bluuebunny/crossref_metadata_2025_split huggingface dataset:
Anaerobic digestion kinetics of wine‐distilleries wastewaters
Authors: Sales D. , Valcarcel M. J. , Romero L. I. , De La Ossa E. Martinez 
Published: July 2010

AbstractExperimental results of anaerobic digestion of wine‐distilleries wastewaters are compared with those obtained from two theoretical kinetic models: the substrate utilization model and the methane fermentation model. Both models predict accurately the performance of this depurative process, except at retention times less than 3 days, because the systems works under non‐steady state conditions.For depuration levels greater than 95%, optimum retention time is 6 days, and methane volumes (at STP) produced per gram of substrate added to the digester are 0.24 dm3 g−1 chemical oxygen demand.
Study on the acid hydrolysis of peat: Composition of the extracts from Sphagnum peat
Authors: Martin Antonio M. , Manu‐Tawiah Wireko 
Published: July 2010

AbstractPeat and its derived products, such as peat extracts or hydrolysates, offer a variety of possibilities as raw materials for the development of chemical and biochemical processes. Utilised as a fermentation substrate, peat extracts could provide a variety of nutrients to culture media, besides carbohydrates. In this work, Sphagnum peat moss and its extract produced by H2SO4 hydrolysis were analysed for total carbohydrates, reducing sugars, nitrogen, lipids, ash, amino acids and minerals. The results are discussed and compared with previous data.
Continuous enzymatic synthesis of Z‐kyotorphin amide in an enzyme‐immobilized fixed‐bed reactor
Authors: Clapés Pere , Mata‐Alvarez Joan , Valencia Gregorio , Reig Francesca , Torres Josep L. , García‐Antón José‐María 
Published: July 2010

Abstractα‐Chymotrypsin immobilized on natural and inexpensive supports such as diatomaceous earth was used as catalyst for Z‐Tyr‐Arg‐NH2 (Z‐kyotorphin amide) synthesis. In order to obtain the optimal reaction conditions, a 22 factorial experimental design was used. The factors considered were cosolvent (dimethylformamide) concentration and temperature; optimal product yield was achieved at 40% (v/v) dimethylformamide and 25°C. A sequential kinetic model was considered which generally gave good agreement between experimental and theoretical data for continuous synthesis of Z‐kyotorphin amide in a packed‐bed immobilized reactor system. The activation energy for the synthesis was determined to be 48.0 ± 2.3 kJ mol−1.
Marine coatings based on metal complexes of 4‐amino‐3‐hydrazino‐5‐thio‐1,2,4‐triazole
Authors: Tadros A. B. 
Published: July 2010

AbstractCopper, cobalt, nickel and tin metal complexes of 4‐amino‐3‐hydrazino‐5‐thio‐1,2,4‐triazole (I) have been prepared and their structure identified through IR and electronic spectra measurements.The cobalt and nickel have been found to be octahedral; on the other hand, a mixed structure is proposed for the copper complex. The complexes are incorporated in marine paint formulations in the presenceo of 4‐(p‐chlorobenzylideneamino)‐3‐(p‐chlorobenzylidenehydrazino)‐5‐thio‐1,2,4‐triazole, 4‐(3,4‐dichlorobenzylideneamino)‐3‐(3,4‐dichlorobenzyl idenehydrazino)‐5‐thio‐1,2,4‐triazole and 4‐(p‐nitrobenzylideneamino)‐3‐(p‐nitrobenzylidenehydrazino)‐5‐thio‐1,2,4‐triazole. Each paint was applied to PVC and mild steel substrate and the panels were tested in Alexandria eastern harbour water. Paints containing copper, cobalt and nickel complexes of (I) in the presence of its chlorinated or nitro derivatives showed antifouling properties till about 4 months, while they protect steel substrate from marine corrosion for 1 month.
Effect of temperature and ph on the adsorption of an anionic detergent on activated carbon
Authors: Leyva‐Ramos Roberto 
Published: July 2010

AbstractAdsorption of an anionic detergent (sodium dodecyl benzene sulfonate) from aqueous solutions onto activated carbon is investigated as an alternative for eliminating detergents from wastewaters. The adsorption isotherm was measured experimentally at 25°C, 30°C and 35°C and the experimental data were correlated reasonably well by the adsorption isotherm of Prausnitz‐Radke. The adsorption capacity is considerably affected by pH and there exists an optimal pH, near pH = 7, where the maximum adsorption takes place. The adsorption capacity increases with rising temperature, the adsorption is irreversible and the heat of adsorption is lessened with the amount of detergent adsorbed and its order of magnitude corresponds to a chemical reaction. It is concluded that the detergent is chemically adsorbed onto the activated carbon.
Barium aluminate hydrates—VI. 2BaO.Al2O3.5H2O and 2BaO.Al2O3.H2O
Authors: Ahmed A. H. Moinuddin , Glasser Lesley S. Dent 
Published: July 2010

