bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sorption of caesium by hexacyanocobaltate(III)
Authors: Mekhail Fikry M. , Ibrahim George S. , Aly Hisham F. 
Published: July 2010

AbstractSorption properties of the commercially available hexacyanocobaltate(III) complex with respect to the retention of caesium have been studied. The saturation capacities are determined from the adsorption isotherms in solutions of pH 6.5, in M HNO3 and in simulated medium‐active waste. The solubility of Co(II) hexacyanocobaltate(III) in acid and in alkaline solutions indicates its stability in acid medium. The sorption of caesium on hexacyanocobaltate(III) complex seems to proceed via an ion‐exhcnage mechanism.
Cell manipulation in ultrasonic standing wave fields
Authors: Coakley W. Terence , Bardsley David W. , Grundy Martin A. , Zamani Freidoun , Clarke David J. 
Published: July 2010

AbstractParticles suspended in either travelling or standing wave fields experience non‐zero time averaged radiation forces. In a standing wave field such forces can result in migration of the particles to preferred positions separated by distances of half an acoustic wavelength. Radiation forces also give rise to either interparticle attraction or repulsion and can exert a torque on suspended particles. The forces depend on some or all of the following properties (i.e. particle size and shape, sound frequency, the square of the sound pressure amplitude) and on the differences between the density and compressibility of the particles and those of the suspending phase. The forces acting on suspended particles are analysed and threshold pressures for the migration of particles to half‐wavelength separations are derived. It is shown that appropriate choice of sound pressure amplitude should lead either to separation of particles of different densities and compressibilities in the sound field or to concentration of mixed samples essentially at the same location. Experimental observations of ultrasonic radiation force effects on cells are reviewed as are applications of radiation forces to effect cell concentration in electrofusion procedures and the use of ultrasound to support cells away from solid surfaces. Examples of cell concentration, cell alignment and cell‐cell interaction are presented.
Extraction and characterisation of extracellular polymers in digested sewage sludge
Authors: Karapanagiotis Nicolas K. , Rudd Thomasine , Sterritt Robert M. , Lester John N. 
Published: July 2010

AbstractFive different bacterial extracellular polymer extraction methods were compared on digested sewage sludge. A washing step was necessary to remove and eliminate the slime from the sludge sample, in order to distinguish it from the material more tightly bound to the sludge solids. An ion‐exchange resin method was the most effective and least disruptive of all treatments tested, based on the relatively high extracellular polymer yield and the small amount of cell disruption demonstrated by the fractionation and characterisation of the extracted material.The extracellular polymer extracted contained protein and polysaccharide in a ratio of approximately 3:1, and contributed a relatively small proportion of the total solids in digested sludge. This was comparatively less than is extracted in activated sludge. The ion‐exchange resin method yielded 1% by weight of polysaccharide and 3% of protein, whereas ethanol‐insoluble material accounted for 3.5% of the solids in digested sludge.
Comparison of alkali and steam (acid) pretreatments of lignocellulosic materials to increase enzymic susceptibility: Evaluation under optimised pretreatment conditions
Authors: Fox David J. , Gray Peter P. , Dunn Noel W. , Marsden Warwick L. 
Published: July 2010

AbstractThe alkali pretreatment of sugar cane bagasse was optimised and compared with an optimised steam (acid) pretreatment. The optimised alkali pretreatment gave an overall sugar yield of 37.4 g sugars per 100 g bagasse accounting for 43.8% of the initial xylan and 64.5% of the glucan. Potential effluent problems were identified with the alkali treatment and several strategies were suggested to minimise them, with liquor recycling showing some promise. The optimised steam (acid) pretreatment gave an overall sugar yield of 55.7 g sugars per 100 g bagasse accounting for 76.5% of the xylan and 89.5% of the glucan. The superiority of the steam (acid) pretreatment over the alkali pretreatment depends on the ability to utilise the xylose produced.
Spectrophotometric determination of nickel in steels
Authors: Zaki M. Tarek M. , Sedra M. N. R. , Attiya S. M. 
Published: July 2010

