bluuebunny/crossref_metadata_2025_split huggingface dataset:
Vapour pressures, molar entropies of vaporisation and liquid‐state conformation of alkoxides
Authors: Thomas Leo H. , Smith Harry , Davies Gwyn H. 
Published: July 2010

AbstractThe vapour pressures of eight alkoxides (of carbon, silicon and boron) are reported, together with the molar entropies of vaporisation deduced therefrom. These data, along with those previously reported for 11 other alkoxides, are correlated by a simple equation containing only two adjustable parameters. The entropy values, which are substantially higher than the Trouton ‘constant’, are explained in terms of molecular parallelism of stretched flexible chains.
Biochemical basis of free and immobilised enzyme applications in industry, analysis, synthesis and therapy
Authors: Wiseman Alan 
Published: July 2010

AbstractBiotechnological use of enzymes has been started with cheap enzymes in soluble form, which were chosen from those that do not require the expense of added cofactors. These simple uses have been mainly in food industry applications, often for hydrolytic purposes in order to improve a process or product. Purified enzymes are finding application in analysis, including immunoassay, stereospecific synthesis and in therapy. In these cases, however, much more enzymological knowledge is needed to understand and control the use of the soluble or immobilised enzyme form. It is the appreciation of enzyme structure‐mechanism relationships that is essential to progress. This, and the control of enzyme stability, as determined by changes in protein conformation and aggregation, is of the greatest importance for the ultimate goal of designing new and better enzymes and enzyme analogues.
Magnetic adsorbents: Properties and applications
Authors: Dixon David R. 
Published: July 2010

AbstractMagnetic adsorbents which are capable of selectively removing impurities of low molecular weight from a food process stream without reducing the nutritional value of the product have been prepared by the methods described. The procedure has been tested by Kraft Food Ltd for a product derived from yeast cells, where it is essential to remove bitter‐tasting isohumulones without removing the valuable proteins and nucleic acids. The handling properties of the magnetic material allow ready separation of the saturated adsorbent from other suspended solids inevitably present in the process stream, prior to regeneration and reuse.
Ion flotation and solvent sublation of cobalt cyanide complexes
Authors: Walkowiak Władysław 
Published: July 2010

AbstractAn experimental investigation into the batch ion flotation of cobalt complex anions with the cationic surfactant, cetylpyridinium chloride is described. The concentration ratio of cetyl‐pyridinium: cobalt in the foam was determined and found to be 2.0–2.7 for CoCl2 plus KCN solution and 3.0–3.3 for K3[Co(CN)6] solution. Spectroscopic measurements of the former anion show that mainly [Co(CN)5H2O]2‐ anions were floated. The [Co(CN)6]3‐ flotation was established in the presence of Cl−, Br−, I−, CN−, NO3− and SO42‐ anions. The accelerating influence of the ion flotation produced by the presence of Cl−, Br−, I−, CN−, NO3− and SO42‐ increased as their partial molal volume increased. The solvent sublation of [Co(CN)6]3‐ anions was established in the presence of these anions.
Catalytic oxide coatings on ceramic supports
Authors: Unger Klaus K. , Engler Martin , Krys Siegfried , Inacker Otto , Plog Carsten , Seidl Max 
Published: July 2010

AbstractThin porous oxide coatings composed of Al2O3, SiO2, TiO2 and ZrO2, respectively, on ceramic carriers have been produced by either a wash‐coat procedure or by liquid coating followed by solidification. By dehydration and calcination of the supported ceramics the pore texture was stabilised. The thickness of the layer, its homogeneity, specific surface area, porosity and pore volume distribution have been shown to be controlled by the properties of the oxides deposited, and by the conditions of the coating procedures. On the basis of the results obtained, it is evident that porous oxide layers can be prepared with tailor‐made and desired properties. The procedures described also permit the incorporation of catalytic components (e.g. CuO) into the layer.
Basic characteristics and applications of a silica derived by flame hydrolysis. XX. Dust‐free handling of solid materials in powder form with extremely low bulk densities
Authors: Ferch H. , Schmitz W. 
Published: July 2010

AbstractPowders of small particle size and low bulk density find widespread use. Methods of handling must minimise their release into the atmosphere so as to reduce environmental and health implications. These methods are considered in detail here.
Cyclohexane dehydrogenation kinetics on a platinum‐rhenium/aluminium oxide catalyst with hydrogen and inert diluents
Authors: Susu Alfred A. , Enoh Felix E. , Ogunye AyöDele F. 
Published: July 2010

