bluuebunny/crossref_metadata_2025 huggingface dataset:
Identification of vapour phase and liquid phase gums found in gas plant and appliances
Authors: Owens P. M.
Published: July 2010

A qualitative method by paper chromatography is described for distinguishing between vapour phase and liquid phase gums found in gas plant and appliances. Details are also given of attempts to determine vapour and liquid phase gums qualitatively, in admixtures with various types of tar by paper chromatography.
Characterisation of crude tars
Authors: McNeil D.
Published: July 2010

Sixty‐one crude tars representing the normal primary distillation feedstocks of almost all tar‐distilling firms in the United Kingdom have been subjected to a method of assay and a number of the properties of (a) the tar after dehydration and (b) the pitch and oils obtained from the tar by a standard distillation have been determined. The results have been examined statistically to find the degree of correlation between the various properties. A characterisation index based on the level of three of the most readily determined properties, viz. the specific gravity of the dry tar, the phenol content of the oils distilling to 250° and the benzene‐insoluble content of the dry tar, is proposed.
Electrochemical principles of the corrosion and protection of metals
Authors: Hoar T. P.
Published: July 2010

The types of anode and cathode reactions commonly found in corrosion by aqueous media are described, and the combination of these reactions in corroding and in passivated systems is discussed.

The principal ways in which corrosion rates are increased or decreased are classified and discussed, as follows: anodic attack and cathodic protection; anodic passivation or protection and cathodic activation; anodic inhibition and stimulation; cathodic inhibition and stimulation; resistance inhibition.

The importance of the use of electrochemical and other theoretical principles in thepracticeof corrosion and protection is emphasised.
Chemical modification of wood. II. Use of trifluoroacetic acid as catalyst for the acetylation of wood
Authors: Arni P. G. , Gray J. D. , Scougall R. K.
Published: July 2010

Sapwood lengths of Ponderosa pine (Pinus ponderosa) have been acetylated, without loss of strength or discoloration, at temperatures of 25–45° to 16–30% acetyl with acetic anhydride, using trifluoroacetic acid and magnesium perchlorate as combined synergistic catalysts. When matched samples were acetylated to similar weight gains and acetyl contents by low‐ and high‐temperature methods, the former method resulted in permanent shrinkage of the wood blocks and a small reduction (∼20%) in swelling property, whilst the latter method, in corroboration of published data, caused permanent bulking and a 75% reduction in swelling property.
Use of the marshall stability test for asphalt mixtures
Authors: Broome D. C.
Published: July 2010

The paper describes the introduction of the Marshall stability test into commercial use in the U.K. and discusses the practical problems which have arisen. Information is given regarding the influence of aggregate grading and particle shape, and of variation in the percentage and nature of the binder employed. It is shown that particle shape is of greater importance than grading, although the latter can be critical and may have a considerable bearing on the optimum binder content. Lower‐penetration bitumens give generally higher stabilities provided that appropriate changes are made in the compaction temperature. For highways, the use of the Marshall test may give mixtures of relatively low durability. It is suggested that B.S. 594 for hot‐rolled asphalt provides an adequate margin of safety against deformation under most highway conditions without the use of a stability test. It is, nevertheless, suggested that the Marshall test should be further investigated in connexion with road surfacing.
The identity of some dicalcium silicate hydrates
Authors: Glasser L. S. Dent , Funk H. , Hilmer W. , Taylor H. F. W.
Published: July 2010

The compounds described as 6CaO, 3SiO2, 2H2O (Flint et al.1), 2CaO, SiO2, 0.5H2O (Jander & Franke2 and Funk3), and Phase Y (Roy4), are all substantially identical. The true composition is probably 6CaO, 3SiO2, H2O, as reported by Roy. New X‐ray powder data are given, and the unit‐cell dimensions have been slightly refined. Thermal weight loss, DTA, and optical data are given.
Reactivity of lime and related oxides. VII crystal size variations in calcium oxide produced from limestone
Authors: Glasson D. R.
Published: July 2010

The calcination of limestone has been studied by determining the changes in the specific surface and crystallite size of the calcium oxide produced when limestone spheres are calcined for various times at each of a number of fixed temperatures either in vacuo or in air.

At lower temperatures (below about 900°) as in rotary‐kiln lime‐burning, the crystallite size of the calcium oxide is determined more by the mode of recrystallisation of the oxide from its CaCO3‐like transition structure than by the sintering of the recrystallised oxide. Since the decomposition rate of the limestone progressively diminishes, the rate of nucleation in the recrystallisation of the oxide becomes lower, so that the crystallite size of the oxide formed in the outer sections of the spheres tends to be less than that formed in the inner sections. The differences in size are minimised if the evolved carbon dioxide is not quickly removed, for it enhances sintering of the calcium oxide.

At higher temperatures (above about 900°), as in conventional lime‐kilning, the crystallite size of the calcium oxide depends mainly on the rate of sintering. Rapid decomposition of the limestone at these temperatures therefore produces lime more homogeneous in surface activity even after only short calcinations, since all of the lime crystallites in each sample still have approximately equal times in which to sinter; the crystallite size of the lime then becomes practically independent of that of the original calcium carbonate.
An experimental survey of rust preventives in water I. Methods of testing
Authors: Hersch P. , Hare J. B. , Robertson A. , Sutherland Sheila M.
Published: July 2010

An assessment of inhibition ability was obtained by two test procedures, which yielded the minimum threshold concentration (range) at which an additive prevents the corrosion of ferrous materials in non‐acid aqueous solutions containing dissolved air. An accelerated procedure was also adopted, in which the basis solution contained a mixture of potassium ferricyanide and sodium chloride.

