bluuebunny/crossref_metadata_2025 huggingface dataset:
Arsenical creosote. VI. Importance of the vicinal hydroxyls in the reaction of phenols with arsenic trioxide
Authors: Johanson R.
Published: July 2010

Only those compounds with vicinal hydroxyls on the benzene ring reacted extensively with As2O3 when heated at 130–16° in high‐temperature coke‐oven creosote. About two moles of 1,2‐dihydroxybenzene, 1,2‐dihydroxy‐3‐methylbenzene and 1,2‐dihydroxy‐4‐methylbenzene reacted with one mole of As2O3; for 1,2,3‐trihydroxybenzene and 3,4‐dihydroxybenzoic acid the ratio was about 2·7 and for 3,4,5‐trihydroxybenzoic acid it was still higher. Similar reactions occurred in heavy petroleum, raw linseed, lubricant and paraffin oils.

Arsenic derivatives have been synthesised either by gentle fusion of mixtures of the above compounds with As2O3, or by heating the reactants for 75 min in paraffin oil. The products, recrystallised from toluene, petroleum ether or toluene–ethanol are white, odourless, non‐volatile and stable at temperatures of 150–200°.
Diffusion coefficients in strong aqueous amine solutions
Authors: Thomas W. J.
Published: July 2010

Diffusion coefficients measured with a flowing junction cell and a wavefront shearing interferometer are reported. These coefficients were correlated with respect to solution concentration for three liquid systems: monoethanolamine‐water, diethanolamine‐water and triethanolamine‐water at 25°. Equations from fundamental electrolytic theory were used as a basis for correlation.
Effect of radiation intensity on photo‐oxidation of an air‐blown bitumen
Authors: Martin K. G. , Tilley R. I.
Published: July 2010

Xenon‐arc irradiation was used to study the influence of a wide range of radiation intensity on the rate of photo‐oxidation of a sample of air‐blown bitumen as determined by infra‐red spectroscopy. The xenon‐arc was monitored to provide information on its rate of decay, and its range of intensity was compared with that of total solar radiation in Melbourne. Thermal (dark) oxidation rates were also determined at various temperatures. The information obtained is discussed in terms of the mechanism of photo‐oxidation of bitumen and the relation to climatological data. Acceleration factors for oxidation of bitumen in the laboratory for prediction of durability were determined by applying the superposition principle to the data.
Kinetics of the formation of diazacyclopropane
Authors: Srihari V. , Viswanath D. S. , Kuloor N. R.
Published: July 2010

The kinetics of formation of diazacyclopropane in hydrazine manufacture was studied, using a 1‐litre three‐necked flask. The temperature effect agreed with thermodynamic calculations. The effect of variables such as temperature (−10 to 25°), stirrer speed (1000–2000 rev/min), and ammonia/chlorine ratio (10: 19), were investigated. The reaction was found to be first order with respect to chlorine, and the activation energy and frequency factor in the Arrhenius equation were found to be 5816 cal/mole and 195 min−1 respectively.
Surface properties of cement hydration products. I. Pore structure of calcium silicate hydrates prepared in a suspension form
Authors: Mikhail R. Sh. , Kamel A. M. , Abo‐El‐Enein S. A.
Published: July 2010

Adsorption–desorption isotherms of water vapour at 30° were determined on preparations of calcium silicate hydrates of different molar ratios of lime/silica before and after free lime and free silica extractions. From these isotherms specific surface areas were measured and total pore structure analysis was evaluated.

A surface layer thickness (t) curve for the adsorption of water vapour on calcium silicate hydrates was constructed, based on experimental curves previously published for the number of layers adsorbed on a variety of non‐porous solids with the same heat of adsorption as the calcium silicate hydrates.

The existence of both wide pores and micropores was detected in the calcium silicate hydrates. When the samples were free from uncombined lime and silica the micropores were estimated to have an average hydraulic radius of 4–5 Å, whereas the wide pores had an average size of 10 Å. Wide pores up to 200 Å also exist. The pores were predominantly parallel plates.
Sorption of sulphur dioxide by indoor surfaces I. Wallpapers
Authors: Spedding D. J. , Rowlands R. P.
Published: July 2010

The sorption of sulphur dioxide by PVC wallcoverings and conventional wallpaper samples has been measured at a maximum sulphur dioxide concentration of 150 μg/m3 by use of 35SO2. The sorption was found to be influenced by the surface finish and design pattern of the wallpapers. Sweat deposits on the samples also influenced the pattern of uptake. The conventional wallpapers showed a greater uptake than did PVC wallcoverings in all cases.
Optical resolution of dl‐amino acids by ligand exchange I. A study of the resolution of DL‐aspartic acid with the aid of copper complexes of L(α)‐alanine
Authors: Van Kan J. J. H. , Bachus J. J. P. M.
Published: July 2010

Spectrophotometric studies were made of the reaction of the Cu complexes of L‐alanine with DL‐aspartic acid to give a precipitate of a Cu‐D‐aspartic acid complex, and the effects of stirring, addition of NaClO4as supporting electrolyte, pH and temperature on the quantity of the complex precipitated were determined.

