed in 35% (w/v) aqueous potassium hydroxide. Platinum, palladium and nickel were separately used as anode catalysts. Air was supplied to the cathode, which was catalysed with cupric oxide. Results are presented for terminal voltage and current density in a flow system, and for terminal voltage and gas composition as a function of time in a static system. Within experimental error the reacting propane was oxidised completely to carbon dioxide and water. Useful electrical energy was developed at the highest efficiency with a platinum catalyst.
Sorption of water on compacts of bottle‐hydrated cement. I. The sorption and length‐change isotherms
Authors: Feldman R. F. , Sereda P. J.
Published: July 2010

To obtain information with regard to the porous structure of hydrated cement and the extent of its interaction with water, sorption and length‐change isotherms were determined for this material.

Compacts of bottle‐hydrated cement were brought to equilibrium in a high‐vacuum system at various humidities, and measurements of the changes in length and weight during this process, were made to draw the isotherms.

Results showed that this system is basically similar to systems composed of other porous materials, although complicated by a discontinuity in the adsorption part of the cycle and a secondary hysteresis. It is considered that these characteristics are related and are the result of water associated with the system by a process other than physical adsorption.

It is also shown that menisci exist in the system on desorption to as low as 31% R.H. and cause considerable contraction. A surface‐area calculation by a new method for estimating the zero adsorbed water yield a value of 80·6 m.2/g.
Distribution of nitric acid between tri‐N‐butyl phosphate and water
Authors: Burns P. E. , Hanson C.
Published: July 2010

The distribution of nitric acid between water and both 20 and 30% v/v solutions of tri‐n‐butyl phosphate in odourless kerosene at 20° and 25° has been studied systematically up to aqueous phase concentrations of 10 moles per litre. An equation is derived to represent the distribution up to aqueous phase concentrations of 4 moles per litre.
The preparation and properties of fractions from high density polyethylenes
Authors: Williamson G. R. , Wright B. , Haward R. N.
Published: July 2010

A 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

Liquid‐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.
New synthesis of 2‐methyl‐1,3‐pentadiene
Authors: Haken J. K.
Published: July 2010

A synthesis of 2‐methyl‐1,3‐pentadiene from 4‐methyl‐4‐methoxy‐2‐pentanol is reported, in which a single reaction produces a pure product in good yield.
Extraction of uranium (VI) from nitric acid solutions by some cyclohexyl‐ and benzyl‐alkylamines
Authors: Sato Taichi
Published: July 2010

The 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

A 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

The 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

A 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

The 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

Controlled 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.
Automatic preparative‐scale gas chromatography as a short‐cut in synthetic organic chemistry
Authors: Boer H.
Published: July 2010

A few examples are given of the application of automatic preparative‐scale gas chromatography for separation of products or intermediates in synthetic organic chemistry. The technique is shown to give a large saving in time, labour and starting materials.
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

The 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

New 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

Amorphous 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

The 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

Moist 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

The 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

Clay 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

Electrical 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

The 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

The 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

The 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

A 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

Single 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

The 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

Type 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

An 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

The 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

The 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

Thio‐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

A 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

The 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.
Density and viscosity of ammonium nitrate, ammonium nitrate–potassium chloride and ammonium nitrate—ammonium phosphate melts
Authors: Booth D. H. , Vinyard V. C.
Published: July 2010

The results of density and viscosity measurements are given for ammonium nitrate and the salt mixtures ammonium nitrate—potassium chloride and ammonium nitrate‐ammonium dihydrogen phosphate. The latter system is complicated because of the formation of non‐ortho phosphates and the results obtained refer to the equilibrium mixture obtained after heating for 3 h at 180°c. After this treatment, about 40% of the phosphate was converted to non‐ortho forms.

The density of ammonium nitrate is given by:

for values of t between 170°c and 190°c. Similar relationships can be deduced for the solutions.

