bluuebunny/crossref_metadata_2025 huggingface dataset:
Dextran fractionation using preparative scale continuous chromatography
Authors: Barker P. E. , Ganetsos G. , England K.
Published: July 2010

The continuous fractionation of dextran feedstocks using preparative scale gel permeation chromatography is reported. A semi‐continuous counter‐current chromatographic refiner has been used, which consisted of ten 5.1 cm i.d. × 70 cm long stainless steel columns, packed with Spherosil XOB075 porous silica beads. The system has proved successful in removing the very low and the very high molecular weight fractions and obtaining products of the required specification. Over 90% recoveries have been achieved at throughputs of 0.470 kg dextran h−1.
Synthesis of DL‐2‐(p‐hydroxyphenyl)glycine by the ammonolysis of p‐hydroxymandelic acid obtained by the condensation of phenol with glyoxylic acid
Authors: Powar Netaji P. , Chandalia Sampatraj B.
Published: July 2010

Synthesis of DL‐2‐(p‐hydroxyphenyl)glycine by the ammonolysis of p‐hydroxymandelic acid obtained by the condensation of phenol and glyoxylic acid was investigated. Different procedures for the isolation of p‐hydroxymandelic acid from the product mixture after the condensation step were considered. The ammonolysis of the mandelic acid could be suitably carried out at 115°C using a 10:1 mole ratio of ammonia to p‐hydroxymandelic acid in the presence of ammonium chloride. A yield of glycine as high as 92% could be obtained when an overall conversion of the mandelic acid was about 80 %. The reaction was found to be first order with respect to the mandelic acid up to a reaction period of 6 h.
Synthesis of wide‐pore alumina support from gibbsite
Authors: Inoue Masashi , Kitamura Kazuhisa , Inui Tomoyuki
Published: July 2010

Gibbsite was treated in a series of primary alcohols at 250°C for 2 h. The surface area of the product increased with the increase in the carbon number of alcohol and reached a maximum when hexanol was used.

Pore texture of aluminas, obtained by the calcination of these products, was investigated by means of the nitrogen adsorption technique. The aluminas prepared from the products of the treatment in alcohols other than propanol and butanol had a pore texture identical to the pore texture of the alumina from well‐crystallized boehmite prepared by hydrothermal treatment of gibbsite. The pore texture of these aluminas was characterized by the presence of micropores. The aluminas prepared from the treatments in butanol and propanol had quite different pore texture. Micropores were not detected in these aluminas: instead, mesopores of c. 20 nm range were detected.

These results are consistent with the reaction mechanisms for the formation of boehmite proposed in a previous paper on the basis of morphology of the products. In lower alcohols boehmite is formed by means of a resolution‐crystallization mechanism, whereas in higher alcohols boehmite is formed by means of intraparticle hydrothermal reaction. In butanol and propanol, boehmite is crystallized from the alcoholic media and has a large population of crystal defects; therefore, pore texture of aluminas derived from these products resembles the aluminas from poorly crystallized aluminum hydroxides.
Ethanol fermentation by Z. mobilis ATCC10988 in repeated batch cultures
Authors: Agrawal Pramod , Veeramallu Uday
Published: July 2010

Repeated‐batch fermentations of glucose to ethanol by Z. mobilis (ATCC 10988) were examined in two semi‐defined nutrient media. The measurement of acid produced by the microorganism was used to study its transient fermentation characteristics. An examination of the inhibitory effect of ethanol in repeated‐batch fermentations supports an earlier finding on the presence of a ‘slow‐acting inhibitory mechanism’ at high ethanol concentration in Z. mobilis (ATCC 10988) cultures. The experimental results also suggest that both microbially produced and exogeneously added ethanol have similar inhibitory effects on the fermentation behavior of this bacterium.
Synthesis of 2‐azo‐3‐cyano‐5‐carbethoxy thiophene derivatives and their application on polyester fibres
Authors: Sabnis Ram W. , Rangnekar Dinesh W.
Published: July 2010

Synthesis of 2‐(hetaryl or aryl)‐azo thiophene derivatives (IVa–IVg) was achieved by diazotisation of ethyl 2‐amino‐3‐cyano‐5‐carbethoxy thiophene‐4‐acetic acid ester (I) using nitrosyl sulphuric acid, coupling with suitable heterocyclic hydroxy and N, N‐dialkyl‐substituted aryl amines, which resulted in thiophene azo dyes. The key intermediate (I), used as the diazonium component was synthesised in one pot and in excellent yield from diethyl acetone dicarboxylate, sulphur and malononitrile, using diethylamine as a catalyst, following the Gewald Synthesis. The spectral properties of these dyes were studied. The dyes when applied as disperse dyes on polyester fibres gave excellent results.
An integrated process for the treatment of apatite obtained from dephosphorization of iron ore
Authors: Zhang Yu , Muhammed Mamoun
Published: July 2010

A process has been proposed for the treatment of apatite concentrate obtained from the dephosphorization of iron ore. In this process, the apatite is acidulated by HNO3 to produce high‐purity H3PO4. The crude acid obtained is shown to be at least equivalent to, if not better than, the typical wet‐process acid. The H3PO4 is purified by extraction and concentrated by evaporation. The spent HNO3 is regenerated by H2SO4 to precipitate gypsum. Rare earths dissolved during the apatite acidulation are recovered by precipitation with oxalic acid. The process is to be integrated with the processing of the solutions obtained from the direct leaching of iron ore (the phosphorus removal) with HNO3. The integrated process is more economical than the single treatment and also it offers the flexibility of producing both sinter‐fines and pellets to meet demand in steel manufacture.
Upgrading of linear alkyl benzene by‐product
Authors: Wedad Abdel Azim M. , Abou Naga H. H. El , Naguib Sidaros K.
Published: July 2010

Heavy alkylated benzene, which is accumulated as a by‐product from linear alkyl benzene synthesis, was evaluated as a starting material for anionic liquid sulphonate surfactants.

