bluuebunny/crossref_metadata_2025_split huggingface dataset:
A kinetic study on the reduction of manganese III in presence of citric acid
Authors: Guindy Nabila M. , Basily E. K. , Milad N. E. 
Published: July 2010

AbstractThe rate of reduction of manganese III stabilised by citric acid under variable conditions of Mn(III) concentration, ionic strength, pH and temperature in buffered media was found to obey a second order rate equation, first order with respect to Mn(III) autocatalysed by Mn(II). The reduction was found to proceed to an equilibrium value. The observed rate constants were found to follow a linear relationship with hydrogen ion concentration. Interpretation of results is based on the assumption that there are two reducible species in equilibrium; the aquocomplex and its hydrolysed form. A reaction mechanism is proposed to account for the experimental results. The overall energy (ΔE) and entropy (ΔS) of activation are compared with those for the reduction of Mn(III) in presence of other organic substrates.
The theory of fed batch culture with reference to the penicillin fermentation
Authors: Pirt S. John 
Published: July 2010

AbstractA batch culture of microbes fed continuously with culture medium is described as a “fed batch culture”. When a portion of a “fed batch culture” is withdrawn at intervals the system is described as a “repeated fed batch culture”.A fed batch culture may reach a “quasi‐steady state” in which the specific growth rate (μh−1) virtually = the dilution rate, that is, the ratio of medium flow rate to culture volume. In a quasi‐steady state the specific growth rate gradually decreases. A unique feature of a fed batch culture is that it allows continuous reproduction of the transient conditions between two specific growth rates, which can be chosen at will. Fed batch culture may be used to determine the relation between specific growth rate and the growth‐limiting substrate concentration and to determine the maintenance energy. Simple relations are derived to enable the concentrations of products to be predicted.The effects of different cycle times in repeated fed batch culture applied to the pencillin fermentation are discussed.Repeated fed batch culture should find a major application in the production of secondary metabolites which often are synthesised at maximum rates only transiently.
Prediction of effective thermal conductivity of two‐phase porous media by nomogram
Authors: Chaurasia P. B. Lal , Chaudhary D. R. , Bhandari R. C. 
Published: July 2010

AbstractA nomogram for the prediction of the effective thermal conductivity of two phase porous media is presented which is constructed according to the Chaudhary and Bhandari equation based upon the geometric mean of maximum and minimum thermal conductivities. A chart estimating the effective thermal conductivity values between probable limits and a nomogram determining porosity values are also included.
Derivation of a generalised monod equation and its application
Authors: Konak A. R. 
Published: July 2010

AbstractA generalised growth rate equation is derived which relates the specific growth rate of bacteria to the concentration of a limiting nutrient in a bacterial culture. Monod's simple hyperbolic and Teissier's exponential equations are shown to be two special cases of this general equation. It is also revealed that the so‐called Michaelis‐Menten constant in Monod's simple equation is inversely proportional to the maximum specific growth rate.
The basic lead nitrates I. Compounds formed by the reaction of orthorhombic lead monoxide with cold aqueous lead nitrate
Authors: Michell E. W. John 
Published: July 2010

AbstractSolid products of the reaction between orthorhombic lead monoxide and cold aqueous lead nitrate solutions in the range of molar proportions 1:3 to 3:1 PbO: Pb(NO3)2 have been studied by X‐ray powder diffraction (X.R.P.D.). Three distinct crystalline phases were recognised.Reasonably pure samples of monobasic lead nitrate dihydrate [dilead (II) monoxide dinitrate dihydrate], PbO.Pb(NO3)2.2H2O, were obtained at temperatures below 20 °C when the reactants were in the range of molar proportions 1:3 to 1:1 PbO: Pb(NO3)2. This compound seems to be stable below 20 °C, but it partially dehydrates at higher temperatures. It does not seem to have been reported elsewhere. Monobasic lead nitrate monohydrate [dilead (II) monoxide dinitrate monohydrate], PbO.Pb(NO3)2.H2O, was formed in isolation at temperatures between 25 and 30 °C when the reactants were in the range of molar proportions 1:3 to 1:1 PbO: Pb(NO3)2. This compound is stable at room temperatures, and is identical to phases which have been reported by other authors. Mixtures of these two substances were obtained at temperatures between 20 and 25 °C. Tribasic lead nitrate trihydrate [tetra lead (II) trioxide dinitrate trihydrate], 3PbO.Pb(NO3)2.3H2O, was formed in isolation at all temperatures in the range 15 to 30 °C when the reactants were in the molar proportion 3:1 PbO: Pb(NO3)2. This compound seems to be stable at room temperatures and has been reported elsewhere. When the reactants were in the molar proportion 2:1 PbO: Pb(NO3)2, mixtures of tribasic lead nitrate trihydrate with one or other (or both, depending on the temperature) of the monobasic lead nitrate hydrates were obtained.X.R.P.D. data are given for these three compounds, and a critical assessment is made of all the results in the cases of the two compounds for which published data already exists. Also, it is suggested that compounds of stoichiometries intermediate between that of a monobasic lead nitrate hydrate and that of a tribasic lead nitrate hydrate (and which have been described in the literature) can be only metastable in contact with water. The nomenclature used in this paper follows common industrial practise in naming basic lead compounds. However, scientific names are also given in parentheses when necessary.
The effect of amino acids and amino acid analogues on growth of an obligate methanotroph, Methylosinus trichosporium OB3b
Authors: Warner Philip J. , Drozd Jan W. , Higgins I. John 
Published: July 2010

