bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of pyrazolo[4′,3′:5,6]pyrazino[2,3‐c]pyrazoles and pyrazolo[4′,3′:5,6]pyrazino[2,3‐d]pyrimidines and their application to polyester fibres
Authors: Rangnekar Dinesh W.
Published: July 2010

4‐Nitroso‐1‐phenyl‐3‐methyl‐5‐aminopyrazole (1) was condensed with ethylcyanoacetate (2), malononitrile (4a) and 2‐cyanomethylbenzimidazole (4b) to yield 6‐hydroxy‐5‐cyano, 6‐amino‐5‐cyano and 6‐amino‐5‐(benzimidazol‐2‐yl)‐3‐methylpyrazolo [3,4‐b]pyrazines 3, 5a and 5b, respectively. 5‐Cyano‐6‐chloro derivative 6 obtained from 3 was converted to 3‐aminopyrazolo[4′,3′:5,6]pyrazino[2,3‐c]pyrazoles 8a and 8b by the treatment with hydrazin hydrate (7a) and phenylhydrazine (7b), respectively. Compound 5a was treated with formamide (9a), urea (9b) and thiourea (9c) to give 4‐aminopyrazolo[4′,3′:5,6]pyrazino[2′3′‐d]pyrimidines 10a–10c. With refluxing acetic anhydride compounds 8a, 8b and 10a gave corresponding acetamido derivatives 8c, 8d and 10d. Compound 5a was treated with ethylorthoformate (11), acetic anhydride (12) or benzoylchloride (13) to give fused benzimidazopyrazolo[4′,3′:5,6]pyrazino[2′,3′‐d]pyrimidines, viz., benzimidazol[1,2‐c]pyrazolo[4,3‐g]pteridines (14a–14c). Some of the compounds 8, 10 and 14 were applied to polyester as disperse dyes and their fastness properties were studied.
An immobilized cell bioprocess for the removal of heavy metals from aqueous flows
Authors: Macaskie Lynne E.
Published: July 2010

Microorganisms can be used to remove toxic heavy metals from liquid industrial wastes. In addition to the chemical toxicity of many of the latter, the production of long‐lived nuclides from nuclear power programmes has introduced additional radiotoxicological hazards. Associated problems of the presence of contaminating, non‐metal co‐pollutants and the presentation of dilute, high‐volume wastes have received little attention.

Traditional biotechnological waste treatments have relied either on the use of non‐living biomass (‘biosorption’) or on the accumulation of metals by living cells with the associated problems of metal toxicity effects and the requirements for cell viability or growth. Identification of an enzymically‐mediated metal accumulation step can permit decoupling of cell growth from metal accumulation. Using pre‐grown biomass immobilized in a flow‐through filter (‘bioreactor’) the metal‐accumulative bioprocess can be described accurately applying traditional Michaelis—Menten kinetics. The effect of copollutants can be then quantified in order to run the bioreactor in the most efficient way.
Amphoterics in household detergents
Authors: Palicka Jadwiga
Published: July 2010

Amphoteric surfactants are widely known for their extreme skin kindness, decreasing the irritation of otherwise irritant surfactants, especially anionics, giving low‐irritant shampoo ingredients.

New high quality amphoteric compounds have been developed. These new amphoterics offer exciting possibilities in several new application areas. Considerable development work has been undertaken to investigate new detergent formulations based on these novel amphoterics.

Because of the very low concentration of Ampholak 7TX, the formulations give most effective products with low biological load. Data concerning the increasingly important subject of biodegradability and toxicity are shown. This includes both primary and inherent biodegradability and toxicity of metabolites.
Developments in sodium perborate
Authors: Walker Michael J.
Published: July 2010

The paper describes the properties of a number of novel variants of sodium perborate bleach suitable for laundry and automatic dish wash detergent formulations, highlighting their advantages over standard commercial products, and offering further opportunities of product differentiation for the detergent manufacturers.
Decreasing effluent pollution by the use of soap‐based building kit detergents
Authors: Hack Jürgen
Published: July 2010

By their nature, detergents create a pollution problem for our inshore waters. Solutions have recently been proposed that could contribute to a lower level of contamination in the effluent. Two aspects are discussed.

The first is to dispense separately major components of detergents such as bleaches and softeners in such a manner that only the quantities required for a specific wash cycle are used.

The second is to select ingredients which are ecologically friendly. For example, as the surfactant, soap is preferred because it is 50 times less toxic to fish than common synthetic materials such as LAS. Soap is completely degraded in the sewage plant, leading to harmless end‐products. ‘Building‐kit system detergents’ can decrease contamination of effluents in a remarkable manner.
Detergency by surfactant/cosurfactant systems
Authors: Krüssmann Helmut , Bercovici Rodica
Published: July 2010

The influence of amphiphilic additives on phase transitions and detergency of nonionic surfactant was examined to solve low temperature detergency problems and to reduce the amount of surfactants necessary to achieve good cleaning results. Optimum detergency correlates to the formation of the lamellar liquid crystalline Lα‐phase and to the intermediate maximum of the phase‐inversion temperature curves. Medium chain alkanols showed as optimum additives which improved low temperature detergency and allowed a reduction of the amount of surfactants necessary. However, fatty acids were not effective, and low degree ethoxylates of fatty alcohols were less effective cosurfactants. The interrelations found could be transferred to solve practical washing problems.
Effect of preparation variables on the activity of Ni‐W/Al2O3 hydrotreating catalysts
Authors: Kural E. , Cant N. W. , Trimm D. L. , Mauchausse C.
Published: July 2010

Studies have been carried out on the influence of preparation parameters on the activity of nickel‐tungsten (Ni‐W) catalysts, used to promote the hydrotreatment of model compounds representative of nitrogen, sulphur, oxygen and aromatic containing compounds which typically occur in coal derived liquids. The preparation variables considered for optimisation were the pH of the impregnating solution, the impregnation order, the starting Ni salts, the Ni/Ni + W ratio, the drying conditions and the calcination temperature.

