bluuebunny/crossref_metadata_2025 huggingface dataset:
Phase equilibria in the system sucrose—glucose—fructose
Authors: Kelly F. H. C. , Brown D. W.
Published: July 2010

The melting points of mixtures of sucrose, glucose and fructose have been determined, so as to cover the full range of concentrations in the two‐ and three‐component systems. Three binary eutectics and one ternary eutectic were identified each with a fixed melting point, but all other concentrations showed a melting point range corresponding to liquidus—solidus characteristics.
Studies on the separation of o‐ and p‐chloronitrobenzene by solvent extraction. II
Authors: Hanson C. , Patel A. N. , Chang‐Kakoti D. K.
Published: July 2010

Ternary phase‐equilibrium diagrams are presented for the o‐ and p‐isomers of chloronitrobenzene with anhydrous methanol and with 90% aqueous solutions of methanol, ethanol and propanol. by means of a leaching process with 90% aqueous methanol, it is possible to obtain some 75% of the p‐isomer in a pure form from a mixture initially containing o‐ and p‐isomers in the ratio 3:7.
Some ageing characteristics of lime
Authors: Swenson E. G. , Sereda P. J.
Published: July 2010

This study involves the special case of lime compacts which are considered to serve as models for the system of lime in hydrated Portland cement paste. The ageing of lime was studied by measuring length changes of powdered samples under various steady‐state and alternating conditions of humidity. As an explanation for the unique behaviour of lime compacts, a primary mechanism is proposed based on the theory that recrystallisation occurs at least at areas of particle contact when lime compacts are exposed to humidities above a certain value. Furthermore, this recrystallised product is more accommodating than the parent material, and hence it can be consolidated by forces due to menisci or changes in surface free‐energy. This action is manifested by irreversible shrinkage on storage at intermediate humidities, by drying after storage or by alternating between two levels of humidity.
Polymerisation of dec‐1‐ene. II. Effect of reaction temperature
Authors: Beynon K. I. , Milne C. B. , Southern D.
Published: July 2010

The effect of temperature on the polymerisation of dec‐1‐ene has been studied, the catalysts used being (a) a catalyst prepared by mixing triethylaluminium and titanium tetrachloride at a molar ratio of 0.3:1 and (b) aluminium chloride. Polymers prepared at room temperature with triethylaluminium/titanium tetrachloride contain an average of one double bond per molecule. Increase in temperature from 20 to 150° produces saturated polymers of higher viscosity. The loss of olefinic unsaturation is due to cyclisation reactions, which produce aromatics and cycloalkanes, and to disproportionation reactions. An increase in reaction temperature from 20 to 150° with aluminium chloride as catalyst has little effect other than to reduce the viscosity of the polymer. The polymers produced at high temperatures by both catalyst systems are very similar. It is concluded that the active catalyst species in the triethylaluminium/titanium tetrachloride system at 150° is aluminium chloride or a complex containing it.
Compressibility of linear polymers
Authors: Warfield R. W.
Published: July 2010

Bulk compressibilities of a series of six linear polymers have been measured at pressures up to 16,000 atmospheres and over the temperature range 21° to 193°. All the polymers exhibited non‐linear pressure vs. change in volume isotherms. In a few cases the polymers exhibited pressure‐induced glass transitions. The coefficient of compressibility at one atmosphere usually increases with increasing temperature. at about 25° most polymers exhibit compressibilities of the order of 10 to 15%. The nature of the observed compressibilities is discussed in relation to the free volume of the system.
Low‐temperature oxidation of p‐xylene in liquid phase using acetaldehyde as accelerator. I. Stirred tank reactor
Authors: Yamamoto Masatoshi , Minoda Takahiko , Nishino Hiroshi , Imoto Tatsuya
Published: July 2010

The oxidation of p‐xylene in the presence of acetaldehyde as accelerator and cobalt acetate as catalyst at 60–100° was studied using a semi‐batch process in a stirred reactor. Better yields of terephthalic acid (up to 98%) were given than with other methods although the operation was similar. Diffusion was the rate‐determining step, and possibilities for improving reaction rate are discussed.
Interaction effects between the constituents of carbon artefacts during graphitisation
Authors: Richards B. P. , Kellett E. A. , Mason I. B.
Published: July 2010

A crystallographic study, using X‐ray diffraction techniques, has been made of the interaction effects between the constituents of coke‐binder artefacts when heat‐treated to graphitising temperatures. It is shown that petroleum and pitch cokes graphitise to a greater extent separately than when combined in petroleum coke/pitch binder artefacts, but for artefacts based entirely on either petroleum or pitch, this effect of the binder in retarding graphitisation of the grist coke is very much less.
Development of new initiators for polymerisation reactions
Authors: Ledwith A.
Published: July 2010

The development of simple, stable, and well defined catalyst systems for the initiation of ionic polymerisation is reviewed. The principles involved are illustrated by reference to the use of potassium t‐butoxide in dimethyl sulphoxide for initiating anionic polymerisation of ethylene oxide and of the hexachloroantimonate salt of the triphenyl methyl cation for polymerisation of tetrahydrofuran. Other stable organic cations initiate polymerisation via charge transfer complexes and can give rise to cation‐radicals as intermediates. It is suggested that related cation‐radicals may play a role in lignin biosynthesis.
Role of carboxyl groups in water absorption by keratin
Authors: Watt I. C. , Leeder J. D.
Published: July 2010

The contribution of carboxyl groups to the water sorbing properties of keratin has been investigated over the complete water vapour pressure range. A series of partially methylated wools were studied: below 80% R.H. there is a reduction in water content linear with the reduction in the number of carboxyl groups, but at humidities above 80% R.H. extra water is absorbed because of disruption of the structural network under the acid conditions of treatment.

