bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermal decomposition products of polyvinyl chloride
Authors: Tsuchiya Yoshio , Sumi Kikuo
Published: July 2010

When plastics are involved in a fire they may yield toxic decomposition products. Some quantitative data on the decomposition products of plastics are available in the literature, but it is difficult to assess the danger from the different amounts of various products because of the absence of a suitable method of evaluation. The authors have proposed a method of evaluation based on pyrolysis followed by gas chromatographic analysis and have used it to assess toxicity from various thermal decomposition products of polyvinyl chloride. Hydrogen chloride was found to be the main toxic decomposition product.
Hydrophilation of glass surfaces I. Investigation of possible promoters of filmwise condensation
Authors: Blackman L. C. F. , Harrop R.
Published: July 2010

The tenacity of bonding of various functional groups to glass was investigated by subjecting glass coated with various silanes and quaternary ammonium compounds to steam. Contact angle and infra‐red absorption results indicated that the most strongly attached compounds were polymethylsiloxane and methyl tri‐chlorosilane followed by some quaternary ammonium compounds. Although some compounds bonded strongly they were found to be inefficient promoters of filmwise condensation because they were readily desorbed from the glass surfaces; this throws doubt on the basic hypothesis of orientated monolayer formation for this type of compound. Oxidation of the olefinic bonds of a siloxane film previously adsorbed on a glass surface formed the most strongly bonded hydrophilic coating.
Selective cation exchange resin I. Selectivity towards alkali metals
Authors: Ratner R. , Itzchaki J. , Kohn D. H.
Published: July 2010

A sulphonic cation‐exchange resin, containing nitro groups in the aromatic ring, was shown to have selective properties towards the heavier of the alkali metals.
Precipitate flotation I. Removal of nickel from dilute aqueous solutions and its separation from cobalt
Authors: Mahne E. J. , Pinfold T. A.
Published: July 2010

A new technique, called precipitate flotation of the second kind, in which no surfactant is used to float precipitates, is described. Nickel is completely removed from 1.5 × 10−5 m‐NiCl2 solutions in 3 minutes using a tenfold excess of nioxime. Flotation improves with increasing temperature between 21° and 40° if the pH is in the range 8–11. Increase in ionic strength has no deleterious effect, unlike conventional precipitate flotation. Nickel can be completely separated from a hundredfold excess of cobalt by complexing the latter with nitroso‐R‐salt before flotation. Iron does not float on its own but recoveries of 50% can be achieved by entrainment of ferric hydroxide in nickel nioximate.
Crystallographic characteristics of carbons derived from cellulose and hemi‐cellulose
Authors: Kellett E. A. , Richards B. P.
Published: July 2010

The crystallographic characteristics of carbons derived from both cellulose and hemi‐cellulose are reported. It is shown that, although such carbons normally exhibit little crystal development, the presence of impurities at the calcining stage catalyses the graphitisation process.

X‐ray examination indicated that the high degree of directional orientation present in the untreated fibres is not carried over into the carbon material produced by heat‐treatment.

Results of electron microscope and X‐ray small‐angle scattering studies are used to demonstrate the existence of a complex pore structure which changes with temperature of heat‐treatment.

Crystal thermal expansion results indicate a large coefficient perpendicular to the layer planes, comparable in magnitude with those observed in graphitic carbons. This fact, together with helium density measurements, indicates that the crystallites in cellulose carbons consist essentially of graphite‐like layers in a ‘turbo‐stratic’ stack.
Infra‐red absorption spectra of ion‐exchange resins
Authors: Whittington D. , Millar J. R.
Published: July 2010

Infra‐red absorption spectra have been obtained by the KBr disc technique for some fifty commercial ion‐exchange resins with quaternary ammonium, tertiary and mixed amine, sulphonic, phosphonic, secondary phosphate, and carboxylic groups, as well as for a number of experimental resins, including some of the solvent‐modified type. The use of the technique in structural characterisation of ion‐exchange resins is discussed.
Alternative methods of calculating particle size from hindered settling measurements
Authors: Dollimore D. , McBride G. B.
Published: July 2010

The derivation of the Steinour equation is discussed in detail and the calculation of particle size critically examined. A new method of calculation is introduced which may facilitate the use of hindered settling as an industrial analytical tool.
FOam separation of colloidal particulates: Rate studies
Authors: Grieves R. B. , Bhattacharyya D.
Published: July 2010

