bluuebunny/crossref_metadata_2025 huggingface dataset:
Mechanism of acetic acid transfer from aqueous sodium chloride solutions to some orgranic solvents
Authors: Abu‐Shady Abdel‐Sattar I. , Amer Samir A. , Hegazi Mohamed F.
Published: July 2010

Salting out of acetic acid from aqueous solutions containing various concentrations of sodium chloride into some organic solvents has been studied at various temperatures. The solvents include cyclohexane, carbon tetrachloride, 1,2‐dichloroethane, isopropyl ether, 2‐pentanone and 1‐heptanol. The results are consistent with a transfer mechanism involving monomer partitioning, dimerization and dimer return to the aqueous phase. Factors favoring monomer partitioning such as rise in both temperature and salt level retard dimer return, a process which is found to be significant in dimerization‐enhancing solvents. The sensitivity of various solvents towards salt effect increases in the order 1‐heptanol < isopropylether < 1,2‐dichloroethane < 2‐pentanone < cyclohexane < carbon tetrachloride which generally parallels in the reverse order the extent of stabilization of the acid by various solvent interactions.
Oxygen diffusion through a developing biofilm of pseudomonas fluorescens
Authors: Patel T. D. , Bott T. R.
Published: July 2010

Using a specially designed miniature probe mounted into a plate across which water contaminated with the bacterium Pseudomonas fluorescens was flowing, oxygen levels at the biofilm/substrate interface have been determined. The experimental results show a rapid fall in the amount of oxygen available to the micro‐organisms in the layers near the interface. As the biofilm approached 300 μm in thickness higher flow velocities across the biofilm had little effect on oxygen availability in the regions near the interface.
Production of low molecular weight esters using vegetable oils or butter oil as reaction media
Authors: Welsh Frank W. , Williams Ross E. , Chang Shirley C. , Dicaire Chantel J.
Published: July 2010

Corn oil, peanut oil, sunflower oil, soybean oil, canola oil, olive oil and butter oil were tested as replacements for nonaqueous solvents in the lipase mediated biosynthesis of ethyl butyrate, butyl butyrate, isoamyl butyrate and isoamyl acetate. The most effective oils tested were butter oil, soybean oil, peanut oil and olive oil (yield = 50–60% after 16 h incubation at 25°C) while corn oil was least effective (yield = 38%). Higher yields were obtained, for all ester syntheses, at a reaction temperature of 50°C. Drying agents were shown to have no effect or to inhibit the synthesis. Of the four enzymes tested, Candida cylindracea lipase was the most effective enzyme for ethyl butyrate synthesis.
Evolution of surface properties in a bentonite as a function of acid and heat treatments
Authors: González‐Pradas E. , Villafranca‐Sánchez E. , Villafranca‐Sánchez M. , del del Rey‐Bueno F. , Valverde‐García A. , García‐Rodríguez A.
Published: July 2010

The evolution of surface properties, such as surface acid centres, porosity and specific surface area, in a bentonite from Almería (Spain) after acid and heat treatments (0.25–2.00 N H2SO4 and 110–40°C) has been studied. The samples were characterized by mercury porosimetry and by X‐ray diffraction. The number of surface acid centres and micropore volume increase as the concentration of H2SO4 used in the acid activation increases. Surface area has been determined from N2 adsorption isotherms at 77.4K by applying the BET equation. Surface area values range from 88 m2 g−1 to 292 m2 g−1, depending on the concentration of H2SO4 used in the acid activation, the maximum value corresponding to the sample activated with 2.00 N H2SO4 and heated at 100°C.
Performance of batch and continuous reactors with coimmobilized yeast and β‐galactosidase
Authors: Axelsson Anders , Nilsson Margareta , Zacchi Guido , Hahn‐Hägerdal Bärbel
Published: July 2010

The anaerobic fermentation of deproteinized whey with β‐galactosidase coimmobilized with Saccharomyces cerevisiae in calcium alginate gel beads for the production of ethanol has been studied in a continuous horizontal packed bed reactor (HPBR). The results are compared with batch experiments in a stirred tank reactor.

The immobilized yeast cells are exposed to conditions that vary with time and location in the reactor, making a true steady state impossible. In spite of a very low specific growth rate—of the order of 0.01 h−1 in the first section of the HPBR—the yeast cell growth, accompanied by bead expansion in this section, was high enough to create a cell concentration gradient along the reactor.

The continuous reactor is preferable to the batch reactor as the galactose conversion is more efficient. The highest volumetric productivity obtained in the HPBR was 125 mol ethanol m−3 h−1 (6 g ethanol dm−3 h−1) at a substrate concentration of 164 mol m−3 lactose (56 g dm−3) and a dilution rate of 0.21 h−1, corresponding to a space velocity of 0.51 dm3 dm−3 gel h−1. The ethanol yield from consumed glucose and galactose was 80%. The ethanol yield from lactose was only 70%, as only 75% of the galactose was consumed while all the lactose and glucose were converted.
Upflow sludge blanket reactors: The effect of bio‐supplements on performance and granulation
Authors: Morgan J. W. , Evison L. M. , Forster C. F.
Published: July 2010

A series of eight upflow sludge blanket digesters was examined as four pairs (one control and three test reactors) to assess the potential for granulation enhancement of adding biopolymers (ECP), a Methanothrix supplement or granular activated carbon to the basic, non‐granular seed sludge. The results showed that, although the ECP was not particularly beneficial, the other two supplements did enhance both the granulation process and the reactor performance.
Stabilization‐activation of pancreatic enzymes adsorbed on to a sepiolite clay
Authors: Cabezas M. J. , Salvador D. , Sinisterra J. V.
Published: July 2010

