bluuebunny/crossref_metadata_2025_split huggingface dataset:
Surface properties of hydrolysed titania. IV. Rates of sorption on porous titania
Authors: Harris M. R. , Whitaker G. 
Published: July 2010

AbstractA technique is described by means of which the pressure changes accompanying the sorption of a gas by a solid adsorbent at −195.8° in a conventional low‐temperature volumetric adsorption apparatus can be followed on a pen recorder. Measurements of both the rates of adsorption and desorption have been taken at all parts of the isotherms for a wide range of samples of hydrolysed titania. Both adsorption and desorption processes have been shown to follow first‐order kinetics. Since the sorption is not isobaric, the rate‐constants calculated from these results will not be the absolute values, but are sufficiently accurate to show quite clearly the relationship existing between pore'size and rate of sorption. For a particular sample, sorption is slowest when it is taking place into or out of a pore. Thus a slow rate of sorption has been used to indicate the presence of pores in a sample even though no hysteresis is shown; this confirms other evidence which indicates the presence of pores in this type of sample. A comparison of rates of sorption between samples of known pore radii shows that, in general, the greater the pore radius, the slower is the rate with which adsorption or desorption takes place. This has been taken to indicate that diffusion in the sorbed layers predominates over gas‐phase diffusion when sorption is occurring in a pore. Certain desorption points show two different values for the first‐order rate constant, the changeover being after about 70% of sorbate has been desorbed. This is considered to correspond to evaporation from the liquid‐like surface in the pore, followed by diffusion through the adsorbed film once liquid has ceased to exist in the pore.
The absorption of carbon monoxide in an aqueous solution of cuprous ammonium lactate in a packed tower
Authors: Thomas W. J. , Watkins S. B. 
Published: July 2010

AbstractThe mechanism of the absorption of carbon monoxide by an aqueous solution of cuprous ammonium lactate is considered, and equilibrium isotherms and an equation relating temperature and the equilibrium constant are established.Pilot plant studies give values for HOL and KLa, and the effects of gas and liquid flow rates on mass transfer coefficients are determined.The solution is viscous and has a surface tension which differs considerably from that of water. The viability of published equations for predicting coefficients and interfacial area are appraised.
The mechanism of electrophoretic deposition
Authors: Brown D. R. , Salt F. W. 
Published: July 2010

AbstractThe conditions under which electrophoretic deposits can be formed from suspensions of a number of metallic and non‐metallic materials have been established, and the zeta‐potentials of the materials have been measured. Calculated values of the minimum field‐strength required to overcome the repulsion between the particles show agreement with the observed values for some materials. For other materials, particularly metallic powders, it is not possible to apply sufficient force by the field to overcome this repulsion. Addition of a suitable amount of certain electrolytes, for example 10−3 M‐aluminium chloride, results in very adherent deposits. Under these conditions the electrolytic reaction produces a binder, such as a polymeric hydroxide, at the cathode, so that the adhesion of the deposit no longer depends only on the London‐van der Waals attractive forces between the original particles.
The reaction of oxygen with metallic chlorides
Authors: Allen J. A. , Clark A. J. 
Published: July 2010

AbstractThe reaction of oxygen with the solid chlorides of copper (I), copper (II), magnesium and yttrium has been examined at temperatures in the range 200—450° and at pressures below 20 cm Hg, in order to try to clarify the behaviour of these chlorides in Deacon and oxychlorination catalysts. Copper (II) chloride neither adsorbs nor reacts with oxygen, while the lower chloride readily reacts to form CuO,CuCl2 (or a mixture of CuO and CuCl2). Both magnesium and yttrium chlorides react to form their respective oxides. For magnesium chloride the reaction proceeds without limit except at the highest temperature studied, while for yttrium chloride the extent of reaction approaches a limiting value. These results are related to energetic criteria previously proposed for these catalysts and the possible need (i) to achieve physical dispersion of the copper (I) chloride in these systems, and (ii) to include only components which exhibit limited, rapid oxygen saturation are indicated.
Electrodeposition of some metals from tetramethylurea
Authors: Billinghurst R. G. , Rajki J. , Rutherford K. G. 
Published: July 2010