AbstractThe sensitivity of the obligate methanotroph, Methylosinus trichosporium OB3b to a number of amino acid analogues and amino acids has been examined. Sulphaguanidine (5 μg ml−1) norleucine (100 μg ml−1) m‐fluorophenylalanine (50 μg ml−1), p‐fluorophenylalanine (50 μg ml−1) and S2‐aminoethyl‐C‐cysteine (1000 μg ml−1) inhibited growth. Proline, threonine, methionine and lysine (2–4 μg ml−1) also inhibited growth, but arginine and leucine at similar concentrations had no effect. Attempts were made to isolate amino acid analogue resistant mutants, which would be expected to overproduce amino acids. Two approaches were made, selection of spontaneous and induced mutants in plate culture, and selection of a spontaneous mutant during growth in continuous culture under selective conditions, but no mutants were obtained. Possible reasons for failure to obtain such mutants are discussed.
The extraction of citric acid from fermentation broth using a solution of a tertiary amine
Authors: Wennersten Ronald 
Published: July 2010

AbstractTertiary amines are effective extractants for citric acid. The effect of diluents on the extraction is very important since it affects the distribution of citric acid, the selectivity and the phase separation properties. The distribution coefficient for citric acid is strongly temperature dependent. This makes it possible to strip the acid into water at a higher temperature. Alamine 336 dissolved in a nonpolar diluent is a suitable solvent. Pilot plant runs show that the process is technically feasible.
Saccharification of bagasse using a counter‐current plug‐flow reactor
Authors: Fox David , Dunn Noel W. , Gray Peter P. , Marsden Warwick L. 
Published: July 2010

AbstractA method for the simulation of a 3‐stage counter‐current plug‐flow reactor (PFR) for the enzymic Saccharification of alkali‐treated (a.t.) sugar cane bagasse is described. The PFR gave higher conversion than a conventional stirred‐tank reactor (STR). The STR achieved 44.3% conversion while the PFR achieved 56.4% conversion using 11 % a.t. bagasse after 48 h. The PFR offers potential for more efficient mass transfer and enzyme utilisation, and reduced end product inhibition.
Growth of Thiobacillus ferrooxidans on ferrous iron in chemostat culture: Influence of product and substrate inhibition
Authors: Jones Carol A. , Kelly D. P. 
Published: July 2010