The addition of small quantities 1–2% (w/w) of the sepiolite clay EXAL to animal feed increases the feed efficiency and weight of animals. α‐Chymotrypsin, lipase and α‐amylase from bovine pancreas adsorbed on to EXAL at different pH values form active stable complexes at enteric pH values. The enzymes are chemisorbed on EXAL by interaction between NH3+ groups of lysines and basic sites of the solid surface. The derivatives obtained are stable, regardless of changes in pH, and the relation between their activity and pH is complementary to that observed with the native enzyme. Therefore, these enzyme‐EXAL derivatives are resistant to proteolysis and increase the amount of active digestive enzymes in the intestine. A more efficient utilization of feed would take place in animals that have ingested EXAL than in those which have not ingested the sepiolite.
The preliminary treatment of wastewater
Authors: Sidwick John M.
Published: July 2010

A commentary on the ‘state of the art’ of the pretreatment of wastewaters with emphasis on the removal of grit and screening practices and the importance of other preliminary treatment processes as essential first stages in most wastewater treatment systems. Note is made of the lack of attention paid to preliminary treatment processes historically and on the paucity of knowledge of the mechanisms involved even today. However, there are developments and not only are conventional preliminary treatment processes reviewed, new processes are discussed and an attempt is made to forecast future trends.
Coupling of gas membrane smooth pervaporation and alcoholic fermentation
Authors: Müller Martina , Pons Marie‐Noëlle
Published: July 2010

The coupling of smooth pervaporation across microporous (PTFE and polypropylene) and nonmicroporous (silicone) membranes to alcoholic fermentation on cane molasses has been investigated as a means to limit the inhibition by ethanol. The use of liquid and gaseous carriers has been examined. Best results in terms of productivity improvement were obtained with the microporous membranes at high carrier flow rates. The complex nature of the natural broth affects the pervaporation efficiency and the hydrophobicity of the microporous membranes.
A simple affinity chromatography method for the separation of gastric proteases from mucous substances
Authors: Łobarzewski J. , Kowalska‐Pyłka H. , Cybulski W.
Published: July 2010

A simple chromatographic method for separating mucous substances contained in the abomasal mucosa from proteases has been developed. The chromatographic technique used controlled porous glass as a matrix, with covalently bound keratin as a ligand. This matrix allowed affinity binding of proteases at pH 7·0. The mucous substances present in calf abomasal mucosa were easily identified in the column eluate. Proteases were eluted from the column with 0·1 ml dm−3 HCl with good recovery (85%) and high purification.
Effect of the preparation on the initial toxicity of supported nickel catalysts deactivated by thiophene
Authors: Aguinaga Alicia , Montes Mario , Asua José M.
Published: July 2010

The influence of the type of support, metal dispersion and degree of reduction on the deactivation of a series of nickel catalysts by thiophene during the hydrogenation of benzene to cyclohexane was investigated. Catalysts with different degrees of metal‐support interaction were prepared. For the catalysts with a weak interaction, the initial toxicity decreased as the nickel particle size increased. On the other hand, neither the metallic particle size nor the type of support affected the initial toxicity for the catalysts with strong interaction. For these catalysts, the initial toxicity increased as the degree of reduction increased.
A convenient preparative method of oxo‐dimethylallyl compounds from carboxylic acid derivatives
Authors: Inaba Teruhiko , Aoki Hideyo , Watanabe Shoji , Sakamoto Masami , Fujita Tsutomu
Published: July 2010

Various oxo‐dimethylallyl compounds were prepared from intermediates which are obtained by the reaction of allylic Grignard reagents with carboxylic acid derivatives. For example, the reaction of prenylmagnesium chloride with ethyl hexanoate gave 3,3–dimethyl‐4–prenyl‐1‐nonen‐4–ol (1) in 92% yield. The thermolysis of 1 at the temperature of 693 K gave 2–methyl‐2–decen‐5–one (2) in 81% yield. Furthermore, 3,3–dimethyl‐1‐alken‐4–ones (E) were prepared by the methylation of 1‐alken‐4‐ones (C), which are obtained by the reaction of allylmagnesium chloride with carboxylic acids (A).
Alternating aerobic and anoxic digestion of waste activated sludge
Authors: Hao Oliver J. , Kim Michael H. , Al‐Ghusain Ibrahim
Published: July 2010

Nitrate generated in situ due to nitrification in an aerobic digester was utilized through endogenous nitrate respiration (ENR). This was done by alternating aerobic/anoxic (A/A) cycles. The destruction of volatile suspended solids (VSS) in the A/A system was the same as compared to a controlled‐aerobic digester. Approximately 33% of total nitrogen was removed in the A/A system of which 27% was due to ENR during anoxic cycles.

During each anoxic cycle, nitrate reduction was found to be a zero order reaction with respect to nitrate. The specific ENR rates decreased significantly with digestion time due to changes in VSS. Both pH and alkalinity increased during anoxic cycles resulting in enhanced VSS decay and complete nitrification under subsequent aerobic conditions.

The energy savings associated with the A/A system and the use of the specific ENR rates are discussed.
Simulation of batch and continuous reactors with co‐immobilized yeast and β‐galactosidase
Authors: Axelsson Anders , Zacchi Guido
Published: July 2010

A reaction‐diffusion model was used to simulate a co‐immobilized system utilizing the numerical method of orthogonal collocation. The production of ethanol from deproteinized whey using β‐galactosidase co‐immobilized with Saccharomyces cerevisiae in calcium alginate gel beads was chosen as a model system. Calculated concentrations of lactose, glucose, galactose and ethanol were compared with experimental data for a batch reactor and a continuous horizontal packed‐bed reactor.

