bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mechanism of re‐crystallisation in calcium sulphate hemihydrate plasters
Authors: Schiller K. 
Published: July 2010

AbstractThe course of a hydration process is uniquely determined by simultaneous consideration of (a) the balance between the matter dissolving from the original phase and growing on the new phase, (b) the mechanism of mass transport (diffusion), (c) the correlation between the mass deposited on the new particles and its rate of growth and (d) the conservation of mass. An estimate shows that, in the case of neat calcium sulphate plasters, diffusion is quantitatively unimportant as a rate‐determining factor and the corresponding simplifications are introduced. As a result, the hydration can be described in terms of one single parameter which depends on the slurry density, the rate of growth constant for the new phase, the difference in solubilities of the two phases, the shape of the new phase, and the effective number of nuclei for the new phase.Supporting experimental evidence is supplied and discussed.
A convenient synthesis of o‐aminobenzaldehyde and its n‐methyl‐derivatives, from o‐aminobenzoic esters
Authors: Barlin G. B. 
Published: July 2010

Abstracto‐Amino‐, o‐methylamino‐, and o‐dimethylamino‐benzaldehyde have been prepared in good yield by alkaline decomposition of the p‐toluenesulphonhydrazides of the corresponding acids. These in turn were readily prepared from the free acids via the methyl esters.
Electrical surface properties of polymers containing bound anionic groups
Authors: Holmes F. H. , Perkins P. G. 
Published: July 2010

AbstractPolystyrene, cross‐linked with divinylbenzene, has been prepared, free from catalyst, in sheet form and has been sulphonated in the surface regions. Sheets incorporating carboxyl groups in various proportions have been prepared by copolynierising styrene, divinylbenzene and methacrylic acid. The electrical conductances of the polymer surfaces, with sodium as mobile cation, have been measured in air at various relative humidities. The observed increase of conductance with relative humidity is consistent with an increase in dielectric constant of the polymer.
Extraction of 2‐hydroxy‐acids from wool wax acids
Authors: Milburn A. H. , Truter E. V. 
Published: July 2010

AbstractBy formation of the copper chelate complex of 2‐hydroxy‐aliphatic acids, the latter may be extracted from natural mixtures in yields of about 95% and purities exceeding 90%. Some of the factors influencing the yields have been explored, and it is shown that commercial samples of wool wax acids contain 5–10% of 2‐hydroxy‐acids.
Solubility of sodium sulphate in spin‐bath acid
Authors: Stannard B. 
Published: July 2010

AbstractA method is provided for the calculation of the solubility of sodium sulphate in spin‐bath acid over a relatively wide range of concentrations. The method is based on the assumption that sodium sulphate and sulphuric acid in spin‐bath acid behave as two modified components–sodium bisulphate and ‘free’ sodium sulphate. Its application to the crystallisation of sodium sulphate from spin‐bath liquor is illustrated and discussed.
Catalytic synthesis of ethyl propionate from diethyl ether and carbon monoxide at high pressure
Authors: Bhattacharyya S. K. , Palit S. K. 
Published: July 2010

AbstractThe catalytic synthesis of ethyl propionate from diethyl ether and carbon monoxide has been studied in the presence of nickel, cobalt and iron catalysts at a pressure range of 175–375 atm., and temperature range of 200–300°. Of the various catalysts tested, the iodides of iron, cobalt and nickel, supported on silica gel, exhibit the maximum catalytic activity. Reduced metals and their carbonyls are practically inactive. Under the optimum conditions (230°/240 atm.) the maximum yields of ethyl propionate and propionic acid were 28.2% and 10.1% respectively. The possible reactions leading to the formation of by‐products have been elucidated by decomposition studies.
Catalytic synthesis of ethyl propionate from ethylene, carbon monoxide and ethanol at high pressure
Authors: Bhattacharyya S. K. , Nag S. N. 
Published: July 2010

AbstractA comprehensive study has been made of the high‐pressure synthesis of ethyl propionate from ethylene, carbon monoxide and ethanol in the presence of iron, cobalt and nickel catalysts at 2000–8200 p.s.i. and 180–300°. Reduced iron, cobalt and nickel and their carbonyls have practically no catalytic effect, but their halides exhibit excellent catalytic activity. The relative catalytic activities of the halides are in the order: iodides > bromides > chlorides. The activities of the metals are in the order: cobalt > nickel > iron.Under the most favourable conditions (catalyst–metal/silica 50: 50; at 230° 6000 p.s.i. with cobalt and nickel iodide catalysts, and 4400 p.s.i. with ferrous iodide catalyst; residence time 2 h.), the process yields of ethyl propionate based on ethanol input are 57.0, 45.1 and 43.4% with cobalt, nickel and iron iodide catalysts, respectively.
The roasting of precipitated copper sulphide
Authors: Razouk R. I. , Farah M. Y. , Mikhail R. S. , Kolta G. A. 
Published: July 2010

