bluuebunny/crossref_metadata_2025_split huggingface dataset:
Heat transfer in bubble column and airlift bioreactors: Newtonian and non‐Newtonian fermentation broths
Authors: Kawase Yoshinori , Kumagai Takahiro 
Published: July 2010

AbstractA theoretical model has been developed for heat transfer in bubble column and airlift bioreactors, which is applicable for Newtonian and non‐Newtonian fermentation media. The proposed model is based on a similarity between heat transfer in gas‐sparged pneumatic reactors and turbulent natural convection. The applicability of the proposed model was discussed using a wide range of experimental data, and good agreement was obtained.
Kinetic model and simulation for catalyst deactivation during dehydrogenation of methylcyclohexane over commercial Pt‐, PtRe‐ and presulfided PtRe‐Al2O3 catalysts
Authors: Chai Mao‐Rong , Kawakami Koei 
Published: July 2010

AbstractThe catalyst deactivation kinetics for the dehydrogenation of methylcyclohexane were studied with Pt‐, PtRe‐, and presulfided Presulfided PtRe‐Al2O3 Catalysts in a fixed‐bed differential reactor. The kinetic analysis was made based on a Langmuir‐Hinshelwood model assuming that the dehydrogenation of methylcyclohexene into methylcyclohexadiene was the rate‐controlling step for the main reaction, and the polymerization of adjacently adsorbed methylcyclohexadiene as coke precursor molecules was the rate‐controlling step for the deactivation reaction. The experimental data for the three catalysts at varying partial pressures of methylcyclohexane and hydrogen were well correlated by the hyperbolic deactivation function derived. The number of active sites involved in the rate‐controlling step of the deactivation was evaluated to be 2.7 in average. The enhanced activity maintenance by the addition of Re as well as sulfur was attributed to a reduction in the concentration of multiple sites occupied by coke precursors adjacently adsorbed, leading to a decrease in the rate constant of the deactivation reaction.
Studies on the dechlorination and detoxification of organochlorine compounds II. Chlorinated cyclodiene insecticides and the polychlorinated insecticide ‘mirex’
Authors: Stojkovski Stojan , Markovec Ladislav M. , Magee Robert J. 
Published: July 2010

AbstractIn the first paper on the dechlorination of organochlorine compounds, results were reported for polychlorinated biphenyls and polychlorinated naphthalenes, using the Ni2B in‐situ catalytic dechlorination technique. In the present study, the work has been extended to the dechlorination and detoxification of some chlorinated polycyclic hydrocarbons belonging to a cyclodiene insecticide group (dieldrin, aldrin and endrin). In addition, a cage‐structured polychlorinated insecticide, ‘mirex’, has also been investigated. During the dechlorination process, intermediates were detected by GC/MS and identified by their characteristic mass fragments and retention in mass.
Ion exchange kinetics in ultra pure water systems
Authors: Harries Richard R. 
Published: July 2010

AbstractThe continuous production of ultra pure water on an industrial scale uses ion exchange mixed beds as a major method of reducing ionic impurities to sub‐μg dm−3 concentrations. Under such demanding operating conditions, particularly the high flow rate and high volume requirements of condensate purification in the power generation industry, it is the kinetics rather than the equilibria of the exchange processes that becomes the main controlling factor. The interactions between anion and cation exchange rates have been studied, particularly with respect to changes in the aqueous phase pH within a bed of exchange resins. The cause and effects of cation exchange resin fouling, both in laboratory tests and in practical applications, have been investigated. The most suitable choice of ion exchange system for ultra pure water production, whether mixed or separate beds, is discussed.
Significance of fluid regime in biological filtration
Authors: Muslu Yilmaz 
Published: July 2010

AbstractA dispersed flow model previously developed to study substrate utilization in unsaturated media was experimentally verified and its practical application was considered. For this purpose, measurements were made using tap water and a synthetic feed solution. The importance of the change in fluid regime as regards to the simultaneous transport and reaction within biological filters were demonstrated. The effect of drop formation and the breakage of liquid jets inside the filters on substrate utilization was also shown.
Kinetics and mechanism of the vapour phase oxidation of 3‐picoline by nitric oxide over nickel oxide–aluminium oxide catalyst
Authors: Prasad R. , Mathews S. , Garg A. 
Published: July 2010

AbstractThe kinetics of the catalytic transformation of 3‐picoline to 3‐cyanopyridine by nitric oxide (NO) have been investigated over nickel oxide‐aluminium oxide catalyst (2NiO·Al2O3) in a differential flow reactor between 300 and 360°C. A maximum yield of 98% was achieved with a catalyst having a Ni: Al atomic ratio of 1:1 and preheated in the presence of air at 600°C for 24 h. The rate equation Rn = kpknPpPn/(kpPp + knPn) deduced, assuming a steady state involving a two‐stage irreversible oxidation‐reduction process, represented the data most satisfactorily for conversion of 3‐picoline to nicotinonitrile. A tentative mechanism for the reaction is proposed.
Kinetics of removal of p‐toluene sulphonic acid from concentrated solution by granular activated carbon
Authors: Borthakur S. , Srivastava R. C. 
Published: July 2010