AbstractThe dehydrogenation of cyclohexane to benzene on a platinum‐rhenium/aluminium oxide (Pt‐Re/Al2O3) catalyst was investigated using both pulse and continuous flow techniques with hydrogen and inert (N2, He, Ar) diluents at the following conditions: 1 and 4 atm (1 atm = 101 kPa) total pressure and 432–623 K. Experiments performed with hydrogen as a carrier in the pulse mode showed anomalous behaviour as cyclohexane conversion was observed to increase with pulse size/pulse width and decrease with temperature and contact time. The dehydrogenation reaction was first‐order with respect to cyclohexane for both the pulse and continuous flow experiments. Lower activation energies were observed for the inert carriers; activation energies were between 37.7–54.4 kJ mol<−1 for inert diluents. With a hydrogen carrier, the activation energies were found to be 87.9 and 121.3 kJ mol−1 for T<553 K and <553 K, respectively. The difference in activation energy between hydrogen and the inert carriers was attributed to a change in mechanism on the coked catalyst surface. Surface conversion of cyclohexane to adsorbed cyclohexane was the slowest step in a hydrogen carrier. For the inert carriers, it was postulated that surface diffusion of adsorbed intermediate for for subsequent conversion was rate determining.
Elimination of ethanol inhibition of yeast growth by a multistream ethanol feed in a multistage tower fermenter
Authors: Páca Jan 
Published: July 2010

AbstractThe effect of several types of ethanol feed into a multistage tower fermenter, under conditions of oxygen supply rate limitation, on growth and physiological activity of the yeast Candida utilis was studied. The measurements were made at steady states of continuous culture for single values of dilution rate, temperature and pH in all stages of the fermenter and with a constant total sum of ethanol supplied. It was found that the type of ethanol feed significantly affects both the economic parameters associated with biomass production and the cell physiology in the individual stages of the fermenter.
Studies on the extraction of aromatics with sulpholane and its combination with thiodiglycol
Authors: Rawat Bachan S. , Gulati Indar B. 
Published: July 2010

AbstractLiquid—liquid equilibria for the systems: toluene—heptane—sulpholane, toluene—heptane—sulpholane plus thiodiglycol at 40°C, and benzene—heptane—sulpholane plus thiodiglycol and benzene—heptane—sulpholane plus 9% water at 110°C have been studied. The results of the combined solvents have been compared with those obtained with sulpholane containing up to 9% water. Several advantages of combined solvents are discussed. The selectivities of the mixed solvents for different hydrocarbon types have been calculated from the limiting activity coefficients determined by gas chromatography.
The use of Caenorhabditis elegans for anthelmintic screening
Authors: Simpkin K. Graham , Coles Gerald C. 
Published: July 2010

AbstractCaenorhabditis elegans maintained on ampicillin‐treated Escherichia coli has been found to be sensitive to the benzimidazole anthelmintics, albendazole, cambendazole, fenbendazole, flubendazole, mebendazole, oxfendazole, oxibendazole, parbendazole, thiabendazole and the non‐benzimidazoles, avermectin B1a, bitoscanate, febantel, levamisole, morantel, nitroscanate, oxantel, phenothiazine, pyrantel, pyrvinium pamoate, rafoxanide and stilbazium iodide at concentrations of 50 μg cm−3 or less. It can therefore be used in a high through‐put in vitro pre‐screen for anthelmintics. It is suggested that C. elegans may also be useful for evaluating the mode of action of drugs and the mechanism of resistance of nematodes to anthelmintics.
Synthesis of some new diarylsulphides and diarylsulphones containing a quinazol‐4‐one moiety
Authors: Abbady Mahmoud A. , Ali Morsy M. , Kandeel Maymouna M. 
Published: July 2010

Abstract4‐Amino‐4′‐nitrodiphenylsulphide and 4‐amino‐2′‐nitrodiphenyl sulphide (I) were smoothly condensed with 2‐methyl‐3,1‐benzoxazin‐4‐one (II) to produce the corresponding 2‐methyl‐3‐diphenylsulphidoquinazol‐4‐ones (III). 2‐Styryl‐3‐diphenylsulphidoquinazol‐4‐ones (IV) were prepared by heating III with the appropriate aromatic aldehydes using piperidine as a basic catalyst. Compounds IV oxidised easily in a hydrogen peroxide‐glacial acetic acid mixture to produce the corresponding sulphones (V). The constitution of some of the prepared products is discussed in the light of their infrared and ultraviolet spectra. The biological activities of some of these compounds were tested.
Development of a correlation between the non‐polar solubility parameter, refractive index and molecular structure. I. Aliphatic hydrocarbons
Authors: Wingefors Stig , Liljenzin Jan‐Olov 
Published: July 2010

