bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrosynthesis of organic compounds. XVI. Cathodic reduction of some haloalkyl naphthyl sulfides and sulfones in nonaqueous solvent
Authors: Ismail Mohamed T. , El‐Zohry Maher F. 
Published: July 2010

AbstractThree aryl haloalkyl sulfur compounds—chloroethyl β‐naphthyl sulfide, chloropropyl β‐naphthyl sulfide and chloroethyl β‐naphthyl sulfone—were subjected to cathodic reduction. The compounds were cathodically electrolyzed under a controlled potential of −2.00 ± 0.03 V vs SCE on a zinc cathode as the working electrode and a platinum anode as helping electrode in absolute methanol containing Ba(ClO4)2 as supporting electrolyte at constant temperature (30°C). The isolated products were alkyl β‐naphthyl sulfides, alkyl β‐naphthyl sulfones, alkenyl β‐naphthyl sulfides, alkenyl β‐naphthyl sulfone, β‐naphthyl thiols (in case of sulfides), naphthalene and other identified products. Suitable mechanisms are suggested.
Kinetics of oxygen absorption in aqueous sodium dithionite solutions
Authors: Shaikh Abdulla A. , Zaidi S. M. Javaid 
Published: July 2010

AbstractThe absorption and reaction of oxygen in aqueous alkaline solutions of sodium dithionite has been experimentally investigated in a novel gas‐liquid contactor. The novel gas‐lift bubble column contactor was used to study the kinetics over wide ranges of reactant concentrations, temperature, and pH. The oxygen‐sodium dithionite reaction was found to be first‐order with respect to dithionite in the range of dithionite concentration < 0.1 M, and second‐order in the range of dithionite concentration > 0.1 M. The reaction with respect to oxygen was found to be zero‐order for all dithionite concentrations. These results and experimental investigations of the effect of solution alkalinity and temperature on the reaction rate are consistent with previous findings obtained in different gas‐liquid contactors. The results thus confirm the feasibility of using the gas‐lift bubble column for the kinetics of gas‐liquid reactions.
Kinetic study of an anaerobic fluidized bed system used for the purification of fermented olive mill wastewater
Authors: Martín A. , Borja R. , Chica A. 
Published: July 2010

AbstractThe anaerobic digestion of olive mill wastewater (OMW) in a fluidized bed, pretreated with Geotrichum candidum, has been studied. The bioreactor used (volume = 3.5 dm3; biomass concentration = 11.5 g VSS dm−3) maintained satisfactory operation for 4 to 35 days, in terms of hydraulic retention time, and removed 92% of the initial COD. The system was used to develop and test a kinetic model which was subsequently employed to determine growth yield and maintenance coefficient. From the results obtained, the Michaelis‐Menten equation accurately described the substrate uptake (i.e. COD removal) in the anaerobic fluidized bed system. Pretreatment of the OMW was found to increase the rate of substrate uptake by a factor of 3.2 when compared to untreated OMW.
Cyclohexanethiol separation from kerosene oil by red mud
Authors: Singh Awadhesh Pratap , Singh P. C. , Singh V. N. 
Published: July 2010

AbstractThe transfer of cyclohexanethiol from kerosene oil to unconventional adsorbent, red mud and the influence of variation in agitation rate, concentration and temperature on separation by adsorption technique has been investigated. The maximum transportation of sulfur compound from oil containing 730.67 mg dm−3 (0.025% by weight sulfur) of cyclohexanethiol was noted at 45°C. The adsorption follows first order kinetics and is a diffusion controlled process. The applicability of Langmuir isotherm indicates monolayer coverage of sulfur on the outer interface of red mud. Calcination of red mud and thermodynamic parameters suggest the favorable separation of cyclohexanethiol from kerosene oil by adsorption.
Mesophilic degradation of butyric acid in anaerobic digestion
Authors: Lin Chiu‐Yue , Hu Yun‐Yao 
Published: July 2010

AbstractSeed sludges acclimatized with iso and normal butyric acids were used in batch‐type anaerobic digestion. Isomerization between iso and normal butyric acid occurred; the formation of isobutyric acid was independent of pH but the reverse process was pH dependent. The relative formation percentages for normal and isobutyric acid, based on the added butyric acid concentrations, were about 2.3% and 6.0%, respectively. Acetic acid inhibited normal butyric acid degradation less than isobutyric acid degradation. Based on the experimental findings, a pathway for the degradation of butyric acid to acetic acid is proposed.
Characterization of products of interaction between kaolin ore and ammonium sulphate
Authors: Fouda M. F. R. , Amin R. S. , Abd‐Elzaher M. M. 
Published: July 2010

