bluuebunny/crossref_metadata_2025 huggingface dataset:
Hydrophilation of glass surfaces III. Synthesis of novel quaternary ammonium compounds tested as possible promoters of filmwise condensation
Authors: Blackman L. C. F. , Harrop R.
Published: July 2010

The preparation of novel compounds containing the quaternary ammonium group is described. These compounds have been tested as promoters of filmwise condensation.
Distribution of hydrochloric acid between tri‐n‐butyl phosphate and water
Authors: Hanson C. , Patel A. N.
Published: July 2010

The distribution of hydrochloric acid between water and 40 vol.‐% solutions of tri‐n‐butyl phosphate (TBP) in six diluents and also between water and 20. 40 and 60 vol.‐% solutions of TBP in odourless kerosene and pure TBP at 20°, 30° and 50° has been studied to find the effects of temperature, diluent and TBP concentration on the extractability of hydrochloric acid and on third‐phase formation.
Kinetics of deposit formation from hydrocarbons. III. Heterogeneous and homogeneous metal effects
Authors: Taylor W. F.
Published: July 2010

The nature of metal surfaces (‘heterogeneous’ metals) and the presence of metal complexes (‘homogeneous’ metals) both markedly influence the rate of formation of deposits from hydrocarbon jet fuels at 200 to 500° F in the presence of oxygen. Copper surfaces and titanium alloy surfaces which contain vanadium were found to be particularly deleterious. The addition of 50 ppm metal using various metal acetylacetonates to the hydrocarbon fuel increased the rate of deposit formation by a factor of from 40 to 120 at 300° F. Copper acetylacetonate produced a higher rate of deposit formation than iron, nickel or cobalt acetylacetonates. The relative rate of deposit formation depended on the square‐root of both the vanadium content of the titanium alloys and the concentration of a ferric acetylacetonate in the fuel.
Surface chemistry of the calcination of gelatinous and crystalline aluminium hydroxides
Authors: Aldcroft D. , Bye G. C. , Robinson J. G. , Sing K. S. W.
Published: July 2010

The surface properties of a range of aluminas, obtained by calcination of crystalline and gelatinous aluminium hydroxides at temperatures from 300° to 1000° and characterised by X‐ray powder diffractometry, have been examined by nitrogen adsorption.

On calcination the hydroxides exhibited two distinct types of behaviour which can be related to their texture. Crystalline hydroxides underwent a pronounced activation, the increased surface area being almost wholly confined to the small pores (micro and transitional pores) formed on dehydration. Gelatinous hydroxides, on the other hand, had high surface areas before calcination and these underwent a progressive diminution in the temperature range studied.

The structures obtained on calcination depended to a marked degree on the crystallinity of the starting materials. Between 500° and 800°, the amorphous hydroxide and poorly organised pseudoboehmites gave ill‐defined γ‐aluminas whereas the crystalline trihydroxides gave well‐defined η‐ and θ‐aluminas. At 1000°, the product from the amorphous hydroxide still retained a surface area of 132 m2/g, this high residual area being in character with the slowness of the conversion to δ‐and α‐alumina.

An empirical approach is used to analyse the adsorption data in terms of three mechanisms of adsorption: monolayer‐multilayer coverage, capillary condensation, and micropore filling.
Oxidation of thiols in gas‐liquid systems. I. Reaction in the absence of added metal catalysts
Authors: Cullis C. F. , Hopton J. D. , Trimm D. L.
Published: July 2010

Studies have been made of the kinetics of the reaction with oxygen of several simple aliphatic and aromatic thiols in alkaline solution and in the absence of added metal catalysts. The results have been shown to be markedly affected by trace amounts of impurities, and the kinetics of the reaction have been measured under conditions of the minimum impurity levels obtainable. Under these conditions in the early stages of reaction, the rate law with, for example, ethanethiol has been found to be:
equation image
which after ≈ 10–30% of reaction changes approximately to:
equation image

Values of the energies of activation and pre‐exponential factors for the oxidation of ethanethiol have been determined and investigations have been made of the effect on the reaction kinetics of the efficient removal, and of the addition of trace quantities of metals.
Observations on calcium sulphate dihydrate formed in media rich in phosphoric acid. II. Derived calcium sulphate hemihydrate
Authors: Adami A. , Ridge M. J.
Published: July 2010

A study was made of the properties of calcium sulphate hemihydrate prepared by the calcination of dihydrate formed in a medium containing finally 29·4% P2O5 and 5·6% H2SO4. When the original dihydrate had been precipitated in uncontaminated acid, hydration of the hemihydrate seemed to be normal. However, when the medium of precipitation contained hydrofluoric acid and salts of iron and aluminium, the calcination product was not susceptible to a retarder that markedly affected the hydration of commercial calcined gypsum. The presence of P2O5 did not appear to be responsible for this type of defect.

The bulk volume and water requirement seemed to be normal when the crystal forms of the component grains were normal.

Observations are made on the strengths of the derived cast gypsum.
Brittle point of road tar
Authors: Briggs D. K. H. , Croft J. A.
Published: July 2010

An automated version of the Fraass brittle‐point test has been constructed which gives easier operation and better reproducibility than either an earlier modification or the original test.