The mathematical model has been used to analyse the influence of internal and external mass transfer for the continuous reactor. The external mass transfer was shown to be of minor importance.

The introduction of baffles decreased the backmixing in the horizontal packed‐bed reactor. Internal mass transfer was found to be the main cause of the reduction in the apparent reaction rate. Thus, much of the expected increase in reaction rate is diminished by mass transfer hindrance when the cell concentration is increased.
The loss of substrate from a vial during freeze‐drying using escherichia coli as a trace organism
Authors: Adams Gerald D. J.
Published: July 2010

The potential for ablation during product freeze‐drying has been assessed using a defined area surrounding the processed vial. This technique has enabled media formulations to be compared. The paper suggests ways in which the mini‐chambers may be used to investigate the extent of ablation and methods for reducing contamination of a freeze‐drier by ablation.
Examination of boron content and properties of magnesium oxide obtained from sea water
Authors: Petric N. , Petric B. , Martinac V.
Published: July 2010

The potentiometric method was used to determine the boron content in magnesium oxide obtained from sea water by sub‐stoichiometric precipitation (where precipitation of magnesium hydroxide took place with 80% of the stoichiometric quantity of the dolomite lime) and by over‐stoichiometric precipitation (which took place with 120% of the stoichiometric quantity of the dolomite lime); the analyses depend on the method of rinsing the product obtained.

The following were examined: the influence of pH of the rinsing solution, duration of stirring and contact of the suspension, influence of the quantity of the rinsing agent, and the method of precipitate separation in sub‐stoichiometric precipitation. It has been proved that the use of the appropriate rinsing method in the case of sub‐stoichiometric precipitation leads to results almost identical to those obtained for over‐stoichiometric precipitation, which is rather important if one bears in mind the advantages of this precipitation method.

Individual samples of magnesium oxide obtained from sea water by sub‐ and over‐stoichiometric precipitation were then sintered. This paper lists densities of samples sintered and presents their photomicrographs.
Production and consumption of sorbitol and fructose by saccharomyces cerevisiae ATCC 36859
Authors: Duvnjak Z. , Turcott G. , Duan Z. D.
Published: July 2010

The production and consumption of sorbitol by Saccharomyces cerevisiae ATCC 36859 have been studied in this work. The results showed that the strain produced ethanol and sorbitol in a fructose medium, but it generated only ethanol while growing in a glucose medium. When the strain was pregrown on fructose and transferred to a sorbitol medium, it consumed that polyol and produced ethanol and fructose. It did not grow on sorbitol when it was transferred from a glucose medium. During the growth of the strain in a glucose‐fructose medium, the sorbitol production started some time after the consumption of glucose. Both glucose and ethanol affected the production of sorbitol. Comparing the strain with a wild S. cerevisiae, it was found that the latter one did not produce sorbitol when it grew either on glucose or fructose. Furthermore, the wild strain grew well on sorbitol, regardless of whether it was pregrown on glucose or fructose but it did not produce fructose.
Biodegradation of black liquor hydroxyacids by micrococcus lylae
Authors: Pekarovičová Alexandra , Mikulášová Mária , Černáková L'udmila
Published: July 2010

Eight bacterial strains utilizing glucoisosaccharinic acid (GISA), which is one of the main components of sulphate black liquor hydroxyacids, were isolated from the environment of a sulphate pulp mill. The best GISA‐utilizing bacterium was isolated from soil and it was identified as Micrococcus lylae. The growth of M. lylae on GISA in the pH range 5.0–9.0 was studied, optimum growth and utilization of GISA being observed at pH 8.0. M. lylae also utilized D,L‐lactic acid and black liquor separated from the lignin.
A packed‐column bioreactor for phenol degradation: Model and experimental verification
Authors: Quail Beverly E. , Hill Gordon A.
Published: July 2010

Pseudomonas putida (ATCC 17484) has been grown in a pure culture, slime layer inside a continuous packed‐column bioreactor. The bioreactor has been characterized in terms of liquid holdup, dispersion, air stripping, fixed biomass concentration, and degradation rate capabilities. The experimental data has been used to develop a predictive model using mechanistic equations for the operation of packed columns and the biokinetics of pure culture phenol degradation.

The liquid holdup, dispersion and liquid‐to‐air mass transfer coefficients were found to be correlated by power law equations commonly used for packed column absorption and stripping equipment. The microorganisms developed a uniform slime layer over the 3‐mm diameter glass spheres, measured to be 200 μm thick. Phenol inlet concentrations of 500 ppm were degraded 100% and at rates up to 1.2 × 10−3 kg m−3 s−1. These results compare favorably with the best biodegradation results reported elsewhere in the literature for other bioreactor designs. The packed‐column bioreactor has the advantages of no moving parts and the need for minimum aeration (air fluxes less than 0.001 ms−1), thereby reducing volatile stripping losses.