AbstractZinc, cadmium and bismuth have been electrodeposited on copper from tetramethylurea, a new organic electrolyte. The nature of the deposits so obtained was good. A more quantitative treatment of the electro‐deposition of these metals from this solvent is suggested.
Separation of o‐ and p‐chloronitrobenzene by solvent extraction. I
Authors: Hanson C. , Patel A. N. 
Published: July 2010

AbstractPhase equilibrium data have been determined for o‐ and p‐chloronitrobenzene in systems containing methanol (both anhydrous and containing 10% v/v water) and n‐heptane and have been used to evaluate the possibility of using distribution between these solvents as a means of separating a mixture of the isomers.
Reduction of hematite with hydrogen in fixed and fluidised beds
Authors: Venkitakrishnan G. R. , Bhat G. N. 
Published: July 2010

AbstractReduction of hematite with hydrogen has been carried out in fixed and fluidised beds at identical gas flow rates. Influence of gas velocity and particle size has been ascertained. The performances of the two types of bed for the reduction of hematite with hydrogen have been compared. The observed difference in performance is considered to be primarily due to the solids movement characteristics of systems studied. This is also influenced by the bubbling phenomena occurring in fluidised systems.
The thermal decomposition of ammonium nitrate in fused salt solution and in the presence of added salts
Authors: Barclay K. S. , Crewe J. M. 
Published: July 2010

AbstractThe thermal decomposition of ammonium nitrate in a fused equimolar mixture of sodium and potassium nitrates has been studied. It is shown that the reaction is first order with respect to ammonium ions. the rate of decomposition is increased by cations of a highly polarising nature, whereas anions, such as sulphates, phosphates and fluorides, which act as bases in the system, decrease the rate of decomposition. the observations are in accord with an ionic mechanism for the decomposition of ammonium nitrate, involving the reaction of ammonia with the nitronium ion.
Reaction of silica with tetraethyl orthosilicate
Authors: Duffy J. V. 
Published: July 2010

AbstractThe reaction of tetraethyl orthosilicate with fumed silica at various temperatures was investigated by means of infra‐red spectroscopy and gas chromatography. It was found that essentially no reaction occurred at 25° while at 100°, traces of reaction by‐products were detected after short reaction periods. When the reaction temperature was raised to 165°, the condensation reaction proceeded with both hydrated and predried silica glass. It was shown that silanol sites on the glass do take part in a reaction which results in the formation of new siloxane bonds. These sites can be rehydrated after thermal degradation of the treated surfaces in vacuum.
Solvent effects in the oxidation of sulphur compounds. Anionic oxidation of high molecular weight thiols and disulphides to sulphonate salts
Authors: Wallace T. J. , Schriesheim A. 
Published: July 2010

AbstractThe base‐catalysed oxidation of high molecular‐weight aliphatic thiols and disulphides to sulphonate salts by molecular oxygen has been studied from 23.5° to 80°. The preferred solvent was hexamethylphosphoramide. Generally, yields and selectivities of the sulphonate salts varied from 95 to 99% at 80°. Potassium and sodium hydroxides were equally effective as the base catalysts. Other solvents and bases were explored and factors which control selectivity to the final product determined. The reactions are believed to involve sulphenate ions produced by attack of hydroxide ion on the disulphide linkage. Such species are unstable and may be oxidised directly by oxygen or disproportionate to sulphonate ions and disulphides.
Effect of vanadium pentoxide on gas‐phase combustion. II. The methane‐oxygen system
Authors: Matthews C. J. , Tipper C. F. H. 
Published: July 2010

AbstractThe slow combustion of methane in a static system, using reaction vessels coated with vanadium pentoxide, has been studied. Coating a vessel eliminated autocatalysis and retarded the oxidation, the rate of which was only measurable at above 500°. Both the overall order (5.9) and the overall activation energy (about 78 kcal/mole) were very high and the initial rate was markedly dependent on the pressure and nature of added inert gas. The products were carbon monoxide, carbon dioxide (CO/CO2 ratio about one) and water, with only traces of formaldehyde and formic acid. Packing the coated vessel virtually eliminated the pressure change, the products being almost exclusively CO2, but did not appreciably alter the rate of consumption of methane.It is concluded that the oxidation involves an unbranched chain mechanism, in which both initiation and termination occur on the walls and the propagation reactions are:

the formaldehyde being rapidly oxidised at the surface so that it cannot act as a branching agent.
Multi‐stage computations for continuous gas chromatography
Authors: Tiley P. F. 
Published: July 2010