The results indicated that both L‐ and D‐aspartic acid react with the Cu‐L‐alanine complex, and the Cu‐D‐aspartic acid complex precipitated is non‐stoicheiometric, with no evidence of Cu‐Cu bonds. After precipitation of the Cu‐D‐aspartic acid complex, a Cu‐L‐aspartic acid complex is precipitated. Resolution occurs only between pH 2.7 and 5.3, and the ‘specificity’ of resolution is determined by kinetics rather than by thermodynamics.
Reduction of aromatic carbonyl compounds with nickel/aluminium alloy
Authors: Tyman J. H. P.
Published: July 2010

The reduction of aromatic carbonyl compounds by means of nickel/aluminium alloy in alkaline solutions and suspensions has been examined and results were obtained that were different from certain of those reported earlier. Improvements in the technique are described.
Surface area and pore structure of thorium dioxide
Authors: Fahim R. B. , Gabr R. M. , Sh. Mikhail R.
Published: July 2010

Water vapour isotherms at 35° were measured on two samples of thorium dioxide, one crystalline and the other an amorphous gel. Specific surface areas and pore size distributions were estimated and compared with those obtained from nitrogen adsorption at −196°. The effect of thermal treatment on both samples was also investigated at 35–500°. It was shown that the adsorption of water vapour on thoria gel is purely physical in nature, and that the gel surface is characterised by the existence of pores of very particular sizes, namely of hydraulic radii 4–6 Ǎ. On the other hand, water seems to interact chemically with the surface of the crystalline sample. In this case the specific surface area could not be evaluated from the adsorption branch of the isotherm, but was successfully evaluated through the application of the ‘corrected modelless’ method to the desorption branch of the water isotherms. This gave the surface area of the total pore system which was found to be in good agreement with the B.E.T.‐nitrogen area.
Surface area and pore structure of ceric oxide
Authors: Sh. Mikhail R. , Gabr R. M. , Fahim R. B.
Published: July 2010

Adsorption‐desorption isotherms of nitrogen at −196°, and of methanol and cyclohexane vapours at 35°, were determined on a sample of microcrystalline hydrated ceria and its products of dehydration formed in air at temperatures up to 1000°. The nitrogen adsorption isotherms were analysed by the de Boer t‐method. In one particular sample, the Va‐t plot gave a straight line passing through the origin, which continued until near the saturation pressure. This sample is known to be porous, and its pore size distribution curve gave a most probable hydraulic radius of 35 Ǎ. In analysing the pore structure, the corrected modelless method was used, and there is an indication that the pores are most likely to be cylindrical in shape. Sintering seems to take place through material transport from wider pores to fill narrower ones, where the total number of pores is reduced. Adsorption of larger molecules than nitrogen, namely methanol and cyclohexane, gave surface area values which are slightly lower than those calculated from nitrogen adsorption. It seems that slight persorption effects can take place in minor fractions of micropores present. However, the remainder of pores present in all samples investigated are accessible to the three adsorbate molecules.
Low‐temperature dehydration of vermiculite I. Rate of isothermal dehydration
Authors: Sh. Mikhail R. , Guindy N. M. , Hanafi S.
Published: July 2010

The kinetics of the isothermal dehydration of sheet and powdered vermiculite were studied both in vacuo and in the presence of a constant water vapour pressure. Dehydration of the sheet form followed a first‐order mechanism both in vacuo and in water vapour. The extent of dehydration under constant vapour pressure was greater than in vacuo, and this is believed to be due to inhibition of the collapse of the fine structure of the dehydration product in a certain direction, thus accelerating the extent of dehydration. The energy of activation was calculated to be comparable to the latent heat of vaporisation of water, and it is suggested that this would measure the ‘heat of desorption’ of water from the surface of the dehydration product.

For the dehydration of powdered vermiculite in vacuo and in water vapour, the kinetics may be discussed in conjunction with Mampel's theory of the decomposition of powders. The mechanism is interfacial, and the energy of activation is much lower than for the sheets. Diffusion plays a dominant role for powder dehydration, and in the present case it is an ‘activated diffusion’, being mainly ‘surface diffusion’ along the grain boundaries of the dehydration product. Water vapour also increases the extent of dehydration, and this could be interpreted in the same manner as for the sheet form.
Measurement of specific surface of colorants in cellulose
Authors: Giles C. H. , Haslam R. , Hill A. R. , Trivedi A. S.
Published: July 2010

A new method is described whereby the specific surface of colorants, i.e. pigments or insoluble or water‐soluble dyes, in cellulose can be measured. The principle of the method is the selective adsorption of p‐nitrophenol (PNP) from water by the colorant particles but not by the cellulose, thus permitting determination of the surface of the particles and the effect thereon of various treatments.

Results with organic pigments in spun‐dyed viscose rayon agree with calculations of specific surface from particle‐size analysis of the pigments before incorporation. This shows that the whole surface of the colorants in the cellulose is accessible to PNP and thus measurements can be made with a variety of dyes.

Azoic dyes and vat dyes give results that correspond to average particle diameters of ∼ 0.1–0.6 μm and the method detects the increase in their particle size on soaping.