A computer model of the bioreactor was found to predict accurately the experimental trend in biodegradation capacities and rates with liquid flux. It is shown to be a useful model for studying design parameter changes or for determining scale‐up characteristics due to its simplicity and mechanistic basis.
Cationic azomethine disperse dyes: Synthesis, antifungal activity and tinctorial properties of N‐arylideneamino p‐substituted pyridinium salts as possible dyes for synthetic fibres
Authors: Hanna M. A. , Girges M. M. , Gawinecki R.
Published: July 2010

In a four‐step synthesis, a series of N‐arylideneamino p‐substituted pyridinium salt derivatives were prepared for use as cationic azomethine disperse dyes for polyester and polyacrylonitrile fibres. The effect of different substituents, in both of homo‐ and heterocyclic ring systems, on position of maximum absorbance in UV‐vis spectra was used to explain the different hues of the prepared dyes. Besides, showing promising tinctorial properties, the synthesised dyes revealed fungicidal activity against Aspergillus niger. The structure of the hitherto prepared dyes was inferred by elemental and spectral data.
The Use of a Mathematical Model for the Study of the Important Parameters in Immobilized Biomass Biosorption
Authors: Tsezos Marios , Deutschmann Ake A.
Published: July 2010

It has been shown that the immobilized, inactive mycelia of Rhizopus arrhizus are preferential to native biomass for use in the biosorption of metal ions. A kinetic mass transfer model for the description of the biosorption of metal ions by immobilized biomass from aqueous solution in a batch reactor, has been developed. The present work examines in detail the ability of this kinetic model to describe well the response of the biosorption system to changes caused by variations in the experimental conditions and the properties of the immobilized biomass as well as the parametric sensitivity of the model to process related parameters. It was shown that the immobilized biomass particle size, the initial solute concentration, the maximum immobilized biomass uptake capacity and mass transport coefficients are significant parameters that affect the model results.
Kinetic Model for Oxidative Dehydrogenation of n‐Butanol over Copper‐Barium Catalyst
Authors: Shiau Ching‐Yeh , Liaw Shin‐Tsi
Published: July 2010

Kinetics for oxidative dehydrogenation of n‐butanol over copper‐barium catalyst was investigated in a fixed‐bed reactor. The effects of oxygen addition, temperature, initial partial pressure, and time factor on the conversion were studied. The results show that the catalyst is quite active and selective for the dehydrogenation of n‐butanol and will become more active when a small amount of oxygen is added in the feed stream. A partial redox model including a pair of redox reaction steps parallel with a direct dehydrogenation reaction step was developed. The rate constants for the three reaction steps were evaluated. The model can predict the experimental data quite well, with a standard deviation less than ±5%.
The Production of the Enzyme Dextransucrase using Unaerated Continuous Fermentations
Authors: Pennell R. D. , Barker P. E.
Published: July 2010

Following the successful production of dextransucrase with activities greater than 21.9 U cm%−3, using the fed‐batch fermentation technique, the process was then studied in the continuous mode. The organism Leuconostoc mesenteroides NRRL B512 (F) was cultured in an unaerated nutritious medium, containing sucrose, with similarly composed medium used as the feed. Using this method of operation, it was possible to produce approximately 5 U cm%−3 of dextransucrase continuously.

Various factors were found to affect dextransucrase production. The sterilization cycle of the feed medium was found to be very important, with temperatures of 125°C causing medium degradation and, hence, a loss in activity. The sucrose concentration of the feed medium and the degree of mixing of the fermentation were also found to be important parameters in this process.
A Novel Approach to the Estimation of Combustion Rates of Solid Fuels
Authors: Jones J. C.
Published: July 2010

By means of basket heating of two fuels individually and also together as a blend, and application of the theory of parallel reactions, Arrhenius parameters for the fuels are obtained on the basis of a first‐order scheme in each case.
The Effect of Nickel on the Conversion of Amorphous Iron(III) Hydroxide into more Crystalline Iron Oxides in Alkaline Media
Authors: Cornell R. M. , Schneider W. , Giovanoli R.
Published: July 2010

The effect of nickel (Ni) on the transformation of amorphous iron(III) hydroxide into more crystalline iron oxides has been followed using X‐ray powder diffraction and chemical analysis. One aim of this study was to determine the fate of Ni that had been co‐precipitated with amorphous iron(III) hydroxide as the amorphous phase recrystallised.

Ni/amorphous iron(III) hydroxide co‐precipitates transformed into Ni substituted α‐FeOOH or α‐Fe2O3, NiFe2O4 and α‐3Ni(OH)2.2H2O in alkaline media. The type of reaction products formed depended on the concentration of Ni in the system and on the pH.

Ni retarded the crystallisation of amorphous iron(III) hydroxide by stabilising the co‐precipitate both against dissolution leading to α‐FeOOH and against the internal rearrangement process which leads to α‐Fe2O3.

Chemical analysis showed that Ni was incorporated into the structure of α‐FeOOH to a maximum level of 5.5 mol% and into the structure of α‐Fe2O3 to up to 7 mol%. Excess Ni was adsorbed on the surface of the iron oxide or taken up by NiFe2O4 or the pure Ni phase. The b0 dimension of the unit cell increased from 0.9960 nm for α‐FeOOH to 0.9965 nm for α‐FeOOH with 5.5 mol% Ni substitution. The same maximum level of Ni could be incorporated in the α‐FeOOH structure in the presence of either Mn (up to 8 mol%) or Co (up to 7 mol%).
Biobleaching of Pulp and Paper Mill Effluents by Phanerochaete chrysosporium
Authors: Mittar Dev , Khanna P. K. , Marwaha S. S. , Kennedy J. F.
Published: July 2010

The potential of white rot fungi, namely, Polyporus versicolor FRI 165, Polyporus hirsutus FRI 534, Polyporus hirsutus FRI 2862, Phanerochaete chrysosporium BKMF 1767 and Sporotrichum pulverulentum for the reduction of colour of pretreated pulp and paper mill effluents under sterilised and unsterilised conditions has been evaluated. Of these, P. chrysosporium BKMF 1767 cultured under sterilised conditions supported maximum colour reduction after 7 days of growth. The optimisation of the process parameters showed that the addition of nutrient sails in selective combination marginally improved the colour reduction. The 7‐day‐old growth of culture at 20% (v/v) inoculum concentration resulted in maximum decolourisation (69.6%) of the effluent with pH adjusted to 4.5 at 40°C along with more than 50% reduction in biological oxygen demand (BOD) and chemical oxygen demand (COD). The irradiation of the effluent with UV light had apparently no effect on the colour, BOD and COD reduction by P. chrysosporium.
Photocatalytic Cyanide Oxidation from Aqueous Copper Cyanide Solutions over TiO2 and ZnO
Authors: Peral JosÉ , Domenech Xavier
Published: July 2010

