bluuebunny/crossref_metadata_2025_split huggingface dataset:
Studies on the fungicidal properties of some organo‐tin compounds
Authors: Chandra Shubhra , James Bruce D. , Macauley Barry J. , Magee Robert J. 
Published: July 2010

AbstractThe results of an investigation into the fungicidal properties of some bi‐functional organo‐tin compounds containing mono‐ and dithiocarbamate ligands are reported. These experiments were conducted against a number of soil and plant pathogenic fungi. While all the compounds examined proved to be powerful fungicides, differences at the concentration levels tested were not sufficiently significant to relate degree of toxicity to ligand structure. Comparison between the fungicidal activity of the di‐and triphenyl‐tin compounds is in agreement with earlier observations that the latter are more toxic than the former.
Kinetics of protein secretion and fractionation in Baker's yeast fermentations
Authors: Park Don‐Hee , Malaney George W. , Tanner Robert D. 
Published: July 2010

AbstractIt has previously been observed that two‐fold differences in total protein concentration can occur between the top and bottom of a baker's yeast fermentation in a laboratory‐scale fermenter.1 This paper considers whether that separation effect may be due to imperfect liquid bulk mixing as characterized by gradients in, say, pH and glucose, or is due to some other effect such as bubble fractionation, resulting from the adsorption of these proteins on the rising bubbles. The results indicate that the latter mechanism may predominate.
Sequential acid and enzymic hydrolysis of sugar beet pulp
Authors: Schaffeld Guillermo , Illanes Andrés , Mejías Gladys , Pinochet Ana María 
Published: July 2010

AbstractFermentable sugars from beet pulp were obtained in a two‐stage hydrolytic process. The first stage involved mild acid treatment to hydrolyze the hemicellulose, producing a pentose‐rich syrup and a cellulose‐rich fraction. The second stage was the enzymic saccharification of the cellulose fraction with fungal cellulases to produce a glucose‐rich syrup. The acid hydrolysis stage was evaluated to optimize the type of acid, acid concentration, temperature and reaction time. Solubilization was markedly temperature‐dependent, whereas the specificity of hemicellulose degradation depended on the type of acid utilized. The effects of different reaction times, enzyme‐to‐substrate ratios and particle sizes on the enzymic stage were studied. Both saccharification rate and the extent of final conversion to glucose were markedly affected by the enzyme‐to‐substrate ratio. Sugars recovered from the enzymic degradation of cellulose were partially fermented by Saccharomyces cerevisiae ATCC 4126.
The use of multivariate analysis for the design of selective isolation conditions for mutants of Streptomyces cattleya with improved antibiotic titre
Authors: Onadipe Adekunle O. , Bushell Michael E. 
Published: July 2010

AbstractTwenty‐three tests which did not include antibiotic production were carried out on ultraviolet‐induced mutants of Streptomyces cattleya NRRL 8057. Principal component analysis of the results indicated the taxometric relationships between members of a population consisting of 77 isolates. Highlitre antibiotic producers were then marked on the population distribution diagram and clusters containing high‐titre antibiotic producers noted. Discriminant analysis for the high‐titre clusters provided a discriminant function which was derived from data from seven of the tests. These were used to formulate a positive selection procedure which was successful in selecting for a population of mutants which contained a significantly higher number of high‐titre isolates than a control population.
Removal of sulfuroxyanions by magnesium aluminium oxides and their thermal decomposition
Authors: Sato Tsugio , Tezuka Mikako , Endo Tadashi , Shimada Masahiko 
Published: July 2010

AbstractThe behaviour of the removal of the sulfuroxyanions, SO2−4, S2O2−3, S2O2−6and S4O2−6, in aqueous solutions by Mg0.61Al0.26□0.13O (□:vacancy) was investigated at 40–80°C. All the sulfuroxyanions were removed from solution competitively with OH−to form the hydrotalcite‐like compounds. The rate of the removal was first order with respect to the concentration of the sulfuroxyanion in the solution, and the apparent activation energy was about 60 kJ mol−1. All the sulfuroxyanions intercalated in the interlayer of hydrotalcite structure decomposed to SO2−4at 100–300°C.
Molar mass distribution of the polyoxyethylene derivatives of alcohols, alkylphenols and alkylamines
Authors: Szymanowski Jan , Atamańczuk Bronisęaw , Szewczyk Henryk 
Published: July 2010