A direct cotton dye of low light fastness and a reactive dye give specific surface values much too low for a monolayer and they appear to exist as multilayers in cellulose. A direct cotton dye of high light fastness appears to be present as three‐dimensional aggregates of diameter ∼ 0.08 μm, in agreement with published electron micrograph values for similar dyes.
Electrolytic decomposition of cyanides, phenols and thiocyanates in effluent streams—a literature review
Authors: Kuhn A. T.
Published: July 2010

A critical review is given of the literature dealing with the treatment of electrolyte decomposition in effluent streams.
Regeneration of silica‐alumina catalyst particles
Authors: Hughes R. , Shettigar U. R.
Published: July 2010

The oxidation of carbon on a silica‐alumina catalyst has been investigated in the temperature range 420–544°c under differential reactor conditions. The reaction was first order in oxygen but the order with respect to the deposited carbon could be interpreted as either a first‐order or surface reaction process. However, a statistical analysis and mechanistic considerations suggest that the surface reaction mechanism is more probable.
Self‐detergence of raw wool. I. ‘Suint scouring’
Authors: Jones G.
Published: July 2010

The degree of partial detergence accomplished by passing representative subsamples of several lots of greasy wools at controlled alkaline pH values (generally constant in each experiment) through the same bath of water at 50°c has been followed by estimations of loss of grease as well as loss of all soiling materials. The degree of detergence usually tends to rise to a maximum and then often falls off as is usual when detergent concentration is increased in other systems. As the pH of the detergence is raised, the maximum attained rises and the fall‐off generally occurs earlier, at least up to pH 10.0. The course of detergence varies with the kind of alkali and its purity. Inorganic salts and amyl alcohol raise the maximum and increase the rate of fall‐off of the self‐detergence. Other methods of raising the degree of detergence are explored. The maintenance of maximum detergence for all wools is a complex problem.
Recent advances in high energy non‐aqueous batteries
Authors: Conti F. , Pistoia G.
Published: July 2010

A survey of the recent progress in the field of high energy non‐aqueous batteries is presented. The newest batteries show some improvements on the existing ones although numerous problems still remain. The use of electrolytic solutions with higher specific conductivities and the use of cathode materials virtually insoluble in these electrolytes has been introduced. Some attention has also been given to systems useful in secondary cells. As a result of these recent researches, batteries capable of sustaining quite high current densities on discharging and having a better shelf‐life have been produced.
Shock‐sensitive cyclotrimethylenetrinitramine (RDX)
Authors: Batten J. J.
Published: July 2010

A form of RDX with a shock sensitivity comparable with that of PETN has been produced by sublimation. However, the material is as insensitive to heat, impact, friction and static discharge as are the normal forms of RDX, and it has a similar storage life. The shock sensitivity tests were performed with these explosives either cast in TNT or bonded in silicone rubber.
Dispersion and solution by fluids near the critical region
Authors: Russell J. H. , Pattle R. E.
Published: July 2010

The capacity of volatile liquids to disperse powders or colloids or to form a water‐in‐oil emulsion was found to decrease as the critical temperature was approached. The phenomena are related to decreased interaction between the volatile component and the less volatile one as the density of the former decreases.

The mixing of some high‐pressure fluids with less volatile liquids has been studied by observing light reflected from the upper aspect of the interface. This reflection disappears at a sharply defined temperature, pressure and composition. A temperature (60°c) at which the pressure required to produce mixing is a minimum (10‐0 N/mm2) occurs in the ethane‐bromoform system; the use of such points as fixed points on the pressure scale is suggested.
Formation of graphitisable carbons from gilsonite pitch and polyvinyl chloride—a mass spectrometric and N.M.R. study
Authors: Marsh H. , Akitt J. W. , Hurley J. M. , Melvin J. , Warburton A. P.
Published: July 2010

Gilsonite pitch and polyvinyl chloride (PVC) were carbonised at slow rates of 0.5°c min−1 and the products of carbonisation examined by chromatography, mass spectrometry, nuclear magnetic resonance spectroscopy, optical microscopy, scanning electron microscopy and electron spin resonance spectroscopy. The original Gilsonite pitch contains ∼ 5% of aromatic protons, rising to 24% in soluble material just prior to formation of the graphitisable semi‐coke at 410°c. The carbonised PVC melts (389°c) to form a black isotropic liquid with 23% aromatic protons, rising to 41% at the onset of the coalescence of the mesophase spheres (420–440°c). The constituent molecules are considered to be hydrogenated cyclic structures possessing a great variety of saturated and unsaturated side‐groups. During carbonisation, there is loss of side‐groups, but it is the essentially aliphatic cyclic structures which co‐condense to form the mesophase. Further aromatisation must occur within the mesophase and semi‐coke. The presence of heteroatoms within the Gilsonite pitch is considered to restrict the growth of the mesophase structures and their ability to coalesce to form the much larger units of anisotropic character observed in the case of PVC. Electron spin resonance spectroscopy suggests that free radicals are not necessary to form the mesophase, the free radical character being developed after formation of the mesophase, probably as the aromaticity is developed.
On the determination of free silica in ceramic raw materials
Authors: El‐Ghany Abd , El Kolali A. , Gad Gamal
Published: July 2010

The accurate quantitative determination of free quartz contained in local feldspars and clays was achieved through special methods of differential thermal analysis, and chemical analysis. and chemical analysis. Aswan feldspar and Aswan clays were found to contain varying free quartz contents and were therefore considered as suitable sources of raw materials for the preparation of clay‐feldspar‐quartz ceramic body mixes. Accordingly, no quartz addition was necessary for the production of pottery and porcelain ceramic bodies.
Isothermal vapour‐liquid equilibria in binary mixtures of ketones and alkanes
Authors: Maripuri V. C. , Ratcliff G. A.
Published: July 2010

Vapour‐liquid equilibrium data were determined at 65 °C for five binary mixtures of ketones and n‐alkanes. The systems studied were acetone/n‐decane, methyl ethyl ketone/n‐hexane, methyl ethyl ketone/n‐octane, diethyl ketone/n‐hexane and di‐n‐propyl ketone/n‐hexane. Activity coefficients were evaluated taking into account vapour phase imperfections, and are presented.
The influence of ph value and ionic strength on the ultrafiltration characteristics of a penicillinase produced by Escherichia coli Strain W3310
Authors: Melling J. , Westmacott D.
Published: July 2010

The effects of pH and phosphate buffer concentration on membrane ultrafiltration of a penicillinase from Escherichia coli strain W3310 were studied using a series of ultrafiltration membranes.

