bluuebunny/crossref_metadata_2025_split huggingface dataset:
A comparison of oxygen mass transfer into sodium sulphite solution and a biological system
Authors: Greenhalgh Spencer H. , McManamey William J. , Porter Kenneth E. 
Published: July 2010

AbstractTo explain previously reported discrepancies between oxygen uptake rates in biological systems and the sodium sulphite test system a comparison was made between oxygen mass transfer into a sodium sulphite solution catalysed by copper(II) ions, and into a biological system, the bacterium E. coli in a mineral medium. A stirred transfer cell, with a relatively low rate of physical mass transfer per unit area, and a bubble column, with a high physical mass transfer rate per unit area, were used to make this comparison; in both cases, the areas of gas/liquid contact could be determined. In the transfer cell the gas/liquid mass transfer coefficient for the biological system was only 10–25% of that for the sulphite oxidation system (for which the absorption rate was increased by chemical reaction). In the bubble column mass transfer into both systems was controlled by physical absorption and the mean mass transfer coefficients were similar for both systems. However, the mass transfer coefficient for the biological system increased with E. coli concentration, probably due to physical effects of the small particles.
Purification and properties of β‐amylase produced bybacillus polymyxa
Authors: Fogarty William M. , Griffin Patrick J. 
Published: July 2010

Abstract1,4‐α‐D‐glucan maltohydrolase (β‐amylase, EC.3.2.1.2.) produced byBacillus polymyxawas isolated and purified. Some of its properties were examined and compared with those of a typical plant β‐amylase. Hydrolysis of periodate oxidised amylose demonstrated an exo mechanism of substrate attack similar to that of sweet potato β‐amylase. The effect of sulphydryl reagents on enzyme activity was similar to that reported for plant β‐amylases. Consistent with the observation that the enzyme has an exo mechanism of action, it also failed to degrade Schardinger cyclodextrins. These latter compounds acted as inhibitors of the enzyme. The optimum temperature for activity was 37 °C. The enzyme was quite stable at temperatures up to and including 37 °C; 90% of the original activity remained after storage at 37 °C for 6 days. However, the stability decreased rapidly when exposed to temperatures above 37 °C; only 20% of the activity remained after 1 h at 45 °C. The hydrolase exhibited a rather sharp optimum at pH 6.8 for stability at 37 °C. However, the enzyme was quite stable in the pH range 6.4–7.2 at 20 °C but it was shown to be less stable in acidic conditions than the corresponding plant enzymes.
A model of sugar utilisation during batch beer fermentation
Authors: Fidgett Michael , Smith Eric L. 
Published: July 2010

AbstractA mathematical model describing the kinetics of sugar utilisation and changes in active yeast concentration during batch fermentation of brewers' wort is presented. Consideration is first given to the problems of modelling multiple substrate systems in which microorganisms can utilise carbohydrates both simultaneously and sequentially. Ideas outlined in the introductory sections are then used to develop a model of the beer fermentation process, and it is shown how the model can be matched to experimental data.
Ammoxidation of propylene by pulse reaction technique
Authors: Oka Hideaki , Ishimoto Seiichi , Miyamoto Toshiki , Harano Yoshio , Imoto Tatsuya 
Published: July 2010

AbstractThe ammoxidation of propylene on Fe‐Bi‐P mixed oxide catalyst was studied at 500 °C by the pulse reaction technique, to examine the effects ofP(P= 0–4) andP(P/P= 0–3) on the catalyst activity. Since the ammoxidation of propylene proceeds through consumption of oxygen from the catalyst even in the absence of oxygen, the reduction of catalyst progresses with the number of O2‐free pulse, losing its activity. In the presence of oxygen, however, the conversion of propylene and the selectivities of acrylonitrile, acetonitrile, CO2, and CO vary with the pulse number, but settle to some steady values corresponding toP/P. It is also found that the conversion and the selectivities depend on the oxidation state of the catalyst, the latter also depending onP/Pin the reactants, and that the catalyst working in the flow system may be being reduced to some extent.
Kinetics and mechanism for the thermal decomposition of chlorate ions in brine acidified with hydrochloric acid
Authors: Dotson Ronald L. 
Published: July 2010

