bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preparation of pyridinemonocarboxylic acids by catalytic vapour phase oxidation of alkylpyridines. I. Oxidation of 2‐ and 3‐picoline and decarboxylation of 2‐ and 3‐pyridinecarboxylic acid in the vapour phase
Authors: Järås Sven , Lundin Sten T. 
Published: July 2010

AbstractThe vapour phase oxidation of 2‐picoline with air using a singly promoted vanadium catalyst (V2O5/SnO2, mole ratio 1/1.5), at a temperature of 375°C and a space velocity of 6130 h−1, gave a 69% conversion with a selectivity of 64% for 2‐pyridinealdehyde. No pyridoin formation was detected. In the vapour phase oxidation of 3‐picoline using a doubly promoted vanadium catalyst (V2O5‐TiO2‐Na2O with V/Ti/Na=100/20/1.15) at a temperature of 400°C and a space velocity of 1450 h−1, a 94% conversion of 3‐picoline was obtained with a selectivity of 51% for niacin (3‐pyridinecarboxylic acid) and 1% for 3‐pyridinealdehyde. By varying the atom ratio V/Ti, the catalyst V/Ti = 100/25 was found to be the most active one. The decarboxylation of 2‐ and 3‐pyridinecarboxylic acid in the vapour phase was also investigated under the conditions used in the oxidation of the picolines to the acids. At 350°C about 90% decarboxylation of picolinic acid occurs under these conditions, while only a few per cent of the niacin decarboxylated to pyridine between 300 and 500°C.
Mechanism of the liquid‐phase oxidation of cumene, cyclohexene and tetralin catalysed by MnO2
Authors: Krishna Lanka V. G. , Srivastava Rameshwar D. , Rao Musti Someswara 
Published: July 2010

AbstractOxygen absorption by solutions of cumene, cyclohexene and tetralin in monochloro‐benzene has been measured at 80, 60 and 65°C with MnO2 catalyst in the inhibition region, and shows second order rate dependence with respect to hydrocarbon concentration. The limiting rate of oxidation is satisfactorily described by a 3‐parameter equation based on the reaction mechanism proposed by Neuburg et al. Statistical estimates of the parameters for cumene are given from this work and for cyclohexene and tetralin from work presented elsewhere.
A convenient one step synthesis of 2,4‐dialkyl‐2‐hydroxy‐alkyl‐γ‐butyrolactone using lithium naphthalenide
Authors: Fujita Tsutomu , Watanabe Shoji , Suga Kyoichi , Hokyo Masamoto 
Published: July 2010

AbstractOne mole of propionic acid (I) reacts with 2 mol of 1,2‐butylene oxide (II) in the presence of lithium naphthalenide to give 4‐hydroxy‐2‐(2′‐hydroxybutyl)‐2‐methylhexanoic acid (V), which can be easily converted into 2‐(2′‐hydroxybutyl)‐2‐methyl‐4‐ethyl‐γ‐butyrolactone (VII). Similarly, 2,4‐dialkyl‐ and 2,4,4‐trialkyl‐2‐hydroxyalkyl‐γ‐butyrolactones were prepared from other carboxylic acids having two hydrogens at 2‐position and various epoxides.
Rapid qualitative identification of sulphonamides by mass spectrometry
Authors: Davis Reg. , Hurst Derek T. , Taylor Albert R. 
Published: July 2010

AbstractRapid qualitative identification of the sulphonamides present in pharmaceutical preparations is conveniently carried out using mass spectrometry. Direct introduction of a small quantity of the powdered tablet into the mass spectrometer results in the production of characteristic ions even in preparations containing a mixture of therapeutically active constituents and without prior separation of the various constituents.
Effect of cooperativity on microbial growth
Authors: Kargi Fikret 
Published: July 2010

AbstractThe classical Monod equation for the specific growth rate of a microbial population can be derived by assuming a single substrate enzyme‐catalysed reaction (Michaelis‐Menten kinetics) as the rate‐limiting step in microbial growth. In some cases the enzyme which catalyses the rate‐limiting step in microbial growth may have more than one substrate binding site and the binding of one substrate molecule to the enzyme facilitates the binding of the next substrate molecule (cooperativity). The presence of cooperativity changes the form of the Michaelis‐Menten equation for enzyme‐catalysed substrate reactions and also the Monod equation for microbial growth. The number of interacting active sites on an enzyme molecule is an additional parameter in this case. In this article, the cooperative growth model for n interacting sites on the enzyme is derived and compared with the classical Monod model.
Biotechnology. The way ahead
Authors: Humphrey Arthur E. 
Published: July 2010

