bluuebunny/crossref_metadata_2025 huggingface dataset:
The behaviour of stannic acid sols in concentrated hydrogen peroxide. I. Factors affecting the stability of stannic acid sols in concentrated hydrogen peroxide
Authors: Lewis T. J. , Walters T. M.
Published: July 2010

Sodium stannate hydrolyses completely in 87% w/w concentrated hydrogen peroxide solution to form a stable lyophobic sol of stannic acid. Precipitation of this sol results by a reduction in the concentration of the potential determining ion (OH− or O2 H−) or by the electrostatic adsorption of small quantities of polyvalent cations, e.g., Al3+. In the presence of colloidal stannic acid the hydrolysis equilibrium of this ion is automatically displaced towards the formation of a stable AlOH3+ ion which, by adsorption, neutralises negative charges on the colloid. Adsorption of aluminium ions is the critical factor governing the stability of stannic acid sols in concentrated hydrogen peroxide solution stored in aluminium tanks. Protection of the sol is afforded by orthophosphate and pyrophosphate ions which are adsorbed and increase its tolerance for aluminium. Pyrophosphate, in addition, provides an alternative sink for aluminium ions which are precipitated as aluminium pyrophosphate, AlHP2O7.
Improved preparation of phthalazine and quinazoline
Authors: Armarego W. L. F.
Published: July 2010

A new synthesis of phthalazine has been effected by reduction of the commercially available 1‐hydrazinophthalazine hydrochloride. The preparation of quinazoline in three steps from anthranilic acid on a large laboratory scale is described. It is believed that these are the most convenient syntheses available for phthalazine and quinazoline.
Purification by fractional crystallisation
Authors: Molony O. W. , Roberts D.
Published: July 2010

Expressions are derived that relate the yield by fractional crystallisation of a melt, to the impurities in the feed and product. The application of the expressions to the purification of benzene is given to illustrate the validity of the expressions.
Flotation with insoluble reagents. I. Collision and spreading behaviour in the coal‐oil‐water system
Authors: Burkin A. R. , Bramley J. V.
Published: July 2010

Interaction between coal particles and oil droplets suspended in an aqueous electrolyte solution can result in collision (defined). Two energy barriers may hinder such interaction : (1) is the result of the interpenetration of the electrical double layers surrounding the surfaces when they have similar sign (2) which prevents spreading of the oil over the wet coal surface and leads to a difference between the advancing and receding contact angles. With an experimental system such that the kinetic energy available to overcome these energy barriers is controlled at a known value, it is shown that three kinds of behaviour can occur : (a) when the kinetic energy is less than the repulsion energy, collision between coal particles and oil droplets does not occur in such a way as to permit permanent attachment of oil to coal; (b) if the kinetic energy is much larger than the repulsion energy, collision occurs but does not necessarily produce coal surfaces which permit flotation of the coal. This is interpreted as meaning that if flotation is impossible the oil has not spread over the coal surface (c) in case (b) if a suitable surface‐active reagent is already adsorbed at the coal surface the oil spreads spontaneously over the surface and air can displace water at the air‐water‐solid interface. This behaviour is held to confirm the model of conditioning and flotation set out.
Infra‐red spectra of textile materials: Identification of fibres and pure fabrics
Authors: Cleverley B. , Herrman Romana
Published: July 2010

Infra‐red spectroscopy provides a sure, rapid method of identifying textile fibres and pure fabrics. A simple standard method of sample preparation using only a few milligrams of powdered material in a potassium bromide disc is outlined. Representative spectra are published, and the identifying features of each curve are briefly discussed.
Silica powders of respirable size. I. Preliminary studies of dissolution rates in dilute sodium hydroxide
Authors: Bergman I. , Paterson M. S.
Published: July 2010

The rates of dissolution in dilute sodium hydroxide solution of a series of size‐graded powders of the four common polymorphic forms of silica (quartz, tridymite, cristobalite and vitreous silica) have been studied and found to be in keeping with their physical properties. The effect of variation of particle size on the dissolution of quratz has been related to the ‘amorphous layer’. The results provide no support for the ‘solubility theory’ of silicosis.
The flow hydrogenation of benzene vapour on silica‐supported nickel catalysts
Authors: Ross R. A. , Walsh B. G.
Published: July 2010

The hydrogenation of benzene vapour has been studied in a flow system using a ‘practical’ nickel‐on‐silica catalyst between 40° and 275° at atmospheric pressure. The reaction rate dependence was zero‐order with respect to benzene partial pressure in the range 60—150 mm. investigated and second‐order with respect to hydrogen. The apparent activation energy changes from 2.0 ± 0.2 kcal./mol. to around 0.9 ± 0.1 kcal./mol. to −19.5 ± 0.5 kcal./mol. in three distinct temperature regions.

The results are discussed in terms of a possible rate limitation and it is suggested that, above 170°, cyclohexane once formed at the surface may possibly be dehydrogenated, since the energetics are favourable. The rate‐controlling step in the mechanism may be the transfer of hydrogen molecules from a van der Waals layer to the catalyst surface where, on dissociation, these react with C6H8(ads.) to give C6H10(ads.) and finally C6H12.

