bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrochemical reduction of carbon dioxide and the effect of the enzyme carbonic anhydrase 11 on iron corrosion
Authors: Zvauya Remigio , Dawson John L. 
Published: May 2005

AbstractThe corrosion of pure iron in carbon dioxide saturated solutions at low temperatures has been investigated in this study. Both dc polarisation and ac impedance techniques were used in conjunction with a rotating disc electrode to investigate the reaction sequence leading to hydrogen evolution at 30°C. The results indicate that protons from the low pH solution, the bicarbonate ion and the undissociated carbonic acid molecule contribute to the reaction sequence leading to eventual hydrogen evolution. The corrosion mechanism involves both activation and diffusion processes. A rotating disc electrode in combination with ac techniques and the enzyme carbonic anhydrate II, EC 4.2.1.1, were used to characterise the diffusion effects. A chemical–electrochemical cathodic reaction mechanism is proposed.
Liquid phase oxidation of α‐pinene. Influence of sodium hydroxide as additive
Authors: Encinar José M. , Beltrán Fernando J. , Frades Jesús M. 
Published: May 2005

AbstractThe liquid phase oxidation of α‐pinene in the presence of sodium hydroxide has been studied. Sodium hydroxide exerts an inhibitor effect on the oxidation rate of α‐pinene but selectivity of the main reaction products, verbenol and verbenone, is increased. A temperature between 90 and 100°C results in the highest selectivity values. The kinetics of α‐pinene oxidation and formation of verbenol and verbenone have also been studied and a free radical mechanism proposed.
Kinetics and mechanism of homogeneous catalytic hydroxylation of maleic acid by hydrogen peroxide. Part III: Hydrolysis of cis‐epoxysuccinic acid with sodium tungstate
Authors: Bukowski Wiktor , Litvintsev Igor Yu. , Sapunov Valentin N. 
Published: May 2005

AbstractThe kinetics of catalytic and non‐catalytic hydrolysis of cis‐epoxysuccinic acid (H2E) to tartaric acid (H2T) have been studied. The hydrolysis proceeded much faster in the presence of sodium tungstate catalyst than with an acid or without any catalyst. The results indicated the formation of complexes {cat · H2E} between sodium tungstate (cat) and cis‐epoxysuccinic acid, presumably in the form of tunstenglycolate of tartaric acid. The reaction has been found to be retarded by tartaric acid or, rather, by its complex with catalyst in the form {cat · 2H2T}. A mathematical model of the overall process has been developed and the mechanism of reaction discussed.
Kinetics and mechanism of homogeneous catalytic hydroxylation of maleic acid by hydrogen peroxide. Part IV: Hydrolysis of cis‐epoxysuccinic acid in the presence of ferric ions
Authors: Bukowski Wiktor , Litvintsev Igor Yu. , Sapunov Valentin N. 
Published: May 2005

AbstractThe kinetics of catalytic and non‐catalytic hydrolysis of cis‐epoxysuccinic acid have been studied. The hydrolysis leading to tartaric acid has been found to proceed much faster in the presence of iron (III) catalyst than the reaction without a catalyst or with tungstate catalyst. A complex of the form {cat · H2E} between iron(III) salts (catalyst) and epoxysuccinic acid seems to be responsible for the main catalytic effect. On the other hand, the reaction has been found to be retarded by the product of hydrolysis, tartaric acid (H2T). The inhibiting effect was caused by the formation of a catalyst deactivating complex in the forms {cat · H2T} and {cat · 2H2T}. A mathematical model for the overall process has been developed and the mechanism of reaction discussed.
Synthesis of heterocyclic metal complexes and their evaluation as marine antifoulants
Authors: Osman Maher M. , El‐Malek Mounir M. Abd , Tadros Aida B. , Michael Atef M. 
Published: May 2005

Abstract4‐Amino‐3‐thio‐1,24‐triazolidine (L1) and 4‐amino‐5‐thio‐1,3,4‐thiadiazole (LII) as well as their metal complexes of the general formulae MLI·2H2O and MLIICl (M; Pb(II), Cd(II) and Zn(II)) were prepared. With Sn(II), we obtained Sn(LI)2·2H2O and SnLIICl, respectively. The structures of the compounds were identified through elemental analysis, and IR and UV spectra measurements, in addition to thermal analysis in case of the metal complexes. The antifouling properties of the compounds were tested by their incorporation into paint formulations which were applied to PVC substrates and tested in water from Alexandria western harbour. When the compounds were added at 17·5% by volume, the coated panels were fouled after 3 months of immersion. The addition of 6·7% by volume of tributyltin oxide to 15·8% of the prepared compounds in one formulation elevated the paint efficiency and prevented fouling for 11 months. Paint containing solely tributyltin oxide at the same concentration was inactive against algae.
Enhancement of biomass and pigment production during growth of Spirulina platensis in mixotrophic culture
Authors: Marquez Facundo J. , Nishio Naomichi , Nagai Shiro , Sasaki Ken 
Published: May 2005