Extrapolation of the plot of equilibrium water content vs. free carboxyl group content of partially methylated wool samples at a particular humidity. made at several humidity values, enables an isotherm to be deduced for wool containing no COO groups. The reduction of water content for wool of zero carboxyl group content, as a function of relative humidity, represents the isotherm attributable to the free carboxyl groups in keratin; this is a simple Langmuir isotherm at low humidities. The reduction of water content is proportionately greater at lower humidities—at 5% R.H., 36% of the total water and at 65% R.H., 22% of the total water absorbed by keratin is associated with free carboxyl groups. The number of water molecules associated with each carboxyl group is greater than previous literature values.
Influence of aluminium hydroxide and lime on the hydration of tricalcium silicate
Authors: de Jong J. G. M. , Stein H. N. , Stevels J. M.
Published: July 2010

Experiments by isothermal calorimetry, indicate that the hydration of 3CaO·SiO2 (C3S) is influenced very little by gibbsite; it is influenced by bayerite to a somewhat larger extent.

In the presence of amorphous Al(OH)3 the reaction of C3S with water shows a very complicated course and gives four heat peaks. If CaO is added in addition to this Al(OH)3, the third and the fourth heat peaks are more pronounced. From qualitative d.t.a., infra‐red, electron‐microscope and X‐ray investigations, as well as from quantitative X‐ray analysis, a reaction mechanism is proposed.

The quantity of C3S reacted, determined by means of quantitative X‐ray analysis, is greater during the reaction of 2·00 g C3S with 0·40 g amorphous Al(OH)3, 0·08 g CaO and 2·00 ml water, than during the reaction of 2·00 g C3S with 2·00 ml water.
Isobaric ternary vapour‐liquid equilibria system: Benzene‐cyclohexane‐n‐butanol
Authors: Subbarao B. V. , Ventakarao C.
Published: July 2010

Vapour/liquid equilibrium data for the system, benzene‐cyclohexane‐n‐butanol, were obtained at 760 ± 1 mm Hg pressure using a modified Colburn equilibrium still. No ternary azeotrope was observed. The experimental activity coefficient data were correlated with Wohl's three‐suffix symmetrical and three‐suffix Margules equations with and without using a ternary constant. From an estimate of the average errors in Y1, Y2, and Y3, Wohl's three‐suffix Margules equations seem to fit the data fairly well using a ternary constant, C = −0.1042. From the equilibrium curve drawn for the ternary system on a n‐butanol‐free basis with percent, n‐butanol as parameter, it was found that the azeotrope disappeared at 90–95% n‐butanol.
Formation and reactivity of nitrides II. Calcium and magnesium nitrides and calcium cyanamide
Authors: Glasson D. R. , Jayaweera S. A. A.
Published: July 2010

Samples of calcium and magnesium nitrides have been prepared and hydrolysed ‘dry’ with water vapour and steam or ‘wet’ with liquid water. Changes in phase composition, surface area, crystallite and aggregate sizes have been correlated with hydrolysis conditions and compared with ‘dry’ and ‘wet’ hydration of lime and magnesia. The reactions involve the splitting of nitride and oxide crystallites and the subsequent ageing of the newly formed calcium and magnesium hydroxides.

Hydrolysis of calcium cyanamide has been studied similarly. The intermediate product, hydrated lime, has been separately reacted with urea solutions and gives calcitic rhombs having a wide crystallite size range.
Preparation of the oleic acid/sulphur dichloride adduct and some derivatives
Authors: Nooi J. R. , Huijben G. J.
Published: July 2010

The preparation of the sulphur dichloride/oleic acid adduct in high yields is described.

The reactivity of the chlorine atoms in the adduct in nucleophilic substitution reactions is demonstrated. Particularly noteworthy is the formation of a factice‐like polyester in almost quantitative yield when the adduct is heated with sodium hydroxide solution.

Some derivatives of the adduct have been converted into polyamides.
Separation of o‐ and p‐ chlorotoluene by solvent extraction
Authors: Hanson C. , Patel A. N. , Chang‐Kakoti D. K.
Published: July 2010

Phase equilibrium data are presented for o‐ and p‐chlorotoluene distributed between n‐heptane and aq. methanol (95 vol.‐%), ‘Sulfolane’ and dimethyl sulphoxide (DMSO) and used to evaluate the possibility of employing distribution between these solvents as a means of separating a mixture of the isomers.
Preparation and properties of some acyloxysilanes
Authors: Emblem H. G. , Hargreaves K. , Oxley C. E.
Published: July 2010

Acyloxy derivatives of silicon were prepared by the interchange reaction between carboxylic acids (including various grades of palmitic acid) and tetraethoxysilane, and by the interchange reaction between palmitic acid and technical ethyl silicate (silica content 40%) or technical isopropyl silicate (silica content 38%). In most of the reactions, sodium methoxide was used as catalyst. Some physical properties of the reaction products were determined, and the materials made from palmitic acid were evaluated as water‐repellent coatings on cotton cloth.
Kinetics of the dissolution of uranium dioxide in nitric acid. I
Authors: Shabbir Muhammed , Robins R. G.
Published: July 2010

The kinetics of the dissolution of uranium dioxide in nitric acid have been investigated over a range of acid concentration from 0·3 to 37·0 molal. A change in the reduction mechanism for nitric acid is indicated at about 16 molal concentration.