Chemical structure analysis by GC/MS showed that the by‐product contains eight different paraffinic side‐chains, within the carbon range C12–C15. Accordingly, sulphonation conditions for it were adjusted to optimize the reaction yield and product quality.

Liquid surfactant formulations based on these anionic sulphonates were established by incorporating other necessary ingredients. The formulations developed have shown high efficiency as detergents, wetting agents and emulsifiers.
Kinetics of 2,3‐butanediol fermentation by Bacillus amyloliquefaciens: Effect of initial substrate concentration and aeration
Authors: Alam S. , Capit F. , Weigand W. A. , Hong J.
Published: July 2010

Most studies on 2,3‐butanediol production by microbial fermentation have been carried out using Klebsiella oxytoca and Bacillus polymyxa. In these fermentations there is a significant conversion of carbon source into ethanol, glycerol and various organic acids as by‐products. On the other hand, this investigation has shown that the major products of fermentation by Bacillus amyloliquefaciens are 2,3‐butanediol and some minor acids. In a typical fermentation about 33 g of butanediol was produced from 100 g of glucose.

The effect of pH, various carbohydrate source, initial glucose concentration and aeration on the 2,3‐butanediol fermentation by B. amyloliquefaciens were investigated. The butanediol productivity and yield was found to be highest with glucose as the carbohydrate source. The glucose concentration was varied between 30 and 100 g dm−3 with oxygen transfer rate controlled between 47.5 and 78.0 h−1. Oxygen and the initial substrate concentrations significantly influence the yield, productivity and by‐product formation.
Adsorption of Streptococcus faecalis on diatomite carriers for use in biotransformations
Authors: Anderson William A. , Bay Pierre , Legge Raymond L. , Moo‐young Murray
Published: July 2010

Adsorption of cells on particulate carriers is potentially one of the most cost‐effective immobilization techniques available. Diatomite carriers, such as Celite, have desirable physical properties, are inexpensive, and are suitable for both mycelial and bacterial systems. This work investigated the use of diatomite carriers as a biocatalyst support in a packed‐bed reactor where L‐tyrosine was enzymatically decarboxylated using adsorbed, non‐growing cells of Streptococcus faecalis. Composition of microbial adsorption on different Celite types, with mean pore sizes ranging from 0.55 to 22 μm, showed there was no significant difference in biomass loading capacity under the conditions used. Using Celite 560, biomass loadings in a packed‐bed reactor varied from 10 to 30 g dm−3 of reactor volume, which compares favourably with other adsorption methods. When used to decarboxylate L‐tyrosine, the reactor was found to have a half‐life of 15–20 h. A combination of enzyme activity loss and slow leakage of biomass from the packed‐bed reactor was responsible for the decline in conversion. Treatment of the S. faecalis cells with glutaraldehyde significantly reduced the enzyme activity loss and extended the reactor half‐life to 65 h, but had little effect on the rate of cell leakage from the reactor. Further work on reduction of cell leakage rate seems necessary for evaluation of the system's practicality.
Photochemical elimination of Cr(VI) from neutral–alkaline solutions
Authors: Domènech Xavier , Muñoz Javier
Published: July 2010

The elimination of Cr(VI) from aqueous solutions at neutral and low alkaline pH by photocatalytic reduction to Cr(III), using ZnO powder as catalyst, is investigated. The study has been performed by determination of the percentage of Cr(VI) eliminated in the presence of some species (i.e. Zn(II), Cd(II), Ni(II), Ca(II), CH3COO−, PO3‐4, CO2‐3, S2‐ and NH3) which usually are found in wastes together with Cr(VI). The results obtained show that the presence of some species prevents the alkalinization of the solution during irradiation, which increases the yield of Cr(VI) photoreduction. Other species, such as S2‐ and NH3, are oxidized during illumination: thus they prevent electron–hole recombination and, consequently, increase the yield of the Cr(VI) elimination.
Amperometric determination of ammonium ions with a microbial sensor
Authors: Riedel K. , Huth J. , Kuehn M. , Liebs P.
Published: July 2010

A sensor for NH+4 ions has been developed, which consists of immobilized micro‐organisms (Bacillus subtilis, Pseudomonas aeruginosa, Trichosporon cutaneum) in combination with an electrochemical transducer. This sensor is based on the measurement of acceleration of respiration after addition of NH+4 in the presence of glucose. The physiological background of this signal and its connection with NH+4 ion uptake and/or metabolism is discussed.

The response time of the sensor is about 5.10 s for NH+4 ions. A linearity was observed between 0.005 and 0.15 mmol dm−3 NH+4 ions. The sensitivity of the sensor remained almost constant for 12 days. The sensor was used to determine NH+4 ions in a microbial fermentation broth.
Pure fructose syrup and ethanol production from high fructose corn syrup supplemented with Jerusalem artichoke juice
Authors: Koren David W. , Duvnjak Zdravko
Published: July 2010

