bluuebunny/crossref_metadata_2025_split huggingface dataset:
Estimation of total aromatics in kerosene fractions by infrared spectroscopy—II
Authors: Ramaswamy Veda , Kothiyal Vimal , Singh Indra D. , Krishna Rajamani 
Published: July 2010

AbstractA general equation for the quick and accurate estimation of total aromatics in straight run kerosene fractions is derived using i.r. absorbances at characteristic wavenumbers from aromatic concentrates of kerosene of different crude oils. The accuracy of the method is found to be ±5%. When compared with the FIA method the deviation was found to be within 5.5%.
Evaluation of acids and cellulase enzyme for the effective hydrolysis of agricultural lignocellulosic residues
Authors: Tewari H. K. , Marwaha S. S. , Kennedy J. F. , Singh L. 
Published: July 2010

AbstractThis paper reports the results of experimentation carried out to compare the ability of mineral acids (HCl and H2SO4) and cellulase enzyme (from Trichoderma reesei QM 9414) in the saccharification of corn‐cob, groundnut shell, sugarcane bagasse and wheat straw. With the exception of corn‐cobs, acids proved to be better saccharifying agents than the cellulase complex, but the former gave a poor substrate for alcoholic fermentation since the saccharified mashes contained large amounts of pentoses which are not metabolized by most strains of yeast. In addition, both acids and enzymes have been found to be substrate specific. Maximal saccharification of groundnut shell, sugarcane bagasse and wheat straw were obtained with sulphuric acid at 15.0, 5.0 and 5.0% (v/v) under 15, 15 and 15 psi pressure for 15, 30 and 30 min, respectively; whereas hydrochloric acid at 7.5% (v/v) with. autoclaving for 30 min at 10 psi resulted in maximum saccharification of corn‐cob. However, the order of susceptibility of substrates to enzymatic attack was corn‐cob > wheat straw > sugarcane bagasse > groundnut shell. Increase in enzyme concentration (1–4 IU ml−1) and treatment duration (12–72 h) improved saccharification, but increases in substrate concentration (>5.0%, w/v) had an inhibitory effect on the hydrolytic ability of the cellulase enzyme complex. Of the various substrate‐acid ratios tested, a ratio of 1:8 was found to be optimal for the eflcient hydrolysis of the substrates under study.
Porosity and texture of basic zirconium nitrate
Authors: Gimblett F. Gareth R. , Hussain Asiah , Sing Kenneth S. W. 
Published: July 2010

AbstractStudies have been made of the development of texture and porosity in basic zirconium nitrate samples subjected to heat treatment at temperatures between 25 and 500°C. Scanning electron microscopy indicates that progressive disintegration of the amorphous material occurs over this temperature range, generating approximately spherical particles. Nitrogen gas adsorption studies, supplemented by mercury porosimetry measurements, show that these particles possess some microporosity (pore diameter < 2 nm), although the major factor controlling their adsorptive properties is an intrinsic mesoporosity related to a pore diameter within the range 2–50 nm and produced by the successive elimination of water and nitrato ligands with increasing temperature. Crystallisation occurs when the system is heated above 500°C, leading to the conversion of the amorphous material to the cubic variety of zirconia.
Effect of uv absorbers containing singlet oxygen quenching groups on the photochemical stability of crystal violet lactone and related colours
Authors: Oda Hironori 
Published: July 2010

AbstractThe photofading behaviour of Crystal Violet Lactone was investigated in solution. The contribution of singlet oxygen to that fading was suggested. UV absorbers containing nickel sulphonate quenching groups were prepared and the protecting effect of these compounds towards the photofading of colour materials derived from colour formers was examined in solution and in solid state. It was proposed that nickel salts of 2,2′‐dihydroxy‐4,4′‐dimethoxybenzophenone‐5‐sulphonic acid and its derivative can be applied as effective stabilisers against the photofading of indicator dyes in pressure (or heat) sensitive recording systems.
Characterization of a chemically modified β‐amylase immobilized on porous silica
Authors: Germain Pierre , Crichton Robert R. 
Published: July 2010