The ability to inhibit the corrosion of zinc was assessed by weight loss experiments.

Stationary current/potential polarisation curves, as well as current/time and potential/time curves, were obtained with a cell which incorporated an iron test specimen as anode, suitably ‘activated,’ a large well‐aerated inert cathode, and a non‐acid aqueous electrolyte.
The effects of hydrogenation and catalytic cracking of various molecular types in middle distillates
Authors: Flinn R. A. , Larson O. A.
Published: July 2010

The response to hydrogenation and catalytic cracking of the various types of hydrocarbons present in petroleum gas oils has been investigated by mass spectrometric analytical techniques. A substantial difference was found between the ease of hydrogenation of mononuclear and dinuclear aromatic compounds. A similar difference does not appear to exist between dinuclear and polynuclear aromatic systems. Some polynuclear compounds are apparently hydrogenated completely under conditions which do not normally saturate mono ring aromatics.

In catalytic cracking, it appears that aromatic compounds are affected largely by the cracking of aliphatic appendages and very few aromatic rings are broken, whereas entirely aliphatic materials present in the reactant stream are cracked quite readily. It is well known that hydrogenation is beneficial to a catalytic cracking charge stock. This work shows that relatively mild hydrogenation of materials which are to be catalytically cracked can, by saturating polyaromatics only to monoaromatics (naphthenes), make the stock much more susceptible to cracking.
Inhibition of the corrosion of pure aluminium in hydrochloric acid solutions
Authors: Sundararajan J. , Char T. L. Rama
Published: July 2010

The corrosion rates and inhibitor efficiencies have been determined for 99.5% aluminium in hydrochloric acid solutions, with the following inhibitors : acridine, thiourea, nicotinic acid, dextrin and tannic acid, of which acridine is the best. Polarisation studies with thiourea show that anodic polarisation is negligible, whereas cathodic polarisation is considerable, so that the corrosion process with this inhibitor appears to be essentially under cathodic control.
A method for recovering small samples of bitumen from road mixtures and surface dressings
Authors: Green E. H.
Published: July 2010

A method has been devised for recovering from surface dressings 30‐g. quantities of cutback or penetration‐grade bitumen. This gives sufficient material for a determination of the viscosity in a Couette viscometer. The method was developed to investigate the rate of hardening on the road of cutback bitumens used in surface dressing.
Measurement of trace quantities of hydrogen sulphide in industrial atmospheres
Authors: Smith A. F. , Jenkins D. G. , Cunningworth D. E.
Published: July 2010

Although methods have been published for the measurement of traces of H2S in air, no mention is made of their reaction to SO2, which is invariably present in the atmosphere, particularly in industrial areas, in concentrations vastly in excess of that of the H2S. In some cases, the calibration and ultimate limits of detection of the methods are also in doubt. The work described here includes a critical practical appraisal of five alternative methods with respect to interference by SO2, maximum flow rate and limit of detection and their accurate calibration to low levels by both volumetric and gas dilution techniques. Modifications to eliminate interference by SO2 are also described.

A description is given of a simple portable field apparatus capable of measuring concentrations of H2S down to 10−4 p.p.m. in a 2 h. sampling period, together with typical levels found when using it.
Phosphorus‐containing polymers
Authors: Bride M. H. , Cummings W. A. W. , Pickles W.
Published: July 2010

A number of amino‐ and carboxyl‐substituted diaryl‐phosphine oxides have been prepared and converted into polyamides. Some esters of vinyl‐ and allyl‐phosphonic acid have also been prepared and converted into addition polymers.
The characteristics and sintering behaviour of uranium dioxide prepared by a homogeneous precipitation route
Authors: Ainscough J. B.
Published: July 2010

Uranium dioxide has been prepared from uranyl nitrate solution by homogeneous precipitation with urea at 95° followed by calcination in argon and reduction in hydrogen. Some properties of the precipitates and of the uranium dioxide powders prepared from them have been measured. The dependence of these latter on the calcination and reduction conditions is discussed. An account is given of the effect of powder preparation conditions and of powder treatment, prior to pressing, on the green and sintered densities of compacts pressed from the powders. To obtain the highest sintered densities it is necessary both to mill the powder and to add a binding agent before pressing. The densities attained after sintering for 2 h. in hydrogen at 1650° are up to 10.5 g./cm. and slightly lower than those of sintered compacts of oxide prepared from ammonium diuarnate prepared under the same conditions.
The precipitation of anhydrous calcium hydrogen phosphate from homogeneous solution
Authors: Burrus H. L.
Published: July 2010

The production of a granular anhydrous calcium hydrogen phosphate for use in phosphors has been investigated by precipitation from homogeneous solution by means of urea hydrolysis. The course of the reaction has been investigated under a wide variety of conditions, and conditions for the precipitation of a suitable material have been established.
Flame photometric determination of calcium and magnesium carbonates in brickmaking raw material
Authors: McGraith J. H.
Published: July 2010

