bluuebunny/crossref_metadata_2025_split huggingface dataset:
Solvent extraction using dialysis through artificial phase boundaries
Authors: Massoumi A. , Edrissi M. , Hedrick C. E. 
Published: July 2010

AbstractSeveral solvent extraction systems were studied using a cellulose dialysis membrane as an artificial phase boundary separating one solvent phase from the other. Solutes were allowed to come to extraction equilibrium by permeation through the membrane. The rate of permeation depended on the osmotic properties of the solute, such as the molecular size and the presence of colloidal species. The extraction equilibrium was established by the solvent‐extraction properties of the solute in each system, and the equilibrium was approached through the cellulose membrane by a first‐order kinetic process. The method appears to be useful for ‘packaging’ organic solvents in membrane containers to be used for extractions in which time is not a factor. In certain cases, equally well extracted solutes, such as zirconium and aluminium 8‐hydroxyquinolates, can be separated because one solute exists as a partially colloidal material [Zr(IV)] and hence does not pass through the membrane rapidly.
Formation and surface properties of electron‐emissive coatings IV. DTA, ETA and dilatometry studies on some alkaline–earth hydroxides
Authors: Judd M. D. , Pope M. I. 
Published: July 2010

AbstractThe decomposition under vacuum of the hydroxides of calcium, strontium and barium was investigated by differential thermal analysis (DTA), electrothermal analysis (ETA) and dilatometry.The results suggest that the rate of sintering of calcium oxide is initially governed by the formation of a pseudo‐hydroxide lattice; rapid sintering occurs only after conversion of this to the true oxide. Compacts of the oxides of strontium and barium show a remarkable resistance to sintering at temperatures up to 1000°. It is proposed that the sintering may have been inhibited by the presence of trace amounts of calcium oxide and strontium oxide formed by decomposition of impurities present in the samples of strontium and barium hydroxides, respectively.
Measurement of rate of anion exchange and the effect of organic fouling
Authors: Wall H. K. , Wakelin L. P. 
Published: July 2010

AbstractA method has been developed for the examination of rates of reaction of a strongly basic ion‐exchange resin with a large organic anion.The results indicate that an organically fouled resin reacts at a slower rate than an unfouled one under standard conditions, and the possibilities of using the method as an aid to solving the problem of organic fouling are discussed.
Assay‐increment and solubilisation of α‐glucosidase and invertase in disruption of brewers' yeast
Authors: Wiseman A. , Jones P. R. 
Published: July 2010

AbstractA variety of disruption techniques were used on brewers' yeast with subsequent estimation of the additional (assay‐increment) α‐glucosidase and invertase made accessible to p‐nitrophenylglucoside (PNPG) and sucrose, respectively, in the total disruptate. The extent of actual solubilisation of these two enzymes in the 0.75 M potassium phosphate buffer (pH 6.5) present, was also measured.Extensive release (i.e. solubilisation) of α‐glucosidase was achieved using ultrasonication or ethyl acetate autolysis, and here differential release of α‐glucosidase over invertase was large. Extensive release of both α‐glucosidase and invertase was obtained with snail gut enzyme and toluene (papain) autolysis, while air drying released some invertase but destroyed 80% of the α‐glucosidase.The assay‐increment, over intact yeast values, for α‐glucosidase in total disruptate, which is due to increased accessibility of PNPG to this enzyme, was high for salt autolysis and toluene (papain) autolysis but was low for the Mickle shaker and the Potter‐Elvehjem homogeniser. No increment was observed using the X‐press, although solubilisation of α‐glucosidase was moderately good.Increment, over intact yeast values, for invertase assay in total disruptate was highest with ultra‐sonication and air drying, but was nevertheless generally low owing to almost complete availability of this cell wall enzyme for assay—but not for isolation—in intact yeast.
Chemistry of by‐product gypsum and plaster III.—Retarder insensitivity in hydrating calcium sulphate β‐hemihydrate
Authors: Kitchen D. , Skinner (deceased) W. J. 
Published: July 2010

AbstractA study has been made of the effect of fluoroaluminium ions on the retarded hydration of calcium sulphate β‐hemihydrate brought about by amino acid retarders. If sufficient fluoroaluminium ions are present (∼0.02–0.03% Al as co‐crystalline AlF2−5 in the hemihydrate), the hemihydrate becomes insensitive to retarder addition because the latter forms stable chelates with the fluoroaluminate ions. The retarder is thus effectively deactivated because the chelates are not sufficiently strongly adsorbed on to the faces of the growing gypsum crystals to influence the rate of advance of the growth steps.
Solubility of hydrogen chloride in ethers. Measurement of vapour pressures and infra‐red studies of ether‐hydrogen chloride solutions
Authors: Kapoor K. P. , Luckcock R. G. , Sandbach J. A. 
Published: July 2010