AbstractThe roasting of precipitated copper sulphide in a current of air has been investigated by thermogravimetric analysis in the temperature range 150–800° under isothermal conditions. Chemical analysis of the products was carried out at intervals in each case to determine the distribution of copper between the sulphide, sulphate and oxide forms, and X‐ray diffraction patterns were used to identify the state of the solid phases.During roasting, cupric sulphide is converted to the cuprous state, formation of sulphate increases with rise of roasting temperature to a maximum at 400° and then decreases, while the copper oxide content increases with rise of roasting temperature first as cuprous oxide at the lower temperatures and then as cupric oxide above 500°.A mechanism of the roasting process is proposed which accounts for the variations of the relative amounts of sulphide, sulphate and oxide formed, and the state of oxidation of the first and last compounds.
The chemistry of the acid‐catalysed setting of phenolformaldehyde resins
Authors: Little G. E. 
Published: July 2010

AbstractThe pH‐depcndcncc ol reactions at room temperature undcrgonc by model phenolic alcohols and ethers is examined. The kinetics of the self‐condensation of 3,5‐dimethyl‐4‐hydroxyhenzyl alcohol and of its condensation with 2,6‐xylenol are determined and mechanisms of reaction deduced. The setting o f plicnol‐formaldelivde resins a t room temperature is discussed in the light of thcsc experiments.
White‐line road‐markings and light‐coloured road surfacings
Authors: Reid J. A. , Sabey Barbara E. , James J. G. 
Published: July 2010

AbstractWhite‐line road‐markings and light‐coloured road surfaces are considered from the point of view of their visibility, durability and non‐skid properties. It includes a survey of the different types of material available, the visibility requirements for white lines and road surfaces under daylight and night conditions (including both street‐light and headlamp illumination), and the requirements for a good resistance to skidding in wet weather. The extent to which the different materials available meet these requirements is also discussed.The thermoplastic road‐marking material covered by B.S. 3262: 1960 is the most satisfactory vet developed for general use. It has good durability and good skidding‐resistance in wet weather. The night visibility under headlamp illumination is improved by the addition of ballotini.For light‐coloured bituminous surfacings, a light‐coloured aggregate is essential. For surface dressings, calcined flint‐gravel is most suitable: in premixed materials the very white calcined flint is better. The skid resistance of these aggregates is adequate for most purposes.
Reactions between solids. IV. Reaction of sodium perchlorate, potassium bromate and potassium iodate with polydivinylbenzene
Authors: Patai S. , Cross H. , Albeck M. 
Published: July 2010

AbstractThe kinetics of the solid–solid reaction between sodium perchlorate, potassium bromate and potassium iodate, with a cross‐linked divinylbenzene/ethylstyrene copolymer (pDVB) was investigated. The two latter reactions were studied also in the presence of various additives, some of which acted as catalysts and others as inhibitors. All these reactions obeyed the empirical rate law proposed in the preceding paper. The effect of various additives and the mechanism of the reaction are discussed.
Determination of oxidation rates of air‐blown asphalts by infra‐red spectroscopy
Authors: Wright J. R. , Campbell P. G. 
Published: July 2010

AbstractOxidation rates for eight air‐blown asphalts were determined by measuring the change in infrared absorption at 5.88 μ with time of exposure to the radiant energy of a carbon arc. While all the asphalts oxidised at different rates, those from the same geographical areas had similar rates; those from different areas varied considerably. The pattern of oxidation was generally the same for each of the eight asphalts, in that there was an induction period followed by a steady oxidation rate until near the failure point, beyond which time the oxidation rate accelerated until film failure as denoted by asphalt film cracking. An inverse relationship was found between the rate of oxidation and the accelerated weathering durability of each asphalt.
Chemistry of peat bitumen: Fractionation and infra‐red studies
Authors: Thomas J. D. R. 
Published: July 2010