AbstractFor non‐polar liquids (e.g. the alkanes) the cohesion energy density (λ2) can be shown to be a function of the refractive index (nD), molal volume (V) and molecular structure according to:

where Δ is the non‐polar solubility parameter and the increments gij are determined from molecular structure. The difference between values of Δ calculated by this formula and experimental data is <0.1% for the C5–C16 n‐alkanes and <0.8% for the C5–C8 branched isomers. The main object of this correlation was to provide a method for estimating the London dispersion force contribution to the cohesive energy of branched polar liquids.
Production of citric acid by submerged fermentation. Effect of medium sterilisation at pilot‐plant level
Authors: Chopra Charanjit L. , Qazi Ghulam N. , Chaturvedi Surya K. , Gaind Chand N. , Atal Chand K. 
Published: July 2010

AbstractIn large‐scale fermenters, in situ sterilisation takes a long time and there is probably thermal degradation of the medium constituents, the products of which generally affect the final yield. Sterilisation cycles were designed according to the microbial load in the broth and their effect on the production of citric acid studied in 4‐m3 fermenters. It was found that the medium could tolerate Del values up to 48 against a calculated value of 35.50. Above this value there was thermal degradation of the medium constituents which adversely affected the morphology of the fungus Aspergillus niger, and consequently the citric acid yields.
Control of the production of cephamycin C and thienamycin by Streptomyces cattleya NRRL 8057
Authors: Lilley Gerald , Clark Anne E. , Lawrence Gordon C. 
Published: July 2010

AbstractBatch and continuous flow chemostat cultures were used to analyse the effect of environment and specific growth rate on thienamycin and cephamycin C production by Streptomyces cattleya NRRL 8057. Thienamycin was shown to be a phosphateregulated product, optimally produced in phosphate‐limited cultures. In batch culture, antibiotic production started as phosphate was exhausted in the medium. In phosphate‐limited chemostat culture, optimal production occurred at low dilution rates and low specific rate of phosphate utilisation. Synthesis was severely repressed in phosphate‐sufficient cultures irrespective of the specific growth rate. In contrast, the growth rate, rather than the nature of the limitation, was a major controlling factor in regulating cephamycin C production. Production of this antibiotic occurred, optimally at low specific growth rates, irrespective of whether phosphate, nitrogen or carbon were limiting the cultures. It was therefore concluded that cephamycin C production could be regulated by phosphate, nitrogen or carbon‐mediated control. Ammonium nitrogen was shown to be more repressive than nitrate nitrogen. Collectively the data emphasised the significance of the growth‐limiting substrate and the specific growth rate on the production of these β‐lactam antibiotics.
Physico‐chemical properties of by‐product gypsum
Authors: Beretka Julius , Crook Douglas N. , King George A. 
Published: July 2010

AbstractFour samples of by‐product gypsum were analysed by chemical and physical methods and subjected to comparable degrees of calcination in a special rotary furnace. The hydration characteristics of the resulting calcium sulphate hemihydrates were determined in terms of three basic parameters viz. α0, a measure of heterogeneous nucleation in the system; k, a measure of self‐acceleration of the reaction; and θ, the period of induction. Measurements were made of the size distribution of particles, pH, water requirement, the colour and compressive strength of cast gypsums made from the hemihydrates, and comparisons were made with two samples of calcined natural gypsum. Additions of calcium oxide were also made to the by‐product gypsums and the same procedures followed. Hydration of the calcined products resulted in considerable differences in the kinetic parameters. Both differences in nucleation and transport of calcium sulphate from the grains of hemihydrate to the growing crystals of the dihydrate seemed to contribute to variations in reactivity. The by‐product gypsums calcined alone, or in the presence of calcium oxide, yielded hemihydrates with water requirements greater than those of the calcined natural gypsums. The compressive strengths of cast gypsums made from these hemihydrates were somewhat less than those made from the calcined natural gypsums. The colour co‐ordinates were about the same. After treatment with calcium oxide, the by‐product gypsum appears to be suitable for making plaster of Paris.
The preparation of thiophenes. III. From aromatic compounds and carbon disulphide
Authors: Azizian Farid , Pizey James S. 
Published: July 2010

AbstractThe high‐temperature, vapour‐phase reaction of carbon disulphide with 2‐isopropyl‐phenol and with o‐methylbenzyl alcohol in the presence of various catalysts gave high yields of 3‐methylbenzo[b]furan and dihydrobenzo[c]thiophene, respectively.
The preparation of 5‐chloromethylfurfuraldehyde from high fructose corn syrup and other carbohydrates
Authors: Szmant H. Harry , Chundury Deena D. 
Published: July 2010