AbstractThe reaction products resulting from the interaction between kaolin ore and ammonium sulphate depend on molar ratios between reactants, reaction temperature and time of interaction. The reaction products were characterized by means of XRD. They were composed of silica, unreacted kaolin ore, traces of iron, magnesium, calcium, titanium and NH4Al(SO4)2 and (NH4)3Al(SO4)3. The last compound was produced alone at 553 K, whereas mixtures of them were produced between 553 and 823 K after a short time of interaction (0.5 h). On other hand the former compound was produced alone after longer heating (c. 2 h). At 823 K, a mixture composed of Al2(SO4) and NH4Al(SO4)2 was identified after 0.5 h, whereas anhydrous aluminium sulphate was detected alone after heating the reaction mixture for 2 h. The transformation of (NH4)3Al(SO4)3 into NH4Al(SO4)3 and alumina leads to a decrease in the percentages of extracted alumina from kaolin ore at relatively higher temperatures and/or longer heating of reaction mixtures. The investigation was also devoted to establishing the possible reactions which lead to the formation of Fe2O3, MgO, CaO and TiO2 as soluble salts together with aluminium compounds. The percentages of their extraction are low compared with the original quantities found in kaolin ore. From the obtained results, both Al2(SO4)3 and NH4Al(SO4)2 can be prepared from local kaolin with a reasonable degree of purity which makes it possible to produce them for use for different industrial and pharmaceutical purposes.
Kinetic studies of Mucor miehei lipase in phosphatidylcholine microemulsions
Authors: Oliveira A. C. , Cabral J. M. S. 
Published: July 2010

AbstractEthanol—oleic acid esterification by a free and microencapsulated lipase from Mucor miehei, using dodecane as solvent and phosphatidylcholine as surfactant, was studied.The initial esterification rate was influenced by the water content in the biphasic system. Kinetic studies with free and microencapsulated enzyme showed that the microencapsulation led to an increase of the kinetic parameters (Vmax and Km), probably due to an increase of the interfacial area. The reaction rate was also affected by the shaking rate, the temperature and the pH. The optimal temperature and pH achieved were, respectively, 40°C and 4.5 using free enzyme, and 50°C and 6 using microencapsulated enzyme.
Ionic mass transfer measurements in the case of submerged multijets impinging on to a flat surface
Authors: Krishna P. Gopala , Venkateswarlu P. 
Published: July 2010

AbstractIn the case of submerged multijets impinging on to a flat surface, the limiting current densities were measured at microelectrodes, fixed flush with the target surface using diffusion controlled electrode reactions (i.e. reduction of ferricyanide ion). The height of the multijet distributor from the target surface (Y) was varied from 5 to 9 cm. The numbers of holes of the distributor (N) studied were 76 and 141. The variation of mass transfer data with radial distance reveals the existence of two different regions, i.e. the impingement region and the wall jet region. The mass transfer rate increased with increase in Y in the impingement region. The effect of Y is negligible in the wall jet region. Decrease in N decreases the mass transfer rate in both the regions. The data are correlated separately for the two regions.
Microencapsulation of Lactococcus lactis within cross‐linked gelatin membranes
Authors: Hyndman Caroline L. , Groboillot Anne F. , Poncelet Denis , Champagne Claude P. , Neufeld Ronald J. 
Published: July 2010

AbstractLactococci were encapsulated within gelatin membranes cross‐linked with toluene‐2,4‐diisocyanate at an oil/water interface. Reagent toxicity was avoided by use of vegetable or silicone oil as a dispersant, and by minimizing cell exposure to the water insoluble cross‐linking agent during membrane formulation. Growth of cells within the gelatin microcapsules was observed during fermentation and acidification activity of the encapsulated cells increased with subsequent reuse. A microencapsulated cell density of 109 cfu cm−3 resulted in acidification of milk to pH 5.5 within 2.8 h, similar to that achieved in free cell fermentations.
Structure—activity relationships for hydroxyoxime metal extractants
Authors: Voelkel Adam , Szymanowski Jan 
Published: July 2010