Saccharomyces cerevisiae ATCC 36859 preferentially consumes glucose from glucose–fructose mixtures. Synthetic media and complex media containing high fructose corn syrup supplemented with Jerusalem artichoke juice were used for the production of pure fructose syrup by the conversion of glucose to ethanol. Fructose was not converted in these processes. Increasing the concentration of Jerusalem artichoke juice increased the yields of ethanol and biomass and decreased the process time. A similar effect was obtained at a low juice concentration when a larger amount of biomass was used for the inoculum. The product from this process contained only fructose and ethanol. Use of food‐grade materials results in a pure fructose syrup that is suitable for human consumption.
Studies on oxidative dehydrogenation of n‐butane on bismuth molybdate on alumina
Authors: Singh Dinesh , Gehlawat J. K. , Rao Musti S.
Published: July 2010

Oslefins and diolefins are important intermediates in the petrochemical industry and the future promises a further substantial increase in demand. While several catalysts have been formulated in the past for the abstraction of hydrogen from butenes and propylene, these catalysts are inefficient in the abstraction of first hydrogen from butane. Bismuth molybdates (β and γ‐phases) containing iron oxide and supported on alumina are used as catalysts in the present investigation on the oxidative dehydrogenation of n‐butane. Effects of catalyst content, temperature and oxygen: n‐butane ratio on conversion and selectivity to butadiene and (C4H8 + C4H6) are studied in the following ranges of experimental conditions: β‐bismuth molybdate/100 mol support I(K), 3–9; γ‐bismuth molybdate/100 mol support I(K), 5‐20; temperature, 400–500°C; O2: butane ratio, 0.6:1.7.
The effect of metal distribution across pellets on the activity of nickel–tungsten hydrotreating catalysts
Authors: Kural M. Esen , Cant Noel W. , Trimm David L.
Published: July 2010

Nickel–tungsten‐based hydrotreating catalysts have been prepared with different metals impregnation profiles and tested for the hydrodesulphurisation, hydrodenitrogenation and hydrogenation of model compounds. Penetration of the catalyst by the model compounds depends on the pore structure of the support and determines activity. Best performance is associated with optimal Ni:W ratios dished across the active region of the catalyst rather than with an even impregnation across all of the support.
Simultaneous saccharification and isomerization by immobilized glucoamylase and glucose isomerase
Authors: Xiao Cha , Hui Zhou , Wei Li , Jiacong Shen
Published: July 2010

Glucoamylase and glucose isomerase, which are often used in industry to produce high‐fructose corn syrup, were immobilized on porous anilino‐sulfonic polystyrene beads and porous triethanolamine methyl polystyrene beads, respectively. These charged supports altered the pH profiles of the two enzymes such that it was possible to carry out simultaneous saccharification and isomerization at pH 6.5 or pH 7.5 using immobilized glucoamylase and immobilized glucose isomerase. This process is very difficult to accomplish with soluble glucoamylase and glucose isomerase because of the large difference in the pH profiles of the two enzymes in their soluble form.
Synthesis and biological activity of some new 2‐chlorophenothiazine derivatives
Authors: El‐ezbawy S. R. , Alshaikh M. A.
Published: July 2010

10‐(Hetero/arylthio)acetyl‐2‐chlorophenothiazines II have been synthesized via interaction of 10‐chloroacetyl‐2‐chlorophenothiazine I with heterocyclic and/or aromatic potassium mercaptide in ethanol. Oxidation of II using H2O2/CH3COOH mixture was studied. Structures of the products were verified by elemental and spectral analyses. Some compounds were screened in vitro for their antibacterial activities.
Mass spectral characterization of acyloxymethyl phosphates
Authors: Srivastva Devendra N. , Srivastva Asha , Smith Ronald G.
Published: July 2010

A series of organophosphates having one or two acyloxymethyl groups have been characterized by methane chemical ionization mass spectrometry: twelve are model compounds with phenyl and benzyl groups while four are derived from pyrimidine‐3′‐deoxyriboside‐5′‐monophosphates. Some are protonated cyclohexyl‐ammonium salts. In addition the phenyl and benzyl phosphate spectra exhibit an abundance of fragmentation and rearrangement ions, the majority of which were products of three processes—expulsion of formaldehyde, loss of the acyloxymethyl group with transfer of hydrogen to the phosphate, and fission of the methylene–acyloxy bond. The pyrimidine‐3′‐deoxyriboside‐5′‐monophosphate esters give less fragmentation under similar circumstances; prominent ions in their spectra are the protonated molecular ions and losses of one and two molecules of formaldehyde from them and the protonated bases.
Production, thermal stability and immobilisation of inulinase from Fmarium oxysporum
Authors: Gupta Anil K. , Rathore Preetima , Kaur Narinder , Singh Rangil
Published: July 2010

Fusarium oxysporum produced maximum extracellular inulinase after 9 days of its growth at 25°C on a medium (pH 5.5) containing 3% fructan and 0.2% sodium nitrate. The level of this enzyme decreased on the addition of either glucose, fructose, galactose or sucrose to F. oxysporum already growing on a fructan‐containing medium. A significant increase in invertase production which resulted in an increase of the invertase/inulinase (S/I) ratio, was observed on addition of inulin to this fungus growing on other carbon sources. Glycerol (10%) gave better protection to inulinase against thermal denaturation at 50°C compared to ethylene glycol and sorbitol. Inulinase immobilised in polyacrylamide gel retained 45% of its original activity. The immobilised enzyme showed a higher optimum temperature (45°C) compared to free enzyme (37°C). The immobilised enzyme after storage at 25°C for 96 h showed 58% activity. Thermal stability of entrapped inulinase increased in the presence of inulin.
Changes in crushing strength of hydrocarbon steam‐reforming catalyst along the reactor tube under operating conditions
Authors: Redwan D. S. , Lee A. K. K. , Aitani A. M.
Published: July 2010

The catalytic hydrocarbon steam reforming process for the production of synthesis gas is accomplished using a nickel‐based catalyst. The catalyst is designed to suit fixed‐bed continuous‐flow tubular reactor operation. It is manufactured in cylindrical form and possesses a relatively high crushing strength. The nickel active ingredient is homogeneously dispersed on the carrier surface in its oxide form. The currently applied reformers are vertical continuous‐flow reactors consisting of several hundred tubes in which the reactants—hydrocarbon and steam—are introduced at the top of the reactor tubes and the reformed gaseous products are collected at their bottom ends. Performance and long‐term uninterrupted operation of hydrocarbon steam reformers are severely affected by the alteration of the crushing strength of catalyst pellets.