Abstractβ‐Amylase was coupled to a periodate oxidized dextran by reductive alkylation in the presence of sodium cyanoborohydride. The loss of activity (57%) during the cross‐linking of the enzyme was the result of steric hindrance near the catalytic site. In order to verify this hypothesis, the residual activity was determined with substrates of variable molecular size. The residual activity was inversely proportional to the particulate size of the substrate. Increases in residual activity, of up to 53% were obtained using an orientated chemical modification in the presence of a substrate which protects the catalytic site.Native and dextran‐conjugated β‐amylase were immobilized on an amino activated silica by a classical method using glutaraldehyde for the native enzyme and by reductive alkylation for the modified enzyme. The relative activity of the enzymes obtained after this insolubilization was very high for the modified amylase, 45% for a medium enzyme concentration, compared with 4% at the same concentration for the native enzyme. This difference can be attributed to the variation of the length of the space arm between the silica and the enzyme.The soluble β‐amylase dextran conjugate had a superior thermoresistance to that of the native enzyme; its optimal temperature of activity was 5°C higher than that of the native enzyme. This stabilization may be attributable to a rigidification of the protein structure.Immobilization of both native and modified enzymes on a amino silica resulted in thermostabilization of the enzymes. The optimal temperature of activity was 70°C for the native immobilized β‐amylase (some 10°C higher than that of the native enzyme) and 75°C for the chemically modified, and subsequently immobilized, β‐amylase.The immobilized forms of the enzymes were used for 14 days at 55°C in continuous substrate processing. The greater eflciency of the chemically modified β‐amylase was demonstrated by a four‐fold increase in maltose production compared to the classical method of immobilization.A kinetic study confirmed the stabilization of the β‐amylase by a reduction of the rate constant of inactivation of the different modified enzymes.
The cross‐flow filtration of an unstable β‐lactam antibiotic fermentation broth
Authors: Harris Tim A. J. , Reuben Bryan G. , Cox David J. , Vaid Aloke K. , Carvell John 
Published: July 2010

AbstractA ceramic cross‐flow filter has been evaluated in a recycle loop connected to a bioreactor containing a viscous Streptomyces sp. broth. Because of the instability of the antibiotics formed, it would be advantageous to extract them continuously as they are produced.The performance of the filter, under conditions of high viscosity and suspended solids, has been calculated. Resistance to filtrate flux, distribution of the antibiotic and sterilisability within the system were also examined.An initial flux at a cross‐flow velocity of 4 ms−1 gave readings of 162 litres m−2 h−1, which dropped to 131 litres m−1 h−1 on subsequent runs because of ‘bedding‐in’. Fluxes were improved by an increase of cross‐flow velocity and, for short periods, by applying pressure. They were reduced by anti‐foam agents and the gradual build‐up of particle polarisation layers. Loop sterilisation and removal of the antibiotic in the filtrate stream were excellent.
Barium aluminate hydrates: Part V. 2BaO·Al2O3·2H2O and 2BaO·Al2O3
Authors: Ahmed A. H. Moinuddin , Glasser Lesley S. Dent 
Published: July 2010

AbstractA new compound of formula 2BaO·Al2O3·2H2O has been synthesised and studied by infra‐red, X‐ray and thermal analytical techniques. This hydrate yielded another crystalline product, 2BaO·Al2O3, during dehydration.
Wollastonite as adsorbent for removal of Fe(II) from water
Authors: Singh A. K. , Singh D. P. , Panday K. K. , Singh V. N. 
Published: July 2010

AbstractWollastonite was used as an adsorbent for the removal of Fe(II) at different experimental conditions. The extent of removal is favourable at low concentration and low temperature. Maximum adsorption was noted at pH 4.0. The batch adsorption kinetics has been described by a first order rate expression, and the surface mass transfer coefficients and diffusion coefficients have been calculated at different temperatures. The intraparticle transport of Fe(II) within the pores of wollastonite is found to be the rate limiting step. The applicability of the Langmuir isotherm for the present system has been tested at different temperatures. Thermodynamic parameters indicate the exothermic nature of Fe(II) adsorption on wollastonite. The variation of adsorption with pH has been explained on the basis of interaction of iron species with negatively charged constituents of adsorbent.
Kinetics of saccharification of raw starch by glucoamylase
Authors: Matsumura Masatoshi , Hirata June , Ishii Satoshi , Kobayashi Jiroh 
Published: July 2010