An experimental investigation is presented of the rate of foam separation of colloidal ferric oxide from aqueous suspension. A cationic surfactant in initial concentrations of from 0·05 to 0·13 mmole/1 is used with negatively charged ferric oxide at pH 10·8. An anionic surfactant in initial concentrations of from 0·03 to 0·10 mmole/1 is used with positively charged ferric oxide at pH 5·8. The initial concentrations of particulates are 2·38 and 1·67 mmole/1, as trivalent iron. The process involves variable volumes and a consideration of relative rates of adsorption and foam separation. The rates of removal of surfactant are directly proportional to the quantities of surfactant in the residual suspension and are independent of the quantities of particulates. The rates of removal of particles are directly proportional to the surfactant to particulate ratio in the residual suspension and are a power function of the quantity of particulates in the residual suspension. In one case, the initial surfactant concentration is significant. The relations obtained are accurate to about 15% for the surfactant removals and to about 24% for the particulate removals; these are reasonable considering process complexities.
Diffusion and mass transfer of ammonium and potassium chloride in aqueous solution
Authors: Nienow A. W. , Unahabhokha R. , Mullin J. W.
Published: July 2010

Differential diffusion coefficients of the systems KClH2O and NH4ClH2O have been measured at 20° by an interferometric technique, over a range of concentration up to saturation. Integral diffusivities have been calculated from these differential coefficients, and it is shown that the former are the preferred quantities to use in the standard mass transfer correlations.
Microbiological deterioration of rubbers and plastics
Authors: Heap Wendy M. , Morrell S. H.
Published: July 2010

The effects of micro‐organisms on rubbers and plastics are reviewed, with reference to the chemical nature of the polymers and their possible additives. The confused and sometimes contradictory nature of the evidence is indicated, and it is concluded that both synthetic and naturally‐occurring polymers are attacked but it is not possible at this stage to say which chemical groups in each polymer are susceptible.
Precipitate flotation. III. Parameters of precipitate flotation of the first kind
Authors: Sheiham I. , Pinfold T. A.
Published: July 2010

Precipitates of strontium carbonate (10−3 mole litre−1) were floated using dodecylpyridinium chloride, hexadecylpyridinium bromide, hexadecyltrimethylammonium chloride and a dialkyldimethylammonium chloride. Flotations were performed at a gas flow‐rate of 7 litre hour−1 for 3 minutes or 2 litre hour−1 for 20 minutes. Complete recoveries were possible by both methods, provided optimum concentrations of collector were used. If too little collector was present, redispersion of precipitate occurred because the foam formed was insufficient to support it. With too much collector, the precipitate was excluded from the bubbles and also became coated by a double layer of collector which gave a hydrophilic surface.

Increase of temperature and of time allowed for precipitation, improved recoveries because of increased particle size. Flotations were not complete below 10−3 m unless the strontium carbonate was co‐precipitated in calcium carbonate, when 10−8 m could be recovered. Increased ionic strength reduced recoveries because it caused precipitation to be slower, attachment of collector to the precipitate to be less secure, flotation of the collector to be more rapid and foam drainage, and hence redispersion, to increase.
Mechanism for the anti‐redeposition action of sodium carboxy‐methyl cellulose with cotton. IV. Practical‐scale tests
Authors: Johnson G. A. , Foster F. G.
Published: July 2010

A variety of cotton articles—such as tea towels, hand towels, and sheets—and test cloths, both cambric and sheeting, have been washed in a ‘Hotpoint’ Empress washing machine in a heavy‐duty detergent product containing radioactive sodium carboxy‐methyl cellulose (SCMC). There was good agreement between the results of laboratory tests using small discs of fabric and results of the practical test. Even when the cotton fabrics had been pre‐washed up to 25 times in a product containing SCMC, some SCMC was still adsorbed (up to 40 μg/g of fabric) in each wash. It is suggested that in each wash some SCMC desorbs from the fabric and is replaced by SCMC adsorbed from solution.
Oil on wet coal—Measurement of contact angle by a suction method
Authors: Clark W. C. , Mason G.
Published: July 2010

A suction potential method is described for the measurement of contact angles in oil‐water‐coal systems. The technique obviates the need to pack identical beds of wet coal. The effect of oiling upon the flow properties of wet fine coal is discussed in the light of these measurements.
Preparation of dialkoxyphosphinothioylthioacetamide insecticides
Authors: Carter P. L. , Lambie A. J. , Lane D. W. J.
Published: July 2010