Changes in the crushing strength of the catalyst along the reformer tube under actual operating conditions were investigated and the results are presented here. The usefulness of the crushing strength as a diagnostic test for catalysts is discussed. This test has direct bearing on the selection of prospective catalyst charge, the reuse of partially used catalyst charge, and the investigation of catalyst failures.
A mechanistic growth model of a methylotroph
Authors: Agrawal Pramod , Lim Henry C.
Published: July 2010

Based on the biochemical knowledge of the RMP‐cycle methylotrophs and the experimental results of batch and continuous culture growth of a methylotroph, L3, a simple mechanistic growth model of L3 was developed. The growth model consists of a basic structure and a regulatory structure. The basic‐model structure was developed by incorporating formaldehyde as a state variable and including a lpump‐and‐leak' mechanism of formaldehyde transport. The regulatory‐model structure was built by acknowledging growth inhibition due to formaldehyde and formaldehyde inhibition of methanol oxidation. The resulting model describes adequately the batch as well as the stable and unstable steady‐state continuous culture behavior of L3 on mixtures of methanol and formaldehyde.
Iron intercalated in graphite as catalysts for ammonia synthesis
Authors: Kalucki K. , Morawski A. W.
Published: July 2010

Catalysts for ammonia synthesis based on iron intercalated in graphite precursors were prepared. This study reveals that the catalysts' activity is associated with a broad electron paramagnetic resonance (EPR) line, and that the iron co‐ordinated by both carbon and potassium influences both the intensity of the EPR signal and activity.
Yeast cell harvesting from cider using microfiltration
Authors: Taddei Christine , Aimar Pierre , Howell John A. , Scott J. Ashley
Published: July 2010

Yeast cell harvesting from cider was performed with a 0.2 μm pore size hydrophilic polyvinylidene fluoride membrane. The microfiltration (MF) membrane exhibited a large flux decline during the first 20 min of operation when challenged with a fermentation broth. This may be attributed to rapid particle polarization initiating membrane fouling. Pore plugging may be more likely to have reduced the flux throughout the experiments than cake formation on top of the membrane, as cross‐flow controls cell build‐up on the membrane and removes some of the cells from the layer.

A small proportion of yeast cells were not retained by the membrane; this was attributed to a proportion (1 in 10 000) of the membrane pores being oversize. Aeration during fermentation affected subsequent fouling during MF, probably through alteration of the ability of the microorganism to attach on to the membrane. A high proportion of nonviable cells typical of an aged broth also improved the flux performance, suggesting that any fermentation change having an effect on the yeast cell surface could influence the MF flux.
The formation of hydroxy monocarboxylic acids and dicarboxylic acids by alkaline thermochemical degradation of cellulose
Authors: Niemelä Klaus
Published: July 2010

Treatment of cotton cellulose with 3 M sodium hydroxide solution at 260°C and 280°C gave a mixture of carboxylic acids with a yield of > 95%. The identified 50 carboxylic acids included both hydroxy monocarboxylic acids and dicarboxylic acids; their routes of formation are discussed. Among the main compounds were lactic, glycolic, 2‐hydroxy‐2‐methylpropanoic, 2‐hydroxybutanoic, 3,4‐dideoxypentonic, anhydroisosaccharinic, 2,3‐dideoxypentaric, and 3,4‐dideoxyhexaric acids. Technical utilisation of this kind of acid mixture requires further studies.

Investigations of the cyclic compounds, formed in small amounts only, resulted in identification of mainly alkyl‐substituted 2‐cyclopenten‐1‐ones.
Biomass production by a thermotolerant yeast: Hansenula polymorpha
Authors: Escalante Javier , Caminal Gloria , de Mas Carles
Published: July 2010

Biomass production at high temperature by Hansenula polymorpha as part of a lignocellulosic utilizing process was studied. Compromise growth conditions (45°C and pH = 4.8) with an eventual saccharification step were established. The effects of stirring rate and initial glucose concentration on biomass yield coefficient, volumetric productivity and maximal cell density were determined. Process optimization led to a fed‐batch fermentation process: high yield (0.63 g dry cell g−1 glucose), volumetric productivity (1.3 g dry cell dm−3 h−1) and cell concentration (60 g dry cell dm−3) were obtained. At these conditions, significant arabitol excretion (18 g dm−3) as a unique by‐product associated with cell mass production was obtained, making more interesting a high temperature operating process.
Sulfur removal from coal through multiphase media containing biocatalysts
Authors: Lee Kwang‐Il , Yen Teh Fu
Published: July 2010

