bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nitrogen containing additives in soda pulping of bagasse pith
Authors: Saad Saad Mohamed , Mohamed Hamdy A. 
Published: July 2010

AbstractUnbleached soda pulp was prepared from Egyptian bagasse pith by varying the alkali concentration and the time of heating at the boiling point of the liquor under atmospheric pressure. A linear relationship was observed between the dissolved pith and the dissolved lignin. Pulping with alkali concentration higher than 10% but not exceeding 16% was more effective, since more delignification took place with lower dissolved pith percentage. p‐ And m‐nitrobenzoic acids and also hydroxylamine hydrochloride had a slight or no effect on the yield of the pulps. The alkali solubility percentage of the pulps prepared in the presence of any of the additives was lower than the control pulp. The delignification was enhanced more on the addition of hydroxylamine hydrochloride than p‐nitrobenzoic acid, while m‐nitrobenzoic acid seemed to have no effect. The yield of the pulps thus prepared, as determined by weighing, showed lower values than those determined by a chemical method. The soda delignification rate was shown to be proportional to the amount of unremoved lignin and the concentration of alkali in the liquor. The delignification reaction was found to follow approximately first‐order kinetics.
Separation of iron from manganese ore roast‐leach liquor
Authors: Sahoo Pravat K. , Das Sarat C. , Bose Subir K. , Sircar Sisir C. 
Published: July 2010

AbstractThe leach liquor obtained after the extraction of manganese from a low grade manganese ore contained both manganese and iron. In this paper an attempt has been made to remove iron by aerial oxidation. Parameters such as pH, temperature and time were varied in order to arrive at an optimum condition. It was observed that at a temperature of 333 K, pH 5.5 and aeration time of 2.25 h the iron could be completely removed at an air‐flow rate of 1000 cm3 min−1 without any loss of manganese.
Benzo(a)pyrene metabolites formed by the action of yeast cytochrome P‐450/P‐448
Authors: Wiseman Alan , Woods Leonard F. J. 
Published: July 2010

AbstractBenzo(a)pyrene metabolites have been identified by high‐pressure liquid chromatography after production by a cytochrome P‐450 in brewer's yeast disruptates. The major metabolites are 7,8‐dihydro‐7,8‐dihydroxy‐benzo(a)pyrene, 9‐hydroxybenzo(a)‐pyrene and 3‐hydroxybenzo(a)pyrene. Pretreatment of the yeast with benzo(a)‐pyrene, during its growth decreases the Michaelis constant (Km) of the enzyme for benzo(a)pyrene, using either NADPH or cumene hydroperoxide as a cofactor.
Extraction of metals from sulphides using sulphur trioxide in fluidised bed
Authors: Ismail Mohamed I. 
Published: July 2010

AbstractThe kinetics of the reaction of chalcopyrite, iron sulphide, copper sulphide, and nickel sulphide with sulphur trioxide gas were studied using a fluidised bed technique. O2, N2, or air was used as a carrier gas for the sulphur trioxide in fluidisation. Binary mixtures of finely ground (0.37–75 μm) samples were reacted with the sulphur trioxide in a Pyrex column at 373–673 K. The reaction products were leached with water and the soluble metals in the solution were determined by atomic absorption spectrometry. The total soluble reaction products were determined gravimetrically. The results obtained showed that a higher yield of soluble salts was obtained when O2 or air was used as a carrier gas for sulphur trioxide than when an inert gas was used. Higher yields of soluble salts were obtained when the samples were most finely ground. Increase of copper sulphide content in binary mixtures with iron or nickel sulphide led to an increase in the yield of soluble salts. For iron sulphide/nickel sulphide mixtures, the yield of soluble salts increased with the nickel sulphide content. There were maximum values for the soluble metal ratios Ni/Fe and Cu/Ni in the corresponding sulphide binary mixtures and this maximum was at about 50% weight. The soluble Cu/Fe ratio increased with copper sulphide content in mixtures with iron sulphide.
Adsorption of phosphate ions by collodion‐coated alumina
Authors: Aharoni Chaim , Sideman Samuel , Hoffer Erica 
Published: July 2010

AbstractThe kinetics and the equilibrium adsorption of phosphate by collodion‐coated alumina granules were investigated. Collodion‐coated alumina can serve as a sorbent for phosphates in the treatment of hyperphosphatemic patients by haemoperfusion. The collodion coating lowers the surface area available for adsorption. The kinetics of adsorption were investigated by experiments in which the initial phosphate concentration, the quantity of sorbent and the grain size of sorbent were varied. The rate of adsorption is proportional to tα‐1 where t is time and α is around 0.7.
Analysis of microporosity and specific vapour sorption by zirconia gel
Authors: El‐Akkad Taghreed M. 
Published: July 2010