An analytical procedure has been developed for the rapid determination of calcium and magnesium in brick blae

Blae is silicious material used for the manufacture of composition bricks.

using the Unicam SP 900 flame spectrophotometer. The interfering effects of mineral acid and aluminium content on the results have been established, and means of allowing for, or eliminating, the interferences are suggested. Results of analyses are compared with those by wet chemical methods.
The corrosion of aluminium in concentrated hydrogen peroxide
Authors: Lewis T. J.
Published: July 2010

A distinction is made between the electrochemical corrosion of metallic aluminium, in which aluminium oxide is formed, and the chemical solution of the aluminium oxide, leading eventually to the interaction of aluminium ions with the stannic acid stabiliser. The electrochemical reaction is facilitated by chloride ions and retarded by nitrate ions, whilst the chemical solution is enhanced by hydrogen ions and the presence of stannic acid sol. Only the chemical reaction affects the stability of the stannic acid stabiliser.
The corrosion of metals by acid vapours from wood
Authors: Clarke S. G. , Longhurst E. E.
Published: July 2010

In tests conducted with air containing known concentrations of acetic acid vapour and moisture, it was found that very small amounts of acetic acid (0.5 p.p.m. or less) can promote corrosion of metals at moisture levels of 80% R.H. and above. The type of corrosion product varies with the concentration of acetic acid and moisture. A number of common metals are affected, but aluminium is relatively resistant, and tin is outstandingly so. With metals exposed to vapours from damp wood, corrosion is markedly promoted when the wood has previously been heated in kiln‐drying after rot‐proofing treatment with aqueous solutions.
The behaviour of stannic acid sols in concentrated hydrogen peroxide. III. The ageing of stannic acid sols in water and hydrogen peroxide
Authors: Lewis T. J. , Richards D. H.
Published: July 2010

Stannic acid sols in concentrated hydrogen peroxide differ greatly in appearance and behaviour from stannic acid hydrosols. In water the sol particles are comparatively large, grow rapidly and are of a feathery appearance, whilst in hydrogen peroxide the particles are small, compact and show a distinct but much less pronounced tendency to increase in size with time. This ageing process in hydrogen peroxide, which apparently consists of the aggregation of the smaller particles in a polydisperse system, takes place mainly during the first week after preparation and results in a reduction of approximately 25% in the adsorptive power of the sol.
Absorption of carbon dioxide in carbolates
Authors: Briggs D. K. H. , Thompson G. H.
Published: July 2010

A streamline jet of absorbing liquid has been used to investigate the rate of uptake of carbon dioxide into water and into commercial carbolates at temperatures in the range 30—60°. The ratio of absorption rates with and without chemical reaction has been correlated with reaction rate constant, hydrogen‐ion concentration and flow factors. In addition, the rate of change of liquid‐film transfer coefficient with temperature has been shown to be similar for all carbolates.
Preparation of uranium peroxide hydrates
Authors: Sato Taichi
Published: July 2010

Uranium peroxide hydrates have been prepared from uranyl nitrate solution and hydrogen peroxide under various conditions. The materials obtained were examined by thermogravimetry, X‐ray diffraction and infra‐red spectroscopy. The results showed that uranium peroxide hydrate exists in two different crystalline forms depending on the temperature of precipitation: UO4,4H2O at below 50°, UO4,2H2O at above 70°. The former is converted into the latter by drying in air at 100° or in vacuo for 24 h. at room temperature.
Formation of aromatics during thermal hydrocracking. II Methylcyclohexane
Authors: Reeve A. C.
Published: July 2010

A study has been made of the thermal hydrocracking of methylcyclohexane in a flow reactor with particular reference to the formation of aromatic hydrocarbons. Although much of the methylcyclohexane is converted into gaseous hydrocarbons, especially methane, the amounts of benzene and toluene formed are interesting in that benzene displaces toluene as the major aromatic product, as the reaction temperature is increased. Both 4‐methylcyclohexene and cyclohexene are found in appreciable quantities and their yields pass through maxima as the conversion of methylcyclohexane increases, while the respective yields of the corresponding aromatics continue to rise. The aromatics, therefore, are formed mainly as a result of dehydrogenation and demethylation of the naphthene. A possible reaction mechanism is discussed.
Solubilities of vapours in relatively involatile liquids
Authors: Burrows G. , Preece F. H.
Published: July 2010

Arising out of the dependence of gas—liquid chromatography on solubility in a manner previously described, the solubilities of five vapours have been measured in a non‐polar solvent and in a polar solvent, both of low vapour pressure, under conditions of dilute solution and over a range of temperatures.

The results have been used in the application of a theory which illustrates the action of dilute solutions of vapours in liquids by means of a mechanical model based on the potential energy of attraction, the kinetic energy of vibration, and a probability distribution function.

A method is examined in the Appendix in which a conventional temperature‐entropy diagram of the kind used by steam engineers is applied to represent the process of desorbing solutes from solutions.
Effect of dehydrogenation on the structure of two coals
Authors: Dicker P. H. , Flagg M. K. , Gaines A. F. , Martin T. G.
Published: July 2010

As the quantity and nature of the non‐aromatic material in coals is uncertain, the dehydrogenation of coals has been reinvestigated.