A novel bioprocess using micelle biocatalysts was developed to minimize several disadvantages of conventional microbial coal desulfurization processes. The multiphase biocatalysis process consists of an organic medium (mineral oil or a mixture with n‐heptane), a surfactant and an aqueous phase containing Thiobacillus ferrooxidans organisms or their cell‐free enzyme extracts. Water‐in‐oil emulsion and reverse micelle processes have been successful for removing sulfur from bituminous coal. The preliminary results indicated that, in the case of water‐in‐oil emulsion, the process that used the cell‐free enzyme extracts of T. ferrooxidans showed higher sulfur reduction than that containing whole cells, and reverse micells were more effective than water‐in‐oil emulsion. With a high concentration of bacteria, more than 50% total sulfur removal was achieved through the reverse micelle system. These results indicate that multiphase biocatalysis may have a significant potential for developing biotechnical coal desulfurization processes.
Recirculation and flow structures of gas in downcomer section of a concentric cylindrical airlift reactor
Authors: Choi Keun Ho , Lee Won Kook
Published: July 2010

Recirculation and flow structures of gas in the downcomer section of a concentric cylindrical airlift reactor for air‐water systems were studied, using an optical probe and the cross‐covariance technique. A semiempirical model for predicting the gas recirculation rates in airlift reactors was developed based on the concept of ideal bubble flow. The entrained gas rate and the gas recirculation rate increased as the superficial gas velocity increased. There were nonuniform radial distributions of local gas holdup and air flow rates in the downcomer. Air flow rates in the downcomer depended on the superficial gas velocity and the distance from the top of the draft tube, but not on the superficial liquid velocity for this experimental range.
Immunoaffinity adsorption: Process‐scale isolation of therapeutic‐grade biochemicals
Authors: Desai Mohamed A.
Published: July 2010

This review describes immunoaffinity purification as a tool for the processscale isolation of high‐value, therapeutic‐grade biochemicals from complex media. To this end, practicalities of activation, antigen coupling and operation in anti‐human IgG monoclonal antibody recovery have been studied using cyanogen‐bromide activated Sepharose CL‐4B and composite Macrosorb K4AX immobilised with polyclonal human IgG as a model for general immunoaffinity systems. The characteristics required of solid phases are discussed in the context of the efficient application of bioselective processes early in the purification sequences. The importance of the technique for isolating biologically active biomolecules for in‐vivo administration has been discussed in the light of current, stringent regulatory requirements. Finally, the prospect of scale‐up and automation of the technique has been evaluated.
Determination of zinc in aluminum metal and alloys using a sensitized murexide reaction
Authors: Zaki M. Tarek M. , Ragheb Abdel‐Ghany , Mohamed Adel S.
Published: July 2010

The spectrophotometric properties of zinc complexes with murexide in the absence and presence of cationic, anionic and nonionic surfactants were studied. The addition of cationic surfactants stabilized the complex and hence improved the intensity of the absorption band (sensitized the reaction). A method for the determination of >0.01% zinc in aluminum metal and some aluminum base alloys was developed. The method was based on measuring the absorbance of the formed complex with murexide and cetylpyridinium bromide at pH 8. The apparent molar absorptivity was 4.7 ± 0.01 × 104 litre mol−1 cm−1 at 470 nm. A linear calibration curve was obtained for up to 1.44 ppm of zinc. In the presence of sodium fluoride and thiourea masking solutions, common ions in aluminum metal and alloys did not interfere.
Cloud Points, solubilisation and interfacial tensions in systems containing nonionic surfactants
Authors: Aveyard Robert , Binks Bernard P. , Clark Stephen , Fletcher Paul D. I.
Published: July 2010

Nonionic surfactants above their critical micelle concentration in aqueous solution phase separate, at the cloud point, as the temperature is raised as a result of concommitant changes in micellar size, shape and interactions. We discuss the ways in which the cloud point changes in the presence of various additives. If (sufficient) alkane is solubilised in aqueous surfactant (or water in an alkane solution) single phase microemulsions result. If further alkane (or water) is added separation into two phases occurs. Depending on temperature, the separation results from either attainment of the natural curvature of the surfactant film coating the microemulsion drops, or from interactions between droplets. In two phase (oil+aqueous) systems, one phase is a microemulsion and the other the excess of the dispersed (droplet) phase. The type of microemulsion obtained (i.e. the hydrophile‐lipophile balance of the system) depends on the temperature, and can be understood in terms of changes in the natural curvature of the surfactant films with temperature.
Isomerization of methylcyclopentadiene dimers
Authors: Díez M. A. , Fantanas F. J. , Blanco C. G. , Bermejo J.
Published: July 2010

A commercial mixture of methylcyclopentadiene dimers mainly consisting of four dimeric compounds with partial structures of 1‐methyl‐ and 2‐methylnorbornene, undergoes slow oxidation and isomerization when it is dissolved in CH2Cl2, CHCl3 or CCl4. Both reactions are simultaneous but independent of each other. Isomerization only concerns those isomers that contain in their structure a 2‐methylnorbornene ring.

The nature of the isomerization and the influence of different acid media is studied.
Effect of diffusional resistances on the action pattern of immobilized alpha‐amylase
Authors: Siso Maria I. G. , Graber Marianne , Condoret Jean‐Stéphane , Combes Didier
Published: July 2010

Alpha‐amylase from Aspergillus oryzae has been immobilized onto corn grits and porous silica (specific areas 180 and 440 m2 g−1). Kinetic parameters of immobilized enzyme have been determined.

Immobilization of alpha‐amylase results in the formation of less polymerized products resulting in an apparent decrease in the number of transglycosylation reactions, for both maltotetraose and starch as substrates, when compared with free enzyme.

