bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pectinlyase immobilization on epoxy supports for application in the food processing industry
Authors: Spagna G. , Pifferi P. G. , Martino A. 
Published: July 2010

AbstractThe immobilization of a pectinlyase (PL, EC 4.2.2.3) contained in a commercial enzymic preparation was studied in view of its use for fruit pulp and juice processing. Two epoxy supports were tested for immobilization. These included Eupergit C (Rohm), a synthetic polymer, and γ‐alumina functionalized with γ‐glycidoxypropyltrimethoxysilane. In both biocatalysts, the catalytic response was not found to be high. The highest response in terms of immobilization yield and immobilized PL activity, however, was reported for Eupergit C (approx. 115 unit g−1 at optimum pH).
Production of enzymes from potato pulp using batch operation of a bioreactor
Authors: Klingspohn Uwe , Vijai Papsupuleti P. , Schügerl Karl 
Published: July 2010

AbstractTrichoderma reesei strains MCG77 and Rut C30 were cultivated in batch operation in a stirred tank reactor on potato pulp (PP) consisting of starch, pectin, cellulose, and hemicellulose; potato pulp residue (PR) without starch and pectin; or enzymatic residue (ER), respectively, as substrate and potato protein liquor (PPL) as supplement. The enzyme mixtures produced by the fungi were characterized by four assays: with avicelase, CMCase, xylanase, and FP‐activities. Trichoderma reesei Rut C30 yielded higher activities than Trichoderma reesei MCG77. The enzyme activities and productivities obtained with PR are comparable to those obtained by other groups using pure cellulose and a synthetic nutrient solution in batch culture. An optimal operation strategy was derived to obtain maximum enzyme activity and productivity. After converting PR with the enzymes produced and using the residue, ER, as substrate for enzyme production, 85% (w/w) of the pulp was utilized.
Micro‐scale modelling of substrate removal kinetics in multicomponent fixed‐film systems
Authors: San H. A. , Tanik A. , Orhon D. 
Published: July 2010

AbstractModelling of fixed‐film reactors, as for suspended growth systems has to account for all the major components and biochemical processes responsible for the removal of substrate. Traditionally fixed‐film reactors are viewed as two‐component (substrate/biomass) systems interacting with the governing effect of molecular diffusion. Recent developments however have shown the importance of viability and product formation in the modelling of biological systems. This paper emphasizes these two new parameters and evaluates the kinetic relationships between the bulk substrate concentration and biofilm composition as it affects substrate removal and residual product formation.
Biosorption of metals by a waste biomass
Authors: Mattuschka Beate , Straube Gunhild 
Published: July 2010

AbstractThe binding of several metals by waste biomass of Streptomyces noursei was investigated. With respect to the binding capacity, the following order was observed: Ag > Cr > Pb > Cu > Zn > Cd > Co > =Ni. The sorption of metal ions increased with the increasing initial concentration of metal. The adsorption equilibrium of copper, lead and chromium sorption, and silver sorption at low concentration can be described by the Freundlich and Langmuir models. The possibilities for desorbing the metals from loaded biomass and the repeated use of biomass were investigated. The influence of various ions in water on metal sorption was tested. The metal capacity and selectivity of metal binding by biomass are important qualities for practical use.
Some implications of structural collapse during freeze‐drying using Erwinia caratovoraL‐asparaginase as a model
Authors: Adams G. D. J. , Irons L. I. 
Published: July 2010

AbstractWhen the enzyme Erwinia caratovora L‐asparaginase was freeze‐dried in mixtures of lactose and sodium chloride, biological activity and protein structure were preserved during drying. However, by altering the ratios of the excipients in the formulation it was possible to obtain products which were pharmaceutically acceptable or unacceptable as assessed by the criteria of dried cake appearance, moisture content or ease of reconstitution.
Utilization of date products in production of oxytetracycline by Streptomyces rimosus
Authors: Abou‐Zeid Abou‐Zeid A. , Baeshin Nabeh A. , Baghlaf Ahmed O. 
Published: July 2010

AbstractThe carbon and nitrogen sources of a synthetic fermentation medium were substituted by equivalent amounts of date‐coat sugar extract and date‐seed hydrolysate. The addition of 1.0 g dm−3 urea and date‐seed lipid into the medium increased the efficacy for antibiotic formation. When the MgSO4, MnSO4, FeSO4 and ZnSO4 components of the medium were replaced by 0.5 g dm−3 date‐seed ash, antibiotic output was also increased.
Effect of polymer additives on hydrodynamics and oxygen transfer in a bubble column bioreactor
Authors: Kawase Yoshinori 
Published: July 2010