AbstractThe compound 2BaO.Al2O3.5H2O has been synthesised and studied by infra‐red, X‐ray and thermal analytical techniques. The compound of approximate formula 2BaO.Al2O3.H2O forms as a dehydration product. The results are interpreted in terms of the known structure.
Factors influencing the reduction of barium sulphate
Authors: Hargreaves Keith , Murray David M. 
Published: July 2010

AbstractThe reduction of pure barium sulphate and of barytes to barium sulphide and soluble barium compounds has been carried out in an indirectly heated tube furnace using carbon as the reducing agent. Increasing the reduction temperature increases the yield of barium compounds. The best yield is obtained with a reduction period of 1–2 h at 850–1100°C, while excluding air during the reduction and subsequent cooling process.The influence of ferric oxide and silica impurities on the yield of soluble barium products has been studied at a reduction temperature of 1000°C. Both reduce the yield of soluble barium products, ferric oxide having a much greater effect. The effect of these two impurities is not additive, silica minimizing the effect of ferric oxide.
Synthesis of 7‐amino‐4‐methylcoumarin (AMC) derivatives and their hydrolysis by plant cysteine proteinases
Authors: Gray C. J. , Sullivan J. M. 
Published: July 2010

AbstractA number of derivatives of citrullyl‐7‐amino‐4‐methylcoumarin (Cit‐AMC) have been synthesised and characterised. Their hydrolysis, releasing the fluorescent 7‐amino‐4‐methylcoumarin, by the plant cysteine proteinases papain, ficin and bromelain was examined. Two derivatives in particular, Z‐Phe‐Cit‐AMC and Z‐Gly‐Phe‐Cit‐AMC, were shown to be good substrates for these enzymes. The possible use of the fluorogenic peptides in assays for these enzymes is discussed.
High density culture of Coptis japonica cells increases berberine production
Authors: Matsubara Koichi , Kitani Shigekazu , Yoshioka Toshihiro , Morimoto Teijiro , Fujita Yasuhiro , Yamada Yasuyuki 
Published: July 2010

AbstractA high density culture method was devised to improve the yield of berberine from highly productive cells of Coptis japonica. By adjusting aeration and stirring, Coptis cells were cultured at densities of up to 75 g dm−3 (dry weight) in a culture tank fitted with a hollow‐paddle type stirrer.Whereas a maximum density of 30 g dm−3 of C. japonica cells could be used in ordinary batch culture, 48 g dm−3 could be used in a fed‐batch culture in which the amounts of the nutrients in the medium were made proportional to the density of the inoculum. Moreover, in fed‐batch culture done with modified medium, the composition of which had been determined from the amounts of components incorporated in cells grown at the usual density for ordinary batch culture, the cell yield was improved to 55 g dm−3 and the berberine yield to 3.5 g dm−3.
Fractionation techniques in process biotechnology
Authors: Scawen Michael D. , Hammond Peter M. 
Published: July 2010

AbstractThe application of fractionation techniques to protein purification at a process or industrial scale is reviewed. The principles of various chromatographic separations are described and the choice and selection of available matrices discussed. Gel filtration, ion‐exchange hydrophobic interaction and affinity chromatographic techniques can all operate at process scale. HPLC is particularly suitable for process development and scale up without loss of efficiency. Magnetic separation, solvent partitioning and electrophoresis also offer potential for process scale operation. Recent developments also include improved matrices and the application of genetic engineering techniques to design proteins for efficient separation.
Partial oxidation of propylene MoO3/iron tellurite catalysts
Authors: Arriagada R. , Reyes P. 
Published: July 2010

AbstractThe catalytic behaviour of the series Fe2(TeO3)3 + × % MoO3 (X = 0–30 mol. %) in the oxidation of propylene in the gaseous phase has been studied. It has been found that the addition of Mo03 to the iron tellurite activates the reaction towards the partial oxidation to acrolein. From the characterisation of solids it is possible to conclude that the addition of MoO3 promotes the crystallinity of the iron tellurite. On the other hand, surface studies of the catalysts show that depending on the MoO3 loading, this component is present in various states which contribute in different ways to the catalytic action. Some explanations for the observed behaviour are proposed.
Review of the hydrolysis of iron(III) and the crystallization of amorphous iron(III) hydroxide hydrate
Authors: Cornell Rochelle M. , Giovanoli Rudolf , Schneider Walter 
Published: July 2010

