bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of residence time spectrum in the oligomerisation of isobutene from mixed butenes
Authors: Gupta Ashok K. , Gupta Om P. , Bhattacharyya Kshitindra K. 
Published: July 2010

AbstractThe influence of the residence time spectrum on the conversion, selectivity and product composition in the oligomerisation of isobutene from mixed butenes in a continuous stirred‐tank reactor was studied at a temperature of 65 °C and impeller Reynolds number in the range of 36 × 104 to 67 × 104. The average residence time and its spectrum affected the conversion of olefins in the feed gas, the selectivity and the octene yields. It was established that for best yields of 2,4,4‐trimethyl pent‐1‐ene obtained from the mixed butenes feed, the residence time spectrum should be as narrow as possible. The results indicate that for good yield and selectivity in iso‐octene production from a C4 olefin fraction, Reynolds number of mixing of around 68 × 104 or slightly higher would be most desirable.
The stabilisation of PVC: A study of the reaction of dry hydrogen chloride with white lead suspended in hot mineral oil
Authors: John Michell E. W. 
Published: July 2010

AbstractThe reaction of dry hydrogen chloride with a suspension of white lead in hot mineral oil (MO) has been studied by withdrawing samples and examining the solids by X‐ray powder diffraction (XRPD). The white lead basic lead carbonate was slowly converted into tribasic lead chloride, which itself reacted to form “basic lead chloride X”, and this was finally converted into normal lead chloride. Similarities between this reaction sequence and that observed when plumbonacrite (another basic lead carbonate) was used as a thermal stabiliser in an unplasticised polyvinyl chloride (PVC) blend indicate that this plumbonacrite behaved to a large extent as a scavenger for hydrogen chloride produced by thermal decomposition of the polymer. However, it is suggested that true stabilisation (by free radical exchange reactions which retard thermal decomposition of the polymer) may also take place to varying extents in rigid (unplasticised) PVC blends, depending on the formation and mobility of intermediate stabilising species (the most effective of which seem to be the lead compounds of organic acids). This behaviour is different from that in plasticised materials where true stabilisation seems to be the dominant reaction. XRPD data are tabulated for the uncharacterised “basic lead chloride X”.
Oxidation of ferrous hydroxide suspensions. II
Authors: Prasad Turaga P. , Ramasastry Vemuri V. 
Published: July 2010

AbstractFerrous hydroxide suspensions, obtained by the addition of sodium carbonate to ferrous sulphate solutions, have been oxidised. The rates and extents of oxidation have been studied at room temperature (28±3°C) as a function of time by varying the air flow rate, concentration of sodium carbonate and concentration of ferrous sulphate. Expressions have been obtained giving the relation between the velocity constant, k, and the air flow rate as well as k and the concentration of ferrous sulphate.
Effect of electric field on isomer ratio formed during the mononitration of toluene
Authors: Hanson Carl , Pratt Michael W. T. , Sohrabi Tahereh , Sohrabi Morteza 
Published: July 2010

AbstractThe distribution of isomers in mononitration of toluene is demonstrated to be dependent upon the properties of the solvents involved. An empirical model has been derived to relate the isomer ratio with the dipole moments and dielectric constants of the solvents. Based on this observation, an investigation into the effect of electric field on the distribution of isomers in continuous mononitration of toluene has been carried out.
Side reactions in hydrogenolyses of substituted benzylic alcohols with palladium–carbon catalysts
Authors: Tyman John H. P. 
Published: July 2010

AbstractIn the hydrogenolysis of methoxy‐substituted benzylic alcohols side reactions of demethoxylation and ring saturation can occur under mild conditions which depend on the activity of the palladium–carbon catalyst used. Chromato‐graphic and spectroscopic examination of reaction products is desirable to find the extent of by‐product formation.
Barley grain as carbon substrate for fungal protein production in a farm process
Authors: Reade Austin E. , Smith Ronald H. 
Published: July 2010