The brittle‐point data for road tars have been shown to vary linearly with the equiviscous temperature of the materials. The use of the test to study the modification of road tar is illustrated, and it is proposed for the examination of the effects of weathering.
Ageing of some commercial oxide powders on storage
Authors: Giles C. H. , Easton I. A. , Trivedi A. S.
Published: July 2010

Some samples of technical grade silica and titania on storage for several years at room temperature show loss of apparent surface. The loss is attributed to dehydration of surface hydroxy‐groups. This can cause adhesion and aggregation of particles whereby the surface measured both by nitrogen and by dyes decreases, and, in some cases, causes a loss of surface reactivity.

With heating at temperatures up to 250°, the loss of apparent surface of silica is increased, but that of titania is partly restored. It is suggested that these effects may influence specific surface measurements made by vapour phase adsorption if high temperature out‐gassing is employed.
Ultra‐violet absorption spectra: 4‐hydroxy coumarins
Authors: Mehta M. J. , Hegde R. S. , Bhatt R. A. , Patel D. J. , Bafna S. L.
Published: July 2010

The ultra‐violet absorption, in the range 250 mμ—350 mμ, of twelve 4‐hydroxy coumarins in methanol and in 10% aqueous methanol over a range of pH, has been studied and discussed.
Foam separation of active carbon
Authors: Grieves R. B. , Chouinard E. F.
Published: July 2010

An experimental investigation is presented of the foam separation of powdered active carbon, equilibriated with an aqueous, synthetic waste water containing phenol and a cationic (ethylhexadecyldimethylammonium bromide (EHDA‐Br)), anionic (dodecyl sodium sulphate), or non‐ionic (alkyl phenoxy polyethoxy ethanol) surfactant. The effect of surfactant, of pH, of initial carbon concentration, and of initial surfactant concentration on the flotation of carbon is investigated. At pH 3, 7, and 10, the cationic surfactant yields the best flotation of carbon, which increases with increasing pH. At pH 7, a suspension containing 800 mg/1 carbon can be reduced to 24 mg/1 in 10 min. with 0·37 mM EHDA‐Br. The relative concentrations of carbon and of surfactant must be controlled carefully to yield sufficient free surfactant to obtain a foam but not excessive free surfactant to impair the foam separation process. Foam volumes are controlled by free (non‐adsorbed) surfactant.
An infra‐red frequency shift method for the determination of the high‐temperature phases of aluminosilicate minerals
Authors: Mackenzie K. J. D.
Published: July 2010

Shifts in the frequency of certain peaks in the i.r. spectrum of kaolinite during mullite formation were correlated with X‐ray analysis data for the high‐temperature phases. The method provides a means of following the high‐temperature reactions of these minerals, and is rapid, requires only small amounts of sample (mg), and is accurate even for samples of low crystallinity.
Reactions of histidine
Authors: Hirsch A. , Richardson K.
Published: July 2010

The reactions of histidine were studied with the aim of converting this amino acid to 4‐vinylimidazole, but a commercially attractive scheme could not be developed.
Formation and reactivity of borides, carbides and silicides. II. Production and sintering of boron carbide
Authors: Glasson D. R. , Jones J. A.
Published: July 2010

The principal methods of boron carbide production are compared and their thermodynamics are examined. Mechanism of carbide formation and sintering of the products are discussed and investigated further. High‐purity stoicheiometric B4C of submicron size was produced on a semi‐technical scale by reduction of diboron trioxide with carbon and magnesium. Rates of sintering were determined from changes in surface areas and average crystallite and aggreagte sizes.

Sintering of boron carbide was enhanced by increased temperature and time of calcination. Addition of chromium accelerated sintering at temperatures above 1600° and especially at 1800°. For more extensive sintering, submicron powders from the magnesium reduction process were more suitable than the coarser samples given by the electro‐thermal carbon reduction; the latter required ballmilling to provide suitable grain size composition for effective hot pressing.
Note on stability of p‐nitrophenol in aqueous solutions
Authors: Rao S. R. , Ramakrishna V.
Published: July 2010

It has been shown that p‐nitrophenol (PNP) solution is stable only at pH ≥ 9 when PNP is in the completely ionised form. In benzene, PNP exists in a neutral molecular form. These considerations are important in the estimation of surface areas of solids by adsorption of PNP from solution.
An impact test for road binders
Authors: Briggs D. K. H.
Published: July 2010

A study has been made of the energy absorbed in rupturing a road binder film in a pendulum impact machine. At high temperatures the energy is absorbed by viscous traction, at low temperatures by elastic strain energy, and in the intermediate visco‐elastic region the energy rises to a marked maximum providing optimum conditions for stone retention by the binder.

A standard test at − 10° gives an energy value, under conditions of brittle fracture, which is demonstrated to be suitable for comparing tars of known equiviscous temperatures and which reflects the width of the visco‐elastic peak, giving a measure of resistance to brittle failure of the binder.
Crystallisation processes in aluminium hydroxide gels. IV. Factors influencing the formation of the crystalline trihydroxides
Authors: Aldcroft D. , Bye G. C. , Hughes C. A.
Published: July 2010

The formation of crystalline aluminium trihydroxides from aqueous suspensions of pseudoboehmite, obtained by the hydrolysis of aluminium s‐butoxide, has been examined by X‐ray diffractometry, nitrogen adsorption and dilatometry.