With a 30 000 molecular weight cut‐off membrane, throughput of the enzyme (molecular weight 22 000) varied from 1.6% to 55% depending upon the buffer pH and concentration. The observed variations in throughput and also in specific activity were attributed to aggregation effects which were reduced near the isoelectric point of the enzyme and also by a shielding effect of increased buffer concentrations. The actions of EDTA and urea on the ultrafiltration characteristics were also examined.

The significance of these results in the use of the technique of ultrafiltration is discussed.
The effect of temperature on the properties of calcined red iron oxide pigments
Authors: Kamel A. H. , Abdallah A. M. , El‐Baradie H. Y.
Published: July 2010

The effect of calcination temperature on the properties of red iron oxide pigments obtained from FeSO4, 7H2O by calcination at constant temperatures over the range from 700 to 900 °C, has been investigated. It was found that the particle diameter increased from 0.065 μm at 700 °C to 0.25 μm at 900 °C; the increase was gradual up to 800 °C and abrupt at 850 and 900 °C. The colour changed from red with decreasing yellowish hue between 700 and 750 °C, to red with increasing bluish hue between 750 and 900 °C; the dominant wavelength increased from 599 nm at 700 °C to 610 nm at 900 °C. The tinting strength was found to vary irregularly with temperature, and to pass through a maximum at 750 °C. The oil absorption was found to decrease with temperature and to be a linear function of the specific surface area.
The preparation and sintering of a high area supported nickel oxide catalyst
Authors: Dollimore David , Jones Thomas E.
Published: July 2010

A detailed study has been made on the preparation and consequent heat treatment of various active nickel oxide—alumina catalysts. The techniques used in this study were surface area measurements, pore size analysis and density determinations. Three methods were employed for catalyst preparation, these being impregnation; co‐precipitation and bulk fusion of the metal nitrates. The results indicate that the catalyst prepared by co‐precipitation was the most suitable. By following surface area changes with temperature and time as variables two modes of sintering were noted, one occurring in the temperature range 1100 to 1164 K giving an activation energy of 98 kJ mol−1, and the other occurring in the temperature range 1182 to 1200 K giving an activation energy of 460 kJ mol−1. It is thought that the mechanism controlling the sintering in the first case is a direct result of surface diffusion, whilst that occurring in the second range is governed by volume diffusion. The decrease in the number of particles as a trend in sintering is calculated for the sample sintered at 1182 K using surface area and density data.
Surface properties of calcined magnesia: Effects of presence of water vapour on surface areas and pore sizes
Authors: Razouk Rashad I. , Mikhail Raouf Sh. , Ragai Jehane
Published: July 2010

Magnesium oxalate dihydrate was used as a “generator” to produce active magnesium oxide by heating both in vacuo and in presence of constant water vapour pressure. Results indicate that sintering is accelerated in presence of water vapour and probably takes place by a different mechanism than by heating in vacuo. Sintering in vacuo is accompanied by widening of pores, whereas in presence of water vapour it is accompanied by narrowing of pores. The role played by water vapour in accelerating the sintering of magnesia is discussed and possible explanations are offered. Dual effects of water vapour might lead to the sintering acceleration of magnesia; chemisorption of OH groups which create cation vacancy on the surface leading to activated surface diffusion, and oxygen bridging between two adjacent/or opposite OH groups, particularly in narrow pores, leading to their narrowing.
Pilot scale preparative microbiology: Cell culture, extraction, and purification of products
Authors: Sargeant Kenneth
Published: July 2010

Methods available for the preparation of microbial cells in kilogram quantities are reviewed. In general it is most convenient to grow the cells in suspension in a stirred culture vessel under controlled conditions designed to maximise the yield of the desired chemical product, and to separate them as a paste by centrifuging the mature culture. Methods for the extraction of products from such cells are discussed.

The further purification of chemical products so extracted, especially enzymes, is reviewed, with emphasis on the earlier stages in which the main aim is to obtain a quick reduction in bulk so that the final purification may be achieved on a small laboratory scale.