AbstractA simple, non‐aseptic, submerged aerobic fermentation was sought in which microbial protein could be synthesised from non‐protein nitrogen, at the expense of barley carbohydrate, to supplement the protein content of barley grain for non‐ruminant feeding. Screening of 23 isolates of fungi in shake flask cultures showed that microbial protein could be successfully produced by a number of different species in a medium containing barley as a source of carbohydrate. Protein synthesis was markedly affected by the addition of different sources of non‐protein N to the fermentation; and (NH4)2SO4 or urea proved to be good N sources in this respect. Aspergillus oryzae was selected as the most suitable species for protein synthesis, based on its performance when supplemented with the various N sources. The growth rate of A. oryzae in stirred culture was such that high yields of mycelial protein could be achieved within 24 h from a culture inoculated with a spore suspension. Under the conditions of growth used in these experiments there appeared to be little advantage in adding more than 2% barley to the medium. Higher yields of protein could be achieved at barley concentrations in excess of 2%, but only if the incubation period was extended. The tolerance of A. oryzae to low pH values was exploited to enable fungal cultures to be grown under non‐aseptic conditions. Good yields of protein were obtained in 40 litre cultures grown at pH 3.5 in a modified domestic washing machine. Although protein yields were poor, non‐aseptic growth was also sucesssful at pH 3.5 in 1000 litre cultures grown in an agricultural feed‐mixing vessel.
A new model for a hollow fibre enzyme reactor
Authors: Mashelkar R. A. , Ramachandran P. A. 
Published: July 2010

AbstractA new model based on the concept of axial dispersion has been developed for predicting the performance of a hollow fibre enzyme reactor. It is shown that a simple closed form analytical solution for the prediction of the reactor performance results. The model parameters are obtained a priori from the welldefined hydrodynamic conditions. The agreement between the model predictions and the numerical solutions is excellent over a wide range of variables. The comparison of the model predictions with the experimental data shows good agreement. The model can be easily extended to include further complications. The extension to non‐Newtonian substrates is discussed and results for reactor performance under these conditions are given.
Thermal conductivity of suspension and emulsion materials
Authors: Chaurasia Pramod B. Lal , Chaudhary Dhanraj R. , Bhandari Roop C. 
Published: July 2010

AbstractA technique for the prediction of effective thermal conductivity of porous materials previously developed by the authors has been extended to suspension and emulsion systems and its capability is supported by the available experimental data. A nomogram which estimates the effective thermal conductivity for these systems from the knowledge of constituent conductivities and proportions is also provided.
Solvent extraction of metals from chloride solutions
Authors: Lawson Gregory J. 
Published: July 2010

AbstractA review is presented of a series of investigations into the extraction of copper, iron, zinc and cadmium into kerosene solutions of Lix or Kelex reagents from aqueous solutions containing chloride ions. The effects of chloride ions on the extraction of copper and iron were smaller than might have been expected to result from the formation of inextractable metal chlorocomplexes, and the extractants retained their selective properties. Extraction with Kelex 100 from chloride solution increased the separation between zinc and cadmium, in comparison with sulphate solutions.
Kinetic analysis of gluconic acid production byPseudomonas ovalis
Authors: Ghose Tarun K. , Ghosh Purnendu 
Published: July 2010

AbstractA simple growth model is proposed on the basis of the reaction scheme for the conversion of glucose to gluconic acid. The model considers the combined effects of both glucose and oxygen substrates. Kinetic analysis of the system has been made. Computer solution of the equations proposed are obtained and the adequacy of the models confirmed.
Recovery of boric acid from ulexite by leaching with hydrochloric acid derived from waste chlorine gas and froth flotation
Authors: Yarar Baki 
Published: July 2010

AbstractA process for producing boric acid from ulexite and the recovery of the product by flotation is described. It was found that the degree of conversion of ulexite to boric acid decreased with rising HCl concentration. The undissolved mineral, together with other impurities such as clays, could be depressed by Quebracho, Orzan‐S, Daxad‐23 or starch, the first two being more effective. Concentrates assaying 97.1% H3BO3 were obtained without resorting to recrystallisation of the product. No flotation reagents other than the above‐mentioned were necessary for the process.
Derivatives of 4‐amino‐2‐nitrodiphenylamine as dyes for synthetic polymer fibres
Authors: Peters Arnold T. 
Published: July 2010

AbstractThe synthesis of a series of substituted 4‐amino‐2‐nitrodiphenylamines is described. These compounds dye synthetic polymer fibres in bordeaux to violet‐blue shades of moderate to poor light fastness. Light fastness properties are enhanced by the use of substituents which decrease the basicity of the 4‐amino group; such substitution, however, results in colour shifts into the yellow to orange region.
Hydrolysis of o‐ and p‐nitrochlorobenzene with aqueous sodium hydroxide to the corresponding nitrophenols
Authors: Bhave Madhav D. , Chandalia Sampatraj B. 
Published: July 2010