The elimination of cyanide from aqueous copper cyanide solutions by oxidation under UV illumination using titanium oxide (TiO2) and zinc oxide (ZnO) as catalyst has been investigated. The study has been carried out by determining the yield of cyanide elimination at different irradiation times, initial cyanide concentrations and pH. It has been observed that cyanide is photo‐oxidised with higher yields in presence than in absence of copper in solution when TiO2 is used as photocatalyst, while the opposite behaviour is reported when ZnO is the photocatalyst employed. This fact is related with the feasibility in which copper species are able to react with photogenerated electrons in the conduction band of the TiO2 particles. Finally, the elimination of cyanide, both free and complexed, from a sample of an electroplating bath has also been studied. The results show that the photocatalytic method is very efficient in the elimination of cyanide in aqueous dilute solutions.
Synthesis of 5,5′‐Oxydimethylenebis (2‐furfural) by Thermal Dehydration of 5‐Hydroxymethyl‐2‐furfural in the Presence of Dimethylsulfoxide
Authors: Larousse Christian , Rigal Luc , Gaset Antoine
Published: July 2010

A new method for the synthesis of 5,5′‐oxydimethylenebis (2‐furfural) by thermal dehydration of 5‐hydroxymethyl‐2‐furfural in the presence of dimethyl‐sulfoxide is described. Optimum conditions are studied by experimental design. Reaction media present a high concentration of HMF. Reaction is supposed to be rapid. Yields reach 55% with a 84% selectivity.
Adaptive linear quadratic gaussian (LQG) control of a bioreactor
Authors: Roux G. , Dahhou B. , Najim K. , Queinnec I.
Published: July 2010

The paper deals with the modelling and adaptive control of a continuous‐flow fermentation process for the production of alcohol.

The fermenter model has been developed from mass balance and leads to nonlinear differential equations. In practice, control strategies are difficult to derive using this non‐linear model. The dilution rate and the substrate concentration have been considered as control and controlled variables, respectively.

The adaptive control algorithm implemented is based on the linear quadratic control approach, where the associated Riccati equation is iterated until the system closed‐loop poles belong to a restricted stability domain which is included in the unit circle.

A single input/output model is used for control purposes. The model parameters are estimated on‐line using a robust identification algorithm which includes: data normalization, time‐varying forgetting factor, covariance matrix factorization, etc. Experimental results show the performance of this adaptive scheme and its ability to control biotechnological processes.
Synthesis and anti‐inflammatory activity of some novel 1,3,4‐oxadiazole derivatives
Authors: El‐Samii Z. K. Abd
Published: July 2010

Some novel 1,3,4‐oxadiazoline and 1,3,4‐oxadiazole derivatives have been synthesized from 3‐hydroxy‐5,6‐diphenyl‐1,2,4‐triazine. Illucidation of the structures of the isolated products has been proved in the light of their elemental analysis, spectroscopic data and unambiguous synthesis in certain cases. Some derivatives have shown promising anti‐inflammatory activity in comparison to phenylbutazone.
Bioconversion of hemicelluloses of rice hull black liquor into single‐cell protein
Authors: Hussein Assem M. , El‐Saied Houssni , Yasin Mohamed H.
Published: July 2010

Rice hulls were treated using several sodium hydroxide concentrations and temperatures. The black liquor contents of silica, lignin and hemicelluloses increased with increase in temperature or sodium hydroxide concentration. Hexoses constituted the major part and pentoses the minor part of the black liquor hemicelluloses. The ratio of pentoses to hexoses increased slightly with the increase of treatment variables.

The pentose content of the black liquor consisted of arabinose and xylose, while the hexose composition was mannose, galactose, rhamnose and glucose. On increasing the alkali concentration, the xylose and mannose concentrations increased greatly, while galactose and glucose increased only slightly.

Using 10 soil samples several isolates of fungi and actinomycetes were obtained. These were identified as five species of the genus Aspergillus, three species of Paecilomyces, two species of Penicillium, one species each of Alternaria, Trichoderma, Chaetomium and Actinopolyspora. These fungi were cultivated on black liquor basal salts medium. The highest bioconversion rate of black liquor hemicelluloses into biomass and single‐cell proteins was achieved by Aspergillus terreus, followed by Paecilomyces simplicissima then Actinopolyspora sp.
Removal of congo red from aqueous solutions by biogas waste slurry
Authors: Namasivayam C. , Yamuna R. T.
Published: July 2010

Removal of Congo Red was carried out using biogas waste slurry as adsorbent at different concentrations of dye, adsorbent dosage, agitation time and pH. The process follows the first‐order rate expression. The equilibrium data fit well in the Freundlich model of adsorption. Maximum removal of dye, 95%, was observed in the pH range 2.3–9.4. Desorption of Congo Red showed that it is solubilised in 50% acetic acid to the extent of 6% and the remainder appears to be chemically complexed irreversibly to the adsorbent. Low desorption of dye from the adsorbent surface in water indicates that the process may not be, essentially, a reversible one.
Kinetics and stability of a chromobacterium viscosum lipase in reversed micellar and aqueous media
Authors: Prazeres D. M. F. , Garcia F. A. P. , Cabral J. M. S.
Published: July 2010

The lipolytic activity of Chromobacterium viscosum lipase B (EC 3.1.1.3.; triacylglycerol hydrolase) solubilized both in water and AOT/isooctane reversed micelles has been investigated using triolein as a substrate. The influence of relevant parameters in the catalytic activity such as temperature, pH, surfactant and substrate concentrations, and water content was tested and compared in both media. A study of stability of the lipase was carried out, with particular reference to the influence of pH.