The results obtained have been interpreted in terms of a mechanism involving dissolution of the pseudoboehmite. For those suspensions with which the recrystallisation was followed dilatometrically, first‐order kinetics were found, suggesting that random nucleation of trihydroxide crystals is involved. The rate of recrystallisation was decreased by the addition of organic solvents to the aqueous suspension and also, initially, by an increase in temperature. At the same time the proportion of gibbsite produced in admixture with bayerite was reduced and that of nordstrandite increased. It is concluded that the retardation is due, at least in part, to an increase in the crystallinity of pseudoboehmite which has been found to accompany the introduction of the organic solvents. The increased crystallinity must result in a decrease in the solubility and rate of solution of pseudoboehmite; under these conditions nordstrandite formation appears to be promoted.

Neutron activation and spectroscopic analysis of hydroxide samples showed that storage of aqueous suspensions in glassware resulted in pick‐up of sodium and silica at the ppm level. The changes in these levels as recrystallisation occurred suggested that retention of the products of glass dissolution was occurring in a way which depended on the surface area of the hydroxide. No variation related to the phase composition of the trihydroxide mixtures was observed.
Formation and reactivity of nitrides. IV. Titanium and zirconium nitrides
Authors: Glasson D. R. , Jayaweera S. A. A.
Published: July 2010

The reactivities of the interstitial titanium and zirconium nitrides have been compared. Samples of these nitrides have been converted to oxides by being calcined in air. Changes in phase composition, surface area, crystallite and aggregate sizes have been correlated with oxidation time and temperature.

Crystallites of rutile, TiO2, split off from the remaining titanium nitride before they sinter, and inhibit further oxidation. Zirconium nitride oxidation is complicated by formation of tetragonal ZrO2 at higher temperatures, particularly over 1200°, and monoclinic ZrO2 at lower temperatures. The nitride initially forms the so‐called ‘amorphous’ cubic ZrO2, notably between 400–600°, which may be stabilised somewhat by the remaining cubic ZrN. Subsequently, there is a further fractional volume increase while formation of monoclinic ZrO2 is being completed.
Arsenical creosote. VII. Structures of reaction products of arsenic trioxide with some hydroxyaromatic compounds
Authors: Johanson R.
Published: July 2010

Arsenic derivatives of aromatic compounds having vicinal hydroxyls have been prepared by reacting the compounds with arsenic trioxide in paraffin oil or by fusion of the reactants. The derivatives have been studied by various methods, including i.r., n.m.r. and mass spectrometry, and it is suggested that they are bis(o‐phenylenedioxy arsenic) ethers, with H, CH3 and OH substituted in the 3 and 4 positions of both benzene rings symmetrically, depending on which dihydroxybenzene derivative was used in their preparation.
Fischer–tropsch waxes. III. Indications of molecular order in molten wax
Authors: le Roux J. H.
Published: July 2010

Although paraffins cannot form liquid crystals, evidence of the existence of some kind of molecular order at temperatures above their melting points can be found in the literature. When the infra‐red spectra of certain Fischer–Tropsch waxes were recorded at different temperatures, it was noticed that the intensity of the 1303 cm−1 band (A1303), which is due to methylene groups in amorphous regions, was abnormally low just above the melting points of the waxes. At higher temperatures the intensity rose to a maximum followed by the normal decline. This effect was shown most strikingly by super‐hard wax, which has a high crystallinity and high average molecular weight.

A dilatometric experiment with super‐hard wax showed that the specific volume rises linearly from the melting point (111°) to ∼ 125°. At higher temperatures, although the volume continues to rise linearly, the slope is reduced by 11%. The explanation presented for both phenomena is that bundles of molecules are present above the melting point. They are remnants from crystallites and disappear at ∼ 125°. in the case of super‐hard wax. Upon cooling, however, the ordering of molecules only starts taking place near the congealing point. This is borne out by the linear changes in A1303 and specific volume that have been observed.
Fischer‐tropsch waxes. IV. Qualitative and quantitative investigation of chain branching
Authors: le Roux J. H.
Published: July 2010

The degree of branching of waxes, expressed as the number of branches per 100 carbon atoms, is important because it determines crystallinity, which in its turn influences physical properties. Among several methods available for the study of branching, an infra‐red spectrometric method was chosen. It consisted of the determination of methyl groups. It was also necessary to determine molecular weight.

The most serious problem encountered was the variation of the specific absorbance at the chosen frequency (1379 cm−1) with the structural position of the methyl group, which necessitated a thorough qualitative investigation of the branches, using infra‐red, nuclear magnetic resonance and mass spectrometry. It was shown that branches in the Fischer‐Tropsch waxes are almost entirely methyl and that the branching is seemingly distributed statistically along the chains. Calibration was effected with pure n‐ and mono‐methyl paraffins, making the determination of degree of branching possible. This method can be applied to other materials provided that certain structural features about them are known.
Surface area and pore structure of talc‐magnesite
Authors: Girgis B. S. , Girgis L. G.
Published: July 2010