AbstractA kinetic model for saccharification of raw starch was derived by taking into account the structural features of glucoamylase. The kinetic parameters were determined by using the results of experiments on saccharification of raw sweet potato starch, which were carried out at various substrate and enzyme concentrations in a temperature range from 23 to 40°C. From analysis of the experimental results it was concluded that the adsorption of enzyme was strongly dependent on temperature, and that two subsites took part in glucose inhibition, which was more pronounced at low temperature. The proposed kinetic model successfully predicted the progress of saccharification up to a high conversion, and also the progress of ethanol production in a simultaneous saccharification and fermentation.
On the retention of n‐butylamine by crystalline and fibrous cerium(IV) phosphate
Authors: Arjona A. Mata , Rodríguez A. García , Bueno F. del Rey , Sánchez E. Villafranca , Conejo G. López 
Published: July 2010

AbstractThe retention of n‐butylamine dissolved in cyclohexane on both crystalline and fibrous cerium(IV) hydrogen phosphate has been studied. The products involved were characterized by thermogravimetry, derivative thermogravimetry, differential scanning calorimetry, IR spectroscopy and X‐ray diffraction. The experimental results obtained reveal that the adsorption of n‐butylamine from cyclohexane solutions results in a net increase in the lattice space of the crystalline variety of the phosphate. Integral enthalpies and entropies, isosteric heats and differential entropies of retention were calculated from the adsorption isotherms run at 10, 15, 20, 25 and 30°C. The results show that variation of the different thermodynamic parameters with the degree of coverage for the two types of phosphate to be rather different.
Characterization and application of glucose oxidase immobilized in silica hydrogel
Authors: Kojuharova Ani , Popova Yanka , Kirova Nadejda , Klissurski Dimitar , Simeonov Danail , Spasov Liubomir 
Published: July 2010

AbstractThe properties of glucose oxidase (EC1134) embedded in silica gel were investigated. The immobilized preparations retained 62% of the activity of the mobilized enzyme. The optimum pH value (5.8) and temperature (30°C) were the same for the immobilized as for the soluble enzyme, but immobilized glucose oxidase had higher thermal and pH‐stability. The constants of thermal and pH inactivation, and the Michaelis constants were calculated.The effects of various cations and proteins on the activity of the immobilized enzyme were studied; NH4, K+, Mg2+ and gelatin all increased the relative activity of the preparations to 93–96% of the soluble enzyme.Combined immobilized preparations of glucose oxidase and catalase were repeatedly used in the oxidation of D‐glucose and the preparation of calcium gluconate.
Continuous preparation of activated carbon supported zinc acetate catalyst and industrial synthesis of vinyl acetate from acetylene
Authors: Kawaguchi Toshio , Wakasugi Toshihisa 
Published: July 2010

AbstractA continuous manufacturing method of an activated carbon supported zinc acetate catalyst has been established. Based on the dipping of a crushed activated palm carbon into a zinc acetate aqueous solution, the catalyst is prepared for the synthesis of vinyl acetate from acetylene in an industrial fluidized reaction vessel.The relationship between the supported amount of zinc acetate and various factors has been studied. Based on these results, an empirical formula was developed. Using this formula, the continuous manufacturing apparatus was designed and constructed for the purpose of preparing the optimum supported fluidized catalyst. To minimize the activated carbon loss due to crushing and wearing, a vibrating conveyor system was employed.This continuous manufacturing process produced a uniform catalyst with an activated carbon feed rate of 0.25 m3 h−1. Using this catalyst, a series of operational tests of the vinyl acetate synthesis was performed for investigating the optimum reaction conditions. These operational tests were carried out using an industrial fluidized reaction vessel of 3.28 m diameter and 50 tons day−1 vinyl acetate production capacity. Based on these test results, the reaction rate constant and the deterioration rate constant were newly introduced, and the optimum operation conditions were then determined.
Application of ultrafiltration to the preparation of defined hydrolysates of bovine haemoglobin
Authors: Piot Jean‐Marie , Guillochon Didier , Leconte Danielle , Thomas Daniel 
Published: July 2010

AbstractMany uses of protein hydrolysates have been developed and applied to areas such as nutritional therapy, culture media, and the isolation of biologically active peptides. All these applications need carefully controlled and characterized hydrolysates. In order to produce such a type of hydrolysate, it is possible to use haemoglobin which is a very well defined and constant protein source. Enzymic hydrolysis of haemoglobin by pepsin was carried out at pilot‐plant scale in an ultrafiltration reactor with mineral membranes. The object was to obtain a reproducible, decolorized, salt‐free enzymic hydrolysate. Two types of membranes were tested having 10000 dalton (M5 type) and 20000 dalton (M4 type) cut‐offs. Little significant difference was observed in the final products when both types of membranes were used. Reproducibility of hydrolysates was verified by amino acid analysis and gel filtration chromatography. The haemoglobin hydrolysates produced contained more than 90% protein and are especially suitable for fine applications.
Adsorption of reaction species for hydrogenation of nitrobenzene on copper chromite at catalytic conditions
Authors: Choudhary V. R. , Sansare S. D. , Thite G. A. 
Published: July 2010

