bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermal decomposition of uranyl sulphate hydrate
Authors: Sato Taichi , Ozawa Fusaji , Ikoma Shuji
Published: July 2010

The 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

The 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

The 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

An 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

1‐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

In 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

Isobaric 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.
Renaturation of irreversibly thermodeactivated invertase
Authors: Yamamoto Ryuzo , Ooshima Hiroshi , Harano Yoshio
Published: July 2010

The renaturation of thermodeactivated invertase was studied by means of a denaturation method with 6.0 mol dm−3 guanidine‐HCl solution and the effects of temperature, pH and concentration of 2‐mercaptoethanol on the activity recovery examined. The optimum pH and temperature for activity recovery were found to be 7.0 and 35°C, respectively. These were found to be in the same region as those for aspartase and trypsin, but the renaturation rate was much slower. This may be due to the contribution of the sugar moiety in invertase (the so‐called ‘glycoenzyme’) which, it has been suggested, contributes to the thermal stability of an enzyme.
Alginate matrix‐supported acetylcholinesterase
Authors: Awad Aida , Awad Olfat
Published: July 2010

A natural matrix‐supported acetylcholinesterase was prepared from alginate extracted from a green algae commonly found in Egyptian fisheries. The COO− ions of alginate‐entrapped acetylcholinesterase protein molecules forming the basic groups. Calcium ions fixed to the anionic groups contributed to preserving the activity of acetylcholinesterase when stored for long periods of time. The effects of thermal denaturation and of various organophosphorus inhibitors upon the matrix‐supported enzyme have been determined. In all cases the supported enzyme appeared to be less affected by the inhibitor than was the free enzyme.
The chemical destruction of polychlorinated biphenyls by sodium naphthalenide
Authors: Smith James G. , Bubbar Gurbachan L.
Published: July 2010

Sodium naphthalenide, which is easily prepared from sodium and naphthalene in tetrahydrofuran (THF) as solvent, is examined as a chemical reagent for chemically destroying polychlorinated biphenyls (PCBs) by quantitatively dechlorinating them. The reaction is shown to be successful with dechlorination occurring in excess of 99.5% at 22°C in 15–30 min. Maximum concentrations of PCBs in THF and minimum naphthalene:chloride ratios are established. Recovery and reuse of THF and naphthalene is investigated as is the nature of the polymeric dechlorinated organic product obtained. A small reactor is described which is used to sequentially destroy PCBs in batch reactions reusing recovered THF and making efficient use of the sodium metal.
2‐Hydroxyacetophenone via fries rearrangement and related reactions: A comparative applied study
Authors: Hocking Martin B.
Published: July 2010

The feasibility of direct preparation of phenyl acetate (I) from phenol and acetic acid has been proved. Thermal rearrangement of I was tested in the presence of the proton acids methane sulphonic, sulphonic cation exchange resin, methane‐ trisulphonic, sulphuric acid and its monohydrate, phosphoric, oxalic, trichloroacetic, sodium hydrogen sulphate, and the potassium fluoride‐hydrogen fluoride complex (KFHF). All except oxalic and trichloroacetic acid and KFHF gave o‐, and p‐hydroxyacetophenone, with a larger proportion of the o‐hydroxyketone at high temperatures. The rates, product ratios, and yields of these processes are recorded and compared. Aluminium chloride, zinc chloride, and boron trifluoride all gave faster reactions than the proton acids, and for low temperatures with the last at least, higher ortho: para ratios. All the Lewis acid catalysts were somewhat more intractable to use. Comparative results between the two sets of catalysts are presented together with the results of a few miscellaneous related experiments.
The activation of alumina spheres with platinum for the catalytic oxidation of organic air pollutants
Authors: Irwin James G. , Moss Ronald L.
Published: July 2010

The activation of alumina spheres with platinum to provide catalysts for the control of malodorous or toxic process emissions by destructive oxidation is examined with respect to the amount of platinum required, its location (determined by electron probe microanalysis) and dispersion (measured by selective chemisorption). The oxidation of dimethyl sulphide (8 volumes 10−6 in air) or n‐butanal (100 volumes 10−6 in air) at realistic space‐velocities were used as test reactions and the best spherical catalysts were compared with platinum‐honeycombs.
Production of active manganese dioxide in an electrochemical pump cell
Authors: Ghoroghchian Jamal , Jansson Robert E. W.
Published: July 2010

Active manganese dioxide has been produced in an electrochemical pump cell by the oxidation of manganese sulphate in sulphuric acid and the production rate and current efficiency have been related to the transport of the intermediate (Mn3+) ions. Space‐time yields of 87–96 mol h−1 m−2 have been obtained, with current efficiencies of 93–86%, depending on current density. It is shown that an energy consumption of about 4 kWh kg−1 can be achieved with continuous production of active MnO2.
Induction and repression of enzymes in microbial culture
Authors: Toda Kiyoshi
Published: July 2010

