bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of volume change effects in a fluidized bed catalytic reactor
Authors: Shiau Ching‐Yeh , Lin Chin‐Jou 
Published: July 2010

AbstractA mathematical model based on the concept of an improved bubble assemblage model is developed for calculating the conversion of a reaction system involving a volume change in fluidized beds. The influence of volume change on the hydrodynamic behavior of gas in the bed, such as bubble size variation, superficial gas velocity change, and volume fraction occupied by each phase, is also investigated. It is found that increasing stoichiometric coefficient values results in larger bubble size, higher superficial gas velocities, higher crossflow rate between emulsion phase and bubble phase, and greater volume fraction of bubble phase, but smaller volume fraction occupied by the emulsion phase as well as lower conversions.
Solubilization of hydrocarbons from oil sludge by synthetic surfactants
Authors: Janiyani K. L. , Wate S. R. , Joshi S. R. 
Published: July 2010

AbstractDisposal of oil sludges poses an environmental pollution problem due to the presence of high molecular weight hydrocarbons which are hydrophobic and hence non‐biodegradable in nature. In‐situ transformation of hydrophobic hydrocarbons into hydrophilic moieties using surfactants and further degradation of solubilized hydrocarbons by microorganisms could be the viable solution for disposal of these sludges. Treatment of oil sludge with the synthetic surfactant polyoxyethylene sorbitan monooleate indicated the release of hydrocarbons in the aqueous phase. Increase in soluble chemical oxygen demand with increase in concentration of surfactant and contact time was observed indicating enhancement in solubility of hydrocarbons in the aqueous phase. The optimum ratio of sludge to surfactant was found to be 10: 1. While a two‐fold increase in solubility of hydrocarbons was observed due to agitation of sludge samples, variation in pH did not affect the solubilization.
Gas‐liquid transfer of atmospheric CO2 in microalgal cultures
Authors: Grima E. Molina , Pérez J. A. Sánchez , Garc Camacho F. Ía , Medina A. Robles 
Published: July 2010

AbstractTransfer of CO2 in an aerated microalgal culture system has been studied. The CO2 absorption rate was not visibly affected by the kinetics of the reactions occurring in the culture medium. Biomass concentration in the bioreactor, within the interval studied, did not significantly affect the overall volumetric coefficient of CO2 transfer (K1a(CO2)). An expression has been proposed for the estimation of K1a(CO2) in the culture as a function of the effective power input to dispersion. Several empirical equations, found in the literature for estimation of the mass transfer parameters, were studied and those which best predicted experimental results are presented. The study concluded that empirical equations for a bubble diameter analogous to that found in the experiments should be used.
Studies on the Vilsmeier‐haack reaction. Part XIII: Novel heterocyclo‐substituted 4,4′‐bi‐pyrazolyl dithiocarbamate derivatives
Authors: Awad Ibrahim M. A. 
Published: July 2010

Abstract5‐Imino‐3‐methyl‐l‐phenyl‐2‐pyrazoline‐4‐dithiocarbamic acid (I) underwent simultaneous formylation and dimerization reactions with the Vilsmeier reagent giving 4‐[5′‐imino‐3‐(1″‐formyl‐2″‐dimethylaminoethenyl)‐3′‐methyl‐1′‐phenyl‐1′H‐pyrazolo‐4′‐dithiocarbamyl‐2,4‐dihydro‐3‐imino‐5‐methyl‐2‐phenyl‐1‐pyrazoline]dithiocarbamate (II) which hydrolysed with sodium hydroxide to give 4‐[3′‐(1″‐formyl‐2″‐hydroxyethenyl)‐3′‐methyl‐1‐phenyl‐1′‐H‐pyrazolo‐4′‐dithiocarbamyl‐1′‐pyrazoline]dithiocarbamate‐5,5′‐dione (IV). Treatment of II and/or IV with morpholine, piperidine, piperazine, hydroxylamine, hydrazine hydrate or phenylhydrazine afforded the corresponding dipyrazolo‐4,4′‐dithiocarbamate derivatives with different heterocyclic systems at the 3‐position. The structures of these compounds were confirmed by microanalysis data, IR and 1H‐NMR spectrometry. All synthesized compounds have been screened in vitro against Gram‐positive and Gram‐negative bacteria, and fungi.
Alkylnaphthalene succinimides as multifunctional additives
Authors: Mohamed M. M. , Naga H. H. Abou El , Meneiry M. F. El 
Published: July 2010