AbstractNumerical integration technique using the Runge‐Kutta method of the fourth order and optimization algorithms using the Monte Carlo method and the simplex Nelder and Mead method were applied for computing the distribution coefficients for polyoxyethylene derivatives of dodecanol, p‐t‐octylphenol and hexylamine. The validity of the proposed more general and quicker computing technique was proven.
Pyrolysed polyacrylonitrile (PPAN)—a novel and highly selective catalyst for the oxidative dehydrogenation of butene to butadiene
Authors: Ademodi B. , Macaulay Stanley R. A. , Cattaneo M. V. 
Published: July 2010

AbstractThe oxidative dehydrogenation of 1‐butene to butadienes over pyrolysed polyacrylonitrile (PPAN), a novel catalyst for the process has been studied. The catalyst was found to be considerably more active than conventional dehydrogenation catalysts, and appears more stable under reaction conditions.Higher conversions and better selectivity were obtained at much reduced temperatures (from about 250°C). The Langmuir‐Hinshelwood mechanism, which assumes that surface reaction between adsorbed oxygen and butene species is rate controlling, has been used to explain the experimental results.
Evaluation of sulphonated by‐products of dodecyl benzene production
Authors: Abou el Naga Hamdi Hassan , Wedad Abdel Azim M. , Naguib Sidaros K. 
Published: July 2010

AbstractLight and heavy alkylated benzene accumulated as by‐products during dodecyl benzene production were studied. The chemical structures of these by‐products were established via various spectroscopy and chromatography techniques. Results showed their suitability for sulphonation and formulation of liquid surfactants.The light by‐product, with its high eicosyl benzene content and likely orthosulphonation, was used satisfactorily to formulate wetting agents and emulsifiers. On the other hand, the heavy alkylated benzene was found to contain a high percentage of C12‐C18 branched side chains. Surfactants formulated from it gave high detergency power and can be recommended for heavy duty applications.
Characterization of hydrous titania from titanous chloride—I. Thermal studies
Authors: Ragai Jehane 
Published: July 2010

AbstractThe thermal properties of a number of titania gels prepared from titanous chloride under various conditions of pH and oxidizing agents, have been studied by simultaneous thermogravimetry, differential thermal analysis and differential thermogravimetry. The results obtained suggest that ligands incorporated in the precipitated gels play a crucial role as far as establishing the dehydration characteristics of these gels. Ageing in water leads, in most cases, to the elimination of coordinatively bound water and to a marked decrease in the final weight loss. In the case of hydrogen peroxide oxidized samples, free radicals incorporated in the inner coordination sphere of titanium control, in most cases, the low temperature behavior.
Kinetic study of sensitized norbornadiene photoisomerization
Authors: Vicente Manuel , Esplugas Santiago 
Published: July 2010

AbstractOne of the best systems for photochemical storage of solar energy is the interconversion between norbornadiene and quadricyclane. This paper presents a kinetic study of norbornadiene photoisomerization sensitized with acetophenone, using ethanol as solvent. This photoreaction was carried out at 25°C and at high reaction conversion yield, quadricyclane being detected as the only reaction product. As a result of that, the global isomerization quantum yield is a norbornadiene and quadricyclane concentration function. In the same way, the influences of temperature and solvent on the photoisomerization kinetics have been studied.
Factors affecting the enzymic susceptibility of alkali and acid pretreated sugar‐cane bagasse
Authors: Fox David J. , Gray Peter P. , Dunn Noel W. , Marsden Warwick L. 
Published: July 2010

AbstractAcid and alkali pretreatments were studied to identify those factors which are critical in determining the susceptibility of a lignocellulosic substrate (bagasse) to enzymic hydrolysis. The different effects of each treatment on the structure of the bagasse affected the subsequent susceptibility to enzymic attack in different ways. The acid treatments appeared to act by disrupting the lignin structure, probably by hydrolysing the carbohydrate chains attached to the lignin, as well as the lignin itself. The attack on the carbohydrate content removed outlying material in the cell wall (i.e. hemicellulose and amorphous cellulose) to expose a ‘core’ of more resistant regions. The alkali treatments appeared to produce a more open structure by penetrating the inner layers and selectively removing hemicellulose molecules as well as breaking some lignin—carbohydrate bonds. The different treatments resulted in structural changes which were found to affect the hydrolysis mechanism.
Accumulation of uranium by biopigments
Authors: Sakaguchi Takashi , Nakajima Akira 
Published: July 2010