AbstractHydrolysis of ferric solutions leads initially to mono‐ and dinuclear species which interact to produce further species of higher nuclearity. These polynuclear species age eventually to either crystalline compounds or to an amorphous precipitate (amorphous iron(III) hydroxide hydrate).Amorphous iron(III) hydroxide hydrate is thermodynamically unstable and gradually transforms to α‐FeO(OH) and α‐Fe2O3. These crystalline products form by competing mechanisms and the proportion of each in the final product depends on the relative rates of formation. The master variable governing the rates at which these compounds form is pH. Other important factors are temperature and the presence of additives.Most additives retard the transformation and by suppressing formation of α‐FeO(OH) lead to an increase in the amount of α‐Fe2O3 in the product; some additives also directly promote formation of the latter compound. Metal ions can oftxen replace a proportion of Fe in the α‐FeO(OH) and α‐Fe2O3 lattices. At high enough concentrations they can induce formation of additional phases. Additives may also modify the morphology of the crystalline products.
Facilitated transport of benzylpenicillin through immobilized liquid membrane
Authors: Marchese José , López Jorge L. , Quinn John A. 
Published: July 2010

AbstractThe rate of benzylpenicillin transport, as an ionic pair with a tetrabutyl ammonium cation, from aqueous media through a liquid membrane consisting of n‐decanol supported in a porous Teflon membrane has been investigated as a function of the chemical composition of the system and the hydrodynamic conditions at 25°C. The measured transfer rates have been explained in terms of the diffusion of the ionic pair species through the liquid membrane. The results are in agreement with theoretical predictions and it is demonstrated that the transport of benzylpenicillin takes place against a concentration gradient.
Mathematical modelling of landfill degradation
Authors: Young Alan 
Published: July 2010

AbstractThis paper presents a mathematical model for the primary and secondary stages of biodegradation within domestic landfills. Quantitative relations are proposed to describe the rates of mass conversion between the major landfill chemicals and the effects of gas evolution. Particular attention is given to the methanogenic stage with the associated bacterial population being modelled explicitly. The processes are phrased in terms of a system of coupled differential equations, and examples of their numerical solution are given for cases in which spatial dependency is neglected. The main inadequacies of this model and the need for more appropriate data are indicated.
Dextran fractionation using preparative scale continuous chromatography
Authors: Barker P. E. , Ganetsos G. , England K. 
Published: July 2010

AbstractThe continuous fractionation of dextran feedstocks using preparative scale gel permeation chromatography is reported. A semi‐continuous counter‐current chromatographic refiner has been used, which consisted of ten 5.1 cm i.d. × 70 cm long stainless steel columns, packed with Spherosil XOB075 porous silica beads. The system has proved successful in removing the very low and the very high molecular weight fractions and obtaining products of the required specification. Over 90% recoveries have been achieved at throughputs of 0.470 kg dextran h−1.
Synthesis of DL‐2‐(p‐hydroxyphenyl)glycine by the ammonolysis of p‐hydroxymandelic acid obtained by the condensation of phenol with glyoxylic acid
Authors: Powar Netaji P. , Chandalia Sampatraj B. 
Published: July 2010

AbstractSynthesis of DL‐2‐(p‐hydroxyphenyl)glycine by the ammonolysis of p‐hydroxymandelic acid obtained by the condensation of phenol and glyoxylic acid was investigated. Different procedures for the isolation of p‐hydroxymandelic acid from the product mixture after the condensation step were considered. The ammonolysis of the mandelic acid could be suitably carried out at 115°C using a 10:1 mole ratio of ammonia to p‐hydroxymandelic acid in the presence of ammonium chloride. A yield of glycine as high as 92% could be obtained when an overall conversion of the mandelic acid was about 80 %. The reaction was found to be first order with respect to the mandelic acid up to a reaction period of 6 h.
Synthesis of wide‐pore alumina support from gibbsite
Authors: Inoue Masashi , Kitamura Kazuhisa , Inui Tomoyuki 
Published: July 2010