AbstractAlkylnaphthalene succinimides are synthesised and evaluated as flow improvers, pour point depressants and ashless dispersant additives for fuels and crankcase lubricating oils. The synthesis is based on reacting alkylated naphthalene with maleic anhydride in the presence of the following amines: ethylene diamine, diethylene triamine and tetraethylene pentamine. Chlorinated paraffin wax is used as an alkylating agent for naphthalene. Results showed that magnitude in pour point depression as well as cold filter plugging point depression for the tested fuels are highly related to the molecular weight of alkylnaphthalene succinimides. As ashless dispersant additives, results showed that the magnitude of dispersive power for the tested oils is related to the amine compound used.
Study of a continuous separation process for 2‐furyl oxirane
Authors: Uhlemann Jens , Borredon Elisabeth , le Lann Marie‐Véronique , Casamatta Gilbert 
Published: July 2010

AbstractThe present work is a study on a continuous separation process for 2‐furyl oxirane from its reaction medium which is a quaternary mixture. Continuous process flowsheeting has been used in order to compare two different separation processes which are based upon solvent extraction and heteroazeotropic distillation. The improved production process totals five unit operations: synthesis of 2‐furyl oxirane; filtration of the reaction medium; heteroazeotropic distillation; synthesis of trimethylsulphonium bromide; and filtration of trimethylsulphonium bromide.
Electrolytic regeneration of bleach solution in the motion picture industry
Authors: Adaikkalam P. , Sathaiyan N. , Visvanathan S. 
Published: July 2010

AbstractCyclic voltammetric and galvanostatic experiments have been carried out with both synthetic and commercial bleach solutions with a view to regenerating the same. Maximum efficiency could be achieved if the oxidation is carried out below an anodic potential of 0·80 V vs SCE. The data obtained in galvanostatic experiments with RCE confirm the results of the earlier technique.
Effects of light, CO2 and inhibitors on the current output of biofuel cells containing the photosynthetic organism Synechococcus sp
Authors: Yagishita Tatsuo , Horigome Takashi , Tanaka Kazuko 
Published: July 2010

AbstractThe current output of the biofuel cells containing a marine alga, Synechococcus sp. and an electron transport mediator, 2‐hydroxy‐1, 4‐naph‐thoquinone (HNQ) was increased under illumination and in the presence of CO2. The inhibitory effects of carbonyl cyanide m‐chlorophenylhydrazone (CCCP), 3‐(3,4‐dichlorophenyl)‐1,1‐dimethylurea (DCMU), 2,5‐dibromomethylisopropyl‐p‐benzoquinone (DBMIB), phenylmercury acetate (PMA) and N,N′‐dicyclohexyl‐carbodiimide (DCCD) on the output current of fuel cells run in the light suggested that HNQ accepts electrons mainly at the site of ferredoxin‐NADP+ reductase (FNR) in the electron transfer chain. The inhibition of light‐induced generation of current output by CCCP indicates that the current is derived from photosynthetic oxidation of water. Endogenous glycogen in algae is required to sustain a steady current output from the fuel cells.
Novel substituted 2‐acetamido thiophene‐4‐styryl disperse dyes
Authors: Rangnekar Dinesh W. , Sabnis Ram W. 
Published: July 2010

AbstractEthyl 2‐acetamido‐3‐cyano‐5‐carbethoxy thiophene‐4‐acetic acid ester has been synthesised by the Gewald reaction of diethyl acetonedicarboxylate, sulphur and malononitrile, followed by acetylation. A variety of aryl and hetaryl aldehydes were condensed with this thiophene derivative in refluxing DMF in the presence of piperidine to yield novel styryl dyes. The fluorescence in solution and dyeing properties of these styryl dyes on polyester were studied.
Synthesis of thieno[2,3‐c]pyridines and related heterocyclic systems
Authors: El‐Kashef H. S. , Geies A. A. , El‐Dean A. M. Kamal , Abdel‐Hafez A. A. 
Published: July 2010

Abstract1‐Isopropyl‐4‐piperidone (1) reacts with sulphur and active methylene nitriles to give thienopyridines (2a‐c). Compounds 2a, b react with CS2 in pyridine to produce pyridothienopyrimidines (3a, b) which upon methylation with MeI give S‐methylated derivatives (4a, b). Dibenzylidene compound (5) reacts with hydrazine hydrate, phenyl hydrazine, thiourea malononitrile or cyanoacetamide to give compounds 6–9 respectively. Piperidylidene malononitrile (10) reacts with benzaldehyde to give derivative 11 which undergoes an addition reaction with malononitrile to give 12 which is also obtained by reacting 1 with one mole of benzaldehyde and two moles of malononitrile.
Immobilization of aminoacylase by encapsulation in poly‐l‐lysine‐stabilized calcium alginate beads
Authors: Lee Kong H. , Lee Pat M. , Siaw Yew S. 
Published: July 2010