AbstractThe influence of polymer additives (polyethylene oxide and polyacrylamide) on the hydrodynamics and oxygen transfer in a bubble column bioreactor was examined. The addition of small amounts of these polymers has been known to cause significant drag reduction in turbulent flow circumstances. The gas hold‐up was slightly decreased and the liquid‐phase mixing was somewhat enhanced due to the addition of the polymers. The addition of polymer additives brought about a reduction of the volumetric oxygen transfer coefficient by about 40%. In dilute polymer solutions, large bubbles formed by bubble coalescence moved with high rise velocities in the presence of many small bubbles and the bubble size distributions were less uniform compared with those in water. The complicated changes in bubble hydrodynamic characteristics were examined to give possible explanations for oxygen transfer reduction.
Constant flowrate filtration of hybridoma cells suspensions
Authors: Favre Eric 
Published: July 2010

AbstractThe fouling mechanism of rotating sieves (also called spinfilters) in suspended mammalian cells reactors is still poorly understood, and their design is consequently largely empirical. A laboratory set‐up enabling constant flowrate filtration experiments is reported and its use described in order to study the fouling kinetics of 10 μm opening sieves by suspended hybridomas. Significant differences were obtained depending upon cell type and cell viability, under similar operating conditions. A roughly linear pressure drop increase, as predicted by constant flowrate incompressible cake filtration models, was obtained for most experiments. However, the influences of pumping flowrate and cell concentration on pressure drop evolution do not obey incompressible cake constant flowrate filtration laws; a surface colonization approach could possibly lead to a better description in that case.
Trifluoromethanesulphonic acid catalysed transalkylation between tetrabromobisphenol‐a and toluene for the production of 2,6‐dibromophenol
Authors: Effenberger Reinhard 
Published: July 2010

AbstractThe preparation of 2,6‐dibromophenol is described. This compound, useful as raw material for brominated poly(phenyleneoxide) and pyrogallol or derived pharmaceuticals/pesticides, was prepared in 80% (isolated) yield by a transalkylation reaction between tetrabromobisphenol‐A and toluene. The catalyst, trifluoromethanesulphonic acid, can be simply recovered and recycled. Perfluorinated resin sulphonic acid (NAFION‐H®, DuPont) did not effectively catalyse this transalkylation.
Regulation of the chlorine content in fresh, regenerated and coked PtRe/Al2O3 catalyst
Authors: Scelza Osvaldo A. , Baronetti Graciela T. , de Miguel Sergio R. , Silber Pablo , Castro Alberto A. 
Published: July 2010

AbstractIn bifunctional naphtha reforming catalysts the regulation of the chlorine content in order to equilibrate both catalytic functions (metallic and acidic) is one of the most relevant topics. In this paper a study of the chlorine regulation in fresh, regenerated and coked samples of a given commercial Pt (0.3 wt%)—Re (0.3 wt%)/Al2O3 catalyst is presented. Results show that an equilibrium chlorine content is reached when the samples are treated with an H2O—HCl mixture vaporized in a gas carrier (air or H2). This equilibrium content depends on the H2O/HCl molar ratio and the temperature of the regulation treatment. For fresh samples the equilibrium chlorine content does not depend on the nature of the gas carrier. Moreover, the retention capacity of chlorine by the support per unit of surface area is the same for fresh and regenerated samples. The presence of different amounts of coke on the surface does not modify the chlorine uptake with respect to the sample without coke.
Microbiological purification kinetics of wine‐distillery wastewaters
Authors: Romero L. I. , Nebot E. , Mart de la Ossa E. Ínez , Sales D. 
Published: July 2010

