bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hardened alite pastes of various porosities. I. Degree of hydration, compressive strength and total porosity
Authors: Abo‐El‐Enein Salah A. , Goto Seishi , Kondo Renichi , Mikhail Raouf Sh. 
Published: July 2010

AbstractThe alite used in this investigation was synthesised from the stoichiometric mixture at 1550°C. The hardened alite pastes were made using initial water/alite ratios of 0.20, 0.30, 0.45 and 0.60. Degree of hydration, compressive strength and total porosity were estimated at various hydration time intervals of 0.5 h, 2 h, 6 h, 1 day, 3 days, 7 days and 28 days. A meaningful relation between compressive strength and water/alite ratio was established at constant values of degree of hydration, total porosity and Powers' gel‐space ratio.
A new method for the purification of Egyptian cotton waste fibres
Authors: Abou‐State M. Amine , Awad Boshra M. , El‐Megeid Fouad F. Abd 
Published: July 2010

AbstractA new pulping method using sodium nitrate was successfully used for the purification of Egyptian cotton waste fibres. Sodium nitrate alone, sodium nitrate in nitric acid solution and sodium nitrate in sodium hydroxide solution were used in pulping. The chemical, physical and sub‐microscopic characteristics of the pulps obtained and their reactivity towards xanthation were estimated. The best results were obtained when a mixture of sodium nitrate and nitric acid were used in pulping.
Convenient synthesis of perhydroindene derivatives from 2,7‐dimethyl‐1,3,7‐octatriene
Authors: Watanabe Shoji , Suga Kyoichi , Tsuruta Haruki , Sato Toshiya 
Published: July 2010

AbstractSeveral perhydroindene derivatives were prepared from 2,7‐dimethyl‐1,3,7‐octatriene (I) via Diels Alder reaction followed by cyclisation. For example, the Diels Alder reaction between I and methyl vinyl ketone (II) in the presence of Lewis acid afforded 4‐acetyl‐3‐(3‐methylbut‐3‐enyl)‐1‐methylcyclohexene (IIIa), which, upon treatment with phosphoric acid, was converted to a mixture of 2‐acetyl‐5,7,7‐trimethyl‐bicyclo [4,3,0]‐non‐1‐(6)‐ene (IV), 2‐acetyl‐5,7,7‐trimethylbicyclo[4,3,0]‐non‐1‐ene (VI) and 2‐isopropyl‐3,6‐dimethylindene (V).
Mechanism of light fading of dyes on cellophane and poly(ethylene terephthalate)
Authors: Shah Champaklal D. , Srinivasan Rajagopalan 
Published: July 2010

AbstractStudies of relative rates of fading of dyes and Hammett σ‐value of substituents in their molecules lead to further evidence that fading of azo dyes on Cellophane and poly‐(ethylene terephthalate) is probably an oxidation type of reaction. Absorption spectra of the same dye on these two substrates tend to indicate a very high state of aggregation of dyes on Cellophane as compared to that on poly(ethylene terephthalate).
Homogeneous and two phase sulphonation of some aromatic hydrocarbons
Authors: Sohrabi Morteza , Kaghazchi Tahereh , Hanson Carl 
Published: July 2010

AbstractThe two phase sulphonation of benzene, toluene and p‐xylene with concentrated sulphuric acid has been studied in a one litre batch reactor. The kinetic rate constants as a function of sulphuric acid concentration and the overall mass transfer coefficient times the interfacial area per unit volume of the acid phase as a function of agitation speed have been determined. The rates of sulphonation of toluene and p‐xylene relative to that of benzene in the range 15.5–17 mol/litre sulphuric acid have been found to be 64 and 280 respectively. Finally, it has been shown that in aromatic sulphonation no linear relationship exists between the logarithms of the partial rate factors and the relative cation localisation energies. This is in contrast to the behaviour of some other electrophilic aromatic substitution such as halogenation, but is similar to aromatic nitration.
Use of Hildebrand and Lamoreaux's theory to predict solubility and related properties of gas‐liquid systems
Authors: Linford Roger G. , Thornhill David G. T. 
Published: July 2010

