bluuebunny/crossref_metadata_2025_split huggingface dataset:
Measurement of specific surface of colorants in cellulose
Authors: Giles C. H. , Haslam R. , Hill A. R. , Trivedi A. S. 
Published: July 2010

AbstractA 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.
Regeneration of silica‐alumina catalyst particles
Authors: Hughes R. , Shettigar U. R. 
Published: July 2010

AbstractThe 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

AbstractThe 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

AbstractA 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

AbstractA 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

AbstractThe 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

AbstractGilsonite 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

AbstractThe 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

AbstractVapour‐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

AbstractThe 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

AbstractThe 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

AbstractA 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

AbstractMagnesium 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

AbstractMethods 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

AbstractAspects 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

AbstractAfter 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

AbstractThe 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

AbstractA 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

AbstractThe 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 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

AbstractMethods 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

AbstractBromination 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

AbstractPRBS 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

AbstractThe 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

AbstractThe 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

AbstractThe 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 imageThe 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

AbstractVarious 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.