bluuebunny/crossref_metadata_2025_split huggingface dataset:
Separation of thorium from uranium and rare‐earth elements by solvent extraction with tri ‐ n ‐ butyl phosphate ‐ xylene
Authors: Menzies I. A. , Rigby F. 
Published: July 2010

AbstractA study is made of three processes for the separation of thorium from uranium and rare‐earth elements in crude thorium nitrate solutions prepared by breakdown of monazite sand. Uranium may be separated from thorium and rare‐earth elements in a preliminary extraction with 5% or 40% v/v tri‐n‐butyl phosphate (TBP) in xylene and the thorium separated from the rare‐earth elements in a subsequent extraction with 40% v/v TBP in xylene. Alternatively thorium and uranium may be extracted simultaneously from the solutions with 40% TBP in xylene and the thorium preferentially backwashed from the loaded solvent with dilute HNO3. The present work indicates that processes in which uranium only is extracted in the first operation will be the most flexible and the simplest to operate. The partition coefficients for zirconium, which occurs as an additional contaminant in solutions prepared from thorite ores, have also been determined by batch extraction with 5% and 40% TBP in xylene and the data confirmed in a continuous countercurrent system.
Chemical constitution of road tars and coal tar pitches
Authors: Wood L. J. 
Published: July 2010

AbstractOils derived by the distillation of primary and refined tars and the solvent treatment of pitch have been examined by high‐temperature gas‐liquid chromatography. The solvent extracts of the pitch have also been analysed by infra‐red spectroscopy and for elementary composition. It has been possible to account for a large part of the tar oils as quantities of individual compounds and to indicate the main changes in chemical types associated with the increasing number of rings in the less soluble pitch fractions.
Electrical conductivity of dilute aqueous phosphate solutions and phosphoric acid at elevated temperatures and pressures
Authors: Whitehead G. 
Published: July 2010

AbstractA combined pressure vessel and conductivity cell suitable for use at pressures up to 16 atm. and temperatures up to 200° is described. This equipment has been used to measure electrical conductivities of sodium phosphates and phosphoric acid at low concentrations (phosphates 0.0006–0.01M, H3PO4 0.13M).With each substance, the conductivity attained a maximum and then decreased with increasing temperature. The temperatures where conductivities were maximum were lower than those previously reported for uni‐ and di‐valent salts.
The properties of tar‐polymer mixtures
Authors: Wood L. J. 
Published: July 2010

AbstractMixtures containing continuous vertical retort tar and small concentrations of long‐ chain polymers have been examined by a number of different flow and brittle tests. In general the addition of polymer causes an increase in resistance to flow without greatly affecting the viscosity/temperature behaviour or the brittleness. A method of rheological analysis is presented for characterising the viscoelastic properties. The practical implications of the measurements are discussed.
Chemical modification of wood. I use of trifluoroacetic anhydride in the esterification of wood by carboxylic acids
Authors: Arni P. C. , Gray J. D. , Scougall R. K. 
Published: July 2010

AbstractTreatment of beech sawdust with a series of mono‐ and dicarboxylic acids in benzene solution at 25–30° in the presence of molar proportions of trifluoroacetic anhydride resulted in esterification of the cell wall components. The esterification is shown to be due in part to acylation by the carboxylic acid and in part to trifluoroacetylation. The latter caused discoloration of the wood due to slow hydrolytic release of trifluoroacetic acid on storage at room temperature. Similar esterification of sapwood lengths of Ponderosa pine resulted in surface modification only and was accompanied by a significant decrease in impact strength property.
Studies in hydrogen‐bond formation. IX Bonding between esters and the chloro‐group
Authors: Giles C. H. , Nakhwa S. N. 
Published: July 2010

AbstractThe refractometric method is used to demonstrate hydrogen‐bond complex formation between aromatic chloro‐groups and the α‐methene or ‐methylene groups of ester residues. The bond between chlorobenzene and ethyl acetate has an energy ∼ −3kcal. /mole in aqueous ethanol. This type of bond probably assists the adsorption by cellulose acetates of dyes containing chloro‐groups. Chlorobenzene is strongly adsorbed by cellulose triacetate, probably by this mechanism. The hypothesis of ‐Cl … HC‐bonding may assist in the interpretation of the relative degrees of plant growth‐hormone activity of chlorinated aryloxyacetic acid derivatives.
The pyrolysis of cellulose and the action of flame‐retardants. I. significance and analysis of the tar
Authors: Holmes F. H. , Shaw C. J. G. 
Published: July 2010