AbstractNew, simple and sensitive spectrophotometric methods for the determination of nickel with hematoxylin in the presence and absence of a cationic surfactant are described. The sensitivity of the color reaction of nickel and hematoxylin is greatly increased by the sensitizing action of cetyltrimethylammonium bromide (CTAB). The optimum pH range for the formation of nickel‐hematoxylin and nickel‐hematoxylin‐CTAB systems is 7.8–8.3 and 7.4–8.1, respectively. The molar absorptivities are 4.1 × 104 and 8.3 × 104 mol−1 cm−1 at 595 and 608 nm, respectively. The corresponding values of Sandell's sensitivity index are 0.0014 and 0.0007 μg cm−2 of nickel. The methods adhere to Beer's law up to 0.52 and 0.60 ppm nickel, respectively. The mole ratio of nickel‐hematoxylin in both complexes is 1:2. Preliminary separation of nickel by extraction as dimethylglyoxime chelate into chloroform makes it possible to determine nickel in steel samples.
A new spectrophotometric method for the determination of ferrous iron in the presence of ferric iron
Authors: Herrera Leandro , Ruiz Pauline , Aguillon Juan C. , Fehrmann Alexis 
Published: July 2010

AbstractA new spectrophotometric method for the determination of ferrous iron concentration in samples containing ferric iron is presented. This new method is a modification of the Muir o‐phenanthroline ferrous iron determination method.The new method consists of the quantitative spectrophotometric determination of Fe(II) by o‐phenanthroline, but in which the ferric iron is complexed with sodium fluoride to eliminate interferences.A critical experimental comparison between the Muir spectrophotometric method, the Kolthoff titrametric method and the new proposed method is presented. Whenever Fe(III) accounts for more than 50% of the total iron in a sample, the method of Muir overestimates Fe(II).The proposed method has a range of 1–10 μg ferrous iron. It is as insensitive to other metal ions as the original method of Muir and is insensitive to Fe(III) up to a point where Fe(III) might be as high as 95% total iron.The proposed method is suitable for Fe(II) determination in bacterial leaching systems, where Fe(II) might be as low as 1% of total iron.
Characterization of hydrous titania from titanous chloride. III: Thermal studies (B) and surface texture
Authors: Ragai Jehane 
Published: July 2010

AbstractThe present investigation deals with the surface properties of titania gels prepared from titanous chloride and ammonium carbonate under acidic and alkaline conditions of pH. The dehydration characteristics of such hydrous oxides are also investigated by means of simultaneous differential thermal analysis, thermogravimetric analysis and differential thermogravimetric analysis. Contrary to hydroxide‐precipitated gels, even at a low pH of precipitation, very little ‘coordinated’ water remains in these gels.It is suggested that it is the concomitant presence of ammonium and carbonate ions in the precipitating agent, acting together, that provide the conditions favorable for the development of microporosity and high surface area in the gels.
Application of powder coatings: Viscosity and density measurements in a conventional fluidized bed
Authors: Damia Augusto J. , Caprari Juan J. 
Published: July 2010

AbstractThe values of dynamic viscosity characteristic of the different stages in a fluidized bed were determined using a torsional viscometer (Dragge Eppretch Rheometer type STVK) with a specially designed cup. Experiments were made with three kinds of rotor: a full paddle, a cylinder and a split paddle.Apparent densities have been determined by measuring differential pressures across known heights in an experimental fluidized bed. A modified Matheson equation has been developed to determine the values of maximum bed density and minimum bed porosity, associated with the inset of fluidization.The experimental determinations were made with a white powder coating in which the granulometric distribution and composition were previously established.
A kinetic model for pretreated wheat straw saccharification by cellulase
Authors: Gonzàlez Gloria , Caminal Gloria , De Mas Carles , Lopez‐Santín Josep 
Published: July 2010

AbstractA kinetic model for enzymatic hydrolysis of pretreated wheat straw able to describe the reaction process considering only macroscopic properties of enzyme and substrate would be useful in reactor design and scale‐up. In this study Michaelis‐Menten equations were used for different reaction schemes to fit experimental results obtained, working with enzyme loads between 5 and 44 i.u. g−1 pretreated straw. Kinetic parameters were obtained by means of an optimization computer program.
Anaerobic digestion of seaweed for biogas: A kinetic evaluation
Authors: Anjaneyulu K. , Tarwadi S. J. , Mehta D. J. 
Published: July 2010