AbstractThere is a need in many fields such as chemical engineering, process chemistry and pharmacology for reliable data on the solubility, entropy of solution and partial molar volume of gases in liquids. Experimental data are not available for many systems of practical and academic importance and consequently a reliable theory to predict values for these properties would be of great use. Recent refinements of solubility parameter theory have been successful in predicting such values for several systems and in this paper results obtained from this theory are compared with experimental measurements on a large range of gas‐liquid systems. The agreement found is satisfactory in the most part, but for helium, neon, xenon, hydrogen and deuterium, the predicted results deviate consistently from the experimental values. This is to be expected on the basis of some of the earlier results of solubility parameter theory and an empirical modification is proposed that yields significant improvements in the predicted values. This has also been used to predict values for carbon dioxide, tetrafluoromethane and sulphur hexafluoride to which the theory is not directly applicable. Values predicted by solubility parameter theory are compared with those obtained by Battino and co‐workers from scaled particle theory. In general, the two theories are equally successful in predicting solubilities, but refined solubility parameter theory yields better values of entropy of solution. It is concluded that the theory provides a useful means of predicting solubility and entropy of solution but that prediction of partial molar volume results is limited because of the paucity of data for the thermal pressure coefficients of the solvents. Attention is drawn to apparent inaccuracies in certain experimental measurements. The interrelationship between the various forms of the entropy of solution used by different workers is clarified. A value of the energy of vaporisation of carbon dioxide, δE2v=2.64±0.15 kcal/mol is calculated.
Preparation of pyridinemonocarboxylic acids by catalytic vapour phase oxidation of alkylpyridines. II. Oxidation of 2‐methyl‐5‐ethylpyridine to niacin
Authors: Järås Sven 
Published: July 2010

AbstractThe vapour phase air oxidation of 2‐methyl‐5‐ethylpyridine (MEP) has been investigated, and the various oxidation products identified. Using a doubly promoted vanadium catalyst, V2O5–TiO2–K2O, a 98% (mole) conversion of MEP was obtained with a yield of 36% for niacin and 18% for recirculatable products (i.e. products with an intact 3‐picoline skeleton) at a temperature of 413°C and a space velocity of 5500 h−1. In a comparison of the singly promoted catalysts, varying the atom ratio V/Ti, the catalyst with V/Ti = 100/25 was found to be most active. In a comparison of different preparation temperatures for the same catalyst, 1250°C was found to be most satisfactory. A reaction scheme is proposed with the corresponding rate constants and apparent activation energies.
Determination of specific surface area of ferric oxide and alumina powders
Authors: Rahman Muhammad A. , Ghosh Ashim K. 
Published: July 2010

AbstractMethods for measuring the surface areas of powdered solids are considered and the specific surface areas of ferric oxide and alumina powders using adsorption of stearic acid from benzene solution are determined. It has been found that the value of the specific surface area of both powders agree with the BET nitrogen gas adsorption area if it is considered that the area occupied per molecule of stearic acid on the powder surface is of the order of 60–70Å2. This finding shows that orientation of the stearic acid molecule on the solid/liquid interface takes place so that stearic acid molecules lie neither completely perpendicular nor completely parallel to the surface. Possible orientations of stearic acid chains on the surface are envisaged.
Synthesis and photochemical stability of 1‐phenylazo‐2‐naphthol dyes containing insulated singlet oxygen quenching groups
Authors: Griffiths John , Hawkins Christopher 
Published: July 2010

AbstractAlthough 1‐arylazo‐2‐naphthols undergo direct and sensitised photochemical fading in solution by a singlet oxygen mechanism, the introduction of singlet oxygen‐quenching substituents (N,N‐dialkylaminomethyl‐) affords no protection against fading, and in many cases accelerates photodegradation. This has been attributed to the high reactivity of the dialkylaminomethyl‐groups towards hydrogen abstraction, thus rendering free radical modes of decomposition more favourable. In the presence of peroxide‐radical scavengers the latter reactions are suppressed, and the dialkylaminomethyl‐groups then show a protecting effect against fading by singlet oxygen.
The H2ONaCl–sucrose phase diagram and applications in cryobiology
Authors: Gayle Frank W. , Cocks Franklin H. , Shepard Marion L. 
Published: July 2010