Aromatic hydrocarbons, unlike phenolic compounds and compounds containing ‘hydroaromatic’ groups attached to aromatic nuclei, could not be dehydrogenated by sulphur below 200°. It was not possible to predict whether the amount of ‘hydroaromatic’ material in coals might be estimated from their treatment with sulphur.

The extent of the dehydrogenation of two coals (rank 902 and 401) with sulphur, and hence the amount of ‘hydroaromatic’ material linked to aromatic nuclei, was estimated from the change in the ratio of the infra‐red absorption at 1430 cm.−1 to that at 1600 cm.−1 Firmer estimates were obtained by dehydrogenating the coals by successive treatment with N‐bromosuccinimide and alcoholic potassium hydroxide. It was concluded that, in agreement with the contentions of the Indian school, 16 ± 2% and 11 ± 2% respectively of the carbon in the coals of rank 902 and 401 was ‘hydroaromatic’ and linked to aromatic nuclei. The manner of the dehydrogenation of the coals by sulphur was considered in some detail and, it being assumed that the above ‘hydroaromaticities’ were correct, it was suggested that the two coals contained few methylene groups which could not be dehydrogenated, and also that the non‐aromatic materials in both coals consisted mainly of ‘hydroaromatic’ methylene groups and methyl substituents.
The production of hypochlorite by direct electrolysis of sea water: Electrode materials and design of cells for the process
Authors: Adamson A. F. , Lever B. G. , Stones W. F.
Published: July 2010

Chlorine treatment of the cooling water of coastal power stations is required to prevent infestation of the circulating water culverts by mussels and marine organisms. As such enormous quantities of cooling water are required at modern coastal power stations, the addition of even a fraction of a p.p.m. of chlorine will result in the consumption of large tonnages of chlorine.

The possibility was therefore investigated of producing hypochlorite (which is claimed to be equally effective for controlling mussels) by the direct electrolysis of sea water.

As the efficiency of the process will depend to a large extent on the electrode materials and cell design, the paper is devoted to the research and development carried out in these fields both in the laboratory and on a pilot scale.

A brief outline of a prototype plant is given.
Phase equilibria in sugar solutions. XI. The ternary system sucrose‐butanol‐water
Authors: Kelly F. H. C. , Rolls J. M.
Published: July 2010

Equilibrium phase relationships for the ternary system sucrose‐water‐isobutanol have been determined at 30° and 60° and for the system with n‐butanol at 60°. These relationships are illustrated to include tie‐line equilibria in the two liquid‐phase concentration ranges. At 30° occasional appearance of an acicular crystalline solid phase was observed at high butanol concentrations but was of low stability and was difficult to reproduce. It was not positively identified.
Bentonite films to protect steel from oxidation
Authors: Ray Satyabrata , Williamson W. O.
Published: July 2010

Bentonite films protect heated steel from oxidation when channels through them are absent or are too narrow for oxygen to pass. Ca, Mg and Fe‐bentonites are flocculated and thus produce films containing channels. Na bentonites, being well‐dispersed, give relatively impervious films.

Films can be effectively scrubbed from the steel if their montmorillonite expands with water, despite prior heating, but the scrubbing of resistant films with cleansing solutions suggests that wettability is also significant.

Na‐Ca‐bentonites showed good overall behaviour when the proportion of Ca was low. A small critical proportion of Ca accelerated thixotropic setting and thus was likely to give a less permeable film. Progressive substitution of Na by Ca produced flocculation, permeable films and difficulty in scrubbing the clay from the steel. This difficulty supervened at different Na/Ca ratios for different bentonites.

Heating was to 700° momentarily. Lower peak temperatures should make a wider range of bentonites acceptable.
The setting of a slurry
Authors: Schiller K.
Published: July 2010

The general view concerning the cause of setting, i.e. solidification, of a hydrating slurry is briefly discussed. The aim of this paper is to put this view on a quantitative basis a theory akin to the one of hydration previously published. It is shown that the setting time of a plaster should be proportional to (1 + 2.75 w)−1/3 where w is the water ratio of the slurry. Experimental curves are presented to show that this is so. An unexpected result is that three of the four plasters tested give lines of equal slope. Several explanations why the fourth should behave differently are possible on the basis of the proposed theory, but it is shown experimentally thatin this case it was a different crystal shape which was responsible for the difference.

Generally speaking, the theory gives useful information about some properties of a slurry by such simple means as a Vicat needle.
Effect of sulphate solutions on normal and sulphate‐resisting portland cement
Authors: Heller L. , Ben‐Yair M.
Published: July 2010

The expansion and changes in phase composition of dilute paste and mortar bars of normal and sulphate‐resisting Portland cement exposed to various sulphate solutions were studied over a period of time. Although strong expansion was usually associated with the presence of considerable amounts of calcium sulphoaluminate, there was no quantitative correlation between expansion and the concentration of crystalline calcium sulphoaluminate. Similar quantities of this compound were found in corresponding samples of normal and sulphate‐resisting cement. It was inferred that, on continued corrosion, calcium sulphoaluminate partially passes into a gel phase which may determine the properties of the cement.