AbstractA kinetic study of biogas production in batch digesters by anaerobic digestion of seaweed, Sargassum tenerrimum, with a mixed bacterial culture consisting of methanogenic bacteria and an algin‐degrading bacterial strain was carried out at different concentrations of dry total solids. Specific rate constants of biogas production during the lag, exponential and monomolecular (stationary) phases of bacterial growth were determined. About half the total volume of biogas was generated during the exponential phase irrespective of the concentration of seaweed in the digesters. The specific rates of substrate destruction and biogas generation in the stationary phase decreased with increasing substrate concentration. The yield of biogas per gram dry total solids of seaweed was about the same at all concentrations, but with a marked decline at 12% (w/v) total solids. The maximum destruction of volatile solids effected was about 63% over a period of 72 days.
Overview of the pulp and paper industry from a chemical industry perspective
Authors: Smook Gary A. 
Published: July 2010

AbstractThe major processes of the pulp and paper industry are overviewed with particular emphasis given to existing chemical requirements; processing trends are identified which may affect future chemical requirements. The pulp and paper industry represents a vast market for chemicals. On the papermaking side, overall chemical usage will probably increase due to ever greater product sophistication and emphasis on value‐added grades. On the pulping side, the pressing needs for fibre conservation and more effective utilization of fibre sources can only be achieved through continuing exploitation of chemical developments.
Effect of plasticizer on the physicochemical properties of vinyl coatings submerged in artificial seawater
Authors: Di Sarli A. R. , Schwiderke E. E. , Podestá J. J. 
Published: July 2010

AbstractThe effect that type and content of plasticizer has on several physicochemical properties of vinyl varnishes was studied.A vinyl resin (VAGD) plasticized with di‐isodecyl phthalate (DIDP) or tricresyl phosphate (TP) in 2:1, 4:1, 6:1 and 10:1 resin:plasticizer ratios was employed. Naval steel plates were coated with the different formulations and submerged in artificial seawater.The coefficients of diffusion, solubility and permeability to water were calculated, measuring the impedance vector evolution during the first 15 min of immersion. Corrosion potential measurements as well as the ionic resistance (Rm) and dielectric capacitance (Cm) were carried out for 40 days.The results obtained make it possible to infer that, independently of the type of plasticizer employed in the formulation, the increase of the resin:plasticizer ratio produces a decrease of water permeability. This effect is associated with more positive corrosion potentials, higher ionic resistances and lower dielectric capacitances. Besides, for equal resin:plasticizer ratios, the samples plasticized with DIDP showed, in general, lower permeability than those plasticized with TP.Finally, the high barrier effect corresponding to samples with 6:1 and 10:1 resin:plasticizer ratios is very important since decreasing solvent content also decreases solvent retention in the film and consequently its adverse effects on the protective properties of the coating.
Dynamic measurement of KLa with oxygen‐enriched air during fermentation
Authors: Kim Dong‐Jin , Chang Ho‐Nam 
Published: July 2010

AbstractA method of KLa estimation, utilising gassing with oxygen‐enriched air, was applied to fermentations of Escherichia coli and Saccharomycopsis lipolytica. The method consists of sudden inlet oxygen concentration increase while total inlet gas flow rate is held constant. Dissolved oxygen concentrations are measured by an oxygen electrode, the response of which is assumed to be first order. KLa can be estimated from the slope of the semilogarithmic plot of the electrode response versus time. The method seems to be valid as long as the dissolved oxygen concentration is higher than the critical oxygen concentration below which oxygen uptake rate is dependent on dissolved oxygen concentration.
Resins for high‐purity water production
Authors: Ball M. , Harries R. R. 
Published: July 2010

AbstractIn plants for the production of feedwater for high‐pressure boilers, it is important to specify appropriate parameters for the ion exchange resins used. The parameters proposed for all make‐up plant resins are total exchange capacity, bead integrity and physical strength (resistance to osmotic shock and attrition), supplemented by maximum, minimum and harmonic mean bead sizes appropriate for use in cation exchange, anion exchange and mixed bed units.For condensate purification plant resins, total exchange capacity, bead integrity, physical strength and bead size are again specified, with tighter limits for resistance to osmotic shock and attrition, to reduce the risk of physical breakdown in service. Bead densities should be included and closer bead size distributions to ensure good overall kinetics for cation and anion exchange, whilst maintaining good separation on backwashing. A minimum mass transfer coefficient is also required to ensure adequate anion exchange kinetics for sulphate at the typical condensate purification plant linear flow rate of 100m/h. Consideration should be given to specifying the maximum organic matter that may be released by new resins in contact with water in an endeavour to limit the amount of deleterious chemical compounds produced in manufacture that can be released into the treated water.
Vernolic and cyclopropenoid fatty acids in Plectranthus mollis, syn. Plectranthus incanus, link seed oil: A rich source of oil
Authors: Mahmood Chirag , Daulatabad Jehan D. , Mirajkar Abdurrazzaque M. 
Published: July 2010

