bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of pyrazolo[4′,3′:5,6]pyrido[1,2‐a]benzimidazole derivatives and study of their fluorescence properties
Authors: Rajadhyaksha D. D. , Rangnekar D. W. 
Published: July 2010

AbstractSynthesis of pyrazolo[4′,3′ :‐5,6′pyrido]1,2‐a benzimidazoles was achieved by the condensation of 1‐chloro‐2‐formyl‐3‐methyl pyrido[1,2‐a]benzimidazole‐4‐carbonitrile and 1‐chloro‐3‐methyl pyrido[1,2‐a]benzimidazole‐2,4‐dicarbonitrile with hydrazine hydrate and phenyl hydrazine. The fluorescence properties of the resulting compounds were studied. Some of the compounds when applied on polyester fibres as fluorescent brighteners gave excellent results.
The use of the F.p.l.c.R system in method development and process monitoring for industrial protein chromatography
Authors: Low D. K. R. 
Published: July 2010

AbstractThe f.p.l.c.R for high performance biomolecular purification is now widely used in laboratory and pilot scale separations, both as a means of developing new methods for purification and for analysing the purity of intermediary and final products. The speed of the technique means that it is possible to analyse fractions from a process step and to receive the results within 15–30 min. Two aspects are examined in this paper: the monitoring of protein product formation during fermentation and the analysis of fractions in large scale chromatography. The suitability of the technique in an operating process is discussed.
New electrochemical techniques applied to medicine and biology
Authors: Frew J. E. , Green M. J. , Hill H. A. O. 
Published: July 2010

AbstractRapid and reversible protein‐electrode interaction has been achieved through the appropriate design of electrode surfaces and choice of electrolyte conditions. This enabled the direct (unmediated) electrochemistry of redox proteins at a range of electrode materials to be examined. Coupling of the electrode reaction to enzymes, for which the redox proteins act as cofactors, extended the study to systems of biological significance. Electrochemical techniques are finding increasing application in clinical analysis and a new type of amperometric enzyme electrode has been devised which exploits ferrocene derivatives as mediators between enzyme and electrode. The synthesis of ferrocene‐drug conjugates permitted the development of an amperometric immunoelectrode.
Characteristics of the pH‐influenced adaptation of methanogenic sludge to ammonium toxicity
Authors: Koster Iman W. 
Published: July 2010

AbstractIncreasing ammonium‐nitrogen concentrations caused failure of methanogenesis at 1900‐2000 mg dm−3. After an adaptation period characterised by an almost nil methane production, methanogenesis appeared to be possible at even higher concentrations. A kinetic analysis of methane production during the adaptation process indicated that the adaptation was the result of a metabolic change in the methanogenic bacteria already present, rather than of growth of new bacteria. A high pH value causing toxic concentrations of un‐ionised ammonia during the adaptation period appeared to result in a decreased maximum specific methanogenic activity of the adapted sludge. A low pH value during the adaptation period resulted in a retarded degradation of propionic acid, probably due to inhibition of the hydrogen consuming methanogenic bacteria by undissociated volatile fatty acids, but this did not result in a decreased maximum specific methanogenic activity in the adapted sludge. The maximum specific methanogenic activity at an ammonium‐nitrogen concentration of 2315 mg dm−3 after adaptation as a percentage of that at 1000 mg dm−3 before adaptation was 31, 65 and 61% for a pH during the adaptation period of 7.6, 7.25 and 7.0 respectively. Except for the sludge which was maintained at pH 7.6 during the adaptation period, after adaptation the maximum specific methanogenic activity at an ammonium‐nitrogen concentration of 2315 mg dm−3 was higher than the maximum specific methanogenic activity at an ammonium nitrogen concentration of 1900 mg dm−3 before adaptation.
Liquid phase oxidation of acetophenone to phenylglyoxal by selenium dioxide alone or with aqueous nitric acid
Authors: Sharma Virendra K. , Chandalia Sampatraj B. 
Published: July 2010