AbstractThe uranium adsorbing abilities of various biopigments were investigated. Extremely high adsorption capacities for uranium were found in melanin and bioflavonols (quercetin and morin) having chelating positions with uranium. As a step towards improving the adsorption characteristics of the bioflavonols, quercetin and morin were immobilized on both Bemberg rayon fiber and polyaminostyrene, and the basic features of uranium adsorption by the immobilized bioflavonols were studied. The bioflavonols immobilized on Bemberg rayon fiber have a highly selective capacity adsorb uranium. Uranium recovery from seawater by the immobilized bioflavonols was markedly affected by the pH value of the seawater, and the uptake at pH 8, which is the pH value of natural seawater, was difficult. However, this adsorbent can accumulate large amounts of uranium from non‐saline water. Thus it can be used to remove and recover uranium from uranium refining waste water and other waste sources.
Characterization of hydrous titania from titanous chloride—II. Infrared studies
Authors: Ragai Jehane 
Published: July 2010

AbstractInfrared studies were carried out on a number of titania gels prepared from titanous chloride under various conditions of pH and oxidizing agents. Oxygen oxidized gels display, below 1200 cm−1, two bands at 1080 cm−1 and 970 cm−1 which are related to the formation of hydroxo complexes of titanium. Heat treatment at 110°C and ageing in water led to successive small shifts of these bands towards higher energies. In the case of hydrogen peroxide oxidized samples, prepared at a low pH, two significant bands appear at 1045 cm−1 and 1389 cm−1 and are attributed to O−2 and HO2 free radicals, respectively. The same kind of gels prepared under neutral or alkaline conditions are shown to incorporate hydroxo complexes of titanium; however, ageing in water leads to the reappearance in these gels of the 1045 cm−1 band attributable to O−2 free radicals. All gels exhibit two sharp bands at around 1400 cm−1 and 1630 cm−1, characteristic of NH+4 ions and molecular water, respectively.
The surface excess and the rate of copper extraction by hydroxyoximes
Authors: Szymanowski Jan , Prochaska Krystyna 
Published: July 2010

AbstractThe interfacial tension is determined for some model 2‐hydroxy‐5‐alkylbenzophenone E‐oximes, and the surface excess is calculated according to the different adsorption isotherms. The relationship between the rate of copper extraction and the surface excess is discussed. It is shown that, depending upon the adsorption isotherm used to calculate the surface excess, different relations both between the extraction rate and the surface excess and between the surface excess and the oxime concentration are obtained. The interfacial activity of hydroxyoximes is only a qualitative parameter suggesting the interfacial mechanism for copper extraction, and it cannot give strong evidence quantitatively supporting this mechanism. The predicted reaction orders against oxime demonstrate that the reaction between the oxime molecules from the sublayer and the absorbed intermediate complex is probably the limiting step.
Use of a novel turbidimeter to monitor microbial growth and control glucose concentration
Authors: Yamashita Sunao , Matsunaga Kazuhiko , Miura Hiroshi , Morikawa Makoto , Shimizu Kazuyuki , Matsubara Masakazu , Kobayashi Takeshi 
Published: July 2010

AbstractA turbidimeter (suspended solid concentration analyser: SSCA) which can measure directly the turbidity of culture broth has been developed. The SSCA was used to monitor baker's yeast and Escherichia coli fermentations. Although the medium conditions changed during the fermentations, the optical densities evaluated from the measurement of SSCA and predetermined calibration curves coincided well with those determined spectrophotometrically. Since SSCA can monitor microbial growth, it was applied to the control of glucose concentration in fed‐batch baker's yeast cultures by assuming a constant growth yield. Glucose concentration in the medium could be maintained between 0.2 and 0.3 g dm−3, and ethanol concentration was less than 4 g dm−3.
Kinetics of untreated orange peel utilisation by fusarium avenaceum
Authors: Moresi Mauro , Clementi Francesca , Rossi Jone 
Published: July 2010

