bluuebunny/crossref_metadata_2025_split huggingface dataset:
The thermal decomposition of ferrous sulphate heptahydrate. I. Dehydration and oxidation
Authors: Kamel A. H. , Sawires Z. , Khalifa H. , Saleh S. A. , Abdallah A. M. 
Published: July 2010

AbstractThe intermediate products of thermal decomposition of ferrous sulphate heptahydrate, in a current of air, have been investigated by X‐ray and chemical analysis. It was found that the monohydrate undergoes dehydration followed by oxidation, or combined hydrolysis and oxidation to Fe2O(SO4)2 and Fe(OH)SO4, respectively. The latter basic salt is converted to the former with loss of H2O. Fe2O(SO4)2 decomposes to Fe2(SO4)3 and α‐Fe2O3 above 400 °C; the transformation is almost complete at 550 °C. Fe2(SO4)3 decomposes to Fe12O3(SO4)15 and SO3 at 475 °C. The last oxide sulphate decomposes to α‐Fe2O3 and SO3 at higher temperatures.
Reactions of iron sulphides in simulated stack gases
Authors: Karr C. , Rahfuse R. V. , Langdon P. F. 
Published: July 2010

AbstractThe rates of production and consumption of SO2 by the reactions of O2, SO2, and mixtures of O2 and SO2 in simulated stack gases with fixed and fluidised beds of FeS prepared from pyrite were determined over the temperature range 800 to 950 °C. The rates of production of SO2 by reaction of Fe2O3 with FeS in different gas systems were also determined. The rate controlling factors were derived for each reaction.
Solubility of hydrogen sulphide, dimethyl ether, methyl chloride and sulphur dioxide in liquids. The prediction of solubility of all gases
Authors: Gerrard W. 
Published: July 2010

AbstractThe solubilities of hydrogen sulphide, dimethyl ether, methyl chloride, and sulphur dioxide expressed as the mole ratio, Xgas, at different temperatures and 1 bara are given for a number of liquid compounds of types commonly used in operational chemistry. Representative curves showing the variations of Xgas, and Ngas (mole fraction), with pressure, pgas, are discussed with reference to Henry's law and Raoult's law. With the exception of hydrogen halides and ammonia, the Xgas (at a stated t° and pgas) for water is much less than for any other liquid reported as examined. The primary factor determining the Xgas value at 1 bar is the boiling point of the gas (He to SO2) at 1 bar; the Raoult's law Xgas value emerges from this, and places the gases in the same order as the overlapping ranges of real Xgas values. The actual Xgas value within a particular range for a chosen gas is, for a chosen liquid, seemingly determined by acid‐base functions as defined herein. The prediction of the Xgas value is discussed in these terms.
The decomposition of N‐benzoylleucomethylene blue during the pressure‐sensitive copying process. I. Identification of reaction products
Authors: Potts H. A. , Wood A. H. , Cook C. C. 
Published: July 2010

AbstractN‐Benzoylleucomethylene blue in benzene, toluene, xylene or petroleum ether when applied to either attapulgus clay or silica gel slowly decomposes to give a blue dye which has always been assumed to be methylene blue. Factors affecting the reaction have been examined and it is suggested that a photon‐induced free radical reaction is operating. Initial products of the reaction are colourless mono‐, di‐ and trimethyl derivatives of N‐benzoylleucothionine and a mixture of methylene blue and mono‐, di and trimethylthiazines. Irradiation of the colourless products gives further quantities of both methylene blue and demethylated products. The irradiation of methylene blue on silica gel gives a mixture of demethylated products but the decomposition is more extensive and the fully demethylated thiazine, thionine is also present in the reaction mixture.
Some observations on the setting of calcium sulphate hemihydrate plaster in the presence of phosphoric acid and hydrated lime
Authors: Berry E. E. 
Published: July 2010

AbstractThe effects of additions of phosphoric acid and hydrated lime on the setting of calcium sulphate hemihydrate plasters have been examined. At two levels of P2O5 concentration (0.75 and 1.5 wt‐% P2O5) it has been found that extreme retardation of the plaster setting process occurs with lime additions in the range, Ca(OH)2/P2O5 (weight ratio) 0.5 to 1.5. The chemical nature of this effect has not been identified. Formation of either CaHPO4. 2H2O or hydroxyapatite in the paste is considered as deleterious to plaster hydration.
Formation and surface properties of electron‐emissive coatings. IX. Thermal decomposition of the alkaline‐earth formates
Authors: Judd M. D. , Pope M. I. , Wintrell C. G. 
Published: July 2010