AbstractThe kinetics for the thermal decomposition of chlorate ions in brine acidified with hydrochloric acid were studied from 0.0 to 4.0 mol/litre salt, within 1 : 1 to 18 : 1 acid to chlorate ratio ranges and from 70 to 105 °C. The rate expression for this process was observed to be first order in chlorate, second order in acid and exponential to the base e in the total molar chloride concentration. The rate limiting step has an activation energy of 35.056 kcal/mol. The overall reaction stoichiometry is explained and a mechanism proposed involving an ionic outer sphere complex and an activated, covalent inner sphere electron bridged penetration complex.
Quantitative effect of gritty contaminants on the sensitiveness of high explosives to initiation by impact. II. A non‐parametric variant of the bruceton procedure
Authors: Scullion Henry J. 
Published: July 2010

AbstractAspects of the quantification of the effects of additives, intentional or otherwise, are briefly discussed in the light of some unpublished work. Addition of gritty particulates causes not only a fall in insensitiveness but also (due to population distortion) a widening in the fiducial limits of any estimate made of that insensitiveness. To cope to some extent with this increased dispersion, i.e. to ascertain with known confidence whether small additions (sensitising or phlegmatising or both) have altered the level of insensitiveness, a simple and economic “non‐parametric” variant of the Bruceton procedure is described.
Studies of light fading of reactive dyes on cellophane
Authors: Shah Champaklal D. , Srinivasan Rajagopalan 
Published: July 2010

AbstractThe ratios of extinction of the short wave (y) and the long wave (x) band in the visible region of the absorption spectra of three reactive dyes on cellophane film and also in aqueous solution, both in the presence and absence of urea, have been measured. Also changes in the ratio with time of exposure were determined. The ratio is found to increase with the concentration of the dye in the fibre and also in aqueous solution. Urea causes disaggregation. The state of aggregation of reactive dyes in cellophane is found to be intermediate between that obtained in a polyester–disperse dye system and nylon or cellulose acetate or cellulose–triacetate–disperse dye system.
Ammoxidation of acrolein on catalyst of Fe–Bi–P mixed oxide system
Authors: Oka Hideaki , Miyake Keishiro , Harano Yoshio , Imoto Tasuya 
Published: July 2010

AbstractAmmoxidation of acrolein (Al) on Fe2O3‐Bi2O3‐P2O5 (44.5:44.5:11.0 mol%) catalyst was studied in a fixed bed reactor. The main products were acrylonitrile (AN), CO2 and acetonitrile; and CO was negligibly small. The rate equations for Al conversion and product formation, together with their apparent activation energies, were obtained. The reaction rates are controlled by the chemical reaction rates at temperatures below 340°C, while the external film diffusion rates are the rate determining steps at temperatures above 380°C. Assuming the chemical reaction controlling region, the conversion rate of Al at 400°C is about 1000 times faster than that of propylene. From the effects of feed composition on selectivities, it is concluded that AN is produced according to Hadley's path.
Multilayer adsorption with molecular orientation of asphalt on mineral aggregate and other substrates
Authors: Ensley E. Keith 
Published: July 2010

AbstractThe adsorption of asphalt on aggregate surfaces was studied by several experimental methods by the Bureau of Mines. The adsorption rate of asphalt on an aggregate surface was found by flowing asphalt through a column of aggregate and measuring the decrease in flow rate. Photomicrographs revealed a striated structure in the asphalt region near the asphalt–substrate interface. The photomicrographs suggest that, as asphalt molecules are adsorbed on substrates, the postulated large, sheet‐like molecules are aligned perpendicular to the interface. Perpendicular orientation of asphalt molecules near the interfacial region is also supported by evidence of dipole fields produced by the alignment of the asphalt dipoles. Contact angle measurements of 1‐bromonaphthalene on asphalt surface in prior contact to a mica surface further supports interfacial structuring. A multilayer adsorption mechanism, with preferred orientation of asphalt molecules on the aggregate surface, is proposed as an explanation of the observations.
Diffusion of benzene and toluene into aqueous nitric acid‐sulphuric acid mixtures
Authors: Hanson Carl , Ismail Hamed A. M. 
Published: July 2010