AbstractThe liquid phase oxidation of acetophenone to phenylglyoxal using selenium dioxide was carried out at 90°C in dioxane or ethyl alcohol with 10% (v/v) of water as a solvent with a 2:1 molar ratio of acetophenone to selenium dioxide. The yield of phenylglyoxal was more than 98% based on acetophenone and the efficiency of utilisation of selenium dioxide was as high as 99%. A novel process version based on the oxidation of acetophenone by aqueous nitric acid in the presence of selenium dioxide as a selective catalyst in a redox cycle was also considered with a view to changing the use of selenium dioxide as a stoichiometric oxidising agent to that of a catalyst, and it was found to be attractive.
Synthesis, spectral behaviour and application of oxazolo/imidazolo pyrimidine cyanines
Authors: Koraiem A. I. M. , Khalil Z. H. , Abu El‐Hamed R. M. 
Published: July 2010

AbstractNew asymmetrical 2‐monomethine cyanine dyes (IIIa—d, IVa—c) and dicationic cyanines(VIIa,b) incorporating oxazolo/imidazolo(3,4‐d)pyrimidine were prepared. The new cyanines were identified by spectral determination. The applications of these dyes in the protometric titrations of acids and bases were investigated. Bactericidal and fungicidal activity of selected cyanines (Ia, IIa, b, IIIb, IVb, c, V, VI and VIIb) was tested.
n‐octane dehydrocyclisation on monofunctional and bifunctional Pt/Al2O3 catalyst
Authors: Ako Churchill T. , Susu Alfred A. 
Published: July 2010

AbstractThe dehydrocyclisation of n‐octane to iso‐octane, ethylbenzene and o‐, m‐ and p‐xylene was investigated on monofunctional (non‐acidic) and bifunctional (acidic) Pt/Al2O3 catalyst in a microcatalytic reactor with hydrogen as carrier at 1.8 atm and 563–673 K. On bifunctional Pt/Al2O3, the total conversion of n‐octane started from a high value and decreased with increasing temperature for all pulse sizes investigated. The primary product of n‐octane conversion on acidic Pt/Al2O3 was iso‐octane. The product yield‐temperature profiles showed a large initial production of iso‐octane which decreased to a minimum as the catalyst temperature increased due to its conversion to ethylbenzene and o‐xylene. On non‐acidic Pt/Al2O3, the total conversion of n‐octane increased initially and then went through a maximum as the catalyst temperature increased. The primary products of the reaction were found to be ethylbenzene and o‐xylene, indicative of the activity of the metal to effect these ring closure reactions.
Removal of ethene to very low concentrations by immobilised mycobacterium E3
Authors: Van Ginkel C. G. , Welten H. G. J. , De Bont J. A. M. , Boerrigter H. A. M. 
Published: July 2010

AbstractRemoval of ethene to concentrations below 1 vpm from the air in storage facilities is necessary to prevent the deterioration of stored fruits, vegetables and flowers. Ethene‐utilising Mycobacterium E3 organisms are able to oxidise ethene to these low concentrations. Ethene was oxidised at the same rate by organisms immobilised on lava or perlite as it was by the suspension of cells. The residence times in a gas/solid bioreactor necessary to convert 66% of the ethene with an initial concentration of 3.2 vpm, and with cell loads on lava of 0.72 or 0.36 mg protein g−1 support, were 15 s and 33 s respectively. Mycobacterium E3 organisms immobilised on lava lost half of their activity in 250 h while organisms immobilised on perlite lost half of their activity in 60 h. Although the operational stability of the biocatalyst should be improved and the biocatalyst is only suitable at temperatures above 10°C, the application of ethene‐utilising bacteria in a gas/solid bioreactor appears attractive.
Preparation and study of functionalized polymers containing pendent pesticide‐active groups
Authors: Akelah A. , Hassanein M. , Selim A. , Rehab A. 
Published: July 2010