Dialkoxyphosphinothioylthioacetamides may be prepared conveniently in good yields and high purity from the reaction between dialkoxyphosphinothioylthioacetic acetic anhydrides and the appropriate amine. The necessary mixed anhydrides were readily prepared under very mild conditions by allowing keten to react with a dialkoxyphosphinothioylthioacetic acid in acetone. The method was applied to the preparation of both dimethoxy‐ and diethoxyphosphinothioylthioacetic anhydrides. The former was then interacted with methylamine to yield N‐methyl dimethoxyphosphinothioylthioacetamide (dimethoate) or with morpholine to yield N‐(dimethoxyphosphinothioylthioacetyl) morpholine. The diethoxy compound was converted to diethoxyphosphinothioylthioacetamide with ammonia. An alternative approach via the acid halides was examined. For this purpose dimethoxyphosphinothioylthioacetyl chloride and diethoxyphosphinothioylthioacetyl chloride and fluoride were prepared. They could not be obtained pure. The alkaline hydrolysis rates of dimethoxy‐ and diethoxyphosphinothioylthioacetic acids were determined and the acid dissociation constant of the latter compound was obtained by two methods.
Persistence of bubbles on inorganic salt solutions
Authors: Bikerman J. J.
Published: July 2010

The lifetime, t, of single bubbles on aqueous solutions of sodium chloride, sodium bromide, sodium sulphate, potassium chloride, magnesium chloride and two salt mixtures was determined. It was almost independent of the salt used, slightly increased with the concentration (e.g., 0·07, 0·09, 0·12 and 0·13 sec for 1·2, 3, 12 and 20% NaCl respectively and bubble diameters, d, between 0·007 and 0·19 cm), was not affected by d as long as this was between 0·002 and 0·06 cm, but was greater (1 sec) when d was 0·08–0·13 cm. The lifetime of mixtures exceeded that of the constituents. The absolute values of t were smaller than those recorded in the literature indicating the extreme sensitivity of bubble persistance to traces of impurities. The effect of d on t, so different from that in detergent solutions, is qualitatively explained.
Influence of amorphous Al(OH)3 on the hydration of tricalcium aluminate
Authors: de Jong J. G. M. , Stein H. N. , Stevels J. M.
Published: July 2010

The influence of amorphous Al(OH)3 on the hydration of tricalcium aluminate was investigated in pastes and in suspensions. In suspensions it was found that amorphous Al(OH)3 started to dissolve almost immediately, and a stage was passed in which most of the anions present in the aqueous phase were polymeric aluminate units. Paste hydration results could be understood by assuming that highly soluble amorphous Al(OH)3 dissolved and, by so doing, adjusted the concentrations in the aqueous phase so as to cause precipitation of some less soluble form of Al(OH)3, thereby retarding hydration.
Quantitative determination of uncombined MgO in portland cement clinker by X‐ray diffractometry
Authors: Rehsi S. S. , Majumdar A. J.
Published: July 2010

A quantitative X‐ray diffractometric method using corundum (α‐Al2O3) as an external standard has been developed for estimating uncombined MgO in high‐magnesia cement clinkers. For these clinkers, separation of the silicate phases by selective hydrolysis is not necessary.

The X‐ray method has provided results reproducible to ± 0·5% and it compares favourably with chemical methods. The non‐destructive nature of the test and its rapidity are the main advantages.
Electron‐activated cracking of gaseous hydrocarbons. II Further results with methane in anomalous glow‐discharges at reduced pressure
Authors: Hesp W. R. , Rigby D.
Published: July 2010

In the course of optimisation studies on the cracking of methane in anomalous glow‐discharges (50 Hz a.c., maximum potential 2000 V, maximum current 300 mA) at sub‐atmospheric pressures (20–270 torr), high yields (up to 80% per pass) of acetylene were obtained. The effects of pressure, contact time, reactor geometry, cooling of reactor wall, pre‐heating of reactant, and solid‐ and vapour‐phase catalysis, as well as the role and mode of decomposition reactions, have been investigated. Further evidence was obtained on the role of electron activation in these reactions. By optimisation of the reaction conditions, it proved possible to achieve a considerable reduction in the specific consumption of electrical energy.
Synthesis of acetic acid and acetone by oxidation of hexanes
Authors: Rouchaud J. , Lutete B.
Published: July 2010