AbstractDiffusion coefficients of toluene and benzene into aqueous mixtures of nitric and sulphuric acids have been measured at 30°C by use of a laminar jet technique. Equations are presented which correlate the data in terms of the acid concentrations and permit extrapolation to acid mixtures of interest for industrial mononitration reactions. The results show the expected dependence on viscosity of the acid phase and are in agreement with values predicted by the Wilke and Chang correlation.
Kinetics of heterogeneous oxidation of ammonium sulphite
Authors: Mishra Girish C. , Srivastava Rameshwar D. 
Published: July 2010

AbstractThe heterogeneous oxidation of ammonium sulphite was investigated with cobalt sulphate catalyst at 30°C. For a wide range of concentrations the reaction was found to be nearly first order in oxygen and zero order in sulphite. These kinetics contrast with the results of homogeneous experiments which indicate that the reaction is zero order in oxygen and three‐halves order in sulphite. The catalytic effect of cobalt ions was found to be proportional to the square root of the total concentration of cobalt. The apparent activation energy for the overall oxidation was calculated to be 13 kcal/g mol. It is concluded that the kinetics in the heterogeneous system are determined by the catalyst regeneration reaction which is diffusion controlled.
Modelling of combined mass transfer‐kinetic effects in an enzyme membrane reactor system with a direct approach to the identification of intrinsic rate parameters
Authors: Hsieh Fengchi , Davidson Burton , Vieth Wolf R. 
Published: July 2010

AbstractA methodology for identifying non‐linear parameters in a generalised Briggs‐Haldane rate expression for immobilised enzyme membrane flow reactors has been developed for the intermediate case where mutually rate‐controlling processes of mass transfer and enzymatic reaction prevail. The technological significance of the estimation procedure lies in the ability of the algorithm to handle parameter identification in non‐linear, two‐point boundary value problems which are prevalent in both immobilised enzyme and non‐enzymic heterogeneous catalysed reactor systems. The methodology was successfully implemented on an experimental level using quasi‐steady‐state conversion data for the model system of urea/collagen‐urease in a spiral‐wound, biocatalytic reactor module. By using a novel procedure of pepsin pretreatment of the collagen host membrane before enzyme impregnation, followed by glutaraldehyde crosslinking, it was possible to enhance the activity and stability of the immobilised enzyme complex to relatively high levels where interphase and intraphase diffusional limitations mutually controlled the rate of reaction. Information on the coefficient of mass transfer at the interface between solid and fluid phases was also obtained as part of the estimation procedure.
Thermodynamic properties of the n‐hexane and benzene system at elevated temperatures
Authors: Medani M. Salah , Hasan M. Asad 
Published: July 2010

AbstractThe total vapour pressure and the composition of the liquid of the n‐hexane and benzene mixtures have been measured under equilibrium conditions at 90, 110, 130, 150, 170 and 190°C. The corresponding vapour phase compositions were estimated using an expression of the liquid phase activity coefficient as a function of composition of the liquid phase. Several expressions were compared and the three‐constant Redlich and Kister equation was found to give the best fit to the experimental vapour pressure data. The virial equation of state as well as a modified Redlich and Kwong equation were used to express the deviation of the vapour phase from the ideal. Results were compared and the discrepancy was found to be within the experimental tolerance. The low values of the liquid phase activity coefficients indicated that the behaviour of this particular system was not far from ideal. Also, it was found that the degree of deviation from the ideal decreased with the increase in temperature. The excess Gibbs free energy of mixing was calculated and it was found to be non‐symmetrical with liquid composition. On increasing the temperature of the system, the liquid composition corresponding to the maximum GE tended to shift to a lower n‐hexane concentration, while at fixed liquid composition, GE initially decreased and then remained stationary or increased again. This was thought to be due to differences in the molar volumes of the two components.
Analysis of cell metabolic products and fermentation gases by gas chromatography
Authors: Unger Petr , Vozňáková Zdena , Páca Jan 
Published: July 2010

AbstractA method for the estimation of ethanol and volatile fatty acids by gas chromatography by direct treatment of cultivation broth is described. The packing material was Hallcomid M‐18 with 1% H3PO4 on Chromosorb W AW. The separation was made at 132°C with nitrogen as a carrier gas; for detection a flame ionisation detector was used. The analysis of oxygen and carbon dioxide of the inlet and outlet gas from a fermentor was also studied. For the separation of the gases the combination of molecular seive 5A and Chromosorb 102 was used. The analysis was performed at 35°C with helium as a carrier gas and a thermal conductivity detector was used. With the experimental conditions found in this study the methods described gave reproducible and accurate results for the analytical control of cell cultivation processes.
Formation of ultrafine iron fluoride by use of the flame‐reactor technology
Authors: Mange Michel , Chatelut Francis , Eyraud Charles 
Published: July 2010

