bluuebunny/crossref_metadata_2025_split huggingface dataset:
Extraction of copper from aqueous solutions with carboxylic acids
Authors: María Díaz Ramona , Fernández Ana María , Xiberta Jorge 
Published: July 2010

AbstractThe distribution equilibrium data at 25°C for the extraction of copper from aqueous solutions, containing sodium nitrate or sodium sulphate, by carboxylic acids using toluene, benzene and carbon tetrachloride as diluents have been measured. The carboxylic acids used are n‐myristic, n‐lauric and n‐capric. The results obtained led to the conclusion that the composition of the extracted species corresponds to (CuR2.HR)2, being irrespective of both the nature of organic phase and the aqueous phase. The addition of sodium sulphate, instead of sodium nitrate, decreases the extraction efficiency due to the formation a CuSO4 ion‐pair into the aqueous phase. The diluent effect has been related to the activity of the dimerised carboxylic acid in the diluent.
Removal and recovery of uranium by polyvinyl polyacrylate
Authors: Nakajima Akira , Sakaguchi Takashi 
Published: July 2010

AbstractVarious polymer esters were screened to determine which adsorb uranium the best. Polyvinyl polyacrylate adsorbed uranium extremely well and its behaviour was investigated in detail. Polyvinyl polyacrylate can selectively accumulate uranium from a solution containing various heavy metals. The uptake of uranium is very rapid and is markedly affected by pH, but not by the co‐existence of the carbonate ion. As it can adsorb uranium in the pH region 4 to 7, it can be used to remove and recover uranium from uranium refining waste water. It can recover uranium almost completely from solution at pH 6 and almost all uranium adsorbed is desorbed easily with 0.1 M HCl. Thus, polyvinyl polyacrylate can be used repeatedly in adsorption‐desorption process.
Corrosion of tin in aqueous solutions of mono‐, Di‐ and trichloroacetic acids
Authors: Abdel‐Wahaab S. M. , Abo‐El Wafa O. , Kamel G. E. , Rashwan S. M. 
Published: July 2010

AbstractThe corrosion behaviour of tin in stagnant mono‐, di‐ and trichloroacetic acids solutions in the pH range 1–6 and at concentrations 4.0 to 5 × 10−4 M was investigated. The results indicate behaviour that is generally the same but there is some dependence on the acid concentration and the pH value. In 4.0 to 10−2 M solutions, the corrosion rate (W) increased with increasing acid concentration and decreasing pH value from 1 to 4 as follows: log W=a+b log C, where b=0.70, 0.42 and 0.35 for tri‐, di‐ and mono‐chloroacetic acids respectively. At high concentrations 4.0 to 10−2 M and in the pH range 1–6, the steady state corrosion potential shifted in the negative direction with increase of acid concentration accompanied by an increase in the corrosion rate, indicating that the corrosion process becomes anodically controlled by the complexing of Sn2+ ions with organic acid anions and that the order of aggressiveness is mono‐<di‐<trichloroacetic acids. In dilute solutions (10−2 to 5.10−4 M) in the pH range 1–6 the steady state potential shifted in the noble direction with increase of acid concentration (accompanied by a remarkable decrease in the corrosion rate). Corrosion inhibition in dilute solutions was attributed to film formation on the surface of tin which may result from the hydrolysis of tin species.
Hydrolysis of sugar cane bagasse with hydrochloric acid, promoted by metallic cations
Authors: Schuchardt Ulf , Duarte Humberto C. 
Published: July 2010

AbstractLithium chloride, in combination with commercial grade hydrochloric acid, is very effective in the hydrolysis of prehydrolysed sugar cane bagasse. After 10 min at 50°C the holocellulosic portion is completely dissolved and after 20 min most of the sugar oligomers are hydrolysed to monomers, making the time‐and energy‐consuming post‐hydrolysis unnecessary. With longer reaction times the sugars start to reoligomerise and decompose. Zinc chloride is a milder promoter, requiring post‐hydrolysis even after reaction for 30 min at 50°C. On the other hand, it does not decompose the sugars giving the highest sugar yields after prolonged reaction time and post‐hydrolysis. Ferric chloride is mostly ineffective in the hydrolysis of cellulose but is a good promoter of the hydrolysis of the sugar oligomers, under the reaction conditions.
A comparative study of a fluidised bed reactor and a gas lift loop reactor for the IBE process: Part I. Reactor design and scale down approach
Authors: Schoutens Gerda H. , Guit Ruud P. , Zieleman Gerard J. , Luyben Karel Ch. A. M. , Kossen Nico W. F. 
Published: July 2010