The effect of thermal treatment on talc‐magnesite in the presence of air in the temperature range 500–1000°, was studied by nitrogen adsorption and followed by t.g.a., d.t.a. and X‐ray analysis. From the nitrogen adsorption isotherms, the specific surface area as well as pore‐size distribution was estimated. The surface area increased with temperature, to reach a maximum at 600°. On immersion of the calcination products in water, magnesium hydroxide was formed. Decomposition of the hydration products in air at 450° resulted in solids of relatively higher surface areas, whereas decomposition in vacuo at the same temperature produced more active solids. Surface area of the products produced in vacuo decreased only slightly with the primary decomposition temperature, and they are characterised by sharp pore‐size distribution curves. Surface areas of the products produced in air were dependent on the primary calcination temperature, although they showed pore‐size spectra similar to those of the other products. Products obtained by direct decomposition in air showed wider pore spectra that shifted towards higher pore radii with rise of temperature.
Synthesis of benzoic acid from chlorobenzene under pressure
Authors: Palit S. K. , Tripathy N.
Published: July 2010

Conversions as high as 76·26% and 80·85% of chlorobenzene to benzoic acid were obtained when chlorobenzene was carboxylated with carbon monoxide and water at high pressure with nickel iodide‐silica gel catalyst (Ni:SiO2 = 50:50) and without any catalyst (thermal) respectively, at the optimum temperature and pressure; these optima were much higher for the latter than for the former process. The lower yield in the catalytic process could be improved to some extent if the catalytic reaction was carried out at a pressure, reached by introducing nitrogen in addition to the usual input of carbon menoxide, almost equal to the optimum pressure of the thermal process.
Dehydration and rehydration behaviour of zinc and magnesium sulphate heptahydrates
Authors: Razouk R. I. , Mikhail R. Sh. , Ghorab H. Y.
Published: July 2010

The kinetics of the isothermal dehydration of zinc and magnesium sulphate heptahydrates were studied both in vacuo and in the presence of air. Decomposition in vacuo followed a first‐order mechanism, while that in the presence of air followed an interfacial mechanism obeying the Avrami–Eroféev equation. In the case of zinc sulphate decomposing in air, the fusion of the salt in its water of crystallisation interfered with the observed phenomena. The energy of activation in both cases was calculated to be comparable to the latent heat of vaporisation of water, and it is suggested that this would measure the heat of desorption of water from the surface of the dehydration product. When decomposition was carried out in vacuo at comparatively elevated temperatures, the process changed to an activated diffusion or surface diffusion. Dehydration in vacuo yielded an amorphous intermediate, as well as final products, whereas dehydration in the presence of air yielded crystalline products. Differential thermal analysis proved the stepwise nature of the dehydration process.

The rehydration from the vapour phase was also studied on the dehydration products of both zinc and magnesium sulphate heptahydrates, and it was shown that the rehydration isotherms could be significantly affected by both the extent and the nature of the surface of the dehydration product. The specific surface areas were measured by low temperature adsorption of nitrogen.
Nuclear magnetic resonance cryoscopy. I. A method of purity control
Authors: Herington E. F. G. , Lawrenson I. J.
Published: July 2010

A cryoscopic method of purity control is described which uses nuclear magnetic resonance to measure the fraction of liquid molten at a temperature below that at which the sample is completely molten. This method, which offers several advantages over other cryoscopic procedures for purity determination, is demonstrated by measurements on several systems, including phenol containing water or one of the three cresols as impurity.
Nuclear magnetic resonance cryoscopy. II. A method for the determination of solid‐liquid phase diagrams
Authors: Herington E. F. G. , Lawrenson I. J.
Published: July 2010

The study of solid‐liquid phase diagrams by nuclear magnetic resonance cryoscopy is demonstrated by measurements on the systems phenol‐m‐cresol, phenol‐o‐cresol and 1‐methylnaphthalene‐2‐methylnaphthalene. This method enables the true position of the equilibrium solidus to be found, even when the two components are not uniformly distributed in the solid and total equilibrium is not achieved.
Effect of high‐temperature direct‐current electrolysis on properties of hydrous aluminosilicates
Authors: Mackenzie K. J. D.
Published: July 2010

The application of a d.c. potential to kaolinite and halloysite pellets during firing under reduced pressure has been found to produce significant improvements in the hardness, tensile strength, and density of the product. Studies of these properties as a function of voltage, electrolysis time and temperature, and firing atmosphere are reported. X‐Ray and i.r. studies of mullite formation at the electrode faces indicate enhanced crystallinity at the negative electrode. The electrolysis mechanism is thought to involve the removal of residual protons normally present even at high temperatures.
Physicochemical studies on the water‐yeast cells‐gas‐oil system
Authors: Srivastava S. P. , Singh H. D. , Baruah J. N. , Krishna P. V. , Iyengar M. S.
Published: July 2010

Physical characteristics of the hydrocarbon fermentation broth obtained during the microbial synthesis of protein concentrates from mineral oil have been studied. The effect of pH and the action of electrolytes and various organic compounds on the stability of the emulsion were investigated. It has been possible to obtain a fairly stable emulsion containing more than 85% of oil in the internal phase by the use of dry yeast cells. The strong hydrophilic character of the yeast cell membrane and the lowering of interfacial tension between the mineral oil and water are responsible for the unique stability.
Solubilisation of some bituminous coals in quinoline by ultrasonic irradiation
Authors: Kessler T. , Friedel R. A. , Sharkey A. G.
Published: July 2010

The solubilisation of 4 hvab and 1 hvbb coals by ultrasonic irradiation of coal‐quinoline systems at ambient temperature was investigated. The amount of coal solvated was found to be a function of time and particle size. The use of a char prepared at the temperature of maximum coal fluidity increased the amount of material solubilised. There was little difference in the amounts of coal solubilised at 36° and 80°. There was a decrease in the sulphur and ash content of the solubilised coal compared with the starting coal. Quinoline can be re‐used as a solvent with no decrease in solubilisation efficiency.