AbstractHighly dispersed iron fluoride samples were prepared by the very fast reaction between gaseous fluorine and iron pentacarbonyl in a flame reactor. The surface area of the sample depended principally on the reactant proportions and on the dilution of the reaction zone with an inert gas.
Lightfastness, phototendering and fluorescence of 3‐methoxybenzanthrone
Authors: Allen N. S. , McKellar J. F. , Protopapas S. 
Published: July 2010

AbstractStudies have been made of the fluorescence quantum yields and lifetimes, the photostability and the phototendering behaviour of 3‐methoxybenzanthrone in nylon 6,6 and in polyester to determine the nature of the primary process responsible for nylon phototendering. The results indicate that in a polar environment such as nylon 6,6 there is an increased probability of dye‐substrate interaction. The results of a study of the fluorescence quenching by amines of varying ionisation potential indicates that the primary process responsible for nylon phototendering may be one of electron abstraction from the substrate.
Thermolysis of mono‐, di‐ and tri‐benzylamines, IV
Authors: Badr M. Zarif A. , Aly Morsy M. , El‐Sherief Hassan A. H. , Rahaman Abdo E. Abdel 
Published: July 2010

AbstractThermolysis of mono‐, di‐ or tri‐benzylamine for some days in the absence of promoters gave the same products: ammonia, toluene, dibenzyl, stilbene and benzaldehyde. Thermolysis of dibenzylamine in isoquinoline as a solvent gave 1‐benzyl‐isoquinoline together with the normal pyrolysis products. When naphthalene and 2‐naphthol are used as solvents, benzylation of the solvent nuclei was observed to give 1‐ and 2‐benzylnaphthalenes and 1‐benzyl‐2‐naphthol respectively. In conclusion, thermolysis of tri‐, di‐ or mono‐benzylamines proceeds through a free radical mechanism with successive conversions of the tertiary, through secondary to primary alkylamines resulting in the same pyrolysis products.
The chemistry of ethyl silicate binders in refractory technology
Authors: Biddle Keith D. , Das Anup K. , Jones Kenneth , Emblem Harold G. 
Published: July 2010

AbstractThe chemistry of the processes involved when an alkyl silicate such as ethyl silicate acts as a binder in refractory technology is described. The gel forming process involving catalysed hydrolysis and condensation of ethyl silicate and tetra‐alkyl silicates has been studied using amine catalysts. Thermal studies of gels obtained from technical ethyl silicate and of gels obtained from technical ethyl silicate incorporated in refractory materials, together with infrared spectroscopy studies of gels obtained from technical ethyl silicate, suggest the nature of the degradation products, and the weight‐loss patterns observed support the proposed mechanisms.
The potentiometric titration of gum karaya aud some other tree‐exudate gums
Authors: Jefferies Martin , Pass Geoffrey , Phillips Glyn O. 
Published: July 2010

AbstractPotentiometric titration of gum karaya was used to determine the acid equivalent weight and the proportions of the acid groups in the salt form and the free acid form. Alkaline hydrolysis was used to determine the acyl groups attached to the gum. These determinations were also carried out with other tree‐exudate gums including gum arabic, gum jeol (Lannea coromandelica gum) and tree‐gums from Sterculia tragacantha, Acacia sieberana, Acacia polyacantha and Albizia zygia. Potentiometric titration also showed the presence of basic groups attached to the polyanion in some gums. The variation of viscosity with pH can be correlated with the potentiometric titration curve.
Photosynthetic production of biomass and starch by Chlorella in chemostat culture
Authors: Pirt Margaret Watts , Pirt S. John 
Published: July 2010