AbstractThe thermal decomposition of alkaline‐earth formates under vacuum has been studied because of the use of barium formate as a binder for cathode coatings. Techniques employed in this work include thermogravimetry, differential thermal analysis and evolved gas detection, in conjunction with gas chromatography and infrared absorption spectroscopy for identification of the gaseous decomposition products.Decomposition occurs in two stages; the first results in formation of carbonate plus a small amount of free carbon. The second stage involves initially reaction of the free carbon with carbonate to form carbon monoxide and the corresponding alkaline earth oxide. Then, at a higher temperature, thermal decomposition of the carbonate itself commences, leading to the formation of the oxide plus carbon dioxide. With calcium formate, the two carbonate decomposition processes occur concurrently; but with strontium and barium formates, reaction with free carbon commences at a significantly lower temperature than thermal decomposition of the pure carbonate.
Chelate formation in high temperature steam
Authors: Turner David J. 
Published: July 2010

AbstractAnalysis of cooled solutions by u.v. spectroscopy shows that oxine, HOx, is thermally and hydrolytically stable at 400 °C in oxygen‐free steam at 200 bars pressure, and that it slowly forms the volatile ferrous complex, Fe(Ox)2. The rate of formation appears to be determined by the normal corrosion rate of the autoclave containing the mixture. It is suggested that oxine is thermally stable up to at least 530 °C, and that this or related compounds could ultimately prove useful additives for high pressure and once‐through boilers.
Phase behaviour in the ammonia‐carbon dioxide system at and above urea synthesis conditions
Authors: Lemkowitz S. M. , Zuidam J. , van den Berg P. J. 
Published: July 2010

AbstractThe bubble‐ and critical‐points in the NH3—CO2 system, at complete chemical equilibrium, have been measured in the range of NH3/CO2 = 2 to 100% NH3, 160 ⩽ T ⩽ 260 °C, and 50 ⩽ P ⩽ 950 atm. With increasing temperature an increasingly large part of the NH3—CO2 system becomes critical. The possible relation between the occurrence of critical conditions and the reported decrease of conversion to urea in the liquid phase at temperatures above 200 °C is discussed. The effect of small quantities of inert gas (N2) on the bubble‐point pressure is also discussed.
Nuclease treatment of broken bacterial suspensions for removal of highly polymerised nucleic acids
Authors: Melling J. , Atkinson A. 
Published: July 2010

AbstractThe use of nucleases for depolymerisation of nucleic acids in suspensions of disrupted bacterial cells has been shown to result in a reduction in the viscosity and an increase in the volume of supernatant recoverable after centrifugation.Precipitation of protein from nuclease treated suspensions, followed by dialysis of the protein precipitate, resulted in removal of most of the nucleotide material from the protein solution.
Electron‐activated cracking of gaseous hydrocarbons III. Some factors affecting reactor design and scaling‐up of operations in the production of acetylene from hydrocarbons
Authors: Hesp William R. , Rigby Donald 
Published: July 2010

AbstractAfter establishing that high yields (up to 80% w/w on carbon basis) of acetylene could be obtained by electron‐activated cracking of methane in anomalous glow‐discharges at reduced (∼ 60–100 torr) pressure, the laboratory tests were scaled up and a 201 spherical reactor was used. The effects of electrode geometry, gas flow rate and high power inputs on the yield and production rate of acetylene and on specific energy consumption were studied and conditions for the economic production of acetylene were established. The applicability of the “electro‐cracking” technique to the production of acetylene from propane has also been demonstrated.
A single point method for evaluating the specific surface area of a solid from nitrogen adsorption isotherms
Authors: Dollimore David , Spooner Peter 
Published: July 2010

AbstractA method which allows the rapid and accurate determination of specific surface area for materials from a single point on the nitrogen adsorption isotherm is described. The calculation is made from a single adsorption point which can lie almost anywhere on the isotherm. The method does not suffer from the theoretical errors involved when the single point BET method is used and so is found to give accurate values over a larger pressure range.
Lead dioxide anodes in the large scale production of potassium chlorate from potassium chloride
Authors: Udupa H. V. K. , Sampath S. , Narasimham K. C. , Nagalingam M. , Thiagarajan N. , Subramanian G. , Subbiah P. , Palanisamy R. , Peter S. John , Pushpavanam S. , Sadagopalan M. 
Published: July 2010