It was found that changes in pH, within the range where binding of the starting ions to alumina takes place, is not a significant variable influencing the activity. The use of nickel nitrate as a precursor yields better catalysts. If W is impregnated first it is redistributed during subsequent nickel impregnation, and better catalysts are obtained when Ni is impregnated first. The optimum Ni/Ni + W ratio is between 0.3 and 0.4, based on the total active metals present on the catalyst. The hydrodesulphurisation hydrodeoxygenation and hydrogenation activities decrease with increase in the drying temperature; the reverse is true for hydrodenitrogenation. An optimum activity is obtained when drying at 100°C in a closed oven. The optimum calcination temperature was found to be 500°C.
Influence of concentration waves on the fischer—tropsch reaction
Authors: Adesina Adesoji A. , Hudgins Robert R. , Silveston Peter L.
Published: July 2010

Investigation of the hydrocarbon rate formation behaviour during the Fischer—Tropsch synthesis under periodic concentration forcing reveals the existence of resonance peaks for certain choices of cycle parameters. These peaks appeared under symmetrical cycling with a mean feed composition of 17–5% CO (balance H2) at both low (less than 0‐001 cps) and high (greater than 0‐01 cps) frequencies for the alkanes. Although methane was more strongly stimulated under periodic operation than other hydrocarbons, the rate enhancement observed for C2 to C6 products signalled the potential for ‘tuning’ selectivity in this mode of operation.
Enantioselective reduction of 1,2‐diformylferrocene by Bakers' yeast
Authors: Izumi Taeko , Hino Toshimi , Kasahara Akira
Published: July 2010

1,2‐Diformylferrocene was enzymatically and preferentially reduced to ( — )‐ (1S,2R)‐1‐formyl‐2‐hydroxymethylferrocene by bakers' yeast.
Synthesis of some new 7‐substituted aminomethyl‐6‐chloroquinoline‐5,8‐quinones
Authors: Yanni A. S. , Khalil Z. H.
Published: July 2010

Some new 7‐alkyl (or aryl) aminomethyl‐6‐chloroquinoline‐5,8‐quinones (II) have been obtained through the reaction of 6‐chloroquinoline‐5,8‐quinone with primary aliphatic or aromatic amines and paraformaldehyde in ethanol. On using secondary amines such as piperidine or morpholine in the above reaction, 6‐chloro‐7‐piperidino (or morpholino) methylquinoline‐5,8‐quinone (III) and (IV) respectively were obtained. The structure of the synthesised compounds was confirmed by elemental analysis and spectral data. The synthesised compounds were also biologically evaluated.
Application of ion‐exclusion chromatography to alkaline pulping liquors; separation of hydroxy carboxylic acids from inorganic solids
Authors: Alén Raimo , Sjöström Eero , Suominen Seija
Published: July 2010

Hydroxy carboxylic acids were separated from inorganic solids on a pilot‐plant scale by using columns containing a strongly acidic polystyrene cation exchange resin with bed volumes of about 1000 and 200 dm3. The liquor samples were obtained from soda–anthraquinone pulping of pine wood and they were first acidified with sulfuric acid to precipitate most of the lignin and to liberate the hydroxy acids. Under appropriate conditions, using warm water (65°C) as eluent, the liquor sample could be resolved into two distinct fractions consisting mainly of hydroxy acids and sodium sulfate, respectively. This separation method seems promising as a complementary technique in connection with the recovery of aliphatic carboxylic acids from kraft black liquors, although further studies are required to optimize the conditions.
Dialkylphosphonodibromo‐acetates and ‐acetonitriles as potential new biocides
Authors: Direktor David , Effenberger Reinhard
Published: July 2010

The preparation of several alkyl dialkylphosphonodibromoacetates and dialkylphosphonodibromoacetonitriles is described. Some of these materials were shown to possess interesting biocidal characteristics both against single micro‐organisms and against wild type mixed micro‐organisms present in cooling water from a fertiliser plant.
N‐benzyl‐N‐ethylaniline; an alternative synthetic approach
Authors: Ayyangar N. R. , Shinde B. S. , Srinivasan K. V.
Published: July 2010

An alternative one‐pot synthesis of N‐benzyl‐N‐ethylaniline, an important dyestuff intermediate, has been achieved by reductive alkylation of easily available aniline as starting material. The reaction has been extended to the preparation of other substituted N‐benzyl‐N‐ethylanilines. New insights into the mechanism of the reactions have been obtained. A more economical two‐stage process involving reductive ethylation of N‐benzylaniline has been examined.
Continuous annular chromatography for the separation of beet molasses
Authors: Barker P. E. , Bridges S.
Published: July 2010

The continuous separation of a multicomponent feedstock on a rotating annular chromatograph is described. The annulus width was 12 mm, diameter 300 mm and height 1400 mm. The annulus was packed with a 420 micron ion‐exchange resin in the sodium form. The feedstock separated was beet molasses which is the final syrup spun off after repeated crystallisations in the extraction of sugar. Two basic mechanisms were in operation to separate sucrose from impurities: ion exclusion and molecular sieving. A statistical approach was made to set up an experimental programme and analyse the results. Four factors were studied: feed flowrate, feed concentration, annulus rotation rate and eluent rate. Two of these, namely feed rate and eluent rate, significantly affected the response. The response was the separation achieved using the annular chromatograph between the sucrose and non‐sucrose solids. A further series of experiments demonstrated the practical considerations to be made when separating beet molasses. A crystallisable product sucrose rate of 207 gh−1 was achieved.
Synthesis and application of some new heterocyclo‐s‐triazole derivatives as antimicrobial agents
Authors: Awad Ibrahim M. A. , Abdel‐Rahman Abdu‐E‐ , Bakite Etify A.
Published: July 2010

