bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of alkyltrimethyl ammonium halides on the stability of potassium ethyl xanthate in aqueous solution
Authors: Finkelstein N. P. 
Published: July 2010

AbstractA 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

AbstractThe 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

AbstractThe 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

AbstractBorides, 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

AbstractThe 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

AbstractVapour–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

AbstractThe 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

AbstractThe 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

AbstractThe 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

AbstractThe 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

AbstractCrude 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

AbstractThe 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

AbstractThe 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

AbstractOxygen 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

AbstractIsoprene 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

AbstractIsobaric 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

AbstractMethyl 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

AbstractThe 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

AbstractPhase 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

AbstractA 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

AbstractA 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

AbstractThe 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

AbstractThe 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+H2OThe 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

AbstractThe 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

AbstractIn 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

AbstractSimplifying 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

AbstractTar 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

AbstractThe 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

AbstractThe 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

AbstractPublished 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.
Kinetics of the vapour‐phase hydrogenation of benzene over a supported nickel catalyst in a stirred‐vessel reactor
Authors: Lakshmanan R. , Rouleau D. 
Published: July 2010

AbstractThe catalytic hydrogenation of benzene was investigated over a supported nickel catalyst in a continuous stirred‐vessel reactor between 260° and 450°F at atmospheric pressure. The effects of temperature, ratio of hydrogen to benzene and total feed rate (or contact time) on the conversion of benzene and yield of cyclohexane were determined.The use of the stirred reactor helped to eliminate mass transfer limitations. The investigation was carried out using surface‐coated catalysts in order to eliminate pore diffusion which might otherwise mask the actual kinetics.Studies of the mixing characteristics of the reactor were carried out under both reacting and non‐reacting conditions, by following conversion as a function of stirrer speed and by a tracer (pulse) technique, respectively.The kinetic data were analysed to determine the most probable model to represent the reaction. The Houghen–Watson type analysis was carried out using non‐linear least squares instead of the usual linear one. The model that satisfactorily correlated the data over the entire temperature range describes the rate‐controlling step as the surface reaction between adsorbed hydrogen and adsorbed benzene, the hydrogen addition being simultaneous. The following Hougen–Watson type equation was proposed:r= keKH3KBPH3PB/(1+KHPH+KBPB+KCPC)4.The constants in this rate equation were expressed as a function of temperature.