AbstractResults are presented of digital computations for a Lewis—Matheson stage‐to‐stage analysis of continuous gas chromatography. for most of the work a column of 80 stages was assumed, but some computations were successfully made for 190 stages.Three semi‐hypothetical binary volatile mixtures were considered in turn and it was assumed that each formed a non‐ideal ternary liquid phase with an involatile solvent. on optimising the ratio of carrier‐gas to solvent flow, it is shown that the efficiency of the separation is dependent both on the ratio of solvent to mixture feed flow and also on the column temperature. The temperature effect is considered in some detail in terms of stripping factor profiles, and is shown to be quite distinct from any temperature‐dependency of the relative volatility.A comparison is made between the results of the stage‐to‐stage analysis and those of standard short‐cut methods.
Thermal treatment of thorium oxide gel at low temperatures
Authors: Mikhail R. Sh. , Fahim R. B. 
Published: July 2010

AbstractInvestigations were carried out on the variation of the specific surface area of thorium oxide gel upon thermal treatment in air at temperatures between 35° and 1000°The specific surface areas and pore volumes of the parent gel and its various dehydration products were calculated from the adsorption of nitrogen at the temperature of liquid nitrogen. The results obtained were compared with those measured from the adsorption of water, methanol and cyclohexane. The adsorbates were chosen to possess different molar volumes and polarities. Water was used because of its known ability to interact with thoria, and the extent to which this interaction limited its use was tested.X‐ray and thermogravimetric analyses were also investigated, and certain structural changes after thermal treatment were noticed. The gel was amorphous to X‐rays at temperatures up to 300°, and then it recrystallised to the cubic ThO2. Below 300°, the surface area decreased continuously, probably by a mechanism of diffusion and material transport from wider pores to fill fine pores ( ‘surface annealing’). This was followed at higher temperatures by a crystallisation (activation) stage, and finally, by a sintering or crystal growth stage.
Growth kinetics of ammonium‐ and potassium‐dihydrogen phosphate crystals
Authors: Mullin J. W. , Amatavivadhana A. 
Published: July 2010

AbstractGrowth rates of ammonium‐ and potassium‐dihydrogen phosphate crystal faces have been measured in a simple laboratory apparatus under carefully controlled conditions of temperature, supersaturation and solution velocity. The growth process, which was found to be second‐order with respect to the supersaturation, is considered to be controlled by surface reaction.Growth rates of the ammonium salt (ADP) are much higher than those of the potassium‐salt (KDP) under equivalent conditions. It is suggested that this is due to the occurrence of hydrogen bonding between ADP molecules, which give larger integrating units (thicker growth layers) than occur with KDP.
The properties of the electrical double layer at a dropping mercury electrode in n‐potassium chloride containing n‐alkyltrimethylammonium ions
Authors: Meakins R. J. 
Published: July 2010

AbstractIn further experiments on the adsorption of n‐alkyltrimethylammonium corrosion inhibitors at a dropping mercury electrode in N‐potassium chloride solution, the potential applied to the dropping mercury electrode was taken as far as ‐1.9 volts S.C.E. The electrocapillary and differential capacitance curves for n‐dodecyl‐and n‐hexadecyltrimethylammonium bromides in N‐potassium chloride were generally similar to those in N‐sulphuric acid, and the calculated surface concentrations of the adsorbed quaternary ammonium ions were almost the same.The wider range of potential in the present experiments enabled the desorption peaks in the differential capacitance curves for the more dilute solutions to be demonstrated. The stronger solutions gave subsidiary peaks, or steps, which may be associated with the formation of double or multiple layers.The results of these and previous experiments are explained on the basis that the adsorbed layer of n‐alkyltrimethylammonium ions does not completely exclude solvated ions, but hinders their approach to the metal surface.
Foam separation of colloidal particulates
Authors: Grieves Robert B. , Bhattacharyya Dibakar , Crandall Clifford J. 
Published: July 2010