AbstractThe future for biotechnology looks very bright. Opportunities are increasing, largely because of advances in genetics and in computer‐aided automation. In the past many biotechnology opportunities have arisen out of crisis‐oriented problems. For example, acetone/butanol fermentations were developed to solve a need for acetone to manufacture cordite during World War I and penicillin fermentations evolved because of the need to develop antibiotics to prevent wound infections in World War II. It is felt that future opportunities will emerge largely from similar crises. These probably will involve chemical feedstock supply, alternative forms of energy, applications of genetics, health care and delivery problems, environmental concerns and computeraided automation.
Industrial‐scale operation of microbial processes
Authors: Brown D. E. 
Published: July 2010

AbstractInteractions between fermentation process development and plant design are explored. An attempt is made to identify the various aspects of microbial reaction and material‐transport control of process rates. In scale‐up some factors remain constant and some can change and the importance of each is discussed. The case for the use of a stirred fermenter in batch processing is developed and the various non‐technical constraints that can determine the scale of operation are described. The production of desirable fluid characteristics at different scales of operation are discussed and it is shown that a deviation from geometrical similarity may be necessary for fermentation process scale‐up. A design procedure for aeration‐limited processes reveals the complex multitude of factors that must be considered in fermentation‐equipment design.
Two‐liquid‐phase biocatalytic reactions
Authors: Lilly M. D. 
Published: July 2010

AbstractThe development of biocatalytic reactors for the conversion of high concentrations of water‐insoluble reactants is at the same stage that systems for water‐soluble reactants had reached almost a decade ago. There are still many problems and much research to be done before we fully understand such systems. Nevertheless, we can confidently expect to see new commercial processes with multiliquid biocatalytic reactors during the next decade.
Immobilised multienzyme systems and organelles
Authors: Legoy M. D. , Gellf G. , Ergan F. , Cocquempot M. F. , Larreta Garde V. , Thomas D. 
Published: July 2010

AbstractEnzyme technology has demonstrated its economic and industrial potentials by the successful development of the ‘first generation’ of immobilised enzymes which concern simple degradative enzymes which by hydrolysis, oxidation and isomerisation yield products with rather limited added values. A new objective is to prepare industries to develop a ‘second generation’ of enzyme reactors in which sophisticated multienzyme systems will catalyse the synthesis of fine chemicals of high added value. There are two kinds of solutions to develop such new systems: immobilisation of subcellular organelles such as mitochondria, whole bacteria or fragments (chromatophores), chloroplasts (thylakoids). etc.; immobilisation of multienzyme systems including cofactor regeneration and realisation of multienzyme reactors like continuous stirred‐tank reactor. Experimental examples dealing with both topics are described.
Current strategies in the search for bioactive microbial metabolites
Authors: Nisbet Louis J. 
Published: July 2010

AbstractNew microbial metabolite screening currently requires an interdisciplinary team consisting of microbial ecologists, geneticists, molecular biologists, biochemists, microbial physiologists, fermentation technologists and chemists. The increasing difficulty in discovering new compounds of clinical potential can only be overcome by maximising the input of the above disciplines. Possible strategies for constructing a genetically diverse ‘bank’ of microorganisms, including naturally occurring and genetically manipulated strains, are reviewed. Also, the design of environmental conditions optimal for the over‐production of metabolites and the types of screens that are selective for compounds of potential utility are discussed. The value of target‐selective screen techniques is illustrated with experiences gained in the search for new β‐lactams.
Role of plasmids in producers of macrolides
Authors: Schrempf Hildgund 
Published: July 2010

AbstractSeveral strains of Streptomycetes producing macrolide antibiotics were found to contain extrachromosomal DNA, but it could be shown that the syntheses of macrolides are not necessarily plasmid‐determined. A plasmid‐bearing strain, Streptomyces reticuli, synthesising melanin and the macrolide leucomycin has been studied together with several variants arising after treatment with intercalating agents. Variants forming no melanin and (or) aerial mycelium possess altered extrachromosomal DNA and those which lack plasmid DNA do not produce aerial mycelium, melanin or the antibiotic on agar plates. In contrast with the wild‐type of S. reticuli, the plasmidless variants contain amplified nucleotide sequences within their chromosomal DNA. The significance of the changes within the chromosomal and extra‐chromosomal DNA in respect to the production of secondary metabolites is discussed.
Immobilised plant cells: General aspects
Authors: Brodelius Peter , Mosbach Klaus 
Published: July 2010