N‐Hexane and 2,3‐dimethylbutane were oxidised separately and as a mixture, in the liquid phase by oxygen at 160°, under 25 atm. pressure and in the presence of 0·30 wt.‐% of manganese as the naphthenate. The variables of the reaction which influence the yield of acetic acid and acetone were studied. It has been shown that the co‐oxidation of a mixture of linear and branched hydrocarbons increases the yield of useful products, and the rate of oxidation. The effect of the molecular structure of the hydrocarbons in the co‐oxidation systems is briefly discussed in relation to the theory of the degenerately branched chain reactions.
Reverse osmosis applied to the recovery of water from aqueous salt solutions
Authors: Shor S. M. , Thodos G.
Published: July 2010

A cellulose acetate membrane was applied to the study of reverse osmosis on aqueous solutions of LiCl, NaCl, KCl, CaCl2, SrCl2 and BaCl2. This membrane, 71 microns thick and having an effective diameter of 1 1/2 in. was mounted within a specially constructed cell, made of stainless steel and designed to withstand pressures up to 1500 psi. The cell consisted of two chambers, which were separated by the membrane, and a porous plate supporting it. Solutions of 0·05 N, for all of these salts, were used to establish the osmotic pressure of each solution, the water fluxes through the membrane, and the extent of salt rejection. These variables were also determined for NaCl normalities of 0·2 and 0·6. On a single pass basis, the salt rejections ranged from 76% for KCl up to 95% for CaCl2.

The results are discussed in terms of the size of the hydrated cation. The water fluxes for all these solutions were found to be essentially the same and were independent of the type of salt. For solutions of 0·05 N, the water fluxes ranged from zero at the osmotic pressure up to about 44 × 10−5 g sec−1cm−2 (8·8 gal day−1ft−2) at 800 psi and 77°F. Also, for the 0·05 N‐NaCl solution, the temperature was varied from 77°F to 120°F. The results of this temperature study show that the extent of salt rejection remains essentially fixed, while the water flux at any given pressure at 120°F becomes nearly double that of 77°F.
Application of thermal analysis in investigations on calcium silicate bricks
Authors: Coldrey J. M. , Purton M. J.
Published: July 2010

The principles of differential thermal analysis and thermogravimetric analysis are outlined and two examples of their application to autoclaved calcium silicate products are given. The proportions of calcium hydroxide and calcium carbonate in samples can be estimated. Useful information on calcium hydrosilicate binding materials can be obtained in experiments where the number of variables is strictly controlled.
Radiometric studies of mercury loss from fungicidal paints. 1. Loss of phenyl mercuric acetate
Authors: Taylor C. G. , Tickle W.
Published: July 2010

Exposure tests have been made on paint films prepared from an emulsion paint containing phenyl mercuric acetate (PMA) labelled with 203Hg. Loss of mercury from the films has been followed radiometrically.

Films exposed indoors in a confined space (no air circulation) showed little, if any, mercury loss for up to 8 months. Films exposed in the open laboratory lost from 20 to more than 60% of mercury after 250 days. This agrees qualitatively with the results of other workers on similar paints. At 50°, films lost mercury at rates about 10 times greater than those at ambient temperature.

Films exposed out‐of‐doors lost the majority of their mercury after a few days of rain. Pre‐treatment of films, e.g. by u.v. radiation, had no effect on their subsequent outdoor behaviour. Even well‐dried films lost mercury at the same rate as newly applied films.

Films with a low PMA content (0·02% Hg) lost mercury at a higher percentage rate than films with a high one (0·2% Hg). Thick films (0·002 in.) lost mercury at a lower rate than thin ones (0·001 in.). A mercury‐free top coat also reduced loss rate. All loss rates decreased with increasing time. These trends applied to all the exposure conditions studied.

Mercury loss appears to be due to both volatilisation and dissolution of PMA and not to decomposition. The results indicate a non‐homogeneous distribution of PMA throughout the paint film, and a diffusion‐controlled process.
Radiometric studies of mercury loss from fungicidal paints. II. Comparison of three phenyl mercury compounds
Authors: Taylor C. G. , Tickle W. , Dwyer A.
Published: July 2010

The fungicides, phenyl mercuric dodecyl succinate (PMS) and phenyl mercuric dimethyldithiocarbamate (PMDDC), have been prepared labelled with 203Hg. Comparative exposure tests have been carried out on emulsion paints each containing one of the labelled compounds phenyl mercuric acetate (PMA), PMS, or PMDDC.