AbstractSpirulina platensis grew mixotrophically on glucose in the light, ehancing biomass and pigment production. Under light‐limited conditions, biomass production was enhanced by supplemental microbial synthesis from heterotrophic metabolism of glucose. Biomass and photosynthetic pigment production were increased 1·5–2·0‐fold compared with those in autotrophic growth.
Azo disperse dyes for synthetic fibres. 3: 2‐Styrylquinazolone derivatives
Authors: Fadda A. A. , Etman H. A. , Amer F. A. , Barghout M. , Samir Kh. M. 
Published: May 2005

AbstractFifteen variously substituted derivatives (IVa–o) of 2‐styrylquinazolone have been prepared for use as dye‐stuffs. The effects of the nature and orientation of substituents on the colour and dyeing properties of these dyes on polyester and acrylic fibres were assessed.
Formulation and optimization of two culture media for the production of tumour necrosis factor‐β in Escherichia coli
Authors: Mak Kenneth W. Y. , Yap Miranda G. S. , Teo Wah Koon 
Published: May 2005

AbstractTwo culture media were designed and optimized by statistical techniques for the growth of Escherichia coli K12 HB101 (pCG402) which expressed human tumour necrosis factor‐β (TNF‐β). Common compounds, such as MgSO4 and KH2PO4, were used to provide the bacteria with the necessary elements for biomass synthesis. For compounds not required for biomass synthesis, such as thiamine, or compounds used for both biomass synthesis and as an energy source, such as glucose, yield coefficients were used. In formulating the composition of the nutrients, carbon was chosen as the limiting substrate in both media. In the complex medium (CM), casein hydrolysate was selected to supply the two auxotrophic amino acids, proline and leucine. The optimal ratio of glucose to casein hydrolysate was determined to be 1:0·6 by using a centre composite design experiment. In the defined medium (DM), the concentrations of the three carbon sources, glucose, proline and leucine were based on their respective yield coefficients (Ybiomass/glucose: 0·5, Ybiomass/proline: 7, Ybiomass/leucine: 13·5). Shake flask experiments based on a fractional design were used to confirm that the two media were glucose limiting. Bacterial growth was improved in CM whereas DM gave higher TNF‐β expression. A 2‐dm3 fed‐batch fermentation using CM was performed and a dry biomass concentration of 20 g dm−3 was obtained with the expression of soluble TNF‐β being 20 mg g−1 dry biomass. With this fed‐batch system, a high biomass concentration and high expression of TNF‐β were achieved concomitantly.
Characterization of extracted complexes in liquid–liquid extraction of rhodium with Kelex 100 in the presence of SnCl2
Authors: Benguerel Elyse , Demopoulos George , Cote Gérard , Bauer Denise , Lautié Alain 
Published: May 2005

AbstractMixed RhSn complexes found in aqueous and organic solutions involved in the liquid–liquid extraction of Rh(III) from chloride solutions, also containing SnCl2, with 7‐(4‐ethyl‐1‐methyloctyl)‐8‐hydroxyquinoline (Kelex 100) were characterized through 119Sn NMR and Raman spectroscopy. At Sn: Rh molar ratios of 3:1 and 12:1, it was found that [RhIIICl3(SnCl3)3]3− and [RhI(SnCl3)5]4−, respectively, are the dominant complexes in both the aqueous and organic solutions. These complexes can be quantitatively extracted from the aqueous solutions in less than 1 min contact time via ion‐pair formation with the protonated 7‐substituted 8‐hydroxyquinoline reagent such that for both Sn:Rh ratios, the same RhSn complex is found in the aqueous feed and in the fully loaded organic. In addition, it was found that [RhI(SnCl3)5]4− is preferentially extracted over excess free Sn(II). Preliminary characterization of the complex stripped from the 12:1 loaded organic using 1·7 M H2SO4 shows an RhSn complex having a ratio of 5:1 Sn:Rh.
Color removal from dye wastewaters by adsorption using powdered activated carbon: Mass transfer studies
Authors: Yeh Ruth Yu‐Li , Thomas Adrian 
Published: May 2005