AbstractThe liquidus surface of the primary ice phase field of the H2ONaCl–sucrose ternary system has been determined by differential thermal analysis (d.t.a.) techniques. Except in the region of high sucrose concentrations, the line of two‐fold saturation bounding this field also was determined. Non‐equilibrium glassy phases were formed throughout the system. The degree of metastability of these phases increases with sucrose concentration. At high sucrose levels, the metastability was such that detection of the line of two‐fold saturation was precluded. In general, it was found that sucrose was less effective on a weight percent basis than dimethyl sulphoxide and glycerol in depressing the melting point of primary ice and, consequently, less effective in suppressing salt concentration effects at low temperatures in the liquid phase which is residual to primary ice formation.
A novel method for the hydrolysis of ethyl and isopropyl silicates
Authors: Emblem Harold G. , Walters Ian R. 
Published: July 2010

AbstractThe hydrolysis of ethyl and isopropyl silicates without the use of an acid or base catalyst is described. The silicate and an alcohol which is a mutual solvent for water and the silicate are treated with water, preferably under reflux. For ethyl silicate the reaction temperature can be as low as 40°C. A liquid hydrolysate is obtained when the rate of water addition is carefully controlled. This hydrolysate will form a rigid coherent gel capable of binding refractory materials. Liquid hydrolysates prepared in this way have been used to make refractory shapes, also foundry moulds and cores for precision piece moulding work and an ethyl silicate hydrolysate can be used to prepare an anti‐corrosion paint based on zinc. It would be expected that other lower alkyl silicates can be treated similarly to form hydrolysates which give a rigid coherent gel capable of binding refractory materials and which can also be used to prepare anti‐corrosion paints based on zinc.
The prediction of the ternary liquid‐liquid equilibrium by means of the NRTL‐equation
Authors: De Fré Raphaël M. , Verhoeye Lucien A. 
Published: July 2010

AbstractThe prediction of ternary liquid‐liquid equilibria by means of the NRTL‐equation and using the parameters obtained by the correlation of the limiting binary systems is examined. The predicted data are compared with experimental data for systems composed of an aromatic and an aliphatic hydrocarbon and sulpholane. The number of sets of binary parameters obtained from the correlation of the binary systems is infinite. For any value of the non‐randomness parameter a corresponding pair of energy parameters can be determined, giving rise to a set fitting the data equally well. Limits to the value of the parameters can only vaguely be determined on the basis of their physical meaning. The upper limit of the non‐randomness parameter related to the heterogeneous binary system is more precisely defined. Some general conclusions for the selection of the parameters could be reached. The predicted heterogeneous area is in general too large but decreases with increasing values of the non‐randomness parameter of the heterogeneous binary system. The value of the parameters of the homogeneous binary system has only a small influence on the position of the binodal. The slope of the tie lines is mainly determined by the non‐ideality of the homogeneous binary systems.
Industrial brine production using power station waste heat to assist solar evaporation of sea water
Authors: Fellows S. Kevin , Rothbaum H. Peter 
Published: July 2010

AbstractThe rate of evaporation from a slightly heated pond of sea water, over and above the rate from an unheated control pond, has been found to be about 5.6 m of depth per year, for each kW/m2 of heat density applied. In winter about 40%, and in summer about 55%, of the added heat goes to increasing evaporation. In conjunction with local data on rainfall and natural evaporation, this value can be used to predict the net evaporation from a heated pond at a chosen site. If a power station in the Auckland area had sea water cooling ponds of the usual size, the combination of natural evaporation, rainfall, and evaporation due to heating would result in a net evaporation of 1.02 m per year and production of a concentrated brine containing at least 200 000 tonnes per year of salt, for a 1400 MWe power station. The degree of concentration allowed in the cooling pond is limited by the formation of scale in the condensers. By adding trisodium phosphate (obtainable cheaply in New Zealand from a low quality phosphate ore) and ammonium chloride to the brine, the scale‐forming calcium and magnesium can be precipitated as a mixture of metal phosphates and metal ammonium phosphates. The precipitate has potential value as a high‐analysis fertiliser or a cattle feed supplement. At the same time a non‐scaling brine is produced, which can safely be concentrated five‐fold in a power station cooling pond. The brine is then suitable as feed for a caustic/chlorine electrolysis plant. A portion of the caustic soda product must be recycled to the preparation of the trisodium phosphate.
Enzyme technology and molecular biology
Authors: Thomas Daniel , Gellf Gérard 
Published: July 2010