AbstractWine alcohol distilleries produce eight volumes of high‐strength waste (known as vinasse) from every volume of ethanol. The waste has an acidic character and a high organic content. Three adequate microbiological treatments (aerobic, mesophilic anaerobic and thermophilic anaerobic) for the purification of vinasses were examined. When around 90% biodegradable chemical oxygen demand (COD) removals were achieved in every treatment, optimum operating conditions had been attained, resulting in an optimum hydraulic retention times (HRT) of 8 days for aerobic, 6 days for mesophilic anaerobic, and 4 days for thermophilic anaerobic processes. The experimental results were compared with those obtained from a substrate utilization kinetic model. The model accurately predicted the performance of these processes, except at HRTs shorter than minimum, since these systems work under transient conditions. A comparison between kinetic coefficients obtained from the model showed that a thermophilic anaerobic process was the more efficient, since the process reached the same purification level, could be energy self‐maintaining and needed smaller process plants than the other two systems.
Cyclic voltammetric behaviour and some surface characteristics of the lead electrode in aqueous HCL solutions
Authors: El‐Halim A. M. Abd , Fawzy M. H. , Saty A. 
Published: July 2010

AbstractThe positive linear sweep voltammograms of lead were investigated in 0.01–2.00 M aqueous HCl solutions. The results revealed the occurrence of one anodic current peak as the result of formation of a thin PbCl2 surface layer. Intensive study of the electrochemical behaviour of the lead electrode in 1.00 M HCl solution was carried out by cyclic voltammetry. The results indicated that the formation of PbCl2 is a reversible process controlled by diffusion of Cl− ions to the electrode surface. Controlling the voltammetric conditions enabled the building up of a relatively thick and porous PbCl2 layer that could resist rupture or breakdown. In addition, the electrode surface products were examined by scanning electron microscopy and X‐ray diffractometry. The morphology of the as‐formed PbCl2 layers showed a primitive dependence on the voltammetric conditions. X‐ray diffraction analysis proved that only PbCl2 was formed on the electrode surface and no other products could be detected.
Propranolol hydrochloride release behaviour of crosslinked chitosan membranes
Authors: Thacharodi D. , Rao K. Panduranga 
Published: July 2010

AbstractChitosan membranes of 20 μm thickness were prepared by a solvent evaporation technique and crosslinked with different concentrations of glutaraldehyde to obtain membranes of various degrees of crosslinking. These membranes were characterized by thermogravimetric (TG) analysis, differential scanning calorimetry (DSC) and tensile strength studies. The effect of crosslinking on the permeability of membranes to propranolol hydrochloride was evaluated by permeation studies conducted in static glass diffusion cells. A decrease in the thermal stability of chitosan membranes due to crosslinking was observed. The tensile strength of the membranes was improved by crosslinking. The introduction of crosslink points within the membrane reduced its permeability to propranolol hydrochloride as evidenced by decreased permeability and diffusion coefficients. Permeability studies revealed the operation of a pore mechanism in the transport of hydrophilic agents such as propranolol hydrochloride through chitosan and crosslinked chitosan membranes.
Catalytic splitting of acetals to unsaturated ethers
Authors: Červeny Libor , Winklerová Petra , Marhoul Antonín 
Published: July 2010

AbstractCatalytic splitting of the dimethylacetals of heptanal, 3‐cyclohexylpropanal, 3‐cyclohexylbutanal, 3‐phenylpropanal and 3‐phenylbutanal to corresponding unsaturated ethers was studied in a gas phase. Acid catalysts were employed in the study. Reaction conditions favorable to high splitting selectivity to ethers were suggested. The original acetals as well as synthesized unsaturated methylethers revealed characteristic odoring properties.
Characterization of unsupported molybdenum oxide—cobalt oxide catalysts
Authors: Halawy Samih A. , Mohamed Mohamed A. , Bond Geoffrey C. 
Published: July 2010

AbstractStudy of the thermal decomposition of mixtures of ammonium heptamolybdate (AM) and Co(NO3)2. 6H2O by TGA and DTA show that small amounts of Co (up to 5 mol % expressed as Co3O4) did not alter the way in which AM decomposed. Larger amounts of Co (10–90 mol% as Co3O4) reduced the number of steps from three to one, and in addition the transformation of Co3O4 to CoO was observed at c. 920°C. Endothermic peaks in DTA at 744–806°C, due to sublimation of MoO3, disappeared at higher Co contents. Samples containing 5, 10 and 30 mol% Co as Co3O4 showed exothermic peaks at 242–290°C due to formation of CoMoO4. The activation energies for the decompositions were calculated using the Coats—Redfern method from the TG results. XRD patterns of the samples calcined at 500°C indicated the formation of CoMoO4 for MoO3–30 mol% Co3O4, while those containing higher contents of Co3O4 (> 50 mol%) gave the typical XRD pattern of Co3O4. These results were confirmed by IR and TPR analyses. XPS analysis showed the presence of Mo(VI) in MoO3, but it was reduced to Mo(V) in the mixed samples. The binding energies for Mo 3d5/2 and Co 2p3/2 levels confirmed the formation of CoMoO4 in the sample MoO3–30 mol% Co3O4.
Studies of alizarine adsorption from solution on to aluminium hydroxide gels
Authors: Bakoyannakis Demetris N. , Stalidis George A. , Zamboulis Demetris , Jannakoudakis Demetris A. 
Published: July 2010