The viscosity of ammonium nitrate, in centipoises, is given approximately by:

for values of T between 443° and 453° k. Similar relationships hold for the nitrate—phosphate solutions.
Reduction of the calcite content of ground shale by liquid—liquid particle transfer
Authors: Coleman R. D. , Sutherland J. P. , Capes C. E.
Published: July 2010

The removal of calcite from a naturally occurring shale is described. The technique used involves making the calcite particles hydrophobic by ball‐milling the shale in aqueous suspension in the presence of sodium oleate conditioner. The calcite particles are then selectively absorbed by a viscous petroleum oil which is brought into contact with the suspension. Calcite removal was improved by increasing conditioner concentration, time of grinding and oil/suspension contact time. Some of the advantages and disadvantages of the process are pointed out.
Reactivity of lime and related oxides. XVII. Sulphating of lime with magnesium and aluminium sulphates
Authors: Glasson D. R. , O'Neill P.
Published: July 2010

Lime water and solid hydrated lime have been sulphated with magnesium and aluminium sulphate solutions. Changes in phase composition and sulphating rates are followed from pH (glass electrode) and conductivity measurements. The crystallinities of the products have been compared with calcium sulphate dihydrate precipitated directly from solution by double decomposition and subsequently aged.

The reactions with the solid hydrated lime are not appreciably impeded by the insoluble products, magnesium and aluminium hydroxides, which are very finely divided. These compounds provide additional surface on which most of the gypsum can form a gel when the gypsum solution saturation ratios have become sufficiently high.

The small amounts of gypsum ultimately separating out from the lime water have crystallinity inferior to the larger amounts formed from the solid hydrated lime. Both are still inferior to gypsum from acid‐sulphated lime, and are more comparable with gypsums precipitated from calcium nitrate in acidic media containing concentrations (±0.1 %) of albumen, or from calcium chloride in neutral media. Slower gypsum precipitation from calcium chloride with sulphuric acid (as in the manufacture of ‘Pearl hardening’) gives a more consistent degree of crystallinity.
Extraction of tar acids from tar oils by aqueous acetamide
Authors: Nair C. S. B. , Sen D. K. , Basu A. N.
Published: July 2010

Aqueous acetamide has been found to be a good solvent for the extraction of tar acids from low temperature carbonisation tar oils. Saturated acetamide solution at 15–30° in the molar ratio acetamide/tar acids of 3 : 1 effects a recovery of about 90% of tar acids originally present in the oil in two extraction stages. The tar acids are obtained in 77% purity, the impurities consisting of neutral oils and tar bases. Re‐extraction with light petroleum can raise the purity of tar acids to 94%. Tar acids can be separated from the purified acetamide extract by suitable dilution with water.

The system tar acids—(bases + neutral oils)—saturated aqueous acetamide has been studied. It has been shown that three theoretical counter‐current extraction stages are required to effect a recovery of 95% of tar acids from a feed oil containing 45% tar acids. 98% recovery of the tar acids could be achieved in four stages.
The characterisation of aluminium hydroxide gels by nitrogen adsorption
Authors: Bye G. C. , Robinson J. G. , Sing K. S. W.
Published: July 2010

Aluminium hydroxide gels with a range of textures have been prepared by the hydrolysis of aluminium s‐ butoxide with water, aqueous ethanol and aqueous glycerol. Crystallisation was permitted to take place to varying extents by ageing of precipitates in their mother liquors at room temperature.

Adsorption isotherms on the outgassed gels were of Types II and IV of the Brunauer classification. An examination of the data by plotting reduced isotherms (V/Vm versus P/Po) revealed the existence of reversible capillary condensation on some of the hydroxides, although the isotherms were of Type II.

The Lippens de Boer t method has been found useful in locating the onset of capillary condensation in an adsorption isotherm, but the t‐plot can be misleading with samples that have a spread of pore dimensions extending into both the micro‐ and transitional‐pore regions. This situation appears to arise in pseudoboehmites aged for extended periods so that cementation is extensive.