AbstractEnzyme technology could lead to a completely new type of chemical industry utilising moderate conditions of pH, temperature and pressure to produce from wastes or by‐products, high yields of complex chemicals without generating new waste products that pollute the environment. The potential of enzyme technology is great and applications are foreseen in industry, chemical analysis and in medicine. The new tools of this branch are immobilised enzymes or whole cells with enzymatic capacity. Methods of modern biochemistry must be applied, including genetic manipulation, molecular aging and protein chemistry.
Global aspects of biotechnology
Authors: Hedén Carl‐Göran 
Published: July 2010

AbstractThe attention given by the media to the turbulence caused by the current moves towards political independence often obscures the fact that a range of major problems, as well as powerful economic and technical forces, point towards increased levels of interdependence. Those two trends breed contradictions that inspire debates which actually give little room for considering the long‐range impact of science and technology. This is quite a serious matter, since the developments in some areas, like microelectronics and bioengineering, will obviously have such far‐reaching effects. Both rich and poor countries realise that such dynamic areas will sharpen the competitive edges between nations, but their potential for solving some common problems tends to be pushed into the background. In an effort to compensate for this tendency not only EEC through FAST, but also UNIDO has, however, recently initiated a series of reviews of the implications that various emerging breakthroughs will have on the economic growth and life‐styles both in developed and in developing countries. A few points that have emerged from the microbiology study and particularly the significance of biotechnology at the interphase between communications and settlement planning are highlighted.
The present state of fermentation reactors
Authors: Sittig W. 
Published: July 2010

AbstractThe actual application of fermenters other than stirred tanks in industry is scarce. Only minor changes have been performed in stirred‐tank design. Due to the increase of energy costs even the trend to higher power‐input rates has been stopped. Progress has been high as far as automatic analysis and control are concerned. For single‐cell protein plants bubble column and air‐lift loop systems have been improved. Surface aeration has regained interest because its energy cost can be kept considerably lower than with submerged systems. In the meantime the experience gathered with deep‐tank fermentation has begun to exert influence even on sewage treatment plants. A number of examples demonstrate that better economy has been achieved when flat basins are replaced by reactors of considerable depth.
Mathematical models and the design of biochemical reactors
Authors: Roels Joop A. 
Published: July 2010

AbstractThe application of so‐called macroscopic methods, that is a widely accepted tool in chemical as well as in biochemical engineering, rests on the possibility to construct a balance equation for the rate of change of the amount of an extensive quantity present in the system. In such a balance equation two types of contribution appear, one due to exchange of matter or energy with the environment and the other due to conversion in the system. A special class of quantities, i.e. the amounts of the chemical elements and energy, are not subject to net conversion in the system. These are termed conserved quantities. This observation leads to useful approaches towards the analysis of the stoicheiometry of aerobic and anaerobic growth and the calculation of heat production. For the kinetic description of the behaviour of systems a reduction of the complexity inherent to reality is a necessary prerequisite to obtain a workable model. The comparison of the relaxation times of the internal mechanisms of the system and those of changes in its environment is shown to be a powerful tool in the reduction of model complexity. An unstructured model, based on a very simplified picture of the complexity of the biomass present in a culture, is treated and its range of validity is analysed. Finally some aspects of the description of transport phenomena inside fermentation equipment and their interaction with microbial metabolism are discussed.
Some basic principles for the layout of tower bioreactors
Authors: Schügerl Karl 
Published: July 2010