AbstractAminoacylase I (EC 3.5.1.14) encapsulated in calcium alginate beads stabilized with poly‐L‐lysine was used for the production of L‐phenylalanine by the hydrolysis of a racemic mixture of N‐acetyl‐DL‐phenylalanine. The immobilized aminoacylase was studied with respect to operational stability, thermal stability, effects of pH and temperature and kinetic constants. The leakage of enzyme from the stabilized beads was eliminated. The immobilized enzyme retained high biological activity. The Km and Vmax values for the stabilized beads were 11.11 mmol dm−3 and 0.076 μmol min−1 respectively. The optimum pH and temperature for the hydrolysis were 6.5 and 55°C respectively. Scanning electron micrographs revealed crosslinked structures on the surface of the beads. The operational performances of the beads in a batch reaction and a packed‐bed bioreactor for continuous reaction were investigated. With batch reaction, only about 5% of enzyme activity was lost within ten reaction cycles and there was no significant loss of activity over 600 h of continuous operation after equilibrium was reached, and a conversion yield of about 80% was obtained.
Lipase‐catalyzed resolution of 1‐hydroxymethyl‐2‐methylferrocene
Authors: Izumi Taeko , Aratani Satoshi 
Published: July 2010

Abstract±‐1‐Hydroxymethyl‐2‐methylferrocene was optically resolved by transesterification with lipases using vinyl esters such as vinyl butyrate, vinyl caproate, vinyl octanoate and vinyl decanoate, as acyl donors.
Reaction steady states and stationary states in modelling semi‐batch enzyme hydrolysis
Authors: Powell Francis E. , Brooks Brian W. 
Published: July 2010

AbstractDimensionless material balance equations describing an uninhibited enzyme hydrolysis process in a semi‐batch reactor (i.e. fed‐batch reactor) are formulated; numerical solution of these equations provided concentration profiles of the enzyme‐substrate complex by using published kinetic parameters. The unrestricted values obtained are compared with estimates based separately on the reaction steady state and stationary state assumptions. Results are discussed in terms of the enzyme/substrate inventory used and it is found that the reaction steady state is a satisfactory approximation only when this ratio is sufficiently small. The stationary state may be a better approximation at other values, particularly when enzyme is added to substrate or when an empty tank is being filled. Reaction yields from semi‐batch and batch operations are compared. Processing takes longer in the semi‐batch operations and complete conversions are only practical in this mode when enzyme is added to substrate.
Effect of polymer matrix on penicillin acylase immobilization on copolymers of butyl acrylate and ethylene glycol dimethacrylate
Authors: Bryjak Jolanta , Trochimczuk Andrzej , Noworyta Andrzej 
Published: July 2010

AbstractCopolymers of butyl acrylate and ethylene glycol dimethacrylate with various degree of crosslinking and aminolysis were used for penicillin acylase immobilization. The amount and activity of the bound protein decreased with the decrease of crosslinking when copolymers having nearly constant degrees of aminolysis were compared. The increase of the carrier amino group content increased the ability to bind the protein (by glutaraldehyde method) without a proportional rise of enzyme activity. The comparative studies of immobilization effect and performance of the derivatives showed 40% crosslinked EGDMA, having an amino group content of 0.67 mmol g−3, to be the carrier of choice. This selected carrier was tested for active protein immobilization by use of crude acylase preparation. It was shown that up to a protein concentration of 9 mg cm−3 in the immobilization mixture the active protein was preferentially bound to the polymer matrix. It was indicated also that the derivative stability was mostly affected by multipoint attachment of the enzyme to the carrier surface.
Cahn's perfect wetting theory in determining monolayer capacity
Authors: Spaull Allan J. B. 
Published: July 2010

AbstractA thermodynamic method is developed to determine the monolayer capacity of an adsorbent from a first order transition in an adsorption isotherm. Using a number of examples, the value of the monolayer capacity determined by the thermodynamic method is compared with that determined by the BET method.
Inhibition of activity of urease in native form and immobilized on chitosan membrane by sodium fluoride
Authors: Leszko Maciej , Zaborska Wieslawa 
Published: July 2010