AbstractPotassium chlorate, which is used mainly in the manufacture of matches, was prepared by the electrolytic oxidation of potassium chloride in an 800 A cell using graphite substrate lead dioxide anode and stainless steel cathode. The cell was operated at an anode current density of 5 A/dm2, a temperature of 55 to 60 °C and a pH of 6.0 to 7.0. A current efficiency of 82 to 85% was obtained and an assay yield of 77% was realised for the recrystallised product. The cell voltage was 3.2 to 3.3 V with an energy consumption of 6.3 to 6.5 kWh (d.c.)/kg of potassium chlorate produced.The cell effluent, being clear and free from suspended impurities, could be processed further without filtration and pure potassium chlorate (>99%) was obtained by recrystallisation.
Bromination of some aromatic compounds by means of bromine in tetrachloroethane medium
Authors: Hashem A. I. 
Published: July 2010

AbstractBromination of some aromatic compounds is carried out using bromine in tetrachloroethane medium in the presence of iodine as a halogen carrier. The compounds investigated here are classified into: (i) compounds which yield pentabromophenol, (ii) compounds which yield other polybromoderivatives, and (iii) those which do not react with the brominating agent.
A study of the electrochemical regeneration of phenol from sodium phenoxide solutions
Authors: Pickett David J. , Akhavan‐Alizadeh Ebrahim 
Published: July 2010

AbstractAn experimental investigation has been made of the regeneration of phenol and caustic soda simultaneously by the electrolysis of aqueous sodium phenoxide in a cell using a cation exchange membrane as diaphragm. Current efficiencies close to 100% for both anodic and cathodic processes have been obtained for short periods of electrolysis but with prolonged operation considerable inefficiency arises due to adsorption and oxidation of phenol and loss of ion selectivity of the diaphragm. The presence of solid manganese dioxide in the electrolyte has been found to be useful in partially inhibiting the adsorption or oxidation of phenol at the anode.
Fischer‐Tropsch waxes VII. The thermal conductivity of hard wax
Authors: Le Roux Johannes H. , Smith Roy D. F. , Turner Richard , Weidema Onno 
Published: July 2010

AbstractThe method used to measure conductivity consisted of embedding resistance wire, around which thermocouple wire had been wound, in the wax. An electric current was passed through the wire and temperature rise was recorded as a function of time. The determination was repeated at various temperatures from 20 to 120 °C, i.e. in the solid and liquid states.The resulting conductivity‐temperature curve has an S shape, like the curves for specific volume and most other physical properties of substances that are crystalline in the solid state. Equations for reduced thermal conductivity were applied. For the solid state external degrees of freedom could be calculated and the partially crystalline nature was confirmed. Experimental and predicted values for reduced conductivity of molten wax differed somewhat, probably because of persisting order in the liquid state. There is a retrograde tendency in conductivity above the melting point. According to the literature measurements on alkanes are likely to be subject to errors due to convection unless extreme precautions are taken. This effect could cause the retrogression.
Simultaneous production of α‐amylase, β‐glucanase and proteolytic enzymes by Bacillus subtilis
Authors: Markkanen Pertti H. , Bailey Michael J. 
Published: July 2010

AbstractThe simultaneous production of α‐amylase, β‐glucanase and proteolytic enzymes by Bacillus subtilis has been studied. The effect of culturing conditions on the simultaneous production of these enzymes has also been investigated. Two known strains were used as standards, the other strains having been isolated and selected in this laboratory for their high enzyme production properties. Of the newly isolated strains three had better enzyme production properties than the standard strains. Selective inhibition was employed to separate total proteolytic activity into two fractions. The strain K160, which was the best strain for enzyme production, produced very few heat stable (100 °C) spores in the culturing conditions used. Enzyme production was correlated with sporulation, which reached its maximum value after about 30 h cultivation. α‐Amylase reached its maximum activity at the same time as sporulation, as did alkaline protease. The maximum for neutral protease activity, however, occurred at an earlier stage, whilst β‐glucanase activity usually continued to increase till the end of the cultivation (48 h). The optimum temperature, agitation and aeration values were determined for the production of enzymes in fermentor cultivation. β‐Glucanase showed remarkably little susceptibility to altered culturing conditions, as did alkaline protease. Sporulation level was always low (5 to 10%) in those cultivations in which enzyme activities reached their maximum values.
Production of phenylacetic acid by the liquid phase oxidation of acetophenone with sulphur in the presence of aqueous ammonia
Authors: Jain Jitendra K. , Chandalia Sampatraj B. 
Published: July 2010