Kinetic models of induction and repression of microbial enzymes are reviewed with a special emphasis on the mathematical formulation of quantitative aspects of the regulation mechanisms. In connection with this, some chemostat data have been collected from the literature. These illustrate several types of relationship existing between enzyme‐specific activity and dilution rate.
Evaluation of extraction properties of N‐methylpyrrolidone and ethylene glycol mixtures by gas chromatography
Authors: Wardencki Waldemar , Tameesh Adnan H. H.
Published: July 2010

Gas chromatography has shown that the selectivity of binary mixtures of N‐methylpyrrolidone with ethylene glycol for aromatic hydrocarbon extraction purposes increases with increasing amounts of ethylene glycol in the mixture and is optimum in the range of 50–70% (w/w) of ethylene glycol. This was attributed to hydrogen bonding between the two solvents used.
Criteria for the prediction of diffusional control within whole cells and cell flocs
Authors: Webster Ian A.
Published: July 2010

Drawing on theory pertaining to diffusion and reaction within porous solids, criteria have been developed which allow the importance of substrate diffusional limitations within whole cells, or cell flocs to be gauged. These criteria are dependent on the rate law used to describe substrate consumption. Criteria have been developed specifically for Monod, substrate‐inhibited, Teissier and maintenance‐type kinetics. Application of these criteria merely requires that certain ‘observable’ physical and kinetic data be known. An example has been described to illustrate the application of these criteria.
The chemical nature of algal (Chlorella) starch and its estimation in whole cells
Authors: Pirt Margaret Watts , Pirt S. John
Published: July 2010

The estimation of the starch content of chlorella cells was based on the sonication of whole cells in 2M NaOH followed by heating to solubilise the starch. The starch content of the solution was estimated by measurement of the glucose equivalents formed by acid hydrolysis. The starch content of the neutral solution was estimated by measuring light absorbance of its blue complex with iodine. The chlorella starch was purified from cells which had been disrupted in a French press, and the starch was solubilised by boiling with water. The starch was deproteinised, desalted and finally precipitated with ethanol before drying. This purification procedure avoided alkali extraction which degrades the starch. β‐Amylase digestion of the purified starch was found to convert 67% of it to maltose. The purified starch gave a bright blue complex with iodine with peak absorbance at 590 nm.
Role of amino acids and micronutrients on biosynthesis of spiramycins
Authors: Ashy Mohamed A. , El‐Galil Abd , Khalil M. , Abou‐Zeid Abou‐Zeid A.
Published: July 2010

The production of spiramycin using a synthetic basal medium, to which amino acids, vitamins and metallic ions were added, was investigated. L‐Tryptophan was found to be the amino acid which best increased the antibiotic yield. Addition of vitamins to the fermentation medium did not increase the antibiotic output, while the addition of different concentrations of trace elements such as Co(NO3)2 ZnCl2 (NH4)2Mo7O24 and MnCl2 improved the antibiotic yield. High concentrations of these trace elements decreased the antibiotic yield and directed the microbial activities towards biosynthesis of spiramycin II and III—these are less toxic than spiramycin I. Optimum concentrations of Co(NO3)2, ZnCl2, (NH4)2Mo24O7, MnCl2 which supported the antibiotic yield were 5 × 10−1, 5 × 10−3, 5 × 10−3 and 5 × 10−3 g dm−3, respectively.
Studies of the uptake of vitamin B12 by styrene‐based porous polymeric adsorbents
Authors: Anand Pritpal S. , Dasare Balkrishna D.
Published: July 2010

Porous polymeric adsorbents based on styrene were studied for the uptake of vitamin B12 from aqueous solutions under static conditions. The effect of various parameters on the uptake was studied. The uptake of vitamin B12 by polymeric adsorbents and their subsequent elution from the polymer matrix was also studied under dynamic conditions to assess their utility for the isolation of this compound. Results obtained point to their potential use for the recovery of vitamin B12.
Studies of the uptake of vitamin B12 and theophylline by phenol‐based porous condensate cation exchangers
Authors: Khose Narayan M. , Dasare Balkrishna D.
Published: July 2010

Porous condensate cation exchangers based on phenol were evaluated for the uptake of vitamin B12 and theophylline from aqueous solutions under static conditions. The effect of various parameters on the uptake was studied. The uptake of these compounds by porous cation exchangers and their elution performance from polymer matrices were studied under dynamic conditions to assess their utility for the isolation of medicinally important compounds. The results obtained indicate that they may prove useful in this respect.
Carbon‐ and nitrogen‐limited growth of Penicillium chrysogenum in fed batch culture: The optimal ammonium ion concentration for penicillin production
Authors: Court Jeremy R. , Pirt S. John
Published: July 2010