AbstractThe surface properties of zirconia gel and its thermal dehydration products obtained in the temperature range 300–1000°C (573–1273 K) were investigated through the adsorption of water, methanol and carbon tetrachloride vapours at 35°C (308 K). The non specific character of carbon tetrachloride makes it a good probe for detecting microporosity in the gel. Hydrophilic centres on the zirconia surface appear to function as favourable adsorption sites for polar water and methanol adsorbate molecule. The high values of the areas obtained from water adsorption for highly hydroxylated samples may be explained by the fact that the smaller polar water molecules can penetrate into narrow pores and interact with the hydroxyl groups located there. The presence of a high concentration of hydroxyl groups in the micropores is evident from the sharp decrease in the methanol uptake by zirconia gel, since methanol is known to interact specifically with hydroxyl groups existing in mesopores or on plane surfaces through hydrogen bonding.
A study of the anodic dissolution of gold in concentrated KCN solution
Authors: Pan Ting P. , Wan Chi Chao 
Published: July 2010

AbstractThe kinetics of anodic dissolution of gold in concentrated potassium cyanide solution was investigated. The mechanism was found to be magnified image with the second step being the rate determining step. Ultrasonic agitation increased the dissolution rate five‐fold. The mechanism however, remained unchanged. From current efficiency measurement, it was observed that no auric ions existed in the dissolution process.
Studies on the preparation of methyl bromide from sulphur, bromine and methyl alcohol
Authors: Bhavnagary Haiderali M. , Krishnamurthy Tirunillai S. , Majumder Suvendu K. 
Published: July 2010

AbstractOptimum conditions have been presented for the production of methyl bromide by employing the reactants, sulphur, methyl alcohol, liquid bromine and water. For the maximum recovery of methyl bromide from liquid bromine used in the reaction, a 5% excess of sulphur and 30% excess of water than the stoichiometric quantities were found necessary. The addition of liquid bromine to the reaction mixture at slower rates of 0.5 to 2.5 cm3 min−1, reduced the loss of bromine as sulphur bromide and increased the yield of methyl bromide from 42 to 94.3%. With these standardised conditions, the product had a methyl bromide content of 98.2% with an overall yield of 94.42% based on liquid bromine.
Partial oxidation of methane to formaldehyde over halogen modified catalyst
Authors: Mann Ranvir S. , Dosi Mahendra K. 
Published: July 2010

AbstractThe partial oxidation of methane to formaldehyde over Pd‐supported on Al2O3 in the presence of small amounts of halogen modifiers was investigated in an isothermal integral flow reactor at atmospheric pressure between 300 and 510°C. The effects of several variables, feed ratio of air to methane, reaction temperature, reciprocal of space velocity, and the type and amount of halogen modifiers on the conversion and product distribution, were determined by gas chromatography. Though 13 different mechanisms were postulated the rate of reaction was most satisfactorily correlated by a mechanism which assumes the rate controlling step to be the surface reaction between charged, adsorbed methane and oxygen.
The role of additives in the impregnation of platinum and ruthenium on alumina catalysts
Authors: Aboul‐Gheit Ahmed Kadry 
Published: July 2010

AbstractPlatinum‐ and ruthenium‐alumina catalysts are prepared in the absence and presence of additives during metal impregnation. In the absence of additives, metal penetration and distribution in the support pellets is poor, whereas in the presence of a proper additive, uniform metal distribution can be achieved. The metal dispersion in the support is found to be a function of its distribution. In Pt/Al2O3, the addition of HCl improve the distribution and dispersion of the metal as its concentration increases. However, the use of monoethanolamine as an additive achieves an abrupt improvement in the distribution and dispersion of platinum, followed by a region of slight improvement (pH range 2.5–6.5). With a further increase in the concentration additive of the platinum distribution and dispersion deteriorates due to excessive metal penetration and accumulation in the centre of the pellet. In ruthenium preparations, citric acid appears to be the best additive. Oxalic acid also improves ruthenium impregnation but needs to be added in larger concentrations than citric acid. The hydrogenation activity of the catalysts reflected the improvement of the Pt and Ru distributions and dispersions in the support pellets.
Solubility of cobalt complex soaps using Co58 as radiotracer
Authors: Jain Ajay K. , Siddiqui Muzayan J. , Singh Ramesh P. B. 
Published: July 2010