AbstractThe liquid phase oxidation of acetophenone by aqueous ammonia and sulphur to phenylacetamide and/or phenylacetic acid was investigated in a stainless steel autoclave maintained under autogenous pressure. The effects of type and amount of solvent, amount of sulphur, concentration of acetophenone and ammonia, temperature and period of reaction, and the presence of impurities in commercial grade acetophenone, on the conversion and yield of phenylacetamide and/or phenylacetic acid were studied with a view to obtain the most suitable conditions for the production of phenylacetic acid. Since the product was a mixture of phenylacetamide and phenylacetic acid, hydrolysis of phenylacetamide was studied with a view to obtaining phenylacetic acid. Also, the solubility of phenylacetamide in water was determined.
Characterisation of manganese dioxides II. Kinetics of Interaction with Manganese (II) Ions in Aqueous Solution
Authors: Rophael Magdy W. , Malati Mounir A. , Barnes Keith F. , Pulford Richard J. 
Published: July 2010

AbstractThe interaction between MnO2 (I.C.S. No. 5), in the Na+ form and 54Mn2+‐labelled solution at pH 6 involves: a rapid process assumed to be Na+/Mn2+ ion‐exchange and a slower process assumed to involve the exchange between Mn2+ ions in solution and Mn ions in a surface phase. The activation parameters ΔH# and ΔS# were found to be 52 and 83 kJ mol−1 and −130 and −63 J mol−1 for the two processes respectively. Exposing the solid to a flux of moderated neutrons had no effect on the rate of the second process. The exchange of Mn ions from the solid to the solution was demonstrated using 56Mn‐labelled solid and inactive Mn2+ solution. There was evidence of a still slower process.
The microstructural and hardening behaviour of tricalcium silicate pastes in the presence of calcium chloride
Authors: Traetteberg Aud , Ramachandran V. S. 
Published: July 2010

AbstractA sequential examination of strength development in terms of microhardness was studied during paste hydration of C3S in the presence of 2 and 5% CaCl2 and at w/s ratios of 0.3 or 0.5. An attempt has been made to relate strength with microstructural features studied by means of Scanning Electron Microscopy. Generally, at earlier periods it was found that the 2% addition of CaCl2 gave the strongest material; the effect was most pronounced in the 6‐month sample of the series with 0.3 w/s. The high strength for the sample prepared at a w/s ratio of 0.3 may be related to a high CaO/SiO2 C‐S‐H‐phase, low porosity, and possibly a hydrated calcium hydroxy chloride complex. The pore size distribution was also measured. In general, the higher the porosity the lower the strengths but the relationship was not perfectly linear even on the semi‐logarithmic plot.
Crystallisation of pentaerythritol
Authors: Rogers John F. , Creasy Dennis E. 
Published: July 2010

AbstractGrowth measurements were made of pentaerythritol crystals in both fluidised beds and stirred suspensions. The measurements were made in both the presence and absence of the two by‐product impurities known to be normally present in the commercial material. Maximum growth rates of the order of 10−9m/s were observed with activation energies of between 100 and 200 kJ/mol depending on the sample tested. The growth rate was second‐order with respect to super‐saturation. The two main impurities were found not to greatly influence the growth rate. There was evidence that a so far undetected third impurity, which was present in only trace amounts, was responsible for the very low growth rates observed.
Preparation and application of some new sulphur dyes
Authors: Osman A. M. , Metwally S. A. M. 
Published: July 2010

AbstractA new series of sulphur dyes was prepared by fusion of aminoquinones and aryl‐azo compounds with sodium polysulphide. These dyes possessed all round good fastness properties and their tendering effects on cellulosic materials were estimated. The complex chemical nature of the prepared dyes was investigated and representative structural formulae were suggested.
The reactivity of calcium oxide towards carbon dioxide and its use for energy storage
Authors: Barker Ronald 
Published: July 2010

AbstractBy using calcium carbonate powder of particle size ∼ 10 nm (and therefore of high surface area) it has been shown that the reaction CaCO3 ⇄ CaO + CO2 can be made almost wholly reversible. A reactivity of 93% was achieved, (i.e. 93% of the calcium oxide reacted with carbon dioxide) and this was maintained for 30 24‐h decomposition‐back reaction cycles at 629 °C with no detectable decrease. This material has an energy storage capacity of 200 Wh/lb, but only about 1 kWh/ft.3 When this calcium carbonate was pressed, however, to increase its bulk density (from 0.1 to ∼ 1 g/ml) there was a large decrease in its surface area and a smaller decrease in its reactivity on undergoing a few decomposition and back reaction cycles. Scaling up of the sample size from 20 mg to 10 g only had a small (× 3) effect on the rates of decomposition and back reaction.
Correlation of salt effect on vapour‐liquid equilibria for benzene‐ethanol system
Authors: Sada Eizo , Kito Shigeharu , Yamaji Hiroshi , Kimura Masato 
Published: July 2010