A brief study of catalyst poisoning by water vapour has been included.
Epoxidation of ethylenic linkages by chromic acid. II. Oxidation of triphenyl(tolyl)ethylene by chromic oxide
Authors: Moussa G. E. M.
Published: July 2010

1,1,2‐Triphenyl‐2‐tolylethylene is oxidised by chromic oxide in acetic anhydride medium to give 1,2‐epoxy‐1,1,2‐triphenyl‐2‐tolylethane with fission products. A tentative explanation of the stability of such epoxides is given. Aqueous chromic acid oxidation brings about oxidative fission of the double bond. The ultra‐violet absorption spectrum of triphenyl(tolyl)ethylene is determined.
Catalytic synthesis of methyl acrylate from acetylene, carbon monoxide and methanol under pressure
Authors: Bhattacharyya S. K. , Sen A. K.
Published: July 2010

Optimum reaction conditions for this synthesis have been evolved. The best catalyst used was nickel iodide supported on silica (Ni/SiO2 50:50). Besides methyl acrylate, the products obtained were acrylic acid, acetaldehyde, liquid hydrocarbons (acetylene polymers), CO2, ethylene, ethane and a trace of methane, and hydrogen. In addition resinous products were obtained (probably polymerised methyl acrylate) which led to low conversions and poor material balances. Possible mechanisms to account for the products are suggested.
Analysis of toxic gaseous combustion products
Authors: Fish A. , Franklin N. H. , Pollard R. T.
Published: July 2010

A rapid and accurate gas‐chromatographic method of analysis of toxic gases produced during the burning of solids containing chlorine has been developed. This technique enables chlorine, hydrogen chloride, phosgene, carbon dioxide and simple hydrocarbons to be estimated from a single sample; one further sample affords determination of carbon monoxide also.

The method was applied to the combustion under a variety of conditions of temperature, oxygen availability and reaction time of a fire‐retardant building paper containing ∼20% of chlorine. Large quantities of carbon dioxide and hydrogen chloride were produced, chlorine, carbon monoxide and phosgene being minor products. The results are compared with maximum permissible concentrations and their application to actual fires is discussed.
Thermal degradation of melamine‐formaldehyde resins
Authors: Moore W. R. , Donnelly E.
Published: July 2010

Thermal degradation of three melamine‐formaldehyde resins in air at temperatures from 150° to 350° has been studied by thermogravimetric and infra‐red analysis. Weight loss is markedly dependent on particle size and, for a given temperature and time, appears to increase with decreasing melamine/formaldehyde ratio. This suggests that degradation involves methylene and/or methylene ether bridges and possibly methylol groups. Below about 250° only these groups appear to be involved and fairly high initial rates of weight loss are followed by decreased rates of loss. At 250° an increased rate of loss follows the initial rate. This is accompanied by a decrease in infra‐red absorption associated with the triazine ring and one of the products of decomposition is melamine. Above 250° breakdown of methylene and/or methylene ether bridges and loss of melamine occur together from the start of heating.
Variation in concentration of some tar constituents in coke‐oven gas
Authors: Girling G. W. , Ormerod E. C.
Published: July 2010

The variation in concentration of some constituents of tar in coke‐oven gas during the carbonising cycle has been investigated. The gas was sampled from the ascension pipe of the oven and examined by gas‐liquid chromatography for eleven hydrocarbons boiling in the range 180 to 340°. The concentrations of naphthalene and phenanthrene increased to maxima late in the cycle; those of methyl‐ and some dimethyl‐naphthalenes reached maxima early in the cycle.
Extraction of thorium from nitric acid solutions by some cyclohexyl‐ and benzyl‐alkylamines
Authors: Sato Taichi
Published: July 2010

The partition of thorium between nitric acid solutions and the solutions of some cyclohexyl‐ and benzyl‐alkylamines in benzene has been investigated at different concentrations of nitric acid and solvent, and at different temperatures. The extraction of nitric acid by these amines in benzene has also been examined. Further an infra‐red spectral study has been made of the organic solutions obtained. The mechanism of thorium extraction in this system is discussed on the basis of the results obtained.
Decomposition of methyl oleate hydroperoxide on the celite/dinitrophenylhydrazine‐hydrochloric acid column
Authors: Horikx M. M.
Published: July 2010

The hydroperoxides in oxidised methyl oleate can be converted in high yield into the dinitro‐phenylhydrazones of aldehydes and aldehyde esters by reaction on a Celite/dinitrophenylhydrazine‐hydrochloric acid column. The aldehydes and aldehyde esters formed are the same as those produced during the thermal decomposition of methyl oleate hydroperoxide.

The dinitrophenylhydrazones of unsaturated conjugated C18 keto esters are also formed.
Sorption of water on compacts of bottle‐hydrated cement. II. Thermodynamic considerations and theory of volume change
Authors: Feldman R. F. , Sereda P. J.
Published: July 2010

In order that the hydrated‐cement—water sorption may be adequately analysed, two thermodynamic processes connected with the material, encountered in adsorption, are discussed.

The B.E.T. surface area computed by the use of a modified form of the Gibbs adsorption equation, is found to be in close agreement with the value obtained by an experimental method of determining zero adsorbed water. The surface area calculated from the pore‐size distribution is also in agreement with these values. It is found that over the range of vapour pressures from 0 to 25% the Gibbs adsorption and Bangham equations are obeyed.

Beyond 25% R.H. physical adsorption and the readmittance of the interlayer hydrate water of tricalcium silicate occur simultaneously. The secondary hysteresis observed in the sorption isotherm and other anomalies previously observed in the system are explained with these data.

