bluuebunny/crossref_metadata_2025_split huggingface dataset:
The use of ferricyanide for the production of 3‐keto sugars by non‐growing suspensions of Agrobacterium tumefaciens
Authors: Fensom Anthony H. , Kurowski W. Martin , Pirt S. John 
Published: July 2010

AbstractFerricyanide serves as an electron acceptor for the conversion of sucrose and other sugars to 3‐keto derivatives by non‐growing suspensions of Agrobacterium tumefaciens. The rate of conversion of sucrose to 3‐ketosucrose is 4‐ to 5‐fold greater in the presence of ferricyanide than the aerobic rate. A continuous flow apparatus in which the cells are retained by a membrane filter while fresh sucrose and ferricyanide are passed through the suspension is described and has been used for study of the kinetics of ferricyanide reduction and 3‐ketosucrose production. The use of ferricyanide obviates the need for aeration for effecting this sugar transformation and has additional advantages in view of the increased rate of reaction. It is proposed that the principle may be extended to other microbial oxidations. The continuous flow apparatus may also have general applicability to study of the kinetics of product formation by non‐growing cell suspensions.
High‐slag cement mortars for brickwork and renderings
Authors: Kamel Abdel Aziz H. , Hassanein Ahmed , Abdel‐Azim Nazek 
Published: July 2010

AbstractThe suitability of clinker‐activated high‐slag cement mortars for use in brickwork construction and in rendered finishes, has been investigated. The study was carried out on a slag cement composed of 80% granulated slag, 15% clinker and 5% raw gypsum; its specific surface area was 4000 cm2/g. It was found that the slag cement mortars and cement‐lime mortars of the proportions commonly used in practice, have higher water‐retentivity than the corresponding mortars of ordinary Portland cement, and that their strengths are comparable to those of the latter mortars.
Carboxylation of o‐dichlorobenzene under pressure
Authors: Goswami A. K. , Palit S. K. 
Published: July 2010

AbstractWhen o‐dichlorobenzene was carboxylated with carbon monoxide in presence of water at high pressure the conversions to phthalic acid and benzoic acid at the optimum reaction conditions were 6.20% and 35.80% respectively without any catalyst, while with a catalyst (nickel iodide on silica gel; Ni : SiO2 = 50 : 50) these conversions were 8.90% and 39.85% respectively. Use of catalyst reduced the optimum temperature and pressure for the conversion to phthalic acid, while it reduced the optimum pressure and residence period for the conversion to benzoic acid.
Antifouling paints II. A more detailed examination of the effect of pigment volume concentration
Authors: Marson Frank 
Published: July 2010

AbstractThe effect of pigment volume concentration upon the leaching of soluble pigments from insoluble binders has been studied and the results used to extend a previously described1 theoretical treatment. The number of interconnecting holes between the cavities left after solution of the pigment from the insoluble binder is assumed to be related to the pigment volume concentration in a similar way to the number of contacts made by smooth spheres regularly packed at the same solids content. An empirical equation is used to relate the number of contacts made between spheres to their density of packing, and consequently to relate the number of interconnecting holes between cavities to the pigment volume concentration.Predictions based on the resulting relationship are compared with the leaching characteristics measured for three different coating compositions, each made with a range of pigment volume concentrations using two different vinyl resins and two grades of copper (I) oxide pigment. The predicted variations with pigment volume concentration of initial leaching rate, and of initial rates of decrease in leaching rates, hold reasonably well for pigment volume fractions between 0.30 and 0.80, the full range studied. Longer term leaching behaviour appears predictable only for paints of pigment fractions above about 0.45; anomalies below this figure are attributed to lack of pigment solution.Statistical analysis of experimental leaching rate data indicate that the initial leaching rates are unaffected within limits by the type of binder and pigment. The two copper oxide pigments used behaved similarly. However, the kind of binder used does affect the rate of decrease in leaching rate. The experimental data is consistent with the theoretical model employed and with the concept that the thickness of binder separating pigment particles and hence the interconnecting hole size remains approximately constant irrespective of pigment volume concentration.
Interaction of gas bubbles with liquid lead
Authors: Ali Anwar , Ray Hem Shanker 
Published: July 2010