AbstractAdsorption of nitrobenzene, aniline and water on copper chromite has been investigated at the temperatures (483–558 K) and partial pressures (0–40 kPa) involved in the catalytic process (viz. hydrogenation of nitrobenzene), using the gas chromatographic pulse technique. The adsorption of reaction species was found to follow the Freundlich adsorption isotherm. The data on isosteric heats of adsorption (at different surface coverages) were obtained from the adsorption isotherms. The results indicated that nitrobenzene and water are physically adsorbed, whereas aniline is chemisorbed on the catalyst. The variation in the heat of adsorption with surface coverage for the adsorption of aniline indicated the presence of surface heterogeneity on the copper chromite.
The stability conditions of the fed‐batch reactor. Part I: Monod type growth kinetics
Authors: Genon Guiseppe , Ruggeri Bernardo 
Published: July 2010

AbstractThe semicontinuous operation of a biological reactor consists of batch operation periods interspaced by withdrawal of part of the contents and its renewal in the form of fresh feed. This system has certain advantages with regard to productivity in some cases and also to the control. A study has been made of this mode of operation for Monod kinetics under both ideal conditions (perfectly mixed reactor, instantaneous withdrawal and renewal) and real conditions. An assessment is given of the operating limits (cycle time, reintegrated volume) within which stable condition can be obtained. A determination is also undertaken of reactor performance in terms of productivity, utilisation of the substrate and final concentrations by comparison with the corresponding parameter values for the chemostat.
Autoclaved gypsum plaster from selenite and by‐product phosphogypsum
Authors: Singh Manjit , Rai Mohan 
Published: July 2010

AbstractInvestigations were carried out to produce an autoclaved gypsum plaster (α‐hemihydrate) by heating the naturally occurring selenite and by‐product phosphogypsum under steam pressure in an autoclave. Various factors effecting the calcination of gypsum such as pressure, time of the autoclaving process and the particle size of gypsum lumps were investigated. The formation of hemihydrate was examined by periodic differential thermal analysis and weight loss determinations. The mineralogical studies of plaster were determined using microscopy and X‐ray diffraction. The data showed that complete inversion of gypsum into hemihydrate takes place by heating gypsum of particle size 15 to 20 mm3 at 1.75 kg cm−2 steam pressure for 7 h. The microscopy of plaster revealed formation of well‐defined euhedral prismatic and tabular shaped crystals showing a higher degree of crystallinity than the conventional β‐hemihydrate. The hydraulic properties of plaster were studied and it was found to possess considerable strength (230 kg cm−2). The α‐plaster has been found suitable for making masonry mortar and fibrous plaster boards according to the relevant Indian Standards for use in construction works.
The stability conditions of the fed‐batch reactor. Part II: Luedeking–piret type growth kinetics
Authors: Ruggeri Bernardo , Genon Giuseppe 
Published: July 2010

AbstractThe performance of a cyclic reactor was examined using a kinetic model allowing for inhibition by the metabolic product of the growth of microorganisms and production coupled with their growth and maintenance. The reactor's stability field was investigated through a search for cyclically stable solutions giving Sf ≠ O and Xf ≠ O. The productivity pattern and substrate utilisation as functions of the operating variables were studied within this field. Comparison of these results with those obtained with a Monod‐type kinetics leads to the conclusion that they are of general validity and do not depend on the kinetic model adopted.
Effect of interphase mixing on a water–organic solvent two‐liquid phase microbial system: ethanol fermentation
Authors: Bar Raphael 
Published: July 2010