A proposed mechanism for the initial rate period of dissolution is consistent with experimental results and with the known thermodynamics of the system.
Changes in surface characteristics of compacted coal during isothermal decomposition
Authors: Broadbent D. , Dollimore D. , Dollimore J.
Published: July 2010

Isothermal decomposition of coal compacts was carried out in nitrogen between 200–700°, and weight loss was recorded against time. Surface area changes, measured by nitrogen adsorption, were determined at 300° and 500°. The porous structure of the coal disappeared for a while during the decomposition owing to blocking of the pores by tarry matter. The surface area then increased when this tarry matter was driven off.
VApour‐liquid equilibria systems: Hexane‐hexylalcohol and heptane‐hexylalcohol
Authors: Rao P. Ramachandra , Chiranjivi C. , Dasarao C. J.
Published: July 2010

Isobaric vapour‐liquid equilibrium data have been determined for the binary systems hexane‐hexylalcohol and heptane‐hexylalcohol at 760 mm of Hg total pressure, using a Scatchard and Ticknor still. The isobaric vapour‐liquid equilibria of both the systems have been correlated satisfactorily by the equations of Redlich & Kister as modified by Chao despite the wide variation in boiling points.

Ewell et al.1 have classified liquids into five groupings based on their properties of forming hydrogen bonds. According to this classification, hydrocarbon‐alcohol combinations involve breaking of hydrogen bonds and always show positive deviations. A systematic study of the vapour‐liquid equilibrium data of these has been attempted and the present work presents the results.
Gelation of casein formaldehyde as influenced by the presence of sodium metasilicate and sodium hexyl sulphate
Authors: Malik W. U. , Agarwal S. K.
Published: July 2010

Concentrated solutions of casein (5·5–6·0%), modified by the addition of formaldehyde, undergo rapid gelation in the presence of sodium metasilicate and sodium hexyl sulphate. This gelation occurs more readily when a mixture of both is used. The presence of an extremely small amount of either of the reagents with the other decreases the time of gelation considerably. The role of different constituents of the gelation mixture is discussed. The use of sodium metasilicate containing small amounts of sodium hexyl sulphate to replace sodium aluminate in the manufacture of casein fibres is suggested.
Bacterial degradation of plasticised PVC‐effect on some physical properties
Authors: Booth G. H. , Robb J. A.
Published: July 2010

Burial tests on plasticised PVC in neutral soil inoculated with species of Pseudomonas and Brevibacterium have shown degradation in 8 weeks that is largely dependent on the nature of the plasticiser. There was no evidence for any attack on the polymer itself. Phthalate and phosphate plasticisers were resistant; adipate, azelate and sebacate plasticisers were susceptible and a number of others, e.g. chlorinated hydrocarbon and epoxy types, occupied an intermediate position. The degree of attack was also dependent on the nature of the stabiliser used in the PVC formulation, lead‐based stabiliser conferring less resistance than barium/cadmium‐based stabiliser. Degradation has been assessed in terms of loss in weight, change of stiffness and loss of energy during cyclic deformation.
Ion‐exchange properties of brown algae. II. Rate mechanism for calcium‐hydrogen ion exchange for particles from Ascophyllum nodosum
Authors: Myklestad S.
Published: July 2010

The ion‐exchange properties of algal particles from A. nodosum have been investigated. The Ca/H ion‐exchange rate at hydrogen ion concentration 0·1 n was shown to be strikingly lower, while the selectivity coefficent K was about ten times higher, for A. nodosum than for L. digitata and L. hyperborea stipe particles. Log K showed a marked decrease with increasing calcium equivalent fraction in the algal particles. The higher Ca/H selectivity of algal particles from A. nodosum was shown to be the cause of the observed difference in exchange rate between this alga and the two other species.

The ion‐exchange rate Ca/H for 36–52 mesh particles from A. nodosum at hydrogen ion concentration 0·1 n was governed by a film‐diffusion mechanism and the diffusion of calcium through a thin liquid film enveloping the particles was suggested as the rate‐determining step. The rate was particle‐diffusion controlled for 10–20 mesh particles. The exchange rate for 36–52 mesh particles increased strongly as the hydrochloric acid concentration was increased from 0·05 to 1 n; this exchange appeared to proceed like a second order reaction at 0·05 n and showed a gradual change to a first order reaction at 1 n‐acid.
Reaction of azo derivatives of acetoacetanilide with aliphatic amines
Authors: Topham A.
Published: July 2010

Azoacetoacetanilides condense with primary aliphatic amines to give azoaminocrotoanilides (I). Comparison of the infra‐red and nuclear magnetic resonance spectra with those of model compounds leads to the proposal of formulae of type (VI) as a refinement of formula (I).