AbstractAdsorption results of alizarine from ethanolic solutions on to aluminium hydroxide gels prepared by precipitation in pure and mixed aqueous and ethanolic media are presented. The gels had different specific surface areas and porous structures resulting from the nature of the solvent and the thermal treatment. Equilibrium took a long time to be established (about 9 h). In general, the higher the activation temperature of the gel the higher the adsorption capacity. The adsorbed amounts of alizarine on to the gels increased by increasing the adsorption temperature. The adsorption could be described equally well by the Freundlich and the Langmuir equations. Finally, the apparent enthalpy of the adsorption indicated an activated endothermic chemisorption.
Kinetics of metal ion exchange in iminodiacetic resins at low concentrations
Authors: Fernández A. , Suárez C. , Díaz M. 
Published: July 2010

AbstractThe kinetics of metal exchange processes with iminodiacetic chelating resin, which occurs with metal concentration change, has been studied. Mechanisms of rate control were analyzed, and diffusivities determined from experiments in batch solutions with decreasing metal concentrations, following the unreacted core model. Metal exchange in binary and ternary systems are analyzed and diffusivity variations of these systems discussed in terms of reaction fronts. The influence of temperature was also studied and energies of activation determined.
Modelling and application of the continuous impinging streams reactors in liquid—liquid heterogeneous reactions
Authors: Sohrabi Morteza , Kaghazchi Tahereh , Yazdani Farshad 
Published: July 2010

AbstractThe two phase mononitration of toluene, as an example of liquid—liquid reactions, has been studied in a continuous impinging streams reactor (CISR). The extent of reaction under different experimental conditions has been determined. A comparison has been made between the performance capability of the CISR and that of the continuous stirred tank reactor (CSTR). Under identical conditions, including mean residence time, temperature, feed compositions and phase ratio, the CISR has shown a higher efficiency. Finally, a stochastic model, based on Markov processes, has been developed for the reaction system which describes the flow pattern and the residence time distribution (RTD) in the reactor.
Studies of pressure build‐up due to particle deposition in a micro‐capillary with the use of three‐dimensional trajectory analysis
Authors: Arshad A. , Rahman M. S. , Rahman S. S. 
Published: July 2010

AbstractA model is proposed to predict the increase in pressure drop in a micro‐capillary due to the particle deposition. Collection efficiency was estimated from three‐dimensional (3D) trajectory analysis which is based on mass balance and considers dispersion forces (London‐van der Waals), hydrodynamic forces (gravity and drag), and electrical force (electrical double layer). An exponential function introduced to 3D trajectory analysis accounts for the effects of fluid velocity on the particle capture probability. Validity of the model is tested experimentally by circulating a 1000 ppm bentonite suspension at different flow rates through a micro‐capillary of diameter 100 μM. Experimental evidence indicates that the 3D trajectory analysis is limited to a few conditions of particle deposition in a micro‐capillary.
Mechanism of phosphate interaction with two reference clays and an anatase pigment
Authors: Malati Mounir A. , Fassam Robert A. , Henderson Ian R. 
Published: July 2010

AbstractThe adsorption of phosphate by well‐characterised kaolin, mica or anatase followed the Langmuir isotherm. At pH values below the point of zero charge of each powder, adsorption was endothermic. A ring closure mechanism involving two adjacent adsorption sites would increase the entropy of the system compensating for the endothermic enthalpy change.
Liquefaction of cellulosic wastes: III. Production, characterization and evaluation of pyrolytic oils
Authors: Gharieb Hussein Kh. , Faramawy Sami , El‐Amrousi Fawzi A. 
Published: July 2010