AbstractGibbsite was treated in a series of primary alcohols at 250°C for 2 h. The surface area of the product increased with the increase in the carbon number of alcohol and reached a maximum when hexanol was used.Pore texture of aluminas, obtained by the calcination of these products, was investigated by means of the nitrogen adsorption technique. The aluminas prepared from the products of the treatment in alcohols other than propanol and butanol had a pore texture identical to the pore texture of the alumina from well‐crystallized boehmite prepared by hydrothermal treatment of gibbsite. The pore texture of these aluminas was characterized by the presence of micropores. The aluminas prepared from the treatments in butanol and propanol had quite different pore texture. Micropores were not detected in these aluminas: instead, mesopores of c. 20 nm range were detected.These results are consistent with the reaction mechanisms for the formation of boehmite proposed in a previous paper on the basis of morphology of the products. In lower alcohols boehmite is formed by means of a resolution‐crystallization mechanism, whereas in higher alcohols boehmite is formed by means of intraparticle hydrothermal reaction. In butanol and propanol, boehmite is crystallized from the alcoholic media and has a large population of crystal defects; therefore, pore texture of aluminas derived from these products resembles the aluminas from poorly crystallized aluminum hydroxides.
Ethanol fermentation by Z. mobilis ATCC10988 in repeated batch cultures
Authors: Agrawal Pramod , Veeramallu Uday 
Published: July 2010

AbstractRepeated‐batch fermentations of glucose to ethanol by Z. mobilis (ATCC 10988) were examined in two semi‐defined nutrient media. The measurement of acid produced by the microorganism was used to study its transient fermentation characteristics. An examination of the inhibitory effect of ethanol in repeated‐batch fermentations supports an earlier finding on the presence of a ‘slow‐acting inhibitory mechanism’ at high ethanol concentration in Z. mobilis (ATCC 10988) cultures. The experimental results also suggest that both microbially produced and exogeneously added ethanol have similar inhibitory effects on the fermentation behavior of this bacterium.
Synthesis of 2‐azo‐3‐cyano‐5‐carbethoxy thiophene derivatives and their application on polyester fibres
Authors: Sabnis Ram W. , Rangnekar Dinesh W. 
Published: July 2010

AbstractSynthesis of 2‐(hetaryl or aryl)‐azo thiophene derivatives (IVa–IVg) was achieved by diazotisation of ethyl 2‐amino‐3‐cyano‐5‐carbethoxy thiophene‐4‐acetic acid ester (I) using nitrosyl sulphuric acid, coupling with suitable heterocyclic hydroxy and N, N‐dialkyl‐substituted aryl amines, which resulted in thiophene azo dyes. The key intermediate (I), used as the diazonium component was synthesised in one pot and in excellent yield from diethyl acetone dicarboxylate, sulphur and malononitrile, using diethylamine as a catalyst, following the Gewald Synthesis. The spectral properties of these dyes were studied. The dyes when applied as disperse dyes on polyester fibres gave excellent results.
An integrated process for the treatment of apatite obtained from dephosphorization of iron ore
Authors: Zhang Yu , Muhammed Mamoun 
Published: July 2010

AbstractA process has been proposed for the treatment of apatite concentrate obtained from the dephosphorization of iron ore. In this process, the apatite is acidulated by HNO3 to produce high‐purity H3PO4. The crude acid obtained is shown to be at least equivalent to, if not better than, the typical wet‐process acid. The H3PO4 is purified by extraction and concentrated by evaporation. The spent HNO3 is regenerated by H2SO4 to precipitate gypsum. Rare earths dissolved during the apatite acidulation are recovered by precipitation with oxalic acid. The process is to be integrated with the processing of the solutions obtained from the direct leaching of iron ore (the phosphorus removal) with HNO3. The integrated process is more economical than the single treatment and also it offers the flexibility of producing both sinter‐fines and pellets to meet demand in steel manufacture.
Upgrading of linear alkyl benzene by‐product
Authors: Wedad Abdel Azim M. , Abou Naga H. H. El , Naguib Sidaros K. 
Published: July 2010

AbstractHeavy alkylated benzene, which is accumulated as a by‐product from linear alkyl benzene synthesis, was evaluated as a starting material for anionic liquid sulphonate surfactants.Chemical structure analysis by GC/MS showed that the by‐product contains eight different paraffinic side‐chains, within the carbon range C12–C15. Accordingly, sulphonation conditions for it were adjusted to optimize the reaction yield and product quality.Liquid surfactant formulations based on these anionic sulphonates were established by incorporating other necessary ingredients. The formulations developed have shown high efficiency as detergents, wetting agents and emulsifiers.
Kinetics of 2,3‐butanediol fermentation by Bacillus amyloliquefaciens: Effect of initial substrate concentration and aeration
Authors: Alam S. , Capit F. , Weigand W. A. , Hong J. 
Published: July 2010