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Preparation of N‐cyclohexylbenzothiazole‐2‐sulphenamide by oxidative condensation
Authors: Banks D. J. , Wiseman P.
Published: July 2010

It has been shown that in the preparation of N‐cyclohexylbenzothiazole‐2‐sulphenamide by the reaction of 2‐mercaptobenzothiazole with cyclohexylamine in the presence of sodium hypochlorite, N‐cyclohexyl‐benzothiazole‐2‐sulphonamide, sodium benzothiazole‐2‐sulphonate, benzothiazole‐2‐sulphonyl chloride, 2,2′‐dithiobisbenzothiazole, and probably sodium benzothiazole‐2‐sulphinate can be formed as by‐products, in amounts depending on pH, temperature and amount of amine used. Mechanisms are suggested for the reactions involved.
Symmetrical‐area tests for the consistency of vapour–liquid equilibrium data. I. Isothermal data
Authors: Herington E. F. G.
Published: July 2010

The need to test experimentally determined vapour–liquid equilibrium data for thermodynamic consistency is now widely recognised. This paper is concerned with general integral tests based on the Duhem–Margules equation and not with particular algebraic solutions of that equation. A family of ‘symmetrical‐area’ tests is presented; these new tests are more powerful tools for the examination of experimental data than the area tests previously developed by the author, and can be used to examine part of a composition range and to identify regions of poor observation. Moreover, the tests can sometimes be used to identify the quantities that are in error. They are applicable to systems with miscibility gaps.
Solution chemistry of the electrochemical machining of titanium, niobium and tantalum
Authors: Rolsten R. F.
Published: July 2010

In the electrochemical machining process the electrolyte, in addition to conducting the required current, has the added function of removing the electrode reaction products—hydrogen from the cathode and metal oxide from the workpiece. This function is facilitated if close control is maintained over the pH of the electrolyte. Titanjum halides form clear solutions if the pH is less than 2 but precipitate if the pH exceeds 3·7. Niobium and tantalum halides were also studied.
Oxidation of thiols in gas‐liquid systems. II. Reaction in the presence of added metal catalysts
Authors: Cullis C. F. , Hopton J. D. , Swan C. J. , Trimm D. L.
Published: July 2010

Comparisons have been made of some kinetic features of the oxidation in alkaline solution of a series of simple aliphatic and aromatic thiols in the presence of added metal catalysts. With ethanethiol as the reactant, the catalytic activity of a wide variety of metals, added to the solution as simple salts, has been determined. Furthermore, using three typical metal catalysts, the oxidation of a series of thiols has been investigated and an attempt has been made to correlate rates of oxidation with the geometric structure and electron‐directing properties of the organic groups present. The size of such groups has been found to be one of the most important factors controlling the overall rate of oxidation.
Kinetics of the reduction of silicon tetrachloride and trichlorosilane by hydrogen
Authors: Ashen D. J. , Bromberger G. C. , Lewis T. J.
Published: July 2010

Reaction products from SiCl4/H2 and SiHCl3/H2 mixtures have been examined over the temperature range 800–1200°K, and the conditions under which equilibrium is reached have been established. The results point to a ΔH° for SiCl4 of between −162 and −163 kcal/mole. The reaction rates expressed in mole/1/sec were: d[SiHCl3]/dt = 7.8 × 1010 [SiCl4] [H2]1/2 exp −55,000/RT and d[SiH2Cl3]/dt = 2.0 × 1010 [SiHCl3] exp −51,000/RT and kinetic mechanisms have been suggested.
New low‐density ceramic material for packing fractional distillation columns. II
Authors: Castellucci N. T. , Krouskop N. C.
Published: July 2010

The paper compares the new, spherical, low‐density ceramic material described in Part I with other packing materials having different geometries. The increased separating power of the new material is due to different liquid flow patterns, spreadability, accessible surface area and surface morphology. Although each of these terms has a distinctive meaning which cannot be employed without some reference to the other two, the first three terms are often erroneously used interchangeably throughout the literature. In this paper, these terms are more accurately defined and used in accordance with experimental evidence.
Distribution of sulphuric acid between tri‐n‐butyl phosphate and water
Authors: Hanson C. , Patel A. N.
Published: July 2010

The distribution of sulphuric acid between water and 40% by vol. solutions of tri‐n‐butyl phosphate (TBP) in six diluents, and also between water and 40, 60 and 80° solutions of TBP in cyclohexane at 20°, and between water and 40% solution of TBP in cyclohexane and pure TBP at 20°, 30° and 50° has been studied to find the effects of temperature, diluent and TBP concentrations on the extractability of sulphuric acid and on ‘third‐phase formation’.
Fischer‐tropsch waxes. I. An infra‐red method for the determination of crystallinity
Authors: le Roux J. H.
Published: July 2010

Crystallinity is, ideally, the fraction or percentage of perfectly crystalline matter in a material which is partially crystalline. Because transition structures can exist, however, measured crystallinity will depend largely on the method used.

The differences in the infra‐red spectra of the same substance in the crystalline and amorphous states can be exploited for quantitative measurement. Methods based on bands that appear only in the ‘amorphous spectrum’, such as the method described here, have definite advantages over those based on ‘crystalline bands’. While testing the method it was found that the rate of cooling has only a small effect on the crystallinity of Fischer–Tropsch waxes. Surface effects play an important role, however. Thin slices cut from the central parts of thick discs were used for measurements. Before they were sampled, certain waxes had to be homogenised by melting. Results were reproducible within ± 1·5 to ±6 per cent for different waxes. Because of the dependence of crystallinity upon the method used, however, the value of this method lies in its use in comparative studies.
Formation and reactivity of oxides and basic salts. III. Titanium dioxides and basic titanic salts
Authors: Glasson D. R. , Johnson J. S. , Sheppard Margaret A.
Published: July 2010

Methods of production and application of titanium dioxides and basic titanic salts have been summarised and the appropriate physical properties of the products have been studied. Variations in phase composition, surface area and crystallite and aggregate sizes have been correlated with experimental conditions.