AbstractColor removal from synthetic dye wastewater which typically emanates from the Taiwan textile industry has been studied using powdered activated carbon (PAC) as an adsorbent. The CIE colorimetric system has been used in the measurement of color for the treatment of disperse‐red‐60 dye wastewater. The effect of contact time, dye concentrations and PAC dosage on color and color removal has been investigated. A film‐pore double resistance diffusion model for mass transfer has also been used in this study to determine the effective diffusivity, Deff, for the adsorption of disperse‐red‐60 dye wastewater to PAC.
A comparative study of the internal architecture of anaerobic granular sludges
Authors: Quarmby Joanne , Forster Christopher F. 
Published: May 2005

AbstractA range of granular sludges was taken from industrial anaerobic sludge blanket reactors treating a wide variety of wastewaters and a comparison was made between their surface and internal structures. Scanning electron microscopy showed a similar surface structure of heterogeneous bacteria, regardless of the type of wastewater being treated. However, a study of the internal structure, using sequential staining of ultra‐thin sections, showed the complexity of granular sludges. The majority of the internally‐located bacteria had a morphology similar to Methanothrix. Much of the area was occupied by Gram‐negative organisms and the area which stained positive for protein was found to increase nearer the centre of the granules. This was accompanied by a decrease in the carbohydrate‐positive areas. Positive areas for lipid were widespread throughout the granules. Changes in the internal structure were observed when the type of wastewater treated by the granules was changed and a comparison between sludges treating the same type of wastewater showed that other factors, such as organic loading rate, pH and chemical oxygen demand may also affect the structure of the granules.
Phospholipid coatings for the prevention of membrane fouling
Authors: Reuben Bryan G. , Perl Orly , Morgan Neil L. , Stratford Peter , Dudley Linda Y. , Hawes Christopher 
Published: May 2005

AbstractThe aim of the present work was the development of phosphorylcholine‐based treatments for biofiltration membranes and the demonstration that such treatments prevent or inhibit protein fouling. Microfiltration membranes of cellulose triacetate, polyether sulphone and polyvinylidene fluoride were etched with oxygen in a plasma chamber to generate surface hydroxyl groups and were then treated with the monomer 2‐methacryloyloxyethyl phosphorylcholine. These membranes were evaluated with water, buffer, bovine serum albumin (BSA), yeast fermentation broth, beer and orange juice. The treatment of cellulose triacetate membranes reduced both the initial flux and the extent of water fouling. In terms of the integrated flux, these factors tended to cancel each other out. For protein, the membranes gave similar or higher fluxes but worse fouling. The cellular feed (yeast) reacted more favourably to the coating than the BSA. The polyether sulphone was scarcely affected by the coating; fouling remaining high with most ‘real’ feeds. There was lower initial flux but less flux decline with water and beer. Washing with water and cleaning with Tergazyme did not restore the initial flux. Polyvinylidene fluoride membranes gave the most positive results. In most cases, the coating both increased initial flux and decreased the rate of fouling. The coating was particularly effective for BSA and for beer and orange juice, where fouling is probably caused by a polysaccharide rather than by a protein. Electron microscopy showed, nonetheless, that fouling by proteins was accompanied by protein adsorption primarily on the upper surface of the membrane and that coated membranes showed less deposition and in different places than did untreated membranes.
Enhancement of uranium bioaccumulation by a Citrobacter sp. via enzymically‐mediated growth of polycrystalline NH4UO2PO4
Authors: Yong Ping , Macaskie Lynne E. 
Published: May 2005

AbstractThe objective of this work was to study the effect of pH and ionic matrix on product release and on the removal of uranyl ion by a Citrobacter. sp phosphatase enzyme‐catalysed reaction. An improvement in the efficiency of uranyl removal was obtained by incorporating ammonium acetate (NH4Ac) into the solution. It was confirmed using X‐ray diffraction (XRD), and other analytical techniques, that the insoluble, cell‐bound product was NH4UO2PO4.
Optimisation of the fibre production system used for the immobilisation of Saccharomyces cerevisiae employed in the production of NADH in a novel bioreactor
Authors: Stevenson Eileen C. , McNally Gerry M. , Spedding Peter L. 
Published: May 2005