In the presence of magnesium ions the bars disintegrated before excessive expansion occurred, since these ions reacted with hydrating cement with the precipitation of magnesium hydroxide, which tends to block the pores and channels, thus preventing penetration of the solutions. Chloride ions increased expansion by forming calcium chloroaluminate. Under the static conditions of the experiments protective surface films developed.
The dielectric, dynamic mechanical and nuclear resonance properties of polyethylene oxide as a function of molecular weight
Authors: Connor T. M. , Read B. E. , Williams G.
Published: July 2010

The components of the complex dielectric constant ε* and complex shear modulus G* and also the nuclear spin—lattice relaxation time T1 have been measured as a function of temperature and frequency for polyethylene oxide [CH2·CH2·O]n in the molecular weight range 200—2·8 × 106 (viscosity average). The dynamic properties of the polymer below the melting point depend strongly on the molecular weight of the samples and also upon their thermal history and the presence of absorbed liquids such as water and dioxan. It is postulated that the relaxation behaviour is largely influenced by the degree of crystallinity of the polymer which depends markedly on molecular weight.
Production of manganese (II) sulphate from low‐grade manganese ores
Authors: Razouk R. I. , Tobia S. K. , Messiha M. A.
Published: July 2010

A new method is described for the production of manganous sulphate from low‐grade manganese ores. The ore is first treated with a calculated amount of concentrated sulphuric acid at 200–220° to form manganic and ferric sulphates, and then heated at 500–640° for 90 min. The percentage conversion to manganous sulphate reaches 80, with almost 100% utilisation of sulphur, and contamination with iron is low.

An explanation is suggested for the rǒle played by iron in increasing both manganese conversion and efficiency of sulphur utilisation.
Gas‐producing agents in the production of lightweight aggregates
Authors: Chopra S. K. , Lal Kishan , Ramachandran V. S.
Published: July 2010

An investigation into the bloating phenomenon in an illitic clay was studied by subjecting the clay to different treatments and employing techniques such as differential thermal analysis, X‐ray diffraction, chemical analysis and gas chromatographic analysis. The results indicate that both organic matter and calcium carbonate behave as gas‐producing agents. The hydroxyl water, entrapped air in the pores and ferric oxide do not significantly contribute to the bloating.
Some properties of concentrated solutions of invert sugar and urea
Authors: Hatt H. H. , Triffett A. C. K.
Published: July 2010

Invert sugar and mixtures of invert sugar and urea containing 20–30% of urea absorb approximately the same amounts of water at all relative humidities and these amounts are about two‐thirds of that absorbed by glycerol under the same conditions. The solutions of the mixtures have much lower viscosities than those of invert sugar and in this resemble solutions of glycerol more closely. The value of the mixtures as humectants is limited by their low thermal stability and by a tendency to deposit an addition compound of glucose and urea. If this addition compound is removed, a humectant remains which is permanently liquid.

The comparatively low viscosities of solutions containing both invert sugar and urea makes it possible to filter the addition compound of glucose and urea from highly concentrated solutions and to obtain it in yields corresponding to 75% of the glucose present. Some partition ratios of glucose, fructose and urea have been measured and it is concluded that efficient separation of those two sugars from urea by liquid‐liquid extraction is unlikely.
Reaction of sodium hydride with boron trichloride to form diborane
Authors: Batha H. D. , Good C. D. , Faust J. P.
Published: July 2010

Sodium hydride and boron trichloride react to form nearly stoicheiometric amounts of diborane in the presence of anhydrous aluminium chloride and aromatic solvents such as benzene. The sodium chloride by‐product, which apparently prevents reaction of sodium hydride if it is not removed from the surface of the hydride, reacts with aluminium chloride and dissolves in benzene. The reaction temperature should be kept below 68° to minimise decomposition of the sodium hydride.
Critical temperatures and critical pressures for the ethane—n‐butane—n‐pentane system
Authors: Mehra V. S. , Thodos G.
Published: July 2010

The limited critical temperatures and pressures resulting from the vapour—liquid equilibrium studies for the ethane—n‐butane—n‐pentane system have been utilised along with the available critical temperatures and pressures of the corresponding binary systems to obtain relationships for the critical temperatures and pressures covering the entire range of compositions for this ternary system.
Molar volumes of mixed nitrate melts
Authors: Al‐Mahdi A. A. K.
Published: July 2010

Densities of liquid potassium nitrate containing from 0·1 mole to 0·4 mole fraction of calcium nitrate have been measured with a manometric densitometer. The lowest liquidus temperature measurement ranged from 160° to about 400°, above which chemical decomposition became prominent.

Isotherms of molar volume as a function of composition were found to be straight lines, and thus the mixtures behave ideally with respect to volume change on mixing. Coefficients of thermal expansion of different mixtures have been calculated.
Determination of dissolved oxygen by the winkler method and the solubility of oxygen in pure water and sea water
Authors: Montgomery H. A. C. , Thom N. S. , Cockburn A.
Published: July 2010

Values for the solubility of oxygen in water obtained by a modification of the Winkler method are shown to be low because of losses of iodine vapour. Iodine vapour is also lost in two of the standard modifications of the Winkler method in common use, the amount lost depending on the technique of the analyst.

The volatilisation of iodine can be avoided by the use of the alkaline iodide reagent of Pomeroy & Kirschman; a procedure employing this reagent is described. Interference by pitrites and ferric iron may be eliminated by sodium azide and phosphoric acid respectively.

The accuracy of the Winkler method, modified to prevent the loss of iodine vapour, has been confirmed using gaseous oxygen as a standard.