Mechanisms of volume changes for the whole extent of the isotherm are presented; thermodynamic equations are applied to different regions of the isotherm to express the volume change and spreading force developed in the system during sorption. These are compared with those used in other volume‐change mechanisms described for this system and the thermodynamic consistency of these is discussed. Calculations of Young's modulus from the above equations lead to the conclusion that the values obtained are for the individual elements of the body and that as such they will yield values larger than those obtained for the body as a whole.
An improved method for the calculation of pore size distribution from adsorption data
Authors: Dollimore D. , Heal G. R.
Published: July 2010

A method for calculating the pore size distribution from adsorption isotherms on porous solids is described, which is more exact and less tedious to use than some previously described methods. The method of compiling tables for calculation is shown and an example of such a calculation is given.
Reactivity of lime and related oxides. XII. Hydration of dolomitic lime
Authors: Glasson D. R.
Published: July 2010

Dolomitic lime samples differing widely in surface activity (specific surface, 5–65 m.2g.−1) have been ‘dry’ hydrated by exposure to water vapour at 22° and ‘wet’ hydrated by liquid water at 22° and 95°.

In general, the calcium oxide hydrates much more rapidly than the magnesium oxide in the dolimes. During the ‘dry’ hydration of dolime, the calcium hydroxide impedes subsequent hydration of the magnesium oxide. In the ‘wet’ hydrations, changes in surface area and crystal structure resemble those during the separate hydration of lime and magnesia.
Catalytic vapour‐phase transformation of isoquinoline to phthalimide
Authors: Ray S. K. , Murty G. S. , Kulsrestha G. N. , Rao H. Shreepathi , Lahiri A.
Published: July 2010

Catalytic oxidation of isoquinoline yields phthalimide (major product) and smaller amounts of pyridine and hydrogen cyanide. The reaction mechanism is discussed.
The action of oxygen on amino‐acids in relation to self‐heating of moist wool
Authors: Rothbaum H. P.
Published: July 2010

The chemical reactions responsible for heating of moist wool above the maximum temperature at which bacteria metabolise, have been investigated. A model system with glycine spread on the surface of asbestos gave large heat outputs in oxygen at 90°, when the R.H. was above 60%. The reaction was studied with radioactive glycine, and was shown to be a decarboxylation‐oxidation reaction producing water‐soluble polymers.

Similar reactions are shown by other organic compounds with functional groups involving oxygen or nitrogen and probably also provide the heat in the ‘wet combustion’ process for sewage treatment. In particular, moist wool oxidises exothermally in oxygen at 90°, giving large amounts of water‐soluble products which lower the equilibrium R.H. and therefore the thermal conductivity of wet wool.

It was also found that glycine and wool decompose to a small extent in nitrogen at 90°, but no significant amounts of heat are produced by this reaction if no oxidation has taken place previously.
Water transport through ion‐exchange membranes by hydraulic pressure
Authors: Seaman P. H.
Published: July 2010

An apparatus has been developed which enables the amount of water forced through an ion‐exchange membrane by hydraulic pressure to be measured continuously by a dilatometer. The results obtained with various commercially available membranes are described.
Retardation of water evaporation by the monolayers of octadecyl alcohol and of its condensation products with ethylene glycol
Authors: Shukla R. N. , Kulkarni S. B. , Gharpurey M. K. , Biswas A. B.
Published: July 2010

Retardation of the evaporation of water by monolayers of octadecyl alcohol, and of the compounds formed by condensing 1, 2 and 3 ethylene oxide molecules with octadecyl alcohol and of a few typical mixtures of these was investigated in the temperature range of 20°–40°. A very good retardation was obtained with the monoethylene oxide condensation product, while the triethylene oxide product was much inferior. Mixed monolayers, even those containing the latter, gave good retardation.
Alkyloxymethyl ethers of sucrose and glucose as surfactants
Authors: Ames G. R. , Blackmore Hazel M. , King T. A.
Published: July 2010

Alkyl chloromethyl ethers react with excess of sucrose in dimethylformamide solution to give, under suitable conditions, mono‐ and di‐alkyloxymethyl ethers. Certain of these compounds have shown a high degree of surface activity and, in the presence of conventional builders, of detergency. In laboratory detergency tests they were more effective than sodium dodecylbenzenesulphonate. The properties of some glucose alkyloxymethyl ethers are also reported.
Thermal transformation of alumina trihydrate, hydrargillite
Authors: Sato Taichi
Published: July 2010

The thermal transformation of hydrargillite (alumina trihydrate) prepared by seeded decomposition of sodium aluminate solution to α‐alumina has been studied by X‐ray diffraction and infra‐red spectra.

It is concluded that the thermal transformation of hydrargillite proceeds in the following sequence: magnified image
Thermal decomposition of uranyl nitrate hexahydrate
Authors: Hartland S. , Nesbitt R. J.
Published: July 2010

Samples of uranyl nitrate hexahydrate weighing between 3·5 and 14·7 mg. were decomposed in a hot air stream flowing at 455–673 cm./sec. and at temperatures between 100 and 350°. Values of percentage weight‐loss for various reaction times were obtained. The decomposition, which involved several phase changes, was also followed visually by means of a colour cine film.

The results between 200° and 350° suggest that decomposition proceeds by way of two first‐order reactions:

magnified image

and

magnified image

where k1 is much greater than k2.