AbstractThe immobilisation of plant cells grown in suspension cultures by entrapment in various gels is described. The viability and biosynthetic capacity of such immobilised cells have been investigated. Model studies covering different aspects of biosynthesis, i.e. biotransformation, synthesis from added precursors and synthesis de novo from a simple carbon source, are described. In some model studies it has been observed that the immobilised cells can produce higher amounts of secondary products than freely suspended cells under the same conditions. Furthermore the permeabilisation of plant cells for continuous release of formed products with subsequent immobilisation is also discussed.
Liposome‐protoplast interactions
Authors: Makins John F. , Holt Geoffrey 
Published: July 2010

AbstractA large number of different biological compounds can be encapsulated in liposomes and then delivered into the cytoplasm of cells by fusing these lipid vesicles with protoplasts. The essential properties of protoplasts and liposomes are briefly described. Examples of two liposome‐protoplast interactions, involving the delivery of intermediates of antibiotic biosynthesis into fungi and DNA into Streptomyces are discussed. References are made to other experiments suggesting that liposomes may be useful in many areas of biotechnology.
X‐ray powder diffraction studies of basic lead carbonate as a stabiliser in plasticised polyvinyl chloride
Authors: John Michell E. W. , Ng Kok Y. 
Published: July 2010

AbstractStrips from a polyvinyl chloride (PVC) sheet plasticised with di‐2‐ethyl hexyl phthalate (dioctyl phthalate, DOP), containing hydrocerussite 2PbCO3‐Pb(OH)2 stabiliser and milled with stearic acid lubricant, and which had been heated for various periods up to the Congo‐red test‐time at 180°C under N2, have been examined in reflection by X‐ray powder diffractometry. The penetration of X‐rays into these strips was rather low and so examination was confined to surface layers. Studies of the inorganic crystalline phases accord with results obtained during recent examinations of sections cut normal to the strip lengths (which represented the bulk materials) showing that the hydrocerussite reacted homogeneously throughout the hot samples and was completely used long before stabilisation failed at the Congo‐red test‐time. Surprisingly, crystalline salts of both orthophthalic and stearic acids were found in the surface regions, but not in the bulk. These results are interpreted in terms of a free‐radical chain mechanism for PVC decomposition and true stabilisation involving exchanges (which trapped chlorine free‐radicals) and temporary polymer esterifications (which inhibited release of chlorine free‐radicals from the PVC), with lead carboxylates being regenerated as the active intermediates. The inhomogeneous distributions for the lead salts of organic acids are then attributed to migration of intermediates towards the surfaces, combating potentially faster degradation than in the bulk (caused by oxidation of polymer in the surface regions when the newly milled PVC sheet was cooling to room temperature in air). It is concluded that true stabilisation involving lead compounds benefits PVC in commercial processes by retarding thermal decomposition and preventing the formation of HCl.
Synthesis of some new unsymmetrical aza‐pyrazolomonomethine cyanine dyes
Authors: El‐Kashef Hussein S. , El‐Shafei Ahmed K. , El‐Khawaga Ahmed M. 
Published: July 2010

AbstractNew aza‐pyrazolomonomethine cyanine dyes IV and V have been prepared by the condensation of some nitroso compounds, namely p‐nitroso‐N,N′‐dimethyl or diethyl aniline, α‐nitroso‐β‐naphthol and β‐nitroso‐α‐naphthoI, with known unsymmetrical pyrazolomonomethine cyanines II and III. The u.v. and visible spectra of all dyes prepared have been investigated.
Catalysed transformation of α‐pinene over platinum‐alumina
Authors: Krishnasamy Vengamuthu , Mathur Praveen , Chandrasekharan Kailasanathen 
Published: July 2010

AbstractThe transformations of α‐pinene have been investigated over platinum‐alumina containing varying amounts of platinum and platinum‐alumina modified with different amounts of Cs+ and F− in the temperature range 200–350°C. A study of the influence of contact time and temperature shows that α‐pinene isomerises via two parallel paths, one giving monocyclic products and the other giving rise to bi‐and tri‐cyclic compounds. Concentrations above 0.6% platinum have no beneficial effect. Impregnation of platinum‐alumina with F− increases the overall conversion of α‐pinene, enhances the disproportionation of menthadienes and decreases the formation of cymene. Conversely, Cs+ increases the formation of cymene, in spite of a reduction in the overall conversion of α‐pinene. Decrease of particle size was found to improve the overall activity of the catalyst. The activity of the catalyst remains almost constant for the overall conversion during the course of the run, but its dehydrogenating activity declines.
Effect of catalyst composition on the selectivity of competitive hydrogenations of mono‐olefinic reactants in the liquid state
Authors: Červený Libor , Kuncová Marcela , Vodová Barbora , Rüžička Vlastimil 
Published: July 2010