3‐Aryloxymethyl‐4‐amino‐5‐mercapto‐s‐triazoles (1a–c) reacted with alkyl/aralkyl halides to give 5‐alkyl/aralkyl thio‐s‐triazole derivatives (2a–i) and with substituted phenacyl bromides afforded s‐triazolo‐thiadiazines (3a–l). Condensation of 1a–c with aromatic/heterocyclic aldehydes furnished the corresponding schiff bases 4a–r. The latter compounds (4b,h,n) were further reacted according to Mannich reaction affording 5a–f and 6a–c. Moreover, interaction of 4b,h,n with phenacyl bromides yielded the bicyclic compounds 7a–l. Some of these compounds were screened in vitro for their antimicrobial activity against seven strains of bacteria.
Biogas generation from bagasse‐based paper mills by anaerobic digestion
Authors: Prasad Duggirala Yogendra
Published: July 2010

Bagasse‐based paper mills in developing countries do not have sophisticated waste water treatment technology to combat water pollution released by these mills. This paper presents an overview of bagasse handling and sources of waste generation, the seriousness of pollution discharge, and treatment options available to tackle the waste water derived from bagasse‐based paper mills. Extensive laboratory treatability studies indicate that anaerobic digestion for biogas generation is a viable method for handling bagasse‐based paper mill wastes. The waste water was treated at an organic loading of 0.8 kg BOD m−3 day−1 and 1.6 kg COD m−3 day−1 and a detention time of 10 days, achieving 90% reduction in BOD and COD without supplementation of any nutrients. With a yield coefficient of 0.5, the average quantity of cells produced per day was calculated to be 1.683 kg day−1 or 0.25 kg cells produced kg−1 BOD removed. Intermittent checking on excess alkalinity in the anerobic system is necessary for achieving maximum treatment efficiency.
Recovery of rhenium from acidic aqueous solutions by pressure reduction with gaseous reducers
Authors: Charewicz Witold A. , Wódka Jerzy , Chmielewski Tomasz
Published: July 2010

Process of rhenium removal from acidic industrial effluents by pressure reduction with gaseous hydrogen and sulphur dioxide was examined. Solutions from two sources were investigated, namely: circulating wash liquors originated from a wet dedusting of converter gases, and from dedusting of Dörschel furnace gases at a copper smelter. The effects of temperature, sulphuric acid concentration, and addition of an activated charcoal carrier were determined on rhenium recovery. Complete removal of rhenium from the solution has been achieved with both hydrogen and sulphur dioxide and the concentration of rhenium in the resultant concentrate reached 3%. The technological process for recovering rhenium from acidic industrial effluents was suggested.
Continuous ethanol fermentation by immobilized yeast cells in a fluidized‐bed reactor
Authors: Bravo P. , Gonzalez G.
Published: July 2010

Continuous alcoholic fermentation of untreated crude sugar beet molasses has been studied. The process was carried out in a vertical fluidized‐bed reactor with beads of calcium‐alginate containing immobilized Saccharomyces cerevisiae. The influence of hydraulic residence time, concentration of substrate and other variables have been studied.
Microbial hydrocarbon degradation—bioremediation of oil spills
Authors: Atlas Ronald M.
Published: July 2010

Bioremediation has become a major method employed in restoration of oil‐polluted environments that makes use of natural microbial biodegradative activities. Bioremediation of petroleum pollutants overcomes the factors limiting rates of microbial hydrocarbon biodegradation. Often this involves using the enzymatic capabilities of the indigenous hydrocarbon‐degrading microbial populations and modifying environmental factors, particularly concentrations of molecular oxygen, fixed forms of nitrogen, and phosphate to achieve enhanced rates of hydrocarbon biodegradation. Biodegradation of oily sludges and bioremediation of oil‐contaminated sites has been achieved by oxygen addition—e.g., by tilling soils in landfarming and by adding hydrogen peroxide or pumping oxygen into oiled aquifers along with addition of nitrogen‐ and phosphorous‐containing fertilizers. The success of seeding oil spills with microbial preparations is ambiguous. Successful bioremediation of a major marine oil spill has been achieved based upon addition of nitrogen and phosphorus fertilizers.
Use of ilmenite decomposition products in a gas desulphurisation process
Authors: Tilly Jadwiga , Lewicki Marek , Tomaszewski Zbigniew , Toczkowski Jacek
Published: July 2010

It has been found that the diluted post‐hydrolytic acid solutions and the solutions of the waste ferrous sulphate show higher catalytic activity in SO2 oxidation than do standard solutions of ferrous sulphate. It has also been demonstrated that during SO2 absorption, Fe(II) ions are the first to undergo oxidation, followed by SO2 oxidation to H2SO4.
Partial purification and characterization of the cellulases from clostridium cellulolyticum h10
Authors: Madarro Alejo , Peña José L. , Lequerica Juan L. , Vallés Salvador , Gay Robert , Flors Agustí
Published: July 2010

The extracellular cellulolytic complex from Clostridium cellulolyticum H10 has been isolated and partially characterized. Through application of gel filtration and ion exchange chromatography techniques it has been established that in its native state this complex essentially consists of highly stable macromolecular structures (Mr c. 20 000 kDa) (similar to those described for different cellulolytic bacteria and currently termed cellulosomes) exhibiting avicelase, carboxymethylcellulase (CMCase) and xylanase activities. Furthermore, immunoaffinity assays show that this extracellular cellutosomal form of the complex is immunochemically similar to the cell‐associated form.