After 236 days of indoor exposure, approximate losses from films are 60 (PMA), 50 (PMS), and 20% (PMDDC). Relative losses from films of low‐Hg content (0·02%) are a few per cent higher than those from comparable films of high‐Hg content (0·2%).

After 56 days of outdoor exposure, approximate losses are 95 (PMA), 90 (PMS), and 40% (PMDDC). PMS and PMDCC films of high‐Hg content show relative losses slightly higher than those of low‐Hg content; a behaviour opposite to that of PMA films. This may be due to the distribution of PMS or PMDDC through a paint film being less uniform than that of PMA. A correlation between mercury loss and rainfall is observed for all three fungicides.

The loss rates from all films decrease with time during indoor exposure. Out‐of‐doors, this decrease becomes well defined only when a substantial portion of the fungicide has been removed by rain.

The results indicate that in emulsion paint films, under the exposure conditions used in this work, PMS is retained slightly better than PMA, but that PMDDC is retained much better than either. The high retention of PMDDC is probably due to its low saturation vapour pressure and to its low solubility in water.

The solubility of PMDDC in water at 20° has been determined radiometrically as 5·7 ppm.
Recovery of plutonium from non‐irradiated refractory plutonium and uranium‐plutonium oxides, nitrides and carbides
Authors: Maurice M. J. , Fischer J. , Kramer G. N.
Published: July 2010

In the recovery of plutonium from high‐fired uranium‐plutonium oxides dissolution is the most critical step. It has been found that 100% solid solutions of uranium‐plutonium oxides are readily soluble in 14 m nitric acid. A procedure has been developed to convert any mixed oxide completely into a solid solution, so that dissolution is faster than the usual direct dissolution in nitric acid‐hydrofluoric acid. The use of the latter acid is thus avoided. Nitrides and carbides are oxidised to oxides which are subsequently dissolved in pure concentrated nitric acid. Detailed procedures are given.
Catalytic hydrogenolysis of saccharides. II. Formation of glycerol
Authors: van Ling G. , Vlugter J. C.
Published: July 2010

The selectivity of the formation of glycerol from saccharides and hexitols by catalytic hydrogenolysis is determined by a number of reaction variables. Evaluation of the results of variations in operating conditions was effected by the use of the parameters: cleavage selectivity, hydrogenation selectivity, and cleavage percentage. There were strong indications that the cleavage selectivity was controlled by the molecular structure of the saccharide used, being considerably higher for a fructofuranose structure than for a pyranose one.

The main reactions were cracking, isomerisation, acid formation, hydrogenation, dehydrogenation, and dehydration. Of these, cracking and hydrogenation reactions had the greatest influence on the glycerol yield. The choice of the catalyst is difficult, because of the conflicting demands for maximum hydrogenation selectivity and maximum cleavage percentage.
Structure and activity of platinum–silica catalysts prepared by a combustion process
Authors: Schachner H. , Bollmann W. , Baumberger B.
Published: July 2010

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

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

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

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

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

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

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

A silica sol was frozen and then thawed yielding a suspension of plate‐like silica which when dried gave a sample which was almost entirely composed of micropores. The silica aged when left to stand in the laboratory, but reached a constant value of activity after a period of about six months or less. No apparent change in microporosity occurred during the ageing process.

Several selected samples were sintered at temperatures up to 800° at which point virtually all the adsorption capacity of the adsorbent was destroyed leaving adsorption to take place only on the external surface.
The lime‐silica‐water system: Equilibria at bulk calcium/silicon ratios of 1·5–2·5 AT 180–250°C
Authors: Ahmed A. H. M. , Taylor H. F. W.
Published: July 2010

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

Examples of formation of troublesome deposits containing ellagic acid in the wood pulping process are mentioned. The deposit from one such process in the U.K. has been examined in detail. This paper is mainly devoted to the determination of some physico‐chemical properties of ellagic acid, which are relevant to the study of minimising the formation of the deposit in the wood digester.

A specially built apparatus was used for the determination of these properties at 170° (the normal digestion temperature). The ultra‐violet and visible absorption spectra measured at different pH values and temperatures were used to determine a dissociation constant of the acid at 20° which was found to be 11·0. The solubility of the acid was determined at 20°, 90° and 170°.