The principal factors influencing the texture of the gels appear to be the extent of crystallisation and the amount of inter‐particle cementation. Thus amorphous material prepared in water was found to be porous whereas that precipitated in glycerol, which apparently protects the surface of the primary particles, was non‐porous (or macro‐porous). Transitional pore systems with the best definition were obtained with pseudoboehmites, especially with those formed by ageing in aqueous ethanol. In water, the ready conversion of pseudoboehmite to low‐area, non‐porous, bayerite is a complicating factor.
Aliphatic hydrocarbons in a low‐temperature tar
Authors: Spence J. A. , Vahrman M.
Published: July 2010

The total aliphatic hydrocarbons from a low‐temperature tar were separated into four groups, each consisting of a similarly wide range of molecules (approximate boiling range of each, 175°–500°): (a) n‐alkanes; (b) branched‐chain alkanes and cycloalkanes; (c) straight‐chain alkenes; and (d) branched‐chain alkenes and cycloalkenes. In (a), n‐alkanes, and in (c), alk‐1‐enes, trans‐alk‐2‐enes and cis‐alk‐2‐enes from C10 to C37 were identified and quantitatively estimated. Group (b) contained pristane and phytane among the few predominant branched‐chain species present, and molecules with isopropyl groups and single and condensed saturated rings. Group (d) was predominantly mono‐olefinic, the double bonds probably being in the terminal position in alkyl chains; isopropyl groups were also present.
Stability of ferrous hydroxide in aqueous suspension at 300°c
Authors: Castle J. E. , Thompson R. G.
Published: July 2010

The decomposition of ferrous hydroxide in aqueous suspension at 300° and in PTFE containers has been studied. The reaction rate is slow but is catalysed by nickel and platinum. This explains the results of earlier workers who have found the decomposition of ferrous hydroxide supported in metallic containers to be rapid.
H2s in natural gas: tolerance of some national acceptance tests
Authors: Williams A. F. , Lom W. L.
Published: July 2010

Traditionally, limits on H2S concentration in town gas have been fixed on the basis of non‐discoloration of lead acetate paper when this is exposed to the gas in a specified manner. Most countries specify their own particular apparatus and conditions for carrying out this test. The limiting concentration of H2S which produces a positive discoloration of the lead acetate paper was investigated with special reference to the U.K., French and German national gas acceptance tests, using Dutch natural gas in both the saturated and dry condition in every case.

H2S was introduced into the gas at a controlled rate by a dynamic line blending procedure. The actual concentration of H2S present was checked by an automated version of the methylene blue colorimetric procedure.

The U.K. tests gave borderline fails at 1.3 and 1.2 ppm for dry and saturated gas, respectively. These results differ markedly from those obtained with the French and German test methods. It may be inferred, therefore, that the maximum acceptable H2S concentration in gas is best fixed by a numerical limit, which is in line with true technical needs, rather than by a qualitative procedure which can be different for different parts of the same distribution system.
Humidity control in the laboratory using salt solutions—a review
Authors: Young J. F.
Published: July 2010

The relative humidities maintained over saturated and unsaturated salt solutions and of some salt hydrate mixtures have been collated from the literature over a wide range of temperature. Results are presented for 38 saturated salt solutions, and details listed for salts which are recommended as suitable for humidity control. The control of humidity in the laboratory by the use of salt solutions is critically discussed.
Non‐ideal kinetics in free‐radical polymerisation
Authors: Smith D. G.
Published: July 2010

The reasons for polymerisation rates not conforming to mathematically predicted relationships are reviewed. Such non‐ideal kinetics may result from one or more of the following causes: invalid basic assumptions, degradative transfer, effect of monomer concentration on rate of initiation, diffusion control of termination, and formation of electron‐donor/acceptor complexes. Details of the characteristics of each effect are given.
Thermal dissociation of Ca(OH)2 at elevated pressures
Authors: Samms J. A. C. , Evans B. E.
Published: July 2010

The equilibrium Ca(OH)2 ⇌ CaO+H2O has been studied at pressures of steam up to 50 bars and at temperatures of up to 800° C. The dissociation pressures determined are in agreement with the data derived by some previous workers at pressures of less than one bar but they conflict with data published for higher pressures. The results can be expressed by the relation
equation image
over the range 530–800°c.
Estimation of the effective thermal conductivities of two‐phase media
Authors: Ratcliffe E. H.
Published: July 2010