AbstractSaccharomyces cerevisiae was immobilised in wet spun calcium alginate fibres for use in a bioreactor as an immobilised catalyst. The actual fibre production system was studied to determine optimum conditions when the fibre was used in the NADH reaction. The extrusion pressure and fibre winding speed were identified as the important variables and were optimised at 0·4 bar (g) and 300 rpm respectively. Other variables had little effect on the efficiency of the whole system.
Oxidative coupling of methane to C2‐hydrocarbons over lithium–cerium‐promoted MgO and MgO–CaO catalysts
Authors: Tiwari Kaushal K. , Roy Tarak N. , Banerjee Somnath , Ganguly Subrato , Bhattacharyya Deba P. 
Published: May 2005

AbstractThe oxidative coupling of methane to ethylene and ethane was studied over lithium–cerium‐promoted MgO and MgO–CaO catalysts in the presence of molecular oxygen at 730°C and at atmospheric pressure in a continuous flow, fixed bed quartz reactor. The catalysts were prepared by an impregnation method and finally calcined at 900°C. The surface area, pore size distribution and pore volume of the catalysts were determined. The feed consisted of only methane and oxygen in the molar ratio of 2:1. The results obtained over the catalyst systems, viz. (i) lithium–cerium‐promoted MgO and (ii) lithium–cerium‐promoted MgO–CaO, have been compared. A relatively high C2‐selectivity has been obtained with Li–Ce‐promoted MgO–CaO catalysts. The optimum yield and selectivity for C2‐hydrocarbons were found to be 21·5% and 76·8% respectively at a methane conversion of 28% over Li (7 wt%)–Ce (2 wt%)‐doped MgO–CaO (3:1 wt ratio) catalyst. The various factors governing the activity and the selectivity of the catalyst systems have been discussed.
Interfacial activity and rate of palladium(II) extraction with decyl pyridine monocarboxylates
Authors: Wiśniewski Maciej , Jakubiak Artur , Szymanowski Jan 
Published: May 2005

AbstractDecyl isonicotiniate and decyl nicotiniate permit a rapid extraction of palladium(II) from its hydrochloride solutions. Decyl picoliniate is not a suitable extractant. 4‐Octylphenylamine can act as a phase transfer catalyst when its concentration in the organic phase is at least 2·5 × 10−4 M. It seems that the interfacial adsorption of pyridine carboxylates and of 4‐octylphenylamine is not the decisive phenomenon in palladium(II) extraction. The negligible protonation of the pyridine‐type extractants and the phase transfer catalysis explains well the quick extraction of palladium(II) with the commercial and highly hydrophobic extractant ACORGA CLX‐50.
Production of the fungal exopolysaccharide scleroglucan by cultivation of Sclerotium glucanicum in an airlift reactor with an external loop
Authors: Wang Yuchun , McNeil Brian 
Published: May 2005

AbstractSclerotium glucanicum NRRL 3006 was cultivated in a 120 dm3 working volume airlift reactor with external recirculation loop for the production of the exopolysaccharide (EPS), scleroglucan. When culture pH was not controlled EPS production, at a range of air flow rates, was poor (<2 kg m−3). Biomass formation generally increased with increasing aeration rate. When culture pH was controlled at 4·5 ± 0·2 EPS production was maximal at an air flow rate of 100 dm3 min−1 and fell as air flow rate decreased. Operation of the reactor at a high (100 dm3 min−1) air flow rate for the early part of the process (up to 96 h), followed by a low air flow rate (20 dm3 min−1), led to reduced biomass and oxalate formation, and a slight increase in EPS concentration relative to operation at a constant air flow rate of 100 dm3 min−1. EPS production in this pneumatically‐agitated reactor was equal to the highest levels reported in small‐scale stirred tank reactors.
Photostabilisation of colour formers for heat‐sensitive recording systems: Effect of counter‐ions on the photofading of fluoran dyes
Authors: Oda Hironori 
Published: May 2005

AbstractFluorans are given considerable attention as functional dyes for heat‐and/or pressure‐sensitive recording media. Numerous potential metal complexes were synthesised to prolong the life of coloured species. The protecting effect of these compounds against the photofading was examined on cellulose. It was found that the zinc or nickel salts of 3,5‐dihydroxy‐2‐naphthoic acid and its derivatives can be applied as effective stabilisers against the fading of fluoran dyes.
Pepsin immobilised by covalent binding to a chitosan derivative
Authors: González Gustavo , Alea Jacqueline 
Published: May 2005

