bluuebunny/crossref_metadata_2025_split huggingface dataset:
Growth rate dependence of enzyme synthesis in chemostat cultures: α‐amylase, β‐galactosidase, acid phosphatase and β‐fructosidase
Authors: Toda Kiyoshi , Takeuchi Toshihiko , Sano Haruhiko 
Published: July 2010

AbstractSpecific rate of enzyme synthesis in microbial cells was correlated to specific growth rate in chemostat culture using three strains of microorganism. α‐Amylase production by Bacillus subtilis was linearly associated with growth rate in a glucose‐limited chemostat culture. β‐Galactosidase production by Saccharomyces fragilis was rather invariable with growth rate in a galactose medium. β‐Fructosidase production by Saccharomyces carlsbergensis in a phosphate‐poor glucose medium was independent on growth rate, except at low dilution rates where it increased with growth rate. Production of acid phosphatase by the same microbe showed a maximum at a particular intermediate dilution rate. These relationships were summarised with an equation of induction—repression model. Comparison of the chemostat results with those of batch fermentation provided some enhancement factors of a continuous fermentation: 1.23–9.82 regarding enzyme productivity and 0.53–2.88 regarding enzyme concentration. The production of β‐fructosidase was much improved among the enzymes tested when continuous culture methods were used.
The electroforming of iron foil
Authors: Lai Stephen H. F. , McGeough Joseph A. 
Published: July 2010

AbstractA process for the high‐speed electroforming of iron foil is described. The electrolyte can be operated over a current density range of 10–100 A dm−2. The quality of the electroformed iron foil is dependent upon process variables, and in terms of its main mechanical, electrical and magnetic properties, is comparable with that of many conventionally‐produced metal foils.
A mechanistic model of a packed‐bed electrode cell to remove metal ions from dilute effluent solutions
Authors: Bryson Anthony W. , Dardis Kevin A. 
Published: July 2010

AbstractA mathematical model of a porous cathode cell is derived in terms of fundamental kinetic parameters for the deposition of metals from dilute solutions. The model is used to design a pilot plant to treat electroplating waste effluents. Experimental results show that the plant can reduce the concentration of copper, nickel, chromium and zinc by at least 90% at acceptable current efficiencies.
The characterisation and evaluation of highly dispersed tungsten carbide electrocatalysts
Authors: Miles Richard 
Published: July 2010

AbstractThe suitability of using highly dispersed tungsten carbide as an inexpensive alternative catalyst to platinum for use in methanol fuel cells has been investigated. The results show that tungsten carbide possesses no activity for the methanol electro‐oxidation reaction. Of the tungsten carbide samples examined only those treated with molybdenum produced any measurable oxidation current. Formaldehyde, however, is oxidised on tungsten carbide though the activity is several orders of magnitude lower than that of platinum catalysts. In the potential region where the electro‐oxidation of methanol and formaldehyde takes place there is significant corrosion of the tungsten carbide catalyst in aqueous sulphuric acid electrolyte, rendering it unsuitable even as a support for platinum.
Phase equilibria in ammonia—carbon dioxide systems at and above urea synthesis conditions
Authors: Lemkowitz Saul M. , Van Erp Jan C. , Rekers Domien M. , Van Den Berg Pieter J. 
Published: July 2010

AbstractA comprehensive temperature‐pressure‐composition phase model is presented which combines all known phase equilibria relating to the binary ammonia‐carbon oxide system (no urea present) at urea synthesis conditions. The bubble‐points and critical‐points of the ammonia‐carbon dioxide section of the ternary ammonia‐water‐carbon dioxide system at chemical equilibrium (urea present) have been measured up to the values of NH3/CO2 = 2, T = 280°C, and p = 2000 atm. The critical temperature and pressure values of a NH3/CO2 = 2 mixture, of importance to the theory describing the maximum conversion to urea, have been found to be 276°C and 1250 atm, respectively.
Mannich bases of 2‐aminothiazoles
Authors: Badr M. Zarif A. , Aly Morsy M. , El‐Naggar Galal M. 
Published: July 2010

AbstractSynthesis of some new Mannich bases, 2(thiazolylaminobenzyl)‐1‐naphthols (I) and 1(thiazolylaminobenzyl)‐2‐naphthols (II) are described. Condensation of 4,5‐disubstituted‐2‐aminothiazoles and the appropriate aldehyde with 1‐naphthol gives (I), while condensation with 2‐naphthol gives (II). Their structures have been ascertained by spectroscopy and by synthesis from the dibromoderivative of 2‐arylidene‐1‐tetralone and the corresponding 2‐aminothiazole.
Re‐use and separation of waste plastics
Authors: Lindfors Lars G. 
Published: July 2010