AbstractThe removal of p‐toluene sulphonic acid (p‐TSA) from concentrated solution by granular activated carbon (GAC) was studied in batch experiments. The first order rate constant was found to be 5.5010 × 10−5 s−1 for a solution of 1000 mg dm−3. In order to establish the rate limiting step the pore and film diffusion coefficients were calculated from the half time equations. Film diffusion was found to be rate limiting. The average value of the external mass transport rate constant was 2.91 × 10−6 cm s−1. The adsorption isotherm was adequately described by the Langmuir model and belongs to type ‘H’ of Giles' classification.
A mathematical model for the production of biosurfactants by Pseudomonas aeuginosa CFTR‐6: Production of biomass
Authors: Ramana K. Venkata , Charyulu N. C. L. N. , Karanth N. G. 
Published: July 2010

AbstractThe fermentation reaction producing biosurfactant using Pseudomonas aeruginosa CFTR‐6 was studied. The progress of the bioreaction was monitored in terms of biomass production, product formation and substrate consumption in shake flask experiments using different initial sugar concentrations. A logistic model for biomass growth was found to be satisfactory. Average estimates of the specific growth rate, biomass yield coefficient and maintenance coefficients were obtained.
Computational fluid dynamics and its application to transport processes
Authors: Collins M. W. , Ciofalo M. 
Published: July 2010

AbstractFluid transport behaviour is of great importance within the chemical process industry and in biotechnology. The complexity of this behaviour, reflected in the nature of the fundamental partial differential equations which describe it analytically, means that it has to be treated by numerical methods.In this paper the basic equations are given, and the approaches necessary to treat laminar and turbulent flows are carefully explained. As digital computers have increased in size, so has the comprehensiveness of the problems which can be treated, and the development of typical computer programs is described.Problems of accuracy and experimental validation are also surveyed, and it is shown that recent developments in whole‐field optical measurement methods, and image and data processing are all involved here. Then, a review of work at City University is shown to comprise typical examples of applications to engineering situations and biotechnology problems. Chosen instances of the former are flow and heat transfer behaviour for convective enhancement caused by roughness elements, and the design balancing of a thermosyphon. The latter include such diverse studies as blood flows in arterial bifurcations, and heat and mass transport in grain storage. They involve the three‐dimensional and transient capabilities of current codes, and their applicability to non‐standard geometries.
Physico‐chemical characterization of the main factors affecting the mode of action of liver alcohol dehydrogenase immobilized on nylon tubing
Authors: Roig M. G. , Bello J. B. , de Cells C. , Cachaza J. M. , Kennedy J. F. 
Published: July 2010

AbstractAlcohol dehydrogenase (ADH) from horse liver (EC 1.1.1.1), cross‐linked through the bifunctional reactive glutaraldehyde, onto nylon tubing was immobilized (35 μg cm−2 internal surface of nylon tubing). ADH inactivation kinetics of the immobilized enzyme are of first order (t1/2 = 84.3 h, k = 5.2 × 10−3 h−1 at 5°C; t1/2 = 2.6h, k = 0.26 h−1 at 50°C). The activity versus pH profile points to a smaller effect of pH on the activity of the enzyme, which is the case of ADH in solution, explicable on the basis of limitations to proton diffusion towards/from the support. A limiting effect to free external diffusion of the substrate (products) towards/from the support was observed; this effect seems to determine the effective kinetic behaviour of immobilized ADH.
The recovery of fructose from inverted sugar beet molasses using continuous chromatography
Authors: Barker Philip E. , Joshi Ketan 
Published: July 2010

AbstractThe continuous chromatographic separation of inverted beet molasses resulting in a fructose rich product and a product containing glucose and other non‐sugars was carried out using a semi‐continuous countercurrent chromatographic refiner (SCCR6), consisting of ten 10.8 cm diameter by 75 cm long stainless steel columns packed with a calcium charged 8% cross‐linked polystyrene resin, zerolit SRC14.It was found that cations present in beet molasses displaced calcium ions from the resin resulting in poor separation of the glucose and fructose. Three methods of maintaining the calcium form of the resin during the continuous operation of the equipment were established. Passing a solution of calcium nitrate through the purge column for half a switch period was found to be most effective as there was no contamination of the main fructose rich product and the product concentrations were increased by 50%.
A bioseparation process for removing lead(II) ions from waste water by using C. vulgaris
Authors: Aksu Zümriye , Kutsal Tülin 
Published: July 2010

