bluuebunny/crossref_metadata_2025_split huggingface dataset:
Renaturation of irreversibly thermodeactivated invertase
Authors: Yamamoto Ryuzo , Ooshima Hiroshi , Harano Yoshio 
Published: July 2010

AbstractThe 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

AbstractA 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

AbstractSodium 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

AbstractThe 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

AbstractThe 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

AbstractActive 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

AbstractKinetic 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

AbstractGas 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

AbstractDrawing 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

AbstractThe 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

AbstractThe 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

AbstractPorous 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

AbstractPorous 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

AbstractFed 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

AbstractHydrogenolysis 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

AbstractThe 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

AbstractThe 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

AbstractSome 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

AbstractCarbons 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

AbstractThe 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

AbstractA 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.
Optimum conditions for the electrochemical synthesis of aminomalononitrile
Authors: Fahmy H. M. , Elnagdi M. H. , Kandeel Z. E. , Pierre G. 
Published: July 2010

AbstractPolarographic 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

AbstractA 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

AbstractSilicalite, 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

AbstractKraft 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

AbstractThe 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

AbstractBombay 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

AbstractThe 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.