AbstractMost studies on 2,3‐butanediol production by microbial fermentation have been carried out using Klebsiella oxytoca and Bacillus polymyxa. In these fermentations there is a significant conversion of carbon source into ethanol, glycerol and various organic acids as by‐products. On the other hand, this investigation has shown that the major products of fermentation by Bacillus amyloliquefaciens are 2,3‐butanediol and some minor acids. In a typical fermentation about 33 g of butanediol was produced from 100 g of glucose.The effect of pH, various carbohydrate source, initial glucose concentration and aeration on the 2,3‐butanediol fermentation by B. amyloliquefaciens were investigated. The butanediol productivity and yield was found to be highest with glucose as the carbohydrate source. The glucose concentration was varied between 30 and 100 g dm−3 with oxygen transfer rate controlled between 47.5 and 78.0 h−1. Oxygen and the initial substrate concentrations significantly influence the yield, productivity and by‐product formation.
Adsorption of Streptococcus faecalis on diatomite carriers for use in biotransformations
Authors: Anderson William A. , Bay Pierre , Legge Raymond L. , Moo‐young Murray 
Published: July 2010

AbstractAdsorption of cells on particulate carriers is potentially one of the most cost‐effective immobilization techniques available. Diatomite carriers, such as Celite, have desirable physical properties, are inexpensive, and are suitable for both mycelial and bacterial systems. This work investigated the use of diatomite carriers as a biocatalyst support in a packed‐bed reactor where L‐tyrosine was enzymatically decarboxylated using adsorbed, non‐growing cells of Streptococcus faecalis. Composition of microbial adsorption on different Celite types, with mean pore sizes ranging from 0.55 to 22 μm, showed there was no significant difference in biomass loading capacity under the conditions used. Using Celite 560, biomass loadings in a packed‐bed reactor varied from 10 to 30 g dm−3 of reactor volume, which compares favourably with other adsorption methods. When used to decarboxylate L‐tyrosine, the reactor was found to have a half‐life of 15–20 h. A combination of enzyme activity loss and slow leakage of biomass from the packed‐bed reactor was responsible for the decline in conversion. Treatment of the S. faecalis cells with glutaraldehyde significantly reduced the enzyme activity loss and extended the reactor half‐life to 65 h, but had little effect on the rate of cell leakage from the reactor. Further work on reduction of cell leakage rate seems necessary for evaluation of the system's practicality.
Photochemical elimination of Cr(VI) from neutral–alkaline solutions
Authors: Domènech Xavier , Muñoz Javier 
Published: July 2010

AbstractThe elimination of Cr(VI) from aqueous solutions at neutral and low alkaline pH by photocatalytic reduction to Cr(III), using ZnO powder as catalyst, is investigated. The study has been performed by determination of the percentage of Cr(VI) eliminated in the presence of some species (i.e. Zn(II), Cd(II), Ni(II), Ca(II), CH3COO−, PO3‐4, CO2‐3, S2‐ and NH3) which usually are found in wastes together with Cr(VI). The results obtained show that the presence of some species prevents the alkalinization of the solution during irradiation, which increases the yield of Cr(VI) photoreduction. Other species, such as S2‐ and NH3, are oxidized during illumination: thus they prevent electron–hole recombination and, consequently, increase the yield of the Cr(VI) elimination.
Amperometric determination of ammonium ions with a microbial sensor
Authors: Riedel K. , Huth J. , Kuehn M. , Liebs P. 
Published: July 2010

AbstractA sensor for NH+4 ions has been developed, which consists of immobilized micro‐organisms (Bacillus subtilis, Pseudomonas aeruginosa, Trichosporon cutaneum) in combination with an electrochemical transducer. This sensor is based on the measurement of acceleration of respiration after addition of NH+4 in the presence of glucose. The physiological background of this signal and its connection with NH+4 ion uptake and/or metabolism is discussed.The response time of the sensor is about 5.10 s for NH+4 ions. A linearity was observed between 0.005 and 0.15 mmol dm−3 NH+4 ions. The sensitivity of the sensor remained almost constant for 12 days. The sensor was used to determine NH+4 ions in a microbial fermentation broth.