Using the procedure recommended, determinations have been made of the solubility of atmospheric oxygen in distilled water between 0·4° and 37°, and in sea water between 2° and 27°. The results for distilled water are in excellent agreement with those of Klots & Benson between 2° and 27°; the new values for sea water agree fairly well with those of Fox.

In measurements of the rate of solution of oxygen, the approach to equilibrium using these values was consistent with the law of Adeney & Becker.
Use of carbon‐14 in the study of metal‐carbon dioxide reactions
Authors: Jepson W. B.
Published: July 2010

When a metal is oxidised in carbon dioxide, the growth of oxide film may be accompanied by the deposition of carbon which may return to the gas phase as carbon monoxide, remain in the oxide film or dissolve in the metal. Isotopic tracer techniques with carbon‐14 provide a simple method by which the amount of carbon deposition may be measured, and they also provide a unique method by which the fate of this carbon may be determined. The current experimental techniques are outlined and numerical values are given, with illustrative results, for the oxidation of beryllium, of a 20/25/niobium austenitic steel and of chromium.
The promotion of dropwise condensation by mono‐layers of radioactive fatty acids II. Chromium surfaces
Authors: Tanner D. W. , Pope D. , Potter C. J. , West D.
Published: July 2010

A study has been made of the promotion of dropwise condensation on chromium surfaces by monolayers of stearic acid‐1‐14C, montanic acid‐19,20‐T(n), and mixed monolayers of stearic acid and octadecane. The desorption of promoter during condensation was followed by carbon‐14 and tritium counting and by autoradiography. The accompanying increase in wettability was characterised by changes in heat transfer. The life of promotion ranged from 50 to 200 min., increasing in the series: mixed monolayer < stearic acid < montanic acid. It is concluded that the promotion life of a fatty acid on chromium is determined by the rate of desorption.
The pick‐up of sulphur dioxide by paper
Authors: Hudson F. Lyth , Grant R. L. , Hockey J. A.
Published: July 2010

The authors have further developed a method, using radioactive sulphur dioxide for examining the effect of variables such as humidity, temperature and furnish on the affinity of sulphur dioxide for paper.

The temperature coefficient indicates that a diffusion process determines the rate of uptake which is also almost linearly related to moisture content, being increased by storage under moist conditions.
The specific heats of linear high polymers
Authors: Melia T. P.
Published: July 2010

Specific heat studies on linear high polymers in the temperature range 0° to 400°K are reviewed and the temperature dependence of the specific heats of high polymers is discussed. The detection of reversible and irreversible transitions in high polymers by specific heat measurements is also considered. Thermodynamic properties derived from specific heat data are listed for several polymers. Suggestions are made for further research.
Piston‐flow reactor model for continuous industrial fermentations
Authors: Grieves R. B. , Pipes W. O. , Milbury W. F. , Wood R. K.
Published: July 2010

Although the piston‐flow (tubular) fermentor would provide operational difficulties, it is of significance for the analysis of mixing imperfections, for the analysis of a large number of stirredtank fermentors operated in series, and for the possibility of more efficient operation than the stirred tank. The basic kinetics of microbial growth are reviewed, noting that the reaction order varies during the course of reaction from autocatalytic first to ordinary first order; the equations describing effluent micro‐organism and limiting substrate concentrations for a stirred‐tank fermentor operated with recycle are reviewed. A rigorous analysis of the piston‐flow fermentor is given, for the first time, by means of a combination of the equations of microbial growth with a mathematical description of the hydraulic regime. A quantitative comparison is made between the two basic reactor types: the type of fermentor used depends on the objective of the process; if the objective is the reduction in effluent concentration of the limiting substrate, the piston‐flow fermentor provides more efficient operation. High recycle and concentration factors are of greater benefit to the piston‐flow unit, which becomes more efficient from the point of view of both objectives.
Influence of radiant energy source on bitumen oxidation
Authors: Martin K. G.
Published: July 2010

By use of the steady change in infra‐red absorption of the carbonyl functional groups of bitumen with increase of radiant energy flux, the oxidation rates of four air‐blown bitumens of coating grade have been obtained for the three sources of radiation, carbon arc, xenon arc, and sunlight. Differences in the pattern of oxidation for the much used carbon arc compared with both xenon‐arc and solar irradiation were found, whereas the last two sources induced nearly identical behaviour in the bitumens. Continuous measurement of the intensity of the solar radiation by pyroheliometry has indicated that the oxidation rates are directly proportional to intensity, sensitive to very low intensities and independent of diurnal changes. Potassium ferrioxalate dosimetry has shown that the intensity of the xenon‐arc irradiation as used in a weatherometer simulated that of summer sunshine extremely well, whereas the carbon‐arc irradiation, as used in the ASTM method of evaluation of weatherometer durability of bitumens, had a fivefold greater intensity. This increased intensity changed the pattern of rate of bitumen oxidation rather than simply accelerating the steady‐state oxidation rates.
Improved methods of deposit analysis. I. Silicon, aluminium, calcium, magnesium, chloride
Authors: Grant J.
Published: July 2010

Methods employed for the analysis of fly ash and high‐temperature bonded deposits for silicon, aluminium, calcium, magnesium and chloride ion are given. These are determined from one solution obtained by fusing a 0·2 g. sample with sodium hydroxide followed by treatment with sulphuric acid and hydrogen peroxide.