AbstractA correlation of salt effect on vapour‐liquid equilibria for nonaqueous binary system is presented. The correlation is applicable to systems in which the salt is dissolved in only one of the volatile components. Assumptions are made to obtain a correlation on the basis of a simplified mechanism of salt effect. The main feature of this correlation is that it does not require an experimental parameter for the salt effect. The applicability of this method is examined by using new experimental salt effect data on benzene‐ethanol azeotropic mixture for the addition of lithium chloride, calcium chloride and zinc chloride. It was found from the examinations that the prediction of the vapour phase composition was successful.
Studies on the system sodium oxide‐calcium oxide‐silica‐water
Authors: Blakeman Elizabeth A. , Gard J. Alan , Ramsay Cameron G. , Taylor Harry F. W. 
Published: July 2010

AbstractIn hydrothermal reactions of lime and quartz with water or aqueous NaOH at 150 °C or 180 °C and Ca: Si = 0.83, the rate of reaction of the quartz increases with NaOH concentration. At 180 °C and Ca: Si = 0.83, the conversion into tobermorite of the semi‐crystalline calcium hydrosilicate initially formed occurs more slowly at NaOH concentrations of 0.15–2.00 M (NaOH: SiO2 = 0.05 to 0.63) than in water or 5 M‐NaOH. With long reaction times at 180 °C and Ca: Si = 0.83, increasing NaOH concentration causes pectolite to replace xonotlite as the main product. At very low water contents, NaCaHSiO4 is formed; this compound is conveniently made by grinding together solid NaOH, Ca(OH)2 and quartz in normally humid air and heating the mixture in a closed vessel at 180 °C.
Thermal alkylation of aromatic nucleus with aryl benzyl ethers
Authors: Osman A. M. , Badr M. Z. A. , Aly M. M. , El‐Sherief H. A. H. 
Published: July 2010

AbstractThe introduction of the benzyl group into the aromatic nucleus is brought about by heating benzyl‐α‐ and β‐naphthyl ethers with the aromatic compounds, such as, naphthalene, 2‐methylnaphthalene and isoquinoline. It has been concluded that the reaction depends initially on homolytic fission of the alkyl aryl ether into aryloxy and alkyl free radicals which are able to react with the aromatic nucleus. The homolytic mechanism of the alkylation studied and the isomer distribution in the alkylation products separated are discussed on bases of theories of free valency and atom localisation energy of aromatic compounds.
On the mechanism of the acid‐catalysed arylation of anthraquinones
Authors: Clark M. C. , Marley T. J. , Lowe P. A. 
Published: July 2010

AbstractSchmidt discovered in 1925 that an unusual arylation occurred when 1,5‐diamino‐4,8‐dihydroxyanthraquinone‐3,7‐disulphonic acid dissolved in conc, sulphuric acid containing boric acid was treated with phenols or anisole. Schmidt incorrectly assumed that the p‐hydroxyphenyl or anisyl group replaced a sulphonic acid group. It has now been shown that this reaction is a stereospecific Friedel‐Crafts type arylation, the aryl moiety entering ortho to the amino group and trans to the sulphonic acid group. The corresponding 3‐monosulphonic acid undergoes the same reaction.
The effect of heat on metal incorporated silica gels
Authors: Girgis B. S. , Mourad W. E. 
Published: July 2010

AbstractSilica gel prepared under varying conditions indicated that, in addition to the pH and kind of acid, the mode of adding the solutions govern the evolution of surface area of the produced xerogel. Co‐precipitation with the oxides of iron, copper, or nickel showed a marked effect in decreasing the surface area of the dry gel. Xerogels incorporated with iron oxide suffered from a sharp sintering that appeared upon heating to 900 °C. Copper oxide‐incorporated silicas showed a small decrease in surface area at the same temperature. However, silica incorporated with nickel oxide seems to be resistant to heat treatment at 900 °C, and exhibits only a small change in surface area. Acid treatment of the incorporated silicas resulted in negligible variations in surface area, probably due to the low content of oxides.