AbstractA 92–95% conversion of high fructose corn syrup (HFCS) or crystalline D‐fructose to 5‐chloromethylfurfuraldehyde (CMF) was achieved using 300 mol% of concentrated hydrochloric acid in chlorobenzene, under a nitrogen atmosphere, a reaction temperature of 75°C and a reaction time of 1–2 h. Constant high‐speed stirring was essential for high yields and purity of CMF. Inferior yields of CMF were obtained from glucose and starch. Saccharine, phenyl sulphone and thiuronium derivatives were prepared and characterised. The use of surfactants did not improve the yields of CMF.
The measurement of effective substrate diffusities within whole cell suspensions using a diffusion‐limited hollow fibre reactor
Authors: Webster Ian A. , Shuler Michael L. 
Published: July 2010

AbstractAn immobilised whole cell membrane reactor system is described which permits estimation of effective substrate diffusivities within whole cell suspensions. The reactor unit uses a membrane to separate the cell slurry from the nutrient solution (e.g. an artificial kidney hollow fibre dialyser). Whole cells are pumped into the shell side of the unit and clamped off. Substrate solution makes one pass through the dialyser tube side at a flow rate such that its conversion over the complete reactor does not exceed 10%. Under such conditions the reactor operates differentially; previously published mathematical expressions being used in evaluating the effective substrate diffusivity, once η (the effectiveness factor) is determined. The value of η can be estimated readily from the true reaction rate (in the absence of diffusional limitations) and the experimentally observed reaction rate. A hypothetical example is presented. The advantages and disadvantages of the method are discussed.
Effect of aeration and pH on gramicidin S production by Bacillus brevis
Authors: Vandamme Erick J. , Leyman Dirk , De Visscher Patrick , De Buyser Dirk , Vansteenkiste Ghislain 
Published: July 2010

AbstractAlthough the biosynthesis of the antibiotic gramicidin S (GS) by Bacillus brevis ATCC 9999 has been studied extensively, almost no attention has been given to environmental control of its fermentation process. In this respect, GS fermentations conducted in a 7.5 dm3 fermentor in complex (YP) medium revealed that a high aeration rate resulted in a high biomass yield (12 g DCW dm−3) with very low GS levels (170 mg GS dm−3). Lowering the aeration rate (5 dm3 air min−1 at 300 rev min−1) caused a dramatic increase in GS formation (2100 mg GS dm−3) and comparable but slower biomass formation. In chemically‐defined (F3/6) medium fermentations, an aeration rate of 5 dm3 air min−1 at 300 rev min−1 was apparently too high as only 0.104 mg GS mg−1 DCW was produced. A much lower aeration rate (2 dm3 air min−1 at 250 rev min−1) was needed to arrive at a higher specific antibiotic level: 0.130 mg GS mg−1 DCW. These data seem compatible with the finding that oxygen is known to inactivate the GS‐synthetases. Furthermore, keeping the pH constant at 7.3 under low aeration conditions increased specific GS production up to 0.220 mg GS mg−1 DCW in YP, as well as in F3/6 fermentations. Both environmental pH and dissolved oxygen tension clearly affect growth pattern, growth extent and GS production in these high yielding media. These data stress the importance of controlling pH and aeration rate during GS fermentations.
The increase in intracellular free‐lysine levels of growing Baker's yeast (Saccharomyces cerevisiae) by sodium chloride
Authors: Tanner Robert D. , Richmond L. Daniel , Wei Chia‐Jenn , Woodward Jonathan 
Published: July 2010

AbstractFermentation by baker's yeast was carried out in medium containing exogenously added sodium chloride. The cell, intracellular free‐lysine, glucose and ethanol concentrations were monitored at intervals of time during the fermentation. Sodium chloride (0.15–0.6M) stimulated the maximum intracellular free‐lysine concentration of baker's yeast. The greatest stimulation was observed using 0.6M sodium chloride and was accompanied by a reduction in the rate of glucose uptake from the medium and a lowering of the ethanol concentration in the medium.
The dynamics of anaerobic phenol biodegradation in lower greensand
Authors: Rees John F. , King John W. 
Published: July 2010