These results do not agree with those of previous workers who used larger samples and lower gas flow rates and did not work in a purely chemical regime.
Performance of turbine impellers in sparger‐aerated fermentation vessels
Authors: Blakebrough N. , Sambamurthy K.
Published: July 2010

The gas‐handling capacity and influence on mass transfer of turbine impellers have been investigated in baffled 5–1, vessels, mainly in a three‐phase mixture containing a high proportion of fibrous solids. The ability of the impellers to disperse the gas was strongly dependent on the speed of rotation and to a smaller extent on blade size. In the non‐Newtonian systems investigated, the correlation of mass transfer and ‘impeller factor’ showed two regions which were characterised by different constants of proportionality. Within each region, mass transfer was directly related to the impeller factor, regardless of the impeller design. The range of power inputs of importance in many industrial fermentation processes lies in the region characterised by the lower constant of proportionality. It is suggested that bubble coalescence is the dominant factor limiting impeller performance in this region.

When the baffles were not in contact with the walls of the vessels, partially‐baffled conditions were produced in Newtonian systems of low viscosity. This resulted in a reduction of the power required for a given rate of mass transfer. This advantage was less marked in non‐Newtonian systems.
Characteristics of porous cellulose acetate membranes for the separation of some inorganic salts in aqueous solution
Authors: Sourirajan S.
Published: July 2010

Experimental results are presented to illustrate the effect of operating variables on the separation and flow characteristics of porous S & S cellulose acetate membranes. The results are discussed from the point of view of the preferential sorption and capillary flow mechanism, together with the concept of related and unrelated solution systems.
Surface properties of precipitated alumina. V. A radiochemical investigation of chloride‐ion contamination
Authors: Lucas J. W. , Newton G. W. , Sing K. S. W.
Published: July 2010

Radiochemical exchange experiments (using 36C1−) have been conducted on ‘hydrous’ alumina precipitates containing chloride ions. The precipitates have been prepared in two ways: (a) by reacting aluminium chloride and sodium hydroxide under controlled conditions of pH, concentration and flow rate, and (b) by the hydrolysis of aluminium s‐butoxide across a benzene‐water interface, with chloride ions added to the aqueous medium. All precipitates were washed and dried at room temperature and portions of some were heated at a series of temperatures up to 1000°.

The radiochemical investigations have revealed that most of the chloride ions held by the precipitates are readily accessible; some of these ions are transferred to the exchange solution and the remainder are available for rapid exchange. Important differences are, however, evident between the two types of precipitate: the fractional surface coverage by the chloride ions, Øc1, calculated from the amount exchanged and the BET surface area, is reasonably constant and close to unity only in the case of the class (a) precipitates. It is suggested that the chloride ions in these samples are present in the form of a well‐defined monolayer, but that the chloride ions held by the class (b) precipitates are probably clustered in the pores of the solid. The Øc1 = 1 relation is maintained with heat treatment of the class (a) precipitates up to at least‐60° and is associated with a relatively low degree of thermal ageing.
Dealkylation of aromatic hydrocarbons
Authors: Harrisson R. J. , Brooks J. D. , McG. Bowling K.
Published: July 2010

A description is given of a thermal dealkylation process in which hydrocarbon vapours and hydrogen are passed through a reactor containing a relatively small incandescent metal surface. No catalyst is required and the reaction proceeds satisfactorily at atmospheric pressure.

Particular attention has been given to the dealkylation of toluene, but other compounds, commercial mixtures of wider boiling range, and even neutral tars, have also been dealkylated. Several distinct types of reactor have been developed and tested to evaluate the potential of the process for larger‐scale operation and eventual practical application.

The effects of the principal operating variables have been studied, and the types and yields of products determined over a wide range of conditions. Preliminary data on energy consumption are given.
Extraction of uranium (VI) from nitric acid solutions by long‐chain aliphatic amines
Authors: Sato Taichi
Published: July 2010

The partition of uranium (VI) between nitric acid solutions and organic solutions of long‐chain aliphatic amines has been investigated at different concentrations of nitric acid and solvent, and at different temperatures. The effects of amine structure and of organic solvent and the mechanism of uranium extraction are discussed on the basis of the results obtained. It is postulated, from infrared spectroscopy measurements, that the complex formed in the extraction of uranium (VI) from nitric acid solution by tri‐n‐dodecylamine in benzene is a nitrato complex of uranium.
Vapour‐liquid equilibria in the system ethanol‐benzene‐cyclohexane
Authors: Deshpande A. K. , Lu B. C.‐Y.
Published: July 2010

Vapour‐liquid equilibrium data were determined at atmospheric pressure for the system ethanolbenzene‐cyclohexane using a modified Gillespie still. The thermodynamic consistency of the data was tested by the Li & Lu method.
Polymeric quinones. III. Functional behaviour and chemical stability of monomolecular and macromolecular quinones
Authors: Lindsey A. S.
Published: July 2010

The factors affecting the functional behaviour and chemical stability of monomolecular and polymeric quinones are appraised, and existing experimental data are critically examined. Some necessary structural features required for polyquinones in practical usage are discussed.
The roasting of copper sulphides. II. Natural copper sulphides
Authors: Razouk R. I. , Kolta G. A. , Mikhail R. Sh.
Published: July 2010

Earlier work on the roasting of precipitated copper sulphide has been extended to comprise a study of the roasting of covellite and chalcopyrite concentrates. It is found that the mechanism of roasting of covellite does not differ from that of precipitated sulphide proposed earlier. In case of chalcopyrite, sulphatation of iron takes place more readily than that of copper, but above 450° interaction between the formed ferric sulphate and copper oxide leads to the production of copper sulphate in increasing quantities. Above 600° both sulphates decompose to yield the corresponding oxides which react together at 900° to form cupric ferrite.
Use of a wetted‐wall column for the examination of a reacting gas‐liquid system in a packing
Authors: Thomas W. J.
Published: July 2010

A wetted‐wall column is used to determine the values of HOL and KLa for the flow of a viscous cuprous ammonium lactate solution countercurrent to a H2/CO gas mixture.