AbstractBitumen extracted from high‐moor peat has an ultra‐violet absorption maximum at 285 mμ. This has been used to follow the fractionation of a methanol‐soluble extract of the bitumen on an anion‐exchange column in the acetate form, with methanol, methanol acetic acid (3:1) and glacial acetic acid as eluants.The infra‐red spectra from 900 to 4000cm.−1 for high‐moor peat, its bitumen and bitumen fractions are also presented and discussed. The spectra suggest that passage of a methanol extract of peat bitumen down an anion‐exchange column in the acetate form gives a separation by which ethers, aliphatic esters and other weakly ionised substances are eluted by methanol. The more acidic eluants appear to release aromatic esters possibly containing phenolic and other acidic or ionisable groups.
Effect of hydrazine on the microdetermination of dissolved oxygen
Authors: Needleman M. 
Published: July 2010

AbstractA method for determination of 0–0.020 p.p.m. of oxygen dissolved in pure water is described. The method, which is based on the ‘reversed‐reagents’ technique, gives a precision (standard deviation) of 0.0008 p.p.m. A detailed investigation of the errors arising in the presence of hydrazine shows that they are due to a non‐compensated reaction between the hydrazine and the manganese oxidised during the Winkler reactions.
The effect of burner orientation on quenching distance
Authors: Sturmon G. R. 
Published: July 2010

AbstractThe effect of burner orientation, from 02(vertically up) to 180° (vertically down), on the quenching distance of laminar, premixed methane, propane, and n‐butane flames was determined experimentally with a plane‐parallel‐plate‐type burner. The mass ratio of the oxygen to oxygen plus nitrogen was held at 0.21 to simulate the combustion of those fuels with air. The gas mixtures were varied from about 50% lean to 50% rich.These tests found no change in quenching distance for orientations from 0 to 90° from any of the three fuels and their mixtures. For orientations between 90 and 165°, two curves were obtained that were tangent at the stoicheiometric mixture, first a quenching curve with quenching distances slightly smaller than the 0–90° curve, and second, a flashback curve with distances slightly larger. For orientations between 165 and 180, the flame was unsteady in a random way, and the separation of the flashback and quenching curves became pronounced.
Polymorphism of thiodipropionic acid
Authors: Bland J. A. , Cudby M. E. A. 
Published: July 2010

AbstractA study has been made of the polymorphism exhibited by thiodipropionic acid making use of infra‐red, X‐ray and optical techniques.Two of the forms, designated A and B, have infra‐red spectra which have differences throughout the observed frequency range, particularly in those regions associated with absorption bands due to the carboxyl and methylene groups.From symmetry and packing considerations based on the X‐ray results, crystal structures have been proposed for the two forms which satisfy infra‐red results. The differences between forms A and B may be explained on the basis of a rotation of one‐half of the molecule of thiodipropionic acid, accompanied by changes in the hydrogen bonding between the molecules in the solid state.Studies of the transitions between phases as a function of temperature with the use of the three techniques, showed that when form B was heated it transformed at 101° ± 0.5° to a third structural modification, C, which had a melting range just below the sharp melting point of pure form A at 128°.
Road building in the tropics
Authors: Millard R. S. 
Published: July 2010

AbstractThe features of the different types of surfaced and unsurfaced road used in tropical countries are described, and an indication is given of some of the typical engineering features of tropical soils, using the ‘red coffee’ soil of Kenya as an example.Natural gravels are used extensivly in road building in tropical countries and the different types of gravel are describedSoil stabilisation is increasingly used to make road bases, and notes are given on the different processes employed. The paper concludes with information on some soft aggregates used in roadmaking, on bituminous surfacings, on the derivation of thermoplastic white‐line material suitable for use in the tropics, and on the control of roadside vegetation.
Thermal decomposition of the nickel and cobalt salts of aliphatic acids
Authors: Leicester J. , Redman M. J. 
Published: July 2010

AbstractThe nickel and cobalt salts of the aliphatic acids studied decompose by primary cleavage into metal oxide and anhydride. The anhydrides then suffer extensive pyrolysis and the ultimate products include metal, metal oxide, carbide and a mixture of vapours (acids, ketones, carbon dioxide, carbon monoxide and hydrogen). The decomposition of nickel acetate in particular provides a good method of preparing nickel carbide Ni3C. The oxide formed from the slow air decomposition of nickel acetate is possibly a useful oxide catalyst. A new modification of cobaltous oxide is formed in good yield from the acetate.
An approach to applicable inorganic polymers. I. Polycondensation by interaction of chloroborazoles and phosphorus esters
Authors: Gerrard W. , Mooney F. F. , Rothenbury R. A. 
Published: July 2010