The effect of certain interfering ions has been determined and a large number of these ions are removed from the test solution, before determination of calcium, magnesium and aluminium, by mercury cathode electrolysis followed by cupferron‐chloroform extraction.

Silicon and aluminium are determined colorimetrically, calcium and magnesium by complexometric methods and the chloride ion by potentiometer.

Estimates of standard deviation of 0·09% for silica, 0·1% for alumina and 0·05% for calcium oxide and magnesia were obtained. The methods are suitable for batch analysis.
The effects of some organic acids and salts on the setting of gypsum plaster. I. Acetates
Authors: Combe E. C. , Smith D. C.
Published: July 2010

The properties of one batch of autoclave calcium sulphate hemihydrate have been determined. A study has been made of the effects of various concentrations of acetic acid, and potassium and calcium acetates on (i) the rate of evolution of heat, (ii) the setting expansion, (iii) the setting time, (iv) the compressive strength, (v) pH and (vi) the crystal morphology of this plaster. A theory of Ridge et al. has been tested and is discussed.

It has been shown that the three additives have some similarities in their effects on the kinetics of setting and it is concluded that the acetate ion plays a major role in the observed retardation of setting.
The kinetics of the thermal hydrocracking of cresols
Authors: Davies G. A. , Long R.
Published: July 2010

A study has been made of the thermal hydrocracking of o‐, m‐ and p‐cresol in the temperature range 580—700° at pressures up to 390 p.s.i.g. with hydrogen/cresol ratios ranging from 0.8/1.0to 4.0/1.0 in a continuous flow reactor. The main products of the reaction, analysed by gas chromatography, are toluene and phenol (primary products) and benzene (secondary product). Small amounts of 2,6‐xylenol are present in the products from o‐cresol.

In the presence of excess hydrogen the results for the overall rate of hydrocracking are found to fit a 1.5‐order rate equation, first‐order with respect to the cresol and 0.5‐order with respect to hydrogen. A possible mechanism for the main reactions taking place has been suggested which accords with the rate equations obtained experimentally.

As the hydrogen/feed ratio is reduced below 1.0/1.0 the products become more complex and the 1.5‐order rate equation no longer applies. When nitrogen is used instead of hydrogen, i.e., under conditions of thermal cracking, the results are found to fit a first‐order rate equation which agrees with that proposed by Neuworth & Jones.

The rate constants for the hydrocracking of the cresol isomers are found to be in the order: ortho > para > meta.
Tensio‐gravimetric determination of the activity of methanol in the sodium methoxide/methanol system, and the solvation of the aqueous hydroxide ion and the methanolic methoxide ion
Authors: Freeguard G. F. , Moodie R. B. , Smith D. J. G.
Published: July 2010

Tensio‐gravimetric analysis is used to determine the activity of methanol for the sodium methoxide–methanol system over the whole range of composition, and the existence of a solid solvate is demonstrated. Solvent activities and acidity function data are combined to deduce solvation numbers of solute species. The treatment is shown to be successful for the aqueous hydroxide ion but not for the methoxide ion in methanol, and reasons for this are discussed.
Extraction of some mineral acids by tri‐n‐octylamine
Authors: Sato Taichi
Published: July 2010

The distribution equilibria of nitric, hydrochloric, perchloric, sulphuric and phosphoric acids between aqueous solutions and benzene solution of tri‐n‐octylamine have been investigated. The partition and infra‐red results indicate that the extraction of these acids is governed by the formation of the mono‐amine salts of monobasic acids, and of the mono‐, di‐(and tri‐) amino salts of di‐(and tri‐) basic acids.
Removal of trace amounts of strontium from aqueous solutions by ion flotation. II Continuous scale operation
Authors: Davis B. M. , Sebba F.
Published: July 2010

A flotation circuit operating on a continuous basis has been designed and constructed for removal of Sr ions from simple aqueous solutions. Under steady‐state conditions, a continuous extraction rate of 97.3% has so far been achieved. The effects of changing the gas rate and flow rates of both the Sr and collector solutions were also examined. Finally a discussion is included where the results of these experiments are compared with those from similar continuous‐scale experiments where Sr ions are removed by the technique of foam separation.
The effect of grinding on precipitated magnesium hydroxide
Authors: Gregg S. J. , Saenz J. P.
Published: July 2010

Magnesium hydroxide, prepared by precipitation, was ground in a vibratory ball mill for 733 h. Samples were withdrawn at intervals, and examined by thermogravimetric analysis and by X‐ray diffraction (the broadening of the lines being analysed using integral breadths), and their specific surfaces were determined by adsorption of nitrogen at —183°.