Another feature of the C. cellulolyticum H10 complex is that the Avicel‐adsorbed fraction consists essentially of three major components, two of them (those of 160–170 and 72 kDa) having no detectable activity and one (that of 95 kDa) being associated with strong CMCase activity.
Kinetic study of urease‐catalysed urea hydrolysis
Authors: Huang Ting‐Chia , Chen Dong‐Hwang
Published: July 2010

The kinetics of the urease‐catalysed hydrolysis of urea in phosphate and citrate buffers have been studied. The effects of urease concentration, substrate concentration, pH and temperature of solutions, and particularly the concentrations of buffers and product on the reaction rate of urea hydrolysis have been examined. The activation energies in two buffer systems indicate that the reaction mechanism catalysed by urease may be the same in each case. A substrate inhibition model has been developed that describes the effect of substrate concentration ranging from 0.001 to 4 mol dm−3. The experimental data indicated that the inhibition of urease by phosphate is of partially mixed type, whilst that by citrate is uncompetitive. In contrast ammonium ions exhibited no significant influence on the rate of urea hydrolysis by urease.
The optimum taper angle for ethanol fermentation in a packed‐bed column reactor
Authors: Colak Teslime , Hamamci Haluk
Published: July 2010

In ethanol fermentation, tapered columns facilitate the liberation of CO2 and, since the bed expands through a larger cross‐sectional area, smaller pressure drops occur. In this work, 0°, 2°, and 4° tapered columns, containing Saccharomyces cerevisiae entrapped in beads of K‐carrageenan, were operated for continuous production of ethanol from glucose. The column inlet diameters and the bead volume were maintained constant for the three columns. With decreasing taper angle, increasing feed glucose concentration, increasing feed flow rate and increasing bead volume in the reactor, the pressure drop across the bed increased. There was no significant difference between the ethanol productivities obtained in the 0°, 2°, and 4° tapered columns when a packed volume of 52% of the total volume was examined. Increasing the packed volume to 84% of the total caused the cylindrical column to become inoperable due to pressure buildup and bead compression. When the columns were packed to 84% capacity, the productivity and pressure drop values obtained on the 2° and 4° tapered columns did not significantly differ. For a feed concentration of 150 g glucose dm−3 and a residence time range of 5.4–15.94 h, the pressure drop varied between 4.5 × 103 and 1.28 × 104 Pa in the 2° and between 4 × 103 and 7.98 × 103 Pa in the 4° tapered column. Conversion in the 2° tapered column varied from 94% to 78.8% and in the 4° tapered column from 92.6% to 78.8%. Defining optimum taper angle as the smallest angle which allows for stable operation without any pressure buildup, the taper angle of 2° was selected as nearest to the optimum value.
A diffuse reflectance fourier transform infra‐red study of carbon dioxide adsorption on silicalite‐I
Authors: Llewellyn Philip L. , Theocharis Charis R.
Published: July 2010

The adsorption of carbon dioxide at room temperature on large, well‐defined crystals of Silicalite‐I was studied by diffuse reflectance Fourier transfer infra‐red spectroscopy. The zeolite samples had a mean crystal size of 180 μm, and a narrow particle size distribution. The results show a displacement of the 1390 cm−1 Si‐O‐Si stretch‐bend peak on adsorption/desorption of guests in the channels. The progress of carbon dioxide adsorption was followed by the 2331 cm−1 band; adsorption of the gas on a sample which already had n‐hexane as a guest in the zeolitic channels led to an initial suppression of the peaks due to the alkane, but the peaks reappeared on standing. This was interpreted as signalling the adsorption of both species within the channel system rather than on the external surface of the sample.
Palladium‐based diffusion membranes as catalysts in ethylene hydrogenation
Authors: Al‐Shammary A. F. Y. , Caga I. T. , Winterbottom J. M. , Tata A. Y. , Harris I. R.
Published: July 2010

Pd‐23 at% Ag and Pd‐7.8 at% Y hydrogen‐diffusion membranes were (1) prepared by argon‐arc melting of the constituent elements, (2) characterised, (3) examined for hydrogen permeation and (4) used as catalysts in ethylene hydrogenation reactions. Ethylene was self‐hydrogenated on the membrane surfaces in the absence of permeate hydrogen. The hydrogenation with and/or without the permeate hydrogen was carried out in the temperature range 100–450°C at ethylene pressures of 1.0–1.5 bars and differential pressures across the membrane in the range 1.0–6.8 bars. Mainly C1‐C4 hydrocarbons and up to 60% conversion of ethylene to products were obtained.
The Extraction of Penicillin G with Aliphatic Amines in Organic Solvents of Different Polarities
Authors: Yang Zhi‐Fa , Yu Shu‐Qiu , Chen Jia‐Yong (Chia‐Yung)
Published: July 2010

The equilibrium constants of the extraction, the molar ratios of amines to penicillin G in the extract and the bonding structures of the extracted species were studied with chemical analysis and the absorbance shift of FT‐IR spectra of the functional groups in penicillin G. Extraction of penicillin G from the filtrate of fermentation broth indicates that amines will be difficult to use as the industrial solvent for the production of penicillin G because of the poor quality of the final crystalline product obtained and the difficulties involved in the stripping and solvent recovery.
Studies on the removal of Cr(VI) from waste‐water by feldspar
Authors: Singh Dhirendra B. , Rupainwar Dinesh C. , Prasad Gur
Published: July 2010

The efficacy of feldspar in the removal of Cr(VI) from representative waste‐water from a plating industry has been investigated in a completely mixed batch reactor at different concentrations, rate of agitation and particle size. The data obey the Langmuir isotherm for the present system and the process of uptake follows first‐order kinetics. The maximum removal (91%) was observed at 40°C and pH 2.5 with initial concentration of 19.23 μmol dm−3 Cr(VI) and 40 g dm−3 feldspar. The process involves both film and pore diffusion to different extents. Column studies have also been carried out using a certain concentration of waste‐water. More than 92% recovery has been achieved and the column can be used for 10 cycles before regeneration. The present technique seems to be quite attractive.
Production of concentrated Bifidobacterium bifidum
Authors: Corre Christian , Madec Marie‐Noëlle , Boyaval Patrick
Published: July 2010