AbstractThe foam‐separation process may be utilised for the separation of hydrophobic (and hydrophilic) colloidal particulates of a flocculent nature from aqueous suspension by the addition of a surfactant with opposite charge and by gas dispersion through the suspension. Process operation and the significant independent and dependent variables are discussed. A model is presented that divides the process into a basic separation step in which the oleophilic particles are adsorbed at the gas/suspension interfaces of the bubbles and an entrainment step in which bulk solution is physically carried into the foam. The model is used to interpret experimental results for the ferric oxide‐dodecyl sodium sulphate system, from consideration of residual ferric oxide concentrations, foam volumes, and removal ratios. A parameter, relative fractionation, is used to compare quantities of surfactant and particulates in the foam and in the bulk solution. Results are used to contrast the effects of surfactants on the foam separation of various particulates of opposite charge, including Escherichia coli, stannic oxide and kaolin clay, with particular emphasis on effects on foaming ability.
Carbonatation of ca(oh)2investigated by thermal andx‐ray diffraction methods of analysis
Authors: Gillott J. E. 
Published: July 2010

AbstractThe carbonatation of calcium hydroxide has been re‐investigated using thermal andX‐ray diffraction methods of analysis. The crystal size and morphology of Ca(OH)2vary with the method of preparation, which also affects the rate and mechanism of the carbonatation reaction. This is also dependent upon the relative humidity established prior to carbonatation. The form of the thermograms is described and the nature of the changes responsible for the peaks discussed.
Emission of corrosive volatiles from wood. III. Effect of treatment with propylene oxide
Authors: Gray J. D. , Cochrane G. C. , Arni P. C. 
Published: July 2010

AbstractA study has been made of the release of corrosive volatiles when wood shavings are sterilised by propylene oxide. Sterilisation of sweet chestnut (Castanea sativa), beech (Fagus sylvatica), Norway spruce (Picea abies), Sitka spruce (Picea sitchensis), Douglas fir (Pseudotsuga taxifolia) and Scots pine (Pinas sylvestris) with propylene oxide at varying relative humidities and subsequent incubation at 48° and 100% R.H. gave a variable release of corrosive volatiles but usually tended to increase the amount of acid released.
Activation of quartz by alkaline earth cations in oleate flotation
Authors: Malati M. A. , Estefan S. F. 
Published: July 2010

AbstractThe activating effect of the alkaline earth cations in the oleate flotation of quartz increases with increase in their adsorbability on to quartz i.e. Ca2+ <Sr2+ <Ba2+ ions, although their effect in enhancing the abstraction of oleate by quartz increases in the reverse order. This is tentatively explained by suggesting two types of adsorption of oleate on to the cation‐activated quartz. One type of adsorption is probably due to electrostatic attraction between the adsorbed hydrated cations and the oleate ions and this is assumed to determine the activating effect of the cation. The latter effect seems to depend also upon the attraction of the cation to the quartz surface. Depression of quartz flotation at high pH values and high oleate concentrations has been also discussed.
Phase equilibria in sugar solutions. XII. Ternary systems: Sucrose—maltose/lactose—water
Authors: Kelly F. H. C. 
Published: July 2010

AbstractEquilibrium phase relationships for the ternary systems of maltose or lactose in aqueous sucrose solutions have been determined at 30°. The results are tabulated and illustrated in appropriate triangular diagrams. Chemical analytical techniques were employed. The solubility of lactose was found to be substantially increased in the presence of sucrose, but otherwise mutual effects on solubilities were not particularly marked.
Hydration of tricalcium silicate
Authors: de Jong J. G. M. , Stein H. N. , Stevels J. M. 
Published: July 2010

AbstractResults of following the quantities of free Ca(OH)2 and of tricalcium silicate (C3S) during the hydration of C3S, and also the influence of the presence of free CaO on this reaction are in accordance with the hypothesis of Stein & Stevels with regard to the hydration of C3S. at the first contact between C3S and water, a surface hydrate, invisible by electron microscope methods, is considered to be formed and to retard the reaction strongly. This hydrate is thought to change into one which retards the hydration reaction less and changes later into a third hydrate, tobermorite gel.
Selective hydrogenation of benzalacetone
Authors: Abdoh Y. , Darvish M. R. 
Published: July 2010