AbstractThe hydrolysis of o‐ and p‐nitrochlorobenzene with aqueous sodium hydroxide was studied at temperatures of 100–160°C and at a pressure corresponding to the vapour pressure of the aqueous solution, so that the system was maintained in the liquid phase. The rate of reaction, as well as the yield and quality of the product, were poor when no catalyst was used. The use of cuprous oxide and manganese dioxide as catalysts was found to be suitable for the process. The effects of temperature, amount of caustic soda, ratio of aqueous phase to organic phase, type and amount of catalyst, speed of agitation and period of reaction on the conversion and yield of nitrophenols were studied with a view to obtaining the most suitable conditions for the production of o‐ and p‐nitrophenol.
Kinetics of the catalytic oxidation of carbon monoxide over oxide catalysts
Authors: Sharma Chandra S. , Ramachandran Palghat A. , Hughes Ronald 
Published: July 2010

AbstractThe kinetics of the oxidation of carbon monoxide over five commercially available oxide catalysts have been determined at CO concentrations of 4–15 mol% and initial temperatures up to 170°C. The reaction showed a fractional dependence on the concentration of CO and was inhibited by CO2. From an analysis of the data a Langmuir‐Hinshelwood reaction scheme is proposed.
Apparatus for slab polyacrylamide gel electrophoresis
Authors: Ewart J. A. D. 
Published: July 2010

AbstractAn apparatus for eight‐channel gel electrophoresis on polyacrylamide slabs is described. It can be easily and cheaply constructed. The use of the buffer for cooling enables high voltage gradients to be applied giving good separation and resolution in under 2 h. A destaining apparatus, which does not use electrophoresis and is suitable for slab or “disc” gels, has been developed.
Reduction characteristics of Fe‐Bi‐P mixed oxide catalysts and their ammoxidation activities of propylene
Authors: Oka Hideaki , Harano Yoshio , Imoto Tatsuya 
Published: July 2010

AbstractThe characteristics of Fe‐Bi‐P mixed oxide catalysts of different compositions for reduction by propylene or ammonia and the ammoxidation activities of propylene were studied using a McBain type thermobalance and the pulse reaction technique respectively. By comparing the dependency of the reduction characteristics and catalytic activity with oxide composition and also the reduction rates and reoxidation rates of the reduced catalyst it was concluded that the ammoxidation of propylene on Fe‐Bi‐P mixed oxide catalyst proceeds through alternate repetition of reduction by propylene and reoxidation by oxygen, and that abstraction of allylic hydrogen from adsorbed C3H6 is the rate determining step.
Polymer‐attached palladium‐τ‐complexes
Authors: Hojabri Fereidun 
Published: July 2010

AbstractPalladium‐τ‐complexes can be attached to polymers producing a new type of palladium catalyst, with the properties of heterogeneous catalysts, for the polymerisation of certain olefins. Two different methods of linkage are described: (a) fixation through a phosphine ligand, and (b) formation of a τ‐complex between palladium and polymer support.
A model for diazacyclopropane synthesis
Authors: Jagannadharao Yaddanapudi , Viswanath Dabir S. 
Published: July 2010

AbstractThe formation of 3‐methyl‐3‐ethyl diazacyclopropane, an intermediate in the manufacture of hydrazine and its derivatives, was studied by reacting chloramine, ammonia and methyl ethyl ketone in a semi‐batch reactor provided with a stirrer. The conversion (based on chlorine) was found to increase with ammonia to chlorine ratio (8–20), agitator speed (1000–3000 rev/min), temperature (5–65°C), and lower ketones. The reaction was mass transfer controlled and first order with respect to chloramine with an activation energy and frequency factor of 5.67 kcal/gmol and 4.61 s−1 respectively. The stirred cell model due to Gal‐Or and Resnick represented the experimental data with an average absolute deviation of 5.3%.
Recovery of sulphur from calcium sulphate by reaction with carbon tetrachloride vapour in the presence of active charcoal
Authors: Bhuiyan Nurul Haque , Rahman Matiur 
Published: July 2010