From the changes in absorbance at 250 nm the decomposition was found to consist of two consecutive firstorder reactions, the rate constant of the first reaction being inversely proportional to a fractional power of hydrogen ion concentration.

The activation energy was estimated to be 5·5 kcal and was independent of pH value.
Epoxidation of ethylenic linkages by chromic acid. III. The course of oxidation of mono‐aryl aliphatic olefins by chromic oxide
Authors: Moussa G. E. M. , Eweiss N. F.
Published: July 2010

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

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

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

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

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

A modified form of an oscillating baffle column previously described by Thomas in which horizontal stator rings are introduced is studied. A theoretical technique is described for establishing true values for the number of transfer units for the continuous phase and disperse phase, NTUc and NTUd.
Valving system for a waste‐heat still
Authors: Aldrich B. M.
Published: July 2010

A pressure‐differential system is described for controlling the flow of water between chambers of a waste‐heat still used to generate potable water from brackish water or sea water.
Formation and surface properties of electron‐emissive coatings III. Thermal decomposition and sintering of some co‐precipitated alkaline‐earth carbonates
Authors: Judd M. D. , Pope M. I.
Published: July 2010

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

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

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

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

The solubilities of hydrogen halides (HCl, HBr, HI), expressed as xHX moles of HX per mole of a liquid compound, have been determined for a representative selection of compounds at room temperature and below to reveal an essential pattern of behaviour to serve as a guide in operational procedures. Compared with the values predicted by Raoult's law at 0° (xHCl = 0.04, xHBr = 0.09, xHI = 0.37), liquids such as n‐heptane and carbon tetrachloride have slightly lower x values, but show increasing divergence on the low side as the temperature is lowered. Other liquids, such as toluene and alkyl halides, have values greater than those predicted by Raoult's law at 0°, and xHX remains correspondingly higher at the lower temperatures. The xHX values for many liquids can be from 2 to 6 times as great as those for water: xHCl = 0.41, xHBr = 0.49, xHI = 0.39 at 0°.

From a consideration of pressure and other effects, a reference pattern of the constitution of the solutions is given. For the non‐aqueous liquids, xHX values greater than Raoult's law values are deemed to be the result of definite chemical reactions involving hydrogen bonding and dynamic equilibria. A case is presented for the desirability of the readjustment of attitudes towards acid‐base function in operational chemistry.
Kinetics of the calcination of calcium sulphate dihydrate
Authors: Taylor J. B. , Baines J. E.
Published: July 2010

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

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

A study was made of the feasibility of using coal as an adsorbent material for the removal of sulphur dioxide from stack gases emitted to the atmosphere by different industries.

From preliminary results, it would appear that coal is to be favoured by a raw materials/cost‐effectiveness ratio of 2:1.

The work shows semi‐quantitatively that the adsorptive capacity of sulphur dioxide on coal varies slightly from one coal to another and that when coal is used and re‐used through numerous (˜40) cycles, its effectiveness as an adsorbent for sulphur dioxide is not greatly reduced.

Moreover, this research supports the view that the heating value, ash, sulphur content, etc. of most types of coal changes only slightly after repeated usage as an adsorbent for sulphur dioxide. If, as these findings indicate, coal can initially be used as a sulphur dioxide adsorbent prior to its use as a fuel, economic potential for commercial applications should be enhanced.

Empirical equations, developed to correlate the adsorption‐desorption characteristics of different coals, can be used as a basis for prediction and comparison by future investigators to further explore this research.
Crystal habit modification studies with ammonium and potassium dihydrogen phosphate
Authors: Mullin J. W. , Amatavivadhana A. , Chakraborty M.
Published: July 2010

Face rates of growth of ammonium and potassium dihydrogen phosphate crystals have been measured for crystallisation from pure solutions and from solutions that contained known amounts of foreign ions. The level of supersaturation and the solution pH both effect the crystal habit. Low supersaturation at normal pH (3.8) tends to give tapered crystals, and at a slightly higher pH (˜5), the linear growth rates of both principal axes are considerably increased. The presence of foreign ions such as Cr3+, Fe3+ and Al3+ in low concentrations (˜ 1 × 10−3 g ion/1 or ˜ 50 ppm) also causes a tapering habit.