AbstractA number of pesticide monomers containing pentachlorophenol as active group attached to vinyl groups, through oxyethylene as spacer group, have been prepared. The resulting monomers were homopolymerized under free‐radical conditions and also copolymerized with styrene and 2‐(2‐hydroxyethoxy)ethyl methacrylate to introduce hydrophobic and hydrophilic nature to the resulting polymers. In addition, crosslinked copolymers were prepared by using different ratios of divinylbenzene.Data on the pentachlorophenol released through hydrolysis show that the degree of crosslinking, the hydrophilicity and the spacer group, as determined by the chemical structure and the polymer composition, as well as the pH, time and temperature appear to be major factors governing the rate at which a given polymer undergoes hydrolysis.
Analysis of gas absorption accompanied by a zero‐order chemical reaction in a liquid‐foam film surrounded by limited gas pockets
Authors: Bhaskarwar Ashok N. 
Published: July 2010

AbstractGas absorption accompanied by a zero‐order chemical reaction in a finite liquid‐foam film has been analysed to obtain expressions for the amount of gas absorbed and for fractional absorption in such a film. These equations may be readily incorporated into a single‐stage model of a foam‐bed reactor to extend it to chemisorption with zero‐order kinetics. The equations for physical absorption result naturally from a special case.
The removal of heavy metals in anaerobic upflow sludge blanket reactors
Authors: Mehrotra I. , Alibhai K. R. K. , Forster C. F. 
Published: July 2010

AbstractThe continuous removal of heavy metals by the biological solids in an anaerobic reactor has been examined. The metals used were chromium (III), zinc and lead. Both competitive and non‐competitive removal was studied. The results were evaluated in terms of adsorption isotherms and were compared with earlier batch studies. This suggested that the sludge acted as a cation‐exchange material, with chromium having a much lower binding intensity than lead and zinc. The data also suggest that the nature of the sludge surface is of considerable significance in determining the capacity and intensity of binding. The effect of the metals on biogas formation was also examined. This showed that inhibition of the gas formation was a function of the metal concentration and that the relative toxicities appeared to be zinc > lead > chromium.
Solution thermodynamic study of several hydrocarbons in γ‐butyrolactone and ethylene glycol mixtures by GLC
Authors: Zainel Hanaa A. , Bender Ali O. , Manook Takoohi , Talib Eman K. 
Published: July 2010

AbstractThe gas—liquid chromatographic technique was used to determine the thermodynamic properties of solutions at infinite dilution for binary and ternary systems of five normal paraffins (C5–‐C9), cyclohexane, benzene and toluene with γ‐butyrolactone and ethylene glycol mixtures. A combination solvent of 50 mol % of γ‐butyrolactone and ethylene glycol was shown to have the highest selectivity towards aromatic hydrocarbons.
Reduction of nitroaromatics with poly(vinylpyridine) complexes of palladium(II) and platinum(II)
Authors: Saha Chitta R. , Bhattacharya Somnath 
Published: July 2010

AbstractPalladium(II) and platinum(II) anchored to 2‐ and 4‐vinylpyridine polymers of different molecular weights were used for the dihydrogen reduction of various nitroaromatics and benzaldehyde in ethanol at 50°C. Palladium(II) complexes were far more effective than their platinum(II) analogues and the activity decreased with increasing molecular weights of the polymers. The nitroaromatics were selectively and almost completely reduced to the corresponding anilines. During reduction, the orange palladium(II) complexes changed to voluminous green precipitates, which could be used repeatedly and preserved for a long time without any loss of activity. A rate equation of the type: rate = K[Cat] [H2] has been derived and a reduction mechanism has been proposed on the basis of experimental results and kinetic data.
Pore diffusion and external mass transport during dye adsorption on to Fuller's earth and silica
Authors: McKay Gordon , Otterburn Michael S. , Aga Jamal A. 
Published: July 2010