AbstractThe interaction of bubbles of hydrogen and argon‐oxygen mixtures with liquid lead has been investigated using an oxide solid electrolyte cell of the type magnified image where O denotes oxygen, of variable concentrations dissolved in molten lead.Oxygen concentration in molten lead has been varied through bubbling oxidising or reducing gases. The variation in concentration has been obtained by measuring continuously the cell e.m.f. by a recorder. The effects of bubble size and temperature on mass transfer coefficient of oxygen during oxygen dissolution and oxygen removal operations have been studied.The liquid phase mass transfer coefficient increases with decreasing bubble size and increasing temperature. The observed variations agree well with equations available in the literature for low temperature liquids.
Thermal decomposition of zinc oxalate dihydrate: Kinetics of dehydration and pyrolysis in various atmospheres
Authors: Mikhail R. Sh. , Guindy N. M. , Ali I. T. 
Published: July 2010

AbstractThermogravimetric analysis has indicated that a convenient range for the study of Zn(COO)2.2H2O dehydration is 120–300 °C, while for pyrolysis it is 320–400 °C. Kinetics of isothermal dehydration and pyrolysis were studied as two consecutive steps in various atmospheres, namely in constant water vapour pressure of 4.8 and 8 mm Hg, in air saturated with water vapour at 25 °C and in vacuo. The kinetic data indicated that dehydration is a pseudo‐first order reaction, which is highly dependent on the surrounding atmosphere. The mechanism of dehydration is either activated diffusion (alternatively surface diffusion) for dehydration in vacuo or in low water vapour pressures, or activated desorption for dehydration in presence of high water vapour pressure. On the other hand pyrolysis is independent of the prevailing atmosphere, and the energy of activation is of the order of the enthalpy change of the reaction.Earlier studies have involved contact of the dehydrated oxalate with air, or have obscured the influence of the prevailing atmosphere, by dehydrating the sample material at the pyrolysis temperature. These conditions are considered in the present investigation.
Synthesis of isohydrazones by the reaction of chlorine and ammonia in the presence of a ketone (a new hydrazine process) II. A colorimetric method of analysis of organic intermediates used in the synthesis of hydrazine
Authors: Jermyn T. J. , Jeffreys G. V. 
Published: July 2010

AbstractA colorimetric method of analysis of azines and isohydrazones which is based on their reaction withp‐dimethylaminobenzaldehyde is discussed. A second method of analysis involving their conversion to hydrazine sulphate has also been developed and excellent agreement between the two methods has been obtained. The colorimetric technique is extremely sensitive, and it was found that at low concentrations the effects of water and ammonia on the calibrations was negligible.
Synthesis of terpene alcohols from isoprene oligomers
Authors: Watanabe Shoji , Suga Kyoichi , Fujita Tsutomu , Takasaka Nobuo 
Published: July 2010

AbstractVarious terpene alcohols were prepared from isoprene oligomers via two steps: epoxidation with peracetic acid and isomerisation with aluminium triisopropoxide. For example, 2‐methylene‐6‐methyl‐7‐octene‐1‐o1 was prepared from 2,6‐dimethyl‐1,7‐octadiene. From 2,6‐dimethyl‐2,7‐octadiene, 3,3,6‐trimethyl‐1,5‐heptadiene, 2,7‐dimethyl‐2,6‐octadiene, 2,6‐dimethyl‐1,3,6‐octatriene, 1‐methyl‐4‐isopropenyl‐1‐cyclohexene, and 1,5‐dimethyl‐1,5‐cyclooctadiene, the corresponding alcohols were obtained, respectively.
Exocellular β‐1,3 glucanase synthesis by continuous‐flow cultures of a thermophilic streptomycete
Authors: Lilley G. , Rowley B. I. , Bull A. T. 
Published: July 2010

AbstractProduction of a β‐1,3‐glucanase by a thermophilic streptomyces species in chemostat cultures was studied. In growth medium containing glycerol, synthesis of β‐1,3‐glucanase synthesis occurred at dilution rates less than 0.20 h−1. Chemostat cultures operating under non‐steady state conditions were optimal for glucanase production. Under the latter conditions of growth the extent of enzyme synthesis was dependent on the magnitude of the step down in dilution rate from an existing steady state value. Furthermore, induction of β‐1,3‐glucanase by gentiobiose only occurred during non‐steady state growth.
The use of continuous ion exchange (CIX) in copper recovery problems
Authors: Naden D. , Evans J. P. 
Published: July 2010