A nomogram scaled in logarithmic units, and a chart are provided for estimation of the effective thermal conductivities of two‐phase media. The former is useful for precise prediction, and the latter as an approximate guide to probable limiting values. The basis is a logarithmic equation proposed by Woodside & Mesmer, biased empirically following the study of about 150 experimental results for two‐phase media. The practical uses are numerous, e.g. estimations of the conductivities of filled plastics, filled rubbers; metal, ceramic and other powders in fluids or gases; ocean sediment; waterlogged and frozen soil, and other materials.
Ion‐exchange properties of brown algae I. Determination of rate mechanism for calciumhydrogen ion exchange for particles from Laminaria hyperborea and Laminaria digitata
Authors: Myklestad S.
Published: July 2010

Algal particles from Laminaria hyperborea stipes and Laminaria digitata were exposed to a stream of hydrochloric acid in a continuous flow apparatus, and the ion‐exchange process Ca/H was investigated. The exchange rate was shown to depend upon such factors as acid concentration, particle size, agitation and time of acid residence.

The results show that the exchange rate followed a first‐order reaction in the conditions used, and the exchange velocity was proportional to the logarithm of the hydrochloric acid concentration. Evidence is given which indicates that the exchange process is governed by a film‐diffusion mechanism, and the diffusion of calcium across a thin liquid film enveloping the particle is suggested to be the rate‐determining step. Exchange experiments with particles from Ascophyllum nodosum show that another rate mechanism has to be considered in this case.
Hydrophilation of glass surfaces II Reaction of quaternary ammonium compounds with surface hydroxyl groups
Authors: Blackman L. C. F. , Harrop R.
Published: July 2010

The reaction mechanism for the adsorption of hexadecyltrimethylammonium bromide (HTAB) on silica was investigated. Although measurements of the effects of pH and concentration of HTAB tended to support a cation exchange mechanism, infra‐red analysis suggested that the adsorption was associated with a charge‐transfer type of reaction.
Thermodynamic properties of methanol–benzene mixtures at elevated temperatures
Authors: Butcher K. L. , Medani M. S.
Published: July 2010

The total pressure and the compositions of the vapour and liquid phases of the methanol–benzene system have been determined under equilibrium conditions at 100°, 120°, 140°, 160°, 180°, 200° and 220° for ten levels of concentration. The corresponding activity coefficients of methanol and benzene are reported; their values indicate that the equilibrium data are thermodynamically consistent.

An azeotrope is found at all temperatures, its methanol content increasing as the temperature is increased. The relationship log Paz = 6·5098—(1,766/T) expresses the interdependence of the azeotrope vapour pressure Paz(lb/in2 abs.) and temperature T(°K).

Estimates of integral heat of mixing (HE) and entropy change due to mixing (SE) as functions of liquid composition (xmeth) have been made from the excess free energy of mixing GE,(T) xmeth functions. Both HE and SE at a given x are positive increasing functions of temperature. These phenomena are discussed in terms of the dissociation of methanol ‘polymer’ and the formation of benzene–methanol ‘complexes’.
Novel process cycle for para‐substituted benzene derivatives
Authors: le Count D. J. , Reid J. A. W.
Published: July 2010

A novel cyclic process produces p‐cresol from toluene; toluene with iodosotoluene (derived from iodo‐toluene) gives the intermediate ditolyliodonium salt converted by catalysed hydrolysis into cresol and iodotoluene (which is recycled as ‘catalyst’.) In the final product, o‐cresol content is low and m‐cresol is undetectable. The process reaches a steady state independent of the o‐/p‐isomer ratio of the iodotoluene ‘catalyst’. In a similar way, p‐chloronitrobenzene can be made by reaction of di‐(p‐chlorophenyl)iodonium salt (derived from chlorobenzene and chloro‐iodosobenzene) with nitrite ions.
Precipitate Flotation II. Separation of palladium from platinum, gold, silver, iron, cobalt and nickel
Authors: Mahne E. J. , Pinfold T. A.
Published: July 2010