AbstractThe adsorption of dyes on to Fuller's earth and silica has been studied. A mass transfer model has been developed to describe the adsorption process based on external mass transfer and internal pore diffusion. Theoretical concentration decay curves have been predicted using the model and compared with experimental decay curves.
Adsorption of 2,4,5‐T by active carbons from aqueous solution
Authors: Gómez‐Jimenez Lourdes , García‐Rodríguez Antonio , de Dios López‐González Juan , Navarrete‐Guijosa Antonio 
Published: July 2010

AbstractThe adsorption isotherms of 2,4,5‐trichloroacetic acid (2,4,5‐T) on activated carbons from aqueous solution have been obtained at several temperatures (10 to 50°C). The activated carbons used were Merck (No. 2514) and another one prepared from almond shells (C‐A‐14).Monolayer capacities, XM, were obtained by applying different theoretical models, such as BET, Langmuir and López‐González, to our data. The XM values were of the order of 10−3 mol g−1, being the lowest corresponding to the Merck sample. Surface areas of the two carbon samples, accessible to the molecules of 2,4,5‐T, have also been determined as well as some thermodynamic data corresponding to the adsorption process.
The use of reactive dyes in protein separation processes
Authors: Stead C. Vivian 
Published: July 2010

AbstractThe salient points of the chemistry of triazine based reactive dyes judged to be of interest to biochemists are summarised and the various alternative reactive systems and chromophores used in reactive dyes outlined. The development of the use of reactive dyes in dye affinity chromatography is discussed, parallels being drawn between textile dyeing and immobilisation techniques to provide suggestions for improvements in technique. The properties of the matrix are considered and structural features in the dye responsible for protein attraction analysed. The recent tailoring of dye structures to enhance utility in dye affinity chromatography and progress in the scaling up of high performance liquid affinity chromatography is reviewed.
The synthesis of fused and pendant pyrazole heterocyclic compounds from 5‐amino‐3‐methyl‐1‐phenylpyrazole and their evaluation as fluorescent brightening agents
Authors: Tagdiwala Prakash V. , Rangnekar Dinesh W. 
Published: July 2010

Abstract5‐Amino‐3‐methyl‐1‐phenylpyrazole (1) has been condensed with EMME (2a) and EMCA (2b) and the resulting ethyl 5‐aminoacrylates (3a–b) cyclized to pyrazolo[3,4,‐b]pyridines (4a–b). 3‐Methyl‐1‐phenylpyrazol‐5‐yl diazonium salt (7), prepared from (1) was coupled with tobias acid (8) and 2‐methoxy‐6‐aminoquinoxaline (9) to get the corresponding O‐aminoarylazo and heterylazo dyes (10) which were oxidatively cyclized to 2‐N‐(3‐methyl‐1‐N‐phenylpyrazol‐5‐yl)‐1,2,3‐triazolo[4,5‐a] naphthalene and [4,5‐f] quinoxaline derivative (11). The spectral properties of the compounds (4a–b, 5, 6, 11a–b) were studied.
Some aspects of electrochemical engineering
Authors: Goodridge Francis 
Published: July 2010

AbstractAfter a short discussion of the concept of electrochemical engineering, the immediate history of electrochemical process engineering (EPE) is briefly mentioned. Topics then considered are electrolytic reactor design, process modelling and optimisation, and the development and scale‐up of electroorganic processes. The article concludes with an assessment of the present state of EPE.
Flotation of perrhenates with cationic surfactants: Effect of surfactant's structure
Authors: Charewicz Witold A. , Walkowiak Wladyslaw , Beger Jörg , Schiefer Horst , Jacobi Renate 
Published: July 2010