Kapitsa's equation is used to calculate the value of the interfacial area on the rippled liquid surface. Values of KL are calculated and the effects of liquid and gas flow on KL are determined. It is shown that there is a significant effect of gas flow even though the absorption is liquid film controlled.

With a viscous solution the wetted‐wall column can simulate conditions in a packing. The results from the wetted‐wall and packed towers are examined by a new method to obtain the degree of wetting of the packing while mass transfer is occurring.
Particle size determination by hindered settling and cluster formation
Authors: Ramakrishna V. , Rao S. R. , Ahuja L. D.
Published: July 2010

The settling of certain clay minerals in benzene‐alcohol solutions has been studied. The determination of particle size from the results indicates a significant influence of the polar nature of the solution on cluster formation.
Thermodynamic properties of phosphorus compounds. II. Low‐temperature heat capacity and entropy of sodium mono‐, di‐, and tri‐phosphates
Authors: Andon R. J. L. , Counsell J. F. , Martin J. F. , Mash C. J.
Published: July 2010

Heat capacities from 10–320°K of nine sodium phosphates have been measured by adiabatic calorimetry and the entropies of the compounds have been calculated. The values of S298 found were: NaH2PO4 30.47; Na2HPO4 35.97; Na3PO4 41.54; Na2H2P2O7 52.63; Na4P2O7 64.60; Na3P3O9 68.47; Na5P3O10.6H2O146.1; Na5P3O10 (I) 91.25; Na5P3O10 (II) 87.37 cal/deg. mole. The estimation of thermodynamic properties of other sodium phosphates is discussed.
Effect of vanadium pentoxide (and other transition metal oxides) on gas‐phase combustion. III. The isobutene‐oxygen system
Authors: Matthews C. J. , Tipper C. F. H.
Published: July 2010

The slow combustion of isobutene at 320–360° in a static system, using vessels coated with vanadium pentoxide, molybdenum oxide and bismuthphosphomolybdate, has been studied. No pressure decrease and little autocatalysis was observed. The maximum rate of oxidation in a V2O5‐coated vessel was independent of isobutene pressure and of added inert gas pressure, but depended markedly on the oxygen pressure. The overall activation energy was about 28 kcal/mole. The main products were CO, CO2 and H2O and there was less acetone, methacrolein, isobutyraldehyde and formic acid. Packing the V2O5‐coated vessel reduced the rate of consumption of isobutene considerably. With a MoO3‐coating the yields of organic products were generally greater and those of carbon oxides were less. With a bismuthphosphomolybdate coating the yield of methacrolein was higher than with other surfaces and that of isobutyraldehyde was lower.

Possible homogeneous and heterogeneous processes in the oxidation mechanism are discussed. It is concluded that most of the isobutene was consumed in the propagation steps of an unbranched chain reaction, initiation being homogeneous and termination heterogeneous. However, some direct heterogeneous oxidation of the olefin occurred, and the methacrolein was formed by oxidative dehydrogenation of the isobutyraldehyde at the surface.
Effect of vanadium pentoxide (and other transition metal oxides) on gas‐phase combustion. IV. oxidation of isobutyraldehyde and related compounds
Authors: Matthews C. J. , Tipper C. F. H.
Published: July 2010

The slow combustion of isobutyraldehyde at 290–330° in a static system, using vessels coated with vanadium pentoxide, molybdenum oxide and bismuthphosphomolybdate, has been studied. Some results have also been obtained with isobutene oxide, isobutyric acid, propionaldehyde and n‐butyraldehyde. A rapid oxidation of isobutyraldehyde occurred at 320°, the initial rate with the phosphomolybdate coating depending markedly on both the aldehyde and oxygen pressures and the overall activation energy being 23 kcal/mole. High yields of methacrolein were obtained using this coating, but much lower ones with the V2O5and MoO3surfaces, considerable quantities of other products such as acetone being formed. Using the phosphomolybdate‐coated vessel much the same analytical results were obtained with isobutene oxide (as with isobutyraldehyde) and quite a high initial yield of methacrylic acid was obtained from isobutyric acid oxidation. However, with the straight‐chain aldehydes, little of the corresponding unsaturated aldehydes was formed.

The oxidative dehydrogenation probably occurred on the surface and involved an allyl type intermediate. The reaction was most likely with carbonyl compounds of the structure R1R2CHC(R3)CO. With isobutyraldehyde, bismuth phosphomolybdate was an active catalyst and specific towards methacrolein formation, while MoO3was not very active but probably quite specific and V2O5was active but not very specific.
Reactivity of lime and related oxides. XVIII. Production of plasters
Authors: Glasson D. R. , O'Neill P.
Published: July 2010

Conditions for production of plasters are surveyed in relation to variations in phase composition, surface area and crystallite size.