Fed batch culture was used to investigate penicillin production when the growth of Penicillium chrysogenum was limited by the supply of either sucrose and or ammonium ions. It was found that a ‘quasi steady state’ (in which the growth rate was virtually equal to the dilution rate) could be established under these conditions. Some metabolic parameters (specific sucrose consumption rate and growth yields) were dependent on the ratio of sucrose: ammonium ions in the feed medium over a range of ammonium concentrations both above and below the double substrate‐limited point. The maximum specific rate of penicillin production required the supply of a large excess of ammonium ion, about five times the growth‐limiting level. That is, the ratio of ammonium‐nitrogen: sucrose, fed to the (sucrose‐limited) culture, was 0.11 and the residual ammonium ion concentration was in excess of 18 mmol dm−3, at a dry biomass concentration of 0.6%.
The kinetics of hydrodesulphurisation of thiophene over a Cobalt‐molybdenum catalyst
Authors: Sharma Nagesh , Chakravarty Purnanand , Kar Anil K.
Published: July 2010

Hydrogenolysis of thiophene in naphtha has been investigated over a series of unsupported and γ‐alumina‐supported cobalt‐molybdenum catalysts at atmospheric pressure using a fixed‐bed microreactor. A kinetic expression describing the effects of temperature and space velocity was verified experimentally. The hydrogenolysis of thiophene was found to be 0.8th‐order with respect to thiophene and first‐order with respect to hydrogen. The activation energy of the reaction over cobalt‐molybdenum (Co3O4—MoO3 weight ratio 25:75) catalysts was found to be 27.5 kJ mol−1. X‐ray analysis of the various cobalt oxide‐molybdenum oxide catalysts shows that MoS2 or MoO2 + MoS2 may be the catalytic agent in this reaction.
Effects of flow and electrical arrangement on the performance of some simple electrochemical reactor systems
Authors: Mustoe L. H. , Wragg A. A.
Published: July 2010

The designer of electrochemical reactors is faced with a wide choice of operating strategies and, especially in multi‐cell systems, with alternative methods of flow and electrical connection. Here, some reactor systems of the type which might be used for the recovery of metals from aqueous solutions are analysed and three specific systems discussed: (i) multi‐cell cathode systems with single pass of electrolyte, with varying connection methods; (ii) a two cell, single reservoir, system with batch recirculation of the electrolyte and galvanostatic operation; and (iii) a single cell single reservoir batch recirculating system with continuous feed and take‐off in four distinct locations. Reactors are considered to operate under diffusion‐controlled kinetics and plug flow conditions and reservoirs are considered to be well mixed.
Effect of ammonia on the thermal decomposition of ammonium nitrate
Authors: Kołaczkowski Andrzej , Biskupski Andrzej , Schroeder Jerzy
Published: July 2010

The effect of the partial pressure of gaseous ammonia on differential thermal analysis and thermogravimetric curves of ammonium nitrate has been determined. Observed variations of the thermal effect and decomposition rate constitute a basis for considering the factors which determine the decomposition and equilibrium of exo‐ and endothermic processes.
Solid‐phase acylating polymer reagents. II. Amino acids acetylation in aqueous solution
Authors: Gosselet Martine , Sebille Bernard
Published: July 2010

Some amino acids have been acetylated in aqueous solution by an active polymeric reagent containing thiolester functions in yields depending upon the nature of the amino acids, and which increased with time and pH (until pH=12). The different reactivities of amino acids can be explained in terms of steric hindrance around the NH2 group. An increase of the transfer yield in the presence of imidazole, BO3H2− or Ag+ ions has also been demonstrated.
Adsorptive properties of carbons prepared by the pyrolysis of binary mixtures of textile fibres
Authors: Ordoyno Neville F. , Rowan S. Michael
Published: July 2010

Carbons prepared by the pyrolysis of binary mixtures of textile fibres (i.e. wool/Courtelle and Terylene/Courtelle) were activated by reaction with carbon dioxide at 1206 K. Adsorption isotherms using carbon dioxide at 195 K were determined for all the activated carbons. The mercury densities of selected polymer carbons were also determined. For the majority of activated carbons from both binary fibre systems the variation of xc (the volume of gas adsorbed measured at a relative pressure P/P0 = 0.3) for each degree of activation examined was found to be a non‐linear function of the composition of the original fibre mixture. In the case of carbons prepared from mixtures of high Courtelle content, increasing activation was found to lead to an initial increase followed by a marked decrease in the magnitude of xc. In addition, the mercury densities of such carbons exhibited an initial decrease followed by a marked increase in magnitude with progressive activation. It is considered that the behaviour of carbons prepared from binary mixtures comprising a fusing fibre (i.e. wool, Terylene) and a charring fibre (i.e. Courtelle) is consistent with that expected if coating of the charring fibre by the fusing fibre occurs during the pyrolysis process. This fused fibre coating is effective in retaining within the residue volatile degradation products from the charring fibre. These degradation products are eventually permanently incorporated within the residue blocking the porosity of the carbon derived from the charring fibre. This pore blocking effect is particularly marked in carbons prepared from mixtures of high charring fibre content where activation to 50% burnout results in a carbon of negligible accessible porosity as determined by gas adsorption measurements.
The effect of nitric oxide and nitrogen dioxide on the thermal decomposition of ammonium nitrate
Authors: Kolaczkowski Andrzej , Biskupski Andrzej
Published: July 2010