Based on high‐resolution mass spectrometric and infra‐red spectroscopic investigations and particle size measurements of the solubilised material, it appears that the increased solubilisation of coal in quinoline results from a grinding action and not a chemical action.
Epoxidation of ethylenic linkages by chromic acid IV. Oxidation of triaryl olefins by chromium trioxide
Authors: Moussa G. E. M. , Abdalla S. O.
Published: July 2010

The oxidation of 1,1,2‐triphenylbut‐1‐ene by chromium trioxide in acetic anhydride gives 1,2‐epoxy‐1,1,2‐triphenylbutane with fission products and 1,1,2‐triphenylacetylethylene. Cis‐ and trans‐1‐p‐chlorophenyl‐1,2‐diphenylprop‐1‐ene yield crystalline epoxides in satisfactory yields under similar conditions. The epoxides are stable towards aqueous sulphuric acid. 1,1,2‐Triphenylethylene, 1,1‐di‐(p‐chlorophenyl)‐2‐phenylethylene and 1,1‐di‐(p‐bromophenyl)‐2‐phenylethylene are similarly oxidised but the epoxides are hydrated to the glycols by the action of aqueous sulphuric acid.

Chromic acid in aqueous sulphuric acid brings about oxidative fission of the double bond without any rearrangement.
Course of oxidation of 1, 1‐disubstituted ethylenes by chromic acid
Authors: Moussa G. E. M. , Eweiss N. F.
Published: July 2010

The oxidation of 1,1‐diphenylethylene by chromic acid gives a fair yield of diphenylacetic acid. 1,1‐Di‐(p‐chlorophenyl)ethylene and 2‐phenylprop‐1‐ene are similarly oxidised to acids which have the same number of carbon atoms as the original olefins. 2‐Phenyl‐3,3‐dimethylbut‐1‐ene and 1,1‐di‐(p‐tolyl)ethylene give abnormal fission products on chromic acid oxidation. The significcane of these results is discussed.
Kinetics of the oxidation of carbon monoxide on a supported ferric oxide catalyst
Authors: Goodridge F. , Nicholson P. J. , Nadim M.
Published: July 2010

Kinetic studies were made of the oxidation of carbon monoxide to carbon dioxide in a fixed bed of ferric oxide catalyst. It was found that the rate of oxidation, R, is given by the equation R = k1 k1pco/1+(k1/k2)pco where k1, k1 and k2 are constants and pco is the partial pressure of carbon monoxide. This rate law is similar to that derived for the same reaction on a vanadium oxide catalyst. The rate equation reduces to first order for carbon monoxide concentrations < 1 %.
Adhesion test for road surface dressing binders
Authors: Briggs D. K. H. , Croft J. A.
Published: July 2010

A study has been made of the adhesion of chippings to a film of road tar, supported on a base plate, under conditions similar to those encountered in surface dressing, but without interlock of stone particles. Chippings are removed by inertial stresses set up in them when a carefully regulated blow is applied to the base plate.

A critical adhesion temperature, above which chippings should be applied to road tar, has been shown to be about 32 deg. c below the equiviscous temperature (e.v.t.) for clean, dry basalt chippings; a lower value is shown to apply in the case of PVC‐modified tar.

Results indicate that the unit reasonably simulates service conditions and its use is proposed for additional studies.
Formation and surface properties of electron‐emissive coatings V. DTA, ETA and dilatometry studies on some alkaline–earth carbonates
Authors: Judd M. D. , Pope M. I.
Published: July 2010

The decomposition under vacuum of the carbonates of calcium, strontium and barium was investigated by differential thermal analysis (DTA), electrothermal analysis (ETA) and dilatometry.

The results indicate that the rates of sintering of the oxide produced by the decomposition of the corresponding carbonate are in the order predicted by their respective Tammann temperatures, i.e. BaO>SrO>CaO. DTA studies on the decomposition of samples of barium carbonate have shown that great care must be taken to ensure that the decomposition is carried out under the highest vacuum attainable, in order to eliminate the formation of a basic carbonate. Further evidence of the formation of free barium by this decomposition process is also reported.
The alleged phospholipid of wool wax
Authors: Morris T. A. , Truter E. V.
Published: July 2010

Analysis of methanolic extracts of wool grease for nitrogen and phosphorus, and laminar chromatography of the ether‐insoluble fraction obtained from the methanol‐soluble portion, showed that wool wax does not contain phospholipids but it does contain traces of polypeptides and inorganic phosphate. These results conflict with the results of other workers, but possible explanations of false conclusions drawn from the latter results are given.
Air‐entraining actions of anionic surfactants in portland cement pastes
Authors: Bruere G. M.
Published: July 2010

