bluuebunny/crossref_metadata_2025_split huggingface dataset:
Structure and activity of platinum–silica catalysts prepared by a combustion process
Authors: Schachner H. , Bollmann W. , Baumberger B. 
Published: July 2010

AbstractBy combustion of a mixture of silicone oil and chloroplatinic acid and organic solvents, Pt–SiO2 catalysts with Pt concentrations between 37 and 90% have been prepared and their activity in benzene hydrogenation has been tested in a static system. The special structural characteristics conferred on the catalysts by the combustion method, i.e. small Pt particles with smooth round surfaces well separated by silica, ensure good resistance to de‐activation by exposure to elevated temperatures as well as to atmospheres with high humidity at low temperatures.
Equilibria of fluorosilicate solutions with special reference to the fluoridation of public water supplies
Authors: Crosby N. T. 
Published: July 2010

AbstractEvidence from specific‐ion electrode and conductivity measurements at 25° confirms that sodium fluorosilicate, at the concentration normally present in public water supplies, is dissociated to at least 95%. The degree of dissociation at other concentrations up to 3,000 ppm as fluoride, is shown to be markedly lower than previous kinetic experiments had suggested. The dissociation of fluorosilicic acid has also been investigated using the same techniques, and the results obtained closely follow the pattern established for the sodium salt.
Liquid extraction of metals from sulphate solutions by alkylphosphoric acids. II. Kinetics of the extraction of copper and cobalt with di‐(2‐ethyl hexyl) phosphoric acid
Authors: Brisk M. L. , McManamey W. J. 
Published: July 2010

AbstractKinetic studies of the transfer of copper and cobalt (separately) between aqueous solutions of their sulphates and organic phases consisting of solutions of di(2‐ethyl hexyl) phosphoric acid (EHPA) in kerosene were made by an ‘equilibrium extraction’ technique, in which radioactive isotopes of the metals were transferred between phases which were otherwise in equilibrium. The total resistance to mass transfer was found to be greater than that predicted from the mass‐transfer resistances of the aqueous and organic phases, the additional resistance to mass transfer being between 30 and 75% of the total resistance. When the concentration of free EHPA in the organic phase was greater than 0·01 g mole/l (which is approximately equivalent to a ratio of the metal concentration in the organic phase to the initial organic‐phase EHPA concentration of less than 0·25), expressions for these additional resistances were obtained from consideration of the kinetics of the extraction reaction, with a rate‐controlling step equivalent to the reaction of a metal ion with an EHPA dimer to form a metal‐EHPA compound and a hydrogen ion. At lower organic‐phase‐free EHPA concentrations, the additional resistances were lower and did not show any marked dependence on pH or reactant concentrations.
The attapulgus clay‐catalysed thermal decomposition of terphenyls
Authors: Juppe G. , Rau H. 
Published: July 2010

AbstractThe kinetics of the pyrolysis of pure o‐, m‐ and p‐terphenyl and of material mixed with Attapulgus clay were studied. 10 to 12 times more o‐, m‐ and p‐terphenyl was decomposed in the clay‐catalysed experiments and a strong isomerisation of o‐ into m‐ and p‐, and m‐ into p‐terphenyl appeared. Twice as much benzene and biphenyl was formed, in the runs to which clay had been added. Similar differences were obtained for the quaterphenyl, triphenyl and triphenylbenzene formations. From the catalysed experiments 50 times as much total gas was found consisting of 41% hydrogen, 19% methane, 7% ethane, 2% propane, 1·5% n‐pentane, 3·8% isopentane, 2·5% ethylene, 0·4% acetylene, 0·9% propene and 32% butenes. The uncatalysed runs yielded 82% hydrogen, 4% methane, 1% ethane, 0·4% propane 0·2% n‐pentane, 0·3% isopentane, 10% ethylene, 2·8% acetylene, 1·2% propene and 2% butenes. It is suggested that the thermal decomposition of pure terphenyls follows a radical mechanism while the clay‐catalysed pyrolysis follows a carbonium ion mechanism.
Role of polymeric flocculants in sediment removal in condenser cooling systems
Authors: Edwards B. C. 
Published: July 2010