AbstractThe distance‐based topological indices and connectivity indices were computed for various homologues of hydroxyoximes and correlated with the partition data and the rate of copper extraction from acidic sulphate solutions. The distance‐based topological indices are more sensitive to the structural changes in extractant molecule than the connectivity indices.
The physicochemical properties of the mixed solvent of 2‐piperidineethanol, sulfolane and water
Authors: Xu Shuo , Wang Yi‐Wei , Otto Frederick D. , Mather Alan E. 
Published: July 2010

AbstractThe physicochemical properties of the mixed solvent of 2‐piper‐idineethanol (2‐PE), sulfolane (TMS) and water were determined over a wide range of temperatures and compositions. The density, the viscosity and the dissociation constant, as well as the solubility of N2O in this mixed solvent were correlated as a function of temperature and composition over the entire experimental range. The models are useful not only for the ternary solvent system, but also for the binary solvent systems, such as 2‐PE+H2O and TMS+H2O. From the regression, it has been found that the interaction of aqueous 2‐PE solution and aqueous TMS solution is negligible.
Influence of serum proteins on the kinetics of attachment of vero cells to cytodex microcarriers
Authors: Mukhopadhyay Asok , Mukhopadhyay Satya N. , Talwar Gursaran P. 
Published: July 2010

AbstractThe attachment characteristics of the Vero cell line on microcarriers has been found to be influenced by the serum proteins. Significant quantities of serum proteins were found to be adsorbed on the carrier surface, which resulted in decreased exchange capacity and a lower attachment rate constant. The kinetics of attachment followed primarily first order with respect to the concentration of free cells. With positively charged microcarriers the attachment process exhibited two distinct phases, an initial phase of normal attachment followed by a second phase characterized by a lower rate of attachment. The attachment rate constant in the first phase (0·062 min−1) was reduced to 0·01 min−1 in the second phase. Presumably, at a low concentration of free Vero cells, the attachment process is retarded by unadsorbed Bovine Serum Albumin (BSA) and other serum proteins present in the medium.
Kinetics of aspartame precursor synthesis catalysed by Pseudomonas aeruginosa elastase
Authors: Lee Kong H. , Lee Pat M. , Siaw Yew S. , Morihara Kazuyuki 
Published: July 2010

AbstractElastase isolated from Pseudomonas aeruginosa IFO 3455 was found to be an efficient protease to catalyse the synthesis of N‐benzyloxycarbonyl‐aspartyl‐phenylalanine methyl ester, the precursor of the dipeptide sweetener, aspartame. The influence of methanol as a cosolvent in this synthetic reaction was investigated. It was found that the synthesis of the dipeptide precursor was most efficient in 25% (v/v) methanol, pH 7·0 at about 25°C for a reaction time of about 3 h. However, the activity of the enzyme was greatly reduced in 90% methanol. The values of K and k2 for N‐benzyloxycarbonyl‐aspartic acid were 0·17 mol dm−3 and 11·9 mol dm−3 s−1 respectively.
Overproduction of EcoRI and SpA::EcoRI fusion protein by Escherichia coli employing the combinations of three different types of multicopy plasmids: Comparison of plasmid stabilities and product concentrations
Authors: Wu Xiaoan , Brandes Lutz , Maschke Hans E. , Schügerl Karl 
Published: July 2010

AbstractThe copy numbers of the expression plasmids (pRTF309 + and pMTC48), the repression plasmids (pcI857 and pRK248cI) and the protection plasmid (pEcoR4) in recombinant E. coli JM103 were investigated. In the absence of the protection plasmid, the copy number of the expression plasmid dropped; in its presence, the copy numbers of the expression plasmids increased after gene expression by temperature‐shift induction. The copy numbers of the repression plasmids were not influenced by the presence or absence of the protection plasmid. The copy numbers of the latter were not changed during temperature‐induced gene expression. In the absence of the protection plasmid, the product concentration (EcoRI enzyme activity) was very low. With the plasmid combination pRTF309 +, pRK248cI, and pEcoR4, the enzyme (EcoRI) activity was higher, but with the plasmid combination pMTC48, pRK248cI, pEcoR4, the enzyme (SpA::EcoRI) activity was highest.
Self‐diffusion of strontium ions in hydrous zirconia and stannic oxide
Authors: Misak Nasr Z. , Ghoneimy Hussein F. , Mikhail Etidal M. , Shabana El‐Said I. 
Published: July 2010