The effect of the partial pressures of nitric oxide and nitrogen dioxide in the gaseous phase (0–0.1 MPa) on the profile of differential thermal analysis and thermogravimetric curves for ammonium nitrate, on its rate of decomposition (from 388 to 548 K), and on nitric acid concentration in the condensed phase have been investigated. Both compounds were found to increase the isothermal decomposition rate and also to lower the temperature of initiation. The results of these studies have led to the conclusion that as the factors causing an increase in the concentration of both compounds in ammonium nitrate increase, the possibility of ignition or explosion also increases.
Electrolytic flotation in effluent treatment
Authors: Backhurst John R. , Matis Kostas A.
Published: July 2010

A study of electrolytic flotation applied to a typical paint effluent is described. The feasibility of the process was determined by the measurement of clarification time and effluent quality. The current density, conductivity of the solution and the initial concentration were taken as the operating variables. Information on flotation characteristics obtained from batch tests were compared with a continuous flow unit. Flotation kinetics were studied and settling was taken as a basis for comparison of results.
Some methods available for treatment of waste water in the dairy industry
Authors: Bull Michael A. , Sterritt Robert M. , Lester John N.
Published: July 2010

Methods of treating dairy waste water are reviewed. Typical ranges of the effluent characteristics are presented, conventional methods of treatment are discussed and their disadvantages highlighted. Emphasis is placed on less common techniques of treatment including processes involving by‐product recovery.
Optimum conditions for the electrochemical synthesis of aminomalononitrile
Authors: Fahmy H. M. , Elnagdi M. H. , Kandeel Z. E. , Pierre G.
Published: July 2010

Polarographic data of a series of methyl hydrazonomesosalonitriles are reported and discussed. The optimum conditions for the electrochemical synthesis, isolation and characterisation of amonimalononitrile are described in detail.
Mathematical model of gluconic acid fermentation by Aspergillus niger
Authors: Takamatsu Takeichiro , Shioya Suteaki , Furuya Toshiyuki
Published: July 2010

A mathematical model for the study of gluconic acid fermentation by Aspergillus niger has been developed. The model has been deduced from the basic biological concept of multicellular filamentous microorganisms, i.e. cell population balance. It can be used to explain the behaviour of both batch and continuous cultures, even when in a lag phase. A new characteristic, involving the existence of dual equilibrium states during fermentation, has been predicted using this mathematical model.
Concentration of alcohols by adsorption on silicalite
Authors: Milestone Neil B. , Bibby David M.
Published: July 2010

Silicalite, a zeolite analogue, selectively adsorbs organic molecules from aqueous solution, the adsorption depending on the stereochemistry and organophilic nature. This provides a possible economic route for the separation of alcohols from dilute solutions. Ethanol has been concentrated from a 2% (w/v) solution to 35%, and butan‐1‐ol from 0.5 to 98% (w/v) by adsorption on silicalite and subsequent thermal desorption.
Thermal studies on kraft black liquor
Authors: Nassar Mamdouh M.
Published: July 2010

Kraft black liquor and lignin from the same batch were subjected to thermal analysis (DTA and TGA) under an inert atmosphere and also in an oxidising atmosphere to simulate conditions which might be encountered in the recovery furnace. Gasification studies were carried out by rapidly heating the sample under helium. Results showed that the thermal decomposition of black liquor can be divided into four characteristic steps: drying up to 200°C, pyrolysis between 200 and 550°C, inorganic sodium salt formation between 550 and 800°C and salt fusion between 800 and 1000°C. Gases evolved during gasification of black liquor are rich in flammable compounds while those from the lignin sample are rich in CO2.
Solution behaviour of some divalent metal carboxylates in organic solvents
Authors: Akanni M. Sola , Burrows Hugh D. , Ellis Henry A. , Asonwed D. Ngu , Babalola H. Babatunde , Ojo Patrick O.
Published: July 2010