Three major effects of the encapsulation of the lipase in the micelles were observed: increased activity (up to 7 times higher than in water), greater stability, specially at pH 7, and higher resistance to thermal deactivation.
Studying production of lovage essential oils in a hydrodistillation pilot unit equipped with a cohobation system
Authors: Perineau Francis , Ganou Leguet , Vilarem Gérard
Published: July 2010

The hydrodistillation procedure for a unit equipped with a cohobation system is presented. The production of lovage root essential oil and the difficult recovery of the phthalide content (60–85%) is studied. The general mechanism and the role of parameters involved in the extraction and co‐distillation step (plant matter/water ratio, loading ratio) then in the water/essential oil separation step (pH, condensation temperature) are investigated. This study takes into account the quantitative results (yield of essential oil, productivity) and the qualitative ones (composition of recovered essential oils). Optimal distillation conditions with respect to the energy consumption are proposed.
Study of the poisoning of γ‐Al2O3 by alkali metals addition
Authors: Cortez Gilberto García , de Miguel Sergio R. , Scelza Osvaldo A. , Castro Alberto A.
Published: July 2010

The effect of alkali metal addition to alumina on the acid characteristics and on the isopropanol dehydration capacity was analyzed. It was found that the incidence on the catalytic and acid properties of the alkali metal doped alumina depended on the ionic radii of the added element. Thus, K produces a higher poisoning of the acid function than Na and Li. Catalytic results can be interpreted in terms of a modification of the acid sites distribution by the alkali metal addition, the stronger acid sites being mainly affected.
Ethanol dehydration by extractive distillation
Authors: Meirelles Antonio , Weiss Siegfried , Herfurth Herbert
Published: July 2010

Experiments and process simulation enable favourable operating conditions to be determined for the extractive distillation of ethanol—water, with ethylene glycol as a solvent. The solvent molar rate to feed molar rate ratio S/F = 0·6 and the reflux ratio R = 0·5 were determined in order to achieve at least 99·5 mole % purity of ethanol. Other parameters examined include feed concentration, purity of solvent, and number of plates.

Extractive distillation can be used to achieve high purity of ethanol at low energy consumption and under simple operating conditions.
Hydrolysis of Fe(OH)SO4 in the presence of metallic iron
Authors: Mahapatra Sipra , Prasad Turaga P.
Published: July 2010

Hydrolysis of Fe(OH)SO4 was carried out in the presence of metallic iron in order to prevent the formation of iron(III) oxides with strongly bonded sulphate. Under the conditions of the experiment, the products were found to be mixtures of ϵ‐Fe2O3 and α‐FeOOH. The occluded sulphate, if any, could be easily washed out with water. The hydrolysis reaction passes through an equilibrium state before coming to completion. The entropy with enthalpy of the hydrolysis corresponding to the equilibrium state were found to be 4 e.u. and 0·5 kJ/mol, respectively. The activation energy of the hydrolysis reaction was found to be 21 kJ/mol.
Oxygen plasma modification of wool fibre surfaces
Authors: Bradley R. H. , Clackson I. L. , Sutherland I. , Crompton J. A. , Rushforth M. A.
Published: July 2010

A range of oxygen plasma treatments has been used to modify the surfaces of woven and fibrous wool samples. The resulting chemistry and composition have been characterised using X‐ray photoelectron spectroscopy (XPS). The extent of oxidation of di‐sulphide bonds to sulphur (SVI), in the form of sulphonic acid groups (−SO3H), by the plasma is shown to be only about 20–30% compared to 100% using a conventional wet chlorination process. However, the plasma does appear to react with surface carbon of the protein structure, leading to an increase in carbon‐oxygen functionalities. Total levels of surface oxygen achieved using the plasma technique are similar to those from the wet process.
Synthesis and application of novel sulpha drugs based on quinoxaline‐2‐one and/or quinoxaline‐2‐thione
Authors: Awad Ibrahim M. A.
Published: July 2010

Some novel azo‐Sulpha drugs as 3‐methyl‐N‐azo‐(4′‐substituted heterocyclo‐benzene‐sulphamoyl) quinoxaline‐2‐ones (1‐11) and 3‐methyl‐N‐azo‐(4′‐substituted heterocyclo‐benzene‐sulphamoyl)‐quinoxaline‐2‐thiones (1′–11′) were synthesized by coupling 4′‐substituted heterocyclo‐benzene‐sulphamoyl diazonium acetates with 3‐methyl‐N‐(1H)‐quinoxaline‐2‐one and/or with 3‐methyl‐N(1H) quinoxaline‐2‐thione in acid medium. The corresponding iron (III) (1a‐11, 1′a‐11′a) copper (II) (1b‐1b′‐7b′) and mercury (II) (1c‐11c, 1c′‐11c) chelates were also prepared in a 1:1 metal‐to‐ligand ratio. The ligands and their chelates were characterized on the basis of microanalysis, UV, IR and H'‐NMR spectrometry and were tested in vitro for their antibacterial and antifungal activities.
Thermodynamic studies of weak aqueous sulfate solutions in solvent extraction systems
Authors: Juang Ruey‐Shin , Su Jenn‐Yih
Published: July 2010