AbstractFor the continuous production of isopropanol‐butanol mixtures by immobilised Clostridium spp. (the IBE process) two reactor types were studied: a fluidised bed reactor with liquid recycling (FBR) and an external loop gas lift reactor (GLR). A large scale design (50–65 m3) was made for both reactors. A regime analysis, by evaluating the time constants for e.g. mixing and conversion, identified the ruling regime. Via the scale down approach two representative model reactors were developed: a 10 dm3 FBR reactor (H/D=25, D=0.08 m) and a 15 dm3 external loop GLR (H/D = 12.5, Dr=Dd=0.08 m). For both reactors the hydrodynamical behaviour and the total reactor performance were studied and are described in parts II and III of this study.
Automated affinity separation processes
Authors: Chase H. A. 
Published: July 2010

AbstractThis paper describes the automation of fixed‐bed affinity separation techniques for the purification of proteins. The basic requirements of an automated system suitable for carrying out such a separation are detailed together with an introduction to the concept of process optimisation by interactive control. Such systems can continue to optimise separations when operating conditions are variable but require that methods for the on‐line analysis of separation performance are available. Such methods require that the levels of particular proteins in the presence of other proteins can be determined and include continuous measurement of enzyme activity and the use of the new technique of rapid chromatographic analysis. The latter technique, which can also be used more generally in the process control of protein purification, is described and its use illustrated.
The use of near infrared reflectance spectroscopy in the control of flour protein content
Authors: Osborne B. G. 
Published: July 2010

AbstractNear infrared reflectance spectroscopy (NIR) is a rapid (50s) and non‐destructive method of analysis of a wide variety of solid, semi‐solid and liquid samples. Since no sample preparation is required for many sample types, particularly powders, NIR is an ideal technique for process control. The use of NIR to monitor the protein content of flour in order to optimise the milling conditions and the composition of the grist is described. Control of the blending of flours or supplementation with wheat gluten to achieve a composite flour of a given protein content is proposed.
Quality control of proteins produced by recombinant DNA technology
Authors: Brewer Stepen J. 
Published: July 2010

AbstractProteins produced by recombinant DNA technology will be contaminated with residues from the organism used to express the protein, from its culture medium and from the downstream processing steps. In addition, heterogeneous proteins with incorrect sequence and/or folding may also arise. Urogastrone, a human protein, has been produced by rDNA technology in Escherichia coli and is used to illustrate methods for controlling production and downstream processing steps. Protein chemical, chemical, and biochemical methods for the characterization of the purified drug substance are then described.
Applications of recombinant DNA technology to diagnostics
Authors: Goldfarb P. 
Published: July 2010

AbstractThe use of recombinant DNA as a routine diagnostic tool is now a reality. Although gene probes have been available to academic researchers for a number of years, only recently has progress in recombinant DNA technology made it possible to extend their use to the screening of large numbers of samples, and make such analytical procedures part of the normal workload of hospital, analytical and commercial laboratories. It is now possible to detect genetic diseases in patients or at risk populations, and to diagnose infectious disease or identify infectious agents present as environmental contaminants. The technology can also be extended to the unambiguous identification of individuals for forensic, paternity or immigration purposes. The application of recombinant DNA technology is therefore of interest to scientists from a wide variety of disciplines.
Dimerised ethyl cyanoacetate in heterocyclic dye synthesis: New pyridine azodyes and tetrazole dyes
Authors: Fahmy Sherif M. , Mohareb Rafat M. , Abd‐All Fatma A. 
Published: July 2010

AbstractA variety of polyfunctional pyridine azodyes and tetrazole dyes were prepared starting from ethyl cyanoacetate dimer. These derivatives were found to dye cellulose acetate, Nylon 6, Nylon 66, silk and wool with colours ranging from canary yellow to light violet.
A comparative study of a fluidised bed reactor and a gas lift loop reactor for the IBE process. Part II: Hydrodynamics and reactor modelling
Authors: Schoutens Gerda H. , Guit Ruud P. , Zieleman Gerard J. , Luyben Karel Ch. A. M. , Kossen Nico W. F. 
Published: July 2010