AbstractBiosorption of heavy metals by microbial cells has been recognized as a potential alternative to existing technologies for removing heavy metals from industrial waste waters. Many aquatic microorganisms, such as algae, can take up dissolved metals from their surroundings to their cells. In this study, the adsorption of lead(II) ions was investigated in a single‐staged batch reactor. Chlorella vulgaris, a green alga, was used as the sorbent. The sorption phenomenon was expressed by the Freundlich adsorption isotherm and this expression was used for the calculation of residual or adsorbed metal ion concentration at equilibrium (Ceq or Cx,eq) at a given ‘volume of waste water containing heavy metal ion/quantity of alga (V0/X0)’ ratio in a single‐staged batch reactor. Experimental Ceq and Cx,eq values were compared to calculated ones. Applications in waste water treatment for lead(II) removal have been suggested.
Inhibition of growth and acetate uptake by ammonia in batch anaerobic digestion
Authors: Poggi‐Varaldo Héctor M. , Tingley Judy , Oleszkiewicz Jan A. 
Published: July 2010

AbstractAmmonia inhibition of unacclimated anaerobic mesophilic mixed cultures was studied in batch mode. Bacterial growth rate and specific acetate‐uptake rate were affected by the concentration of un‐ionised ammonia (UAN) in a three‐stage pattern: initial inhibition, plateau and final inhibition stage. The un‐competitive inhibition model provided the most reasonable data fit. The stage pattern of inhibition suggested that more than one mechanism of UAN inhibition are acting on the mixed culture. The effects of UAN on the length of initial lag‐time also followed a three‐staged curve. High concentration of UAN resulted in acetate release. The biological basis and origin of the acetate release were not determined.
Urease immobilized on chitosan membrane. Inactivation by heavy metal ions
Authors: Krajewska Barbara 
Published: July 2010

AbstractHeavy metal ion inactivation of urease covalently immobilized on glutaraldehyde‐pretreated chitosan membrane was compared with that of free urease. The relative toxicity sequence of metal ions toward free urease: Hg2+ > Ag+ > Cu2+ > Ni2+ > Cd2+ > Zn2+ > Co2+ > Fe2+ > Pb2+ > Mn2+ correlates well with metal sulfide solubility product constants (except for Fe3+). The stability of urease against metal ion inactivation was considerably improved after immobilization: Ni2+, Co2+, Fe3+, Pb2+ and Mn2+ do not inactivate the immobilized urease in the range of concentrations at which free urease is thoroughly inactivated. Hg2+, Ag+, Cu2+, Zn2+ and Cd2+ inactivate the enzyme at considerably higher concentrations. The improved stability may be a consequence of structural changes introduced to the enzyme by the immobilization and of chelating effect of chitosan.
Mechanism of acetic acid transfer from aqueous sodium chloride solutions to some orgranic solvents
Authors: Abu‐Shady Abdel‐Sattar I. , Amer Samir A. , Hegazi Mohamed F. 
Published: July 2010

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

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

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

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

AbstractThe anaerobic fermentation of deproteinized whey with β‐galactosidase coimmobilized with Saccharomyces cerevisiae in calcium alginate gel beads for the production of ethanol has been studied in a continuous horizontal packed bed reactor (HPBR). The results are compared with batch experiments in a stirred tank reactor.The immobilized yeast cells are exposed to conditions that vary with time and location in the reactor, making a true steady state impossible. In spite of a very low specific growth rate—of the order of 0.01 h−1 in the first section of the HPBR—the yeast cell growth, accompanied by bead expansion in this section, was high enough to create a cell concentration gradient along the reactor.The continuous reactor is preferable to the batch reactor as the galactose conversion is more efficient. The highest volumetric productivity obtained in the HPBR was 125 mol ethanol m−3 h−1 (6 g ethanol dm−3 h−1) at a substrate concentration of 164 mol m−3 lactose (56 g dm−3) and a dilution rate of 0.21 h−1, corresponding to a space velocity of 0.51 dm3 dm−3 gel h−1. The ethanol yield from consumed glucose and galactose was 80%. The ethanol yield from lactose was only 70%, as only 75% of the galactose was consumed while all the lactose and glucose were converted.
Upflow sludge blanket reactors: The effect of bio‐supplements on performance and granulation
Authors: Morgan J. W. , Evison L. M. , Forster C. F. 
Published: July 2010

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

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

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

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

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

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

AbstractVarious oxo‐dimethylallyl compounds were prepared from intermediates which are obtained by the reaction of allylic Grignard reagents with carboxylic acid derivatives. For example, the reaction of prenylmagnesium chloride with ethyl hexanoate gave 3,3–dimethyl‐4–prenyl‐1‐nonen‐4–ol (1) in 92% yield. The thermolysis of 1 at the temperature of 693 K gave 2–methyl‐2–decen‐5–one (2) in 81% yield. Furthermore, 3,3–dimethyl‐1‐alken‐4–ones (E) were prepared by the methylation of 1‐alken‐4‐ones (C), which are obtained by the reaction of allylmagnesium chloride with carboxylic acids (A).