AbstractSelf‐diffusion coefficients (D̄) of strontium ions in hydrous zirconia and stannic oxide heated at different temperatures have been determined at different apparent capacities. The study throws some light on the effects of capacity, acidity and porous texture on D̄. Except in the totally microporous stannic oxide heated at 50–200°C, D̄ in both oxides decreases continuously with capacity. For the former sample, the size of the diffusing entity seems to be relatively more important, and D̄ remains almost the same over a wide capacity range.
Synthesis, characterization and antitumour studies of metal chelates of N1‐isonicotinoyl‐3‐methyl‐4‐(p‐hydroxybenzilidene)‐2‐pyrazolin‐5‐one
Authors: Kuncheria Joshi , Aravindakshan K. K. 
Published: July 2010

AbstractThe cobalt(II), nickel(II) and copper(II) complexes of N‐Isonicotinoyl‐3‐methyl‐4‐(p‐hydroxybenzilidene)‐2‐pyrazolin‐5‐one (IMHBP) with different counter anions have been prepared and characterized. An octahedral geometry has been assigned to the cobalt(II) and nickel(II) complexes and a square‐planar structure to the copper(II) complexes. IMHBP acts as a neutral bidentate ligand in all these complexes by coordinating through the oxygen atoms of the amide group and carbonyl at position‐5. The other coordination sites are satisfied by anions alone or anions and water molecules. The ligand and the complexes were screened for their possible antitumour activity. The copper(II) complexes are appreciably active in reducing mice tumours.
Immobilization of penicillin acylase on copolymer of butyl acrylate and ethylene glycol dimethacrylate
Authors: Bryjak Jolanta , Noworyta Andrzej 
Published: July 2010

AbstractThe effects of glutaraldehyde, enzyme concentrations and reactants volumes, ionic strength, pH value and carrier particle diameter on immobilization of penicillin acylase onto acrylic carriers were studied. The activity of immobilized enzyme preparations was also studied over a range of pH values and temperatures and thermal and pH stabilities were determined. The use of the immobilized preparation for penicillin G hydrolysis in a batch reactor was investigated. The immobilized enzyme gave a significant reduction in hydrolysis time compared to hydrolysis by the native enzyme.
An investigation of phosphate adsorption by Clays and its relation to the problems of eutrophication of the river stour, Kent
Authors: Fox Ian , Malati Mounir A. 
Published: July 2010

AbstractEutrophication of the River Stour in Kent and its potential remedy are related to the adsorption of phosphates by its bed deposits, which are derived largely from Gault and Weald clays. The main minerals in these clays are: kaolin, mica, vermiculite and smectite. Four reference samples of these clays and samples of Gault and Weald clays were characterised by X‐ray diffraction, thermal analysis (DTA and TGA) as well as by infrared spectroscopy and BET surface area. For the reference clays, also characterised by chemical analysis, the cation exchange capacity (CEC) and the point of zero charge (PZC) were determined. A kinetic study of phosphate adsorption showed an initial fast step followed by a slower process. The effects of pH, phosphate concentration, rate of shaking and temperature, on the rate of adsorption, are reported. Desorption of phosphate also revealed two consecutive kinetic stages. Adsorption isotherms of phosphate on the reference clays are presented over a range of pH values. In the case of kaolin, the heat of adsorption was found to be 17 kJ mol−1. Electrophoretic mobilities of the mica particles were measured in the presence and in the absence of phosphate, over a pH range. The mechanisms of adsorption are discussed.
Influence of cultural conditions on coal solubilization by Penicillium simplicissimum
Authors: Achi Ome K. , Emeruwa Augustine C. 
Published: July 2010

AbstractSub‐bituminous coal, preoxidized with nitric acid and treated with sodium hydroxide solutions to obtain a water‐soluble extract, was used for the study of coal degradation by Penicillium simplicissimum. The influence of different carbon and nitrogen sources was examined in connection with growth and production of acid‐precipitable coal polymers. The yield was increased after the addition of maltose, lactose and cellobiose while glucose, fructose and xylose had little effect. An organic nitrogen source, yeast extract, was an improved source of nitrogen compared with ammonium chloride. The coal‐degrading system appeared before the depletion of the carbon or nitrogen source. In addition, the effects of initial pH of the culture medium demonstrated an increase in the yield of coal polymers up to a pH of 7.5. Above this pH, non‐biological catalysis increased gradually. However Ca2+ and Mn2+ increased the yield of coal polymers over a 14‐day period, but yield was unaffected by Cu2+, Al3+ and Fe2+.
Causticization of sodium carbonate with rock‐salt type magnesium aluminium oxide formed by the thermal decomposition of hydrotalcite‐like layered double hydroxide
Authors: Sato Tsugio , Onai Satoshi , Yoshioka Toshiaki , Okuwaki Akitsugu 
Published: July 2010