Examples are given, mainly from recent experience at Porton.
Microbial aspects of fermentation process development
Authors: Calam Christopher T. , Russell David W.
Published: July 2010

Aspects of fermentation dynamics are discussed, especially from the point of view of process development. Initial examples are from laboratory work in continuous culture. After this the economic and dynamic aspects of protein production by continuous culture are reviewed. In the last part the optimisation of the pencillin fermentation is considered, based on the use of a model which predicts yields, with a fermentation limited by the rate of oxygen transfer to the culture, when penicillin production falls at low growth‐rates. A process involving a sugar feed is considered, the main factors being the concentration of nitrogen in the medium, which governs initial cell production, and sugar feed rate which maintains further growth. The model predicts high yields over a wide variety of conditions. This indicates the difficulty of a pilot‐plant optimisation programme, when the maximum yield point is not critical. Other factors in the fermentation are also discussed.
Selectivity in the acylation of amino‐sulphonamides
Authors: Davi Sloan A. D. B.
Published: July 2010

After the identification of unexpected products formed from methyl dichloro‐acetate and an amino‐sulphonamide during the attempted synthesis of a derivative of 3,4‐dihydro‐2H‐1,2,4‐benzothiadiazine 1,1‐dioxide, unprecedented selective acylation of the sulphonamido group in sulphanilamide was found to occur when esters of activated carboxylic acids were allowed to condense at 25 °C with the sodium salt of sulphanilamide in methanol.

The scope of this reaction was examined both with respect to the amino‐sulphonamide and with respect to the ester used as acylating agent. No limitations to the reaction were found among the amino‐sulphonamides examined, each of which was acylated exclusively at the sulphonamido group. Methyl dichloro‐acetate and methyl tricyloroacetate were effective acylating agents, ethyl dichloro‐acetate was less so, and ethyl chloroacetate was ineffective.

The mechanisms of the new reaction and of the classical acylation by acyl‐pyridinium ions are discussed and compared, and explanations are offered for the contra‐selectivity of the two reactions.

The infrared spectra of the N‐aminoarenesulphonyl‐2, 2‐dichloroacetamides and N‐aminoarenesulphonyl‐2, 2, 2‐trichloroacetamides made by the new method reveal that in many cases these compounds have a zwitterionic structure in the solid state which is lost in their azo‐β‐naphthol derivatives.
Examples of computer‐aided fermentation systems
Authors: Ryu Dewey D. Y. , Humphrey Arthur E.
Published: July 2010

The optimal control of a fermentation process can be achieved through the parameter optimisation that is based on the quantitative physiology of the fermentation system. One must first identify the most important state and control variables to the production rate of a particular fermentation product. These variables must be measured accurately and monitored continuously for the control of the process. This necessitates a reliable instrumentation system that is compatible with computer interfacing. A specific method of parameter optimisation of a few key variables and a development of a process control scheme for penicillin fermentation are illustrated as an example. In this example, understanding of quantitative physiological aspect of the fermentation process is emphasized. As the understanding of a process is further advanced, any partial process control scheme can be gradually expanded into an ultimate automatic control of the overall fermentation process. As the complexity of the process control scheme and the multiplicity of the control variables increase, the use of a computer system becomes an economic necessity for the control and monitoring of fermentation process. An example of how this might be done is shown in an information flow‐sheet for a computer‐coupled fermentation system. Other examples of industrial use of computers for fermentation facilities are shown.
A device for production of microbial extracellular enzymes in concentrated form
Authors: Fogarty William M. , Griffin Patrick J.
Published: July 2010

A novel device has been constructed that permits the concentrated production of microbial extracellular enzymes. The apparatus is an all glass structure containing a number of ports, two of which extend to form cylindrical projections, three‐quarters the length of the vessel. These projections are highly perforated and do not impede nutrient movement to the inner growth chambers which are constructed of visking tubing. The concentrated enzyme is recovered from the growth chamber after removal of microorganisms by centrifugation. The applicability of this apparatus to studies with different physiological types has been established using Bacillus polymyxa, Serratia marcescens and Streptococcus thermophilus for exo‐protease production and Clostridium acetobutylicum for elaboration of exo‐amylase. In each instance, the level of enzyme produced was concentrated in a small volume, although the total yield was lower.
The use of a membrane electrode to study the crystallisation of calcium sulphate from aqueous solution. II. The influence of organic additives on the crystallisation of calcium sulphate
Authors: Ching William , McCartney Eric R.
Published: July 2010

The activity of the calcium ion was measured by means of a membrane electrode during the crystallisation of calcium sulphate dihydrate from an aqueous solution in which were dissolved additives previously shown to retard this crystallisation. Evidence was thus obtained that the additives did not act by reducing the thermo‐dynamic activity of the calcium ion and so must influence the kinetics of the crystallisation, probably by adsorption on subcritical embryos.
The effects of sterilisation on the properties of calcium sulphate hemihydrate
Authors: Frame John W. , Combe Edward C.
Published: July 2010

Plaster of Paris has been recommended as a suitable bone substitute material. In this project both calcined and autoclaved plasters have been prepared and the effects of sterilisation on their properties determined. Samples of plaster suitable for use in animal experimentation have been prepared.
The large scale preparation of chromatographic grade hydroxylapatite and its application in protein separation procedures
Authors: Atkinson Anthony , Bradford Paul A. , Selmes Ian P.
Published: July 2010

Methods are described for both the laboratory and plant scale preparations of hydroxylapatite to give 200 ml and 22 litre settled bed volumes respectively. These materials have an average particle size of 75 μm, give flow rates of up to 45 ml cm−2h−1 and bind up to 50 mg protein/ml hydroxylapatite at pH 6.8. Examples of protein separations and purifications on hydroxylapatite are given and the nature and basis of hydroxylapatite chromatography is discussed.
Bromination of some aromatic compounds by means of bromine in chlorosulphonic acid medium
Authors: Hashem A. I.
Published: July 2010