AbstractWith a view to recovering the sulphur component of calcium sulphate, the action of carbon tetrachloride vapour on calcium sulphate in the presence of active charcoal was studied in the temperature range 600–900°C. The reactions that took place can be represented as
Aerobic degradation of hydrocarbons in soil. Significance of an initial rise in oxygen uptake rate following contamination with oil
Authors: Blakebrough Norman , Garner Philip J. , Knap Arne H. , Raisbeck J. Micheal , Heppell David 
Published: July 2010

AbstractThe addition of hydrocarbon oil to soil results in a marked, though brief, increase in the rate of oxygen uptake by the soil. Investigation of this phenomenon in an electrolytic respirometer has shown that it cannot be accounted for by oxidation of part of the added hydrocarbon. It is probably due to microbial lysis or the release of nutrients induced by addition of the oil.
Energy requirements for single cell protein production
Authors: Lewis Christopher W. 
Published: July 2010

AbstractThe direct and indirect energy inputs to SCP production by microbial fermentations from six different substrates are assessed, together with labour and land area requirements. Future energy savings envisaged with improving technology are described, and found to be of minor significance. From an energy point of view SCP production from hydrocarbon substrates compares most unfavourably with that from carbohydrates, particularly carbohydrate wastes, although the former is less land intensive. Large‐scale units give greater protein yields per unit of labour than do small‐scale plants. The applicability of SCP to Third World food problems seems limited due to its high energy production requirements.
Azeotropic data for the systems formed by representatives of the homologous series of alkanes and alcohols
Authors: Roekens Edward J. L. , Verhoeye Lucien A. J. 
Published: July 2010

AbstractData on azeotropic mixtures published in the literature often show large scattering. In this study two experimental methods are developed for determination of these data: one method is based on determination of the position of the minimum in the boiling point curve; the other method is based on distillation by means of a very efficient column. Both methods are applied to the systems formed by the representatives of the homologous series of alkanes from pentane to nonane branched hydrocarbons also included and of the homologous series of alcohols from ethanol to pentanol. The results obtained by both methods are in good mutual agreement. This increases the reliability of the data. The data are also computed by means of a method based on the group contribution method. Agreement of computed and experimental data is satisfactory.
Ammoniothermal treatment of silica gel and simultaneous changes in surface area
Authors: Girgis Badie S. 
Published: July 2010

AbstractA high surface area silica gel was structurally modified by autoclaving in ammonium hydroxide solutions with pH values of 9–12, at temperatures of 100–180°C, and for periods up to 5 h. Drastic variations in the texture of the xerogel took place leading to a considerable decrease in the specific surface, and to an accompanying increase in the mean particle diameter, pore radius, and number of OH groups per unit area. The extent of change depends generally on the temperature, duration of treatment, and pH of solution, although the last factor seems to be the most prominent. Such variation is ascribed to the enhanced dissolution of silica in the alkaline solution. Activation energies of hydrolysis of the siloxane bond were calculated as 17.2–19.0 kJ/mol, from a relationship correlating change in surface area with time.
Synthesis of some new styryl oxazolophenoxazines
Authors: Metwally Saoud A. M. , Youssef Mohamed S. K. 
Published: July 2010

AbstractReductive acetylation of 3‐aminophenoxaz‐2‐one (II) gave 3‐acetylamino‐2‐acetoxy‐phenoxazine (IV). Thermolysis of (IV) gave 2‐methyl‐5H‐oxazolo(4,5‐b)phenoxazine (V). The styryl derivatives (VIII) were synthesised by condensation of (V) with aromatic aldehydes. Quaternisation of (V) was carried out giving (VII). Oxidation of (V) using SeO2 gave 2‐formyl‐5H‐oxazolo(4,5‐b)phenoxazine (VI). Fragmentation patterns of certain of the products under electron impact are suggested.
Analysis of some adsorption isotherms on calcium silicate hydrates
Authors: Bye Gerald C. , Chigbo Gilbert O. 
Published: July 2010