AbstractEthanol fermentation by Saccharomyces cerevisiae was investigated in broth‐organic solvent two‐liquid phase systems with and without interphase mixing. The effect of interphase mixing with aliphatic alcohols as polar solvents and with alkanes as apolar solvents was determined from investigations in three distinct systems: a solvent‐saturated broth, a solvent‐broth dispersion system and a dispersion‐free solvent‐broth system.Microbial activities, measured as a function of solvent volume and inoculum size, revealed that a dispersed polar solvent caused a longer growth lag time and a slower growth rate. Viability measurements showed that yeast cells were gradually killed in a dodecanol‐water dispersion system and not in a dispersion‐free one. This process was believed to be initiated and enhanced by cell adhesion to the solvent interface as observed under a microscope. Yeast activity was also measured as a function of an apolar solvent volume and inoculum size. A full fermentative activity was observed in an initially alkanesaturated broth unlike in an intermixed biphasic system. As a result of these investigations, it was concluded firstly that microbial activity in initially solvent‐saturated broths with and without contact with a stagnant solvent phase can be different and secondly that the process efficiency of a biphasic bioreactor, unlike that of a chemical reactor, can be hampered by interphase mixing.The yeast activities in the presence of the various alcohols and alkanes were correlated with ‘log P’ values of the solvents. Full activity was observed at log P > 5 and almost none at log P < 4.
Effect of nitrous acid on antipyrine. II. Synthesis of fluoro‐organic derivatives
Authors: Abd‐Alla Mohamed A. , Atta Ferial M. , Abd‐Elmonem Maisa E. , Metwally Saoud A. 
Published: July 2010

AbstractInteraction of antipyrine (I) with nitrous acid in the presence of excess sodium nitrite as buffer, followed by the addition of fluoroboric acid afforded the direct and short way to synthesis of antipyrine‐4′‐diazonium fluoroborate (II). Pyrolysis of (II) at 165°C gave 4′‐fluoroantipyrine (III). The structure of (III) was determined by IR and 13C NMR analyses.
Studies on bimetallic catalyst behavior during naphtha reforming
Authors: Das Shantanu , Srivastava Ramesh D. , Saraf Deoki N. 
Published: July 2010

AbstractReforming of naphtha over Pt–Sn/Al2O3 and Pt–Re/Al2O3 catalysts has been investigated. Addition of nitrogen accelerated the catalyst deactivation process, enabling the study of activity decline and subsequent regeneration. Effect of presulfiding on the activity, selectivity and regeneration capacity of the catalyst was also examined.Presence of nitrogen promoted the dealkylation of C7 hydrocarbons, resulting in a higher initial benzene yield which declined with loss in catalyst activity. Sulfiding lowered the aromatics yield by blocking some of the active sites but deactivation rate declined, prolonging catalyst life between regenerations. Performance of Pt–Sn catalyst was similar to that of Pt–Re catalyst except that the aromatics yield was somewhat higher in the latter case.
A comparison between the performance of continuously stirred‐tank bioreactors and a TORUS bioreactor with respect to highly viscous culture broths
Authors: Krebser Urs , Meyer Hans‐Peter , Fiechter Armin 
Published: July 2010

AbstractTwo different designs of stirred‐tank bioreactor, the ‘conventional’ continuously stirred‐tank bioreactor (CSTR, 42 dm3 and 300 dm3) and a horizontal‐loop bioreactor (TORUS, 114 dm3) were used for the cultivation of Xanthomonas campestris, and their performances with respect to oxygen‐transfer rates and xanthan production were compared. The strictly aerobic yeast Trichosporon cutaneum was also cultivated in the TORUS bioreactor in a synthetic medium with up to 3% (w/v) xanthan added. Xanthan solutions are pseudoplastic and therefore an apparent viscosity at a shear rate (y) of 28.8 s−1 was used to compare the rheological behavior of the different test media. Maximal apparent viscosities of 1100mPa s were measured with xanthan concentrations between 20 and 25 g dm−3. With apparent viscosities of up to 800 mPa s, the performance of the TORUS bioreactor was found to be equivalent to the performance of the CSTR bioreactor in terms of oxygen transfer and xanthan production rates. However, the amount of glucose converted to xanthan was greater in the TORUS bioreactor. Since the power consumption for the TORUS is lower compared to that for the CSTR, this new design is an interesting alternative to the CSTR for the production of xanthan.
Adsorption of microorganisms on activated charcoal cloth: A material with potential applications in biotechnology
Authors: George Neil , Davies John T. 
Published: July 2010

AbstractAdsorption studies of Escherichia coli and Saccharomyces cerevisiae to a new, flexible and robust activated carbon in the form of a cloth, have revealed it to be capable of removing large numbers of microorganisms from suspension. Under the conditions used, Langmuir‐type adsorption of E. coli was obtained and the monolayer coverage predicted by this adsorption isotherm was backed up by both microscopic examination and estimations of available surface area. Applications in fermentation technology, medicine and downstream processing have been suggested.