AbstractCommercial and pilot‐scale methods for the re‐use of clean, unmixed scrap plastic are described. Mixed scrap presents greater problems and efforts have been made to improve its properties with additives or by altering its composition. Separation methods are surveyed. Mixed wastes find limited re‐use in low quality products. Re‐use of waste plastics as fuel is now probably the most economical alternative. Economic rather than technical obstacles remain for this recycling.
Interactions between an electrochemical reactor and associated unit processes
Authors: Plimley Raymond E. 
Published: July 2010

AbstractIt is shown that in the presence of interactive variables, the optimum operating conditions for a reactor cannot be determined in isolation from its associated unit operations. The argument is illustrated by a process model developed for a continuous electrochemical reactor linked to a distillation unit which recycles unconverted feedstock. The model reveals that if conditions in the distillation unit are ignored a false optimum well removed from the true optimum would be identified.
The hydrolysis of brilliant green and some derivatives. I. A kinetic and equilibrium study of the hydrolysis of brilliant green
Authors: Fox Brenda M. , Hallas Geoffrey , Hepworth John D. , Mason Donald 
Published: July 2010

AbstractThe hydrolysis of Brilliant Green has been studied over the pH range 6–11. In neutral aqueous solution and in the absence of light, the system reaches equilibrium. In alkaline solution, complete conversion into the dye base occurs. Rate constants and activation parameters have been obtained for the hydrolysis and a reaction scheme is proposed.
Adsorption of streptomycin on ion exchange resins: Equilibrium and kinetic studies
Authors: Prasad Rajendra , Gupta Ashok K. , Bajpai Rakesh K. 
Published: July 2010

AbstractEquilibrium and kinetic studies of streptomycin adsorption from aqueous solutions of streptomycin sulphate were carried out using four weakly acidic ion exchange resins: Indion 236 [Ion Exchange (India) Ltd], Amberlite IRC‐50 (Rohm and Haas Co, USA), KB‐2 and KB4‐P2 (both Russian resins), initially in the sodium form. The maximum amounts of streptomycin taken up by the exchangers were about 1640, 1560, 2050 1400 mg g−1 dry resin (sodium form), respectively. The rate of adsorption of the antibiotic was highest with the ion‐exchanger KB‐2, and lowest with KB4‐P2. The initial diffusivity values calculated for the four exchangers at a temperature of 9°C were 2.87 × 10−8, 1.87 × 10−8, 3.42 × 10−8 and 0.468 × 10−8 cm2 s−1, respectively.
Methane production from acids in piggery‐waste digesters
Authors: Hobson Peter N. , McDonald Ian 
Published: July 2010

AbstractResults from piggery‐waste digestion fit those from a continuous culture of acetate utilising methanogenic bacteria showing that the acid to methane step of this digestion can be regarded as an independent continuous culture behaving as predicted by a simple continuous culture model with a wash‐out dilution rate of about 0.4 day−1 and a Ks value of about 800–900 mg acetic acid dm−3. However, this was only possible because the waste contained a high concentration of free acid and the application of the results to other digestions is discussed.
Catalysed hydrogenation of hydroxynitroanthraquinones in strong acid
Authors: Morley John O. , Hutcheson Raymond 
Published: July 2010

AbstractThe catalytic hydrogenation of hydroxynitroanthraquinones such as 1,8‐dihydroxy‐4,5‐dinitroanthraquinone over either palladium‐carbon or platinum‐carbon catalysts proceeds readily in 75% sulphuric acid at 125°C during 6–12 h at 100 kPa pressure to give the corresponding aminohydroxyanthraquinones in high yield. Catalyst recoveries are excellent. A combined process has been developed to give diaminochrysazin in 93% overall yield by a combined nitration of chrysazin and in situ catalytic reduction of the nitration liquors.
Microbial production of L‐lysine
Authors: Misra Anjani K. , Dasgupta Jyotirmoy , Vora Vinay C. 
Published: July 2010

AbstractThe production of lysine by fermentation was studied, using a homoserine‐deficient and aminoethylcysteine‐resistant strain of Corynebacterium glutamicum, in 1‐dm3 shake flasks and a 14‐dm3 laboratory fermentor. Molasses was used as substrate. Superphosphate‐treated black strap molasses gave better lysine production. Lysine production, residual sugar and dry cell mass were measured as a function of fermentation time. It was observed that 1 g of cell mass produced 3.36 g of lysine.
Recovery of titanium dioxide from naturally occurring ilmenite by high‐temperature borate fusion
Authors: Easteal Allan J. , Morcom Anthony T. 
Published: July 2010