When titanic sulphate or chloride is hydrolysed by sodium hydroxide, the basic salts initially formed are decomposed subsequently to hydrous titanium dioxide as the pH becomes stabilised at higher values. The specific surface of the basic sulphate increases considerably when it hydrolyses to anatase. On calcination at temperatures up to about 750°, the anatase crystallites can grow from about 0·006 μm to the requisite 0·1–0·5 μm range, but the aggregate sizes vary widely. Shock‐heating at temperatures between 600° and 900° removes the remaining water and breaks up the larger aggregates.

At higher temperatures, the anatase is transformed to rutile which subsequently sinters. The rutile produced by shorter calcinations at 1100°–1150° is similar in crystallite size to that obtained by complete oxidation (‘burning’) of titanic chloride vapour at the same temperatures. Results emphasise the need for close control of residence time in the high‐temperature zone in the production of pigmentary titanium dioxide.
Precipitate flotation. IV. Flotation of silver, uranium and gold
Authors: Mahne E. J. , Pinfold T. A.
Published: July 2010

The conditions for the flotation of silver using α‐nitroso‐β‐naphthol and β‐nitroso‐α‐naphthol, that of uranium using α‐nitroso‐β‐naphthol and benzoylacetone, and that of gold using phenyl‐α‐pyridylketoxime were examined. Recoveries of over 90% were possible from 5 × 10−5 M solutions of silver, 10−4 M solutions of uranium (VI) and 3 × 10−4 M solutions of gold (III). Extractions were best in the pH range 7–9, 6–9 and 3–5 respectively. Silver could be separated from 10‐fold molar excesses of copper, zinc and lead; uranium from 10‐fold molar excesses of gold and iron and 100‐fold molar excesses of sulphate and manganese: gold from a 10‐fold molar excess of uranium. Methods are suggested whereby redispersion in precipitate flotation of the second kind can be avoided. The efficiency of this kind of flotation is considered.
Influence of alkyltrimethyl ammonium halides on the stability of potassium ethyl xanthate in aqueous solution
Authors: Finkelstein N. P.
Published: July 2010

A study has been made of the stability of potassium ethyl xanthate in solutions containing alkyltrimethyl ammonium halides. It has been shown that the presence of these compounds leads to an increased rate of decomposition, if the solution is in contact with an atmosphere that contains oxygen and its pH is between 6 and 12. Under other conditions, the stability of the xanthate is unaffected by the presence of the co‐solute. It is concluded that the quaternary ammonium compounds catalyse reaction between oxygen and xanthate, and it suggested that at least two different types of oxygenative reaction take place.
Thermal properties of acetylacetone
Authors: Melia T. P. , Merrifield R.
Published: July 2010

The vapour pressure of acetylacetone has been measured over the temperature range 297–398°k. The results are summarised as:
equation image

Heat capacity measurements have been carried out on the enol form of acetylacetone over the temperature range 80–300° k. An estimate has been made of heat capacity values below 80° k. Entropy, enthalpy and free energy values have been derived and are listed at ten degree intervals. The melting point (254·80°0·05° k) and heat of fusion (144·8°0·5 abs.Jg−1) of the enol form have been determined. The results have been used in conjunction with previously published data to evaluate the entropies and the heats, entropies and free energies of formation of the keto and enol forms of acetylacetone in the gaseous and liquid phases at 298·16° k.
Fischer‐tropsch waxes. II. Crystallinity and physical properties
Authors: le Roux J. H.
Published: July 2010

The density, congealing point, and hardness were considered in relation to crystallinity, determined by an infra‐red spectrometric method, of a series of waxes which are fractions from crude Fischer–Tropsch wax. Values ranging between 65 and 93, expressed as molecular percentages of crystalline material present, have been obtained. Data on molecular weights and physical properties were available. Smooth curves could be drawn for the variations of density, congealing point and hardness (or rather penetration) with molecular weight, but only for the more highly crystalline waxes. Two waxes, with crystallinities below 75, were found to have abnormally low congealing points and densities and to be abnormally soft, in relation to their molecular weights. This can be explained in terms of the less dense packing of molecules in the amorphous state.

The effect of crystallinity on density was examined more closely, and a set of equations expressing the relationship between these entities and molecular weight was derived. These contain an unknown factor, however, which is dependent upon molecular weight distribution.
Formation and reactivity of borides, carbides and silicides. I. Review and introduction
Authors: Glasson D. R. , Jones J. A.
Published: July 2010

Borides, carbides and silicides are reviewed with special reference to newer production methods and fabrication techniques. Crystal structures and types of bonding in binary and ternary compounds are classified and discussed. The scope and limitations of the Pauling‐Rundle theory, molecular orbital treatment and the Ubbelohde‐Samsonov theory are examined critically and appropriate experimental evidence is summarised.