AbstractThe solubility of cobalt dichloro tetrammine soaps in aqueous and non‐aqueous solvents has been determined by using Co58 as a tracer. The soaps have been found to be relatively more soluble when compared with simple cobalt soaps and cobalt hexammine soaps. The results are interpreted in terms of weaker polar interactions between the ionic groups of soaps. The solubility data in benzene, toluene and m‐xylene has also been used to calculate the critical solution temperature and critical micelle concentration values of the soaps. It has been found that the higher the solubility of the soap, the lower is its critical solution temperature and the higher is its critical micelle concentration in a solvent.
Electroreduction of lauronitrile and stearonitrile
Authors: Krishnan V. , Mahalingam N. , Udupa H. V. K. 
Published: July 2010

AbstractHigher aliphatic amines are extensively used as wetting agents, corrosion inhibitors and as anti‐dusting agents. An electrochemical method for preparing laurylamine and stearylamine from their corresponding nitriles using nickel black cathode has been standardised in our laboratories. Both these nitriles underwent smooth reduction in ethanolic sulphuric acid medium to give a yield of around 80% amine for a current efficiency of 40–50%. Galvanostatic polarisation measurements indicated that the reduction is smooth only at lower current densities.
Direct measurement of microbial ATP in activated sludge samples
Authors: Kucnerowicz Felix , Verstraete Willy 
Published: July 2010

AbstractA procedure is described to determine ATP directly (i.e. without separated extraction) in sludge samples. For a series of laboratory units, linear relationships were observed between their ATP‐contents and their respective cell residence times, loading rates, substrate removal and oxygen uptake rates. The potential use of ATP as a control parameter for activated sludge is discussed.
The effect of polymer structure on soil physico‐chemical properties and soil water evaporation
Authors: Callebaut Freddy , Gabriels Donald , Boodt Marcel De 
Published: July 2010

AbstractThe effect of water‐soluble polymers and polymer emulsions upon the physico‐chemical properties of silt‐loam aggregates has been tested. The efficiency of soluble polymers depends on their concentration and molecular weight. Polymer emulsions induce hydrophobocity of soil surfaces. Waste lignosulphonates appear attractive at reducing soil water evaporation.
Hydrolysis of aromatic sulphonic acids in industrial effluents. II. Hydrolysis of amido‐J‐acid
Authors: Rossinelli Luca , Thies Hans , Richarz Werner 
Published: July 2010

AbstractThe kinetics of the acid‐catalysed hydrolysis of 6‐amino‐1,3‐naphthalenedisulphonic acid (amido‐J‐acid) were measured at temperatures of 533–573 K. The only product of the reaction is 2‐naphthol, the amino group being hydrolysed much faster than both sulpho groups. The hydrolysis can be described kinetically as a two‐step consecutive reaction. Rate constants and activation parameters were determined.
Electronic absorption spectra and acid—base equilibria of some arylaminoanthraquinones in aqueous medium
Authors: Idriss Kamal A. , Seleim Mohamed M. 
Published: July 2010

AbstractThe visible absorption spectra of 1,4‐di‐(4′‐methylanilino)anthraquinone (Alizarin Cyanin Green) and its disulphonated derivative (Quinizarin Green); 7,8‐dihydroxy‐1,4‐di‐(2′‐sulpho‐4′‐methylanilino)anthraquinone (Alizarin Viridine); 1‐hydroxy‐4(2′‐sulpho‐4′‐methylanilino)anthraquinone (Alizarin Irisol R) and 1,4‐dihydroxy‐2‐(2′‐sulpho‐4′‐methylanilino)anthraquinone (Alizarin Heliotrope) have been recorded in aqueous solutions at different pH values. The spectral changes are explained in terms of shifts in equilibria between different molecular and ionic species in the solutions. The pKa values have been determined for different acid‐base equilibria and discussed in relation to molecular structure. Release of a proton from the NH‐group in 1,4‐bis(arylamino) derivatives is liable to occur through mesomeric interaction between the imino‐nitrogen and CO group. The mesomeric shift is influenced by the pH of solution as well as the nature of compound.
The fate of carbon compounds in the landfill disposal of organic matter
Authors: Rees John F. 
Published: July 2010