AbstractA study has been made of the pyrolysis of different cottons in vacuum, and in dry air, mainly at 418°C and the products have been fractionated and analysed. From a purified cotton cellulose, the main products are a combustible tar and water, but when a flame‐retardant is present less tar and more gas and carbonaceous residue (char) are produced. The tar is highly flammable, and is a major factor in the burning of cotton. There is a correlation between the amount of tar formed and the flammability of the cotton. Removal of the impurities from the cotton cellulose leads to the formation of more tar on pyrolysis. The tar is a mixture of organic compounds of which the major component is laevoglucosan. Acids, carbonyl compounds and unsaturated compounds have been found and determined quantitatively.It is concluded that for a treated cotton cellulose material to be flame‐resistant the amount of tar formed on pyrolysis must be small.
The removal of copper extrusion sheaths from zirconium and its alloys
Authors: Menzies I. A. , Rigby F. 
Published: July 2010

AbstractThe rates of dissolution of copper and zirconium in mixed nitric and hydrofluoric acid solutions have been determined at laboratory temperature. It has been shown that such solutions can be used for the removal of copper extrusion sheaths from zirconium without significant loss of zirconium or absorption of hydrogen by the zirconium. There was no evidence of the formation of powdery or active surfaces on the zirconium after removal of copper and no explosions were encountered in the present work.The anodic dissolution of copper in aq. ammonia‐ammonium sulphate solutions has also been studied. Copper dissolves with an apparent valence number equal to unity and it is thought that copper(I) is stabilised in such solutions by complex formation. Copper extrusion sheaths can be removed from zirconium by anodic dissolution in such media without loss of zirconium or absorption of hydrogen by the zirconium. This process also facilitates the recovery of copper.The two processes are discussed with respect to safety in the light of present knowledge. It is concluded that the nitric acid‐hydrofluoric acid process is unsuitable for the removal of copper from uranium‐zirconium alloys, and that the possibility of explosion during the removal of copper sheaths from unalloyed zirconium cannot be completely ruled out. The anodic dissolution process appears to be a safe one, and could probably be used for uranium‐zirconium alloys in addition to unalloyed zirconium.
An experimental survey of rust preventives in water III. Some general results
Authors: Hersch P. , Hare J. B. , Robertson A. , Sutherland Sheila M. 
Published: July 2010

AbstractThe influence of pH, apart from the case of amines discussed in Part II,1 and geometrical factors on the inhibition thresholds for mild steel in non‐acid aqueous solutions containing dissolved air, are described. Modifying the standard corrosion tests by partial or complete removal of the air‐formed oxide film increased the inhibition threshold concentration with some but not all inhibitors. Conversely, pre‐immersing the specimen in an inhibiting solution reduced the threshold value below the normal value.Substances which form soluble iron complexes, such as catechol and EDTA, were often found to increase the inhibition threshold for mild steel, but the results nevertheless indicate that inhibition is not necessarily associated with the deposition of an insoluble iron salt. The iron complex solutions were themselves found to inhibit in some instances, a fact probably relevant to the well‐known inhibition effect of tannins.Generally no marked differences appeared in the threshold values for a number of irons and low alloy steels. Azide showed a resemblance to nitrite in its behaviour, which suggests a similar inhibition process, i.e. adsorption. The cast irons, especially the ferritic varieties, were considerably more difficult to inhibit. Many inhibitors for ferrous materials were also found to inhibit zinc corrosion, which indicates that unfilled electron energy bands or vacant atomic orbitals are not necessary for inhibition to occur.The results described in the three papers of this series are summarised, and a novel hypothesis is presented by one of us (P.H.) to account for inhibition by anions.
The surface properties of silica gels. III Adsorption of benzene and ethanol vapours
Authors: Horvat Danica M. , Sing K. S. W. 
Published: July 2010

AbstractSilica gels were prepared under various conditions from sodium silicate and two organic silicates. The gels prepared by the hydrolysis of ethanolamine polysilicate were less active than those obtained from sodium silicate, but a gel with a substantial surface area was prepared by the slow hydrolysis in acid solution of isopropyl silicate.Adsorption isotherms of benzene and ethanol were determined gravimetrically on samples of the gels at temperatures between 0° and 35°. Evidence is presented to show that the Brunauer‐Emmett‐Teller (B.E.T.) values of the monolayer capacity for ethanol are more reliable than those for benzene. For most gels, the area occupied by the ethanol molecule in the adsorbed monolayer appears to be close to 31 Å2.
Variations in the kinetics of setting of calcined gypsum. II. The action of retarder‐accelerator mixtures
Authors: Ridge M. J. , Surkevicius H. 
Published: July 2010