The solubility behaviour is reported of long chain carboxylates of lead(II), zinc(II), mercury(II), copper(II), cadmium(II) and manganese(II) in various organic solvents. Two types of behaviour were observed. In dekalin and pentan‐3‐one, the temperature at which 1 % concentration gave a solution was found to be higher than that for higher concentrations. This behaviour is interpreted in terms of solubilisation of a mesophase of the soap. In all other cases, Krafft type behaviour was followed, where the solubility was low up to a certain critical temperature and then increases dramatically. Krafft points have been determined in these cases, and were found to be linear functions of the carbon chain length of the carboxylate. The solubility of lead(II) decanoate and tetradecanoate has been studied in a series of aliphatic alcohols, and Krafft points are found to be linearly related to the alcohol chain length. Values in the branched chain alcohol octan‐2‐ol are higher than in the corresponding straight chain alcohol. The results are interpreted in terms of hydrophobic interactions. Values of Krafft points of the hexadecanoates of various divalent metals in toluene showed a good linear correlation with second ionization potentials of the metals for all cases, except lead. Electronic spectra of copper(II) carboxylate solutions indicate the presence of aggregates, probably reversed micelles. Dilute solutions of copper(II) decanoate in hexan‐1‐ol decomposed on warming to give a black precipitate, whereas concentrated solutions were stable. This unusual concentration effect is interpreted in terms of reaction of soap monomers with impurities.
Study of the composition of heavy ends of petroleum
Authors: Chandra Dinesh , Bhatia Virendra K.
Published: July 2010

Bombay High Crude comes from the most potential oilfield of India. Its dewaxed distillate, of boiling range 370–520°C, was subjected to ion exchange and coordination chromatography to separate acids, bases and neutral nitrogen compounds. The remaining hydrocarbon plus fraction was separated into saturates, mono‐, di‐ and polyaromatics on a dual column of silica‐alumina. The polar non‐hydrocarbons were characterised by infrared spectroscopy, and saturates and aromatics by n.m.r. and mass spectrometry.
Two‐resistance mass transfer models for the adsorption of dyestuffs from aqueous solutions using activated carbon
Authors: McKay Gordon
Published: July 2010

The adsorption of telon blue (acid blue 25) dye and deorlene yellow (basic yellow) dye on to carbon has been studied. A two‐resistance mass transfer model has been developed based on film resistance and homogeneous solid phase diffusion. The model may be applied over a wider range of operating conditions than previous models since it has more extensive analytical components. The variables investigated were initial dye concentration and solid: liquid ratio, and the experimental and theoretical results were in good agreement. The adsorption of telon blue on to carbon has been described using an external mass transfer coefficient of 2.0 × 10−3 cm s−1 and a homogeneous solid phase diffusion coefficient of 2.0 × 10−9 cm2 s−1. The adsorption of deorlene yellow has been described using an external mass transfer coefficient of 1.0 × 10−3 cm s−1 and a homogeneous solid phase diffusion coefficient of 3.0 × 10−10 cm2 s−1.
Kinetics of reaction of low concentration mixtures of oxides of nitrogen, ammonia and water vapour
Authors: Mearns Alexander M. , Ofosu‐Asiedu Kingsley
Published: July 2010

The kinetics of reaction between oxides of nitrogen, ammonia, water vapour and oxygen in ppm quantities in nitrogen were studied. The kinetics of the nitrogen dioxide‐ammonia reaction and of the nitrogen dioxide‐water reaction were investigated separately, and a reaction model was developed to predict the rate of disappearance of nitrogen dioxide in the overall reaction system based on the reaction rate expressions deduced for the separate reactions. There was satisfactory agreement between measured and predicted dioxide concentrations as a function of time. The results have relevance to consideration of clean‐up processes of tail gases in nitric acid plants and to studies of reactions in polluted atmospheres.
Spectrophotometric and electron spin resonance studies on the chloro complexes of manganese (II), cobalt (II) and copper (II) in solvent extraction by trioctylamine and trioctylmethylamrnonium chloride
Authors: Sato Taichi , Nakamura Takato
Published: July 2010

The complexes of bivalent manganese, cobalt and copper formed in the extraction from hydrochloric acid solutions by trioctylamine (TOA, R3N) and trioctylmethylammonium chloride (Aliquat‐336, R3R'NCl) in benzene have been examined by spectrophotometry and electron spin resonance spectroscopy. It was found that the moiety MCl2‐4 in all complexes studied had a tetrahedral geometry, and that the M‐Cl bond in the species (R3R′N)2MCl4 was rather more ionic than that in the species (R3NH)2MCl4, in which M = Mn, Co and Cu.
Polymer‐supported catalysts—selective hydrogenation of acid chlorides over palladium/polyamide
Authors: Cum Giampietro , Gallo Raffaele , Galvagno Signorino , And Agatino Spadaro , Vitarelli Pietro
Published: July 2010

The catalytic behaviour of palladium supported on aromatic polyamides was studied in the liquid phase hydrogenation of benzoyl chloride at 1 atm total pressure and between 348 and 408 K. The specific activity of the catalysts as a function of palladium concentration was found to increase with metal loading. It is suggested that palladium in a metallic state is the active site for the acid chloride hydrogenation. A decrease in the reaction rate has been observed at the highest temperatures indicating that under these conditions the availability of hydrogen becomes the rate determining step. Results on the liquid phase hydrogenation of acyl‐ and aroyl‐chlorides are reported. No strong influence of the nature of the substituents was observed on reaction parameters.
Spontaneous ignition hazards in stockpiles of cellulosic materials: Criteria for safe storage
Authors: Gray Brian F. , Griffiths John F. , Hasko Stephen M.
Published: July 2010