The commercially known α‐ and β‐hemihydrate plasters prepared by autoclaving and dry calcination are not two distinct phases—they differ in crystal habit, surface area, crystallite size and lattice perfection. The terminal β‐hemihydrate and γ‐CaSO4 produced in vacuo have greater surface areas than samples produced in air.

The most active γ‐CaSO4 (Class C plaster) samples are finely porous and rapidly rehydrate in atmospheric water vapour with considerable loss of surface area and porosity. ‘Wet’ rehydration (liquid water) or γ‐CaSO4 causes more rapid development of the 6.01 Å (10.10) spacing, in accord with the c‐direction elongation of the ‘α’‐hemihydrate crystals prepared by autoclaving or precipitation from 50% HNO3.

The porosity of the γ‐CaSO4 diminishes considerably between 200° and 300°, but remains to a smaller extent up to 500° when the γ‐CaSO4 has changed to β‐CaSO4, anhydrite (Class D plaster). Anhydrite sintered extensively between 500° and 900° before decomposing to lime at temperatures up to 1400° (Estrich Gips plaster). Removal of the SO2 and O2 is facilitated by streams of nitrogen or carbon dioxide, which increases the decomposition rate. Calcination at temperatures below 1200° gives anhydrite and lime crystals of more comparable sizes, and avoids complete ‘dead‐burning’ of the lime.
Chemical aspects of the production of television tube screen. III. The dry screen
Authors: Lines F.
Published: July 2010

The adhesion of phosphor to glass in the dried screen has been measured. It was found to depend on the quantity and composition of the solution left in the screen pores after removal of the bulk of the settling liquid. Adhesion was produced by drying of the solute. Delay between draining and drying allowed gelation to proceed, thereby reducing the quantity of dry binder available.

Migration of solution through the screen towards the drying patch, if allowed to proceed for too long a time, caused uneven binder distribution.

Measurement of the light output of screens under electron excitation confirmed the usual effect of variation in screen thickness on screen luminescence. Whilst controlling screen thickness, factors in settling were varied, but these factors were found to be irrelevant as long as good screen structure was maintained. Type and purity of potassium silicate had no effect within the usual settling range. Flocculation or very high silicate concentration depressed light output, but could be easily avoided.
Grafting of methyl methacrylate on isoprene rubber
Authors: Waterman J. A. , la Heij G. E. , van Hoorn H.
Published: July 2010

Methyl methacrylate has been grafted on artificial isoprene rubber (IR) latex, with use of redox initiation. The properties of latices containing up to 40 phr

Parts per hundred parts of rubber.

methyl methacrylate (MMA) as well as solid products containing up to 80 phr of this compound were studied. Compared with ungrafted IR latex with the same solids content, the grafted IR latices had a lower viscosity, owing to their particle size being larger. Vulcanised films obtained from the grafted latices showed a considerably higher modulus, particularly at large deformations, than those based on IR or blends of IR with polymethyl methacrylate. by incorporation of certain reinforcing white fillers in the MMA‐grafted IR latices, a further increase in the modulus of the latex films was effected.
Thermosetting resins curing by the arbuzov reaction
Authors: Stark B. P. , Duke A. J. , Martin R. J.
Published: July 2010

The usefulness of the ‘catalytic’ Arbuzov reaction as a curing mechanism for thermosetting polymerisation has been examined, using a range of bis‐(cyclic phosphites). Such a cure is strongly catalysed by Lewis bases.
The reaction of kaolin with fluorides. III. Hydrolysis of silicon tetrafluoride by kaolinite at elevated temperatures
Authors: Semmens B.
Published: July 2010

The reaction between kaolinite and silicon tetrafluoride has been studied over the temperature range 300–700°. Above the dehydroxylation temperature of kaolinite the formation of metakaolinite was accompanied by an increase in sample weight rather than a loss. In the presence of an excess of SiF4 the reaction products showed signs of interaction with one another, possibly to form a fluoroaluminate.
The examination of disperse crystalline phases in polyvinyl chloride
Authors: Michell E. W. J. , Pearson D. G.
Published: July 2010

The examination by microscopy and X‐ray diffraction, of fine crystalline powders embedded in polyvinyl chloride is described. These techniques are applied to an investigation of the stabilising reaction of white lead during thermal degradation of PVC. It is shown that the white lead reacts as a compound, being completely converted to lead chloride by the time hydrogen chloride gas is evolved from the PVC specimen. An unidentified intermediate crystalline phase is also formed. Both this phase and the final lead chloride, nucleate at sites away from the white‐lead stabiliser particles, which indicates that lead compounds must have a solubility in hot PVC plastic. During the thermal degradation neither normal lead carbonate nor gas bubbles have been detected.

The PVC fabrication processes cause the stabiliser crystallites to take up preferred orientation and this makes microscopic examination of the crystallites easier, but can cause difficulty in identification by X‐ray diffraction.
Determination of bound styrene in insoluble emulsion polymerised styrene‐butadiene copolymers
Authors: Post Mildred A.
Published: July 2010

Bound styrene is determined in insoluble emulsion polymerised styrene‐butadiene copolymers by measurement of the 10.3 μm/13.2 μm absorbence ratio using the baseline method. This ratio is obtained from the infra‐red spectrogram of the copolymer. The styrene content is then determined from a standard curve. The standard curve is constructed from absorbence ratios of 10.3 μm/13.2 μm derived from the infra‐red spectrograms of cast films of styrene‐butadiene latices over a range of compositions in which the bound styrene has been determined by nitration of the isolated and extracted copolymers. Styrene content based on nitration is determined from standard curves relating styrene concentration to spectrophotometric absorbence measurements at wavelengths of 285.0 nm, 273.8 nm and 265.0 nm. The source of the styrene for these curves is NBS standard rubber #1500.
Kinetic study of formation of bisphenol a
Authors: Ghosh P. K. , Guha T. , Saha A. N.
Published: July 2010