AbstractA proprietary water‐soluble organic polymer (polymeric flocculant) of high molecular weight has been used to remove sediment from cooling water systems; current explanations of the mechanism are inadequate. A new flow‐cell has been designed to study sediment‐flocculant interactions under simulated practical conditions. Quantitative measurements of the conditions required for sediment removal in the flow‐cell together with flocculation tests on the same systems have been made. The effects of an inorganic coagulant on the removal mechanism have also been studied. Sediment removal is interpreted in terms of flocculation theory; flocculation of a dispersed phase is found to be essential to the removal process.
Kinetics of fast alkaline hydrolysis of esters
Authors: Sharma R. C. , Sharma M. M. 
Published: July 2010

AbstractThe kinetics of alkaline hydrolysis of a variety of esters (liquid and solid), which are sparingly soluble in water, was studied by using the theory of mass transfer accompanied by fast pseudo first‐order reaction. This method, under certain conditions, can cover a wide range of second‐order rate constants (∼ 1 to 104 1/g mole sec). Whenever possible the values of the rate constants obtained by the above method were compared with those obtained by a study of the kinetics in the homogeneous phase.
Ternary vapour–liquid equilibrium data for the system: n‐butanol–n‐butyl acetate–1,2‐propylene glycol
Authors: Nageshwar G. D. , Mene P. S. 
Published: July 2010

AbstractVapour–liquid equilibrium data for the ternary system n‐butanol–n‐butyl acetate–1,2‐propylene glycol are reported at pressures between 725 and 735 mm Hg. The activity coefficient data are satisfactorily correlated by Wohl's two‐suffix van Laar equation. Thermodynamic consistency is checked by both the McDermott & Ellis point‐to‐point consistency test and by the Li & Lu closed‐loop method.
Ageing of microporous silica
Authors: Dollimore D. , Shingles T. 
Published: July 2010

AbstractA silica sol was frozen and then thawed yielding a suspension of plate‐like silica which when dried gave a sample which was almost entirely composed of micropores. The silica aged when left to stand in the laboratory, but reached a constant value of activity after a period of about six months or less. No apparent change in microporosity occurred during the ageing process.Several selected samples were sintered at temperatures up to 800° at which point virtually all the adsorption capacity of the adsorbent was destroyed leaving adsorption to take place only on the external surface.
The lime‐silica‐water system: Equilibria at bulk calcium/silicon ratios of 1·5–2·5 AT 180–250°C
Authors: Ahmed A. H. M. , Taylor H. F. W. 
Published: July 2010

AbstractThe stability relationships of xonotlite, foshagite and hillebrandite relative to kilchoanite and calcio‐chondrodite have been studied under saturated steam pressures at 180° and 250°. Kilchoanite was unstable relative to xonotlite plus hillebrandite at 180°, or to foshagite plus hillebrandite at 250°; calcio‐chondrodite was unstable relative to hillebrandite plus some more lime‐rich phase, possibly Ca(OH)2, at both temperatures. Foshagite was stable relative to xonotlite plus hillebrandite at 250°, but unstable relative to these phases at 180°.
Some physico‐chemical properties of ellagic acid
Authors: Press R. E. , Hardcastle D. 
Published: July 2010

AbstractExamples of formation of troublesome deposits containing ellagic acid in the wood pulping process are mentioned. The deposit from one such process in the U.K. has been examined in detail. This paper is mainly devoted to the determination of some physico‐chemical properties of ellagic acid, which are relevant to the study of minimising the formation of the deposit in the wood digester.A specially built apparatus was used for the determination of these properties at 170° (the normal digestion temperature). The ultra‐violet and visible absorption spectra measured at different pH values and temperatures were used to determine a dissociation constant of the acid at 20° which was found to be 11·0. The solubility of the acid was determined at 20°, 90° and 170°.From the changes in absorbance at 250 nm the decomposition was found to consist of two consecutive firstorder reactions, the rate constant of the first reaction being inversely proportional to a fractional power of hydrogen ion concentration.The activation energy was estimated to be 5·5 kcal and was independent of pH value.
Epoxidation of ethylenic linkages by chromic acid. III. The course of oxidation of mono‐aryl aliphatic olefins by chromic oxide
Authors: Moussa G. E. M. , Eweiss N. F. 
Published: July 2010

AbstractThe results of oxidation of some mono‐aryl aliphatic olefins by chromic acid in aqueous sulphuric acid and by chromic oxide in acetic anhydride are compared and discussed.
Separation of thiophen from benzene by solvent extraction. I
Authors: Hanson C. , Patel A. N. , Chang‐Kakoti D. K. 
Published: July 2010