AbstractPlectranthus mollis, syn. Plectranthus incanus Link seed oil contains the following acids: palmitic (7.2%), stearic (13.6%), oleic (21.7%), linoleic (46.5%), malvalic (2.3%), sterculic (3.2), and vernolic (6.1%).
Landfill co‐disposal: Hydraulic loading rate considerations
Authors: Watson‐Craik Irene A. , Senior Eric 
Published: July 2010

AbstractSingle‐stage laboratory models, with liquid recycle, were used to examine the attenuation of phenol (2 mmol dm−3) in domestic refuse. High hydraulic loading rates (≥37.3 cm3 h−1) maximised phenol attenuation rates although, with lower loading rates (20.9 cm3 h−1), residual substrate concentrations remained low. With successive reservoir supplementations, these patterns were repeated although for each loading rate the maximum phenol concentration attenuated by each column passage increased. A semilogarithmic plot of hydraulic load against filter efficiency approximated to a straight line and thus indicated that further increases in hydraulic loading rates would not facilitate significantly improved total phenol removals.
Factors affecting biosurfactant production using Pseudomonas aeruginosa CFTR‐6 under submerged conditions
Authors: Ramana K. Venkata , Karanth N. G. 
Published: July 2010

AbstractStudies on the biosurfactants produced by Pseudomonas aeruginosa CFTR‐6 revealed that they consisted of glycolipids R‐1 and R‐2. A time course study of fermentation indicated that the appearance of glycolipids in the fermentation broth coincided with the exhaustion of nitrogen and the commencement of the stationary phase with respect to biomass. The effect of variation of the media components such as carbon, nitrogen, phosphate and metal ions has been investigated. The following values were found to be optimum for biosurfactant production: glucose, 20 g dm−3; carbon to nitrogen ratio, 38; phosphate, 30 mmol dm−3; MgSO4.7H2O, 100 mg dm−3. Addition of iron to the medium significantly diminished the glycolipid yield.
Effects of oxygen diffusion on recombinant E. coli B (pTG201) plasmid stability, growth rate, biomass production, and enzyme activity in immobilized and free bacteria during continuous culture
Authors: Huang Jun , Dhulster Pascal , Barbotin Jean‐Noël , Thomas Daniel 
Published: July 2010

AbstractThe influence of oxygen diffusion on kinetic properties, plasmid instability, biomass production and enzyme production of recombinant Escherichia coli B containing plasmid pTG201 was investigated. The experiments were carried out using continuous cultures and two types of medium, with immobilized bacteria in carrageenan gel and free bacteria. The specific growth rate of immobilized bacteria was a monotonic function of dissolved oxygen (DO) level from 0% DO to 100% DO, and it increased 63% in L‐Broth medium and 70% in minimal medium with respect to 0% DO, but the growth rate was quickly reduced above 75% DO (L‐Broth medium) or 50% DO (minimal medium) in free bacteria. The specific growth rate was generally higher for free bacteria than for immobilized bacteria. The plasmid was substantially more stable at 0% than at 50% or 100% DO in both immobilized and free bacteria. Biomass production was proportional to the growth rate, and this in turn was greatly influenced by the DO concentration. Measurements of enzyme production showed that the enzyme activity was diminished in both immobilized and free bacteria when oxygen was eliminated. The observed increase in plasmid stability may have resulted from the disturbance of low growth rate and decreased expression of the enzyme.
Influence of the contact model and support characteristics on the partition constant for kinetically controlled synthesis of peptides
Authors: Clapés Pere , Mata‐Alvarez Joan , Valencia Gregorio , Reig Francesca , Haro Isabel , García‐Antón José‐María 
Published: July 2010