AbstractTrialkyl phosphates (3 mol.) form a hydrogen‐bonded complex with B‐trichloroborazole (1 mol.), and at 100°, this gives alkyl chloride and a solid borazole system with ‐OP(: O)(OR)2 structure attached to each boron atom. At about 200°, trialkyl phosphate is eliminated, and borazole rings appear to become attached by the structure ‐O.P(: O)(OR).O‐. Further polycondensation occurs at ∼500–800°, to give an infusible, insoluble and hydrolytically stable inorganic polymer containing boron, nitrogen and phosphorus.Related observations with N‐methyl‐ and N‐phenyl‐B‐trichloroborazoles are recorded. Equimolal systems, and dialkyl hydrogen phosphite‐trichloroborazole systems are described.Triphenyl phosphate reacted differently with B‐trichloroborazole, but did not react at all with N‐trimethyl‐B‐trichloroborazole.Techniques of gas chromatography, infra‐red spectroscopy and thermogravimetric analysis were used.
The de‐aeration of aqueous solutions
Authors: Gilroy D. , Mayne J. E. O. 
Published: July 2010

AbstractThe efficiency of the method of de‐aerating aqueous solutions devised by Hersch has been examined. The method is more convenient and efficient than those in current use, because within 1 h. the residual oxygen content of a solution can be reduced either to 0.003 ± 0.001 p.p.m. by weight by use of ‘White Spot’ nitrogen (less than 10 p.p.m. of oxygen) as the scrubbing gas, or 0.0005 p.p.m. when purifited nitrogen is used.
Inert diluents for use in nuclear energy extraction plants. II Pretreatments for improving kerosene and related diluents
Authors: Lane E. S. , Field B. O. , Willans J. L. 
Published: July 2010

AbstractOdourless kerosene was treated by steam distillation, sulphuric acid washing and extractive crystallisation with urea, then examined for stability to nitric acid at 70° by use of a radiochemical procedure. Combinations of these processes can be used to produce an inert diluent with an improved performance factor of up to 8 over the untreated material. The improvement is attributed largely to removal of residual unsaturation. The results are compared with recent U.S. work on the subject and attempts are made to correlate the improvement factors with the chemistry involved in the different pre‐treatment processes.
Some approaches to the permanent flameproofing of cotton: Systems containing phosphorus
Authors: Jones D. M. , Noone T. M. 
Published: July 2010

AbstractThe flame‐retardant properties of several compounds containing phosphorus bonded to (a) nitrogen and (b) carbon have been studied with particular reference to their behaviour on cotton under alkaline laundering conditions. The compounds containing P‐N bonds are not suitable for use as permanent flameproofing agents. Polymers containing P‐C bonds are much more promising. These findings are discussed in relation to the chemical structures involved.
Effect of ammonium diuranate precipitation conditions on the characteristics and sintering behaviour of uranium dioxide
Authors: Ainscough J. B. , Oldfield B. W. 
Published: July 2010

AbstractAmmonium diuranate has been prepared by adding aqueous ammonia to uranyl nitrate solution under different conditions of temperature and final pH. The resulting precipitates, when dried, can be considered as loosely bound compounds with an ammonia/uranium ratio of 0.37 containing varying amounts of water and ammonium nitrate. As well as differing in composition these precipitates differ markedly in their specific surface areas. After calcination to U3O8 in argon at 700° and reduction in hydrogen at the same temperature, all the diuranates yield uranium dioxide of similar specific surface, and it is concluded that the calcination temperature is the principal factor in determining this. The powders when milled, mixed with an organic binding agent, granulated, pressed and sintered in hydrogen for 2 h. at 1650° give uranium dioxide compacts with bulk densities greater than 96.5% of the X‐ray density (10.96 g./cm.3). Little, if any, correlation has been found between the precipitation conditions and the sintered densities of the compacts. although a relatively rapid rate of addition of ammonia seems to give a slightly denser compact and it seems possible that some uncontrolled variation during milling or pressing outweighs any effects due to differences between the powders.
Potential purine antagonists. XXXIII. Synthesis of chloropurines
Authors: Beaman A. G. , Robins R. K. 
Published: July 2010