AbstractSolid ion exchange using commercially available resins is suggested as a method for recovering copper directly from the slimes streams in copper recovery operations. The presence of slimes often reduces the efficiency of vat leach operations and the slimes are therefore separated and treated in a separate sulphuric acid leach stream. A similar pre‐leach separation of sands and slimes is suggested in flowsheets where a fine ore grind results in the necessity to wash the leached ore in large counter‐current washing and thickening units with a resulting dilution of the leach stream. Separation of the slimes, with CIX recovery of copper directly from the slimes stream, greatly reduces the size of the leached ore washing units and results in lower flows of more concentrated solution. Copper specific resins are not required in these flowsheets as the high sulphuric acid CIX eluate is passed to the sands leach unit as make up acid and all the copper may then be recovered by a copper specific solvent extraction step in the sands leach stream. Conventional equipment may be used for all the unit operations suggested.A laboratory investigation has shown that commercially available resins with suitable properties are available. Techniques of estimating a CIX process design from laboratory scale tests, for any process situation, have been developed by Davy Powergas Research and Development Division for the resins examined.
The production of NPK fertilisers by ion exchange
Authors: Knudsen K. C. 
Published: July 2010

AbstractIon‐exchange technique is used for the production of chloride‐free NPK‐fertilisers. Phosphate Rock (calcium phosphate) is solubilised in nitric acid, and calcium ions in the solution are exchanged with potassium ions from a cation exchanger, which is regenerated with a potassium chloride solution. The process permits low cost production of high grade fertilisers because it is based on the cheapest available raw materials. Special ion exchange method and apparatus have been developed in order to avoid excessive dilution of the product solution, to obtain low chemicals consumption for regeneration and to cope with the demand for a simple and reliable system.
Bound water in sewage sludges and its relationship to sludge surfaces and sludge viscosities
Authors: Forster C. F. 
Published: July 2010

AbstractAn examination of activated and digested sludges has shown that surface components are significant in determining the rheological characteristics of these sludges. On the basis of a series of enzymic treatments, it would appear that in activated sludge the most important constituents are polysaccharide and protein; whilst in digested sludge, lipopolysaccharide and, at times, proteins are the most significant surface polymers. Subsidiary studies showed that the bound water content of the sludges was associated with the rheology and that this association could be modified by the action of metal ions.
Effect of the polymer matrices on the immobilisation of microbial cells by radiation polymerisation
Authors: Kumakura Minoru , Kaetsu Isao 
Published: July 2010

AbstractStreptomyces phaeochromogenes cells were immobilised by radiation polymerisation, at low temperature, using various acrylate and diacrylate monomers. The form and enzymatic activity of the immobilised cell composites were affected by the molecular structure of the monomers. The activities of the composites from acylate and diacrylate monomers increased with increased numbers of methylene or ethylene glycol units in the monomers. The water content of the immobilised cell composites was also affected by the molecular structure of the monomers. The pH and heat stabilities of the immobilised cell composites were increased when the polymer matrix had a porous sponge structure.
Cellulolytic properties of Chaetomium crispatum
Authors: Geeraerts Herman A. M. , Vandamme Erick J. 
Published: July 2010

AbstractThe cellulolytic properties of a Chaetomium crispatum strain were investigated. The cellulolytic enzyme complex i.e.: exo‐1,4‐β‐glucosidase (EC 3.2.1.74); endo‐1,4‐β‐glucanase (EC 3.2.1.4.) and β‐glucosidase or cellobiase (EC 3.2.1.21) displayed optimal activity at pH 5.0 and 25°C. Although carboxymethyl‐celluloses are the usual pseudo‐substrates for this enzyme complex, those with a high degree of substitution gave rise to poor growth and low cellulase activity. Insoluble crude cellulosics such as newsprint, recycled paper, rice and flax straw were substantially solubilised at 28°C within 3–5 days of fermentation. A study of the cellulase‐complex formation during the growth cycle revealed that β‐glucosidase was produced mainly intracellularly in the early exponential phase, while the overall exo‐1,4‐β‐glucosidase and endo‐1,4‐β‐glucanase formation gradually increased during the total fermentation cycle. The mycelial protein of Chaetomium crispatum grown on crude cellulosics displayed a favourable amino acid pattern, indicating its potential value as a source of single cell protein (SCP).
The significance of ATP in the settlement of activated sludge
Authors: Clarke Alan R. , Forster Christopher F. 
Published: July 2010