AbstractThe effect of the amount of platinum and the type of the carrier on the selectivity for competitive hydrogenation of 2‐methyl‐3‐butene‐2‐ol and hex‐l‐ene in methanol on platinum carrier catalysts has been studied. The effect of the type of the active component and carrier on the selectivity for competitive hydrogenation of 2‐methyl‐3‐butene‐2‐ol and 2‐phenylpropene in methanol and cyclohexane on various types of catalyst has also been investigated. Selectivity decreased with increasing amounts of platinum on the carrier and also with decreasing polarity of the carrier. The change in selectivity was greatest for a change in the active (metal) component of the catalysts; being in most cases several times higher in cyclohexane compared with methanol.
Production of furfural from agricultural wastes by using pressurised water in a batch reactor
Authors: Sharma Durlubh K. , Sahgal Prakash N. 
Published: July 2010

AbstractAgricultural wastes such as rice husks and sawdust can be used for the manufacture of chemicals including furfural and acetic acid. In the present work the conventional use of superheated steam has been replaced by the use of superheated water in the acidic hydrolysis of rice husk and sawdust. Comparable yields of furfural have been obtained by using superheated water in place of superheated steam in the same temperature and pressure range. This is an attempt to economise the heat requirement and reduce the cost of production of furfural.
Optimal biofilm thickness for fluidised‐bed biofilm reactors
Authors: Kargi Fikret , Park Jung Keug 
Published: July 2010

AbstractFluidised‐bed biofilm reactors (FBFR) have been used extensively for the removal of BOD and nitrogen from wastewater. However, no attempt has been made to identify the optimal design of such reactors to maximise the rate of removal of waste substances. A theoretical analysis of FBFRs is presented and it is revealed that there is an optimal biofilm thickness for a given support particle size which maximises the volumetric removal rate of waste substance from the liquid stream.
Oxidation of ethanol over ferric molybdate catalyst
Authors: Srihari Voruganti , Viswanath Dabir S. 
Published: July 2010

AbstractOxidation of ethanol vapour over ferric molybdate catalyst in an isothermal flow reactor was investigated at 530–578 K and alcohol partial pressure range of 0.811–3.344 kPa. The rate data collected were well represented by a steady‐state two‐stage redox model conforming to an order of reaction of unity with respect to ethanol and 0.5 with respect to oxygen. Non‐linear least‐squares procedures gave a lower sum of squares of residuals in the estimation of the parameters of the rate equation compared with linear least‐squares methods. The activation energies for the first and second steps of the redox model were found to be 56.36 and 52.26 kJ mol−1 respectively.
Influence of the neutralising agent on jarosite precipitation
Authors: Ghodsi Mehdi , Detournay Jacquy , Marion Anne‐Marie 
Published: July 2010

AbstractThe study of the removal of iron from Zn electrolytic solutions by jarosite precipitation shows that it occurs irrespective of whether calcine or sinter is used. In both cases the iron residue has similar characteristics. Moreover it is clearly shown that the thermal treatment to which the calcine is submitted has a fundamental influence on the Zn loss in the ferruginous residue.
The utilisation of citrus waste as substrate for microbial protein production by the fungus Sporotrichum pulverulentum
Authors: Karapinar Mehmet , Okuyan Melahat 
Published: July 2010

AbstractThe growth and protein synthesis of Sporotrichum pulverulentum was studied in shake flask cultures using orange waste as carbon source. The influence of factors such as nitrogen source, initial pH, incubation time and temperature were investigated, ammonium sulphate being the best source of supplementary nitrogen. Biomass containing about 31.9% protein was obtained with a medium pH of 5.0 in 4 days incubation.
Desiccant characteristics of coconut pith
Authors: Idiculla Roschen , Seshadri S. K. 
Published: July 2010

AbstractAn experimental study has been made of the capacity, rate and efficiency of moisture adsorption by coconut pith. Regeneration characteristics at different temperatures have also been studied and its properties are compared with those of standard desiccants, especially silica gel. The results indicate that coconut pith shows good promise as a cheap, yet effective desiccant.
Homogeneous catalysis of the reduction of nitrobenzene by bromotris(triphenylphosphine) copper (I)
Authors: Datta Manik C. , Saha Chitta R. , Sen Debabrata 
Published: July 2010