AbstractBenzalacetone was hydrogenated using a Raney nickel catalyst, and various amounts of HCl, NaCl and H3PO4 in ethyl alcohol were added to test their inhibiting effect on catalytic activity. In the presence of HCl and H3PO4, Raney nickel lost its catalytic activity, and the rate of hydrogenation was decreased, but NaCl had no effect. While the hydrogenation of the ethylenic bond of benzalacetone was retarded, the decrease in hydrogen uptake by the carbonyl group was affected much more, and the amount of alcohol produced was markedly reduced.
Thermal stability of p‐phenylene sulphide polymers
Authors: Black R. M. , List C. F. , Wells R. J. 
Published: July 2010

AbstractThe thermal stability of a series of linear and branched p‐phenylene sulphide polymers at 350° has been evaluated by differential thermal analysis, thermogravimetric analysis and weight‐loss studies. It has been concluded that there is some indication that the thermal stability increases with the degree of branching present in the polymer and that the stability can be further improved by a preliminary heat treatment in the absence of air. The mechanism of ageing appears to involve a combination of crosslinking, chain scission and oxidation reactions.
Mechanism for the anti‐redeposition action of sodium carboxy‐methyl cellulose with cotton. II. colloid‐stability theory applied to the fibre‐soil system
Authors: Johnson G. A. , Lewis K. E. 
Published: July 2010

AbstractThe deposition of particulate soil on to a fabric in a wash system has been treated as a particular case of the general colloid stability theory of Derjaguin, Landau, Verwey & Overbeek. The zeta potentials on the fabric and the soil in detergent solutions have been calculated from electrophoretic mobility measurements. The colloid stability of the systems was determined by a sedimentation method. In particular, it is shown that the anti‐redeposition action of sodium carboxy‐methyl cellulose may be adequately explained by repulsive electrostatic and attractive van der Waals forces.
Synthesis and spectroscopic study of resins from aroyl propionic acids and formaldehyde
Authors: Price R. C. , Spedding H. 
Published: July 2010

AbstractThermoplastic resins have been prepared by the reaction of formaldehyde and aroyl propionic acids derived from the succinoylation of aromatic hydrocarbons. A study has been made of the condensation reaction, and nuclear magnetic resonance (n.m.r.) spectroscopy has been found to be extremely useful in the elucidation of the reaction mechanism. Two types of initial reaction with formaldehyde have been shown to occur: firstly, attack at the aromatic nucleus to give a substituted benzyl alcohol (which may condense further); and, secondly, reaction at the CH2 groups α to C = O groups leading to the formation of a γ‐lactone. The relative extents of the two reactions are determined by the activity of the aromatic nucleus to formaldehyde attack. In the case of resins from 2,4,6‐trimethylbenzoylpropionic acid, γ‐lactone formation is virtually absent and attempts have been made to consider the further condensation reactions of the substituted benzyl alcohol formed initially.
Electron‐activated cracking of gaseous hydrocarbons. I. Effect of process variables on cracking of methane in anomalous glow‐discharges at reduced pressure
Authors: Hesp W. R. , Halasz I. , Gerlach H. O. 
Published: July 2010

AbstractCracking of methane in anomalous glow‐discharges in a small bench‐scale apparatus (25mm diameter, 42 mm inter‐electrode distance) at pressures of 20–80 torr, feed flow rates of 5–40 l/h and power inputs of 100–300 W has resulted in high degrees of total conversion (up to 98% on carbon basis) and acetylene formation (up to 60%). Dependence on these process variables of the formation of diffuse and concentrated discharges is described and the desirability of the latter for acetylene formation pointed out. The effect of the process variables on yields is complex, but for a given temperature or contact time, specific energy input is the underlying factor which determines yields. Electron‐activation plays an important role in the cracking reactions. The possibility of practical applications is discussed.
Qualitative and quantitative determination of emulsion‐polymerised binders in latex paints
Authors: Post Mildred A. 
Published: July 2010

AbstractMethods for the separation and identification by infra‐red absorption spectroscopy of styrene‐butadiene, acrylic, vinyl‐acrylic and polyvinyl acetate homopolymer and vinyl acetate‐dibutyl maleate copolymer in emulsion paints based on these materials are presented. Detailed procedures for their quantitative determination are discussed.