AbstractLandfill sites containing domestic refuse should be managed so as to optimise methane production when hydrogeological conditions permit. On large sites this would be both economically profitable and environmentally desirable as uncontrolled pollution would be minimised and sites could be reclaimed as quickly as possible. Landfill microbiology has been confined to public health aspects, and clearly, further microbiological studies are required to optimise the degradation of carbon compounds. Knowledge of the fate of synthetic polymers is poor. It is interesting to consider whether they constitute a reservoir of delayed‐potential methane generation. Contrary to previous ideas it is concluded that there is no requirement for added nitrogen and phosphorus sources. The interaction of refuse density and water content is identified as a major factor which must be controlled to optimise methane generation. The high solids content and reactivity of this anaerobic bioreactor coupled with the poor thermal conductivity of refuse enables the landfill to generate and sustain high temperatures. The roles of refuse pretreatment, placement methods and water management techniques in the control and stimulation of refuse fermentation are also discussed.
The precipitation and some properties of alumina coatings on rutile
Authors: Cornell Rochelle M. , Posner Alan M. , Quirk James P. 
Published: July 2010

AbstractAlumina was precipitated on to rutile in four different ways to provide a series of alumina‐coated rutiles. There were two main types of precipitate. Type A with alumina precipitated in an acid medium and type B with alumina precipitated at pH 8. The two types of coating differed in appearance, surface area and in the nature of alumina present. For the type A coatings, the precipitate was irregular with much interstitial material and consisted of amorphous alumina of surface area < 100 m2 g−1. The type B coatings were compact and almost invisible and had surface areas > 140 m2 g−1. Alumina gels were precipitated under similar conditions to the type A and type B coatings and compared with these coatings to see if the presence of rutile had modified the type of alumina that formed.
Kinetics and diffusion processes in colour removal from effluent using wood as an adsorbent
Authors: McKay Gordon , Poots Victor J. P. 
Published: July 2010

AbstractThe rates of adsorption of a basic dye, Astrazone Blue, and an acidic dye, Telon Blue, on wood have been studied. The rate controlling step is mainly intraparticle diffusion, although a small resistance due to a boundary layer is experienced. The activation energies for the adsorption of Astrazone Blue and Telon Blue on wood are 16.8 kJ mol−1 and 9.6 kJ mol−1, respectively. The diffusion coefficients vary from 6×10−13 cm2 s−1 to 18×10−13 cm2 s−1 for Astrazone Blue at 18°C and from 3 × 10−13 cm2 s−1 to 8 × 10−13 cm2 s−1 for Telon Blue at 18°C. The variation in diffusivities is attributed to boundary layer effects.
Production of aromatic acids during anaerobic digestion of citrus peel
Authors: Lane Alan G. 
Published: July 2010

AbstractCommercially prepared citrus oils, distilled citrus oils, limonene and the non‐volatile fraction of lemon oils were all found to be toxic to the anaerobic digestion process for conversion of citrus waste to methane. Toxicity was characterised by appearance of benzoic, phenylacetic and phenylpropionic acids in the digestion liquors, though these acids were not in themselves toxic. The bulk of the phenylpropionic acid was derived from flavonoids.
Thermal decomposition of uranyl sulphate hydrate
Authors: Sato Taichi , Ozawa Fusaji , Ikoma Shuji 
Published: July 2010

AbstractThe thermal decomposition of uranyl sulphate hydrate (UO2SO4‐3H2O) has been investigated by thermogravimetry, differential thermal analysis, X‐ray diffraction and infrared spectrophotometry. As a result, it is concluded that uranyl sulphate hydrate decomposes thermally.
The dynamics of aerobic phenol biodegradation in lower greensand
Authors: Rees John F. , King John W. 
Published: July 2010

AbstractThe dynamics of phenol degradation in sedimentary rocks was examined by percolating phenol solutions, with no added nutrients, through columns of disturbed Lower Greensand. Phenol degradation was achieved at concentrations up to 16.7 g dm−3. Inhibition was evident at higher concentrations. Sterilisation of Lower Greensand by moist heat or irradiation completely destroyed its ability to degrade phenol. Non‐growing bacterial cells attached to sand and clay particles were responsible for phenol degradation. Zero‐ and first‐order rate values for phenol degradation increased with increasing flowrate. First‐order kinetics operated with respect to substrate concentration. At flowrates of 1 cm3 h−1 (0.063 cm h−1) the reaction approached zero‐order at phenol concentration above 9.2 g dm−3 but at flowrates of 3 cm3 h−1 (0.19 cm h−1) increasing the phenol input concentration above 9.7 g dm−3 resulted in strong inhibition of activity. The results are explained in terms of phenol degradation being limited by the diffusion of phenol across a stagnant liquid film surrounding the microbes.
Optimisation of methane production and refuse decomposition in landfills by temperature control
Authors: Rees John F. 
Published: July 2010