AbstractFusion of naturally‐occurring ilmenite at 1273 K with Li2O·XB2O3 solvents (where X = 2, 4, 5, 6, 7 and 8) gives, after boiling water extraction of the crushed solidified melts, maximum (68.1%) recovery of TiO2 (as rutile) for X = 6. Extraction with hot 9 mol dm−3H2SO4 of the water‐insoluble residue from the fusion of ilmenite with Li2O·6B2O3 yields a product containing 86 weight % TiO2 and only a trace of iron. The overall process is a possible route for upgrading ilmenite to a rutile‐enriched product.
Catalytic activity of pure and doped ceria
Authors: Fahim R. B. , Zaki M. I. , Gabr R. M. 
Published: July 2010

AbstractStructural and phase changes accompanying the thermal dehydration of pure and doped hydrated eerie oxide have been followed by thermogravimetric analysis, differential thermal analysis, and X‐ray diffraction studies. Doping has been affected by either Zn2+, Al2+ or U6+ ions. Texture investigation has been studied by analysis of nitrogen adsorption isotherms. Variation in porosity due to annealing and/or doping, as well as mechanisms of foreign ion incorporation, have been correlated with catalyst activity towards decomposition of isopropanol.
Extraction of uranium (VI) by di‐(2‐ethylhexyl)phosphoric acid gels based on a styrene‐divinylbenzene copolymer
Authors: Shakir Kamal , Beheir Shokry G. 
Published: July 2010

AbstractUranium (VI) can be efficiently extracted using hydrophobic gel particles prepared by swelling styrene‐divinylbenzene copolymer beads with di‐(2‐ethylhexyl)phosphoric acid packed into columns. Retained U (VI) can be quantitatively eluted with acid solutions. The effects of incorporating different organic solvents into the gel on its capacity and performance have been investigated. It was found that nitrobenzene gave the best results. The conditions required for the preparation of gels of high capacity have been established.
Electrical control and optimisation of the electrochemical batch reactor
Authors: Kreysa Gerhard 
Published: July 2010

AbstractFor galvanostatic, potentiostatic and constant cell voltage control, parameters such as conversion degree, energy efficiency, space‐time yield, specific energy consumption and their time‐dependencies have been calculated for a diffusion‐controlled reaction in an electrochemical batch reactor. Comparison of the results showed that potentiostatic control is the most efficient operation mode, but that constant cell voltage control is more useful and provides a similar efficiency. Some results from model calculations were compared with those from laboratory experiments. A numerical optimisation procedure was applied to an electrochemical batch reactor with constant cell voltage control. The resulting optimum batch electrolysis time, the optimum conversion degree, and the minimum costs were calculated as functions of the initial reactant concentration, specific electrode surface area, costs of raw materials and investment costs.
Quantitative effect of gritty contaminants on the sensitiveness of high explosives to ignition by impact. Probabilistic calculations via the K‐parameter
Authors: Scullion Henry J. 
Published: July 2010

AbstractTests on contaminated high explosives afford values of K in the equation. Which are used to calculate, inter alia, the probability of a hot‐spot precursor (HSP) with specific grits at selected levels, the mean mass of grit for one HSP, and the initial (i.e. ‘zero’ grit) rate of fall in insensitiveness with increasing contaminant.
Compositional study of crude oils using fourier transform n.m.r. Characterisation
Authors: Srivastava Shanti P. , Singh Indra Deo 
Published: July 2010

AbstractThe Fourier transform (FT) 1H‐ and 13C‐nuclear magnetic resonance (n.m.r.) spectra of three crude oils have been recorded at room temperature on a Jeol pulsed FT‐n.m.r. spectrometer. The branchiness index has been calculated from 1H‐n.m.r. spectra and the percentage of aromatic carbons (% CA) from the 13C‐spectra. The results are discussed and the usefulness of n.m.r. techniques in such studies considered.
Surface texture of strontium carbonate
Authors: Amin Anwar , Selim Suzy A. 
Published: July 2010