AbstractA fluidised bed reactor with liquid recycle (FBR) and an external loop gas lift reactor (GLR) were designed for the production of isopropanol—butanol mixtures by immobilised Clostridium spp. and scaled down to laboratory scale (part I). Hydrodynamic models were set up for the two laboratory scale reactors. Liquid mixing in the 10 dm3 FBR was described by 10 tanks in series. Fluidisation velocities, bed expansions and axial dispersion coefficients agreed well with literature data. Liquid mixing in the 15 dm3 GLR was described by 100 tanks in series. The gas hold‐up and circulation velocity were found to decrease with increasing hold‐up of solids, in accordance with literature indications. No influence of the hold‐up of solids on the axial dispersion coefficient was determined. An integrated reactor model was set up for both reactors, using the hydrodynamic and kinetic model. Actual fermentation data are presented and compared with model predictions in part III of this study; this part will also include a comparison of reactor performances and scale up aspects.
Synthesis by enzymatic catalysis. III. Copolymerisation of amino acids and dipeptides using papain
Authors: Selvi Christine , Baboulene Michel , Speziale Vincent , Lattes Armand 
Published: July 2010

AbstractAfter studying the oligomerisation reaction of L‐tyrosine, we investigated polymerisation of a mixture of methionine and tyrosine, which also led to the formation of a polypeptide. Various substrate concentrations and substrate/enzyme ratios were investigated. A hexapeptide was isolated containing three tyrosine and three methionine residues. Extension of the method to enzymatic polymerisation of dipeptide esters was also examined. After optimisation of the reaction, we obtained a peptide made up of four monomers using methyl L‐leucyl‐L‐tyrosinate as substrate. The results are discussed in the light of a possible reaction mechanism.
Galvanostatic and temperature kinetic studies of acid corrosion of low carbon steel in sulphuric acid in presence of malonate hydrazide
Authors: Abd el Wahaab Saad M. , Gomma Gamal K. , El‐Barradie Hussny Y. 
Published: July 2010

AbstractThe inhibitive effect of malonate hydrazide on the corrosion of low carbon steel (0.05% C) in 1 M sulphuric acid at different temperatures was investigated. The corrosion potential, corrosion current, and corrosion rate, as well as heat of adsorption and effective energies were calculated from the Evan's curves at different temperatures.
A process control system for the fractional precipitation of human plasma proteins
Authors: Foster Peter R. , Dickson Alan J. , Stenhouse Alexander , Walker Ewan P. 
Published: July 2010

AbstractPrecipitation is the principal technique used by the blood plasma fractionation industry for the separation and concentration of human proteins for clinical use. Although precipitation has many attractions it is particularly difficult to control and the resultant overshoot of key parameters is responsible for loss of product yield and sometimes quality. Much of this problem is due to the inefficiency of mixing and heat transfer in large bulk volumes of protein solution; hence control is limited by the process design. Therefore we have applied the concept of continuous‐flow processing to scale‐down process volumes, to improve the efficiency of mixing and heat transfer and to allow the opportunity for in‐line monitoring and control of important parameters. Ten years experience with a routine manufacturing process of this type has illustrated the benefits of this approach and has led to the modernisation of the process with replacement of centralised computer control by a microprocessor‐based system.
Intrinsic kinetic constants of an immobilised glucose‐isomerase
Authors: Benaiges M. D. , Solà C. , De Mas C. 
Published: July 2010

AbstractThe isomerization of glucose into fructose using a commercial immobilised glucose‐isomerase has been studied and an initial transitory state of the enzyme, probably due to an establishment of stationary concentration profiles, was observed. Operational conditions to minimise the effects of external and internal mass transfer were determined using immobilised enzyme particles with diameters less than 0.064 mm. Thermal enzyme deactivation of the enzyme was insignificant if it was pre‐treated with cobalt. The intrinsic kinetic constants of the reversible reaction Michaelis—Menten equation were calculated, in operational conditions free of mass transfer effects.
Biomass for energy—a review
Authors: Boyles D. T. 
Published: July 2010