AbstractThe effects were studied of some retarder‐accelerator mixtures on the kinetics of setting of samples of seven calcined gypsums with different characteristics. Egg albumin, calcium acetate, sodium hexametaphosphate and borax were the retarders used in conjunction with precipitated calcium sulphate, potassium sulphate and sodium chloride as accelerators. Some of the retarder‐accelerator mixtures reduced the range of the induction periods of the samples, the most effective being those based on calcium acetate as a retarder and precipitated calcium sulphate as accelerator the least effective were those based on borax as retarder and potassium sulphate as accelerator.The effects were tested of the retarder‐accelerator mixtures in reducing the sensitivity of plaster to contamination with retarders and accelerators. All the formulations except sodium hexameta‐phosphate and borax with potassium sulphate reduced the difference between the retarded induction period and the accelerated induction period.The observations made are discussed in terms of the theories already developed for the actions of retarders and accelerators.
Determination of endothermal heat effects of clays in the study of thermal efficiency of brick kilns
Authors: Ramachandran V. S. , Majumdar N. G. 
Published: July 2010

AbstractThe heat of dehydration of clays caused by the loss of combined water between 425 and 750° accounts for nearly 10% of the total heat input in estimating the thermal efficiency of kiins used for the production of structural clay products. Heat of dehydration is usually assessed from a determination of the ‘ residual ignition loss’, using certain assumptions. This paper discusses the possibility of applying Differential Thermal Analysis to calculate directly the heats of dehydration of brick clays, potassium sulphate being used as a standard.
Electrode potential studies of iron in dilute solutions of sodium nitrite
Authors: Baghurst H. C. 
Published: July 2010

AbstractPrevious workers have shown that inhibitors having relatively strong oxidising anions, such as chromate and nitrite, passivate iron both in the presence of air and in de‐aerated solutions. Evidence is presented to show that while this may be so in 0.1M solutions, the behaviour in de‐aerated dilute solutions ranging from 200 to 1600 p.p.m. of inhibitor is quite different. Further, the action of nitrite is essentially different from that of chromate, in that, in the absence either of dissolved oxygen or of a pre‐immersion oxide film, nitrite is impotent in preventing corrosion of iron.
Influence of some additives on the hydration reactions of portland cement I. Non‐ionic organic additives
Authors: Stein H. N. 
Published: July 2010

AbstractThe influence of some non‐ionic organic additives, dissolved in the water used for mixing cement pastes, on cement hydration was determined by isothermal calorimetry. The additives, all poly‐alcohols, exert a retarding action on cement hydration. Glycerol has, in addition, a particular influence on the crystallisation of ettringite and calcium hydroalumino‐monosulphate, accelerating the consumption of sulphate ions.
Surface properties of hydrolysed titania. III. Titania prepared from titanium chloro‐alkoxides
Authors: Harris M. R. , Whitaker G. 
Published: July 2010

AbstractSamples of titania gels were prepared by the hydrolysis with steam of titanium chloro‐alkoxides and titanium tetrachloride, and their surface characteristics studied by the adsorption of nitrogen at low temperatures. All the gels were active, but they exhibited a wide range of pore sizes and surface areas. The gels were stable, but the freshly prepared samples when refluxed with water underwent an unusual form of ageing in which the surface areas and pore volumes rose considerably. Raising the pH, preferably by dialysis but also by the addition of ammonia solution, changed the surface characteristics of the gels but did not destroy their activity; after this treatment the gels aged normally under reflux, with a reduction in surface area. By comparison of these results with those obtained in Parts I and II, a scheme has been drawn up for the preparation of active titania gels with any desired pore radius in the range 10–100 A.
An approach to applicable inorganic polymers. IV. Interaction of boron or silicon halides with esters of phosphonic acids
Authors: Chainani G. , Gerrard W. , Patel J. K. , Twaits R. 
Published: July 2010

AbstractInteraction of phosphonate esters with boron trichloride, B‐trichloroborazole and chlorosilanes is studied. The boron trichloride systems gave hard, sometimes brittle, resins; the trichloroborazole reactions gave almost quantitative yields of alkyl chloride and polyanhydrides with P‐O‐B linkages; the methylchlorosilanes yielded, in the main, softer and more soluble products than those from boron trichloride. The applicability of the products as inorganic polymers is rather doubtful.
Decomposition equations of ammonium perchlorate
Authors: Simchen A. E. 
Published: July 2010