AbstractTwo batches of strontium carbonate (SrCO3) prepared at temperatures ⩽333 K (A) and 373 K (B) were investigated using differential thermal analysis (DTA), thermogravimetric (TG), X‐ray diffraction (XRD) and N2 adsorption techniques. Heat treatment up to 1073 K causes no material decomposition of the carbonate and DTA and TG results indicate impurity action. XRD patterns of both samples though slightly different at low temperatures, are identical with orthorhombic SrCO3 above 773 K. The N2 specific surface area of sample B is about three times that of sample A. Thermal treatment of batch A shows two regions of area development resulting from two different types of entrapped water whereas batch B shows only one region and contains only one type of entrapped water. Both samples and their decomposition products are predominantly lyophobic towards cyclohexane adsorption. With sample A the parent material was mesoporous. These pores widen at 423 K due to growth in grain size, but narrowing commences with the evolution of area at 573 K. At temperatures ⩾ 773 K the pores widen again. Sample B contains both micro‐ and mesopores with the latter dominating at higher temperatures where sintering operates.
Studies on the use of chromium ferrocyanide gels in the treatment of radioactive wastes
Authors: Srivastava Suresh K. , Bhattacharjee G. , Kumar Satish , Oberoi Chander K. , Sharma Ashok K. 
Published: July 2010

AbstractThe sorption and distribution of some radioisotopes on chromium ferrocyanide gels under different physical conditions has been investigated. The exchanger shows high selectivity for Tl+, Cs+, Cd2+ and Pb2+. A complete elution of Cs+, Tl+ and Rb+ is possible with suitable eluants whereas Pb2+ and Cd2+ cannot be desorbed. The uptake of monovalent ions is by an ion exchange process unlike the sorption of bivalent ions.
An interpretation of proton acidity and its relevance to catalysis in low sodium content Y zeolites from studies of heats of immersion in methanol
Authors: Coughlan Brendan , Carroll William M. , Kavanagh Patrick , Nunan John 
Published: July 2010

AbstractThe interrelationship of acidity and catalytic activity in reactions involving carbonium ions in zeolite‐type catalysts has been studied. Heats of immersion of a range of HNaY zeolites in methanol at 293 K are presented. It has been shown that the interaction energy of the basic methanol molecule with the zeolite framework reflects the acid nature of the zeolite surface and this is correlated with catalytic results for the competitive ethylation of toluene and benzene, and also for cracking and isomerisation reactions. Assessment of acidity in decationated zeolite catalysts by this method should prove useful where other methods of measurement of acidity prove difficult.
Studies in the adsorption and diffusion of ions in chitosan
Authors: Blair Hal S. , Ho Ting‐Chung 
Published: July 2010

AbstractChitin was obtained from shell of the tail portions of the prawn Nephrops norvegicus (L) and was deacetylated to give chitosan. The adsorption and diffusion of copper (II) ions were studied and the diffusion of the acid dye CI Acid Orange 10 through chitosan films containing different amounts of chelated copper was investigated. It was found that with increasing copper content the rate of diffusion through the membrane decreased.
Single‐cell protein from methanol: Economic aspects of the norprotein® process
Authors: Ericsson Magnus , Ebbinghaus Lars , Lindblom Marianne 
Published: July 2010

AbstractNorprotein is a subsidiary of the Norwegian chemical group Norsk Hydro A.S and the Swedish food company AB Marabou. Since 1974 the main activity of research has been to develop a process for single‐cell protein production from methanol. At present, research activities are directed towards finding alternative applications for the developed technology within the field of biotechnology.
Bioconversion of Macrocystis pyrifera to methane
Authors: Ghosh Sambhunath , Klass Donald L. , Chynoweth David P. 
Published: July 2010

AbstractMethane production by anaerobic digestion of kelp is a relatively new approach to augmenting the national gas supply. Digestion of the giant marine kelp Macrocystis pyrifera, investigated in a series of bench‐scale experiments at the Institute of Gas Technology (IGT), is reported. Conducted with both untreated and chemically pretreated plants, the tests have evaluated the effects of major limits on bioconversion of kelp, including temperature, indigenous salt concentration, external nutrients, inocula source, loading, residence time, manner of mixing and frequency of feeding. A detailed chemical characterisation of the kelp samples is presented. Raw‐kelp digestion was not limited by nitrogen or phosphorus. Temperature ranges of 35–40°C and 50–55°C were found to be optimum for mesophilic and thermophilic digestion of raw kelp. The mesophilic methane yield in the semicontinuous mode was about 4.5 SCF/lb (280.94 cm3 g−1) of volatile solids (VS) added compared with a thermophilic methane yield of 2.4 SCF/lb (149.83 cm3 g−1) of VS added. The mesophilic organisms could be acclimatised to a salt concentration that has a conductivity of 43 000 μmho cm−1 without any deleterious effect. Thermophilic methanogens were more sensitive to high salt concentrations than the mesophilic organisms. Raw kelp had an estimated ultimate biodegradability of 80%. Mannitol and algin were the most biodegradable components.
Kinetics of two‐phase reduction of aromatic nitro compounds by aqueous solutions of sodium sulphides
Authors: Bhave Ramesh R. , Sharma Man M. 
Published: July 2010