The ambient temperature at which ignition is brought about in various sizes, shapes and masses of sieved bagasse pith was investigated on a laboratory scale. ΔT‐time and ΔT‐position profiles were obtained, and critical temperatures are determined to closer than 0.5 K; this is the highest precision for location of the sub‐critical/super‐critical margin so far reported for any thermal ignition system. Such quality is a pre‐requisite for quantitative extrapolation in order to predict the critical sizes for field stock‐piles in normal climatic conditions. Scaling rules based on stationary‐state, thermal ignition theory are used and comparisons of the results are made with real piles. The predictions are shown to grossly over‐estimate the safe size of stock‐piles, and the reasons for this discrepancy are discussed. Distinctions between the reactivity in perfectly dry substrates (as is inevitable at the temperatures prevailing in laboratory experiments) and that of natural, wet piles, and the part played by water are important features. A need for supplementary measurements of heat‐release rates at temperatures close to those prevailing in stock‐piles is stressed. The results are found to be consistent with similar measurements in woodflour and the conclusions are, therefore, applicable to all cellulosic materials at high temperatures.
Kinetics of the reaction between chloroform and 2,5‐dimethylpyrrole in the vapour phase
Authors: Busby Reginald E. , Dorgan Laura E. , Lazaar Kenneth I. , Parrick John , Rizvi S. Mumtaz H. , Shaw C. J. Granville , Zor Lale D.
Published: July 2010

A kinetic study of the reaction between chloroform and 2,5‐dimethylpyrrole in a continuous flow vapour phase system at 733 K showed the rate to be first order with respect to chloroform.
Electroplating of nickel‐cadmium alloys from alkaline solutions
Authors: Rehim Saye D. S. Abd El , Wahaab Soad M. Abd El , Abdella Osama M.
Published: July 2010

The electroplating of Ni‐Cd alloy coatings was carried out from alkaline baths (pH 10). For comparison, electroplating of the parent metals, Ni and Cd, was performed individually under the same conditions. The cathodic current efficiency for codeposition was high and decreased with increasing current density. The codeposition process is an anomalous type of plating with Cd being the preferentially deposited metal. The Ni content in the deposits increased with increasing current density. This increase in Ni content improves the corrosion resistance and microhardness of the deposits. X‐ray diffraction analysis showed that the deposits consist of a mixture of Ni, β, γ, γ1 phases.
Synthesis and characterisation of a submicrometre silicon carbide powder
Authors: Hanna S. B. , Abdel‐Mohsen F. F.
Published: July 2010

A beta‐silicon carbide powder with a surface area of 30m2g−l and a mean particle size of < 1μm was produced from the thermal conversion of silicon resin in an atmosphere of hydrogen. The amount of product increased with increasing iron content (0–2.1 wt%) and firing temperature (1200–1500°C). Chemical analysis, X‐ray diffraction and i.r. absorption spectrometry were used to follow the conversion reaction.
Coke formation during steam cracking of hydrocarbons. Part 2. Effect of preoxidation and prereduction of the reactor surface
Authors: Holmen Anders , Lindvaag Odd A. , Trimm David L.
Published: July 2010

Coke formation by steam cracking of propane over preoxidised and prereduced alloy foils has been studied in a tubular reactor at 810–850°C. Coke formation on preoxidised steel involves coke formation on the oxide scale which is low and coke formation on metal exposed by spalling of the scale which is high. Surface analysis by Auger spectroscopy (AES) reveals that the surface concentration of iron and nickel is low on the oxide scale and high on the exposed metal. Coke formation on the surface of the prereduced steel is low and the surface contains chromium and manganese as the predominant metal components. Differences in the product spectra obtained over preoxidised and prereduced steels is suggested to be due to the presence of surface iron and nickel which increases the production of coke and hydrogen and decreases the production of olefins in steam cracking.
Dissolution kinetics of colemanite in water saturated by carbon dioxide
Authors: Alkan Mahir , Kocakerim M. Muhtar , Çolak Sabri
Published: July 2010

The dissolution kinetics of original and calcinated samples of the boron containing mineral colemanite, in CO2‐saturated water were studied. Effects of particle size, calcination temperature and reaction temperature were evaluated. It was observed that the dissolution is chemically‐controlled. The reaction rate decreased with increase in particle size, and increased with increase in the calcination and reaction temperatures. The activation energy for solution of the sample calcinated at 400°C as calculated as 57.7 kJ mol−1.
Photochemical Energy Conversion by a Thiazine Photosynthetic‐Photoelectrochemical Cell
Authors: Pan R. L. , Bhardwaj R. , Gross E. L.
Published: July 2010