AbstractDepending on the bubble‐coalescence property of the fermentation medium different aerator types should be used in tower bioreactors. When bubble coalescence is suppressed the use of concentrated gas‐dispersion at the tower bottom and for a coalescence‐promoting medium distributed gas‐dispersion along the tower are recommended. The latter can be realised in multistage towers with stage‐separating trays. The aerator efficiency depends on the structure of the turbulence which is produced by the aeration. The smaller the turbulence scale the higher the efficiency of the aerator. By using a loop the bubble‐coalescence rate is reduced and the cells are uniformly distributed along the column, but mixing time is increased and volumetric mass‐transfer is reduced.
Recovery of microbial polysaccharides
Authors: Smith Ian H. , Pace Gary W. 
Published: July 2010

AbstractMicrobial polysaccharides are a class of water‐soluble polymers which have grown in industrial importance over the past 20 years and present special problems of postfermentation recovery. Extracellular polysaccharides of commercial interest are considered with particular emphasis on the underlying principles and problems associated with each stage of processing.
Scale‐up of formate dehydrogenase by partition
Authors: Kroner K. H. , Schütte H. , Stach W. , Kula M.‐R. 
Published: July 2010

AbstractDetails of the process development and a flow diagram for the isolation of formate dehydrogenase from Candida boidinii are presented. Formate dehydrogenase was isolated from 30–50 kg of wet cells of C. boidinii to produce a technical‐grade enzyme, purity about 2–3 units mg−1 with yields of up to 75%. The preparation is suitable for NADH‐regeneration in a membrane reactor. A summary and comparison of different possible routes for the isolation and purification are given and analysed with regard to process time and volumes handled. It is shown, that the time required is much smaller and the resulting productivity is much higher, when aqueous two‐phase systems are fully utilised in the process.
Soluble temporarily immobilised biocatalysts
Authors: Hahn‐Hägerdal Bärbel , Mattiasson Bo , Andersson Elis , Albertsson Per Åke 
Published: July 2010

AbstractHigh catalytic density, good catalytic stability, simple catalyst recovery and facilitated product up‐grading are necessary requirements for the industrial application of biocatalysts such as enzymes and cells. These requirements can be met by using soluble immobilised biocatalysts. The biocatalysts are usually confined in space to one of two aqueous phases, both of which have high water content and therefore are biocompatible and non‐toxic to biological material. The products are either evenly distributed among the phases or partitioned to one of the phases. Soluble immobilised biocatalysts are particularly useful for bioconversions of particulate or macromolecular substrates, as well as for bioconversions involving product inhibition. The feasibility of soluble immobilised biocatalysts has been studied on the enzymic saccharification of cellulose, glucose fermentation with Saccharomyces cerevisiae and the bioconversion of cellulose into ethanol.
Protein recovery from dairy industry wastes with aerobic biofiltration
Authors: Wheatley Andrew D. , Mitra Ruth I. , Hawkes Herbert A. 
Published: July 2010

AbstractExperiments were carried out to improve the economics of effluent treatment by the recovery of single cell protein. Field observations showed that acidic strong wastes, such as those from the dairy industry, produced a predominantly fungal biomass. Mixtures of dairy waste and domestic sewage did not produce fungal films. The most common fungi isolated were Fusarium and Geotrichum, but the species was affected by local conditions, i.e. creamery, yoghurt, milk or cheese wastes and the load to the plant. Batch culture was used to determine the growth requirements of Fusarium and Geotrichum and continuous culture, on vertical and horizontal fixed films, to determine growth and sloughing at different organic loads. The fungi grew well on acidic strong wastes which would discourage other organisms. A 1 m3 h−1 pilot plant was built to treat the wastes from cheese, butter and cream production. The plant was run at pH 4–5 and at between 5 and 10 kg of BOD day−1 m−3. BOD removal was between 30 and 50% and biomass production between 0.1 and 0.5 kg of dry solids day−1. The filamentous fungal growth was separated from the tower effluent by an inclined screen. The amino acid content of the product was similar to other single‐cell protein. Feeding trials are being carried out.