AbstractThe causticization behaviour of Na2CO3 with rock‐salt type oxide, Mg2(1‐x/(2+x) O (M = Al3+ and Fe3+, x = 0.2 and 0.33), produced by the thermal decomposition of hydrotalcite‐like layered double hydroxide was investigated at 30–60°C. The degree of causticization increased with increasing the molar ratio of [rock‐salt type oxide]/[Na2CO3] and increasing the temperature but decreased with increasing the initial concentration of Na2CO3. The causticization behaviour could be adequately described by the equation of anion exchange equilibria between CO32‐ and OH− for layered double hydroxide.
Growth and kinetic parameters of ajuga hairy root in fed‐batch culture on monosaccharide medium
Authors: Uozumi Nobuyuki , Kohketsu Katsuhito , Kobayashi Takeshi 
Published: July 2010

AbstractThe batch culture of a transgenic plant, Ajuga hairy root, in sucrose and MS medium exhibited glucose and fructose accumulation with culture time and depletion of phosphate ion after 16 days. The use of a monosaccharide instead of sucrose in fed‐batch culture avoided the difficulty of estimating the concentration of saccharides. Glucose was the most adequate monosaccharide for attaining a high cell mass. In fed‐batch culture using a turbine blade fermentor, 27.2 kg‐dry cell m−3 was obtained at 39 days in glucose medium, with the final cell mass and production of 20‐hydroxyecdysone increasing 2.6‐fold and 2.0‐fold, respectively, compared with batch culture results with sucrose in a shake flask. The growth of the hairy root was divided into two phases, an exponential growth phase and linear growth phase. The linear growth phase from 5 through 25 kg‐dry cell m−3 predominated over the growth curve. On the basis of the data of the fed‐batch culture with glucose, the cell yield, 0.77 g g−1, and maintenance coefficient, 0.105 g g−1 day−1, for Ajuga hairy root were comparable to those of various calluses. The cell yield of the plant cell was larger than the yields of microorganisms and the maintenance coefficient was smaller.
Salt effect in vapour liquid equilibria
Authors: Subbaiah T. 
Published: July 2010

AbstractIn the present work the effect of ammonium chloride on the vapour liquid equilibrium of the system 1,4 dioxane‐water at atmospheric pressure of 760 ± 1 mm Hg has been studied. It was observed that the ammonium chloride is helpful in shifting the azeotropic composition. Linear relationships are developed between the relative volatilities and salt concentrations.
Inactivation of rice bran lipase with metal ions
Authors: Munshi S. K. , Bhatia Neena , Sekhon B. S. , Sukhija P. S. 
Published: July 2010

AbstractThe inactivation of rice bran lipase was studied in vitro and in vivo using metal ions in methanol or HCl. Lipase was extracted from rice bran in 0.1 M potassium phosphate buffer, pH 7.0 and purified by ammonium sulphate fractionation. The 25–55% ammonium sulphate fraction was subjected to DEAE‐cellulose ion exchange chromatography and the fraction (F6) eluted at Ve/Vo of 14.37 was purified about 333‐fold. In‐vitro studies on F6 lipase showed that Fe3+ and Ni2+ completely inhibited the lipase activity at 5 × 10−5 M concentration, while Zn2+ and Cu2+ did so at 2.5 × 10−4 M. The results on in‐vivo inactivation of rice bran lipase showed that Fe3+ and Ni2+ at 200 μg g−1 significantly checked the release of free fatty acids (FFA) from rice bran for 6 days of storage when compared with using concentrated HCl (2%, v/w) only. The triglyceride content of oil was also maximum with Fe3+ and Ni2+ treatment at 200 μg g−1. The present results suggest that Fe3+ and Ni2+ could be effectively used to arrest the release of FFA in rice bran and thus contribute to improving the edible quality of rice bran oil.
Enzymatic synthesis of (R)‐ and (S)‐2‐cyclohexen‐1‐ol
Authors: Izumi Taeko , Nakamura Toshihiko , Eda Yuji 
Published: July 2010

AbstractThe synthetically useful chiral synthons (R)‐ and (S)2‐cyclohexen‐1‐ol can be prepared by an enantioselective transesterification of racemic trans‐2‐(phenylseleno) cyclohexanol using lipases, followed by selenoxide elimination and hydrolysis.