AbstractValues of the solubilities of hydrogen chloride in 21 ethers over the range ‐ 75°to + 30°c at 1 atm are given. It has been found that solubilities are controlled by both inductive and steric factors. Vapour pressures of hydrogen chloride in methyl and ethyl n‐butyl ethers have been measured, and these results have been used to calculate differential heats of solution. Preliminary results are given for infra‐red shifts of ether‐hydrogen chloride complexes.
Barium aluminate hydrates I. General survey and preparative methods
Authors: Ahmed A. H. M. , Dent Glasser L. S. 
Published: July 2010

AbstractThe conditions of formation of the barium aluminate hydrates have been reinvestigated, and new compounds in this system are reported. Preparative methods used included reaction of barium hydroxide solutions with aluminium wire and with various forms of hydrated alumina and also reactions of mixtures under hydrothermal conditions. The methods used for the investigation and characterisation of the products are described.
Barium aluminate hydrates II. BaO.Al2O3.H2O or 1.1 BaO.Al2O3.H2O
Authors: Ahmed A. H. M. , Dent Glasser L. S. 
Published: July 2010

AbstractThe compound of approximate formula BaO.Al2O3.H2O has been synthesised. Infra‐red and X‐ray studies suggest a structure based on a framework of AlO4 tetrahedra. Thermal dehydration and differential thermal analysis curves are presented, and are explained in terms of the suggested structure.
Rates of low‐temperature dehydration of montmorillonite and illite
Authors: Sh. Mikhail R. , Guindy N. M. 
Published: July 2010

AbstractThe kinetics of the isothermal dehydration of the clay minerals, montmorillonite and illite, were studied in vacuo as well as in the presence of a constant water vapour pressure. The dehydration followed a first‐order law, and the presence of water vapour led to (i) an increase in the extent of dehydration, compared with that in vacuo; (ii) a retardation to the rate of dehydration; and (iii) a great increase in the energy of activation required for the dehydration.Dehydration in vacuo appears to be diffusion‐controlled with an activation energy of 2–4 kcal/mole, whereas the desorption of water appears to control dehydration in the presence of water vapour, with an activation energy of 12–15 kcal/mole. The results are discussed in conjunction with the mechanical contraction of the layer structure, and the introduction of diffusion barriers when dehydration in vacuo takes place.
Continuous production of high‐purity water by electro‐deionisation
Authors: Matějka Z. 
Published: July 2010

AbstractOperating conditions were investigated for a packed‐bed membrane cell for electro‐deionisation of brackish or tap water to give high‐purity water with electrical conductivity of the order 0.1 μmho/cm. Flow rates of 10–40 h−1, current densities of 0.5–5 mA/cm2, and incoming solution concentrations of up to 0.01 N were used. It was shown that strongly acidic cation‐exchange resin plus strongly basic anionexchange resin in volume ratio 1:1 was the most effective, and that particle size needed to be 60–80 mesh and resin bed thickness 3 mm for optimum current efficiency in purifying water to the required standard.
Kinetics of absorption of isobutylene in acetic acid
Authors: Gehlawat J. K. , Sharma M. M. 
Published: July 2010

AbstractThe kinetics of absorption of isobutylene in acetic acid in the presence of concentrated sulphuric acid (98 wt.‐%) as catalyst, which results in the formation of t‐butyl acetate, was studied in a 10‐cm i.d. agitated glass reactor. The solubility of isobutylene in acetic acid and t‐butyl acetate was determined experimentally. The reaction is relatively slow and the diffusional factors could be completely eliminated. The values of the second‐order reaction rate constant were 0.82 and 2.7 cm3 mole−1 sec−1 at 20° and 40°c, respectively.
Silver rubidium iodide solid electrolyte
Authors: Scrosati B. 
Published: July 2010