A low‐cost medium was developed to produce expensive dairy starter cultures easily and economically. Concentrated suspensions of Bifidobacterium bifidum were obtained in a continuous process using a continuous stirred tank reactor coupled to an ultrafiltration device in non‐anaerobic conditions. Bacterial productivity of 2 × 108 organisms cm−3 h−1 were achieved using a whey‐based medium, a 15‐fold improvement on batch productivity. The starter culture suspensions could be stored at 4°C or frozen without washing, or with the addition of cryoprotective media, with maintenance of high viability.
Optimisation of the alkaline peroxide pretreatment for the delignification of rice straw and its applications
Authors: Patel Meenoti M. , Bhatt Ranjan M.
Published: July 2010

Alkaline peroxide pretreatment for the delignification of rice straw was optimised by varying the concentrations of H2O2 and NaOH and changing the temperature and duration of the pretreatment. Changes in the lignin content, content of total carbohydrates and weight loss were measured during the pretreatments. Maximum delignification of 62% was obtained by pretreating rice straw at 50°C for 5h with 1.5% (w/v) NaOH and 1% (v/v) H2O2, The preferential loss of hemicellulose and lignin from the straw resulted in an increase in the cellulose content of the insoluble residue after pretreatment from 47% (untreated) to 67.79% (treated).

The product of this treatment is characterised by having higher cellulose digestibility than untreated rice straw. It also has use as a carbohydrate source in ruminant feed since the in‐vivo digestibility by the cow increased from 56.85 % to 76.54% (P < 0.001). The treated rice straw could also be used for commercial process such as the generation of Single Cell Protein. Growth of Sporotrichum pulverulentum on treated rice straw gave a protein product of 24.41 % as compared to 3.8% on untreated rice straw.
Properties of β‐fructosidases (invertases and inulinases) of Fusarium oxysporum grown on an aqueous extract of Cichorium intybus roots
Authors: Kaur Narinder , Kaur Maninder , Gupta Anil K. , Singh Rangil
Published: July 2010

Four different forms of invertase and inulinase named as Invertase, I, II, III, IV and inulinase I, II, III, IV were purified from a culture filtrate of Fusarium oxysporum, grown on a fructan containing medium, by ammonium sulphate fractionation, gel permeation and ion exchange chromatography. Invertases had a higher optimum temperature (55–60°C) as compared to that of inulinases (35–45°C). Of sucrose, raffinose, stachyose and inulin, sucrose was the best substrate for all the four invertases and none of the invertases showed activity with inulin. Inulinases showed maximum activity with inulin. The optimum pH of invertase I and II was 5.5 whereas invertase III and IV showed a maximum activity at pH 4.0. Inulinases I, II, III and IV had an optimum pH of 5.5, 5.5, 6.0 and 6.5, respectively. The thermal stability of invertases was in the order of invertase III > IV > II > I. Inulinase II was more stable than inulinase I whereas inulinase III and IV were the least stable. Inulinases showed a low Km in the range of 10–95 μmol dm−3 of inulin, thereby showing their high affinity for inulin. Km for invertases varied from 2 mmol dm−3 to 4 mmol dm−3 of sucrose. HgCl2 and CuSO4 were found to be strong inhibitors for both invertases and inulinases.
Synthesis and antibacterial activity of certain quinoline and quinazoline derivatives containing sulfide and sulfone moieties
Authors: El‐Zohry Maher F. , Ahmed Abd El‐Hamed N. , Omar Farghaly A. , Abd‐Alla Mohamed A.
Published: July 2010

Some aryl and/or heterocyclic mercaptans were allowed to react with 8‐quinolyl chloroacetate (II), 8‐quinolinoxyacetyl chloride (IV) and 3‐(2′‐chloroethyl)‐2‐methyl‐3,4‐dihydroquinazolin‐4‐one (X) in dry benzene and/or sodium hydroxide in absolute ethanol to give corresponding 8‐quinolyl‐α‐mercaptoacetate (V), 8‐quinolinoxythioacetate (VI) and 3‐(2′‐arylmercaptoethyl)‐2‐methyl‐4‐(3H)quinazolin‐4‐ones or 3‐(2′‐heterocyclicmercaptoethyl)‐2‐methyl‐4(3H)‐quinazolin‐4‐ones (XIa‐h). The mercaptans V and XI were subjected to oxidation with hydrogen peroxide/acetic acid mixture (1:2) to afford the corresponding sulfones VII and XII. The structures of the synthesized compounds were elucidated by spectroscopic (IR and 1H‐NMR) and elemental analyses.

Some of these compounds were tested for their antimicrobial activities in comparison with tetracycline as a reference compound.
Application of a recycle dialysis system in a reversed micellar reactor
Authors: Chiang Chen‐Li , Tsai Shau‐Wei
Published: July 2010

A recycle dialysis stirred cell has been successfully used for integrating the reaction and product recovery of the lipase‐catalyzed hydrolysis of olive oil in bis (2‐ethylhexyl) sodium sulfosuccinate (AOT)‐iso‐octane reversed micelles. The resistance of membrane to reversed micelles was monitored by the water content and found to be 95.9% rejection after 24 h and 93.4% rejection after 48 h. The resistance of the membrane to free surfactants, by monitoring the UV absorption, was found to be 98.5% rejection after 10 h and 97.3% rejection after 24 h. Mathematical formulations involving the enzymatic reaction coupled with mass transfer were developed for predicting the performance of a membrane reactor. Theoretical predictions in terms of time course of oleic acid concentrations were found to be in agreement with the experimental results.
Water soluble imide—amide copolymers: Iv. Flocculation and surface active properties of poly(acrylamide‐co‐sodium N‐(4‐sulfophenyl)maleimide)
Authors: Hocking Martin B. , Syme David T. , Axelson David E.
Published: July 2010

Six new poly(acrylamide‐co‐sodium N‐(4‐sulfophenyl)maleimide) (PAMSM) water‐soluble copolymers have been prepared with several levels of imide ring incorporation into the backbone of the polymer chain to test the effectiveness of increased chain stiffness on the efficiency of fiocculation. Sufficient material was obtained from the synthetic experiments to enable the surface active properties of three of these copolymers to be tested.