The air‐entraining actions of a number of anionic surfactants in cement pastes were studied in order to determine whether precipitated calcium surfactants influence the air‐entrainment process. Air contents of pastes containing both soluble and precipitated calcium surfactants were higher than those containing only soluble calcium surfactants, thus indicating that precipitated material contributed towards air‐entrainment. It was shown further that the precipitated calcium surfactant could re‐dissolve appreciably during mixing and supply additional surfactant ions in solution to replace those adsorbed on cement. It was concluded that these additional ions contributed to air‐entrainment by further adsorption on cement particles and by augmenting the foam capacity of the mixing water.
Sorption of sulphur dioxide by indoor surfaces III.—Leather
Authors: Spedding D. J. , Rowlands R. P. , Taylor J. E.
Published: July 2010

The sorption of sulphur dioxide by a wide range of leather samples has been investigated at a concentration of ∼ 100 μg/m3 using sulphur‐35 dioxide. In general, the sulphur dioxide was sorbed evenly over the leather surfaces, the sorbed sulphur being water‐soluble. The position on the hide from which the leather was taken had no significant effect on the amount of sulphur dioxide sorbed. The total uptake of the gas was reduced by the application of a finish and by dyeing. The penetration of sulphur dioxides into the samples was influenced by the nature of the organic retanning process used, condensed tannins leading primarily to surface sorption. Leather greases were also shown to reduce penetration of sulphur dioxide. Some implications of these results in the degradation of leathers by atmospheric sulphur dioxide are discussed.
Fluidised‐bed fuel‐cell electrodes
Authors: Berent T. , Mason R. , Fells I.
Published: July 2010

A study is described of both anodic and cathodic fluidised‐bed fuel‐cell electrodes operating with dissolved reactants. Two different trends were observed. With cathodes, the apparent polarisation decreased with increase in fluidisation and with anodes the apparent polarisation increased with increase in fluidisation. These effects are thought to be due to different reaction mechanisms and the different nature of the bed materials.
Kinetic relationship of coal hydrogenation, pyrolysis and dissolution
Authors: Wiser W. H. , Anderson L. L. , Qader S. A. , Hill G. R.
Published: July 2010

Data are presented concerning the production of gaseous and liquid products from coal. The processes considered include pyrolysis, dissolution in solvent with and without the application of ultrasonic energy, batch hydrogenation, and continuous hydrogenation. The products are compared with respect to both quantity and type. Activation energies are presented and mechanisms discussed. Coal hydrogenation in the presence of an appropriate catalyst shows very great promise as a means of converting coal to liquid and gaseous fuels. Yields of 30% high octane gasoline, 5% diesel oil, 35% high Btu gas, and 30% char, on a weight basis, have been achieved.
Dimerisation and double‐bond isomerisation of olefins with a homogeneous nickel II‐complex as catalyst
Authors: Hojabri F.
Published: July 2010

Dimerisation of propylene and double‐bond isomerisation of olefins with a new nickel catalyst are described.
Comparison of isothermal adsorption data by the technique of absolute adsorption
Authors: Clough P. S. , Dollimore D. , Nicklin T.
Published: July 2010

A method of comparing adsorption data, obtained for samples within a series and having similar surface characteristics, is described. It is shown that the surface interaction with polar molecules increases quite markedly as the polar nature of the surface changes. The use of a non‐polar molecule established that the effects observed were genuine.
Formation and surface properties of electron‐emissive coatings VI. Structure and decomposition of co‐precipitated carbonates
Authors: Judd M. D. , Pope M. I.
Published: July 2010

The decomposition, under vacuum, of some co‐precipitated alkaline‐earth carbonates has been further investigated by applying the techniques of differential thermal analysis (DTA),† electrothermal analysis (ETA) and dilatometry.

The results supplement previous work by confirming that decomposition of double and triple carbonates proceeds in two and three distinct stages, respectively. Loss of carbon dioxide from the strontium carbonate component of a double (SrBa) carbonate leads to a breakdown in the crystal structure, forming a mixture of strontium oxide and barium carbonate. Decomposition of the barium carbonate commences before decomposition of the strontium carbonate is complete. With a triple (CaSrBa) co‐precipitated carbonate, thermal decomposition of the calcium carbonate component results in a mixture of calcium oxide with the corresponding double carbonate: DTA shows conclusively that the mixture does not contain the single strontium and barium carbonates.
Application of the B.E.T. method to differentiating manganese dioxide modifications
Authors: Kolta G. A. , Abdul Azim A. A. , Girgis B. S.
Published: July 2010

Manganese dioxide samples belonging to the α‐, γ‐ and δ‐groups have been subjected to surface area measurements (B.E.T. method) and X‐ray examination before and after heat treatment at 350 and 450°c. The change in surface area of the different samples is explained in terms of two processes which act in opposite ways, namely, creation of pores and cavities (left by the escaping water), and crystal growth. The surface areas of some local and imported natural samples of manganese dioxide as well as the β‐group have been also determined.
Mechanical properties of bitumen in relation to road performance
Authors: Dormon G. M. , Snashall H. M.
Published: July 2010

The importance of the flow and fracture of bitumens was investigated, and the conditions arising during the application of a dense asphalt mix and the performance in service of various asphalt surfacings were considered. Methods of measuring these properties are described.