AbstractSilver rubidium iodide (RbAg4I5) is a unique solid electrolyte because of its extremely high conductivity which has an almost negligible electronic contribution. This characteristic makes RbAg4I5 a very promising electrolyte for the development of high‐power solid‐state batteries. Consequently, a considerable amount of work has been carried out on this compound since its discovery in 1967. In the first part of this paper the physicochemical and electrochemical properties of this electrolyte are reviewed, and then the characteristics and performances of RbAg4I5 solid‐state cells are discussed.
Kinetics of the iron(III)‐catalysed oxidation of oxalate by permanganate
Authors: Mapstone G. E. 
Published: July 2010

AbstractThe method of reaction times has been used to investigate the kinetics and mechanism of the iron‐catalysed reaction between permanganate and oxalic acid.The rate‐controlling step is the decomposition of the dioxalatoiron(III) ion.The reaction rate is independent of the initial permanganate concentration below 0.0015 N but is proportional to the initial concentration above 0.002 N. The rate equation for the reaction at 24°c is dx/dt= −(9.9 × 10−3 a+ 1.8 × 10−5[Fe3+]1/3).[H2C2O4]2/3 where a is the initial permanganate concentration.
Self‐heating and ignition of chemically activated carbon
Authors: Bowes P. C. , Cameron A. 
Published: July 2010

AbstractFollowing the occurrence of fires in chemically activated carbon in transit, a study has been made of the self‐heating and ignition properties of this material.Thermal ignition theory has been applied to the results of laboratory scale self‐ignition experiments and has enabled realistic prediction of critical sizes of pile for self‐heating to ignition at ordinary ambient temperatures. However, predictions of times to ignition at ordinary temperatures are much larger than found in practice.A distinction emerges between a long‐term self‐heating process responsible for the observed ignition of the ‘weathered’ carbon and short‐term processes which probably include the establishment of moisture equilibrium with the atmosphere and which are largely completed during the standard ‘weathering’ time of 8 days. The long‐term process is not affected by this weathering but is dependent on the temperature of carbonisation and weathering at elevated temperatures (e.g. 100°C).Safe carriage of the carbon in economically worthwhile quantities is ensured by packing in polyethylene bags. These can sustain a small amount of damage with impunity.
Deposition of primary kainite from marine bitterns in solar evaporation
Authors: Choudhari B. P. 
Published: July 2010

AbstractMother liquor compositions during the solar evaporation of marine bitterns have been compared with corresponding isothermal equilibria in the NaCl‐KCl‐MgCl2‐MgSO4‐H2O system. The compositions indicate that on solar evaporation of bitterns, potassium is deposited solely in the form of kainite, and that co‐deposition of free sylvite and epsomite does not take place. It is also shown that during solar evaporation, the concentration of potassium is relatively low and that of magnesium relatively high, resulting in a more efficient precipitation of potassium in solar evaporation than in the forced or isothermal evaporation of sea water or of pure salts.
Reactions of unsaturated compounds II. Structure and chromic acid oxidation of the hydrocarbon C19H22 obtained by the dehydration of 1,1‐diphenyl‐2‐ethyl‐2‐methylbutan‐1‐01
Authors: Moussa G. E. M. , Eweiss N. F. 
Published: July 2010

AbstractDehydration of 1,1‐diphenyl‐2‐ethyl‐2‐methylbutan‐1‐01 gives a hydrocarbon C19H22 which was identified as 3‐ethyl‐4,4‐diphenylpent‐2‐ene.Oxidation of C19H22 with chromium trioxide in acetic anhydride gave acetophenone, benzophenone and α,α‐diphenylpropionic acid. Oxidation with chromium trioxide in aqueous sulphuric acid gave 2,2‐diphenylpentan‐3‐one, benzophenone and benzoic acid.A tentative explanation for the production of abnormal fission products is given.
The formation and surface properties of electron emissive coatings VIII. Structure of strontium‐barium double carbonates
Authors: Judd M. D. , Pope M. I. 
Published: July 2010

AbstractThe double carbonates of strontium and barium SrxBa2‐x(CO3)2 have been shown to undergo, on heating, a transition from an orthorhombic to a hexagonal crystal form. The temperature at which this phase change occurs, and the heat required for the transition, are dependent on the value of x.
The reversed two‐environment model of micromixing and growth processes
Authors: Tsai B. I. , Fan L. T. , Erickson L. E. , Chen M. S. K. 
Published: July 2010