AbstractThe growth behaviour of Fusarium avenaceum in slurry fermentation systems using untreated orange peel as substrate was studied in order to assess the eventual effect of impeller speed on mechanical disruption of mycelial hyphae. By applying the elementary balance method in combination with a Monod‐type kinetic equation, it was possible to formulate not only an unstructured model, but also the stoichiometry for such a mycelial fermentation process. In particular, the main yield coefficients, as well as the kinetic parameters, appeared to be independent of the impeller speed, at least within the experimental range of 450–900 min−1 (equivalent to peripheral impeller speeds of 3.8–7.5 m s−1). Moreover, as far as the kinetic parameters are concerned, it was impossible to discriminate the contribution of μM and Ks on the overall mycelial kinetics at the orange peel concentration studied. The rate of fungal formation was found to be first order in the concentration of the limiting substrate, probably because the concentrations of the organic carbon compounds utilisable by F. avenaceum were smaller than Ks.
Kinetics of homogeneous catalytic chlorination of acetic acid
Authors: Martikainen Päivi , Salmi Tapio , Paatero Erkki , Hummelstedt Leif , Klein Paul , Damén Henrik , Lindroos Torsten 
Published: July 2010

AbstractThe kinetics of the chlorination of acetic acid (HAc) to monochloroacetic acid (MCA) and the physical solubility of chlorine in HAc and its mixtures with MCA were investigated in a laboratory scale semibatch reactor. The temperature dependence of the Henry's constant was determined from solubility data obtained at temperatures between 70°C and 110°C. The kinetic experiments were performed at 75–100°C with 3–13 mol % acetyl chloride (AcCl) and 0–5 weight % H2SO4added as catalysts. Gas chromatography was used to determine the concentrations of HAc, MCA, dichloroacetic acid and AcCl during the experiments. The results indicate that the reaction rate is independent of the concentrations of HAc and Cl2whereas the reaction is significantly enhanced by MCA and H2SO4. The effects are explained by a reaction mechanism involving the acid catalyzed enolization of AcCl as the rate‐determining step. A rate equation based on this mechanism was derived. Kinetic constants included in the equation were determined by regression analysis.
Textural study of a coal from villanueva de rio y minas (sevilla, spain) and of samples prepared from it by acid and heat treatments
Authors: Calahorro Cristobal Valenzuela , Gonzalez Carmen Fernandez , Garcia Alvaro Bernalte , Serrano Vicente Gomez 
Published: July 2010

AbstractA coal with high inorganic matter content from the mine of Villanueva de Rio y Minas (Sevilla, Spain) (VRMO) was classified by following the ASTM norms as a high volatile matter A bituminous coal. The starting coal was treated either with HCl (VRMH) or thermally at 1000°C for 2 h (VRMOC), the resultant yield values (referred to as VRMO, dry) being, respectively, 97 and 79%; also VRMH was either treated with HNO3 (VRMN) or HF (VRMF), and the yield values (referred to as VRMH, dry) of the process were then 95 and 59%. The textural characterization of samples was effected by adsorption of CO2 at 273 K and of N2 at 77 K, as well as by mercury porosimetry. VRMN presents the highest value of the apparent surface area (SD‐R=219 m2 g−1) (CO2, 273 K) and of the specific surface area of mesopores and macropores (Sme+ma=5.2 m2 g−1) (N2, 77 K), while the greatest value of the cumulative specific surface area of macropores (Sma=1.2 m2 g−1) (mercury porosimetry) corresponds to VRMOC; S values are expressed on a per gram of original sample basis. The micropore volume accessible to CO2 at 273 K increases in both the HCl and the HNO3 treatment and decreases in the HF and heat treatments. The HCl and HNO3 treatments produce an increase of the mesoporosity; the HF treatment seems to affect in a special way the mesoporous texture. Furthermore, the heat treatment gives rise to a notable development of the macroporosity.
Some remarks about the estimation of the solubility parameter of low volatile compounds from gc data
Authors: Bermejo Jenaro , Guillén Maria D. 
Published: July 2010

AbstractApproximate solubility parameters of monomeric stationary phases can be calculated from gas chromatographic retention volumes of aliphatic saturated hydrocarbons; and some other properties, such as the molar volume and the latent heat of vaporization, by applying the regular solution model to the chromatographic process. By including data of aromatic hydrocarbons, solubility parameters of aromatic stationary phases, nearer to the experimental ones, can be obtained. The inclusion of data of olefines, however, is irrelevant. The method can be applied to low volatile compounds usable as the stationary phase in gas chromatography (GC) of hydrocarbons.
Phase transfer catalysed esterification of phenols with aliphatic acid chlorides. Part II: Phenyl acrylates from 3‐chloropropionyl chloride
Authors: Direktor David , Effenberger Reinhard 
Published: July 2010