PAMSM copolymers containing 7, 15, and 25 mol % imide performed poorly compared to commercial partially hydrolyzed polyacrylamides (HPAM) when used to flocculate an aqueous 3% calcium‐montmorillonite suspension at pH 4·0 and pH 7·5. This was probably because of a major difference between the dissociation constants of the anionic functionalities of the new vs existing commercial polymer flocculants, complicated by the possibility that the molecular weights of the new copolymers were too low.

The three PAMSM copolymers behaved as dispersants instead of flocculants when tested on a 3% kaolinite suspension in water at pH 4·5. Their effectiveness as dispersants increased with increasing imide content.

PAMSM‐1a (7% imide), PAMSM‐3 (25% imide) and polystyrene sulfonate (500 000 mol. wt) all acted as weak dispersants when tested on a 3% hematite suspension in water at pH 4·5, 6–0, and 8·7.
Surface properties of aluminium hydroxide gels prepared from pure and mixed aqueous, ethanolic and acetonic media
Authors: Stalidis George A. , Bakoyannakis Demetris N. , Zamboulis Demetris X.
Published: July 2010

This work deals with the preparation of aluminium hydroxide gels by precipitation from pure and mixed solvents in the presence of propylamine acting as proton acceptor in the hydrolysis reaction. As solvents were used water, ethanol and 50% v/v water‐ethanol and water‐acetone mixtures. Pure acetone could not be used because the aluminium salt used (AlCl3.6H2O) was not sufficiently soluble in it. The samples were freeze‐dried and activated to temperatures up to 773 K. The samples prepared from aqueous solutions showed the structure of poorly crystallized pseudoboehmite, while the sample prepared from pure ethanol was nearly amorphous and presented the highest specific surface area of all the samples (570 m2 g−1 for thermal activation at 473 K). The sample prepared from aqueous acetone exhibited the highest porosity (about 4 cm3 g−1) consisting of pores of nearly uniform size. This porosity remained almost constant throughout the range of thermal activation temperatures.
Effective diffusion coefficient of chloride in porous concrete
Authors: Lin Sheng H.
Published: July 2010

A simplified diffusion model is given in the present paper to represent the chloride diffusion in porous concrete. The model with appropriate effective diffusion coefficient is shown to represent equally well as the more complex diffusion/reaction model proposed by Pereira and Hegedus.4 However the present model has the main advantages of being amenable to an analytic solution and ease of model parameter estimation.
Cyclic voltammetric behaviour and some surface characteristics of the lead electrode in aqueous NaBr solutions
Authors: El‐Halim A. M. Abd , Fawzy M. H. , Saty A.
Published: July 2010

The anodic behaviour of the lead electrode in aqueous 0.05–3.00 M NaBr solutions was investigated by means of linear sweep voltammetry. The voltammograms showed one anodic peak current density (jap) corresponding to the formation of a thin passivating layer of PbBr2. The obtained data depicted a gradual increase of jap and shifting of the corresponding potential (Eap) to more negative values with increase of CNaBr.

A detailed study of the formation/reduction of PbBr2 on the surface of lead electrodes in aqueous 0.10–1.00 M NaBr solution was carried out by cyclic voltammetry. The results indicated that the formation of PbBr2 is controlled by diffusion of Br− ions to the anode surface. Irrespective the voltammetric conditions, the study proved that the formation/reduction of the PbBr2 surface layer is a reversible process. The role played by the operating voltammetric conditions in the building up of a relatively thick PbBr2 surface layer that could resist rupture and/or breakdown is discussed.

The as‐formed PbBr2 layers were examined by scanning electron microscopy and X‐ray diffractometry. The microstructure showed some morphological modifications which could be correlated to the operating conditions. On the other hand, X‐ray diffiaction analysis proved that, under all conditions, the anodic surface products consist solely of PbBr2 in the orthorhombic crystalline structure.
Bubble column fermentation of olive mill wastewaters by Aspergillus niger
Authors: Hamdi Moktar , Ellouz Radhouane
Published: July 2010

A bubble column (tower) fermenter was used to study the growth of Aspergillus niger on olive mill wastewaters (OMW). The gas hold‐up, mixing time and oxygen transfer coefficient values were studied in terms of superficial air velocity. These characteristics were clearly affected by OMW. The growth of A. niger resulted in a filamentous suspension with no pellet formation and the specific growth rate was 0–2 h−1. The growth rate was limited by the oxygen transfer rate at 90 mmol dm−3 h−1 when pO2 was lower than 2%.
Studies on the synthesis of SAPO‐5
Authors: Bhattacharya Anjana , Das Jagannath , Mitra Swapan , Roy Sisir K.
Published: July 2010