AbstractThiobacillus ferrooxidans was grown at pH 1.6 in continuous flow chemostat culture on ferrous sulphate as growth limiting substrate at dilution rates between 0.02–1.33 h−1. Iron oxidation and growth were subject to product inhibition by ferric iron and under some conditions substrate inhibition by ferrous iron. Product inhibition could be predominantly competitive or non‐competitive, and the mode observed depended partly on previous steady state conditions. The inhibition phenomena resulted in unique anomalous washout curves and complex relationships between steady‐state substrate, product and biomass concentrations, for which mathematical models are developed. For the growth states subject to non‐competitive inhibition by Fe3+ at D 0.073–0.99 h−1, the growth yield coefficient corrected for maintenance (YG) was 1.33 g dry wt (g atom Fe2+ oxidized)−1 and the maintenance coefficient (m) was 0.43 g atom Fe2+ oxidized (g dry wt)−1 h−1). For predominantly competitive states (D, 0.05–0.268 h−1) with 2–70 mM Fe3+ in steady states, YG was 0.36–0.38 and m was 0–0.04. A consequence of product inhibition and substrate inhibition was the possibility of more than one steady state product value and yield for a single steady state substate concentration. This was demonstrated experimentally. Substrate saturation coefficient, Ks (giving half maximum specific growth rate) for Fe2+, was 0.7–2.4 mM and maximum specific growth rate (μm) 1.25–1.78 h−1. The results presented reveal unusual and novel properties of T. ferrooxidans relevant to describing its activities in natural environments or in mineral leaching systems.
Study on the acid hydrolysis of Peat: 1. extraction of carbohydrates
Authors: Martin Antonio M. , Bailey Valerie I. 
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. Acid hydrolysis of peat yields soluble carbohydrates which can be utilised as fermentation media. In this work, Sphagnum peat moss was hydrolysed under various conditions of H2SO4 concentration, retention time, temperature, peat concentration, peat particle size distribution and original moisture content in the peat. The results suggest that mild conditions of hydrolysis, which will minimise possible negative effects on other nutrients available in peat, are adequate for the release of the carbohydrates present in peat. It was found that peat particle size distribution and original moisture content as well as peat concentration will also affect the yield of carbohydrates obtained.
Equalisation of specific growth rates for syntrophic associations in batch culture
Authors: Powell Godfrey E. 
Published: July 2010

AbstractThis paper describes an aspect of the growth dynamics exhibited by a ‘tight’ syntrophic association of two species in batch culture. Species X utilises substrate S and forms a product P. The substance P both inhibits the growth of X, by virtue of the thermodynamic back reaction, and constitutes the growth‐limiting substrate of the organism Y. It is predicted that the resulting dynamical balance in the level of P results in an equalisation of the specific growth rates of the two populations. It is demonstrated that the equalisation of specific growth rates is a characteristic property of tight syntrophic associations in general, and occurs whenever the growth dependencies on substances S and P satisfy certain qualitative conditions.
The influence of gas inlet design on gas hold‐up values for water and various solutions in a loop‐type air‐lift fermenter
Authors: McManamey William J. , Wase D. A. John , Raymahasay Sugat , Thayanithy Kuganakathasan 
Published: July 2010

AbstractGas hold‐up was measured in an external loop air‐lift fermenter for air in water, in sodium chloride and sodium sulphate solutions (concentrations between 0.025 and 1.0 kmol m−3), in glucose solutions (0.025 to 0.25 kmol m−3), sodium carboxymethyl cellulose (CMC) solutions (0.1, 0.2 and 0.5 mass %) and in suspensions of cellulose powder in water. Gas superficial velocities were up to 0.03ms−1. Two types of gas spargers were used: one had six holes each of 1.6mm diameter, the other was of porous metal, which produced very small bubbles. Porous metal spargers with different diameters were also used, to alter the fraction of the cross‐sectional area of the riser which was aerated (the ‘fractional aerated area’). The use of dimensionless gas velocities, obtained by dividing the superficial gas velocities by a characteristic velocity for each of the non‐Newtonian liquids and solid suspensions, made possible a general correlation between gas hold‐up, dimensionless gas velocity and the fractional aerated area, in bubbly flow conditions. The characteristic velocities for the electrolyte solutions could be related to the concentrations of the electrolytes. No general correlation could be obtained for gas slug‐flow conditions, although theoretically‐based relationships represent the results for each liquid. Gas slug‐flow was observed for the non‐Newtonian CMC solutions for most of the gas rates used at the lower concentrations; only at the highest concentration was bubbly flow found over a wide range of gas rates.
Functional properties of proteins in foods
Authors: Wilding Peter , Lillford Peter J. , Regenstein Joe M. 
Published: July 2010

AbstractThe measurement of functionality of protein food ingredients has developed somewhat haphazardly, probably due to the wide range of proteins used as ingredients and the diversity of foods. Studies of the physiochemical properties of proteins should enable prediction of a proteins response to process environments and prove more fruitful than many of the empirical measurements of functionality. The effects of pH, salt type and concentration on the phase behaviour of the oilseed globulin and arachin, demonstrates the complexity of protein solubility and the inadequacies of simple tests that have arisen. Studies of the effects of salts and conditioning on meat fibres, coupled with measurement of the location of water in pellets from water holding tests enable the latter to be applied with increased confidence. Comparison of the endothermic transitions observed on heating with the development of storage and loss moduli allow the contributions of domains of skeletal muscle myosin to gel structure to be investigated.
Modification of a novel protein product
Authors: McNairney James 
Published: July 2010