AbstractThe enthusiasm, in recent years, for biologically derived fuels has not been repaid by the emergence of major new industries. Where they have been adopted, biofuels have needed extensive subsidies or other community support. This review examines the inherent problems of the bioenergy concept, which may ensure that biofuels will never enjoy more than a purely local exploitation. These problems derive from the relatively small usable biomass resource, its high cost and the cost of upgrading biomass to usable fuels, the unfavourable energy balance in converting high entropy feedstocks to low entropy fuels, and the anticipated effects of such processes on the environment.
Hydration of calcium sulphate hemihydrate in the presence of phosphoric acid and calcium oxide: III. Phosphogypsum
Authors: Beretka Julius , Brown Trevor 
Published: July 2010

AbstractThe kinetics of hydration and physical properties of plaster slurries and cast gypsums of three calcined industrial phosphogypsums containing 0.09, 0.38 and 0.73% ‘soluble’ P2O5, respectively, were investigated. The materials were neutralised with lime as in industry, and the lime addition was expressed in terms of CaO/P2O5 wt ratio from 0 to 5. It was found that the presence of 0.09% P2O5 had relatively little effect on the kinetics of hydration and physical properties of calcined phosphogypsum. However, with the material containing 0.38% P2O5 the rate of hydration of the slurry was severely retarded within the CaO/P2O5 wt ratio range of 1 to 2; the setting time increased, the strength was reduced, and all the other physical properties of the slurries and cast gypsums were greatly affected. Similar findings were observed with the material containing 0.73% P2O5, except that these changes took place within the higher and broader weight ratio range of 1.5 to 3.5 CaO/P2O5. The practical implications of these findings on the industrial conversion of phosphogypsums to good quality plaster of Paris and cast gypsum are discussed.
Mixing and mass transfer in concentric‐tube airlift fermenters: Newtonian and non‐newtonian media
Authors: Kawase Yoshinori , Moo‐Young Murray 
Published: July 2010

AbstractThe mixing and mass transfer characteristics in concentric‐tube airlift gas‐liquid contactors intended for possible use as fermenters are discussed. Liquid velocities, circulation times, gas hold‐ups, and volumetric mass transfer coefficients were measured in water and aqueous carboxy methyl cellulose solutions. Measurements were made in an inverted conical‐bottom device with draft tubes of three different diameters. An increase of liquid velocities at the column axis and a corresponding decrease of volumetric mass transfer coefficients due to the introduction of draft tubes were found for water as the liquid medium. For the non‐Newtonian fluids, a complicating influence of the draft tubes on liquid velocity and mass transfer, which is attributed to a combination of factors related to improvement of liquid circulation and reduction of apparent viscosity, was observed.
Effects of nutrients on α‐amyiase production and plasmid stability in fed‐batch culture of recombinant bacteria
Authors: Iijima Shinji , Kai Kenichi , Mizutani Satoru , Kobayashi Takeshi 
Published: July 2010

AbstractEscherichia coli harbouring a recombinant plasmid containing the α‐amylase gene (HB101/pHI301) and its derivative which can stably maintain the plasmid (HB101/pHI301A) were cultivated in a mini‐jar fermenter. By controlling dissolved oxygen (DO) at a concentration of 2–3 μg/l and supplementing with suitable amounts of nutrients, the organisms could grow to a concentration (up to 40 g dry cell l−1) in a semi‐synthetic casamino acid medium. During culture the plasmid was maintained stably in both strains. In a synthetic medium, both micro‐organisms grew less well and plasmid‐free segregants were observed with HB101/pHI301 during the fed‐batch culture. On the other hand, plasmid pHI301A was stably maintained throughout the fed‐batch culture of HB101/pHI301A. Growth inhibitors, which may be metabolic products, accumulated in the medium and reduced bacterial growth.
Laboratory simulation of municipal solid waste fermentation with leachate recycle
Authors: Mata‐Alvarez Joan , Martinez‐Viturtia Angel 
Published: July 2010

AbstractMunicipal solid waste fermentation, simulating landfill conditions, was studied using five test cells operated at different temperatures. The digestion was carried out under enhanced conditions. Leachate recycle was set up in all the test cells. Depending on temperature, the digestion was complete (more than 90% biodegradable matter converted) in a period of 25 to 57 days. Optimum operating temperatures were in the range of 34 to 38°C. Two kinetic models were fitted to experimental data. Their kinetic constants were related to temperature using an Arrhenius expression. Landfill life operated under the studied conditions could be reduced to less than 2 years.
Flotation of metal hydroxide precipitates. II. Flotation of zinc and cobalt hydroxides
Authors: Basak Sergiusz , Charewicz Witold A. 
Published: July 2010