AbstractThe previously described synthesis of 2,6,8‐trichloropurine by the oxidation of 2,6,8‐purinetrithiol with chlorine gas has been applied to the synthesis of the six remaining simple chloropurines. The synthesis of the previously unknown 8‐chloropurine is described. The new method is general and is superior to the previously described methods for the synthesis of the various chloropurines.
Physical properties of calcined gypsum
Authors: Ridge M. J. , Boell G. R. 
Published: July 2010

AbstractGypsum plaster is a flocculated suspension and the water requirement of calcined gypsum is related to the yield value of the suspension it forms in water. The strength of the structure that forms in the suspension will determine the yield value. The effects of physical factors such as temperature, entrained air and stirring on the water requirement are discussed.The bearing on the water requirement of physical characteristics of the grains of hemihydrate such as porosity, surface area and condition of the surface is also discussed. Sedimentation volumes in ethanol and benzene were studied and an appreciable correlation found between surface area and the sedimentation volume in benzene. The results indicate that ethanol offers a satisfactory medium for separating calcined gypsum into fractions according to particle size.
Composition of ammoniacal liquors. III. Analysis of the organic bases by gas chromatography
Authors: Hughes M. A. 
Published: July 2010

AbstractOrganic bases are removed from a gas works ammoniacal liquor, which has been made strongly alkaline with sodium hydroxide, by steam distillation, and are recovered from the distillate by extraction with benzene. After the removal of solvent, the residue is applied to gas chromatography columns containing either silicone M.S.550 or glycerol. Liquors from a coke oven plant and a continuous vertical retort system have been investigated.
Corrosion and electrochemical properties of titanium, zirconium and titanium‐zirconium alloys in acid solutions. II
Authors: Andreeva V. V. , Glukhova A. I. 
Published: July 2010

AbstractThe corrosion and electrochemical behaviour of titanium, zirconium and titanium‐zirconium alloys in solutions of sulphuric, nitric and phosphoric acids and also in mixtures of nitric and phosphoric acids, has been investigated.Alloying titanium with zirconium increases the titanium corrosion‐resistance in sulphuric acid solutions at 100° when the concentration of the latter is 80%. At concentrations higher than that neither of the metals nor titanium‐zirconium alloys are stable. In phosphoric and nitric acid solutions, titanium‐zirconium alloys have no advantage over titanium and zirconium.
Use of synthetic branched carboxylic soaps in the emulsion copolymerisation of styrene and butadiene
Authors: Duck E. W. , Waterman J. A. , la Helj G. E. 
Published: July 2010

AbstractSodium soaps of highly branched saturated monocarboxylic acids, in particular those containing 15–20 carbon atoms, are valuable substitutes for both rosin acid soaps and sodium stearate in cold emulsion polymerisation SBR recipes such as ASTM types 1500, 1502, and 1509. Indications are that they possess various process advantages over the normal types of emulsifier. At comparable concentrations they give higher rates of polymerisation than do the commercially available rosin acid emulsifiers and their solutions do not gel at temperatures between 5° and 20°, as is the case with sodium stearate. Moreover, they show a relatively good tolerance towards hard water.Potassium, ammonium and lithium salts of these synthetic acids are also excellent emulsifiers for the preparation of SBR latices.
Effect of dead sea water on portland cement
Authors: Heller L. , Ben‐Yair M. 
Published: July 2010

AbstractThe effect of Dead Sea water on pastes and mortars of normal and sulphate‐resisting Portland cement has been studied. The principal reaction products include magnesium hydroxychloride, calcium chloroaluminate and hydrated magnesium silicate. The use of Dead Sea water as mixing water in the preparation of the bars appears to enhance their stability. The reasons are discussed.
Relation between the zeta potential of rutile and its flotation with sodium dodecyl sulphate
Authors: Graham K. , Madeley J. D. 
Published: July 2010

AbstractThe influence of pH on the surface electrokinetic properties of the rutile‐solution interface has been studied; below pH 3.5 the surface is positively charged and above this pH value it is negatively charged. Adsorption of dodecyl sulphate anions from aqueous solution on to the rutile surface is influenced profoundly by the electrokinetic properties of the mineral‐solution interface, the surface showing decreased adsorption of anions with increase in pH. Flotation tests have shown that at constant pH, the flotation rate increases with collector concentration and that for a fixed collector concentration, a decrease in flotation rate occurred as the pH increased from 3 to 7.