AbstractThe influence of sodium fluoride inhibitor on the activity of urease in native form and immobilized covalently on glutaraldehyde‐pretreated chitosan membrane was studied. Initially, in the presence of fluoride ions (I), a complex EI is formed which undergoes slow isomerization into a secondary form EI*. Both stages are represented on the progress curves. The dissociation constant of EI, Ki, for native and bonded urease were determined. The apparent rate constant as a function of the initial urea concentration for a given fluoride ion concentration was calculated, k = k ([I], [S]). It was found that sodium fluoride is a competitive slow‐binding inhibitor of urease. Hydrolysis of urea in the standard conditions, at pH = 7.0, at 25° and a constant ionic strength and variable concentrations of substrate and of inhibitor has been studied. The reaction was initiated by addition of enzyme and was observed over a period of 10 min. The rate of hydrolysis at any point of time for both forms of urease, free and bound, may be calculated from the inhibition constants Ki, K*i and apparent rate constant, k. It was found that immobilized urease is more resistant to the action of the inhibitor than the native one. This property offers potential for practical application.
Mass transfer and substrate utilization in biofilm reactors
Authors: Muslu Yilmaz 
Published: July 2010

AbstractMass transfer within microbial films is described using Monod‐type biological kinetics in terms of properties of packing material and the feed solution. For this purpose, computer techniques have been developed for the numerical evaluation of the normalized biofilm mathematical model. A second‐order partial differential equation, describing the mechanisms of dispersion phenomena inside the liquid layer, was then solved to determine the mass transfer coefficient. The application of the theory to earlier experimental data has also been demonstrated.
Screening of white rot fungi for the treatment of olive mill waste‐waters
Authors: Sayadi Sami , Ellouz Radhouane 
Published: July 2010

AbstractSeveral white rot fungi were evaluated for their ability to decolorize olive mill waste‐waters (OMW). Among these, Phanerochaete chrysosporium showed the highest potential for the biological depollution of OMW. Approximately 65% of the color and 73% of the chemical oxygen demand (COD) were removed by P. chrysosporium strain HD. Phlebia radiata, Dichomitus squalens, Polyporus frondosus and Coriolus versicolor could also decolorize the OMW but to a lesser extent. The different abilities of these white rot fungi to decolorize OMW correlated with their rates of depolymerization of high molecular weight aromatics and the degradation of the low molecular weight aromatic compounds. Fourteen strains of P. chrysosporium were compared on the basis of their lignin peroxidase (LiP) production, OMW decolorization and residual material dry weight. High lignin peroxidase producer strains, such as strains HD and BKM‐F‐1767, showed the highest rates of OMW decolorization, P. chrysosporium strains 79–36 and FP 104297 (low LiP producer strains) did not exhibit any decolorization activity.
Kinetics of lipase‐catalyzed hydrolysis of lipids in biphasic organic—aqueous systems
Authors: Tsai Shau‐Wei , Chang Chun‐Sheng 
Published: July 2010

AbstractA kinetic model has been proposed which is applicable to the hydrolysis of lipids by lipases in biphasic organic‐aqueous systems. An analytical rate equation, based on the interfacial substrate concentration, was derived and confirmed from previous experimental data. The equation may be reduced further to the Michaelis‐Menten form for the system by adding a water‐immiscible organic solvent (or using hydrophobic particles but for hydrophilic substrates). The reduced form cannot be obtained when the organic phase only contains the hydrophobic substrate. Moreover, the concept of substrate inhibition and certain conflicting expressions for the apparent maximum velocity and Michaelis‐Menten constant, that previous investigators claimed, have been clarified in the present study.
Influence of the physical‐chemistry properties of an acid‐activated bentonite in the bleaching of olive oil
Authors: González‐Pradas E. , Villafranca‐Sánchez M. , Gallego‐Campo A. 
Published: July 2010

AbstractThe bleaching process at 90°C of an olive oil from Jaen (Spain) using natural bentonite and bentonite acid treated with H2SO4 (over a concentration range between 0.50 M and 5.00 M) has been studied. The bleaching capacities of the bentonite samples were calculated by applying the Freundlich equation to the experimental data points corresponding to the bleaching process. The bleaching capacities (KF parameter) range from 2.5 × 10−7 for non‐treated bentonite up to 0.85 for 2.50 M H2SO4 treated bentonite. The bleaching capacity of the 5.00 M H2SO4 treated bentonite (KF = 0.81) is less than that of the 2.50 M H2SO4 treated bentonite.
Modelling of catalyst pellet poisoning for benzene hydrogenation
Authors: Rušić Davor , Zrnčević Stanka 
Published: July 2010