AbstractLiquefaction of municipal solid wastes has been achieved in an atmosphere of hydrogen gas and in the presence of boric acid which catalyzes the pyrolysis reaction. Two petroleum distillates, namely gas oil and residual fuel oil, were used as carrier media of solid refuse. The yield of pyrolytic oil was studied as a function of different operational conditions (temperature, pressure of hydrogen, carrier oil medium and concentration of boric acid). Hydrocarbon constituents of the oil mixtures, produced by liquefaction of cellulosic wastes slurried in fuel oil, were investigated by means of gas chromatography. It was found that the oil mixture, obtained at optimum reaction conditions, showed pronounced occurrence of low hydrocarbons in the range C3‐C15 as compared with the original fuel oil and the oil resulting from the pyrolysis of carrier oil without solid refuse. The residual pyrolytic char exhibited catalytic activity towards hydrocracking. It was suggested that the activity of char is due to the presence of transition metals as evidenced by an electron dispersion system (EDS). The hydrocracking activity of char seemed to be dependent on the operational conditions of the liquefaction. Multiple analytical parameters including API gravity, calorific value, total acid number and wt% of residue over 450°C were used to evaluate the oil mixtures produced as a petroleum crude oil. Carrier oils, particularly fuel oil, seemed to be highly modified in the course of the pyrolysis process. Also, the oil mixtures produced were distinguished from the original carrier oils by a considerably higher acidity due to association with oxygenated compounds which could be derived from cellulose macromolecules.
The osmometry of high polymers. I. Technique of osmometry
Authors: Cleverdon D. , Laker D. 
Published: July 2010

AbstractPoints of technique in the use of the Fuoss‐Mead osmometer, as modified by Masson and Melville, are discussed. In particular, a new criterion is described for the impermeability of the membrane to solute. Older criteria are critically reviewed. Problems of extrapolation of reduced osmotic pressure v. concentration curves are considered, and tentative explanations given for the negative slope sometimes observed.
Design of packed distillation columns. II. Operating vapour rates for packed distillation columns
Authors: Hands C. H. G. , Whitt F. R. 
Published: July 2010

AbstractRelatively simple correlations of the important variables associated with allowable vapour rates in packed columns are presented. These are similar to those already used for the same purpose in connexion with plate columns. The suggested method of calculation of limiting velocity is simpler than those methods derived from correlations of a more complex type which are described in the literature on packed columns; it is nevertheless adequate for preliminary design of columns operating at atmospheric pressure or below.
Orientation problems. V. The nitration of the isomeric tolylsuccinimides
Authors: Evans W. H. , McGookin A. 
Published: July 2010

AbstractIt is shown that 2‐ and 4‐tolylsuccinimides, on nitration, form derivatives where the nitro groups occupy positions meta to the acylamino group, whereas 3‐tolylsuccinimide nitrates ortho‐para to the acylamino group; hence the methyl radical is the directing agent in these compounds.
The determination of free sulphur in vulcanizates by a polarographic method
Authors: Poulton F. C. J. , Tarrant L. 
Published: July 2010

AbstractUsing a buffered pyridine electrolyte, sulphur gives a regular polarographic wave suitable for its quantitative determination. A method based on this principle has been developed for the determination of ‘true’ free sulphur in rubber. The method has been compared with gravimetric and volumetric processes, and found to give slightly lower results than either of these, since sulphur combined in any form in the acetone extract is not included. It is particularly suited to routine replicate determinations as it is considerably quicker than older methods.
A spinning‐band column for vacuum fractionation of fatty‐acid esters
Authors: Williamson L. J. 
Published: July 2010

AbstractA spinning‐band column which is specially adapted for the vacuum fractionation of fatty‐acid esters is described. Plate‐efficiency tests carried out at 760 mm. and in the range 3.0‐0.5 mm. show that the lowest value for the H.E.T.P. is 2.64 cm. at atmospheric pressure, this value increasing at the lower pressures. Distillation curves for ester mixtures show that the column is very suitable for analytical ester fractionation at pressures of the order of 1 mm.
Conversion of the simple electric furnace to precision high‐temperature maintenance
Authors: Warren D. R. 
Published: July 2010

AbstractA simple and inexpensive method adaptable to most electric furnaces of reasonable internal dimensions is described. The furnace is converted into an air‐bath of very quick response, controlled with a simple and easily adjustable form of gas‐expansion thermostat. High temperatures may be maintained with very small fluctuation, and trouble from temperature gradients made negligible.