Diffusional limitations for substrate and products have been quantified in the case of the three supports used. External diffusional resistances were important in all cases for the reaction products, whilst they became negligible for the substrate in the case of silica supports. Moreover, internal transfer limitations were identified with silica 180 m2g−1 support. It was demonstrated that diffusional resistances were in direct relation to the apparent modification of the enzyme action pattern after immobilization.
Measured activation energies of ignition of solid materials
Authors: Clifford Jones J. , Wake Graeme C.
Published: July 2010

Measured activation energies of ignition of a wide variety of solid materials of practical importance are tabulated. The Frank‐Kamenetskii model of thermal ignition was used in their determination. Comments are made on the values in terms of the nature of the respective materials and in terms of the value of the measured quantities as input to mathematical simulation of ignition.
Isolation and characterization of a nitrile hydratase from a Rhodococcus sp.
Authors: Hjort Carsten M. , Godtfredsen Sven Erik , Emborg Claus
Published: July 2010

A new nitrile hydratase producing strain of Rhodococcus has been found. A method for purification of the nitrile hydratase and a characterization of the enzyme is described. The hydratase is a 52‐kdal protein consisting of two subunits of molecular weights, 26 and 23 kdal, respectively.

The hydratase exhibits a broad substrate specificity. Aliphatic saturated or unsaturated nitriles, as well as aromatic nitriles, are substrates for the enzyme. Inhibition of the enzyme activity by amides and carboxylic acids was observed. The optimum pH of the hydratase is 7.5. The enzyme is rather unstable, even at room temperature.

The enzyme may be applied for the production of acrylamide. For this application of the enzyme, the optimal temperature is about 4°C, where the enzyme exhibits a satisfactory activity and stability.
Immobilization of enzymes to porous‐bead polymers and silica gels activated by graft polymerization of 2,3‐epoxypropyl methacrylate
Authors: Wójcik Anna , Öobarzewski Jerzy , BlaszczyłSka Teresa
Published: July 2010

Three types of organic polymers and bead‐shape silica gels were activated by graft polymerization of 2,3‐epoxypropyl methacrylate; in some cases, epoxide groups on the support surface were modified to NH2 groups. Eight active matrices so obtained were assessed as supports for immobilized enzymes using peroxidase, glucoamylase and urease. The immobilization yield of protein and specific activities of enzymes were better with supports containing NH2 groups than with those containing epoxide spacer arms. Maximum enzyme immobilization and storage stabilities were obtained with silica‐gel beads activated by graft polymerization of 2,3‐epoxypropyl methacrylate. With all eight matrices tested, the immobilized enzymes showed good stability with not less than 82% of the original activity persisting after 28 days. The developed matrices have potential for use in process‐scale biotechnological operations.
A novel method for continuous production of cyclodextrins using an immobilized enzyme system
Authors: Su Chein‐Shyong , Yang Chin‐Ping
Published: July 2010

Selected specific α‐amylase and glucoamylase enzymes were immobilized and combined with immobilized cyclodextrin glycosyltransferase to continuously produce cyclodextrin (CD). The liquefied starch was cyclized to CD by ICGTase and then treated by immobilized α‐amylase and glucoamylase to contain CD and glucose only. β‐CD and soluble CD (α‐ and γ‐CD) in the final CD solution could be easily separated. The pH‐activity curve, temperature‐activity curve, batch re‐usability and continuous operation stability of immobilized enzymes were discussed. The continuous production of CD by an immobilized enzyme system was also reported. The optimal conditions for using immobilized α‐amylase and glucoamylase simultaneously were 40°C and pH 4.5 adjusted by 1 mol dm−3 HCl/NaOH. A 70% yield of CD could be obtained from 1% (w/v) of liquefied starch under continuous operation at 0.055 h−1 space velocity, and almost all the oligosaccharides (β 98%) were converted to glucose. In this study, the separation of α‐CD, γ‐CD and glucose, using organic solvent from the final product after precipitating β‐CD, was also investigated.
Discrimination of fetal bovine serum from other sera by silver staining or lectin blotting of SDS/PAGE‐separated serum proteins
Authors: Bockman Jeffrey M.
Published: July 2010

In order to develop a methodology to discriminate fetal bovine serum from other sera with which it might be contaminated, proteins from fetal bovine, newborn calf, colostrum‐free newborn, and calf sera were separated by SDS/PAGE and analyzed by silver staining of the gels or lectin blotting, using concanavalin A (Con A), following transfer of the proteins to nitrocellulose. A high molecular weight Con A‐reactive glycoprotein of an apparent molecular mass greater than 200000 daltons was present in newborn, colostrum‐free, and calf sera, but absent or at a significantly lower concentration in fetal serum. These two methods accurately and reliably identified contamination of fetal serum with other sera in a series of blind studies on unknown, coded samples. As little as 1% colostrum‐free serum in a batch of fetal serum can be detected by either procedure.
Experimental and simulation studies on intermittent aeration in an oxidation ditch
Authors: Terashima Yutaka , Ozaki Hiroaki , Hashim Mohd A.
Published: July 2010

The simultaneous removal of nitrogen and organic substances can be enhanced by establishing an anoxic stage through intermittent aeration in the oxidation ditch system. In this study, investigations on substrate removal and the optimal operating conditions of a laboratory‐scale oxidation ditch system with intermittent aeration were carried out using synthetic wastewater. Up to 96% of the carbonaceous substances and 93% of total nitrogen were removed. A theoretical model developed for this system gave good agreement with the experimental data.
Interfacial mass transfer in extraction of amino acid by aliquat 336 in organic phase
Authors: Uddin Mohammad S. , Hidajat Kus , Lim Bee‐Gim , Ching Chi‐Bun
Published: July 2010