Silicoaluminophosphate (SAPO‐5) molecular sieves have been synthesised from reaction mixtures having a molar composition of: 0.7–1.0 Al2O3:0.7–1.0 P2O5:0.01–2.0 SiO2:xR:40 H2O (where R = (C2H3)3N or (C2H3)4NOH and x = 1.5–2.5 for (C2H5)5N and 0.5 for (C2H5)4NOH, at 473 K using various sources of alumina and silica. The effects of (i) varying the crystallinity of the alumina source (boehmite) and (ii) the use of different silica sources such as freshly prepared silica either from sodium silicate or paddy husk extract, silica gel from commercial water‐glass, and tetraethyl orthosilicate have been studied. The crystallinity of boehmite has been found to have a strong effect on its reactivity towards the formation of SAPO‐5. The activity of boehmite for SAPO‐5 formation increased with a decrease in its crystallinity (or with increase in its moisture content). Any silica source devoid of sodium ions could be employed for the synthesis of SAPO‐5. The process of crystallisation started as early as within 1.5 h of reaction and incorporation of silicon into the AlPO4 framework has been noted at this stage. Formation of some tridymite phase as impurity has been observed under conditions such as (i) SiO2 concentration > 1.7 mole and (ii) x > 2.0 when R = (C2H5)3N.
Kinetics of wine spoilage by acetic acid bacteria
Authors: Kösebalaban F. , Özilgen M.
Published: July 2010

Acid production in wines inoculated with acetic acid bacteria from vinegar was studied at 15°C, 20°C, 25°C and 30°C and simulated with kinetic models. Results indicated that major wine spoilage did not occur during the growth of the microorganisms, but during their extended presence at high concentrations during the stationary and death phases. Acetophilic species were observed to resist death, which is in agreement with the mechanism suggested by Kittelmann et al.9 for the development of gradual acid tolerance by acetic acid bacteria.
Local mass transfer measurements from a submerged jet parallel to a flat surface
Authors: Krishna P. Gopala , Das S. C. , Subbaiah T. , Das R. P.
Published: July 2010

The local mass transfer rates from a submerged vertical jet parallel to the vertical electrode surface were measured by a limiting current density technique. For these studies, the parameters considered are a plate Reynolds number in the range of 1965 to 136500, electrode height over the orifice of the jet (Y) which varied from 0 to 12 times the jet orifice diameter (d), and the vertical distance of the microelectrode on the electrode plate in the range of 0.7 to 12.5 cm. The system used for measuring the limiting current was the reduction of copper ions. The relationship between the local Sherwood number (Sh) and Reynolds number (Re) was found to be Sh = 0.0004(Re)1.5 (Sc)0.33

This relationship is valid for Y/d ≤ 6.0.
Kinetics and mechanism of homogeneous catalytic hydroxylation of maleic acid by hydrogen peroxide. Part II: Analysis of material balance conformities and the mathematical model
Authors: Oludipe John O. , Koiki Kolawole K. , Litvintsev Igor Yu. , Sapunov Valentin N.
Published: July 2010

The general kinetic laws relating the changes in reactants and products ratios with changes in the operating conditions of the catalytic epoxidation and hydroxylation reaction of maleic acid by hydrogen peroxide have been analyzed. In the course of the hydroxylation reaction, the formation of epoxysuccinic and tartaric acids, and the decomposition of hydrogen peroxide to molecular oxygen have been observed to take place in parallel. The catalytic complex (Cat.2H2T) formed between sodium tungstate (catalyst) and tartaric acid in the course of the reaction is found to be inactive in the epoxidation reaction but active in the catalysis of the decomposition of hydrogen peroxide. This fact explains the non‐formation of tartaric acid at high maleic acid conversion. The mathematical model for the overall process has been developed.
Electrolytic removal of cupric ions from dilute liquors using reticulated vitreous carbon cathodes
Authors: Walsh Frank C. , Pletcher Derek , Whyte Ian , Millington J. Peter
Published: July 2010

The performance of a divided laboratory reactor, which utilises a 5.0 cm × 5.0 cm × 1.2 cm RVC cathode, is examined for copper removal from 0.5 m Na2SO4 solutions at pH 2 under potentiostatic, mass transport controlled conditions. The practical values of kLAe (the product of averaged mass transfer coefficient and cathode area per unit electrode volume) are shown to depend upon the grade of RVC and the electrolyte velocity. The presence of dissolved oxygen decreases the current efficiency but the effect may be minimised by careful choice of the cathode potential. For the 100 ppi material, kLAe values of up to 0.23 s−1 were realised. Even in air saturated solutions, the overall current efficiency was as high as 69% during the reduction of a 10 ppm cupric ion level to less than 0.1 ppm. Normalised space velocity values were in the range 50‐450 m3 m−3 h−1 while the normalised volumetric power consumption was 1.3‐6.4 kW m−3.
Distribution of an enzyme in porous polymer beads
Authors: Ampon Kamaruzaman
Published: July 2010

Trypsin has been immobilized by adsorption onto Amberlite XAD‐7 beads. The Michaelis constant (Km) of the enzyme was increased about sevenfold following the immobilization. Its rate of penetration into the porous beads was determined by staining the beads, which had been split, with naphthol blue black. The extent of diffusional rate limitation of immobilized trypsin was related to the penetration depth of the enzyme into the beads. This can be controlled by manipulating the conditions during the preparation of the immobilized enzyme.
A study on the removal of urea from aqueous solution with immobilized urease and electrodialysis
Authors: Huang Ting‐Chia , Chen Dong‐Hwang
Published: July 2010

A five‐compartment electrodialyzer with immobilized urease was developed for the removal of urea from aqueous solution. The immobilized urease, supported on polyurethane foam, was placed in the central (dilute) compartment, where urea was hydrolyzed and the products NH4+ and CO32‐/HCO3− were removed simultaneously by electrodialysis. The system was studied both under constant current and under constant voltage. The effects of urea concentration and applied current or voltage on the removal of urea and ammonium ions from the dilute solution were investigated. The variations of the pH of dilute solution, the current or voltage of system, and current efficiency were also examined during reaction‐electrodialysis. The removal of urea by enzymic reaction was not affected significantly by the applied electric field. The current effieiencies for removing ammonium ions from dilute solution were mostly within 40‐80%, and the removal percentage of ammonium ions was dependent on current density and current efficiency.
Oxygen utilisation by isopenicillin n synthase from penicillium chrysogenum
Authors: Bainbridge Zoë A. , Scott Robert I. , Perry David
Published: July 2010