AbstractThe major contributions to the thermal regime of an anaerobic domestic refuse landfill are identified and quantified. These are heat of reaction, specific heat of water/refuse mixtures, heats of neutralisation, heat losses to air and soil, solar radiation and aerobic metabolism. It is shown that even in temperate climates, landfill temperatures can rise to 45°C and above under anaerobic conditions with the concomitant reduction in fatty acid concentrations in leachate. This has been confirmed with field observations. Management requirements for establishing and maintaining temperatures of about 45°C in an anaerobic landfill are identified. Principally these involve allowing water into the site from the bottom and maintaining an insulating layer of refuse of about 4 m above the water‐table in the landfill. The advantages of a bioreactive landfill are briefly discussed.
The use of the rotating platinum electrode at zero electromagnetic force for the microdetermination of phosphorus in phosphinic acid or phosphinate
Authors: Hammam Abbas M. , Idriss Kamal A. , El‐Komi Zanati R. 
Published: July 2010

AbstractAn amperometric method is described for the microdetermination of phosphorus using the rotating platinum electrode vs solid calomel electrode at zero electromagnetic force, based upon oxidation of phosphinic acid and phosphinate with potassium permanganate to phosphorus acid and phosphite, respectively, under the conditions described. The equivalence point is reproducible and lower concentrations can be determined than with the potentiometric method.
Synthesis of some new disperse anthraquinone dyes
Authors: Metwally Saoud A. M. , Youssef Mohamed S. K. , Younes Mansour I. 
Published: July 2010

Abstract1‐Hydroxy and/or 1‐aminoanthraquinone was allowed to react with formaldehyde in an alkaline medium to give 1‐hydroxy or 1‐amino‐2‐hydroxymethyl‐9,10‐dihydroxy‐anthracenes, which gave on air oxidation, hydroxymethylanthraquinone derivatives (I). Interaction of 1‐amino‐2‐hydroxymethylanthraquinone or its 4‐bromo derivative with carbonyl compounds in the presence of an acid catalyst gave (1,3)oxazine derivatives (II). The methylene group in position‐2 of the (1,3)oxazine ring was found to be highly reactive and reacted with carbonyl compounds to form the corresponding arylidenes (III). Selective oxidation of dimethyl oxazine derivatives with SeO2 gave the corresponding dialdehyde (IV), which interacted with aromatic amines to give the corresponding Schiff bases (V). The bromine atom in the 6‐position of II was easily replaced by aromatic amines to give blue disperse dyes (VI).
Use of the empirical slopes approach to predict gas solubility properties in some pure polar solvents and in binary mixtures containing polar solvents
Authors: Linford Roger G. , Thornhill David G. T. 
Published: July 2010

AbstractIn previous papers1,2 the theory of Hildebrand and Lamoreaux3 has been developed into the empirical slopes approach. This approach can be used to provide useful predictions of solubility, entropy of solution and related properties for gases in relatively non‐polar pure liquids and binary mixtures. It was anticipated1 that the empirical slopes approach could not be applied to polar solvent systems because the approach is based on regular solution theory,4,5 which is inapplicable to such systems. In this paper, however, it is shown that the empirical slopes approach can predict the solubility and entropy of solution of gases in polar solvents, and in binary mixtures containing these solvents. The predictions are compared with the experimental values and they are also given for certain gas‐pure solvent combinations which have not been studied experimentally. For gas solubilities in the binary mixtures the predictive accuracy and the merits of the empirical slopes approach are compared with those of some other theories.
Isobaric vapour‐liquid equilibria of the ternary system hexane‐benzene‐sulpholane
Authors: Rawat Bachan S. , Goswami Amar N. , Krishna Sri 
Published: July 2010

AbstractIsobaric vapour‐liquid equilibria for the ternary system hexane‐benezene‐sulpholane have been determined at 760 mmHg pressure. The data have been compared with those calculated using the NRTL equation. The NRTL constants obtained from the literature were evaluated from ternary liquid‐liquid equilibrium data for this system. The agreement between experimental and calculated values is reasonable.