The condensation reaction of phenol with acetone in an acidic medium to produce bisphenol A has been studied with and without the use of promoters. The promoters used were thioglycollic acid, ethyl mercaptan, butyl mercaptan and hexyl mercaptan. The kinetic study of the reaction shows a first order dependence of the reaction rate individually on phenol and on acetone. The mercaptans greatly enhance the reaction rate whereas thioglycollic acid appears to be only a moderate promoter. The rate‐controlling step of the reaction has been found to be the formation of the intermediate carbinol, 2‐(4‐hydroxyphenyl)‐propan‐2‐ol.
Equilibria and hysteresis in the system Mn2O3Mn3O4O2
Authors: Shenouda F. , Aziz S.
Published: July 2010

In the light of the present and previous experimental observations, the discrepancy between the dissociation pressures and the thermodynamic results of the system 6 Mn2O3 = 4 Mn3O4+O2 is discussed. The degree of fineness and the related lattice defects of the solid phases, the oxygen content of the Mn2O3 modification and the sintering of the fine solid material are thought to be causes of such inconsistency. Less probable is the effect of the mutual solubility of α‐Mn2O3 and α‐Mn3O4.

The thermodynamic results for the association of α‐Mn2O3 are given.

At given time intervals during a dissociation run, the pressure values are stable and independent of time and can be reached from both directions when it is a matter of small shifts about the equilibrium state. Higher oxygen pressures are attained on combination when dissociation and combination processes are carried out successively in the same run. The difference in pressure decreases with increase of temperature. The results may indicate a hysteresis phenomenon.
Synthesis of formaldehyde and methanol from methane and water in an electrical discharge two‐phase reactor
Authors: Sergio R. , Thornton J. D.
Published: July 2010

The synthesis of formaldehyde and methanol from methane and water vapour initiated by a d.c. discharge has been carried out in a two‐phase gas‐liquid reactor in which liquid water was present as a pool covering one electrode. Decomposition reactions, responsible for the low energy efficiency, are limited by a shorter residence time of the soluble products in the gas phase. The experimental results, when compared with those obtained in the absence of water, show a considerable increase in the energy yield.
Length change characteristics of Ca(OH)2 compacts on exposure to water vapour
Authors: Ramachandran V. S. , Feldman R. F.
Published: July 2010

The presence of large quantities of Ca(OH)2 in hydrated Portland cement suggests that a study of the length change‐sorption characteristics of Ca(OH)2 in the form of compacts should provide useful information.

Length change‐sorption data were obtained for water from 0 to 76% RH and various cycling experiments between 0 to 58 and 0 to 93% RH were performed during which length change data were obtained. Preliminary experiments were also performed in relation to the carbonatation of Ca(OH)2 compacts.

Large irreversible shrinkages were observed while repeatedly determining the isotherms during the cycling experiments and it is suggested that these were the result of ionic diffusion from the points of contact of crystallites and the pulling together of these crystallites by van der Waals forces.

The carbonatation of calcium hydroxide also produced shrinkage and it is considered that this could also be due to van der Waals surface forces.
Hysteresis in rubbers and its influence on strength
Authors: Harwood J. A. C.
Published: July 2010

The most important dissipative mechanisms contributing to hysteresis when a rubber is stretched to breaking point are discussed. A quantitative examination of the influence of hysteresis on the work required to break the rubber produces a sensitive criterion of failure for a number of rubbers with and without carbon‐black filler.
Solubility of chlorine in a brine solution at different pH values
Authors: Bott T. R. , Schulz S.
Published: July 2010

The solubilities of chlorine in a solution containing 250 g/litre of sodium chloride, at different pH values (in the range 1–2.5) have been experimentally determined at different chlorine partial pressures and at temperatures of 50° and 75°. The results show some slight divergence from data previously reported in the literature but these were obtained by a different procedure.
Solubility of calcium sulphate dihydrate in hydrochloric acid solutions
Authors: Gupta R. K.
Published: July 2010

Solubilities of CaSO4, 2H2O in hydrochloric acid solutions of concentration up to normal have been studied for temperatures from 20° to 70°. Results are discussed in relation to the Debye‐Huckel theory.
Formation and reactivity of nitrides I. Review and introduction
Authors: Glasson D. R. , Jayaweera S. A. A.
Published: July 2010

Methods of nitride production are summarised and their thermodynamics surveyed. Crystal structures and types of bonding in binary and ternary nitride compounds are classified and discussed. Kinetics of nitride formation are related to structural changes in the materials, which control diffusion of metals and nitrogen and cause nitride scaling. Metal nitridation with ammonia and nitride formation during ammonia synthesis are discussed.

Information so far available on the sintering of nitrides and its effect on their chemical reactivity is reviewed. This effect is influenced by additives or impurities such as oxides formed by partial nitride hydrolysis and oxidation. Sintering and hot pressing increase the resistance of nitrides to hydrolysis and oxidation, so that they become more suitable for use as refractories. Often, corrosion resistance of nitride layers on metal surfaces is impaired by poor scaling resistance in air or oxygen at comparatively low temperatures. The kinetics and products of oxidation of nitrides so far studied, notably AlN, TiN and UN, depend mainly on the intrinsic reactivity of the material and the available surface at which oxidation can occur.