AbstractAn experimental investigation is presented on the flotation of perrhenate anions from diluted aqueous solutions (5.10−5 M) with numerous cationic surfactants of systematically varying molecular structure. Alkyltrimethyl‐ammonium bromides, alkoxycarbonylmethyl‐trimethylammonium chlorides, alkoxycarbonylmethyl‐dimethylbenzylammonium chlorides, ethoxycarbonylmethyl‐dimethylalkylammonium chlorides, N‐substituted dodecylamines, and diquaternary ammonium bromides were investigated at their initial concentrations in the feed solution, 1.10−4 M or 2.10−4 M. It was found that both the length of the main hydrocarbon chain and of the short hydrocarbon groups govern the affinity of a cationic surfactant towards perrhenate anions. In order to achieve the effective flotation of perrhenate or similar anions the value of C:N atomic ratio for a tertiary or a quaternary ammonium surfactant should be in the range 15 to about 26. This value can be used as a primary criterion for the sufficient flotation capability of an alkylammonium surfactant.
Effects of changes in agitation rate on steady‐state penicillinase titres in continuously‐cultivated Bacillus cereus
Authors: Wase D. A. John , Patel Yatish R. 
Published: July 2010

AbstractIncreases in agitation rates at a constant dilution rate in aerobic continuous culture of Bacillus cereus furnished corresponding increases in extracellular penicillinase titres. The ratio of titre to biomass supported by the apparatus increased when the agitation rate was raised, even if the medium was diluted to half its original concentration. Potential causes of the phenomenon are discussed.
Production of acid from cocoa sweatings and its use for coagulation of natural rubber latex
Authors: Sarath‐Kumara Subaddarage J. , Jansz Errol R. , Mendis Leslie P. , Tillekedratne L. M. Kirthi , Wickremasinghe L. Kirthi G. 
Published: July 2010

AbstractCocoa sweatings drain off during the fermentation of cocoa beans and are normally a waste. These sweatings were converted to ethanol and then to a mixture of acids by successive fermentation by yeast and bacteria. Of the acid formed, 25 to 50% was non‐volatile and was unidentified. The acid was used to coagulate rubber latex to form RSS No. 1 smoked sheet rubber which was similar to rubber from latex coagulated with formic acid.
Effect of alumina‐deficiency and promotion with platinum and rhenium on the catalytic and diffusional behaviour of mordenite catalysts
Authors: Aboul‐Gheit A. K. , Menoufy M. F. , El‐Morsi A. K. , Abdel‐Hamid S. M. 
Published: July 2010

AbstractThe hydroconversion of n‐heptane on catalysts containing platinum hydrogen‐mordenite, platinum/alumina‐deficient hydrogen mordenite and platinum‐rhenium/alumina‐deficient hydrogen mordenite was carried out in a continuous high‐pressure plug‐flow reactor system and product analysis was carried out by gas chromatography (GC). The effectiveness factor for each catalyst was calculated by iteration on estimated rate constant at various reaction temperatures and the effect of diffusion on the catalytic behaviour was correlated. Catalysts exhibiting larger values of effectiveness factor were found to enhance production of 2,3‐dimethylpentane on account of 3‐methylhexane, whereas the reverse is true with respect to catalysts exhibiting lower values of effectiveness factor.
Selective liquid‐phase hydrogenation of 2,6‐dinitrotoluene with platinum catalysts
Authors: Kut Oemer M. , Yücelen Füsun , Gut Günther 
Published: July 2010

AbstractThe kinetics of the consecutive liquid‐phase hydrogenation of 2,6‐dinitrotoluene to 2‐amino‐6‐nitrotoluene and 2,6‐diaminotoluene was studied in ethanol with 0·5% Pt/Al2O3 as a catalyst using a stirred tank slurry reactor in the temperature and pressure ranges of 313 to 348 K and 0·5 to 10 MPa, respectively. The intrinsic kinetics of the consecutive reaction can be described by a Langmuir‐Hinshelwood type model with non‐competitive adsorption of organic species and hydrogen on the catalyst surface. At 313 K a maximum yield for the intermediate 2‐amino‐6‐nitrotoluene of over 95% can be achieved if heat and mass transfer effects are eliminated.
The thermal degradation of zinc O, O‐dialkyl phosphorodithioates and related compounds in petroleum media. Part II. Kinetic studies of zinc O, O‐diisobutyl phosphorodithioate
Authors: Lake Peter J. , Marshall Roger A. G. 
Published: July 2010