AbstractA reversed two‐environment model of micromixing in a flow reactor in which the feed enters a maximum mixedness environment and then passes to a segregated environment is presented. The performance equations for an arbitrary residence time distribution are developed and employed to analyse the behaviour of growth processes in a continuous stirred tank reactor under intermediate states of micromixing. The results, which are bounded by the two extremes of micromixing, indicate that micromixing is important in growth processes and that segregation appears to reduce the rate of cell production.
The preparation and hydrolysis of silicon isopropoxides
Authors: Emblem H. G. , Fothergill E. W. , Hargreaves K. 
Published: July 2010

AbstractThe preparation of tetraisopropoxysilane by the liquid phase reaction between tetrachlorosilane and isopropanol is described, together with the preparation of ‘isopropyl silicate’ by treating tetrachlorosilane or crude tetraisopropoxysilane with a mixture of isopropanol and water in which the molar ratio SiCl4: H2O is less than 1:1. This ‘isopropyl silicate’ is a mixture of tetraisopropoxysilane and isopropoxypolysiloxanes. The formation of isopropoxypolysiloxanes from pure tetraisopropoxysilane saturated with hydrogen chloride is also described. The hydrolysis of silicon isopropoxides is discussed. Under suitable conditions, hydrolysates which may be used to bind powdered refractories can be obtained.
The synthesis of barium hexaferrite from iron oxide and barium carbonate: 1. General features of the reaction
Authors: Bye G. C. , Howard C. R. 
Published: July 2010

AbstractThe reaction between BaCO3and Fe2O3in the proportions necessary for the formation of the hexaferrite has been studied in air. The decarbonation reaction was followed by measuring weight loss isothermally, the formation of hexaferrite by measurement of saturation magnetisation and by X‐ray diffractometry.The only kinetically important intermediate found was the monoferrite and its rate of formation could be correlated with the rate of decarbonation. An unexpected feature of this process was the rapid apparent disintegration of the barium carbonate lattice: this was far more rapid than the weight loss suggested.An examination of the pseudobinary system BaO‐Fe2O3in air at 1000°C using the electron micro‐probe analyser on reaction products at an interface between partly reacted Fe2O3and BaCO3revealed the high barium ferrites 2BaO.Fe2O3; 3BaO.Fe2O3; 5BaO.Fe2O3but no compound intermediate in composition between mono‐ and hexaferrite, nor any solid solution of Fe2O3in monoferrite.With powdered reactants the high barium phases were not formed in sufficient concentration and or crystallinity to be revealed by X‐ray diffraction. But their presence could be inferred, because of their reaction with water vapour and/or carbon dioxide, from infrared (i.r.) absorption in the range 700–900 cm−1. An absorption peak at 880 cm−1appeared to be associated with a very small amount of incompletely reacted material as saturation magnetisation approached the maximum achievable.In the presence of only 0.5% lithium fluoride both decarbonation and the conversion of mono‐ to hexaferrite were greatly accelerated; scanning electron microscopy revealed a big change in crystal size and the form suggested a mechanism involving a liquid phase.
Sorption of benzene by Kenya diatomite
Authors: Odhiambo D. , Desai N. C. 
Published: July 2010

AbstractSamples of Kenya diatomite were washed with dilute hydrochloric acid and both untreated and acid‐treated samples then heated to various temperatures. Benzene adsorption isotherm on each sample was determined at 25°c. Hysteresis occurred in all the isotherms except isotherms on diatomite preheated at 1000°c. The suitability of these isotherms for BET surface area calculation has been examined. For the untreated and acid‐treated samples which were not preheated, the pore‐size distribution and pore‐volumes have also been calculated from the isotherms.
The evaporation of fruit juices
Authors: Robbins R. H. , Gresswell D. M. 
Published: July 2010

AbstractAn historical introduction to the production of fruit juices and their concentrates is provided. The introduction of modern evaporative techniques is examined. The storage properties of concentrates and the evaporation of citrus juices is discussed. It is concluded that with high initial juice quality and the use of volatile recovery satisfactory fruit juice concentrates can be produced by all evaporator types, although those with short residence times give the best effects on flavour except in certain special cases.
The centri‐therm evaporator and its application to heat sensitive foods
Authors: Shinn B. E. 
Published: July 2010

AbstractA description of the theory of the Centri‐Therm evaporator is given, together with illustrations of the parts. The application of the evaporator to a number of heat sensitive foodstuff liquids is examined. Comparison of the cost of operation of the Centri‐Therm evaporator with other comparable evaporation methods is provided.
Organic polysulphides in town gas: II. The chemistry of the mercaptan/sulphur reaction
Authors: McGrath L. , Prebble K. A. 
Published: July 2010