AbstractThe kinetics of two‐phase reduction of aromatic nitro compounds (e.g. m‐chloronitrobenzene, m‐dinitrobenzene and p‐nitroaniline) by aqueous solutions of sodium monosulphide and sodium disulphide was studied in a mechanically‐agitated glass contactor. For p‐nitroaniline, the effect of temperature in the range of 333 K to 363 K was studied. Diffusional resistance could be eliminated. The reaction between the dissolved nitroaromatic and sulphide species was found to be first‐order with respect to the nitroaromatic concentration and first‐order with respect to the sulphide concentration. The value of the activation energy for p‐nitroaniline was found to be 55.2 kJ mol−1. The values of the second‐order rate constant for a variety of nitroaromatic compounds, which varied by a factor of 150, have been correlated by the Hammett's equation.
A vapour‐liquid equilibrium model of the NH3CO2H2O‐urea system at elevated pressure
Authors: Kotula Edward 
Published: July 2010

AbstractVapour‐liquid equilibrium measurements on the NH3CO2H2O‐urea system within the operating range of the absorption and condensation steps of the recycle urea process have been made. From the Margules formulae, a generalised formula for activity coefficients of components in multicomponent system has been derived. Equations for NH3 and H2O partial pressures over solutions of the system investigated were developed using the Raoult's law and an ionic equilibrium principle.
The preparation of 5‐hydroxymethylfurfuraldehyde from high fructose corn syrup and other carbohydrates
Authors: Szmant H. Harry , Chundury Deena D. 
Published: July 2010

Abstract5‐Hydroxymethylfurfuraldehyde (HMF) was prepared from high fructose corn syrup (HFCS), or crystalline D‐fructose, in high yield and purity. A 95–97% conversion of fructose to HMF was achieved using 25 mol% (based on fructose) boron trifluoride etherate catalyst in dimethyl sulphoxide, under a nitrogen atmosphere, a reaction temperature of 273 K and 30 min reaction time. Inferior yields of HMF were obtained from glucose and starch.
The pyrolysis of propane. I. Production of gases, liquids and carbon
Authors: Trimm David L. , Turner C. J. 
Published: July 2010

AbstractStudies have been carried out on the formation of gases, tars and carbon from the pyrolysis of propane under conditions pertinent to steam cracking. Careful analysis has been carried out to relate the production of gases, liquids and solids in the presence and absence of hydrogen and helium diluents. The experimental observations agree with predictions of gas production from a mathematical model. The reactor surface is shown to influence the production of carbon and possibly the production of gases and tars. Minimisation of coke formation in steam cracking is shown to depend, at least in part, on the correct choice of material for reactor construction.
Extraction of copper from acid sulphate solutions by 2‐hydroxy‐5‐n‐nonyl and 2‐hydroxy‐4′‐n‐nonylbenzophenone oximes
Authors: Goszczyński Stefan , Szymanowski Jan , Borowiak‐Resterna Aleksandra 
Published: July 2010

AbstractThe study of copper extraction shows that the position of the chain (5 or 4′) does not influence the statics of copper extraction from ammonia solutions by alkyl derivatives of 2‐hydroxybenzophenone oxime. Acid solutions of 2‐hydroxy‐4′‐n‐nonylbenzo‐phenone oxime can extract more copper than 2‐hydroxy‐5‐n‐nonylbenzophenone oxime, but less than 2‐hydroxy‐5‐n‐alkylbenzaldehyde oxime.
A kinetic study of the metathesis of propene on a rhenium‐aluminium catalyst
Authors: El‐Sawi Mahmoud , Iannibello Antonio , Morelli Fernando , Gatalano Ganfranco , Intrieri Francesco , Giordano Girolamo 
Published: July 2010

AbstractBased on integral kinetic measurements and in accordance with the results of previous investigations, two mechanistic initial rate expressions based on different reaction mechanisms have been found to be statistically equivalent. Applying the Boudart criteria in a test for the physical significance of the parameter estimates, only one of the suggested expressions is significant and the corresponding reaction mechanism is, therefore, considered adequate.