AbstractThe anaerobic biodegradation of phenol in the unsaturated zone beneath landfill sites has been simulated by percolating an artificial landfill leachate containing phenol through columns of disturbed Lower Greensand. The columns were inoculated with microbes from a laboratory‐scale landfill simulator. Phenol degradation was observed at concentrations up to 8.2 g dm−3 but decomposition was increasingly inhibited above 3.0 g dm−3. Maximum rates of decomposition were observed at concentrations between 1.5 and 3.0 g dm−3. The Vmax value at a flow rate of 0.5 cm3 h−1 was 1.05 g dm−3h−1 and the Km value was 450 mg phenol dm−3. Zero‐ (r0) and first‐order (r1) rate constants increased with increasing flow rate. The data are used to calculate the rates of phenol degradation which might be obtained in real landfill.
Coke formation during cracking of hydrocarbons. I. The effect of pre‐sulphiding on coke formation on a nickel‐chromium‐iron alloy under steam cracking conditions
Authors: Trimm David L. , Holmen Anders , Lindvag Odd 
Published: July 2010

AbstractStudies have been carried out on the effect of pre‐sulphiding a nickel‐chromium‐iron alloy on coke formation under steam cracking conditions. Pre‐sulphiding has no great effect on the gaseous product spectrum as long as some sulphur is present, but the coking rate is dependent on the amount of sulphur pre‐deposited. Small amounts of sulphur reduce the coke formation, but the coking rate increases with increasing amounts of pre‐deposited sulphur. As the sulphur content increases still further, coke formation passes through a maximum. A tentative explanation of these observations is advanced in terms of the effect of metal sulphides on the established mechanism of coke formation. Initial sulphiding is suggested to increase grain boundary penetration by coke and to result in the accumulation of iron sulphide on the surface. Eventually this may act to seal off grain boundaries, thereby inhibiting further coke formation.
Fundamental aspects of lead extraction and stripping by a liquid ion exchange reagent
Authors: Hoh Ying‐Chu , Wang Wei‐Ko 
Published: July 2010

AbstractLIX 34 liquid ion exchange reagent was introduced commercially by General Mills in 1976. The fundamental aspects of lead extraction and stripping using LIX 34 as the organic extractant in acetic solution has been studied here. Equilibrium isotherms for extraction and stripping, isothermal pH effects, temperature effect, loading capacity and the rate of extraction and stripping on the system Pb2+‐HAc‐LIX 34—Kermac 470B are reported.
The kinetics of reduction of selenious(IV) ions in hydrochloric acid with sulphur dioxide
Authors: Chiu Tai‐Ming , Hoh Ying‐Chu , Wang Wei‐Ko 
Published: July 2010

AbstractThe reduction of selenious ions to its elemental state has been found to be a function of selenious ion concentration, solution acidity, gas flow rate and temperature. The rate equation can be written as:

where α = −1/2, β = 1, γ = 0.9, E = −53 411 kJ kg−1mol−1, R = 8314 kJ kg−1 mol−1 K−1 and k0 = 194. The reaction temperature starts to decrease when the conversion rate reaches a maximum. This observation can be used to determine the end of the reaction.
Some aspects of homogeneous and two‐phase aromatic sulphonation
Authors: Sohrabi Morteza , Kaghazchi Tahereh 
Published: July 2010

AbstractThe two‐phase sulphonation of benzene and toluene with concentrated sulphuric acid solutions at 30°C has been studied in a continuous stirred tank reactor (1.06 dm3 capacity). The rates of reaction, as a function of sulphuric acid concentration and the overall mass transfer coefficient times, and the interfacial area per unit volume of the acid phase as a function of agitation speed, have been determined. In homogeneous systems, the kinetic rate constants and the relative rates of sulphonation of a series of aromatic hydrocarbons have been measured in the range of 13–16 mol dm−3 sulphuric acid. It has been shown that the rates of sulphonation of compounds, with levels of reactivity beyond that of m‐xylene, are likely to be affected by diffusional phenomena.
Influence of oxygen and medium conditions on the performance of a tower reactor with an external loop
Authors: Buchholz Heinrich , Luttman Reiner , Zakrzewski Wolfgang , Schügerl Karl 
Published: July 2010

AbstractHansenula polymorpha was cultivated using ethanol and/or glucose as substrate in a bubble column, air lift, loop reactor. The optimum aeration rate was determined for extended culture operation. Considerable influence of the ethanol concentration on the volumetric mass transfer coefficient (kLa), and the specific gas‐liquid inter‐facial area (a) was found. Glucose concentration had no comparable influence on kLa and a. The influence of lack of substrate and/or dissolved oxygen on the culture was investigated. For 30 min the absence of substrate did not influence μm, whereas a lack of dissolved oxygen for 2.5 min reduced μm to one half of its original value.