AbstractThe production of single cell protein (SCP) on an industrial scale has now been established using the ICI ‘Pruteen’ process. An economic process for the reduction of nucleic acid in the product has been developed: potentially it could be used to produce a protein concentrate suitable for human consumption. Controlled enzymic hydrolysis of this concentrate yields a range of protein products with improved functional properties.
Control of the proteolytic reaction and of the level of bitterness in protein hydrolysis processes
Authors: Adler‐Nissen Jens 
Published: July 2010

AbstractA generally acknowledged problem encountered in the use of enzymic hydrolysis for modification of food proteins is the formation of bitter taste. The bitter taste can be ascribed to hydrophobic peptides and results from the degradation of the protein substrate. The control of the level of bitterness is therefore to a large extent dependent on the control of the proteolytic reaction itself. Two methods for monitoring the proteolytic reaction are described: the pH‐stat technique and osmometry. Both methods give a quantitative expression for the degree of hydrolysis (DH) which is the percentage of peptide bonds cleaved. A low bitterness can usually be ascertained by restricting DH to low values (e.g. DH 3–5%). However, in certain protein hydrolysis processes which involve separation of the insoluble material, the reaction is continued to higher DH‐values. A reduced bitterness can then be obtained by iso‐electric precipitation of bitter peptides.
Inclusion of gas in casein and leaf protein precipitate particles and its effect on particle density
Authors: Munro Peter A. , Tan Boon K. 
Published: July 2010

AbstractFloating precipitates often encountered in laboratory and industrial protein precipitate handling operations include isoelectric casein precipitates, casein precipitates formed by salting‐out with ammonium sulphate, and heat precipitated leaf (lucerne) protein. These were investigated by measuring water‐free densities and the variation in particle moisture content with temperature, and for each type of protein precipitate the density of degassed particles was greater than the density of the suspending medium, though the density difference was always small. Floating protein precipitates were therefore caused by the inclusion of gas in precipitate particles. Gas bubbles are easily incorporated into protein solutions. Furthermore for many types of protein precipitate, the physicochemical changes used to cause protein precipitation also drive dissolved gas from solution. Calculations showed that the amount of gas evolved is sufficient to cause flotation of all the precipitate formed.
Photosynthetic production of Dunaliella biomass from natural salt water and carbon dioxide
Authors: Cortiñas Teresa I. , Silva Humberto J. , Ertola Rodolfo J. 
Published: July 2010

AbstractA Dunaliella strain has been isolated and grown in a medium containing saline lake water. Using 40% saline water and mixture of CO2‐air (4% CO2) the algae grew with a specific growth rate of 0.073 h−1. The maximum cell concentration was 5.6 × 107 cells cm−3 which corresponded to 3.63 g dm−3 of dry biomass. Using 80% saline water, a glycerol concentration of 1.47 g glycerol g−1 of, protein was obtained which amounted to 44.3% of Dunaliella dry weight. Fermentor CO2 from a continuous yeast culture was also used as carbon source for photosynthetic growth. At 2.5% CO2 in the exit gas a decrease of the specific growth rate was observed but the final concentration attained was comparable to that obtained with CO2‐air mixtures.
Electrochemical treatment of effluents: A preliminary study of anodic oxidation of simple sugars using lead dioxide‐coated titanium anodes
Authors: Ho C. C. , Chan C. Y. , Khoo K. H. 
Published: July 2010

AbstractThe electrolysis of simple sugar solutions, containing 0.5% NaCl or Na2SO4, using lead dioxide‐coated titanium mesh anodes in a simple electroflotation cell indicated that electrode corrosion and dissolution of polluting Pb2+ ions from the electrode material were negligible even after prolonged use; the sugars were concomitantly electrooxidised at such anodes. The rate of electrooxidation followed linear removal kinetics and the relative ease of electrochemical destruction was in the order sucrose>maltose∼glucose. Such oxidation processes represent added advantages in the use of these electrodes in electrochemical treatment of effluent containing the sugars. Cyclic voltammetric analysis of the glucose solution indicated that oxygen evolution on the lead dioxide‐titanium anode appeared to be promoted by the presence of the sugar. A much more detailed study is required to give further insight into the mechanism of the anodic oxidation of these compounds.
Preparation and characterisation of dipotassium trizinc hexacyanoferrate (II)
Authors: Dave T. N. , Indusekhar V. K. 
Published: July 2010