AbstractPhase equilibrium data are presented for thiophen and benzene distributed between n‐heptane and ‘Sulpholane’, dimethyl sulphoxide and dimethyl formamide. They are used to evaluate the possibility of employing distribution between these solvents as a means of separating a mixture of thiophen and benzene.
Mixed bed de‐ionisation by weak electrolyte ion‐exchange resins regenerated in situ by carbon dioxide
Authors: Kadlec V. , Matějka Z. 
Published: July 2010

AbstractIt has been shown that phenol‐carboxylic types of weakly acidic cation exchangers have significant salt‐splitting characteristics, which improve the kinetics of a mixed bed composed of weakly dissociated ion‐exchange resins. This system seems to be effective for de‐ionisation of high‐salinity water and has produced water of suitable quality and sufficient break‐through capacity. It was demonstrated that weak electrolyte ion‐exchange resins in a mixed bed can be regenerated with water saturated with carbon dioxide with possible re‐use of the gas.
Condensation of ammonium dihydrogen orthophosphate to diammonium dihydrogen pyrophosphate in ammonium nitrate
Authors: Bennett D. , Bradley J. K. , Thatcher K. F. J. 
Published: July 2010

AbstractThe equilibrium between ammonium dihydrogen orthophosphate, diammonium dihydrogen pyrophosphate and water has been studied at temperatures between 150 and 200° in ammonium nitrate. At constant temperature, increasing ammonium nitrate content was associated with increases in apparent equilibrium constant for the condensation reaction, and in apparent heat of condensation from −13·7 to −6·5 keal per mole of diammonium dihydrogen pyrophosphate.
Phase behaviour of fischer‐tropsch wax fractions under high pressure
Authors: Stokhuyzen R. , Pistorius C. W. F. T. 
Published: July 2010

AbstractThe phase behaviour of five distillation fractions of a Fischer‐Tropsch wax were investigated at pressures up to 40 kbar by means of differential thermal analysis. The approximate constancy in the number of significant components (i.e. greater than 5% by wt.) in each wax fraction is probably responsible for them appearing to behave as a series. Similarity of the phase diagrams of the individual wax fractions gave rise to the construction of a ‘master’ phase diagram. A possible new high‐pressure phase was detected in the heaviest fraction, but the possibility of phase separation cannot be excluded.
An oscillating baffle column fitted with stator rings I. Theoretical model for a counter‐current extraction column
Authors: Thomas W. J. , Weng P. K. J. 
Published: July 2010

AbstractA modified form of an oscillating baffle column previously described by Thomas in which horizontal stator rings are introduced is studied. A theoretical technique is described for establishing true values for the number of transfer units for the continuous phase and disperse phase, NTUc and NTUd.
Formation and surface properties of electron‐emissive coatings III. Thermal decomposition and sintering of some co‐precipitated alkaline‐earth carbonates
Authors: Judd M. D. , Pope M. I. 
Published: July 2010

AbstractThe thermal decomposition of co‐precipitated alkaline‐earth carbonates, prepared in a manner similar to that used in the manufacture of oxide cathode coatings, has been studied by preparing a calcination series, under vacuum, up to 1200°. Samples were heated in the sorption balance, described previously, up to set temperatures, after which the specific surface and total pore volume of the cooled residue were calculated, using data obtained from the sorption of nitrogen at 77°. The results indicated that the co‐precipitated carbonates decompose in several distinct stages.
Study of the reactions of surface hydroxyl groups of a chrysotile asbestos with organic silanes by means of infra‐red spectroscopy
Authors: Edwards H. 
Published: July 2010

AbstractA chrysotile asbestos having different surface finishes has been prepared by reaction of asbestos with silane coupling agents and chloro‐organosilanes. The type of bond formed between fibre and ‘finish’ has been investigated by infra‐red spectroscopy.
Hydroperoxidation of organic compounds at the LIQUID/GAS interface I. Apparatus and method
Authors: Vodnár I. 
Published: July 2010

AbstractA new method and apparatus are described for hydroperoxidation of organic compounds at the liquid/gas interface which is formed in a spirally curved tube. The energy required for stirring is removed, although extra energy is required for the compressors to enable the gas to provide the necessary agitation. The reaction rate should be higher than that in methods used at present.
Studies in transesterification VI. Ion‐exchange catalysis
Authors: Haken J. K. , Ho D. K. M. 
Published: July 2010