Information so far available on the sintering of borides, carbides and silicides is summarised in relation to their chemical reactivity. The sintering is influenced by additives or impurities such as oxides formed by partial hydrolysis and oxidation. Resistance to oxidation is increased by sintering and hot pressing the refractories, but since the affinity of the metals is exclusively higher for oxygen, exchange reactions diminish the quality of the materials. Boride and carbide coatings generally have poor resistance in air or oxygen, but some silicides are more suitable. The kinetics and products of oxidation of borides, carbides and silicides so far studied depend mainly on the intrinsic reactivity of the material and the available surface at which oxidation can occur.
Formation and reactivity of nitrides. III. Boron, aluminium and silicon nitrides
Authors: Coles N. G. , Glasson D. R. , Jayaweera S. A. A.
Published: July 2010

The reactivities of boron, aluminium and silicon 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 alumina, α‐Al2O3, split off from the remaining aluminium nitride before they sinter and inhibit further oxidation. The diboron trioxide, B2O3, and silica, SiO2 (α‐cristobalite), immediately act as mineralisers for the remaining boron and silicon nitrides, and progressively retard the oxidations.
Vapour–liquid equilibrium data for n‐butyl acetate–1,2‐propylene glycol
Authors: Nageshwar G. D. , Mene P. S.
Published: July 2010

Vapour–liquid equilibrium data for the binary system n‐butyl acetate–1,2‐propylene glycol have been obtained at pressures between 725 and 735 mm Hg. The activity coefficient data were correlated by Chao's modified Redlich Kister equation and van Laar's equation. The vapour composition was also correlated by the equations of Nagata and Hirata. Thermodynamic consistency was confirmed by Herington's area test.
Separation of small amounts of 229Thorium from large quantities of 233Uranium
Authors: Jenkins I. L. , Lidington Dallas E. , Waint A. G.
Published: July 2010

The separation of 6·6 mg of 229Th from 400 g of 233U is described. The process involves the preferential extraction of 233U from an aqueous solution in nitric acid into dibutyl carbitol and the purification of the thorium left in the aqueous phase by ion exchange. Thorium recovery was 91% and the thorium was decontaminated from uranium by a factor of at least 4 × 10°.
Kinetics of deposit formation from hydrocarbons. IV. Additive and surface coating effects
Authors: Taylor W. F.
Published: July 2010

The effect of various additives, and of coating a catalytically active metal surface with polymeric materials, on the formation of autoxidative deposits from hydrocarbon jet fuels at 250–425 °F has been investigated. Various anti‐oxidant additives including alkyl substituted phenols and a phenylenediamine were found to be ineffective in reducing the rate of deposit formation. The use of rust preventive and metal de‐activator additives increased the rate of deposit formation above 350°F. Coating a catalytically active titanium alloy surface with various polymeric materials increased the rate of deposit formation, particularly at temperatures above 35°F. This latter result suggests that these polymeric surfaces are catalytically active for either primary or secondary radical‐producing reactions in the hydrocarbon autoxidation system which leads to the formation of deposits.
Effect of curing conditions on the total water content of hardened portland cement paste
Authors: Hanna K. M. , El‐Hemaly S. A.
Published: July 2010

The effect of various curing conditions on the amount of water held by pastes with low water/cement ratios was investigated. It was concluded from the results that factors significantly influencing the total water content of a cement paste made with ordinary Portland cement and cured at room temperature are: water/cement ratio, curing medium, curing period and curing history.
Absorption of oxygen by n‐butyraldehyde
Authors: Ladhabhoy M. E. , Sharma M. M.
Published: July 2010

The kinetics of absorption of oxygen by n‐butyraldehyde dissolved in n‐butyric acid, in the range of concentrations up to 3·1 × 10−3 gmole/cm3 (25 wt.‐%), in the presence of manganese acetate, was studied in stirred cells and a bubble column. It was found that diffusion of oxygen is important. The reaction was found to be first‐order in oxygen and second‐order with respect to the aldehyde. The overall third‐order reaction rate constant was found to be about 4 × 106 (cm3/gmole)2 sec−1 at 20°. The effect of the catalysts, cobaltous acetate and (cobaltous + 4 cupric) acetates, on the specific rates of absorption of oxygen was also studied. Manganese acetate was found to be the best catalyst.
Weathering of road tar. I
Authors: Green E. H.
Published: July 2010

Crude tars from six sources have been used in a full‐scale experiment to determine the physical and chemical changes that occur in road tar used in wearing‐course macadam. Samples taken from the road at intervals up to two years have been studied in the laboratory. It has been shown that when tars weather, there is an increase in viscosity due to two main processes, evaporation and oxidation. In the oxidation mechanism, ‘C2 resin’, soluble in pyridine but not in benzene, is formed from material of lower molecular weight; it increases both the viscosity and the temperature coefficient of viscosity, so that in cold weather very high viscosities are attained. In the case of lower‐gravity tars, evaporation and oxidation account for similar amounts of hardening, but with coke‐oven tars, evaporation predominates.
Weathering of road tar. II
Authors: Bartle K. D. , Smith J. A. S. , Wilman W. G.
Published: July 2010

The techniques employed on samples from the Hercies Road Experiment (Part I) were used to determine if chemical changes occurring during the weathering of road tar could be detected and to obtain information on the nature of these changes.

The main changes were attributable to evaporation and condensation, and chemical changes due to the action of air and light play a relatively minor part.
Loss of platinum from platinised titanium in hypochlorite cells at low electrolyte temperatures
Authors: Marshall C. , Millington J. P.
Published: July 2010

The conditions under which platinum is lost from platinised titanium anodes during the electrolysis of dilute brine solutions have been studied. The phenomenon is explained in terms of a potential‐dependent change in surface structure and it is shown that platinum loss can be avoided by control of the anode potential.
Thermal decomposition of 1‐bromo‐2‐methylbutane
Authors: Hargreaves M. K. , Dossor J. M. , Isaac B.
Published: July 2010