The results indicate that the particles initially consist of small piles of plate‐like crystallites and that they become progressively fractured across their (001) faces, until they are approximately equi‐dimensional. By a process of shearing and re‐adhesion, the piles become increasingly turbostratic in structure, but distortion of the lattice appears only after 350 h. Water is adsorbed on the surface temporarily exposed during grinding and some, at least, of it becomes buried in the interior of the particles.
Residual odour in plasticisers: Measurement of volatile components by a modified glc technique
Authors: Sully B. D. , Janes J. F. , Williams P. L. , Andrews B. R.
Published: July 2010

A method is described for the determination of volatile odorous impurities in plasticisers using a modified GLC technique in which the plasticiser itself acts as its own stationary phase. Assessments made by an odour panel show that for ester‐type plasticisers there is a good correlation with the content of free alcohol down to at least 10 ppm.
The reaction between ethylene and chlorine‐water in a wetted‐wall column. I. The mechanism of reaction
Authors: Dun P. W. , Wood T.
Published: July 2010

A wetted‐wall column was used to measure rates of sorption of ethylene into the following liquids: pure water, aqueous hypochlorous acid, and chlorine‐water acidulated with hydrochloric acid. Experimentally determined diffusivities of ethylene in water, at 20° and 30°, are consistent with previously reported values. The experimental evidence supports Shilov's mechanism viz., that the reaction between ethylene and chlorine‐water takes place via a liquid‐phase complex of ethylene and free chlorine.
The adsorption of benzene vapour from an air stream, by beds of charcoal. II. The rate‐controlling mechanism
Authors: Jones W. M.
Published: July 2010

The rate‐controlling mechanisms discussed are: (i) mass transport of vapour in the air; (ii) an irreversible surface reaction, controlled by a thin, stagnant layer of air around the charcoal granules; (iii) a reversible surface reaction, also controlled by a thin layer of air; (iv) diffusion of vapour into the granules. In each case, a linear equilibrium adsorption isotherm of benzene vapour by charcoal is assumed. An electrical analogue of the uptake (linear isotherm) is described and its use and the results obtained are discussed. It is concluded that diffusion of vapour into the granule as the rate‐controlling mechanism, gives the best description of the observed results.
Thermodynamics of addition polymerisation I. The system trioxane‐polyoxymethylene
Authors: Melia T. P. , Bailey D. , Tyson A.
Published: July 2010

The thermodynamic functions of trioxane have been calculated at various temperatures in the range 0° to 1,000°k. These results have been used in conjunction with previously published data for trioxane and polyoxymethylene to calculate the enthalpy, entropy and free energy changes associated with the polymerisation of trioxane.
The analysis of gypsum plasters and minerals by thermogravimetry
Authors: Keattch C. J.
Published: July 2010

A procedure is described for determining calcium sulphate hydrates by thermogravimetry. the carbonate content, if desired, can also be determined simultaneously. the method has been applied to gypsum plasters and minerals, and has also proved useful in determining the degree of hydration of set gypsum plasters.
Vapour phase adsorption measurements of c6 hydrocarbon mixtures on synthetic faujasite
Authors: Eberly P. E. , Kimberlin C. N. , Baker L. E.
Published: July 2010

A new apparatus is described for measuring pure component isotherms of condensable vapours at temperatures of 25°–150° and pressures up to 600 mm. Facilities are also incorporated into the unit to permit the study of multicomponent adsorption. Without disturbing the adsorption equilibrium, the gas phase can be separated from the adsorbed phase for subsequent analysis by independent methods. With n‐hexane, hexene‐1, 1,5‐hexadiene and benzene on synthetic faujasite at 97°, the pure component isotherms follow the Langmuir equation and the amount adsorbed at saturation has a nearly constant value of 0.23 liq. ml/g. In the adsorption of binary mixtures of benzene and n‐hexane at 97°, the separation factor varies strongly with composition and ranges in value from 13 to 52. A maximum factor is observed at intermediate compositions. Hexene‐1‐n‐hexane mixtures under the same conditions give a lower separation factor of 2–3 which is more nearly constant with composition. Data on multicomponent adsorption of other mixtures are also presented.
The reaction between ethylene and chlorine‐water in a wetted‐wall column. II. Rate equations
Authors: Dun P. W. , Wood T.
Published: July 2010

Second‐order rate constants have been estimated for the reaction at 20° and 30°. The activation energy, 11 kcal per g‐mol., is consistent with other gas‐liquid systems. Prediction of sorption rates based on the theory for very rapid reaction is adequate, provided that the concentration of free chlorine in the liquid phase is known. In solutions containing 0.3n‐HCl the free chlorine concentration is equal to the total dissolved chlorine concentration; but, in aqueous solutions, the free chlorine concentration in the reaction zone appears to be greater than that calculated for equilibrium conditions.
The enrichment of gases of low calorific value with liquefied petroleum gases
Authors: Cross R. A.
Published: July 2010

Equilibria have been established between a lean gas of steam reformer composition and each of a number of light hydrocarbons whose mole fractions in the vapour phase were measured at pressures from 100 to 1000 p.s.i.g. at four temperatures around 0°.

The manner in which the levels of saturation achieved at pressure depend on the molecular forces between the particular hydrocarbon added and each constituent of the gas is demonstrated.

The experimental results enable hydrocarbon dew points to be calculated for a gas, initially of low calorific value, which has been enriched with a commercial hydrocarbon mixture.
Vapour‐liquid equilibria. System: Acetone—hexyl alcohol
Authors: Ramachandra Rao P. , Chiranjivi C. , Dasarao C. J.
Published: July 2010

Isobaric vapour‐liquid equilibrium results have been determined for the binary system acetone‐hexyl alcohol at 760 mm total pressure by use of a Scatchard still. The vapour‐liquid equilibrium results for this system are satisfactorily correlated by Wohl's three‐suffix Margules equations.