AbstractA laboratory‐scale activated sludge plant treating simulated coke oven liquors was used to examine the settleability of the sludge in relation to its ATP concentration. On the basis of the data obtained a model was developed which described sludge settlement and was based on Monod kinetics and sludge activity (measured as ATP). The model was tested against data obtained previously from a sewage‐fed plant.
An extended bottleneck model: Accounting for the metabolic turnover effect in microorganisms
Authors: Agrawal Pramod , Lim H. C. , Ramkrishna D. 
Published: July 2010

AbstractThe bottleneck model proposed by Powell1 can describe the growth rate hysteresis effect, but fails to account for the stationary state of microbial cultures. It is modified to obtain an extended bottleneck model (EBM), which adequately represents the stationary state of microbial cultures. The basis for modification is the metabolic turnover of proteins in microorganisms. Under special conditions the EBM can be reduced to the Powell bottleneck model or the Monod model. The EBM yields improved predictions of the transient growth of E. coli in nitrogen limited cultures.
Mechanisms of biofilm formation on aluminium tubes
Authors: Bott T. R. , Miller P. C. 
Published: July 2010

AbstractThe development of biofilms in contact with flowing liquids was monitored in a biofouling culture apparatus which contained aluminium tubes and which was inoculated with Pseudomonas fluorescens. Tests were carried out in which, alternately, the nutrient feed or the bacterial supply was stopped. Results showed that once the surface is colonised, the predominant mechanism for biofilm development was growth within the film. Maximum biofilm development occurred at liquid flow velocities around 1 m s−1. Rapid development occurred even in the presence of very small amounts of nutrient.
A study of biogas generation from coconut pith
Authors: Radhika L. G. , Seshadri S. K. , Mohandas P. N. 
Published: July 2010

AbstractBiogas production from cowdung is well studied. Coconut pith is an agricultural waste available in large quantities in Kerala: the possibility of using coconut pith for biogas production was studied. It was found that coconut pith in combination with cowdung gives considerable amount of biogas, while alone it did not produce any gas. The optimum combination was found to be 60% pith and 40% cowdung. Study of dilution effect on the slurry showed that the optimum solid‐liquid ratio is 1:20. Partial removal of lignin from pith increased the rate of biogas production. Gas produced from a mixture of cowdung and pith was found to have a higher methane content than that produced from cowdung only.
The influence of COD, hydraulic, temperature and pH shocks on the stability of an unheated fluidised bed reactor
Authors: Bull Michael A. , Sterritt Robert M. , Lester John N. 
Published: July 2010

AbstractAn anaerobic fluidised bed reactor, operating at room temperature, was used to treat a synthetic meat extract wastewater with an influent COD of 1250 mg 1–1. It was subjected to large increases in influent COD and flow rate for 4‐and 8‐h periods. The reactor tolerated these transient changes satisfactorily and with no long term detrimental effects. Normal operation was regained within 9h. Variations in operating temperature and influent pH were also examined. Four hour duration, 10°C temperature increases and decreases had little effect on effluent quality, but long term operation at a low influent pH was considered inadvisable. A simulated working week experiment was carried out with a 48‐h 90% influent flowrate reduction, followed by a return to normal operation. The reactor tolerated these conditions well, with full recovery made within a few hours. The resistance of the reactor to unfavourable process conditions is discussed. The extrapolation of laboratory data to practical operating conditions is also considered.
Optimisation of cellulose conversion into fungal cell mass
Authors: Hecht Volker , Schügerl Karl , Scheiding Wolfgang 
Published: July 2010

AbstractChaetomium cellulolyticum was cultivated on Avicel and/or stream‐and NH3‐pre‐treated straw in a 20 litre stirred tank reactor with batch and/or fed‐batch operation. The influence of the substrate concentration, the impeller speed and the fed‐batch operation on cell productivity was investigated. Steam‐pretreated straw can be better utilised by the fungus than NH3‐pretreated straw. The optimal conditions at which maximum cell productivity and/or maximum cell mass concentration can be attained were evaluated for stream‐pretreated straw. At the beginning of the growth phase the oxygen consumption rate reaches a significant maximum. At this point the enzyme activity begins to increase. The investigations with Avicel indicate that the cell productivity could be significantly increased by fed‐batch operation. A microprocessor‐controlled fed batch process controlled by alkaline consumption is recommended.
Electron‐transfer coupling in microbial fuel cells: 1. comparison of redox‐mediator reduction rates and respiratory rates of bacteria
Authors: Roller Sibel D. , Bennetto H. Peter , Delaney Gerard M. , Mason Jeremy R. , Stirling John L. , Thurston Christopher F. 
Published: July 2010