A thiazine photoelectrochemical cell has been developed involving thiazine photo‐reduction using EDTA as the electron donor together with photosynthetic electron transport in chloroplasts to generate electricity with a higher power conversion efficiency than for thiazine‐EDTA alone. Thionine and methylene blue have been shown to be electron acceptors of Photosystem I. The cell employed had a high ratio of the area of chloroplast‐impregnated membrane compared to the volume of thiazine solution. This emphasised the photosynthetic contribution. An open circuit photovoltage (Voc) of 415 mV, a maximum power density (Pa) of 4.15 m̈W cm‐2, a short circuit current density (Isc) of 50 m̈A cm‐2and a power conversion efficiency (Sp) of 0.145% were observed using thionine as the electron acceptor compared to aVocof 383 mV, aPdof 3.0 m̈W cm‐2, andIscof 43.0 m̈A cm‐2and anpof 0.095% when methylene blue was used as the electron acceptor. These results show that the thiazine photogalvanic cell can be combined with the chloroplast solar battery in order to increase the power conversion efficiency of the system.
Substitutent effects on the spectral behaviour and acid‐base properties of arylidene derivatives of salicylic hydrazide
Authors: El‐Baradie H. Y. F. , Khattab M. A. , Issa R. M. , Maghrabi J. Y.
Published: July 2010

The u.v. and i.r. spectra of some arylidene derivatives of salicylic hydrazide have been studied. The u.v. spectra in organic solvents are considered in terms of medium effect and molecular structure. The changes of the spectra in buffer solutions are explained on the basis of the shifts in the acid‐base equilibrium set; the various pK values are determined and commented upon in relation to substituent effects. The main bands in the i.r. spectra are assigned and the shift in their positions is discussed in the light of substituent effects.
Hydrodynamic and micellar properties of sodium alkyl benzene sulphonates
Authors: Anand Onkar N. , Malik Ved P. , Kumar Vijay
Published: July 2010

This paper provides hydrodynamic data and micellar properties of some sodium alkyl benzene sulphonates. The free energy of micellisation. as deduced from experimental data, is compared with that calculated from the structural parameters and shows that these sulphonates form spherical and ellipsiodal micelles in aqueous medium. The ease of micellisation and micelle size increases as one goes from sodium decyl to sodium hexadecyl benzene sulphonates. The solubilisation data of n‐octane and ethyl benzene in aqueous sodium alkyl benzene sulphonate solutions above the cmc indicates that aliphatic hydrocarbons when solubilised reside within the micellar core whereas aromatic hydrocarbons reside in the micellar core as well as in the annular space between hydrodynamic shear surface and surface of the micellar core,
Hydrogenation of benzene to cyclohexene on an unsupported ruthenium catalyst: an esca study of titanium poisoned catalysts
Authors: Ingemar Odenbrand C. U. , Anderson S. Lars T.
Published: July 2010

ESCA data show that the addition of titanium to a ruthenium catalyst gives a catalyst containing some metallic ruthenium and a mixed titanium‐ruthenium hydrous oxide. The ratio of ruthenium in the metallic form to ruthenium in the hydrous oxide form decreases with increasing titanium concentration. The poisoning effect of titanium on the hydrogenation activity results from the reduced amount of ruthenium metal available.
An investigation of the recovery of cryolite from alumina‐electrolyte froth by flotation
Authors: Kula Hayriye , Gürkan T¨︁Rker , özbelge H. önder
Published: July 2010

In the industrial production of aluminium by the electrolysis of alumina, electrolyte froth, which is a mixture of carbon and cryolite is obtained at a rate of 50 kg of froth per ton of aluminium produced. Cryolite can be recovered from this mixture by flotation. In this study, the effects of the following parameters on flotation were experimentally investigated: particle size, type, combination, dosage and ratio of reagents, and conditioning time. It is found that it is possible to decrease the carbon content of cryolite below 1% by suitably choosing the operating parameters. Electrolyte froth must be ground to —100 mesh size for the liberation of carbon particles captured in the cryolite matrix. Any combination of two of the reagents, kerosene, fuel oil, creosote and terebenthene yield good results if used together with pine oil. Pine oil is found to be a more effective frother compared to Pril, a commercial detergent. Satisfactory separations are obtained when a kerosene‐fuel oil mixture (50:50, v/v) is used as the collector with a dosage of 3.7 kg per ton of feed together with pine oil, the frother, with a dosage of 0.095 kg per ton of feed.
The effect of β‐dicalcium silicate, α‐monocalcium silicate and calcium hydroxide upon the removal of lead (pb2+) ions from aqueous solution
Authors: Grau Benitez N. F. , Saul G. M.
Published: July 2010