A mechanism of habit modification based on the presence of aquo ions at the crystal face is suggested.
Radical intermediates III. Infra‐red spectra of alkali‐metal nitrobenzenides
Authors: Gross J. M. , Barnes J. D. , Brown J. K.
Published: July 2010

The infra‐red spectra of alkali‐metal nitrobenzenides are reported and compared with that of nitrobenzene. Tentative assignments of some of the major bands are proposed.
Adsorption of alcohols on finely divided powders
Authors: Allen T. , Patel R. M.
Published: July 2010

The flow micro‐calorimeter has been used for the determination of energies of adsorption at monolayer coverage (mcal/g of powder) from solution for a homologous series of long‐chain alcohols, the solvent in each case being n‐heptane. The results show that the energies increase with increase in length of the carbon chain until the chain has six carbon atoms; the energies then fall to a constant value.

The area occupied by one adsorbed molecule increases slowly at first, more rapidly for a chain length of four to eight carbon atoms and then approaches a constant value. The heat of adsorption (kcal/mole of solute adsorbed) rises rapidly at first and smoothes off to a constant value as the length of the carbon chain increases above ten.

It is suggested that this indicates that the molecules orientate themselves in the form of a spiral with six carbon atoms on the surface of the solid; this requires a bond angle of 120° which is in agreement with the findings of Calvet & Astruc.
Reaction between mono‐oxiranes and alkyl or aryl (aminoalkoxy)silanes
Authors: Emblem H. G.
Published: July 2010

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

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

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

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

The samples studied were two types of magnesite containing calcium oxide (dolomite) as the principal impurity. Mixes were made with appropriate addition of serpentine and/or chromite rocks and an attempt was made to assess their suitability as magnesite refractories.

The phase reactions that occurred during the firing at 1600° of refractory body mixes containing the five‐component system CaO‐MgO‐Fe2O3‐Al2O3‐SiO2 and the six‐component system CaO‐MgO‐Fe2O3‐Al2O3‐Cr2O3‐SiO2 were investigated

The free lime content and the phase constituents of the fired mixes, determined experimentally and calculated from the available thermal equilibrium data, were in close agreement, which indicated that the chemical reactions had attained equilibrium in the fired mixes.

The physical and refractory properties of the selected mixes were found to comply with the standard international specifications.
Laboratory studies on solvent extraction of low‐temperature tar oils by aqueous sodium salicylate
Authors: Raj P. , Khaleel Akmal M. A. , Subba Rao Y. V. , Moinuddin Ahmed S. , Vaidyeswaran R.
Published: July 2010

The use of aqueous saturated sodium salicylate for the extraction of tar acids from a low‐temperature tar fraction is discussed. Solubility and equilibrium data for the system:neutral oil‐tar acids‐aqueous sodium salicylate when plotted on a ternary diagram showed two types of curves: an ordinary bite type and another a loop containing solid and liquid phases. The tie‐line data agree with most of the empirical relationships reported in the literature. The plait point for the system had a tar acid concentration of 47%. The results have been compared with the earlier data for the system: phenol‐α‐methylnaphthalene‐aqueous sodium salicylate.
Performance of a rotating disc contactor using the system carbon tetrachloride–acetic acid–water
Authors: Thomas W. J.
Published: July 2010

A typical rotating disc contactor of small scale was examined using the system carbon tetrachloride–acetic acid–water. The efficiency of extraction was established experimentally for a range of operating variables including rotational speed and phase flow rates and ratios. The results are compared with those of Russian authors for the same liquid system.
Reactions of saturated hydrocarbons I. Oxidation of isoparaffins by chromic acid
Authors: Moussa G. E. M. , Omar M. T.
Published: July 2010

Measurements of the rate of reduction of chromium(VI) oxide in acetic acid–acetic anhydride solution by 2‐methyl‐pentane, 3‐methylpentane, 2,3‐dimethylbutane and 2,4‐dimethylpentane show that the initial rate depends on the number and nature of carbon atoms in the hydrocarbon. When steric or other interaction effects prevail between adjacent atoms or groups in the molecule, these effects also influence the rate.

The values obtained for the oxidation rates agree with those calculated from a proposed expression (Rnp+R'ns+R'nt)/(np+ns+nt) based on the formula of Chambers & Ubbelohde.
Analysis of brake fluids by gel permeation chromatography
Authors: Lambert A.
Published: July 2010

The non‐volatile component of a brake fluid can be identified by comparing the gel permeation chromatogram of the fluid with those of a range of possible non‐volatile components.