Reactive extraction of L‐phenylalanine from alkaline aqueous solution into xylene in the presence of tri‐octyl‐methyl‐ammonium chloride (ALIQUAT 336) as complexing agent was studied using a stirred transfer cell. The study investigated the effects of carrier concentration and temperature on mass transfer rates. Transfer rate across the interface in the presence of surfactant molecules was also studied. A two‐film model was proposed by considering film mass transfer resistances at the aqueous and organic phases. The model predicted adequately the experimental time‐concentration data at different carrier concentrations and temperatures. The model was modified to take into account the presence of surfactant in the organic phase.
Thermodynamics and kinetics of lipase catalysed hydrolysis of oleyl oleate
Authors: Rostrup‐Nielsen Thomas , Pedersen Lars Saaby , Villadsen John
Published: July 2010

The kinetics of enzymatic hydrolysis of oleyl oleate in the boundary layer between stagnant organic and aqueous phases was studied using a commercial lipase preparation which was dissolved in the aqueous phase. Three aspects of the reaction were investigated. (1) The hydrolysis equilibrium in the organic phase cannot be expressed in terms of the concentrations of ester, alcohol and organic acid alone since the activity of the organic compounds changes dramatically with conversion, i.e. with the water content in the organic phase. An empirical correlation that accounts for the water activity and the unknown activity coefficients of the organic compounds is determined. (2) The influence of the interfacial area was examined, and it was found that the amount of ester converted per unit area of interface is independent of the available interfacial area and of the amount of ester. (3) The inhibition of the reaction by the hydrolysis products and by n‐alkanes was measured. Both acid and alcohol inhibit the hydrolysis reaction while the influence of long‐chained alkanes is very small.

It is concluded that the reaction rate is determined by the interfacial concentrations, and that these concentrations differ from the bulk concentrations because of the different surface affinities of the components.
A convenient preparative method of unsymmetrical ketones and aliphatic aldehydes by thermolysis of homoallylic alcohols
Authors: Inaba Teruhiko , Sakamoto Masami , Watanabe Shoji , Takahashi Ikufumi , Fujita Tsutomu
Published: July 2010

The thermolyses of various homoallylic alcohols, which are prepared from 1‐alken‐4‐ones (B) by Grignard reaction or reduction, afforded unsymmetrical ketones or aliphatic aldehydes in good yields. For example, the reaction of methylmagnesium iodide with 1‐nonen‐4‐one (1) gave 4‐methyl‐1‐nonen‐4‐ol (2) in 87% yield. The thermolysis of (2) at the temperature of 753 K gave 2‐heptanone (3) in 92% yield. By use of this method, we obtained a variety of 1‐alken‐5‐ones (J) which can be used as important intermediates of the preparation for dihydrojasmone or cis‐jasmone.
Liquid‐phase oxidation of anthracene in acetic acid with an oxygen/Nitric acid system
Authors: Das C. K. , Das N. S.
Published: July 2010

Oxidation of anthracene in acetic acid by the oxygen/nitric acid system has been studied and an attempt has been made to ascertain a practical limit of the amount of solvent keeping the commercial prospects in view. The effects of other reaction parameters such as flow rate, amount of nitric acid and water, residence time, etc., have been investigated. While opting for a solvent/substrate ratio of 10, the optimum conversion of anthracene to anthraquinone free from nitro‐compounds has been found to be 91% with purity of 98.7%, acceptable to dye‐stuff industries.
Studies on the synthesis of norbornadiene
Authors: Sen A. K. , Kumar Ramesh , Lal Darshan , Srivastava A. K.
Published: July 2010

The dimers and trimers of norbornadiene have a unique polycyclic strained structure and are of great practical value. A systematic study of the synthesis of norbornadiene from dicyclopentadiene and acetylene under pressure has been carried out. The effects of various operating parameters on product distribution have been determined. The optimum conditions for the synthesis are: (i) temperature, 290°C; (ii) residence period, 16 min; (iii) mole ratio of C2H2:N2: dicyclopentadiene, 1:1:0.4; and (iv) initial pressure at ambient temperature, 8.894 × 105 nm−2. Under these conditions the conversion of norbornadiene is 41.74% on the basis of dicyclopentadiene consumed. The loss of dicyclopentadiene due to polymerisation has been estimated from its balance.

A kinetic study of the synthesis from cyclopentadiene has also been carried out.
Enzymatic saccharification of canola meal
Authors: Gattinger Loni D. , Duvnjak Zdravko , Khan Waheed A.
Published: July 2010

For the enzymatic saccharification of canola meal by enzyme preparations from Trichoderma reesei as well as by commercially available hemicellulase and multienzyme preparations, a pretreatment consisting of autoclaving is necessary. These enzyme preparations hydrolysed over 20% (w/w) of pretreated canola meal, which constitutes over 70% saccharification of the total polysaccharides present in canola meal. The results show that saccharification of canola meal is mainly brought about by hemicellulases capable of degrading arabinogalactan, arabinoglucan, galactan and galactomannan, while cellulases and xylanases play a minor role. These hemicellulases were found to be more stable at 50°C than cellulases or xylanases. This pretreatment also released water‐soluble polysaccharides consisting mainly of arabinose and glucose. Trichoderma reesei was unable to produce enzymes capable of hydrolysing this polysaccharide when cultivated on canola meal as substrate.
Design and operation of anaerobic digesters using multi‐objective optimization criteria
Authors: Videla Sebastian , Chamy Rolando , Navarrete Eduardo , Lema Juan M.
Published: July 2010

A methane fermentation system can be considered as a multi‐objective optimization problem characterized by conflicting objectives such as investment cost, net biogas production and chemical oxygen demand (COD) removal. To this end, a k‐objective ‐constraint method was used to determine the optimal design and operation parameters of a continuously stirred anaerobic digester. This equipment treats leachates from the controlled solid urban wastes landfill at Garraf (Barcelona, Spain), which receives 5–6 × 105 tonnes of wastes per year. The optimal solutions were generated for two design criteria: (a) reduction of cost to a minimum and (b) maximization of net energy production with at least 75% removal of COD. The preferred solution was obtained by using the non‐inferior solution set.
Development of a chromatographic process for largescale purification of staphylococcal enterotoxin B
Authors: Johansson Hans J. , Pettersson Torbjörn N. , Berglöf Jan H.
Published: July 2010

A process for large‐scale purification of staphylococcal enterotoxin B (SEB) is presented. The process consists of three chromatographic steps. The first two steps are based on ion‐exchange chromatography and the final one on gel filtration.