Oxygen and hydrogen bromide catalyse the decomposition of 1‐bromo‐2‐methylbutane. The relative proportion of the main reaction products, 3‐bromo‐2‐methylbutane and 2‐bromo‐2‐methylbutane, varies according to whether the decomposition occurs in a sealed tube or under atmospheric pressure. The decomposition of any one sample proceeds rapidly to a certain extent and then slows to a stop.
Dimerisation of isoprene
Authors: Suga K. , Watanabe S. , Watanabe T. , Kuniyoshi M.
Published: July 2010

Isoprene was dimerised by lithium naphthalene to linear isoprene dimer, a mixture of 2,6‐dimethyl‐2,6‐octadiene and 2,7‐dimethyl‐2,6‐octadiene, in 80% yield.
Vapour‐liquid equilibria for the system: Methylcyclohexane‐methylisobutyl ketone
Authors: Seetharamaswamy V. , Subrahmanyam V. , Dakshinamurty P.
Published: July 2010

Isobaric and isothermal vapour‐liquid equilibria have been determined for the binary system: methylcyclo‐hexane‐methylisobutyl ketone at a temperature of 80° and total pressure 760mm Hg. The activity coefficient data were satisfactorily tested for their thermodynamic consistency and also a satisfactory correlation was obtained through the three‐suffix equations of Wohl for both conditions of restraint. Azeotropes were obtained for both conditions of restraint.
Catalytic syntheses of methyl and ethyl lactates under pressure
Authors: Bhattacharyya S. K. , Palit S. K. , Das A. R.
Published: July 2010

Methyl and ethyl lactates have been synthesised under pressure from acetaldehyde, carbon monoxide and methyl or ethyl alcohol with various supported nickel, cobalt and iron catalysts. Under the optimum conditions, in the presence of nickel iodide supported on silica gel (Ni:SiO2 = 50:50), the maximum yields of methyl lactate and by‐product lactic acid were 20.7% and 15.2% respectively, whereas the maximum yields of ethyl lactate and lactic acid were 12.6% and 12.3% respectively (all on the input acetaldehyde basis).
Correlation of vapour pressure, temperature, and latent heat of vaporisation
Authors: Thomas H. L. , Smith H.
Published: July 2010

The vapour pressures of six liquids have been measured in the approximate range 0.05 to 200 torr and correlated with that of benzene by a method published in an earlier paper. The relationship so obtained which is linear for non‐associated substances and is valid from critical conditions to a vapour pressure at least as low as 0.1 torr presents a reliable method of extrapolation of vapour pressure data. It may also be used (at vapour pressures below ˜ 100 torr) to evaluate the entropy and latent heat of vaporisation of a liquid from even scant vapour pressure data.
Separation of thiophen from benzene by solvent extraction. II
Authors: Hanson C. , Patel A. N. , Chang‐Kakoti D. K.
Published: July 2010

Phase equilibrium data for thiophen and benzene with water and ‘Sulpholane’, dimethyl sulphoxide (DMSO) and dimethyl formamide (DMF) are presented and used to evaluate the possibility of using aqueous solutions of these solvents to separate small amounts of thiophen from benzene.
Emanation method for estimating reactivity of ferric oxides prepared from different sources
Authors: Balek V.
Published: July 2010

A method for estimating the reactivity of ferric oxide in solid state reaction processes is proposed. The temperature of the emanation curve maximum is taken as a characteristic parameter for the testing of the reactivity.

The reactivity of ferric oxides prepared from ferrous sulphate, Mohr's salt (ferrous ammonium sulphate), ferrous oxalate and basic carbonate of iron by decomposition at 700°, 900° and 1100° has been studied. The results of the proposed method are compared with those of specific surface and catalytic activity measurements. The method is more objective and representative of the compound's ability to react with other solids.
Thin‐layer chromatography for identification of petroleum and coal‐tar oils and residues
Authors: Matthews P. J.
Published: July 2010

A thin‐layer chromatographic (t.l.c.) method has been developed for the systematic identification of petroleum and coal‐tar oils and residues. The method is based on observation of varying chromatographic characteristics of the sample with different t.l.c. systems. The chromatograms are viewed under ultra‐violet light of 350 nm wavelength. By using a systematic table the nature of the sample may be determined to within narrow limits. The method has so far been successfully applied to water pollution control problems.
Cluster formation of kaolin using the hindered settling technique
Authors: Kwatra B. , Ahuja L. D. , Ramakrishna V.
Published: July 2010

The settling of kaolin has been studied in various alcohol‐benzene mixtures, under controlled moisture conditions. The influence of the parameters of the settling apparatus has been evaluated. From the log Q/ϵ2 vs. ϵ plots, the average particle size has been calculated, and the effect of absorbed moisture and the nature of the solvent mixture on cluster formation have been discussed. The constants of Oliver's equation for these systems have been obtained and their significance in the light of Landel's theory has been discussed.
Thermal decomposition of ammonium sulphate
Authors: Halstead W. D.
Published: July 2010

The thermal decomposition and vaporisation of ammonium sulphate, (NH4)2SO4, is shown to take place via two distinct sets of reactions. In the first, ammonium pyrosulphate, (NH4)2S2O7, is the primary condensed phase product: 2(NH4)2SO4 ← (NH4)2S2O7+2NH3+H2O

The second stage concerns the decomposition of the pyrosulphate. Ammonia, sulphur dioxide, nitrogen and water are the major products, the dominant reaction being 3(NH4)2S2O7 ← 2NH3+6SO2+2N2+9H2O
Preparation and uses of titanium and zirconium chloroalkoxides
Authors: Emblem H. G. , Maskery S. E.
Published: July 2010