AbstractThe period of usefulness and the mode of action of zinc O, O‐dialkyl phosphorodithioates as multipurpose oil additives are affected by their thermal decomposition. Therefore, solutions of the diisobutyl derivative in pentadecane solution were heated under a nitrogen atmosphere at temperatures from 176 to 228°C in an all‐glass apparatus which enabled periodic removal of samples. The rate of loss of zinc from solution and the rates of formation of the products O, O, S‐triisobutyl phosphorodithioate, isobutanethiol and isobutene were then determined by atomic absorption spectroscopy and gas chromatography. It was found that all the zinc O, O‐diisobutyl phosphorodithioate had reacted in a time varying from 225 to 324 min depending upon its concentration at 215°C, but that O, O, S‐triisobutyl phosphorodithioate and isobutanethiol underwent further reaction. Induction periods varying from 33 to 120 min were observed for loss of zinc from solution and the formation of all the products; these were ascribed to the formation of an elusive intermediate which reacted at a rate comparable to that at which it was formed.
Synthesis of (1RS, 2SR)‐(±)‐2‐amino‐1‐phenyl‐1‐propanol from (R)‐(−)‐1‐hydroxy‐1‐phenyl‐2‐propanone
Authors: Subramanian Prema M. , Chatterjee Sunil K. , Bhatia Mahesh C. 
Published: July 2010

AbstractSynthesis of (1RS, 2SR)‐(±)‐2‐amino‐1‐phenyl‐1‐propanol (2) by reductive animation of (R)‐(−)‐1‐hydroxy‐1‐phenyl‐2‐propanone (1) using ammonia and Raney nickel as a catalyst was investigated. Compound 1 was produced by fermentation of molasses with a strain of yeast and benzaldehyde was added during the course of fermentation.
Investigation of asphaltenes association by a vapour pressure osmometric method
Authors: Al‐jarrah Mustafa M. F. , Apikian Rita L. 
Published: July 2010

AbstractThe number average molecular weights of asphaltenes have been studied by vapour pressure osmometry using benzene and tetrahydrofuran as solvents at three different temperatures, viz. 37, 45 and 60°C. The degree of association in each solvent at each temperature was determined and is found to be dependent on the nature of solvent and temperature. Results indicated that asphaltenes could be similar to macromolecules structurally.
Two‐step fermentation process for improved xanthan production by Xanthomonas campestris NRRL‐B‐1459
Authors: Vuyst Luc De , Loo Jan Van , Vandamme Erick J. 
Published: July 2010

AbstractXanthan formation by Xanthomonas campestris NRRL‐B‐1459 was optimised in a two‐step fermentation cycle. In conventional batch fermentation a cell growth phase was followed by a xanthan production phase. This was replaced by a two‐step process, comprising an initial biomass formation step followed by a xanthan formation step that required a high C/N ratio and higher aeration and agitation levels. The optimal moment of process change was critical and occurred 25–30 h after inoculation; at this time the contents of one biomass production fermenter could then be subdivided to feed 10 xanthan production tanks. Relatively high levels of residual sucrose remained even after the completion of xanthan formation.
Aerosol‐jet produced, magnetic carrageenan‐gel particles: A new affinity chromatography matrix
Authors: Lochmüller Charles H. , Wigman Larry S. , Kitchell Barbara S. 
Published: July 2010

AbstractA new method was developed to produce uniform spherical magnetic carrageenan‐gel particles suitable for the affinity chromatography purification of large molecules. A sol‐phase of k‐carrageenan is pumped into an air jet to produce an aerosol of gel particles. The particle size can be varied by adjusting the air jet velocity. The gel particles are stable in 0‐5 mol dm−3 KCI to 190 psi. The gel particles were used to immobilize soy trypsin inhibitor for the affinity purification of trypsin. The affinity matrix was tested in a packed‐bed separator, fluidized‐bed separator and a magnetically‐stabilized fluidized‐bed separator with similar column capacity for each separator.