Diluted culture supernatant (2000 dm3) with a SEB content of 0.4 mg dm−3 were processed and purified. SEB was obtained in 1.5 dm3 of 0.1 mol dm−3 ammonium hydrogen carbonate buffer, pH 8.0. The final product produced a single band on SDS polyacrylamide gel electrophoresis and a single peak when subjected to analytical gel filtration. The overall recovery was 74%.
Synthesis and biological activity of some 5‐substituted aminomethyl‐8‐hydroxyquinoline‐7‐sulphonic acids
Authors: Yanni A. S. , Mohharam A. M.
Published: July 2010

5‐Aryl (or alkyl)‐8‐hydroxyquinoline‐7‐sulphonic acids have been prepared by the Mannich reaction of 8‐hydroxyquinoline‐7‐sulphonic acid with primary and secondary amines. Their bactericidal activities have been determined.
Studies on amalgam electrodes. The reaction of but‐1‐yn‐3‐ol at copper amalgam
Authors: Lee J. B. , Boardman W. , Edwards G. S.
Published: July 2010

The copper amalgam electrode can be used for clean oxidative coupling of but‐1‐yn‐3‐ol in good yield. An electrochemically generated intermediate can be further coupled in a solution process by aeration of the electrolyte giving increased yields. Addition of pyridine depresses coulombic yields in the electrochemical system, although it increases the rate of the purely chemical process.
Separation and concentration processes of solutions of Co(II), Ni(II), Cr(III), Fe(III) and Mn(II) by extraction with toluene‐dissolved rosin
Authors: Gomez S. Jimenez , Valdivia L. M. Lopez , Iglesias C. Gonzalez , Selas M. I. Rico
Published: July 2010

The extraction and stripping of Co(II), Ni(II), Cr(III) and Fe(III) from aqueous solutions by rosin dissolved in toluene has been investigated. Results obtained show that rosin is better extractant than abietic or n‐lauric acids under comparable conditions.

From these results, and the data of Mn(II) solvent extraction studied previously under the same conditions, a separation and concentration process for these five cations in aqueous solutions has been designed. Saturated solutions of Fe(III), Cr(III), Mn(II) and finally Co(II) and Ni(II) have been obtained successively by extraction and stripping, by addition of ammonium hydroxide to obtain the appropriate pH value, and by modifying adequately the organic phase/aqueous phase volume ratio.
Synthesis of arylazopyrazolo[1,5‐a]pyrimidines and their application to synthetic fibres
Authors: Rangnekar Dinesh W. , Puro Sanjay S.
Published: July 2010

4‐Phenyl‐5‐aminopyrazole 2 obtained from phenylcyanoacetaldehyde 1 and hydrazine hydrate reacted with diethyl malonate to give 3‐phenyl‐5,7‐dioxopyrazolo[1,5‐a]pyrimidine 3, used as the key compound in the synthesis of arylazo dyes. The key compound 3 was coupled with various aryldiazonium salts 4 to yield 3‐phenyl‐7‐hydroxy‐6‐arylazopyrazolo[1,5‐a]pyrimid‐5‐ones 5. The resulting arylazo dyes (5) were refluxed in phosphorus oxychloride to give 3‐phenyl‐5,7‐dichloro‐6‐arylazo‐pyrazolo[1,5‐a]pyrimidines 6, which subsequently reacted with refluxing morpholine and piperidine to yield 3‐phenyl‐5,7‐bis(morpholino and piperidino)‐6‐aryiazopyrazolo[1,5‐a]pyrimidines 7. The arylazo dyes 5 and 7 were applied to polyester fibres as disperse dyes and the arylazo dyes 6 were applied to polyamide fibres as disperse reactive dyes. The spectral and dyeing properties of the dyes were studied.
Biosorption of Radionuclides by Fungal Biomass
Authors: White Christopher , Gadd Geoffrey M.
Published: July 2010

Four kinds of bioreactor were evaluated for thorium removal by fungal biomass. Static‐bed or stirred‐bed bioreactors did not give satisfactory thorium removal probably because of poor mixing. An air‐lift bioreactor removed approximately 90–95% of the thorium supplied over extended time periods and exhibited a well‐defined breakthrough point after biosorbent saturation. The air‐lift bioreactor promoted efficient circulation and effective contact between the thorium solution and the mycelial pellets. Of several fungal species tested, Rhizopus arrhizus and Aspergillus niger were the most effective biosorbents with loading capacities of 0.5 and 0.6 mmol g−1 respectively (116 and 138 mg g−1) at an inflow thorium concentration of 3 mmol dm−3. The efficiency of thorium biosorption by A. niger was markedly reduced in the presence of other inorganic solutes while thorium biosorption by R. arrhizus was relatively unaffected. Air‐lift bioreactors containing R. arrhizus biomass could effectively remove thorium from acidic solution (1 mol dm−3 HNO3) over a wide range of initial thorium concentrations (0.1–3 mmol dm−3). The biotechnological application and significance of these results are discussed in the wider context of fungal biosorption of radionuclides.