AbstractBased on the kinetics of benzene hydrogenation, pore diffusion and catalyst deactivation, time‐dependent effectiveness behaviour of a single NiSiO2Al2O3 catalyst pellet where the chemical reaction rate is determined by pore diffusion was simulated for different conditions of operation.Poisoning kinetics were measured in a series of differential reactor experiments at atmospheric total pressure at temperatures ranging from 403 to 473 K.A computed effectiveness factor has been compared with experimental values for a catalyst pellet of industrial size. A good degree of correlation between theoretical prediction and the experimental results was found.
Biodegradation of wood‐pulp black liquor hydroxyacids by Micrococcus lylae
Authors: Mikulášová Mária , Pekarovičová Alexandra , Rybáriková Daniela , Košík Martin 
Published: July 2010

AbstractWhen Micrococcus lylae grew on the black liquor from wood pulping, glucoisosaccharinic and acetic acids were completely used in 48 h, 2‐hydro‐xybutanoic acid decreased by 67%, lactic acid by 45% and glycolic acid by 38%. Conditions of the utilization of glucoisosaccharinic acid were optimized.
Aspects of the efficiency of calcium salts for the retention of sulphur in coal ash during combustion at 1200 k
Authors: Brady Mark E. , Burnett Michael G. , Galwey Andrew K. 
Published: July 2010

AbstractElectron microprobe analyses were made of the residual ash particles remaining after combustion in air at 1200 K of samples of representative coals used in thermal power plants and of samples of Northern Ireland lignite. Local associations of sulphur and calcium in the small areas analysed (c. 10 μm) were ascribed to the formation of the relatively stable CaSO4. This correlation was not linear and it was concluded that locally CaO reacted preferentially with the acidic oxides of silicon and aluminium to form calcium alumino‐silicates. We recommend, therefore, that in assessing the amount of CaCO3 or Ca(OH)2 that must be added to a given fuel to achieve effective desulphurisation, due account must be taken of the ability of the constituent oxides in that coal to react with the additive.
Liquid‐phase oxidation accompanied by skeletal rearrangement of acetophenone and acetone by hydrogen peroxide in the presence of selenium dioxide
Authors: Shah Kamlesh J. , Chandalia Sampatraj B. 
Published: July 2010

AbstractTreatment of acetophenone and acetone with hydrogen peroxide in tertiary butanol with selenium dioxide as catalyst gave phenylacetic acid and propionic acid with selectivities of 80% and 97%, respectively. The effects of various process parameters on the reaction rate and selectivity with respect to the acid have been investigated. The reactions were first‐order with respect to the substrates.
Preparation of needle‐like hydroxyapatite by homogeneous precipitation under hydrothermal conditions
Authors: Fujishiro Yoshinobu , Yabuki Hiroshi , Kawamura Kunio , Sato Tsugio , Okuwaki Akitsugu 
Published: July 2010

AbstractPreparation of hydroxyapatite was carried out by a homogeneous precipitation technique using hydrothermal reactions of Ca(EDTA)2‐ and PO43‐ at 130–250°C and pH 4–10. Hydroxyapatite and monetite were formed above pH 6 and below pH 4, respectively. Needle‐like hydroxyapatite was formed at high temperatures above 130°C. The length of the needle‐like hydroxyapatite crystal increased with increasing working solution pH and temperature.
Effects of temperature and Cu2+ catalyst on liquid‐phase oxidation of industrial wastewaters
Authors: Chang Chiehming J. , Lin Jung‐Chou , Chen Chung‐Kuo 
Published: July 2010

AbstractWet air oxidation is a process in which partial oxidations arise in an aqueous medium. Elevated temperature and pressure have enhanced solvent power for both oxygen in air and organics in wastewaters. Oxidations have therefore been carried out either in a kinetic‐controlling or in a diffusion‐controlling operation. Spent caustic and neutralized wastewaters obtained from a petrochemicals‐manufacturing process, were employed in this study for wet oxidation in a semi‐batch reactor. Temperature was indicated by preliminary kinetic data to be the primary factor influencing a situation where there was little control by diffusion. The oxidation reactions of hydrocarbon organic compounds were demonstrated to be enhanced if Cu2+ was used as the catalyst. Designing and developing wet oxidation for processing industrial wastewaters was pursued in this present study by successfully adopting homogeneous kinetic models which were, subsequently, employed for calculating rate constants of oxidation reactions by correlating organics removal efficiency with oxidation time.
Epoxidation of methallyl chloride with t‐butyl hydroperoxide
Authors: Milchert Eugeniusz , Paździoch Waldemar 
Published: July 2010

AbstractBy applying a statistical method of experiment planning the optimum conditions of methallyl chloride epoxidation with t‐butyl hydroperoxide have been determined. The influences of the temperature, molar ratio of the methallyl chloride to t‐butyl hydroperoxide, catalyst concentration and reaction time on the selectivity of the synthesis of methylglycerol epichlorohydrine in relation to reacted t‐butyl hydroperoxide have been examined.