Bromination of a series of aromatic compounds is carried out by means of bromine in chlorosulphonic acid medium in the presence of iodine as a halogen carrier. Some compounds are brominated and oxidised, the others are brominated only with brominolysis of the groups present, e.g. ‐CHO, ‐COOH, ‐NO2 and ‐CN groups.
Dynamic behaviour of mixer‐settlers. III. Testing mathematical models using dynamic behaviour of mixer‐settlersflow rates as input signals
Authors: Aly Gharib , Ottertun Harald
Published: July 2010

PRBS or step response techniques have shown that linearised simple mathematical models are adequate for simulating the dynamics of mixer‐settler units. The fact that the ratio between the hold‐up volumes in the mixer part is equal to the phase flow ratio is confirmed both experimentally and by the identification of state space models.
The hydrolysis rate of sulphamic acid
Authors: Notley John M.
Published: July 2010

The rate of hydrolysis of sulphamic acid has been measured over the pH and temperature range of interest to electroplaters. The results have been correlated with accurate results at other temperatures reported in the literature, and are presented as a plot of half‐life of sulphamic acid as a function of pH, from 50 to 95 °C, and as a plot of half‐life against temperature, at pH 1.4, 2 and 3. Guidelines are given for estimating the half‐life at temperatures and pH's not covered by the experimental results.
The kinetics of the catalytic hydrogenation of toluene
Authors: Karanth N. Ganesh , Hughes Ronald
Published: July 2010

The kinetics of the vapour phase hydrogenation of toluene over a silica‐supported nickel catalyst have been determined in the temperature range from 100 to 210 °C and at toluene concentrations of 3 to 16 mol‐%. The reaction was found to be first order with respect to hydrogen and of a low fractional order in toluene which increased slightly with temperature. From an analysis of the kinetic data an Eley‐Rideal type mechanism for the reaction is proposed.
Hydrogenation of cyclopentadiene on a nickel catalyst
Authors: Sakamoto H. , Takasaki K. , Harano Y. , Imoto T.
Published: July 2010

The hydrogenation of cyclopentadiene on Ni catalyst was carried out with a fixed bed reactor.

The initial reaction rates were expressed by the following equations. magnified image

The activation energies of overall‐and surface‐reaction rates were, respectively, 1.9 and 6.5 kcal/mol and the heats of adsorption of hydrogen and cyclopentadiene were, respectively, 5.6 and 1.6 kcal/mol.

The hydrogenation of cyclopentadiene on Ni catalyst is a consecutive reaction passing through cyclopentene, where the activation energy of the 1st stage is higher than that of the 2nd one, namely, E1 > E2. At the lower ratio of PH/PC, cyclopentene is produced with 100% selectivity, whereas, increasing PH/PC or W/F0, the selectivity decreases. At the intermediate reaction temperature, there appears the minimum selectivity. This phenomenon is considered to be due to E1 > E2.
Use of mutagenic agents in improvement of α‐amylase production by bacillus subtilis
Authors: Bailey Michael J. , Markkanen Pertti H.
Published: July 2010

Various mutagenic agents were employed in succession to produce mutant strains of Bacillus subtilis with improved yields of α‐amylase. The parent strain had previously been selected as a good producer of α‐amylase. Highly productive mutant strains were selected throughout the work as the basis for further treatment. In shake cultures the yields of α‐amylase of the best strains were double that of the parent strain, and in fermentor cultivation the improvement was even greater.
A comparison of oxygen mass transfer into sodium sulphite solution and a biological system
Authors: Greenhalgh Spencer H. , McManamey William J. , Porter Kenneth E.
Published: July 2010

To explain previously reported discrepancies between oxygen uptake rates in biological systems and the sodium sulphite test system a comparison was made between oxygen mass transfer into a sodium sulphite solution catalysed by copper(II) ions, and into a biological system, the bacterium E. coli in a mineral medium. A stirred transfer cell, with a relatively low rate of physical mass transfer per unit area, and a bubble column, with a high physical mass transfer rate per unit area, were used to make this comparison; in both cases, the areas of gas/liquid contact could be determined. In the transfer cell the gas/liquid mass transfer coefficient for the biological system was only 10–25% of that for the sulphite oxidation system (for which the absorption rate was increased by chemical reaction). In the bubble column mass transfer into both systems was controlled by physical absorption and the mean mass transfer coefficients were similar for both systems. However, the mass transfer coefficient for the biological system increased with E. coli concentration, probably due to physical effects of the small particles.
Purification and properties of β‐amylase produced bybacillus polymyxa
Authors: Fogarty William M. , Griffin Patrick J.
Published: July 2010

1,4‐α‐D‐glucan maltohydrolase (β‐amylase, EC.3.2.1.2.) produced byBacillus polymyxawas isolated and purified. Some of its properties were examined and compared with those of a typical plant β‐amylase. Hydrolysis of periodate oxidised amylose demonstrated an exo mechanism of substrate attack similar to that of sweet potato β‐amylase. The effect of sulphydryl reagents on enzyme activity was similar to that reported for plant β‐amylases. Consistent with the observation that the enzyme has an exo mechanism of action, it also failed to degrade Schardinger cyclodextrins. These latter compounds acted as inhibitors of the enzyme. The optimum temperature for activity was 37 °C. The enzyme was quite stable at temperatures up to and including 37 °C; 90% of the original activity remained after storage at 37 °C for 6 days. However, the stability decreased rapidly when exposed to temperatures above 37 °C; only 20% of the activity remained after 1 h at 45 °C. The hydrolase exhibited a rather sharp optimum at pH 6.8 for stability at 37 °C. However, the enzyme was quite stable in the pH range 6.4–7.2 at 20 °C but it was shown to be less stable in acidic conditions than the corresponding plant enzymes.
A model of sugar utilisation during batch beer fermentation
Authors: Fidgett Michael , Smith Eric L.
Published: July 2010