Palladium is completely removed from 5 × 10−5 M‐PdCl2 solutions using the new technique of precipitate flotation of the second kind, in which no surfactant is used to float precipitates. Recoveries were best at pH 1–2 and were not markedly dependent on temperature. Increase in ionic strength had no deleterious effect, unlike conventional precipitate flotation. Palladium can be completely separated from a 400‐fold excess of nickel, a 100‐fold excess of platinum, iron and cobalt, a 10‐fold excess of gold but not from silver in the presence of chloride ions. Equimolar amounts of palladium, nickel and platinum were completely separated from each other by successive flotations. Photographs taken of the bubbles during flotation showed that, at a flow‐rate of 3.1 litre/hour, a mean surface area of 2.07 metre2 passed through the cell per minute.
Production of Escherichia coli as a source of nucleic acids
Authors: Elsworth R. , Miller G. A. , Whitaker A. R. , Kitching D. , Sayer P. D.
Published: July 2010

Present‐day chemical and physical studies of the nucleic acid system of bacteria frequently call for quantities of cells which are beyond the capacity of traditional culture methods such as that of the shake flask. The case is therefore argued for an increased use of stirred deep cultures because a greater rate of output, at a higher cell concentration and with improved control of cultural conditions can be achieved. For the isolation of deoxyribonucleic acid and transfer ribonucleic acid, low growth‐rate cells should be the most prolific source: whereas for ribosomes, ribosomal ribonucleic acid and messenger ribonucleic acid, high growth cells should give bigger yields. It is concluded that the information is somewhat obscure on what are the best growth conditions for the production of the related‐enzymes.

A batch method for producing low growth‐rate cells of Escherichia coli, in lots of 1 kg dry wt., is then described, followed by a continuous method for producing high growth‐rate cells, with an output of 3 kg of dry cells per day. Both cultures have been designed to give maximum yield of cells by promoting maximum assimilation of the carbon substrate. From the point of view of designing a culture, the section dealing with the continuous process discusses the rationale of medium formulation, the calculation of aeration requirements and briefly reviews earlier work on the kinetics of continuous culture.
Development of a graphite (HX30) with improved gas diffusional characteristics
Authors: Longstaff B. , Jenkins T. R. , Morris J. B. , Graham L. W.
Published: July 2010

The specification of a graphite suitable for DRAGON fuel tubes which operate on the ‘back‐sweep’ purge principle includes the two requirements: (i) the viscous permeability constant B0 < 3 × 10−11 cm2, and (ii) the fission‐gas transmission coefficient D' < 1 × 10−6 cm2/sec at 20 atm., 7500, and 2 psi pressure drop. Calculations, based on the results of a study of the counter‐diffusion of gases in graphite, suggested that, providing the first criterion was satisfied, the second requirement would be met by a material whose pores were on the average at least 5·5 μm in diameter.

A series of experimental graphites based on grists of scrap nuclear‐grade graphite was made with the object of producing artefacts whose pore sizes were in the region of 10 μm, without exceeding the specified limit on permeability. After several adjustments to the size distribution of the grist, one was obtained which yielded an artefact which, after subsequent pitch impregnation, satisfied the reactor specification. The family of graphites based on this particular grist is known as HX30. A second series of experiments demonstrated that this material could be made in full‐sized rods 8 ft long by 3·25 in. dia. Any of four baking routes was possible, depending on whether the primary bake and the re‐bake after impregnation were carried out under atmospheric pressure or at 100 psig. An appropriate number (1 to 3) of impregnations yielded an acceptable graphite.

The superior properties of HX30 are considered to be due chiefly to the exclusion of fines (below 300 BSS mesh) from the grist but the nature of the grist (graphite and not coke) and the use of re‐extrusion are probably also significant. The original theoretical approach appeared to be largely vindicated by the pore‐size distribution of the successful product.