AbstractThis paper summarises our findings on the properties and cation exchange behaviour of a new silica‐based dipotassium trizinc hexacyanoferrate (II) (DTH) prepared under varying conditions of precipitation which possesses good ion‐exchange properties. The product is characterised by i.r. spectra, thermal decomposition, X‐ray diffractogram and its ion‐exchange properties have been studied under different conditions. The separation of Rb+ and Cs+ is described.
Studies on oxidative dehydrogenation of n‐butane on bismuth molybdate‐aluminium phosphate catalysts. II. Activity and selectivity
Authors: Shenoy Subhash C. , Rao Musti S. 
Published: July 2010

AbstractOlefins and diolefins are important intermediates in the petrochemical industry, and the future promises a further substantial increase in demand. Several catalysts have been formulated in the past for the abstraction of hydrogen from butenes and propylene. However, these catalysts are inefficient in the abstraction of first hydrogen from n‐butane. Bismuth molybdates (β‐ and γ‐phases) on aluminium phosphate have been found to be good catalysts for the oxidative dehydrogenation of n‐butane. Optimal conditions for the yield of (butene+butadiene) have been established in the ranges of variables studied, using response surface methodology and the following ranges of experimental conditions: temperature, 400 to 500°C; W/F (catalyst to feed ratio), 0.25 to 2.5g/(mg mol/min); butane to oxygen ratio, 0.5 to 2.0mol/min; bismuth molybdate to o‐AIPO4 ratio, 0 to 100mol/100 mol. A maximum yield of approximately 13% (butenes+butadiene) was obtained in the ranges of experimental variables studied.
Effect of selected impurities on the continuous precipitation of calcium sulphate (gypsum)
Authors: Budz Jerzy , Jones Alan G. , Mullin John W. 
Published: July 2010

AbstractThe effects of selected cationic and anionic impurities on the precipitation of gypsum in aqueous brine have been studied in a continuous MSMPR crystalliser. Crystal size distributions, determined by in situ Malvern laser light‐scattering measurements, were found to be bimodal. The suspected presence of agglomerates was confirmed by microscopy. Aluminium and maleate ions both enhanced the degree of agglomeration, but reduced the overall growth and nucleation rates. Contrary to expectation, fumarate ions also exerted an observable effect on both agglomeration and crystal growth.
Interaction of isobutene and methacrolein with silica‐supported uranium and molybdenum oxide catalysts
Authors: Fierro Jose Luis G. , Salazar Emilio , Legarreta Juan A. 
Published: July 2010

AbstractThe adsorption of isobutene (in the temperature range 309–341K) and methacrolein (in the temperature range 296–336 K) on a Mo/(Mo+U)=0.89 catalyst were studied. The equilibrium data were analysed according to Freundlich's model. The high coverages observed at lower temperatures suggest some participation of physical adsorption in the reversible adsorption. Entropy calculations showed that these adsorbed species are best described by a mobile model which assumes bidimensional translation and two rotational degrees of freedom. Isobutene is weakly chemisorbed, producing reversible species which were identified as a π‐complex formed by interaction with surface OH groups through π‐electrons (infrared bands at 1655, 1615, 1470 and 1375 cm−1), and only a small fraction of isobutene interacts strongly via lattice oxygen forming intermediate species in the oxidation reaction. However, in the presence of oxygen at 523 K a majority of the surface species are strongly held by the surface (infrared bands at 1775, 1723, 1610, 1460 and 1350 cm−1 associated to a methacrylic complex and bands at 1590 and 1538 cm−1 of carbonate‐carboxylate species).
Crushing strength as a diagnostic test for catalysts
Authors: Hutchings Graham J. 
Published: July 2010

AbstractThe usefulness of catalyst pellet crushing strength as a diagnostic test for catalysts is discussed with reference to examples using industrial catalysts. In particular, the applicability of the technique for (i) re‐use of partially used catalyst charges, (ii) comparison of prospective catalysts and (iii) investigation of the effect on catalysts of probable plant failures is described.