A mathematical model describing the kinetics of sugar utilisation and changes in active yeast concentration during batch fermentation of brewers' wort is presented. Consideration is first given to the problems of modelling multiple substrate systems in which microorganisms can utilise carbohydrates both simultaneously and sequentially. Ideas outlined in the introductory sections are then used to develop a model of the beer fermentation process, and it is shown how the model can be matched to experimental data.
Ammoxidation of propylene by pulse reaction technique
Authors: Oka Hideaki , Ishimoto Seiichi , Miyamoto Toshiki , Harano Yoshio , Imoto Tatsuya
Published: July 2010

The ammoxidation of propylene on Fe‐Bi‐P mixed oxide catalyst was studied at 500 °C by the pulse reaction technique, to examine the effects ofP(P= 0–4) andP(P/P= 0–3) on the catalyst activity. Since the ammoxidation of propylene proceeds through consumption of oxygen from the catalyst even in the absence of oxygen, the reduction of catalyst progresses with the number of O2‐free pulse, losing its activity. In the presence of oxygen, however, the conversion of propylene and the selectivities of acrylonitrile, acetonitrile, CO2, and CO vary with the pulse number, but settle to some steady values corresponding toP/P. It is also found that the conversion and the selectivities depend on the oxidation state of the catalyst, the latter also depending onP/Pin the reactants, and that the catalyst working in the flow system may be being reduced to some extent.
Kinetics and mechanism for the thermal decomposition of chlorate ions in brine acidified with hydrochloric acid
Authors: Dotson Ronald L.
Published: July 2010

The kinetics for the thermal decomposition of chlorate ions in brine acidified with hydrochloric acid were studied from 0.0 to 4.0 mol/litre salt, within 1 : 1 to 18 : 1 acid to chlorate ratio ranges and from 70 to 105 °C. The rate expression for this process was observed to be first order in chlorate, second order in acid and exponential to the base e in the total molar chloride concentration. The rate limiting step has an activation energy of 35.056 kcal/mol. The overall reaction stoichiometry is explained and a mechanism proposed involving an ionic outer sphere complex and an activated, covalent inner sphere electron bridged penetration complex.
Quantitative effect of gritty contaminants on the sensitiveness of high explosives to initiation by impact. II. A non‐parametric variant of the bruceton procedure
Authors: Scullion Henry J.
Published: July 2010

Aspects of the quantification of the effects of additives, intentional or otherwise, are briefly discussed in the light of some unpublished work. Addition of gritty particulates causes not only a fall in insensitiveness but also (due to population distortion) a widening in the fiducial limits of any estimate made of that insensitiveness. To cope to some extent with this increased dispersion, i.e. to ascertain with known confidence whether small additions (sensitising or phlegmatising or both) have altered the level of insensitiveness, a simple and economic “non‐parametric” variant of the Bruceton procedure is described.
Studies of light fading of reactive dyes on cellophane
Authors: Shah Champaklal D. , Srinivasan Rajagopalan
Published: July 2010

The ratios of extinction of the short wave (y) and the long wave (x) band in the visible region of the absorption spectra of three reactive dyes on cellophane film and also in aqueous solution, both in the presence and absence of urea, have been measured. Also changes in the ratio with time of exposure were determined. The ratio is found to increase with the concentration of the dye in the fibre and also in aqueous solution. Urea causes disaggregation. The state of aggregation of reactive dyes in cellophane is found to be intermediate between that obtained in a polyester–disperse dye system and nylon or cellulose acetate or cellulose–triacetate–disperse dye system.
Ammoxidation of acrolein on catalyst of Fe–Bi–P mixed oxide system
Authors: Oka Hideaki , Miyake Keishiro , Harano Yoshio , Imoto Tasuya
Published: July 2010

Ammoxidation of acrolein (Al) on Fe2O3‐Bi2O3‐P2O5 (44.5:44.5:11.0 mol%) catalyst was studied in a fixed bed reactor. The main products were acrylonitrile (AN), CO2 and acetonitrile; and CO was negligibly small. The rate equations for Al conversion and product formation, together with their apparent activation energies, were obtained. The reaction rates are controlled by the chemical reaction rates at temperatures below 340°C, while the external film diffusion rates are the rate determining steps at temperatures above 380°C. Assuming the chemical reaction controlling region, the conversion rate of Al at 400°C is about 1000 times faster than that of propylene. From the effects of feed composition on selectivities, it is concluded that AN is produced according to Hadley's path.
Multilayer adsorption with molecular orientation of asphalt on mineral aggregate and other substrates
Authors: Ensley E. Keith
Published: July 2010