The molalities and activity coefficients of various chemical species in the 0.5 M (H,Na,Me)SO4 aqueous solutions (Me = Cu, Co or Zn) were calculated by the Bromley and the simplified Pitzer methods for strong electrolyte solutions. The validity of the conventional constant ionic medium method applied to these extraction systems was studied. The thermodynamic constants of these trace metal extractions with di(2‐ethylhexyl)phosphoric acid (D2EHPA) were also evaluated, based on simple experiments and the calculated thermodynamic results.
Interfacial activity of 4‐alkylphenylamines and the rate of palladium(II) extraction
Authors: Wisniewski Maciej , Szymanowski Jan , Walkowiak Wladyslaw , Michalewska Malgorzata
Published: July 2010

Interfacial tension isotherms were determined in hydrocarbon‐water systems for 4‐alkylphenylamines containing from 6 to 16 carbon atoms in their alkyl chains, and the surface excess isotherms were computed and interpreted using various adsorption isotherms.

Palladium(II) was extracted with 4‐alkylphenylamines from 3 M HCI solutions. The maximum extraction rate of palladium(II) is observed for 4‐decyl‐ and 4‐dodecylphenylamines which exhibit good interfacial activity. Compounds soluble in the aqueous phase (4‐hexylphenylamine) or in toluene (4‐hexadecylphenylamine) extract palladium(II) slower than 4‐decyl‐ and 4‐dodecyl‐ phenylamines.
Bioprocess applications of model‐based estimation techniques
Authors: Massimo Christine Di , Lant Paul A. , Saunders Aidan , Montague Gary A. , Tham Ming T. , Morris A. Julian
Published: July 2010

The last decade has seen the development of a number of approaches for estimating those variables which are difficult to measure on‐line in industrial process situations. Whilst a range of techniques is available, a common element is the use of process knowledge in the form of a system model. In the case of bioprocess systems, although a large range of models has been presented in the literature, their use in estimation schemes on an industrial scale has been limited. A number of reasons can be identified for their low level of utilisation. Of particular significance is the uncertainty which exists in quantifying system performance and the process‐model mismatch which inevitably results. The level of ‘pre‐defined model’ uncertainty, together with the knowledge gained during the course of the fermentation, serves to dictate estimator structure. The paper considers a range of estimation strategies and contrasts, through industrial applications, their performance characteristics and utility.
Effect of temperature on fermentation kinetics of waste sulphite liquor by Saccharomyces cerevisiae
Authors: Rousseau S. , Rouleau D. , Yerushalmi L. , Mayer R. C.
Published: July 2010

The optimum operating temperatures for the maximum production of ethanol and the maximum utilization of substrate in batch fermentations of a waste sulphite liquor (WSL) as well as a synthetic medium using Saccharomyces cerevisiae were determined. The fastest consumption of substrate resulting in the shortest fermentation times of 13 h and 45 h was achieved at 35°C and 30°C for the synthetic medium and the WSL, respectively. The concentrations of ethanol in the two media were also maximum under these conditions: 11.6g dm−3 and 9.4 g dm−3 for the synthetic medium and the WSL, respectively. The productivities of biomass and ethanol increased with the increase of temperature and reached maximum values of 0.89 g dm−3 h−1 and 0.21 g dm−3 h−1 in the synthetic medium and the WSL, respectively. The inhibiting agents in the waste sulphite liquor affected the metabolic rates of microbial activities and prolonged the overall fermentation time while decreasing the productivities of biomass and ethanol. From analysis of the fermentation kinetics a mathematical model based on the Monod model was developed to describe the cellular growth and ethanol production. The model included inhibition terms for ethanol and the inhibiting agents in the waste liquor. The temperature dependence of the model parameters followed the Arrhenius law for temperatures between 15°C and 35°C. The activation energies (E) and the frequency constants (A) of these parameters were also determined.
A comparison of properties of inulinases of Fusarium oxysporum immobilised on various supports
Authors: Gupta Anil K. , Kaur Maninder , Kaur Narinder , Singh Rangil
Published: July 2010

Extracellular inulinase was obtained after growing Fusarium oxysporum for 9 days on a medium containing an aqueous extract of Cichorium intybus roots. After partial purification, inulinase was immobilised by cross‐linking it with water insoluble protein supports prepared from flour of soybean and mungbean, and egg white. Inulinase was also immobilised by adsorbing it on DEAE‐cellulose. Inulinase immobilised on soybean and mungbean supports had a higher optimum temperature of 45°C as compared to 37°C of the free enzymes. Inulinase adsorbed on DEAE‐cellulose was thermally the most stable whereas the inulinase cross‐linked on soybean support was the least stable. Inulinase immobilised on DEAE‐cellulose and on supports obtained from mungbean and soybean had a pH optima of 5.5, 6.5 and 6.0, respectively. The Km values of various immobilised inulinases with inulin varied from 0.25 to 0.44 mmol dm−3.
Adsorption of 2,4‐D onto activated carbon: Application of Nth order approximation
Authors: Bhaskar Ganugapati V. , Bhamidimarri Rao S. M.
Published: July 2010

Adsorption kinetics of 2,4‐dichlorophenoxyacetic acid (2,4‐D) onto activated carbon is presented in this paper. The equilibrium adsorption of 2,4‐D is described by a Freundlich type isotherm and the batch kinetic experiments are analysed using a surface diffusion model. The model equations are simplified by an nth order approximation and, when applied to the experimental data, the approximation predicted the film transfer and diffusion coefficients with a good accuracy.
Disperse dyes: 4‐hetarylazo derivatives from N‐β‐cyanoethyl‐N‐β‐hydroxyethylaniline
Authors: Peters Arnold T. , Gbadamosi Adam
Published: July 2010