The enzyme isopenicillin N synthase (IPNS) converts δ‐(L‐α‐aminoadipyl)‐L‐cysteinyl‐D‐valine (ACV) to isopenicillin N; an equimolar amount of oxygen is used in this oxidative ring closure reaction. Oxygen uptake rates of the reaction catalysed by partially purified IPNS from Penicillium chrysogenum SC 6140 and P2 were measured using an oxygen electrode. In contrast to published properties of Cephalosporium acremonium IPNS, the enzyme from P. chrysogenum was not stimulated by the addition of glutathione and showed reduced stimulation by Fe2+. The analysis of oxygen uptake rates showed the reaction to be first order with respect to oxygen concentration and the Km for ACV to be 0·4 mmol dm−3. The implications of these results for cell‐free reactions using this enzyme and penicillin fermentations are discussed.
Pore diffusion: Dependence of the effective diffusivity on the initial sorbate concentration in single and multisolute batch adsorption systems
Authors: Al‐Duri Bushra , McKay Gordon
Published: July 2010

The present work studies the intraparticle diffusivity in batch adsorption systems as a function of the initial sorbate concentration. The systems under investigation are basic dyes, namely Basic Blue 69, Basic Red 22 and Basic Yellow 21 and their binary and ternary combinations, all adsorbing onto activated carbon Filtrasorb 400. They study is based on the film‐pore diffusion model and the output is a combination of the external mass transfer coefficient, kf and the effective diffusivity, Deff that yields congruent experimental and theoretical kinetic data.

It has been found the Deff varies with Co in an exponential decay function. Furthermore. Deff values undergo a general reduction in the multisolute systems compared to the single component systems. Also, the relative diffusion rates in the multisolute systems are found to change such that Deff of the slower diffuser is enhanced and that Deff of the faster diffuser is inhibited.
Treatment of carpet and metallic effluents by China clay
Authors: Gupta Ghan S. , Singh Arun K. , Tyagi Balbir S. , Prasad Gur , Singh Vishwa N.
Published: July 2010

This paper addresses the treatment of carpet and metallic effluents containing some popular chrome dyes, i.e. Omega Chrome Red ME (CI 18735), Metomega Chrome Orange GL and Omega Chrome Fast Blue B (C.I. 16680) and heavy metals, i.e. iron, zinc and manganese by adsorption on china clay. China clay exhibits a good affinity for Metomega Chrome Orange GL and zinc, significant uptake of Omega Chrome Red ME, manganese and iron but a poor scavenger for Omega Chrome Fast Blue B. High removal of the above pollutants has been noted at low initial concentration. The process of uptake follows a first order adsorption rate expression and obeys Langmuir's model of adsorption. The removal process has also been found to be partially diffusion controlled and mass transfer coefficients have been determined to explain the results. The effect of temperature on the removal of adsorbates has also been studied. Acidic pH has been found to be more effective in the case of dyes and iron while in the case of zinc and manganese a basic pH around 8·0 has showed appreciable results. The effect of pH has been discussed incorporating various surface site reactions.
Continuous ethanol fermentation using immobilized yeast in a fluidized bed reactor
Authors: Nguyen Van T. , Shieh Wen K.
Published: July 2010

Continuous ethanol fermentation of glucose using fluidized bed technology was studied. Saccharomyces cerevisiae were immobilized and retained on porous microcarriers. Over two‐thirds of the total reactor yeast cell mass was immobilized. Ethanol productivity was examined as dilution rate was varied, keeping all other experimental parameters constant.

Ethanol yield remained high at an average of 0.36 g ethanol g−1 glucose (71% of theoretical yield) as the dilution rate was increased stepwise from 0.04 h−1 to 0.14 h−1. At a dilution rate of 0.15 h−1, the ethanol yield steeply declined to 0.22 g ethanol g−1 glucose (44% of theoretical yield). The low maximum percentage of theoretical yield is primarily due to an extended mean cell residence time, and possibly due to the inhibitory effect of a high dissolved carbon dioxide concentration, enhanced by the probable intermittent levels of low pH in the reactor.

Constant ethanol production was possible at a high glucose loading rate of 840 g dm−3 day−1 (attained at a dilution rate of 0.14 h−1). Although the highest average ethanol concentration (97.14 g dm−3) occurred at the initial dilution rate of 0.04 h−1, the peak average ethanol production rate (2.87 g (g yeast)−1 day−1) was reached at a greater dilution rate of 0.11 h‐1. Thus, the optimal dilution rate was determined to be between 0.11 h−1 and 0.14 h−1.

Ethanol inhibition on yeast cells was absent in the reactor at average bulk‐liquid ethanol concentrations as high as 97.14 g dm−3. In addition, zero‐order kinetics on ethanol production and glucose utilization was evident.
s‐Triazole systems. Part IV: Novel substituted thio‐s‐triazole derivatives
Authors: Awad Ibrahim M. A. , Bakhite Etify A. , Abdel‐Rahman Abdu E.
Published: July 2010

Interaction of (3‐aryloxymethyl‐4‐phenyl‐striazol‐5‐yl)thioacethydraz‐ide (la‐c) with phenyl isocyanate and/or with methyl/phenyl isothiocyanate gave semicarbazides (2a‐c) and thiosemicarbazides (3a‐f) respectively. Cyclization of (3a‐f) yielded s‐triazoles (4a‐f). Compounds 4b,d,f were easily alkylated giving S‐substituted thio‐s‐triazoles (5a‐e). Furthermore, compounds 4b,d,f underwent a Mannich reaction to give the expected Mannich bases (6a‐f). All compounds were fully confirmed by elemental and spectral analyses and have been screened in vitro, for antimicrobial activity.