AbstractAn insoluble active preparation of pepsin was made by covalent binding of the enzyme to succinylated chitosan through amide bond formation, with carbodiimide as condensing agent. The enzyme retained 80% specific activity and showed greater stability on storage than the soluble enzyme.
Cloning, expression and characterisation of a single‐chain antibody fragment to the herbicide paraquat
Authors: Graham Barbara M. , Porter Andy J. R. , Harris William J. 
Published: May 2005

AbstractNew cost effective methods for the detection and removal of pesticides from water samples are required to meet modern safety standards. The recent development of techniques to produce antibody fragments in bacteria has provided the opportunity to exploit antibodies as specialised chemicals for affinity detection/removal technologies. The variable heavy and light polypeptide chains of the anti‐paraquat monoclonal antibody PQXB1/2 have been cloned into the single‐chain antibody (ScAb) expression vector pBG1. The construct was expressed in Escherichia coli and 0·4 mg functional antibody produced from 1 dm3 of induced culture. Characterisation of ScAb by antigen binding profile and competition ELISA showed it to have a sensitivity one order of magnitude below that of the parent monoclonal. ScAb was purified as a monomer or dimer and analysed by HPLC size exclusion chromatography. When immobilised on polystyrene beads the ScAb could remove 85% of a paraquat–bovine serum albumin conjugate from solution in a single step.
Reaction of thioxanthen‐9‐one with the superoxide anion in an aqueous system containing dodecyltrimethylammonium bromide
Authors: Duty Robert C. , Carothers Larry D. , Roark Robin , Sahni Irvine 
Published: May 2005

AbstractThis research deals with the oxidation of thioxanthen‐9‐one with the superoxide anion to the sulfoxide and to the sulfone. We were also interested in determining whether the thioxanthen‐9‐one could be oxidized further to carbon dioxide. The experiments revealed that no carbon dioxide was formed from the oxidation of thioxanthen‐9‐one. However, it was found that carbon dioxide was formed from the anode reacting with the superoxide anion.
Kinetics of addition of acetic acid to epichlorohydrin in the presence of alkali metal acetates
Authors: Bukowska Agnieszka , Guskov Andrei K. , Makarov Mikhail G. , Rokaszewski Edward , Svets Valery F 
Published: May 2005

AbstractThe kinetics of the reaction between acetic acid and epichlorohydrin in the presence of lithium, sodium and potassium acetates have been studied. The composition of the reaction mixture was followed chromatographically. Beside the two isomeric products of addition of epichlorohydrin to acetic acid, the presence was found of glycidyl acetate, glycerine dichlorohydrin and other products of parallel and subsequent reactions between the substrates and chlorohydroxyesters. A mechanism of the reaction, which takes into account the formation of the identified compounds has been proposed and a set of appropriate differential and balance equations developed. The rate constants for individual reactions as well as the catalysts used have been determined.
A novel way to treat refractory waste: Sonication followed by wet oxidation (SONIWO)
Authors: Ingale Muralidhar N. , Mahajani Vijaykumar V. 
Published: May 2005

AbstractThe effectiveness of the hybrid system sonication followed by wet oxidation (SONIWO) to treat otherwise refractory waste has been demonstrated. In such a hybrid system homogeneous CuSO4 catalyst was found to be very efficient.
Onset of gas self‐induction and power consumption after gas induction in an agitated tank
Authors: Hsu Yung Chien , Chang Hung‐Ch'i 
Published: May 2005

AbstractThe behavior of inducted gas from liquid surface and the; power requirements in an agitated tank using a mechanical agitator are studied in order to increase the amount of gas self‐induction and the gas retention time for gas absorption. A 45° six‐blade downward impeller turbine was utilized in this study. Air and water, air and 40 wt% 60 wt%, and 80 wt% of glycerin water, and air and 106 cP silicon oil were employed as gas and liquid phases. Variables which were studied included geometrical factors (immersed depth of impeller, baffle with and diameter of impeller) and the physical properties of the liquid (viscosity, density, and surface tension). The correlations for the onset speed of impeller and power consumption after gas induction in the agitated tank are established from our experimental results. The amount of gas self‐induction from the liquid surface in the agitated tank increases with increasing impeller diameter and speed and decreases with increasing baffle width, depth of impeller and viscosity of liquid.