The adsorption of asphalt on aggregate surfaces was studied by several experimental methods by the Bureau of Mines. The adsorption rate of asphalt on an aggregate surface was found by flowing asphalt through a column of aggregate and measuring the decrease in flow rate. Photomicrographs revealed a striated structure in the asphalt region near the asphalt–substrate interface. The photomicrographs suggest that, as asphalt molecules are adsorbed on substrates, the postulated large, sheet‐like molecules are aligned perpendicular to the interface. Perpendicular orientation of asphalt molecules near the interfacial region is also supported by evidence of dipole fields produced by the alignment of the asphalt dipoles. Contact angle measurements of 1‐bromonaphthalene on asphalt surface in prior contact to a mica surface further supports interfacial structuring. A multilayer adsorption mechanism, with preferred orientation of asphalt molecules on the aggregate surface, is proposed as an explanation of the observations.
Diffusion of benzene and toluene into aqueous nitric acid‐sulphuric acid mixtures
Authors: Hanson Carl , Ismail Hamed A. M.
Published: July 2010

Diffusion coefficients of toluene and benzene into aqueous mixtures of nitric and sulphuric acids have been measured at 30°C by use of a laminar jet technique. Equations are presented which correlate the data in terms of the acid concentrations and permit extrapolation to acid mixtures of interest for industrial mononitration reactions. The results show the expected dependence on viscosity of the acid phase and are in agreement with values predicted by the Wilke and Chang correlation.
Kinetics of heterogeneous oxidation of ammonium sulphite
Authors: Mishra Girish C. , Srivastava Rameshwar D.
Published: July 2010

The heterogeneous oxidation of ammonium sulphite was investigated with cobalt sulphate catalyst at 30°C. For a wide range of concentrations the reaction was found to be nearly first order in oxygen and zero order in sulphite. These kinetics contrast with the results of homogeneous experiments which indicate that the reaction is zero order in oxygen and three‐halves order in sulphite. The catalytic effect of cobalt ions was found to be proportional to the square root of the total concentration of cobalt. The apparent activation energy for the overall oxidation was calculated to be 13 kcal/g mol. It is concluded that the kinetics in the heterogeneous system are determined by the catalyst regeneration reaction which is diffusion controlled.
Modelling of combined mass transfer‐kinetic effects in an enzyme membrane reactor system with a direct approach to the identification of intrinsic rate parameters
Authors: Hsieh Fengchi , Davidson Burton , Vieth Wolf R.
Published: July 2010

A methodology for identifying non‐linear parameters in a generalised Briggs‐Haldane rate expression for immobilised enzyme membrane flow reactors has been developed for the intermediate case where mutually rate‐controlling processes of mass transfer and enzymatic reaction prevail. The technological significance of the estimation procedure lies in the ability of the algorithm to handle parameter identification in non‐linear, two‐point boundary value problems which are prevalent in both immobilised enzyme and non‐enzymic heterogeneous catalysed reactor systems. The methodology was successfully implemented on an experimental level using quasi‐steady‐state conversion data for the model system of urea/collagen‐urease in a spiral‐wound, biocatalytic reactor module. By using a novel procedure of pepsin pretreatment of the collagen host membrane before enzyme impregnation, followed by glutaraldehyde crosslinking, it was possible to enhance the activity and stability of the immobilised enzyme complex to relatively high levels where interphase and intraphase diffusional limitations mutually controlled the rate of reaction. Information on the coefficient of mass transfer at the interface between solid and fluid phases was also obtained as part of the estimation procedure.
Thermodynamic properties of the n‐hexane and benzene system at elevated temperatures
Authors: Medani M. Salah , Hasan M. Asad
Published: July 2010

The total vapour pressure and the composition of the liquid of the n‐hexane and benzene mixtures have been measured under equilibrium conditions at 90, 110, 130, 150, 170 and 190°C. The corresponding vapour phase compositions were estimated using an expression of the liquid phase activity coefficient as a function of composition of the liquid phase. Several expressions were compared and the three‐constant Redlich and Kister equation was found to give the best fit to the experimental vapour pressure data. The virial equation of state as well as a modified Redlich and Kwong equation were used to express the deviation of the vapour phase from the ideal. Results were compared and the discrepancy was found to be within the experimental tolerance. The low values of the liquid phase activity coefficients indicated that the behaviour of this particular system was not far from ideal. Also, it was found that the degree of deviation from the ideal decreased with the increase in temperature. The excess Gibbs free energy of mixing was calculated and it was found to be non‐symmetrical with liquid composition. On increasing the temperature of the system, the liquid composition corresponding to the maximum GE tended to shift to a lower n‐hexane concentration, while at fixed liquid composition, GE initially decreased and then remained stationary or increased again. This was thought to be due to differences in the molar volumes of the two components.
Analysis of cell metabolic products and fermentation gases by gas chromatography
Authors: Unger Petr , Vozňáková Zdena , Páca Jan
Published: July 2010

A method for the estimation of ethanol and volatile fatty acids by gas chromatography by direct treatment of cultivation broth is described. The packing material was Hallcomid M‐18 with 1% H3PO4 on Chromosorb W AW. The separation was made at 132°C with nitrogen as a carrier gas; for detection a flame ionisation detector was used. The analysis of oxygen and carbon dioxide of the inlet and outlet gas from a fermentor was also studied. For the separation of the gases the combination of molecular seive 5A and Chromosorb 102 was used. The analysis was performed at 35°C with helium as a carrier gas and a thermal conductivity detector was used. With the experimental conditions found in this study the methods described gave reproducible and accurate results for the analytical control of cell cultivation processes.