AbstractThe phase transfer catalysed reaction of phenols with 3‐chloropropionyl chloride was carried out in a basic bi‐phasic aqueous—organic medium. Phenyl acrylates were isolated in good yields with high (>99%) purity.
Synthesis by enzymatic catalysis. IV. Transesterification of n‐acetyl‐L‐tyrosine ethyl ester with α‐chymotrypsin in water—hexanol—aot micelles
Authors: Testet Eric , Baboulene Michel , Speziale Vincent , Lattes Armand 
Published: July 2010

AbstractA new type of microemulsion system (Aerosol‐OT, water, hexanol) was used to entrap an enzyme (α‐chymotrypsin) in a reverse micelle. N‐acetyl L‐tyrosine ethyl ester can be solubilised in this medium to give N‐acetyl L‐tyrosine hexyl ester in a good yield (80%). This is the first report of a successful enzymatic transesterification in a micellar medium.
The treatment of anaerobically digested palm oil mill effluent by pressurised activated sludge
Authors: Ho C. C. , Tan Y. K. 
Published: July 2010

AbstractThe application of the pressurised activated sludge process in the secondary treatment of anaerobically digested liquor of palm oil mill effluent (POME) as influent under various physical conditions was studied. Separation of the particulates was by way of a dissolved air flotation unit. Results showed that a high efficiency in pollutant removals could be achieved and the final treated water was of good effluent quality. The high efficiency of the process was linked to the high rate of oxygen transfer at elevated pressure in the reactor. With a dissolved oxygen level of 10–14 mg dm−3 in the reactor, filamentous growth and sludge bulking were prevented. The kinetic coefficients for the process were also evaluated. It is envisaged the process could complement the anaerobic digestion in a two‐stage complete treatment system for POME.
Study of subbituminous coal chars: Effect of heat treatment temperature on their structural characteristics
Authors: Gutierrez Maria Del Carmen , Cukierman Ana Lea , Lemcoff Norberto O. 
Published: July 2010

AbstractChanges in the apparent surface area that are produced by carbonisation of a subbituminous coal at different temperatures are followed by adsorption of CO2 at 273 K and 298 K, the Dubinin—Radushkevich equation being used. Activated diffusion effects are found for the char samples prepared at 973 and 1173 K. A maximum in the apparent surface area is found at 1073 K.
The conversion of polysaccharides to hydrogen gas. Part II: The catalytic decomposition of formaldehyde in the aqueous phase
Authors: Hill S. P. , Winterbottom J. M. 
Published: July 2010

AbstractThe aqueous phase decomposition of formaldehyde, to hydrogen gas, catalysed by platinum—copper chromite, has been carried out in the temperature range 20–60°C, at a solution pH of 12.The production of hydrogen was favoured by intermediate temperatures (40–50°C) and an activation energy of 22.2 kJ mol−1 (5.3 kcal mol−1) was recorded. The rate of reaction was first order with respect to OH− ion concentration at low alkali concentrations and was first order with respect to HCHO concentration at all concentrations. At high alkali concentrations the reaction should become zero order with respect to OH− ion concentration, but initial rates actually decrease under these conditions having passed through a maximum. The rate of reaction was directly proportional to catalyst weight at low catalyst loading, but the relationship became non‐linear at high catalyst loadings. Conversions of formaldehyde to hydrogen gas were substantially less than theoretical.The decomposition reaction has to compete with a number of side reactions such as polymerization of formaldehyde at low temperatures (<40°C) and at higher temperatures with the Cannizzano reaction, aldol condensation, and possibly formaldehyde hydrogenation to methanol. In addition hydrogen loss may occur due to copper chromite reduction. A reaction mechanism is proposed involving a surface formate intermediate.
Drop formation in non‐newtonian liquids under pulsed conditions
Authors: Yaparpalvi Ravindra , Das Tarun R. , Mukherjee Ashok K. 
Published: July 2010

AbstractDrop formation from single nozzles under pulsed flow conditions in non‐Newtonian fluids following the power law model has been studied. An existing model has been modified to explain the experimental data. The flow conditions employed correspond to the mixer—settler type of operation in pulsed sieve‐plate extraction columns. The modified model predicts the drop sizes satisfactorily. It has been found that consideration of non‐Newtonian behaviour is important at low pulse intensities and its significance decreases with increasing intensity of pulsation. Further, the proposed model for single orifices has been tested to predict the sizes of drops formed from a sieve‐plate distributor having four holes, and has been found to predict the sizes fairly well in the absence of coalescence.