AbstractFlotation of zinc and cobalt hydroxide precipitates was investigated at total initial metal concentrations of 1 × 10−2 M with sodium dodecylbenzenesulphonate (DBSNa) and dodecyldimethylbenzylammonium bromide (DDMBABr), both at initial concentrations of 1 × 10−4 M. In particular, the granulometric analysis of precipitates and measurements of their electrokinetic potential were carried out over a wide range of acidity of aqueous precipitate suspensions. Moreover, adsorption of the flotation collectors by the precipitates as well as the rate of their sedimentation were measured. It was found that the extent of collector sorption, changes in the electrokinetic potential of precipitate grains and their aggregation affected the flotability and course of flotation of the examined precipitates. These dependencies were irregular and could be discussed in terms of chemisorption of collectors on the surface of the precipitate grains.
A new route to 4‐, 5‐, and 6‐indolecarboxylic acids
Authors: Kasahara Akira , Izumi Taeko , Yanai Hiroshi , Murakami Satoshi , Takatori Masayuki 
Published: July 2010

AbstractThere are many indole derivatives bearing carboxyl or methoxycarbonyl groups on the benzene ring and these often have patent physiological activities. Synthesis of these compounds usually starts from indoles having a halogen group at the desired position on an indole ring. We now report a facile synthesis of 4‐, 5‐, and 6‐indolecarboxylic acids from 2‐bromoaniline derivatives (1). The synthetic route is shown in Figure 1.
A comparative study of a fluidised bed reactor and a gas lift loop reactor for the ibe process: Part III. Reactor performances and scale Up
Authors: Schoutens Gerda H. , Guit Ruud P. , Zieleman Gerard J. , Luyben Karel Ch. A. M. , Kossen Nico W. F. 
Published: July 2010

AbstractContinuous fermentations using Clostridium spp. DSM 2152 immobilised in calcium alginate beads to produce butanol and isopropanol from glucose were carried out in a fluidised bed reactor with liquid recycle (FBR, 10.9 dm3 working volume, 41 % solids) and in a gas lift loop reactor (GLR, 11.4 dm3 working volume, 32% solids). In the FBR in‐situ produced non‐coalescing gas bubbles had a negligible influence on the fluidisation pattern and the steady state results of the fermentation were in accordance with those predicted by a reactor model. The FBR was operated reliably for 5 weeks without decrease of activity. The GLR behaved as a three phase reactor because of the recycled fermentation gas. The steady state fermentation results were as predicted by the GLR model. Scale up to a 50 m3 FBR and a 65 m3 GLR led to development of a plug flow with recycle model for the FBR and a stirred tank model for the GLR. On the basis of overall reactor performance and ease of integration with a simultaneous product recovery the FBR is preferred to the GLR for application in a large scale butanol/isopropanol process using immobilised Clostridia spp.
Thermal properties of tetraalkoxysilanes
Authors: Alagar M. , Krishnasamy V. 
Published: July 2010

AbstractTetraalkoxysilanes were prepared by reacting SiCl4with alcohols in the liquid phase in the presence of pyridine. Based on the experimental evidence and theoretical calculations, tentative structures have been proposed. Thermal conductivity measurements for these samples were done over a temperature range 303–463 K and the data are compared with the theoretical values derived from empirical equations. In addition, other properties such as specific heat (Cp), thermal expansion (α) and oxidation stability were determined and the values are compared with the reported values for polymethy Isiloxanes.
Some styrene alkyl‐methacrylate copolymers as viscosity index improvers
Authors: Abou el Nage H. H. , Abd el Azeim W. M. , Zanib Fathy , Ibrahim Saad H. 
Published: July 2010

AbstractStyrene alkyl‐methacrylate copolymers were synthesised at different monomer percentage ratios and under varied reaction conditions. Evaluation of obtained copolymers as viscosity index improvers in multigrade motor oils has been carried out in relation to different reaction variables and a comparative evaluation with commercially available viscosity index improvers in their performance properties (e.g. thermal oxidation and shear stabilities) was investigated.