With the aid of results obtained by methods devised for the direct measurement of bitumen properties at short and long times of loading, suitable for all kinds of binders, or using results deduced by means of nomographs, it should be possible to draft bitumen specifications covering their mechanical properties in engineering terms, which will be significant from the point of view of road performance over the whole range of conditions likely to be experienced in practice.
Thermal decomposition of sodium dithionite
Authors: Flaherty B. , Bather J. M.
Published: July 2010

The thermal decomposition of sodium dithionite (Na2S2O4) in the solid state was investigated by differential scanning calorimetry and the exothermic heat of decomposition was determined. The effect of isothermal pretreatment at various selected temperatures on the subsequently determined decomposition temperature was studied, together with the effect of sample weight on the decomposition temperature and degree of exothermicity.
Preparation of schoenite and sulphate of potash from mixed salts obtained in solar evaporation
Authors: Choudhari B. P.
Published: July 2010

Potassium is deposited as kainite and/or carnallite by solar evaporation of sea and inland bitterns, respectively. The solubility of this natural kainite in water was found to be at 20 g magnesium chloride per 100 g water as against at 27.5 g obtained with synthetic kainite. As a result, the equilibrium data available from conventional phase diagrams were found to be not applicable for the conversion of kainite to potassium schoenite, an intermediate product to obtain potassium sulphate. Therefore applicability of the system K2Cl2‐MgSO4‐H2O to natural kainite was investigated and equilibria in reactions in slurries and optimum yields were worked out.
Microstructure of hardened gypsum pastes
Authors: Sh. Mikhail R. , Malek R. I. A.
Published: July 2010

Specific surface areas and pore size distribution analysis were taken as essential parameters to explore the microstructure of hardened gypsum pastes. The hydration of gypsum plaster is essentially affected by the water/plaster ratio of the mix, and by the presence of additives which might act as retarders or accelerators to the hydration process. Affecting the microstructure would mutually lead to variations of the compressive strength of the hardened pastes, and these variations are also discussed.

Results are mainly expressed in terms of the solid (measured by the extent of its specific area) to the space (pore) ratios. Dual distribution of pore sizes was observed and the two groups of pores are designed as S (small) and L (large) pores. Similarities to the microstructure of hardened Portland cement pastes are indicated. Accelerators appear to function differently from retarders, and the effects of water/plaster ratios were investigated in both cases. The results obtained may carry many significant practical implications to the future use of hardened gypsum pastes.
Studies on the autoclave dehydration of gypsum
Authors: Combe E. C. , Smith D. C.
Published: July 2010

The effects of some additives on the autoclave dehydration of gypsum have been determined. It was possible to accelerate the reaction by the addition of calcium sulphate hemihydrate or orthorhombic calcium sulphate to the gypsum. Plasters prepared by the sodium succinate method in the presence of the latter additive had a high water requirement and poor mechanical properties.
The catalytic dealkylation of alkylphenols at atmospheric pressure
Authors: Milnes M. H. , Dean R. E.
Published: July 2010

A comparative survey has been made of alkaline, fluorine‐containing, and charcoal‐based materials as potential catalysts for the vapour phase dealkylation of alkylphenols. o‐Cresol was used as the feed in an initial screening, and those catalysts showing most activity were then subjected to a more detailed study using higher‐boiling feedstocks. The most interesting results were obtained using aluminium borofluoride or zinc fluoride, each on a γ‐alumina support. In addition to extensive dealkylation, these catalysts also gave rise to isomerising effects. Their activity, however, rapidly declined because of carbon deposition, but could be fully restored by heating in an oxygen/nitrogen stream. The use of metal‐impregnated charcoals gave more selective dealkylation than active charcoal alone, but the improvement did not warrant the additional cost; moreover these materials could not be revivified by conventional means. The alkaline catalysts displayed a lower level of activity and could not be completely regenerated after deactivation because of carbonation in addition to carbon deposition.
Organic polysulphides in town gas: I. The corrosion problem
Authors: McGrath L. , Prebble K. A.
Published: July 2010

Blockage of small‐bore copper tubing in gas appliances has sometimes arisen from the presence of copper sulphide scale formed by attack on the copper by organic sulphur compounds in the gas. The sulphur compounds responsible for this attack which occurs at atmospheric temperatures, are identified as organic polysulphides, probably the lower aliphatic trisulphides and tetrasulphides, formed from mercaptans and elemental sulphur. Such reactions are shown to occur under the influence of a base catalyst such as lime, and under the conditions existing in the iron‐oxide purifying plants used to remove hydrogen sulphide from fuel gases; mercaptans are present in the gas, and sulphur in the purifying material.

A colorimetric test using piperidine has been developed for determining organic polysulphides in fuel gases at concentrations below 1 part/million v/v.

Some comments are given on the relevance of polysulphide formation and corrosion to the distribution of North Sea natural gas.
Design and construction of a freeze dryer incorporating improved standards of biological safety
Authors: Parker J. , Smith H. M.
Published: July 2010

This paper describes the design of a mobile, versatile manifold‐type freeze dryer which is sealed continuously throughout primary drying, secondary drying, ampoule sealing and in situ steam disinfection of all potentially contaminated surfaces. Construction is based upon standard components, modular in design and fully interchangeable. An all‐metal liquid nitrogen‐refrigerated vapour condenser, Pyrex glass ampoules and rigid glass‐to‐metal or metal‐to‐metal “O” ring connections are features dictated by the use of low pressure steam for in situ disinfection.