AbstractThe influence of the physical characteristics of the support and the contact model on the partition constant (p) in kinetically controlled peptide synthesis was studied. Large values for p were obtained using a small pore size carrier and a recirculation reactor. However, with a larger pore size carrier and the same contact model, p values were lower, the latter conditions were more favorable for product synthesis.
Equilibrium adsorption isotherms for basic dyes onto lignite
Authors: Allen Stephen J. , McKay Gordon , Khader K. Y. H. 
Published: July 2010

AbstractThe adsorption of two basic dyes in aqueous solutions onto lignite is reported. The adsorption equilibrium isotherms are recorded for the dyes in single component solution. The isotherms are plotted to obtain the Freundlich constants, the Langmuir constants, and the Redlich‐Peterson constants.
Formation of submillimeter liquid‐encapsulated gas bubbles in an immiscible liquid
Authors: Mori Yasuhiko H. , Kogo Yasuyuki , Kaminaga Keiji 
Published: July 2010

AbstractA simple device is described which enables a steady formation of small ‘two‐phase bubbles’ each consisting of a core of a gas and a shell of a liquid which is immiscible with the surrounding liquid. The device is essentially a fine double‐tube nozzle which permits parallel feedings of the gas and the liquid to its tip having a particular configuration. It has been found that the device successfully releases into a pool of pure water, liquid‐fluorocarbonencapsulated bubbles of uniform diameter of less than 1 mm. The function of the device is lost, however, when the water is contaminated with surfactants. The device may be applicable to some extraction processes whose efficiency should be increased by producing small liquid‐encapsulated bubbles.
Removal and recovery of uranium by modified Pinus radiata D. Don bark
Authors: Freer Juanita , Baeza Jaime , Maturana Hernán , Palma Graciela , Durán Nelson 
Published: July 2010

AbstractBark from Pinus radiata D. Don was treated with both sulfuric acid/formaldehyde and nitric acid/formaldehyde. The ability to adsorb uranium by the bark was improved by these treatments, with essentially zero bleed colour into solution. The resin produced by nitric acid/formaldehyde treatment showed, in general, a better retention capacity than that of sulfuric acid/formaldehyde treatment. The nitric acid/formaldehyde modified bark showed 96 % of adsorption of uranium after 1 h and 63 % of desorption from the loaded resin after 3 h in 0.5 M sulfuric acid solution. Unmodified bark and some bark components were also analyzed. Bark was shown to be an excellent adsorber, comparable in efficiency, but costing less than the commercial adsorbing agents.
Purification and characterization of cellulases from Clostridium papyrosolvens
Authors: Garcia Vicenta , Madarro Alejo , Peña Jose L. , Piñaga Francisco , Vallès Salvador , Flors Agusti 
Published: July 2010

AbstractThe extracellular cellulolytic enzyme complex from Clostridium papyrosolvens was isolated from a culture of this organism grown on filter paper. The complex showed xylanase, carboxymethyl cellulase (CMCase) and Avicelase (but not β‐glucosidase) activities. Non‐denaturing polyacrylamide gel electrophoresis (PAGE) revealed two dominant bands, sited at the origin (corresponding to a fraction of high molecular weight) and at 280 kDa, and eight other very weak bands in the 20–180 kDa MW range. Gel overlay techniques showed strong CMCase activity in the region comprised between the origin and 320 kDa and in three distinct sites in the 40–230 kDa region. Xylanase activities were detected as a continuous band almost covering all the track. SDS—PAGE gave a multiplicity of different intensity bands in the 20–130 kDa range. Cellulolytic activities (CMCase in the 85–90 kDa range) and hemicellulolytic activities (xylanase at approximately 95, 60, 42 and 32 kDa) were detected through application of the corresponding CMC and xylan overlay techniques. Though anion‐exchange chromatography (DEAE‐Sephadex A‐50) and gel filtration (Biogel P‐100) techniques did not permit a good separation of the different cellulolytic activities, an 11.3‐fold increase of the Avicelase specific activity was achieved in a fraction containing 38.5% of the original total activity. Maximum enzymatic activities in crude preparations were observed at pH 5.4 and 50°C for xylanase and at pH 4.8 and 45°C for CMCase. The Michaelis constants for CMCase and xylanase were respectively: Vmax = 9.1 μg glucose equivalents min− ml−, Km=3.3 g CMcellulose liter− and Vmax=44.5 μg xylose equiuulents min− ml− and Km=2.7 g xylun liter−. Both enzymes were inhibited by a competitive mechanism.