AbstractThe preparation of methacrylate esters by transesterification with ion‐exchange resins as acidic catalysts and n‐butanol as the reactant alcohol is described. Conventional cellular cation exchangers have been used together with a resin having a solid centre and a reactive outer surface. The latter resin is of lower capacity but the reaction rate compares favourably with that of conventional resins while its performance on repeated use is vastly superior.
Significance of the solubility of hydrogen halides in liquid compounds
Authors: Ahmed W. , Gerrard W. , Maladkar V. K. 
Published: July 2010

AbstractThe solubilities of hydrogen halides (HCl, HBr, HI), expressed as xHX moles of HX per mole of a liquid compound, have been determined for a representative selection of compounds at room temperature and below to reveal an essential pattern of behaviour to serve as a guide in operational procedures. Compared with the values predicted by Raoult's law at 0° (xHCl = 0.04, xHBr = 0.09, xHI = 0.37), liquids such as n‐heptane and carbon tetrachloride have slightly lower x values, but show increasing divergence on the low side as the temperature is lowered. Other liquids, such as toluene and alkyl halides, have values greater than those predicted by Raoult's law at 0°, and xHX remains correspondingly higher at the lower temperatures. The xHX values for many liquids can be from 2 to 6 times as great as those for water: xHCl = 0.41, xHBr = 0.49, xHI = 0.39 at 0°.From a consideration of pressure and other effects, a reference pattern of the constitution of the solutions is given. For the non‐aqueous liquids, xHX values greater than Raoult's law values are deemed to be the result of definite chemical reactions involving hydrogen bonding and dynamic equilibria. A case is presented for the desirability of the readjustment of attitudes towards acid‐base function in operational chemistry.
Kinetics of the calcination of calcium sulphate dihydrate
Authors: Taylor J. B. , Baines J. E. 
Published: July 2010

AbstractThe kinetics of calcination of calcium sulphate dihydrate were studied at 100° at air pressures from 760 to less than 10−5 mm Hg. Any reduction in air pressure below atmospheric caused an increase in reaction rate. Water vapour removal initially facilitated the dehydration at higher pressures, but began to impede the reaction at low pressures.
High‐resolution mass spectrometric study of weathered road tars
Authors: Shultz Janet L. , Sharkey A. G. , Friedel R. A. 
Published: July 2010

AbstractFractions of road tars of coke‐oven and vertical retort origin were examined by high‐resolution mass spectrometry before and after exposure to road conditions. Molecular formulae and relative concentrations were determined for eleven series of peaks. A progressive increase in the proportion of components of high molecular weight (> mass 200) was indicated with exposure to road conditions. In the high molecular‐weight range, the heterocyclic structures containing oxygen showed larger increases than the polynuclear aromatic hydrocarbons.
Adsorption of sulphur dioxide on coal
Authors: Kotb A. K. 
Published: July 2010

AbstractA study was made of the feasibility of using coal as an adsorbent material for the removal of sulphur dioxide from stack gases emitted to the atmosphere by different industries.From preliminary results, it would appear that coal is to be favoured by a raw materials/cost‐effectiveness ratio of 2:1.The work shows semi‐quantitatively that the adsorptive capacity of sulphur dioxide on coal varies slightly from one coal to another and that when coal is used and re‐used through numerous (˜40) cycles, its effectiveness as an adsorbent for sulphur dioxide is not greatly reduced.Moreover, this research supports the view that the heating value, ash, sulphur content, etc. of most types of coal changes only slightly after repeated usage as an adsorbent for sulphur dioxide. If, as these findings indicate, coal can initially be used as a sulphur dioxide adsorbent prior to its use as a fuel, economic potential for commercial applications should be enhanced.Empirical equations, developed to correlate the adsorption‐desorption characteristics of different coals, can be used as a basis for prediction and comparison by future investigators to further explore this research.
Crystal habit modification studies with ammonium and potassium dihydrogen phosphate
Authors: Mullin J. W. , Amatavivadhana A. , Chakraborty M. 
Published: July 2010

AbstractFace rates of growth of ammonium and potassium dihydrogen phosphate crystals have been measured for crystallisation from pure solutions and from solutions that contained known amounts of foreign ions. The level of supersaturation and the solution pH both effect the crystal habit. Low supersaturation at normal pH (3.8) tends to give tapered crystals, and at a slightly higher pH (˜5), the linear growth rates of both principal axes are considerably increased. The presence of foreign ions such as Cr3+, Fe3+ and Al3+ in low concentrations (˜ 1 × 10−3 g ion/1 or ˜ 50 ppm) also causes a tapering habit.A mechanism of habit modification based on the presence of aquo ions at the crystal face is suggested.
Adsorption of alcohols on finely divided powders
Authors: Allen T. , Patel R. M. 
Published: July 2010