AbstractThe mechanism of the lime‐catalysed reaction between alkyl mercaptans and elemental sulphur has been investigated, and is found to be essentially the same as that of amine‐catalysed reactions. From the following and other reported results, the reaction is interpreted in terms of electron delocalisation by pπ‐dπ orbital overlap in sulphur chains, leading to predictable, ordered, stepwise nucleophilic degradations of these sulphur chains.The appearance of polysulphides during the dry‐purification of town gas (to remove hydrogen sulphide) results from mercaptan/sulphur reactions; the present study indicates that, under conditions existing in dry‐purification systems, it is not possible to interfere with these reactions and thus prevent polysulphide formation.
4‐Fluoro‐3‐nitroaniline and its N‐substituted derivatives
Authors: Bil Milos S. 
Published: July 2010

Abstract4‐Fluoro‐3‐nitroaniline has become of significant importance in the U.S.A. as a novel dye intermediate. Its use for pharmaceuticals, insecticides, and more dyes might soon be extended. Preparations of its various N‐substituted derivatives are briefly reviewed in this article.
A study of the growth mechanism of calcium carbonate in the carbonatation process for refining of raw sugar
Authors: Kelly F. H. C. , Keng Mak Fong , Sim Chua Gek 
Published: July 2010

AbstractA study of the size distribution of calcium carbonate particles obtained by precipitation in a sucrose medium containing different polar additives has been made, including a series of tests to determine the polar property of the precipitate surface via electrophoresis and measurements of heat of adsorption. A mechanism of polar growth has also been suggested to explain the present results.
The reduction of ferric chloride by aluminium in aluminium chloride melts
Authors: Foley E. , Moyle F. J. 
Published: July 2010

AbstractThe rate of reduction of FeCl3 to FeCl2 by metallic aluminium in AIcl3 melts has been studied at 212, 227 and 242 °C. Within the range of conditions investigated, the rate of reduction was proportional to the ferric ion concentration in the melt and to the surface area of the aluminium. After an initial coverage of the aluminium by a protective film of iron the reduction proceeded effectively only to the ferrous state.
Influence of the conditions of preparation on the texture of some silica gels
Authors: Girgis B. S. 
Published: July 2010

AbstractSilica gels were prepared at pH values varying from 1.5 to 8, and at temperatures of 20 to 90 °C. Specific surface areas were evaluated from the nitrogen adsorption isotherms, employing the BET method, t‐plots, αs‐plots, and Kiselev's integrai equation. Pore‐size distributions as well as cumulative surface areas were determined by the procedure of Cranston and Inkley. An increase in pH causes a decrease in the specific area, and an increase in both the mean pore radius and pore volume of the xerogel. An increase in the BET'S C value appeared with an increase in the mean pore radius and the number of OH‐groups (NOH) of the material.
Kinetics of oxidation of 2‐methylpropene over chlorine modified copper oxide catalyst
Authors: Mann R. S. , Yao K. C. , Dosi M. K. 
Published: July 2010

AbstractThe vapour phase air oxidation of 2‐methylpropene to methacrolein over a copper oxide catalyst supported on pumice, modified by a continuous supply of chlorine, was investigated in an isothermal integral flow reactor at atmospheric pressure between 300 and 450 °C. The effects of several variables, weight ratio of modifier (CI) to 2‐methylpropene in the feed, feed ratio of oxygen to 2‐methylpropene, reaction temperature and the reciprocal of space velocity on the conversion and product distribution were determined by gas chromatography. The results indicate that the promotional effect of the modifier is mainly due to successful suppression of further oxidation of aldehyde to undesired products. Though several mechanisms were postulated, the rate of reaction was most satisfactorily correlated by a mechanism, which assumes the rate controlling step to be the surface reaction between charged adsorbed 2‐methylpropene and oxygen.
A study of the thermal decomposition of ammonium nitrate using a gas chromatographic technique
Authors: Bennett D. 
Published: July 2010

AbstractThe thermal decomposition of ammonium nitrate and associated mixtures in the range 170 to 200 °C has been studied by measuring the rate of evolution of nitrous oxide using a flow system in conjunction with a gas chromatograph enabling measurements to be made at temperatures of practical importance not covered in most previous investigations. The rate constant calculated from the data for pure ammonium nitrate was compared with the values of other workers.The effects of water and of monoammonium phosphate on the decomposition rate were studied. The effect of several metal ions on the decomposition rate was also studied, but no clear pattern emerged from the results.