Subsequent work will be concerned with changes in phase composition, surface area and crystallite and aggregate sizes and their correlation with production, sintering, hydrolysis and oxidation conditions for single and mixed nitrides. Suitable experimental techniques are summarised in this paper.
Measurement of the permeability of thick membranes to liquefied hydrocarbons by a radioactive tracer technique
Authors: Evans R.
Published: July 2010

A radioactive tracer technique has been devised to measure the permeability of thick membranes and layers of synthetic rubbers and glass‐fibre laminates to liquefied hydrocarbons. The technique involves the use of the tritium‐labelled hydrocarbon, prepared by treating the appropriate Grignard reagent with tritiated water. The labelled hydrocarbon is transferred to a thermostatted permeability cell. Permeate is trapped in a vial which contains liquid scintillation phosphor and is cooled in liquid air. The trapped permeate is measured by liquid scintillation counting of the sealed vial. Such measurements, made over an appropriate period, allow permeability constants to be calculated.

Propane transfer rates down to 10−10 g/h have been measured, with membranes of thickness ranging from about 0·5 to 1·5 mm, giving permeability constants of the order of 10−11 g cm−1 h−1 atm−1. Abnormal rate/time curves have been found for some membranes.

Factors affecting the accuracy of the measurements, and the safety precautions necessary, are discussed. Finally, extension of the technique to the study of hydrocarbons of low boiling point such as methane is considered.
Mechanism of the carbonatation shrinkage of lime and hydrated cement
Authors: Swenson E. G. , Sereda P. J.
Published: July 2010

Carbonatation of hydrated lime compacts produces shrinkage and changes in mechanical properties comparable with those found in similarly treated compacts of bottle‐hydrated cement and samples of hardened Portland cement paste. From experimental results obtained with the simpler lime system a mechanism for carbonatation shrinkage is proposed that postulates a through‐solution reaction and induced cycles of wetting and drying.

Experiments on compacts of bottle‐hydrated cement show that carbonatation of the ‘combined lime’ is at least as rapid and extensive as the carbonatation of the ‘free lime,’ and that contrary to current opinion the former reaction results in even greater carbonatation shrinkage. The mechanism for carbonatation shrinkage of this system is considered to be connected with dehydration and polymerisation of the hydrous silica product of carbonatation.
Some molten ionic oxides as chemical reagents
Authors: Araten D.
Published: July 2010

Molten ionic oxides possess important desirable properties: thermal stability, and useful chemical properties resulting from their acid or basic behaviour, i.e., from their capacity to accept or donate an oxygen ion, and, in several cases, relatively low melting points, well below 1000°c.

Bismuth trioxide was found to effect a two‐temperature decomposition of ammonium chloride, yielding ammonia and hydrogen chloride. Molten antimony trioxide was found to attack rock phosphate and convert part of the phosphate to a water‐soluble form. Molten lead monoxide was found to dissolve calcium oxide readily, to dissolve chromic sesquioxide, to decompose chromite ore and to permit an extraction of iron‐free lead chromate into an upper layer of molten alkali chloride. Addition of lead sulphide to a lead monoxide melt caused formation of elemental lead and lead sulphate.

Vanadium pentoxide was found to decompose ammonium chloride, yielding first, hydrogen chloride and then, ammonia. The reaction of a vanadium pentoxide melt with rock phosphate, studied in some detail, resulted in water‐solubilisation of the phosphate. The product formed in the melt is probably a calcium phosphate vanadate, from the aqueous solution of which calcium can be precipitated by ammonium carbonate; the ensuing ammonium phosphate and vanadate solution can be separated by known methods, permitting recovery of the vanadium pentoxide, and yielding ammonium phosphate.
New low‐density ceramic material for packing fractional distillation columns
Authors: Castellucci N. T. , Krouskop N. C.
Published: July 2010

This paper presents a general comparison between glass beads and new low‐density ceramic spheres as packing materials for fractional distillation columns. The light‐weight ceramic spheres have higher through‐puts, lower pressure drops, better separating power and higher wettability than glass beads.
Sorption of sulphur dioxide by paper
Authors: Edwards C. J. , Hudson F. Lyth , Hockey J. A.
Published: July 2010

Sulphur dioxide is sorbed by paper and slowly converted to sulphuric acid; the presence of this severely reduces the useful life of the material. The sorption (‘pick‐up’) of sulphur dioxide has been investigated for a representative range of papers for exposures lasting many months at concentrations approaching those found in polluted urban atmospheres.

It was found that the relative humidity does not significantly affect the long‐term pick‐up rate and that this rate remains constant for prolonged exposures, being proportional to the square root of the gas phase sulphur dioxide concentration. Rosin size increases markedly the long‐term rate while certain other paper additives, e.g. Turkey Red Oxide and Anatase, have no such effect.
Continuous multistage fractional crystallisation I. laboratory investigation
Authors: Betts W. D. , Freeman J. W. , McNeil D.
Published: July 2010

The application of a laboratory scale rotating helix crystalliser to the separation of a number of organic and aqueous systems is described. The results show separations equivalent to several stages with systems exhibiting the phenomenon of solid solution and the recovery of components in high purity from multi‐eutcetic systems.