AbstractTricalcium silicate was hydrated in suspension at a water/solid ratio (w/s) of 9 and as a paste at a w/s of 0.7. Water contents after outgassing at room temperature were 23–25% for the suspension hydrates and 19–20% for the pastes. Outgassing was standardised so that subsequent increases in BET nitrogen surface area were small even when the pumping time was doubled. Nitrogen adsorption isotherms were similar for both types of product except for the greater volume of mesopores in the suspension hydrates filled at relative pressures greater than ca 0.9p0(rp > 100 Ǎ). Electron microscopy suggested that the additional uptake of nitrogen involved capillary condensation between bundles of fibrils. Adsorption at low relative pressures would have occurred principally between the fibrils which were of the order of 20 Ǎ thick. Pore sizes could be seen to extend continuously from the mesopore to micropore range and the fact that all the isotherms contained a hysteresis loop closing with an abrupt desorption at ca0.44p0 was regarded as a property of liquid nitrogen rather than as an indication of the pore size distribution. A more quantitative indication of the pore size range present was obtained using the αs method with standard data for Fransil (silica). Plots for pastes were similar to those for suspension hydrates indicating a similar texture accessible to nitrogen in the pastes at the high w/s used. In order to characterise further the surface of the hydrates argon and carbon dioxide adsorptions were determined and the data compared using the Frenkel–Halsey–Hill equation.
Effect of thermal treatment on Egyptian rice straw hardboard
Authors: Fadl Naim A. , Sefain Magdi Z. , Rakha Mohomed 
Published: July 2010

AbstractThe effects of thermal treatment on the bending strength and water resistance of Egyptian rice straw hardboard manufactured with, or without, different amounts of resins, were investigated. The bending strength falls with increase in heating time and temperature for samples up to 1.5% resin; whereas hardboard with 3% resin showed an initial improvement in bending strength after heating at 140, 160 and 180°C. Heating samples at 200°C drastically reduces bending strength. Water resistance of all samples was improved by heat treatment.
Reactions of substituted anthracenes with nitric acid
Authors: Morley John O. 
Published: July 2010

AbstractThe reactions of sodium anthracene‐1‐ and 2‐sulphonates and disodium anthracene‐1,5‐ and 1,6‐disulphonates with concentrated nitric acid at 100°C lead to the formation of the corresponding anthraquinonesulphonates in good yield. Similarly, 1,5‐dichloroanthracene gives 1,5‐dichloroanthraquinone. In contrast, disodium anthracene‐1,8‐disulphonate, 1,8‐dichloro‐ and 1,4,5,8‐tetrachloro‐anthracene and sodium 4‐5,dichloroanthracene‐1‐sulphonate react under the same conditions to give the appropriate substituted 9,10‐dihydro‐9‐hydroxy‐10‐oxoanthracene (oxanthrone) as the major product.
Influence of inorganic salts on the hydration of tricalcium silicate
Authors: Kondo Renichi , Daimon Masaki , Sakai Etsuro , Ushiyama Hiraotaka 
Published: July 2010

AbstractThe influence of various chlorides and potassium salts on the hydration of alite (3CaO·SiO2solid solution) has been studied by conduction calorimetry and an explanation based on diffusion experiments in hardened Portland cement is presented. The mechanism of the action of inorganic electrolytes on cement hydration was also investigated. In hardened Portland cement the diffusion rate of the Cl−ion was greater than that of the coexisting cations. The accelerating effect of inorganic electrolytes was dependent mainly on the mobility of anions. The higher the anion mobility, the greater was the accelerating effect on the hydration. It is shown that the hydration of alite is a topochemical reaction and that the rate of hydration of alite is controlled by the rate of the dissolution of Ca2+or OH−ions into a liquid phase. It is concluded that the dissolution of OH−ions from the hydrate layer around the cement particle is increased when the reciprocal diffusion action of the anion accelerates the hydration.
Spectroscopic investigation of some derivatives of oxycellulose in cadoxen solution
Authors: Blair Henry S. , Cromie Ronald 
Published: July 2010

AbstractCondensation methods for the estimation of carbonyl groups in oxycellulose are briefly reviewed. The u.v. absorption spectra of solutions of oxycellulose and some of its derivatives in cadoxen have been examined. The results show that solutions of oxycellulose, its semicarbazide derivative and its thiosemicarbazide derivative are unsatisfactory for the spectrophotometric determination of carbonyl content, whereas the phenylhydrazine derivative may be used for an approximate determination; p‐nitrophenylhydrazine however is shown to be an excellent reagent for this determination.