Aminothiazoles, benzothiazoles, thiadiazoles and thiophenes were diazotised and coupled to N‐β‐cyanoethyl‐N‐β‐hydroxyethylaniline to give dyes which coloured polyester in orange to blue hues. The colour of the dyes is discussed with respect to the nature of the heterocyclic ring and substituents therein. Solvent effects on the visible absorption maxima of some of the dyes are also reported.
Production of vitamins, coenzymes and related biochemicals by biotechnological processes
Authors: Vandamme Erick J.
Published: July 2010

Vitamins and related biofactors belong to those few chemicals with a direct positive appeal to people. There is indeed a large need for extra vitamins, other than those derived from plant and animal food sources, due to unbalanced food habits or processing, food shortage or disease. Added vitamins are now either prepared chemically or biotechnologically via fermentation or bioconversion processes. Several vitamins and related biofactors are now only or mainly produced chemically (vitamin A, cholecalciferol (D3), tocopherol (E), vitamin K2, thiamine (B1), niacin (PP or B3), pantothenic acid (B5), pyridoxine (B6), biotin (H or B8), folic acid (B9) or via extraction processes (β‐carotene or provitamin A, provitamin D3, tocopherol, vitamin F‐group).

However, for several of these compounds microbiological or algal methods also exist or are rapidly emerging. Others are produced practically exclusively via fermentation (ergosterol or provitamin D2, riboflavin (B2), cyanocobalamin (B12), orotic acid (B13), vitamin F‐group, ATP, nucleosides, coenzymes, etc. or via microalgal culture (β‐carotene, E, F). Both chemical and microbial processes are run industrially for vitamin B2 while vitamin C (ascorbic acid) is produced via a combination of chemical reactions and fermentation processes. A survey is given here of the current state of vitamin production, with emphasis on developments and strategies for improved biotechnological production and its significance, as compared to existing chemical processes.

The screening or construction of vitamin hyperproducing microbial strains is a difficult task; pathway elucidation and metabolic (de)regulation need further study; r‐DNA technology has only recently been introduced; improved fermentation processes and immobilised biocatalysts bioconversions for the synthesis of chiral vitamin compounds or intermediates or derivatives are gaining importance; the recovery and purification of these vitamin compounds from their fermentation broths remains equally complex.
Modelling of hydrolysis controlled anaerobic digestion
Authors: Jain Sanjay , Lala Anil K. , Bhatia Suresh K. , Kudchadker Arvind P.
Published: July 2010

A mathematical model of anaerobic digestion has been developed which considers the process as occurring through hydrolysis followed by a sequence of steps which have been considered together as a pseudo‐first order process. The Michaelis‐Menten equation has been modified to incorporate variable enzyme concentration. An immobilized reactor has been designed, fabricated and operated on cowdung feed to obtain data for estimating the model parameters by non‐linear regression. These model parameters were used to predict the performance of the reactor and good agreement between experimental and predicted values was observed. The model was further tested satisfactorily on data from the literature. From the parameters estimated it was concluded that hydrolysis was the slowest stage and that the mass transfer of hydrolytic enzyme from microbe to bulk was the rate controlling step in this stage. The hydrolysis reaction, represented by a modified Michaelis‐Menten equation, was reduced to first order in bulk enzyme concentration and zero order in substrate concentration thereby emphasizing the significance of bulk enzyme concentration.
Prediction of binary component isotherms for adsorption on heterogeneous surfaces
Authors: Al‐Duri B. , Khader Y. , McKay G.
Published: July 2010

The adsorption of three basic dyes onto peat has been studied as single and bisolute equilibrium isotherms. The Freundlich equilibrium isotherm, suitable for heterogeneous adsorption systems has been selected to describe the single component data. Furthermore, the extended Freundlich formula for binary systems has been used to describe binary system equilibrium. A very good agreement is obtained between experiment and theory. The dyes under investigation are: Basic Blue 3, Basic Red 22 and Basic Yellow 21 in their single phases and binary solutions, respectively, all onto peat.
Interfacial mass transfer in stripping of phenylalanine in a liquid‐liquid extraction process
Authors: Uddin Mohammad S. , Hidajat Kus , Lim Bee‐Gim , Ching Chi‐Bun
Published: July 2010

Stripping of L‐phenylalanine from organic phase containing ALIQUAT 336 (tri‐octyl‐methyl‐ammonium chloride) as complexing agent was studied using a stirred transfer cell. The study investigated the effects of concentration of the stripping agent, potassium chloride, in strip solution and temperature on mass transfer rates. A two‐film model based on organic and aqueous phases mass transfer resistances was proposed to estimate mass transfer coefficients and it predicted adequately the experimental time‐concentration data at different conditions studied. A comparison of mass transfer coefficients for stripping and previously published results on extraction for the same system was made.
Suspension culture of Nicotiana tabacum cells in a rotary‐drum bioreactor
Authors: Shibasaki Naomi , Hirose Kenji , Yonemoto Toshikuni , Tadaki Teiriki
Published: July 2010

Suspension cultures of Nicotiana tabacum (tobacco) were studied using a rotary‐drum bioreactor and the effects of various operating factors on culture growth were investigated. Conditions of oxygen concentration, aeration and drum rotation rates required for optimum culture growth rate were determined. The results were compared with those obtained in an air‐lift bioreactor with a draft tube. The culture growth rates were higher in the rotary‐drum bioreactor than in the air‐lift bioreactor under the same conditions of aeration. The rotary‐drum bioreactor was superior to the air‐lift bioreactor in respect of oxygen mass transfer and the level of shear damage to N. tabacum cells.