The machine attains standards of biological safety and control not available with commercial freeze dryers but which would seem of considerable value to the many specialist laboratories lyophilising reference or stock samples of various microorganisms.
The self heating of commercial powdered activated carbons
Authors: Cameron A. , Macdowall J. D.
Published: July 2010

The self heating characteristics of a series of activated carbon samples have been studied in relation to their chemical/physical properties. It appears that ease of self heating is related to the oxygen content of the carbon on a dry ash free basis, and from this it can be shown that all carbons manufactured by the steam activation process can be considered non‐hazardous for shipping purposes.

A simple test is described to differentiate between the potentially hazardous and non‐hazardous in chemically activated carbons and semi‐products.

The results of this investigation are fully supported by the shipping records over the past 40 years of European carbon manufacturers who are responsible for over 50% of activated carbon shipped world wide.
The synthesis of barium hexaferrite from iron oxide and barium carbonate: II. The role of iron oxide texture
Authors: Bye G. C. , Howard C. R.
Published: July 2010

The texture of several samples of laboratory‐prepared and commercial iron oxide and their reactivity with barium carbonate (BaCO3.6Fe2O3) has been examined. The first stage of the reaction involves decarbonation with the formation of monoferrite and dynamic thermogravimetry was used to assess mix reactivity. While some of the variation in the behaviour of iron oxide powders could be appreciated from an examination of their texture by scanning electron microscopy and porosity determination, prediction of their reactivity was not possible. In fact the reactivity of the mix can best be considered to give an indication of the efficiency of mixing of the finer iron oxide particles with the barium carbonate. In the subsequent formation of barium hexaferrite the coarse end of the iron oxide particle size range is of primary importance since it controls the rate of completion of the reaction. The larger aggregates in an iron oxide sample can readily be detected by scanning electron microscopy but conclusions regarding reactivity may be erroneous if this coarse material is dispersed during mixing. It was shown by scanning electron microscopy that the least reactive iron oxide sample examined contained aggregates which survived the mixing process employed.
Thermodynamic properties of the benzene and n‐heptane system at elevated temperatures
Authors: Butcher K. L. , Ramasubramanian K. R. , Medani M. S.
Published: July 2010

The total vapour pressure and the composition of the liquid and vapour phases of the benzene and n‐heptane system have been experimentally determined under equilibrium conditions at 110, 125, 140, 155, 170, 185, 200 and 215 °C. The corresponding composition of the vapour phase was also estimated using an expression for the liquid phase activity coefficient as a function of the composition of the liquid phase. Several expressions were compared and it has been found that the three‐constant Redlich and Kister equation gave the best fit of the experimental vapour pressure data than the other equations.

Comparison between the calculated and measured vapour compositions has shown a discrepancy of ymeas,—ycalc. of the order of 0.02 mol fraction or 10 times the experimental tolerance. Nevertheless, the experimental values were reasonably thermodynamically consistent.

The low values of the liquid phase activity coefficients indicated that the behaviour of this particular system was not far from ideality. Also, it was found that the degree of non‐ideality decreased with the increase in temperature. The behaviour of the vapour phase was shown also to be nearly ideal.

The excess Gibbs free energy of mixing was calculated, and it was found to be non‐symmetrical with mole fraction. On increasing the temperature of the system, the liquid composition corresponding to the maximum GE tended to shift to a higher benzene concentration, whilst at a fixed liquid composition, GE initially decreased and then remained stationary or increased again. This was thought to be due to differences in the molar volumes of the two components.
Dynamic behaviour of mixer‐settlers: II. Mathematical models and identification methods
Authors: Aly G. , Wittenmark B.
Published: July 2010

Mathematical models explaining the dynamics of the mixer‐settler unit are investigated. It is shown that the static model is inadequate in this context and a two‐part dynamic model is proposed.
The electrochlorination of aliphatic hydrocarbons
Authors: Acquah F. , Kuhn A. T. , Mortimer C. J.
Published: July 2010

Reported electrochlorinations of saturated hydrocarbons have been investigated. It is concluded that the results reported can all be accounted for by homogenous processes. Various apparent discrepancies between similar conclusions reached by some researchers for the case of unsaturated aliphatic hydrocarbons and the results reported by other workers have also been resolved.
Chlorination and bromination of some aromatic compounds by means of aqua regia and hydrobromic‐nitric acid mixture
Authors: Hashem A. I.
Published: July 2010

Chlorination and bromination of a series of aromatic compounds with mixtures of nitric acid and hydrochloric or hydrobromic acids yielded chloranil and bromanil respectively. The reaction was promoted by ‐OH, ‐NH2 and ‐OCH3 groups and inhibited by alkyl, ‐CHO, ‐COOH, ‐CN and ‐NO2 groups.
Oxidation of acetaldehyde to glyoxal by nitric acid
Authors: Hotanahalli S. S. , Chandalia S. B.
Published: July 2010

The liquid phase oxidation of acetaldehyde or paraldehyde by aqueous nitric acid to glyoxal was investigated in a stainless steel autoclave maintained under autogenous pressure. The presence of nitrous acid was necessary for the reaction. Acetic acid and glyoxalic acid were the major by‐products. The effects of concentration of nitric acid, nitrous acid and acetaldehyde as well as temperature and period of reaction on the conversion and yield of glyoxal were studied with a view to obtaining the most suitable conditions for the production of glyoxal.