The preparation of titanium and zirconium chloroalkoxides by the treatment of titanium tetrachloride with ethylene oxide vapour and zirconium tetrachloride with either ethylene oxide vapour or 1,2‐propylene oxide is described. Under the reaction conditions used, ethylene oxide gives mainly the tetra‐(2‐chloroethoxide). Zirconium tetrachloride and 1,2‐propylene oxide give the tetra‐(chloropropoxide). Titanium and zirconium chloroalkoxides, particularly the tetra‐(2‐chloroethoxides), can be used to bind suitably graded refractory powders. In admixture with diethanolamine, both titanium and zirconium tetra‐(chloroethoxide) are good thixotropy developers for aqueous emulsion paints.
Petrographic and thermal evaluation of dolomites for the manufacture of magnesium oxychloride cement
Authors: Kacker K. P. , Mehrotra G. S. , Rai M.
Published: July 2010

In the preparation of magnesium oxychloride cement from MgO and MgCl2.6H2O solution, MgO is sometimes replaced by partially calcined dolomite, MgO.CaCO3. In this paper, the suitability of dolomites for this purpose was studied by use of petrographic, d.t.a. and X‐ray diffraction techniques. It is shown that for making good oxychloride cement, the dolomite should be compact and microcrystalline. Impurities such as siderite, haematite, magnetite and clayey matter which are generally present in dolomites, form a coating over the MgO particles during partial calcination at 750° and make the fired material less reactive and generally unsuitable for making oxychloride cement.
Quantitative effect of gritty contaminants on the sensitivity of high explosives to initiation by impact
Authors: Scullion H. J.
Published: July 2010

Simplifying postulates facilitate the derivation of a two‐parameter equation which relates the deterioration in impact insensitivity to the magnitude of grit additions. The impact insensitivity (ϕmax) of an adulterated explosive is related to the insensitivity (ϕmax) of the uncontaminated explosive by the equation: θ where g is the weight fraction of added particulate grit (mixtures contained 0‐0.1% grit) and R and k are constants which depend on the explosive‐grit system and the method of testing. The equation was found to be in reasonable accord with the results of a series of tests using TNT, RDX and HMX in various admixtures with fine, gritty particles.
Characterisation of the neutral oil from a low‐temperature coal tar
Authors: Bartle K. D. , Jones D. W. , Martin T. G. , Wise W. S.
Published: July 2010

Tar resulting from fluidised‐bed, low‐temperature carbonisation of coal was treated to yield a neutral oil from which a series of six other samples was extracted. These were examined by proton magnetic resonance (p.m.r.) spectroscopy, low‐ionising‐voltage (11 eV) mass spectroscopy (m.s.), gel chromatography followed by fluorescent indicator analysis, and cryoscopy. Aliphatic fractions separated chromatographically were also examined by infra‐red spectroscopy.

Distributions of hydrogen between chemical types were found for the several fractions from 60 MHz p.m.r. spectra and presented in terms of average structural parameters. M.s. analysis indicated negligible cracking of paraffin components, and the average molecular weight of 197 agreed well with cryoscopic determinations. For the carbon ratio,fa, between aromatic and total, agreement between m.s. and p.m.r. depends on the p.m.r. structural analysis scheme adopted. P.m.r. and m.s. structural analyses of the aromatics emphasise the predominance of di‐ and tri‐nuclears, with about 40% of available sites substituted, and the importance of acenes in lowtemperature carbonisation material. Gas and gel chromatography showed urea‐adductable paraffins to be largely straight‐chain C10‐C26, much as for tars from carbonisation at higher temperature.
Kinetics of hydration of autoclaved calcium sulphate hemihydrate
Authors: Combe E. C. , Smith D. C. , Braden M.
Published: July 2010

The kinetics of the hydration of two sources of autoclaved calcium sulphate hemihydrate have been followed by an essentially isothermal method. Experiments have been carried out at different temperatures, water/powder ratios, and with added nuclei of crystallisation. A kinetic equation, based on the Avrami theory of crystallisation, and assuming the reaction to be diffusion‐controlled, has been developed and tested and found to be moderately successful under most conditions. The effects of variations of temperature and water/powder ratio are discussed.
Comparison of the binding properties of hydrated lime and cement in brick manufacture
Authors: Purton M. J.
Published: July 2010

The effect of replacing cement by hydrated lime in autoclaved brick specimens with binder contents of 7.5–25% has been studied on a laboratory scale and the results have been compared with non‐autoclaved cement‐bound specimens.

It has been shown that the strength of cement‐bound specimens autoclaved for 8 h was similar to that of specimens air‐cured for 28 days.

Lime was shown to be superior to cement in autoclaved specimens for strengths up to the maximum of 23 MN/m2 obtainable with the lime binder. For a given compressive strength up to this value, half as much binder was required in the mix and, in addition, the green strength was greater and the drying shrinkage was lower when lime was used instead of cement.

Maximum strengths of up to 42 MN/m2 were achieved at high binder contents with blends of lime and cement.
Rationalisation of the sizes of small molecules in gel permeation chromatography
Authors: Lambert A.
Published: July 2010

Published data on the sizes of small molecules measured by gel permeation chromatography are reconsidered after subjecting them to a recalculation procedure which gives molecular sizes in consistent units. Almost half the results are rejected as being unreliable.

A set of molar volume values for n‐alkanes is recommended as a standard which should be used to calibrate gel permeation chromatographs irrespective of operating conditions.

Molar volumes of some simple gases are given.