AbstractThe flow micro‐calorimeter has been used for the determination of energies of adsorption at monolayer coverage (mcal/g of powder) from solution for a homologous series of long‐chain alcohols, the solvent in each case being n‐heptane. The results show that the energies increase with increase in length of the carbon chain until the chain has six carbon atoms; the energies then fall to a constant value.The area occupied by one adsorbed molecule increases slowly at first, more rapidly for a chain length of four to eight carbon atoms and then approaches a constant value. The heat of adsorption (kcal/mole of solute adsorbed) rises rapidly at first and smoothes off to a constant value as the length of the carbon chain increases above ten.It is suggested that this indicates that the molecules orientate themselves in the form of a spiral with six carbon atoms on the surface of the solid; this requires a bond angle of 120° which is in agreement with the findings of Calvet & Astruc.
Reaction between mono‐oxiranes and alkyl or aryl (aminoalkoxy)silanes
Authors: Emblem H. G. 
Published: July 2010

AbstractThe preparation of ethyltri‐(2‐aminoethoxy)silane and diphenyldi‐(2‐aminoethoxy)silane, together with their treatment with 1,2‐epoxypropane and 1,2‐epoxybutane, is described. The products are typical of the reaction products of mono‐oxiranes and alkyl or aryl (aminoalkoxy)silanes. Such products have widely varying properties and industrial uses. Some are water‐soluble and can be used in water‐based stoving finishes. Others can be used in conjunction with epoxy resins or diisocyanates to prepare surface‐coating compositions which on stoving produce tough films having good adhesion.
Electro‐winning of chromium from chromic oxide by chlorination in fused salt and subsequent electrolysis
Authors: Schreiner G. D. L. , Ellis C. P. 
Published: July 2010

AbstractThe electro‐winning of chromium from chromic oxide after chlorination in a carbon‐containing fused sodium chloride flux is described. Only low values of current efficiency (based on the reaction Cr3+ + 3e ← Cr) can be attained. The effects of concentration of chromic and chromous chlorides in the melt, of current density and of melt temperature are reported. The conclusion is reached that the major factor responsible for the low current efficiency is the re‐solution of deposited metal by anodic chlorine.
Sorption of sulphur dioxide by indoor surfaces II. Wood
Authors: Spedding D. J. 
Published: July 2010

AbstractThe sorption of sulphur dioxide by untreated wood samples has been investigated at a concentration of 90 μg/m3 by use of 35SO2. The softwoods sorbed less sulphur dioxide than the hardwoods and the sites of sorption were different in each class. Most of the sorbed sulphur dioxide was found in the outermost 0.05 mm of each sample and a large portion of it was water‐soluble. The possible role of sulphur dioxide in the weathering of woods is discussed.
Graphical analysis of the reaction of iron ores in fluidised beds
Authors: Takitani M. , Yano M. , Imoto T. 
Published: July 2010

AbstractA study was made of the rate of reaction and the overall performance of a continuous fluidised bed operating in the reduction of iron ore. Analytical methods are described for the unsteady state and a relationship is deduced between the extent of reduction and the feed rates of ore and hydrogen.
Refractory aspects of some dolomitic magnesite rocks
Authors: Girgis L. G. , Gad G. 
Published: July 2010

AbstractThe samples studied were two types of magnesite containing calcium oxide (dolomite) as the principal impurity. Mixes were made with appropriate addition of serpentine and/or chromite rocks and an attempt was made to assess their suitability as magnesite refractories.The phase reactions that occurred during the firing at 1600° of refractory body mixes containing the five‐component system CaO‐MgO‐Fe2O3‐Al2O3‐SiO2 and the six‐component system CaO‐MgO‐Fe2O3‐Al2O3‐Cr2O3‐SiO2 were investigatedThe free lime content and the phase constituents of the fired mixes, determined experimentally and calculated from the available thermal equilibrium data, were in close agreement, which indicated that the chemical reactions had attained equilibrium in the fired mixes.The physical and refractory properties of the selected mixes were found to comply with the standard international specifications.