AbstractHomogeneous reduction of nitrobenzene by hydrogen in presence of complex [CuIBr(PPh3)3] as catalyst has been investigated. From a study of various operational parameters, it has been observed that maximum reduction occurred at 2.5 × 103 kPa pressure and at 473–513 K and resulted in 75% aniline, 10% azobenzene, 2% nitrosobenzene in ethanol, and 70% aniline, 5% azobenzene, 7% nitrosobenzene in dimethylformamide, calculated on the basis of input nitrobenzene. In an attempt to elucidate the reduction mechanism two new intermediates, [CuHPPh3Br]2 (I) and [(C6H5N=NC6H5)Cu2(PPh3)4Br2] (II), have been isolated and characterised by elemental analysis, spectral, thermal, magnetic and p.m.r. studies.
Synthesis of 2‐alkyl‐3‐methyl‐2‐cyclopentenones from carboxylic acids or methylketones
Authors: Fujita Tsutomu , Watanabe Shoji , Suga Kyoichi , Inaba Teruhiko 
Published: July 2010

AbstractVarious 2‐alkyl‐3‐methyl‐2‐cyclopentenones were prepared via 2‐alkyl‐4‐penten‐2‐ols serving as common intermediates from carboxylic acids or methylketones. For example, dihydrojasmone was prepared from heptanoic acid as follows: Grignard reaction of heptanoic acid (I) with allylmagnesium chloride gave 1‐decen‐4‐one (II) and re‐Grignard reaction of (II) with methylmagnesium iodide produced 4‐methyl‐1‐decen‐4‐ol (IV). 4‐Methyl‐1,4‐decanediol (V) was obtained by hydroboration of (IV). Oxidation of (V) with chromium trioxide gave 4‐hexyl‐4‐methyl‐4‐butanolide (VI). Dihydrojasmone may be prepared by dehydration of (VI) with polyphosphoric acid. Several new 2‐alkyl‐3‐methyl‐2‐cylopentenones were obtained by this method.
Some aspects of the chlorination of bauxite
Authors: Raval Rajesh P. , Dixit Sharad G. 
Published: July 2010

AbstractRemoval of iron and titanium impurities in bauxite by selective chlorination has been obtained by controlling the addition doses of coke and restricting the temperatures to below 323 K. The chlorination of iron and titanium free bauxite has been studied as regards the effect of coke addition, Cl2 flow rates and partial pressures and temperatures. The rate equation 1‐(1 ‐ R)1/3 = kt has been shown to fit the experimental data. It is concluded that the diatomic Cl2 molecule does not dissociate to atomic Cl during chlorination.
The preparation of pure L‐leucine. Separation of L‐leucine and L‐isoleucine
Authors: Hongo Chikara , Yoshioka Ryuzo , Yamada Shigeki , Chibata Ichiro 
Published: July 2010

AbstractExisting methods for prepaiing pure L‐leucine from protein hydrolysates are unsatisfactory, especially when L‐leucine, isoleucine‐free, is required in high purity. Using a commercial crude leucine containing 73% of L‐leucine, 10% of L‐isoleucine and other impurities, the preparation of pure L‐leucine was investigated. As a result, the fractional crystallisation of the sulphonates of L‐leucine with benzenesulphonic acid and p‐toluenesulphonic acid was found to be very effective for the purification of L‐leucine. The pure L‐leucine in which no other amino acid was detected by an amino acid analyser was obtained by passing aqueous solutions of these sulphonates through ionic resin columns to separate L‐leucine and sulphonic acids. The overall yield of leucine was 59±62% of the theoretical. The present purification methods are considered to be very promising for the industrial production of L‐leucine from protein hydrolysates.
Solvent extraction in platinum group metal processing
Authors: Cleare Michael J. , Charlesworth Peter , Bryson David J. 
Published: July 2010

AbstractThis paper indicates the various ways in which the chemistry of the platinum group metals (PGM) can be manipulated to achieve separations using solvent extraction techniques and is not intended to be a comprehensive review of published work. Differences in the chemistry of PGM and base metals are emphasised as the latter are present in refinery liquors. Mechanisms of solvent extraction processes are discussed and related to PGM complex chemistry. Potential economic advantages for solvent extraction over conventional selective precipitation processes are considered.
The impact of solvent extraction and ion exchange on the hydrometallurgy of tungsten and molybdenum
Authors: Macinnis Martin B. , Kim Tai K. 
Published: July 2010

AbstractThis paper is concerned with the impact that solvent extraction and/or ion exchange has on the design of hydrometallurgical processes for the recovery of tungsten and molybdenum. The chemistries of tungsten and molybdenum will be discussed and flowsheets for the commercially important products will be presented.