A study was conducted of the influence of pH, initial reactant concentration and reaction time upon the rate of removal of lead ions from solutions of lead nitrate. Three different reactants were used: β‐dicalcium silicate (β‐C2S)*, α‐monocalcium silicate (α‐CS), in the form of finely ground clinkers, and commercial calcium hydroxide. The initial concentration of lead in solution was varied between 5 and 1000 mg cm‐3 Pb2+ for different additions of reactant. For each concentration of lead ion the effect of time of shaking on the removal of lead was followed by the determination of residual lead concentration in the filtrate. Lead was reduced to low levels by all the precipitants. The precipitated reaction products were identified by X‐ray diffraction techniques, electron diffraction analysis and infrared spectroscopy. The analysis characterised the products of the precipitation reactions as basic lead carbonate, basic lead nitrates and lead hydroxide.
Recovery of chromium from waste electroplating liquors by ion‐exchange on casein. part ii. modelling eluate concentrations
Authors: Houchin Martin R.
Published: July 2010

An empirical mathematical model has been derived to elucidate the factors influencing the eluate concentrations observed in a previously reported ion‐exchange study.1 The efficiency of the experimental procedure used in that study is evaluated in relation to the model, and an empirical 'efficiency' parameter used in the model is discussed with respect to its physical significance. The more general applicability of an expression derived for limiting maximum eluate concentration is also considered.
Oxidative decarboxylation of toluic acids to cresols
Authors: Sharma M. P. , Chatterjea J. N.
Published: July 2010

The reported procedure for obtaining cresols from copper salts of toluic acids has been examined and certain improvements in yields have been obtained. It has been found that oxygen is preferable to the use of air in this reaction. The variables, oxygen flow rate, reaction temperature, reaction time and copper oxide concentration have been examined, and the effect on the percentage yields of cresols has been found. In the case ofp‐toluic acid, the molar yield ofm‐cresol could be raised to 70 % while the molar conversion was 21–22%. Form‐toluic acid the molar yield was considerably lower.
Stability constants and complexation capacities of complexes formed between heavy metals and extracellular polymers from activated sludge
Authors: Rudd Thomasine , Sterritt Robert M. , Lester John N.
Published: July 2010

Conditional stability constants and complexation capacities of extracellular polymers extracted from activated sludge with copper, nickel, cadmium and cobalt have been determined at high and low free metal concentrations using gel complexometry. The results compare favourably with those for other bacterial extracellular polymers, but less well with those for competing metal‐binding ligands present in sewage. The affinity of extracellular polymers for metals has been discussed in terms of their contribution to metal removal during the biological phase of wastewater treatment.
Thermal decomposition of aluminium hydroxycarboxylates—lactate, citrate and tartrate
Authors: Sato Taichi , Ikoma Shuji , Ozawa Fusaji
Published: July 2010

The thermal transformation of anhydrous alumina obtained by the decomposition of the lactate, citrate and tartrate of aluminium has been examined by thermal analysis(TGA and DTA), infrared spectrophotometry and X‐ray diffraction study. It is found that under an atmosphere of air the thermal decomposition of aluminium hydroxycarboxylates to anhydrous amorphous alumina, which transforms to α‐alumina via γ‐, δ‐ and θ‐aluminas, proceeds as follows for Al[CH3CH(OH)COO]3, the decomposition of skeleton and the combustion of its decomposition products; for Al[CH2C(OH)CH2(COO)3] and Al2{[CH(OH)COO]2}3, dehydroxylation, decomposition of skeleton and the combustion of its decomposition products.
Adsorption of reaction species on raney nickel for slurry‐phase hydrogenation of p‐nitrotoluene
Authors: Choudhary V. R. , Chaudhari S. K.
Published: July 2010

Adsorption of hydrogen, p‐nitrotoluene, p‐toluidine and water on Raney nickel from their methanol solutions has been investigated under catalytic conditions. The isotherms of reversible adsorption of hydrogen are linear and the estimated heat of adsorption is 28.9 kJ mol−1. The amount of hydrogen held irreversibly on the catalyst is very large as compared to that adsorbed reversibly. The isotherms of adsorption of p‐nitrotoluene, p‐toluidine and water have different shapes (viz. types H3, S1 and L3 respectively). Among the reaction species, p‐toluidine is not adsorbed on the catalyst at low concentrations (< 0.8 mmol cm−3).
The use of microfinance services among economically active disabled people: Evidence from Uganda
Authors: Beisland Leif Atle , Mersland Roy
Published: July 2010

This study investigates the use of microfinance services among economically active disabled people in Uganda. The findings suggest that disabled people make more use of microfinance services than previously assumed. A total of 89 per cent of the survey's respondents state that they have used at least one type of microfinance service. Informal self‐help schemes are more easily accessed than formal institutional schemes, and disabled people access more savings than loans. The multivariate analysis shows that access to microfinance services is positively related to education level. In addition, deaf people generally have less access to microfinance than those in other disability categories. Copyright © 2010 John Wiley & Sons, Ltd.