AbstractRedox mediators promote electron transfer in microbial fuel cells. The reduction of a range of redox mediators by bacteria was studied in some detail in order to identify effective mediator—organism combinations. Rates of reduction of mediator dyes by bacteria were measured spectrophotometrically at 30°C under anaerobic conditions for standardised concentrations of organism, substrate and dye. The kinetics of dye reduction showed two general patterns: a simple, exponential curve or a complex curve with an initial linear rate followed by a faster exponential rate of reduction. Dye‐reduction rates were greater than rates of oxygen consumption (QO2) for several combinations of organism and redox dye. Thionine, brilliant cresyl blue, methylene blue and benzyl viologen were tested in combination withAlcaligenes eutrophus, Azotobacter chroococcum, Bacillus subtilis, Escherichia coli, Proteus vulgaris, Pseudomonas aeruginosaandPseudomonas putida, using glucose and succinate as substrates. Rates of reduction of alizarin brilliant blue, 2,6‐dichlorophenolindophenol, gallocyanine, new methylene blue,N,N‐dimethyl‐disulphonated thionine, phenazine ethosulphate, resorufin, safranine‐O, phenothiazinone and toluidine blue‐O were also measured withPr. vulgarisonly. ForE. coli, both QO2and the rate of thionine reduction increased with increasing temperature in the range 25 to 37°C, but forPr. vulgaristhionine reduction rates did not correlate with temperature in this way. Dye‐reduction rates and QO2forAz. chroococcumwere dependent on the components of the washing solution and/or the temperature at which cell suspensions were prepared. The results are discussed in relation to the use of these dyes as electron‐transfer mediators in microbial fuel cells.
CO2 absorption rate in an algal culture: Effect of pH
Authors: Lee Yuan‐Kun , Pirt S. John 
Published: July 2010

AbstractIn a CO2‐limited algal culture, grown in a tubular loop photobioreactor, the maximum rate of CO2 absorption increased about 1.5‐fold when the culture pH value was increased from 6.5 to 7.5 with a fixed initial PCO2. The mean volumetric CO2 transfer coefficient (KLa) increased about 1.8‐fold. The bicarbonate ion concentration would be increased 10‐fold by the pH increase. The effect of pH on the absorption rate is attributed to changes in either the CO2 diffusivity, the gas bubble size, or the CO2 reaction kinetics at the gas/liquid boundary.
Production and properties of Aspergillus niger inulinase
Authors: Derycke Dirk G. , Vandamme Erick J. 
Published: July 2010

AbstractAn inulinase producing Aspergillus niger strain was isolated from Compositae rhizosphere soil samples. High inulinase levels were produced on a corn steep liquor (CSL)‐maltose medium in the absence of inulin at 28°C within 110 h of fermentation. Media based on CSL‐sucrose yielded high cell‐bound inulinase activity; on inulin‐based media the enzyme was mainly extracellularly produced. Both crude extra‐and intracellular inulinase preparations displayed identical pH and temperature optima with maximal activity at pH 4.3–4.4 and at 55–56°C. These properties are favourable in view of large scale inulinase application for pure fructose production. High operation temperatures would avoid microbial contamination of reactors and would allow the use of high inulin‐substrate concentrations, a limiting factor in obtaining high conversion ratios. The remarkably low pH optimum prevents colour formation and undesirable chemical side reactions. An advantageous low ratio of invertase to inulinase activity (S/I value) of 0.85 was found for the crude extracellular enzyme preparation. Crude inulin (chicory) extracts are hydrolysed faster than pure inulin. Apart from inulin (100% hydrolysis), sucrose (45%) and raffinose (20%) are also hydrolysed, and no liberation of oligomers or of sucrose from inulin was observed. These facts indicate that the A. niger enzyme is an exo‐acting inulinase. The above characteristics make this A. niger inulinase an industrially attractive enzyme for the preparation of pure fructose from inulin‐containing agricultural crops.