AbstractA high temperature strain of Chlorella was grown photosynthetically with nitrogen limitation of growth over a range of dilution rates up to the critical value of 0.22 h−1. The “total cell dry weight” is distinguished from the “real biomass” which is total cell dry weight less starch. Nitrogen‐limited growth of Chlorella, in terms of real biomass, obeyed the simple Monod model of chemostat culture. In a low EDTA medium (about 1 mol of EDTA per mol Fe3+) ferric hydroxide precipitated at pH 7 and caused iron‐limited growth to occur at high dilution rates. Iron precipitation and consequently iron‐limited growth, were prevented by increasing the EDTA to 2 mol per mol Fe3+. It was deduced that Fe3+ was available to the cells only as Fe‐EDTA complex, not as free Fe3+ in the medium. A glycogen‐like starch was stored in the cells and the starch content approached 50% of the total dry weight of cells at low dilution rates. The starch content of the total cell dry weight was practically independent of the growth temperature over the range 28–40°C and the pH over the range 5.5–8.5. The specific rate of starch production (qstarch) reached 0.05 g of starch/g real biomass h.
Influence of high partial pressure of carbon dioxide and/or oxygen on nitrification
Authors: Jones Gordon L. , Paskins Andrew R. 
Published: July 2010

AbstractThe advent of new intensive wastewater treatment processes with high rates of solution of oxygen, such as the oxygen activated‐sludge process and the Deep‐Shaft process, implies that there will be conditions of high concentrations of carbon dioxide and oxygen in the mixed liquor. These processes, as operated, have problems in maintaining nitrification. To determine how the above conditions affect the nitrifying bacteria, other than by reducing the pH, a mixed culture of nitrifying bacteria was maintained on a synthetic substrate in a computer‐controlled chemostat at constant pH and temperature, with different proportions of carbon dioxide and oxygen in the aeration gas. The specific growth rate of the ammonia‐oxidising bacteria was independent of the concentration of carbon dioxide in the gaseous phase when this was between 0.03 and 2.0%. The ammonia‐oxidising bacteria were initially inhibited by high partial pressures of oxygen but eventually became acclimatised and retained this property, even when grown for several generations at lower partial pressures.
Substrate utilisation by plant‐cell cultures
Authors: Fowler Michael W. 
Published: July 2010

AbstractPlant cell cultures have been grown on a wide range of carbon sources in addition to the traditional ones of sucrose and glucose. Biomass yields and growth rates vary greatly between the different carbon sources and there is a variation in response between different cell cultures to individual carbon sources. Some attempts have been made to grow cell cultures on ‘waste’ and related carbon sources, such as lactose, maltose, starch, molasses and milk whey. Only maltose was found to support growth to anything near the levels observed with glucose and sucrose. In the case of molasses carbon source cell growth was either non‐existent or only just measurable. All the data point to glucose as being the most suitable carbon source, principally on the grounds of biomass yield and growth rate. It should be noted, however, that other carbon sources do appear to have a major (positive) influence on natural product synthesis. Uptake into the cell is an important aspect of carbohydrate utilisation. There is strong evidence that from disaccharides upwards, major degradation to smaller units occurs before uptake. In some cases the necessary enzymes appear to be excreted into the culture broth, in others they may be located within the cell wall; invertase that hydrolyses sucrose is a good example. Once the products of carbohydrate degradation and mobilisation enter the cell they may suffer one of two fates, oxidation or utilisation for biosynthesis. The precise split between these two varies depending on such factors as cell growth rate, cell size, nutrient broth composition and carbohydrate status of the cells. In general rapidly growing cells have a high rate of oxidation, whereas cells growing more slowly tend to be more directed towards biosynthesis. Carbohydrate utilisation is a key area of study, underpinning as it does both biomass yield and natural product synthesis.
TAN: A new molluscicide and algicide from the fruits of Acacia nilotica
Authors: Ayoub Saad Mohamed Hussein 
Published: July 2010

AbstractTAN, a new molluscicide and algicide from the fruits of Acacia nilotica subsp. nilotica was produced on a pilot scale by spray‐drying. Being a natural product, TAN could, after treatment, become also an economic concentrated raw material in the tanning and pharmaceutical industries, and in the manufacture of dyes and inks.
Adsorption of dyestuffs from aqueous solutions with activated carbon II: Column studies and simplified design models
Authors: McKay Gordon 
Published: July 2010

AbstractThe design of batch contact and fixed‐bed adsorption systems has been discussed. A simplified design model (the Bed‐Depth Service Time model) has been proposed and tested. The effects of bed depth, dye flow rate and carbon particle size, for the adsorption of Telon Blue and Deorlene Yellow, have been correlated with this design procedure.