AbstractThe data existing for the thermal decomposition equations of ammonium perchlorate (AP) have been reviewed after reducing them to a common basis (100 moles of AP). They have been evaluated from two points of view: (a) stoicheiometric balance of the elements present, and (b) establishment of thermodynamic equilibrium of the final gaseous products. From a knowledge of the distribution of the nitrogen between N2, N2O and NO, and of the chlorine between Cl2 and HCl (the latter derived from the equilibrium constant for the Deacon process), the corresponding equilibrium temperatures (Teq) and the flame temperatures (Tt) have been calculated. These temperatures agree in a number of cases with the measured heating temperatures and temperatures of the gas flame.Extrapolation of the equilibrium gas compositions calculated for different pressures indicates that the gas composition at equilibrium lies between two asymptotic extremes which are:For zero pressure or for relatively low Teq

and for high pressures or for relatively high Teq,

Below 300° some ClO2 forms, and N2O instead of NO. NO when, formed reacts giving nitrosy1 compounds.At all temperatures there may occur a ‘freezing’ of non‐equilibrium compositions.
An extension of the Nelsen‐Eggertsen continuous flow method of surface area measurement
Authors: Haley A. J. 
Published: July 2010

AbstractOne of the simplest methods of surface area measurement is extended to include the size distribution of pores in the 10–300 Å radius range. This technique involves passing a mixture of 10% nitrogen in helium over the sample cooled in liquid nitrogen at a fixed rate and at various pressures to 150 p.s.i.a. causing the nitrogen partial pressure to reach its liquefaction point. Consequently the nitrogen relative pressure in the sample tube is varied in the range of about 0.16 to 1. Nitrogen adsorbed or desorbed by increasing or decreasing pressure in the sample tube is measured continuously at near atmospheric pressure by thermal conductivity. The thermal conductivity cell always ‘sees’ a reference of 10% nitrogen in helium. Hence the measured composition differences fall within a comparatively narrow range where the thermal conductivity cell output is linear. Isotherms developed by this method are compared with isotherms obtained by the pressure‐volume method of adsorption measurement and show good agreement. Simplicity of design and operation of the instrument provides fast and reliable results.
Catalytic esterification of saturated carboxylic acids with ethylene under high pressure
Authors: Bhattacharyya S. K. , Lahiri G. R. 
Published: July 2010

AbstractThe syntheses of ethyl acetate, propionate and butyrate from the corresponding acids and ethylene in presence of catalysts have been studied in the pressure range of 50–180 atm. and temperature range of 120–200° under shaking conditions. Of the catalysts tried, dilute sulphuric acid proved the best. Agitation leads to improved yields of ester over static operation. Under optimum conditions the maximum yields of ethyl acetate, propionate and butyrate were 86.9%, 79.4% and 61.5% respectively.
The reaction between anhydrous ethyleneimine and water
Authors: Pascoe P. F. , Sherbrogk‐Gox W. A. 
Published: July 2010

AbstractIt has been demonstrated by several physical measurements that one molecule of anhydrous ethyleneimine reacts with two molecules of water. The reaction product appears to be a chelated ethanolamine‐hydrate which is remarkably stable even in the vapour phase. On prolonged heating the chelate ring opens and a mixture of ethanolamine and water is obtained. The chelated hydrate has the previously unknown structure of a chelate ring held together solely hydrogen bonds.Sodium hydroxide converts part of the chelate into anhydrous ethyleneimine, which can be recovered distillation. Chelated ethanolamine‐hydrate and anhydrous ethyleneimine behave differently towards certain solvents. Solid sodium hydroxide in the presence of such selective solvents converts the aqueous solution of the chelated ethanolamine‐hydrate effectively to anhydrous ethyleneimine.The conversion of β‐aminoethylsulphuric acid ester or of β‐chlorethylamine hydrochloride into ethyleneimine occurs in two stages via the chelated ethanolamine‐hydrate as intermediate. The mechanism of this reaction is discussed.
Determination of nickel and iron carbonyls in town gas
Authors: Densham A. B. , Beale P. A. A. , Palmer R. 
Published: July 2010

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

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

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

AbstractTo obtain information with regard to the porous structure of hydrated cement and the extent of its interaction with water, sorption and length‐change isotherms were determined for this material.Compacts of bottle‐hydrated cement were brought to equilibrium in a high‐vacuum system at various humidities, and measurements of the changes in length and weight during this process, were made to draw the isotherms.Results showed that this system is basically similar to systems composed of other porous materials, although complicated by a discontinuity in the adsorption part of the cycle and a secondary hysteresis. It is considered that these characteristics are related and are the result of water associated with the system by a process other than physical adsorption.It is also shown that menisci exist in the system on desorption to as low as 31% R.H. and cause considerable contraction. A surface‐area calculation by a new method for estimating the zero adsorbed water yield a value of 80·6 m.2/g.
Distribution of nitric acid between tri‐N‐butyl phosphate and water
Authors: Burns P. E. , Hanson C. 
Published: July 2010

AbstractThe distribution of nitric acid between water and both 20 and 30% v/v solutions of tri‐n‐butyl phosphate in odourless kerosene at 20° and 25° has been studied systematically up to aqueous phase concentrations of 10 moles per litre. An equation is derived to represent the distribution up to aqueous phase concentrations of 4 moles per litre.